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

Osteochondritis Dissecans Lesions of the Knee: Evidence-Based Treatment

Osteochondritis dissecans (OCD) of the knee is a potentially disabling condition in adolescent and young adults, which is likely multifactorial in origin. In recent years, there have been notable improvements in identification and treatment. Clinical presentation varies based mostly on OCD lesion stability. Patients with stable lesions generally present with vague knee pain and altered gait while mechanical symptoms and effusion are more common with unstable lesions. Lesions most commonly occur on the lateral aspect of the medial femoral condyle in patients aged 10 to 20 years. Magnetic resonance imaging is vital to diagnose and predict clinical treatment, which is largely based on stability of the fragment. Conservative treatment of stable lesions in patients with open physis is recommended with protected weight-bearing and gradual progression of activities over the course of 3 to 6 months. Stable OCD lesions which failed a nonsurgical course can be treated with transarticular or retrograde drilling while unstable lesions usually require fixation, autologous chondrocyte implantation (ACI), osteochondral autograft transfer (OATS), or osteochondral allograft transplantation. This review highlights the most current understanding of knee OCD lesions and treatment options with the goal of optimizing outcomes in this difficult pathology.

A rabbit osteochondral defect (OCD) model for evaluation of tissue engineered implants on their biosafety and efficacy in osteochondral repair

Osteochondral defect (OCD) is a common but challenging condition in orthopaedics that imposes huge socioeconomic burdens in our aging society. It is imperative to accelerate the R&D of regenerative scaffolds using osteochondral tissue engineering concepts. Yet, all innovative implant-based treatments require animal testing models to verify their feasibility, biosafety, and efficacy before proceeding to human trials. Rabbit models offer a more clinically relevant platform for studying OCD repair than smaller rodents, while being more cost-effective than large animal models. The core-decompression drilling technique to produce full-thickness distal medial femoral condyle defects in rabbits can mimic one of the trauma-relevant OCD models. This model is commonly used to evaluate the implant's biosafety and efficacy of osteochondral dual-lineage regeneration. In this article, we initially indicate the methodology and describe a minimally-invasive surgical protocol in a step-wise manner to generate a standard and reproducible rabbit OCD for scaffold implantation. Besides, we provide a detailed procedure for sample collection, processing, and evaluation by a series of subsequent standardized biochemical, radiological, biomechanical, and histological assessments. In conclusion, the well-established, easy-handling, reproducible, and reliable rabbit OCD model will play a pivotal role in translational research of osteochondral tissue engineering.

Understanding Osteochondritis Dissecans: A Narrative Review of the Disease Commonly Affecting Children and Adolescents

BACKGROUND

Osteochondritis dissecans (OCD) is a joint disorder predominantly affecting the knee, elbow, and ankle of children and adolescents. This comprehensive review delves into the epidemiology, etiology, clinical manifestations, diagnostic approaches, and treatment of OCD.

RESULTS

The most common cause of OCD is repetitive microtrauma, typically associated with sports activities, alongside other significant factors such as genetic predisposition, ischemia, and obesity. In early stages or when lesions are small, OCD often presents as non-specific, vaguely localized pain during physical activity. As the condition progresses, patients may experience an escalation in symptoms, including increased stiffness and occasional swelling, either during or following activity. These symptom patterns are crucial for early recognition and timely intervention. Diagnosis in most cases is based on radiographic imaging and magnetic resonance imaging. Nonsurgical treatment of OCD in young patients with open growth plates and mild symptoms involves activity restriction, immobilization methods, and muscle strengthening exercises, with a return to sports only after symptoms are fully resolved and at least six months have passed. Surgical treatment of OCD includes subchondral drilling in mild cases. Unstable lesions involve methods like restoring the joint surface, stabilizing fractures, and enhancing blood flow, using techniques such as screws, anchors, and pins, along with the removal of fibrous tissue and creation of vascular channels. The specifics of OCD treatment largely depend on the affected site.

CONCLUSIONS

This synthesis of current research and clinical practices provides a nuanced understanding of OCD, guiding future research directions and enhancing therapeutic strategies.

Bilateral juvenile osteochondrosis dissecans in monozygotic twins: a case report

INTRODUCTION

The etiology of osteochondrosis dissecans (OCD), a chondropathy associated with detachment of the subchondral bone and the overlaying cartilage, is not yet fully understood. While repetitive physical exercise-related stress is usually assumed to be the main risk factor for the occurrence of OCD, genetic predisposition could have an underestimated influence on the development of the disease.

CASE REPORT

We report a case of monozygotic twins with almost identical stages of bilateral osteochondrosis dissecans of the knee joint. In both patients, initially, a unilateral lesion occurred; despite restricted physical exercise, in the further course of the disease a lesion also developed on the contralateral side. While the lesion found most recently demonstrated an ongoing healing process at a 6-month follow-up, the other three lesions showed a natural course of healing under conservative treatment with significant clinical as well as radiological improvements after one year and complete consolidation in magnetic resonance imaging (MRI) after 2 years.

CONCLUSION

There could be a genetic component to the development of OCD, although this has not yet been proven. Based on a two-year MRI follow-up, we were able to show the self-limiting characteristics of juvenile osteochondrosis dissecans.

Comparison of Outcomes After Primary Versus Salvage Osteochondral Allograft Transplantation for Femoral Condyle Osteochondritis Dissecans Lesions

Background

Osteochondral allograft transplantation (OCAT) allows the restoration of femoral condyle osteochondritis dissecans (OCD) lesions using an osteochondral unit. When OCD lesions are irreparable, or treatments have failed, OCAT is an appropriate approach for revision or salvage surgery. Based on its relative availability, cost-effectiveness, lack of donor site morbidity, and advances in preservation methods, OCAT is also an attractive option for primary surgical treatment for femoral condyle OCD.

Hypothesis

OCAT for large femoral condyle OCD lesions would be highly successful (>90%) based on significant improvements in knee pain and function, with no significant differences between primary and salvage procedure outcomes.

Study Design

Cohort study; Level of evidence, 3.

Methods

Patients were enrolled into a registry for assessing outcomes after OCAT. Those patients who underwent OCAT for femoral condyle OCD and had a minimum of 2-year follow-up were included. Reoperations, treatment failures, and patient-reported outcomes were compared between primary and salvage OCAT cohorts.

Results

A total of 22 consecutive patients were included for analysis, with none lost to the 2-year follow-up (mean, 40.3 months; range, 24-82 months). OCD lesions of the medial femoral condyle (n = 17), lateral femoral condyle (n = 4), or both condyles (n = 1) were analyzed. The mean patient age was 25.3 years (range, 12-50 years), and the mean body mass index was 25.2 kg/m2 (range, 17-42 kg/m2). No statistically significant differences were observed between the primary (n = 11) and salvage (n = 11) OCAT cohorts in patient and surgical characteristics. Also, 91% of patients had successful outcomes at a mean of >3 years after OCAT with 1 revision in the primary OCAT cohort and 1 conversion to total knee arthroplasty in the salvage OCAT cohort. For both primary and salvage OCATs, patient-reported measures of pain and function significantly improved at the 1-year and final follow-up, and >90% of patients reported that they were satisfied and would choose OCAT again for treatment.

Conclusion

Based on the low treatment failure rates in conjunction with statistically significant and clinically meaningful improvements in patient-reported outcomes, OCAT can be considered an appropriate option for both primary and salvage surgical treatment in patients with irreparable OCD lesions of the femoral condyles.

Osteochondritis dissecans of the temporomandibular joint: a scoping review

PURPOSE

To perform a scoping review to identify the available evidence regarding osteochondritis dissecans (OCD) of the temporomandibular joint (TMJ).

METHODS

An electronic search of the PubMed, Web of Science and Scopus databases was performed using the following terms: 'Temporomandibular Joint Disorders', 'Osteochondritis Dissecans', 'Joint Loose Bodies' and 'Temporomandibular Joint'. Full-text articles were obtained from the records after applying the inclusion/exclusion criteria.

