Juvenile osteochondritis dissecans of the knee: predictors of lesion stability

Osteochondritis Dissecans of the Medial Femoral Condyle: MRI Findings of Instability

BACKGROUND: Osteochondritis dissecans (OCD) of the medial femoral condyle (MFC), a common cause of pediatric chronic knee pain, is often found to be stable at arthroscopy. OBJECTIVE: To investigate the performance of MRI for identifying instability of MFC OCD in children. METHODS: This retrospective study included 59 children (37 boys, 22 girls; mean age, 12.5±2.2 years) with 69 MFC OCD lesions, who underwent knee MRI from January 2016 to October 2023. Two radiologists independently reviewed examinations to determine regional findings (effusion, skeletal maturity, secondary physis visibility, progeny composition), as well as direct (osteochondral defect, intraarticular body, cartilage alteration, bone plate disruption, receded ossification front) and indirect (progeny-parent bone interface, radius of curvature, parent-bone low-signal intensity (SI) marginal rim, perilesional marrow edema) findings of instability; disagreements were resolved through consensus. Two investigators assessed an additional indirect finding, cyst(s), in consensus. Demographic characteristics, and lesion volume were collected. The reference standard for lesion stability was arthroscopy (n=52) or follow-up evaluation (based on symptoms and imaging findings) in patients managed conservatively (n=17). Stable and unstable lesions were compared. RESULTS: Forty-nine lesions were stable, and 20 were unstable. Sensitivity and specificity for instability, among features showing significant associations with instability, were 70.0% and 100.0% for skeletal maturity, 75.0% and 75.5% for osteochondral progeny composition, 100.0% and 85.7% for cartilage alteration, 85.0% and 81.6% for presence of progeny-parent bone interface, 30.0% and 100.0% for extensive interface, 90.0% and 34.7% for cyst(s), 45.0% and 91.8% for altered radius of curvature, 80.0% and 89.8% for parent-bone low-SI rim, and 50.0% and 81.6% for extensive perilesional marrow edema. In multivariable analysis, factors independently associated with instability included larger lesion volume and indirect signs (presence of interface, cyst(s), altered radius of curvature, parent-bone low-SI rim, and extensive perilesional marrow edema). Frequency of instability was 0.0%, 7.4%, 16.7%, 75.0%, 83.3%, and 100.0% for lesions with 0, 1, 2, 3, 4, and 5 indirect signs. CONCLUSION: Lesion instability was associated with an increasing number of indirect MRI signs. CLINICAL IMPACT: Assessment of lesion stability by MRI can help guide decisions between arthroscopy and conservative management for MFC OCD in children.

The Immature Pediatric Appendicular Skeleton

Growth and maturation occur in a predictable pattern throughout the body and within each individual bone. In the appendicular skeleton, endochondral ossification predominates in long bones and growth plates. The ends of these long bones are sites of relative weakness in the immature skeleton and prone to injury from acute insult and overuse. We present the normal histoanatomy and physiology of the growth plate complex, highlighting the unique contribution of each component and shared similarities between primary and secondary complexes. Components of the growth plate complex include the physis proper, subjacent vascularity within the growth cartilage, and the ossification front. The second section describes imaging considerations and features of normal and abnormal growth. Finally, we review the Salter-Harris classification for acute fractures and offer examples of characteristic overuse injury patterns involving the epiphyseal (proximal humerus and distal radius), apophyseal (medial epicondyle and tibial tubercle), and secondary growth plate complexes (medial femoral condyle and capitellar osteochondritis dissecans). This article provides a foundation and basic framework to better understand and anticipate potential complications and growth disturbances and to ensure optimal follow-up and early intervention when treatment can be less invasive.

Juvenile Osteochondritis Dissecans: Current Concepts

Osteochondritis dissecans (OCD) primarily damages the subchondral bone, leading to damage to the articular cartilage. Juvenile OCD (JOCD) of the knee is limited to skeletally immature and young patients with open growth plates on radiographs. We conducted a review of PubMed articles up until March 16, 2024, using a combination of the following keywords: knee, juvenile, and osteochondritis dissecans. This narrative review included a total of 56 relevant articles that investigated the etiology, incidence, clinical presentation, imaging, classification, and treatment of JOCD of the knee in patients less than 20 years of age. The exact etiology is controversial. Most authors believe that the disease involves multiple theories, such as ischemia, recurrent trauma, and genetic predisposition. Radiographs, the first imaging study in this patient group, cannot determine the stability or instability of the surface cartilage of the OCD lesion. As a result, MRI has become a recommended diagnostic method for determining OCD stability and providing important information for determining a treatment plan. For stable JOCD lesions, nonsurgical treatment is often advised. For unstable and stable lesions that do not respond to nonsurgical treatment, several surgical techniques with good healing rates are available.

S.P.O.R.R.T.-A Comprehensive Approach to the Assessment and Non-Operative Management of Overuse Knee Conditions in Youth Athletes

PURPOSE OF REVIEW

The evaluation of a young athlete with an overuse injury to the knee involves a comprehensive approach. There are a number of elements to consider including assessments of skeletal maturity (biologic maturation), workload (training load + competition load), sport specialization status, and biomechanics. The type of injury and treatment, as well as future prognosis, may be influenced by these and other factors.

