Femoral cross-pin breakage and its effects on the results of anterior cruciate ligament reconstruction using a hamstring autograft

Abstract

Purpose: The primary aim was to determine the rate and risk factors of double biodegradable femoral cross-pin breakage after anterior cruciate ligament reconstruction using a hamstring autograft. In addition, we compared clinical outcomes and magnetic resonance imaging (MRI) findings related to grafts for knees with and without a broken cross-pin.

Methods: A retrospective review of 53 knees (53 patients) was performed. Cross-pin breakage was determined by follow-up MRI. Age, sex, weight, height, presence of a posterior transcortical cross-pin breach, time between surgery and follow-up MRI, graft diameter, and cross-pin position (superior or inferior) were included in the analysis. Differences in Lysholm knee scores, International Knee Documentation Committee grades, anterior laxity, and pivot-shift test results were examined in relation to cross-pin breakage. In addition, anterior cruciate ligament graft integrity and osseous graft integration by MRI were assessed and compared between knees with broken cross-pins and knees with intact cross-pins.

Results: A cross-pin was broken in 25 of 53 knees. A cross-pin posterior transcortical breach was the only factor found to be significantly correlated with cross-pin breakage (odds ratio, 6.117; P = .033) by univariate analysis. No significant differences in clinical outcomes were found to be related to cross-pin breakage, but femoral tunnel enlargement was more frequent in knees with breakage than in those without (P = .002).

Conclusions: Breakage of biodegradable cross-pins used for femoral fixation is relatively common but did not affect clinical outcomes. However, femoral tunnel enlargement was found to be greater in knees with a broken cross-pin. The only significant relation found was between a cross-pin posterior transcortical breach and breakage, which suggests that pin breakage is related to a technical error. These findings should be borne in mind when a double biodegradable cross-pin is being considered for femoral fixation.

Level of evidence: Level IV, therapeutic case series.