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Bone & Joint Research
Vol. 9, Issue 8 | Pages 468 - 476
1 Aug 2020
Parsons NR Costa ML Achten J Griffin XL

Aims

To assess the variation in pre-fracture quality of life (QoL) within the UK hip fracture population, and quantify the nature and strength of associations between QoL and other routinely collected patient characteristics and treatment choices.

Methods

The World Hip Trauma Evaluation (WHiTE) study, an observational cohort study of UK hip fracture patients, collects a range of routine data and a health-related QoL score (EuroQol five-dimension questionnaire (EQ-5D)). Pre-fracture QoL data are summarized and statistical models fitted to understand associations between QoL, patient characteristics, fracture types, and operations.


The Bone & Joint Journal
Vol. 102-B, Issue 8 | Pages 1003 - 1009
1 Aug 2020
Mononen H Sund R Halme J Kröger H Sirola J

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.

Methods

Data used in this study were compiled from several Finnish national health registers, including the Finnish Arthroplasty Register (FAR) which was the primary source for prosthesis-related data. Other registers used in this study included the Finnish Health Care Register (HILMO), the Social Insurance Institutions (SII) registers, and Statistics Finland. The study was conducted as a prospective retrospective cohort study. Cox proportional hazards regression and Kaplan-Meier survival analysis were used for analysis.


Bone & Joint Research
Vol. 9, Issue 8 | Pages 515 - 523
1 Aug 2020
Bergiers S Hothi H Henckel J Eskelinen A Skinner J Hart A

Aims

The optimum clearance between the bearing surfaces of hip arthroplasties is unknown. Theoretically, to minimize wear, it is understood that clearances must be low enough to maintain optimal contact pressure and fluid film lubrication, while being large enough to allow lubricant recovery and reduce contact patch size. This study aimed to identify the relationship between diametrical clearance and volumetric wear, through the analysis of retrieved components.

Methods

A total of 81 metal-on-metal Pinnacle hips paired with 12/14 stems were included in this study. Geometrical analysis was performed on each component, using coordinate and roundness measuring machines. The relationship between their as-manufactured diametrical clearance and volumetric wear was investigated. The Mann-Whitney U test and unpaired t-test were used, in addition to calculating the non-parametric Spearman's correlation coefficient, to statistically evaluate the acquired data.


The Bone & Joint Journal
Vol. 102-B, Issue 8 | Pages 1010 - 1015
1 Aug 2020
Robinson PG Maempel JF Murray IR Rankin CS Hamilton DF Gaston P

Aims

Responsiveness and ceiling effects are key properties of an outcome score. No such data have been reported for the original English version of the International Hip Outcome Tool 12 (iHOT-12) at a follow-up of more than four months. The aim of this study was to identify the responsiveness and ceiling effects of the English version iHOT-12 in a series of patients undergoing hip arthroscopy for intra-articular hip pathology at a minimum of one year postoperatively.

Methods

A total of 171 consecutive patients undergoing hip arthroscopy with a diagnosis of femoroacetabular impingement (FAI) under the care of a single surgeon between January 2013 and March 2017 were included. iHOT-12 and EuroQol 5D-5L (EQ-5D-5L) scores were available pre- and postoperatively. Effect size and ceiling effects for the iHOT-12 were calculated with subgroup analysis.


Bone & Joint Research
Vol. 9, Issue 8 | Pages 484 - 492
1 Aug 2020
Zhang W Fang X Shi T Cai Y Huang Z Zhang C Lin J Li W

Aims

To explore the effect of different types of articulating antibiotic-loaded cement spacers in two-stage revision for chronic hip prosthetic joint infection (PJI).

Methods

A retrospective cohort study was performed involving 36 chronic PJI patients treated with different types of articulating antibiotic-loaded cement spacers between January 2014 and December 2017. The incidence of complications and the therapeutic effects of different types of antibiotic-loaded articulating cement spacers were compared.


Bone & Joint Open
Vol. 1, Issue 7 | Pages 431 - 437
17 Jul 2020
Rodriguez HA Viña F Muskus MA

Aims

In elderly patients with osteoarthritis and protrusio who require arthroplasty, dislocation of the hip is difficult due to migration of the femoral head. Traditionally, neck osteotomy is performed in situ, so this is not always achieved. Therefore, the purpose of this study is to describe a partial resection of the posterior wall in severe protrusio.

Methods

This is a descriptive observational study, which describes the surgical technique of the partial resection of the posterior wall during hip arthroplasty in patients with severe acetabular protrusio operated on between January 2007 and February 2017.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 1 - 1
1 Jul 2020
Fernquest S Palmer A Gimpel M Birchall R Broomfield J Wedatilake T Dijkstra H Lloyd T Pereira C Newman S Carr A Glyn-Jones S
Full Access

Background

Cam morphology develops during adolescence and predisposes individuals to future hip pain and osteoarthritis. An improved understanding of cam development is required to determine whether the process is modifiable.

Hypothesis/Purpose

The aim of this study was to characterise the risk factors, timing, and pathogenesis of cam formation.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 8 - 8
1 Jul 2020
Holleyman R Kuroda Y Saito M Khanduja V Malviya A
Full Access

Background

The purpose of this study was to report functional outcome scores following arthroscopic acetabular chondral procedures using the U.K. Non-Arthroplasty Hip Registry (NAHR).

Methods

Data on adult patients who underwent hip arthroscopy between January 2012 and December 2018 was extracted from the NAHR. Patients who underwent femoral sided chondral procedures were excluded. Patients who underwent osteophyte excision or a concurrent extra-articular procedure were also excluded. Cases were then classified according to the acetabular chondral procedure performed – ‘chondroplasty’, ‘microfracture’ or ‘none’ (no chondral procedure recorded). Outcomes comprised EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool 12 (iHOT-12), preoperatively and at 6 and 12 months.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 9 - 9
1 Jul 2020
Uzoigwe C Mostafa A Middleton R
Full Access

Background

In a number of disciplines, positive correlations have been reported between volume and clinical outcome. This has helped drive the evolution of specialist centres to deal with complex or high risk medical conditions. Hip fractures are a common injury associated with high morbidity and mortality.

Aim

To assess whether volume of hip fracture cases attended to by individual hospitals is associated with the quality of care provided and clinical outcomes.


Aim

To assess the effect of different polyethylene modifications on Total Hip Replacement survival.

Methods

We combined the NJR dataset with polyethylene manufacturing properties as supplied by the manufacturers. Cause specific and overall reasons for revisions were analysed using Kaplan-Meier and multi-variate Cox proportional hazard regression survival analyses. Revision for aseptic loosening was the primary endpoint. Modification variables included resin type, radiation source, multiple cross-linking treatments, cross-linking dose, terminal sterilisation method, terminal sterilisation radiation dose, stabilisation treatment, total radiation dose, and packaging.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 15 - 15
1 Jul 2020
Holleyman R Critchley R Jameson S Mason J Reed M Malviya A
Full Access

Prosthetic joint infections (PJI) are a devastating consequence in total hip arthroplasties (THA) with both significant morbidity and sometimes mortality, posing a significant health economic burden. Studies, both clinical and in-vitro have suggested possible reduction in PJI with the use of ceramic bearings.

We have investigated the relationship of ceramic-on-ceramic (CoC), ceramic-on-polyethylene (CoP) or metal-on-polyethylene (MoP) bearing surface in affecting outcome of revision surgery after primary THA using data collected from National Joint Registry for England and Wales, Northern Ireland and the Isle of Man between 2002 and 2016. We used a competing risk regression model to investigate predictors of each revision outcome, such as infection, dislocation, aseptic revision and all cause revisions. The results were adjusted for age, gender, ASA grade, BMI, indication for surgery, intraoperative complications and implant data.

We identified 456,457 THA (228,786 MoP, 128,403 CoC and 99,268 CoP). In a multivariable model, the adjusted risk of revision for PJI was lower with CoC (OR-0.748, p<0.001) and CoP (OR-0.775, p<0.001) when compared to MoP bearing. Additionally there was also a significant reduction in the risk of all cause revision for CoC (OR-0.918, p=0.002) and CoP (0.806, p<0.001), bearings as compared with MoP. The protective effect of ceramic bearing was predominantly seen after two years of implantation with a significant (p<0.0001) reduction of revision for PJI in both CoC (by 42.8%) and CoP (by 41.3%) group. Similarly significant effect was seen for aseptic revision beyond two years and overall all cause revision rate beyond two years reduced by 21.6% for CoC and 27.1% for CoP (p<0.001).

Within the limits of registry analysis, this study has demonstrated an association between the use of ceramic bearing and lower rates of revision for all cause revisions especially infection and aseptic loosening. This finding supports the use of ceramic bearings in THA.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 16 - 16
1 Jul 2020
Evans J Blom A Howell J Timperley J Wilson M Whitehouse S Sayers A Whitehouse M
Full Access

Total hip replacements (THRs) provide pain relief and improved function to thousands of patients suffering from end-stage osteoarthritis, every year. Over 800 different THR constructs were implanted in the UK in 2017. To ensure reliable implants are used, a NICE revision benchmark of 5% after 10 years exists. Given the 10-year cumulative mortality of patients under 55 years of age receiving THRs is only 5% and that a recent study suggests 25-year THR survival of 58%, we aim to produce revision estimates out to 30 years that may guide future long-term benchmarks.

The local database of the Princess Elizabeth Orthopaedic Centre (PEOC), Exeter, holds data on over 20,000 patients with nearly 30-years follow-up with contemporary prostheses. A previous study suggests that the results of this centre are generalisable if comparisons restricted to the same prostheses. Via flexible parametric survival analysis, we created an algorithm using this database, for revision of any part of the construct for any reason, controlling for age and gender. This algorithm was applied to 664,761 patients in the NJR who have undergone THR, producing a revision prediction for patients with the same prostheses as those used at this centre.

Using our algorithm, the 10-year predicted revision rate of THRs in the NJR was 2.2% (95% CI 1.8, 2.7) based on a 68-year-old female patient; well below the current NICE benchmark. Our predictions were validated by comparison to the maximum observed survival in the NJR (14.2 years) using restricted mean survival time (P=0.32). Our predicted cumulative revision estimate after 30 years is 6.5% (95% CI 4.5, 9.4). The low observed and predicted revision rate with the prosthesis combinations studied, suggest current benchmarks may be lowered and new ones introduced at 15 and 20 years to encourage the use of prostheses with high survival.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 36 - 36
1 Jul 2020
DaVries Z Salih S Speirs A Dobransky J Beaule P Grammatopoulos G Witt J
Full Access

Purpose

Spinopelvic parameters are associated with the development of symptomatic femoroacetabular impingement and subsequent osteoarthritis. Pelvic incidence (PI) characterizes the sagittal profile of the pelvis and is important in the regulation of both lumbar lordosis and pelvic orientation (i.e. tilt). The purpose of this imaging-based study was to test the association between PI and acetabular morphology.

