The direct anterior approach in total hip replacement anatomically offers the chance to minimise soft-tissue trauma because an intermuscular and internervous plane is explored. This motivated us to abandon our previously used transgluteal approach and to adopt the direct anterior approach for total hip replacement. Using MRI, we performed a retrospective comparative study of the direct anterior approach with the transgluteal approach. There were 25 patients in each group. At one year post-operatively all the patients underwent MRI of their replaced hips. A radiologist graded the changes in the soft-tissue signals in the abductor muscles. The groups were similar in terms of age, gender, body mass index, complexity of the reconstruction and absence of symptoms.

Detachment of the abductor insertion, partial tears and tendonitis of gluteus medius and minimus, the presence of peri-trochanteric bursal fluid and fatty atrophy of gluteus medius and minimus were significantly less pronounced and less frequent when the direct anterior approach was used. There was no significant difference in the findings regarding tensor fascia lata between the two approaches.

We conclude that use of the direct anterior approach results in a better soft-tissue response as assessed by MRI after total hip replacement. However, the impact on outcome needs to be evaluated further.

Intact abductors of the hip play a crucial role in preventing limping and are known to be damaged through the direct lateral approach. The extent of trauma to the abductors after revision total hip replacement (THR) is unknown. The aim of this prospective study was to compare the pre- and post-operative status of the gluteus medius muscle after revision THR. We prospectively compared changes in the muscle and limping in 30 patients who were awaiting aseptic revision THR and 15 patients undergoing primary THR. The direct lateral approach as described by Hardinge was used for all patients. MRI scans of the gluteus medius and functional analyses were recorded pre-operatively and six months post-operatively. The overall mean fatty degeneration of the gluteus medius increased from 35.8% (1.1 to 98.8) pre-operatively to 41% (1.5 to 99.8) after multiple revision THRs (p = 0.03). There was a similar pattern after primary THR, but with considerably less muscle damage (p = 0.001), indicating progressive muscle damage. Despite an increased incidence of a positive Trendelenburg sign following revision surgery (p = 0.03) there was no relationship between the cumulative fatty degeneration in the gluteus medius and a positive Trendelenburg sign (p = 0.26). The changes associated with other surgical approaches to the hip warrant investigation.

Cite this article: Bone Joint J 2014;96-B:1618–22.

Aims. The aim of this study was to determine the clinical outcomes and factors contributing to failure of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, for advanced osteoarthritis secondary to hip dysplasia. Methods. We reviewed patients with Tönnis grade 2 osteoarthritis secondary to hip dysplasia who underwent TOA between November 1998 and December 2019. Patient demographic details, osteotomy-related complications, and the modified Harris Hip Score (mHHS) were obtained via medical notes review. Radiological indicators of hip dysplasia were assessed using preoperative and postoperative radiographs. The cumulative probability of TOA failure (progression to Tönnis grade 3 or conversion to total hip arthroplasty) was estimated using the Kaplan-Meier product-limited method. A multivariate Cox proportional hazards model was used to identify predictors of failure. Results. This study included 127 patients (137 hips). Median follow-up period was ten years (IQR 6 to 15). The median mHHS improved from 59 (IQR 52 to 70) preoperatively to 90 (IQR 73 to 96) at the latest follow-up (p < 0.001). The survival rate was 90% (95% CI 82 to 95) at ten years, decreasing to 21% (95% CI 7 to 48) at 20 years. Fair joint congruity on preoperative hip abduction radiographs and a decreased postoperative anterior wall index (AWI) were identified as independent risk factors for failure. The survival rate for the 42 hips with good preoperative joint congruity and a postoperative AWI ≥ 0.30 was 100% at ten years, and remained at 83% (95% CI 38 to 98) at 20 years. Conclusion. Although the overall clinical outcomes of TOA in patients with advanced osteoarthritis are suboptimal, favourable results can be achieved in selected cases with good preoperative joint congruity and adequate postoperative anterior acetabular coverage. Cite this article: Bone Joint J 2024;106-B(8):783–791

