Aims. The objective of this study was to evaluate the clinical and radiological outcomes of patients younger than six months of age with developmental dysplasia of the hip (DDH) managed by either a Pavlik harness or Tübingen hip flexion splint. Methods. Records of 251 consecutive infants with a mean age of 89 days (SD 47), diagnosed with DDH between January 2015 and December 2018, were retrospectively reviewed. Inclusion criteria for patients with DDH were: younger than 180 days at the time of diagnosis; ultrasound Graf classification of IIc or greater; treatment by Pavlik harness or Tübingen splint; and no prior treatment history. All patients underwent hip ultrasound every seven days during the first three weeks of treatment and subsequently every three to four weeks until completion of treatment. If no signs of improvement were found after three weeks, the Pavlik harness or Tübingen splint was discontinued. Statistical analysis was performed. Results. The study included 251 patients with Graf grades IIc to IV in 18 males and 233 females with DDH. Mean follow-up time was 22 months (SD 10). A total of 116 hips were graded as Graf IIc (39.1%), nine as grade D (3.0%), 100 as grade III (33.7%), and 72 as grade IV (24.2%). There were 109 patients (128 hips) in the Pavlik group and 142 patients (169 hips) in the Tübingen group (p = 0.227). The Tübingen group showed a 69.8% success rate in Graf III and Graf IV hips while the success rate was significantly lower in the Pavlik group, 53.9% (p = 0.033). For infants older than three months of age, the Tübingen group showed a 71.4% success rate, and the Pavlik group a 54.4% success rate (p = 0.047). Conclusion. The Tübingen splint should be the preferred treatment option for children older than three months, and for those with severe forms of DDH such as Graf grade III and IV, who are younger than six months at time of diagnosis. The Tübingen hip flexion splint is a valid alternative to the Pavlik harness for older infants and those with more severe DDH. Cite this article: Bone Joint J 2021;103-B(5):991–998

Aims. The aim of this study was to reassess the rate of neurological, psoas-related, and abdominal complications associated with L4-L5 lateral lumbar interbody fusion (LLIF) undertaken using a standardized preoperative assessment and surgical technique. Methods. This was a multicentre retrospective study involving consecutively enrolled patients who underwent L4-L5 LLIF by seven surgeons at seven institutions in three countries over a five-year period. The demographic details of the patients and the details of the surgery, reoperations and complications, including femoral and non-femoral neuropraxia, thigh pain, weakness of hip flexion, and abdominal complications, were analyzed. Neurological and psoas-related complications attributed to LLIF or posterior instrumentation and persistent symptoms were recorded at one year postoperatively. Results. A total of 517 patients were included in the study. Their mean age was 65.0 years (SD 10.3) and their mean BMI was 29.2 kg/m. 2. (SD 5.5). A mean of 1.2 levels (SD 0.6) were fused with LLIF, and a mean of 1.6 (SD 0.9) posterior levels were fused. Femoral neuropraxia occurred in six patients (1.2%), of which four (0.8%) were LLIF-related and two (0.4%) had persistent symptoms one year postoperatively. Non-femoral neuropraxia occurred in nine patients (1.8%), one (0.2%) was LLIF-related and five (1.0%) were persistent at one year. All LLIF-related neuropraxias resolved by one year. A total of 32 patients (6.2%) had thigh pain, 31 (6.0%) were LLIF-related and three (0.6%) were persistent at one year. Weakness of hip flexion occurred in 14 patients (2.7%), of which eight (1.6%) were LLIF-related and three (0.6%) were persistent at one year. No patients had bowel injury, three (0.6%) had an intraoperative vascular injury (not LLIF-related), and five (1.0%) had ileus. Reoperations occurred in five patients (1.0%) within 30 days, 37 (7.2%) within 90 days, and 41 (7.9%) within one year postoperatively. Conclusion. LLIF involving the L4-L5 disc level has a low rate of persistent neurological, psoas-related, and abdominal complications in patients with the appropriate indications and using a standardized surgical technique. Cite this article: Bone Joint J 2024;106-B(1):53–61

Aims. Rotational acetabular osteotomy (RAO) is an effective joint-preserving surgical treatment for acetabular dysplasia. The purpose of this study was to investigate changes in muscle strength, gait speed, and clinical outcome in the operated hip after RAO over a one-year period using a standard protocol for rehabilitation. Patients and Methods. A total of 57 patients underwent RAO for acetabular dysplasia. Changes in muscle strength of the operated hip, 10 m gait speed, Japanese Orthopaedic Association (JOA) hip score, and factors correlated with hip muscle strength after RAO were retrospectively analyzed. Results. Three months postoperatively, the strength of the operated hip in flexion and abduction and gait speed had decreased from their preoperative levels. After six months, the strength of flexion and abduction had recovered to their preoperative level, as had gait speed. At one-year follow-up, significant improvements were seen in the strength of hip abduction and gait speed, but muscle strength in hip flexion remained at the preoperative level. The mean JOA score for hip function was 91.4 (51 to 100)) at one-year follow-up. Body mass index (BMI) showed a negative correlation with both strength of hip flexion (r = -0.4203) and abduction (r = -0.4589) one year after RAO. Although weak negative correlations were detected between strength of hip flexion one year after surgery and age (r = -0.2755) and centre-edge (CE) angle (r = -0.2989), no correlation was found between the strength of abduction and age and radiological evaluations of CE angle and acetabular roof obliquity (ARO). Conclusion. Hip muscle strength and gait speed had recovered to their preoperative levels six months after RAO. The clinical outcome at one year was excellent, although the strength of hip flexion did not improve to the same degree as that of hip abduction and gait speed. A higher BMI may result in poorer recovery of hip muscle strength after RAO. Radiologically, acetabular coverage did not affect the recovery of hip muscle strength at one year’s follow-up. A more intensive rehabilitation programme may improve this. Cite this article: Bone Joint J 2019;101-B:1459–1463

