Novel Magnetic Resonance Imaging Classification of Osteochondritis Dissecans of the Knee: A Reliability Study.

BACKGROUND: Current advanced imaging classification systems for osteochondritis dissecans (OCD) of the knee grade severity of disease by identifying certain lesion characteristics. The most widely used are the Hefti and Nelson systems. A novel classification presents a simpler 3-group approach to diagnose knee OCD by magnetic resonance imaging (MRI), compared with the Hefti (5-group) and Nelson (4-group) classifications. The purpose of this study was to compare the reliability of this novel classification with that of the more complex, established systems-an initial step in establishing validity and clinical utility. METHODS: In total, 120 standardized knee MRIs of patients with established knee OCD were preselected to capture the spectrum of lesion types, with regard to both progression and location of the lesion. Each of the MRIs were independently classified by 2 readers into the novel, Hefti, and Nelson classification systems. A random sample was rereviewed by 1 rater 6 weeks after initial review. The inter-rater and intrarater agreements were evaluated by estimating Krippendorff α. RESULTS: In total, 106 knees were classified by the novel, Hefti, and Nelson classification systems, as 14 of the knees lacked the necessary MRI sequences. There were no differences in inter-rater and intrarater agreement across classification systems. Krippendorff α for inter-rater agreement was 0.51 (95% confidence interval, 0.33-0.66) for the Hefti classification, 0.50 (0.34-0.64) for the Nelson classification, and 0.49 (0.32-0.65) for the novel classification. The intrarater agreement was 0.88 (0.75-0.97) for the Hefti classification, 0.94 (0.86-0.99) for the Nelson classification, and 0.98 (0.94-1.00) for the novel classification system. CONCLUSIONS: The novel classification for knee OCD demonstrated near-perfect intrarater agreement and moderate inter-rater agreement, consistent with the current, well-established classification systems. Pending a subsequent study on validity and clinical utility, this simpler classification system may offer an alternative, noninvasive diagnostic method to guide clinical treatment. LEVEL OF EVIDENCE: Level IV.

Stable childhood osteochondral lesions of the talus: short-term radiographic outcomes suggest risk for early osteoarthritis.

Recent literature suggests that adults do not necessarily develop osteoarthritis if they have an osteochondral lesion of the talus (OLT). The purpose of this study was to determine if children with OLT are at risk to develop any radiographic evidence of early joint degeneration despite treatment efforts. Fifty-six ankles were identified over 6 years with stable OLT that underwent operative treatment. Preoperatively, each lesion was classified according to Berndt-Hardy for radiographs, Hepple for MRI, and Ferkel and Sgaglione for computed tomography. Radiographs were also evaluated for physeal status, OLT characteristics (location, border, size), and signs of osteoarthritis (Kellgren and Lawrence Scale). Despite incomplete treatment to radiographic resolution, the Kellgren-Lawrence scores still worsened in 23% of the children (pre-op score: mean 0.42 and median 0 versus post-op score: mean 0.69 and median 1). No risk factors (preoperative classification, age, physeal patency) were associated with advancing radiographic evidence of articular degeneration utilizing univariate analysis. However, a classification and regression tree analysis revealed that a patient age of 11.5 years old could be predictive of advancing Kellgren-Lawrence scores with one-third of older children worsening (P = 0.038). Despite active treatment of OLT, the ultimate prognosis is guarded with approximately one out of four children advancing their Kellgren and Lawrence score during treatment. In contrast to the natural history of adult OLT, the short-term advancement of degenerative disease in childhood OLT suggests a potentially different outcome and warrants further investigation into better treatment methods to preserve ankle health in these young patients.

Osteochondritis dissecans shows a severe course and poor outcome in patients with juvenile idiopathic arthritis: a matched pair study of 22 cases.