RESULTS

Ten articles were included in the analysis - six case reports, one case series, one retrospective study, one comparative study and one correlational study - with a total of 39 patients. The most frequently reported clinical presentation involved TMJ pain, locked jaw and articular noises (clicking and crepitus). The imaging methods used to identify OCD were radiographs, tomography, arthrography and magnetic resonance imaging. The reported imaging findings varied widely, but the most frequent were (single or multiple) calcified intra-articular loose bodies, signs of degenerative osseous changes, disc displacements, widening of the joint space and alterations in condylar morphology. Seven articles reported treatments (surgical or conservative), but the treatment outcome was not reported in all of the articles, which makes it difficult to make comparisons.

CONCLUSION

OCD of the TMJ may present various non-specific clinical characteristics, and given the heterogeneous imaging findings, multiplanar images are required for an accurate diagnosis. Finally, the results do not allow recommending a standard treatment for OCD of the TMJ.

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.

Osteochondritis Dissecans of the Knee Associated With Mechanical Overload

BACKGROUND

Osteochondritis dissecans (OCD) of the knee is a rare but potentially incapacitating disorder in which subchondral bone detaches, leading to an osteochondral fragment that can become unstable and progress into a loose body. The exact cause is unknown, although several biological and mechanical factors have been described.

PURPOSE

To provide insight into epidemiological data of a large cohort of patients affected by OCD of the knee and to identify potential factors contributing to the cause of this disorder.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

A total of 236 patients (259 knees) affected by OCD were included in our Knee Registry (2005-2022) and retrospectively analyzed. Patient characteristics were extracted from the medical records. Location and International Cartilage Regeneration & Joint Preservation Society grade (1-4) of OCD were assessed using magnetic resonance imaging. If available, a full-leg standing radiograph was used to assess alignment. Additionally, a statistical scoring system for instability risk was created.

RESULTS

A total of 263 OCD lesions were identified in 259 knees, 66.2% on the medial femoral condyle (MFC), 26.6% on the lateral femoral condyle (LFC), 3.8% on the trochlea, 2.7% on the patella, and 0.8% on the lateral tibia plateau. Male patients made up 57.6% of the sample, which had a mean age of 21.8 years. A very high percentage of patients (77.1%; n = 182) practiced sports, of whom 67.6% (n = 123) were engaged in high-impact sports. The location of the OCD lesions and the leg alignment (n = 110) were significantly correlated: MFC lesions were associated with more varus than valgus alignment (47.5% vs 11.3%) and patients with LFC lesions had more valgus than varus alignment (46.7% vs 20.0%; P = .002). Based on age, smoking, sports activity, and preceding trauma, a multivariable scoring system (0-11 points) was created. An increased risk of lesion instability was associated with an increased score: 29.0% at 0 points and 97.0% at 11 points.

CONCLUSION

This study provides detailed epidemiological data for 236 patients affected by OCD of the knee. Older age, smoking, inactivity, and preceding trauma were predictive for instability of OCD lesions. There was an association between OCD of the MFC and varus malalignment and between OCD of the LFC and valgus malalignment. This finding, in combination with the high percentage of patients practicing high-impact sports, suggests an important role for mechanical overload in the pathogenesis of OCD.

[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.

Physician preferences in diagnostics and treatment of juvenile osteochondritis dissecans are diverse across the knee, ankle and elbow: an ESSKA survey

PURPOSE

To investigate the current preferences regarding the work-up and treatment choices of juvenile osteochondritis dissecans (JOCD) of the knee, ankle and elbow among orthopaedic surgeons.

METHODS

An international survey was set up for all European Society of Sports Traumatology, Knee Surgery and Arthroscopy (ESSKA) members, which assessed various questions on diagnosis and treatment of JOCD of different joints. Respondents answered questions for one or more joints, based on their expertise. Proportions of answers were calculated and compared between joints. Consensus was defined as more than 75% agreement on an item; disagreement was defined as less than 25% agreement.

RESULTS

Fifty physicians responded to the survey, of whom forty-two filled out the questions on the knee, fourteen on the ankle and nine on the elbow. Plain radiography and MRI were the most used imaging modalities for the assessment and follow-up of JOCD in the knee and ankle, but not for the elbow. MRI was also the preferred method to assess the stability of a lesion in the knee and ankle. There was universal agreement on activity and/or sports restriction as the non-operative treatment of choice for JOCD. Size, stability and physeal closure were the most important prognostic factors in determining the operative technique for the elbow. For the knee, these factors were size and stability and for the ankle, these were size and location.

CONCLUSION

Activity and/or sports restriction was the non-operative treatment of choice. Furthermore, plain radiography and MRI were the preferred imaging modalities for the knee and ankle, but not for the elbow. For determining the operative technique, physicians agreed that the size of the lesion is an important prognostic factor in all joints. These findings help us understand how juvenile osteochondritis dissecans is treated in current practice and may provide opportunities for improvement.

LEVEL OF EVIDENCE

Level V.

Trauma-induced spontaneous union of a talar osteochondritis dissecans: case report

We encountered a case of an 18-year-old woman with persisting ankle pain after a healed Weber-B fracture. Additional imaging through a computed tomography (CT) scan revealed a fully united fragmentous osteochondral lesion of the talus (OLT) (17 ​mm ​× ​9 ​mm ​× ​8 ​mm) of the right ankle-as opposed to a non-united OLT when the fracture was diagnosed 19 months prior to the presentation. Our proven hypothesis is that the fragmented OLT was non-symptomatic for many years, based on an osteochondritis dissecans. The ipsilateral ankle trauma induced a fresh fracture in the interface between the talus and the fragmented OLT, and consequently the destabilized fragmented OLT became symptomatic. The ankle trauma initiated fracture healing that resulted in a complete union of the OLT without clinical symptoms. The existing symptoms were established to be based on anterior osseous ankle impingement, due to the presence of osseous fragments in the medial gutter of the ankle joint. Therefore, a nettoyage of the medial gutter including a resection of the corpora libera from the medial gutter with the shaver was performed. Intraoperative macroscopic assessment of the medial osteochondritis dissecans was performed and showed union with completely intact hyaline cartilage at the level of the surrounding articular cartilage requiring no interventions. An increased range of motion was achieved. The patient recovered well with and experienced no more recognizable pain. In this article, the unstable fragmentous lesion of the patient reached spontaneous union within 19 months after destabilization. Although this is not common for an unstable fragmentous OLT, this could be a stepping stone toward an increased role of conservative treatment for fragmentary OLTs.

Medial Patellofemoral Ligament Tear Associated with an Intra-articular Axial Spilt Osteochondral Fracture of the Lateral Femoral Condyle: a "Knee Trap-door" Fracture

Introduction

Medial patellofemoral ligament (MPFL) prevents lateral dislocation of the patella and acts as a major stabilizer. The tear could be associated with osteochondral avulsion fractures; however, intra-articular split fractures are not seen. Here, we present one unusual case of such a presentation.

Case Report

A 16-year-old male presented with a history of recurrent patellar dislocation and inability to bear weight following the last episode. The patient was diagnosed with an MPFL tear with an unusual intra-articular femoral condyle split fracture. The case had significant improvement in functional scores post-surgery.

Conclusion

In physically active populations, twisting of the knee could result in an MPFL tear, leading to recurrent patellar dislocation. The treatment remains ligament reconstruction, open, or arthroscopic. Associated intra-articular fractures are very rare with such injuries and need to be addressed due to the high rate of non-union.

Increased lesion depth, higher body mass index and older age are risk factors for osteoarthritis during long-term follow-up in patients with osteochondritis dissecans of the knee

INTRODUCTION

To report on the long-term prognosis of osteochondritis dissecans (OCD) patients regarding radiological and patient-reported outcomes and to analyze possible risk factors.

