Mechanical irritation or impingement of the iliopsoas tendon accounts for 2–6% of persistent postoperative pain cases after total hip arthroplasty (THA). The most common trigger is anterior cup overhang. CT-scan can be used to identify and measure this overhang; however, no threshold exists for symptomatic anterior iliopsoas impingement. We conducted a case–control study in which CT-scan was used to define a threshold that differentiates patients with iliopsoas impingement from asymptomatic patients after THA.

We analyzed the CT-scans of 622 patients (758 CT-scans) between 2011 and 2020. Out of this population we identified 136 patients with symptoms suggestive of iliopsoas impingement. Among them, 6 were subsequently excluded: three because the diagnosis was reestablished intra-operatively (one metallosis, two anterior instability related to posterior prosthetic impingement) and three because they had another obvious cause of impingement (one protruding screw, one protruding cement plug, one stem collar), leaving 130 patients in the study (impingement) group. They were matched to a control group of 138 patients who were asymptomatic after THA. The anterior cup overhang (anterior margin of cup not covered by anterior wall) was measured by an observer (without knowledge of the clinical status) on an axial CT slice based on anatomical landmarks (orthogonal to pelvic axis).

The impingement group had a median overhang of 8 mm [IQR: 5 to 11] versus 0 mm [IQR: 0 to 4] for the control group (p<.001). Using ROC curves, an overhang threshold of 4 mm was best correlated with a diagnosis of impingement (sensitivity 79%, specificity 85%, PPV = 75%, NPV = 85%).

Pain after THA related to iliopsoas impingement can be reasonably linked to acetabular overhang if it exceeds 4 mm on a CT scan. Below this threshold, it seems logical to look for another cause of iliopsoas irritation or another reason for the pain after THA before concluding impingement is present.

Degenerative hip and spine pathologies often co-exist, as Hip-Spine-Syndrome (HSS). Many patients eventually need surgery in both hip (THR) and spine [decompression-spinal-arthrodesis (DSA)]. This case-control study aims to determine whether the presence of a DSA compromised THR outcome and whether outcome of THR is better if performed prior to- (THR-1. st. ) or after- DSA (THR-2. nd. ). This is a single centre, multi-surgeon, retrospective, case-control study. Of the 748 patients that underwent DSA between 2004–15, 43 patients (54 THRs) have also had a 1° THR(s) at our unit and formed the cases. Thirty-two THRs were performed prior to the DSA (THR-1. st. ) and 22 were done following the DSA (THR-2. nd. ). Most cases had either 1- (n=3) or 2-level (n=20) DSA. The most common DSA level was L4/5 (n=23). The mean THR-DSA interval was 3.6 years. Controls were patients (n=67) without DSA or previous spinal surgery, that had a THR in our unit over the same study period matched for age, gender and type of THR implanted. Patient Reported Outcome Measures (PROMs) were obtained using the Oxford-Hip- and Harris-Hip-Scores (OHS/HHS), with the difference between post- and pre-operative scores defined as Δ. Outcome was compared between Cases and Controls and between THR-1. st. and THR-2. nd. Groups. Outcome measures included complications, revisions, PROMs and cup orientations achieved. The mean age at THR was 67 years old (SD: 11) and most patients were female (n=82, 68%). The mean cup inclination and anteversion angles were 41° (SD:8) and 21° (SD:8). At a mean follow-up of 6 years, the OHS improved from OHS. pre. :16 (SD: 7) to OHS. fu. :41 (SD:10) and the HHS improved from HHS. pre. :51 (SD:14) to HHS. fu. :88 (SD:13). A greater incidence of complications were seen in the Cases (n=10; ARMD-3, infection-4, loosening-2, dislocation-1) compared to the Controls (n=3; dislocation-2, loosening-1) (p=0.01). Consequently, more THRs required revision in the Cases (n=7) compared to the Controls (n=1) (p=0.01). There were no differences in OHS. pre. /OHS. fu. /ΔOHS/HHS. pre. /HHS. fu. /ΔHHS between cases and controls (p=0.1 – 0.9). There were no difference in complications (7/29 Vs. 3/25; p=0.3), nor revision rates (5/29 Vs. 2/25; p=0.3) between THA-1. st. and THA-2. nd. Groups. Greater differences in PROMs were detected between the groups. The THA-1. st. Group, compared to the THA-2. nd. Group had higher OHS. pre. (19 Vs 12), HHS. pre. (54 Vs 48), OHS. fu. (43 Vs 32) and HHS. fu. (93 Vs 76), (p=0.001–0.005). However, no statistically significant difference in ΔOHS (24 Vs 17) and ΔHHS (39 Vs 26) were seen between the THA-1. st. and THA-2. nd. Groups (p=0.1). Patients with a 1° THR and DSA, had a greater rate complications and revisions compared to a matched control. Overall, no difference in PROMs were seen between Cases and Controls. No significantly increased risk of dislocation was seen in this predominantly 1- and 2-level DSA cohort. The superior PROMs detected in the THA-1. st. Group provide evidence that the hip pathology should be addressed 1. st. (in cases with 1- or 2-level planned DSA)