Aims. This study of patients with osteoarthritis (OA) of the hip aimed to: 1) characterize the contribution of the hip, spinopelvic complex, and lumbar spine when moving from the standing to the sitting position; 2) assess whether abnormal spinopelvic mobility is associated with worse symptoms; and 3) identify whether spinopelvic mobility can be predicted from static anatomical radiological parameters. Patients and Methods. A total of 122 patients with end-stage OA of the hip awaiting total hip arthroplasty (THA) were prospectively studied. Patient-reported outcome measures (PROMs; Oxford Hip Score, Oswestry Disability Index, and Veterans RAND 12-Item Health Survey Score) and clinical data were collected. Sagittal spinopelvic mobility was calculated as the change from the standing to sitting position using the lumbar lordosis angle (LL), sacral slope (SS), pelvic tilt (PT), pelvic-femoral angle (PFA), and acetabular anteinclination (AI) from lateral radiographs. The interaction of the different parameters was assessed. PROMs were compared between patients with normal spinopelvic mobility (10° ≤ ∆PT ≤ 30°) or abnormal spinopelvic mobility (stiff: ∆PT < ± 10°; hypermobile: ∆PT > ± 30°). Multiple regression and receiver operating characteristic (ROC) curve analyses were used to test for possible predictors of spinopelvic mobility. Results. Standing to sitting, the hip flexed by a mean of 57° (. sd. 17°), the pelvis tilted backwards by a mean of 20° (. sd. 12°), and the lumbar spine flexed by a mean of 20° (. sd. 14°); strong correlations were detected. There was no difference in PROMs between patients in the different spinopelvic mobility groups. Maximum hip flexion, standing PT, and standing AI were independent predictors of spinopelvic mobility (R. 2. = 0.42). The combined thresholds for standing was PT ≥ 13° and hip flexion ≥ 88° in the clinical examination, and had 90% sensitivity and 63% specificity of predicting spinopelvic stiffness, while SS ≥ 42° had 84% sensitivity and 67% specificity of predicting spinopelvic hypermobility. Conclusion. The hip, on average, accounts for three-quarters of the standing-to-sitting movement, but there is great variation. Abnormal spinopelvic mobility cannot be screened with PROMs. However, clinical and standing radiological features can predict spinopelvic mobility with good enough accuracy, allowing them to be used as reliable screening tools. Cite this article: Bone Joint J 2019;101-B:902–909

Aims. The purpose of this study is to evaluate early outcomes with the use of a smartphone-based exercise and educational care management system after total hip arthroplasty (THA) and demonstrate decreased use of in-person physiotherapy (PT). Methods. A multicentre, prospective randomized controlled trial was conducted to evaluate a smartphone-based care platform for primary THA. Patients randomized to the control group (198) received the institution’s standard of care. Those randomized to the treatment group (167) were provided with a smartwatch and smartphone application. PT use, THA complications, readmissions, emergency department/urgent care visits, and physician office visits were evaluated. Outcome scores include the Hip disability and Osteoarthritis Outcome Score (HOOS, JR), health-related quality-of-life EuroQol five-dimension five-level score (EQ-5D-5L), single leg stance (SLS) test, and the Timed Up and Go (TUG) test. Results. The control group was significantly younger by a mean 3.0 years (SD 9.8 for control, 10.4 for treatment group; p = 0.007), but there were no significant differences between groups in BMI, sex, or preoperative diagnosis. Postoperative PT use was significantly lower in the treatment group (34%) than in the control group (55.4%; p = 0.001). There were no statistically significant differences in complications, readmissions, or outpatient visits. The 90-day outcomes showed no significant differences in mean hip flexion between controls (101° (SD 10.8)) and treatment (100° (SD 11.3); p = 0.507) groups. The HOOS, JR scores were not significantly different between control group (73 points (SD 13.8)) and treatment group (73.6 points (SD 13); p = 0.660). Mean 30-day SLS time was 22.9 seconds (SD 19.8) in the control group and 20.7 seconds (SD 19.5) in the treatment group (p = 0.342). Mean TUG time was 11.8 seconds (SD 5.1) for the control group and 11.9 (SD 5) seconds for the treatment group (p = 0.859). Conclusion. The use of the smartphone care management system demonstrated similar early outcomes to those achieved using traditional care models, along with a significant decrease in PT use. Noninferiority was demonstrated with regard to complications, readmissions, and ED and urgent care visits. This technology allows patients to rehabilitate on a more flexible schedule and avoid unnecessary healthcare visits, as well as potentially reducing overall healthcare costs. Cite this article: Bone Joint J 2021;103-B(7 Supple B):91–97

