Clinical Assessment and Treatment Options for Posterior Hip Pain.

BACKGROUND: Diagnosis and treatment of posterior hip pain has increased due to advancements in clinical, anatomical, biomechanical, and related pathological understandings of the hip. Due to its complexity and close anatomical relationship with many osseous, neurovascular, and musculotendinous structures, posterior hip pain must be appropriately categorized based on its origin. Therefore, it is crucial that clinicians are able to determine whether patient complaints are of extra-articular or intra-articular nature so that they can implement the optimal treatment plan. In the current review article, we discussed posterior hip pain with an emphasis on the main differential diagnoses of deep gluteal syndrome, ischiofemoral impingement, and hamstring tear/hamstring syndrome. For the appropriate diagnosis and etiology of posterior hip pain, a thorough and conclusive clinical history is imperative. Physicians should rule out the possibility of spinal involvement by physical examination and if necessary, by magnetic resonance imaging (MRI). Furthermore, because of the vicinity to other, non-orthopedic structures, an obstetric and gynecologic history, general surgery history, and urologic history should be obtained. Following the collection of patient history clinicians should adhere to an established and efficient order of evaluation starting with standing then to seated, supine, lateral, and prone testing. Imaging assessment of posterior hip pain begins with a standard anterior-posterior pelvic radiograph, in addition to frog-leg lateral. MRI is pivotal for assessing soft tissue-related extra-articular causes of hip in patients with posterior hip pain. Non-surgical treatment is preferred in most cases of deep gluteal syndrome, ischiofemoral impingement, pudendal nerve entrapment, and proximal hamstring pathologies. Surgical treatment is saved as a last resort option in cases of failed non-surgical treatment.

Maximal hip muscle strength and rate of torque development 6-30 months after hip arthroscopy for femoroacetabular impingement syndrome: A cross-sectional study.

OBJECTIVES: Reduced sports function is often observed after hip arthroscopy for femoroacetabular impingement syndrome (FAIS). Impaired muscle strength could be reasons for this. We aimed to investigate hip muscle strength after hip arthroscopy for FAIS and its association with sports function and participation. DESIGN: Cross-sectional study. METHODS: We included 45 patients (34 males; mean age: 30.6 ±â€¯5.9 years) after unilateral hip arthroscopy for FAIS (mean follow-up [range]: 19.3 [9.8-28.4] months). Maximal isometric hip muscle strength (Nm/kg) including early- (0-100 ms) and late-phase (0-200 ms) rate of torque development (Nm∗kg-1∗s-1) for adduction, abduction, flexion, and extension was measured with an externally fixated handheld dynamometer and compared between operated and non-operated hip. Associations between muscle strength and self-reported sports function and return to sport were investigated. RESULTS: For maximal hip muscle strength, no between-hip differences were observed for adduction, abduction, flexion, and extension (p ≥ 0.102). For rate of torque development, significantly lower values were observed for the operated hip in flexion at both 0-100 ms (mean difference: 1.58 Nm∗kg-1∗s-1, 95% CI [0.39; 2.77], p = 0.01) and 0-200 ms (mean difference: 0.72 Nm∗kg-1∗s-1, 95% CI [0.09; 1.35], p = 0.027). Higher maximal hip extension strength was significantly associated with greater ability to participate fully in preinjury sport at preinjury level (odds ratio: 17.71 95% CI [1.77; 177.60]). CONCLUSIONS: After hip arthroscopy for FAIS subjects show limited impairments in maximal and explosive hip muscle strength between operated and non-operated hip. Higher muscle strength was positively associated with higher sports function and ability to participate in sport.

Hip Strength Before and After Arthroscopic Femoroacetabular Impingement Surgery.

Femoroacetabular impingement (FAI) and labral pathology are associated with pain, decreased function, and hip strength deficits. Existing data are in conflict regarding when hip strength normalizes following arthroscopic treatment of FAI. The objective of this study was to identify preoperative hip strength relative to the contralateral hip not undergoing surgery as well as when postoperative strength in 4 functional muscle groups normalizes following arthroscopic treatment of FAI. Ninety-eight individuals with radiographic evidence of FAI and labral pathology underwent arthroscopic labral repair. Pre-surgical hip strength testing was performed in the symptomatic "surgical hip" and the contralateral "non-surgical hip." Hip strength measurements were repeated at 8 and 16 weeks postoperatively. Significant preoperative hip strength deficits were noted in the surgical hip compared with the non-surgical hip in flexion, extension, and adduction. At 8 weeks postoperatively, hip strength in the surgical hip improved to being equivalent to that in the non-surgical hip in adduction and extension, remained equivalent to that of the non-surgical hip in abduction, and decreased in flexion relative to the non-surgical hip. At 16 weeks, hip strength remained equivalent in the surgical hip and the non-surgical hip in abduction and adduction, but the surgical hip exceeded the non-surgical hip in extension. While flexion strength improved between 8 and 16 weeks postoperatively for the surgical hip, it had not fully recovered to that of the non-surgical hip. Using a structured postoperative rehabilitation protocol, abduction strength was maintained at 8 weeks postoperatively, while adduction and extension strength had improved to those of the non-surgical hip. At 16 weeks postoperatively, hip abduction and adduction had strength equivalent to those of the non-surgical hip. Despite preoperative improvement, flexion of the surgical hip lagged behind that of the non-surgical hip 16 weeks postoperatively. [Orthopedics. 2021;44(3):148-153.].

