Iliopsoas impingement is a common cause of groin pain post-total hip replacement (THR) and has a reported incidence as high as 8.3%.1Iliopsoas impingement causes ill-defined groin pain which is worsened by active hip flexion. Pain exacerbated by activities such as walking up stairs and lifting the leg in and out of a motor vehicle can be helpful diagnostic clues. The most common site of impingement is at the acetabular cup where there is friction with the deep aspect of the iliopsoas tendon. The iliopsoas tendon is positioned immediately anterior to the hip, separated from the capsule only by the iliopsoas bursa. Causes of impingement include bony excrescence, cement extrusion, a Rouviere’s sulcus, inadequate implant anteversion, or projecting studs or screws, excessive size of reinforcement ring, or by an increase in hip offset or hip length ≥1 cm.1 We describe iliopsoas tendon impingement secondary to bony excrescence.

Conservative management of iliopsoas tendon impingement includes ultrasound (US)-guided anesthetic/corticosteroid injections, activity modification and nonsteroidal anti-inflammatory medications are often initially trialed. After conservative management options fail, surgical alternatives such as open or arthroscopic psoas tenotomy and revision hip arthroplasty can reliably improve the patient’s symptoms. Open surgical procedures however carry a higher risk of infection, accrue longer hospital and recovery periods,2 and arthroscopic procedures have increased risk of neurovascular damage. The use of US is gaining traction in orthopedic procedures, with some utilizing its benefits for placement of portal placement in hip arthroscopies.3 We propose US-guided tenotomy and ostectomy for management of ilipsoas impingement post-THR as it provides a less invasive option with reduced hospital stay and recovery time.

TECHNIQUE

The patient was appropriately consented before involvement with ethics provided by Benson’s institutional review board. The procedure was performed on an individual 6 months postuncomplicated total right hip replacement. The patient had complaints of right groin pain exacerbated by activity and had previously trialed an US-guided corticosteroid injection 2 months prior. Dynamic US and computed tomography demonstrated a bony excrescence adjacent to the anterior acetabular cup, impinging upon the iliopsoas tendon (Figs. 1A, B). A fellowship trained musculoskeletal radiologist provided the US guidance and needle positioning, with an orthopedic surgeon performing the tenotomy and osteectomy (Fig. 2A).

The procedure should be performed under sterile conditions in an operating theater. Real time US guidance (Canon Aplio 500 US machine with a curved 10 MHz probe). With the patient supine, the hip was internally rotated, allowing for an anterolateral approach, medialisation of the femoral neurovascular bundle, and tension to the iliopsoas tendon. The US probe is held in the axial plane, at the level of the acetabular cup. A 14-gauge co-axial needle was positioned down into the iliopsoas tendon, traversing between the proximal sartorius and tensor fascia lata. A stiff 1.5 mm diameter guide wire was placed through the bore of the needle and the needle was withdrawn. An Arthrex retractable cannulated knife was then slid over the guide wire, down to the site of iliopsoas tendon (Fig. 2B). The guide wire is removed. The safety latch of the Arthrex retractable cannulated knife is removed, and under visualization the knife is deployed by pushing the movable slide lock forwards. A tenotomy was performed under real time US guidance. The Arthrex retractable cannulated knife was subsequently removed. Of note, if there is difficulty cutting the iliopsoas tendon, further tension can be placed on the tendon to facilitate tenotomy by extending the hip. The needle was then repositioned down to the bony excrescence. The guide wire was passed through the bore of needle and the needle was withdrawn. An Arthrex Retractable Hood Burr slid over the guide wire, down to the site of the bony excrescence (Fig. 2C). The guide wire was removed. An osteectomy was performed under real time US guidance. The Arthrex Retractable Hood Burr was subsequently removed. Local anaesthestic and steroid was infiltrated through the in-situ needle. FIGURE 1:

A, Preoperative sagittal ultrasound image demonstrating the bony excrescence (arrow) impinging upon the iliopsoas tendon (star). B, Preoperative axial computed tomography images demonstrating the bony excrescence (arrow).

FIGURE 2:

A, Intraoperative: Musculoskeletal trained radiologist and orthopedic surgeon performing the tenotomy and osteectomy under real time ultrasound guidance. B, Intraoperative: axial ultrasound image showing the needle tip of the Arthrex Retractable Cannulated Knife (arrow) within the iliopsoas tendon at the site of iliopsoas impingement. C, Intraoperative: axial ultrasound image showing the needle tip of the Arthrex Retractable Hood Burr (arrow) angling toward the bony excrescence (star).

Immediate postprocedural US imaging demonstrated a discontinuous iliopsoas tendon fiber and a smoothed anterior acetabulum in keeping with successful tenotomy and ostectomy, respectively (Fig. 3A). There were no postoperative complications, and the patient was discharged from hospital day 1 postprocedure. The patient was reviewed at 2 weeks and 3 months postprocedure. At 2 weeks, the patient reported being completely pain free with complete resolution of his symptoms. At 3 months, he reported development of right hip discomfort, localizing to the right groin and exacerbated by hip flexion. Follow up computed tomography at 3 months showed denudation of the bony excrescence/spur which was previously seen impinging on the iliopsoas tendon at the level of the superior acetabular cup (Fig. 3B). There was no evidence of complication at the ostectomy site.

