A Strategy for Repair, Augmentation, and Reconstruction of Knee Extensor Mechanism Disruption: A Retrospective Review

Abstract

Background: The loss of extensor mechanism continuity that occurs with patellar and quadriceps tendon rupture has devastating consequences on patient function. Purpose: To describe a treatment strategy for extensor mechanism disruption and evaluate the outcomes of 3 techniques: primary repair, repair with semitendinosus tendon autograft augmentation, and reconstruction with Achilles tendon allograft. Study Design: Case series; Level of evidence, 4. Methods: The authors reviewed surgeries for extensor mechanism disruption performed by a single surgeon between 1999 and 2019. Patient characteristics, imaging studies, surgical techniques, and outcomes were recorded. Primary ruptures with robust tissue quality were repaired primarily, and first-time ruptures with significant tendinosis or moderate tissue loss were repaired using quadrupled semitendinosus tendon autograft augmentation. Patients with failed previous extensor mechanism repair or reconstruction and poor tissue quality underwent reconstruction with Achilles tendon allograft. The primary outcome was extensor mechanism integrity at a minimum 1-year follow-up, with extensor mechanism lag defined as >5° loss of terminal, active knee extension. Secondary outcomes included postoperative knee range of motion, International Knee Documentation Committee (IKDC) and Tegner activity scores, and the radiographic Caton-Deschamps Index. Results: Included were 22 patellar tendon and 21 quadriceps tendon surgeries (patients: 82.5% male; mean age, 48.1 years; body mass index, 31). Seventeen (39.5%) cases underwent primary tendon repair, 13 (30.2%) had repair using semitendinosus tendon autograft augmentation, and 13 (30.2%) underwent reconstruction using an Achilles tendon allograft. Seventeen (39.5%) cases had at least 1 prior failed extensor mechanism surgery performed at an outside facility. At the last follow-up, 4 (9.3%) cases had an extensor mechanism lag, no cases required additional extensor mechanism surgery, and all cases were able to achieve >90° of knee flexion. Postoperative IKDC scores were significantly improved with all methods of extensor mechanism surgery, and postoperative Tegner activity scores were significantly improved in patients who underwent primary repair and Achilles tendon allograft reconstruction ( P < .05 for all). Conclusion: Primary repair alone, repair using quadrupled semitendinosus tendon autograft augmentation, and reconstruction using Achilles tendon allograft were all effective methods to restore extensor mechanism and knee function with the proper indications. Persistent knee extensor lag was more common in chronic extensor mechanism injuries after failed surgery, although patients still reported significantly improved postoperative functional outcomes.

Satisfactory outcomes of patellar tendon reconstruction using achilles’ tendon allograft with bone block after infected total knee arthroplasty

“…These findings are in accordance with previously reported data presenting the Achilles tendon allograft as an effective treatment for reconstructing ruptured patellar tendon [ 8 , 10 , 25 ]. Barrack et al [ 4 ] reported a summary average of clinical and functional Knee Society Score, which improved from 32 to 128 points, representing a highly significant improvement.…”

Extensor mechanism ruptures

“…Primary repair is indicated for acute complete patellar tendon ruptures with good tissue quality ( 13 ). Transosseous tunnels or suture anchors are the most common methods of fixation.…”

Iliotibial band reconstruction with allograft fasciae latae tissue: Imaging aspects of a novel surgical technique

“…Tendon allografts have an important role in tendon reconstruction in a number of anatomical sites, being able to overcome the obstacles of poor tissue quality and availability of autologous tissue besides avoiding the donor site morbidity associated with autologous grafts [ 27 , 28 ]. They have become increasingly popular for a variety of tendon repairs, especially when there is a deficient, scarred, and retracted tendon, preventing a primary repair [29] , [30] , [31] . Besides, allografts provide a sufficiently long tendon length that allows various methods of fixation and suture [32] .…”