Differences in lower-extremity kinematics between the male military personnel with and without plantar fasciitis.

OBJECTIVE: To evaluate the factors that influence gait by comparing lower extremity kinematics during the stance phase of the gait cycle between individuals with and without plantar fasciitis. DESIGN: A cross-sectional study. SETTING: Motion analysis research laboratory. PARTICIPANTS: Thirty subjects with plantar fasciitis and 30 aged-matched controls. MAIN OUTCOME MEASURE(S): Range of motion of the lower extremity and multi-segment foot during gait using a three-dimensional motion analysis system. RESULTS: The plantar fasciitis group showed significant differences in motion in the multi-segment foot, ankle, knee, and hip from the control group during various subphases of the stance phase. Specifically, relative to the control group, the plantar fasciitis group had more rearfoot adduction, forefoot eversion, ankle abduction, and hip abduction. They also had less midfoot dorsiflexion, forefoot dorsiflexion, knee extension, knee external rotation, and hip extension (all Ps < 0.05). CONCLUSIONS: Individuals with plantar fasciitis exhibited more flexibility in the ankle-foot complex and poorer quality of lower-extremity movement than the group that did not have plantar fasciitis. Thus, differences in structures in both the ankle-foot complex as well as those in the hip and knee joints appear to be associated with the presence of plantar fasciitis.

Does Patient-specific Functional Pelvic Tilt Affect Joint Contact Pressure in Hip Dysplasia? A Finite-element Analysis Study.

