Osteochondritis dissecans of the lateral femoral condyle following total resection of the discoid lateral meniscus

Tibiofemoral Subluxation on Radiograph as a Predictor of Location and Size of Osteochondritis Dissecans Lesions of the Knee

Background

Lower limb malalignment has been associated with osteochondritis dissecans (OCD). However, the location of the OCD lesion often is not concordant with the mechanical leg axis. Other potentially modifiable alignment parameters may influence the propensity for impingement of the femoral condyles.

Purpose

To assess differences in lower limb alignment (LLA) and relative tibiofemoral position between patients with medial (MFC-OCD) or lateral OCD (LFC-OCD) of the femoral condyle.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients ≤30 years old who were diagnosed with unicondylar OCD between January 2010 and January 2020 were eligible for this study. Included were 55 patients (age, 20.8 ± 4.5 years)-46 with MFC-OCD and 9 with LFC-OCD. Preoperative standing long-leg radiographs were studied to obtain primary outcomes-including LLA and mechanical alignment analyses-and secondary outcomes-including knee joint obliquity angle; rotation angle; medial, central (c-subluxation), and lateral subluxation (L-subluxation) of the tibia relative to the femur in the coronal plane; and tibiofemoral joint line center distance (TFJCD).

Results

With regard to primary outcomes, LLA was significantly different between MFC-OCD (1.7°± 3.1° varus) and LFC-OCD (2.7 ± 3.1° valgus) (P < .001), and 78% (36/46) of patients with MFC-OCD had varus alignment, whereas 78% (7/9) of patients with LFC-OCD had valgus alignment (P < 0.002). With regard to secondary outcomes, patients with MFC-OCD had a more medial tibial position in relation to the femur, with a significantly smaller rotation angle (5.6°± 2.4° vs 9.6°± 3.6°; P < .001), a smaller C-subluxation (7.2 ± 6.6 vs 14.9 ± 8.8 mm; P < .01), a smaller L-subluxation (2.3 ± 2.6 vs 4.4 ± 2.7 mm; P < .05), and reduced TFJCD (3.5 ± 1.7 vs 6.6 ± 1.8 mm; P < .001) compared with the LFC-OCD group. For patients with MFC-OCD, the size of the OCD was significantly correlated with C-subluxation (r = 0.412; P = .006).

Conclusion

LLA was significantly different according to OCD location. In patients with MFC-OCD, the tibia was subluxated medially, resulting in a change of joint geometry by approximation of the medial tibial eminence toward the medial femoral condyle, potentially causing excessive pressure overload and microtrauma of the cartilage. Interestingly, the extent of subluxation was correlated with OCD size.

[Treatment of osteochondritis dissecans]

Osteochondritis dissecans (OD) is a rare condition with an incidence of 30/100,000. It especially affects male patients aged 10-20 years old. During the staged progression the osteochondral fragments can detach from their base. These can damage the adjacent articular cartilage, which can lead to premature osteoarthritis. Most commonly affected are the knee, ankle and elbow joints. The exact pathogenesis of OD has so far not been clearly confirmed. Several risk factors that can lead to the development of OD are discussed. These include repeated microtrauma and vascularization disorders that can lead to ischemia of the subchondral bone and to a separation of the fragments close to the joint and therefore to the development of free joint bodies. For an adequate clarification patients should undergo a thorough radiological evaluation including X‑ray imaging followed by magnetic resonance imaging (MRI) to assess the integrity of the cartilage-bone formation with determination of the OD stage. The assessment is based on criteria of the International Cartilage Repair Society (ICRS). The instability of the cartilage-bone fragment increases with higher stages. Stages I and II with stable cartilage-bone interconnection can be treated conservatively. For stages III and IV, i.e., instability of the OD fragment or the presence of free fragments, surgical treatment should be performed. Primarily, refixation of a free joint body should be carried out depending on the size and vitality of the fragment. In cases of unsuccessful conservative treatment or fixation, a debridement, if necessary in combination with a bone marrow stimulating procedure, can be employed corresponding to the size of the defect. For larger cartilage defects, an osteochondral graft transplantation should be considered. Overall, OD lesions in stages I and II show a good healing tendency under conservative treatment. In cases of incipient unstable OD, refixation can also lead to good clinical and radiological results.

Update on imaging of the discoid meniscus

Discoid menisci represent a range of morphological meniscal variants, most commonly involving the lateral meniscus. Clinical presentation ranges from an asymptomatic incidental finding to snapping, pain, swelling and reduced range of knee movement. Symptomatic presentation of discoid menisci is usually due to meniscal tears and instability resulting from abnormal meniscal morphology and ultrastructure, with absent peri-meniscal ligamentous and meniscocapsular attachments characteristic of the Wrisberg sub-type. This article reviews the current classification systems of discoid menisci, gross morphological characteristics of each sub-type and ultrastructure. Clinical presentation, arthroscopic findings and indirect radiological diagnostic criteria are described, as are the MRI findings of normal and pathological discoid menisci. Current concepts of surgical management and outcomes of the discoid meniscus are also briefly discussed.

Examination of refractory discoid lateral meniscus injury

BACKGROUND

Lateral discoid meniscus (LDM) should be treated and preserved with saucerization and/or suture repair. However, repair of the meniscal hoop structure is sometimes difficult due to displacement or large defects. In this study, we aimed to examine tear patterns based on the Ahn classification in those requiring meniscal repair and those undergoing subtotal meniscectomy.

METHODS

Twenty-three patients were evaluated (mean age, 27.4 years; mean follow-up period, 2.5 years). The following were evaluated: displacement morphology based on the Ahn classification, site of tear under arthroscopy, morphology, surgical procedure, Lysholm score at final postoperative follow-up, and clinical outcome of meniscus using Barrett's criteria.

RESULT

There were 16 knees without displacement (saucerization with suture repair, 13 knees; subtotal meniscectomy, 3 knees) and 10 knees with displacement (reduction with suture repair, 3 knees; subtotal meniscectomy, 7 knees). Subtotal meniscectomy was performed more often in cases with dislocation, especially in the central shift type as defined by the Ahn classification. The mean Lysholm score was 65.0 points preoperatively and 95.3 points postoperatively. Twenty-three knees (88%) were postoperatively categorized under the Barrett's criteria as healing and 3 knees (12%) were categorized as non-healing. The number of non-healing cases that underwent subtotal meniscectomy was relatively small (1 of 10 knees), and the short-term results were not poor.

CONCLUSION

Localized peripheral longitudinal tears tended to be repairable even with displacement, while peripheral tears covering the entire meniscus or with severe defects/tears in the body of the meniscus tended to be difficult to repair, leading to subtotal meniscectomy.

