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

Spine-Abductor Syndrome: Novel Associations Between Lumbar Spine Disease and Hip Gluteal Muscle Pathology

BACKGROUND

Risk factors for gluteal tears include age-related deterioration, female sex, and increased body mass index. As the literature that supports the sagittal relationship between the lumbar spine and the hip is increasing, there may be a parallel relationship between the perturbations in spinopelvic alignment caused by lumbar spine disease and gluteal muscle tears. Because no prior studies other than single-institution series have reported on this phenomenon, we investigated spine-abductor syndrome at the population level.

METHODS

This study utilized TriNetX, a federated research network that continuously aggregates deidentified electronic health record data from >92 million patients across the United States. The relative risks of gluteal tear encounter diagnoses and procedures were calculated for patients with and without the following characteristics: age ≥45 years, female sex, obesity, lumbar spine diagnoses, lumbar spine injections, and lumbar spine surgery. Utilizing the Cox proportional hazard model, we also analyzed gluteal tear-free survival over a period of ≥10 years in subgroups of patients who had been diagnosed with lumbar pathology, had been administered a lumbar injection, or had received lumbar surgery.

RESULTS

Of the 8,475,800 patients who had received lumbar spine diagnoses, undergone lumbar injections, and/or undergone lumbar surgeries, 458,311 patients (5.4%) had gluteal tears, representing a relative risk of 13.6 (95% confidence interval [CI]:13.6 to 13.6). After controlling for age, sex, and obesity, survival analysis showed markedly increased hazard ratios (HRs) for patients having a gluteal tear encounter diagnosis in the intervening 13 years (2010 to 2023) if they had had a previous lumbar spine pathology encounter diagnosis (HR: 4.8, 95% CI: 4.5 to 5.1), had undergone lumbar spine injections (HR: 7.7, 95% CI: 6.2 to 9.5), or had undergone lumbar spine surgery (HR: 6.6, 95% CI: 5.3 to 8.1) in 2010.

CONCLUSIONS

These findings suggest a strong association between lumbar spine pathology and abductor tears. Further biomechanical and neuroanatomic studies may elucidate the effects of lumbar spine disease in relation to gluteal tears. Additionally, there may be a need to optimize diagnostic protocols for lateral hip pain in patients with a history of lumbar spine disease.

LEVEL OF EVIDENCE

Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Ischiofemoral Impingement Syndrome in 2024: Updated Concepts and Imaging Methods

Ischiofemoral impingement syndrome (IFI) is a source of extra-articular pain caused by narrowing between ischium and femur in native hips. Secondary compression of quadratus femoris muscle leads to edema, tears, and deep gluteal pain. IFI is more frequent in females, with evidence pointing to a combination of hip, spine, and pelvic biomechanics and morphology leading to abnormal osseous relationships. This article provides updated concepts regarding the diagnosis, biomechanics, imaging, and treatment strategies for IFI. Moreover, IFI is emphasized as a multifactorial native hip syndrome, in contrast to ischiofemoral narrowing from secondary causes such as surgery, trauma, or masses.

Increased Femoral Neck Anteversion is Prevalent in Male Elite Youth Soccer Players with Chronic Ankle Instability

Purpose

The aim of this study was to compare femoral neck anteversion (FNA) and determine the prevalence of increased FNA in male elite youth soccer players with and without chronic ankle instability (CAI). Secondary aims were to evaluate the utility of FNA in predicting CAI and compare ankle and hip muscle strength in the two groups.

Materials and methods

The study included a total of 44 male elite youth soccer players, 22 with CAI (mean age 16.09 ± 1.34) and 22 without CAI (mean age 16.73 ± 1.28). FNA was measured with Craig's test, range of motion (ROM) was measured with a universal goniometer, and ankle and hip maximum voluntary isometric strength (MVIS) was measured with a handheld dynamometer.

Results

The mean FNA angles of the CAI and control groups were 15.82° ± 1.44° and 12.09° ± 2.37°, respectively (p > 0.05). FNA was greater than 15° in 72% of the CAI group versus 4% of the control group (p < 0.05). A 1° increase in FNA was associated with threefold higher odds of having CAI (odds ratio 3.06, 95% confidence ratio: 1.37-6.81, p < 0.01). Mean ankle eversion and hip abduction MVIS values were 2.67 ± 0.52 Nm/kg and 3.83 ± 0.48 Nm/kg in the CAI group, compared to 3.03 ± 0.58 Nm/kg and 4.46 ± 0.98 Nm/kg in the control group, respectively (p < 0.05).