RECENT FINDINGS

Calculating the percentage of predicted adult height (PPAH) is a valuable tool in assessing overuse injury patterns and diagnoses in youth athletes. Modifiable and non-modifiable overuse injury risk factors require monitoring from clinicians as young athletes mature and develop over time. Training and rehabilitation programs should be adapted to account for these. In this manuscript, we seek to introduce a novel, comprehensive approach: S.P.O.R.R.T. (Skeletal Maturity, Prior Injury Risk, One Sport Specialization, Rehabilitation, Return to Play, Training Recommendations) (Fig. 1). Overuse, non-traumatic injuries to the knee in youth athletes will be presented in a case-based and evidence-based model to provide a framework for a comprehensive approach to the assessment and treatment of youth athletes with overuse injuries.

The "hump" a new arthroscopic phenomenon guiding for reliable therapy of osteochondritis dissecans of variable stability status

INTRODUCTION

Despite 150 years of research, there are currently no reliable morphological characteristics that can be used to differentiate between stable and unstable juvenile osteochondritis dissecans (JOCD) lesions in the knee joint. Arthroscopic probing is still the gold standard. In arthroscopic evaluation, a previously undescribed pattern of a cartilaginous convex elevation ("hump") was identified as a new feature and potential sign of JOCD in transition to instability. The aim of the study was to evaluate the clinical outcomes after surgical intervention (drilling) on the "hump".

MATERIALS AND METHODS

In a retrospective case series of sixteen patients with an arthroscopically detectable "hump", the analysis of clinical function scores (Lysholm, Tegner) and morphological MRI monitoring of radiological healing were performed. The assessment of lesion healing was based on pre- and postoperative MRI examinations. The "hump" was defined as an arthroscopically impressive protrusion of the femoral articular surface with a minimally softened, discolored, but intact cartilage margin that, is not mobile upon in the arthroscopic palpation hook test. The primary therapy of choice was drilling of all "humps".

RESULTS

The "hump" could be detected arthroscopically in 16 of 59 JOCD lesions. Specific MRI correlations with the "hump" or arthroscopic unstable lesions could not be detected. Not all "humps" showed signs of MRI-based healing after the drilling, and in some a dissection of the osteochondral flap occurred within the first postoperative year. As a result, secondary refixation became necessary.

CONCLUSION

In the present study, the "hump" was identified as an important differential diagnostic arthroscopic feature of an arthroscopically primarily stable JOCD lesion, potentially placing the lesion at risk of secondary loosening over time. Therefore, drilling alone may not be appropriate in the event of arthroscopic "hump" discovery, but additional fixation may be required to achieve the healing of the lesion.

LEVEL OF EVIDENCE

III.

Osteochondritis dissecans of the knee in adolescents: How to treat them?

Background

Osteochondritis dissecans is an acquired condition of the joint that affects the articular surface and the subchondral bone. The juvenile form of osteochondritis dissecans presents in those aged 5-16 years with open growth plates. The causes of osteochondritis dissecans are unknown.

Methods

The goals of treatment are to promote healing of the subchondral bone and prevent chondral collapse, subsequent fracture, osteochondral defect formation, and early joint degeneration. Treatment modality is influenced on clinical symptoms, skeletal maturity, as well as the size, stability, and location of the lesion. This article will review the treatment strategies of juvenile form of osteochondritis dissecans of medial femoral condyle and of atypical regions, such as lateral femoral condyle, patellofemoral joint, and tibial plateau.

Level of evidence

level III.

An update on osteochondritis dissecans of the knee

Osteochondritis dissecans of the knee (OCD) is a multifactorial pathology in where repetitive microtrauma plays a central role in the etiopathogenesis. Knee MRI is indicated in young, active patients who have knee pain and/or effusion, to make an early diagnosis and decide about treatment, according essentially to the MRI stability signs. The choice of treatment should be also tailored, based on the patient's skeletal maturity, as well as the size and location of the lesion. Conservative treatment with restricting sports activities is the first line treatment and often sufficient to ensure healing in patients with open physes. Surgical treatment depends on the persistence of symptoms after 6 months of conservative treatment and/or based on the development of signs of instability of the lesion. Stable lesions with intact articular cartilage may be treated by drilling of the subchondral bone aiming to stimulate vascular ingrowth and subchondral bone healing. Every attempt should be made to retain the osteochondral fragment when possible. Instable lesions should be fixed or "replaced" with salvage procedures to prevent the onset of early osteoarthritis in this young population. Furthers studies are needed to improve the knowledge and optimizing non-operative and surgical treatment and to develop noninvasive diagnostic tools to predict with more accuracy the fragment's stability.