Methods

Measurements of the pelvis and acetabulum were performed for 96 control patients and 29 hip dysplasia patients using 3D-computed topography (3D-CT) scans. Using previously validated measurements the articular cartilage and cotyloid fossa area of the acetabulum, functional acetabular version/inclination, acetabular depth, pelvic tilt, sacral slope, and PI were calculated. Non-parametric statistical tests were used; significance was set at p<0.05.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 26 - 26
1 Jul 2020
Roberts T Smith T Simon H Goodmaker C Hing C
Full Access

Aims

Urinary catheter use in the peri-operative and post-operative phase following arthroplasty may be associated with increased risk of urinary tract infection (UTI) and deep prosthetic joint infection (PJI). These can be catastrophic complications in joint arthroplasty. We performed a systematic review of the evidence on routine use of antibiotics for urinary catheter insertion and removal following arthroplasty.

Methods

Electronic databases were searched using the HDAS interface. Grey literature was also searched. From 219 citations, six studies were deemed eligible for review. Due to study heterogeneity a narrative approach was adopted. Methodological quality of each study was assessed using the CASP appraisal tool. Included studies were found to have moderate to good methodological quality.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 27 - 27
1 Jul 2020
Wyatt M Whitehouse M Kieser D Frampton C Hooper G
Full Access

Background

Reduced dislocation rates using lipped polyethylene (PE) liners in modular uncemented acetabular components has been shown, yet there may be increased wear because of impingement, which may lead to aseptic loosening. We used New Zealand Joint Registry (NZJR) data to compare survival rates, revision rates for dislocation and aseptic loosening between lipped and neutral liners.

Methods

31,247 primary THAs using the four commonly used uncemented modular cups were identified (January 1, 1999 to December 31, 2018). The lipped liner group comprised 49% males vs 42% in the neutral group (p < 0.001); 96% had OA vs 95% in the neutral group (p < 0.001). There was no difference in other patient characteristics. Mean follow-up was 5.1 years (SD 3.9); longest follow-up 19.3 years. Kaplan Meier survival rates were compared (20,240 lipped and 11,007 neutral PE liners). Highly cross-linked PE was used in 99% of lipped liner cups vs 85% of neutral liner cups. Associated hazard ratios were calculated using a Cox regression analysis.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 78 - 84
1 Jul 2020
Roof MA Feng JE Anoushiravani AA Schoof LH Friedlander S Lajam CM Vigdorchik J Slover JD Schwarzkopf R

Aims

Previous studies have reported an increased risk for postoperative complications in the Medicaid population undergoing total hip arthroplasty (THA). These studies have not controlled for the surgeon’s practice or patient care setting. This study aims to evaluate whether patient point of entry and Medicaid status plays a role in quality outcomes and discharge disposition following THA.

Methods

The electronic medical record at our institution was retrospectively reviewed for all primary, unilateral THA between January 2016 and January 2018. THA recipients were categorized as either Medicaid or non-Medicaid patients based on a visit to our institution’s Hospital Ambulatory Care Center (HACC) within the six months prior to surgery. Only patients who had been operated on by surgeons (CML, JV, JDS, RS) with at least ten Medicaid and ten non-Medicaid patients were included in the study. The patients included in this study were 56.33% female, had a mean age of 60.85 years, and had a mean BMI of 29.14. The average length of follow-up was 343.73 days.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 27 - 32
1 Jul 2020
Heckmann N Weitzman DS Jaffri H Berry DJ Springer BD Lieberman JR

Aims

Dual mobility (DM) bearings are an attractive treatment option to obtain hip stability during challenging primary and revision total hip arthroplasty (THA) cases. The purpose of this study was to analyze data submitted to the American Joint Replacement Registry (AJRR) to characterize utilization trends of DM bearings in the USA.

Methods

All primary and revision THA procedures reported to AJRR from 2012 to 2018 were analyzed. Patients of all ages were included and subdivided into DM and traditional bearing surface cohorts. Patient demographics, geographical region, hospital size, and teaching affiliation were assessed. Associations were determined by chi-squared analysis and logistic regression was performed to assess outcome variables.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 13 - 13
1 Jul 2020
Stone M Smith L Kingsbury S Czoski-Murray C Judge A Pinedo-Villanueva R West R Wright J Smith C Arden N Conaghan P
Full Access

Follow-up of arthroplasty varies widely across the UK. The aim of this NIHR-funded study was to employ a mixed-methods approach to examine the requirements for arthroplasty follow-up and produce evidence-based and consensus-based recommendations. It has been supported by BHS, BASK, BOA, ODEP and NJR.

Four interconnected work packages have recently been completed: (1) a systematic literature review; (2a) analysis of routinely collected National Health Service data from four national data sets to understand when and which patients present for revision surgery; (2b) prospective data regarding how patients currently present for revision surgery; (3) economic modelling to simulate long-term costs and quality-adjusted life years associated with different follow-up care models and (4) a Delphi-consensus process, involving all stakeholders, to develop a policy document to guide appropriate follow-up care after primary hip and knee arthroplasty.

We will present the following Recommendations:

For ODEP10A∗ minimum implants, it is safe to disinvest in routine follow-up from 1 to 10 years post non-complex hip and knee replacement provided there is rapid access to orthopaedic review

For ODEP10A∗ minimum implants in complex cases, or non-ODEP10A∗ minimum implants, periodic follow-up post hip and knee replacement may be required from 1 to 10 years

At 10 years post hip and knee replacement, we recommend clinical, which may be virtual, and radiographic evaluation

After 10 years post hip and knee replacement, frequency of further follow-up should be based on the 10-year assessment; ongoing rapid access to orthopaedic review is still required

Overarching statements

These recommendations apply to post primary hip and knee replacement follow-up

The 10-year time point in these recommendations is based on a lack of robust evidence beyond ten years

The term complex cases refer to individual patient and surgical factors that may increase the risk for replacement failure


Over 800 total hip replacement (THR) constructs were implanted in the UK in 2017. To ensure reliable implants are used, a NICE revision benchmark of 5% after 10 years exists. Surgeons are guided in choice by organisations such as the Orthopaedic Data Evaluation Panel (ODEP). Currently, ODEP publishes ratings for stem and cup separately and not for constructs. We used NJR data to investigate whether revision estimates of an individual stem (with all cups) is an accurate indicator of survival of all constructs using that stem.

The dataset comprised 234,289 THRs using the most frequently implanted stem between 2004 and 2017. Crude ten-year revision estimates were calculated using Kaplan-Meier for all THRs and for the five most implanted constructs. Adjusted comparisons between individual constructs and the overall stem revision estimate were made using flexible parametric survival analysis.

The 10-year crude, revision estimate for all THRs was 2.3% (95% CI 2.2, 2.4). Only four of the most frequently used constructs had long enough follow-up to analyse. 10-year estimates for these constructs ranged from 1.8% (95% CI 1.5, 2.1) to 3.7% (95% CI 3.2, 4.1), a log-rank test revealed strong evidence against the null hypothesis that revision estimates were the same for all constructs (p<0.001). Adjusted for age, sex and ASA, three of the four constructs showed a difference in 10-year revision estimates compared to this stem with all cups (P=0.03, P<0.001, P<0.001).

This study suggests 10-year revision estimates for all THRs using the most implanted stem in the NJR are not representative of all constructs involving that stem in crude or adjusted analyses. Current benchmarking systems report survival for the stem in combination with all cups and not for constructs. We suggest that benchmarking ratings basing on revision estimates for THR constructs would provide more accurate information, enabling informed construct decisions.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 2 - 2
1 Jul 2020
Holleyman R Kuroda Y Saito M Malviya A Khanduja V
Full Access

Objectives

The aim of this study was to use registry data to report and compare early patient outcomes following arthroscopic repair or debridement of the acetabular labrum.

Methods

Data on adult patients who underwent arthroscopic labral debridement or repair between January 2012 and March 2019 was extracted from the UK Non-Arthroplasty Hip Registry dataset. Patients who underwent microfracture, osteophyte excision or a concurrent extra-articular procedure were excluded. Outcomes comprised EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool 12 (iHOT-12), preoperatively and at 6 and 12 months.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 5 - 5
1 Jul 2020
Marusza C Lazizi M Hoade L Bartlett G Fern E Norton M Middleton R
Full Access

Introduction

Open and arthroscopic hip debridement may be used for treatment of femoral acetabular impingement (FAI). There is a paucity of evidence regarding the efficacy of one over the other.

Aim

To compare survivorship in terms of further surgical procedure at five years, in patients having undergone either arthroscopic or open hip debridement.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 11 - 11
1 Jul 2020
Magill P Hill J Bryce L Dorman A Hogg R Campbell C Benson G Beverland D
Full Access

Background

91% of blood loss in Total Hip Replacement (THR) occurs in the period after skin closure and the first 24 post-operative hours. TRAC-24 was established to identify if an additional 24-hour post-operative oral regime of Tranexamic acid (TXA) is superior to a once-only intravenous dose at surgery.

Methods

This was a prospective, phase IV, single centered, open label, parallel group controlled trial on patients undergoing primary elective THR. A history of thromboembolic or cardiovascular disease were not exclusion criteria. The primary outcome was indirect calculated blood loss at 48 hours (IBL). 534 patients were randomized on a 2:2:1 ratio over three different groups. Group 1 received an intravenous dose of TXA at the time of surgery and an additional 24-hour post-operative oral regime, Group 2 only received the intra-operative dose and Group 3 did not receive any TXA.


Background

Few studies have compared aspirin with DOACs (direct oral anticoagulants = direct thrombin inhibitors and factor Xa inhibitors) for venous thromboembolism (VTE) prophylaxis following total hip and knee replacement (THR and TKR). We assessed the efficacy and safety of aspirin compared with DOACs for VTE prophylaxis following THR and TKR using the world's largest joint replacement registry.

