Bioabsorbable versus metallic interference screws in anterior cruciate ligament reconstruction: a systematic review of overlapping meta-analyses

Purpose: Multiple meta-analyses of randomized controlled trials have been conducted to compare clinical and functional outcomes after anterior cruciate ligament (ACL) reconstruction using metallic interference screw (MIS) versus bioabsorbable interference screw (BIS) fixation, but discrepancies in their findings have prevented a consensus conclusion. The purposes of this study were (1) to conduct a systematic review of meta-analyses comparing MISs and BISs in ACL reconstruction, (2) to provide surgical treatment recommendations for ACL graft fixation based on the highest available evidence, and (3) to propose future research avenues in areas of practice lacking high-level evidence.

Methods: The literature was systematically reviewed to identify meta-analyses comparing MISs and BISs in ACL reconstruction. Data were extracted for clinical and functional outcomes, and methodologic quality was assessed using the validated Quality of Reporting of Meta-analyses and Oxman-Guyatt systems. To determine which meta-analyses provided the current best available evidence, the Jadad decision algorithm was used.

Results: One Level I and 2 Level II meta-analyses were included. None showed differences between BISs and MISs in validated outcome scores, pivot-shift testing, KT arthrometry (MEDmetric, San Diego, CA), or loss of knee motion. Subgroup analyses found no differences in clinical outcomes or knee stability across biomaterials. All meta-analyses were of high quality according to the Quality of Reporting of Meta-analyses and Oxman-Guyatt systems. Two meta-analyses were determined by the Jadad algorithm to represent the current best available evidence. Both studies showed prolonged knee effusion with BIS use, with 1 also showing an increased incidence of femoral tunnel widening and screw breakage with BIS use.

Conclusions: Whereas clinical and functional outcomes are similar with MISs and BISs, prolonged knee effusion, femoral tunnel widening, and screw breakage are more common with BIS use. Future cost-effectiveness analyses may help weigh the known advantages of BISs against their costs and adverse-event profile.

Level of evidence: Level II, systematic review of Level I and II studies.