Aims. The purpose of this study was to evaluate spinopelvic mechanics from standing and sitting positions in subjects with and without femoroacetabular impingement (FAI). We hypothesize that FAI patients will experience less flexion at the lumbar spine and more flexion at the hip whilst changing from standing to sitting positions than subjects without FAI. This increase in hip flexion may contribute to symptomatology in FAI. Patients and Methods. Male subjects were prospectively enrolled to the study (n = 20). Mean age was 31 years old (22 to 41). All underwent clinical examination, plain radiographs, and dynamic imaging using EOS. Subjects were categorized into three groups: non-FAI (no radiographic or clinical FAI or pain), asymptomatic FAI (radiographic and clinical FAI but no pain), and symptomatic FAI (patients with both pain and radiographic FAI). FAI was defined as internal rotation less than 15° and alpha angle greater than 60°. Subjects underwent standing and sitting radiographs in order to measure spine and femoroacetabular flexion. Results. Compared with non-FAI controls, symptomatic patients with FAI had less flexion at the spine (mean 22°, . sd. 12°, vs mean 35°, . sd. 8°; p = 0.04) and more at the hip (mean 72°, . sd. 6°, vs mean 62°, . sd. 8°; p = 0.047). Subjects with asymptomatic FAI had more spine flexion and similar hip flexion when compared to symptomatic FAI patients. Both FAI groups also sat with more anterior pelvic tilt than control patients. There were no differences in standing alignment among groups. Conclusion. Symptomatic patients with FAI require more flexion at the hip to achieve sitting position due to their inability to compensate through the lumbar spine. With limited spine flexion, FAI patients sit with more anterior pelvic tilt, which may lead to impingement between the acetabulum and proximal femur. Differences in spinopelvic mechanics between FAI and non-FAI patients may contribute to the progression of FAI symptoms. Cite this article: Bone Joint J 2018;100-B:1275–9

Aims. We aimed to determine hip-related quality of life and clinical findings following treatment for neonatal hip instability (NHI) compared with age- and sex-matched controls. We hypothesized that NHI would predispose to hip discomfort in long-term follow-up. Methods. We invited those born between 1995 and 2001 who were treated for NHI at our hospital to participate in this population-based study. We included those that had Von Rosen-like splinting treatment started before one month of age. A total of 96 patients treated for NHI (75.6 %) were enrolled. A further 94 age- and sex-matched controls were also recruited. The Copenhagen Hip and Groin Outcome Score (HAGOS) questionnaire was completed separately for both hips, and a physical examination was performed. Results. The mean follow-up was 18.2 years (14.6 to 22.0). The HAGOS scores between groups were similar and met statistical and clinical significance only in the Symptoms subscale (mean difference 3.80, 95% confidence interval (CI) 0.31 to 7.29; p = 0.033). Those patients who had undergone treatment for NHI had a higher frequency of positive flexion-adduction-internal rotation test (odds ratio (OR) 2.6, 95% CI 1.2 to 5.6; p = 0.014), resisted straight leg rise test (OR 4.5, 95% CI 1.4 to 14.9; p = 0.014), and also experienced more pain in the groin during passive end range hip flexion (OR 2.5, 95% CI 1.2 to 5.3; p = 0.015) than controls. Conclusion. NHI predisposes to hip discomfort in clinical tests, but no clinically relevant differences in experience of pain, physical function, and hip-related quality of life could be observed between the treated group and matched controls in 18 years of follow-up. Cite this article: Bone Joint J 2020;102-B(12):1767–1773

Understanding spinopelvic mechanics is important for the success of total hip arthroplasty (THA). Despite significant advancements in appreciating spinopelvic balance, numerous challenges remain. It is crucial to recognize the individual variability and postoperative changes in spinopelvic parameters and their consequential impact on prosthetic component positioning to mitigate the risk of dislocation and enhance postoperative outcomes. This review describes the integration of advanced diagnostic approaches, enhanced technology, implant considerations, and surgical planning, all tailored to the unique anatomy and biomechanics of each patient. It underscores the importance of accurately predicting postoperative spinopelvic mechanics, selecting suitable imaging techniques, establishing a consistent nomenclature for spinopelvic stiffness, and considering implant-specific strategies. Furthermore, it highlights the potential of artificial intelligence to personalize care.

Cite this article: Bone Joint J 2024;106-B(11):1206–1215.

