Ischiofemoral Impingement Syndrome Research Articles

The quadratus femoris muscle anatomy: Do we know everything?

IntroductionThe purpose of this study was to characterize the morphological variations in the quadratus femoris muscle (QF) and to create an anatomical classification that could be used in the planning of surgical procedures in this area, radiological imaging, and rehabilitation. Materials and methodsNinety-two lower limbs from 46 cadavers, fixed in 10 % formalin solution, were examined. ResultsThe QF muscle was present in all specimens. According to morphology, the QF muscle was classified into three types. The most common type was Type I, characterized by one muscular belly (78.3 %), while the second most common type was Type II, characterized by two bellies, was observed in 17.4 % of cases. The rarest type was Type III. It was characterized by three bellies and was found in 4.3 % of the cases. ConclusionsThe current classification system on quadratus femoris morphological variability is novel. Morphological variants may contribute to clinical issues, such as the ischiofemoral impingement syndrome, that could arise from type I quadratus femoris. Hence, the current study may be applicated to planning surgical procedures, imaging, and rehabilitation.

Hip External Rotation Decreases Ischiofemoral Distance: A Positive Correlation Between Cadaveric and Fluoroscopic Studies

PurposeTo determine the effect of hip external rotation or extension/adduction on minimizing the ischiofemoral distance (IFD) and assess the correlation between cadaveric and fluoroscopic IFD measurements in difference hip positions. MethodsThis cadaveric study involved 33 hip joints from 17 embalmed cadavers. IFD, the distance between the lesser trochanter and lateral ischium, was measured in different hip positions: neutral, external rotation at 30° and external rotation at 60° with the hip in both neutral extension and adduction as well as 10° hip extension and 10° hip adduction. Difference in IFD related to positions and correlation between cadaveric and fluoroscopic measurement were analyzed. ResultsIFD measurements showed that the greatest reduction occurred at 60° of external hip rotation, with a significant difference observed only between neutral and 60° external rotation in cadaveric groups (7.60±4.68 vs 5.05±3.48, 95% CI, 0.14 to 4.96; p=0.036). No substantial difference was observed between extension and adduction positions . Positive correlations were observed between cadaveric and fluoroscopic measurements, especially in the neutral position (r=0.492, p=0.004), external rotation at 30° (r=0.52, p=0.002), external rotation at 60° (r=0.419, p=0.015), and the extension/adduction positions combined with neutral rotation (r=0.396, p=0.023). ConclusionThe IFD significantly decreased with increasing degrees of hip external rotation, particularly at 60°. No significant reduction was observed in the extension/adduction positions. Additionally, positive correlations were observed between cadaveric and fluoroscopic measurements for specific hip positions: neutral rotation, external rotation at 30° and 60°, and extension/adduction at 10° with neutral rotation. Clinical RelevanceSurgeons can use this knowledge to improve hip impingement assessment through radiography, focusing on positions where IFD reduction is most notable. Understanding the relationship between hip positions and IFD can enhance the diagnosis of ischiofemoral impingement syndrome and benefiting patient care and outcomes.

Deep Gluteal syndrome: An underestimated cause of posterior hip pain.

Deep gluteal syndrome (DGS) is a significant cause of posterior hip pain resulting from the compression of the sciatic or other peripheral nerves in the deep gluteal space. Understanding the anatomy of the deep gluteal space and the kinematics of the sciatic nerve, as it passes through this region is crucial for understanding DGS. Despite increasing awareness, DGS is still often overlooked. This review focuses on conditions that specifically contribute to posterior hip pain as a consequence of DGS. Predominantly addressing piriformis syndrome, gemelli-obturator internus syndrome, ischiofemoral impingement syndrome, and proximal hamstring syndrome, the review also touches upon rare cases such as inferior and superior gluteal nerve entrapment.

