Lateral Epicondylitis (Tennis Elbow)

The most common overuse syndrome is related to excessive wrist extension and commonly referred to as “tennis elbow,” but it is actually more common in non-tennis players. It is also commonly referred to as lateral epicondylitis, but this is usually a misnomer because, in general, microscopic evaluation of the tendons does not show signs of inflammation, but rather angiofibroblastic degeneration and collagen disarray. Light microscopy reveals both an excess of fibroblasts and blood vessels that are consistent with neovessels or angiogenesis.[1]

The tendons are relatively hypovascular proximal to the tendon insertion. This hypovascularity may predispose the tendon to hypoxic tendon degeneration and has been implicated in the etiology of tendinopathies.[2] Most typically, the primary pathology is tendinosis of the extensor carpi radialis brevis (ECRB) tendon 1-2 cm distal to its attachment on the lateral epicondyle.[2, 3]

The area of maximal tenderness is usually an area just distal to the origin of the extensor muscles of the forearm at the lateral epicondyle. Most typically, the ECRB is involved, but others may include the extensor digitorum and extensor carpi ulnaris.

The radial nerve splits into the superficial radial and posterior interosseus nerve (PIN) at the radiocapitellar joint. The PIN may become entrapped by pericapsular structures, causing radial tunnel syndrome.

Tennis is the most common sport to cause lateral epicondylitis, but the condition can also be seen in those who play squash and badminton. Symptoms can occur after an improper backhand hitting technique, which can occur when the athlete attempts to increase power by increasing forearm force rather than relying on core, rotator cuff, and scapular power. This results in snapping the wrist with supination and irritation of the extensor tendons. Symptoms can also occur with improper technique when an athlete does not get his or her feet into position and hits the ball late or when the athlete strikes the ball with a bent "leading" elbow. The power of the hit is again generated from the forearm instead of the core. This condition has also been observed more frequently in novice players when compared with more experienced players. This may be secondary to the ability of experienced players to decrease the impact forces from the racquet to the wrist.

In comparing one-handed versus two-handed backhand stroke, electromyography (EMG) results demonstrated reduced amplitude with a two-handed backhand versus a one-handed backhand stroke.[4]

Other causes of extensor tendinopathy in tennis are using new racquet, using a racquet that is strung too tightly, or using a racquet that is too heavy, as well as hitting wet or heavy balls or hitting into the wind. It is unclear if a grip that is sized too small or too large contributes to the development of lateral epicondylitis. However a recent, very small study by Rossi et al revealed that there may be an optimal grip size to reduce grip forces as well as reduce extensor tendon loading during a tennis stroke.[5] In addition, string vibration dampeners have not been shown to decrease the incidence of lateral epicondylitis.[6]

Industrial athletes have certain occupational and leisure activities that lead to overuse injuries of the forearm wrist extensors, causing pain at the lateral epicondyle. These include carpenters, bricklayers, seamstresses and tailors, politicians (excessive handshaking), and musicians (eg, pianists, drummers). Such injuries can also be seen in individuals who perform a great deal of computer work, typing, and mouse work for their occupations.

The causes of lateral epicondylitis include the following:

• Poor general conditioning leads to fatigue of the core and shoulder muscles, which puts an overemphasis on the extensor muscles of the forearm

• Improper training (eg, poor positioning when striking a tennis ball)

• Improper technique (eg, hitting a tennis ball late on the backhand)

• Poor or improper equipment (eg, a racquet that is strung too tightly)

• Scapular dyskinesis will lead to a compensatory increased load placed on the ipsilateral wrist extensors

United States statistics

The annual incidence is 1-3% of the U.S. population. Men and women are equally affected. Typically, lateral epicondylitis affects individuals greater than age 40 years. There is usually a history of repetitive activity aggravating the extensor tendons of the forearm. Repetitive, eccentric motion of the wrist extensor muscles may increase risk of injury. Individuals with a current or prior history of tobacco use were also noted to be at increased risk.

A study reported the age- and sex-adjusted annual incidence of lateral elbow tendinosis decreased from 4.5 per 1000 people in 2000 to 2.4 per 1000 in 2012. The recurrence rate within 2 years was 8.5% and the proportion of surgically treated cases within 2 years of diagnosis tripled from 1.1% during the 2000-2002 time period to 3.2% after 2009. The study also added that about 1 in 10 patients with persistent symptoms at 6 months required surgery.[7]

International statistics

Herquelot et al conducted a study that aimed to estimate the association between repeated measures of occupational risk factors and the incidence of lateral epicondylitis in a large working population. The study highlights the importance of temporal dimensions for occupational risk factors on the incidence of lateral epicondylitis. The authors conclude that further research should evaluate the risk associated with the duration and repetition of occupational exposure on the incidence of lateral epicondylitis.[8]

Although most patients with lateral epicondylitis tend to improve in 9-18 months, they need to be made aware that successful treatment may be a prolonged course. Refractory cases may need surgical intervention.

Complications

The most serious complication is complete tendon rupture. Such an injury often causes a palpable defect in the extensors, which results in weakness on attempted wrist extension. Frequently, the treatment of this complication is surgical repair.

Advise the athlete on proper technique and equipment. Formal sport lessons may be beneficial to prevent individuals from acquiring bad habits.

For patient education resources, see the Hand, Wrist, Elbow, and Shoulder Center, as well as Tennis Elbow.

The typical age of those affected is 40 to 50 years.

Patients most typically report an insidious onset, but they will often relate a history of overuse without specific trauma. Symptom onset generally occurs 24-72 hours after repeated wrist extension activity. Delayed symptoms are probably due to microscopic tears in the tendon.

The patient complains of pain over the lateral elbow that worsens with activity and improves with rest. The patient will also often describe aggravating conditions such as a backhand stroke in tennis or the overuse of a screwdriver.

Pain may radiate down the posterior aspect of the forearm. The patient can often pinpoint pain 1.5 cm distal to the origin of the extensor carpi radialis brevis (ECRB).

Pain can vary from being mild (eg, with aggravating activities like tennis or the repeated use of a hand tool), or it can be such severe pain that simple activities like picking up and holding a coffee cup (ie, "coffee cup sign") will act as a trigger for the pain.

The following may be noted on physical examination:

• Inspection: Very rarely does one notice swelling or ecchymosis.

• Palpation: Maximal tenderness is elicited 1-2 cm distal to the origin of the ECRB at the lateral epicondyle.

• Pain is increased with resisted wrist extension, with the wrist radially deviated and pronated and the elbow extended

• Pain may also increase when the patient attempts to lift the back of a chair with the elbow extended and the wrist maximally pronated.

• Resisted extension of the middle finger is also painful secondary to stress placed on the ECRB tendon, as it is preferentially stressed in this position when it must contract synergistically to anchor the third metacarpal, such that extension can take place at the digits.[9]

• Increased pain is noted with resisted supination, gripping hand shaking.

• Always examine range of motion (ROM) of the shoulder, elbow, and wrist on the affected side.

• Examine ROM and test for crepitus at the radiohumeral joint of the affected limb to evaluate for radiohumeral bursitis, osteochondritis of the capitellum, or PIN entrapment.

• If decreased ROM if noted on physical examination, consider obtaining an x-ray to further evaluate the joint.

Laboratory studies

Laboratory studies are typically not useful in the workup of lateral epicondylitis.

Imaging studies

Imaging studies are rarely needed in the initial workup of lateral elbow pain. Consider plain film radiologic evaluation if the patient's symptoms persist despite adequate treatment or to evaluate for osteophytes, degenerative joint disease, or osteochondritis dissecans (OCD). Plain films may reveal osteophytes or calcifications along the lateral epicondyle.

Consider magnetic resonance imaging (MRI), bone scanning, and/or computed tomography (CT) scanning to evaluate for OCD or stress fractures.