Aims. The aims of this study were to measure sagittal standing and sitting lumbar-pelvic-femoral alignment in patients before and following total hip arthroplasty (THA), and to consider what preoperative factors may influence a change in postoperative pelvic position. Patients and Methods. A total of 161 patients were considered for inclusion. Patients had a mean age of the remaining 61 years (. sd. 11) with a mean body mass index (BMI) of 28 kg/m. 2. (. sd. 6). Of the 161 patients, 82 were male (51%). We excluded 17 patients (11%) with spinal conditions known to affect lumbar mobility as well as the rotational axis of the spine. Standing and sitting spine-to-lower-limb radiographs were taken of the remaining 144 patients before and one year following THA. Spinopelvic alignment measurements, including sacral slope, lumbar lordosis, and pelvic incidence, were measured. These angles were used to calculate lumbar spine flexion and femoroacetabular hip flexion from a standing to sitting position. A radiographic scoring system was used to identify those patients in the series who had lumbar degenerative disc disease (DDD) and compare spinopelvic parameters between those patients with DDD (n = 38) and those who did not (n = 106). Results. Following THA, patients sat with more anterior pelvic tilt (mean increased sacral slope 18° preoperatively versus 23° postoperatively; p = 0.001) and more lumbar lordosis (mean 28° preoperatively versus 35° postoperatively; p = 0.001). Preoperative change in sacral slope from standing to sitting (p = 0.03) and the absence of DDD (p = 0.001) correlated to an increased change in postoperative sitting pelvic alignment. Conclusion. Sitting lumbar-pelvic-femoral alignment following THA may be driven by hip arthritis and/or spinal deformity. Patients with DDD and fixed spinopelvic alignment have a predictable pelvic position one year following THA. Patients with normal spines have less predictable postoperative pelvic position, which is likely to be driven by hip stiffness. Cite this article: Bone Joint J 2018;100-B:1289–96

Aims

Spinopelvic pathology increases the risk for instability following total hip arthroplasty (THA), yet few studies have evaluated how pathology varies with age or sex. The aims of this study were: 1) to report differences in spinopelvic parameters with advancing age and between the sexes; and 2) to determine variation in the prevalence of THA instability risk factors with advancing age.

Aims

Internal hemipelvectomy without reconstruction of the pelvis is a viable treatment for pelvic sarcoma; however, the time it takes to return to excellent function is quite variable. Some patients require greater time and rehabilitation than others. To determine if psoas muscle recovery is associated with changes in ambulatory function, we retrospectively evaluated psoas muscle size and limb-length discrepancy (LLD) before and after treatment and their correlation with objective functional outcomes.

Aims

Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA.

Aims

It has been well documented in the arthroplasty literature that lumbar degenerative disc disease (DDD) contributes to abnormal spinopelvic motion. However, the relationship between the severity or pattern of hip osteoarthritis (OA) as measured on an anteroposterior (AP) pelvic view and spinopelvic biomechanics has not been well investigated. Therefore, the aim of the study is to examine the association between the severity and pattern of hip OA and spinopelvic motion.

Aims. It is important to consider sagittal pelvic rotation when introducing the acetabular component at total hip arthroplasty (THA). The purpose of this study was to identify patients who are at risk of unfavourable pelvic mobility, which could result in poor outcomes after THA. Patients and Methods. A consecutive series of 4042 patients undergoing THA had lateral functional radiographs and a low-dose CT scan to measure supine pelvic tilt, pelvic incidence, standing pelvic tilt, flexed-seated pelvic tilt, standing lumbar lordotic angle, flexed-seated lumbar lordotic angle, and lumbar flexion. Changes in pelvic tilt from supine-to-standing positions and supine-to-flexed-seated positions were determined. A change in pelvic tilt of 13° between positions was deemed unfavourable as it alters functional anteversion by 10° and effectively places the acetabular component outside the safe zone of orientation. Results. For both men and women, the degree of lumbar flexion was a significant predictor of risk in hip flexion (p < 0.0001) with increased odds of unfavourable pelvic mobility in those with lumbar flexion of < 20° (men, odds ratio (OR) 6.74, 95% confidence interval (CI) 3.83 to 11.89; women, OR 2.97, 95% CI 1.87 to 4.71). In women, age and standing pelvic tilt were significant predictors of risk in hip extension (p = 0.0082 and p < 0.0001, respectively). The risk of unfavourable pelvic mobility was higher in those aged > 75 years (OR 2.28, 95% CI 1.56 to 3.32) and those with standing pelvic tilt of < -10° for extension risk (OR 7.10, 95% CI 4.10 to 10.29). In men, only standing pelvic tilt was significant (p < 0.0001) for hip extension with an increased risk of unfavourable pelvic mobility (OR 8.68, 95% CI 5.19 to 14.51). Conclusion. Patients found to have unfavourable pelvic mobility had limited lumbar flexion and more posterior standing pelvic tilt in both men and women, as well as increasing age in women. We recommend that patients undergo preoperative functional radiographic screening to determine specific parameters that can affect the functional orientation of the acetabular component. Cite this article: Bone Joint J 2018;100-B:845–52

Aims

To examine the long-term outcome of arthrodesis of the hip undertaken in a paediatric population in treating painful arthritis of the hip. In our patient population, most of whom live rurally in hilly terrain and have limited healthcare access and resources, hip arthrodesis has been an important surgical option for the monoarticular painful hip in a child.

