Imaging changes following surgery for ischiofemoral impingement.

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.

Anterior Electronic Hip Pain Drawings Are Helpful for Diagnosis of Intra-articular Sources of Pain: Lateral or Posterior Drawings Are Unreliable.

Purpose: The purpose of this study was to determine the accuracy of electronic hip pain drawing to diagnose intra-articular source of pain in nonarthritic hips, defined by response to an intra-articular injection. Methods: A retrospective assessment was performed in consecutive patients who had an intra-articular injection completed within a 1-year period. Patients were classified as responders or nonresponders to intra-articular hip injection. A positive injection was defined as greater than 50% hip pain relief within 2 hours after injection. Electronic pain drawings collected before injection were then evaluated according to the hip region marked by the patients. Results: Eighty-three patients were studied after applying inclusion and exclusion criteria. Anterior hip pain on drawing had a sensitivity of 0.69, specificity of 0.68, positive predictive value (PPV) of 0.86, and negative predictive value (NPV) of 0.44 for intraarticular source of pain. Posterior hip pain on drawing had a sensitivity of 0.59, specificity of 0.23, PPV of 0.68, and NPV of 0.17 for intra-articular source of pain. Lateral hip pain on drawing had a sensitivity of 0.62, specificity of 0.50, PPV of 0.78, and NPV of 0.32 for intraarticular source of pain. Conclusion: Anterior hip pain on electronic drawing has a sensitivity of 0.69 and specificity of 0.68 for intra-articular source of pain in nonarthritic hips. Lateral and posterior hip pain on electronic pain drawings are not reliable to rule out intra-articular hip disease. Level of Evidence: Level III, case-control study.

Hip physical examination extension loss and radiographic osseous findings in patients with low back pain and nonarthritic hips.

The association between hip and spine abnormalities is frequent, and limitation in hip extension has been linked with low back pain. The purpose of this study was to assess the radiographic osseous findings in nonarthritic hips of patients with hip pain, low back pain, and limited hip extension. Ninety patients (92 hips) were included in this study. Hip extension was tested in the contralateral decubitus position with the hip in neutral abduction/adduction and neutral rotation. In sequence, hip extension was tested by adding passive abduction, followed by internal/external rotation of the hip. A hip extension limitation was defined as less than zero degrees of extension. Imaging studies were assessed for the following osseous morphologies: decreased ischiofemoral space (≤17 mm), increased femoral torsion (≥30°), decreased femoral torsion (≤5°), and posterior acetabular overcoverage. Fifty-seven out of 92 hips (62%) had at least one osseous imaging finding for limitation in hip extension: decreased ischiofemoral space (38/92, 41%), increased femoral torsion (5/92, 5%), decreased femoral torsion (24/92, 26%), and posterior acetabular overcoverage (21/92, 23%). Decreased ischiofemoral space, femoral torsional abnormalities, and/or posterior acetabular wall overcoverage are observed in imaging studies of most individuals with limitation of hip extension and low back pain.

Usefulness of magnetic resonance imaging to diagnose greater trochanteric-ischial impingement.

Extra-articular impingement between the femur and ischium is increasingly recognized as a cause of hip pain. The purpose of this study was to assess the diagnostic parameters for greater trochanteric-ischial impingement (GTI) in magnetic resonance imaging (MRI) studies. Seven patients (seven hips) diagnosed with GTI were retrospectively identified. For each of these seven patients, three controls were matched by gender, height, and weight to create a control group of 21 asymptomatic hips. The same technique and positioning were utilized to acquire the MRIs in the GTI and control groups. The MRI was performed with the lower limbs in a functional position reproducing the midstance phase of the gait cycle. The greater trochanteric-ischial distance was measured in the axial cut showing the shortest distance between the greater trochanter and the ischial tuberosity. The mean greater trochanteric-ischial distance was 26.2 mm in the GTI group and 33.8 mm in the control group (P < 0.01). Greater trochanteric-ischial distance ≤28 mm had a sensitivity of 86% and specificity of 86% in identifying GTI. In conclusion, utilizing MRI with functional positioning of the lower limbs, greater trochanter-ischial distance ≤28 mm is helpful to diagnose GTI in women.