Ischiofemoral Impingement: Assessment of Diagnosis through MRI and Physical Examination

Objective: The objective of this study is to assess the precision of physical examination tests in individuals diagnosed with ischiofemoral impingement syndrome (IFI), analyze magnetic resonance imaging (MRI) findings and measurements, and explore the correlation between imaging methods and physical examination tests. Methods: The MRIs of 27 hips of 20 patients who have presented with complaints of hip/groin pain in the study group and 40 hips of 20 patients in the control group were analyzed. Patients were evaluated for the severity of pain, clinical findings, and physical examination tests. Quadratus femoris muscle (QFM) edema was graded and quadratus femoris space (QFS), hamstring tendon area (HTA) and especially ischiofemoral space (IFS), were measured on MRI. Results: Both the IFS (12.44±3.49) and QFS (6.38±2.09) were significantly reduced in the study groups compared to the control groups (IFS:23.06±4.5, p<0.001; QFS:15.36±4.45, p<0.001). Measurements of the IFS (cut-off:≤18.58) and the QFS (cut-off:≤10.27) demonstrated high specificity (87.5%) and sensitivity (100%) in identifying IFI. The long-step walking (LSW) test was positive in 59.3% of cases. Conclusion: The results suggest that MRI is a valuable tool for providing detailed information on various aspects related to IFI. It allows for the assessment of the narrowing of the IFS and QFS, as well as the presence of edema. MRI, when combined with LSW test, can contribute to a comprehensive evaluation and diagnosis of IFI, enabling clinicians to gather important clinical and radiological data for accurate assessment.

Ischiofemoral Impingement Syndrome Masked by Proximal Hamstring Tendinopathy as a Cause of Gluteal Pain in a Marathon Runner.

Ischiofemoral Impingement Syndrome Masked by Proximal Hamstring Tendinopathy as a Cause of Gluteal Pain in a Marathon Runner.

A novel method for in vivo measurement of dynamic ischiofemoral space based on MRI and motion capture.

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 1.42mm/1.84° and 1.58mm/2.19°, respectively. During normal walking, the in vivo dynamic IFS was significantly larger in healthy hips (ranged between 15.09 and 50.24mm) compared with affected hips (between 10.16 and 39.74mm) 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 51.99mm) than affected hips (between 9.63 and 44.22mm) 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.

Chronic Knee Pain is the Paramount Presentation in Patients with Nail-Patella Syndrome

Background: Arthralgia in connection with patellar instability have been studied thoroughly in a number of pediatric and adult patients. Small and dysplastic patellae accompanied by hypoplasia of the lateral femoral condyle may results in recurrent subluxation or dislocation of the patellae, knee discomfort and pain. We aimed to detect the underlying etiology of every single patient. Patients and Methods: A total of seven children presented with long term painful knee joints have been refered from the departments of rheumatology. We added adult female patient of a-35-years-old. She was a chronic client of rheumatology clinics since her postadulthood. In addition to her early life knee pain. Recently she experienced additional chronic pain of the groin (located at the posterior buttocks). All our patients showed episodes of knee pain with variable intensity as a constant complaint and all received antirheumatic treatments for years despite the negative results of the implemented tests. In order to commence the diagnostic process, clinical and radiological phenotypic characterization were the main core of our stratregy followed by molecular genetic confirmation. Results: Seven unrelated children (aged from 8-17 years old) were consistent with the diagnosis of Nail- Patella syndrome. The adult female patient of a-35-years-old- manifested patellar instability since her early childhood. Her clinical phenotype was totally compatible with the diagnosis of Nail-Patella syndrome. Surprisingly, the clinical examination of the female patient and the standing AP pelvis radiograph revealed massive encroachment of the medial aspect of the femoral neck and the lesser trochanters onto the ischium. The latter resulted in the diagnosis of Ischiofemoral Impingement (IFI) syndrome. Her genetic tests showed heterozygous mutation in the LIM-homeodomain protein LMX1B on chromosome 9q33. Conclusion: Arthralgia associated with abnormal gait (mostly antalgic gait and waddling gait) was the paramount clinical presentation in all our patients. Dysplasia of the nails and patellar instability were the characteristic clinical findings in our patients with the definite diagnosis of osteo-onychodysplasia syndrome. We approached to the diagnosis from the first session of clinical examination. Interestingly, the constant groin pain in the adult female patient which has been totally overlooked by other instutions, were in favor of the diagnosis of Ischiofemoral Impingement (IFI) syndrome. As well as the existing abnormality of the elbows associated with defective pronation and supination as due to impingement of the olecranon. The task of establishing the diagnostic process in complex clinical conditions is the most challenging. Sadly speaking, none of the aforemnetioned dignostic criteria attracted the attention of dozens of clinicians. Admistering medications to overcome knee pain through dozens of useless laboratory tests were the main false issue. Clinicians who are actively involved in clinical diagnosis with minimal dependency on laboratory aid are generally at the forefront of their medical fields.