Juvenile osteochondritis dissecans (JOCD) and juvenile idiopathic arthritis (JIA) are both common diseases which may affect joints and bony structures in pediatric patients. In some cases, JOCD and JIA occur at the same time. In this study, the course of JOCD in patients with JIA was therefore evaluated to provide possible recommendations for further treatment opportunities and control examinations. From 06/2012 to 03/2018 55 children with JOCD with or without JIA were examined. Inclusion criteria were: (1) age ≤ 16 years, (2) diagnosis of a JOCD with or without JIA and (3) two routine MRI controls. The JOCD evaluation based on the classification according to Bruns and the measurement of the largest extent via MRI. 18 of these 55 children met our criteria: 11 JOCD findings of 7 patients with JIA (group A) were matched according to age and localization of JOCD to 11 patients without JIA (group B). Mean age of disease onset of JIA was 8.2 years (oligo JIA) and of JOCD 11.6 years. The mean time follow-up was 17.7 months. At all observation time points more JOCD findings (with stage III° and IV°, respectively) along with a significant deterioration was seen in group A compared to group B. The comparison of the last MRI control between group A and group B shows a significant smaller defect size (decrease of 54.5%, p = 0.028) in group B (97.9 ± 48.9 mm2) as in group A (185.1 ± 102.9 mm2). In comparison of first (169.7 ± 84.2 mm2) and last MRI (97.9 ± 48.9 mm2) a significant decrease in lesion size of JOCD in group B was seen (decrease of 58.4%, p = 0.048). Patients with JIA show a more progressive and severe course of JOCD. Therefore, we recommend (1) the early use of MRI in patients with JIA and persistent joint pain to detect potential JOCD and (2) in presence of JIA and JOCD regular MRI follow-up controls to identify deteriorating JOCD findings and prevent early joint destruction in pediatric patients.

Tissue Bioengineering in the Treatment of Osteochondritis Dissecans of the Talus in Children With Open Physis: Preliminary Results.

BACKGROUND: Juvenile osteochondritis dissecans of the talus (JOCDT) is a focal idiopathic lesion primarily of the subchondral bone leading to subsequent cartilaginous damage. The majority of the papers dealing with JOCDT reported heterogeneous case studies of patients treated with different cartilage repair techniques. The purpose of this paper is to retrospectively review both clinical and radiologic results among 7 patients affected by JOCDT treated with arthroscopic bone marrow aspirate concentrate (BMAC) transplantation with the 1-step technique. METHODS: Both standard anterior-posterior and lateral radiographs and a 1.5 T magnetic resonance imaging of the affected ankle were preoperatively performed in all the patients. The American Orthopaedic Foot and Ankle Society (AOFAS) score and the visual analogue scale were administered to the patients preoperatively and at the final follow-up. RESULTS: Patients were followed up to an average of 48.1±18.4 months. According to the Berndt and Harty classification, 6 lesions were found to be in stage III and 1 lesion in stage IV. The average preoperative AOFAS score was 58.8±7.6 points. At the mean follow-up of 48.1 months the average AOFAS score improved to 95.7±5.4 points (P<0.05). Visual analogue scale improved from 6.3 preoperatively to 0.4 at final follow-up (P<0.05). Complete radiographic healing, in terms of complete bony filling, was observed in 3 of 7 cases. The magnetic resonance imaging analysis showed a complete filling of the osteochondral defect in 4 patients, whereas in 1 patient a hypotrofic tissue was observed. CONCLUSIONS: BMAC transplantation is able to provide good to excellent results in the treatment of JOCDT. The 43% of our patients showed a complete radiographic healing, but all the patients were satisfied with the procedure. Because of the rareness of the lesion, further studies involving more patients and with a longer follow-up are required, to establish the advantage of performing a regenerative procedure like the BMAC transplantation in a pediatric population. LEVEL OF EVIDENCE: Level IV.

Osteochondritis dissecans of the knee: a practical guide for surgeons.

