Arthroscopic Ischial Tuberoplasty: Treatment of Ischiofemoral Impingement

Abstract

Background:

Ischiofemoral impingement is a rare but increasingly recognized as a source of hip pain. Its etiology is often multifactorial and can be due to congenital, iatrogenic, or extra-articular pathology. Prior literature has described lesser trochanter osteoplasty and iliopsoas release for the treatment of ischiofemoral impingement, but postoperative hip flexor weakness has been noted with this technique. We present a novel technique for the treatment of ischiofemoral impingement, with resection of the ischial tuberosity.

Indications:

Patients with ischiofemoral impingement that remain symptomatic despite nonsurgical management, or patients with persistent gait abnormalities, are considered for surgery.

Technique Description:

In the prone position, direct posterior and posterolateral arthroscopic portals are created in the gluteal fold. The posterior femoral cutaneous and sciatic nerve are identified. Fluoroscopy is used to identify the region of impingement on the ischial tuberosity and the overlying hamstring tendon is elevated off the tuberosity. An arthroscopic burr is used to resect the tuberosity. Fluoroscopy is utilized to confirm adequate resection. This is combined with a dynamic examination under direct arthroscopic visualization with the hip in an extended, adducted, and externally rotated position. To repair the hamstring tendon, 2 double-loaded anchors are placed into the ischium, the sutures of which are used to repair the hamstring tendons using a horizontal mattress configuration. Patients undergo a stepwise postoperative physical therapy protocol, followed by a functional testing profile prior to return to competitive sport.

Results:

Significant improvements in patient-reported outcomes have been reported following treatment of ischiofemoral impingement, with some studies reporting Hip Outcome Score—Activities of Daily Living (HOS-ADL) >90 at 2 years postoperatively. Athletes have been able to return to sport at a mean 5.6 months after surgery. Large studies have yet to report on outcomes compared with nonsurgical or open techniques.

Discussion/Conclusion:

Recent advancements in endoscopic techniques have allowed for adequate visualization and release of ischiofemoral impingement. We present our endoscopic technique of ischial tuberoplasty, which, compared to lesser trochanter osteoplasty and iliopsoas release, may reduce the incidence of postoperative hip flexor weakness.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

The following video describes a technique for an arthroscopic ischial tuberoplasty in the treatment of ischiofemoral impingement. These are our disclosures.

We will begin with a background on ischiofemoral impingement, followed by a case presentation, where we will discuss preoperative planning as well as surgical technique for our ischial tuberoplasty. The video will then conclude with postoperative management guidelines as well as return to sport guidelines, followed by a review of patient outcomes in the literature.

Ischiofemoral impingement is defined as the narrowing of the space between the lateral aspect of the os ischium and lesser trochanter of the femur. Patients commonly present with load dependent buttock pain, however, they may also describe groin and medial thigh pain as well. Patients often describe a snapping, clunking, or locking sensation of the hip joint while taking long strides as well. On physical examination, pain with passive extension, adduction, and external rotation of the hip is the most common test of choice. The long-stride walking test has also been described for ischiofemoral impingement, which consists of pain provoked with the patient taking large steps. Patients often also display compensatory abduction of the impaired leg to increase the distance between the lesser trochanter and the ischium.

The etiology of ischiofemoral impingement is multifactorial, and can be due to congenital, iatrogenic, and extra-articular pathology. Axial T2-weighted MRI imaging is the preferred method do identify ischiofemoral impingement, where <2 cm of space between the lesser trochanter and ischium would be concerning for impingement. Increased signal at the quadratus femoris would also be consistent, but not necessary for the diagnosis. Conservative treatment in the form of physical therapy, activity modification, injections, and oral anti-inflammatories are the initial treatment for ischiofemoral impingement. Operative intervention is considered with the failure of nonsurgical treatment or persistent gait abnormalities. While an endoscopic lesser trochanterplasty is one described technique for operative management of ischiofemoral impingement, it may be limited by a theoretical risk of psoas weakness. Our preferred technique is an ischial tuberoplasty, which may be especially beneficial for patients who have concomitant proximal enthesopathy of the hamstrings or ischial bursitis.

Our patient is a 42-year-old woman a 2-year history of right hip pain in the buttock and groin. She had previously undergone an extensive history of nonsurgical treatment in the form of activity modification, physical therapy, and injections without relief in symptoms. On physical examination, she had limited internal rotation, with provocative pain with extension, adduction, and external rotation of the hip. Axial T2-weighted MRI imaging demonstrated narrowing of the ischiofemoral space, which measured as 9.47 mm.