FIGURE 3:

A, Postoperative: axial ultrasound image displaying discontinuous iliopsoas tendon fibers (arrows) with an expandable cleft (star) following a successful tenotomy and corticosteroid/local anesthetic infiltration. B, Postoperative: axial computed tomography image demonstrating the smooth acetabulum at the site of the ostectomy (arrow).

EXPECTED OUTCOMES

This technique has shown that US is a successful modality for achieving ostectomy and iliopsoas tenotomy. Multiplanar views and manipulation with ongoing instrument visualization give surgeons proprioceptive feedback in localizing the bony landmark of interest. A percutaneous image guided approach was chosen because of the relatively non-invasive nature, and reduced hospital stay and recovery times. Open and arthroscopic procedures have been reported to have a length of stay up to three nights,4 whereas an US-guided technique will require an overnight stay at most. Both open and arthroscopic procedures incur longer recovery times in comparison to percutaneous procedures, and report variable long-term successful outcomes with one study describing total resolution in 75% of open procedures, and 93% in arthroscopic procedures at 6 months.1 The utility of US allows for less invasive method of accessing the deeper hip structures, real time visualization of neurovascular structures, confirmation of ostectomy and tenotomy postprocedure, and guidance for infiltration of steroid and anesthetic. The utility of doppler mode allows for visualization of neurovascular structures and minimizes their risk of damage. In arthroscopic procedures injury to one or more branches of the lateral femoral cutaneous nerve using the traditional anterior portal has been described, and late bleeding postoperatively attributed to laceration of a branch of the superior gluteal artery has been described.5 Without image guidance it has been reported there is a higher risk of iatrogenic injury to the articular surface, acetabular labrum, or other surrounding structures.3 When compared with fluoroscopic guidance for port access, USs benefits include versatile/handheld equipment, no need for a technologist, nil radiation exposure, and visualization of structures outside of the surgical field.3

COMPLICATIONS

Recurrence of symptoms without bony excrescence is unclear at the 3-month mark, however, has been reported postopen procedure as well.1 The recurrence of symptoms could be explained by the tenotomy site forming a neotendon from granulation and scarring resulting in ongoing impingement. Releasing the tendon from its insertion on the lesser trochanter could be a more effective alternative than cutting it at the myotendinous junction at the hip level. This may provide a better outcome as the degree of retraction would be greater given there are no adjacent supporting muscle fibers and the increased retraction would make it more difficult for the tendon to form scar tissue. This is a procedure that could potentially be performed using the same methodology albeit technically more difficult because of the increased depth of the tendon at this site. We advise in performing this procedure that recurrence of a nondisabling and/or persistent pain should be consented for, and the short-term relief of this procedure weighed against the undertaking of this procedure itself, with an emphasis on quality of life. We expect the degree of, and power in hip flexion to be reduced, but not in a matter that effects daily living as the remaining hip flexor muscles will compensate.

We believe the use of this technique would be technically difficult if the patient is obese, or if there is development of anterior heterotopic ossification. With obese patients, US is limited secondary to the increased depth and reduced sonographic penetration, which will lead to poor visualization of the deeper hip structures. In circumstance where there is anterior heterotopic ossification, we recommend open or arthroscopic techniques as there will be reduced visibility of structures, and technically will be more difficult.

LIMITATIONS

This case was performed in a single institution on one patient, on an operator dependent modality (US). With refinement of technique, the success of this technique could be optimized, however, will require more study. The patient was followed up immediately, at 2 weeks and at 3 months, and the longer-term outcomes are unclear.

CONCLUSION

Iliopsoas tenotomy and ostectomy at the level of the acetabular cup in the treatment of iliopsoas impingement post-THR can be performed under US guidance and may provide short-term relief. Utilizing US may prove to be a potential alternative to open and arthroscopic procedures with refinement of technique. We believe this intermediary technique will require further refinement and study amongst the population of THR patients with iliopsoas impingement, and should be compared with arthroscopic and open procedures. We propose the percutaneous approach may allow for reduced infection risk, neurovascular bundle injuries, and faster recovery time and the potential for better efficacy. Performance of this procedure in a larger population will be able to verify its efficacy.

REFERENCES 1. O’Connell RS, Constantinescu DS, Liechti DJ, et al. A systematic review of arthroscopic versus open tenotomy of iliopsoas tendonitis after total hip replacement. Athroscopy. 2018;34:1332. 2. Di Benedetto P, Niccoli G, Magnanelli S, et al. Arthroscopic treatment of iliopsoas impingement syndrome after hip arthroplasty. Acta Biomed. 2019;90(suppl):104–109. 3. Keough T, Wilson D, Wong I. Ultrasound-guided portal placement for hip arthroscopy. Arthrosc Tech. 2016;5:e851–e856. 4. Yun A, Qutami M, Pasko KB. Surgical management of iliopsoas impingement with combined acetabular revision and partial psoas tenotomy. Cureus. 2021;13:e13193. 5. Simpson J, Sadri H, Villar R. Hip arthroscopy technique and complications. Orthop Traumatol Surg Res. 2010;96(suppl 8):S68–S76.