UNLABELLED: Osteochondritis Dissecans (OCD) is a condition for which the aetiology remains unknown. It affects subchondral bone and secondarily its overlying cartilage and is mostly found in the knee. It can occur in adults, but is generally identified when growth remains, when it is referred to as juvenile OCD. As the condition progresses, the affected subchondral bone separates from adjacent healthy bone, and can lead to demarcation and separation of its associated articular cartilage. Any symptoms which arise relate to the stage of the disease. Early disease without separation of the lesion results in pain. Separation of the lesion leads to mechanical symptoms and swelling and, in advanced cases, the formation of loose bodies. Early identification of OCD is essential as untreated OCD can lead to the premature degeneration of the joint, whereas appropriate treatment can halt the disease process and lead to healing. Establishing the stability of the lesion is a key part of providing the correct treatment. Stable lesions, particularly in juvenile patients, have greater propensity to heal with non-surgical treatment, whereas unstable or displaced lesions usually require surgical management. This article discusses the aetiology, clinical presentation and prognosis of OCD in the knee. It presents an algorithm for treatment, which aims to promote healing of native hyaline cartilage and to ensure joint congruity. TAKE HOME MESSAGE: Although there is no clear consensus as to the best treatment of OCD, every attempt should be made to retain the osteochondral fragment when possible as, with a careful surgical technique, there is potential for healing even in chronic lesions Cite this article: Bone Joint J 2016;98-B:723-9.

Novel Arthroscopic Classification of Osteochondritis Dissecans of the Knee: A Multicenter Reliability Study.

BACKGROUND: Several systems have been proposed for classifying osteochondritis dissecans (OCD) of the knee during surgical evaluation. No single classification includes mutually exclusive categories that capture all of the salient features of stability, chondral fissuring, and fragment detachment. Furthermore, no study has assessed the reliability of these classification systems. PURPOSE: To determine the intra- and interobserver reliability of a novel, comprehensive arthroscopic classification system with mutually exclusive OCD lesion types. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 3. METHODS: The Research in OsteoChondritis of the Knee (ROCK) study group developed a classification system for arthroscopic evaluation of OCD of the knee that includes 6 arthroscopic categories-3 immobile types and 3 mobile types. To optimize comprehensibility and applicability, each was developed with a memorable name, a brief description, a line diagram corresponding to the archetypal arthroscopic appearance, and an arthroscopic photograph depicting this archetype. Thirty representative arthroscopic videos were evaluated by 10 orthopaedic surgeon raters, who classified each lesion. After 4 weeks, the raters again classified the OCD lesions depicted in the 30 videos in a new, randomly selected order. Reliability was assessed via the intraclass correlation coefficient (ICC). RESULTS: The interobserver reliability of this novel arthroscopy classification was estimated by an ICC of 0.94 (95% CI, 0.91-0.97) for the first round and 0.95 (95% CI, 0.93-0.98) for the second round. According to the standards for the magnitude of the reliability coefficient of Altman, these ICCs indicate that interobserver reliability was very good. The intraobserver reliability was estimated by an ICC of 0.96 (95% CI, 0.95-0.97), which indicates that the intraobserver reliability was similarly very good. CONCLUSION: The ROCK OCD knee arthroscopy classification system demonstrated excellent intra- and interobserver reliability. In light of this reliability, this classification system may be used clinically and to facilitate future research, including multicenter studies for OCD.

Treatment of Osteochondritis Dissecans of the Talus in Skeletally Immature Population: A Critical Analysis of the Available Evidence.

UNLABELLED: Juvenile osteochondritis dissecans of the talus (JOCDT) is a subchondral bone alteration and a partially or completely detached osteochondral fragment, affecting skeletally immature patients. A review of the English literature on PubMed was conducted. Conservative treatment was applied in patients up to Berndt-Harty stage III. Surgical indications were conservative management failure and loose bodies. The most performed procedures were drilling, subchondral bone grafting, fragment fixation, or excision. High rate of clinical success were achieved, whereas radiographic results were much lower. None of the surgical options demonstrated to be superior. Future long-term qualitative studies focusing on chondral tissue restoration are needed. LEVELS OF EVIDENCE: Therapeutic, Level IV.