MATERIALS AND METHODS

All patients diagnosed with knee OCD between 2004 and 2014 with radiographic Kellgren-Lawrence (K-L) grades 0-2 at the time of diagnoses, ability to understand the language of the interview, and willingness to participate in the study were retrospectively reviewed. Current knee radiographs and the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire were prospectively collected between May 2020 and March 2021. The extent of osteoarthritis (OA) and KOOS questionnaire results were evaluated.

RESULTS

90 patients (103 knees) with a mean age of 21 years (range 6-60) were included. The mean follow-up time was 12 years (range 7-20). 24 knees (23%) were treated conservatively, and 79 knees (77%) operatively. At the time of diagnoses, 90% of the patients had K-L grades of 0-1; during the follow-up period, 45% of the patients showed radiological progression of OA. Patient body mass index (BMI) (p = 0.004; 95% CI 0.25-0.29), age (p = 0.003; 95% CI 0.18-0.30), operative treatment (p = 0.0075; 95% CI 0.41-0.65) and lesion depth (p = 0.0007) were statistically significantly connected to K-L grade change. Patients with no progression in joint space narrowing had statistically significantly better overall KOOS scores (p = 0.03; 95% CI 0.77-0.88) than patients whose K-L grades worsened.

CONCLUSIONS

During the long-term follow-up of 12 years, patients with knee OCD had good clinical results. Lac of radiological progression of cartilage degeneration was noted in 55% of the patients, regardless of treatment method. Lesion depth, higher BMI and older age were associated with the progression of OA. The progression of OA was related to a worsening of functional scores.

LEVEL OF EVIDENCE

IV.

Long-Term Outcome and Athletic Level following Operative Treatment for Osteochondritis Dissecans of the Knee in Pediatric and Adolescent Patients

Research on the long-term outcomes following surgical therapy for osteochondritis dissecans (OCD) of the knee is scarce. A single-center retrospective cohort study was conducted to investigate surgically treated patients for knee OCD between 1993 and 2007. A total of 37 patients with an average follow-up duration of 14 years (range 8-18) were in the final cohort. IKDC and Lysholm scores were assessed. The duration and types of sport activity were reported. Long-term results were compared with existing midterm data. Knee scores showed a very good outcome with a mean of 91.3 in the IKDC score and 91.7 in the Lysholm score. Compared to midterm outcomes, both IKDC (p = 0.028) and Lysholm scores (p = 0.01) improved on final follow-up. Patients with open physes showed a significantly better Lysholm score compared to patients with closed physes (p = 0.034). Defect localization and size did not influence the outcome, but a defect depth of <0.8 cm² achieved significantly better scores than ≥0.8 cm². Of all surgical interventions, refixation achieved the best outcome. Long-term results significantly improved compared to midterm results with a follow-up of 40 months (p = 0.01). Thirty-six out of 37 patients were physically active, with 56% of sports being knee-straining activities. Long-term results following surgically treated OCD fragments show excellent function and a good athletic level. Patients with open physes potentially have better knee outcomes. Midterm results are sustainable and could improve further in the long term.

Characteristics of Pressure on the Apophysis in the Course of Paediatric Heel Pain-Preliminary Report

Increased pressure on the heel apophysis is often implicated as a cause of paediatric heel pain. However, there are few reports on the causes of the increased pressure and its origin. Therefore, the aim of this study was to analyse the distribution of pressure on the feet in children with heel pain. The study included 33 paediatric patients with non-traumatic heel pain, i.e., 24 boys (73%) and 9 girls (27%), aged on average 11.2 years (±3 years). Pedobarographic diagnostics proved a decrease in the pressure on the heels in relation to the ground and the transfer of the projection of the centre of gravity to the forefoot. While standing, the average contribution of the pressure on the heel was 0.52, SD = 0.14 in children with normal and reduced weight. In overweight children, the average pressure on the heel was higher (0.60, SD = 0.08), but the small number of children with this characteristic (n = 4) did not allow conclusions to be drawn in this area. Heel underload was also demonstrated during gait. However, the assessment of this aspect requires additional observational analyses in the field of propulsion and gait phases. The reduced pressure on the heel promotes apophysis traction, causing intracanal compression. Studies have shown that the causes of apophysis traction may be postural defects (in particular, forward inclination of body posture) and overpronation of the foot, or defects in the metatarsal area.

Naturally occurring osteochondrosis latens lesions identified by quantitative and morphological 10.5 T MRI in pigs

Juvenile osteochondritis dissecans (JOCD) is a pediatric orthopedic disorder that involves the articular-epiphyseal cartilage complex and underlying bone. Clinical disease is often characterized by the presence of radiographically apparent osteochondral flaps and fragments. The existence of early JOCD lesions (osteochondrosis latens [OCL] and osteochondrosis manifesta [OCM]) that precede the development of osteochondral flaps and fragments is also well recognized. However, identification of naturally occurring OCL lesions (confined to cartilage) using noninvasive imaging techniques has not yet been accomplished. We hypothesized that 10.5 T magnetic resonance imaging (MRI) can identify naturally occurring OCL lesions at predilection sites in intact joints of juvenile pigs. Unilateral elbows and knees (stifles) were harvested from three pigs aged 4, 8, and 12 weeks, and scanned in a 10.5 T MRI to obtain morphological 3D DESS images, and quantitative T2 and T1ρ relaxation time maps. Areas with increased T2 and T1ρ relaxation times in the articular-epiphyseal cartilage complex were identified in 1/3 distal femora and 3/3 distal humeri and were considered suspicious for OCL or OCM lesions. Histological assessment confirmed the presence of OCL or OCM lesions at each of these sites and failed to identify additional lesions. Histological findings included necrotic vascular profiles associated with areas of chondronecrosis either confined to the epiphyseal cartilage (OCL, 4- and 8-week-old specimens) or resulting in a delay in endochondral ossification (OCM, 12-week-old specimen). Future studies with clinical MR systems (≤7 T) are needed to determine whether these MRI methods are suitable for the in vivo diagnosis of early JOCD lesions in humans.

Osteochondritis dissecans of the knee: Epidemiology, etiology, and natural history

Osteochondritis dissecans of the knee is a disease that typically affects skeletally immature patients. Clinically manifested with knee pain, limping, and joint disfunction, this condition has remained misunderstood and undervalued for a long period. Although being a rare condition, its awareness is of utmost clinical interest because of the possible severe consequences it can bring when misrecognized or inadequately treated. Its etiology remains unclear and is still debated. Many theories have been proposed, including inflammation, local ischemia, subchondral ossification abnormalities, genetic factors, and repetitive mechanical microtrauma, with a likely interplay of the same. This review article aims to deliver and discuss current and up-to-date concepts on epidemiology, etiology, and natural history of this pediatric condition. Level of evidence: level V.

Chondrocyte Isolation from Loose Bodies-An Option for Reducing Donor Site Morbidity for Autologous Chondrocyte Implantation

Loose bodies (LBs) from patients with osteochondritis dissecans (OCD) are usually removed and discarded during surgical treatment of the defect. In this study, we address the question of whether these LBs contain sufficient viable and functional chondrocytes that could serve as a source for autologous chondrocyte implantation (ACI) and how the required prolonged in vitro expansion affects their phenotype. Chondrocytes were isolated from LBs of 18 patients and compared with control chondrocyte from non-weight-bearing joint regions (n = 7) and bone marrow mesenchymal stromal cells (BMSCs, n = 6) obtained during primary arthroplasty. No significant differences in the initial cell yield per isolation and the expression of the chondrocyte progenitor cell markers CD44 + /CD146+ were found between chondrocyte populations from LBs (LB-CH) and control patients (Ctrl-CH). During long-term expansion, LB-CH exhibited comparable viability and proliferation rates to control cells and no ultimate cell cycle arrest was observed within 12 passages respectively 15.3 ± 1.1 mean cumulative populations doublings (CPD). The chondrogenic differentiation potential was comparable between LB-CH and Ctrl-CH, but both groups showed a significantly higher ability to form a hyaline cartilage matrix in vitro than BMSC. Our data suggest that LBs are a promising cell source for obtaining qualitatively and quantitatively suitable chondrocytes for therapeutic applications, thereby circumventing donor site morbidity as a consequence of the biopsies required for the current ACI procedure.