Methods

We studied the National Joint Registry linked to English hospital inpatient episodes for 218,650 THR and TKR patients. Patients receiving aspirin were matched separately to (1) direct thrombin inhibitors, and (2) factor Xa inhibitors using propensity scores. Outcomes assessed at 90 days included VTE, length of stay, and adverse events.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 22 - 22
1 Jul 2020
Mayne A Cassidy R Magill P Diamond O Beverland D
Full Access

Introduction

Previous research has demonstrated increased early complication rates following total hip arthroplasty in obese patients, as defined by body mass index (BMI). Subcutaneous fat depth has been shown to be an independent risk factor for wound infection in cervical and lumbar spine surgery as well as after abdominal laparotomy. The aim of this study was to investigate whether increased peri-trochanteric fat depth was associated with increased risk of early complication following total hip arthroplasty.

Methods

We analysed prospectively collected data on a consecutive series of 1220 patients undergoing primary total hip arthroplasty from June 2013 until May 2018. The vertical soft tissue depth from the most prominent part of the greater trochanter to the skin was measured using a sterile ruler and recorded to the nearest millimetre. BMI was calculated at the patient's pre-operative assessment review. All complications (infection, dislocation and peri-prosthetic fracture) occuring within the initial 12 month follow-up were identified.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 29 - 29
1 Jul 2020
Innmann M Reichel F Schaper B Merle C Beaulé P Grammatopoulos G
Full Access

Aims

Our study aimed to 1) determine if there was a difference for the HOOS-PS score between patients with stiff/normal/hypermobile spinopelvic mobility and 2) to investigate if functional sagittal cup orientation affected patient reported outcome 1 year post-THA.

Methods

This prospective diagnostic cohort study followed 100 consecutive patients having received unilateral THA for end-stage hip osteoarthritis. Pre- and 1-year postoperatively, patients underwent a standardized clinical examination, completed the HOOS-PS score and sagittal low-dose radiographs were acquired in the standing and relaxed-seated position. Radiographic measurements were performed for the lumbar-lordosis-angle, pelvic tilt (PT), pelvic-femoral-angle and cup ante-inclination. The HOOS-PS was compared between patients with stiff (ΔPT<±10°), normal (10°≤ΔPT≤30°) and hypermobile spinopelvic mobility (ΔPT>±30°).


INTRODUCTION

Quality monitoring is increasingly important to support and assure sustainability of the Orthopaedic practice. Many surgeons in a non-academic setting lack the resources to accurately monitor quality of care. Widespread use of electronic medical records (EMR) provides easier access to medical information and facilitates its analysis. However, manual review of EMRs is inefficient and costly. Artificial Intelligence (AI) software has allowed for development of automated search algorithms for extracting relevant complications from EMRs. We questioned whether an AI supported algorithm could be used to provide accurate feedback on the quality of care following Total Hip Arthroplasty (THA) in a high-volume, non-academic setting.

METHODS

532 Consecutive patients underwent 613 THA between January 1st and December 31st, 2017. Patients were prospectively followed pre-op, 6 weeks, 3 months and 1 year. They were seen by the surgeon who created clinical notes and reported every adverse event. A random derivation cohort (100 patients, 115 hips) was used to determine accuracy. The algorithm was compared to manual extraction to validate performance in raw data extraction. The full cohort (532 patients, 613 hips) was used to determine its recall, precision and F-value.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 32 - 32
1 Jul 2020
Horga L Henckel J Fotiadou A Laura AD Hirschmann A Hart A
Full Access

Background

Over 30 million people run marathons annually. The impact of marathon running on hips is unclear with existing literature being extremely limited (only one study of 8 runners).

Aim and Objectives

We aimed to better understand the effect of marathon running on the pelvis and hip joints by designing the largest MRI study of asymptomatic volunteers. The objectives were to evaluate the pelvis and both hip joints before and after a marathon.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 39 - 39
1 Jul 2020
El-Bakoury A Parkar A Powell J
Full Access

Background

One of the potential complications of polyethylene liner (PL) is its dissociation from the metal shell. This is a rare but catastrophic complication of total hip replacement (THR).

Objective

was to analyze the retrieved dissociated components (PL and shell) (Depuy Pinnacle, Warsaw, IN, USA) to evaluate the mechanism of failure. All these components were dissociated within four years of implantation.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 33 - 40
1 Jul 2020
Gustafson JA Pourzal R Levine BR Jacobs JJ Lundberg HJ

Aims

The aim of this study was to develop a novel computational model for estimating head/stem taper mechanics during different simulated assembly conditions.

Methods

Finite element models of generic cobalt-chromium (CoCr) heads on a titanium stem taper were developed and driven using dynamic assembly loads collected from clinicians. To verify contact mechanics at the taper interface, comparisons of deformed microgroove characteristics (height and width of microgrooves) were made between model estimates with those measured from five retrieved implants. Additionally, these models were used to assess the role of assembly technique—one-hit versus three-hits—on the taper interlock mechanical behaviour.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 25 - 25
1 Jul 2020
Radha S Afzal I Field R
Full Access

Clinical decision-making is often based on evidence of outcome after a specific treatment. Surgeons and patients may, have different perceptions and expectations of what to achieve following a Total Hip Replacement (THR). Several studies have shown that unfulfilled expectations are a principal source of patient dissatisfaction and patients are typically overly optimistic with regards to expected outcomes following surgery. Published data on clinical and functional outcomes show that persistence of symptoms, such as pain, and failure to return to preoperative levels of function are normal. To measure patient's expectations we undertook prospective study reviewing patients' expectations in 1800 THRs over a 21-year period (1997–2018).

Of the whole cohort, 48.98% patients reported they wanted a THR to overcome unbearable pain. 11.75 % wanted a THR to be able to walk without a limp. 9.69% wanted to a THR to increase walk endurance. 61.97% reported it was extremely important to decrease pain following a THR. In 2001, the most important reason for a THR reported by patients was to relieve unbearable pain and this remained the same most important reason in 2018. This result was also statistically significant with a p-value of 0.001. 80.36% reported they anticipated ‘no pain’ after recovery from a THR, 16.75% reported they anticipated ‘some pain’ and 2.89% reported they anticipated ‘extreme pain’ following a THR. 74.71% reported it was extremely important to increase their ability to undertake normal activities. 22.06% reported it was very important, 2.40% reported it was moderately important, 0.55% slightly important and 0.28% reported it was not all to important to increase their ability to undertake normal activity.

In conclusion patients' want to reduce their pain, walk normally and increase their level activities. Differences in expectation fulfilment may be due to unrealistic expectations. To achieve optimal outcome managing patient expectations is vital.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 33 - 33
1 Jul 2020
Palmer J Wilson C Wilson D Garrett S
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Background

Orthopaedic surgeons are exposed to high levels of noise when performing common surgical procedures. Noise induced hearing loss (NIHL) has been demonstrated amongst senior orthopaedic staff. The objective of this study was to investigate the prevalence of hearing loss amongst arthroplasty surgeons compared to non-surgical clinicians and explore the factors associated with hearing loss.

Methods

A cross-sectional prevalence study. Arthroplasty surgeons and non-surgical clinicians were recruited from orthopaedic and medical conferences.

All participants were given a paper questionnaire including demographic details, hearing history and Tinnitus and Hearing Survey (THS). All participants were screened for hearing loss in a quiet room using the HearCheck Screener™ (Siemens, UK).

Logistic regression was used to identify factors associated with hearing loss. All statistical models were adjusted for age, gender, smoking status and personal noise exposure. A power calculation estimated a sample size of 100 participants.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 38 - 38
1 Jul 2020
Govaers K Philips T Vandekelft A
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We report on a cadaveric study and early experience using patient specific drill guides to prevent cortex perforations and reduce the need for a trochanteric osteotomy in revision THA.

Mimic software (Materialise) was used for 3D analysis of the cement mantle and cement plug. Based on the CT findings a Cannulated drill guide with the shape of the femoral stem was printed in medical graded nylon intraoperative findings and complications were recorded on videotape using a standard 5mm laparoscope for medullary inspection

Surgical Technique was to attain a pre-operative CT scan with MARS protocol of the proximal femur to evaluate the femoral stem positioning, the 3D anatomy of the cement mantle, the length of the cement plug and the quality of the surrounding bone. Subsequent a 3D printing of patient specific cannulated drill guide with the shape of the removed femoral component but an eccentric cannulation was made.

Endoscopic inspection was performed of the inside of the cement mantle, then insertion of the autoclaved cannulated drill guide in the existing cement mantle. After perforation of the distal plug through the PSI drill guide using either a long drill or an ultrasound plug perforation tool (Zimmer Biomet, Warsaw) the excessive cement was removed with standard available flexible femoral shaft reamers (Zimmer Biomet). Further laproscopic examination of the femoral canal performed to verify completeness of the cement removal

Results

CT scans with 3D reconstruction of the existing cement mantle is possible using Modern CT with MARS protocols. After the training on sawbones and cadaveric bones a predictable plug perforation was obtained in all clinical cases. There were no intraoperative cortex perforations and no intraoperative femoral fractures.

Conclusion

CT scan analysis of femoral cement mantles together with patient specific drill guides are promising tools to reduce the risk of femoral perforation in revision total hip arthroplasty.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 37 - 37
1 Jul 2020
Poznalska G Auckland C Heddon S Phillips J Wilson M
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Joint replacement is a life-enhancing, cost-effective surgical intervention widely used to treat disabling joint pain mainly caused by osteoarthritis. Hip and knee joint replacements are common, highly successful operations bringing many patients relief from pain, and improve mobility.

Prosthetic joint infections (PJI) are often difficult to diagnose; diagnosis often relying on a combination of clinical findings, microbiological data and histological evaluation of periprosthetic tissue. The majority of recent studies demonstrate a higher sensitivity for the culture of sonication fluid (62–94%) than periprosthetic tissue (55–88%).

The Royal Devon & Exeter NHS Foundation Trust provided a specialist multidisciplinary team. We evaluated the use of sonication for identifying pathogens during revision hip and knee replacement in our unit with the intention of applying for further grants to study this technology in more detail; it was a diagnostic feasibility study. The target recruitment was 50 patients; 25 consecutive patients undergoing revision hip arthroplasty for any reason, and 25 undergoing revision knee arthroplasty for any reason. The majority of patients were identified in outpatient clinics.

Our results show that tissue culture remains more sensitive than sonication. The sensitivity for direct sonication was 75% compared with 80% for tissue culture; sensitivity of enriched sonication was 80 %, compared to the unit results for tissue culture of 83%. The combined sensitivity of tissue culture was better as a higher number of tissue specimens were obtained.

