Endoscopic Iliopsoas Fractional Lengthening After Total Hip Arthroplasty: Surgical Technique

Abstract

Iliopsoas tendinitis is a potential cause of persistent anterior hip pain after total hip arthroplasty. After infection and aseptic loosening are ruled out, the diagnosis is primarily based on clinical suspicion and radiographic analysis and is confirmed through ultrasound-guided injections. In refractory cases, surgical intervention may be required. We present a step-by-step endoscopic technique for fractional lengthening of the iliopsoas tendon. By addressing the tendon at the musculotendinous junction, this approach minimizes the impact on hip flexion and strength.

Iliopsoas tendinitis is a recognized cause of persistent anterior hip pain after total hip arthroplasty (THA), particularly during activities requiring active or repetitive hip flexion.1, 2, 3 Iliopsoas tendinitis is often multifactorial, and some reports have suggested that this condition may result from impingement or mechanical irritation. Potential risk factors can include acetabular malposition, an oversized acetabular component, prominent acetabular screws through the ilium, excessive femoral retroversion, collared stems, leg length discrepancies greater than 10 mm, and increased overall offset.4, 5, 6, 7, 8

After infection and aseptic loosening are excluded, the diagnosis of iliopsoas tendinitis is primarily based on clinical suspicion and radiographic analysis and is confirmation through ultrasound-guided diagnostic and therapeutic injections.9, 10, 11, 12, 13 Conservative management is typically the first line of treatment, including activity modification, physical therapy, nonsteroidal anti-inflammatory drugs, and peritendinous injections, which are often effective.¹⁴ Surgical intervention is reserved for refractory cases.15, 16, 17, 18

We present a step-by-step guide to an endoscopic technique for iliopsoas fractional lengthening. This approach addresses the tendon at the musculotendinous junction, minimizing the impact on hip flexion strength and preserving hip range of motion.

Surgical Technique

Video 1 provides a detailed description of the endoscopic iliopsoas fractional lengthening technique performed after THA.

Positioning

After informed consent is obtained, the appropriate extremity is identified and marked in the preoperative area. The patient is then transported to the operating room, where general anesthesia is administered. The patient is positioned supine on an operating traction table, ensuring access for fluoroscopy with a clear anterior-posterior view. The surgical limb is prepared using ChloraPrep (Becton Dickinson, Franklin Lakes, NJ) and draped to allow full range of motion. The surgical field is covered with Ioban (3M, Maplewood, MN).

Surgical Approach

Traction is not required for this procedure. In step 1, the operative extremity is placed in slight flexion with 10° to 15° of foot internal rotation. Fluoroscopy is used to mark an anterolateral portal, located 2 cm proximal to the level of the lesser trochanter of the femur. A mid-anterior portal is positioned 3 to 4 cm medial and 1 to 2 cm superior to the anterolateral portal, facilitating triangulation between the arthroscope and surgical instruments (Fig 1).

Fig 1.

Left hip. (A) Portal positioning: anterolateral portal (1) (visualization portal) and mid-anterior portal (2) (working portal) (∗) portal entry. (B) Fluoroscopic visualization with instrument triangulation at level of femoral calcar.

In step 2, under fluoroscopic guidance, a spinal needle is inserted through the anterolateral portals; a 30° scope with a blunt trocar is introduced, aiming to reach the level of the femoral calcar; and the mid-anterior portal is then opened under direct visualization. A fluid pump (Arthrex, Naples, FL) set at 40 mm Hg is used. In step 3, once in the pre-capsular space, a shaver is used to carefully develop a plane between the anterior capsule and the iliopsoas tendon at the hip joint level, ensuring the anterior hip joint capsule remains intact. In step 4, the medial and lateral borders of the iliopsoas tendon are exposed, and any surrounding tissue is released to fully mobilize the tendon (Fig 2).

Fig 2.

Left hip visualization through anterolateral portal. (A) Plane development between anterior capsule and iliopsoas tendon. (B) Adequate identification of iliopsoas tendon borders.

In step 5, by use of a radiofrequency ablation wand, the iliopsoas tendon is incised transversely at the musculotendinous junction, where the tendon is approximately 50% to 60% tendon and 40% to 50% muscle. The muscular portion is left intact to develop fractional lengthening, potentially preserving hip flexion strength (Fig 3).

Fig 3.

Left hip visualization through anterolateral portal. (A) Identification of iliopsoas musculotendinous junction. (B) Iliopsoas tenotomy, preserving muscular portion of iliopsoas.

Postoperative Rehabilitation Protocol

For all patients, we recommend the use of crutches for 2 weeks after surgery and the use of a hip brace to limit extension and flexion to 0° and 90°, respectively. Furthermore, patients are allowed full weight bearing on the operative extremity. Physical therapy is recommended for a minimum of 6 to 8 weeks, and patients are able to start on postoperative day 1 day with a focus on range of motion and flexion strength. Postoperative follow-up appointments are scheduled at the 2-week, 4-month, and annual intervals.