Aims

Dislocation of the hip remains a major complication after periacetabular tumour resection and endoprosthetic reconstruction. The position of the acetabular component is an important modifiable factor for surgeons in determining the risk of postoperative dislocation. We investigated the significance of horizontal, vertical, and sagittal displacement of the hip centre of rotation (COR) on postoperative dislocation using a CT-based 3D model, as well as other potential risk factors for dislocation.

Aims

Hip arthroscopy has gained prominence as a primary surgical intervention for symptomatic femoroacetabular impingement (FAI). This study aimed to identify radiological features, and their combinations, that predict the outcome of hip arthroscopy for FAI.

Aims

Professional dancers represent a unique patient population in the setting of hip arthroplasty, given the high degree of hip strength and mobility required by their profession. We sought to determine the clinical outcomes and ability to return to professional dance after total hip arthroplasty (THA) or hip resurfacing arthroplasty (HRA).

Aims

Eccentric reductions may become concentric through femoral head ‘docking’ (FHD) following closed reduction (CR) for developmental dysplasia of the hip (DDH). However, changes regarding position and morphology through FHD are not well understood. We aimed to assess these changes using serial MRI.

Aims

The purpose of this study was to evaluate the mid-term outcomes of autologous matrix-induced chondrogenesis (AMIC) for the treatment of larger cartilage lesions and deformity correction in hips suffering from symptomatic femoroacetabular impingement (FAI).

Aims

Surgical approaches that claim to be minimally invasive, such as the direct anterior approach (DAA), are reported to have a clinical advantage, but are technically challenging and may create more injury to the soft-tissues during joint exposure. Our aim was to quantify the effect of soft-tissue releases on the joint torque and femoral mobility during joint exposure for hip resurfacing performed via the DAA.

The aim of this cadaver study was to identify the change in position of the sciatic nerve during arthroplasty using the posterior surgical approach to the hip. We investigated the position of the nerve during this procedure by dissecting 11 formalin-treated cadavers (22 hips: 12 male, ten female). The distance between the sciatic nerve and the femoral neck was measured before and after dislocation of the hip, and in positions used during the preparation of the femur. The nerve moves closer to the femoral neck when the hip is flexed to > 30° and internally rotated to 90° (90° IR). The mean distance between the nerve and femoral neck was 43.1 mm (standard deviation (. sd. ) 8.7) with the hip at 0° of flexion and 90° IR; this significantly decreased to a mean of 36.1 mm (. sd. 9.5), 28.8 mm (. sd. 9.8) and 19.1 mm (. sd. 9.7) at 30°, 60° and 90° of hip flexion respectively (p < 0.001). In two hips the nerve was in contact with the femoral neck when the hip was flexed to 90°. . This study demonstrates that the sciatic nerve becomes closer to the operative field during hip arthroplasty using the posterior approach with progressive flexion of the hip. Cite this article: Bone Joint J 2015;97-B:1056–62

Of 47 patients with spina bifida who had had transplantation of the iliopsoas more than 10 years previously, 32 (68%) were community walkers, 3 were household walkers and 12 were non-walkers. Comparison with other published reports showed that, at the very least, the patients reviewed had not had their walking ability jeopardized by the inevitable loss of hip flexor power. Furthermore, all but three of the community walkers were able to climb and descend stairs. There was a high proportion of non-walkers in those patients whose operation had been performed in the first year of life and such early surgery is no longer recommended. We also found that the pre-operative assessment of muscle power had, in some patients, been inaccurate. Finally, we found that, at review, the power of the transferred muscles was poor, suggesting that transplantation is beneficial because it achieves permanent and major reduction in hip flexor power; this usually prevents recurrent hip flexion deformity and dislocation

Aims

Spinopelvic mobility plays an important role in functional acetabular component position following total hip arthroplasty (THA). The primary aim of this study was to determine if spinopelvic hypermobility persists or resolves following THA. Our second aim was to identify patient demographic or radiological factors associated with hypermobility and resolution of hypermobility after THA.

Aims

Pelvic incidence (PI) is a position-independent spinopelvic parameter traditionally used by spinal surgeons to determine spinal alignment. Its relevance to the arthroplasty surgeon in assessing patient risk for total hip arthroplasty (THA) instability preoperatively is unclear. This study was undertaken to investigate the significance of PI relative to other spinopelvic parameter risk factors for instability to help guide its clinical application.

