Hybrid Knot and Knotless Suture Anchor Repair for Patellar Tendon Rupture

Abstract

Background:

Patellar tendon ruptures are the third-most common injury involving the knee extensor mechanism. They typically occur in men under 40 years old as a result of eccentric quadriceps contraction while the knee is flexed and the foot is planted.¹ The optimal treatment is surgical repair within 2 weeks of injury to prevent scar formation, degeneration, and loss of tendon excursion.

Indications:

Operative management is generally indicated for patellar tendon ruptures. In this case, a physically active, healthy 24-year-old man presented with acute pain, extensor lag, and patella alta related to a basketball injury. He was diagnosed with acute patellar tendon rupture/extensor mechanism disruption and indicated for surgery.

Technique description:

We describe a technique for primary patellar tendon repair which uses both knot-based and knotless suture anchor fixation. Using a pulley effect, sutures in the inferior patellar anchors are used to reduce and repair the patellar tendon back to its bony origin. Patellar anchor-based tapes and a suprapatellar traction suture are affixed with knotless anchors to the proximal tibia to reinforce the repair. Anchor-based suture limbs are used to repair the medial and lateral retinacula.

Results:

The senior authors’ experience with this technique has been excellent restoration of extensor mechanism function, with rehabilitation permitting early range of motion and no major complications or failures. This patient returned to unassisted activities of daily living between 8 and 12 weeks and had returned to gym workouts and recreational sports at 12 months.

Discussion/conclusion:

Biomechanical studies have demonstrated that compared with transosseous repair, suture anchor repair decreases gap formation and improves ultimate load to failure. Advantages of suture anchor repair include smaller incision, less tissue dissection, shorter operative time, and improved repair biomechanics. Our technique follows a principle of tendon repair using a high number of suture and tape limbs to span the repair. In addition, this technique incorporates a “double row” of suture anchors and spans the primary repair with a suture and tape “internal brace.”

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

We present a technique using both knot-based and knotless suture anchor fixation for repair of patellar tendon ruptures.

These are our disclosures.

This talk will cover a case presentation, imaging and diagnosis; indications and contraindications for surgery, pearls and pitfalls for the surgeon, and a brief literature review.

An otherwise healthy, physically active 24-year-old man presented to the emergency department with an acute left knee injury sustained while rebounding a ball playing basketball. He felt and heard a pop. He felt acute, immediate pain, swelling, and could not bear weight on, or bend his injured knee. On physical examination, left knee swelling with effusion, a high riding patella, pain with attempted flexion, and an extensor lag were noted.

The lateral view radiograph demonstrated patella alta consistent with patellar tendon rupture.

Our patient was diagnosed with an extensor mechanism disruption and indicated for surgical repair using the suture anchor-based technique shown in this video.

The indication for this technique is acute extensor mechanism disruption of the knee.

Contraindications include an active infection, excessive soft tissue compromise, and medical comorbidities with a prohibitive surgical risk.

The patient was positioned supine on a standard surgical table with bony prominences padded, a tourniquet applied high on the thigh, and a small pad under the ipsilateral buttock to control hip external rotation. The operation can be performed under tourniquet or without tourniquet inflation per surgeon preference. An anterior approach to the knee is used via a midline longitudinal incision.

