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

Abstract

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.