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. Computer-assisted 3D preoperative planning software has the potential to improve postoperative stability in total hip arthroplasty (THA). Commonly, preoperative protocols simulate two functional positions (standing and relaxed sitting) but do not consider other common positions that may increase postoperative impingement and possible dislocation. This study investigates the feasibility of simulating commonly encountered positions, and positions with an increased risk of impingement, to lower postoperative impingement risk in a CT-based 3D model. Methods. A robotic arm-assisted arthroplasty planning platform was used to investigate 11 patient positions. Data from 43 primary THAs were used for simulation. Sacral slope was retrieved from patient preoperative imaging, while angles of hip flexion/extension, hip external/internal rotation, and hip abduction/adduction for tested positions were derived from literature or estimated with a biomechanical model. The hip was placed in the described positions, and if impingement was detected by the software, inspection of the impingement type was performed. Results. In flexion, an overall impingement rate of 2.3% was detected for flexed-seated, squatting, forward-bending, and criss-cross-sitting positions, and 4.7% for the ankle-over-knee position. In extension, most hips (60.5%) were found to impinge at or prior to 50° of external rotation (pivoting). Many of these impingement events were due to a prominent ischium. The mean maximum external rotation prior to impingement was 45.9° (15° to 80°) and 57.9° (20° to 90°) prior to prosthetic impingement. No impingement was found in standing, sitting, crossing ankles, seiza, and downward dog. Conclusion. This study demonstrated that positions of daily living tested in a CT-based 3D model show high rates of impingement. Simulating additional positions through 3D modelling is a low-cost method of potentially improving outcomes without compromising patient safety. By incorporating CT-based 3D modelling of positions of daily living into routine preoperative protocols for THA, there is the potential to lower the risk of postoperative impingement events. Cite this article: Bone Jt Open 2023;4(6):416–423

Introduction. Gluteus medius is disrupted during lateral approach total hip arthroplasty (THA) which may impact its function and ability to control the pelvis. The objective was to compare gluteus medius activation and joint mechanics associated with a Trendelenburg sign (pelvic drop, trunk lean) during gait and hip abductor strength between patients that underwent lateral or posterior THA approaches one year post-surgery and healthy adults. Methods. Participants that underwent primary THA for hip osteoarthritis using lateral (n=21) or posterior (n=21) approaches, and healthy adults (n=21) were recruited for this cross-sectional study. Participants completed five walking trials. Surface electromyography captured gluteus medius activation. A 3-dimensional optical motion capture system measured frontal plane pelvic obliquity and lateral trunk lean angles. Participants performed maximum voluntary isometric contractions (MVIC) on a dynamometer to measure hip abductor torque. Characteristics from gait waveforms were identified using principal component analysis, and participant waveforms were scored against these characteristics to produce principal component scores. One-way analysis of variance and effect sizes (d) compared gait principal component scores and isometric hip abductor torque between groups. Results. Lateral THA group had statistically significant higher gluteus medius PC-scores indicating higher overall amplitudes during gait (p<0.01, d=0.97) and prolonged midstance activation (p=0.01, d=0.95) compared to the healthy group (Figure). There were no statistically significant (p>0.05) differences in pelvis or trunk angles. Isometric hip abductor torque was significantly (p=0.03, d=0.74) lower in the lateral THA than healthy group. There were no statistically significant differences between THA groups (d=0.27–0.50). Conclusions. Although the lateral THA group had lower abductor torque, there were no Trendelenburg signs during gait. Elevated gluteus medius activation in this group was a compensation for the weakness, and the muscle produced sufficient force to control the pelvis. Also, 1 year post-THA there were no statistically significant gait differences between lateral and posterior approaches. For any tables or figures, please contact the authors directly

Introduction. Hip abductor tendon tears have been referred to as “rotator cuff tears of the hip,” and are a recognized etiology for persistent, often progressive, lateral hip pain, weakness, and limp. Multiple repair techniques and salvage procedures for abductor tendon tears have been reported in the literature; however, re-tear remains a frequent complication following surgical repair. This study compares the short-term outcomes of open abductor tendon repairs with decortication and suture fixation (DSF) compared to a modified technique repair into a bone trough (BT), to determine best surgical results for large abductor tendon avulsions. Additionally, surgical treatment of small tears versus large tears was examined. Methods. The outcomes of 37 consecutive hip abductor tendon repairs treated between January 2009 and December 2017 were retrospectively reviewed. Large tears were defined as detachment of 33–100% of the gluteus medius insertion. There were 15 DSF and 10 BT cases. Postoperative pain, ability to perform single leg stance, hip abduction, and Trendelenburg lurch, were examined. Small tears (12 cases) were defined as having no gluteus medius avulsion from the trochanteric insertion and were comprised of longitudinal tears (repaired side-by-side) and isolated gluteus minimus tears (repaired by tenodesis to the overlying gluteus medius). Standard statistical analyses were utilized. Type I error for all analyses was set at α=0.05. Results. When comparing large tear repair outcomes, repairs into a BT had superior outcomes to repairs with DSF: 0 (BT) versus 6 (DSF, 40%) failure rate (p<0.05), and greater reductions in pain at one-year post surgery (Δ VAS: BT, −5.70±0.97 | DSF: −2.73±0.69; p<0.01), ability to perform a single leg stance and hip abduction (90% and 100% vs 47% and 73%) (p<0.05). Clinical strength ratings were higher for repairs into a BT, but this did not reach statistical significance. When comparing large to small tear repair outcomes, small tears were found to have lower VAS pain scores and higher clinical strength ratings during both the pre-op and 1-year post-op time points (p<0.05). A higher percentage of those with small tears were able to perform a single leg stance and hip abduction (100%) compared to those with large tears (64% and 78% respectively) (p<0.05). A significantly higher frequency of residual lurch was also observed for those with large tears; 56% compared to small tears at 0%. Conclusions. Utilizing a BT repair significantly improved surgical results for large abductor tendon avulsions. Level of evidence: Therapeutic level IV case series