Magnetic Resonance Imaging of Osteochondritis Dissecans: Validation Study for the ICRS Classification System.

RATIONALE AND OBJECTIVES: In this retrospective case series, we utilize arthroscopy as the gold standard to determine if magnetic resonance imaging (MRI) of the knee can predict osteochondritis dissecans (OCD) lesion stability, the most important information to guide patient treatment decisions. It is hypothesized that the classification system of the International Cartilage Repair Society (ICRS) will allow for improved assessment of lesion grade and stability in OCD. MATERIALS AND METHODS: Routine MRI studies of 46 consecutive patients with arthroscopically proven OCD lesions (mean age: 23.7 years; 26 male, 16 female) were assessed by three radiologists who were blinded to arthroscopic results. Arthroscopic images were evaluated by two orthopedic surgeons in consensus. The OCD criteria of the ICRS were applied to arthroscopy and imaging interpretations. Inter-rater correlation statistics and accuracy of magnetic resonance (MR) grading with respect to arthroscopy were determined. RESULTS: Only 56% of the available MR reports assigned a label of stable or unstable to the lesion description. Of these, 58% of the lesions were deemed unstable and 42% were stable. Accuracy was 53% when reports addressed stability. Utilizing the ICRS classification system, for all three readers combined, the respective sensitivity, specificity, and accuracy of MR imaging to determine lesion stability were 70%, 81%, and 76%. When compared to the original MRI report, the overall accuracy increased from 53% to 76% when readers were given the specific criteria of the OCD ICRS classification. However, inter-reader variability remained high, with Krippendorf's alpha ranging from 0.48 to 0.57. CONCLUSIONS: In this paper, we utilize arthroscopy as the gold standard to determine if MRI can predict OCD lesion stability, the most important information to guide patient treatment decisions. To our surprise, the analysis of the existing radiology reports that addressed stability revealed an overall accuracy in defining OCD lesion stability of about 53%. The classification system of the ICRS, created by an international multidisciplinary, multi-expert consortium, did markedly improve the accuracy, but consistency among different readers was lacking. This retrospective study on OCD reporting and classification highlights the inadequacy of existing classification schemes, and emphasizes the critical need for improved diagnostic MRI protocols in musculoskeletal radiology in order to propel it toward evidence-based medicine.

Discrepancy between morphological findings in juvenile osteochondritis dissecans (OCD): a comparison of magnetic resonance imaging (MRI) and arthroscopy.

PURPOSE: The aim of this study was to assess the reliability of preoperative MRI for the staging of osteochondritis dissecans (OCD) lesions of the knee and the talus in juvenile patients, using arthroscopy as the gold standard of diagnosis. METHODS: Sixty-three juvenile patients (range 8-16 years) with an OCD of the knee or the talus underwent arthroscopy after MRI. In 54/9 out of 63 cases, 1.5/3 T MR scanners were used. The OCD stage was classified according the staging criteria of Dipaola et al. Arthroscopic findings were compared with MRI reports in each patient. RESULTS: From the 63 juvenile patients, MRI/arthroscopy revealed a stage I OCD in 4/19 patients, stage II in 31/22 patients, stage III in 22/9 patients and stage IV in 6/6 patients. No osteochondral pathology was evident in arthroscopy in seven out of 63 patients. The overall accuracy of preoperative MRI in staging an OCD lesion of the knee or the talus was 41.3%. In 33 out of 63 patients (52.4%), arthroscopy revealed a lower OCD stage than in the preoperative MRI grading, and in four out of 63 cases (6.4%), the intraoperative arthroscopic grading was worse than in preoperative MRI prior to surgery. The utilization of the 3 T MRI provided a correct diagnosis with 44.4%. CONCLUSIONS: Even with today's modern MRI scanners, it is not possible to predict an accurate OCD stage in children. The children's orthopaedist should not solely rely on the MRI when it comes to the decision to further conservative or surgical treatment of a juvenile OCD, but rather should take surgical therapy in consideration within persisting symptoms despite a low OCD stage provided by MRI. LEVEL OF EVIDENCE: III.