Low Back Pain Improves After Surgery for Lesser Trochanteric-Ischial Impingement.

PURPOSE: To assess the effects of surgery for lesser trochanteric-ischial impingement (LTI) on low back pain. METHODS: The records of patients with LTI who underwent endoscopic partial resection of the lesser trochanter (LT) between May of 2017 and February of 2019 were reviewed. Inclusion criteria were the presence of low back pain in association with hip pain, diagnosis of LTI, and partial resection of the LT to treat LTI. Exclusion criteria were less than 12 months of postoperative follow-up and hip or spine surgery after the LTI surgery. Patients were assessed before surgery and at the most recent follow-up with the modified Harris Hip Score and Oswestry Disability Index for lumbar spine. RESULTS: Thirty patients (31 hips) met the inclusion criteria. Four patients were lost to follow-up. Two patients with borderline dysplasia and grade 1 and 2 osteoarthritis underwent total hip arthroplasty after the partial resection of the LT. The results are presented considering the remaining 24 patients (25 hips). The average age at surgery was 51 years (range 32-65 years). The mean follow-up after the surgery for LTI was 19 months (range 12-35 months). The mean ± SD ODI improved from 48% ± 15 before the LTI surgery to 21% ± 22 (P < .001) at the most recent follow-up. Improvement in the Oswestry Disability Index above the minimal clinical important difference was observed in 16 patients (67%) following the LTI surgery. The mean ± SD modified Harris Hip Score improved from 55.8 ± 14 before LTI surgery to 81.3 ± 14.3 (P < .001). CONCLUSIONS: Decrease in low back pain above the minimal clinically important difference is observed in 2 of 3 patients after partial resection of the LT. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Femoral Derotation Osteotomy Improves Hip and Spine Function in Patients With Increased or Decreased Femoral Torsion.

PURPOSE: To evaluate the outcomes of proximal femoral derotation osteotomy (PFDO) on the hip and spine function of patients with abnormal femoral torsion. METHODS: This retrospective study included patients who underwent PFDO to treat increased or decreased femoral torsion between July 2014 and February 2019. The exclusion criteria were: previous fracture, fixation of slipped capital femoral epiphysis or osteotomy in the ipsilateral femur; PFDO associated to varus or valgus osteotomy; Tönnis grade 2 or 3 osteoarthritis; and PFDO performed to treat knee abnormalities. Hip function was assessed through the modified Harris Hip Score (mHHS). A subgroup of consecutive patients with low back pain before the PFDO and operated after 2017 had the spine function assessed through the Oswestry disability index (ODI). RESULTS: A total of 37 hips (34 patients) were studied: 15 hips with increased femoral torsion and 22 with decreased femoral torsion. Eight patients were male and 26 were female. The average age at PFDO was 33 years (range, 15-54 years). At a mean follow-up of 24 months (range, 12-65 months), the mean mHHS improved from 58.1 ± 14.3 before PFDO to 82 ± 15.6 at the most recent follow-up (P < .001). Improvement in the mHHS above the minimum clinically important difference (MCID) was observed in 33 hips (89%). In the subgroup of 14 consecutive patients with ODI available, the ODI improved from a mean of 45% ± 16% before the PFDO to 22% ± 17% at the most recent follow-up (P = .001). Nine (64.3%) of the 14 patients presented improvement in the ODI above the MCID. Revision procedure with a larger intramedullary nail was necessary in 2 hips to treat nonunion. CONCLUSION: Proximal femoral derotation osteotomy improves the hip and spine function in patients with increased or decreased femoral torsion and nonarthritic hips. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Postoperative Deep Gluteal Syndrome After Hip Arthroscopic Surgery.

