An Isolated Transosseous Flexible Suture Frame in the Treatment of Patellar Tendon Rupture Provides Adequate Mechanical Resistance.

INTRODUCTION Acute patellar tendon ruptures are frequently observed in patients with metabolic comorbidities, and the benchmark treatment is surgical repair. It is desirable not to harm an already fragile biologic environment with sutures and hardware. We aimed to compare the mechanical requirements of an isolated, flexible, high-strength nonabsorbable transosseous suture frame with that of the Krackow suture technique. METHODS A total of 12 cadaveric pieces were randomized into two groups: the isolated flexible frame group (n = 6) and the standard Krackow fixation group (n = 6). A traumatic rupture of the patellar tendon was performed, and a transosseous displacement sensor was installed on a validated biomechanical system. Gap formation was measured during 50 cycles of flexion and extension with traction on the quadriceps (250 N). Subsequently, specimens underwent progressive loading in a fixed flexion position until failure occurred. The data were analyzed using nonparametric statistical tools with a significance level of 5%. RESULTS The isolated frame group had a smaller gap formation (1.7 mm) than the Krackow group (3.4 mm; P = 0.01). No significant difference existed in the median failure end points of the two groups (676 and 530 N, respectively; P = 0.11). DISCUSSION Patellar tendon repair using an isolated, transosseous, flexible, suture frame outperformed using the traditional Krakow repair technique in gap formation. Further studies are needed to determine if this will result in better functional outcomes or fewer clinical failures. LEVEL OF EVIDENCE Level IV, experimental case series.