Osteochondritis Dissecans Lesions of the Pediatric and Adolescent Knee

Osteochondritis dissecans of the knee in pediatric and adolescent patients remains an incompletely understood entity, with multiple theories proposed for its underlying cause and variable treatment modalities. In addition to the importance of history and examination, treatment is primarily guided by lesion stability, which can be determined by MRI and arthroscopic findings. Other important factors that can influence healing include patient skeletal maturity, lesion location, and the size of the lesion. The purpose of this article is to review the most current epidemiology, classification, and pathoanatomy of the disease and discuss the different treatment options.

Incidence of Subsequent Surgical Intervention at Short-term Follow-up in Previously Healing and Stable Juvenile Osteochondritis Dissecans of the Knee

BACKGROUND

Juvenile osteochondritis dissecans (OCD) of the knee is a defect of subchondral bone seen primarily in active children and adolescents. Studies have evaluated the incidence of surgery in knee OCD, but the incidence of subsequent surgery in patients with stable, healing lesions cleared to return to activities is unknown. This study sought to determine the incidence of surgery in participants with knee OCD lesions cleared to return to activities and evaluate predictors of subsequent surgery.

METHODS

A single center, retrospective review was performed of participants aged 7 to 18 with knee OCD. Inclusion criteria were stable lesion, skeletal immaturity, no history of previous knee surgery, release to activity without surgery, and at least 12 months of follow-up. Documentation of subsequent surgery was queried in the electronic health record. Participants with no recorded surgery were contacted through phone. Analysis included bivariate and logistic regression.

RESULTS

Twenty-five individuals were included in this study, with 7 undergoing surgery after returning to activity. Medial femoral condyle lesions were less likely to undergo surgery (B=-2.6, P=0.038). Average lesion size for the Surgery and No Surgery groups was 1.76±0.65 and 1.32±0.81 cm2, respectively, though not significantly different (P=0.21). The Surgery group returned to activity sooner (3.7 mo, range 1.1 to 6.4) than the No Surgery group (8.1 mo, range 1.8 to 35.4), though not significantly different (P=0.18). Mean follow-up time for the study was 42.7 (range 12.6 to 77.6) months. No participants contacted by phone progressed to surgery or reported symptoms that limited their activities.

CONCLUSIONS

While the majority of participants with stable, healing, and asymptomatic knee OCD lesions have favorable outcomes with nonoperative management, some lesions may progress to surgery. Lesions on the medial femoral condyle may be predictive of lower likelihood of progression to surgery. Our study provides insight on the outcomes of nonoperative management of OCD lesions.

LEVEL OF EVIDENCE

Level IV-prognostic study.

Comparison of Weightbearing and Nonweightbearing Juvenile Osteochondritis Dissecans Lesions of the Lateral Femoral Condyle

Background:

Repetitive microtrauma may contribute to osteochondritis dissecans (OCD) lesions of the femoral condyle. The effect of differential loading between OCD weightbearing (WB) zones has not been studied.

Purpose:

To determine whether clinical and radiographic variables differ by WB zone in lateral femoral condyle OCD lesions.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

We retrospectively reviewed a consecutive series of patients aged <18 years with lateral femoral condyle OCD lesions presenting at a single institution between 2004 and 2018. Patients with OCD lesions outside of the lateral femoral condyle were excluded. Lesions were localized on radiographs using the Cahill and Berg classification, referencing the Blumensaat line and an extension of the posterior femoral cortex. Progeny bone characteristics evaluated at baseline and 24-month follow-up included ossification, distinct borders from parent bone, and displacement. Baseline lesion dimensions were measured on magnetic resonance imaging (MRI) scans. We evaluated posttreatment pain level, return-to-activity rate, and patient-reported outcome measures (PROMs) including the Pediatric International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, and Pediatric Functional Activity Brief Scale.

Results:

A total of 62 lateral femoral condyle OCD lesions (mean follow-up, 24.1 months) presented within the study period: 26 WB lesions and 36 nonweightbearing (NWB) lesions. At presentation, no differences between the lesion types were observed in symptom chronicity or symptomatology. NWB lesions were deeper on MRI scans (sagittal depth, 7.11 vs 5.96 mm; P = .046; coronal depth ratio, 0.05 vs 0.01 mm; P = .003), were more likely to develop progeny bone (69.4% vs 44%; P = .047), and demonstrated higher radiographic healing rates (52.8% vs 24%; P = .025) compared with WB lesions. PROMs at follow-up were available for 25 of 62 patients (40.3%), with no statistically significant differences between cohorts at any time. Return to full activity was observed in 72% of WB and 82.1% of NWB lesions (P = .378).

Conclusion:

Lateral femoral condyle OCD lesions of the knee in WB and NWB zones presented similarly at initial evaluation; however, NWB lesions demonstrated higher rates of progeny bone formation and radiographic healing at mean 2-year follow-up.

Osteochondritis Dissecans: Current Understanding of Epidemiology, Etiology, Management, and Outcomes

➤

Osteochondritis dissecans occurs most frequently in the active pediatric and young adult populations, commonly affecting the knee, elbow, or ankle, and may lead to premature osteoarthritis.

