Gluteal pain is a frequent cause of medical attention in the daily clinical practice. It can be caused by multiple pathologies, being ischiofemoral impingement syndrome among those included in its differential diagnosis. Encompassed within the deep gluteal syndromes, this entity occurs as a consequence of the entrapment of the neuromuscular structures between the lesser femoral trochanter and the ischial tuberosity, causing pain in the root of the lower limb, with irradiation towards the thigh or the gluteal region and poor tolerance to deambulation and sedestation. The magnetic resonance imaging of the hip is fundamental for its diagnosis, and its management consists on medical treatment at onset. Despite not being a frequent diagnosis in the clinical practice in Rheumatology, keeping it in mind helps improving its prognosis by establishing an early and adequate treatment.

We report on the case of a 52-year-old female who presented with a stress fracture after undergoing an endoscopic resection of the lesser trochanter in ischiofemoral impingement, which was resistant to maximal conservative treatment. To the best of our knowledge, this complication has not been previously described. Non-weight-bearing and intravenous alendronic acid were prescribed for management. No additional surgery was required. The patient was pain free with the ability to perform sports on the same level as before and had no complaints.

Dental professionals are exposed to significant unavoidable physical stress, and theoretical ergonomic recommendations for a sitting workplace are inapplicable in many dental activities. Work-related musculoskeletal disorders (WMSDs) represent a serious health problem among dental professionals (prevalence: 64-93%), showing involvement of 34-60% for the low back and 15-25% for the hips. Muscle stress; prolonged sitting; forward bending and twisting of the torso and head; unbalanced working postures with asymmetrical weight on the hips and uneven shoulders; and others are inevitable for dental professionals. Therefore, the approach for the prevention and treatment of WMSDs must be therapeutic and compensatory. This project was conceived to provide a Yoga protocol for dental professionals to prevent or treat WMSDs from a preventive medicine perspective, and it would represent a Yoga-based guideline for the self-cure and prevention of musculoskeletal problems.
METHODS: Specific Yoga positions (āsana, such as Virāsana, Virabhadrāsana, Garudāsana, Utkatāsana, Trikonāsana, Anuvittāsana, Chakrāsana, Uttanāsana, Pashimottanāsana) have been selected, elaborated on and adapted to be practiced in a dental office using a dental stool or the dental office walls or a dental unit chair. The protocol is specifically devised for dental professionals (dentists, dental hygienists and dental assistants) and targeted for the low back, hips and legs (including knees and ankles). The protocol includes Visranta Karaka Sthiti (supported positions) in sitting (Upavistha Sthiti) and standing (Utthistha Sthiti) positions, twisting/torsions (Parivrtta), flexions/forward bend positions (Pashima) and extensions/arching (Purva) for musculo-articular system decompression and mobilization.
RESULTS: Over 60 Yogāsana-specifically ideated for back detensioning and mobilization, lumbar lordosis restoration, trunk side elongation, hip release and leg stretches and decontraction-are shown and described. The paper provides a meticulous description for each position, including the detailed movement, recommendations and mistakes to avoid, and the breathing pattern (breath control) in all the breath-driven movements (āsana in vinyāsa). An exhaustive analysis of posture-related disorders affecting the lower body among dental professionals is reported, including low-back pain, hip pain and disorders, piriformis syndrome and quadratus femoris dysfunction (gluteal pain), iliopsoas syndrome, multifidus disorders, femoroacetabular and ischiofemoral impingement, spinopelvic mobility, lumbopelvic rhythm, impairment syndromes, lower crossed syndrome, leg pain, knee pain and ankle disorders.
CONCLUSIONS: A detailed guideline of āsana for low-back decompression, hip joint destress, piriformis and gluteal muscle release, lumbar lordosis recovery and a spinopelvic mobility increase has been elaborated on. The designed Yogāsana protocol represents a powerful tool for dental professionals to provide relief to retracted stiff muscles and unbalanced musculoskeletal structures in the lower body.

OBJECTIVE: To assess the feasibility of flexion-abduction-external rotation (FABER) magnetic resonance imaging (MRI) of the hip to visualize changes in the ischiofemoral interval and ability to provoke foveal excursion over the acetabular rim.
METHODS: IRB-approved retrospective single-center study. Patients underwent non-contrast 1.5-T hip MRI in the neutral and FABER position. Two readers measured the ischiofemoral interval at three levels: proximal/distal intertrochanteric distance and ischiofemoral space. Subgroup analysis was performed for hips with/without high femoral torsion, or quadratus femoris muscle edema (QFME), respectively. A receiver operating curve with calculation of the area under the curve (AUC) for the prediction of QFME was calculated. The presence of foveal excursion in both positions was assessed.
RESULTS: One hundred ten patients (121 hips, mean age 34 ± 11 years, 67 females) were evaluated. FABER-MRI led to narrowing (both p < .001) of the ischiofemoral interval which decreased more at the proximal (mean decrease by 26 ± 7 mm) than at the distal (6 ± 7 mm) intertrochanteric ridge. With high femoral torsion/ QFME, the ischiofemoral interval was significantly narrower at all three measurement locations compared to normal torsion/no QFME (p < .05). Accuracy for predicting QFME was high with an AUC of .89 (95% CI .82-.94) using a threshold of ≤ 7 mm for the proximal intertrochanteric distance. With FABER-MRI foveal excursion was more frequent in hips with QFME (63% vs 25%; p = .021).
CONCLUSIONS: Hip MRI in the FABER position is feasible, visualizes narrowing of the ischiofemoral interval, and can provoke foveal excursion.
UNASSIGNED: FABER MRI may be helpful in diagnosing ischiofemoral impingement and detecting concomitant hip instability by overcoming shortcomings of static MR protocols that do not allow visualization of dynamic changes in the ischiofemoral interval and thus may improve surgical decision making.
CONCLUSIONS: • FABER MRI enables visualization of narrowing of the ischiofemoral interval proximal to the lesser trochanter. • Proximal intertrochanteric distance of ≤ 7 mm accurately predicts quadratus femoris muscle edema. • Foveal excursion was more frequent in hips with quadratus femoris muscle edema.