BACKGROUND: Deep gluteal syndrome (DGS) is an uncommon source of buttock and groin pain, resulting from entrapment of the sciatic nerve in the deep gluteal space. The incidence and risk factors of postoperative DGS after primary hip arthroscopic surgery are currently unknown. PURPOSE: To investigate the incidence and risk factors of postoperative DGS after primary hip arthroscopic surgery. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This study reviewed 1167 patients who underwent arthroscopic surgery between 2010 and 2018 by a single surgeon at a single center in Japan. DGS was defined using the seated piriformis stretch test, active hamstring test, and evidence of a hypertrophic sciatic nerve on magnetic resonance imaging. Overall, 11 of 1167 patients were diagnosed with DGS postoperatively. The DGS group (n = 11) was compared with the non-DGS group (n = 1156). Patient age, sex, body mass index (BMI), generalized joint laxity (GJL; Beighton score >6), number of hip arthroscopic procedures, and radiographic parameters including lateral center-edge angle, Sharp angle, vertical center anterior angle, Tönnis angle, alpha angle, ischiofemoral distance, ischiofemoral space, and quadratus femoris space were compared. The prevalence of developmental dysplasia of the hip (DDH) and borderline DDH (BDDH) was also compared. Logistic regression analysis was conducted to identify potential predictors for a postoperative DGS diagnosis. RESULTS: The incidence of postoperative DGS in our study was 0.9%. Female sex (male:female ratio: 0:11 in DGS group vs 568:588 in non-DGS group; P < .01), mean number of hip surgical procedures (1.8 ± 0.9 in DGS group vs 1.1 ± 0.4 in non-DGS group; P < .01), and GJL (P < .01) were significantly higher in the DGS group, while the mean BMI was significantly lower in the DGS group (19.8 ± 1.8 vs 22.7 ± 3.6 kg/m2, respectively; P < .01). Radiographic parameters were not significantly different between groups. Logistic regression analysis revealed that female sex (odds ratio [OR], 22.0 [95% CI, 1.29-374.56]), multiple surgical procedures (OR, 7.8 [95% CI, 2.36-25.95]), GJL (OR, 40.9 [95% CI, 8.74-191.70]), lower BMI (OR, 0.77 [95% CI, 0.644-0.914]), and DDH/BDDH (OR, 18.1 [95% CI, 2.30-142.10]) were potential predictors of postoperative DGS. CONCLUSION: The incidence of postoperative DGS in our study was 0.9%. The predictors for postoperative DGS after hip arthroscopic surgery were female sex, GJL, multiple hip surgical procedures, and DDH/BDDH. Although hip arthroscopic surgery can provide favorable clinical outcomes, surgeons should be aware of the risk factors for DGS as a complication of hip arthroscopic surgery.

Spinopelvic Parameters Do Not Predict the Sagittal Orientation of the Acetabulum.

BACKGROUND: The orientation of the acetabulum has a fundamental role in impingement and instability of the hip, and the spinopelvic parameters are thought to predict the sagittal orientation of the acetabulum (SOA). However, similar to the acetabular version (axial orientation) and inclination (coronal orientation), the cephalic or caudal orientation of the acetabulum in the sagittal plane, or SOA, may primarily be an intrinsic feature of the acetabulum itself. PURPOSE: To determine whether the spinopelvic parameters predict the sagittal orientation of the acetabulum in individuals without lumbar deformity. STUDY DESIGN: Cross-sectional study; Level of evidence, 4. METHODS: A retrospective analysis was performed in 89 patients (94 hips; 62 female, 27 male; mean ± SD age, 45.9 ± 15.4 years) without lumbosacral deformity who underwent magnetic resonance arthrogram (MRA) for assessment of hip pain. The SOA was determined in the sagittal cut MRA. A line was drawn at the distal limit of the anterior and posterior acetabular horns longitudinally to the transverse ligament, and the angle between this line and the axial plane represented the SOA. The sacral slope, pelvic incidence, and spinopelvic tilt were determined using a 3-dimensional cursor and the axial, sagittal, and coronal cuts. All MRA studies were performed with the patient in the supine position. RESULTS: The SOA had a mean ± SD cephalic orientation of 18° ± 6.6°. No significant correlation was observed between the SOA and the sacral slope (r = -0.03; P = .77). A weak correlation was observed between the SOA and the pelvic incidence (r = 0.22; P = .03) and between the SOA and the spinopelvic tilt (r = 0.41; P < .01). CONCLUSION: The SOA cannot be presumed based on the spinopelvic parameter. Similar to the well-known parameters to assess the axial and coronal orientation of the acetabulum, the assessment of the SOA demands acetabular-specific parameters. Additional studies are necessary to assess the SOA in asymptomatic hips, including disparities between genders. Clinically significant values for abnormal SOA of the acetabulum remain to be defined.