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While generally considered an idiopathic phenomenon, various etiopathogenetic theories are being investigated, including local ischemia, aberrant endochondral ossification of the secondary subarticular physis, repetitive microtrauma, and genetic predisposition.

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Diagnosis is based on the history, physical examination, radiography, and advanced imaging, with elbow ultrasonography and novel magnetic resonance imaging protocols potentially enabling early detection and in-depth staging.

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Treatment largely depends on skeletal maturity and lesion stability, defined by the presence or absence of articular cartilage fracture and subchondral bone separation, as determined by imaging and arthroscopy, and is typically nonoperative for stable lesions in skeletally immature patients and operative for those who have had failure of conservative management or have unstable lesions.

➤

Clinical practice guidelines have been limited by a paucity of high-level evidence, but a multicenter effort is ongoing to develop accurate and reliable classification systems and multimodal decision-making algorithms with prognostic value.

Bilateral osteochondral defects of the patellae in an 11-year-old girl

Osteochondral defect or osteochondritis dissecans (OCD) of the knee usually affects young, active populations. It is a challenging diagnosis as patients typically present with poorly localised activity-related pain, which is non-specific and covers many differentials. We present an active 11-year-old girl with bilateral osteochondral defects of the patellae: a rare clinical disorder which was affecting her sporting activities. She had a 12-month history of bilateral anterior knee pain before the diagnosis was achieved with appropriate imaging. Her pain significantly improved with activity modification and physiotherapy. Follow-up will require outpatient clinic assessment and imaging to determine if non-operative management continues to be successful or surgery may be required. This case report emphasises the importance of appropriate high index of suspicion when managing patients with non-specific knee pain. It also demonstrates the importance of judicious use of imaging to avoid a missed or delayed diagnosis.

Prevalence and Severity of Juvenile Osteochondritis Dissecans in Patients With Juvenile Idiopathic Arthritis

Background:

Juvenile idiopathic arthritis (JIA) is a heterogeneous group of chronic arthritides presenting in patients aged ≤16 years, with a prevalence of 16 to 150 per 100,000. Juvenile osteochondritis dissecans (OCD) is an idiopathic disease of articular cartilage and subchondral bone, has an onset age of 10 to 16 years, and often affects the knee, with a prevalence of 2 to 18 per 100,000. Currently, there are few studies that have evaluated the relationship between JIA and OCD.

Hypothesis:

OCD is more prevalent in children with JIA, and when diagnosed in such patients, OCD often presents at an advanced state.

Study Design:

Case series; Level of evidence, 4.

Methods:

The medical records of patients with diagnoses of both JIA and OCD treated between January 2008 and March 2019 at a single children’s hospital were retrospectively reviewed. Associations between timing of diagnoses, number and types of corticosteroid treatments, category of arthritis, timing of diagnoses, and lesion stability were examined with Spearman correlation coefficients.

Results:

A total of 2021 patients with JIA were identified, 20 of whom (19 female, 1 male) had OCD of the knee and/or talus for a prevalence of 1 in 100 or 1000 in 100,000, or approximately 50 to 500 times that of the general population. These 20 patients had a total of 28 OCD lesions: 43% (9 femur, 3 talus) were radiographically stable over time, 50% (10 femur, 2 patella, 2 talus) were unstable at initial diagnosis, and 7% (2 femur) were initially stable but progressed to unstable lesions despite drilling. Twelve patients (60%) underwent surgery: 4 (20%) with stable femoral lesions for persistent symptoms despite prolonged nonoperative treatment and 8 (40%) for treatment of their unstable lesions (femoral and patellar). Within our study design, we could identify no significant associations between lesion stability and timing of diagnoses, number of joint injections, or limb deformities, nor were there associations between timing of JIA and OCD diagnoses and category of arthritis.

Conclusion:

In our population of patients with JIA, OCD lesions were found to be 50 to 500 times more prevalent when compared with published rates in the general population and often presented at an advanced state, with instability or delayed healing requiring surgery for stabilization or resolution of symptoms.

Management of bilateral osteochondritis dissecans of the trochlea in a skeletally immature patient

Osteochondritis dissecans (OCD) lesions are injuries that occur more commonly in the skeletally immature population. In most cases, the aetiology is not well understood, but fortunately, many OCD lesions may heal on their own over time, particularly in skeletally immature patients with open physes. Conversely, if the lesion is considered unstable, surgical intervention may be required. This case demonstrates an especially rare presentation of bilateral OCD lesions within the lateral femoral trochlear facet. The lesions became symptomatic approximately 1 year apart without a specific injury. Non-operative treatment was not recommended in either case due to the size and instability of each lesion. The surgical treatment used an augmented microfracture technique. At 12 and 23 months after surgery, both knees remain asymptomatic and the patient has returned to their desired activities.

Osteochondritis Dissecans of the Tibial Plateau in Children and Adolescents: A Case Series

Background:

Osteochondritis dissecans (OCD) of the knee is a relatively well-known condition, most commonly arising in the femoral condyle. Lesions arising in the tibial plateau are rarely described.