BACKGROUND: Although individual and postural variations in the physiologic pelvic tilt affect the acetabular orientation and coverage in patients with hip dysplasia, their effect on the mechanical environment in the hip has not been fully understood. Individual-specific, finite-element analyses that account for physiologic pelvic tilt may provide valuable insight into the contact mechanics of dysplastic hips, which can lead to further understanding of the pathogenesis and improved treatment of this patient population. QUESTION/PURPOSE: We used finite-element analysis to ask whether there are differences between patients with hip dysplasia and patients without dysplasia in terms of (1) physiologic pelvic tilt, (2) the pelvic position and joint contact pressure, and (3) the morphologic factors associated with joint contact pressure. METHODS: Between 2016 and 2019, 82 patients underwent pelvic osteotomy to treat hip dysplasia. Seventy patients with hip dysplasia (lateral center-edge angle ≥ 0° and < 20° on supine AP pelvic radiographs) were included. Patients with advanced osteoarthritis, femoral head deformity, prior hip or supine surgery, or poor-quality imaging were excluded. Thirty-two patients (32 hips) were eligible to this finite-element analysis study. For control groups, we reviewed 33 female volunteers without a history of hip disease. Individuals with frank or borderline hip dysplasia (lateral center-edge angle < 25°) or poor-quality imaging were excluded. Sixteen individuals (16 hips) were eligible as controls. Two board-certified orthopaedic surgeons measured sagittal pelvic tilt (the angle between the anterior pelvic plane and vertical axis: anterior pelvic plane [APP] angle) and acetabular version and coverage using pelvic radiographs and CT images. Intra- and interobserver reliabilities, evaluated using the kappa value and intraclass correlation coefficient, were good or excellent. We developed individual-specific, finite-element models using pelvic CT images, and performed nonlinear contact analysis to calculate the joint contact pressure on the acetabular cartilage during the single-leg stance with respect to three pelvic positions: standardized (anterior pelvic plane), supine, and standing. We compared physiologic pelvic tilt between patients with and without dysplasia using a t-test or the Wilcoxon rank sum test. A paired t-test or the Wilcoxon signed rank test with a Bonferroni correction was used to compare joint contact pressure between the three pelvic positions. We correlated joint contact pressure with morphologic parameters and pelvic tilt using the Pearson or the Spearman correlation coefficients. RESULTS: The APP angle in the supine and standing positions varied widely among individuals. It was greater in patients with hip dysplasia than in patients in the control group when in the standing position (3° ± 6° versus -2° ± 8°; mean difference 5° [95% CI 1° to 9°]; p = 0.02) but did not differ between the two groups when supine (8° ± 5° versus 5° ± 7°; mean difference 3° [95% CI 0° to 7°]; p = 0.06). The mean pelvic tilt was 6° ± 5° posteriorly when shifting from the supine to the standing position in patients with hip dysplasia. The median (range) maximum contact pressure was higher in dysplastic hips than in control individuals (in standing position; 7.3 megapascals [MPa] [4.1 to 14] versus 3.5 MPa [2.2 to 4.4]; difference of medians 3.8 MPa; p < 0.001). The median maximum contact pressure in the standing pelvic position was greater than that in the supine position in patients with hip dysplasia (7.3 MPa [4.1to 14] versus 5.8 MPa [3.5 to 12]; difference of medians 1.5 MPa; p < 0.001). Although the median maximum joint contact pressure in the standardized pelvic position did not differ from that in the standing position (7.4 MPa [4.3 to 15] versus 7.3 MPa [4.1 to 14]; difference of medians -0.1 MPa; p > 0.99), the difference in the maximum contact pressure varied from -3.3 MPa to 2.9 MPa, reflecting the wide range of APP angles (mean 3° ± 6° [-11° to 14°]) when standing. The maximum joint contact pressure in the standing position was negatively correlated with the standing APP angle (r = -0.46; p = 0.008) in patients with hip dysplasia. CONCLUSION: Based on our findings that individual and postural variations in the physiologic pelvic tilt affect joint contact pressure in the hip, future studies on the pathogenesis of hip dysplasia and joint preservation surgery should not only include the supine or standard pelvic position, but also they need to incorporate the effect of the patient-specific pelvic tilt in the standing position on the biomechanical environment of the hip. CLINICAL RELEVANCE: We recommend assessing postural change in sagittal pelvic tilt when diagnosing hip dysplasia and planning preservation hip surgery because assessment in a supine or standard pelvic position may overlook alterations in the hip's contact mechanics in the weightbearing positions. Further studies are needed to elucidate the effect of patient-specific functional pelvic tilt on the degeneration process of dysplastic hips, the acetabular reorientation maneuver, and the clinical result of joint preservation surgery.

Evaluation of the bent knee fall out test pre- and post- an adductor longus tenotomy.

OBJECTIVE: To investigate the immediate effect of an adductor longus tenotomy on the results of the bent knee fall out test, and whether there was a correlation between pre-tenotomy measures and the magnitude of change. DESIGN: Observational study. METHODS: We included recreational to elite athletes with longstanding adductor-related groin pain (specifically adductor longus insertion pain) undergoing unilateral or bilateral full adductor longus tenotomy. The bent knee fall out test was performed immediately prior and immediately after the surgical procedure. We used Wilcoxon signed-rank test to compare test results pre- and post-tenotomy, and Spearman's rho (rs) to analyse correlation between pre-tenotomy values and the magnitude of change in the bent knee fall out test. RESULTS: We consecutively included 60 male adult athletes. There was a statistically significant difference (p < 0.001) in the bent knee fall out result from pre-surgery (median 11.5 cm [IQR 9-15], range 5-25 cm) to post-surgery (median 8 cm [IQR 6-10], range 3-15 cm). The mean difference was 3.9 ± 2 cm, range 0-11 cm, corresponding to a large effect size, d = 1.92. There was a moderate correlation between the bent knee fall out measurement pre-tenotomy and the difference from pre-to-post, rs = 0.75, p < 0.001. CONCLUSION: The bent knee fall out measurements changed considerably immediately after an adductor longus tenotomy, showing that the test is assessing adductor longus flexibility in male athletes with longstanding adductor-related groin pain. There was a moderate correlation between the bent knee fall out measure pre-tenotomy and the magnitude of change.

The relationship of coronal trunk motion on the hip abductor moment impulse in pre-operative hip pathology patients during walking.