Carbon dioxide gas endoscopy of the deep gluteal space.

The treatment of hip and pelvic pain associated with abnormalities of the deep gluteal space has evolved and increasingly involves endoscopic techniques with a saline expansion medium. This investigation presents a surgical technique utilizing carbon dioxide as the insufflation medium for deep gluteal space endoscopy in 17 cadaveric hips. This technique was successful in 94% (16/17) of the hips, allowing for visualization of the sciatic nerve, posterior femoral cutaneous nerve, pudendal nerve, branch of the inferior gluteal artery crossing the sciatic nerve, piriformis muscle, hamstring tendon origin, and lesser trochanter. Our experience suggests that gas expansion presents several advantages over fluid expansion.

Snapping of the Sciatic Nerve and Sciatica Provoked by Impingement Between the Greater Trochanter and Ischium: A Case Report.

CASE: A 64-year-old woman developed worsening sciatica associated with snapping at the hip over a period of 4 years. The physical examination and dynamic ultrasound revealed the snapping of the sciatic nerve (SN) provoked by impingement between the greater trochanter (GT) and the ischium. Additional imaging studies demonstrated hyperintense signal in the SN at the hip, sagittal imbalance, decreased ischiofemoral space, and increased femoral torsion. CONCLUSION: Snapping and entrapment of the SN provoked by impingement between the GT and the ischium should be considered in the differential diagnosis of snapping hip and/or sciatica.

Deep gluteal syndrome is defined as a non-discogenic sciatic nerve disorder with entrapment in the deep gluteal space: a systematic review.

PURPOSE: Clinicians are not confident in diagnosing deep gluteal syndrome (DGS) because of the ambiguity of the DGS disease definition and DGS diagnostic pathway. The purpose of this systematic review was to identify the DGS disease definition, and also to define a general DGS diagnostic pathway. METHODS: A systematic search was performed using four electronic databases: PubMed, MEDLINE, EMBASE, and Google Scholar. In eligibility criteria, studies in which cases were explicitly diagnosed with DGS were included, whereas review articles and commentary papers were excluded. Data are presented descriptively. RESULTS: The initial literature search yielded 359 articles, of which 14 studies met the eligibility criteria, pooling 853 patients with clinically diagnosed with DGS. In this review, it was discovered that the DGS disease definition was composed of three parts: (1) non-discogenic, (2) sciatic nerve disorder, and (3) nerve entrapment in the deep gluteal space. In the diagnosis of DGS, we found five diagnostic procedures: (1) history taking, (2) physical examination, (3) imaging tests, (4) response-to-injection, and (5) nerve-specific tests (electromyography). History taking (e.g. posterior hip pain, radicular pain, and difficulty sitting for 30 min), physical examination (e.g. tenderness in deep gluteal space, pertinent positive results with seated piriformis test, and positive Pace sign), and imaging tests (e.g. pelvic radiographs, spine and pelvic magnetic resonance imaging (MRI)) were generally performed in cases clinically diagnosed with DGS. CONCLUSION: Existing literature suggests the DGS disease definition as being a non-discogenic sciatic nerve disorder with entrapment in the deep gluteal space. Also, the general diagnostic pathway for DGS was composed of history taking (posterior hip pain, radicular pain, and difficulty sitting for 30 min), physical examination (tenderness in deep gluteal space, positive seated piriformis test, and positive Pace sign), and imaging tests (pelvic radiographs, pelvic MRI, and spine MRI). This review helps clinicians diagnose DGS with more confidence. LEVEL OF EVIDENCE: IV.