Magnetic Resonance Imaging T2 Relaxation Times of Articular Cartilage Before and After Arthroscopic Surgery for Discoid Lateral Meniscus

PURPOSE

To quantitatively evaluate degeneration of articular cartilage using magnetic resonance imaging (MRI) T2 mapping before and after arthroscopic surgery for discoid lateral meniscus (DLM).

METHODS

We retrospectively reviewed the medical records of patients who underwent arthroscopic reshaping surgery for symptomatic DLM from September 2013 to October 2017 and who had undergone follow-up for ≥2 years. MRI T2 relaxation examinations had been performed preoperatively and at 3, 6, 12, and 24 months postoperatively. The T2 relaxation times of the whole lateral femoral condyle and the tibial plateau were assessed. In addition, the lateral femoral condyle was divided into 3 subcompartmental areas: anterior, middle, and posterior.

RESULTS

In total, 30 knees of 27 patients were included in this study. The patients' mean age at operation was 13.3 years (range 6-23 years), and the mean follow-up period was 31.6 months. Saucerization alone was performed in 3 knees and saucerization with repair in 27 knees. The T2 relaxation time of the whole lateral femoral condyle was significantly increased at 3 and 6 months postoperatively and significantly decreased at 12 and 24 months. The T2 relaxation time of the whole lateral tibial plateau was significantly increased at 3 months postoperatively and significantly decreased at 24 months. The T2 relaxation time of the posterior subcompartment of the lateral femoral condyle was significantly increased at 3 months and significantly decreased at 12 and 24 months.

CONCLUSIONS

The T2 relaxation time of the lateral femorotibial joint cartilage increased at 3 and 6 months postoperatively and then had decreased at 12 and 24 months. Quantitative MRI allowed us to monitor the substantial changes in the cartilage during the early postoperative period and the recovery at the distant time point after reshaping surgery for DLM.

LEVEL OF EVIDENCE

Level IV, case series.

Predictive factors for developing osteochondritis dissecans after surgery for discoid lateral meniscus are younger age and shorter meniscal width

PURPOSE

This study aimed to identify the predictive factors for postoperative osteochondritis dissecans (OCD) in juvenile and adolescent knees with discoid lateral meniscus (DLM).

METHODS

In total, 242 patients with symptomatic DLM who underwent surgery were identified. Inclusion criteria were set as follows: (1) age ≤ 17 years with an open growth plate, (2) follow-up magnetic resonance imaging, and (3) absence of preoperative OCD. Consequently, 52 patients were retrospectively investigated. Average age during surgery, body mass index (BMI), and follow-up duration were 12 years [95% confidence interval (CI) 11-13], 19.2 kg/m² (95% CI 18.4-20.1), and 27.3 months (95% CI 20.9-33.7), respectively. Age, sex, sports activities, BMI, symptomatic OCD in other joints, postoperative rehabilitation, preoperative shift of DLM by Ahn's classification, surgical procedures (saucerization alone or with stabilization, and subtotal meniscectomy), and postoperative meniscal width were analyzed as possible predictive factors.

RESULTS

Postoperatively, 42 patients without OCD and 10 with OCD were observed. In univariate analysis, younger age [odds ratio (OR) 1.5; p = 0.003], subtotal meniscectomy (OR 6.3; p = 0.027), and shorter meniscal width (OR 2.7; p = 0.005) were predictive factors for postoperative OCD. Multivariate analysis demonstrated that younger age (OR 1.6; p = 0.009) and shorter meniscal width (OR 1.5; p = 0.003) were predictive factors.

CONCLUSIONS

To prevent postoperative OCD after DLM surgeries, achieving stabilization with adequate meniscal width is necessary for juvenile knees.

LEVEL OF EVIDENCE

III.

Factors Related to Postoperative Osteochondritis Dissecans of the Lateral Femoral Condyle After Meniscal Surgery in Juvenile Patients With a Discoid Lateral Meniscus

PURPOSE

The purpose was to assess the incidence of postoperative osteochondritis dissecans (OCD) and the related epidemiologic factors following meniscal surgery for juvenile discoid lateral meniscus (DLM).

METHODS

The study was a retrospective review of 103 knees in 89 patients with a mean age of 12.1 years who underwent arthroscopic meniscal surgery for DLM. Mean follow-up was 4.2 years. The surgical procedures were either saucerization, saucerization with repair or subtotal meniscectomy, depending on the type of DLM tear. Postoperative OCD lesions were identified radiographically. Age, sex, weight, Lysholm score, Tegner activity scale, exercise frequency, and surgical procedure were compared between the postoperative OCD diagnosis group and non-OCD control group.

RESULTS

Postoperative OCD was diagnosed in 8/103 (7.8%) knees following DLM surgery. The incidence of postoperative OCD was significantly greater for patients age less than 10 years old, and male sex, low weight, Lysholm score, Tegner activity scale preinjury and after returning to sports, and exercise frequency per week on univariate analyses. On multivariate analyses, postoperative OCD occurred more commonly with subtotal meniscectomy than with saucerization or saucerization with repair, and in patients less than 11 years of age. Receiver operating characteristic curve analysis revealed a cutoff value of age at surgery of 10 years.

CONCLUSIONS

Subtotal meniscectomy and patients younger than 10 years at the time of surgery are at greater risk for postoperative OCD. To decrease this risk, if possible, we recommend performing saucerization or saucerization with repair in patients undergoing surgery for DLM.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Osteochondritis Dissecans of the Knee: Etiology and Pathogenetic Mechanisms. A Systematic Review

OBJECTIVE

The purpose of this manuscript is to analyze the evidence regarding etiopathogenesis of knee osteochondritis dissecans (OCD) lesions through a systematic review, so to summate the current understanding of the origin and progression of this pathologic articular processes.

DESIGN

A systematic review of the literature was performed on the PubMed and Cochrane databases on October 2017 by 2 independent authors and included all levels of evidence. This included all English language literature, pertaining specifically to etiopathology of knee OCD with exclusions for review articles and expert opinion. Of 965 identified records, 154 full-text articles were assessed for eligibility and 86 studies met the inclusion criteria.

RESULTS

According to these studies, the etiology of OCD can be of a biological or mechanical origin: 40 articles proposed a biological hypothesis, including genetic causes (27), ossification center deficit (12), and endocrine disorders (9); conversely, 52 articles supported a mechanical hypothesis, including injury/overuse (18), tibial spine impingement (5), discoid meniscus (16), and biomechanical alterations (20) as the cause of the onset of OCD. The pathogenic processes were investigated by 36 of these articles, with a focus on subchondral bone fracture and ischemia as the ultimate events leading to OCD.