Purpose:

To present a case series of OCD lesions of the tibial plateau.

Study Design:

Case series; Level of evidence, 4.

Methods:

Medical records and diagnostic imaging of patients <20 years of age with confirmed diagnosis of OCD of the tibial plateau from a single institution were retrospectively reviewed. Characteristic and radiographic features as well as details of both nonoperative and surgical management were investigated. Lesion characteristics and treatment outcomes were also analyzed.

Results:

A total of 9 lesions were identified in 9 patients (5 females, 4 males) who fit the inclusion criteria. The mean age at diagnosis was 14.2 years (range, 9-17 years). Knee pain (8/9) of longer than 1 year in duration was the most common presenting symptom. All 9 lesions were located on the lateral tibial plateau, and concomitant lateral compartment pathology was present in 5 of 9 patients (4 lateral femoral condyle OCDs, 3 lateral meniscal tears [1 discoid], and 1 discoid meniscus). Only 2 lesions were visible on initial radiographs; all 9 were visible on magnetic resonance imaging. All patients underwent initial nonoperative treatment; 2 patients demonstrated resolution of symptoms. Two patients underwent surgery for concomitant pathology, and the OCD was not addressed surgically. A total of 5 patients continued to be symptomatic after nonoperative treatment, prompting surgical intervention, which consisted of microfracture and chondroplasty in all 5 cases. A total of 2 of the 5 microfracture patients had resolution of symptoms, while another 2 patients had continued symptoms ultimately responsive to steroid injection treatment. One patient had revision microfracture, followed by autologous chondrocyte implantation and an arthroscopic lysis of adhesions. At final follow-up, ranging from 7 months to 10 years, 8 patients were asymptomatic, while 1 patient had developed early osteoarthritis.

Conclusion:

OCD of the tibial plateau in young patients is rare, usually involves the lateral side, and may have significant long-term implications for knee function. Presenting symptoms are often vague, and lesions may not always be visible on initial radiographs, which may lead to delayed treatment and adversely affect outcomes.

Osteochondral lesion of the talus in children: Are there MRI findings of instability?

PURPOSE

The purpose of our study was to investigate the performance of MRI findings to predict instability of osteochondral lesion of the talus (OLT) in children and the association between skeletal maturity and lesion stability.

MATERIALS AND METHOD

This retrospective IRB-approved and HIPPA-compliant study included children with OLT, who underwent an ankle MRI examination between March 1, 2011, and May 31, 2018. Blinded to the clinical outcome, 2 radiologists retrospectively assessed each MRI study for the presence or absence of various features on the articular side, along the interface, and on the subchondral side of each lesion. Regional skeletal maturity was recorded. Lesion stability was classified using clinical and surgical findings. Mann-Whitney U, Chi-square, Fisher's exact, and Cochran-Armitage tests were used to compare demographic and MRI findings between children with stable and unstable lesions.

RESULTS

Of the 48 ankles identified, 36 were stable (12.7 + 3.9 years) and 12 were unstable (14.2 + 1.6 years) lesions. None of the lesions presented as a detached fragment. Skeletal immaturity (p = 0.01) was significantly more common in stable than unstable lesions. No other MRI features were found to be significantly different between stable and unstable lesions, which included the presence of an effusion (p = 0.27), intra-articular body (p = 0.25), cartilage changes (p = 0.19), subchondral disruption (p = 0.51), T2-weighted signal intensity rim (p = 0.16), cysts (p = 0.48), marginal sclerosis (p = 0.70), and perilesional marrow edema (p = 0.17).

CONCLUSION

Results from our study suggest that previously published OCD criteria using conventional MRI are not sufficient for predicting stability of OLT in children. Regional skeletal maturity and older age were more predictive of unstable lesions.

Juvenile osteochondritis dissecans (JOCD) of the knee: current concepts review

Juvenile osteochondritis dissecans (JOCD) is a joint disorder of the subchondral bone and articular cartilage that affects skeletally immature patients.

The aetiology of JOCD is unknown and the natural history is poorly characterized in part due to inconsistent and largely retrospective literature.

Most OCD in children and adolescents presents as a stable lesion amenable to non-operative treatment or minimally invasive drilling. However, unstable forms can require a more aggressive approach.

This article reviews the most recent literature available and focuses on the pathophysiology, diagnosis and treatment of JOCD of the knee.

