Patellar Tendon Rupture with Transosseous Tunnel Repair

Abstract

Background:

Patellar tendon rupture is an injury most often occurring in adults and commonly caused by tensile overload to the extensor mechanism of the knee or direct trauma to the tendon. Early diagnosis and timely surgical repair lead to good functional outcomes and high rates of return to activity.

Indications:

In patients with impaired knee extensor mechanisms, inability to perform a straight leg raise, or evidence of complete tendon rupture on imaging, surgical tendon repair is indicated.

Technical Description:

The surgical technique demonstrated here presents a standard patellar tendon repair with transosseous tunnels of a 32-year-old man. Briefly, dissection was performed down to the retinacular layer, and the patellar tendon stump was identified. Any devitalized soft tissue was removed from the inferior pole of the patella and the proximal tendon stump by a rongeur. Two locking Krackow sutures were placed along the medial and lateral aspect of the patellar tendon. Then, a drill bit was used to create 3 transosseous tunnels in the patella and a nitinol basket was used to pass sutures through each tunnel. The retinacular layer was closed by figure-of-eight stiches, followed by layered closure of the subcutaneous layer, and finally, the skin.

Results:

Early surgical repair of the patellar tendon leads to good functional outcomes and return to sport rates. In a retrospective study of 38 knees, at average of 9.3 years follow-up, 96% of patients reported they were satisfied/very satisfied, with a 100% returning to work. High rates of return to sports have been reported from a retrospective study, with a 94.4% and 83.3% rate of return to sport and rate of return to sport at the same level, respectively.

Discussion:

In this surgical technique video, we review the common presentation, indications of surgical repair, key steps and technique pearls for a case of a ruptured patellar tendon. Furthermore, we review complications and postoperative rehabilitation guidelines, postoperative clinical outcomes, and return-to-sport rates existing in the literature. Finally, we assess key differences between 2 commonly used surgical techniques, knotless suture anchors versus transosseous tunnels, in patellar tendon repair.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

The following is our presentation on our preferred technique for patellar tendon repair with transosseous tunnels.

The authors have no relevant disclosures.

Patellar tendon ruptures most commonly occur in the third and fourth decade in life and are more common in men than women.^2,3,5 The most common mechanism of injury is a jumping mechanism, whereby a tensile overload of the extensor mechanism occurs. Direct trauma to the tendon can also cause a patellar tendon rupture.^2,3,5 Avulsion of the proximal insertion on the patella, with or without bone, is the most common location of injury. However, injuries can also occur as a distal avulsion from the tibial tubercle or as a midsubstance rupture.^2,5 Patients most commonly present with sudden pain, with an associated popping or tearing sensation, as well as a large effusion or hemarthrosis, and a noted inability to actively extend their knee.^3,5

In our case presentation, a 32-year-old man presents with pain of the left knee that occurred 2 weeks ago after landing awkwardly while playing basketball. He states that he heard an audible “pop” at the time of injury and since then he has had an inability to weight bear, with severe pain, located at the inferior aspect of the patella. He finds his knees buckling when he attempts to weight bear and is unable to actively extend his knee. His pain is limiting his normal activities of daily living.

On examination, we noted a moderate effusion of the left knee, tenderness to palpation at the inferior pole of the patella, an inability to actively extend his knee with positive extension lag, a palpable gap at the inferior pole of the patella, and an inability to perform a straight leg raise.^2,3,6

Preoperative radiographs demonstrate clear patella alta, consistent with patella tendon rupture.

Preoperative magnetic resonance imaging, similarly, demonstrates a full-thickness patellar tendon rupture with retraction of the distal stump and noted hemarthrosis.

Surgical indications for patellar tendon rupture include a complete patellar tendon rupture demonstrated on imaging, an impaired knee extensor mechanism, and an inability to perform a straight leg raise.^2,3,6

An approximate 10-centimeter skin incision is made over the central aspect of the patella. Soft-tissue dissection is carried out raising medial and lateral flaps down to the retinacular, at which point, the patellar tendon rupture should be clearly visualized. A traction suture, in this case, was placed through the proximal end of the patellar tendon for ease and mobility. Devitalized tissue is removed from the inferior aspect of the patella, as well as the proximal end of the patellar tendon, to allow for an ideal surface for bone to tendon healing.