UNASSIGNED: The location of posterior hip impingement at maximal extension in patients with posterior femoroacetabular impingement (FAI) is unclear.
UNASSIGNED: To investigate the frequency and area of impingement at maximal hip extension and at 10° and 20° of extension in female patients with increased femoral version (FV) and posterior hip pain.
UNASSIGNED: Cross-sectional study; Level of evidence, 3.
UNASSIGNED: Osseous patient-specific 3-dimensional (3D) models were generated of 50 hips (37 female patients, 3D computed tomography) with a positive posterior impingement test and increased FV (defined as >35°). The McKibbin index (combined version) was calculated as the sum of FV and acetabular version (AV). Subgroups of patients with an increased McKibbin index >70° (24 hips) and FV >50° (20 hips) were analyzed. A control group of female participants (10 hips) had normal FV, normal AV, and no valgus deformity (neck-shaft angle, <139°). Validated 3D collision detection software was used for simulation of osseous impingement-free hip extension (no rotation).
UNASSIGNED: The mean impingement-free maximal hip extension was significantly lower in patients with FV >35° compared with the control group (15° ± 15° vs 55° ± 19°; P < .001). At maximal hip extension, 78% of patients with FV >35° had osseous posterior extra-articular ischiofemoral hip impingement. At 20° of extension, the frequency of posterior extra-articular ischiofemoral impingement was significantly higher for patients with a McKibbin index >70° (83%) and for patients with FV >35° (76%) than for controls (0%) (P < .001 for both). There was a significant correlation between maximal extension (no rotation) and FV (r = 0.46; P < .001) as well as between impingement area at 20° of extension (external rotation [ER], 0°) and McKibbin index (0.61; P < .001). Impingement area at 20° of extension (ER, 0°) was significantly larger for patients with McKibbin index >70° versus <70° (251 vs 44 mm2; P = .001).
UNASSIGNED: The limited hip extension found in our study could theoretically affect the performance of sports activities such as running, ballet dancing, or lunges. Therefore, although not examined directly in this study, these activities are not advisable for these patients. Preoperative evaluation of FV and the McKibbin index is important in female patients with posterior hip pain before hip preservation surgery (eg, hip arthroscopy).

Partial resection of the lesser trochanter (LT plasty) has been increasingly recommended to treat ischiofemoral impingement. However, there is a lack of studies on the imaging findings following LT plasty. The purpose of this study was to assess magnetic resonance imaging (MRI) changes on the lesser trochanter and surrounding musculotendinous structures following LT plasty to treat ischiofemoral impingement. Twenty-one patients (21 hips) were studied. The LT length and cross-sectional area of the iliopsoas muscle were measured on MRI before and after surgery. The MRIs were performed on average 11 months (range, 3 to 25 months) after surgery. The mean ±  standard deviation amount of LT resected (difference between pre- and postoperative LT length) was 7.3 mm ±  2.5 mm. The iliopsoas cross-sectional area decreased after the LT plasty in 95% of the hips (20/21) by an average of 35% ± 16%. The reduction in iliopsoas size had no significant correlation with improvement on the modified Harris Hip Score at a mean follow-up of 17 months after surgery (r = -0.13, P = 0.58). The iliopsoas muscle size decreased on average 35% following endoscopic LT plasty. The decrease was not correlated with midterm functional outcomes.

