Endoscopic reconstruction of the anterior cruciate ligament using bone-patellar tendon-bone grafts fixed with bioabsorbable or metal interference screws: a prospective randomized study of the clinical outcome

Abstract

Background: During the past decade, bioabsorbable interference screws have become increasingly popular in endoscopic reconstructions of the anterior cruciate ligament. With these screws, there is no need for a second operation for removal and no complicating factor if later revision surgery is necessary. Several pullout studies have found similar results between metal and bioabsorbable interference screws; however, few studies have investigated the clinical outcome.

Hypothesis: There is no difference in the clinical outcome of bioabsorbable interference screws compared with metal screws.

Study design: Randomized controlled clinical trial; Level of evidence, 1.

Methods: Forty-one patients were randomized for the use of either metal interference screws (20 patients) or bioabsorbable poly-l-lactic acid screws (21 patients). The patients were followed with clinical examinations at 6, 12, and 24 weeks and at 1 and 2 years postoperatively.

Results: Subjective knee function was better in the patients in the metal screw group; they had less pain at rest, a higher Tegner score, a higher Lysholm score, and better subjective knee function at 2 years compared to the bioabsorbable screw group. However, there was no difference in stability between the groups.

Conclusion and clinical relevance: Because of the inferior results in the bioabsorbable screw group in our study, and until larger studies show otherwise, we do not find the advantages of using bioabsorbable screws sufficient to warrant the routine use of poly-L-lactic acid screws in anterior cruciate ligament reconstructions.