Classification and assessment of juvenile osteochondritis dissecans knee lesions.

PURPOSE OF REVIEW: Juvenile osteochondritis dissecans (JOCD) knee lesions are common abnormalities in adolescents and children, and have higher rates of spontaneous healing with nonoperative management compared to adult osteochondritis dissecans (OCD) lesions. Multiple classification and assessment systems have been established in order to help clinicians determine which lesions are amenable to nonoperative management. However, these assessments often use adult OCD classification systems of lesion stability, which have poor reliability in JOCD lesions. The purpose of this review is to assess these various classification systems proposed for JOCD lesions. RECENT FINDINGS: Although arthroscopy remains the gold standard for the definitive assessment of lesion stability, recent evidence suggests that MRI characteristics indicative of instability in adult OCD lesions are not applicable in determining JOCD lesion instability. In addition, the correlation between arthroscopic and MRI indications of instability is highly varied in these younger patients. SUMMARY: In order for the pediatric orthopedic surgeon to more accurately predict treatment outcomes in patients with JOCD knee lesions, further investigation into the radiographic characteristics specific to JOCD lesion instability and healing is warranted.

Osteochondritis dissecans of the humeral capitellum: reliability of four classification systems using radiographs and computed tomography.

BACKGROUND: The radiographic appearance of osteochondritis dissecans (OCD) of the humeral capitellum varies according to the stage of the lesion. It is important to evaluate the stage of OCD lesion carefully to guide treatment. We compared the interobserver reliability of currently used classification systems for OCD of the humeral capitellum to identify the most reliable classification system. METHODS: Thirty-two musculoskeletal radiologists and orthopaedic surgeons specialized in elbow surgery from several countries evaluated anteroposterior and lateral radiographs and corresponding computed tomography (CT) scans of 22 patients to classify the stage of OCD of the humeral capitellum according to the classification systems developed by (1) Minami, (2) Berndt and Harty, (3) Ferkel and Sgaglione, and (4) Anderson on a Web-based study platform including a Digital Imaging and Communications in Medicine viewer. Magnetic resonance imaging was not evaluated as part of this study. We measured agreement among observers using the Siegel and Castellan multirater κ. RESULTS: All OCD classification systems, except for Berndt and Harty, which had poor agreement among observers (κ = 0.20), had fair interobserver agreement: κ was 0.27 for the Minami, 0.23 for Anderson, and 0.22 for Ferkel and Sgaglione classifications. The Minami Classification was significantly more reliable than the other classifications (P < .001). CONCLUSIONS: The Minami Classification was the most reliable for classifying different stages of OCD of the humeral capitellum. However, it is unclear whether radiographic evidence of OCD of the humeral capitellum, as categorized by the Minami Classification, guides treatment in clinical practice as a result of this fair agreement.

A review of arthroscopic classification systems for osteochondritis dissecans of the knee.

Multiple systems for classifying osteochondritis dissecans (OCD) of the knee have been reported. These existing classification systems have some similar characteristics, such as stable lesion/intact articular cartilage and presence of a loose body. However, variations are found in the number of stages and specific lesion characteristics assessed. Currently, no system has been universally accepted. A future classification system should be developed that reconciles the discrepancies among the current systems and provides a clear, consistent, and reliable method for classifying OCD lesions of the knee during arthroscopy.

Magnetic Resonance Imaging Staging to Evaluate the Stability of Capitellar Osteochondritis Dissecans Lesions.

