Patellar Tendon Debridement and Reconstruction With Hamstring Tendon Autografts in the Setting of Severe Patellar Tendinopathy

Abstract

Background:

Patellar tendinopathy is a multifactorial condition characterized by micro-degenerative changes in the patellar tendon. This results from repeated stress to the knee extensor mechanism from explosive movement, axial malalignment, and/or abnormal patellar height. Currently, there is no standard surgical procedure for the treatment of severe patellar tendinopathy.

Indications:

Patellar tendon reconstructions for patellar tendinopathy may be indicated when >50% of the tendon attachment is degenerative and detached from the distal patella and non-operative treatment, like physical therapy, bracing, and injections, have not relieved symptoms. Debridement may not offer long-term viability against augmentation of the patellar tendon with autografts, with a risk of recurrent breakdown of the patellar tendon attachment with resumption of previous activities that initially lead to overload.

Technique Description:

An anterior incision was made from the superior pole of the patella to the tibial tubercle. Then, dissection was performed medially to harvest the gracilis and semitendinosus tendons. Open harvesters were used, and the hamstring tendons were released proximally, keeping the tibial insertions attached. A horizontal pin was drilled across the tibial tubercle and reamed with a 4.5 mm reamer. A passing stitch was fed through the tunnel. The proximal and distal margins of the patella were localized with spinal needles and a pin was drilled across its midportion, 5 mm deep to the dorsal cortical margin, and then rearmed. Degenerative tissue at the patellar tendon was excised. The gracilis tendon was passed medial to lateral through the tibial tubercle, and a Q-Fix anchor anchored the grafts medially and laterally. The semitendinosus graft was passed medial to lateral through the patella followed by the gracilis tendon lateral to medial. Appropriate reconstruction graft tension was confirmed and grafts were whipstitched together.

Results:

Clinical outcomes for the debridement of severe patellar tendinopathy report 77% symptomatic relief. With many unable to return to activity, patellar tendon reconstruction can be indicated. Outcomes for reconstructions for severe patellar tendinopathy are not reported.

Discussion:

Patellar tendon reconstruction with hamstring autografts for the treatment of severe patellar tendinopathy can provide a strong reconstruction graft to allow for the resumption of high-level activities.

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

This is a video presentation depicting a right patellar tendon debridement with subsequent patellar tendon reconstruction using hamstring autografts in the setting of severe patellar tendinopathy.

Shown here are the authors’ disclosures.

Background

Patellar tendinopathy is caused by microtears in the patellar tendon and leads to pain and overall dysfunction. ⁷ This condition predominates in adolescents, athletes, and males. Patellar tendinopathy occurs from the overuse of the knee extensor mechanism, typically from repeated biomechanical stress through explosive movements. ² Several factors including an excessive Q-angle, increased ligamentous laxity, muscle tightness in the quadriceps and hamstring groups, excessive exertive volume, and increased patellar height increase the prevalence of this pathology. ⁹ Long-term, a poor prognosis may occur without proper treatment and preventative care. ⁷ Conservative treatment should be attempted before surgical intervention and includes load reduction, therapeutic exercise, patellar tendon bracing, and anti-inflammatory injections. ⁸ For severe cases of patellar tendinopathy, either patellar tendon debridement and/or reconstruction may be indicated. Previous literature has reported on reconstructions for acute and chronic patellar tendon tears using this reconstruction technique with successful outcomes.^1,3,6 A 16-year-old otherwise healthy male presented after reporting bilateral knee pain. He reported that the pain had been ongoing for 10 months. There was no reported trauma. The patient appreciates some significant pain localized anteriorly over his bilateral knees. He localizes the pain on the inferior pole of the patella and significant pain in deep flexion. He denies radiating pain, weakness, numbness, or tingling in lower extremities. His pain was provoked by running, jumping, and while performing squats. He has tried a number of nonoperative treatments that have not seen improvement. He has no history of injury or surgery to the affected knee.

Examination of the patient’s right knee revealed tenderness to palpation at the inferior pole of the patella and proximal aspect of the patellar tendon. He had no pain at the tibial tubercle, proximal pole of the patella, joint line, pes anserine bursa pain, or plica. He has a stable ligamentous exam and good range of motion from 4 cm of heel height to 140° of flexion bilaterally. He had discomfort to palpation of the patellar tendon at its attachment on the inferior aspect of the patella remained at 90° of knee flexion.