Chronic Knee Pain is the Paramount Presentation in Patients with Nail-Patella Syndrome

Background: Arthralgia in connection with patellar instability have been studied thoroughly in a number of pediatric and adult patients. Small and dysplastic patellae accompanied by hypoplasia of the lateral femoral condyle may results in recurrent subluxation or dislocation of the patellae, knee discomfort and pain. We aimed to detect the underlying etiology of every single patient. Patients and Methods: A total of seven children presented with long term painful knee joints have been refered from the departments of rheumatology. We added adult female patient of a-35-years-old. She was a chronic client of rheumatology clinics since her postadulthood. In addition to her early life knee pain. Recently she experienced additional chronic pain of the groin (located at the posterior buttocks). All our patients showed episodes of knee pain with variable intensity as a constant complaint and all received antirheumatic treatments for years despite the negative results of the implemented tests. In order to commence the diagnostic process, clinical and radiological phenotypic characterization were the main core of our stratregy followed by molecular genetic confirmation. Results: Seven unrelated children (aged from 8-17 years old) were consistent with the diagnosis of Nail- Patella syndrome. The adult female patient of a-35-years-old- manifested patellar instability since her early childhood. Her clinical phenotype was totally compatible with the diagnosis of Nail-Patella syndrome. Surprisingly, the clinical examination of the female patient and the standing AP pelvis radiograph revealed massive encroachment of the medial aspect of the femoral neck and the lesser trochanters onto the ischium. The latter resulted in the diagnosis of Ischiofemoral Impingement (IFI) syndrome. Her genetic tests showed heterozygous mutation in the LIM-homeodomain protein LMX1B on chromosome 9q33. Conclusion: Arthralgia associated with abnormal gait (mostly antalgic gait and waddling gait) was the paramount clinical presentation in all our patients. Dysplasia of the nails and patellar instability were the characteristic clinical findings in our patients with the definite diagnosis of osteo-onychodysplasia syndrome. We approached to the diagnosis from the first session of clinical examination. Interestingly, the constant groin pain in the adult female patient which has been totally overlooked by other instutions, were in favor of the diagnosis of Ischiofemoral Impingement (IFI) syndrome. As well as the existing abnormality of the elbows associated with defective pronation and supination as due to impingement of the olecranon. The task of establishing the diagnostic process in complex clinical conditions is the most challenging. Sadly speaking, none of the aforemnetioned dignostic criteria attracted the attention of dozens of clinicians. Admistering medications to overcome knee pain through dozens of useless laboratory tests were the main false issue. Clinicians who are actively involved in clinical diagnosis with minimal dependency on laboratory aid are generally at the forefront of their medical fields.

Ischiofemoral Impingement Syndrome: Clinical and Imaging/Guidance Issues with Special Focus on Ultrasonography.

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.

Ischiofemoral impingement syndrome: a case report and review of literature

IntroductionThe etiology of ischiofemoral impingement (IFI) syndrome, an unusual and uncommon form of hip pain, remains uncertain. Some patients demonstrate narrowing of the space between the ischial tuberosity and lesser trochanter from trauma or abnormal morphology of the quadratus femoris muscle. Combined clinical and imaging aid in the diagnosis.Case reportA 32-year-old female presented with a 3 years history of pain over the lower aspect of the right buttock, aggravated by movements of the right hip, and partially relieved with rest and medications. The right hip showed extreme restriction of abduction and external rotation. MRI of the right hip showed reduced ischiofemoral space and quadratus femoris space when compared to the left hip. The patient underwent endoscopic resection of the right lesser trochanter, with no recurrence of pain at 2 years.ConclusionAn unusual cause of hip pain, IFI syndrome, should be suspected when hip pain at extremes of movement is associated with signal abnormality of quadratus femoris muscle. Management is tailored to address the inciting factors that precipitated the IFI syndrome.

