Aims. Our aim in this study was to describe the long-term survival of the native hip joint after open reduction and internal fixation of a displaced fracture of the acetabulum. We also present long-term clinical outcomes and risk factors associated with a poor outcome. Patients and Methods. A total of 285 patients underwent surgery for a displaced acetabular fracture between 1993 and 2005. For the survival analysis 253 were included, there were 197 men and 56 women with a mean age of 42 years (12 to 78). The mean follow-up of 11 years (1 to 20) was identified from our pelvic fracture registry. There were 99 elementary and 154 associated fracture types. For the long-term clinical follow-up, 192 patients with complete data were included. Their mean age was 40 years (13 to 78) with a mean follow-up of 12 years (5 to 20). Injury to the femoral head and acetabular impaction were assessed with CT scans and patients with an ipsilateral fracture of the femoral head were excluded. Results. A total of 36 patients underwent total hip arthroplasty (THA). The overall ten-year survival of the hip joint was 86% (95% confidence interval (CI) 81% to 90%) and the 20-year survival was 82% (95% CI 76% to 87%). Injury to the femoral head and acetabular impaction were the strongest predictors of failure, with the long-term survival rate falling towards 50% in these patients. The survival fell to 0% at three years when both these risk factors were present in patients aged > 60 years. Conclusion. The long-term survival of the native hip joint after acetabular fractures was good, but the presence of injury to the femoral head and acetabular impaction proved to be strong predictors of failure, especially in patients aged > 60 years. These patients may be better treated with a combination of open reduction and internal fixation and primary arthroplasty. Cite this article: Bone Joint J 2017;99-B:834–40

Introduction. Nociceptive and neuropathic components both contribute to chronic pain. Since these components require different pain management strategies, correct pain diagnosis before and during treatment is important. Freynhagen et al. (2006) reported that they had developed and validated the pain-DETECT questionnaire (PD-Q) to detect neuropathic components in chronic low back pain patients. They also reported that 37% of unselected cohort of chronic LBP patients had predominantly neuropathic pain. However, the extent to which neuropathic components relate to the pathomechanism of pain deriving from osteoarthritis of hip joint remains unknown. The purpose of this study was to utilize PD-Q to investigate the relationship between neuropathic components and pain deriving from osteoarthritis of the hip joint. Methods. Between March and August 2010, 125 patients with osteoarthritis of hip joint completed PD-Qs about their pain. From this data set, we investigated whether or not the patients’ pain contained neuropathic components. Results. Only 6.4% of the patients had a score 19, indicating that a neuropathic component was likely (90%). Conversely, 79.2 % had a score 12, indicating that a neuropathic component was unlikely (15%). For the remaining 14.4% with an intermediate score (13–18), the presence of a neuropathic component remained uncertain. Conclusion. In this set of patients with osteoarthritis of hip joint, the PD-Q responses indicated that only a small percentage (6.4%) were likely to have a neuropathic component to their hip pain

INTRODUCTION. Hip wear simulator test results could be affected by many non-bearing related factors such as fixation surface conditions, equipment calibration and component set-up. In an effort to improve the accuracy, reliability and repeatability of hip simulator test, a quality management system has been established at the IDC hip tribology laboratory, which has been accredited by UKAS (United Kingdom Accreditation Service) in accordance with the recognised international standard ISO17025. This study demonstrates that under well-controlled laboratory and testing conditions, satisfactory repeatability can be achieved during hip simulator studies. METHODS. Between 2008 to 2010, ten 50 mm Birmingham Hip Resurfacing (BHR) devices were tested by the IDC tribology laboratory using two ProSim hip wear simulators in three different tests (T1, T2 and T3). All tests were performed following the same IDC testing protocols at 1 Hz frequency for 5 million cycles (Mc) or until after a steady state was reached. Paul type stance phase loadings with a maximum load of 3 kN and a swing phase load of 0.3 kN was used. The flexion and extension angles were 30 and 15 degree. The internal/external rotation angel was ±10 degree. Wear was measured gravimetrically using an analytical balance (Mettler, Toledo xp504) with an accuracy of 0.1 mg. RESULTS. Results showed that wear of all the components tested followed the typical biphasic trend of wear for MoM hip joint device with a high “running-in” wear during the initial stage followed by a low “steady state” wear in the later stage. The data points scattered in a narrow range following the same trend line throughout the tests. The maximum difference in accumulated volume loss between any two tests at any given cycle was less in 0.2 mm3. The average running-in wear rates (±SD) were 0.72 ±0.17, 0.86 ±0.01 and 0.71 ±0.19 mm3/Mc respectively for test T1, T2 and T3. The running-in wear rates for test T1 and T3 were identical, whilst that for T2 was slightly higher. In spite of this, the wear rates for the bearings tested in T2 were still in the same range as those tested in T1 and T3 during the running-in stage. The steady state (>1.0Mc) wear rate of three different tests was practically the same, being 0.18 ±0.02, 0.18 ±0.06 and 0.16 ±0.04 mm3/Mc respectively for test T1, T2 and T3. Overall, the mean running-in wear rate was 0.74 ±0.16 mm3/Mc, and the steady state wear rate was 0.17 ±0.04 mm3/Mc for the 10 BHR devices tested in three different studies. DISCUSSIONS. This study shows that satisfactory repeatability can be achieved during hip simulator test of metal on metal hip joint devices. Well controlled test procedures including calibration of testing and measurement equipment, correct and consistence test set-up and attention to non-bearing surfaces are some of the most important prerequisites for reliable and accurate hip simulator test results