Musculoskeletal ultrasonography is emerging as a useful modality to characterize areas of tendinosis, partial tearing, or calcifications and may assist with treatment options.

Other tests

A local anesthetic block may lead to symptom resolution and confirmation of the diagnosis.

There are numerous treatment options, but no one single treatment is completely effective.

Watchful waiting

Smidt et al noted a greater improvement in pain symptoms from lateral epicondylitis at 52 weeks when employing watchful waiting relative to the administration of corticosteroid injections.[10] In addition, watchful waiting was about equally as effective as physiotherapy at 52 weeks. However, corticosteroid injections were significantly better than both watchful waiting and physiotherapy at 6 weeks.[10]

In 2006, Bisset et al investigated treating lateral epicondylitis with physiotherapy, corticosteroid injection, or watchful waiting in 198 individuals with symptoms for greater than 6 weeks.[1] Outcomes were global improvement in symptoms, pain-free grip force, and assessment of severity of complaints. There were significant reductions in all outcomes measured for corticosteroid injections over watchful waiting at 6 weeks. In the corticosteroid group, 78% reported success, versus 27% for those in the watchful waiting group. Corticosteroid injections also outperformed physiotherapy at 6 weeks, with 65% of the physiotherapy group having success versus 78% of the corticosteroid group. Physiotherapy was superior to watchful waiting at 6 weeks. However, the improvement in symptoms with corticosteroid injections was not sustained at 52 weeks.

At 52 weeks, the injection group was significantly worse on all outcomes compared with the physiotherapy group and worse on 2 of 3 measures compared with watchful waiting. Finally, at 52 weeks, there was not much of a difference in comparing physiotherapy to watchful waiting. Fifty-nine of 63 much improved or completely recovered in the physiotherapy group, versus 56 of 62 in the watchful waiting group. This study again elucidates that corticosteroid injections may have some benefit in the short term, but the long-term benefits are definitely lacking in the treatment of lateral epicondylitis. Physiotherapy demonstrated improvement versus watchful waiting at 5 weeks, with only slight improvement at 52 weeks.[1]

Nonsteroidal anti-inflammatory drugs

Topical nonsteroidal anti-inflammatory drugs (NSAIDs) such as diclofenac may offer some short-term relief.[11, 12] In a study with oral diclofenac, this agent improved short-term pain and function, but there was no difference noted when comparing naproxen and placebo for pain reduction in lateral epicondylitis. Corticosteroid injection demonstrated greater benefit at 4 weeks when compared with NSAIDS, but no long-term differences were seen.

A Cochrane review looked at 17 comparisons of 759 participants and noted: “There remains limited evidence from which to draw firm conclusions about the benefits or harms of topical or oral NSAIDs in treating lateral elbow pain. Although data from five placebo-controlled trials suggest that topical NSAIDs may be beneficial in improving pain (for up to 4 weeks), non-normal distribution of data and other methodological issues precluded firm conclusions.”[13]

Corticosteroid injection

One study demonstrated that a corticosteroid injection had superior efficacy in pain relief at 6 weeks when compared with physiotherapy that consisted of ultrasound, massage, and exercise. However, the authors noted that corticosteroid injection was not as effective as physiotherapy at 12 weeks.[10] Smidt et al found that administering a corticosteroid injection decreased pain in lateral epicondylitis at 6 weeks but not beyond that period.

A study looked at 297 patients with lateral epicondylitis and found that individuals treated with structured physical therapy had less pain than patients treated with corticosteroid injections or NSAIDs and experienced better function than those treated with corticosteroid injections. The intervention group had a lower recurrence and fewer sick leave days at the time of the visit to the healthcare center.[14]

In another study, when corticosteroid injection was compared with arm bracing, the use of a corticosteroid injection demonstrated decreased pain at 2 weeks, but there was no difference noted at 6 weeks.[15] There was also no significant difference noted in the type of steroid that was injected.

A study by Gosens et al compared corticosteroid with platelet-rich plasma (PRP) injections in patients who had refractory lateral epicondylitis symptoms for longer than 6 months. Primary outcome measures were pain and daily use of the elbow. One hundred patients blindly received either PRP or corticosteroid injection, followed by a similar standard rehabilitation protocol. Success was defined as a 25% reduction in pain on a visual analogue scale (VAS) score or on a disabilities of the arm, shoulder, and hand (DASH) score.

At 4 weeks, the corticosteroid injection group reported a 32.8% improvement in VAS scores and a 25.8% improvement in DASH scores. At 4 weeks, the PRP group had a 21% improvement in VAS scores and a 15.7% improvement in DASH scores. Both had similar improvements at 8 weeks. The PRP group had a greater and more sustained symptom improvement; the individuals were followed for longer period of time. At 12 weeks, the PRP group demonstrated a 44.8% improvement in VAS and a 43% improvement in DASH scores. At 12 weeks, the corticosteroid group reported improvements of 32.8% in VAS and 29.8% in DASH scores. These trends continued at 6 months, 12 months, 1 year, and 2 years. The PRP group continued to show improvement in VAS and DASH scores at 6 months, 12 months, and 2 years. The corticosteroid group had less successful symptom resolution the longer the individuals were followed.[16]

A study by Lebiedziński et al found that betamethasone injections give more rapid improvement, but the therapeutic effect is longer lasting in the autologous conditioned plasma group.[7]

In summary, administering a corticosteroid injection is effective in reducing pain from lateral epicondylitis in the short term, but this procedure may not be as effective in the long term.

Counterforce bracing

Counterforce braces are used in an attempt to reduce the tension forces on the wrist extensor tendons, and these orthotics may be superior to lateral epicondyle bandages in reducing resting pain.[17] The brace should be applied firmly approximately 10 cm distal to the elbow joint. Use of a counterforce brace may decrease pain and increase grip strength at 3 weeks in individuals with lateral epicondylitis.[18] However, some authors believe that no firm conclusions can be drawn from the use of orthotics in the treatment of lateral epicondylitis.[19] Counterforce braces are possibly inferior in the treatment of lateral epicondylitis when compared with topical NSAIDs and corticosteroid injections.

Jafarian et al compared 3 common types of orthoses for their effect on grip strength in patients with lateral epicondylosis.[20] In a randomized controlled laboratory study in 52 patients, maximum and pain-free grip strength were assessed with the patient wearing an elbow strap orthosis, an elbow sleeve orthosis, a wrist splint, or a placebo orthosis. Use of the elbow strap and sleeve orthoses resulted in an immediate and equivalent increase in pain-free grip strength (P< 0.02); consequently, the researchers suggest that either of these types of orthosis may be used.[20] The wrist splint provided no immediate improvement in either pain-free or maximum grip strength.

A study by Altan and Kanat compared treating 50 individuals with symptoms of lateral epicondylitis for less than 12 months with either a typical counterforce forearm brace versus treatment with a 10-15° dorsiflexion wrist splint.[2] Parameters of pain at rest and with extension, sensitivity, hand grip strength, and a subjective response to treatment were measured at baseline, 2 weeks, and 6 weeks. No formal physical therapy or home exercise program was recommended. The counterforce brace group demonstrated significant reduction in pain at rest and during movement at 2 weeks, while sensitivity and grip strength were not changed at 2 weeks.