CONCLUSIONS

Biological and mechanical factors are found to result in subchondral bone remodeling alterations, acting independently or more likely synergically in the progression of knee OCD. The former includes genetic causes, deficit of ossification centers and endocrine disorders; the latter, tibial spine impingement, discoid meniscus, and biomechanical alterations, together with injuries and overuse. The resultant subchondral bone ischemia and/or fracturing appears to determine the onset and progression of OCD.

LEVEL OF EVIDENCE

Systematic review of level II-IV studies, level IV.

Osteochondritis Dissecans: Etiology, Pathology, and Imaging with a Special Focus on the Knee Joint

This article is a review of the current understanding of the etiology, pathogenesis, and how to diagnose and treat knee osteochondritis dissecans (OCD) followed by an analysis of and outcomes of the treatments available. OCD is seen in children and adolescents with open growth plates (juvenile OCD) and adults with closed growth plates (adult OCD). The etiology of OCD lesions remains unclear and is characterized by an aseptic necrosis in the subchondral bone area. Mechanical factors seem to play an important role. Clinical symptoms are unspecific. Thus, imaging techniques are most important. Regarding treatment, a tremendous number of publications exist. Spontaneous healing is expected unless there is an unstable fragment, and treatment involves rest and different degrees of immobilization until healing. Patients with open physes and low-grade lesions have good results with conservative therapy. When surgery is necessary, the procedure depends on the stage and on the state of the cartilage. With intact cartilage, retrograde procedures are favorable. When the cartilage is damaged, several techniques can be used. While techniques such as drilling and microfracturing produce reparative cartilage, other techniques reconstruct the defect with additional osteochondral grafts or cell-based procedures such as chondrocyte transplantation. There is a tendency toward better results when using procedures that reconstruct the bone and the cartilage and there is also a trend toward better long-term results when comorbidities are treated. Severe grades of osteoarthrosis are rare.

Internal Fixation of Unstable Osteochondritis Dissecans: Do Open Growth Plates Improve Healing Rate?

BACKGROUND

Osteochondritis dissecans (OCD) is a disorder of unknown origin that can affect knees in skeletally mature and immature patients. Surgical management is an important cornerstone of treatment for unstable OCD lesions.

PURPOSE

To determine the (1) healing rate after internal fixation of unstable OCD between skeletally immature and mature knees, (2) risk factors for failure, and (3) patient-reported outcomes among healed patients.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A multicenter retrospective cohort study was conducted with patients who underwent internal fixation of unstable knee OCD lesions from 2000 to 2015. Skeletal immaturity was defined as open or partially open physes. Healing was assessed through clinical findings and imaging. Definitive reoperation for the same OCD lesion was classified as failure.

RESULTS

Among 87 patients included, 66 (76%) had healed lesions at ≥2 years postoperatively, while 21 (24%) failed. Skeletal maturity made no significant difference in failure rate (risk ratio, 0.68; 95% CI, 0.29-1.72; P = .40). For skeletally immature patients, lateral versus medial condylar location conferred an increased hazard of 18.2 (95% CI, 1.76-188.07; P < .01). Multivariate analysis factoring in skeletal maturity showed that lateral condylar location was an independent risk factor for failure (hazard ratio, 4.25; 95% CI, 1.47-19.85; P < .01). Mean patient-reported outcome scores (International Knee Documentation Committee [IKDC] and Knee injury and Osteoarthritis Outcome Score [KOOS]) increased significantly after surgery, except the KOOS symptoms score for the skeletally mature group. Final scores (mean ± SD) were as follows at a mean follow-up of 60 months (range, 24-166): IKDC, 83.5 ± 20.2; KOOS pain, 89.7 ± 14.1; KOOS symptoms, 87.4 ± 18.4; KOOS activities of daily living, 93.9 ± 12.7; KOOS sports, 80.7 ± 25.9; KOOS quality of life, 78.9 ± 23.1.

CONCLUSION

Skeletally immature and mature patients heal at comparable rates after internal fixation of OCD lesions, resulting in functional and subjective improvement. Lateral femoral condylar lesion location is an independent risk factor for failure.

Evolution of Osteochondritis Dissecans of the Lateral Femoral Condyle Combined with Discoid Meniscus

The discoid meniscus is a rare anomaly of the knee that affects mostly the lateral meniscus and is often asymptomatic. The osteochondritis dissecans is a disorder of the subchondral bone and articular cartilage and occurs frequently associated with the discoid lateral meniscus. In the present case, we showed the evolution of this association related to surgical treatment. A patient with lateral knee pain and a magnetic resonance depicting a torn discoid lateral meniscus and osteochondritis dissecans of the lateral femoral condyle was treated with partial meniscectomy and meniscal sutures. After 1 year, the symptoms reappeared, and a new meniscal repair was performed to treat a bucket-handle tear, while cartilage was apparently intact. After 4 years, there was a new recurrence of symptoms, and the knee developed a valgus deformity. Cartilage was treated with microfractures, and a subsequent distal femoral osteotomy associated with lateral meniscal scaffold was performed. The patient was followed up clinically, with radiographs and magnetic resonance for 5 years with an improvement of the results up to 2 years and no signs of deterioration of results over time.

Progression of stable juvenile osteochondritis dissecans after 10 years of meniscectomy of the discoid lateral meniscus

Ten years after a meniscectomy of discoid lateral meniscus, a 19-year-old man presented a loose body in his right knee with limited range of motion. At the time of meniscectomy, a stable osteochondritis dissecans in the lateral femoral condyle with a T2 high area in MRI was recognized; however, the lesion was left without surgical treatment. We performed fixation of a fragment and osteochondral grafting. Surgical treatment for stable juvenile osteochondritis dissecans still remains controversial; however, drilling will help to increase the healing potential and to prevent lesion progression, especially after meniscectomy that alters the mechanical stress on immature osteochondral structures.

Arthroscopic treatment of symptomatic discoid meniscus in children

PURPOSE

To study discoid meniscus in children who underwent arthroscopic surgery at our center.

SUBJECTS AND METHODS

Thirty-four patients (39 knees) younger than 15 years with discoid lateral meniscus (mean age, 12.9 years; 13 males, 21 females) who underwent arthroscopic surgeries since 2007 were studied. The surgical procedure consisted of, in principle, saucerization with additional suture repair in the case of meniscal instability at the peripheral rim of the residual meniscus. The mechanisms of symptom onset, symptoms, complications and postoperative outcome in these cases were examined. In addition, Lysholm scores were obtained before surgery and at the last postoperative follow-up in all patients.