Thirteen methods of hip scoring were applied in the postoperative assessment of 47 hip arthroplasties. Their results were found to be inconsistent, often giving contrary measures of success in the same patient. Ten variables were measured during the postoperative review of 256 hip arthroplasties and the data were submitted to multivariate factor analysis. This revealed that the ten variables could be reduced to three factors: pain, which correlated poorly with any other variable (Spearman correlation, r < 0.02); functional activity (distance walked, use of walking aids, stair climbing, use of public transport, limp, sitting and tying shoelaces); and deformity and range of movement. The range of hip flexion correlated closely with the sum of the arcs of movement and with Gade's index (Spearman correlation, r > 0.9). We suggest that, for outcome assessment, only three variables need to be recorded: pain, walking distance and range of hip flexion. The combination of these three measures into a single hip score is misleading

The piriformis muscle is an important landmark in the surgical anatomy of the hip, particularly the posterior approach for total hip replacement (THR). Standard orthopaedic teaching dictates that the tendon must be cut in to allow adequate access to the superior part of the acetabulum and the femoral medullary canal. However, in our experience a routine THR can be performed through a posterior approach without sacrificing this tendon. We dissected the proximal femora of 15 cadavers in order to clarify the morphological anatomy of the piriformis tendon. We confirmed that the tendon attaches on the crest of the greater trochanter, in a position superior to the trochanteric fossa, away from the entry point for broaching the intramedullary canal during THR. The tendon attachment site encompassed the summit and medial aspect of the greater trochanter as well as a variable attachment to the fibrous capsule of the hip joint. In addition we dissected seven cadavers resecting all posterior attachments except the piriformis muscle and tendon in order to study their relations to the hip joint, as the joint was flexed. At flexion of 90° the piriformis muscle lay directly posterior to the hip joint. The piriform fossa is a term used by orthopaedic surgeons to refer the trochanteric fossa and normally has no relation to the attachment site of the piriformis tendon. In hip flexion the piriformis lies directly behind the hip joint and might reasonably be considered to contribute to the stability of the joint. We conclude that the anatomy of the piriformis muscle is often inaccurately described in the current surgical literature and terms are used and interchanged inappropriately. Cite this article: Bone Joint J 2013;95-B:764–9

Aims

Cross-table lateral (CTL) radiographs are commonly used to measure acetabular component anteversion after total hip arthroplasty (THA). The CTL measurements may differ by > 10° from CT scan measurements but the reasons for this discrepancy are poorly understood. Anteversion measurements from CTL radiographs and CT scans are compared to identify spinopelvic parameters predictive of inaccuracy.

Aims

Patients with spinal pathology who undergo total hip arthroplasty (THA) have an increased risk of dislocation and revision. The aim of this study was to determine if the use of the Hip-Spine Classification system in these patients would result in a decreased rate of postoperative dislocation in patients with spinal pathology.

Evaluating musculoskeletal conditions of the lower limb and understanding the pathophysiology of complex bone kinematics is challenging. Static images do not take into account the dynamic component of relative bone motion and muscle activation. Fluoroscopy and dynamic MRI have important limitations. Dynamic CT (4D-CT) is an emerging alternative that combines high spatial and temporal resolution, with an increased availability in clinical practice. 4D-CT allows simultaneous visualization of bone morphology and joint kinematics. This unique combination makes it an ideal tool to evaluate functional disorders of the musculoskeletal system. In the lower limb, 4D-CT has been used to diagnose femoroacetabular impingement, patellofemoral, ankle and subtalar joint instability, or reduced range of motion. 4D-CT has also been used to demonstrate the effect of surgery, mainly on patellar instability. 4D-CT will need further research and validation before it can be widely used in clinical practice. We believe, however, it is here to stay, and will become a reference in the diagnosis of lower limb conditions and the evaluation of treatment options.

Cite this article: Bone Joint J 2021;103-B(5):822–827.

Aims

Iliopsoas pathology is a relatively uncommon cause of pain following total hip arthroplasty (THA), typically presenting with symptoms of groin pain on active flexion and/or extension of the hip. A variety of conservative and surgical treatment options have been reported. In this retrospective cohort study, we report the incidence of iliopsoas pathology and treatment outcomes.

Aims

To compare changes in gait kinematics and walking speed 24 months after conventional (C-MLS) and minimally invasive (MI-MLS) multilevel surgery for children with diplegic cerebral palsy (CP).

In an adult man the mean femoral anteversion angle measures approximately 15°, for which the reasons have never been fully elucidated. An assortment of simian and quadruped mammalian femora was therefore examined and the anteversion angles measured. A simple static mathematical model was then produced to explain the forces acting on the neck of the femur in the quadruped and in man. Femoral anteversion was present in all the simian and quadruped femora and ranged between 4° and 41°. It thus appears that man has retained this feature despite evolving from quadrupedal locomotion. Quadrupeds generally mobilise with their hips flexed forwards from the vertical; in this position, it is clear that anteversion gives biomechanical advantage against predominantly vertical forces. In man with mobilisation on vertical femora, the biomechanical advantage of anteversion is against forces acting mainly in the horizontal plane. This has implications in regard to the orientation of hip replacements

Aims

The complex relationship between acetabular component position and spinopelvic mobility in patients following total hip arthroplasty (THA) renders it difficult to optimize acetabular component positioning. Mobility of the normal lumbar spine during postural changes results in alterations in pelvic tilt (PT) to maintain the sagittal balance in each posture and, as a consequence, markedly changes the functional component anteversion (FCA). This study aimed to investigate the in vivo association of lumbar degenerative disc disease (DDD) with the PT angle and with FCA during postural changes in THA patients.