BACKGROUND: Compensatory mechanisms for hip pain, pathology, and weakness include excessive trunk lean towards the stance limb, counteracting pelvic drop to maintain stability during single leg stance. Trunk lean shifts the center of mass towards the hip joint center to decrease the moment arm and reduce hip abductor demand. The purpose of this study was to evaluate whether adolescent patients with symptomatic hip pain demonstrate excessive trunk lean and the effect on the hip abductor moment impulse. METHODS: Self-selected speed walking data collected through an approved study were reviewed on pre-operative patients clinically diagnosed with a hip deformity. Instrumented motion analysis was performed to analyze trunk kinematics and the hip abductor moment impulse. FINDINGS: There was a weak, but significant correlation between hip abductor moment impulse and trunk lean. Patients diagnosed with Acetabular Dysplasia demonstrated an increased trunk lean and a decreased hip abductor moment impulse (r = - 0.311, p = 0.001). Of those who presented with excessive trunk lean, 62% of these patients had a normal hip abductor moment impulse. There was no correlation between hip abductor moment impulse and hip abductor strength. INTERPRETATION: Excessive trunk lean was not seen uniformly across adolescent patients with symptomatic hip deformities, despite pain being reported in 80% of patients. Furthermore, a majority of those that presented with excessive trunk lean did not present with a reduced moment, suggesting that although the amount of lean was greater than normal, it was not enough to significantly reduce the demand on the hip musculature.

Prearthritic Hip Disease: Important Issues.

Prearthritic hip disease is challenging to define, diagnose, and treat. The mechanically abnormal hip, which has not yet suffered irreversible damage but will do so if its abnormal mechanics are not corrected, can be considered to be in a prearthritic stage. A conundrum regarding the treatment of many patients with a variety of hip diseases involving a hip at mechanical risk is that the best opportunity for preventing progressive osteoarthritis lies in the period before symptoms are severe enough to demand treatment solely on that basis. It is difficult to institute treatment for a minimally symptomatic but at-risk hip because of the multitude of variables that affect symptoms and hip longevity. Input from an established team of multiple hip experts with varying areas of expertise is ideal. Shared decision-making is highly effective in this prearthritic situation of high patient sensitivity. The cornerstone of treatment of the prearthritic hip is the correction of the problematic mechanical abnormality. As methods of analysis and treatment methods evolve and as long-term outcomes of treatments become understood, the role of intervention during the prearthritic stage of hip disease is likely to increase.

Hip Muscle Forces and Contact Loading During Squatting After Cam-Type FAI Surgery.

BACKGROUND: The purpose of this study was to compare muscle forces and hip contact forces (HCFs) during squatting in patients with cam-type femoroacetabular impingement (cam-FAI) before and after hip corrective surgery and with healthy control participants. METHODS: Ten symptomatic male patients with cam-FAI performed deep squatting preoperatively and at 2 years postoperatively. Patients were matched by age and body mass index to 10 male control participants. Full-body kinematics and kinetics were computed, and muscle forces and HCFs were estimated using a musculoskeletal model and static optimization. Normalized squat cycle (%SC) trials were compared using statistical nonparametric mapping (SnPM). RESULTS: Postoperatively, patients with cam-FAI squatted down with higher anterior pelvic tilt, higher hip flexion, and greater hip extension moments than preoperatively. Preoperative patients demonstrated lower anterior pelvic tilt and lower hip flexion compared with the participants in the control group. Postoperative patients showed increased semimembranosus force compared with their preoperative values. Preoperative forces were lower than the control group for the adductor magnus, the psoas major, and the semimembranosus; however, the preoperative patients showed greater inferior gluteus maximus forces than the patients in the control group, whereas the postoperative patients did not differ from the control patients. Higher posterior, superior, and resultant HCF magnitudes were identified postoperatively in comparison with the preoperative values. Preoperative posterior HCF was lower than in the control group, whereas the postoperative posterior HCF did not differ from those in the control group. CONCLUSIONS: Higher postoperative anterior pelvic tilt was associated with an indication of return to closer to normal pelvic motion, which resembled data from the control group. Lower preoperative anterior pelvic tilt was associated with muscle force imbalance, indicated by decreased semimembranosus and increased gluteus maximus forces. The overall increased postoperative muscle forces were associated with improved pelvic mobility and increased HCFs that were comparable with the control-group standards. CLINICAL RELEVANCE: Muscle forces and HCFs may be indicative of postoperative joint health restoration and alleviated symptoms.

Impingement-free hip range of motion after osteochondroplasty and relative neck lengthening in adults with healed Perthes disease.