RESULTS

Symptom onset was associated with sports in 18 knees, fall in 3 knees, and no definitive trigger in the remaining knees. The presenting symptoms were pain in 32 knees, catching in 11 knees, and locking in 6 knees. According to Watanabe classification, 26 knees were complete type and 13 knees were incomplete type. The modes of tear included horizontal tear in 10 knees and longitudinal tear in 10 knees, while no definitive tear was present on the knee joint surface. The surgical procedures included saucerization only in 22 knees, partial meniscectomy in 10 knees, and saucerization with suture repair in 5 knees. The mean Lysholm score was 63.9 before surgery, and improved significantly to 92.3 at the last follow-up. Only two knees developed osteochondritis dissecans after surgery. Two knees required reoperation; one knee underwent subtotal meniscectomy and one knee had partial meniscectomy with suturing.

CONCLUSION

Although the short-term outcome after saucerization with or without suture repair for discoid meniscus is favorable, degenerative change or change of lower limb alignment may occur in the long term. Further long-term study is required.

Analysis of risk factors for poor prognosis in conservatively managed juvenile osteochondritis dissecans of the lateral femoral condyle

BACKGROUND

The purpose of this study was to examine factors affecting the prognosis of conservative treatment for stable juvenile osteochondritis dissecans (OCD) of the lateral femoral condyle based on review of our patient population.

METHODS

A consecutive series of 43 knees in 37 patients with stable OCD of the lateral femoral condyle with open physes undergoing conservative treatment were included in the study. The mean age of the included subjects was 10.7±2.5years (range, seven to 16years) with the mean follow-up period of 33.3±15.1months (range, 12 to 67months). Conservative treatment consisting of prohibition of sports activities and use of a brace locking the knee in full extension was applied to all included patients. Potential prognostic factors examined were the presence of discoid meniscus, radiographic stage, lesion size on radiographs, time period from onset of symptoms to evaluation/consultation, number of hours of sporting activity per week, and age at starting sports activities. Prognosis of a patient was deemed to be poor when an apparent healing response was not detected in follow-up radiographic studies within six months.

RESULTS

The prognosis was defined to be poor for 14 knees (32.6%). The presence of discoid meniscus was identified in 100% of the knees in the poor prognosis group and time-period from onset to consultation of six months or more was shown to be a risk factor with statistical significance.

CONCLUSIONS

A majority of patients with juvenile OCD in the lateral femoral condyle could be managed with conservative treatment. The presence of discoid meniscus and longer time-period from onset to consultation were significantly related with poor prognosis.

LEVEL OF EVIDENCE

IV (case series).

Diseases of Subchondral Bone 1

The subchondral zone plays an important role in both the structural and biochemical maintenance of articular cartilage. Knowledge of the structure, function, and pathophysiology of the normal subchondral bone/articular surface interface is essential for an understanding of the pathogenesis of many of the disease entities that we will review in this chapter.

Arthroscopic Treatment for Symptomatic Discoid Meniscus in Children: Midterm Outcomes and Prognostic Factors

PURPOSE

To investigate the clinical and radiologic outcomes and prognostic factors of arthroscopic partial meniscectomy with or without suture repair of the remnant rim and subtotal meniscectomy in children with discoid menisci.

METHODS

We retrospectively reviewed all consecutive patients aged younger than 18 years who underwent arthroscopy between 2003 and 2012, excluding patients with follow-up less than 2 years, concomitant injuries, underlying diseases, or a lost videotape. Patients were grouped by treatment method: partial meniscectomy with or without suture repair and subtotal meniscectomy. Clinical outcomes were determined based on symptoms, complications, and Lysholm scores. Degenerative changes were assessed radiologically. Risk factors for a lower Lysholm score were investigated.

RESULTS

Of 100 knees (86 patients; mean age, 10.7 years), 87 underwent partial meniscectomy with (n = 42) or without (n = 45) suture repair and 13 underwent subtotal meniscectomy. The Lysholm score at a mean of 4.7 years (range, 2.0 to 10.9 years) improved to more than 90, regardless of meniscectomy method (P = .767; 95% confidence interval [CI], -5.1 to 6.9) or the addition of suture repair (P = .797; 95% CI, -3.5 to 4.6). Early degenerative changes were found in 11 knees. Patients aged younger than 10 years at surgery had a 2.37 times higher chance of having excellent Lysholm scores (P = .032; 95% CI, 1.1 to 5.1). A reoperation history was associated with lower Lysholm scores with a marginal significance (P = .054; 95% CI, -0.9 to 12.3).

CONCLUSIONS

Arthroscopic partial meniscectomy with stabilization of the unstable remnant rim was effective in preserving knee function with few early degenerative changes during the midterm follow-up period. Subtotal meniscectomy appears to be a valid treatment for unsalvageable cases. There was no difference in outcomes among the partial meniscectomy, partial meniscectomy with suture repair, and subtotal meniscectomy groups. Less satisfactory functional outcomes may follow in children aged 10 years or older or when a reoperation has been performed.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Discoid Meniscus: Diagnosis and Management

Discoid lateral meniscus is a common abnormal meniscal variant in children. Detailed history and physical examination combined with an MRI of the knee predictably diagnose a discoid meniscus. The clinical presentation varies from being asymptomatic to snapping, locking, and causing severe pain and swelling of the knee. Because of the pathologic anatomy and instability, discoid menisci are more prone to tearing. Treatment options for symptomatic patients vary based on the type of anomaly, the age of the patient, stability, and the presence or absence of a tear. Improvements in arthroscopic equipment and technique have resulted in good to excellent short-term outcomes for saucerization and repair.

Intact bone vitality and increased accumulation of nonmineralized bone matrix in biopsy specimens of juvenile osteochondritis dissecans: a histological analysis

BACKGROUND

Although commonly proposed to be the starting point of juvenile osteochondritis dissecans (JOCD), avascular osteonecrosis (AVN) has been an inconsistent finding in histological studies. Analysis of early-stage lesions is required to elucidate the origins of OCD and justify proper treatment.

PURPOSE

To analyze histological sections of JOCD lesions with special emphasis on bone vitality.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Of 64 patients with 74 JOCD lesions (20 females, mean age, 11.4 years; 44 males, mean age, 12.7 years), 34 required surgery because of lesion instability or failed nonoperative treatment. From 9 patients, 11 histological specimens were obtained. Lesions were classified according to the International Cartilage Repair Society (ICRS). Two additional histological control sections were harvested from children without JOCD manifestation. Undecalcified histological sections were histomorphometrically analyzed. To analyze the skeletal health of the patients, biochemical analyses with special emphasis on bone metabolism were performed.