Aims

Intravenous dexamethasone has been shown to reduce immediate postoperative pain after total hip arthroplasty (THA), though the effects are short-lived. We aimed to assess whether two equivalent perioperative split doses were more effective than a single preoperative dose.

Version of the femoral stem is an important factor influencing the risk of dislocation after total hip replacement (THR) as well as the position of the acetabular component. However, there is no radiological method of measuring stem anteversion described in the literature. We propose a radiological method to measure stem version and have assessed its reliability and validity. In 36 patients who underwent THR, a hip radiograph and CT scan were taken to measure stem anteversion. The radiograph was a modified Budin view. This is taken as a posteroanterior radiograph in the sitting position with 90° hip flexion and 90° knee flexion and 30° hip abduction. The angle between the stem-neck axis and the posterior intercondylar line was measured by three independent examiners. The intra- and interobserver reliabilities of each measurement were examined. The radiological measurements were compared with the CT measurements to evaluate their validity. The mean radiological measurement was 13.36° (. sd. 6.46) and the mean CT measurement was 12.35° (. sd. 6.39) (p = 0.096). The intra- and interobserver reliabilities were excellent for both measurements. The radiological measurements correlated well with the CT measurements (p = 0.001, r = 0.877). The modified Budin method appears reliable and valid for the measurement of femoral stem anteversion. Cite this article: Bone Joint J 2013;95-B:877–80

Injuries to the hamstring muscle complex are common in athletes, accounting for between 12% and 26% of all injuries sustained during sporting activities. Acute hamstring injuries often occur during sports that involve repetitive kicking or high-speed sprinting, such as American football, soccer, rugby, and athletics. They are also common in watersports, including waterskiing and surfing. Hamstring injuries can be career-threatening in elite athletes and are associated with an estimated risk of recurrence in between 14% and 63% of patients. The variability in prognosis and treatment of the different injury patterns highlights the importance of prompt diagnosis with magnetic resonance imaging (MRI) in order to classify injuries accurately and plan the appropriate management.

Low-grade hamstring injuries may be treated with nonoperative measures including pain relief, eccentric lengthening exercises, and a graduated return to sport-specific activities. Nonoperative management is associated with highly variable times for convalescence and return to a pre-injury level of sporting function. Nonoperative management of high-grade hamstring injuries is associated with poor return to baseline function, residual muscle weakness and a high-risk of recurrence. Proximal hamstring avulsion injuries, high-grade musculotendinous tears, and chronic injuries with persistent weakness or functional compromise require surgical repair to enable return to a pre-injury level of sporting function and minimize the risk of recurrent injury.

This article reviews the optimal diagnostic imaging methods and common classification systems used to guide the treatment of hamstring injuries. In addition, the indications and outcomes for both nonoperative and operative treatment are analyzed to provide an evidence-based management framework for these patients.

Cite this article: Bone Joint J 2020;102-B(10):1281–1288.

Aims

Patients with abnormal spinopelvic mobility are at increased risk for instability. Measuring the change in sacral slope (ΔSS) can help determine spinopelvic mobility preoperatively. Sacral slope (SS) should decrease at least 10° to demonstrate adequate posterior pelvic tilt. There is potential for different ΔSS measurements in the same patient based on sitting posture. The purpose of this study was to determine the effect of sitting posture on the ΔSS in patients undergoing total hip arthroplasty (THA).

Aims

Despite the increase in the surgical repair of proximal hamstring tears, there exists a lack of consensus in the optimal timing for surgery. There is also disagreement on how partial tears managed surgically compare with complete tears repaired surgically. This study aims to compare the mid-term functional outcomes in, and operating time required for, complete and partial proximal hamstring avulsions, that are repaired both acutely and chronically.

Aims

Natural Language Processing (NLP) offers an automated method to extract data from unstructured free text fields for arthroplasty registry participation. Our objective was to investigate how accurately NLP can be used to extract structured clinical data from unstructured clinical notes when compared with manual data extraction.

In a randomised trial involving 598 patients with 600 trochanteric fractures of the hip, the fractures were treated with either a sliding hip screw (n = 300) or a Targon PF intramedullary nail (n = 300). The mean age of the patients was 82 years (26 to 104). All surviving patients were reviewed at one year with functional outcome assessed by a research nurse blinded to the treatment used. The intramedullary nail was found to have a slightly increased mean operative time (46 minutes (. sd. 12.3) versus 49 minutes (. sd. 12.7), p < 0.001) and an increased mean radiological screening time (0.3 minutes (. sd. 0.2) versus 0.5 minutes (. sd. 0.3), p <  0.001). Operative difficulties were more common with the intramedullary nail. There was no statistically significant difference between implants for wound healing complications (p = 1), or need for post-operative blood transfusion (p = 1), and medical complications were similarly distributed in both groups. There was a tendency to fewer revisions of fixation or conversion to an arthroplasty in the nail group, although the difference was not statistically significant (nine versus three cases, p = 0.14). The extent of shortening, loss of hip flexion, mortality and degree of residual pain were similar in both groups. The recovery of mobility was superior for those treated with the intramedullary nails (p = 0.01 at one year from injury). In summary, both implants produced comparable results but there was a tendency to better return of mobility for those treated with the intramedullary nail