The different methodology might explain reported differences between this and other studies; however, our study does not support the use of sonication as the only tool in the diagnosis of PJI.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 7 - 7
1 Jul 2020
Holleyman R Kuroda Y Saito M Malviya A Khanduja V
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Background

This study aimed to investigate the effect of body mass index (BMI) on functional outcome following hip preservation surgery using the U.K. Non-Arthroplasty Hip Registry (NAHR).

Methods

Data on adult patients who underwent hip arthroscopy or periacetabular osteotomy (PAO) between January 2012 and December 2018 was extracted from the UK Non-Arthroplasty Hip Registry dataset allowing a minimum of 12 months follow-up. Data is collected via an online clinician and patient portal. Outcomes comprised EuroQol-5 Dimensions (EQ-5D) index and the International Hip Outcome Tool 12 (iHOT-12), preoperatively and at 6 and 12 months


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 10 - 10
1 Jul 2020
Saito M Kuroda Y Khanduja V
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Background

Slipped capital femoral epiphysis (SCFE) creates a complex deformity of the hip that can result in cam type of femoroacetabular impingement (FAI), which may in turn lead to the early development of osteoarthritis of the hip. The purpose of this study was to evaluate the existing literature reporting on the efficacy of hip arthroscopic treatment of patients with FAI secondary to SCFE.

Methods

A systematic computer search was conducted based on the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using Embase, PubMed (Medline), and Cochrane Library up to November 2019. Data such as patient demographics, surgical outcomes and complications that described arthroscopic surgery following FAI secondary to SCFE were retrieved from eligible studies. Two authors independently reviewed study inclusion and data extraction with independent verification.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 71 - 77
1 Jul 2020
Gonzalez Della Valle A Shanaghan KA Nguyen J Liu J Memtsoudis S Sharrock NE Salvati EA

Aims

We studied the safety and efficacy of multimodal thromboprophylaxis in patients with a history of venous thromboembolism (VTE) who undergo total hip arthroplasty (THA) within the first 120 postoperative days, and the mortality during the first year. Multimodal prophylaxis includes discontinuation of procoagulant medications, VTE risk stratification, regional anaesthesia, an intravenous bolus of unfractionated heparin prior to femoral preparation, rapid mobilization, the use of pneumatic compression devices, and chemoprophylaxis tailored to the patient’s risk of VTE.

Methods

Between 2004 to 2018, 257 patients with a proven history of VTE underwent 277 primary elective THA procedures by two surgeons at a single institution. The patients had a history of deep vein thrombosis (DVT) (186, 67%), pulmonary embolism (PE) (43, 15.5%), or both (48, 17.5%). Chemoprophylaxis included aspirin (38 patients), anticoagulation (215 patients), or a combination of aspirin and anticoagulation (24 patients). A total of 50 patients (18%) had a vena cava filter in situ at the time of surgery. Patients were followed for 120 days to record complications, and for one year to record mortality.


The Bone & Joint Journal
Vol. 102-B, Issue 7 | Pages 822 - 831
1 Jul 2020
Kuroda Y Saito M Çınar EN Norrish A Khanduja V

Aims

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

Methods

Literature reporting on preoperative patient-related risk factors and outcomes following hip arthroscopy were systematically identified from a computer-assisted literature search of Pubmed (Medline), Embase, and Cochrane Library using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and a scoping review.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 52 - 56
1 Jul 2020
Elkins JM Dennis DA Kleeman-Forsthuber L Yang CC Miner TM Jennings JM

Aims

Of growing concern in arthroplasty is the emergence of atypical infections, particularly Cutibacterium (formerly Propionibacterium) sp. infections. Currently, the dermal colonization rate of Cutibacterium about the hip is unknown. Therefore, the aim of this study was to investigate colonization rates of Cutibacterium sp. at locations approximating anterior and posterolateral approaches to the hip joint.

Methods

For this non-randomized non-blinded study, 101 adult patients scheduled for hip or knee surgery were recruited. For each, four 3 mm dermal punch biopsies were collected after administration of anaesthesia, but prior to antibiotics. Prebiopsy skin preparation consisted of a standardized preoperative 2% chlorhexidine skin cleansing protocol and an additional 70% isopropyl alcohol mechanical skin scrub immediately prior to biopsy collection. Two skin samples 10 cm apart were collected from a location approximating a standard direct anterior skin incision, and two samples 10 cm apart were collected from a lateral skin incision (suitable for posterior, direct-lateral, or anterolateral approaches). Samples were cultured for two weeks using a protocol optimized for Cutibacterium.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 19 - 19
1 Jul 2020
Innmann M Reichel F Schaper B Merle C Beaulé P Grammatopoulos G
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Aims

Our study aimed to 1) Describe the changes in spinopelvic mobility when transitioning from standing, to ‘relaxed-seated’ and thereafter to ‘deep-seated’ position and 2) Determine the change in spinopelvic mobility types 1 year post-THA compared to preoperatively.

Methods

This prospective diagnostic cohort study followed 100 consecutive patients 1 year post-THA. Preoperatively and one year postoperatively, radiographic measurements were performed for the lumbar-lordosis-angle, pelvic tilt and pelvic-femoral-angle on lateral radiographs in the standing, ‘relaxed-seated’ and ‘deep-seated’ position (torso maximally leaning forward). Patients were classified according to their spinopelvic mobility type, according to the change in PT between the standing and relaxed-seated position (stiff:ΔPT<±10°, normal:10°≤ΔPT≤30°, hypermobile:ΔPT>±30°).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 20 - 20
1 Jul 2020
Fowler T Aquilina A Blom A Sayers A Whitehouse M
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Aims

The aim of this study was to conduct evidence synthesis on the available published literature of the impact of the training status of the operating surgeon (trainee vs. consultant) on the survival and revision rate of primary hip and knee replacements.

Patients and Methods

We conducted a systematic review according to Cochrane guidelines. Separate searches were performed for hip and knee replacements, with meta-analysis and presentation of results in parallel. We searched MEDLINE and Embase databases from inception to 17 September 2019 and included controlled trials and cohort studies reporting implant survival estimates, or revision rates of hip and knee replacements according to the grade of the operating surgeon. This study was registered with PROSPERO (CRD42019150494).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 21 - 21
1 Jul 2020
Nandra R Ahmed U Berryman F Brash L Dunlop D Matharu G
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Introduction

Many worldwide regulatory authorities recommend regular surveillance of metal-on-metal hip arthroplasty patients given high failure rates. However concerns have been raised about whether such regular surveillance, which includes asymptomatic patients, is evidence-based and cost-effective. We determined: (1) the cost of implementing the 2015 MHRA surveillance in “at-risk” Birmingham Hip Resurfacing (BHR) patients, and (2) how many asymptomatic hips with adverse reactions to metal debris (ARMD) would have been missed if patients were not recalled.

Methods

All BHR patients subject to the 2015 MHRA recall (all females, and males with head sizes 46mm or below, regardless of symptoms) at one specialist centre were invited for review (707 hips). All patients were investigated (Oxford Hip Score, radiographs, blood metal ions, and targeted cross-sectional imaging) and managed accordingly. Surveillance costs were calculated using finance department data, as was the number needed to treat (NNT) to avoid missing one case of asymptomatic ARMD.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 3 - 3
1 Jul 2020
Chan G Aladwan R Hook S Rogers B Ricketts D Stott P
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Introduction

Dislocated hip hemiarthroplasties (HA) are associated with a 45% revision rate and 40% mortality rate.

Implant selection for HA operations vary with no universally accepted implant choice. The WHiTE3 trial suggested older designs such as the Thompson has equitable outcomes to more modern and expensive implants such as the Exeter V40+Unitrax.

Our multi-centre consecutive series of NOFs patients treated with HA assesses the impact of surgical and patient factors on dislocation risk.

Methods

Medical and radiographic records for patients treated between 1stJanuary 2009 and 30thSeptember 2017 with a HA at three acute hospitals were reviewed.

Implant and dislocation data were recorded. Patient demographics, comorbidities and operation details were extracted from the medical records and NHFD. Patients were excluded if there were no postoperative radiographs or when HA had been performed as a revision procedure.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 4 - 4
1 Jul 2020
Salih S Grammatopoulos G Witt J
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Acetabular dysplasia (AD) can cause hip pain and early osteoarthritis. Lateral Centre Edge Angle (LCEA) and sourcil angle (AI) are plain radiographic measures of acetabular morphology, however there is little agreement as to what constitutes mild, moderate or severe dysplasia. This study aims to establish the correlation, if any, between two-dimensional (XR) and three-dimensional (CT) measurements of acetabular morphology and to establish the level of femoral head cover (CTFHC) for different levels of dysplasia.

Methods

Governance board approved retrospective study. 353 PAOs performed by the senior author between January 2014 and December 2017 were included. Exclusion criteria were inadequate pre-operative CT imaging and/or plain radiographs, previous pelvic/hip surgery, acetabular retroversion, or femoral head asphericity. Of the remainder, 84 had 3D analysis by clinical graphics giving measurements for CTFHC, LCEA at 1100, 1200, 1300 and sourcil angle (AI). XRLCEA, AI, posterior wall index (PWI), and anterior wall index (AWI), were measured from supine AP pelvis radiographs. Pearson correlation coefficient, and mean CTFHC for stratified LCEAs were calculated. A linear regression model to predict CTFHC from XRLCEA was validated against these.

Results

XRLCEA correlated very strongly with total femoral head coverage (Pearson=0.917, p<0.001). Mean CTFHC with XRLCEA between 15°-19.9° was 55% (range 51–59%). At 25° −29.9° mean CTFHC was 61%.

There was a linear relation of CTFHC with XR LCEA such that CTFHC = 41.5 + 0.78(XRLCEA). This linear regression model predicted CTFHC 55% (95%CI 54–56%) for XRLCEA of 17.5°, and CTFHC 63% (95%CI 62–64%) for XRLCEA 27.5°.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 28 - 28
1 Jul 2020
Corten K Vanbiervliet J Vandeputte F
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INTRODUCTION

The capsular releasing sequence is crucial to safely conduct the Direct Anterior Approach for THA on a regular OR table. The release of the anterior capsule is the first step of the releasing sequence and allows for optimal exposure. This can be done by either resecting a part of the anterior capsule or by preserving it. Our zero hypothesis was that clinical outcomes would not be different between both techniques.