Frequency of ischiofemoral space discrepancy when comparing magnetic resonance images of distinct institutions for the same patient.

Inaccuracy of ischiofemoral space (IFS) measurement may result in radiographic misdiagnosis of ischiofemoral impingement, as well as insufficient or excessive osseous resection when surgery is indicated. This study compared the IFS measured in magnetic resonance imaging (MRI) performed in distinct health services for the same patient. Sixty-five patients (95 hips) who had hip MRI performed at an outside institution (noncontrolled MRI) followed by a hip MRI with lower extremity positioning reproducing the standing position (controlled MRI) were studied. For each hip, the IFS measured in the noncontrolled MRI was compared to the IFS measured in the controlled MRI. The categorization of a hip as presenting decreased IFS (≤17 mm) or normal IFS (>17 mm) changed in 19% of the hips when comparing the noncontrolled MRI to the controlled MRI. From the 32 hips (34%) with a difference ≥4 mm in the IFS, the predominant positioning change was hip flexion/extension in 47%, hip rotation in 44%, and hip abduction/adduction in 9%. In conclusion, a difference >4 mm in the IFS was observed in 1 out of every 3 hips when comparing noncontrolled MRI with controlled MRI reproducing the lower limb positioning in the standing position.

Hip-spine syndrome: rationale for ischiofemoral impingement, femoroacetabular impingement and abnormal femoral torsion leading to low back pain.

The term 'hip-spine syndrome' was introduced in recognition of the frequent occurrence of concomitant symptoms at the hip and lumbar spine. Limitations in hip range of motion can result in abnormal lumbopelvic mechanics. Ischiofemoral impingement, femoroacetabular impingement and abnormal femoral torsion are increasingly linked to abnormal hip and spinopelvic biomechanics. The purpose of this narrative review is to explain the mechanism by which these three abnormal hip pathologies contribute to increased low back pain in patients without hip osteoarthritis. This paper presents a thorough rationale of the anatomical and biomechanical characteristics of the aforementioned hip pathologies, and how each contributes to premature coupling and limited hip flexion/extension. The future of hip and spine conservative and surgical management requires the implementation of a global hip-spine-pelvis-core approach to improve patient function and satisfaction.

A biomechanical analysis of ischiofemoral impingement in a cadaver model.

Ischiofemoral impingement (IFI) occurs due to the diminishing of space between the ischium and lesser trochanter. During a robotic hip study, one hip presented with indications of IFI, an opportunity to explore the pathophysiology and treatment strategies for this unusual condition. This specimen underwent kinematic tests in two states: (i) native lesser trochanter and (ii) resected lesser trochanter. The 'Resected lesser trochanter' state was found to increase the hip range of motion and decrease femoral head translation by eliminating contact between the femur and pelvis. These results suggest that lesser trochanteric resection would provide physical benefit for IFI patients.

Anteroinferior Hip Instability in Flexion During Dynamic Arthroscopic Examination Is Associated With Abnormal Anterior Acetabular Horn.