OBJECTIVE: Our main objective is to assess the efficiency of the osteochondroplasty with relative neck lengthening in adults with healed Perthes clinically (through assessment of impingement-free hip ROM, functional scores) and radiographically. PATIENTS AND METHODS: This was a prospective case series study included 30 hips of 30 patients who underwent osteochondroplasty and RNL due to symptomatic healed LCPD. This study included 16 males (53.3%) and 14 females (46.7%). The age of patients ranged from 19 to 40 years with mean age 26.4 years at the date of surgery (SD 6.4). RESULTS: Median time of follow-up was 27.7 months after surgery (range 12-60 months). Two patients (6.6%) developed avascular necrosis (AVN) and needing total hip replacement; none of our patients developed nerve injury, detachment of the trochanteric fragment, and wound infection needing treatment. Preoperative Stulberg classes II and III improved more than preoperative Stulberg classes IV and V, although not statistically significant (P = 0.1104, n = 30). The mean HHS and WOMAC score values for each patient were higher in the Stulberg II and III groups compared to the Stulberg IV and V groups CONCLUSION: Head and neck osteochondroplasty performed through the surgical dislocation approach, combined with RFNL, relieved pain and restored function in most of the patients with reasonable complications. LEVEL OF EVIDENCE: IV.

Hip and Shoulder Involvement and Their Management in Axial Spondyloarthritis: a Current Review.

PURPOSE OF REVIEW: Hip and shoulder disease can occur in patients with spondyloarthritis (SpA). While hip involvement has been widely assessed in axial SpA patients, studies in the overall SpA population as well as studies focused on shoulder involvement are scarce. Here, we review the most recent studies on the epidemiology, evaluation, and treatment of root joint involvement in SpA patients. RECENT FINDINGS: Radiological hip involvement can affect up to 25% of patients with SpA, reflecting more severe disease and associated with functional impairment. Shoulder involvement in SpA patients is characterized by cuff tendinitis and enthesitis, while primary glenohumeral joint involvement is rare. Anti-tumor necrosis factor (anti-TNF) treatment in SpA patients seems to have an effect on hip arthritis, showing a change in trend in the frequency of hip replacement in this population. The majority of studies evaluating hip involvement have focused on axial SpA patients, but further studies evaluating root joint involvement in the overall SpA population are needed. Anti-TNF therapy should be considered in patients with hip involvement, and root joint involvement should be assessed routinely in clinical practice.

Return to play after hip arthroscopy among tennis players: outcomes with minimum five-year follow-up.

BACKGROUND: Playing tennis is associated with various movements that can lead to labral injuries and may require arthroscopic surgery. While hip arthroscopies have demonstrated good outcomes in athletes, there is limited literature reporting patient reported outcomes (PROs) and return to sport (RTS) in competitive or recreational tennis players after arthroscopic hip surgery. Therefore, the purpose of the present study was to (1) report minimum five-year PROs and RTS in tennis players who underwent arthroscopic hip surgery and (2) compare outcomes between recreational and competitive tennis players. METHODS: Data for patients who underwent hip arthroscopy surgery in the setting of femoroacetabular impingement and labral tears between March 2009 and January 2014 and who played tennis within one-year of surgery were retrospectively reviewed. Patients with preoperative and minimum five-year postoperative scores for the following PROs were included: modified Harris Hip Score (mHHS), Non-Arthritic Hip Score (NAHS), Hip Outcome Score-Sport Specific Subscale (HOS-SSS), and visual analog scale (VAS) for pain. Patient Acceptable Symptomatic State (PASS) and Minimal Clinically Important Difference (MCID) for mHHS and HOS-SSS were calculated. RESULTS: Of 28 patients, 31 hips met all inclusion and exclusion criteria of which 28 (90.3%) had minimum 5-year follow-up (mean: 72.8 ± 13.9 months). There were 3 professional, 3 collegiate, 2 high school, 2 organized amateur, and 18 recreational level tennis players. All PROs significantly improved at latest follow-up: mHHS from 67.0 to 86.7 (P <  0.001), NAHS from 65.9 to 87.2 (P <  0.001), HOS-SSS from 50.0 to 77.9 (P = 0.009), and VAS from 5.4 to 1.8 (P <  0.001). There was a 75.0% RTS rate. Additionally, 66.7% of patients achieved MCID and 83.3% achieved PASS for mHHS, and 63.6% achieved MCID and 58.3% achieved PASS for HOS-SSS. CONCLUSION: Regardless of the level of participation, tennis players who underwent arthroscopic hip surgery reported statistically significant PRO improvements. A favorable rate of RTS was also achieved by players with a continued interest in playing. The data here may be useful in counseling tennis players of various levels who are considering arthroscopic treatment of a hip injury. LEVEL OF EVIDENCE: IV.

Gluteus Maximus Transfer as an Augmentation Technique for Patients With Severe Abductor Deficiency of the Hip.