RESULTS

Histologically, no osteonecrosis was visible in any of the cases. Osteocyte distribution was similar among OCD lesions and controls. ICRS OCD I lesions (n = 6) showed no intralesional separation. In ICRS OCD II and III lesions (n = 5), there was a subchondral fracture concomitant with histological characteristics of active repair mechanism (increased bone formation: osteoid volume P = .008, osteoblast number P = .046; resorption: osteoclast number P = .005; and tissue fibrosis compared with controls). Instead, in ICRS OCD I lesions, subchondral osteoid volume (P = .010) and osteoblast number (P = .046) were significantly increased compared with controls; however, no active repair mechanisms (no increased bone resorption or fibrous tissue) were detected, suggesting a focal lack of mineralization. Fifty-seven of 64 patients (89.1%) showed a vitamin D deficiency. The median vitamin D serum level of the patients with ICRS OCD I lesions was 13.6 µg/L.

CONCLUSION

In the present study, osteonecrosis was not found in histological specimens of JOCD. As a secondary finding, focal accumulations of nonmineralized bone matrix indicating a lack of mineralization in ICRS OCD I lesions were revealed. This finding correlated with a low level of vitamin D in the affected children.

Bilateral Wrisberg discoid menisci mimicking bucket handle tears associated with osteochondritis dissecans: case report

Discoid menisci are frequently associated with osteochondritis dissecans (OCD) of the knee and are often bilateral. Patients usually present with no or few symptoms disproportionate to the size of the lesions. We report the case of a 14-year-old boy who had bilateral unstable lateral discoid menisci with unilateral stage 3 OCD treated with meniscoplasty, meniscal rim stabilization, and fixation of the OCD.

Functional and radiographic outcomes of unstable juvenile osteochondritis dissecans of the knee treated with lesion fixation using bioabsorbable pins

BACKGROUND

The purpose of this study was to evaluate the functional and radiographic outcome of fixation of unstable juvenile osteochondritis dissecans lesions of the knee after a minimum of 2 years of follow-up.

METHODS

A total of 33 unstable juvenile osteochondritis dissecans lesions in 30 patients underwent fixation using bioabsorbable pins through arthrotomy or under arthroscopy. The patients consisted of 23 males and 7 females, and the average age at the time of operation was 14.4 years (range, 11 to 17 y). The functional outcomes were evaluated using the Lysholm score and Hughston's criteria at a mean follow-up of 3.3 years (range, 2.1 to 6.3 y). Healing of the osteochondritis dissecans lesions were confirmed by plain radiographs and magnetic resonance imaging.

RESULTS

The Lysholm score improved significantly at 3 months after the surgery, and was maintained until the final follow-up. Radiographically, 32 of 33 lesions healed after fixation of the lesion (healing rate was 97.0%). Healing was achieved at an average of 2.4 months on plain radiographs and 4.2 months on magnetic resonance imaging. According to Hughston's criteria, 25 patients were graded as excellent, 4 as good, and 1 as poor at the final follow-up.

CONCLUSIONS

The fixation of the unstable juvenile osteochondritis dissecans lesions with bioabsorbable pins demonstrated improved clinical outcomes and radiographic high healing rates at a mean of 3.3 years of follow-up. We advocate this procedure for patients with unstable juvenile osteochondritis dissecans lesions of sufficient quality to enable fixation which will preserve the normal contour of the distal femur.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Osteochondritis dissecans of the lateral tibial condyle associated with agenesis of both cruciate ligaments

Osteochondritis dissecans is a rare cause of painful knees in children. Only 10 cases of lateral tibial condyle involvement have been reported in the literature. Congenital agenesis of both cruciate ligaments has been described even less, and its prevalence is unknown. The authors report an atypical association of osteochondritis dissecans of the tibia with congenital absence of both cruciate ligaments. A 12-year-old male soccer player presented with a painful right knee. Magnetic resonance imaging revealed the diagnosis. The child was treated conservatively. At 18-month follow-up, radiographs showed osseointegration of the osteochondritis dissecans, and the patient had resumed normal athletic activity without pain. To the authors' knowledge, this is the only report describing such an association. The authors discuss the possible etiology of osteochondritis dissecans associated with agenesis of the cruciate ligaments and highlight the possibility of this association when osteochondritis dissecans of the tibia is diagnosed in a child with a painful knee. In this patient, the strain due to anteroposterior instability may have been the cause of osteochondritis. Conservative treatment should be considered in this setting.

Surgical management of juvenile osteochondritis dissecans of the knee

PURPOSE

Operative management of osteochondritis dissecans (OCD) in the juvenile knee is generally indicated upon failure of conservative treatment, in unstable lesions, and in lesions nearing physeal closure. We hypothesized that juvenile OCD lesions have improved clinical and radiographic outcomes with surgical treatment following failed non-surgical management, in unstable lesions, and in lesions nearing physeal closure.

METHODS

Multiple medical databases were searched for Levels I-IV evidence with specific study inclusion and exclusion criteria. Length of mean follow-up was minimum 2 years. Studies were included if an analysis of clinical outcomes following surgical treatment of juvenile OCD was performed. All surgical techniques and defect classifications were potentially inclusive.

RESULTS

Thirty studies (29 Level IV evidence) were included for analysis (783 subjects, 862 knees). Mean post-operative follow-up was 77 months. Nearly all studies within this review demonstrated significant clinical and radiographic improvements in outcomes in surgically treated juvenile OCD at short-, mid-, and long-term follow-up. Isolated excision of weight-bearing OCD lesions led to poorer clinical and radiographic results than other surgical techniques. Outcomes were significantly better with juvenile OCD versus adult OCD.

CONCLUSIONS

Surgical treatment of juvenile OCD has significantly improved clinical and radiographic outcomes at short-, mid-, and long-term follow-up. No difference in clinical or radiographic outcome was demonstrated in comparing different surgical techniques, with the exception of poorer results with isolated fragment excision.

LEVEL OF EVIDENCE

IV.

Comparison between normal and loose fragment chondrocytes in proliferation and redifferentiation potential

PURPOSE

Loose fragments in osteochondritis dissecans (OCD) of the knee require internal fixation. On the other hand, loose fragments derived from spontaneous osteonecrosis of the knee (SONK) are usually removed. However, the difference in healing potential between OCD- and SONK-related loose fragments has not been elucidated. In this study, we investigated proliferative activity and redifferentiation potential of normal cartilage-derived and loose fragment-derived chondrocytes.