Aims. The aim of this study was to investigate the association between fracture displacement and survivorship of the native hip joint without conversion to a total hip arthroplasty (THA), and to determine predictors for conversion to THA in patients treated nonoperatively for acetabular fractures. Methods. A multicentre cross-sectional study was performed in 170 patients who were treated nonoperatively for an acetabular fracture in three level 1 trauma centres. Using the post-injury diagnostic CT scan, the maximum gap and step-off values in the weightbearing dome were digitally measured by two trauma surgeons. Native hip survival was reported using Kaplan-Meier curves. Predictors for conversion to THA were determined using Cox regression analysis. Results. Of 170 patients, 22 (13%) subsequently received a THA. Native hip survival in patients with a step-off ≤ 2 mm, > 2 to 4 mm, or > 4 mm differed at five-year follow-up (respectively: 94% vs 70% vs 74%). Native hip survival in patients with a gap ≤ 2 mm, > 2 to 4 mm, or > 4 mm differed at five-year follow-up (respectively: 100% vs 84% vs 78%). Step-off displacement > 2 mm (> 2 to 4 mm hazard ratio (HR) 4.9, > 4 mm HR 5.6) and age > 60 years (HR 2.9) were independent predictors for conversion to THA at follow-up. Conclusion. Patients with minimally displaced acetabular fractures who opt for nonoperative fracture treatment may be informed that fracture displacement (e.g. gap and step-off) up to 2 mm, as measured on CT images, results in limited risk on conversion to THA. Step-off ≥ 2 mm and age > 60 years are predictors for conversion to THA and can be helpful in the shared decision-making process. Cite this article: Bone Joint J 2023;105-B(9):1020–1029

Aims. The aim of this study was to describe services available to patients with periprosthetic femoral fracture (PPFF) in England and Wales, with focus on variation between centres and areas for care improvement. Methods. This work used data freely available from the National Hip Fracture Database (NHFD) facilities survey in 2021, which asked 21 questions about the care of patients with PPFFs, and nine relating to clinical decision-making around a hypothetical case. Results. Of 174 centres contributing data to the NHFD, 161 provided full responses and 139 submitted data on PPFF. Lack of resources was cited as the main reason for not submitting data. Surgeon (44.6%) and theatre (29.7%) availability were reported as the primary reasons for surgical delay beyond 36 hours. Less than half had a formal process for a specialist surgeon to operate on PPFF at least every other day. The median number of specialist surgeons at each centre was four (interquartile range (IQR) 3 to 6) for PPFF around both hips and knees. Around one-third of centres reported having one dedicated theatre list per week. The routine discussion of patients with PPFF at local and regional multidisciplinary team meetings was lower than that for all-cause revision arthroplasties. Six centres reported transferring all patients with PPFF around a hip joint to another centre for surgery, and this was an occasional practice for a further 34. The management of the hypothetical clinical scenario was varied, with 75 centres proposing ORIF, 35 suggested revision surgery and 48 proposed a combination of both revision and fixation. Conclusion. There is considerable variation in both the organization of PPFF services England and Wales, and in the approach taken to an individual case. The rising incidence of PPFF and complexity of these patients highlight the need for pathway development. The adoption of networks may reduce variability and improve outcomes for patients with PPFF. Cite this article: Bone Jt Open 2023;4(5):378–384