BACKGROUND: Treatment for capitellar osteochondritis dissecans (COCD) lesions is usually based on their stability from the bony floor after arthroscopic or open direct observation. Thus, a noninvasive means of lesion stability assessment by use of imaging is desirable to preoperatively determine treatment strategy. PURPOSE: To evaluate our modified MRI staging system for COCD, we compared the results of MRI staging with the International Cartilage Repair Society (ICRS) classification for lesion stability. Intra- and interrater reliability for MRI staging was examined as well. STUDY DESIGN: Cohort study (diagnosis); Level of evidence, 2. METHODS: Fifty-two COCD lesions were preoperatively evaluated by T2-weighted MRI and classified into 5 stages: stage 1 = normally shaped capitellum with several spotted areas of high signal intensity that is lower than that of cartilage; stage 2 = as with stage 1 but with several spotted areas of higher intensity than that of cartilage; stage 3 = as with stage 2 but with both discontinuity and noncircularity of the chondral surface signal of the capitellum and no high signal interface apparent between the lesion and the floor; stage 4 = lesion separated by a high intensity line in comparison with cartilage; and stage 5 = capitellar lesion displaced from the floor or defect of the capitellar lesion noted. The MRI staging results were compared with the intraoperative ICRS classification for lesion stability of each patient. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were all determined for fragment instability. Intra- and interrater correlations for our MRI staging were calculated among 3 examiners. RESULTS: Preoperative MRI grading correctly matched ICRS classification in 49 of 52 patients (94%), with a sensitivity of 100% and a specificity of 80%. The PPV and NPV were 93% and 100%, respectively, for diagnosing lesion instability. Intrarater reliability (intraclass correlation coefficient [ICC]) for MRI staging was high at ICC(1, 1) = 0.86 and ICC(1, 2) = 0.90, as was interrater reliability at ICC(2, 1) = 0.82 and ICC(2, 3) = 0.88. CONCLUSION: The MRI staging system provides accurate and reliable evidence for estimating ICRS classification and instability of COCD and is useful to decide appropriate treatment.

A review of arthroscopic classification systems for osteochondritis dissecans of the knee.

Multiple systems for classifying osteochondritis dissecans (OCD) of the knee have been reported. These existing classification systems have some similar characteristics, such as stable lesion/intact articular cartilage and presence of a loose body. However, variations are found in the number of stages and specific lesion characteristics assessed. Currently, no system has been universally accepted. A future classification system should be developed that reconciles the discrepancies among the current systems and provides a clear, consistent, and reliable method for classifying OCD lesions of the knee during arthroscopy.

Juvenile osteochondritis dissecans of the knee: current concepts in diagnosis and management.

Osteochondritis dissecans of the knee is a diagnosis that encompasses a wide spectrum of pathologies that can result in irreversible damage to articular cartilage and subchondral bone. Osteochondritis dissecans was first described more than 100 years ago, and despite substantial research on the topic, large gaps remain in the understanding of its etiology and optimal treatment. An underlying vascular insult, resulting in separation of the progeny lesion from the parent subchondral bone, is a suspected cause but remains unproven. No single standardized classification exists to accurately predict long-term risk. Nonsurgical treatment with activity modification remains an option for stable lesions in young patients. Surgical treatment to encourage vascular ingrowth and healing is gaining popularity and represents a shift in thinking regarding the risk of disease progression. Unstable and displaced lesions remain a difficult treatment challenge. Various salvage procedures have shown promise, but the potential for long-term morbidity remains.

MR grading system of osteochondritis dissecans lesions: comparison with arthroscopy.

