Osteochondritis Dissecans Treatment & Management

OCD of the knee

Therapy for osteochondritis dissecans of the knee is guided in large part by the age of the patient. Symptomatic lesions in children, or skeletally immature patients, who do not have loose bodies upon radiographic examination should initially be treated with conservative measures for 3 months. Conservative treatment in these patients includes limitation of activity and protected weight bearing to allow healing and prevent further displacement. Children should be offered a knee immobilizer during this time to limit the stress at the lesion.

Full activity may be permitted once the patient has no subjective reports of pain, normal physical examination findings, and radiographic evidence of healing. After 3 months, patients who are still symptomatic or whose repeat radiographs do not show improvement should be offered surgery. Earlier surgical intervention should be considered for lesions in children who are approaching physeal closure. Adults may also be given a trial of conservative treatment for knee OCD; however, they are less likely to improve without surgical intervention. Therefore, in adults, the threshold for surgery should be lower.

Incidental findings in asymptomatic patients with osteochondral lesions should be followed with repeat radiography every 4-6 months until the lesion has healed or until skeletal maturity is achieved. If the patient remains asymptomatic at skeletal maturity and the radiographic findings have not progressed, the patient may be reassured that no further treatment is indicated.

OCD of the ankle

Therapy for OCD of the ankle is guided primarily by two considerations, the location of the lesion and the radiographic findings. Patients with medial or lateral lesions and normal radiographic findings or radiographic findings that reveal only a partially detached osteochondral fragment may be treated conservatively. Conservative treatment in these patients includes immobilization of the limb in a cast or brace and no weight bearing for 6-12 weeks. Patients with a medial lesion and radiographic findings of a completely detached fragment that remains in the underlying crater bed may also be treated with 6 months of conservative care. However, symptomatic patients with a lateral lesion and radiographic findings of a completely detached fragment that remains in the underlying crater bed require surgical intervention.

OCD of the elbow

The natural history of OCD of the elbow is not well understood. Treatment of severe lesions is typically surgical; however, the results of surgery are often suboptimal, and patients are advised to expect some limitation of range of motion and possibly function after surgery. Therefore, in patients with mild-to-moderate and, possibly, severe disease, conservative therapy consisting of avoidance of the offending activity and immobilization of the elbow joint seems reasonable if the growth plates are open. The best therapy for this difficult population of patients may be early detection and prevention by avoidance of the offending activity.

In a study of 317 pediatric patients with a total of 334 OCD lesions, 35% progressed to surgery. Progression to surgery did not differ significantly between sexes with OCD of any joint, but did strongly correlate with patient age for OCD of the knee, elbow, and ankle. Progression to surgery in those cases was 8.2 times more likely in patients who were 12 to 19 years old at the time of diagnosis than in those 6 to 11 years old. ^[14]

Surgical options include the following ^{[15, 16]} :

• Arthroscopic subchondral drilling, to create channels that link the subchondral bone to the fragment
• Arthroscopic debridement and fragment stabilization
• Arthroscopic excision, curettage, and drilling
• Open removal of loose bodies, reconstruction of the crater base, mosaicplasty for fragment healing, and potential replacement with fixation
• Autologous chondrocyte transplantation
• Radical removal of sclerotic bone with bone grafting of the defect and autologous chondrocyte transplantation (ie, sandwich technique)

The decision for a given surgical procedure is based on findings from the preoperative evaluation. Patients should undergo preoperative MRI to better define the lesion. Some authors advocate the use of arthroscopy as a diagnostic tool in addition to MRI prior to more invasive procedures.

Patients with indications for surgery and lesions less than 3 cm in diameter should be offered arthroscopic intervention in the form of subchondral drilling and, possibly, debridement and fragment stabilization. Bone grafting may be required.

Patients with lesions 3 cm or greater in diameter or patients with multiple loose bodies may have their lesions fixed and replaced through an open procedure. Patients may also be offered autologous chondrocyte transplantation or mosaicplasty.