At 6 weeks, significant improvement was noted in all parameters with the implementation of counterforce bracing. The wrist splint group demonstrated improvement in all parameters measured at 2 and 6 weeks except for sensitivity at 2 weeks. Comparison of the 2 groups showed significant improvement in resting pain at 2 weeks for the wrist splint group over the counterforce brace group. No other significant differences were noted between the 2 groups. This study was limited by lack of a control group. In summary, all patients improved with either counterforce elbow bracing or wrist splint bracing at 2 and 6 weeks. Wrist splint bracing, however, demonstrated an advantage on some measured subjective and objective parameters.[2]

A study looked at the immediate effect on grip strength in treating lateral epicondylitis with 3 different kinds of orthoses, a counterforce elbow strap, a counterforce elbow sleeve, and a wrist splint versus a placebo control brace proximal to the elbow. This involved 52 subjects with symptoms of a mean duration of 18 weeks. The counterforce strap and sleeve provided an improvement in pain free grip strength; however, there were no differences between the 2 counterforce braces. The wrist splint did not change pain free grip strength compared with placebo.[3]

Garg et al randomized 42 patients with acute symptoms of lateral epicondylitis to either a wrist extension splint or a counterforce brace. Again, there was no control, nonbraced, group. Ice and home stretching exercised were recommended to both groups. Clinical outcomes were measured at the time of enrollment and at 6 weeks of follow up. Both groups overall improved at the 6-week mark. Specifically looking at some of the outcomes measured, however, pain was significantly more reduced in the wrist splint group than the counterforce brace group.

At 6 weeks, significant improvement was noted in all parameters with the implementation of counterforce bracing. The wrist splint group demonstrated improvement in all parameters measured at 2 and 6 weeks, except for sensitivity at 2 weeks. Comparison of the 2 groups showed significant improvement in resting pain at 2 weeks for the wrist splint group over the counterforce brace group. No other significant differences were noted between the 2 groups. This study was limited by lack of a control, nonbraced, group. In summary, all patients improved with either counterforce elbow bracing or wrist splint bracing at 2 and 6 weeks. Wrist splint bracing, however, demonstrated an advantage on some measured subjective and objective parameters.[21]

Najafi et al investigated the benefits of a spiral hand-forearm splint that restricted wrist extension and limited supination and pronation of the forearm in patients with lateral epicondylitis for at least 3 weeks. The normal range of supination and pronation were 98° and 85°, but the new splint reduced these rates by 59% and 53%, respectively, compared with the without-splint condition in healthy subjects. After 4 weeks of continually wearing the splint, pain was about a quarter of what it was at baseline, grip strength had improved by 18%, and function had also greatly increased based on the DASH score. This study was limited by its being non-blinded, with no control group.[22]

Saremi et al performed a non-randomized double-blinded clinical trial examining the immediate effects of a newly designed orthosis (wedged brace) for patients with lateral epicondylitis. This small study included 12 individuals who had symptoms for at least 6 weeks. The main difference between this brace and the traditional counterforce strap is that there are “two separated medium- density fiberboard wedges incorporated into the proximal part.” Patients wore the new brace for 48 hours and then were evaluated. The new strap was removed for at least 48 hours before patients were given the traditional tennis elbow strap. Patients were evaluated a second time after 48 hours of wearing the traditional strap.[23]

Grip strength and pain (VAS) were the outcome measures. Pain scores were lower than baseline when using both braces, but the new orthosis, on average, gave a 2-point lower VAS score than the traditional brace. While wearing the braces, patients’ grip strength increased some from baseline, but there was not a statistical significance between the two straps.

Extracorporeal shock wave therapy

Until recently, there was little evidence demonstrating a benefit in using extracorporeal shock wave therapy (ECSWT) to treat patients with lateral epicondylitis.[24]

A study by Aydin et al reported that both ECSWT and wrist-extensor splints resulted in improvements in pain and handgrip strength in 67 patients with lateral epicondylitis.[25]

Twenty-six patients participated in a non-blinded, controlled study that evaluated both clinical and functional improvement in muscle strength in patients with lateral epicondylitis who had symptoms for at least 6 months that were treated using ECSWT. Improvement was measured using VAS, Mayo Elbow Performance Index scores, and handgrip strength. A decrease in pain and a recovery of function were noted. However, a decrease in muscular handgrip strength was also noted after treatment. The patients were followed up for only 1 month after the intervention.[26]

A small prospective, non-controlled, non-blinded study was performed in Istanbul using ECSWT as a treatment for lateral epicondylitis in 12 patients. Mean duration of symptoms was 3.5 ± 3.2 months. Each person received 1 session of treatment a week for 3 weeks. Measurements of VAS score and grip strength were taken at baseline and 1 month following treatment. The average VAS scores decreased by about 1.5 points and the average grip strength scores increased by about 16 points, which was considered significant. Researchers concluded that ECSWT is an effective treatment in the short term (1 month). More research must be done to determine the long-term efficacy of ECSWT in the treatment of lateral elbow pain.[27]

Koksal et al compared ECSWT in patients with acute lateral epicondylitis versus those with chronic lateral epicondylitis. The study included a total of 55 patients. There was no control group. Twenty-four patients had been experiencing symptoms for less than 3 months and were considered acute; 30 patients had symptoms for longer than 3 months and were considered chronic. Each patient in both groups received the same 3 sessions of ECSWT that were 5 minutes long and were spread out by 3 days between sessions. Progress was checked at 2, 12, and 24 weeks following the conclusion of the third session. Pain was measured while resting, stretching, while lifting a chair, while working, when pressed, and at nighttime. VAS scores in both groups had improved in all categories at the 2-week checkup. Scores continued to improve for the subsequent follow-up visits as well. This result led researchers to conclude that ECSWT is an effective treatment for both acute and chronic lateral epicondylitis.[28]

Lizis conducted a randomized study of 50 participants to compare ECSWT to ultrasound therapy for the treatment of lateral epicondylitis symptoms from about 15 months in patients who had failed 6 months of previous treatments. The ECSWT group received treatment once a week for 5 weeks.  The ultrasound group had 3 treatments per week for a total of 10 sessions. Follow-up was done immediately after treatment and again after 3 months. Prior to treatment, VAS scores were similar among the groups. Both groups reported decreased pain at both follow-up visits, but the improvement was statistically greater in the ECSWT group than in the ultrasound group.[29]

Trentini et al completed a small non-controlled observational study (n=37) that examined ultrasound-guided ECSWT as a treatment for chronic lateral epicondylitis. Seventeen of the patients had previously received physical therapy, but the others had not. Patients received 3-4 weekly sessions, with a small portion continuing for 8-10 weeks owing to relapsing symptoms. Physical therapy was not prescribed after treatment. VAS and QuickDASH (qDASH) scores significantly decreased from baseline to the final follow-up (24.8-month average; range, 14-45). The number of patients who had tenderness at palpation, pain with resisted wrist extension, or pain with resisted third finger extension decreased significantly as well. However, among individuals who did not respond to the first cycle of ECSWT, only 33% responded to further treatments.[30]

Beyazal et al compared non–ultrasound-guided corticosteroid injection with ECSWT for the treatment of chronic lateral epicondylitis in 64 patients.  There was no placebo group. In the corticosteroid group, 20 mg of methylprednisolone acetate with 1 mL of prilocaine was used. VAS scores improved at both follow-up visits for both groups at 4 and 12 weeks. The percentage of improvement was higher in the ECSWT group at both follow-up visits when compared with the corticosteroid injection group. At the conclusion of the study, VAS scores in the ECSWT group had improved by 90%, compared with a 30% improvement in the corticosteroid injection group.[31]

Ultrasound-guided percutaneous radiofrequency thermal lesioning

Lin et al published a study looking at a novel method of treating chronic refractory lateral epicondylitis with ultrasound-guided percutaneous radiofrequency thermal lesioning (RTL).[9] They enrolled 34 patients (35 elbows) with symptoms of lateral epicondylitis for greater than 6 months in whom previous interventions had failed. Patients were examined at baseline and then at 1, 3, and 6 months after the index procedure. Outcomes measures were VAS at rest and activity, QuickDASH scores, and the Modified Mayo Clinic Performance Index (MMCPI) for the elbow.

