Knee osteochondritis dissecans-treatment technical aspects

Return to Activity After Patellofemoral Osteochondral Fracture: A Comparison of Metallic Screw and Bioabsorbable Fixation

Background

Patellofemoral osteochondral fractures (OCFs) have the potential to hinder patients' function and quality of life. Several fragment fixation techniques have been described, with both metallic screw and bioabsorbable fixation showing favorable functional outcomes. Despite the promising results associated with both fixation methods, no study has directly compared their functional outcomes.

Purpose

To compare the functional and radiographic outcomes between bioabsorbable and metallic screw patellofemoral OCF fixation in an adolescent cohort.

Study Design

Cohort study; Level of evidence, 2.

Methods

A retrospective review was conducted identifying surgically treated pediatric patients (<18 years of age) with OCFs of the patellofemoral joint. Inclusion criteria were treatment with metallic screw or bioabsorbable fixation (bioabsorbable compression screw, suture bridge, or chondral darts), with preoperative radiographs and operative notes available for review. Patient information, injury characteristics, treatments, and outcomes were collected with a specific focus on return-to-activity time and postoperative complications. Univariate analyses were conducted to compare radiographic and functional outcomes between groups.

Results

According to the study criteria, 37 knees in 37 patients (84% male), with a mean age of 14.2 ± 1.8 years, were identified. A total of 24 patients were injured during sports participation, with basketball and football being the most common sports. OCF fixation cohorts consisted of 12 patients treated with metallic screw fixation and 25 with bioabsorbable fixation. No statistically significant differences were appreciated when comparing median time to full activity between the fixation groups (P = .427). However, time to full activity was unequally distributed, with 66.7% of the metallic screw fixation group returning to activity later than the total cohort's median, compared with 42.9% of the bioabsorbable fixation group (P = .04). Two-thirds (8/12) of patients treated with metallic screws required return to the operating room for hardware removal compared with no patient treated with bioabsorbable fixation (P < .001). Two complications occurred with no significant differences appreciated between groups (P = .202). However, both postoperative complications were recorded in the metallic screw fixation group: 1 patient with osteochondral malunion and another with arthrofibrosis.

Conclusion

This study demonstrated that pediatric patellofemoral OCFs had good outcomes with high healing and low complication rates regardless of fixation type. Because of the high rate of secondary hardware removal procedures, metallic screw constructs delayed the return to sports and activity time. Patients treated with bioabsorbable fixation did not require a secondary operation for hardware removal and thus were more likely to recover sooner. Future studies are necessary to assess the potential outcome differences between different types of bioabsorbable fixation methods. Based on these findings, surgeons can consider bioabsorbable fixation as an option for the management of OCF lesions.

Determinants of joint effusion in tarsocrural osteochondrosis of yearling Standardbred horses

Tarsocrural osteochondrosis (OCD) is a developmental orthopedic disease commonly affecting young Standardbreds, with different fragment localization and size. Clinically, it is characterized by variable synovial effusion in the absence of lameness, whose determinants are ill-defined. We hypothesized that localization and physical characteristics of the osteochondral fragments like dimensions, multifragmentation, and instability influence joint effusion and correlate with synovial markers of cartilage degradation and inflammation. Clinical data, synovial fluid and intact osteochondral fragments were collected from 79 Standardbred horses, aged between 12 and 18 months, operated for tarsocrural OCD. The severity of tarsocrural joint effusion was assessed semi-quantitatively. The osteochondral fragment site was defined radiographically at the distal intermediate ridge of the tibia (DIRT), medial malleolus (MM) of the tibia, and/or lateral trochlear ridge (LTR) of the talus. Size, stability, and arthroscopic appearance (unique or multi-fragmented aspect) of the fragments were determined intra-operatively. Synovial concentrations of C-terminal cross-linked telopeptides of type II collagen (CTX-II), leukotriene B4 (LTB4), and prostaglandin E2 (PGE2) were quantified. Tarsocrural synovial effusion was significantly affected by localization and stability of the fragments, with MM-located and unstable fragments being associated with highest joint effusion. Concentrations of CTX-II, LTB4, and PGE2 positively correlated with the severity of synovial effusion. This study underlines characteristics of the osteochondral fragments determining higher synovial effusion in OCD-affected tarsocrural joints and suggests both inflammation and extra-cellular matrix degradation are active processes in OCD pathology.

[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.

Autologous chondrocyte implantation in the knee is effective in skeletally immature patients: a systematic review

PURPOSE

This systematic review evaluated the efficacy and safety of autologous chondrocyte implantation (ACI) for chondral defects of the knee in skeletally immature patients. Current available data from patients reported outcome measures (PROMs) and complications were collected, analyzed, and discussed.

METHODS

This systematic review was conducted according to the PRISMA guidelines. The following databases were accessed in May 2022: PubMed, Google scholar, Embase, and Scopus. All the clinical studies investigating the efficacy of ACI to manage chondral defects of the knee in skeletally immature patients were accessed. Articles treating patients with surgical procedures other than ACI were not eligible, nor were studies with a follow-up shorter than 12 months.

RESULTS

Data from 9 studies (251 procedures) were collected. 32% (80 of 251) of patients were females. The mean length of follow-up was 44.2 ± 29.4 (range, 12-115) months. The mean age of the patients was 16.4 ± 0.7 (range, 15-17) years. The Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Document Committee (IKDC) increased of + 41.9/100 (P = 0.003) and + 33.2/100 (P =  < 0.0001) points, respectively. The Lysholm Knee Score improved of + 20.6/100 (P = 0.02) points. The Visual Analogue Scale (VAS) for pain reduced of - 3.6/10 (P = 0.004) points. The Tegner scale did not show any statistically significant improvement from baseline to follow-up (P = n.s.). The rate of graft hypertrophy was 12.5% (5 of 40 patients), and the rate of failure 5.6% (8 of 142 patients).

CONCLUSION

ACI for chondral defects of the knee is effective to improve PROMs in skeletally immature patients. The safety profile of ACI still remains controversial.

LEVEL OF EVIDENCE

III.