Introduction

Acetabular retroversion (AR) can cause pain and early osteoarthritis. The sagittal pelvic position or pelvic tilt (PT)has a direct relationship with acetabular orientation. As the pelvis tilts anteriorly, PT reduces and AR increases. Therefore, AR may be a deformity secondary to abnormal PT (functional retroversion) or an anatomical deformity of the acetabulum and/or pelvic ring.

This study aims to:

Define PT at presentation is in AR patients and whether this is different to controls (volunteers without pain).

Introduction

The changes in sagittal spino-pelvic balance from standing to sitting in patients with end-stage osteoarthritis (OA) of the hip remain poorly characterized. Our aim was to 1) investigate the contribution of sagittal spino-pelvic movement and hip flexion when moving from a standing to sitting posture in patients with hip OA; 2) determine the proportion of OA-patients with stiff, normal or hypermobile spino-pelvic mobility and 3) identify radiographic parameters correlating with spino-pelvic mobility.

Introduction

The resultant cup orientation depends upon the orientation of the pelvis at impaction. No studies to date have assessed whether patient-position during total hip arthroplasty (THA) has an effect on cup orientation. This study aims to 1) Determine the difference in pelvic position that occurs between surgery and radiographic, supine, post-operative assessment; 2) Examine how the difference in pelvic position influences subsequent cup orientation and 3) Establish whether pelvic orientation, and thereafter cup orientation, differences exist between THAs performed in the supine versus the lateral decubitus positions.

Introduction

The mechanisms of how spinal arthrodesis (SA) affects patient function after total hip replacement (THA) remain unclear. The objectives of this study were to a) Determine how outcome post-THA compares between patients with- and without-SA, b) Characterize sagittal pelvic changes that occur when moving between different functional positions, and test for differences between patients with- and without-SA, and c) Assess whether differences in sagittal pelvic dynamics are associated with outcome post-THA.

Introduction

Acetabular and spino-pelvic (SP) morphological parameters are important determinants of hip joint dynamics. This study aims to determine whether acetabular and SP morphological differences exist between hips with and without cam morphology and between symptomatic and asymptomatic hips with cam morphology.

Introduction

This study aims to determine how the acetabular version changes during the key developmental stage of adolescence, and what contributes to this change. In addition, we examined whether patient factors (BMI, activity levels) or the femoral-sided anatomy contribute to any observed changes.

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.

A modular hemiarthroplasty has a Metal-on-Metal (MoM) taper-trunnion junction, which may lead to increased wear and Adverse-Reaction-to-Metal-Debris (ARMD). To-date no wear related issues have been described in the elderly and less active that receives a hemiarthroplasty. This study aims to determine in vivo wear (i.e. serum metal ion levels) in hip hemiarthroplasty, and identify factors associated with increased wear.

This is a prospective, IRB approved, single-centre, cohort study of patients that received an uncemented, modular hemiarthroplasty of proven design for the treatment of hip fracture between 2013–2015. All, alive, patients at 12-months post-implantation with AMTS≥6 were invited to participate. Of the 125 eligible patients, 50 accepted the invitation and were reviewed, including clinical/radiological assessment, metal-ion ([Chromium (Cr) and Cobalt (Co)]) measurement and Oxford Hip Score (OHS). Acetabular erosion was graded (0–3: normal-protrusio). Metal ion levels were considered high if ≥7ppb.

The mean OHS was 37 (SD: 10). No acetabular erosion was detected in 21, whilst the remaining had either grade-1 (n=21) or grade-2 (n=8). The median Cr and Co levels were 2.9 (SD:9) and 2.2 (SD:4) respectively. There were 8 cases (16%) with high ion levels. To-date only 2 of them has an ARMD lesion, and none have been revised. Patients with metal ion levels had similar pre-fall mobility, taper- and head- size and OHS to those with low metal ion levels (p=0.2–0.7) However, all hips with high metal ion levels had evidence of acetabular erosion (≥1).

Modular Hip hemiarthroplasties and their taper-trunnion junction are not immune to high wear and ARMD despite being implanted in a less active cohort. Acetabular erosion should alert clinicians, as it is associated with 20× increased-risk of taper wear, presumably due to the increased transmitted torque. Whether the use of modular hemiarthroplasties should remain is debatable.

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).