METHODS

Cells were prepared from normal articular cartilages and loose fragment cartilages derived from knee OCD and SONK. Cellular proliferation was compared. Redifferentiation ability of pellet-cultured chondrocytes was assessed by real-time PCR analyses. Mesenchymal differentiation potential was investigated by histological analyses. Positive ratio of a stem cell marker CD166 was evaluated in each cartilaginous tissue.

RESULTS

Normal and OCD chondrocytes showed a higher proliferative activity than SONK chondrocytes. Chondrogenic pellets derived from normal and OCD chondrocytes produced a larger amount of safranin O-stained proteoglycans compared with SONK-derived pellets. Expression of chondrogenic marker genes was inferior in SONK pellets. The CD166-positive ratio was higher in normal cartilages and OCD loose fragments than in SONK loose fragments.

CONCLUSIONS

The OCD chondrocytes maintained higher proliferative activity and redifferentiation potential compared with SONK chondrocytes. Our results suggest that chondrogenic properties of loose fragment-derived cells and the amount of CD166-positive cells may affect the repair process of osteochondral defects.

Massive osteochondritis of the lateral femoral condyle associated with discoid meniscus: management with meniscoplasty, rim stabilization and bioabsorbable screw fixation

Discoid menisci without tears and before surgical intervention may be an aetiological factor in the development of osteochondritis dissecans (OCD). We present the case of a massive OCD lesion in the lateral femoral condyle of a 12-year-old boy who presented with relatively few symptoms despite the size of the lesion. This was treated with meniscoplasty and rim stabilization, which has become established as the gold standard treatment for symptomatic discoid menisci. This was combined with bioabsorbable screw fixation of the OCD lesion, resulting in rapid resolution of symptoms and a return to normal magnetic resonance image appearances after 6 months. It is likely that instability of discoid menisci is a key causal component when present concurrently with OCD lesions. Therefore, stabilization of this is required as well as saucerization of the meniscus. OCD lesions which are of a sufficient size such that if they became unstable or dislocated would result in a significant defect should also be stabilized. We believe that bioabsorbable screw fixation presents a good solution for fixation in these cases and this combination of treatment should result in a satisfactory outcome.

Characteristic shape of the lateral femoral condyle in patients with osteochondritis dissecans accompanied by a discoid lateral meniscus

BACKGROUND

There are various indirect signs of a discoid lateral meniscus in radiographs, for example lateral joint space widening, hypoplasia of the LFC, etc. There has, however, been no previous report of the characteristic shape of the lateral femoral condyle (LFC) in patients with osteochondritis dissecans (OCD) accompanied by a discoid lateral meniscus. The purpose of this study was to evaluate the characteristic shape of the LFC in patients with OCD accompanied by a discoid lateral meniscus, and sex differences associated with the shape of the LFC in those patients.

METHODS

This study included 29 males (31 knees) and 29 females (32 knees) of average age 17.7 years. There were 15 knees in 15 patients that were accompanied by OCD of the LFC (9 males, 9 knees; 6 females, 6 knees; average age 14.9 years; OCD group). There were 48 knees in 43 patients that were not accompanied by OCD of the LFC (20 males, 22 knees; 23 females, 26 knees; average age 17.6 years; non-OCD group). Standardized Rosenberg view radiographs of the knee were obtained for all patients. We evaluated the shape of LFC using the Rosenberg view and measured the condylar prominence ratio of the medial and lateral condyles adjacent to the intercondylar notch, in accordance with Ha's procedure.

RESULTS

The OCD group had a significantly larger prominence ratio than the non-OCD group. The prominence ratio for males was significantly larger than that for females.

CONCLUSION

We clearly demonstrated that the prominence ratio in the OCD group was significantly larger than that in the non-OCD group, indicating that the shape of the LFC and OCD in the LFC may be associated with the development of these lesions.

[Minimally invasive retrograde drilling of osteochondral lesions of the femur using an arthroscopic drill guide]

OBJECTIVE

Retrograde drilling for penetration of subchondral sclerotic bone in osteochondrosis dissecans (OCD) of the femoral condyle with preserved cartilage integrity. Hereby, revascularization of the OCD and immigration of bone marrow cells to achieve stable reintegration of the OCD into the surrounding subchondral bone.

INDICATIONS

Stable juvenile and adult osteochondrosis dissecans (stage I-II of the International Cartilage Repair Society (ICRS) classification) of the medial and lateral femoral condyle with an intact articular surface and surrounding sclerosis zone, which is visible in the x-ray.

CONTRAINDICATIONS

OCD stage III-IV of the ICRS grading scale. Relative contraindication: preceding retrograde drilling.

SURGICAL TECHNIQUE

Arthroscopic inspection and palpation of the cartilage defect. Minimal incision over the M. vastus medialis (when the defect is located in the medial condyle) or the M. vastus lateralis (when the defect is located in the medial condyle). Preparation and dissection of the fascia of the vastus muscle. Insertion of retractors underneath the vastus muscle to expose the metaphysis of the distal femur. Intraarticular positioning of the arthroscopic drill guide, placement of the wire guide and a Kirschner(K) wire on the femur metaphysis and retrograde drilling with a 2.0-2.2 mm K wire under radiographic visualization. Length measurement of the intraosseous wire distance. Switch the guide mechanism to a multiple hole drill guide and, depending on the defect size, insertion of a further 7-10 K wires of same thickness and defined length.

POSTOPERATIVE MANAGEMENT

Sterile bandage and slightly compressive dressing. Continuous active and passive knee motion. Weight bearing of 20 kg for 6 weeks, with subsequent transition to continuous weight bearing. Radiographic controls at 6 and 12 weeks postoperatively. In case of a persistent sclerosis zone in the control x-ray or clinical abnormalities, control MRI is indicated.

RESULTS

A total of 55 patients with a mean age of 19.6 years were treated using the described technique: 49 patients (89.1%), and 54 knees respectively (35 juvenile OCD, 19 adult OCD), were seen with a mean follow-up of 37.9 months. An improvement was observed in 81.6% of the knees using the radiographic score, i.e., a mean improvement of 1.13 of the radiographic score published by Rodegerdts and Gleissner (preoperative 3.04 vs. postoperative 1.91). Juvenile OCD showed better radiographic results overall (88.2% healing) than adult OCD (66.7% healing).

MRI-guided percutaneous retrograde drilling of osteochondritis dissecans of the knee

OBJECTIVE

The purpose of this study was to evaluate the feasibility of a new method for osteochondritis dissecans (OCD) treatment.