Patients with lesions 8 cm or greater in diameter may be offered radical removal of sclerotic bone with bone grafting of the defect and autologous chondrocyte transplantation (sandwich technique).

Arthroscopic subchondral drilling

Multiple perforations of the lesion are made using Kirschner wires. If the patient has open physes, care must be taken to avoid penetrating too deeply into the physis.

Arthroscopic debridement and stabilization using bioabsorbable nails or pins, versus nonabsorbable screw fixation

A bioresorbable bone fixation nail (eg, SmartNail) tip is used on the arthroscopic handle and inserted into the top of the fragment. Care must be taken to align the fracture before fixing it with Kirschner wires. The hole should be drilled through the fragment to the desired depth and screwed into place. If necessary, multiple pins may be placed for greater fixation. However, the pins should be placed at an angle and not parallel to one another.

Nonabsorbable screws (eg, Acutrak or Herbert screws) may be used in larger lesions with a firm crater. However, these generally must be removed after healing, which can be difficult. Screw removal is made easier if screws with reverse cutting threads (eg, Synthes 4-mm cannulated screws) are used.

Barrett et al reported that headless metal compression screws, which can be left in place, provide a satisfactory union rate for treatment of unstable osteochondritis dissecans of the femoral condyles in patients who are skeletally mature. At a mean of 31 months postoperatively (range, 2-262 months), fragment union was observed in 18 of 22 knees (82%). ^[17]

If bone loss is significant, cancellous bone grafting may be required.

Arthroscopic excision, curettage, and drilling

The lesion may be arthroscopically excised and the crater debrided and drilled to promote vascularity and healing.

Open removal of loose bodies, reconstruction of crater base, and replacement with fixation

The base of the crater is drilled to enhance vascularity. The fragment is trimmed, replaced, and securely fixed with Kirschner wires. The Kirschner wires are later removed in a retrograde fashion.

Fixation with bone pegs

Autogenous matchstick-sized strips of corticocancellous bone graft are used for internal fixation of the OCD lesion to the site of the defect. The cancellous bone graft is packed as needed into the lesion to restore articular congruity.

Autologous osteochondral mosaicplasty

Cylindrical osteochondral grafts from the minimal weight-bearing periphery are arthroscopically removed and transplanted into prepared defects in the weight-bearing or affected area. Combinations of the different graft sizes are used to allow a greater filling rate. Fibrocartilage grouting, stimulated by abrasion arthroplasty or sharp curettage at the base of the defect, completes the new surface.

Autologous chondrocyte transplantation

Chondrocytes are arthroscopically harvested and cultured in a cell culture laboratory for 2-3 weeks. During chondrocyte transplantation, care is taken to not provoke bleeding from the osseous bottom of the defect during debridement. Cultured cells are injected into the defect, which is covered with a periosteal flap. This technique is required for extensive defects in which other treatments have failed.

Radical removal of sclerotic bone with bone grafting of the defect and autologous chondrocyte transplantation (sandwich technique)

The defect is excised to the normal surrounding cartilage, and the sclerotic bone is excavated down to the bleeding cancellous bone. The osseous defect is filled with cancellous bone to the subchondral bone plate, and a periosteal flap is harvested and used to secure the graft. A second periosteal flap is then used for the autologous chondrocyte transplantation, which is performed as previously described.

Postoperative images of osteochondritis dissecans are shown below:

Following arthroscopic subchondral drilling without debridement or fixation, the affected joint is immobilized and a motion-restricting brace is prescribed. Patients are also instructed to be bearing weight on a toe-touch basis until signs of healing are evident upon radiographic examination. Once signs of healing are evident, patients should perform range-of-motion exercises for 20 minutes, 3 times per day. A similar rehabilitation protocol should be used after fixation with bone pegs.

Following all other surgeries, immobilization is not necessary. Continuous passive motion is administered on the same day as surgery and continued for 48 hours. Rehabilitation exercises with emphasis on limb function and muscle recruitment are initiated after 48 hours and are continued for 8 weeks. Weight bearing is gradually introduced into the patient's rehabilitation schedule, and the patient is progressed to full weight bearing by 6-8 weeks.