Longitudinal 3T MRI T2 * mapping of Juvenile osteochondritis dissecans (JOCD) lesions differentiates operative from non-operative patients-Pilot study

Juvenile osteochondritis dissecans (JOCD) is an orthopedic joint disorder of children and adolescents that can lead to premature osteoarthritis. Thirteen patients (mean age: 12.3 years, 4 females), 15 JOCD-affected and five contralateral healthy knees, that had a baseline and a follow-up magnetic resonance imaging (MRI) (mean interval of 8.9 months) and were treated nonoperatively during this interval were included. Retrospectively, patients were assigned to operative or nonoperative groups based on their electronic medical records. Volumetric mean T2 * values were calculated within regions of interest (progeny lesion, interface, parent bone) and region matched control bone in healthy contralateral knees and condyles. The normalized percentage difference of T2 * between baseline and follow up MRI in nonoperative patients significantly increased in progeny lesion (-47.8%, p < 0.001), parent bone (-13.9%, p < 0.001), and interface (-32.3%, p = 0.011), whereas the differences in operative patients were nonsignificant and below 11%. In nonoperative patients, the progeny lesion (p < 0.001) and interface T2 * values (p = 0.012) were significantly higher than control bone T2 * at baseline, but not at follow-up (p = 0.219, p = 1.000, respectively). In operative patients, the progeny lesion and interface T2 * values remained significantly elevated compared to the control bone both at baseline (p < 0.001, p < 0.001) and follow-up (p < 0.001, p < 0.001), respectively. Clinical Significance: Longitudinal T2 * mapping differentiated nonhealing from healing JOCD lesions following initial nonoperative treatment, which may assist in prognosis and improve the ability of surgeons to make recommendations regarding operative versus nonoperative treatment.

Physeal fusion status and lesion size are more important than patient age for healing of juvenile osteochodritis dessicans lesions of the distal femur

PURPOSE

The purpose of the study was to evaluate the effect of skeletal age and lesion size, location, and grade on the success of nonoperative treatment for juvenile osteochondritis dissecans (OCD). It is hypothesized that skeletal maturity, including a combination of maturation phenotypes, correlates with nonoperative lesion healing.

METHODS

The clinical and radiographic data on 52 patients aged 7-20 years treated for OCD of the distal femur between 2010 and 2019 were retrospectively reviewed. Knee radiographs were assessed for number of lesions present and lesion location, size, and stage. Assessments of skeletal maturation were performed on all antero-posterior knee radiographs using the Roche, Wainer, and Thissen (RWT) method. Patients were categorized as healed if they demonstrated no pain on clinical examination. The relationship between skeletal maturity and nonoperative lesion healing was determined using Spearman rank correlations on available variables.

RESULTS

Neither chronological nor skeletal age was associated with surgical status (Rho = 0.03, n.s., and Rho = 0.13, n.s., respectively) or the healing status of nonoperatively treated OCD lesions (Rho = 0.44, n.s., and Rho = 0.03, n.s., respectively). Epiphyseal fusion status of the distal femoral physis was moderately correlated with nonoperative healing, but was not statistically significant (lateral femoral physis: Rho = 0.43, p = 0.05; medial femoral physis: Rho = 0.43, n.s.). Lesion length correlated with surgical status (Rho = - 0.38, p = 0.009).

CONCLUSION

The extent of fusion of the distal femoral physis (multi-stage grading) may be more strongly correlated with nonoperative healing than other markers of skeletal maturity or chronological age. Clinicians can use this as an additional radiographic sign when considering nonoperative treatment for juvenile OCD lesions in the distal femur. OCD lesion length and physeal fusion status appear to be more important for healing than patient age.

Knee osteochondritis dissecans-treatment technical aspects

Purpose and objective

Current treatments of different stages of knee osteochondritis Dissecans (OCD) are depending on the age of the patients and the stability of the diseased osteochondral area. The purpose of this paper was to summarize the treatment alternatives in order to simplify the choice for the treating surgeon.

Background and principle results

Osteochondritis dissecans (OCD) of the knee is an idiopathic and local osteochondral abnormality that affects mainly children and adolescents with risk of loosening of osteochondral fragments. A good clinical result can be expected when the physes are still open, when the osteochondritis is small and when the osteochondritis can be assessed as stable by MRI. Unstable OCD lesions most often need to be treated operatively by different fixation methods and when the osteochondral cannot be refixated, different local chondral and osteochondral repairs are available to fill up the defect area to congruity.

Summary and major conclusions

The final choice of which treatment to use is depending on fragment viability and forms. Viable fragments are refixated while poor quality fragments are removed followed by a local biological osteochondral repair. Such osteochondral resurfacing may be single bone marrow stimulation with or without scaffold augmentation or different cell seeded grafts.

[Juvenile osteochondrosis and osteonecrosis]

BACKGROUND

Juvenile osteonecrosis is an important topic in orthopedics. A wide variety of body regions of the growing patient are affected, predominantly during adolescence. All are characterized by a usually unknown aetiology as well as a stadium-like course. The main problem is a local osseous circulatory disorder, which causes osteonecrosis.

RISK FACTORS

Mechanical overloading due to increased body weight, axial misalignment, and sports activity is discussed as a risk factor. Healing depends on the localization and extent of the osseous necrosis.

DIAGNOSTICS

Diagnostically, radiologic imaging is used, in which the typical bony remodeling can be followed.

THERAPY

The therapeutic procedure depends on the affected region but is usually accompanied by a reduction of mechanical loading. If the clinical and radiological findings worsen, surgical treatment must be considered. The recognition and treatment of juvenile osteonecrosis is important and significantly influences the further development of the patient.

Males and Females Exhibit Comparable Outcomes Following Treatment of Osteochondritis Dissecans Lesions of the Knee: A Systematic Review

PURPOSE

The purpose of this study was to evaluate the impact of patient sex on outcomes after treatment of osteochondritis dissecans (OCD) lesions of the knee through a systematic review of current evidence.

METHODS

This review was conducted according to the PRISMA guidelines using the PubMed, PubMed Central, Embase, Ovid Medline, Cochrane Libraries, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases. Relevant outcomes included functional (e.g., International Knee Documentation Committee and Subjective Knee Evaluation, Lysholm Knee Score) and clinical outcomes (e.g., symptom/pain resolution, reoperation rates) for males and females after operative or nonoperative treatment of knee OCD lesions.

RESULTS

Ten articles with a total of 691 (73%) males and 260 (27%) females were included. Mean age ranged from 11.3 ± 2.1 years to 34.5 ± 10.3 years, and follow-up ranged from 6 months to 16.3 years. In four studies reporting functional outcomes, no significant differences were found between males and females in any metric assessed (all P > .05). Seven studies reported clinical outcomes after treatment of knee OCD lesions. One study determined males were more likely to have a successful nonoperative outcome than females (OR: 1.85, 95% CI: 1.00-3.40). Another study found males had a lower risk of developing symptomatic knee pain following operative or nonoperative treatment at a mean 14-year follow-up (HR: 0.24; 95% CI: 0.07-0.81). The remaining 5 studies reported statistically comparable clinical outcomes between males and females (all P > .05).

CONCLUSION

The present systematic review found mostly comparable clinical and functional outcomes between males and females following treatment of knee OCD lesions. Despite sex-related differences in the prevalence of these lesions and limited evidence of differences in clinical outcomes, these data suggest that sex does not independently predict outcomes after treatment.

LEVEL OF EVIDENCE

III, systematic review of Level II and III studies.