Significant pain reductions were noted at 1, 3, and 6 months of follow-up. Grip strength improved significantly at 3 and 6 months of follow-up but not significantly at the 1 month of follow-up. DASH and MMCPI scores improved significantly at all follow-up measurements. Eighty-five percent of the patients reported pain relief at the 1-month follow-up. Ninety-one percent of the subjects reported good-to-excellent satisfaction results at 6 months. Five patients needed a repeat procedure because of unsatisfactory symptom relief, and, of these, 4 reported satisfactory results after the second procedure. No change was noted on ultrasound in the thickness of the origin of the extensor tendon.[9]

Acupuncture

Systemic reviews and meta-analyses have demonstrated some evidence of short-term improvement in pain reduction at 2 to 8 weeks in patients suffering from lateral epicondylar pain.[19, 32] However, other studies demonstrated insufficient evidence to recommend its use.[12]

The Beijing Sport Institute performed a non-blinded prospective study comparing the treatment of external humeral epicondylitis with electroacupuncture, massage, and blocking therapy versus treatment using only blocking therapy. Eighty-three patients were divided equally into two groups. The electrotherapy, massage, and blocking group received electrotherapy once a day for 10 days. Massage was administered once a week for 10 weeks. Blocking therapy was administered twice, with 1 week in between treatments. Patients in both groups saw improvements on VAS, grip strength index, and Mayo elbow performance scores after 6 months. At 12 months, the control group relapsed. By 24 months, both groups had relapsed. These treatment options may be effective in delaying recurrence but are not a cure for the condition.[33]

Wong et al conducted a randomized study comparing the treatment effects of ECSWT and acupuncture in patients with lateral epicondylitis. The ECSWT group received 1 session per week for 3 weeks. The acupuncture group received 2 sessions per week for 3 weeks. Outcomes were assessed at baseline, immediately after treatment, and then again 2 weeks later. Both groups had significant improvement in pain, but there was no significant difference between the groups at either follow-up. This follow-up is very short, and long-term conclusions cannot be made.[34]

Autologous blood injection

Autologous blood injections are thought to initiate an inflammatory process and promote improved healing of degenerative tissue via the relatively atraumatic injection itself as well as by providing necessary cellular and humoral mediators to induce a healing cascade.[35] Edwards and Calandruccio studied 28 people in whom conservative therapy had failed to resolve the symptoms of lateral epicondylitis.[36] The participants were given a cock-up wrist splint and told to avoid any other bracing or physical therapy for 3 weeks. A home exercise program was initiated at week 3. The study demonstrated that 22 (79%) of the 28 patients had a reduction in Nirschl pain scores over 9.5 months after autologous blood injection therapy.[36] Most often, this occurred after only one injection. However, this study is limited, as it lacked a control group.[10]

A study by Connell et al looked at ultrasound-guided autologous blood injections as a treatment for 35 individuals with lateral epicondylitis confirmed on MRI. These patients had symptoms for a median of almost 14 months, and conservative therapy had not been successful. Outcomes were measured as reduction in VAS and Nirschl pain scores at 4 weeks and 6 months. No formal physical therapy or home exercise program was recommended. Autologous blood injections demonstrated significant improvements in VAS and Nirschl pain measurements at 4 weeks and at 6 months. Autologous blood injections also demonstrated statistical improvements in tendon thickness, interstitial cleft formation, echoic foci, hyperechoic change, and neovascularity.[11]

A small study compared autologous blood, corticosteroid, and saline injection in the treatment of lateral epicondylitis of less than 6 months’ duration in 28 individuals. Patients were followed for 6 months after the injections, and the outcomes measured were reduction in DASH scores and pain- and disease-specific functional scores. Participants were not given any formal physical therapy regimen or orthotics. They were simply given a standard sheet of stretching exercises to which compliance was not measured. All 3 injections caused a decrease in DASH scores at 2 weeks and 2 months and a significant decrease at 6 months; however, there were no significant differences between the 3 groups. In addition, patient reported scores of pain and function also improved among all 3 groups.[12]

Kazemi et al performed a single blinded, randomized clinical trial comparing autologous blood injections to corticosteroid injection in 60 individuals with lateral elbow tendinopathy during the past year.[15] Bracing, physical therapy, or anti-inflammatory medications were not allowed during the duration of the study.

Outcomes were measurement of VAS pain scale, DASH questionnaire, modified Nirschl pain scores, maximum grip strength, and pain pressure threshold. Short-term follow-up was ascertained at 4- and 8-week intervals. Corticosteroid injections demonstrated improvements at 4 weeks in all outcome scores except pain pressure threshold. There was no significant improvement from 4-8 weeks in the steroid group for any of the outcomes except a decrease in limb pain and a worsening of grip strength. The autologous blood group demonstrated statistically significant improvements in all outcomes measured at 4 and 8 weeks. Autologous blood injections demonstrated superiority to corticosteroid injections at 4 and 8 weeks in all parameters measured.[15]

Ozturan et al performed a 3-armed randomized trial of 60 patients with symptoms consistent with lateral epicondylitis for greater than 6 months with no previous physical therapy in the past 3 months to a corticosteroid injection, autologous blood injection, or ECSWT.[37] Outcomes measured were Thomsen provocative test scores, upper extremity functional scores, and maximal grip strength. Assessment was at 4, 12, 26, and 52 weeks. Sixteen of the 20 patients in the autologous blood group received a second injection at 6 weeks.

In this study, at 4 weeks, the corticosteroid group had a significant improvement in a functional score and Thomsen provocative tests over both the autologous blood group and the ECSWT group. There was no difference between the autologous blood group and the ECSWT at 4 weeks. There was no significant difference in these tests at the 12-week mark. Following patterns from other studies, the corticosteroid group performed less well the longer that the patients were followed up. There was a statistically significant improvement for the autologous blood and ECSWT groups compared with the corticosteroid groups at the 26- and 52-week follow-up appointments for functional scores and Thomsen provocative tests.

Grip strength was also assessed at the same time intervals and noted an improvement for the corticosteroid group at 4 weeks compared with autologous blood and ECSWT. There was no difference noted in grip strength at 12 weeks between the three groups. ESWT performed better at the 26-week follow-up with respect to grip strength when compared with autologous blood and corticosteroid injections. At 52 weeks, there was no significant difference between the three groups with respect to grip strength. At 52 weeks, the success rate for corticosteroid injections was 50%, compared with 83% for autologous blood injections and 89% for ECSWT treatments.

This study supported the idea the corticosteroid injections can be helpful for temporary and short-term improvement in patients with chronic lateral epicondylitis, but that autologous blood and ECSWT tend to have more lasting improvements.[38]

A very small study also demonstrated the effectiveness of autologous blood injections for the treatment of chronic lateral epicondylitis. However, the patients were placed in a long arm cast for 3 weeks after the injection. Long arm cast immobilization is not the standard of care after proinflammatory injections.[39]

A non-blinded, non-controlled study by Bostan et al investigated the long-term effects of autologous blood injections for recalcitrant lateral epicondylitis in 20 patients (21 elbows).  All patients had failed conservative therapies and had symptoms for at least 3 months. Autologous blood (3 mL) was drawn from the contralateral arm and injected to the area of maximum tenderness. These were blinded injections with a “dry needling” technique. Four patients received a second injection at the end of the 4th week because of persistent symptoms. Patients were examined at 2, 4, and 6 weeks; at 6 months; and at 1 and 3 years.[40]

The average VAS score decreased significantly from baseline, and the decrease continued through the 3-year follow up. Significant improvement in grip strength and the Nirschl score was also noted and persisted throughout the 3-year follow up.[40]

Arik et al compared non-US guided autologous whole blood and corticosteroid injection as treatment methods for individuals with lateral epicondylitis symptoms for an average of about 4 months. Eighty patients were randomly divided into 2 equal groups. The researchers found that patients who received corticosteroids improved faster for the first 15 days but then started to decline at day 90. The patients who received whole blood improved steadily, and their scores eventually surpassed those of the corticosteroid group when pain, function, and grip strength were analyzed at 90 and 180 days after the intervention.[41]

Platelet-rich plasma injection

A systematic review and meta-analysis by Chen et al reported that platelet-rich plasma (PRP) may reduce pain associated with lateral epicondylitis and rotator cuff injuries.[42]  Another study demonstrated significantly reduced pain when treating chronic elbow tendinosis with buffered PRP. Mishra and Pavelko evaluated 140 patients with elbow epicondylar pain; 20 patients continued to consider surgical intervention after conservative therapy failed to resolve their symptoms.[43] These patients were then administered either a single percutaneous injection of PRP or bupivacaine (control group).