Surgical complications may include infection and neurovascular injuries, but these complications are particularly rare in these procedures.

The natural history and prognosis with different treatments vary depending on the age of the patient, the joint affected, and the stage of the lesion. Still, treatment and prognosis remain somewhat controversial because of the relative lack of clinical exposure by most physicians to patients with osteochondritis dissecans. In addition, the literature often describes juvenile and adult OCD as the same condition. Nonetheless, data suggest certain definite trends. ^{[18, 19]}

OCD of the knee

Juvenile OCD in the knee, without a loose body lesion, frequently heals with conservative therapy. Successful results have been reported in as many as 94% of these patients when treated with casting or bracing for 4 months. After conducting a systematic review of 27 studies with a total of 908 conservatively treated knees, Andriolo et al concluded that restriction of strenuous activity appeared to have favorable outcomes, whereas there was no evidence of benefit from physical instrumental therapy, immobilization, or weightbearing limitation. ^[3]  

Adult OCD in the knee, by contrast, rarely responds to conservative measures. One study examined patients who had knee OCD after physeal closure and found that 38 of 48 patients had gonarthrosis at 33-year follow-up. ^{[15, 20, 21]}

OCD of the ankle

Juvenile patients with ankle OCD seem to respond significantly better to conservative treatment than do their adult counterparts. In one study, juvenile ankle OCD treated with conservative care had a 95% success rate. Another study reported an 82% successful rate for juvenile ankle OCD with conservative therapy.

A review of 14 clinical studies evaluating 201 patients without distinction between juvenile and adult ankle OCD found that only 45% of patients responded successfully to conservative management. However, in addition to combining juvenile and adult patients, these studies did not provide consistent criteria for conservative treatment; they also did not consistently delineate what conservative treatment was provided. If adult patients are appropriately selected (stage I and II lesions and stage III medial lesions) and conservative care is appropriately provided, the successful response rate is likely to be significantly higher. ^[22]

In a study of juvenile patients with ankle OCD who required surgical intervention, 40% had good results, 53% had fair results, and 7% had poor results. Adult ankle OCD seems to respond better than juvenile ankle OCD when surgical intervention is required. One prospective study found excellent or good results in 82% of adult patients treated with arthroscopic excision, curettage, and drilling of the ankle OCD defect at a mean follow-up of 4.8 years.

OCD of the elbow

Few long-term studies have evaluated elbow OCD. One study evaluated five female gymnasts aged 11-13 years. Three of these gymnasts were treated conservatively, and two underwent arthroscopic removal of a loose body. Four continued to compete in gymnastics at the 3-year follow-up. Another study, however, evaluated 7 female gymnasts at an average age of 13.3 years. All underwent surgery, and all lost extension, with only one continuing to compete in the sport. ^[2]

Adult patients with elbow OCD may respond better to surgical treatment. One study evaluated 35 adult athletes treated with arthroscopic surgery and reported successful results in 90%. However, although these patients did not lose function, many of them did lose up to 10° of extension. ^[2]

Surgical intervention

Pascual-Garrido et al examined the outcomes of surgical procedures for osteochondritis dissecans in 46 adult patients (48 knees), with patients ranging in age from 20 to 49 years. Patients who were treated with surgical cartilage procedures showed durable function and symptomatic improvement at a mean of 4 years follow-up. Patients treated with arthroscopic reduction and internal fixation and loose-body removal had greater improvement in outcome scores than those treated with an osteochondral allograft. Seven knees required revision procedures at a mean follow-up of 14 months. ^[23]

Outcomes with the following procedures are described below ^{[1, 2, 7, 20, 21, 22]} :

• Arthroscopic subchondral drilling
• Fixation with bone pegs
• Fixation with bioabsorbable implants
• Autologous chondrocyte transplantation
• Autologous osteochondral mosaicplasty

Arthroscopic subchondral drilling

Arthroscopic subchondral drilling in patients with juvenile OCD in the knee yields an approximate 80% success rate at 1-year follow-up. In adult OCD in the knee, arthroscopic subchondral drilling appears to be less effective, with approximately 70% success.

