Comparison of Compression Capabilities of Biointegrative Screw Fixation System Versus Titanium Lag Screws in Transverse Patellar Fracture Fixation: A Cadaveric Comparative Study

Abstract

Background: Transverse patellar fractures, accounting for 50–80% of patellar injuries, often require surgical fixation to restore knee function. Traditional methods like modified tension band wiring are effective but associated with hardware irritation and high rates of implant removal. Bio-integrative compression screws made of poly-L-co-D,L-lactic acid (PLDLA), offer a potential solution to mitigate these complications.

Objective: To evaluate the compression capabilities of titanium lag screws, bio-integrative compression screws alone, and bio-integrative screws augmented with a tension band in the fixation of transverse patellar fractures. Methods: Sixteen cadaveric patellae (8 males, 8 females; mean age 62.83 ± 9.06 years) were osteotomized to simulate transverse fractures. Three fixation methods were tested: titanium lag screws (n=11), bio-integrative screws alone (n=16), and bio-integrative screws with a tension band (n=5). A piezoresistive force sensor measured the compression force at the fracture site during fixation. Statistical analysis was performed using independent and paired t-tests, with significance set at p < 0.05.

Results: Titanium lag screws produced a mean compression force of 104.76 ± 31.70 N, significantly higher than bio-integrative screws alone (62.02 ± 19.19 N; p < 0.001). Augmenting bio-integrative screws with a tension band increased the mean compression force to 96.20 ± 18.71 N, which was significantly greater than screws alone (p = 0.035) and not significantly different from titanium lag screws (p = 0.588).

Conclusion: The addition of a tension band to bio-integrative compression screws significantly enhances compression forces at the fracture site, achieving results comparable to traditional titanium lag screws. This bio-integrative fixation system may reduce hardwarerelated complications and the need for implant removal associated with metallic implants in transverse patellar fracture fixation.