Anterior cruciate ligament reconstruction using biodegradable transfemoral fixation at 5‐year follow‐up: clinical and magnetic resonance imaging evaluation

AbstractPurposeBiodegradable transfemoral graft fixation devices used in anterior cruciate ligament (ACL) reconstruction have recently been reported to precociously lose structural integrity.MethodsThis study investigated outcomes after ACL reconstruction using hamstring grafts and biodegradable transfemoral fixation at 5‐year follow‐up. The condition of both graft and fixation device was evaluated by magnetic resonance imaging (MRI) and related to clinical outcomes. In total, 85 patients on whom index ACL reconstructive surgery by means of a quadrupled semitendinosus–gracilis graft and biodegradable transfemoral fixation was performed were included in the study.ResultsFifty‐nine patients could be assessed by clinical and MRI examinations at a mean follow‐up of 61 months (range, 52–69 months). Completely intact pins were found in 17 patients (29%), intact pins with delicate areas of resorption in 8 patients (14%), pin deformation in 5 patients (8%), pin fracture in 22 patients (37%) and pin migration in 3 patients (5%). In 40 patients (68%), pins had undergone degradation at the graft suspension point. Hamstring graft integrity and signal intensity scores were found to be significantly higher in patients with deformed, broken or dislocated pins as compared to patients with fully or mainly intact pins. Clinically, the mean side‐to‐side difference in anterior‐posterior‐laxity was 1.1 ± 1.6 mm, while Lysholm, IKDC and Tegner scores were 89 ± 11, 84 ± 14 and 4 (1–9). No statistically significant correlation was found between pin condition and clinical outcomes.ConclusionBiodegradable fixation pins lose structural integrity in a way that suggests continuous loading of the pin/graft construct, thereby questioning osseous incorporation of the graft. This situation is clinically relevant in terms of improved graft condition.Level of evidenceRetrospective case series, Level III.