Summary

Chronic rupture of the patellar tendon is even rarer since most acute ruptures receive timely treatment. Various techniques for reconstructing chronic ruptures are described in the literature.

Abstract

Introduction

Rupture of the patellar tendon is infrequent in daily practice and is generally associated with trauma, underlying metabolic conditions, or medication use. Chronic rupture is even rarer since most acute ruptures receive timely treatment. Various techniques for reconstructing chronic ruptures are described in the literature; however, the use of hamstring grafts has proven to be the most effective technique for restoring biomechanics and function of the extensor mechanism.

Material And Methods

This report discusses the case of a 27-year-old female patient with a history of morbid obesity and trauma to the left knee from a fall down stairs. The patient presented with pain, edema, and limited knee extension. Simple radiography revealed patellar elevation, with an Insall-Salvatti index of 1.4, and no associated fractures. Magnetic resonance imaging (MRI) showed a complete rupture of the patellar tendon. Surgical repair was recommended, but the patient did not return for follow-up until five months after the initial injury due to a new trauma, which resulted in persistent functional limitation of the extensor mechanism. A subsequent MRI showed fatty infiltration of the patellar tendon consistent with chronic rupture, leading the knee team to recommend patellar tendon reconstruction using a hamstring graft.

Results

Six months after the injury, the surgical procedure was performed using an anteromedial inferior approach, obtaining a free hamstring graft. A direct anterior knee approach revealed total atrophy of the patellar tendon. Horizontal tunnels were then created at the patellar and tibial levels, through which the free grafts were passed using the X-Wave technique. The graft ends were secured with 1/0 braided polyester suture in a spike configuration. Additionally, augmentation was performed around the rupture site with the remaining graft. Postoperatively, immobilization with a Mar del Plata orthosis was maintained for two weeks to control soft tissue, and full weight-bearing with immediate physiotherapy was initiated. Follow-up was conducted at 2, 6, and 12 weeks.

Discussion

Various techniques for reconstructing the patellar tendon in chronic cases have been described. Among the most commonly used are Achilles tendon grafts with a bone block, bone-patellar tendon-bone (contralateral), cadaveric grafts, coronal sutures with wire augmentation, among others. In our setting, cadaveric grafts are not available, so reconstruction was performed with an ipsilateral hamstring graft using the X-Wave technique, which is reproducible, widely accepted in the literature, and yields excellent functional results with minimal sequelae.

Conclusion

Chronic patellar tendon injury is extremely rare, as acute injuries are typically repaired surgically in a timely manner. In certain cases, these injuries become chronic, posing a significant challenge for the treating surgeon, who must evaluate different techniques for reconstruction. Reconstruction with a hamstring graft is the best option for addressing this pathology, offering good functional outcomes in the medium and long term.