Arthroscopic Lesser Trochanter Osteoplasty, Quadratus Femoris Debridement, and Sciatic Neurolysis via Posterior Approach for Ischiofemoral Impingement.

Ischiofemoral impingement (IFI) syndrome is considered the narrowing of the ischiofemoral space (IFS), leading to pathological changes in the quadratus femoris and sciatic nerve, causing posterior hip and sciatica-like pain. Open or arthroscopic resection of the lesser trochanter to enlarge the IFS is the main surgical procedure. However, there is a lack of research on isolated IFI, and currently known surgical procedures are at risk of weakening the flexion strength of the hip joint. In this study, four patients, who were diagnosed with isolated IFI and had undergone arthroscopic treatment with partial resection of the lesser trochanter, debridement of the quadratus femoris, and decompression of the sciatic nerve, were reviewed. To the best of our knowledge, this is the first study to describe the management of IFI using a series of surgical procedures via a posterior approach as an effective treatment option. The outcomes of this study broadened the strategies for IFI management.

Quadratus Femoris Partial Tear Secondary to Occult Ischiofemoral Impingement

Introduction:Hip pain in children and adolescents may become a diagnostic challenge. A wide range of causes must be considered in the deferential diagnosis. Ischiofemoral impingement (IFI) is a pathological condition defined by hip pain associated with narrowing of the ischiofemoral (IF) space. We report the case of an adolescent patient with non-traumatic quadratus femoris (QF) tear secondary to an occult IFI syndrome. To the best of our knowledge, this is the first such case reported in the literature.Case Report:A 15-year-old girl reported persisting hip pain for a month following increased physical activity. The symptoms had started a couple of days following a weekend of increased activity due to her participating in a dancing contest. Physical examination and imaging studies (standard anterior pelvis radiograph and MRI-scan) failed to reveal any pathology apart from an area of diffused edema in the IF space. Standard hematology and biochemistry laboratory tests were all within normal range. Conservative treatment for 6 months with rest and modification of physical activities failed. A new MRI scan showed partial edema resolution and marked reduction in the IF and QF spaces (12 mm and 8 mm, respectively), thus suggesting IFI, which, in turn, led to a partial rupture of the QF. The patient underwent a local infiltration of the QF with betamethasone sodium phosphate and betamethasone acetate (6+6 mg/2 ml) under CT guidance, which led to the complete resolution of all her symptoms. She remains symptoms free for 24 months.Conclusion:IFI is a rather uncommon condition in the developing skeleton. As in adults, in adolescents as well, MRI is the study of choice in cases of IFI, since it shows QF pathology and allows measurement of the IF and QF spaces, assisting physicians in establishing the right diagnosis. However, the coexistence of a QF hematoma and/or edema, may temper with the initial MRI measurements and render the diagnosis of the primary condition rather difficult. Conservative treatment (with local infiltration of the QF) was proven to be successful in the hereby described case.

MRI measurement assessment on ischiofemoral impingement syndrome.

To explore the value of MRI upon diagnosis of ischiofemoral impingement syndrome (IFI) and to recognise deformation or oedema of the quadratus femoris muscle. MRI applied to measure the ischial femoral space (IFS), the average width of quadratus femoral space (QFS), and the ischial intertuberal diameter. A retrospective analysis was carried out of 213 hip joints MRI images of 58 cases diagnosed with IFI and 61 cases of normal subjects. IFS, QFS and ischial intertuberal diameter were measured by axial T1WI sequence. The morphological and signal changes of the quadratus femoris muscle were observed through proton density weighted image fat suppression sequence (PDWI-FS). The widths of IFS and QFS in the normal group were larger than those in the case group, while the ischial intertuberal diameter was significantly smaller (p < 0.05). Pearson correlation analysis revealed that there was a positive correlation (r = 0.824) between IFS and QFS in all hip joints and a negative correlation between the ischial intertuberal diameter and the widths of IFS and QFS (r = -0.213, -0.222, p < 0.05) respectively. As the grade of oedema in quadratus femoris muscle increased, the corresponding IFS gradually decreased. The corresponding IFS width of grade 0 oedema of the quadratus femoris muscle oedema was significantly higher than that of grade 1, grade 2 and grade 3. The receiver operating characteristic curve (ROC) of the subjects was applied to determine the diagnostic boundary value of the IFS and QFS in IFI patients, which was 1.98 cm and 1.05 cm respectively. The area under the curve (AUC) was 0.948 and 0.953 respectively. MRI examination could provide a reliable basis for the diagnosis of ischiofemoral impingement syndrome. The narrowing of IFS and QFS with deformation and oedema in the quadratus femoris muscle may be the features of manifestation of IFI.