OBJECTIVE: To assess the diagnostic performance of combined three-dimensional (3D) gradient-echo (GRE) T1-weighted and routine MR imaging protocol for the evaluation of osteochondritis dissecans (OCD). MATERIALS AND METHODS: This prospective study was approved by our institutional review board and all patients gave informed consent. Three-dimensional GRE MR sequence was added to the routine protocol performed on 40 consecutive patients (35 men, 5 women; age range, 12-57 years; mean age, 20 years) with 17 juvenile and 24 adult OCD lesions (27 in knees; 14 in elbows) which were confirmed by arthroscopy. Two independent musculoskeletal radiologists reviewed all MR images. The OCD lesions were classified into five stages by assessing the signal intensity of fragment-bone interface and the integrity of articular cartilage on MR images. Stage-IV and -V lesions were considered as unstable. The sensitivity, specificity, accuracy, and interobserver agreement (κ statistics) were calculated. RESULTS: The sensitivity, specificity, and accuracy for detection of OCD instability were 100% (11 of 11), 100% (6 of 6), and 100% (17 of 17) in juvenile lesions; and 93% (14 of 15), 100% (9 of 9), and 96% (23 of 24) in adult lesions. The overall accuracy of MR findings in determining the staging was 90% (37 of 41) for reader 1 and 83% (34 of 41) for reader 2. Agreement between readers was substantial with a κ value of 0.75 for MR staging of OCD lesions. CONCLUSIONS: Three-dimensional GRE T1-weighted MR imaging combined with the routine sequences demonstrates excellent diagnostic capabilities in detecting unstable OCD lesions.

Elbow arthroscopy: capitellar osteochondritis dissecans and radiocapitellar plica.

The combination of excessive radiocapitellar compressive forces and the limited vascularity of the capitellum are responsible for the development of osteochondritis dissecans. Repetitive compressive forces are generated by throwing or racket swinging motions or from constant axial compressive loads on the elbow, which are common in athletes such as gymnasts. Symptoms include activity-associated pain and stiffness. Physical examination findings show tenderness over the radiocapitellar joint and, commonly, loss of extension. Plain radiographs may show flattening and sclerosis of the capitellum, lucencies, and possibly intra-articular loose bodies. MRI can detect bone edema early in the disease process and further delineate the extent of the injury. The management of osteochondritis dissecans lesions is primarily based on the demands of the patient, the size and location of the lesion, and the status and stability of the overlying cartilage. Possible treatments include transarticular drilling; removing detached fragments or loose bodies, followed by drilling; and mosaicplasty. Radiocapitellar plica can cause chondromalacic changes on the radial head and capitellum, with symptoms including painful clicking and effusions. Arthroscopic plica resection is indicated when nonsurgical treatment fails.

Patella osteochondritis dissecans end stage: The osteochondral mosaicplasty option.

INTRODUCTION: Patellar damage during osteochondritis dissecans of the knee is rare. There were two objectives to this study: evaluate the functional results of surgical treatment by mosaicplasty in this disease as well as evaluate articular surface reconstruction and cylindrical bone plugs incorporation. MATERIALS AND METHODS: Six consecutive cases of patella osteochondritis dissecans in young athletes were treated using mosaicplasty by the same senior surgeon between 2002 and 2007. All these cases presented ICRS stage IV osteochondritis dissecans with an empty defect lesion. The average age at diagnosis was 20.5 ± 9.2 years old. The pre- and post-operative clinical evaluation was based on the IKDC subjective knee evaluation, the Lysholm and Tegner scores, CT arthrography and MRI. RESULTS: Evaluation of the functional results of surgical treatment at a mean follow-up of 26 months showed an average IKDC subjective evaluation score of 66.3, a Lysholm score of 85 and a Tegner score of 5.7 (37.2, 58.3 and 3.5 respectively before surgery). The radiological evaluation showed articular surface reconstruction with satisfying congruency and good incorporation of the graft into the bone at the receptor site, except in one patient in whom a 5mm diameter cartilage defect and a loose body were identified. DISCUSSION: Osteochondral grafting with the mosaicplasty technique has been shown to be effective and give satisfying functional results. The problem of the per-operative cylindrical bone plugs choice requires to be addressed during the procedure course itself, according to the patella lesion location.