Two neonates, treated by the Pavlik harness for congenital dislocation of the hip, developed inferior dislocation due to excessive hip flexion. Early recognition of the complication and diminution of the angle of flexion gave a stable relocation of the hip in both patients

Aims

The aetiologies of common degenerative spine, hip, and knee pathologies are still not completely understood. Mechanical theories have suggested that those diseases are related to sagittal pelvic morphology and spinopelvic-femoral dynamics. The link between the most widely used parameter for sagittal pelvic morphology, pelvic incidence (PI), and the onset of degenerative lumbar, hip, and knee pathologies has not been studied in a large-scale setting.

Deep gluteal syndrome is an increasingly recognized disease entity, caused by compression of the sciatic or pudendal nerve due to non-discogenic pelvic lesions. It includes the piriformis syndrome, the gemelli-obturator internus syndrome, the ischiofemoral impingement syndrome, and the proximal hamstring syndrome. The concept of the deep gluteal syndrome extends our understanding of posterior hip pain due to nerve entrapment beyond the traditional model of the piriformis syndrome. Nevertheless, there has been terminological confusion and the deep gluteal syndrome has often been undiagnosed or mistaken for other conditions. Careful history-taking, a physical examination including provocation tests, an electrodiagnostic study, and imaging are necessary for an accurate diagnosis.

After excluding spinal lesions, MRI scans of the pelvis are helpful in diagnosing deep gluteal syndrome and identifying pathological conditions entrapping the nerves. It can be conservatively treated with multidisciplinary treatment including rest, the avoidance of provoking activities, medication, injections, and physiotherapy.

Endoscopic or open surgical decompression is recommended in patients with persistent or recurrent symptoms after conservative treatment or in those who may have masses compressing the sciatic nerve.

Many physicians remain unfamiliar with this syndrome and there is a lack of relevant literature. This comprehensive review aims to provide the latest information about the epidemiology, aetiology, pathology, clinical features, diagnosis, and treatment.

Cite this article: Bone Joint J 2020;102-B(5):556–567.

The pattern of fracture-dislocation of the upper part of the sacrum is demonstrated in three patients. The fracture line followed the segmental form of the sacrum and was usually caused by a posterior force against the pelvis which had been locked by hip flexion and knee extension. Fractures of the lumbar transverse processes also occurred, presumably from avulsion by the quadratus lumborum muscle. The damage to the sacral plexus found in all three cases recovered after several months. Radiographs of the injury are difficult to obtain in severely injured patients but oblique views of the sacrum help to determine the extent of the forward dislocation

Aims

There is evidence that prior lumbar fusion increases the risk of dislocation and revision after total hip arthroplasty (THA). The relationship between prior lumbar fusion and the effect of femoral head diameter on THA dislocation has not been investigated. We examined the relationship between prior lumbar fusion or discectomy and the risk of dislocation or revision after THA. We also examined the effect of femoral head component diameter on the risk of dislocation or revision.

The Brittain V-arthrodesis is a satisfactory procedure for osteoarthritis of the hip. It is particularly suitable for elderly patients when the range of hip flexion is less than 60 degrees. If the four deaths are excluded, two-thirds of the patients secured a sound bony fusion. This occurs slowly. All but one of the patients who survived for three years or more after operation had a sound bony fusion. It is evident that the operation, given time, yields a high rate of sound bony fusion in the hip. It seems likely that use of the McLaughlin nail plate would prevent the one serious complication, namely fracture of the shaft of the femur through or immediately below the drill hole made for the fibular graft

Aims

This paper aims to review the evidence for patient-related factors associated with less favourable outcomes following hip arthroscopy.

We studied 1061 children with myelomeningocele, reviewing 3184 pelvic radiographs from 802 patients. Hip dislocation had occurred by the age of 11 years in 28% of children with a thoracic neurosegmental level, 30% of those with an L1/2 level, 36% of L3, 22% of L4, 7% of L5 and only 1% of those with sacral levels. Hip dislocation was not inevitable even when there was maximal muscle imbalance about the hip. The average hip flexion contracture in children aged 9 to 11 years was significantly greater in those with thoracic (22 degrees) and L1/2 (33 degrees) levels than in those with L4 (9 degrees), L5 (5 degrees) or sacral (4 degrees) levels. Our findings indicate that muscle imbalance is not a significant factor in the production of flexion deformity or dislocation of the hip; both are commonly seen in the absence of imbalance. The restoration of muscle balance should no longer be considered to be the principal aim of the management of the hip in children with myelomeningocele

Aims

The aims of this study were to determine the effect of osteophyte excision on deformity correction and soft tissue gap balance in varus knees undergoing computer-assisted total knee arthroplasty (TKA).