Osteochondral Allograft Transplantation of the Lateral Femoral Condyle and Distal Femoral Osteotomy in the Setting of Failed Osteochondritis Dissecans Fixation

Osteochondritis dissecans (OCD) is a pathologic condition, most commonly affecting the knee joint in adolescents and young adults, although pathology can also be found at the elbow and ankle. Lesions to the medial femoral condyle are classically associated with varus alignment, while lesions to the lateral femoral condyle are seen in patients with valgus malalignment. Common risk factors for failed fixation of OCD lesions include unstable lesions to the lateral femoral condyle, screw breakage, older age, and closed physes. The purpose of this technical note is to describe the preoperative planning and step-by-step surgical approach for treatment of failed fixation of an OCD lesion of the posterior aspect of the lateral femoral condyle in young, active patients using an osteochondral allograft, a lateral opening wedge distal femoral osteotomy to correct malalignment, and a tibial tubercle osteotomy to facilitate access to the lesion.

Gel-Based Autologous Chondrocyte Implantation in a Patient with Noncontained Osteochondral Knee Defect at 9-Year Follow-Up

Osteochondritis dissecans (OCD) is a disorder of the subchondral bone affecting the adjacent articular cartilage that may lead to cartilage and bone fragment detachment. It commonly occurs in the knee joint, elbow, wrist, and ankle. Although several surgical concepts have been described to treat OCD (fragment fixation, microfracture, autologous chondrocyte implantation (ACI), and mosaicplasty), no gold standard treatment has been accepted for managing OCD. Multiple factors like age, stability of defect, and defect size should be considered while selecting a specific treatment for OCD. Here, we discuss the case of an 18-year-old patient with horizontal and noncontained OCD. The MRI and CT scan evaluations of condylar notch view showed a defect ( $23\text{mm}\times 19\text{mm}\times 8\text{mm}$ ) with ICRS grade IV lateral femoral condyle OCD that was successfully managed by gel-based ACI. After 9 years of ACI, the patient was asymptomatic with full range of motions at the knees. Improvement in visual analog scale score, International Knee Documentation Committee score, and Magnetic Resonance Observation of Cartilage Repair Tissue score was also seen at 9 years post-ACI. No further surgical interventions were needed post-ACI.

Free vascularised osteochondral flap for the treatment of osteochondritis dissecans of the talus

We present a case report of a man in his 20s with osteochondritis dissecans of the talus, treated with autologous transplantation of a vascularised osteochondral flap. The patient with high level of activity presented to our orthopaedic outpatient department for progressive limping and pain, mainly related to sports. An osteochondritis dissecans grade IV of the medial talus was identified by MRI. A microvascular transfer of osteochondral tissue was performed successfully. At follow-up 1 year after surgery, the MRI examination revealed vital cartilage; the patient was free of pain and had returned to his previous level of activity.

Arthroscopic Drilling for Stable Juvenile Osteochondritis Dissecans of the Knee Is Safe and Patients Reliably Return to Daily Activities by 3 Months

Purpose

To assess the postoperative timeline for the return to activities of daily living (ADLs) in pediatric patients after arthroscopic drilling of a stable osteochondritis dissecans (OCD) lesion of the knee and to determine the rate of and risk factors for complications after the procedure.

Methods

In a retrospective chart review, data from all patients aged 18 years or younger who underwent arthroscopic drilling for a stable OCD lesion of either femoral condyle from May 2009 through July 2017 were collected. Demographic data, lesion characteristics, operative data, postoperative course, radiographic outcomes, and complications were recorded. Statistical analysis was performed to determine the risk factors for reoperations.

Results

A total of 139 knees in 131 patients were evaluated, with a mean age of 12.7 years, of which 102 (73%) were male knees. The average follow-up period was 17.8 ± 13.2 months after surgery. All patients regained full extension and flexion within 5° of the contralateral knee at a mean of 12.9 ± 3.2 weeks postoperatively, with 95% having returned fully to ADLs by the 3-month postoperative visit. No cases of infection, stiffness, arthrofibrosis, or other procedure-related complications were recorded. A total of 133 knees (95.7%) showed healing on radiographs, whereas 6 knees (4.3%) underwent additional surgical procedures, all of which were performed for treatment failure related to nonhealing lesions (including loose body removal, chondroplasty, and repeated drilling). Lesion size was the only significant risk factor for reoperation (P = .02).

Conclusions

Our findings suggest that arthroscopic drilling for stable, intact OCD lesions in the pediatric knee is a safe procedure with reliable outcomes and return to ADLs and a minimal risk of complications. Most patients return to their preoperative daily activity level with a full range of motion of the knee by 3 months after surgery. Complications, including reoperations, are related to the progression of the OCD lesion rather than to the surgical procedure. Each 1-cm² increase in lesion size increases the likelihood of reoperation by 2.93 times.

Level of Evidence

Level IV, therapeutic case series.

Novel missense ACAN gene variants linked to familial osteochondritis dissecans cluster in the C-terminal globular domain of aggrecan

The cartilage aggrecan proteoglycan is crucial for both skeletal growth and articular cartilage function. A number of aggrecan (ACAN) gene variants have been linked to skeletal disorders, ranging from short stature to severe chondrodyplasias. Osteochondritis dissecans is a disorder where articular cartilage and subchondral bone fragments come loose from the articular surface. We previously reported a missense ACAN variant linked to familial osteochondritis dissecans, with short stature and early onset osteoarthritis, and now describe three novel ACAN gene variants from additional families with this disorder. Like the previously described variant, these are autosomal dominant missense variants, resulting in single amino acid residue substitutions in the C-type lectin repeat of the aggrecan G3 domain. Functional studies showed that neither recombinant variant proteins, nor full-length variant aggrecan proteoglycan from heterozygous patient cartilage, were secreted to the same level as wild-type aggrecan. The variant proteins also showed decreased binding to known cartilage extracellular matrix ligands. Mapping these and other ACAN variants linked to hereditary skeletal disorders showed a clustering of osteochondritis dissecans-linked variants to the G3 domain. Taken together, this supports a link between missense ACAN variants affecting the aggrecan G3 domain and hereditary osteochondritis dissecans.

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.

What Do We Currently Know About Patellofemoral Osteochondritis Dissecans?

OBJECTIVE

Knee osteochondritis dissecans (OCD) is a still poorly understood pathological condition of the articular subchondral bone and its overlying cartilage. Patellofemoral involvement accounts for less than 1% of cases; tibial plateau and multifocal involvement is an even rarer instance. The purpose of this study is to review what is currently known about patellofemoral OCD (PF-OCD) and to present an unusual case of PF-OCD which progressed to become multifocal in an adult female patient.

METHODS

A comprehensive literature search was conducted on PubMed/Medline, Cochrane, Embase, Web of Science, and Scopus databases on September 2021 for all levels of evidence and English language. After duplicate removal, 234 papers pertaining to PF-OCD were retrieved. Thirty-nine studies met inclusion criteria and were included in the review. As an example, a unique case of delamination of patellar cartilage consistent with PF-OCD with progressive involvement of trochlea and both tibial plateau in a 35-year-old woman is also presented.

RESULTS

PF-OCD is a rare localization of knee OCD. Two hundred eighty-eight cases have been reported in the literature to date. Mean age at time of diagnosis was 16 years and the location could also be bilateral and multifocal. The etiology is still debated but traumatic, vascular, and hereditary mechanisms are likely. Management mirrors that of classical OCD.

CONCLUSIONS

PF-OCD is an uncommon cause of anterior knee pain but should be considered even when physeal plates are closed. Current available evidence on treatment is of low quality, based on single case reports or small retrospective case series.

