Endoscopic Iliopsoas Tendon Lengthening and Iliac Fossa Debridement After Total Hip Arthroplasty: A Surgical Technique

Video Transcript

Background

Iliopsoas tendinopathy is a common source of hip pain after total hip arthroplasty (THA), with an overall incidence ranging^1,5,7 from 2% to 6%. This often occurs secondary to malposition of the acetabular component, resulting in anterior overhang and tendon impingement. ⁶ However, in certain instances, patients may experience symptoms despite the presence of appropriately positioned implants. Ultrasound-guided injection targeting the iliopsoas tendon can be a valuable diagnostic and potentially therapeutic tool for confirming the source of the patient's symptoms.^2,10 Surgical indications include persistent anterior-based groin pain secondary to iliopsoas impingement that has been refractory to nonoperative treatment modalities, including physical therapy and ultrasound-guided injections. ⁴ Surgical treatment options include arthroscopic or open iliopsoas tendon release or lengthening.

We present a case of a 42-year-old male, a previous high-level dancer who underwent a THA for end-stage osteoarthritis 18 months prior. He experienced complete resolution of his arthritic pain, but experienced persistent and worsening anterior-based hip flexor tendon pain that was refractory to a 3-month course of physical therapy. Specifically, he had pain and difficulty going up stairs and getting into his car. On physical examination, he had pain with resisted straight-leg raise and resisted hip flexion with tenderness to palpation along the iliopsoas tendon and negative flexion–adduction–internal rotation and flexion–abduction–external rotation testing. He then underwent an ultrasound-guided corticosteroid injection into the iliopsoas tendon, which provided 2 weeks of symptom relief. Imaging with a computed tomography scan was performed, demonstrating appropriately positioned acetabular implants without evidence of anterior overhang. There was evidence of anterior osteophyte formation just superior to the acetabulum within the iliac fossa. Standard workup for a painful THA includes bloodwork with a complete blood count and C-reactive protein to rule out infection and a bone scan to assess for component loosening, which was ruled out in this case. The following anatomic depiction demonstrates the course of the iliopsoas tendon as it traverses the iliac fossa.

Given that a prolonged course of nonoperative treatment modalities failed in our patient and osteophyte formation was present in the iliac fossa, the shared decision was made to proceed with arthroscopic iliopsoas tendon lengthening and iliac fossa osteophyte debridement.

Technique Description

The patient is positioned supine on a hip distraction table. Given the previous THA, no traction is placed, and an outside-in approach is used for access. An anterolateral portal is created just proximal and anterior to the greater trochanter and localized under fluoroscopy just superficial to the femoral head implant. The 70° arthroscope is then inserted to confirm extracapsular placement, and the mid-anterior portal is established under direct arthroscopic visualization. Exposure begins by utilizing the radiofrequency ablator to carefully feel for the acetabular rim and slowly and methodically create a dissection plane, peeling the soft tissues off the acetabulum. Identification of the iliopsoas begins with locating the acetabular rim above the implant, after which anatomic landmarks and fluoroscopy allow differentiation of the iliopsoas medially at the 3 o'clock position from the rectus laterally at the 12 o'clock position. The iliopsoas tendon was then identified, demonstrating significant tendinopathy within the tendon with associated pericapsular and bursal inflammation. As such, a careful and systematic debridement of the tendinopathic portion of the iliopsoas was performed using an arthroscopic shaver and radiofrequency ablation, ensuring the removal of all diseased tendon tissue systematically. We then turned our attention to the iliac fossa and carefully exposed this space to fully visualize osteophyte formation, which remained prominent relative to the iliopsoas tendon. Specifically, we used a radiofrequency ablator to identify and carefully peel away any adhesive tissue beneath the iliopsoas tendon, fully exposing the osteophyte in this region. Intraoperative fluoroscopy demonstrates the location of the osteophyte within the iliac fossa. We elected to perform a careful debridement and osteoplasty of this region. We used an arthroscopic bur to carefully and systematically remove osteophytes in the iliac fossa until there was no longer any evidence of bony impingement on the iliopsoas tendon in this region. We then confirmed that we were satisfied with our osteoplasty, with no remaining prominence in relation to the iliopsoas tendon. At this point, the remainder of the tendon was still under significant tension; thus, a fractional lengthening was performed at the myotendinous junction to restore appropriate tension on the tendon. We ensured that we incised only the tendinous portion and preserved as much muscle as possible to minimize postoperative weakness. Care is taken to avoid a complete tenotomy while ensuring satisfactory lengthening is performed.

Pearls and key steps of this procedure include appropriately identifying the extracapsular space, which can be done under fluoroscopy by localizing just superficial to the femoral head implant and turning the inflow on immediately once the arthroscope is inserted to create a potential space. Visualization is optimized by placing the arthroscope in the mid-anterior portal, which allows for a clear view of the iliopsoas tendon. Finally, ensuring systematic debridement of all tendinotic tendon tissue to its proximal extent within the iliac fossa is critical to fully address this pathology in its entirety.

Results

Postoperatively, the patient will be weightbearing as tolerated on the operative extremity. They will begin working on gluteal strengthening and hamstring, quadriceps, and piriformis stretching exercises, while avoiding hip flexor stretching exercises. This is because iliopsoas lengthening deliberately increases tendon length, and early hip flexor stretching risks overlengthening the healing tendon leading to potential weakness and pain. They will begin working on isometric strengthening exercises at the 6-week mark and active hip flexor stretching exercises at that point as well. They will begin working on hip flexor strengthening at the 12-week mark with gradual light sport-specific movements beginning at the 16-week mark, with progression to more advanced and explosive movements thereafter. Potential complications include injury to neurovascular structures, neuropraxias of femoral or sciatic nerves, infection, and flexor tendon weakness.

Discussion

Several clinical studies have reported outcomes after endoscopic iliopsoas tendon lengthening after THA. The first study on 17 patients, with a minimum 2-year follow-up, demonstrated significant improvements in PROs, with 82% of patients achieving the minimal clinically important difference for the modified Harris Hip Score, 92% for the International Hip Outcome Tool 12 score, and 94% for the visual analog scale score. ⁸ Another study demonstrated similar improvements in PROs and a 20% reduction in hip flexor strength postoperatively compared with the contralateral side. ³ The same study also demonstrated no correlation between cup overhang and clinical outcomes. ³ Finally, a recently published systematic review comparing operative with nonoperative management demonstrated that nonoperative management failed to provide long-term resolution of symptoms. ⁹ Comparison of the 2 surgical treatment strategies—iliopsoas tenotomy and acetabular component revision—revealed a significantly lower complication rate after tenotomy. ⁹

Compared with iliac fossa lengthening, iliopsoas release at the lesser trochanter has stronger clinical evidence, demonstrating high patient-reported outcome (PRO) improvements and low failure and complication rates, whereas iliac fossa release is theoretically more tendon-sparing but remains controversial with limited outcome data and no proven functional advantage. In our case, lengthening at the iliac fossa was required because the patient's symptoms and mechanical impingement were directly attributable to osteophyte formation at the pelvic brim, making proximal decompression and targeted tendon lengthening the most anatomically and pathophysiologically appropriate approach.