Here, we see complete disruption of the extensor mechanism with full thickness tearing of the patellar tendon adjacent to the inferior pole of the patella. We placed a No. 5 fiber wire through the quadriceps tendon at the superior aspect of the patella as a traction stitch. We debrided tear margins and prepared the inferior aspect of the patella to fresh bleeding bone. Next, we reamed and tapped pilot holes in the inferior pole of the patella for two 4.75-mm SwiveLock (Arthrex; Naples, FL) anchors. These anchors are double loaded with two No. 2 retention sutures, and we load each anchor eyelet with FiberTape or TigerTape (Arthrex) before placement. We passed the limbs of the Fiber and TigerTape proximally to incorporate that tissue. We then passed one limb of each No. 2 core FiberWire (Arthrex) and TigerWire (Arthrex) distally and proximally along the patellar tendon creating a running stitch. This was repeated using both No. 2 retention sutures from the second anchor. Once our repair suture limbs were passed, we tensioned the opposite suture limb from each pair through the anchors, using a pulley effect to appose the tendon margin back to the inferior patella. The suprapatellar No. 5 FiberWire traction stitch was used to assist with reducing the tendon to the patella. With tension held to maintain reduction, we tied our repair sutures pairwise, reserving tails for retinacular repairs. Attention was then turned to the proximal tibia, where medial and lateral holes were reamed and tapped for 4.75 mm SwiveLock anchors. We loaded each anchor with a limb of TigerTape and FiberTape and suprapatellar No. 5 FiberWire to create a box and cross-configuration about our repair. Once both distal anchors were placed, we passively ranged the knee and confirmed that our construct was stable. We used the tails of our retention sutures to repair the retinacular tears in running fashion.

Here are lateral radiographs of our patient at injury, at 3 months, at 6 months, and at 1 year follow-up.

Some pearls for the surgeon: a No. 5 fiber wire placed as a traction stitch over the superior patella assists with reduction of the patella. The suture should pass at the quadriceps tendon insertion to directly contact the superior pole of the patella. Using a 5.5 mm tap for placement of the 4.75 mm anchors in the patella, and tibia can help avoid anchor breakage in dense bone. The use of a double-loaded suture anchor with an added tape through the closed eyelet provides ample suture for tendon and retinacular repair. It is important that slack is removed from the suture prior to proceeding with the next pass for the running repair stitches. We believe this robust construct may help minimize postoperative residual patella alta. This technique easily accommodates an allograft to augment deficient or poor-quality tissue, as can be encountered in revision cases. ⁹

Some potential pitfalls: Incomplete debridement prior to repair may leave poor-quality tissue margins resulting in attenuation or lengthening of the repair while it heals. Failure to sufficiently mobilize the proximal extensor mechanism may limit the surgeon’s ability to correct patella alta. Failing to tension slack from repair sutures increases the risk of creep within the repair and increases risk of development of patella alta and extensor lag after healing. Overtensioning the tapes and/or the suprapatellar suture could result in iatrogenic patella baja and/or limit flexion resulting in a captured stiff knee.

Our postoperative rehabilitation protocol allows immediate weight-bearing as tolerated with crutches and a hinged knee brace locked in extension. Flexion range of motion is progressed to 90° over 4 to 6 weeks, and the brace is unlocked and range of motion is gradually increased as quadriceps, core, and lower extremity motor control return. At 6+ weeks, the brace is weaned and remaining range of motion is progressively increased to full. Beyond 12 weeks, phased strengthening and conditioning continues with the exercise bike, open-chain quadriceps work, progression to running, and eventually return to sport progressions at 24+ weeks postoperatively.

Biomechanical studies have demonstrated that compared to transosseous repair, suture anchor repair decreases gap formation, and improves ultimate load to failure.^2,4,7,8

Good clinical outcomes have been reported for augmentation in patellar tendon repair, including wiring and synthetic tape.^1,5,10 West and colleagues ¹⁰ studied 30 patellar tendon repairs augmented with a No. 5 suprapatella augmentation suture passed through a tibial tunnel and tied back to itself. All patients reached preinjury levels of injury by 6 months and no postoperative complications were reported. Beranger et al ¹ reported 94% return to sports, 83% at the same level, 8 to 18 months following patellar tendon repair augmented with a nonmetallic tibiopatellar suture. Kasten et al ³ reported good intermediate to long-term results with average follow-up of 8 years in 2 cohorts, one with reinforcement with a wire cerclage and the other with a polydioxanone cord.

Here are our references. Thank you for your attention.