Cite this article: EFORT Open Rev 2019;4:201-212. DOI: 10.1302/2058-5241.4.180079

Limitation of in-situ arthroscopic fixation for stable juvenile osteochondritis dissecans in the knee

Current treatment algorithms for stable juvenile osteochondritis dissecans (JOCD) of the knee have not been established. For arthroscopically stable lesion, in-situ arthroscopic fixation with bioabsorbable pins was introduced as a more desirable approach because of less surgical morbidity and faster recovery. However, there is a paucity of literature that concludes on its efficacy. The aim of this study is to determine the efficacy and limitation of in-situ arthroscopic fixation on stable JOCD lesion in the knee. Ninety-six patients with 110 affected knees were reviewed. Subsequently, patients who underwent in-situ arthroscopic fixation for arthroscopically stable JOCD lesions were grouped for further analysis. Arthroscopic lesion stability was graded according to the Guhl's grading system from the surgical description of each lesion. The grade I and II were defined as 'stable' lesions. The lesion status was also evaluated with the MRI grading system described by Dipaola in preoperative images retrospectively. The grade I and II lesions were also defined as 'stable' and more than III as 'unstable'. Clinical outcomes were evaluated by the Lysholm score at the final office visit. If the patient had a revision surgery, the case was classified as a complete failure. There were 13 lesions in 13 patients with open physis treated with in-situ arthroscopic fixation using bioabsorbable pins. In this population, radiographical lesion status and the Lysholm score were significantly improved in 10 cases (preoperative: 77.5±11.2, postoperative: 98.9±3.1, P=0.002); however, we found three revision cases (failure rate, 23%). Of these revision cases, all lesions were graded as 'unstable' in MRI. In this series, the failure rate was 23% for in-situ arthroscopic fixation for arthroscopically stable JOCD lesion of the knee. Because of the potential risk for underestimation of lesion instability, we strongly suggest that this less invasive approach should be chosen with great care for the lesion that presents arthroscopically stable, but as unstable status on MRI.

LEVEL OF EVIDENCE

Level IV, case series.

Juvenile Osteochondritis Dissecans: Cartilage T2 Mapping of Stable Medial Femoral Condyle Lesions

Purpose To determine whether a T2 mapping sequence could depict early changes in the composition and microstructure of cartilage overlying stable lesions of the medial femoral condyle in patients with juvenile osteochondritis dissecans (JOCD). Materials and Methods This retrospective study analyzed a sagittal T2 mapping sequence performed between September 1, 2015, and March 31, 2017, on 16 patients (10 boys and six girls; median age, 11.5 years) with 18 stable medial femoral condyle JOCD lesions and 18 age-, sex-, and skeletal maturation-matched control participants (11 boys and seven girls; median age, 11.5 years). Cartilage T2 values were quantitatively measured within regions of interest placed around the cartilage within and overlying the JOCD lesion in patients with JOCD and around the cartilage on the weight-bearing medial femoral condyle in patients with JOCD and controls. Wilcoxon signed rank and Wilcoxon rank sum tests were used to compare T2 values. Results T2 values were significantly higher (P < .001) for cartilage within the JOCD lesion than for cartilage overlying the JOCD lesion in patients with JOCD. However, there were no significant differences in T2 values between cartilage overlying the JOCD lesion and cartilage on the weight-bearing medial femoral condyle in patients with JOCD (P = .67) or in T2 values of the cartilage on the weight-bearing medial femoral condyle between patients with JOCD and controls (P = .30). Conclusion There were no significant quantifiable differences in T2 values of cartilage overlying stable JOCD lesions and normal cartilage on the medial femoral condyle, suggesting no substantial changes in cartilage composition and microstructure.

Predictive factors for osteochondritis dissecans of the lateral femoral condyle concurrent with a discoid lateral meniscus

PURPOSE

Osteochondritis dissecans (OCD) of the lateral femoral condyle is relatively rare, and it is often reported in combination with discoid lateral meniscus. However, little is known about the mechanism underlying this connection. Predictive factors for OCD coinciding with discoid lateral meniscus in Japanese children and adolescents were assessed.

METHODS

During 2000-2015, 152 knees in 133 patients aged 5-15 years were diagnosed with symptomatic complete discoid lateral meniscus. Patients were evaluated using radiography and magnetic resonance imaging (MRI). OCD was radiographically graded using the Brückl classification. Based on Ahn's MRI classifications, discoid lateral meniscus was divided into four types of meniscal shift: no shift (N), anterocentral (AC), posterocentral (PC), or central (C). Relationships between OCD and patient sex, age and Ahn's shift type were analysed.

RESULTS

OCD of the lateral femoral condyle was associated with discoid lateral meniscus in 22 (14.5%) of 152 knees. OCD was classified as Brückl's stage 1 in 5 knees, stage 2 in 12, stage 3 in 3, stage 4 in 1, and stage 5 in 1. OCD was found in 12 of 96 knees (12.5%) with type N meniscal shift, 4 of 24 knees (16.7%) with type AC, 0 of 21 knees (0%) with type PC, and 6 of 11 knees (54.5%) with type C. Multivariate logistic regression analysis showed that males had a significantly increased odds ratio (OR) [14.8; 95% confidence interval (CI) 2.6-83.4]. Those aged 5-11 years had a significantly higher OR (12.5; 95% CI 2.8-55.9) than those aged 12-15 years. The OR for type C coinciding with OCD was significantly elevated (13.4; 95% CI 2.3-78.7).

CONCLUSIONS

Concurrent OCD was found in 22 (14.5%) of 152 knees with discoid lateral meniscus. Male sex, young age (5-11 years), and having a type C meniscal shift of the discoid lateral meniscus as shown by MRI were found to be predictive factors for OCD of the LFC.