We aim to determine the differences in lower limb joint kinematics during the golf swing of patients who had undergone Total Knee Arthroplasty (TKA) and a control group of native knee golfers. A case-control study was undertaken with ten golfers who had undergone TKA (cruciate retaining single radius implant) and five age and matched golfers with native knees. Each golfer performed five swings with a driver whilst being recorded at 200Hz by a ten-camera motion capture system. Knee and hip three-dimensional joint angles (JA) and joint angular velocities (JAV) were calculated and statistically compared between the groups at six swing events. The only significant differences in knee joint kinematics between TKA and control groups was a lower external rotation JA in the left knee during the backswing (p=0.010). There was no significant difference in knee JAV between the groups. Both hips demonstrated significantly (p=0.023 for left and p=0.037 for right) lower flexion in the TKA group during the takeaway swing event, and there was lower internal rotation in the backswing and greater external rotation in the downswing of the right hip. There was also slower left hip extension JAV in the downswing. Normal knee kinematics were observed during the golf swing following TKA, with the exception of reduced external rotation in the left knee during the back swing and the right during the down swing. The differences demonstrated in the hip motion indicate that they may make compensatory movements to adjust to the reduced external rotation demonstrated in the knee

Aims

Posterior column plating through the single anterior approach reduces the morbidity in acetabular fractures that require stabilization of both the columns. The aim of this study is to assess the effectiveness of posterior column plating through the anterior intrapelvic approach (AIP) in the management of acetabular fractures.

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To assess the feasibility of a randomized controlled trial (RCT) that compares three treatments for acetabular fractures in older patients: surgical fixation, surgical fixation and hip arthroplasty (fix-and-replace), and non-surgical treatment.

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Musculoskeletal infection is a devastating complication in both trauma and elective orthopaedic surgeries that can result in significant morbidity. Aim of this study was to assess the effectiveness and complications of local antibiotic impregnated dissolvable synthetic calcium sulphate beads (Stimulan Rapid Cure) in the hands of different surgeons from multiple centres in surgically managed bone and joint infections.

Aims. Displaced, comminuted acetabular fractures in the elderly are increasingly common, but there is no consensus on whether they should be treated non-surgically, surgically with open reduction and internal fixation (ORIF), or with acute total hip arthroplasty (THA). A combination of ORIF and acute THA, an approach called ’combined hip procedure’ (CHP), has been advocated and our aim was to compare the outcome after CHP or ORIF alone. Patients and Methods. A total of 27 patients with similar acetabular fractures (severe acetabular impaction with or without concomitant femoral head injury) with a mean age of 72.2 years (50 to 89) were prospectively followed for a minimum of two years. In all, 14 were treated with ORIF alone and 13 were treated with a CHP. Hip joint and patient survival were estimated. Operating times, blood loss, radiological outcomes, and patient-reported outcomes were assessed. Results. No patient in the CHP group required further hip surgery, giving THA a survival rate of 100% (95% confidence interval (CI) 100 to 100) after three years, compared with 28.6% hip joint survival in the ORIF group (95% CI 12.5 to 65.4; p = 0.001). No dislocations or deep infections occurred in the CHP group. No patient died within the first year after index surgery, but patient survival was lower in the CHP group after three years. There were no relevant differences in patient-reported outcomes. Conclusion. The CHP confers a considerably reduced need of further surgery when compared with ORIF alone in elderly patients with complex acetabular fractures. These findings encourage both further use of, and larger prospective studies on, the CHP. Cite this article: Bone Joint J 2019;101-B:478–483

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Acetabular fractures are associated with long-term morbidity. Our prospective cohort study sought to understand the recovery trajectory of this injury over five years.

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Patients with A1 and A2 trochanteric hip fractures represent a substantial proportion of trauma caseload, and national guidelines recommend that sliding hip screws (SHS) should be used for these injuries. Despite this, intramedullary nails (IMNs) are routinely implanted in many hospitals, at extra cost and with unproven patient outcome benefit. We have used data from the National Hip Fracture Database (NHFD) to examine the use of SHS and IMN for A1 and A2 hip fractures at a national level, and to define the cost implications of management decisions that run counter to national guidelines.

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Despite multiple trials and case series on hip hemiarthroplasty designs, guidance is still lacking on which implant to use. One particularly deficient area is long-term outcomes. We present over 1,000 consecutive cemented Thompson’s hemiarthroplasties over a ten-year period, recording all accessible patient and implant outcomes.

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The purpose of this study was to determine the weightbearing practice of operatively managed fragility fractures in the setting of publically funded health services in the UK and Ireland.