BACKGROUND: The stabilization of the femoral head is provided by the distal acetabulum when the hip is in a flexed position. However, the osseous parameters for the diagnosis of hip instability in flexion are not defined. PURPOSE/HYPOTHESIS: To determine whether the osseous parameters of the distal acetabulum are different in hips demonstrating anteroinferior subluxation in flexion under dynamic arthroscopic examination, compared with individuals without hip symptoms. The hypothesis was that the morphometric parameters of the anterior acetabular horn are distinct in hips with anteroinferior instability compared with asymptomatic hips. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: A total of 30 hips with anteroinferior instability in flexion under dynamic arthroscopic examination were identified. A control group of 60 hips (30 patients), matched by age and sex, was formed from individuals who had undergone pelvis magnetic resonance imaging (MRI) for nonorthopaedic reasons. Unstable and control hips were compared according to the following parameters assessed on axial MRI scans of the pelvis: anterior sector angle (ASA), anterior horn angle (AHA), posterior sector angle (PSA), posterior horn angle (PHA), acetabular version, lateral center-edge angle, acetabular inclination (Tönnis angle), and femoral head diameter. RESULTS: The coverage of the femoral head by the anterior acetabular horn was decreased in unstable hips compared with the control group (mean ASA, 54.8° vs 61°, respectively; P < .001). Unstable hips also had a steeper anterior acetabular horn, with an increased mean AHA compared with controls (52.5° vs 46.8°, respectively; P < .001). An ASA <58° had a sensitivity of 0.8, a specificity of 0.68, a negative predictive value of 0.87, and a positive predictive value of 0.56 for anteroinferior hip instability. An AHA >50° had a sensitivity of 0.77, a specificity of 0.72, a negative predictive value of 0.86, and a positive predictive value of 0.57 for anteroinferior hip instability. There was no statistically significant difference in the mean PSA, PHA, acetabular version, lateral center-edge angle, acetabular inclination, or femoral head diameter between unstable hips and controls. CONCLUSION: Abnormal morphology of the anterior acetabular horn is associated with anteroinferior instability in hip flexion. The ASA and AHA can aid in the diagnosis of hip instability.

Proximal iliotibial band thickness as a cause for recalcitrant greater trochanteric pain syndrome.

To investigate iliotibial band (ITB) diameter thickness at the greater trochanter in patients requiring iliotibial band release who have failed conservative modalities, in comparison to an asymptomatic patient population. A total of 68 subjects were selected to be reviewed using T2 axial plane MRI. The ITB diameter thickness was measured in 34 subjects who underwent surgical ITB release, and compared with a match-paired asymptomatic hip cohort consisting of 34 subjects. ITB diameter thickness was measured at the thickest location for each subject twice by two different examiners. Inter/intra class correlation coefficient was determined for ITB measurement technique accuracy, and the presence of recalcitrant proximal hip pain was evaluated. Interclass correlation coefficient with 95% confidence was measured to be 0.953. The average thickness for ITB surgical release subjects was measured to be 5.61 ± 2.10 mm, and for asymptomatic subjects 3.77 ± 0.79 mm (P < 0.001). The results of this study demonstrate a statistically significant positive relationship of an increased diameter thickness in the ITB in symptomatic patients who failed conservative therapy and underwent surgical intervention for treatment.

Current Concepts Review: Evaluation and Management of Posterior Hip Pain.

Understanding the etiology of and evolving research on intra- and extra-articular hip complaints requires comprehensive diagnosis and management of the spectrum of posterior hip diseases. Interest in posterior hip disorders has increased in recent years as new studies and theories have emerged regarding the disease process. Although most of the differential diagnoses around the posterior hip have traditionally been considered uncommon, recent reports suggest that these complaints have instead been commonly overlooked. Failure to identify the cause of posterior hip pain in a timely manner can increase pain perception, deteriorate the patient's hope, and consequently affect quality of life. Posterior hip pain could be differentiated as intrapelvic and extrapelvic, and differential diagnosis is made based on a comprehensive history, physical examination, and imaging studies. Plain radiography, CT, MRI, 3T MRI, and imaging-guided injection tests are usually necessary for accurate diagnosis. Surgical intervention, whether endoscopic or open, is required for patients with long-standing symptoms for whom nonsurgical treatment has been unsuccessful and who have experienced temporary relief of their symptoms after injection. Orthopedic surgeons are uniquely trained in understanding the anatomy, biomechanics, clinical evaluation and treatment of all five layers of the hip.