Introduction

Acetabular dysplasia is associated with an increased risk of hip pain and early development of osteoarthritis (OA). The Bernese peri-acetabular osteotomy (PAO) is the most well-established technique in the Western world for the treatment of symptomatic acetabular dysplasia. This case-control study aims to assess whether the severity of acetabular dysplasia has an effect on outcome following Peri-Acetabular Osteotomy (PAO) and/or the ability to achieve desired acetabular correction.

Aims. A revision for periprosthetic joint infection (PJI) in total hip arthroplasty (THA) has a major effect on the patient’s quality of life, including walking capacity. The objective of this case control study was to investigate the histological and ultrastructural changes to the gluteus medius tendon (GMED) in patients revised due to a PJI, and to compare it with revision THAs without infection performed using the same lateral approach. Methods. A group of eight patients revised due to a PJI with a previous lateral approach was compared with a group of 21 revised THAs without infection, performed using the same approach. The primary variables of the study were the fibril diameter, as seen in transmission electron microscopy (TEM), and the total degeneration score (TDS), as seen under the light microscope. An analysis of bacteriology, classification of infection, and antibiotic treatment was also performed. Results. Biopsy samples from the GMED from infected patients revealed a larger fibril diameter than control patients, as seen in the TEM (p < 0.001). Uninfected patients were slightly older and had their revisions performed significantly later than the infected patients. Histologically, samples from infected patients revealed significantly more vascularity (p < 0.001), the presence of glycosaminoglycans (p < 0.001), and a higher TDS (p = 0.003) than the control patients. The majority of patients had staphylococcal infections of various species. Conclusion. More histological degeneration in the GMED was found in patients undergoing THA revision surgery due to PJI than in patients undergoing THA revision surgery due to other reasons. Cite this article: Bone Jt Open 2023;4(8):628–635

Aims. Hip resurfacing remains a potentially valuable surgical procedure for appropriately-selected patients with optimised implant choices. However, concern regarding high early failure rates continues to undermine confidence in use. A large contributor to failure is adverse local tissue reactions around metal-on-metal (MoM) bearing surfaces. Such phenomena have been well-explored around MoM total hip arthroplasties, but comparable data in equivalent hip resurfacing procedures is lacking. In order to define genetic predisposition, we performed a case-control study investigating the role of human leucocyte antigen (HLA) genotype in the development of pseudotumours around MoM hip resurfacings. Methods. A matched case-control study was performed using the prospectively-collected database at the host institution. In all, 16 MoM hip resurfacing 'cases' were identified as having symptomatic periprosthetic pseudotumours on preoperative metal artefact reduction sequence (MARS) MRI, and were subsequently histologically confirmed as high-grade aseptic lymphocyte-dominated vasculitis-associated lesions (ALVALs) at revision surgery. ‘Controls’ were matched by implant type in the absence of evidence of pseudotumour. Blood samples from all cases and controls were collected prospectively for high resolution genetic a nalysis targeting 11 separate HLA loci. Statistical significance was set at 0.10 a priori to determine the association between HLA genotype and pseudotumour formation, given the small sample size. Results. Using a previously-reported ALVAL classification, the majority of pseudotumour-positive caseswere found to have intermediate-grade group 2 (n = 10; 63%) or group 3 (n = 4; 25%) histological findings. Two further patients (13%) had high-grade group 4 lesions. HLA-DQB1*05:03:01 (p = 0.0676) and HLA-DRB1*14:54:01 (p = 0.0676) alleles were significantly associated with a higher risk of pseudotumour formation, while HLA-DQA1*03:01:01 (p = 0.0240), HLA-DRB1*04:04:01 (p = 0.0453), HLA-C*01:02:01 (p = 0.0453), and HLA-B*27:05:02 (p = 0.0855) were noted to confer risk reduction. Conclusion. These findings confirm the association between specific HLA genotypes and the risk of pseudotumour development around MoM hip resurfacings. Specifically, the two ‘at risk’ alleles (DQB1*05:03:01 and DRB1*14:54:01) may hold clinical value in preoperative screening and prospective surgical decision-making. Cite this article: Bone Jt Open 2023;4(3):182–187