Background. Femoroacetabular impingement due to a reduced femoral head-neck-offset or excessive acetabular coverage will lead to early cartilage lesions of the hip joint. The purpose of the present study was to analyze the relationship between the extent of bony deformity and the presence and extent of cartilage lesions in femoroacetabular impingement. Methods. On the radiographs of 92 hip joints in 86 patients with a mean age of 36.5 ± 9.2 years who were operated on for with femoroacetabular impingement by surgical hip dislocation, the acetabular index of the weight-bearing zone, the center-edge-angle, the inclination of the acetabulum, the lateral-head-extrusion-index, retroversion signs of the acetabulum, the neck-shaft-angle, asphericity, superior and anterior alpha angles, and superior and anterior offset and offset ratios were assessed and correlated to the presence and extent of chondromalazia. Results. Acetabular chondromalazia was found in 60 hip joints. Full-thickness delamination of the acetabular cartilage was present in 42 of these hips with an average size of 1.1 ± 0.5 cm2. Femoral-sided chondromalazia was found in 9 hip joints. Hip joints with chondromalazia had a lower center-edge-angle (p = 0.014) and anterior offset ratio (p = 0.028) and a higher lateral-head-extrusion-index (p = 0.029). Hip joints with acetabular cartilage delamination had a significantly lower center-edge-angle (p = 0.012) and anterior offset (p = 0.03) and a significantly higher lateral-head-extrusion-index (p = 0.001) and superior (p = 0.006) and anterior alpha angles (p = 0.003). Conclusions. Marked cam-type femoral deformity and lesser coverage of the femoral head are associated with the acetabular cartilage lesions, arousing suspicion to the assumption that a large lateral aperture of the acetabulum abets proximal femora with cam-type deformity to inflict cartilage damage in femoroacetabular impingement

Aims. The anterior pelvic internal fixator is increasingly used for the treatment of unstable, or displaced, injuries of the anterior pelvic ring. The evidence for its use, however, is limited. The aim of this paper is to describe the indications for its use, how it is applied and its complications. Patients and Methods. We reviewed the case notes and radiographs of 50 patients treated with an anterior pelvic internal fixator between April 2010 and December 2015 at a major trauma centre in the United Kingdom. The median follow-up time was 38 months (interquartile range 24 to 51). Results. Three patients were excluded from the analysis leaving 47 patients with complete follow-up data. Of the 47 patients, 46 achieved radiological union and one progressed to an asymptomatic nonunion. Of the remaining patients, 45 required supplementary posterior fixation with percutaneous iliosacral screws, 2 of which required sacral plating. The incidence of injury to the lateral femoral cutaneous nerve (LFCN) was 34%. The rate of infection was 2%. There were no other significant complications. Without this treatment, 44 patients (94%) would have needed unilateral or bilateral open reduction and plate fixation extending laterally to the hip joint. Conclusion. The anterior pelvic internal fixator reduces the need for extensive open surgery and is a useful addition to the armamentarium for the treatment of anterior pelvic injuries. It is associated with injury to the LFCN in a third of patients. Cite this article: Bone Joint J 2017;99-B.1232–6

Introduction. It was the purpose to evaluate the biomechanical changes that occur after optimal and non-optimal component placement of a hip resurfacing (SRA) by using a subject specific musculoskeletal model based on CT-scan data. Materials and Methods. Nineteen hips from 11 cadavers were resurfaced with a BHR using a femoral navigation system. CT images were acquired before and after surgery. Grey-value segmentation in Mimics produced contours representing the bone geometry and identifying the outlines of the 3 parts of the gluteus medius. The anatomical changes induced by the procedure were characterised by the translation of the hip joint center (HJCR) with respect to the pelvic and femoral bone. The contact forces during normal gait with ‘optimal’ component placement were calculated for a cement mantle of 3 mm, a socket inclination of 45° and anteversion of 15°. The biomechanical effect of ‘non-optimal placement’ was simulated by varying the positioning of the components. Results. There was a significant (p<0.01) shortening of the muscle length with the ‘optimal’ component placement for all parts of the gluteus medius with the largest shortening of the posterior part by 6mm. This was caused by a significant shortening of the femoral offset by 2.3mm (p<0.01). Because of a significant (p<0.01) medialisation of the HJCR by 4 mm, there was no significant increase in contact force. The hip joint contact forces increased by 0.5% per mm HJCR displacement. Each millimeter of cranial and lateral displacement of the femoral HJCR increased the contact force by 0.5% and 1%, respectively. The contact stresses changed significantly by 0.8% and 0.2% per degree of socket inclination and anteversion. The contact force increased 1% per mm lateral displacement of the acetabular HJCR. Discussion. Optimal placement of the SRA components did not completely restore the biomechanics of the native hip joint. The contact forces were not increased due to the compensatory effect of the medialisation of the acetabular HJCR. This suggests that reaming to the acetabular floor should be conducted in SRA. Femoral component displacement in the cranial and lateral direction significantly increased the hip joint loading. Errors of socket placement in the coronal and sagital plane significantly increased the contact stresses. Accumulative errors of both component displacements could lead to increased contact stresses of 18% to 23% with socket inclinations of 50° and 55°. Surgeons should reconsider continuing the SRA procedure if a neck length loss and lateralisation of the HCJR by >5 mm is anticipated as this would increase the contact stresses by >12%