MATERIALS & METHODS

190 Patients operated between November 2017 and May 2018, met the inclusion criteria and were randomly allocated in a double blinded study to either the capsular resection (CR)(N=99) or capsular preservation (CP)(N=91) cohort. The same cementless implant was used in all cases. Patient-reported outcome measures (PROMS) were collected pre- and post-operatively at 6 weeks, 3 months and 1 year. Adverse events were recorded. Outcomes were compared with the Mann-Withney U test and a significance level of p<0,05.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 35 - 35
1 Jul 2020
Higgins M Salih S Bhaskar D Buckley S Townsend R Davies M
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Introduction

Prosthetic joint infection (PJI) is the leading cause of failure of primary and revision hip and knee arthroplasty. It is challenging condition which represents a growing burden on hospital resources. In-patient hospital stay for antibiotic therapy post-operatively is costly and access to out-patient IV therapy (OPAT) varies between regions. In a tertiary referral centre for revision and infection, the suitability and cost-effectiveness of Dalbavancin was reviewed as a “single-shot” therapy following DAIR or revision lower limb arthroplasty for PJI.

Methods & Materials

A prospective service evaluation was carried out for consecutive patients treated for PJI of the hip or knee who received Dalbavancin. Treatment was indicated by Consultant Microbiologist advice within an MDT setting where clinical or patient factors made alternative therapies eg. OPAT inappropriate. Service-level data was collected to allow calculation of bed-day savings compared to a traditional 14-day course of IV treatment. Readmission rates to the trust within 30 days were reviewed as a marker of clinical efficacy and safety.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 47 - 51
1 Jul 2020
Kazarian GS Schloemann DT Barrack TN Lawrie CM Barrack RL

Aims

The aims of this study were to determine the change in the sagittal alignment of the pelvis and the associated impact on acetabular component position at one-year follow-up after total hip arthroplasty (THA).

Methods

This study represents the one-year follow-up of a previous short-term study at our institution. Using the patient population from our prior study, the radiological pelvic ratio was assessed in 91 patients undergoing THA, of whom 50 were available for follow-up of at least one year (median 1.5; interquartile range (IQR) 1.1 to 2.0). Anteroposterior radiographs of the pelvis were obtained in the standing position preoperatively and at one year postoperatively. Pelvic ratio was defined as the ratio between the vertical distance from the inferior sacroiliac (SI) joints to the superior pubic symphysis and the horizontal distance between the inferior SI joints. Apparent acetabular component position changes were determined from the change in pelvic ratio. A change of at least 5° was considered clinically meaningful.


The Bone & Joint Journal
Vol. 102-B, Issue 7 | Pages 832 - 837
1 Jul 2020
Dover C Kuiper JH Craig P Shaylor P

Aims

We have previously demonstrated raised cobalt and chromium levels in patients with larger diameter femoral heads, following metal-on-polyethylene uncemented total hip arthroplasty. Further data have been collected, to see whether these associations have altered with time and to determine the long-term implications for these patients and our practice.

Methods

Patients from our previous study who underwent Trident-Accolade primary total hip arthroplasties using a metal-on-polyethylene bearing in 2009 were reviewed. Patients were invited to have their cobalt and chromium levels retested, and were provided an Oxford Hip Score. Serum ion levels were then compared between groups (28 mm, 36 mm, and 40 mm heads) and over time.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 11 - 19
1 Jul 2020
Shohat N Goswami K Tan TL Yayac M Soriano A Sousa R Wouthuyzen-Bakker M Parvizi J

Aims

Failure of irrigation and debridement (I&D) for prosthetic joint infection (PJI) is influenced by numerous host, surgical, and pathogen-related factors. We aimed to develop and validate a practical, easy-to-use tool based on machine learning that may accurately predict outcome following I&D surgery taking into account the influence of numerous factors.

Methods

This was an international, multicentre retrospective study of 1,174 revision total hip (THA) and knee arthroplasties (TKA) undergoing I&D for PJI between January 2005 and December 2017. PJI was defined using the Musculoskeletal Infection Society (MSIS) criteria. A total of 52 variables including demographics, comorbidities, and clinical and laboratory findings were evaluated using random forest machine learning analysis. The algorithm was then verified through cross-validation.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 20 - 26
1 Jul 2020
Romero J Wach A Silberberg S Chiu Y Westrich G Wright TM Padgett DE

Aims

This combined clinical and in vitro study aimed to determine the incidence of liner malseating in modular dual mobility (MDM) constructs in primary total hip arthroplasties (THAs) from a large volume arthroplasty centre, and determine whether malseating increases the potential for fretting and corrosion at the modular metal interface in malseated MDM constructs using a simulated corrosion chamber.

Methods

For the clinical arm of the study, observers independently reviewed postoperative radiographs of 551 primary THAs using MDM constructs from a single manufacturer over a three-year period, to identify the incidence of MDM liner-shell malseating. Multivariable logistic regression analysis was performed to identify risk factors including age, sex, body mass index (BMI), cup design, cup size, and the MDM case volume of the surgeon. For the in vitro arm, six pristine MDM implants with cobalt-chrome liners were tested in a simulated corrosion chamber. Three were well-seated and three were malseated with 6° of canting. The liner-shell couples underwent cyclic loading of increasing magnitudes. Fretting current was measured throughout testing and the onset of fretting load was determined by analyzing the increase in average current.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 99 - 104
1 Jul 2020
Shah RF Bini S Vail T

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.

Methods

A group of 1,000 randomly selected clinical and hospital notes from eight different surgeons were collected for patients undergoing primary arthroplasty between 2012 and 2018. In all, 19 preoperative, 17 operative, and two postoperative variables of interest were manually extracted from these notes. A NLP algorithm was created to automatically extract these variables from a training sample of these notes, and the algorithm was tested on a random test sample of notes. Performance of the NLP algorithm was measured in Statistical Analysis System (SAS) by calculating the accuracy of the variables collected, the ability of the algorithm to collect the correct information when it was indeed in the note (sensitivity), and the ability of the algorithm to not collect a certain data element when it was not in the note (specificity).


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 105 - 111
1 Jul 2020
Engh, Jr. CA McAsey CJ Cororaton AD Ho H Hopper, Jr. RH

Aims

The purpose of this study is to examine six types of bearing surfaces implanted at a single institution over three decades to determine whether the reasons for revision vary among the groups and how long it takes to identify differences in survival.

Methods

We considered six cohorts that included a total of 1,707 primary hips done between 1982 and 2010. These included 223 conventional polyethylene sterilized with γ irradiation in air (CPE-GA), 114 conventional polyethylene sterilized with gas plasma (CPE-GP), 116 crosslinked polyethylene (XLPE), 1,083 metal-on-metal (MOM), 90 ceramic-on-ceramic (COC), and 81 surface arthroplasties (SAs). With the exception of the COC, all other groups used cobalt-chromium (CoCr) femoral heads. The mean follow-up was 10 (0.008 to 35) years. Descriptive statistics with revisions per 100 component years (re/100 yr) and survival analysis with revision for any reason as the endpoint were used to compare bearing surfaces.


Bone & Joint Research
Vol. 9, Issue 7 | Pages 360 - 367
1 Jul 2020
Kawahara S Hara T Sato T Kitade K Shimoto T Nakamura T Mawatari T Higaki H Nakashima Y

Aims

Appropriate acetabular component placement has been proposed for prevention of postoperative dislocation in total hip arthroplasty (THA). Manual placements often cause outliers in spite of attempts to insert the component within the intended safe zone; therefore, some surgeons routinely evaluate intraoperative pelvic radiographs to exclude excessive acetabular component malposition. However, their evaluation is often ambiguous in case of the tilted or rotated pelvic position. The purpose of this study was to develop the computational analysis to digitalize the acetabular component orientation regardless of the pelvic tilt or rotation.

Methods

Intraoperative pelvic radiographs of 50 patients who underwent THA were collected retrospectively. The 3D pelvic bone model and the acetabular component were image-matched to the intraoperative pelvic radiograph. The radiological anteversion (RA) and radiological inclination (RI) of the acetabular component were calculated and those measurement errors from the postoperative CT data were compared relative to those of the 2D measurements. In addition, the intra- and interobserver differences of the image-matching analysis were evaluated.


Background

Total hip replacement (THR) is clinically and cost-effective. The surgical approach influences outcomes, however there is little generalisable and robust evidence to guide practice. We assessed the effect of surgical approach on THR outcomes.

Methods

723,904 primary THRs captured in the National Joint Registry, linked to hospital inpatient, mortality and patient reported outcome measures (PROMs) data with up to 13.75 years follow-up were analysed. There were seven surgical approach groups: conventional posterior, lateral, anterior and trans-trochanteric groups and minimally invasive posterior, lateral and anterior. Survival methods were used to compare revision rates and 90-day mortality. Groups were compared using Cox proportional hazards and Flexible Parametric Survival Modelling (FPM). Confounders included age at surgery, sex, risk group (indications additional to osteoarthritis), ASA grade, THR fixation, thromboprophylaxis, anaesthetic, body mass index (BMI), and deprivation. PROMs were analysed with regression modelling or non-parametric methods.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 40 - 40
1 Jul 2020
Bhaskar D Higgins M Mosby D Townsend R Harrison T
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Literature debates whether fluid aspirates for suspected PJI should undergo prolonged incubation for cultures. We looked at sensitivity and specificity of 14-day cultures, compared to 7-days, for aspirates from prosthetic hips and knees.

Design and methods

Conducted at a quaternary referral centre for PJIs from Jan 2017 to July 2019. Suspected PJIs who underwent aspiration, incubated 14 days and later surgical intervention with minimum three tissue samples were included.

Results

176 aspirates were included. This is an increased number compared to our historic figures (average 88 Vs 48 pts/yr).

47 patients had fluid and tissue positive (true positive), 20 fluid +ive but tissue -ive (false positive), 98 fluid and tissue -ive (true negative) and 15 fluid negative but tissue +ive (False negative). Thus, sensitivity 76%, specificity 83%, positive predictive value70% and negative predictive value 87%.

Of 88 positive aspirates, only 75% were within 7-day cultures. Low virulence organisms as Propionibacterium acnes and coagulase negative staph were grown later.

Of 48 with only one tissue sample positive, 38 were culture-negative on aspiration and 6 grew different organisms on aspirate and tissues. Also, as many were cultured later, it suggests contamination.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 42 - 42
1 Jul 2020
Lotfi N Hughes E McCulloch R Horner C Shepherd D Grover L Nightingale P Davis E
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Polymethylmethacetate (PMMA) is a bone cement used in over 725,000 primary hip arthroplasties in 2018. Cement integrity is affected by external factors, including temperature, mixing technique and moisture uptake, which can influence cement microstructure. Changes in the cement microstructure may ultimately threaten the survivorship of the implant.

