Tension Band Fixation for Displaced Transverse Patella Fractures Using Cannulated Cancellous Screws Versus Kirschner Wires: A Six-Month Prospective Randomized Controlled Study

Abstract

BACKGROUND: The optimal fixation method for displaced transverse patella fractures remains debated. While Kirschner wire (K-wire) tension band wiring is traditional, cannulated cancellous screws (CCS) may offer superior biomechanical stability and clinical outcomes. This study compared functional and radiological outcomes of these techniques over six months. METHODS: We conducted a prospective, single-center, parallel-group randomized controlled trial following the Consolidated Standards of Reporting Trials (CONSORT) Outcomes 2022 guidelines. Forty patients with displaced transverse patella fractures (Association for the Study of Osteosynthesis (AO)/Orthopaedic Trauma Association (OTA) 34-C1) were randomly allocated to receive tension band wiring with either K-wires (n=20) or 4.0 mm CCS (n=20). The primary outcome was the Bostman score at six months. Secondary outcomes included the Visual Analog Scale (VAS) for pain, range of motion (ROM), radiological union, and complications. RESULTS: At six months, the CCS group demonstrated significantly superior Bostman scores (28.40 ± 2.65 vs 27.50 ± 3.15, p=0.032). The CCS group showed significantly lower VAS scores at all early time points and a better ROM (140° vs. 130°, p=0.015). Hardware-related complications were significantly lower in the CCS group (10% vs 50%, p=0.008), with reduced hardware removal requirements (5% vs. 30%, p=0.047). Return to pre-injury activity was higher in the CCS group (85% vs. 65%, p=0.021). CONCLUSION: At six months, the CCS group achieved statistically higher but clinically marginal functional scores compared to K-wires, while also resulting in significantly less pain and far fewer hardware-related issues. This suggests that CCS fixation provides similar knee function, with added benefits of improved patient comfort, early rehabilitation, and a lower risk of complications.