Conclusion

Male elite youth soccer players with CAI had greater FNA and were more likely to have increased FNA than those without CAI. They also exhibited ankle eversion and hip abduction muscle strength deficiencies compared to peers without CAI. FNA may be useful as a predictor of CAI in male elite youth soccer players.

Machine Learning Models for Low Back Pain Detection and Factor Identification: Insights From a 6-Year Nationwide Survey

This study aimed to enhance performance, identify additional predictors, and improve the interpretability of biopsychosocial machine learning models for low back pain (LBP). Using survey data from a 6-year nationwide study involving 17,609 adults aged ≥50 years (Korea National Health and Nutrition Examination Survey), we explored 119 factors to detect LBP in individuals who reported experiencing LBP for at least 30 days within the previous 3 months. Our primary model, model 1, employed eXtreme Gradient Boosting (XGBoost) and selected primary factors (PFs) based on their feature importance scores. To extend this, we introduced additional factors, such as lumbar X-ray findings, physical activity, sitting time, and nutrient intake levels, which were available only during specific survey periods, into models 2 to 4. Model performance was evaluated using the area under the curve, with predicted probabilities explained by SHapley Additive exPlanations. Eleven PFs were identified, and model 1 exhibited an enhanced area under the curve .8 (.77-.84, 95% confidence interval). The factors had varying impacts across individuals, underscoring the need for personalized assessment. Hip and knee joint pain were the most significant PFs. High levels of physical activity were found to have a negative association with LBP, whereas a high intake of omega-6 was found to have a positive association. Notably, we identified factor clusters, including hip joint pain and female sex, potentially linked to osteoarthritis. In summary, this study successfully developed effective XGBoost models for LBP detection, thereby providing valuable insight into LBP-related factors. Comprehensive LBP management, particularly in women with osteoarthritis, is crucial given the presence of multiple factors. PERSPECTIVE: This article introduces XGBoost models designed to detect LBP and explores the multifactorial aspects of LBP through the application of SHapley Additive exPlanations and network analysis on the 4 developed models. The utilization of this analytical system has the potential to aid in devising personalized management strategies to address LBP.

Ischiofemoral impingement syndrome: A five-case series report

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

[Preoperative MR imaging for hip dysplasia : Assessment of associated deformities and intraarticular pathologies]

BACKGROUND

Developmental dysplasia of the hip (DDH) is a known reason for hip pain for adolescents and young adults. Preoperative imaging is increasingly recognized as an important factor due to the recent advances in MR imaging.

OBJECTIVES

The aim of this article is to give an overview of preoperative imaging for DDH. The acetabular version and morphology, associated femoral deformities (cam deformity, valgus and femoral antetorsion) and intraarticular pathologies (labrum and cartilage damage) and cartilage mapping are described.

METHODS

After an initial evaluation with AP radiographs, CT or MRI represent the methods of choice for the preoperative evaluation of the acetabular morphology and cam deformity, and for the measurement of femoral torsion. Different measurement techniques and normal values should be considered, especially for patients with increased femoral antetorsion because this could lead to misinterpretation and misdiagnosis. MRI allows analysis of labrum hypertrophy and subtle signs for hip instability. 3D MRI for cartilage mapping allows quantification of biochemical cartilage degeneration and yields great potential for surgical decision-making. 3D-CT and, increasingly, 3D MRI of the hip to generate 3D pelvic bone models and subsequent 3D impingement simulation can help to detect posterior extraarticular ischiofemoral impingement.