Editorial Commentary: Hip Labral Revision Reconstruction in a Fellowship Training Center: A Report From the Mountains.

Hip labral reconstruction has proven to be a successful technique in restoring normal labrum function. However, sometimes revision surgery is required. A recent, well-designed prospective study provides significant support for revision labral reconstruction, showing how it leads to improved hip mechanics and reduction in pain. The success of the study design and this report is a testament to an educational institution dedicated to fellowship training.

Incorporating Hip Arthroscopy Into A Practice.

Hip arthroscopy is one of the most rapidly growing areas in orthopaedic surgery because of increased awareness of nonarthritic hip pathologies, advanced imaging modalities, and advanced techniques to reproducibly manage nonarthritic hip pathologies within a deep soft-tissue envelope and a constrained joint. In addition, more academic medical centers are providing residents with education on hip arthroscopy, and many hip preservation fellowships and courses are helping increase awareness of nonarthritic hip pathologies. Nonarthritic hip pathologies currently managed via hip arthroscopy include nonrepairable labral lesions, femoroacetabular impingement, hip instability, and hip fractures. Periarticular hip pathologies currently managed via endoscopy include greater trochanteric pain syndrome, tendinopathy and tears of the gluteus medius and minimus, partial and complete hamstring avulsions, and sciatic nerve entrapment. Ischiofemoral impingement may be addressed endoscopically via the deep gluteal space. Orthopaedic surgeons should understand the role and safety of hip arthroscopy in the pediatric population, specifically in the management of slipped capital femoral epiphysis, Legg-Calvé-Perthes disease, and septic arthritis of the hip. The efficacy of hip arthroscopy is limited, and hip arthroscopy is relatively contraindicated in patients with osteoarthritis and hip dysplasia. Complications can occur and likely are underreported in patients who undergo hip arthroscopy. Orthopaedic surgeons should understand practical issues associated with incorporating hip arthroscopy into a practice, including the difficult learning curve associated with hip arthroscopy and the reluctance of some payors to reimburse procedures performed arthroscopically because hip arthroscopy is a relatively new technology.

Accuracy of 3 Clinical Tests to Diagnose Proximal Hamstrings Tears With and Without Sciatic Nerve Involvement in Patients With Posterior Hip Pain.

PURPOSE: To determine the diagnostic accuracy of the active hamstring test at 30° (A-30) and 90° (A-90) of knee flexion, the long stride heel strike (LSHS) test, and combination of the 3 tests for individuals with hamstring tendon tears, with and without sciatic nerve involvement. METHODS: A retrospective review of 564 consecutive clinical records identified 42 subjects with a mean age of 50.31 ± 15 years who underwent a standard physical examination prior to magnetic resonance imaging (MRI) evaluation and diagnostic injection for posterior hip. The physical examination included the A-30, A-90, and LSHS tests. Sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were calculated to determine the diagnostic accuracy of these 3 tests. RESULTS: Forty-two subjects (female = 32 and male = 10) with a mean age of 50.31 years (range 15-77, ± SD 14.52) met the inclusion criteria and were included in the review. Based on MRI and/or injection, 64.28% (27/42) of subjects were diagnosed with hamstring tear. Fourteen (51.85%) presented with sciatic nerve involvement. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio for each test were as follows: A-30 knee flexion: 0.73, 0.97, 23.43, 0.28, and 84.73; A-90 knee flexion: 0.62, 0.97, 20.00, 0.39, and 51.67; LSHS: 0.55, 0.73, 2.08, 0.61, and 3.44. The most accurate findings were obtained when the results of the A-30 and A-90 were combined, with sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio of 0.84, 0.97, 26.86, 0.17, and 161.89, respectively. CONCLUSION: The combination of the active hamstring A-30 and A-90 tests proved to be a highly accurate and valuable tool to diagnose proximal hamstring tendons tears with or without sciatic nerve involvement in subjects presenting with posterior hip pain. LEVEL OF EVIDENCE: Level III, diagnostic study.