The introduction of enhanced recovery and various local anaesthetic infiltration techniques have been adopted in an attempt to facilitate early mobilisation and reduce length of stay. Our study aims to investigate if the mechanical properties of PMMA are altered with exposure to Ropivacaine LA.

Cements were cured in three separate states (air, serum and serum with LA) and the mechanical properties tested at 24 hours and 28 days. Using Refobacin bone cement provided by ZimmerBIOMET, cylindrical molds (12×6mm) were constructed with a split-mold. The LA used was 2mg/ml Ropivacaine hydrochloride solution. Using pilot data, this study was powered to 80% and a sample size of 10 per group (n=60) was calculated.

Cement samples were subjected to compressive loading using a universal testing apparatus (Zwick/Roell). Yield-strength and modulus values were extracted from the respective stress versus strain curves. Significant differences were determined by one-way anova for each time point, and Bonferroni post-hoc testing to determine significance between actual groups.

At 24-hours there were no significant differences in strength or modulus between groups. At 28-day strength and modulus increased in all groups. Compared to the air group, both serum and LA groups show a significant decrease in compressive strength. The modulus for the LA group is significantly less stiff compared to the air group.

The results suggest that the initial exposure to LA has a significant impact on the physical properties of the PMMA. We propose increased awareness of the potential effects this may have on the longevity and survivorship of cemented implants.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 6 - 6
1 Jul 2020
Hall A Holt G
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Background

National hip fracture programmes are becoming widespread, but this practice is nascent and varied. The Scottish Hip Fracture Audit (SHFA) was an early adopter of this strategy and is credited with substantial systemic improvements in quality and outcomes.

Objectives

To provide evidence and incentive to clinicians and administrators to adopt successful improvement strategies, and to facilitate data-driven change hip fracture care.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 17 - 17
1 Jul 2020
Innmann M Merle C Phan P Beaulé P Grammatopoulos G
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Introduction

Patients with reduced lumbar spine mobility are at higher risk of dislocation after THA as their hips have to compensate for spinal stiffness. Therefore our study aimed to 1) Define the optimal protocol for identifying patients with mobile hips and stiff lumbar spines and 2) Determine clinical and standing radiographic parameters predicting high hip and reduced lumbar spine mobility.

Methods

This prospective diagnostic cohort study followed 113 consecutive patients with end-stage hip osteoarthritis (OA) awaiting THA. Radiographic measurements were performed for the lumbar lordosis angle, pelvic tilt and pelvic-femoral angle on lateral radiographs in the standing, ‘relaxed-seated’ and ‘deep-seated’ (i.e. torso maximally leaning forward) position. A “hip user index” was calculated in order to quantify the contribution of the hip joint to the overall sagittal movement performed by the femur, pelvis and lumbar spine.


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Aims

The aims of the study were to determine the differences in spinopelvic mobility between a cohort of hip OA patients and a control group for the 1) standing to relaxed-seated and 2) standing to deep-seated task.

Methods

A cohort of 40 patients with end-stage hip OA and a control group of 40 subjects, matched for age, gender and BMI were prospectively studied. Clinical data and lateral view radiographs in different positions were assessed. Sagittal spinopelvic mobility was calculated as the change when moving from the standing to relaxed-seated and standing to deep-seated positions for the lumbar lordosis angle, pelvic tilt and pelvic-femoral angle.


Aim

To assess the effect of the bearing surface and head size on the survival of total hip replacements with modern bearing surface combinations.

Methods

We combined the NJR dataset with polyethylene manufacturing properties as supplied by the manufacturers to sub-divide polyethylene into conventional (PE) and highly crosslinked (XLPE). Cause specific and overall reasons for revisions were analysed using Kaplan-Meier and multi-variate Cox proportional hazard regression survival analyses. The bearing surface analysis was repeated in patients undergoing THR under the age of 55.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 24 - 24
1 Jul 2020
Di Laura A Henckel J Belzunce M Hothi H Hart A
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Introduction

The achieved anteversion of uncemented stems is to a large extent limited by the internal anatomy of the bone. A better understanding of this has recently become an unmet need because of the increased use of uncemented stems.

We aimed to assess plan compliance in six degrees of freedom to evaluate the accuracy of PSI and guides for stem positioning in primary THAs.

Materials and Methods

We prospectively collected 3D plans generated from preoperative CTs of 30 consecutive THAs (17 left and 13 right hips), in 29 patients with OA, consisting of 16 males and 13 females (median age 68 years, range 46–83 years). A single CT-based planning system and cementless type of implant were used.

Post operatively, all patients had a CT scan which was reconstructed using state-of-the-art software solution: the plan and CT reconstruction models were

Outcome measures: 1) discrepancy between planned and achieved stem orientation angles Fig.2&3; 2) clinical outcome.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_5 | Pages 41 - 41
1 Jul 2020
Holland T Jeyaraman D David M Davis E
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The use of routine sampling for histological analysis during revision hip replacement has been standard practice in our unit for many years. It is used to assess for the presence of inflammatory processes that may represent peri-prosthetic infection.

Our study examines 152 consecutive patients who underwent revision hip replacement in our centre for all reasons, excluding malignant neoplasm or metastasis. We reviewed the cases from a prospectively collated database, comparing microbiology results with histology results. Both microscopic and macroscopic analysis by specialist musculoskeletal histopathologist was included in our study.

We found 17 (11.2%) patients had cultured bacteria from intra-operative samples. Eight patients (5.3%) had histological findings interpreted as infection. Only one patient who had macroscopic and microscopic histology findings suggestive of infection also had culture results that identified a pathogen. Furthermore, the macroscopic analyses by the histopathologist suggested infection in nine patients. Only one patient with positive culture in greater than 2 samples had histological features of infection.

Of the 4 patients who were found to have 3 or more samples where an organism was identified only one had histological features of infection. This represents 25% sensitivity when using histology to analyse samples for infection. Of the 8 patients who had both macroscopic and microscopic features of infection only 1 patients cultured bacteria in more than 3 samples (PPV 12.5%).

Our experience does not support the routine sampling for histology in revision hip replacement. We suggest it is only beneficial in cases where infection is suspected or where a multi-procedure, staged revision is performed and the surgeon is planning return to theatre for the final stage. This is a substantial paradigm shift from the current practice among revision arthroplasty surgeons in the United Kingdom but will equate to a substantial cost saving.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 112 - 115
1 Jul 2020
Waly FJ Garbuz DS Greidanus NV Duncan CP Masri BA

Aims

The practice of overlapping surgery has been increasing in the delivery of orthopaedic surgery, aiming to provide efficient, high-quality care. However, there are concerns about the safety of this practice. The purpose of this study was to examine the safety and efficacy of a model of partially overlapping surgery that we termed ‘swing room’ in the practice of primary total hip (THA) and knee arthroplasty (TKA).

Methods

A retrospective review of prospectively collected data was carried out on patients who underwent primary THA and TKA between 2006 and 2017 in two academic centres. Cases were stratified as partially overlapping (swing room), in which the surgeon is in one operating room (OR) while the next patient is being prepared in another, or nonoverlapping surgery. The demographic details of the patients which were collected included operating time, length of stay (LOS), postoperative complications within six weeks of the procedure, unplanned hospital readmissions, and unplanned reoperations. Fisher's exact, Wilcoxon rank-sum tests, chi-squared tests, and logistic regression analysis were used for statistical analysis.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 41 - 46
1 Jul 2020
Ransone M Fehring K Fehring T

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).

Methods

In total, 51 patients undergoing THA were reviewed to quantify the variability in preoperative spinopelvic mobility when measuring two different sitting positions using SS for planning.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 85 - 89
1 Jul 2020
Barrack TN Abu-Amer W Schwabe MT Adelani MA Clohisy JC Nunley RM Lawrie CM

Aims

Routine surveillance of primary hip and knee arthroplasties has traditionally been performed with office follow-up visits at one year postoperatively. The value of these visits is unclear. The present study aims to determine the utility and burden of routine clinical follow-up at one year after primary arthroplasty to patients and providers.

Methods

All patients (473) who underwent primary total hip (280), hip resurfacing (eight), total knee (179), and unicompartmental knee arthroplasty (six) over a nine-month period at a single institution were identified from an institutional registry. Patients were prompted to attend their routine one-year postoperative visit by a single telephone reminder. Patients and surgeons were given questionnaires at the one-year postoperative visit, defined as a clinical encounter occurring at nine to 15 months from the date of surgery, regarding value of the visit.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 62 - 70
1 Jul 2020
Tompkins G Neighorn C Li H Fleming K Lorish T Duwelius P Sypher K

Aims

High body mass index (BMI) is associated with increased rates of complications in primary total hip arthroplasty (THA), but less is known about its impact on cost. The effects of low BMI on outcomes and cost are less understood. This study evaluated the relationship between BMI, inpatient costs, complications, readmissions, and utilization of post-acute services.

Methods

A retrospective database analysis of 40,913 primary THAs performed between January 2013 and December 2017 in 29 hospitals was conducted. Operating time, length of stay (LOS), complication rate, 30-day readmission rate, inpatient cost, and utilization of post-acute services were measured and compared in relation to patient BMI.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 57 - 61
1 Jul 2020
Woolson ST

Aims

To establish whether there was a consensus among the members of the Hip Society (HS) on the role of direct anterior approach (DAA) contemporary primary total hip arthroplasty (THA).

Methods

An online survey was sent to all 112 active and senior members of the HS, to which 71 members responded. The survey was constructed to determine whether they believed that evidence-based medicine proves, in modern clinical practice, that the DAA has significant benefits compared to risks when contrasted with other approaches. In addition, they were asked if they currently used the DAA.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 122 - 128
1 Jul 2020
Sodhi N Acuna A Etcheson J Mohamed N Davila I Ehiorobo JO Jones LC Delanois RE Mont MA

Aims

Earlier studies dealing with trends in the management of osteonecrosis of the femoral head (ONFH) identified an increasing rate of total hip arthroplasties (THAs) and a decreasing rate of joint-preserving procedures between 1992 and 2008. In an effort to assess new trends in the management of this condition, this study evaluated the annual trends of joint-preserving versus arthroplasties for patients aged < or > 50 years old, and the incidence of specific operative management techniques.