RESULTS AND DISCUSSION

Acetabular morphology can be divided in anterior, lateral and posterior hip dysplasia. Combined osseous deformities are common, such as hip dysplasia combined with cam deformity (86%). Valgus deformities were reported in 44%. Combined hip dysplasia and increased femoral antetorsion can occur in 52%. Posterior extraarticular ischiofemoral impingement between the lesser trochanter and the ischial tuberosity can occur in patients with increased femoral antetorsion. Typically, labrum damage and hypertrophy, cartilage damage, subchondral cysts can occur in hip dysplasia. Hypertrophy of the muscle iliocapsularis is a sign for hip instability. Acetabular morphology and femoral deformities (cam deformity and femoral anteversion) should be evaluated before surgical therapy for patients with hip dysplasia, considering the different measurement techniques and normal values of femoral antetorsion.

Hip-Spine Syndrome in the Nonarthritic Patient

Hip-spine syndrome refers to concurrent hip and spine pathology with overlapping symptoms. Most of the literature has studied it in relation to total hip arthroplasty literature and has been shown to increase dislocation risk. Lumbar spine and pelvic mobility have been studied less frequently in relation to nonarthritic pathologic hip states. Understanding the biomechanical relationship between the lumbar spine, pelvis, and hip can help elucidate how hip-spine syndrome affects the nonarthritic hip and how it impacts outcomes of hip arthroscopy. Changes in lumbar spine motion may be the reason certain predisposed patients develop symptomatic femoroacetabular impingement (FAI) or ischiofemoral impingement. Some athletes may be "hip users" with a low pelvic incidence, making them more reliant on hip motion due to less-intrinsic lumbopelvic motion. When these patients have FAI morphology, their increased reliance on hip motion makes them prone to experiencing femoroacetabular contact and concurrent symptoms. Other athletes may be "spine users," with larger pelvic incidence and more baseline lumbopelvic motion, making them less reliant on hip motion and therefore less prone to experiencing hip impingement even with hip FAI morphology. Hip-spine syndrome also appears to have an impact on patient selection, role of nonoperative treatment, and hip arthroscopy surgical outcomes. Identifying patients with concurrent pathology may allow surgeons to recommend targeted physical therapy or counsel patients better on their expectations after surgery.

Neuromuscular Consequences of Lumbopelvic Dysfunction: Research and Clinical Perspectives

Injuries involving the lumbopelvic region (ie, lumbar spine, pelvis, hip) are common across the lifespan and include pathologies such as low back pain, femoroacetabular impingement syndrome, labrum tear, and osteoarthritis. Joint injury is known to result in an arthrogenic muscle response which contributes to muscle weakness and altered movement patterns. The purpose of this manuscript is to summarize the arthrogenic muscle response that occurs across lumbopelvic region pathologies, identify methods to quantify muscle function, and propose suggestions for future research. While each lumbopelvic region pathology is unique, there are a few common impairments and a relative consistent arthrogenic muscle response that occurs across the region. Hip muscle weakness and hip joint range of motion limitations occur with both lumbar spine and hip pathologies, and individuals with low back pain are known to demonstrate inhibition of the transversus abdominis and multifidus. Assessment of muscle inhibition is often limited to research laboratory settings, but dynamometers, ultrasound imaging, and electromyography offer clinical capacity to quantify muscle function and inform treatment pathways. Future studies should systematically determine the arthrogenic muscle response across multiple muscle groups and the timeline for changes in muscle function and determine whether disinhibitory modalities improve functional outcomes beyond traditional treatment approaches.

[A study of low back pain and changes in spinal sagittal parameters after total hip arthroplasty in patients with unilateral Crowe type developmental dysplasia of the hip]

Objective

To investigate the changes of low back pain (LBP) and spinal sagittal parameters in patients with unilateral Crowe type Ⅳ developmental dysplasia of the hip (DDH) after total hip arthroplasty (THA).

Methods

The clinical data of 30 patients who met the selection criteria between October 2018 and March 2020 were retrospectively analyzed. Patients were divided into LBP group (16 cases) and control group (14 cases) according to whether there was LBP before operation. There was no significant difference between the two groups of patients in gender, age, body mass index, affected sides, preoperative Harris score ( P>0.05). Full-length lateral X-ray films of the spine were taken within 1 week before operation and at 1 year after operation, and the following imaging indicators were measured: sacral slope (SS), lumbar lordosis (LL ), spinal tilt (ST), spine-sacral angle (SSA), sagittal vertebral axis (SVA). The visual analogue scale (VAS) score, lumbar Oswestry disability index (ODI), the Harris score of the hip joint before operation and at 1 year after operation, and the occurrence of postoperative complications were collected and analysed.