Porous Bioactive Prosthesis With Chitosan/Mesoporous Silica Nanoparticles Microspheres Sequentially and Sustainedly Releasing Platelet-Derived Growth Factor-BB and Kartogenin: A New Treatment Strategy for Osteoarticular Lesions

Osteochondral lesions represent a major clinical challenge, especially in the elderly. Traditional treatment strategies, such as arthroplasty or tissue engineering, have limitations and drawbacks. In this study, we presented a new treatment concept for the application of an innovative porous bioactive prosthesis with regenerative activity for the treatment of osteoarticular lesions. For regenerative activity, we fabricated chitosan/mesoporous silica nanoparticles (CS/MSNs) composite microspheres via the microfluidic method as a dual-factor carrier for the sequential release of platelet-derived growth factor BB (PDGF-BB) and kartogenin (KGN). We then integrated the factor carrier and a nondegradable polyetheretherketone (PEEK) scaffold through a surface modification technique to construct the porous sulfonated PEEK (SPK) @polydopamine (polydopamine)-CS/MSNs scaffold. We systematically evaluated the biocompatibility and biofunctionality of the SPK@PDA-CS/MSNs scaffold and implanted the scaffold in an in vivo cartilage defect model in rabbits. These results suggest that the SPK@PDA-CS/MSNs scaffold is biocompatible, promotes cell migration, enhances chondrogenic differentiation of BMSCs in vitro, and promotes cartilage regeneration in vivo. The porous bioactive prosthesis with regenerative activity presented first in this study may comprise a new therapeutic concept for osteoarticular lesions.

Cost-effectiveness analysis of arthroscopic injection of a bioadhesive hydrogel implant in conjunction with microfracture for the treatment of focal chondral defects of the knee - an Australian perspective

AIM

JointRep is a bioadhesive hydrogel arthroscopically injected to facilitate cartilage regeneration. The cost-effectiveness of JointRep with microfracture surgery compared to microfracture alone was evaluated from the Australian healthcare system perspective, in patients with symptomatic focal chondral defects (Outerbridge Grade 3 or 4) of the knee who had failed conservative treatment and were indicated for surgery.

MATERIALS AND METHODS

A de novo Markov model comprising two health states- 'Alive' and 'Dead' was developed. Model transition probability was based on the general population mortality rates. Clinical outcomes were assessed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, a validated patient-reported tool measuring pain, stiffness, and physical function. The utility was derived by mapping WOMAC scores to EQ-5D scores using a published algorithm. Cost inputs were based on published Australian costs from AR-DRGs, Medicare Benefits Schedule, and Prostheses List. Model outcomes included costs, Quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER). Base-case analysis was conducted for a time horizon of 3 years and a cycle length of 1 year. Cost and health outcomes were discounted at 5% per annum. Sensitivity and scenario analyses were also conducted.

RESULTS

Total QALYs were estimated to be higher for JointRep with microfracture surgery (2.61) compared to microfracture surgery alone (1.66), an incremental gain of 0.95 QALY. JointRep with microfracture surgery was associated with an incremental cost of $6,022 compared to microfracture surgery alone, thus leading to an ICER of $6,328. Results were substantially robust to varying parameters in the sensitivity analyses conducted, alternative model settings and assumptions in scenario analyses.

LIMITATIONS

The clinical inputs used in the model were based on data from short duration, non-randomized, post-market clinical trial.

CONCLUSIONS

JointRep with microfracture surgery is a cost-effective treatment option compared to microfracture alone from the Australian health care system perspective.

Effect of Amniotic Membrane/Collagen-Based Scaffolds on the Chondrogenic Differentiation of Adipose-Derived Stem Cells and Cartilage Repair

Objectives: Repairing articular cartilage damage is challenging. Clinically, tissue engineering technology is used to induce stem cell differentiation and proliferation on biological scaffolds to repair defective joints. However, no ideal biological scaffolds have been identified. This study investigated the effects of amniotic membrane/collagen scaffolds on the differentiation of adipose-derived stem cells (ADSCs) and articular cartilage repair.

Methods: Adipose tissue of New Zealand rabbits was excised, and ADSCs were isolated and induced for differentiation. An articular cartilage defect model was constructed to identify the effect of amniotic membrane/collagen scaffolds on cartilage repair. Cartilage formation was analyzed by imaging and toluene blue staining. Knee joint recovery in rabbits was examined using hematoxylin and eosin, toluidine, safranine, and immunohistochemistry at 12 weeks post-operation. Gene expression was examined using ELISA, RT-PCR, Western blotting, and immunofluorescence.

Results: The adipose tissue was effectively differentiated into ADSCs, which further differentiated into chondrogenic, osteogenic, and lipogenic lineages after 3 weeks’ culture in vitro. Compared with platelet-rich plasmon (PRP) scaffolds, the amniotic membrane scaffolds better promoted the growth and differentiation of ADSCs. Additionally, scaffolds containing the PRP and amniotic membrane efficiently enhanced the osteogenic differentiation of ADSCs. The levels of COL1A1, COL2A1, COL10A1, SOX9, and ACAN in ADSCs + amniotic membrane + PRP group were significantly higher than the other groups both in vitro and in vivo. The Wakitani scores of the ADSC + amniotic membrane + PRP group were lower than that in ADSC + PRP (4.4 ± 0.44**), ADSC + amniotic membrane (2.63 ± 0.38**), and control groups (6.733 ± 0.21) at week 12 post-operation. Osteogenesis in rabbits of the ADSC + amniotic membrane + PRP group was significantly upregulated when compared with other groups. Amniotic membranes significantly promoted the expression of cartilage regeneration-related factors (SOX6, SOX9, RUNX2, NKX3-2, MEF2C, and GATA4). The ADSC + PRP + amniotic membrane group exhibited the highest levels of TGF-β, PDGF, and FGF while exhibiting the lowest level of IL-1β, IL6, and TNF-α in articular cavity.

Conclusion: Amniotic membrane/collagen combination-based scaffolds promoted the proliferation and cartilage differentiation of ADSCs, and may provide a new treatment paradigm for patients with cartilage injury.

The Assessment of Steroid Injections as a Potential Risk Factor for Osteochondral Lesions in Children with Juvenile Idiopathic Arthritis

OBJECTIVE

Intra-articular corticosteroid injections (IACIs) are frequently used to suppress local inflammation, that is, in children with juvenile idiopathic arthritis (JIA). While systemic high-dosage corticosteroids are known to trigger osteonecrosis and result in osteochondral (OC) lesions, the effect of IACIs on joint cartilage and subchondral bone remains unclear. This study was conceived to analyze the coincidence of IACI and the subsequent manifestation of osteochondral lesions in a large cohort of pediatric JIA patients.

DESIGN

Retrospective data assessment and comparative analysis of skeletally immature JIA patients treated with IACIs between 1993 and 2017.

RESULTS

A total of 280 JIA patients were included in the analysis, the majority were girls (64%). Osteochondral lesions were present in 16 patients (5.7%) at a mean age of 10.7 years (range 4-14 years) and appeared on average after 63-month duration of disease. The majority was present at atypical locations such as the lateral femoral condyle. Multivariable analysis using cox regression showed that steroid injections were a risk factor to develop an OC lesion (hazard ratio [95%CI] for number of steroid injections per year, 8.20 [3.18, 21.16]).

CONCLUSIONS

Pediatric patients with JIA show a relatively high incidence of osteochondritic lesions, which present at an early age and in rather atypical locations and repetitive steroid injection need to be considered an associated risk factor.

Internal Fixation of Lateral Trochlear Groove Osteochondritis Dissecans With Simultaneous Lateral Retinacular Lengthening in Adolescent Athletes

BACKGROUND

The goals of operative treatment for the adolescent athlete with unstable osteochondritis dissecans (OCD) lesion are rigid fixation and prevention of recurrence.

PURPOSE

To evaluate clinical and radiological outcomes of internal fixation of lateral trochlear groove OCD with simultaneous lateral retinacular lengthening.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Adolescent athletes who had undergone internal fixation and simultaneous lateral retinacular lengthening for an unstable OCD lesion of the lateral trochlear groove were retrospectively reviewed. Subjective assessments included the Lysholm score, International Knee Documentation Committee (IKDC) subjective score, Tegner activity scale, and an athletic questionnaire. Functional tests included isokinetic muscle strength, single-leg hop for distance, single-leg vertical jump, and Y-balance. Pre- and postoperative radiographs and magnetic resonance images were reviewed.