At 8 weeks after therapy, the authors demonstrated a 60% pain improvement in the group who received PRP compared with a 16% pain improvement in the control group.[43] At 6 months and final follow-up (mean, 25.6 mo; range, 12-38 mo), the patients who had received PRP continued to report significant pain reduction.

A study compared PRP therapy injections with autologous blood injections in 28 patients who had symptoms of lateral epicondylitis for greater than 3 months. Patients were instructed on home physical therapy consisting of eccentric exercises. Reevaluation was done at 6 weeks, 3 months, and 6 months to assess symptoms on a VAS pain scale and a Liverpool elbow score, which measured range of motion, activity level, and ulnar nerve function. On the VAS scale, both groups demonstrated improvements at all follow-up appointments. The PRP group had better results at each visit, with statistically better results at 6 weeks. Both groups also showed improvements on the Liverpool elbow score at all visits, with no significant differences noted.[16]

Creany et al compared PRP injections to autologous blood injections in 130 individuals with refractory symptoms of lateral epicondylitis in whom conservative physical therapy had failed. These injections were performed under ultrasound guidance, and each group had two injections, at initial visit and then 1 month later. The outcome measured was the Patient-Related Tennis Elbow Evaluation (PRTEE) score. Success was defined as a 25-point improvement in this score. Measurements were obtained at 0, 1, 3, and 6 months. At 6 months, there was a 66% success rate in the PRP group and a 72% success rate in the autologous blood group. However, 20% of the autologous blood group went on to have surgery, versus 10% of the PRP group.[44]

More recently, Raeissadat et al performed a randomized clinical trial involving 40 patients who had symptoms consistent with lateral epicondylitis for greater than 3 months. They looked at improvement in pain and function when comparing PRP with autologous blood. Both groups were given a counterforce brace and a home exercise program. At 4 weeks, Mayo and VAS scores significantly improved in both the PRP and the autologous blood groups. However, only the PRP group demonstrated significant improvement at 8 weeks with respect to the VAS and Mayo scores.[45]

A non-blinded, non-controlled study looked at 40 patients with lateral epicondylitis symptoms of greater than 3 months. It compared treating lateral epicondylitis with a non-ultrasound guided single injection of 2 mL of PRP vs a single injection of 2 mL of whole autologous blood. Patients were asked to refrain from heavy labor, wear a tennis elbow strap, and perform a 5-week physical therapy program following injection. Pain (VAS score) and functional improvement (modified Mayo clinic performance index) were measured before the injection as a baseline and then again at 4 and 8 weeks after the operation. At 4 weeks both the VAS and Mayo scores had improved significantly for both groups. At 8 weeks, however, the PRP group scores had continued to improve, whereas the whole blood group scores had remained about the same. This study was limited by very short follow-up.[46]

A non-blinded, non-controlled study compared the long-term effects of non-ultrasound guided injections of PRP versus autologous whole blood in patients with chronic tennis elbow. Seventy-six patients who had experienced at least 3 months of chronical lateral humeral epicondylitis (LHE) symptoms were randomly divided into 2 groups. The first group received a single injection of 2 mL of autologous leukocyte-rich PRP. The second group received 2 mL of autologous whole blood. After the injection, both groups were prescribed the use of a tennis elbow strap and stretching and strengthening exercises. Pain and function were assessed using the VAS, Mayo score, and Physical Performance Test (PPT). Measurements were taken at 0, 4, and 8 weeks and then again at 6 and 12 months.[47]

Both groups saw significant improvement in all 3 scores at each follow-up interval. There was not, however, a significant difference between the groups. The investigators concluded that both methods are effective treatment to treat chronic LHE, with the benefit of the effects persisting long term. PRP was not superior to autologous whole blood long term.[47]

Krogh et al examined whether a single injection of PRP is more effective than placebo (saline) or glucocorticoid in reducing pain in adults with lateral epicondylitis after 3 months. The authors concluded that neither injection of PRP nor glucocorticoid was superior to saline with regard to pain reduction in lateral epicondylitis at the primary end point at 3 months. However, injection of glucocorticoid had a short-term pain-reducing effect at 1 month in contrast to the other therapies. Injection of glucocorticoid in lateral epicondylitis reduces both color Doppler activity and tendon thickness compared with PRP and saline.[48]

A non-blinded, randomized prospective study of 60 lateral epicondylitis patients by Yadav et al compared PRP therapy (single injection of 1 m L with a 1 million platelet count) to methyl-prednisolone local injection. The duration of symptoms ranged from 1 to 6 months (mean, 2.26-1.93). After a 2-week wash-out of treatments (NSAIDs and analgesics), both groups received a single non-ultrasound guided injection in the same location of their designated treatment. There was no physical therapy after the intervention.[49]

VAS scores and grip strength were better in the steroid group at 15 days and at 1 month, but the PRP group was significantly superior at the 3-month follow-up. Functional outcome (qDASH) gradually increased at each follow-up in both groups, with the steroid group having more improvement until the 3-month follow-up, when the PRP patients reported significantly better outcomes.[49]

A small study conducted by Gautam et al included 30 patients who were randomly selected to receive either PRP or corticosteroid injection. All patients had been experiencing symptoms for at least 6 months and were not responsive to oral medication or other non-invasive treatment. Two mL of PRP was injected using the peppering technique. Post injection, rest and ice were advised over NSAIDs. VAS, DASH, Oxford Elbow, and Modified Mayo scores all improved significantly in both groups from baseline to the 6-month follow-up. The scores for the corticosteroid group, however, tended to be higher at 3 months than at 6 months. The cortisone group also had a decrease in the thickness of the common extensor tendon on ultrasound.[50]

Behera et al examined how leukocyte-poor PRP compared with bupivacaine injection as a treatment for lateral epicondylitis. The study was small, including only 25 patients, but the groups were randomized. The groups had failed conservative therapies for more than 3 months. All patients received a single ultrasound-guided injection and were instructed to rest for 2 days and then begin an at-home physical therapy program that included stretching and strengthening. At baseline the results between the two groups were roughly the same. At the 1-month follow-up, the PRP group had a lower percentage of improvement than the bupivacaine group, but at 3 months, 6 months, and 1 year, the PRP results were superior. The researchers found PRP to be an acceptable treatment for improving function and pain based on the VAS, modified MAYO, and Nirschl scores.[51]

Mishra et al evaluated the clinical value of tendon needling with PRP in patients with chronic tennis elbow compared with an active control group. No significant differences were found at 12 weeks in this study; however, at 24 weeks, clinically meaningful improvements were found in patients treated with leukocyte-enriched PRP compared with an active control group.[52]

Arirachakaran et al performed a systematic review and network meta-analysis of 10 studies. This analysis compared PRP to autologous whole blood and to steroid injection in patients with lateral epicondylitis. PRP injection significantly improved pain and Patient Rated Tennis Elbow Evaluation (PRTEE) score when compared with autologous blood injection and steroid injection after 2 months. Autologous whole blood injection was the best treatment for improving disabilities scores (DASH, PRTEE) and increasing pressure threshold (PPT) both within and after 2 months. The chances of adverse effects from PRP injection and steroid injection were not significantly different, but autologous blood injection had a significantly higher likelihood of adverse effects when compared with steroid injection.[53]