Results

In the LBP group, LBP was relieved to varying degrees at 1 year after operation, of which 13 patients (81.3%) had complete LBP remission; VAS score decreased from 4.9±2.3 preoperatively to 0.3±0.8, ODI decreased from 33.5±22.6 preoperatively to 1.3±2.9, the differences were all significant ( t=7.372, P=0.000; t=5.499, P=0.000). There was no new chronic LBP in the control group during follow-up. The Harris scores of the two groups significantly improved when compared with those before operation ( P<0.05); there was no significant difference between the two groups at 1 year after operation ( t=0.421, P=0.677). There was no significant difference in imaging indexes between the two groups before operation and the difference between pre- and post-operation ( P>0.05). At 1 year after operation, ST and SVA in the LBP group, SSA in the control group, and SS in the two groups significantly improved when compared with those before operation ( P<0.05); there was no significant difference in the other indexes between the two groups before and after operation ( P>0.05).

Conclusion

Unilateral Crowe type Ⅳ DDH patients with LBP before operation were all relieved of LBP after THA. The relief of LBP may be related to the improvement of spinal balance, but not to lumbar lordosis and its changes.

Limited lumbopelvic mobility does not influence short-term outcomes after primary hip arthroscopy: a propensity-matched controlled study

There is a paucity of literature investigating the effect of lumbopelvic mobility on patient-reported outcome scores (PROs) after primary hip arthroscopy. The purpose of this study was (i) to report minimum 1-year PROs in patients with limited lumbopelvic mobility (LM) who underwent primary hip arthroscopy for femoroacetabular impingement syndrome (FAIS) and (ii) to compare clinical results with a propensity-matched control group of patients with normal lumbopelvic mobility (NM). Data were reviewed for surgeries performed between November 2019 and March 2020. Patients were considered eligible if they received a primary hip arthroscopy for FAIS in the setting of LM (seated to standing change in sacral slope ≤ 10°). LM patients were propensity-matched to a control group of patients with normal lumbopelvic motion (seated to standing change in sacral slope > 10°) for comparison. A total of 17 LM and 34 propensity-matched NM patients were included in the study. LM patients showed significant improvement in all outcome measures and achieved the minimum clinically important difference (MCID) and patient acceptable symptomatic state (PASS) at high rates for modified Harris Hip Score (MCID: 94% and PASS: 82%) and International Hip Outcome Tool-12 (iHOT-12; MCID: 94% and iHOT-12: 76%). When LM patients were compared to a propensity-matched control group of NM patients, they demonstrated similar postoperative PROs and rates of achieving MCID/PASS. LM patients who undergo primary hip arthroscopy may expect favorable short-term PROs at minimum 1-year follow-up. These results were comparable to a control group of NM patients.

What is the pelvic tilt in acetabular dysplasia and does it change following peri-acetabular osteotomy?

To quantify the pelvic tilt (PT) in patients with symptomatic acetabular dysplasia and determine if it represents a compensatory mechanism to improve femoral head coverage, we studied a cohort of 16 patients undergoing 32 bilateral staged PAOs for acetabular dysplasia and compared this to a matched cohort of 32 patients undergoing PAO for unilateral acetabular dysplasia all with >1 year follow-up. The change in PT was determined with two validated methods, namely, the sacro-femoral-pubic (SFP) angle and the pubic symphysis to sacroiliac index (PS-SI). Despite an improvement in the lateral centre-edge and Tönnis angles to within normal limits following PAO, patients with unilateral and bilateral acetabular dysplasia have similar PT pre-operatively (8° ± 5°) and post-operatively (9° ± 5°). A change of >5° was observed in only six patients (13%) using the SFP angle, and five patients (10%) using the PS-SI, all increased (posterior rotation of the pelvis). No patients were observed to have a change in PT >10°. The observed PT in our study group is equivalent to that found in the normal population and in patient with symptomatic acetabular retroversion. These findings all suggest that PT is morphological rather than a result of a compensatory mechanism, and even if it was compensatory, it does not appear to reverse significantly following PAO. The target for acetabular reorientation, therefore, remains constant.