Radiographs revealed that the patient was in moderate valgus alignment bilaterally. His anteroposterior (AP) and flexion posteroanterior (PA) views did not demonstrate any osseous pathology or joint line narrowing. On the lateral right knee view, there was a non-ossifying fibroma in the proximal aspect of the tibia, but there were no other obvious findings. Patellar sunrise views demonstrate well-preserved patellofemoral joints with no degeneration and no acute osseous pathology.

A magnetic resonance imaging (MRI) demonstrated a full thickness detachment of the central portion of the patellar tendon. The peripheral medial and lateral 20% margins were intact without any significant signs of tendinopathy, but the central 60% of the tendon was grossly pathologic with areas of full-thickness detachment. Otherwise, it was an unremarkable right knee MRI with no medial or lateral meniscus, cruciate, or collateral ligament tears.

The diagnosis was severe patellar tendinopathy with a high-grade partial rupture (greater than 50%) of the right patellar tendon. The patient’s conditions were discussed, and the risks and benefits of surgery were provided. The patient elected to undergo right knee surgery to debride and reconstruct the patellar tendon with hamstring tendon autograft augmentation to resolve anterior knee pain and restore mechanical function.

Technique Description

The patient was induced under general anesthesia without complications. The examination under anesthesia was consistent with our previous clinical exam and thus surgery proceeded.

We performed the anterior knee exposure incision first so that we could identify structures prior to fluid extravasation from the arthroscopy. An anterior incision was made extending from the superior pole of the patella down to just distal to the tibial tubercle. We then dissected down and exposed the extensor mechanism.

We proceeded to dissect medially and identified both the gracilis and semitendinosus tendons. We then proceeded to detach them proximally at the musculotendinous junctions with an open hamstring harvester (Arthrex), leaving them attached to the tibia.

We now outlined the tibial tubercle where we wished to drill the reconstruction tunnel. An anterior cruciate ligament (ACL) guide (Arthrex) was used to drill a beath pin transversely across the tibial tubercle, followed by a 4.5 mm EndoButton reamer (Smith & Nephew). A passing stitch was placed through the tunnel.

We dissected proximally and identified the midportion of the patella. We placed spinal needles at the proximal and distal patellar margins to help us localize them and then made a landing for the Beath pin both medially and laterally at the mid-patella about 5 mm posterior to the anterior cortical edge of the patella, and positioned an ACL drill guide (Arthrex) at these margins. We then drilled a Beath pin across the patella. We then over-reamed this with a 4.5 mm EndoButton reamer (Smith & Nephew) and placed a passing suture.

The gracilis and semitendinosus tendons were whipstitched at their ends to facilitate later graft passage.

A vertical incision was made into the patellar tendon at its attachment to the inferior pole of the patella at the midline. A clear demarcation between the normal tendon and the glistening white degenerative tendon was present. The deeper degenerative tendon was excised until normal tendon margins were obtained. A rongeur was used to decorticate the distal pole of the patella.

We now proceeded with the arthroscopy. Medial and lateral portals were made. The camera was inserted into the joint space.

His suprapatellar pouch had some mild synovitis.

The distal pole of his patella had some mild grade 2 chondromalacia with some pannus-like scar tissue on this, and a patellar chondroplasty was performed. The articular cartilage of his trochlear groove was normal.

His medial compartment and medial meniscus were normal. His medial meniscus root attachment and the ramp attachment areas were also normal. There were no loose bodies posteromedially.

His ACL and posterior cruciate ligament (PCL) were normal. He had a thick ligamentum mucosum, and this was excised.

The articular cartilage of his lateral compartment was normal. His lateral meniscus, including the root attachment, was also normal. His popliteus tendon attachment on the femur was normal.

We now evacuated the fluid from the joint.