Arthroscopic drilling with fixation in patients with knee OCD yields good or excellent results in approximately 94% of patients. Open removal of loose bodies, reconstruction of the crater base, and replacement with fixation yield a success rate of approximately 70%.

Adachi et al evaluated the functional and radiographic outcome of retroarticular drilling without bone grafting in 12 patients with juvenile osteochondritis dissecans after 6 months of unsuccessful nonoperative treatment. The mean Lysholm score significantly improved postoperatively (from 72.3 to 95.8). All lesions except 1 healed after retroarticular drilling, and healing was achieved at a mean of 4.4 months on plain radiographs and 7.6 months on magnetic resonance imaging. ^[24]

Fixation with bone pegs

Fixation with bone pegs had 100% effectiveness in one study of 17 patients with knee OCD. Another study in a military population evaluated fixation with bone pegs with supplementary Kirschner-wire fixation and found that 47 of 54 patients were able to return to active military duty.

Fixation with bioabsorbable implants

Tabaddor et al evaluated the efficacy and safety of poly 96L/4D-lactide bioabsorbable copolymer fixation for unstable OCD in 24 adolescents (mean age, 14.4 y). Plain films at an average of 19.2 months after surgery showed interval healing in 9 patients, no significant change in 1, complete healing in 13, and loose bodies with no interval healing in 1. MRIs showed interval healing in 16 of 17 knees at a mean follow-up of 22.4 months. ^[25]

Autologous chondrocyte transplantation

Autologous chondrocyte transplantation for the treatment of OCD lesions of the femoral condyle was found to yield good results at 2-year follow-up in 52 of 53 patients. ^[21] In one study, autologous chondrocyte transplantation for ankle OCD in adults achieved a 100% effectiveness rate in all 8 patients treated, with a mean follow-up of 17.6 months. ^[22]

Another prospective study evaluated the effectiveness of autologous osteochondral grafts in adult ankle OCD and found excellent results in 82% of patients. This study found that patients younger than 45 years, patients who do not smoke, and patients with active lifestyles had the best chance for optimal outcome.

An additional consideration for autologous chondrocyte transplantation is that preparing the cells for implantation is an expensive process. Some insurers may not offer coverage for this method because of the expense.

Lyon et al reviewed 11 cases of children with OCD of the knee who were treated with a fresh osteochondral allograft. The study concluded that the allografts restored short-term function in patients in whom standard treatment was unsuccessful. ^[26]

Sacolick and colleagues reviewed the outcomes from 179 patients and found a failure rate of 8.2%. Complications were reported in 15.6% of cases. Males, active patients, smaller lesion sizes, and younger age at the time of surgery were positive prognostic factors. ^[27]

Autologous osteochondral mosaicplasty

Autologous osteochondral mosaicplasty was found to be 94% effective for OCD lesions requiring surgery in the femoral condyle and 88% effective for OCD lesions requiring surgery in the talus. However, a prospective, randomized study that directly compared autologous chondrocyte implantation with mosaicplasty for OCD lesions in the knee found that autologous chondrocyte implantation had significantly better results for lesions in the medial femoral condyle, lateral femoral condyle, and patella. Although mosaicplasty was effective for medial and lateral femoral condyle lesions, it was inferior to autologous chondrocyte implantation. For patellar lesions, the study showed no effectiveness for mosaicplasty. ^[20]

Autologous chondrocyte implantation and mosaicplasty are still relatively new procedures. Their initial results are promising; however, further data are needed before firm recommendations can be made. This is especially true with regard to their use in ankle and elbow OCD. Future research will also need to differentiate responses between juvenile and adult OCD because the two patient populations affected by these conditions seem to respond differently to various treatments.