OBJECTIVE: To describe the technique, efficacy, and safety of CT-guided quadratus femoris injection with corticosteroid and local anesthetic for the treatment of ischiofemoral impingement in a series of cases at our institution.
METHODS: Cases of CT-guided quadratus femoris injections from 2000 to 2021 were identified in the enterprise-wide electronic medical record of our institution. Patient charts and our institutional picture archiving and communication system (PACS) were searched for demographics, pain level on a 0-10 scale before and immediately following the procedure, procedure technique, and follow-up outcomes if available.
RESULTS: There were 13 cases among 12 patients with clinical and imaging findings of ischiofemoral impingement included in this study. Of the 12 patients, 10 were female and two were male. There were eight posterior approaches and five posterolateral approaches. Of the 13 cases, 11 resulted in immediate pain reduction. The median reduction in pain score was four (average 3.46, range 0-8.5). There was no statistically significant difference in pain reduction between the posterior approach cases and the posterolateral approach cases. No cases reported immediate complications or increases in pain score. Of the 12 cases, seven resulted in at least 1 month of pain relief, three had subsequent surgeries, and three had no follow-up.
CONCLUSIONS: CT-guided quadratus femoris injection is safe and effective for treating ischiofemoral impingement. Further and larger scale study is needed to fully delineate differences in technique effectiveness.
CONCLUSIONS: • CT-guided quadratus femoris injection is safe and effective for treating ischiofemoral impingement. • We found no statistically significant difference in pain reduction between the posterior approach and the posterolateral approach.

The study aimed to investigate how hip bone and muscular morphology features differ between ischiofemoral impingement (IFI) patients and healthy subjects among males and females. Three-dimensional models were reconstructed based on magnetic resonance imaging images from IFI patients and healthy subjects of different sexes. Bone morphological parameters and the cross-sectional area of the hip abductors were measured. The diameter and angle of the pelvis were compared between patients and healthy subjects. Bone parameters of the hip and cross-sectional area of the hip abductors were compared between affected and healthy hips. The comparison results of some parameters were significant for females but not males. For females, the comparison results of pelvis parameters showed that the anteroposterior diameter of the pelvic inlet (p = 0.001) and intertuberous distance (p < 0.001) were both larger in IFI patients than in healthy subjects. Additionally, the comparison results of hip parameters showed that the neck shaft angle (p < 0.001) and the cross-sectional area of the gluteus medius (p < 0.001) and gluteus minimus (p = 0.005) were smaller, while the cross-sectional area of the tensor fasciae latae (p < 0.001) was significantly larger in affected hips. Morphological changes in IFI patients demonstrated sexual dimorphism, including bone and muscular morphology. Differences in the anteroposterior diameter of the pelvic inlet, intertuberous distance, neck shaft angle, gluteus medius, and gluteus minimus may explain why females are more susceptible to IFI.

Purpose: To use a novel in vivo method to simulate a moving hip model. Then, measure the dynamic bone-to-bone distance, and analyze the ischiofemoral space (IFS) of patients diagnosed with ischiofemoral impingement syndrome (IFI) during dynamic activities. Methods: Nine healthy subjects and 9 patients with IFI were recruited to collect MRI images and motion capture data. The motion trail of the hip during motion capture was matched to a personalized 3D hip model reconstructed from MRI images to get a dynamic bone model. This personalized dynamic in vivo method was then used to simulate the bone motion in dynamic activities. Validation was conducted on a 3D-printed sphere by comparing the calculated data using this novel method with the actual measured moving data using motion capture. Moreover, the novel method was used to analyze the in vivo dynamic IFS between healthy subjects and IFI patients during normal and long stride walking. Results: The validation results show that the root mean square error (RMSE) of slide and rotation was 1.42 mm/1.84° and 1.58 mm/2.19°, respectively. During normal walking, the in vivo dynamic IFS was significantly larger in healthy hips (ranged between 15.09 and 50.24 mm) compared with affected hips (between 10.16 and 39.74 mm) in 40.27%-83.81% of the gait cycle (p = 0.027). During long stride walking, the in vivo dynamic IFS was also significantly larger in healthy hips (ranged between 13.02 and 51.99 mm) than affected hips (between 9.63 and 44.22 mm) in 0%-5.85% of the gait cycle (p = 0.049). Additionally, the IFS of normal walking was significantly smaller than long stride walking during 0%-14.05% and 85.07%-100% of the gait cycle (p = 0.033, 0.033) in healthy hips. However, there was no difference between the two methods of walking among the patients. Conclusions: This study established a novel in vivo method to measure the dynamic bone-to-bone distance and was well validated. This method was used to measure the IFS of patients diagnosed with IFI, and the results showed that the IFS of patients is smaller compared with healthy subjects, whether in normal or long stride walking. Meanwhile, IFI eliminated the difference between normal and long stride walking.

Ischiofemoral impingement syndrome is a neglected cause of posterior hip pain which is derived from narrowing of the space between the lateral aspect of the ischium and the medial aspect of the lesser trochanter. Its diagnosis is challenging and requires the combination of physical tests and imaging studies. In the present narrative review, we found that femoral anteversion predisposes patients to the narrowing of the ischiofemoral space and subsequent quadratus femoris muscle injury. Magnetic resonance imaging serves as the gold-standard diagnostic tool, which facilities the quantification of the ischiofemoral distance and the recognition of edema/fat infiltration/tearing of the quadratus femoris muscle. Ultrasound is useful for scrutinizing the integrity of deep gluteal muscles, and its capability to measure the ischiofemoral space is comparable to that of magnetic resonance. Various injection regimens can be applied to treat ischiofemoral impingement syndrome under ultrasound guidance and they appear to be safe and effective. Finally, more randomized controlled trials are needed to build solid bases of evidence on ultrasound-guided interventions in the management of ischiofemoral impingement syndrome.