Abstract
Background:
Ischiofemoral impingement (IFI) syndrome is the narrowing of the space between the lateral aspect of the ischium and the medial aspect of the lesser trochanter. IFI is a frequently unrecognized generator of vague or posterior hip pain that is commonly preceded by trauma or previous hip surgery. IFI can also be a result of atypical pelvic/proximal femur anatomy, adductor/abductor imbalances, or ischial tuberosity enthesopathies. Management typically consists of conservative treatments, including activity modification, anti-inflammatories, physical therapy, and corticosteroid injections. Endoscopic decompression of the ischiofemoral space has been shown to be an effective surgical intervention in treating IFI.
Indications:
Indications for endoscopic ischioplasty and secondary repair of the proximal hamstring origin include symptomatic IFI that has failed extensive conservative treatment measures.
Technique Description:
The width of the ischium is measured. The sciatic nerve is identified and protected. The proximal hamstring origin is exposed, and an arthroscopic burr is used to perform an osteoplasty of the lateral ischium. An endoscopic repair of the proximal hamstring is performed on the decorticated ischial tuberosity.
Results:
Limited clinical studies exist that report outcomes after ischioplasty for IFI. Many studies reporting outcomes after endoscopic treatment of IFI focus on iliopsoas release and lesser trochanter osteoplasty. The endoscopic treatment of IFI has been demonstrated to provide effective results after 2 years of follow-up in appropriately selected patients. Specifically, lesser trochanter osteoplasty has also shown satisfactory outcomes with symptom relief and good functional results in patients with IFI.
Discussion/Conclusion:
Endoscopic ischioplasty in the setting of IFI, while concomitantly performing a secondary repair of the proximal hamstring origin, allows for the enlargement of the ischiofemoral space. This approach spares the need to perform a lesser trochanter osteoplasty, which disrupts the insertion of the iliopsoas.
Patient Consent Disclosure Statement:
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.
This is a visual representation of the abstract.
Video Transcript
In this video, we present the technique of an ischioplasty and secondary proximal hamstring repair for the treatment of ischiofemoral impingement syndrome (IFI).
Background
IFI is a condition characterized by pain produced from a narrowing of the space between the lateral aspect of the ischium and the medial aspect of the lesser trochanter. 6 IFI is a frequently unrecognized generator of vague or posterior hip pain that is often preceded by trauma or previous hip surgery. 6 Alternatively, IFI can be a result of atypical pelvic/proximal femur anatomy, adductor/abductor imbalances, or ischial tuberosity enthesopathies. 6 Management typically consists of extensive conservative treatment, including activity modification, oral anti-inflammatory medications, physical therapy, and corticosteroid injections. 4 Endoscopic decompression of the ischiofemoral space has been shown to be an effective surgical intervention in treating symptomatic IFI recalcitrant to conservative management. 4
The ischiofemoral space is demarcated by the cortices of the lesser trochanter laterally and the ischial tuberosity medially. 8 This space encompasses muscular (quadratus femoris and obturator externus) and nervous structures (sciatic and inferior gluteal nerves). 8 IFI syndrome is frequently a diagnosis of exclusion. The diagnosis is made by correlating radiographic findings with a consistent clinical history and physical examination. Objective quantification of the ischiofemoral space is typically performed on an axial magnetic resonance imaging (MRI) sequence. Objective threshold values in the literature consistent with narrowing of the ischiofemoral space range from <15 to 22 mm2,7,8,9
Indications
Here we present the case of a 49-year-old woman with a chief complaint of long-standing right posterior hip pain that worsened after a slip and fall on ice approximately 1 year ago. She noted associated radiating pain down the posterior aspect of her thigh. Her pain was recalcitrant to extensive conservative management, including activity modification, oral anti-inflammatory medications, and physical therapy. Notably, a diagnostic and therapeutic corticosteroid injection into the ischiofemoral space provided near complete, but temporary, relief of her symptoms. This patient had also undergone a previous lumbar spine, pelvic floor, and urogynecologic evaluation, without identification of inciting pathoanatomy.
Physical examination was notable for her deep posterior hip pain being reproduced with hip extension and adduction with the patient in the lateral decubitus position (positive IFI test). Pain was also reproduced with hip flexion, abduction, and external rotation (FABER) and with hip flexion, adduction, and internal rotation (FADIR) maneuvers.
Radiographs were obtained, which demonstrated no acute osseous abnormalities and minimal degenerative change to the femoroacetabular joint.
An MRI of the pelvis was ordered, demonstrating a constellation of findings consistent with IFI, including narrowing of the ischiofemoral space (19 mm) with interposed muscular edema and proximal hamstring tendinosis.
The measurement of the ischial width on the coronal MRI section was 24.5 mm.
Given the patient's clinical history, physical examination, and radiographic findings consistent with IFI, she was indicated for surgical intervention due to the failure of conservative management to achieve significant relief of pain and improvement in function. Surgical intervention, including an endoscopic ischioplasty with secondary proximal hamstring repair, ischial bursectomy, and sciatic neurolysis, was planned.
Various factors were considered when determining the optimal treatment plan for the patient, including an open versus endoscopic approach and whether to perform an ischial versus femoral-sided decompression. An endoscopic approach was favored due to the reduced surgical morbidity. The decision to conduct an ischioplasty was made based on the presence of proximal hamstring tendinosis and partial-thickness tearing seen on MRI, and the patient's activity level. It was felt that hip flexor weakness resulting from a lesser trochanter osteoplasty and iliopsoas release would have been incompatible with the patient's recreational and occupational demands.
