Rehabilitation Program
Physical Therapy
The basic exercise principles for the management of patellofemoral syndrome (PFS) are improving the range of motion of the iliotibial band, hip flexors, and quadriceps; strengthening the core, quadriceps, hip abductors, hip extensors, and hamstrings; and restricting the offending physical activity. Quadriceps strengthening traditionally is performed while the knee is flexed 0-30°. Controversy remains regarding the extent to which the individual muscle groups making up the quadriceps can selectively be strengthened. Usually, the lateral forces of the vastus lateralis need to be countered better by the vastus medialis. This goal is accomplished best by strengthening all of the quadriceps.
Stretching of the quadriceps should be of long duration (20-30 seconds) and performed with low force. This technique allows for overcoming neural and connective tissue barriers to lengthening. Exercises to stretch the iliotibial band, hip, hamstring, and calf also are important for patients with PFS. Manual stretching of the lateral retinaculum may be used as a conservative approach, partially mimicking the effect of lateral retinacular release. Physical therapists should educate patients about home exercise programs that include stretching and strengthening exercises.
Syme et al found that selective and general physical therapy are valuable for the rehabilitation of patients with PFS. [12] In a prospective, single-blind, randomized, controlled trial, 8 weeks of physical therapy—which in one group of patients selectively emphasized retraining of the vastus medialis, and in another group, emphasized general strengthening of the quadriceps—proved superior to the provision of no treatment, for pain reduction and improvement in subjective function and quality of life. The investigators suggested that selective physical therapy may be appropriate early in rehabilitation.
Further evidence for the effectiveness of quadriceps strengthening in PFS therapy was found in a systematic literature review by Kooiker et al. The investigators reported that an analysis of seven studies strongly supported the superiority of physical therapist–guided quadriceps-strengthening exercises over placebo or advice/information alone in treating pain and increasing function in PFS. [13]
In a prospective, independent, group comparison by Chiu et al, 15 participants with and without PFS were given an MRI evaluation for knee strength, patellofemoral joint contact area, and patellar tilt angle. All the participants performed lower-limb weight training 3 times a week for 8 weeks. The outcomes were evaluated both before and after training. The study concluded that the weight-training exercises increased knee muscle strength and the patellofemoral joint contact area. This may reduce mechanical stress in the joint, which would lessen pain and improve function for those with PFS. [14]
A study by Kölle et al of the effects of a 12-week home exercise program on patients with PFS found benefits with regard to pain and function, as demonstrated by a 27-point improvement on the visual analog scale score and a 10-point improvement on the Kujala Anterior Knee Pain Scale score. The investigators also reported that when, on EMG, the vastus medialis showed delayed onset or reduced activity compared with the vastus lateralis, this imbalanced was reduced following the exercise program. [15]
A literature review by Alba-Martín et al indicated that the most effective therapeutic exercise programs for patellofemoral syndrome with regard to pain relief and functional improvement include “proprioceptive neuromuscular facilitation stretching and strengthening exercises for the hip external rotator and abductor muscles and knee extensor muscles.” [16]
A systematic literature review by Peters and Tyson indicated that proximal exercises are more effective than knee exercises in the treatment of PFS. In an analysis of eight studies, the investigators found that proximal exercise programs consistently reduced pain and improved function, with patients demonstrating short- and long-term improvement, while the results from knee exercise programs were more variable. [17]
In contrast to the above studies, a literature review by van der Heijden et al stated that while consistent evidence for the benefits of exercise therapy in reducing pain and improving function in PFS exists, the data is of very low quality. The investigators also stated that the evidence is too weak to indicate which type of exercise therapy is most effective. [18]
Ice packs frequently are used to decrease pain and inflammation associated with PFS, especially after completing the exercises. Other modalities that may be useful and commonly are incorporated into physical therapy include electrical stimulation and biofeedback.
Patellar taping techniques are used in patients with PFS to reduce the friction on the patella. Many physical therapists are trained in the McConnell method of taping of the knee. Some patients report reduction of pain when wearing the tape. Some individuals report that the taping allows them to complete more functional quadriceps-strengthening activities without anterior knee pain. If successful, the physician or physical therapist can teach the patient self-taping techniques to use at home. (A study by Araújo et al reported, however, that in patients with PFS engaged in proprioceptive exercises, McConnell patellar taping does not change knee and hip muscle activation differences in comparison with placebo taping. [19] )
A study by Yoon and Son indicated that during stair ambulation, both the McConnell and Kinesio taping methods reduce pain and improve gait parameters. However, McConnell taping was associated with a greater decrease in pain and, as a result, more improvement in gait variables. The investigators used the Kujala anterior knee pain scale, in which lower scores signify greater pain. Prior to intervention, scores in the McConnell and Kinesio groups were 65.16 and 65.87, respectively, while post intervention they were 74.64 and 70.24, respectively. [20]
Proper footwear also is important for individuals with PFS. Overpronation of the foot contributes to dynamic knee valgus moments. The physical therapist can evaluate the patient's biomechanics and recommend proper shoes and orthoses, which in turn can lessen knee pain.