Impaired abductor function of the hip following severe abductor deficiencies can be devastating for functionality and quality of life. Recently, gluteus maximus transfer has been proposed as a solution to these difficult problems. However, outcome results are sparse. The aim of this study was to evaluate the effects of gluteus maximus transfer on improvement of pain, disability, and quality of life in patients with severe hip abductor deficiencies. Gluteus maximus transfer was performed in 16 patients with severe disruption of the abductor muscles of the hip. Data were collected preoperatively and at 6 weeks, 3 and 6 months, and 1 to 2 years after surgery. The measurements pertained to complications, healing of the flap based on magnetic resonance imaging (MRI) findings (in 10 patients), evaluation of Trendelenburg gait and sign, and patient-reported outcome measures of pain, disability, and quality of life. Preoperatively, all patients had a positive Trendelenburg sign and reported severe pain at the level of the greater trochanter. At a mean follow-up of 20 months, the Trendelenburg sign was negative in 7 patients and the Trendelenburg gait had disappeared in 7 patients. There was an improvement in patient-reported outcome measures but not to a significant level except for the pain subscores. Two patients had a postoperative seroma that resulted in a visible bump on the lateral side. Seven of 10 repairs with MRI follow-up showed perfect ingrowth on MRI without signs of rerupture. Gluteus maximus transfer for abductor deficiency of the hip may be effective for pain relief and functional improvements. Most patients showed an improved quality of life but were not completely pain free. [Orthopedics. 2020;43(4):e299-e305.].

Long-term results of total hip arthroplasty in developmental dysplasia of hip patients.

OBJECTIVES: This study aims to report the physiological and radiological long-term results of total hip arthroplasty (THA) combined with or without subtrochanteric osteotomy in a group of developmental dysplasia of hip (DDH) patients. PATIENTS AND METHODS: This retrospective study included 90 hips of 59 patients (3 males, 56 females; mean age 45.7±10.9 years; range, 24 to 67 years) who underwent THA between January 1979 and March 2006. Thirteen patients needed subtrochanteric shortening. The evaluation was performed through Harris hip scores, physical examination, and radiological imaging. RESULTS: The follow-up period ranged from 5 to 32 years, and the mean follow-up period was 10.3±6.4 years. Revision was required in 17 hips out of 90. Twelve revisions were needed because of aseptic loosening of femoral or acetabular component, three were for fracture of the femoral stem, and two for protrusio acetabuli. Four patients had transient nerve palsy, and one had permanent nerve function loss. In one patient, nonunion was observed around the femoral osteotomy site. Harris hip score was remarkably improved compared to top preoperative values (48 vs. 88.2, p<0.01). CONCLUSION: Although revision rates tend to increase in long-term follow-up, THA is one of the best treatment options in DDH patients to relieve pain, improve daily activity levels, and minimize the damage of the knee and lumbar region.

Consensus recommendations on the classification, definition and diagnostic criteria of hip-related pain in young and middle-aged active adults from the International Hip-related Pain Research Network, Zurich 2018.

There is no agreement on how to classify, define or diagnose hip-related pain-a common cause of hip and groin pain in young and middle-aged active adults. This complicates the work of clinicians and researchers. The International Hip-related Pain Research Network consensus group met in November 2018 in Zurich aiming to make recommendations on how to classify, define and diagnose hip disease in young and middle-aged active adults with hip-related pain as the main symptom. Prior to the meeting we performed a scoping review of electronic databases in June 2018 to determine the definition, epidemiology and diagnosis of hip conditions in young and middle-aged active adults presenting with hip-related pain. We developed and presented evidence-based statements for these to a panel of 37 experts for discussion and consensus agreement. Both non-musculoskeletal and serious hip pathological conditions (eg, tumours, infections, stress fractures, slipped capital femoral epiphysis), as well as competing musculoskeletal conditions (eg, lumbar spine) should be excluded when diagnosing hip-related pain in young and middle-aged active adults. The most common hip conditions in young and middle-aged active adults presenting with hip-related pain are: (1) femoroacetabular impingement (FAI) syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without a distinct osseous morphology (labral, chondral and/or ligamentum teres conditions), and that these terms are used in research and clinical practice. Clinical examination and diagnostic imaging have limited diagnostic utility; a comprehensive approach is therefore essential. A negative flexion-adduction-internal rotation test helps rule out hip-related pain although its clinical utility is limited. Anteroposterior pelvis and lateral femoral head-neck radiographs are the initial diagnostic imaging of choice-advanced imaging should be performed only when requiring additional detail of bony or soft-tissue morphology (eg, for definitive diagnosis, research setting or when planning surgery). We recommend clear, detailed and consistent methodology of bony morphology outcome measures (definition, measurement and statistical reporting) in research. Future research on conditions with hip-related pain as the main symptom should include high-quality prospective studies on aetiology and prognosis. The most common hip conditions in active adults presenting with hip-related pain are: (1) FAI syndrome, (2) acetabular dysplasia and/or hip instability and (3) other conditions without distinct osseous morphology including labral, chondral and/or ligamentum teres conditions. The last category should not be confused with the incidental imaging findings of labral, chondral and/or ligamentum teres pathology in asymptomatic people. Future research should refine our current recommendations by determining the clinical utility of clinical examination and diagnostic imaging in prospective studies.