Cross-Sectional Imaging Useful in Melorheostosis.

ABSTRACTMelorheostosis is a rare disease of bone overgrowth that is primarily diagnosed based on imaging studies. Recently, the association of different radiological patterns of the disease with distinct genetic cause was reported. Several case reports have described the radiological findings in patients with melorheostosis. However, the added value of cross‐sectional imaging with CT and MRI beyond X‐rays has not been investigated. The aim of the current study was to investigate this existing gap in knowledge. Forty patients with melorheostosis seen at the National Institute of Health Clinical Center were included in the study, and all their imaging studies were analyzed. The sequence of interpretation was X‐ray followed by CT and then MRI. CT images were extracted from whole‐body 18F‐sodium fluoride positron emission tomography/CT studies. The information from CT reclassified the initial X‐rays based radiological pattern in 13 patients. Additionally, CT comprehensively identified joint involvement and disease extent. In 76% of patients (n = 29) who underwent MRI, additional findings were noted, ranging from soft tissue edema to identification of soft tissue masses and incidental findings. MRI did not provide additional information on skeletal lesions beyond CT scans. However, it revealed the extension of soft tissue ossification into ischiofemoral space in four patients who complained of deep gluteal pain consistent with ischiofemoral impingement syndrome. In addition, MRI revealed soft tissue edema in 20 patients, 9 of whom had bone marrow edema and periosteal edema in the tibias consistent with shin splints. These findings suggest that select patients with melorheostosis should be evaluated with both CT and MRI, particularly patients in whom the distribution of pain does not correlate with the anatomic location of the disease in plain radiographs. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Deep gluteal syndrome as a cause of posterior hip pain and sciatica-like pain

Deep gluteal syndrome is an increasingly recognized disease entity, caused by compression of the sciatic or pudendal nerve due to non-discogenic pelvic lesions. It includes the piriformis syndrome, the gemelli-obturator internus syndrome, the ischiofemoral impingement syndrome, and the proximal hamstring syndrome. The concept of the deep gluteal syndrome extends our understanding of posterior hip pain due to nerve entrapment beyond the traditional model of the piriformis syndrome. Nevertheless, there has been terminological confusion and the deep gluteal syndrome has often been undiagnosed or mistaken for other conditions. Careful history-taking, a physical examination including provocation tests, an electrodiagnostic study, and imaging are necessary for an accurate diagnosis. After excluding spinal lesions, MRI scans of the pelvis are helpful in diagnosing deep gluteal syndrome and identifying pathological conditions entrapping the nerves. It can be conservatively treated with multidisciplinary treatment including rest, the avoidance of provoking activities, medication, injections, and physiotherapy. Endoscopic or open surgical decompression is recommended in patients with persistent or recurrent symptoms after conservative treatment or in those who may have masses compressing the sciatic nerve. Many physicians remain unfamiliar with this syndrome and there is a lack of relevant literature. This comprehensive review aims to provide the latest information about the epidemiology, aetiology, pathology, clinical features, diagnosis, and treatment. Cite this article: Bone Joint J 2020;102-B(5):556-567.