Chou et al conducted a meta-analysis of randomized controlled trials involving autologous blood injection for treatment of lateral epicondylitis. A total of nine studies were included: three compared autologous blood injection with PRP, and six compared autologous blood injection with corticosteroid injection. There was a high degree of heterogeneity among the studies. Autologous blood injection were better at decreasing pain than corticosteroid injection. PRP performed better than autologous blood injection in treating lateral epicondylitis, but the authors state that it was not significant when they accounted for bias. [54]

Montalvan et al performed a double-blinded, randomized, controlled study assessing the efficacy of 2 PRP injections as a treatment for lateral epicondylitis in 50 persons who reported symptoms for no more than 3 months. They had not received any previous treatments. Each group received a single 2 mL ultrasound-guided injection of either PRP or saline. Four weeks later each patient received a second injection in the same manner.  Rehabilitation and physical therapy, as well as local corticosteroid injection, were not allowed.  Follow-ups were done at 1, 3, 6, and 12 months, and both efficacy and safety were evaluated at each. VAS scores decreased in both groups at a similar rate and were only 0.1 different (1-10 scale) at the 12-month follow-up. The difference between groups' averages was not statistically significant at any follow-up. At the 12-month follow-up, both groups reported 14 patients as asymptomatic, meaning they had a VAS score of less than 1.[55]

Tonk et al conducted a non-blinded, non-controlled study comparing PRP treatment with low-level laser therapy in patients who had poorly defined subacute to chronic lateral elbow pain. Patients were initially treated with a brace, nonsteroidal analgesics, and cold therapy for 7 days before beginning the study. Eighty-one patients who did not respond to these methods were admitted into the study. Thirty-nine patients received non-ultrasound guided PRP injections, and 42 received low-level laser therapy. Both methods reduced pain based on the Nirschl pain score. Laser therapy showed better short-term results until about 2 months post baseline. At this time, PRP patients began to see significantly lower pain scores than laser therapy when followed for 12 months, suggesting that PRP is a better treatment for long-term pain reduction.[56]

Tetschke et al compared autologous conditioned plasma with low-level laser applications in 52 patients who had at least 3 months of lateral epicondylitis symptoms. All patients had previous unsuccessful physiotherapy or medical treatment. The autologous conditioned plasma group received 3 non-ultrasound guided fan-like injections in a single session. The low-level laser group received 12 total applications. All groups followed up with standard physical therapy. Follow-ups were done at 2, 6, and 12 months. In both groups, improvements in VAS and DASH scores were seen at each follow-up, with the autologous conditioned plasma group's scores trending to be better on average.[57]

A retrospective cohort study by Karaduman et al investigated ultrasound-guided PRP injections (36 patients, 60 elbows) versus an open surgical release procedure, the Nirschl technique (44 patients, 55 elbows). Patients had symptoms for at least 12 months and were unresponsive to at least 6 months of conservative treatment. All patients’ rehabilitation was done by the same physical therapist according to the same rehabilitation protocol. Patients were evaluated at 1, 2, and 6 months and at 1 year. In regard to the Mayo Elbow score and VAS, the PRP group had consistent improvement to the 1-year follow-up and was significantly better than the surgical group at all follow-ups. Grip strength steadily improved in both groups but was statistically better in the PRP group at all follow-up visits.[58]

Hyaluronate injection

A novel approach to the treatment of chronic lateral epicondylitis is hyaluronate injections. Petrella et al looked at treating 331 individuals with lateral elbow pain of greater than 3 months with either 1% sodium hyaluronate or saline. This was a double-blinded study, and each group received an injection at baseline and then 1 week later. Participants had not had any recent injections. They were instructed on postinjection care of rest, ice, compression, elevation (RICE), and no formal physical therapy was prescribed. Primary outcomes were improvement on VAS at rest and after elbow grip testing. VAS pain at rest and after grip testing was significantly better in the hyaluronate group versus the saline group. There was also improvement in secondary outcomes of grip strength, patient global satisfaction, and assessment of normal elbow function in the hyaluronate group versus the saline group. These differences persisted at the 90-day and 365-day follow-up appointments.[59]

Kumai et al conducted a non-blinded, non-controlled study examining high-molecular-weight hyaluronic acid as a treatment for 61 patients with a variety of different enthesopathies. Of those patients, 16 experienced symptoms consistent with lateral epicondylitis, with a mean duration of symptoms ranging from 1.5 to 55 months. Each patient received up to 2.5 mL of hyaluronate via a non-ultrasound guided injection. There was no specified rehabilitation protocol after the intervention. Of the patients with lateral epicondylitis, 62.5% noted a decrease in VAS score by at least 2 cm at follow-up 1 week after the intervention. This study is limited by low numbers, lack of control and blinding, and very short-term follow-up.[60]

Polidocanol

Polidocanol is a vascular sclerosant. Zeisig et al looked at 32 patients with symptoms of chronic lateral epicondylitis in whom conservative therapy had failed.[61] Some patients had previously had injections (cortisone = 24, botulism = 5). Eccentric strengthening was previously used in 22 participants, and 2 participants had tendon-lengthening surgery. Symptoms were present for more than 3 months, and there had been no previous treatment in the past 3 months. Groups were randomized to either an ultrasound-guided blinded injection of polidocanol or lidocaine plus epinephrine. Patients were followed for 3 months for primary endpoints of satisfaction with treatment and elbow pain during grip activities of daily life. At 3 months, if they still had pain, they were offered another injection of polidocanol. They were then followed for a total of 12 months. At 3 and 12 months, there was a significant improvement in patient satisfaction and in VAS grip pain from baseline for both groups. However, there was no significant difference between the groups.

Branson et al conducted an assessor-blinded, randomized, controlled trial comparing the effects of ultrasound-guided injections of corticosteroid, autologous blood, and polidocanol in treating 44 patients with chronic lateral epicondylitis symptoms of at least 2 months' duration. All patients had evidence of neovascularization on Doppler ultrasound studies. The corticosteroid group received a single injection, and the autologous blood group and the sclerosant group each received 2 injections separated by 4 weeks. All patients saw a physical therapist and were instructed on an eccentric home exercise program. Participants were assessed at baseline, 4, 12, and 26 weeks.[62]

The corticosteroid group had superior results when compared with the autologous blood and polidocanol groups at 4 weeks. Polidocanol was significantly superior to corticosteroid injection at 26 weeks. Patients who received autologous blood injections also performed better, and these differences neared significance. There were no significant differences between corticosteroid injections and autologous blood injections at any time point. Patients in the corticosteroid group had a higher rate of recurrent symptoms than those in both the autologous blood and sclerosant groups. Polidocanol and autologous blood had no significant difference at any of the follow-up evaluations.[62]

Botulinum toxin

Wong et al demonstrated that an injection of botulinum toxin decreased patients' pain from lateral epicondylitis at 4-12 weeks when compared with saline injection; however, there was an increased incidence of side effects in the botulinum toxin–treated group, which included digit paresis and weakness of finger extension.[63] In addition, the trial was small (60 patients), most of the patients were women, and the blinding of the study may have been affected by some of the patients possibly knowing which treatment they received (4 patients experienced digit paresis and may have correctly deduced they received the botulinum toxin injection).

