A Randomized Controlled Trial of PEEK Versus Titanium Interference Screws for Anterior Cruciate Ligament Reconstruction With 2-Year Follow-up

Abstract

Background: Graft fixation with interference screws for anterior cruciate ligament (ACL) reconstruction is a highly successful technique. Polyether ether ketone (PEEK) is a novel thermoplastic polymer with high biocompatibility and mechanical properties that mimic native bone, and it can be imaged on computed tomography or magnetic resonance imaging (MRI) without signal flare. Purpose: To compare the clinical performance of ACL reconstruction with PEEK and titanium interference screws at 2 years and to evaluate a novel method of measuring tunnel volume. Study Design: Randomized controlled trial; Level of evidence, 1. Methods: A total of 133 patients underwent arthroscopic ACL reconstruction with 4-strand hamstring autografts and were randomized to have titanium or PEEK interference screws for femoral and tibial tunnel fixation. At 2 years, subjective Lysholm and International Knee Documentation Committee scores were assessed and clinical examination performed. At 12 months, MRI was performed to assess graft incorporation and cyst formation, and a novel technique was employed to measure tunnel volumes. Results: There were no significant differences in graft rerupture rate, contralateral ACL rupture rate, subjective outcomes, or objective outcomes. In the titanium and PEEK groups, MRI demonstrated high overall rates of graft integration (96%-100% and 90%-93%, respectively) and ligamentization (89% and 84%) and low rates of synovitis (22% and 10%) and cyst formation (0%-18% and 13%-15%). There was a higher proportion of patients with incomplete graft integration within the femoral tunnel in the PEEK group as compared with the titanium group (10% vs 0%, P = .03); however, the authors suggest that metal artifact precluded proper assessment of the graft in the titanium group by MRI. Tunnel volumes also appeared to be equivalent in the 2 groups and were measured with a novel technique that was highly reproducible in the PEEK group secondary to the absence of flare. Conclusion: Two-year clinical analysis of PEEK interference screws for femoral and tibial fixation of ACL reconstructions showed equivalent clinical performance to titanium interference screws. Given the excellent mechanical characteristics, biological compatibility, and absence of metal artifact on MRI, PEEK has become our material of choice for interference screw fixation in ACL reconstruction.

Hydroxyapatite-incorporation improves bone formation on endosseous PEEK implant in canine tibia

“…5,6 Clinical studies support that load-bearing medical devices made of PEEK offer promising outcomes even better than equivalent of metals or allograft. [7][8][9][10] The integration of implants with the surrounding bone, a process termed osseointegration, is pivotal for long-term clinical success in dental rehabilitation. Although PEEK may overcome some drawbacks of titanium implant, the poor osseointegration is the primary limitation for its application in long-term functional loading.…”

“…5,6 Clinical studies support that load-bearing medical devices made of PEEK offer promising outcomes even better than equivalent of metals or allograft. 7–10…”

Incidence and prognostic factors of knee extension deficits following anterior cruciate ligament reconstruction: A systematic review and meta-analysis of randomised controlled trials

“…The database search strategy combined with citation retrieval returned a total of 8594 non-duplicate records for title screening. A sample of 48 randomised trials 24–71 met the inclusion criteria and were examined (Figure 1). The studies included were published between 1987 and 2019 and were randomised on the time from surgery to extension measurement (recovery trajectory) (6.3%), postoperative management (rehabilitation 12.5%, range of motion restriction 25.0%) and variations in surgical technique (graft type 45.9%, graft placement 2.1% and graft fixation%).…”

“…Maximum extension loss reported within a study group and across any time-point, and overall effect size for LOE for included studies with a non-zero incidence of extension loss 24–29,31–38,40–45,48–54,56,58–60,62–64,68,69,71 .…”

“…The copyright holder for this this version posted November 30, 2020. ; https://doi.org/10.1101/2020.11.26.20239046 doi: medRxiv preprint 14 Figure 3 Maximum extension loss reported within a study group and across any time-point, and overall effect size for LOE for included studies with a non-zero incidence of extension loss [24][25][26][27][28][29][31][32][33][34][35][36][37][38][40][41][42][43][44][45][48][49][50][51][52][53][54]56,[58][59][60][62][63][64]68,69,71 . is the author/funder, who has granted medRxiv a license to display the preprint in (which was not certified by peer review) preprint…”