We now proceeded to pass the gracilis tendon graft from medial to lateral across the tibial tubercle tunnel. We then placed 2 Q-Fix anchors (Smith & Nephew) at the entry and exit sites of the tibial tubercle tunnel and used these Q-Fix anchors to secure the grafts at these locations. We then tunneled under the far medial and lateral edges of the subcutaneous tissues adjacent to the patellar tendon and passed the grafts up through these soft tissue channels to the patellar tunnel. We then passed the semitendinosus graft from medial to lateral through the patellar tunnel. This was followed by passing the gracilis tendon graft from lateral to medial through the patellar tunnel. We then ensured that the grafts were under appropriate tension and proceeded to tie down the grafts by whipstitching them to each other where they exited the tunnels for about a centimeter distal starting at the edge of the patellar tunnel. The extra portions of the grafts are passed back down under the subcutaneous tissues and further whipstitched back to each other.

We now closed the patellar tendon debridement site with 0 Vicryl sutures (Ethicon Inc.).

We now noted that his patellar tendon was under proper tension, and we could easily flex him past 90° without any increase in tension or laxity on the reconstruction grafts.

The tourniquet was now let down and hemostasis was obtained. The deep tissues were closed with 0 and 2-0 Vicryl followed by a Monocryl (Ethicon, Inc) stitch for the skin.

On postoperative day 1, the patient will start therapy to work on quadriceps activation, edema control, and knee motion. We will limit his flexion to 90° for the first 2 weeks and then he may increase his range of motion as tolerated. He will be nonweightbearing on his right lower extremity for 6 weeks, after which he will begin a weightbearing protocol until he can ambulate without a limp. We will plan to obtain a baseline AP and lateral radiograph of his right knee on postoperative day 1 after physical therapy.

Discussion

When addressing patellar tendinopathy with a patellar tendon reconstruction, there are a handful of pitfalls that should be considered. First, the hamstring autografts can be too short if they are not harvested properly. The hamstring grafts must be routed around the patella and longer grafts can be secured back down onto each other for extra strength. In order to avoid harvesting short hamstring autografts, all adhesions around the tendons should be removed using an elevator. The hamstring harvester should be used forcefully, but carefully, to ensure the harvester follows the tendon rather than amputating the graft. Furthermore, the hamstring autografts should remain attached to the tibia but a portion of them can be peeled off the more medial tibial attachment to gain 1 to 2 cm of length for the graft.

A second pitfall is a failure to properly remove all degenerative tissue from the affected patellar tendon. Failure to remove all degenerative tissue can cause residual inflammation and pain following the procedure. A rongeur and various scalpels can be used to ensure proper excision of the degenerative tissue.

Finally, improper tunnel placement could lead to fracture, especially in the patella, and poorer outcomes. An increase in patellar tunnel diameter can lead to a stress riser which can lead to increased susceptibility to fractures. Perpendicular placement relative to the vertical tibial axis equidistant in the sagittal plane aids in the reduction of jeopardizing the cortical integrity.

Results

A systematic review of 24 studies on surgical outcomes by Khan and Smart ⁴ for long-term patellar tendinopathy investigates differing procedural success. Overall, the success rate for operative measures was 76.6% Return to sport ranged from 15.8% to 92.5% and had a weighted average of 77.1%. For return to sport, proximal tendon bony procedures and arthroscopic surgery performed the best with more rapid return to play.

A more recent study by Lang et al ⁵ investigated the long-term outcomes of 35 patients with chronic symptomatic patellar tendinopathy undergoing patellar release. At follow-up (mean 8.80 ± 2.82 years), 23 patients (76.7%) experienced no pain. Twenty-four (80%) patients returned to sport at their previous level without any pain at mean return to sport time of 4.02 ± 3.18 (range: 0.5-12) months. Positive significant outcomes were observed from all 4 standardized assessment surveys (Victorian Institute of Sport Assessment-Patella [VISA-P], Blazina, Visual Analogue Scale [VAS], and Single Assessment Numeric Evaluation [SANE]) given postoperatively.

Severe cases of patellar tendinopathy may necessitate open debridement, bony excision, and or reconstruction when indicated for optimal postoperative outcomes.

Right knee AP and lateral radiographs were obtained and reviewed in clinic. There was no evidence of acute fractures or soft tissue abnormalities appreciated. All joint spaces were preserved compared to prior imaging. The reconstruction tunnels were well positioned.