Cartilage Restoration in the Adolescent Knee: a Systematic Review

Reconstruction of Large Osteochondral Lesions in the Knee: Focus on Fixation Techniques

Large (>3 cm²), focal osteochondral lesions (OCL) may result in poor functional outcomes and early secondary osteoarthritis of the knee. The surgical management of these OCL remains challenging. The treatment strategy must be tailored to various aspects, including lesion-specific (e.g., size, location, chronicity), joint-specific (e.g., instability, limb alignment, meniscal status), and patient-specific factors (e.g., age, activity level, comorbidities). Simple chondroplasty and bone marrow stimulation (BMS) techniques should be reserved for smaller lesions, as they only realize midterm clinical benefits, related to inferior wear characteristics of the induced fibrocartilage (type I collagen). Therefore, much attention has been focused on surgical restoration with hyaline cartilage (type II collagen), based on chondrocyte transplantation and matrix-assisted autologous chondrocyte implantation (MACI). Limited graft availability, staged procedures (MACI), and high treatment costs are limitations of these techniques. However, acute traumatic OCL of the femoral condyles and patellofemoral joint may also be suitable for preservation by surgical fixation. Early detection of the fragment facilitates primary repair with internal fixation. The surgical repair of the articular surface may offer promising clinical and cost-effective benefits as a first-line therapy but remains under-investigated and potentially under-utilized. As a unique characteristic, the fixation technique allows the anatomic restoration of the hyaline articular surface with native cartilage and the repair of the subchondral bone. In this manuscript, we present a case series of large OCL around the knee that were preserved by surgical fixation. Furthermore, various implants and techniques reported for this procedure are reviewed.

Osteochondral Allograft Transplantation of the Knee in Adolescent Patients and the Effect of Physeal Closure

PURPOSE

The primary aim was to compare osteochondral allograft (OCA) transplantation outcomes between adolescent patients aged 16 years or younger and those older than 16 years. A secondary aim was to analyze the association between physeal closure status and outcomes.

METHODS

Consecutive patients aged 18 years or younger who underwent OCA transplantation with a minimum 2-year follow-up were identified from a prospectively collected database. Patients were divided into 2 groups: those aged 16 years or younger (group 1) and those aged 17 to 18 years (group 2). Outcomes included patient-reported outcomes (PROs), complications, reoperations, and cartilage revision surgery. Outcomes were compared between groups, and physeal status was analyzed as a prognostic indicator.

RESULTS

A total of 36 patients met the inclusion criteria: 18 in group 1 and 18 in group 2. There were no significant differences between the groups in terms of demographic characteristics, prior surgical procedures, and surgical details, including concomitant procedures. The mean overall follow-up period was 4.6 ± 2.5 years (range, 2-10.3 years), with no significant difference between the groups (P = .21). There were 10 reoperations (28.8%), 4 in group 1 and 6 in group 2 (P = .47). The overall time to reoperation was 2.8 years and did not significantly differ between groups (P = .75). The failure rate was 5.6%, with 1 patient in each group undergoing either graft debridement or revision OCA transplantation. All PROs were significantly improved postoperatively (P < .05), except for the Western Ontario and McMaster Universities Arthritis Index stiffness score (P = .28) and the Short Form 12 mental score (P = .19). There were no significant between-group differences in terms of PROs. Patients with closed physes had a significantly greater increase in most PROs compared with patients with open physes (P < .05).

CONCLUSIONS

OCA transplantation in adolescents results in significant PRO score improvement and a low failure rate, albeit reoperations are not uncommon. Patients with closed physes show greater PRO score improvement than those with open physes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.