Buttock Pain - Cross Country Skier

HISTORY: A 32 year old male cross country skier presented with a multi-year history of right posterior “deep” buttock pain. He endorsed associated radiation down his posterior right thigh, leg and into the plantar foot. He described “burning” and “tingling” that increased with prolonged sitting and standing. Surgical history was significant for bilateral hip arthroscopic surgeries for femoral acetabular impingement. He denied any significant weakness or change in bowel/bladder function. PHYSICAL EXAMINATION: Exam revealed right toe flexor weakness. Straight leg raise reproduced his right lower limb and buttock pain. Reflexes were physiologic and symmetric. Hip range of motion was full and pain free. Intraarticular provocative maneuvers were negative. He had tenderness to palpation of his deep hip external rotators. FABER’s test and passive piriformis stretch reproduced his right buttock and lower limb symptoms. DIFFERENTIAL DIAGNOSIS: S1 Radiculopathy Sacroiliac Joint Dysfunction Piriformis Syndrome Hip Osteoarthritis Proximal Hamstrings Tendinopathy Ischiofemoral Impingement Syndrome TEST AND RESULTS: Lumbar spine x-rays showed anterolisthesis of L5 on S1 with associated disc space narrowing and MRI showed paracentral disc protrusion at L5-S1 effacing the right S1 nerve root. Electromyogram showed evidence of a chronic, inactive right S1 radiculopathy. Ultrasound of the right hip identified a small nerve fascicle, separate from the sciatic nerve, appearing to pierce the piriformis muscle. MRI of the pelvis with lumbosacral plexus protocol demonstrated the sciatic nerve coursing deep to the right piriformis muscle and identified the right S2 nerve root coursing through the piriformis muscle. FINAL WORKING DIAGNOSIS: Piriformis syndrome resulting in active, compressive, right S2 neuritis Superimposed, chronic, inactive right S1 radiculopathy TREATMENT AND OUTCOMES: Extensive PT with plateau in improvement. No relief with right S1 selective nerve root block. Ultrasound guided piriformis corticosteroid injection provided temporary relief of buttock pain. Ultrasound guided sciatic nerve hydrodissection coupled with neural flossing provided several months of relief and allowed the patient to return to cross country skiing. Surgical referral for consideration of piriformis release.

Quadratus femoris muscle: spectrum of MR imaging findings in 51 patients presenting with painful hip

Purpose: To provide an overview of magnetic resonance (MR) imaging findings related to quadratus femoris muscle (QFm) pathologies in symptomatic patients. Material and Methods: MR imaging studies from 51 patients, who were retrospectively recruited within a 2-year period, in 5 health care centers were reviewed. Inclusion criteria included: (i) hip pain; (ii) QFm abnormal signal; (iii) identification of other pathology in the QFm anatomical area. Exclusion criteria included: (i) other symptomatic hip/pelvic pathology; (ii) incomplete MR examination. The presence/location of QFm oedema and configuration of QFm fibers were evaluated and classified. Hamstring tendons were assessed for tendinosis/tear. Ischiofemoral impingement syndrome (IFIs) was indicated by QFm oedema and restriction of ischiofemoral space (IFS)/quadratus femoris space (QFS). QFm tears were categorised as complete/partial/chronic. Fisher’s exact test was used for statistical analysis. Results: IFIs diagnosis, related to various aetiologies, was suggested in 39 patients. The absence of severe QFm oedema and crowded configuration of QFm fibers correlated with IFIs diagnosis (p<0.05). In 18/39 (46.2%) of patients, restriction of the IFS/QFS was due to an underlying pathology. QFm tears were diagnosed in 5 patients. QFm oedema, usually mild, located at the myotendinous junction, was revealed in 4/5 patients. In 7 patients various pathologies related to the QFm were disclosed, which broadly included neoplastic disorders, myositis and bursitis. Conclusions: MR imaging can depict and characterise various QFm pathologies including IFIs, traumatic lesions, myositis and neoplastic disorders. Detailed analysis of the oedema pattern and the configuration of muscular fibers matched with clinical findings can lead to precise diagnosis.

ISCHIOFEMORAL IMPINGEMENT: ASSESSMENT OF MRI FINDINGS AND THEIR RELIABILITY.