RESULTS

The mean ± SD age of the 17 patients included in this study was 15.9 ± 0.9 years; last clinical follow-up duration was 37.7 ± 8.1 months. At the last follow-up, the Lysholm score improved from 68.7 ± 15.3 to 93.4 ± 12.4 and the IKDC subjective score from 60.2 ± 14.7 to 88.7 ± 12.7 (P < .001). The mean Tegner activity scale score was 9.4 ± 0.5 before injury and 8.9 ± 1.2 at the last follow-up (P = .059). The limb symmetry indices of isokinetic muscle strength, single-leg hop for distance, single-leg vertical jump, and Y-balance improved at the last follow-up; the mean limb symmetry index was ≥85% in each functional test. Regarding the athletic questionnaire, 16 (94.1%) patients were satisfied with the surgery. At the last follow-up, 2 patients had higher ability after returning to sports, 11 had the same ability, and 3 had lower ability than the preinjury level. Postoperative magnetic resonance imaging at 12-month follow-up showed that the OCD lesion appeared healed in 7 (41.2%) patients and partially healed in 9 (52.9%).

CONCLUSION

Internal fixation of lateral trochlear groove OCD with simultaneous lateral retinacular lengthening in adolescent athletes achieved satisfactory clinical and radiological outcomes. Therefore, this combined surgical technique could be considered an effective treatment for lateral trochlear groove OCD, with a high rate of return to sport.

Osteochondral Lesions of the Talus: A Review on Talus Osteochondral Injuries, Including Osteochondritis Dissecans

This is a review on talus osteochondritis dissecans and talus osteochondral lesions. A majority of the osteochondral lesions are associated with trauma while the cause of pure osteochondritis dissecans is still much discussed with a possible cause being repetitive microtraumas associated with vascular disturbances causing subchondral bone necrosis and disability. Symptomatic nondisplaced osteochondral lesions can often be treated conservatively in children and adolescents while such treatment is less successful in adults. Surgical treatment is indicated when there is an unstable cartilage fragment. There are a large number of different operative technique options with no number one technique to be recommended. Most techniques have been presented in level II to IV studies with a low number of patients with short follow ups and few randomized comparisons exist. The actual situation in treating osteochondral lesions in the ankle is presented and discussed.

The Modified Hedgehog Technique to Repair Pure Chondral Shear-off Lesions in the Pediatric Knee

OBJECTIVE

The paediatric knee is prone to pure chondral shear-off lesions due to the developing osteochondral unit. Refixation of the chondral fragment is commonly done using metalwork or absorbable biomaterials. Both fixation methods come with biomaterial-related drawbacks. Earlier work on chondral allografts for cartilage repair in adults has shown successful osteochondral integration when the chondral allograft is treated with multiple incisions and then glued to the subchondral bone using fibrin glue. This is commonly referred to as the "hedgehog technique." This study investigates the feasibility of a modification of the hedgehog technique in autologous cartilage to repair shear-off lesions in children.

DESIGN

Three consecutive patients (aged 11, 12, and 14 years) with shear-off chondral fragments of 2, 5, and 8 cm² were treated using this modified hedgehog technique. The calcified side of the chondral fragments were multiply incised and trimmed obliquely for an interlocking fit in the defect site. Fibrin glue and, if indicated sutures, were applied to fix the fragment to the defect. In 1 patient, an anterior cruciate ligament (ACL) repair was also performed. Patients were evaluated clinically and by magnetic resonance imaging (MRI) up to 12 months postoperatively.

RESULTS

Twelve months after surgery, all patients reported no pain and showed complete return to sport and full range of motion. MRI showed no signs of fragment loosening.

CONCLUSIONS

The modified hedgehog technique is a feasible treatment option to repair pure chondral shear-off lesions in the paediatric knee. This was the first time this technique was used in autografting.

Treatment of knee osteochondritis dissecans with autologous tendon transplantation: Clinical and radiological results

BACKGROUND

Defect treatment with tendon autograft in osteochondral lesions has been published in the literature with an experimental study in dogs. To demonstrate that it is possible to treat knee osteochondral lesions with the technique of autologous tendon transplantation.

AIM

To evaluate the clinical and radiological results of patients with knee osteochondral lesions who were treated with autologous tendon transplantation.

METHODS

Twenty patients (22 knees) with osteochondritis dissecans (OCD) lesions involving the knee were treated with autologous tendon transplantation between 2005-2018. All lesions were International Cartilage Repair Society grade IV. All patients were evaluated clinically at final follow-up with knee injury and osteoarthritis outcome score (KOOS); and radiologically with magnetic resonance observation and cartilage repair tissue (MOCART) and Kellgren-Lawrence (KL) classification.

RESULTS

A total of 20 patients (22 knees) with a mean age of 25.5± 6.8 years were included. The average defect size was 4.2 ± 2.1 cm², and the average defect depth was 0.9 ± 0.4 cm. Total KOOS score was preoperatively 29.4 ± 5.5 and was later found to be 81.5 ± 5.9 after an average of 68.7 ± 37.7 mo follow-up. The mean MOCART score was 56.2 ± 10.7. Preoperatively, all of the patients had KL grades of 0–1; during the follow-up period, 80% of the patients showed no radiological progress of osteoarthritis. Patients with less than 4 cm² lesion had statistically significantly better overall KOOS than patients whose more than 4 cm² lesion, particularly in sport and quality of life subscales.

CONCLUSION

The autologous tendon transplantation is a single-step, safe, simple, cost-effective method for the treatment of knee OCD with satisfactory clinical and radiological outcomes, particularly in patients with less than 4 cm² lesion.

Methods of Modification of Mesenchymal Stem Cells and Conditions of Their Culturing for Hyaline Cartilage Tissue Engineering

The use of mesenchymal stromal cells (MSCs) for tissue engineering of hyaline cartilage is a topical area of regenerative medicine that has already entered clinical practice. The key stage of this procedure is to create conditions for chondrogenic differentiation of MSCs, increase the synthesis of hyaline cartilage extracellular matrix proteins by these cells and activate their proliferation. The first such works consisted in the indirect modification of cells, namely, in changing the conditions in which they are located, including microfracturing of the subchondral bone and the use of 3D biodegradable scaffolds. The most effective methods for modifying the cell culture of MSCs are protein and physical, which have already been partially introduced into clinical practice. Genetic methods for modifying MSCs, despite their effectiveness, have significant limitations. Techniques have not yet been developed that allow studying the effectiveness of their application even in limited groups of patients. The use of MSC modification methods allows precise regulation of cell culture proliferation, and in combination with the use of a 3D biodegradable scaffold, it allows obtaining a hyaline-like regenerate in the damaged area. This review is devoted to the consideration and comparison of various methods used to modify the cell culture of MSCs for their use in regenerative medicine of cartilage tissue.

Fresh Osteochondral Allograft Transplantation in Osteochondritis Dissecans in the Knee Joint

Osteochondritis dissecans (OCD) is a chronic and painful joint condition that can occur from childhood through to adult life. Microtrauma, vascular insufficiency, or abnormal endochondral ossification are the most common causes of OCD. Reconstructive techniques for OCD of the knee are typically necessary when either non-operative or reparative/regenerative operative treatments fail, or when the OCD is irreversible. To analyze the clinical outcomes and failure rates of fresh osteochondral allograft transplantation (FOCA) used as a reconstructive strategy in OCD patients, an in-depth search was carried out on the PubMed, Scopus, and Web of Science databases concerning the existing evidence related to the use of FOCA for OCD patients in the knee joint. A total of 646 studies were found through the search and 2 studies were added after a cross-referenced examination of the articles within the bibliography. Six studies with a total of 303 OCD lesions treated with FOCA, with a mean follow-up of 6.3 years, were included. Although a limited number of low-level evidence studies on this topic are available in previous research, satisfactory clinical results and survival rates of the reconstruction are reported. However, to better define the real advantages of FOCA in the healing process of OCD lesions, comparative studies with different techniques are needed.