MATERIALS AND METHODS

Ten OCD lesions of the knee unresponsive to conservative management were treated with MRI-guided percutaneous retrograde drilling to reduce symptoms and promote ossification of the lesion. All lesions were located in distal femoral condyles. Only stable OCD lesions were included (preprocedural MRI grade I or II). Five lesions were of juvenile type and five lesions were of adult type OCD. All the patients had severe limitation of activity due to the OCD-related pain. By using a 0.23 T open MRI scanner and spinal anesthesia, percutaneous retrograde drilling of the OCD lesions was performed (3 mm cylindrical drill, one to three channels). Optical tracking and MRI imaging were used to guide instruments during the procedure. Mean postprocedural clinical follow-up time was 3 years. Eight patients had a post-procedural follow-up MRI within 1 year.

RESULTS

All the OCD lesions were located and drilled using the 0.23 T open MRI scanner without procedural complications. All the patients had pain relief, mean visual analog score (VAS) declined from 6 to 2. Follow-up MRI showed ossification in all lesions. Eight patients could return to normal physical activity with no or minor effect on function (Hughston score 3-4). Treatment failed in two cases where the continuation of symptoms led to arthroscopy and transchondral fixation.

CONCLUSION

[corrected] MR-guided retrograde OCD lesion drilling is an accurate, feasible, and effective cartilage-sparing techique in OCD management.

Histological evaluation of juvenile osteochondritis dissecans of the knee: a case series

Osteochondritis dissecans (OCD) is an acquired, potentially reversible idiopathic disease of subchondral bone resulting in delamination and sequestration. Although juvenile-type OCD lesions typically appear stable on superficial examination, conservative treatment results in cure in approximate 50% of patients. We hypothesized that juvenile-type OCD lesions exhibit an underlying instability despite stability at the articular surface and this underlying instability might underlie the lack of effectiveness of conservative treatment. In this study, osteochondral cylindrical tissue samples obtained from stable juvenile OCD lesions located at the medial femoral condyle (classical site) were examined. Eight patients with symptomatic juvenile-type OCD at the classical site underwent arthroscopy. Osteochondral cylindrical tissue samples were obtained from the central portion using a biopsy needle. The samples underwent macroscopic and microscopic examination. All cylindrical samples demonstrated macroscopic separation. On microscopic examination, no degenerative changes in articular cartilage and no bone necrosis were observed. Histological examination revealed two distinct patterns in the samples: (1) thick homogeneous hyaline cartilage alone with little fibrous tissue surrounding areas of separation and (2) nearly normal, thin hyaline cartilage above a mixed layer of hyaline cartilage and subchondral trabeculae and fibrous/fibro-cartilaginous tissue at the areas of separation, indicating delayed or nonunion. Pathological findings in stable juvenile OCD lesions indicate an underlying instability at deeper layers of articular cartilage and poor healing at areas of separation. Improved knowledge of the histology of juvenile-type OCD lesions may support surgical treatment. Early marrow stimulation and/or fixation may be the treatment of choice to promote healing even in macroscopically stable juvenile-type OCD lesions.

Current concepts in pediatric and adolescent arthroscopy

Arthroscopy continues to grow as a treatment modality for pediatric and adolescent orthopaedic pathologies. In recent years arthroscopic procedures previously reserved for adult patients have become more frequently used in the treatment of younger individuals. Advancements in arthroscopic instrumentation including smaller arthroscopes and tools have made the constraint of smaller joint spaces in the pediatric and adolescent populations less of a limiting factor when addressing surgical options for care. This is valuable considering the consistent increase in pediatric sports- and activity-related injuries, of which many are treatable arthroscopically. Currently, arthroscopy is indicated for the treatment of various chronic and acute injuries of the shoulder, elbow, wrist, hip, knee, and ankle. This review aims to highlight the current literature regarding arthroscopy in this population while also offering treatment algorithms, rehabilitation guidelines, and surgical tips for various pathologies in pediatric and adolescent patients.

Mini-arthrotomy for lateral discoid menisci in children

BACKGROUND

Long-term results after partial, extended, or complete resection of lateral discoid meniscus in children revealed knee arthritis. The purpose of this study was to evaluate whether the operative approach, arthrotomy or arthroscopy, has an impact on the outcome and the development of arthritis.

METHODS

A retrospective comparison of 2 well matching groups totaling 40 children with symptomatic lateral discoid meniscus (48 knees, mean age 8.9 years, 13 male and 27 female patients). Meniscus resection was performed via mini-arthrotomy in group 1 (n=17 patients, 20 knees) and arthroscopically in group 2 (n=23 patients, 28 knees).

RESULTS

In the follow-up (mean 57 months in group 1, 62 months in group 2), functional results indicated a trend to better results in the International Knee Documentation Committee score (P=0.12) and in the Lysholm score for group 1 (P=0.13) but not in the Ikeuchi score (P=0.48). The comparison of the radiographic arthritis grading in the follow-up showed no significant arthritis in either group (P=0.22). The overall complication rate was similar in both groups (2/20, 10% in group 1; 3/28, 12% in group 2).

CONCLUSIONS

Most likely because of the appropriate visualization of the children's joint and the easier instrumentation, the mini-arthrotomy led to slightly superior results compared with those after arthroscopic resection regarding functional outcome and 5 years after surgery. We can recommend the mini-arthrotomy for the resection of lateral discoid meniscus particularly in young children with narrow joint spaces and for surgeons that are not familiar with arthroscopies of small joints.

LEVEL OF EVIDENCE

III (therapeutic study, case series with control group).

Functional and radiographic outcome of stable juvenile osteochondritis dissecans of the knee treated with retroarticular drilling without bone grafting

PURPOSE

The purpose of this study was to evaluate the functional and radiographic outcome of retroarticular drilling for patients with juvenile osteochondritis dissecans after 6 months of unsuccessful nonoperative treatment.

METHODS

A total of 20 osteochondritis dissecans lesions in 12 skeletally immature patients were treated with retroarticular drilling without bone grafting. There were 10 boys and 2 girls with a mean age of 12.0 years (range, 9 to 15 years). The functional outcomes were evaluated by use of the Lysholm score at a mean follow-up of 2.7 years after drilling, and healing of the lesions was confirmed by use of plain radiographs and magnetic resonance imaging.

RESULTS

The mean Lysholm score significantly improved postoperatively (from 72.3 to 95.8). All lesions except 1 healed after retroarticular drilling. Healing was achieved at a mean of 4.4 months on plain radiographs and 7.6 months on magnetic resonance imaging.

CONCLUSIONS

This study shows that retroarticular drilling without bone grafting leads to improved clinical outcomes and high healing rates. We advocate retroarticular drilling for patients with stable juvenile osteochondritis dissecans of the knee whose initial nonoperative treatment has failed.