We determined the association between frailty and 30-day mortality following total hip arthroplasty (THA) and the impact of THA on 30-day mortality compared to a control population. We used primary care data (Clinical Practice Research Datalink), linked secondary care data (Hospital Episode Statistics) and Office for National Statistics mortality data. Frailty was assessed using a validated frailty index based on coded data in the primary care record and categorised as fit, mild, moderate, and severe frailty. The association between frailty and 30-day mortality following THA due to osteoarthritis was assessed using Cox regression, adjusted for year of birth, sex, quintile of index of multiple deprivation and year of surgery. Mortality following THA was also compared to a control population who had osteoarthritis but no previous THA, matched on year of birth, sex, and quintile of index of multiple deprivation. 103,563 cases who had a THA and their matched controls contributed data. Among those who had THA, compared to fit participants, 30-day mortality increased with increasing frailty; adjusted hazard ratio (HR) (95% CI) among mild frailty, 0.87 (0.66, 1.15); moderate frailty 1.73 (1.26, 2.38); and severe frailty, 2.85 (1.84, 4.39). Compared to fit controls who did not have surgery, 30-day mortality was higher among fit people who had THA, adjusted HR 1.60 (1.15, 2.21). There was, however, no statistically significant difference in 30-day mortality among cases with mild, moderate and severe frailty compared to controls in the same frailty category. Among people who had THA, 30-day mortality increased with increasing frailty. While 30-day mortality was increased among fit individuals who had THA compared to fit controls who did not have surgery, there did not appear to be increased mortality among individuals with mild, moderate or severe frailty compared to controls in the same frailty category. A healthy surgery (selection) effect may have impacted on the comparison of mortality among cases and controls

Aims

Periprosthetic joint infections (PJIs) with prior multiple failed surgery for reinfection represent a huge challenge for surgeons because of poor vascular supply and biofilm formation. This study aims to determine the results of single-stage revision using intra-articular antibiotic infusion in treating this condition.

Aims

Septic arthritis of the hip often leads to irreversible osteoarthritis (OA) and the requirement for total hip arthroplasty (THA). The aim of this study was to report the mid-term risk of any infection, periprosthetic joint infection (PJI), aseptic revision, and reoperation in patients with a past history of septic arthritis who underwent THA, compared with a control group of patients who underwent THA for OA.

Aims

One-stage revision hip arthroplasty for periprosthetic joint infection (PJI) has several advantages; however, resection of the proximal femur might be necessary to achieve higher success rates. We investigated the risk factors for resection and re-revisions, and assessed complications and subsequent re-revisions.

Introduction. There has been a renewed interest in the surgical approach used for total hip arthroplasty (THA). Risk factors for periprosthetic joint infection (PJI) have been well studied over the past decade, yet PJI remains one of the most devastating complications following THA. We studied the impact of direct anterior (DA) versus non-direct anterior (NA) surgical approaches on PJI, and examined the impact of new perioperative protocols on PJI rates following all surgical approaches at a single institution. Methods. 6086 continuous patients undergoing primary THA at a single institution from 2013–2016 were retrospectively evaluated. Data obtained from electronic patient medical records included age, sex, body mass index (BMI), medical comorbidities, surgical approach, and presence of deep PJI. Deep PJI was defined according to National Healthcare Safety Network's (NHSN) criteria for joint space infection following prosthetic hip replacement. Infection rates were calculated yearly for the DA and NA approach groups. Covariates were assessed and used in multivariate analysis to calculate adjusted odds ratios for risk of development of PJI with DA compared to NA approaches. In order to determine the effect of adopting a set of infection prevention protocols and patient optimization on PJI, we calculated odds ratios for PJI comparing patients undergoing THA for two distinct time periods: 2013–2014 and 2015–2016. These periods corresponded to before and after we implemented a set of perioperative infection protocols. Results. There were 1985 patients in the DA group and 4101 patients in the NA group. The overall rate of PJI at our institution during the study period was 0.82% (50/6086) and decreased from 0.96% (12/1245) in 2013 to 0.53% (10/1870) in 2016. There were 24 deep PJI's in the DA group (1.22%) and 26 deep PJI's in the NA group (0.63%) (p=0.0231). After multivariate analysis, the DA approach was 2.2 times more likely to result in PJI than the NA approach (95% CI OR 1.1–3.9, p=0.0062) for the overall study period. When stratified by time, patients undergoing THA utilizing any approach prior to adopting the infection prevention protocols (2013–2014), were 1.8 times more likely to have PJI compared to patients undergoing THA after the adoption of the protocols, however this result did not reach significance (95% CI OR 0.901–3.653, p=0.0953). Conclusions. We found a higher rate of PJI in DA versus NA approaches. However, adoption of infection prevention protocols patient optimization mitigated these PJI rates, such that they were equalized between the approach groups for the period following the use of infection prevention and patient optimization protocols. Institutional learning curves and adaptation of interventions aimed at PJI prevention positively contributed to the decreased rate of PJI observed for all approaches over time. Evidence: Level II – Case control