Acute Arthritis in Children: How to Discern between Septic and Non-Septic Arthritis?

The term septic arthritis refers to an infection of the synovial space. This is an infrequent condition in healthy children, but it should be considered a medical emergency potentially leading to irreversible articular damage. Therefore, prompt diagnosis and antimicrobial treatment play a crucial role in improving the prognosis. Although septic arthritis is the most common cause of acute arthritis, many other diseases may mimic a similar clinical picture, constituting a diagnostic challenge for the clinician who first approaches the patient. Herein we analyze the main features of septic arthritis, offering an overview of the main conditions involved in the differential diagnosis and suggesting a diagnostic workup plan.

Carbon-Based Nanomaterials for Bone and Cartilage Regeneration: A Review

As the main load-bearing structure in the human body, bone and cartilage are susceptible to damage in sports and other activities. The repair and regeneration of bone and articular cartilage have been extensively studied in the past decades. Traditional approaches have been widely applied in clinical practice, but the effect varies from person to person and may cause side effects. With the rapid development of tissue engineering and regenerative medicine, various biomaterials show great potential in the regeneration of bone and cartilage. Carbon-based nanomaterials are solid materials with different structures and properties composed of allotropes of carbon, which are classified into zero-, one-, and two-dimensional ones. This Review systemically summarizes the different types of carbon-based nanomaterials, including zero-dimensional (fullerene, carbon dots, nanodiamonds), one-dimensional (carbon nanotubes), and two-dimensional (graphenic materials) as well as their applications in bone, cartilage, and osteochondral regeneration. Current limitations and future perspectives of carbon-based nanomaterials are also discussed.

Osteochondritis Dissecans of Smaller Joints: The Elbow

This review presents the current understanding of the etiology, pathogenesis, and how to diagnose and treat osteochondritis dissecans (OCD) at the elbow joint followed by an analysis of particular characteristics and outcomes of the treatment. OCD is seen in patients with open growth plates (juvenile OCD [JOCD] and in adults [AOCD] with closed growth plates [adult OCD). The etiology at smaller joints remains as unclear as for the knee. Mechanical factors (throwing activities [capitulum] seem to play an important role. Clinical symptoms are unspecific. Thus, imaging techniques are most important for the diagnosis. In low-grade and stable lesions, treatment involves rest and different degrees of immobilization until healing. When surgery is necessary, the procedure depends on the OCD stage and on the state of the cartilage. With intact cartilage, retrograde procedures are favorable while with damaged cartilage, several techniques are used. Techniques such as drilling and microfracturing produce a reparative cartilage while other techniques reconstruct the defect with osteochondral grafts or cell-based procedures such as chondrocyte implantation. There is a tendency toward better results when reconstructive procedures for both the bone and cartilage are used. In addition, comorbidities at the joint have to be treated. Severe grades of osteoarthritis are rare.

The incidence and risk factors of osteoarthritis following osteochondritis dissecans of the knees: a systematic review and meta-analysis

PURPOSE

The current systematic review and meta-analysis aim to pool together the incidence and risk factors of osteoarthritis following osteochondritis dissecans of the knee.

METHODS

The systematic review was conducted according to PRISMA guidelines. A search was conducted using PubMed and Cochrane Library with the keywords being "knee" and "osteochondritis dissecans" or "osteochondral lesion". All original human studies that reported the incidence or risk factors of osteoarthritis following osteochondritis dissecans of the knee were included.

RESULTS

Nine studies with 496 patients were included. The incidence of osteoarthritis following osteochondritis dissecans is 0.39 (95% CI 0.19-0.59). Patients with a body mass index greater than 25 kg/m² had a significantly increased risk of osteoarthritis. Fragment excision had an increased relative risk of 1.89 (95% CI 1.19-3.01) of osteoarthritis as compared to fragment preservation. Significant heterogeneity was identified when comparing between juvenile and adult osteochondritis dissecans. The size of the lesions moderated the between-study heterogeneity with regards to the incidence of osteoarthritis, with the relative risk of osteoarthritis in lesions bigger than 4 cm² being 2.29 (95% CI 1.24-4.23). No other risk factors, including gender of the patient, location of osteochondritis dissecans, stability of osteochondritis dissecans, and surgical versus non-surgical management were significant risk factors.

CONCLUSION

Significant risk factors for osteoarthritis were increased body mass index and fragment excision. Probable but inconclusive risk factors were the age of the patients and the size of the osteochondritis dissecans. The gender of the patient, location of osteochondritis dissecans, the stability of osteochondritis dissecans, and surgical versus non-surgical management of osteochondritis dissecans when appropriate were not significant risk factors.

Harvest, Transport, and Storage of Fresh Humeral Head Osteochondral Allograft: Step-by-Step Protocol

Articular cartilage defects are not common in the glenohumeral joint and are mostly found in patients after shoulder trauma, in patients with recurrent instability, or in patients who underwent previous surgical treatment. Articular cartilage defects lead to pain and loss of motion, consequently causing shoulder function impairment and reducing quality of life. In young patients, the use of osteochondral allografts for the treatment of humeral head defects may avoid well-known complications of shoulder arthroplasty. The goal of this Technical Note is to describe a step-by-step protocol for the harvesting, transport, and preservation of fresh humeral head osteochondral tissue for use in allograft transplantation.

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

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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.

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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.

Narrative Review - Knee Pain in the Pediatric Athlete

PURPOSE OF REVIEW

This review article seeks to highlight common youth athlete knee conditions due to overuse or trauma and elucidate differences from the adult populations.

RECENT FINDINGS

Overuse conditions presented include apophysitis, osteochondritis dissecans plica syndrome, and discoid meniscus. Traumatic conditions presented include patellar instability, patellar sleeve fracture, and patellofemoral osteochondral fractures. Knee injuries affect a significant proportion of youth athletes. These injuries place athletes at higher risk of chronic pain and potentially osteoarthritis. We have reviewed common overuse and traumatic knee injuries and differentiating factors between the adult population to improve and expedite the diagnosis, treatment, and prognosis for youth athletes with knee injuries.

Treatment of osteochondritis dissecans of the patella in adolescents with nanofractured autologous matrix-induced chondrogenesis (NAMIC): A report of five cases

PURPOSE

Osteochondritis dissecans (OCD) of the patella is a very rare affliction. The aim of this case series is to evaluate the effectiveness of the Nanofractured Autologous Matrix-Induced Chondrogenesis (NAMIC) technique for the treatment of OCD in young adults.

METHODS

Five consecutive patients with patellar osteochondral lesions treated with NAMIC were prospectively studied. There were 4 males and 1 female with a mean age of 15.2 years, ranging from 12 to 18 years. Clinically, they presented pain when going up and down stairs or squatting, effusion, swelling and functional limitation. The International Cartilage Repair Society (ICRS) grade was III in 4 patients and IV in 1 patient. Patients were functionally evaluated with the Lysholm knee score, the Tegner Activity Score (TAS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) and radiologically using the Magnetic resonance Observation of Cartilage Repair Tissue (MOCART) score.

RESULTS

All the scores significantly improved two years after surgery with respect to pre-operative values (Lysholm score from 63.8 ± 3.9 before surgery to 91 ± 3.2 at 2 years; Tegner activity score from 3.6 ± 0.5 to 8.2 ± 0.8 and the KOOS score from 45.2 ± 2.6 to 91.2 ± 2.4). Both the X-rays and the Magnetic Resonance Imaging (MRI) showed good joint regularity with an average MOCART of 80 ± 7.1/100.

CONCLUSIONS

Treatment of juvenile patellar osteochondritis dissecans with the NAMIC technique seems to be a reliable technique in the short term to restore the patella joint surface and obtain good functional results.