Bilateral osteochondritis dissecans of the lateral femoral condyle following bilateral total removal of lateral discoid meniscus: a case report

Osteochondritis dissecans (OCD) of the lateral femoral condyle sometimes occurs with a discoid lateral meniscus. Recently, it was reported that OCD of the lateral femoral condyle occurred after total removal of the lateral meniscus. We report the case of a 12-year-old boy with bilateral OCD of the lateral femoral condyle following bilateral total removal for discoid lateral meniscus. Valgus deviation of the knee after total removal and increased sporting activity might have concentrated excessive stress on the lateral condyles in the standing position. As a result, bilateral OCD might have occurred. Drilling of the areas of OCD on the bilateral lateral femoral condyles was done and the patient wore inner wedge arch supports postoperatively. After 2 years, neither knee pain nor arthrosis has occurred so far, but long-term follow-up of this patient is considered to be necessary.

Effects of arthroscopic meniscectomy on the long-term prognosis for the discoid lateral meniscus

This study compared the long-term clinical and radiological outcomes, according to the extent of arthroscopic meniscectomy, of complete and incomplete types of the discoid lateral meniscus. A total of 125 discoid menisci (74 complete and 51 incomplete types) without significant cartilage erosion at the time of surgery were included. The extent of meniscectomy was decided along with tear patterns and the stability of the discoid meniscus. Both clinical and radiological results were evaluated after total or partial meniscectomy. In the complete type of discoid meniscus with less than 5 years of follow-up, the total meniscectomy group showed better clinical results than the partial meniscectomy group. However, with over 5 years of follow-up, there were no differences between the two groups. In the radiological results, there was no significant difference between the two groups during the first 5 years after operation. However, with more than 5 years of follow-up, the partial meniscectomy group showed better results than the total meniscectomy group. In the incomplete-type discoid meniscus, clinical results were better in the partial meniscectomy group regardless of the follow-up periods. In the radiological results, the partial meniscectomy group showed better results for only more than 5 years of follow-up. The long-term prognosis after arthroscopic meniscectomy for the torn discoid lateral meniscus was related to the volume of the meniscus removed.

Arthroscopic resection of the discoid lateral meniscus: long-term follow-up for 16 years

PURPOSE

Although the clinical outcome of arthroscopic resection for a torn discoid lateral meniscus is known to be successful in the short term, long-term successful results are necessary. We reviewed the clinical results of arthroscopic meniscectomy for a torn discoid lateral meniscus in 29 knees, with an average follow-up of 16 years.

METHODS

Subjective symptoms were evaluated with the use of a questionnaire developed by the International Knee Documentation Committee (IKDC). The trends of IKDC scores and patient age at the time of surgery were statistically evaluated through a stepwise piecewise linear regression analysis. Radiographic examination was performed in 15 knees.

RESULTS

The average IKDC score was 87 points. Statistical analysis conducted with the use of a regression model of scores revealed that the regression line declined from 90 to 72 points at ages between 25 and 30 years at the time of surgery. Radiographic examination revealed that patients with degenerative changes at the lateral joint compartment, such as joint space narrowing and subchondral sclerosis, were of greater average age at the time of surgery than did patients who did not develop these changes.

CONCLUSIONS

Results suggest that clinical outcomes associated with this method are successful for longer than 10 years for patients younger than 25 years of age; however, older patients may develop problems caused by degenerative changes that may result from increased stress on the affected joint compartment.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Management of osteochondritis dissecans of the knee: current concepts review

Osteochondritis dissecans of the knee is being seen with increased frequency in pediatric and young adult athletes and is thought to be, in part, owing to earlier and increasingly competitive sports participation. Despite much speculation, the cause of both juvenile and adult osteochondritis dissecans remains unclear. Early recognition is essential. Whereas adult osteochondritis dissecans lesions have a greater propensity to instability, juvenile osteochondritis dissecans lesions are typically stable, and those with an intact articular surface have a potential to heal with nonoperative treatment through cessation of repetitive impact loading. The value of adjunctive immobilization, protected weightbearing, and unloader bracing has not been established. Skeletally immature patients with stable lesions that have not healed with nonoperative treatment should have consideration given to arthroscopic drilling to promote healing before the lesion progresses and requires more involved treatment with a less optimistic prognosis. Magnetic resonance imaging may allow early prediction of lesion healing potential. The majority of adult osteochondritis dissecans cases as well as those skeletally immature patients with unstable lesions and secondary loose bodies require fixation and possible bone grafting. Many unstable lesions will heal after stabilization, but long-term prognosis is not clear. Chronic loose fragments can be difficult to fix and have poor healing potential. Results of excision of large lesions from weightbearing zones are poor. Chondral resurfacing techniques have limited long-term data for cases of osteochondritis dissecans in skeletally immature patients.

[Osteochondritis dissecans of the knee joint]

BACKGROUND

Osteochondritis dissecans (OD) is an affection of the subchondral bone involving progressive detachment of an osteochondral fragment.

METHODS

This article describes the epidemiology, etiology, clinical appearance, possibilities for radiological diagnostics, and classification of OD and presents conservative and surgical therapeutic techniques.

RESULTS

Treatment of OD depends on the size, location, stability of the fragment, and skeletal maturity. The majority of young patients can be treated conservatively. Surgical interventions include antegrade or retrograde drilling with optional refixation and osteochondral transplantation as well as autologous chondrocyte transplantation.

CONCLUSION

The results of surgical intervention are quite promising; nevertheless, further prospective comparative studies are necessary to evaluate effectivity.

Osteochondritis dissecans of the knee in children

Osteochondritis dissecans is a term used to describe the separation of an articular cartilage subchondral bone segment from the remaining articular surface. Juvenile osteochondritis dissecans describes an osteochondritis dissecans lesion found in skeletally immature children with a maximum incidence occurring between the ages of 10 and 20. It is found more frequently in children who are active athletically and involved in organized sports and is twice as common in males as in females. Although the etiology of these lesions is unclear, it is believed that repetitive microtrauma may interrupt the already tenuous epiphyseal blood supply in the growing child and contribute to the development of osteochondritis dissecans lesions. Treatment is dependent upon age at presentation, fragment size, fragment location, and fragment stability. Stable lesions in skeletally immature patients are generally amenable to conservative management. Failed conservative management or unstable lesions will more likely require surgical intervention. Lesions in skeletally mature patients have a more unpredictable course and may require surgery. This review article discusses the anatomy, etiology, evaluation, classification, treatment, and expected outcome of osteochondritis dissecans lesions.