Objectives. The objective of this study was to assess all evidence comparing the Thompson monoblock hemiarthroplasty with modular unipolar implants for patients requiring hemiarthroplasty of the hip with respect to mortality and complications. Methods. A literature search was performed to identify all relevant literature. The population consisted of patients undergoing hemiarthroplasty of the hip for fracture. The intervention was hemiarthroplasty of the hip with a comparison between Thompson and modular unipolar prostheses. Pubmed, Embase, CINAHL, Web of Science, PROSPERO and the Cochrane Central Register of Controlled Trials. The study designs included were randomised controlled trials (RCTs), well designed case control studies and retrospective or prospective cohort studies. Studies available in any language, published at any time until September 2015 were considered. Studies were included if they contained mortality or complications. Results. The initial literature search identified 4757 items for examination. Four papers were included in the final review. The pooled odds ratio for mortality was 1.3 (95% confidence Interval 0.78 to 2.46) favouring modular designs. The pooled odds ratio for post-operative complications was 1.1 (95% CI 0.79 to 1.55) favouring modular designs. Outcomes were reported at 12 or six months. These papers all contained potential sources of bias and significant clinical heterogeneity. Conclusion. The current evidence comparing monoblock versus modular implants in patients undergoing hemiarthroplasty is weak. Confidence intervals around the pooled odds ratios are broad and incorporate a value of one. Direct comparison of outcomes from these papers is fraught with difficulty and, as such, may well be misleading. A well designed randomised controlled trial would be helpful to inform evidence-based implant selection. Cite this article: A. L. Sims, A. J. Farrier, M. R. Reed, T. A. Sheldon. Thompson hemiarthroplasty versus modular unipolar implants for patients requiring hemiarthroplasty of the hip: A systematic review of the evidence. Bone Joint Res 2017;6:–513. DOI: 10.1302/2046-3758.68.BJR-2016-0256.R1

Introduction. Although DDH is one of the most common skeletal dysplasias (incidence 1.5 cases per 1000 births), it remains slow and costly to recruit large-scale patient cohorts for powerful genetic association studies. In this work we have successfully used the NJR as a platform to generate a DDH biobank of 907 individuals, upon which we have conducted the first ever genome-wide association study (GWAS) for DDH. Methods. 5411 patients recorded as having a hip replacement for ‘hip dysplasia’ between March 2003 and December 2013 were approached to participate in the study. Following filtering by questionnaire for non-DDH cases and non-European Caucasians, 907 patients returned a completed saliva sample. A randomly selected sample of individuals participating on the UK Household Longitudinal Study that had been previously genotyped using the same platform were used as controls at a case:control ratio of 1:4. A further data set consisting of 332 cases, 1375 controls and 26 variants was used to replicate the top signals. Results. Of 256833 variants that passed QC, 11 variants reached genome-wide significance. All these variants came from the same signal, with rs143384 as the index SNP (allele A, allele frequency 0.60, OR [95% CI] 1.58[1.40–1.77], P=1.1×10. −14. ). Twenty-six independent variants were prioritized to follow up through de novo replication. Variant rs143384 was found to be significantly associated with DDH after meta-analysing discovery and replication datasets (allele A, allele frequency 0.60, OR [95% CI] 1.50[1.36–1.66], P=2.81×10. −16. ). Discussion. Using eHR case-ascertainment and distance recruitment strategies we conducted the first GWAS for DDH and confirmed association of the GDF5 variant rs143384 with DDH (P=2.81×10. −16. ). We establish the first genome-wide significant locus for DDH, discovered through linking EHRs with genomics as a proof of principle in enabling powerful genetic association studies of relatively rare but complex diseases

Aims

Type 2 diabetes mellitus (T2DM) impairs bone strength and is a significant risk factor for hip fracture, yet currently there is no reliable tool to assess this risk. Most risk stratification methods rely on bone mineral density, which is not impaired by diabetes, rendering current tests ineffective. CT-based finite element analysis (CTFEA) calculates the mechanical response of bone to load and uses the yield strain, which is reduced in T2DM patients, to measure bone strength. The purpose of this feasibility study was to examine whether CTFEA could be used to assess the hip fracture risk for T2DM patients.