Technique Description
The patient was positioned prone on a radiolucent operating room table with all bony prominences padded. Medial and lateral portals are created in standard fashion within the gluteal fold. The medial portal is made first, and is located approximately 2 cm medial to the lateral border of the ischial tuberosity. The lateral portal is made under direct visualization approximately 4 cm lateral to the border of the ischial tuberosity. After the lateral portal is created, the 70° arthroscope is moved to the lateral portal. Viewing from the lateral portal, the sciatic nerve is identified, and an arthroscopic shaver (CrossBlade Smooth Bite, 3.5 mm; Stryker Corp) is inserted through the medial portal and utilized to debride the ischial bursal tissue and open a space deep to the gluteal muscles. Care should be taken to visualize the posterior femoral cutaneous nerve and avoid inadvertent injury to this structure. Notably, the sciatic nerve may reliably be found ventral and lateral to the ischial tuberosity, beyond a cleft present lateral to the proximal hamstring tendon. Fluoroscopy may be utilized to confirm the location of the arthroscopic instruments within the ischiofemoral space. In the absence of noticeable tearing, the proximal hamstring tendon origin may also be evaluated by tissue ballottement with palpation, utilizing a switching stick.
In this case, the region of the tendon with partial-thickness tearing was identified and exploited to access the ischial tuberosity to perform the planned ischioplasty. A radiofrequency ablation device (SERFAS 90-S 4.0 mm; Stryker Corp) was used to create a longitudinal split within the proximal hamstring tendon. Fluoroscopy is, again, used to confirm the location of the instruments on the lateral aspect of the ischium and perform preresection measurement of the ischial width before the osteoplasty is performed. A direct posteroanterior fluoroscopic image provides an appropriate radiographic trajectory for resection of the lateral ischium. Next, an arthroscopic burr is used to perform the ischioplasty under direct arthroscopic visualization. Intraoperative measurement of ischial width can then be performed after the ischioplasty to confirm adequate decompression.
A secondary repair of the proximal hamstring tendon origin is then performed through the existing tendinous split onto the decorticated ischial tuberosity. An awl is advanced into the ischium before tapping and placement of a 4.75-mm, triple-loaded suture anchor (Stryker Alphavent; Stryker Corp). A second suture anchor is placed in a similar fashion.
Next, a combination of a self-capturing suture passer (Arthrex FastPass Scorpion SL Suture Passer; Arthrex Inc) and a penetrator-retriever (Arthrex Penetrator Suture Retriever; Arthrex Inc) is used to pass like-colored pairs of suture from the most distal suture anchor through the medial and lateral leaflets of the tendon split, respectively, in a simple fashion. The process is then repeated for the more proximal suture anchor. Passes are evenly spaced throughout the length of the tendon split. Careful suture management is paramount. The like-colored pairs of suture from each anchor are then withdrawn together through a cannula sequentially and tied under direct visualization. The final repair construct is seen here.
Here, we would like to highlight some technical pearls of the procedure that may help avoid complications and optimize clinical outcomes. 5 Given the location of the surgery, direct visualization of the sciatic nerve is paramount throughout the case to ensure its safety. Next, a longitudinal split through the proximal hamstring tendon must be made to access the ischium. We recommend that this be performed preferentially in the area of identified partial-thickness tearing to preserve the healthy tendon footprint. Finally, the decortication of the ischial tuberosity as part of the ischioplasty may help promote tendon healing after secondary repair, while concomitantly addressing IFI syndrome.
Results
Rehabilitation protocols are similar to protocols after endoscopic hamstring repair. Phase 1 spans from immediately postoperatively to week 6. Patients are immediately placed in a hinged knee brace at 45° of flexion postoperatively for 6 weeks. During this phase, patients are instructed to use crutches to remain toe-touch weightbearing. Physical therapy typically begins around 4 weeks postoperatively. Phase 2 spans from weeks 6 through 12, where concentric strengthening with progression to eccentric strengthening begins. During this phase, patients are gradually progressed off of crutches and start to weightbear as tolerated. Phase 3 spans from month 3 to 4 and includes the return to light jogging and closed-chain plyometric exercises. During this phase, patients begin sport-specific movements. Patients are allowed to return to sport at 6 months postoperatively, provided they have completed a graduated return-to-sport progression.
Discussion/Conclusion
Investigations regarding the surgical outcomes after endoscopic treatment of IFI are limited and particularly focus on lesser trochanter osteoplasty. To our knowledge, no clinical studies have reported outcomes after ischioplasty for IFI. With regard to the surgical treatment of IFI, Hatem et al 3 performed a retrospective case series consisting of 5 patients and demonstrated that the endoscopic treatment of IFI with a partial resection of the lesser trochanter was effective after 2 years of follow-up. The authors demonstrated a significant improvement in the modified Harris Hip Score (mHHS) and the visual analog scale for pain. 3 They reported a mean return to sport at 4.4 months postoperatively. 3 Aguilera-Bohórquez et al 1 also conducted a retrospective case series demonstrating that endoscopic resection of the lesser trochanter provides symptom relief and significant improvement in mHHS scores in 13 patients (n = 16 hips) with IFI. Ischiofemoral space measurements within their cohort ranged from 6.4 mm to 22.4 mm preoperatively. Postoperatively, the ischiofemoral space was widened to a measure of >17 mm in 15 of the 16 included hips.
Footnotes
Submitted January 13, 2025; accepted August 14, 2025.
One or more of the authors has declared the following potential conflict of interest or source of funding: S.J.N. has received financial support for prior consultation from Stryker and SI-BONE; T.E.M. has received educational support from Fortis Surgical. AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.