LEVEL OF EVIDENCE

III.

Grade I Osteochondritis Dissecans in a Young Professional Athlete

BACKGROUND

Osteochondritis dissecans (OCD) is a disorder primarily affecting subchondral bone, with secondary effects on the overlying articular cartilage. Knee joint (75%) and radiocapitellar joint (6%) are the most common sites for OCD lesions. The presence of an open growth plate differentiates juvenile osteochondritis dissecans from adult form of osteochondritis. Early diagnosis and treatment produce best long term results. The objective of this study is to determine the best mode of management of a Grade I osteochondritis lesion in a young athlete.

MATERIALS AND METHODS

A PubMed search was made using the keywords "OCD" and "athlete". Articles that were based on participants between the ages of 6-24 years (children, adolescent and young adult) and early stages of OCD were included in this study. A total of 25 articles were thus included for the review.

RESULTS

The healing potential is based on the age of the patient, status of physis, and stage of the lesion. Most authors have observed good to excellent results of drilling of early OCD in skeletally mature patients. Similarly, most authors also reported equally successful outcomes of nonoperative treatment for early OCD in skeletally immature patients.

CONCLUSIONS

We recommend initial nonoperative line of management in patients with open physis. In case of progression of the lesion or failure of conservative treatment a reparative, restorative or palliative surgical intervention can be done. For Stage I OCD lesions in patients with closed physis, we advocate reparative surgery either by means of retro- or trans-articular drilling.

Juvenile Osteochondritis Dissecans of the Knee: Does Magnetic Resonance Imaging Instability Correlate With the Need for Surgical Intervention?

BACKGROUND

Several magnetic resonance imaging (MRI) classification systems have been developed to determine the degree of instability of juvenile osteochondritis dissecans (JOCD) lesions. Our current practice involves correlating the patients' symptoms with their MRI findings, but there are many cases in which this correlation is poor and results in incorrect classification of the stability of a JOCD lesion.

PURPOSE

To determine whether certain MRI findings of JOCD instability are associated with the necessity for arthroscopic intervention to assess lesion stability. A secondary objective was to determine the interobserver agreement of the Kijowski et al (2008) MRI criteria for osteochondritis dissecans (OCD) instability.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A retrospective review was performed of patients who had documented femoral condyle OCD lesions, had open growth plates, and had been evaluated with serial MRI examinations. Each OCD lesion on MRI was classified according to the Kijowski classification as either stable or likely unstable.

RESULTS

The study included 16 patients (17 knees) with 49 MRI examinations. The initial MRI lesion was graded as stable in 59% (10/17), and 7 of these remained stable throughout the study period, with only 1 requiring operative intervention. Two became unstable on MRI, with 1 requiring surgery and 1 reverting back to stable with nonoperative management. The initial MRI lesion was graded as unstable in 41% (7/17) of the knees, with 2 of these becoming stable on MRI during the follow-up period with nonoperative management. The other 5 lesions remained unstable, with 3 eventually requiring surgery. The most important finding in this study was that MRI instability is a poor predictor of the necessity for surgery for JOCD lesions. The correlation between a nonradiologist and a trained musculoskeletal radiologist in the interpretation of the MRI criteria by Kijowski et al showed only substantial agreement for multiple cysts.

CONCLUSION

MRI criteria for OCD instability in the pediatric knee do not always correlate with the necessity for surgery. They are, at times, a helpful adjunct to the management of these patients; however, care must be taken to interpret all available clinical and radiographic information in surgical decision making.

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.

Pediatric Knee Osteochondritis Dissecans Lesions

Osteochondritis dissecans (OCD) can cause knee pain and dysfunction in children. The etiology of OCD remains unclear; theories on causes include inflammation, ischemia, ossification abnormalities, genetic factors, and repetitive microtrauma. Most OCD lesions in skeletally immature patients will heal with nonoperative treatment. The success of nonoperative treatment decreases once patients reach skeletal maturity. The goals of surgical treatment include maintenance of articular cartilage congruity, rigid fixation of unstable fragments, and repair of osteochondral defects with cells or tissues that can adequately replace lost or deficient cartilage. Unsalvageable OCD lesions can be treated with various surgical techniques.

Running Injuries During Adolescence and Childhood

The popularity of running among young athletes has significantly increased over the past few decades. As the number of children who participate in running increases, so do the potential number of injuries to this group. Proper care of these athletes includes a thorough understanding of the unique physiology of the skeletally immature athlete and common injuries in this age group. Treatment should focus on athlete education, modification of training schedule, and correction of biomechanical deficits contributing to injury. Early identification and correction of these factors will allow a safe return to running sports.

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.

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.