Introduction. Aim of this study was to review a single surgeon series and analyse the results of hip reconstruction and compare them to an historical cohort. Methods and results. Retrospective review from a prospective database was undertaken of 113 CFD children since 1999. 31 of these patients had hip reconstruction with combined soft tissue and bony procedures akin to the Superhip. This cohort was compared to the results of the previous series using deformity planning methods on radiographic imaging, quantification of acetabular and femoral geometry, focussing upon the effects and results of hip reconstruction and lengthening. Compared to the previous series, this cohort achieved greater objective increases in length and significantly fewer complications involving the hip joint during the process.11 hips out of 45 (24.4%) that were treated in the previous cohort subluxed during lengthening. Since 1999 there were no subluxations with improved hip geometry. Primary difference between the cohorts was the recent group's preparatory hip surgery before the commencement of any lengthening even for borderline dysplasias. This had not been the case for all children in the previous cohort. This indicates a steep learning curve in the last 3 decades concerning the importance of primary hip reconstruction as a preparatory stage of treatment before lengthening in CFD with almost normalised acetabulae. Conclusion. Management of CFD needs detailed and methodical planning of soft tissue and bony deformities and better understanding has evolved over time to provide improved results and outcomes. Level of evidence. Therapeutic III

INTRODUCTION. Analysis of retrieved ceramic components have shown areas of localized ‘stripe wear’, which have been attributed to joint laxity and/or impingement resulting in subluxation of the head, causing wear on the edge of the cup. Studies have been conducted into the effects of mild subluxation, however few in vitro tests have looked at severe subluxation. The aim of this study was to develop a more clinically relevant subluxation protocol. MATERIALS & METHODS. Seven (Subluxation n=4; standard test n=3) of 36mm Biolox Forte (R3, Smith & Nephew) ceramic devices were tested for 0.5m cycles (mc). Two of the subluxed joints were further tested to 1 Mc. The devices were subjected to subluxation under standard testing conditions. The flex/ext was 30° and 15° respectively, with internal/external rotation of ±10°. The force was Paul type stance phase loading with a maximum load of 3 kN, and a standard ISO swing phase load of 0.3 kN at 1 Hz. The test was conducted on a ProSim hip joint wear simulator (SimSol, UK). The simulator is equipped with a novel mechanism to achieve translation of the head, to achieve subluxation. During the ISO swing phase load of 0.3kN, a controlled lateral force required for the translation of the head is applied by a cam mechanism, head retraction then occurs during heel strike. The lubricant used was new born calf serum diluted with de-ionised water to achieve average protein concentration of 20 g/l, with 0.2 wt % concentration NaN3, and changed every 250k cycles. Measurements have been taken at 0.5 & 1 mc stages. RESULTS. Linear wear measurements conducted on the subluxed joints resulted in stripe wear similar to that reported in vivo. Average length, width and depth dimensions were 25.34±1.96 mm, 8±1.60 mm and 16.95±3.87 μm (± 95% CL) respectively. Linear wear at 0.5 Mc for standard joints, were undistinguishable from the original profile. Gravimetrically, weight loss was undetectable for joints tested under standard conditions. The volume loss of the joints under subluxation was 1.9± 0.7 mm3 at 0.5 mc. Two joints tested to 1mc generated an average volume loss of 3.1±2.3 mm3. The stripe wear length, width and depth at 1 Mc were 25.30±3.33mm, 8±3.92mm and 35±17.07 μm respectiveley. DISCUSSION. The current study presents test results of a hip joint simulator with a novel subluxation mechanism to simulate severe and clinically relevant hip joint. Past techniques have had to reduce the swing phase load to achieve stripe wear patches of varying size and depth. The subluxed joints produced significantly higher volumetric wear than the standard joints. Dimensional measurements in terms of length, width and depth of wear patches of subluxed joints generated similar results to that which have been observed following retrieval analysis. Tests that can simulate different types of activity in hip joint simulators will help to improve the design and understanding of implant behaviour in vivo

Aims

Hospital case volume is shown to be associated with postoperative outcomes in various types of surgery. However, conflicting results of volume-outcome relationship have been reported in hip fracture surgery. This retrospective cohort study aimed to evaluate the association between hospital case volume and postoperative outcomes in patients who had hip fracture surgery. We hypothesized that higher case volume would be associated with lower risk of in-hospital and one-year mortality after hip fracture surgery.