Objectives. High failure rates of metal-on-metal hip arthroplasty implants have highlighted the need for more careful introduction and monitoring of new implants and for the evaluation of the safety of medical devices. The National Joint Registry and other regulatory services are unable to detect failing implants at an early enough stage. We aimed to identify validated surrogate markers of long-term outcome in patients undergoing primary total hip arthroplasty (THA). Methods. We conducted a systematic review of studies evaluating surrogate markers for predicting long-term outcome in primary THA. Long-term outcome was defined as revision rate of an implant at ten years according to National Institute of Health and Care Excellence guidelines. We conducted a search of Medline and Embase (OVID) databases. Separate search strategies were devised for the Cochrane database and Google Scholar. Each search was performed to include articles from the date of their inception to June 8, 2015. Results. Our search strategy identified 1082 studies of which 115 studies were included for full article review. Following review, 17 articles were found that investigated surrogate markers of long-term outcome. These included one systematic review, one randomised control trial (RCT), one case control study and 13 case series. Validated surrogate markers included Radiostereometric Analysis (RSA) and Einzel-Bild-Röntgen-Analyse (EBRA), each measuring implant migration and wear. We identified five RSA studies (one systematic review and four case series) and four EBRA studies (one RCT and three case series). Patient Reported Outcome Measures (PROMs) at six months have been investigated but have not been validated against long-term outcomes. Conclusions. This systematic review identified two validated surrogate markers of long-term primary THA outcome: RSA and EBRA, each measuring implant migration and wear. We recommend the consideration of RSA in the pre-market testing of new implants. EBRA can be used to investigate acetabular wear but not femoral migration. Further studies are needed to validate the use of PROMs for post-market surveillance. Cite this article: T. T. Malak, J. A. J. Broomfield, A. J. R. Palmer, S. Hopewell, A. Carr, C. Brown, D. Prieto-Alhambra, S. Glyn-Jones. Surrogate markers of long-term outcome in primary total hip arthroplasty: A systematic review. Bone Joint Res 2016;5:206–214. DOI: 10.1302/2046-3758.56.2000568

The major advantage of hip resurfacing is the decreased amount of bone resection compared with a standard total hip replacement. Fracture of the femoral neck is the most common early complication and poor bone quality is a major risk factor. We undertook a prospective consecutive case control study examining the effect of bone mineral density changes in patients undergoing hip resurfacing surgery. A total of 423 patients were recruited with a mean age of 54 years (24 to 87). Recruitment for this study was dependent on pre-operative bilateral femoral bone mineral density results not being osteoporotic. The operated and non-operated hips were assessed. Bone mineral density studies were repeated over a two-year period. The results showed no significant deterioration in the bone mineral density in the superolateral region in the femoral neck, during that period. These findings were in the presence of a markedly increased level of physical activity, as measured by the short-form 36 health survey physical function score

Aims

Concurrent hip and spine pathologies can alter the biomechanics of spinopelvic mobility in primary total hip arthroplasty (THA). This study examines how differences in pelvic orientation of patients with spine fusions can increase the risk of dislocation risk after THA.

Aims

The Corail stem has good long-term results. After four years of using this stem, we have detected a small group of patients who have presented with symptomatic metaphyseal debonding. The aim of this study was to quantify the incidence of this complication, to delineate the characteristics of patients presenting with this complication and to compare these patients with asymptomatic controls to determine any important predisposing factors.

Aims

The most effective surgical approach for total hip arthroplasty (THA) remains controversial. The direct anterior approach may be associated with a reduced risk of dislocation, faster recovery, reduced pain and fewer surgical complications. This systematic review aims to evaluate the current evidence for the use of this approach in THA.

Aims

The optimal management of intracapsular fractures of the femoral neck in independently mobile patients remains open to debate. Successful fixation obviates the limitations of arthroplasty for this group of patients. However, with fixation failure rates as high as 30%, the outcome of revision surgery to salvage total hip arthroplasty (THA) must be considered. We carried out a systematic review to compare the outcomes of salvage THA and primary THA for intracapsular fractures of the femoral neck.

Aims

The widely used and well-proven Palacos R (a.k.a. Refobacin Palacos R) bone cement is no longer commercially available and was superseded by Refobacin bone cement R and Palacos R + G in 2005. However, the performance of these newly introduced bone cements have not been tested in a phased evidence-based manner, including roentgen stereophotogrammetric analysis (RSA).