A study by Placzek et al also demonstrated improvement in painful symptoms arising from lateral epicondylitis when botulinum toxin injections were used compared with saline.[64] However, another randomized controlled trial demonstrated no significant difference when comparing injections of botulinum toxin and saline in the treatment of lateral epicondylitis.[65]

A double-blind randomized controlled study did not find significant differences between corticosteroid and botulinum toxin injections.[66]  Another study by Creuzé et al reported that botulinum toxin A 40 IU injected into the extensor carpi radialis brevis muscle was an effective treatment for chronic lateral epicondylar tendinopathy that was otherwise resistant to medical treatment.[67]

A double-blinded, randomized, active drug-controlled trial by Lin et al compared the treatment effects of two different sites of botulinum toxin injection with a non-ultrasound guided steroid injection in 16 patients with lateral epicondylitis (19 elbows). Almost all of the patients had symptoms for less than 3 months. Group A received a 1 mL injection containing 20 U of botulinum toxin 1 cm distal to the painful lateral epicondyle. Group B received a 1 mL injection also containing 20 U of botulinum at the most tender point of the common extensor muscle. Group C received a 1 mL injection containing 40 mg of triamcinolone acetonide 1 cm distal to the painful lateral epicondyle. The primary outcome measure was VAS.

All 3 treatments were successful at reducing pain for at least 16 weeks. At 4 weeks of follow-up, VAS scores for groups A, B, and C were 20.4, 10.1, and 46.0, respectively, which was statistically significant. The botulinum toxin groups exhibited a trend toward diminished pain ratings as time progressed, whereas the steroid group reported less reduction as time progressed, but the differences were not statistically significant. A small decrease in grip strength was observed in the botulinum toxin groups at 4 weeks, and this decrease was less evident at 8 and 12 weeks.[68]

Topical nitrates

Topical nitrates are thought to stimulate collagen synthesis and improve healing. Paoloni et al demonstrated that application of topical nitrates is an effective method of treating pain from lateral epicondylitis.[69]

A study evaluated the effect of topical glyceryl trinitrate (GTN) on lateral epicondylitis. Forty patients with chronic symptoms (of 4-8 months' duration), who were selected based on pain, tenderness, and positive pain-stimulating maneuvers, were divided into 2 equal groups. One received a GTN patch that was applied once daily to the area where maximal tenderness was felt. The second group applied a placebo patch in the same manner. Results were evaluated using VAS and calculated with the Mann-Whitney U-test and chi squared test.

The GTN group had lower VAS scores (3.15 vs 6.45) and less elbow pain after 3 weeks of treatment than the control group. No patient in the control group had good results; in contrast, 90% of those in the treatment group (18 people) reported success. At the 6-month follow-up, the VAS score gap between the groups had increased further. The treatment group had an average score of 0.7, whereas that of the control group was 4.85. The researchers determined that these data were statistically significant, making topical GTN an effective treatment for chronic lateral epicondylitis.[70]

Bone marrow injection

In a non-blinded, non-controlled prospective study, Singh et al presented evidence that bone marrow injection could be a potential treatment option for lateral epicondylitis. A total of 26 male and female patients, who were experiencing symptoms of lateral epicondylitis but had not been previously treated, completed the study. There was no mention of chronicity of symptoms. The injections were given without ultrasound guidance. Significant improvements were observed, as measured by the PRTEE scale at short- to moderate-term follow-up at 2, 6, and 12 months.[71]

Autologous tenocyte injection

A case series examined the effects of autologous tenocyte injections for 17 patients who had chronic symptoms of lateral epicondylitis for more than 6 months despite conservative treatments. Ultrasonography or MRI was used to confirm the lesion. No adverse event was reported at either biopsy or injection sites. Three weeks after patella tendon biopsy, patients received a single injection of autologous tenocytes. No supervised physical therapy was recommended. Clinical evaluation revealed an improvement in mean VAS scores; QuickDASH and grip strength scores also significantly improved over the 12-month follow-up period. Wang et al also noted improvement in the grade of tendinopathy on a validated MRI scoring system at 12 months.[72]

Wang et al conducted a follow-up study that examined the long-term effects (4.5-year average follow-up) on their patients who underwent ultrasound-guided autologous tenocyte injections to treat severe refractory lateral epicondylitis. Significant improvements in pain, function, and structural repair were seen at the 1-year follow-up, and this study aimed to determine whether the improvements were maintained up to 5 years later. For the small group that completed the trial (n=15), VAS scores had improved by 78%, QuickDASH by 84%, and grip strength by 208% at the long-term follow-up assessment.[73]

Allogenic adipose-derived mesenchymal stem cells 

Lee et al conducted a very small (n=12) pilot study investigating the potential therapeutic effects of allogenic adipose-derived mesenchymal stem cells (allo-ASC) for patients with lateral epicondylitis. The study had two groups of 6 people each. Group 1 received a 1 mL ultrasound-guided injection of 106 cells. Group 2 also received a 1 mL ultrasound-guided injection but with 107 cells.  There was no control or placebo group.

Follow-up evaluations were performed at 6, 12, 26, and 52 weeks. VAS scores progressively decreased across the follow-up assessments. Group 2 scores improved at a greater rate until 26 weeks, when there was no statistical difference between the groups. Group 2 VAS scores did slightly increase from 26 to 52 weeks but remained significantly below the baseline. Group 1 scores gradually decreased and did not increase between any two follow-up evaluations. 

Performance (Mayo Elbow Performance Index [MEPI]) increased to 6 weeks but then appeared to have plateaued to 26 weeks. At 52 weeks, the MEPI was slightly lower than at 26 weeks for both groups but still significantly improved from baseline. There was no statistically significant difference between the 2 groups in regard to the MEPI at any follow-up evaluation. 

Structural improvement was also measured. The defect area at the long and short axis decreased from baseline at 6, 12, and 26 weeks.  At 52 weeks, however, the area of the defect was larger (both long and short axis) than it was at 26 weeks but still smaller than baseline. This could be a sign of relapse; however, the data are not conclusive on this matter.[74]

Percutaneous tenotomy

The Mayo department of orthopedics performed a small non-controlled study testing the efficacy of percutaneous ultrasonic tenotomy (Tenex) for chronic elbow tendinosis. Twelve patients had lateral epicondylitis, specifically, and had been experiencing symptoms for at least 3 months. After treatment, patients had activity restrictions and follow-up appointments. Results were determined by measurements on the VAS and QuickDASH scale. Both scores improved from baseline to 6 weeks, and continued improvement was seen at each subsequent follow-up visit at 3, 6, and 12 months. There were no procedural complications.[75]

Transcutaneous electrical nerve stimulation

Chesterton et al investigated whether transcutaneous electrical nerve stimulation (TENS) provides favorable outcomes when used in conjunction with primary care management. They performed a randomized controlled trial with 241 adults. The control group received primary care management alone. Elbow pain intensity was reported by patients using a scale of 1-10 at 0 and 6 weeks, as well as at 6 and 12 months. The researchers found no significant pain difference between the groups at any of the benchmarks and concluded that TENS is not an effective treatment method.[76]

Low-level laser therapy

There is not much evidence for low-level laser therapy as an effective treatment for patients with pain from lateral epicondylitis.[77]

High-intensity laser therapy

Dundar et al randomized 93 patients with lateral elbow pain of less than 3 months' duration to receive high-intensity laser therapy (HILT), sham HILT, or a counterforce brace. The HILT treatment groups were treated once a day for 15 days during a period of 3 weeks. The HILT and brace groups showed significant improvement in multiple areas of measurement including pain, strength, and function, whereas the sham HILT treatment group did not. This improvement was noted at both 4 and 12 weeks. However, the improvement was not reflected on ultrasonographic evaluation before and after treatment.[78]

Salli et al compared HILT and the use of an epicondylitis bandage (counterforce brace) as treatments for chronic lateral epicondylitis. Patients in the HILT group (n=31) were treated 10 times total, 5 times a week for 2 weeks. The first 4 sessions were 75 seconds long. The next 6 doses were administered in 30-second intervals for 12 total minutes. Patients in the bandage group (n= 4) were instructed to wear the bandage for 6 weeks.

