Bilateral multipartite patellae avulsions associated with a unilateral quadriceps tendon rupture

Multipartite (or bipartite) patella is a developmental anomaly that occurs in 2%–6% of individuals. In 50%, the variant is bilateral. Multipartite patella is usually an asymptomatic condition. Quadriceps tendon rupture is also a rare entity occurring mostly in men aged >40 years and usually results from an acute eccentric quadriceps contracture. The authors present a case of a patient with bilateral multipartite patellae that sustained bilateral multipartite avulsions as well as an associated unilateral quadriceps tendon rupture. This constellation of injuries has never been reported in the literature. The patient was treated with excision of the multipartite patella fragments and quadriceps tendon repair on the side with the extensor mechanism disruption. He was treated non-operatively for the contralateral lower extremity multipartite patella avulsion. This report, along with a thorough review of the literature, serves to demonstrate the clinical and radiographic characteristics of this unusual injury.

Revision Quadriceps Tendon Repair With Bone-Achilles Allograft Augmentation

Background: Surgical repair of chronic quadriceps tendon ruptures can be daunting, especially after failure of a prior repair. In this setting, tissue quality is usually poor, necessitating graft augmentation. In this video, we describe our technique for Achilles tendon allograft augmentation for revision quadriceps tendon repair. Indications: Failed quadriceps tendon repair defined as ongoing extensor mechanism deficit including patella baja, functional deficit, or palpable quadriceps defect with confirmed retear on advanced imaging. Technique Description: Patient is placed in the supine position, and a midline incision is extended to the tibial tubercle. Full thickness medial and lateral flaps are raised, nonviable scar tissue is excised, and suprapatellar adhesions are released to ensure full mobilization of the viable remnant quadriceps. A plane is then developed deep to the patellar tendon paratenon from proximal to distal. A reamer is used to prepare a socket just medial to the tibial tubercle. The calcaneal bone block of the Achilles allograft is fashioned to match the recipient site on the tibia with a sagittal saw. The graft is shuttled deep to the paratenon, and the bone plug is fixed to the tibia with an interference screw. Suture from the patellar anchors is then used to place 2 running Krackow stitches spanning the remnant quadriceps tendon proximally. The remnant tissue is subsequently reduced and tied with an anchor pull-through technique. The soft tissue component of the Achilles graft is laid over the repair and oversewn with free nonabsorbable suture. Patient is placed in a brace locked in extension for 6 weeks and allowed to be weight bearing as tolerated. Results: Long-term patient-reported outcomes of Achilles allograft reconstruction for revision extensor mechanism repairs are limited. Two studies of 17 reconstructions each reported this to be a reliable and durable option at a mean follow-up of 65 and 52 months, respectively. Discussion/Conclusion: Revision surgery for extensor mechanism deficits can be a challenging procedure. Our preference is to perform augmentation with Achilles allograft with bone plug fixation on the tibial side. This allows for augmentation of the entire extensor mechanism, as well as bone-to-bone healing on the tibial side.

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

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.