At this point, we are now ready to begin our running Krackow sutures. The suture is first entered through the proximal end of the tendon and then run in a running locking configuration, from proximal to distal, followed by running it back distal to proximal, as seen here. Finally, the suture is exited once again through the most proximal aspect of the tendon rupture. Once this is done, it can now be repeated using a second suture, in a very similar configuration, running from proximal to distal, and distal to proximal. It is essential, in order to maintain the strength of the construct, that all excess slack from the suture be removed at the end of each suture passage. Here we can see our end running Krackow suture configuration with both Krackow stitches and 4 suture ends.

At this point, we are now ready to create our bone tunnels. Using a 2-5 drill bit, a central transosseous tunnel is then created through the patella. It is essential not to penetrate with the drill bit through the articular surface, or, alternatively, too superficially through the bone. Once this is done, this step can be repeated creating both lateral and medial transosseous bone tunnels. It is a good idea to use an electro-cautery to mark the soft tissues where the drill bit is exiting, in order to facilitate ease of passage with the Hewson suture passer at the next step.

Now that 3 transosseous bone tunnels have been created in the patella, we can now sequentially pass our sutures through these tunnels. First, through the most medial bone tunnel, the most medial suture end is passed through using a Hewson suture passer. This step is now replicated using 1 of the 2 central suture ends from each Krackow suture through the middle bone tunnel. The most lateral suture end is passed through the lateral bone tunnel. The 2 central suture ends are passed in 2 steps in this case, due to the small bone tunnel, in order to facilitate ease of passage, due to the relatively thick nature of the suture that is being passed. The tendinous repair was performed using a #2 FiberWire suture (Arthrex, Naples, FL). Now that all 4 ends of the suture are passed through the transosseous bone tunnel, we are now able to fully extend the knee, fully reducing the patellar tendon to the inferior aspect of the patella. Sequential knots can now be tied by the treating surgeon. It is recommended that the assistant pull full traction on the other 2 sutures while these are being tied down to help reduce any gap formation. It is essential that there be no slack in the system and that tight knots be tied. Any retinacular tissue that is torn should be closed, followed by a layer closure, and in this case, a monocryl skin closure.

Key steps in this procedure include removing devitalized tissue from the patella and the tendon stump to allow for good bone to tendon healing. All slack must be removed from the running Krackow stiches as they are performed. When tying the final knots, we must ensure that the patellar tendon is fully reduced down to the bone to reduce any gap formation. Finally, very commonly as a part of the patellar tendon rupture, the retinacular tissue will also be torn, and this should be repaired during the final closure.

In terms of postoperative management, many different rehabilitation protocols exist.^3,5,8 In our case, our preferred rehabilitation protocol encourages early emphasis on mobilization and range of motion to present stiffness, including initiation of range of motion at approximately 10 days postoperatively, with a focus on passive extension and active flexion. Patients are allowed to fully weight bear without crutches by approximately 4 to 6 weeks. Immediately, they are protected weight-bearing with crutch support. Patients are given a knee brace locked in extension for 4 to 6 weeks postoperatively during ambulation, with the goal of being brace free by 6 weeks.^3,5,8

Potential complications include knee stiffness, anterior knee pain, hemarthrosis, patellar tendon re-rupture, wound infection, or quadriceps atrophy/loss of full knee extension.^2,3,6,7

Overall, good outcomes are reported after patellar tendon repair in the literature. ¹ In this study, a 94.4% rate in return to sport and an 83.3% rate of returned to sport at the same level was reported after a patellar tendon repair. ⁶

This study reported on the clinical outcomes both early and late after patellar tendon repair. They found that overall, 96% of patients were either satisfied or very satisfied at long-term follow-up, and that all patients were capable of returning to their previous jobs once again, with a rate of return to sport.

Suture anchor repair is a popular alternative to using transosseous bone tunnels. In this biomechanical study, it was found that there was no significant difference in mean load to failure between the 2 repair techniques. ⁴ However, they did notice a repair site gap distance that was significantly different and in favor of the suture anchor technique.

These are the citations that were used in this presentation.

Thank you.