ABSTRACTObjective: To evaluate the Magnetic Resonance Imaging (MRI) findings and their validity in patients with ischiofemoral impingement syndrome (IFI) .Methods:We retrospectively analyzed 55 hips. MRI findings of 30 hips were consistent with IFI syndrome. Twenty five hips had no MRI findings consistent with IFI syndrome. We compared the ischiofemoral space (IFS), quadratus femoris space (QFS), ischial angle (IA) and femoral neck angle (FNA) between the age and gender matched groups. We also analyzed edema, fatty replacement and partial or total rupture of quadratus femoris muscle. Mann Whitney U test was used to compare the data.Results: We observed atrophy in eight, fatty replacement also in eight and edema in all of the quadratus femoris muscle. QFS (p<0.001) and IFS (p<0.001) were significantly lower in patients as compared to the control group. IA (p=0.012) and FNA (p=0.010) values were significantly higher in patients compared with the control group.Conclusion: MRI findings of IFI include narrowing of QFS and IFS and increase in IA and FNA. This condition should be kept in mind for patients with hip pain. Level of Evidence III, Retrospective Study.

Ultrasound-Guided Quadratus Femoris Muscle Injection in Patients with Lower Buttock Pain: Novel Ultrasound-Guided Approach and Clinical Effectiveness

Background: The quadratus femoris (QF) muscle is a possible source of lower buttock pain as evidenced by what is known about the pathophysiology of ischiofemoral impingement syndrome. However, there are few reports about the interventional management of the QF muscle as a pain generator. Objective: To describe an ultrasound-guided QF muscle injection technique in patients with lower buttock pain suspected of QF muscle pathology and to report the result of treatment. Study Design: Retrospective evaluation. Setting: Outpatient department for interventional pain management at a university hospital. Methods: We studied 14 patients who had deep tenderness localized to the lower buttock region at a point halfway between the lateral prominence of the greater trochanter and the ischial tuberosity corresponding to the location of the QF muscle belly. Under ultrasound guidance, 8 mL of 0.25% lidocaine was injected into the QF muscle. Pain scores were assessed prior to the first injection and 2 weeks after the last injection. Patient satisfaction was also assessed. Results: When compared before and 2 weeks after last QF muscle injection, the mean pain score decreased by 49.3% (6.7 ± 2.3 to 3.4 ± 2.1, P &lt; 0.001). Two weeks after the last injection, approximately 70% of patients (10 of 14 patients) expressed their satisfaction as excellent or good and the average frequency of injection was 2.5 times. There were no complications observed. Limitations: The results of this study should be considered preliminary owing to the small sample size and lack of a control group, and the retrospective characteristics of this study may have introduced a selection bias. Conclusions: Ultrasound-guided QF muscle injection with local anesthetic helps alleviate pain in patients with lower buttock pain attributed to the QF muscle, and leads to high levels of satisfaction for patients. A randomized placebo-controlled trial should be considered in the future. Key words: Buttocks, injections, intramuscular, myofascial pain syndromes, quadratus femoris, ultrasonography

Evaluation and management of ischiofemoral impingement: a pathophysiologic, radiologic, and therapeutic approach to a complex diagnosis.

Ischiofemoral impingement syndrome (IFI) is an underrecognized form of atypical, extra-articular hip impingement defined by hip pain related to narrowing of the space between the ischial tuberosity and the femur. The etiology of IFI is multifactorial and potential sources of ischiofemoral engagement include anatomic variants of the proximal femur or pelvis, functional disorders as hip instability, pelvic/spinal instability, or abductor/adductor imbalance, ischial tuberosity enthesopathies, trauma/overuse or extreme hip motion, iatrogenic conditions, tumors and other pathologies. Magnetic resonance imaging (MRI) is the diagnostic procedure of choice for assessing IFI and may substantially influence patient management. The injection test of the ischiofemoral space (IFS) has both a diagnostic and therapeutic function. Endoscopic decompression of the IFS appears useful in improving function and diminishing hip pain in patients with IFI but conservative treatment is always the first step in the treatment algorithm. Because of the ever-increasing use of advanced MRI techniques, the frequent response to conservative treatment, and the excellent outcomes of new endoscopic treatment, radiologists must be aware of factors that predispose or cause IFI. In addition, focused treatment in these conditions is often more important than in secondary impingement. In this article, we briefly describe the anatomy of the IFS, review the clinical examination and symptoms, assess the diagnostic imaging criteria and pathophysiological mechanisms, and develop an understandable classification of IFI, with particular focus on its etiology, predisposing factors, and associated musculoskeletal abnormalities. We also assess the role of the radiologist in the diagnosis, treatment, and preoperative evaluation of both primary and secondary IFI.