Introduction. Femoroacetabular impingement (FAI) is a morphological hip joint deformity associated with pain and early degenerative changes. Cam-type FAI is prevalent in young male athletes. While biomechanical deficiencies (decreased hip muscle strength and range of motion (ROM)) have been associated with symptomatic cam-type FAI (sFAI), results have been conflicting and little is known about biomechanical characteristics during dynamic tasks. Objectives. (1) Compare coronal-plane hip muscle strength, activation and joint rotation during movement tasks in sFAI hips against healthy controls. (2) Investigate the effect of hip internal rotation ROM (IR-ROM) on these outcomes. Methods. 11 sFAI and 24 well-matched healthy control hips from 18 young adult male athletes were recruited (Table.1). Passive hip IR-ROM was measured with goniometry. Weight-normalised hip abductor and adductor isometric maximal voluntary contraction torques were quantified with handheld dynamometry. Gluteus medius and adductor longus activation and hip coronal-plane kinematics were collected with surface electromyography (EMG) and motion-capture during time-defined phases of sit-to-stand (Fig.1) and single-leg-squat (Fig.2) tasks. Effect of sFAI with hip IR-ROM as a separate independent variable was calculated with 1-way MANCOVA. Results. sFAI had significantly less IR-ROM (19.25°±5.94) than controls (28.83°±7.24) (p<0.001). During the sit-to-stand ascent phase, significantly more hip abduction (F=4.93, p=0.03) was observed in sFAI (13.06°±3.16) compared to controls (10.16°±3.72). With IR-ROM differences controlled for, significantly higher gluteus medius:adductor longus EMG activation ratio (F=4.32, p=0.046) was observed in the same phase in sFAI (0.16±0.34) compared to controls (−0.11±0.31). No other significant results were found. Conclusion. sFAI hips demonstrate altered muscle activation and movement patterns when ascending from seated positions compared to controls, with reduced hip IR-ROM in sFAI hips influencing findings. Abductor and adductor function imbalance may explain why sFAI increases risk of early degenerative changes. Despite study limitations (no imaging for sFAI diagnosis), these findings should be considered when optimising rehabilitation in this population. For any figures and tables, please contact the authors directly

Introduction. Patients with hip abductor tendon tears amenable to endoscopic repair tend to be severely disabled and older. However, low preop baseline patient reported outcome (PRO) and advancing age are each often reported to be a harbinger of poor result with hip arthroscopy. Thus, the purpose of this study is to report the demographic makeup of this population and how these patients faired in terms of preop scores and reaching both Minimal Clinically Important Difference (MCID) and Substantial Clinical Benefit (SCB). Methods. Sixty-six consecutive hips in 64 patients (2 bilateral) undergoing endoscopic abductor tendon repair with a hollow core bioabsorbable suture anchor and having achieved two-year follow-up were prospectively assessed with modified Harris Hip Score (mHHS) and international Hip Outcome Tool (iHOT) scores. The MCID for patients undergoing hip arthroscopy has previously been determined as 8 for the mHHS and 13 for the iHOT. SCB has been determined as 20 for the mHHS and 28 for the iHOT. Subgroups were compared using the independent samples t-test. Results. The average age was 57 years (range 22–83 years) with 59 females and 5 males. Post-operative follow-up averaged 28 months (range 24–60). There were 33 full-thickness and 33 partial-thickness tears; 39 gluteus medius tears, 25 medius and minimus tears, and 2 isolated minimus tears. Among the 66 hips, the average preop mHHS was 48.8 with 98.5% achieving MCID and 93.8% SCB. Among 60 hips that had complete iHOT data, the average preop score was 30.0 with 98.3% achieving MCID and 88.3% SCB. There were no complications. One patient underwent repeat arthroscopy for joint debridement at 12 months following abductor repair, and one subsequently underwent total hip replacement at 11 months following repair. There was no statistically significant difference between subgroups of full thickness/partial thickness tears, or single/two tendon tears. Conclusion. This report of endoscopic abductor tendon repair represents a heterogeneous group of single and two tendon involvement with partial and full thickness tears. Collectively these patients can respond exceptionally well in terms of MCID (98.5% mHHS; 98.3% iHOT) and SCB (93.8% mHHS; 88.3% iHOT), even in the presence of low preop baseline scores (average 48.8 mHHS; 30 iHOT) and older age (average 57 years). For any tables or figures, please contact the authors directly