Hip Kinematics During Single-Leg Tasks in People With and Without Hip-Related Groin Pain and the Association Among Kinematics, Hip Muscle Strength, and Bony Morphology.

OBJECTIVE: To compare 3-D hip kinematics during the single-leg squat and step-down in patients with hip-related groin pain to those in asymptomatic participants, and to assess relationships among hip kinematics, muscle strength, and bony morphology. DESIGN: Controlled laboratory cross-sectional study. METHODS: Forty patients with hip-related groin pain and 40 matched, asymptomatic participants between 18 and 40 years of age participated. A handheld dynamometer was used to assess hip abductor and external rotator strength. An 8-camera motion-analysis system was used to quantify 3-D kinematics during the single-leg squat and step-down. Magnetic resonance imaging was used to quantify bony morphology. The independent t test and Mann-Whitney U test were used to assess between-group differences. Pearson coefficient correlations were used to assess relationships. RESULTS: Patients with hip-related groin pain had smaller peak hip flexion angles, smaller knee flexion angles, and lesser squat depth compared to asymptomatic participants during the single-leg squat. Among patients with hip-related groin pain, smaller hip flexion angles during the single-leg squat were associated with hip abductor weakness (r = 0.47, P≤.01). Among asymptomatic participants, smaller peak hip flexion angles during the single-leg squat were associated with less acetabular coverage (r = 0.33, P = .04) and shallow squat depth (r = 0.48, P≤.01); a smaller hip internal rotation angle during the step-down was associated with larger femoral neck shaft angle (r = -0.43, P<.01). CONCLUSION: Compared to asymptomatic participants, patients with hip-related groin pain had smaller hip and knee flexion angles and shallower squat depth during the single-leg squat. Smaller hip flexion angles were associated with hip abductor weakness among those with hip-related groin pain. J Orthop Sports Phys Ther 2020;50(5):243-251. Epub 6 Jan 2020. doi:10.2519/jospt.2020.9150.

Portable imageless navigation system and surgeon's estimate for accurate evaluation of acetabular cup orientation during total hip arthroplasty in supine position.

BACKGROUND: This prospective study aimed to clarify whether this novel device can evaluate the cup orientation during total hip arthroplasty (THA) more closely to that measured in postoperative computed tomography (CT) compared to the surgeon's estimate using a manual goniometer. METHODS: We prospectively performed 30 cementless THAs via the anterolateral approach in supine position between October 2018 and July 2019, wherein cup orientation was evaluated by both a portable imageless navigation system (HipAlign) and a manual goniometer during surgeries. Primary outcome was the absolute estimate error [the absolute value of the difference between cup angles measured by postoperative CT and those measured by HipAlign (group H) or surgeon's estimate using the manual goniometer (group S) during surgery]. The number of outliers of the absolute estimate error (> 10°) in each group was also estimated. RESULTS: The absolute estimate error of cup inclination in groups H and S was 3.3° ± 2.7° and 3.0° ± 2.5°, respectively (p = 0.51), whereas that of cup anteversion was 3.8° ± 3.4° and 6.0° ± 3.7°, respectively (p = 0.0008). The number of outliers of the estimate error in groups H and S was one case (3.3%) and six cases (20.0%), respectively (p = 0.04). In all six outlier cases, surgeons underestimated cup anteversion during surgeries. CONCLUSIONS: This portable imageless navigation system was a useful method, especially for avoiding incorrect cup anteversion. Underestimation of cup anteversion during THA in the supine position with the conventional alignment assisting device should be given attention.

A reliable time-series method for predicting arthritic disease outcomes: New step from regression toward a nonlinear artificial intelligence method.