Foot orthoses are often of benefit in returning the subtalar joint to a nearly neutral position; this reduces foot pronation, thereby decreasing rotational forces in the tibia that affect tracking of the patella during locomotion. [21] Improvement in quality of life measures has been demonstrated following provision of custom orthoses to individuals with PFS and excessive foot pronation.
One study compared the effectiveness of off-the-shelf foot orthoses in the treatment of PFS pain with that of either flat inserts or physical therapy; the report also investigated whether the combined use of orthoses and physical therapy is more effective than the employment of physical therapy alone. [21] The prospective, single-blind, randomized trial utilized 179 patients (including 100 women) between ages 18 and 40 years.
By 6 weeks, patients using orthoses had experienced greater improvement than had persons using flat inserts, but the orthotic group had experienced no significant difference in improvement over patients treated with physical therapy or with a combination of orthoses and physical therapy. By 52 weeks, a significant improvement in patellofemoral pain had occurred in all of the patient groups.
Another study focused on identifying individuals with PFS who would most likely benefit from foot orthoses. The determination was that patients who had 3 of the following clinical predictors were most likely to benefit: footwear motion control properties score of less than 5 (indicating less supportive footwear), lower levels of pain (< 22 mm), ankle dorsiflexion range of motion (< 41°), and reduced single-leg squat pain when wearing the orthoses. [22]
Soft knee braces may also be of benefit to patients with PFS by enhancing proprioception. Bracing involves control of the tracking position of the patella and restriction of full knee flexion. Braces vary in the manner in which the patella is restricted (eg, patellar window, patellar bar, patellar horseshoe), but they accomplish the same theoretical result. Braces that are tightly applied directly over the patella should be avoided, because they actually increase patellofemoral pressures and may exacerbate the condition.
A study by Uboldi et al reported that in patients with patellofemoral syndrome (PFS), employment of an elastomeric knee brace may permit faster return to sport. The brace used elastomeric bands to create an anterior weblike structure, with the extensible components elongating to reduce impact forces on the patellofemoral joint and proprioceptive contact maintained over the whole range of motion. The investigators found that at 6-month follow-up, 24 out of 30 patients (80%) in whom brace use was combined with a rehabilitation program had returned to sport, compared with 14 out of 30 patients (47%) who underwent rehabilitation without use of the brace. [23]
Occupational Therapy
Recommend a change in activity level or the ergonomics of the offending activity until the symptoms of patellofemoral syndrome are under control. Activities that require repetitive squatting are a good example. The task or sport may need to be modified to reduce the frequency of squatting, or the patient may need to choose an alternate occupation or recreational activity. Occupational therapists can be of assistance when reviewing the ergonomics of the environment in which symptoms occur with individual patients.
Recreational Therapy
Introducing alternative recreational pursuits and means of fitness may be of benefit in alleviating symptoms of patellofemoral syndrome when conservative measures are not effective. Modifications in recreational pursuits may need to be only temporary measures if other conservative measures are effective.
Medical Issues/Complications
Most symptoms of patellofemoral syndrome resolve with simple measures. As with many exercise routines, patients often fail to adhere to the exercise prescription, producing treatment results that appear to be refractory but which are actually caused by the fact that the therapeutic approach has not been given a fair trial. Follow-up studies suggest that more than 95% of persons who are compliant with treatment have results that are acceptable or better.
Surgical Intervention
Surgical intervention for patellofemoral syndrome usually is in the form of arthroscopic evaluation followed by release of the lateral attachments of the patella. Most authors agree that surgical treatment rarely is indicated. Arthroscopy has been cited as assisting the physician with clinical diagnoses; however, the visualization procedure, in and of itself, does not significantly help the symptoms of patellofemoral pain. [24]
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Surgical procedures performed for patellofemoral arthritis include lateral facetectomy and patellar resurfacing.
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Follow-up evaluations long after anterior advancement of the tibial tuberosity suggest limited results with this procedure.
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Research on cartilage transplantation is being performed. Additional surgical options may be added in the future.
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Arthroscopic drilling of osteochondral defects allows healing of the defect with fibrocartilage. This procedure routinely is performed. This form of cartilage is not of the normal type but provides for an improved surface compared to an osteochondral defect.
Consultations
Management of patellofemoral syndrome overlaps many specialties, including primary care, physical medicine and rehabilitation, and orthopedics.
Other Treatment
Knee pain secondary to defined degenerative changes may be relieved by injecting the joint with steroid or synthetic hyaluronic acid. Such management of patellofemoral syndrome is rare. Injection may be used when many symptoms result from disruption of the joint surface and when all other reasonable measures have failed.
Medical Care
NSAIDs may assist with pain relief.
Prevention
PFS is a common overuse injury. Varying workouts, incorporating strengthening and stretching into routines, employing proper hydration and nutrition, and increasing focused activity by 10% weekly are general guidelines to reduce the risk of developing overuse injuries.