We investigated the detailed anatomy of the gluteus maximus, gluteus medius and gluteus minimus and their neurovascular supply in 22 hips in 11 embalmed adult Caucasian human cadavers. This led to the development of a surgical technique for an extended posterior approach to the hip and pelvis that exposes the supra-acetabular ilium and preserves the glutei during revision hip surgery. Proximal to distal mobilisation of the gluteus medius from the posterior gluteal line permits exposure and mobilisation of the superior gluteal neurovascular bundle between the sciatic notch and the entrance to the gluteus medius, enabling a wider exposure of the supra-acetabular ilium. This technique was subsequently used in nine patients undergoing revision total hip replacement involving the reconstruction of nine Paprosky 3B acetabular defects, five of which had pelvic discontinuity. Intra-operative electromyography showed that the innervation of the gluteal muscles was not affected by surgery. Clinical follow-up demonstrated good hip abduction function in all patients. These results were compared with those of a matched cohort treated through a Kocher–Langenbeck approach. Our modified approach maximises the exposure of the ilium above the sciatic notch while protecting the gluteal muscles and their neurovascular bundle. Cite this article: Bone Joint J 2014;96-B:48–53

We undertook a multicentre, prospective study of a series of 112 unstable trochanteric fractures in order to evaluate if internal fixation with a sliding screw device combined with augmentation using a calcium phosphate degradable cement (Norian SRS) could improve the clinical, functional and radiological outcome when compared with fractures treated with a sliding screw device alone. Pain, activities of daily living, health status (SF-36), the strength of the hip abductor muscles and radiological outcome were analysed. Six weeks after surgery, the patients in the augmented group had significantly lower global and functional pain scores (p < 0.003), less pain after walking 50 feet (p < 0.01), and a better return to the activities of daily living (p < 0.05). At follow-up at six weeks and six months, those in the augmented group showed a significant improvement compared with the control group in the SF-36 score. No other significant differences were found between the groups. We conclude that augmentation with calcium phosphate cement in unstable trochanteric fractures provides a modest reduction in pain and a slight improvement in the quality of life during the course of healing when compared with conventional fixation with a sliding screw device alone

Topographic anatomy and general distribution of LFCA is well described in anatomy textbooks. Its contribution to the vascularization of specific anatomic structures in the hip region is poorly defined. The purpose of this study was to demonstrate the importance of LFCA in hip circulation, especially in the vascularization of hip abductors. The LFCA was specifically studied in 30 hips from 26 fresh cadavers after injection of common iliac artery or aorta with colored silicone for a more extensive hip vascular study. 24 hours after intra-arterial setting of silicone, dissection was performed through the anterior iliofemoral approach to expose the artery and its branches from the origin to the terminal distribution. In all specimens, the ascending branch of the LFCA was found as consistent supplier of gluteus minimus, gluteus medius, and tensor fasciae latae muscles by a variable number of branches. The proximal part of the abductor muscles was mainly supplied by the superior gluteal artery. We conclude, that ligating the ascending branch of the LFCA during anterior approach to the hip joint is likely to affect the vascularity and function of the abductor muscles especially in situations when perfusion of these muscles by the superior gluteal artery is compromised

Aims

The aim of this study was to evaluate the suitability of the tapered cone stem in total hip arthroplasty (THA) in patients with excessive femoral anteversion and after femoral osteotomy.

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Contemporary outcomes of primary total hip arthroplasties (THAs) with highly cross-linked polyethylene (HXLPE) liners in patients with inflammatory arthritis have not been well studied. This study examined the implant survivorship, complications, radiological results, and clinical outcomes of THA in patients with inflammatory arthritis.

Aims

Hyaline cartilage has a low capacity for regeneration. Untreated osteochondral lesions of the femoral head can lead to progressive and symptomatic osteoarthritis of the hip. The purpose of this study is to analyze the clinical and radiological long-term outcome of patients treated with osteochondral autograft transfer. To our knowledge, this study represents a series of osteochondral autograft transfer of the hip with the longest follow-up.

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To clarify the mid-term results of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, combined with structural allograft bone grafting for severe hip dysplasia.

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This study aimed to develop and validate a fully automated system that quantifies proximal femoral bone mineral density (BMD) from CT images.

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The aim of the HIPGEN consortium is to develop the first cell therapy product for hip fracture patients using PLacental-eXpanded (PLX-PAD) stromal cells.

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Although there are various pelvic osteotomies for acetabular dysplasia of the hip, shelf operations offer effective and minimally invasive osteotomy. Our study aimed to assess outcomes following modified Spitzy shelf acetabuloplasty.

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Achieving accurate implant positioning and restoring native hip biomechanics are key surgeon-controlled technical objectives in total hip arthroplasty (THA). The primary objective of this study was to compare the reproducibility of the planned preoperative centre of hip rotation (COR) in patients undergoing robotic arm-assisted THA versus conventional THA.