A modified transosseous quadriceps tendon refixation technique demonstrates advantageous primary stability: A biomechanical investigation.

PURPOSE: Recent biomechanical research suggests suture anchor (SA) refixation may be superior to conventional transosseous longitudinal (TL) repair for quadriceps tendon ruptures. This study aimed to evaluate whether a modified transosseous technique with anteriorly angled drill holes enhances primary stability compared to the aforementioned techniques.

METHODS

Twenty-one human cadaveric patellae were randomly assigned to three groups (n = 7): SA (two SAs), TL (three longitudinal transosseous drill holes) and TA (three anteriorly angled 45° transosseous drill holes). Identical suture material (Ethibond #2) and a four-strand suture configuration were used in all groups. Prior to fixation, computed tomography (CT) scans measured bone mineral density (BMD) and cortical thickness. Biomechanical testing simulated early postoperative loading using a universal testing machine: preload (20 N for 30 s), cyclic loading (500 cycles, 20-100 N at 1 Hz) and a load-to-failure test (20 mm/s). As primary outcome, ultimate load to failure was recorded; secondarily, cyclic elongation and stiffness were measured. One-way analysis of variance (ANOVA) with Bonferroni-corrected post hoc t tests was used for statistical analysis.

RESULTS

The TA group had a significantly higher ultimate load to failure than the TL group (472.7 ± 22.4 vs. 344.8 ± 108.8 N, p < 0.05). No significant differences were found between the SA group (438.9 ± 77.4 N) and the other groups. The TL group showed significantly greater cyclic elongation (6.22 ± 1.03 mm) compared to the SA group (4.42 ± 0.82 mm, p < 0.01). The TA group (5.03 ± 0.73 mm) showed no significant difference compared to either group. Stiffness did not differ significantly (p > 0.05).

CONCLUSION

The modified transosseous technique with anterior drill holes yields higher failure loads and less elongation than the conventional TL method, with biomechanical performance comparable to SA fixation, supporting its use as a viable alternative.

LEVEL OF EVIDENCE: N/A.