Achilles Tendon-Bone Allograft is Advantageous for Chronic Patellar Tendon Ruptures Using a Modified Fixation Technique

Objectives: A patellar tendon rupture is an extremely disabling extensor mechanism injury. This follow-up study describes the clinical and radiologic outcomes of a new modified technique for reconstructing chronic patellar tendon ruptures. Materials and Methods: From 2014 to 2018, we reconstructed 15 chronic patellar tendon ruptures using Achilles tendon-bone allograft. Clinical and radiologic outcomes were evaluated preoperatively and during the final follow-up, 2 to 7 years after reconstruction. Assessments involved the International Knee Documentation Committee (IKDC), Lysholm, and Kujala scores, as well as quadriceps muscle strength and extension lag. Radiologic results were evaluated using the Insall-Salvati index on plain radiography and allograft integration through magnetic resonance imaging. Results: At the final follow-up, the Lysholm, IKDC, and Kujala scores improved by 57, 58, and 54 points, respectively (P<0.001). The average quadriceps muscle strength improved from 2.6 (2 to 3) before the operation to 4.6 (4 to 5) at the final follow-up (P<0.001). The extension lag also improved significantly from 31.7 degrees (25 to 40) to 0.6 degrees (0 to 10). The preoperative Insall-Salvati index was 1.6 (1.5 to 1.9), which improved significantly to 1.2 (1 to 1.3) postoperatively (P<0.001). Two years after the operation, magnetic resonance imaging showed good allograft integration in all pateints. Conclusion: Combining an Achilles tendon-bone allograft with a robust fixation method led to favorable clinical and radiologic outcomes. Level of Evidence: Level IV.