Surgical Video Demonstrates Hamstring Autograft Augmentation for Midsubstance Patellar Tendon Rupture Repair

Editor’s note: The following article is a review of a video available via the AAOS Orthopaedic Video Theater (OVT). AAOS Now routinely reviews OVT Plus videos, which are vetted by topic experts and offer CME. For more information, visit aaos.org/OVT.

Patellar tendon ruptures are challenging clinical problems that can result in persistent disability, particularly when they are chronic or when they occur in the presence of total knee arthroplasty (TKA). Although these injuries are relatively uncommon, with an incidence ranging from 0.48 to 1.09 cases per 100,000 person years, the number appears to be increasing.

The injuries are more common in men and in patients in their 30s or 40s. Risk factors include previous knee surgery, tendon degeneration, steroid use, and connective tissue disorders, and injuries typically occur with sudden quadriceps loading of the flexed knee. Physical examination often demonstrates a palpable defect inferior to an often high-riding patella. Usually there is significant extension weakness, often accompanied by extensor lag. Outcomes of primary repair without augmentation are mixed because tissue quality often is poor. Failure rates range from 5 percent in acute tears to 25 percent in patients with chronic tears, with a failure rate of up to 66 percent in patients with TKA.

Multiple techniques to repair and augment the tendon have been described in an effort to improve outcomes. An OVT video from Babatunde Bankole Fariyike, MD; Laith M. Jazrawi, MD, FAAOS; and Dylan Lowe, MD, illustrates a useful technique to enhance a suture anchor–based repair with autologous tissue. The technique combines suture anchors using high-strength suture tape with semitendinosus and gracilis autograft. In the video, Dr. Fariyike briefly discusses patellar tendon ruptures and reviews the history, radiographs, and MRI imaging of a patient with a midsubstance rupture (Fig. 1). The surgical video then narrates the approach, repair, and augmentation in a step-by-step fashion, followed by discussion of postoperative protocol and outcomes. 

Procedure
During the procedure, the surgical team exposes the ruptured tendon and retinaculum, then harvests the gracilis and semitendinosus tendons using an open tendon stripper, leaving the tendons attached to the tibia. They place two suture anchors loaded with high-strength suture tape in the tibial tubercle, then use a Krackow suture technique to reapproximate the patellar tendon remnants. The hamstring tendons are then prepared with a Krackow technique for the free ends. Slits are made on the medial and lateral sides of the quadriceps tendon, and the hamstring tendons are passed through the quadriceps mechanism and brought down to the tubercle (Fig. 2). The patellar tendon sutures are tied with the knee in extension, and the retinaculum is repaired. The hamstring tendons are then anchored to the tibial tubercle with two anchors (Fig. 3), and side-to-side sutures are used to attach the graft to the repaired extensor mechanism and patella. The authors also show use of a collagen scaffold to augment the repair site.

Why consider autologous augmentation?
As previously noted, there is a significant failure rate with primary repair, and even when repair does not result in revision, there is often elongation of any degenerative repaired tissue, resulting in significant knee extension weakness. Augmentation can improve the strength of the repair above sutures alone and can allow for accelerated rehabilitation and early range of motion. One advantage of the authors’ technique is that no drill holes are made in the patella, unlike other techniques that rely on tunnels for suture, tendon, or anchor placement. This technique can avoid additional stress on the bone, which may already be compromised by other surgery, such as placement of a patellar button for TKA. Autologous tissue also reduces cost compared with allograft or synthetic augmentation. Finally, autologous reinforcement of chronic injury or post-TKA repair has a significantly lower failure rate (0 to 5 percent) and fewer complications (e.g., wound infection).

Some disadvantages of this technique include potential knee flexion weakness related to hamstring harvest and expense related to the use of multiple suture anchors. The anchors may also potentially impinge on a tibial component of a total knee. However, many studies show little functional deficit related to hamstring harvest in other procedures, and the relative benefit of avoiding tunnels in the patella may outweigh the cost savings of avoiding anchor use.

In conclusion, the authors demonstrate an interesting technique for enhancing patellar tendon repair. Augmentation has been beneficial in chronic cases, and the avoidance of tunnels in the patella may be of particular interest in post-TKA knees.

Jason L. Koh, MD, MBA, FAAOS, is an orthopaedic surgeon specializing in sports medicine and shoulder surgery. He is the Mark R. Neaman Family Chair of Orthopaedic Surgery and director of the Orthopaedic and Spine Institute at Endeavor Health in Illinois, as well as a clinical professor at the University of Chicago Pritzker School of Medicine. Dr. Koh is chair of the AAOS Communications Committee and a member of the AAOS Now Editorial Board.

Video details

Title: Repair of Midsubstance Patellar Tendon Rupture with Hamstring Autograft Augmentation
Authors: Babatunde Bankole Fariyike, MD; Laith M. Jazrawi, MD, FAAOS; Dylan Lowe, MD
Published: Feb. 27, 2023
Time: 10:18
Tags: Sports Medicine, Tendon Injuries, Autograft

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