Following treatment, VAS scores decreased both at rest and during activity in the two groups. There was not a statistical significance in the improvement of VAS scores during activity between the two groups, but there was for resting VAS scores in favor of HILT. DASH scores also decreased in both groups, but the decrease was larger in the HILT group. There was no control group, and the follow-up was only 6 weeks.[79]

Akkurt et al performed an observational study evaluating the effectiveness of HILT for chronic lateral epicondylitis symptoms. The 23 patients (37 elbows) were treated with HILT for 5 sessions per week for 2 weeks (10 sessions in total), and then they were followed up for 6 months. Significant improvements were noted in VAS activity scores, DASH scores, hand grip strength, and quality of life assessments when comparing baseline scores with the scores at 6 months' assessment.[80]

 

Rehabilitation program

Physical therapy

Strength training, exercise, and stretching have been shown to decrease pain in patients with lateral epicondylitis.[19] It is important to have the patients progress from concentric to eccentric exercises and then stress eccentric exercises when the individual is able to tolerate them. NSAID iontophoresis is also an effective method of treating pain from lateral epicondylitis, but corticosteroid iontophoresis has not been shown to be effective.[19] Occupational therapy can be employed in an attempt to modify the workplace environment to eliminate aggravating activities.

Ultrasound (US) therapy has demonstrated modest pain reduction,[19, 77] although US- and color Doppler-guided intratendinous injections with polidocanol in the extensor origin have shown promising clinical results,[61] and there is insufficient evidence to support the use of transverse friction, soft-tissue therapy in the treatment of lateral epicondylitis.[81]

Adjunctive interventions

Sevier et al conducted a randomized, parallel, single-blinded (physician) two-group study that examined the relatively new noninvasive treatment Astym and its potential value in treating lateral epicondylitis. In group 1, the Astym group, 36 of the 46 patients met the resolution criteria, compared with 18 of the 44 patients in group 2, the eccentric exercise group. The Astym group had greater reductions in pain (DASH) and increased grip strength over the eccentric exercise group. Improvements were maintained at the 6- and 12-month follow-up visits. Additionally, the patients who did not respond to exercise were allowed to receive Astym treatment after the 4-week randomized control period was over. These patients also had statistically significant improvement.[82]

Surgical intervention

Surgical intervention can be very effective for refractory cases of lateral epicondylitis, with a large percentage of individuals reporting improvement in their symptoms. However, surgical intervention is only indicated after 6 months of conservative care has failed to relieve the patient's symptoms. A long-term follow-up study (mean, 130 mo; range, 106-173 mo) of arthroscopic treatment of recalcitrant lateral epicondylitis by Baker and Baker demonstrated that arthroscopic removal of pathologic tendinosis tissue can be a successful treatment strategy in such cases.[83]

See the image below.

It is important that each case is evaluated individually, because some patients may have multiple relapses or lack progression through therapy. These patients may opt for surgery after a shorter trial of conservative care.

Medical intervention is geared toward the joint goals of decreasing inflammation and providing analgesia. The major concern with all the drugs used is their effect on the gastrointestinal (GI) tract with long-term use. Renal function must also be monitored with long-term NSAID use. Long-term corticosteroids have a myriad of side effects, which are beyond the scope of this article.

Class Summary

NSAIDs are used to help reduce inflammation and are used as analgesics. Multiple drugs are in this class and every physician should be aware of drugs in each subclass because some patients respond better to one subclass than another. A few of the medications are named not to belabor the wide variety of choices available.

Diclofenac (Cataflam, Voltaren)

Designated chemically as 2-[(2,6-dichlorophenyl) amino] benzeneacetic acid, monosodium salt, with an empirical formula of C14 H10 Cl2 NO2 NA. One of a series of phenylacetic acids that has demonstrated anti-inflammatory and analgesic properties in pharmacologic studies. Believed to inhibit the enzyme cyclooxygenase, which is essential in the biosynthesis of prostaglandins. Can cause hepatotoxicity; hence, liver enzymes should be monitored in the first 8 weeks of treatment.

Rapidly absorbed; metabolism occurs in liver by demethylation, deacetylation, and glucuronide conjugation. The delayed-release, enteric-coated form is diclofenac sodium, and the immediate release form is diclofenac potassium. Has a relatively low risk for bleeding GI ulcers.

Ibuprofen (Motrin, Ibuprin)

DOC for patients with mild to moderate pain. Inhibits inflammatory reactions and pain by decreasing prostaglandin synthesis.

Naproxen and naproxen sodium (Aleve, Naprelan, Naprosyn)

For relief of mild to moderate pain; inhibits inflammatory reactions and pain by decreasing the activity of cyclooxygenase, which is responsible for prostaglandin synthesis.

Available in many dosages and delivery systems. Oral suspension is available at a dose of 125 mg/5 mL. Fairly inexpensive and has a similar therapeutic profile to the other NSAIDs.

Class Summary

Although increased cost can be a negative factor, the incidence of costly and potentially fatal GI bleeds is clearly less with COX-2 inhibitors than with traditional NSAIDs. Ongoing analysis of cost avoidance of GI bleeds will further define the populations that will find COX-2 inhibitors the most beneficial.

Celecoxib (Celebrex)

Primarily inhibits COX-2. COX-2 is considered an inducible isoenzyme, induced by pain and inflammatory stimuli. Inhibition of COX-1 may contribute to NSAID GI toxicity. At therapeutic concentrations, COX-1 isoenzyme is not inhibited, thus the incidence of GI toxicity, such as endoscopic peptic ulcers, bleeding ulcers, perforations, and obstructions, may be decreased when compared with nonselective NSAIDs. Seek the lowest dose for each patient.

Neutralizes circulating myelin antibodies through anti-idiotypic antibodies; downregulates proinflammatory cytokines, including INF-gamma; blocks Fc receptors on macrophages; suppresses inducer T and B cells and augments suppressor T cells; blocks complement cascade; promotes remyelination; may increase CSF IgG (10%).

Has a sulfonamide chain and is primarily dependent upon cytochrome P450 enzymes (a hepatic enzyme) for metabolism.

Class Summary

Corticosteroids are some of the strongest anti-inflammatory agents available. The injectable preparations make it possible to deliver the drug directly to the joint in a concentrated dose while greatly decreasing the systemic effects.

Triamcinolone (Amcort, Aristospan Intra-Articular)

Decreases inflammation by suppressing migration of polymorphonuclear leukocytes and reversing capillary permeability.

Betamethasone (Celestone Soluspan)

Author's drug of choice for intra-articular injections. Preparation does not crystallize if used with paraben-free anesthetic preparations.

Class Summary

Vasodilators may stimulate collagen synthesis and improve healing. These agents may also effectively treat pain.

Nitroglycerin transdermal (Nitro-Dur)

Causes relaxation of vascular smooth muscle by stimulating intracellular cyclic guanosine monophosphate production.

The dosages available include 0.1mg/h, 0.2mg/h, 0.3mg/h, 0.4mg/h, 0.6mg/h, 0.8mg/h per patch

Class Summary

Neuromuscular blocker agents have been shown to decrease pain.

Botulinum Toxin Type A (Botox)

Botulinum neurotoxin is produced by the gram-negative anaerobic bacterium Clostridium botulinum. This agent acts by interrupting signal transmission within the peripheral and sympathetic nervous system, leaving sensory transmission intact. Botulinum toxins block acetylcholine release, causing a chemical denervation.

Gradual return to play is recommended, with an emphasis on the patient employing improved form to avoid aggravating activities and techniques. The athlete should be able to perform pain-free ROM activities. Continued attention should be placed on a strengthening and conditioning program.

Attention to proper form and technique will decrease the risk of developing tendinosis of the lateral elbow extensor muscles. Other preventive strategies include the following:

• Proper equipment (ie, size and weight of racquet, size of grip, dry balls)
• Improved conditioning, improved core strength
• Gradual increase in intensity and duration of activity