Following intubation, patients are placed prone on a Wilson frame. Towels and pillows under the feet allow for knee flexion to relax the hamstring tendons and sciatic nerve. Careful attention must be paid to pad all bony prominences. Prior to prepping and draping, preoperative fluoroscopy shots should be obtained to ensure the ischial tuberosity can be visualized. Often, the Wilson frame may need to be adjusted to adequately visualize the tuberosity.

Following establishment of direct posterior and posterolateral working portals in the gluteal fold, 2-cm medial and 2-cm lateral to the ischial tuberosity, an oscillating shaver is used to create a submuscular plane. The posterior femoral cutaneous nerve is then identified, as seen in the center of this picture here. The posterior cutaneous nerve is often seen superficial and distal following establishment of the portals. The sciatic nerve is then identified primarily using blunt dissection with a switching stick. An oscillating shaver is used sparingly to release resistant bands of tissue. The sciatic nerve is often found proximally and laterally, draping 1.2-cm lateral to the ischial tuberosity. In this part of the video, the switching stick is pointing to the underlying sciatic nerve.

Using fluoroscopy, the region of impingement on the tuberosity is identified. The overlying hamstring tendon is then elevated off the tuberosity to fully expose this region. A stitch is then passed through the hamstring tendon to retract it and fully expose the underlying ischial tuberosity. Typically only the biceps femoris tendon needs to be elevated to gain adequate exposure. A 5.5-mm, round, arthroscopic burr is then utilized to resect the ischial tuberosity. The hood of the burr can be utilized to provide additional retraction on the hamstring tendon, as well as to protect the tendon from iatrogenic damage. Fluoroscopic shots are periodically utilized to confirm the depth and location of resection. Approximately 1 to 2 cm of the ischium are resected to adequately decompress this region. A dynamic examination using both fluoroscopy and direct arthroscopic visualization with the hip in an extended, adducted, and externally rotated position can be used to confirm an adequate decompression as well. Final fluoroscopic shots are then used to confirm adequate decompression of the ischiofemoral space.

We now proceed to repairing the elevated hamstring tendon. Two, 4.5 mm, doubled-loaded anchors are placed into the ischium. This is followed by a placement of a cannula for passing the suture through the hamstring tendon. All sutures are shuttled through the tendon using a tissue penetrating device that ensures full-thickness passage along the hamstring tendon, and the sutures are tied in a mattress fashion. All sutures are passed, tensioned, and tied with a knot pusher to secure the tendon to the tuberosity.

The final repair of the hamstring tendon is inspected to ensure that the hamstring footprint is restored. Each arthroscopic knot is inspected for appropriate tension using the switching stick. Finally, the sciatic nerve is once again visualized in its continuity. A switching stick is utilized to ensure that the sciatic nerve is free and mobile, taking care to note that no suture is surrounding or piercing the nerve.

Postoperative rehabilitation begins with toe-touch weight-bearing restrictions, avoiding positions of repair tension and preventing active hamstring motion for 4 to 6 weeks after surgery. Patients are instructed to ambulate with crutches and a knee orthosis. An extension stop is set to 45° on the knee orthosis and gradually brought to full extension over a period of 4 to 6 weeks. Knee flexion can be left open to allow for ease of transition between sitting and standing.

Advancements in hip and knee motion, as well as increased weight bearing and core strengthening, begin at 4 to 6 weeks after surgery. Concentric strengthening is permitted after 8 weeks, and eccentric strengthening may be initiated at 3 months postoperatively. Light jogging, light short sprints, and closed chain plyometrics begin between 3 and 6 months postoperatively. Sport-specific drills and activity begin at 4 to 6 months after surgery. Return to competitive sport is allowed when athletes are able to perform multiplane activities at high velocity without pain or swelling. They must also display less than 10% deficit in comparison to the contralateral side on functional testing profile.

While literature on outcomes is limited to small cohorts using the lesser trochanter resection technique, patients show improved outcomes following arthroscopic decompression for ischiofemoral impingement. In a sample of 16 hips, Aguilera-Bohórquez et al report a 50% improvement in modified Harris hip scores at an average 2 years postoperative. Spencer-Gardener et al report similar outcomes, with 50% of patients rating their hip as near normal and the other 50% of patients rating their hip as normal. In a sample of 7 patients, Wilson and Keene report a full resolution of snapping and buttock pain; 4 of these patients were athletes, and all patients returned to sport at a mean 5.6 months after surgery. While there is a theoretical risk for failure of the hamstring repair required for this technique, this has not been seen in our practice.

Here are the references cited for this video.

We would like to thank you for your time and watching this novel technique video for the treatment of ischiofemoral impingement utilizing an ischial tuberoplasty. Thank you.