Methods

A total of 219,371 patients with ONFH were identified from a nationwide database between 1 January 2009 and 31 December 2015. The mean age was 54 years (18 to 90) and 105,298 (48%) were female. The diagnosis was made using International Classification of Disease, Ninth revision, Clinical Modification (ICD-9-CM) and Tenth Revision, Clinical Modification (ICD-10-CM) procedure codes. The percentage of patients managed using each procedure during each year was calculated and compared between years. The trends in the use of the types of procedure were also evaluated.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 3 - 10
1 Jul 2020
Sosa BR Niu Y Turajane K Staats K Suhardi V Carli A Fischetti V Bostrom M Yang X

Aims

Current treatments of prosthetic joint infection (PJI) are minimally effective against Staphylococcus aureus biofilm. A murine PJI model of debridement, antibiotics, and implant retention (DAIR) was used to test the hypothesis that PlySs2, a bacteriophage-derived lysin, can target S. aureus biofilm and address the unique challenges presented in this periprosthetic environment.

Methods

The ability of PlySs2 and vancomycin to kill biofilm and colony-forming units (CFUs) on orthopaedic implants were compared using in vitro models. An in vivo murine PJI model of DAIR was used to assess the efficacy of a combination of PlySs2 and vancomycin on periprosthetic bacterial load.


The Bone & Joint Journal
Vol. 102-B, Issue 7 | Pages 838 - 844
1 Jul 2020
Chen L Hong G Hong Z Lin T Chen Z Zhang Q He W

Aims

The aim of this study was to report the medium-term outcomes of impaction bone allograft and fibular grafting for osteonecrosis of the femoral head (ONFH) and to define the optimal indications.

Methods

A total of 67 patients (77 hips) with ONFH were enrolled in a single centre retrospective review. Success of the procedure was assessed using the Harris Hip Score (HHS) and rate of revision to total hip arthroplasty (THA). Risk factors were studied, including age, aetiology, duration of hip pain, as well as two classification systems (Association Research Circulation Osseous (ARCO) and Japanese Investigation Committee (JIC) systems).


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 116 - 121
1 Jul 2020
Heise G Black CM Smith R Morrow BR Mihalko WM

Aims

This study aimed to determine if macrophages can attach and directly affect the oxide layers of 316L stainless steel, titanium alloy (Ti6Al4V), and cobalt-chromium-molybdenum alloy (CoCrMo) by releasing components of these alloys.

Methods

Murine peritoneal macrophages were cultured and placed on stainless steel, CoCrMo, and Ti6Al4V discs into a 96-well plate. Cells were activated with interferon gamma and lipopolysaccharide. Macrophages on stainless steel discs produced significantly more nitric oxide (NO) compared to their control counterparts after eight to ten days and remained elevated for the duration of the experiment.


Bone & Joint Research
Vol. 9, Issue 7 | Pages 386 - 393
1 Jul 2020
Doyle R van Arkel RJ Muirhead-Allwood S Jeffers JRT

Aims

Cementless acetabular components rely on press-fit fixation for initial stability. In certain cases, initial stability is more difficult to obtain (such as during revision). No current study evaluates how a surgeon’s impaction technique (mallet mass, mallet velocity, and number of strikes) may affect component fixation. This study seeks to answer the following research questions: 1) how does impaction technique affect a) bone strain generation and deterioration (and hence implant stability) and b) seating in different density bones?; and 2) can an impaction technique be recommended to minimize risk of implant loosening while ensuring seating of the acetabular component?

Methods

A custom drop tower was used to simulate surgical strikes seating acetabular components into synthetic bone. Strike velocity and drop mass were varied. Synthetic bone strain was measured using strain gauges and stability was assessed via push-out tests. Polar gap was measured using optical trackers.


The Bone & Joint Journal
Vol. 102-B, Issue 7 Supple B | Pages 90 - 98
1 Jul 2020
Florissi I Galea VP Sauder N Colon Iban Y Heng M Ahmed FK Malchau H Bragdon CR

Aims

The primary aim of this paper was to outline the processes involved in building the Partners Arthroplasty Registry (PAR), established in April 2016 to capture baseline and outcome data for patients undergoing arthroplasty in a regional healthcare system. A secondary aim was to determine the quality of PAR’s data. A tertiary aim was to report preliminary findings from the registry and contributions to quality improvement initiatives and research up to March 2019.

Methods

Structured Query Language was used to obtain data relating to patients who underwent total hip or knee arthroplasty (THA and TKA) from the hospital network’s electronic medical record (EMR) system to be included in the PAR. Data were stored in a secure database and visualized in dashboards. Quality assurance of PAR data was performed by review of the medical records. Capture rate was determined by comparing two months of PAR data with operating room schedules. Linear and binary logistic regression models were constructed to determine if length of stay (LOS), discharge to a care home, and readmission rates improved between 2016 and 2019.


The Bone & Joint Journal
Vol. 102-B, Issue 6 | Pages 699 - 708
1 Jun 2020
Nieuwenhuijse MJ Vehmeijer SBW Mathijsen NMC Keizer SB

Aims

Short, bone-conserving femoral components are increasingly used in total hip arthroplasty (THA). They are expected to allow tissue-conserving implantation and to render future revision surgery more straightforward but the long-term data on such components is limited. One such component is the global tissue-sparing (GTS) stem. Following the model for stepwise introduction of new orthopaedic implants, we evaluated early implant fixation and clinical outcome of this novel short-stem THA and compared it to that of a component with established good long-term clinical outcome.

Methods

In total, 50 consecutive patients ≤ 70 years old with end-stage symptomatic osteo-arthritis were randomized to receive THA with the GTS stem or the conventional Taperloc stem using the anterior supine intermuscular approach by two experienced hip surgeons in two hospitals in the Netherlands. Primary outcome was implant migration. Patients were followed using routine clinical examination, patient reported outcome using Harris Hip Score (HHS), Hip Disability And Osteoarthritis Outcome Score (HOOS), EuroQol five-dimension questionnaire (EQ5D), and Roentgen Stereophotogrammetric Analysis (RSA) at three, six, 12, and 24 months. This study evaluated the two-year follow-up results.


The Bone & Joint Journal
Vol. 102-B, Issue 6 | Pages 709 - 715
1 Jun 2020
Abdelsamie KR Elhawary I Ali H Ali M EL-Shafie M Dominic Meek RM

Aims

Femoral revision component subsidence has been identified as predicting early failure in revision hip surgery. This comparative cohort study assessed the potential risk factors of subsidence in two commonly used femoral implant designs.

Methods

A comparative cohort study was undertaken, analyzing a consecutive series of patients following revision total hip arthroplasties using either a tapered-modular (TM) fluted titanium or a porous-coated cylindrical modular (PCM) titanium femoral component, between April 2006 and May 2018. Clinical and radiological assessment was compared for both treatment cohorts. Risk factors for subsidence were assessed and compared.


The Bone & Joint Journal
Vol. 102-B, Issue 6 | Pages 683 - 692
1 Jun 2020
Arnold N Anis H Barsoum WK Bloomfield MR Brooks PJ Higuera CA Kamath AF Klika A Krebs VE Mesko NW Molloy RM Mont MA Murray TG Patel PD Strnad G Stearns KL Warren J Zajichek A Piuzzi NS

Aims

Thresholds for operative eligibility based on body mass index (BMI) alone may restrict patient access to the benefits of arthroplasty. The purpose of this study was to evaluate the relationship between BMI and improvements in patient-reported outcome measures (PROMs), and to determine how many patients would have been denied improvements in PROMs if BMI cut-offs were to be implemented.

Methods

A prospective cohort of 3,449 primary total hip arthroplasties (THAs) performed between 2015 and 2018 were analyzed. The following one-year PROMs were evaluated: hip injury and osteoarthritis outcome score (HOOS) pain, HOOS Physical Function Shortform (PS), University of California, Los Angeles (UCLA) activity, Veterans Rand-12 Physical Component Score (VR-12 PCS), and VR-12 Mental Component Score (VR-12 MCS). Positive predictive values for failure to improve and the number of patients denied surgery in order to avoid a failed improvement were calculated for each PROM at different BMI cut-offs.


The Bone & Joint Journal
Vol. 102-B, Issue 6 | Pages 693 - 698
1 Jun 2020
Viswanath A Malik A Chan W Klasan A Walton NP

Aims

Despite few good-quality studies on the subject, total hip arthroplasty (THA) is increasingly being performed for displaced intracapsular fractures of the neck of femur. We compared outcomes of all patients with displacement of these fractures treated surgically over a ten-year period in one institution.

Methods

A total of 2,721 patients with intracapsular fractures of the femoral neck treated with either a cemented hemiarthroplasty or a THA at a single centre were retrospectively reviewed. The primary outcomes analyzed were readmission for any reason and revision surgery. We secondarily looked at mortality rates.


Bone & Joint Open
Vol. 1, Issue 5 | Pages 152 - 159
22 May 2020
Oommen AT Chandy VJ Jeyaraj C Kandagaddala M Hariharan TD Arun Shankar A Poonnoose PM Korula RJ

Aims

Complex total hip arthroplasty (THA) with subtrochanteric shortening osteotomy is necessary in conditions other than developmental dysplasia of the hip (DDH) and septic arthritis sequelae with significant proximal femur migration. Our aim was to evaluate the hip centre restoration with THAs in these hips.

Methods

In all, 27 THAs in 25 patients requiring THA with femoral shortening between 2012 and 2019 were assessed. Bilateral shortening was required in two patients. Subtrochanteric shortening was required in 14 out of 27 hips (51.9%) with aetiology other than DDH or septic arthritis. Vertical centre of rotation (VCOR), horizontal centre of rotation, offset, and functional outcome was calculated. The mean followup was 24.4 months (5 to 92 months).


The Bone & Joint Journal
Vol. 102-B, Issue 5 | Pages 580 - 585
1 May 2020
Gibbs VN McCulloch RA Dhiman P McGill A Taylor AH Palmer AJR Kendrick BJL

Aims

The aim of this study was to identify modifiable risk factors associated with mortality in patients requiring revision total hip arthroplasty (THA) for periprosthetic hip fracture.

Methods

The electronic records of consecutive patients undergoing revision THA for periprosthetic hip fracture between December 2011 and October 2018 were reviewed. The data which were collected included age, sex, body mass index (BMI), American Society of Anesthesiologists (ASA) classification, the preoperative serum level of haemoglobin, time to surgery, operating time, blood transfusion, length of hospital stay, and postoperative surgical and medical complications. Univariate and multivariate logistic regression analyses were used to determine independent modifiable factors associated with mortality at 90 days and one year postoperatively.


The Bone & Joint Journal
Vol. 102-B, Issue 5 | Pages 573 - 579
1 May 2020
Krueger DR Guenther K Deml MC Perka C

Aims

We evaluated a large database with mechanical failure of a single uncemented modular femoral component, used in revision hip arthroplasty, as the end point and compared them to a control group treated with the same implant. Patient- and implant-specific risk factors for implant failure were analyzed.