Discussion

Iliopsoas tendinitis after THA can be particularly debilitating, especially when conservative treatments fail.¹⁹ For recalcitrant cases, surgical intervention is necessary, with distal iliopsoas tendon tenotomy traditionally performed in this patient population.20, 21, 22, 23, 24 Several studies have reported favorable outcomes with this approach.25, 26, 27 For instance, in a prospective multicenter study involving 64 endoscopic tenotomies, Guicherd et al.²⁰ observed significant improvements in the Oxford score, with 92% of patients reporting pain relief. However, concerns remain regarding the potential for reduced hip flexion strength and range of motion after distal tenotomy.

Recently, Finsterwald et al.¹⁶ reported on 36 patients who underwent endoscopic iliopsoas tenotomy, showing significant improvements in functional outcomes. However, the study noted a 12% reduction in active hip flexion and a 20% reduction in isometric hip flexion strength at 6-month follow-up, highlighting the associated risks with this technique.

The iliopsoas fractional lengthening technique offers an alternative for addressing recalcitrant iliopsoas tendinitis, aiming to improve on existing techniques. This method has been extensively described in the hip preservation literature, showing minimal to no impact on hip range of motion or flexion strength after surgery.^28,29 By addressing the iliopsoas tendon at the musculotendinous junction, this technique minimizes the reduction in hip flexion strength and range of motion compared with distal tenotomy while preserving the hip capsule integrity, thus reducing the risk of secondary hip instability.

Advantages and disadvantages and technical pearls and pitfalls are outlined in Tables 1 and 2, respectively. In conclusion, the iliopsoas fractional lengthening technique offers a refined surgical option that enhances efficiency while minimizing potential impacts on hip motion.

Table 1.

Advantages and Disadvantages of Endoscopic Iliopsoas Fractional Lengthening After Total Hip Arthroplasty

Advantages

Easy access

Spares anterior capsule

Minimizes potential impact on hip flexion

Minimizes potential impact on hip flexion strength

Disadvantages

Challenging when anatomic variance of iliopsoas tendon is present

Potential impact on hip stability

Table 2.

Pearls and Pitfalls of Endoscopic Iliopsoas Fractional Lengthening After Total Hip Arthroplasty

Pearls

The surgeon should begin by marking the location 2 cm proximal to the lesser trochanter under fluoroscopy.

Slight flexion ensures easier mobilization of the iliopsoas tendon.

An adequate release of the iliopsoas tendon facilitates identification of the muscular-tendon interface.

Pitfalls

Capsular penetration should be avoided because it could impact anterior hip stability.

Careful dissection is required to avoid penetration of the anterior capsule.

Disclosures

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: R.Q.J. receives travel reimbursement from Arthrex, Stryker, and Zimmer Biomet. A.H.K-R. receives travel reimbursement from Arthrex, Stryker, and Zimmer Biomet. B.G.D. reports a consulting or advisory relationship with Arthrex, Medacta, Stryker, and SI-Bone; receives funding grants from Arthrex, Stryker, Smith & Nephew, and Ossur; receives nonfinancial support from Arthrex, DJO Global, Medacta, Stryker, Medwest Associates, Zimmer Biomet, DePuy Synthes, Medtronic, SI-Bone, Trice Medical, Xiros, Intellijoint Surgical, and Electronic Waveform Lab; receives speaking and lecture fees from Arthrex; receives royalties from Arthrex, DJO Global, Medacta, and Orthomerica; receives travel reimbursement from Arthrex and Stryker; has patent 8920497 with royalties paid from Arthrex; has patent 2612625 with royalties paid from Orthomerica and DJO Global; has patent RE47811 with royalties paid from Arthrex; has patent 0338177 with royalties paid from Orthomerica; is a board member of American Hip Institute Research Foundation, AANA Learning Center Committee, Journal of Hip Preservation Surgery, Arthroscopy, American Orthopaedic Society for Sports Medicine Research Committee, and International Society for Hip Arthroscopy Executive Board; is Director of Hip Preservation at St. Alexius Medical Center; and has had ownership interests in the American Hip Institute and affiliates, North Shore Surgical Suites, and Munster Specialty Surgery Center. All other authors (M.E.F., I.A.W., D.H.P.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Supplementary Data

Video 1

The patient is positioned supine on a traction table; however, traction is not required for this technique. The left hip is prepared in a sterile fashion and placed in slight flexion and internal rotation to reduce tension on the iliopsoas muscle. Under fluoroscopic guidance, 2 portals are created: The anterolateral portal, located 2 cm proximal to the lesser trochanter and targeting the femoral calcar, is used for visualization, while the mid-anterior portal, positioned 3 to 4 cm medial and 1 to 2 cm superior to the anterolateral portal, serves as the working portal. Once in the pre-capsular space, a plane is developed between the anterior hip capsule and the iliopsoas tendon. The tendon is then identified and traced proximally to the musculotendinous junction, where it consists of approximately 60% muscle and 40% tendon. The tenotomy is performed at this level.