BACKGROUND AND OBJECTIVE: The interrupted time-series (ITS) concept is performed using linear regression to evaluate the impact of policy changes in public health at a specific time. Objectives of this study were to verify, with an artificial intelligence-based nonlinear approach, if the estimation of ITS data could be facilitated, in addition to providing a computationally explicit equation. METHODS: Dataset were from a study of Hawley et al. (2018) in which they evaluated the impact of UK National Institute for Health and Care Excellence (NICE) approval of tumor necrosis factor inhibitor therapies on the incidence of total hip (THR) and knee (TKR) replacement in rheumatoid arthritis patients. We used the newly developed Generalized Structure Group Method of Data Handling (GS-GMDH) model, a nonlinear method, for the prediction of THR and TKR incidence in the abovementioned population. RESULTS: In contrast to linear regression, the GS-GMDH yields for both THR and TKR prediction values that almost fitted with the measured ones. These models demonstrated a low mean absolute relative error (0.10 and 0.09 respectively) and high correlation coefficient values (0.98 and 0.78). The GS-GMDH model for THR demonstrated 6.4/1000 person years (PYs) at the mid-point of the linear regression line post-NICE, whereas at the same point linear regression is 4.12/1000 PYs, a difference of around 35%. Similarly for the TKR, the linear regression to the datasets post-NICE was 9.05/1000 PYs, which is lower by about 27% than the GS-GMDH values of 12.47/1000 PYs. Importantly, with the GS-GMDH models, there is no need to identify the change point and intervention lag time as they simulate ITS continually throughout modelling. CONCLUSIONS: The results demonstrate that in the medical field, when looking at the estimation of the impact of a new drug using ITS, a nonlinear GS-GMDH method could be used as a better alternative to regression-based methods data processing. In addition to yielding more accurate predictions and requiring less time-consuming experimental measurements, this nonlinear method addresses, for the first time, one of the most challenging tasks in ITS modelling, i.e. avoiding the need to identify the change point and intervention lag time.

Bone Health Following Bariatric Surgery: An Update.

Obesity rates are increasing rapidly, and bariatric surgery is currently the most effective tool for weight loss. Recently, bariatric surgery induced bone loss has gained attention. Such detrimental effect on bone is multifactorial and causes may include nutrient deficiencies, gut and gonadal hormonal changes, mechanical unloading, loss of lean mass, increased bone marrow fat, and increased risk of fall. This review describes the available evidence on bone loss and fracture risk following bariatric surgery and summarizes the guidelines on the topic. Increased bone resorption starts early postsurgery, and bone markers peak at 1-2 yr. Across studies, the drop in areal bone mineral density is inconsistent at the lumbar spine, while a 2%-5% drop at 6 mo and a 6%-10.5% at 9-12 mo are observed at the total hip. Conversely, studies using quantitative CT showed a 6%-7% decrease in volumetric bone mineral density at the lumbar spine at 6-12 mo postsurgery. These studies also report significant bone loss at the radius and tibia, in addition to alteration in bone microarchitecture. Fracture risk increases 2 yr after surgery, more so following malabsorptive procedures. Fractures were reported at axial, weight bearing sites and at appendicular sites. The available evidence is very heterogeneous, and mostly derived from studies on Roux-en-y gastric bypass in premenopausal women. Data on restrictive procedures is scarce. Our findings suggest that the early postoperative phase represents the "golden window" to intervene and promote bone health. More research is needed to determine the effect of different bariatric procedures on bone, to identify optimal interventions to prevent bone loss and to characterize high risk individuals who should be targeted.

Relaxed Hip Precautions Do Not Increase Early Dislocation Rate Following Total Hip Arthroplasty.

INTRODUCTION: Historically, hip precautions have been prescribed after total hip arthroplasty (THA) to limit certain motions felt to place the arthroplasty construct in a position at increased risk for dislocation. This study aimed to determine whether relaxed hip precautions after primary THA done via a posterolateral approach resulted in a higher early dislocation rate compared with standard hip precautions. METHODS: The hip precaution protocol was changed from standard to relaxed at our institution for all patients with THA in December 2016. One cohort had THA in the 18 months before the protocol change and had standard hip precautions, and the second cohort had THA in the 18 months after the protocol change and had relaxed precautions. We determined the early dislocation rate (within 3 months postoperatively) for both cohorts and controlled for selected demographic and surgical details. RESULTS: The standard precaution group included 597 primary THAs and the relaxed precaution group included 692 hips. No notable differences were found between the groups in terms of age at surgery, body mass index, sex, laterality, or diagnosis. Early dislocation occurred in seven hips (1.2%) in the standard precaution cohort and in nine hips (1.4%) in the relaxed precaution cohort. This difference was not statistically significant (P = 0.77). DISCUSSION: The results of our study suggest that well-trained, high-volume surgeons may potentially relax hip precautions prescribed to the patients after primary THA done via a posterolateral approach without subjecting patients to a markedly higher incidence of dislocation. However, unlike previous studies, this study controlled for femoral head size, which is a well-known confounder for dislocation risk.