Image-guided intra-articular hip injection of local-anaesthetic and steroid is commonly used in the management of hip pain. It can be used as a diagnostic and/or therapeutic tool and is of low cost (£75). The aim of this study was to assess how often a hip injection has a therapeutic effect.

This is a retrospective, consecutive, case series of intra-articular hip injections performed in a tertiary referral hospital over a 2-year period (2013–4). Patients were identified from the radiology department's prospectively entered database. Clinical information, reason for injection and subsequent management was obtained from hospital records. All patients prospectively reported their pain levels in a numeric pain scale diary (out of 10) at various time points; pre-, immediately post-, 1st day-, 2nd day- and 2 weeks- post-injection. Only patients with complete pain scores at all time points were included (n=200, of the 250 injections performed over study period, 80%).

The majority of injections were performed for osteoarthritis (OA) treatment (82%). The pain was significantly reduced from a pre-injection score of 7.5 (SD:2) to 5.0 (SD:3) immediately post-injection(p<0.001); only 24 (11%) reported any worsening of pain immediately post-injection. Pain significantly reduced further to 3.8(SD:3) at 2-weeks post-injection (p<0.001). 50% of patients had at least a 3 point drop in reported pain. No improvement was seen in 18 patients and 10 (5%) reported worse pain at 2-weeks compared to pre-injection. Of the OA cohort, 10% have required repeat injections, 45% required no further intervention and 45% underwent or are due for hip replacement. No immediate complications occurred.

Intra-articular hip injection reduced pain in 86% of cases and has delayed any further surgical treatment for at least 2 years in over 50% of OA cases. It is hence a cost-effective treatment modality. Further work is necessary to describe factors predicting response.

The management of proximal femoral bone loss is a significant challenge in revision hip arthroplasty. A possible solution is the use of a modular proximal femur endoprosthesis (EPR). Although the survivorship and functional outcome of megaprostheses used in tumour surgery has been well described, outcome of EPRs used in revision hip surgery has received less attention. The aim of this study was to determine the 5-year outcome following proximal femur EPR and determine factors that influence it.

This was a retrospective consecutive case series of all EPRs (n=80) performed for non-neoplastic indications, by 6 surgeons, in our tertiary referral centre, between 2005–2014. Patient demographics and relevant clinical details were determined from notes. The most common indications for the use of EPRs included infection (n=40), peri-prosthetic fracture (n=12) and failed osteosynthesis of proximal femoral fractures/complex trauma (n=11). Outcome measures included complication and re-operation rates, implant survival and assessment of functional outcome using the Oxford-Hip-Score (OHS).

The mean age at surgery was 69 years and mean follow-up was 4 (0 – 11) years. The mean number of previous hip operations was 2.4 (range: 0 – 17). Twenty-five patients sustained a complication (31%), the most common being infection (n=9) and dislocation (n=4). By follow-up, further surgery was required in 18 (22%) hips, 9 of which were EPR revisions. 5-yr implant survivorship was 87% (95%CI: 76 – 98%). Mean OHS was 28 (range: 4 – 48). Inferior survival and outcome were seen in EPRs performed for the treatment of infection. Infection eradication was achieved in 34/41 with the index EPR procedure and in 40/41 hips by follow-up.

Limb salvage was achieved in all cases and acceptable complication- and re-operation rates were seen. EPRs for periprosthetic fractures and failed osteosynthesis had best outcome. We recommend the continued use of proximal femur EPR in complex revision surgery.

Introduction

The value of Debridement-Antibiotics-and-Implant-Retention (DAIR) in prosthetic-joint-infection (PJI) is still a matter of debate as most studies to-date are underpowered with variable end-points. In our, tertiary referral, bone infection unit we consider DAIR to be a suitable option in all PJIs with soundly fixed prostheses, despite chronicity. The aims of this study were to define the long-term outcome following DAIR in hip PJI and identify factors that influence it.

Introduction

Joint preserving procedures have gained popularity in an attempt to delay arthroplasty in young, dysplastic hips. Excellent results can be achieved with peri-acetabular osteotomy (PAO) in congruent non-arthritic hips. The role of salvage procedures such as the Shelf acetabuloplasty remains undefined. This study aims to determine the long-term survival and functional outcome following Shelf acetabuloplasty and to identify factors that influence outcome.