Surgical treatment for osteochondritis dessicans of the knee

Osteochondritis dissecans (OCD) of the knee is a disease of the subchondral bone with secondary injury to the overlying articular cartilage. OCD lesions are generally categorized as juvenile-growth plates open-or adult-growth plates closed. This maturity-based classification scheme has a prognostic value in that many juvenile OCD lesions will heal with conservative care while most symptomatic adult OCD lesions need surgical intervention. OCD can result in pain, knee joint effusions, loose body formation, and arthritis. Short-term treatment goals include pain and symptom resolution while the long-term goal is to minimize arthritis. Surgical options include debridement, drilling, microfracture, reduction and fixation, autograft osteochondral transplantation, autologous chondrocyte implantation, and allograft osteochondreal transplantation.

Management strategies for osteochondritis dissecans of the knee in the skeletally immature athlete

SYNOPSIS

Osteochondritis dissecans (OCD) is a disorder resulting in focal breakdown of the subchondral bone, with potential disruption of the overlying articular cartilage. The femoral condyles of the knee are the most common locations for OCD, and the incidence of OCD appears to be increasing among active children. Juvenile OCD (JOCD) can be distinguished from adult OCD by the presence of open growth plates. Due to a lack of evidence on its early diagnosis, optimal treatment, and long-term course of healing, JOCD presents a unique challenge for the health care team. Approximately 50% to 67% of stable JOCD lesions heal successfully with nonoperative treatment. For unstable lesions and stable lesions that fail nonoperative treatment, a variety of surgical interventions can be utilized to stimulate bony healing and address articular cartilage lesions. It is recommended that rehabilitation of JOCD be tailored to the individual patient, based on the stage and radiographic status of the lesion and the mode of surgery employed when surgically addressed. Although there is a growing body of literature on this condition, the etiology and optimal methods for treatment, rehabilitation, and evaluating outcomes remain inconclusive due to a lack of quality evidence.

LEVEL OF EVIDENCE

Therapy, level 5.

The golf ball sign: arthroscopic localization of an osteochondritis dissecans lesion of the knee

We report on the arthroscopic treatment of a 12-year-old boy diagnosed with an osteochondral defect of the medial femoral condyle. He underwent arthroscopic fixation of the defect, and during the surgery, a blunt trocar was used to localize the lesion. The trocar created a transient dimpling effect on the cartilage overlying the osteochondral defect that resembled the surface of a golf ball. This "golf ball sign" then served as a visual guide during placement of a chondral dart. When present, it is believed that this sign can benefit arthroscopists by helping to improve intraoperative localization of an osteochondral defect.

Nonoperative treatment of osteochondritis dissecans of the knee

Osteochondritis dissecans is a potentially devastating cause of knee pain in adolescents and adults. Prognosis and treatment depends on the stability of the lesion and the age of the patient. Skeletally immature patients with stable lesions are amenable for nonoperative treatment. Nonoperative treatment is less predictable in skeletally mature patients and patients with unstable lesions. Lesion size, location, stability along with symptomatology should all be considered before initiating treatment. Modalities of nonoperative treatment can range from activity modification to complete immobilization. Close follow-up is recommended to monitor healing progression and symptom resolution.

Arthroscopic preparation and internal fixation of an unstable osteochondritis dissecans lesion of the knee

We present our arthroscopic technique for fixation of an unstable osteochondritis dissecans (OCD) lesion. This technique includes arthroscopic evaluation of cartilage and bone quality of the OCD fragment, hinging open the lesion, debridement of fibrous nonunion tissue, reducing the fragment, and obtaining multi-point compression screw fixation. This technique avoids the morbidity of an open arthrotomy and should be considered when treating an unstable OCD lesion with adequate bone for fixation.

Treatment of a lateral tibial plateau osteochondritis dissecans lesion with subchondral injection of calcium phosphate

Osteochondritis dissecans lesions occur frequently in children and adolescents. Treatment can be challenging and depends on the status of the articular cartilage and subchondral bone. Injection of calcium phosphate bone substitute into the area of subchondral bone edema (Subchondroplasty; Knee Creations, West Chester, PA) may be an option. We present a case of a lateral tibial plateau osteochondritis dissecans lesion treated with subchondral injection of nanocrystalline calcium phosphate. Preoperative magnetic resonance imaging is used to determine the area of subchondral edema, and intraoperative fluoroscopy is used to localize this area with the injection cannula. Calcium phosphate is injected by use of a series of syringes until the appropriate fill is obtained. Treatment of concomitant cartilage defects may also be carried out at this time.

Surgical management of osteochondritis dissecans of the knee

Osteochondritis dissecans of the knee primarily affects subchondral bone, with a secondary effect on the overlying articular cartilage. This process can lead to pain, effusions, and loose body formation. While stable juvenile lesions often respond well to nonoperative management, unstable juvenile lesions, as well as symptomatic adult lesions, often require operative intervention. Short-term goals focus on symptomatic relief, while long-term expectations include the hope of preventing early-onset arthritis. Surgical options include debridement, loose body removal, microfracture, arthroscopic reduction and internal fixation, subchondral drilling, osteochondral autograft or allograft transplantation, and autologous chondrocyte implantation. Newer single-stage cell-based procedures have also been developed, utilizing mesenchymal stem cells and matrix augmentation. Proper treatment requires evaluation of both lesional (size, depth, stability) and patient (age, athletic level) characteristics.