Outcome of transtibial AperFix system in anterior cruciate ligament injuries

The anterior cruciate ligament (ACL) is one of the major stabilizing factor of the knee that resist anterior translation, valgus and varus forces. ACL is the most commonly ruptured ligament of the knee. The graft fixation to bone is considered to be the weakest link of the reconstruction. According to the parallel forces to the tibial drill hole and the quality of tibial metaphyseal bone is inferior to femoral bone stock, graft fixation to the tibia is more difficult to secure. AperFix system (Cayenne Medical, Inc., Scottsdale, Arizona, USA) which consists femoral and tibial component that includes bioinert polymer polyetheretherketone (PEEK) is one of the new choice for ACL reconstruction surgery. aim of this study was to assess the clinical outcomes and fixation durability of the AperFix (Cayenne Madical, Inc., Scottsdale, Arizona, USA) system and to determine the effect of patient's age in arthroscopic reconstruction of the anterior cruciate ligament.

Patients with symptomatic anterior cruciate ligament rupture underwent arthroscopic reconstruction. Patients were evaluated in terms of range of motion (ROM) values; Lysholm, Cincinati and Tegner activity scales; laxity testing and complications. Femoral tunnel widening was assessed by computer tomography scans. Early postoperative and last followup radiographs were compared.

Fifty one patients were evaluated with mean followup of 29 months (range 25-34 months). Mean age at the surgery was 26.5 ± 7.2 years. Lysholm, Cincinati and Tegner activity scales were significantly higher from preoperative scores (Lysholm scores: Preoperative: 51.4 ± 17.2, postoperative: 88.6 ± 7.7 [P < 0.001]; Tegner activity scores: Preoperative 3.3 ± 1.38, postoperative: 5.3 ± 1.6 [P < 0.001]; Cincinati scores: Preoperative: 44.3 ± 17, postoperative: 81.3 ± 13.9 [P < 0.001]). The mean femoral tunnel diameter increased significantly from 9.94 ± 0.79 mm postoperatively to 10.79 ± 0.95 mm (P < 0.05). The mean ROM deficit (involved vs. contra knee) was -7.2 ± 16 (P < 0.001). There was no significant difference for knee score, ROM deficits (<30 years: -7.3 ± 15 and >30 years -7.06 ± 19) and femoral tunnel enlargement (<30 years: 0.83 ± 0.52 and >30 years 0.87 ± 0.43) of the patients with below and above 30 year. There was no significant difference for knee scores and femoral tunnel enlargement between patients with meniscal injuries and don't have meniscus lesions.

The AperFix system gives satisfactory clinical and radiological results with low complication rate. However, long term clinical and radiological results are needed to decide the ideal anterior cruciate ligament reconstruction method.