Methods

All cases of a fractured uncemented modular revision femoral component from one manufacturer until April 2017 were identified and the total number of implants sold until April 2017 was used to calculate the fracture rate. The manufacturer provided data on patient demographics, time to failure, and implant details for all notified fractured devices. Patient- and implant-specific risk factors were evaluated using a logistic regression model with multiple imputations and compared to data from a previously published reference group, where no fractures had been observed. The results of a retrieval analysis of the fractured implants, performed by the manufacturer, were available for evaluation.


Bone & Joint Research
Vol. 9, Issue 5 | Pages 242 - 249
1 May 2020
Bali K Smit K Ibrahim M Poitras S Wilkin G Galmiche R Belzile E Beaulé PE

Aims

The aim of the current study was to assess the reliability of the Ottawa classification for symptomatic acetabular dysplasia.

Methods

In all, 134 consecutive hips that underwent periacetabular osteotomy were categorized using a validated software (Hip2Norm) into four categories of normal, lateral/global, anterior, or posterior. A total of 74 cases were selected for reliability analysis, and these included 44 dysplastic and 30 normal hips. A group of six blinded fellowship-trained raters, provided with the classification system, looked at these radiographs at two separate timepoints to classify the hips using standard radiological measurements. Thereafter, a consensus meeting was held where a modified flow diagram was devised, before a third reading by four raters using a separate set of 74 radiographs took place.


Bone & Joint Research
Vol. 9, Issue 5 | Pages 250 - 257
1 May 2020
Png ME Griffin XL Costa ML Achten J Pinedo-Villanueva R

Aims

This feasibility study investigates the utilization and cost of health resources related to formal and informal care, home adaptations, and physiotherapy among patients aged 60 years and above after hip fracture from a multicentre cohort study (World Hip Trauma Evaluation (WHiTE)) in the UK.

Methods

A questionnaire containing health resource use was completed at baseline and four months post-injury by patients or their carer. Completion rate and mean cost of each health resource item were assessed and sensitivity analysis was performed to derive a conservative estimate of the informal care cost. All costs are presented in 2017/18 pound sterling.


Bone & Joint Open
Vol. 1, Issue 4 | Pages 80 - 87
24 Apr 2020
Passaplan C Gautier L Gautier E

Aims

Our retrospective analysis reports the outcome of patients operated for slipped capital femoral epiphysis using the modified Dunn procedure. Results, complications, and the need for revision surgery are compared with the recent literature.

Methods

We retrospectively evaluated 17 patients (18 hips) who underwent the modified Dunn procedure for the treatment of slipped capital femoral epiphysis. Outcome measurement included standardized scores. Clinical assessment included ambulation, leg length discrepancy, and hip mobility. Radiographically, the quality of epiphyseal reduction was evaluated using the Southwick and Alpha-angles. Avascular necrosis, heterotopic ossifications, and osteoarthritis were documented at follow-up.


Bone & Joint Open
Vol. 1, Issue 4 | Pages 55 - 63
7 Apr 2020
Terjesen T Horn J

Aims

When the present study was initiated, we changed the treatment for late-detected developmental dislocation of the hip (DDH) from several weeks of skin traction to markedly shorter traction time. The aim of this prospective study was to evaluate this change, with special emphasis on the rate of stable closed reduction according to patient age, the development of the acetabulum, and the outcome at skeletal maturity.

Methods

From 1996 to 2005, 49 children (52 hips) were treated for late-detected DDH. Their mean age was 13.3 months (3 to 33) at reduction. Prereduction skin traction was used for a mean of 11 days (0 to 27). Gentle closed reduction under general anaesthesia was attempted in all the hips. Concurrent pelvic osteotomy was not performed. The hips were evaluated at one, three and five years after reduction, at age eight to ten years, and at skeletal maturity. Mean age at the last follow-up was 15.7 years (13 to 21).


The Bone & Joint Journal
Vol. 102-B, Issue 4 | Pages 414 - 422
1 Apr 2020
Gwynne-Jones DP Gray AR

Aims

To compare long-term survival of all-cemented and hybrid total hip arthroplasty (THA) using the Exeter Universal stem.

Methods

Details of 1,086 THAs performed between 1999 and 2005 using the Exeter stem and either a cemented (632) or uncemented acetabular component (454) were collected from local records and the New Zealand Joint Registry. A competing risks regression survival analysis was performed with death as the competing risk with adjustments made for age, sex, approach, and bearing.


Bone & Joint Research
Vol. 9, Issue 4 | Pages 182 - 191
1 Apr 2020
D’Ambrosio A Peduzzi L Roche O Bothorel H Saffarini M Bonnomet F

Aims

The diversity of femoral morphology renders femoral component sizing in total hip arthroplasty (THA) challenging. We aimed to determine whether femoral morphology and femoral component filling influence early clinical and radiological outcomes following THA using fully hydroxyapatite (HA)-coated femoral components.

Methods

We retrospectively reviewed records of 183 primary uncemented THAs. Femoral morphology, including Dorr classification, canal bone ratio (CBR), canal flare index (CFI), and canal-calcar ratio (CCR), were calculated on preoperative radiographs. The canal fill ratio (CFR) was calculated at different levels relative to the lesser trochanter (LT) using immediate postoperative radiographs: P1, 2 cm above LT; P2, at LT; P3, 2 cm below LT; and D1, 7 cm below LT. At two years, radiological femoral component osseointegration was evaluated using the Engh score, and hip function using the Postel Merle d’Aubigné (PMA) and Oxford Hip Score (OHS).


The Bone & Joint Journal
Vol. 102-B, Issue 4 | Pages 423 - 425
1 Apr 2020
Hoggett L Cross C Helm A

Aims

Dislocation remains a significant complication after total hip arthroplasty (THA), being the third leading indication for revision. We present a series of acetabular revision using a dual mobility cup (DMC) and compare this with our previous series using the posterior lip augmentation device (PLAD).

Methods

A retrospective review of patients treated with either a DMC or PLAD for dislocation in patients with a Charnley THA was performed. They were identified using electronic patient records (EPR). EPR data and radiographs were evaluated to determine operating time, length of stay, and the incidence of complications and recurrent dislocation postoperatively.


The Bone & Joint Journal
Vol. 102-B, Issue 3 | Pages 293 - 300
1 Mar 2020
Zheng H Gu H Shao H Huang Y Yang D Tang H Zhou Y

Aims

Vancouver type B periprosthetic femoral fractures (PFF) are challenging complications after total hip arthroplasty (THA), and some treatment controversies remain. The objectives of this study were: to evaluate the short-to-mid-term clinical outcomes after treatment of Vancouver type B PFF and to compare postoperative outcome in subgroups according to classifications and treatments; to report the clinical outcomes after conservative treatment; and to identify risk factors for postoperative complications in Vancouver type B PFF.

Methods

A total of 97 consecutive PPFs (49 males and 48 females) were included with a mean age of 66 years (standard deviation (SD) 14.9). Of these, 86 patients were treated with surgery and 11 were treated conservatively. All living patients had a minimum two-year follow-up. Patient demographics details, fracture healing, functional scores, and complications were assessed. Clinical outcomes between internal fixation and revisions in patients with or without a stable femoral component were compared. Conservatively treated PPFs were evaluated in terms of mortality and healing status. A logistic regression analysis was performed to identify risk factors for complications.


Bone & Joint Open
Vol. 1, Issue 3 | Pages 13 - 18
1 Mar 2020
Png ME Fernandez MA Achten J Parsons N McGibbon A Gould J Griffin X Costa ML

Aim

This paper describes the methods applied to assess the cost-effectiveness of cemented versus uncemented hemiarthroplasty among hip fracture patients in the World Hip Trauma Evaluation Five (WHiTE5) trial.

Methods

A within-trial cost-utility analysis (CUA) will be conducted at four months postinjury from a health system (National Health Service and personal social services) perspective. Resource use pertaining to healthcare utilization (i.e. inpatient care, physiotherapy, social care, and home adaptations), and utility measures (quality-adjusted life years) will be collected at one and four months (primary outcome endpoint) postinjury; only treatment of complications will be captured at 12 months. Sensitivity analysis will be conducted to assess the robustness of the results.


The Bone & Joint Journal
Vol. 102-B, Issue 2 | Pages 198 - 204
1 Feb 2020
Perlbach R Palm L Mohaddes M Ivarsson I Schilcher J

Aims

This single-centre observational study aimed to describe the results of extensive bone impaction grafting of the whole acetabular cavity in combination with an uncemented component in acetabular revisions performed in a standardized manner since 1993.

Methods

Between 1993 and 2013, 370 patients with a median age of 72 years (interquartile range (IQR) 63 to 79 years) underwent acetabular revision surgery. Of these, 229 were more than ten years following surgery and 137 were more than 15 years. All revisions were performed with extensive use of morcellized allograft firmly impacted into the entire acetabular cavity, followed by insertion of an uncemented component with supplementary screw fixation. All types of reoperation were captured using review of radiographs and medical charts, combined with data from the local surgical register and the Swedish Hip Arthroplasty Register.


The Bone & Joint Journal
Vol. 102-B, Issue 2 | Pages 191 - 197
1 Feb 2020
Gabor JA Padilla JA Feng JE Schnaser E Lutes WB Park KJ Incavo S Vigdorchik J Schwarzkopf R

Aims

Although good clinical outcomes have been reported for monolithic tapered, fluted, titanium stems (TFTS), early results showed high rates of subsidence. Advances in stem design may mitigate these concerns. This study reports on the use of a current monolithic TFTS for a variety of indications.

Methods

A multi-institutional retrospective study of all consecutive total hip arthroplasty (THA) and revision total hip arthroplasty (rTHA) patients who received the monolithic TFTS was conducted. Surgery was performed by eight fellowship-trained arthroplasty surgeons at four institutions. A total of 157 hips in 153 patients at a mean follow-up of 11.6 months (SD7.8) were included. Mean patient age at the time of surgery was 67.4 years (SD 13.3) and mean body mass index (BMI) was 28.9 kg/m2 (SD 6.5). Outcomes included intraoperative complications, one-year all-cause re-revisions, and subsidence at postoperative time intervals (two weeks, six weeks, six months, nine months, and one year).


The Bone & Joint Journal
Vol. 102-B, Issue 1 | Pages 90 - 101
1 Jan 2020
Davis ET Pagkalos J Kopjar B

Aims

The aim of this study was to identify the effect of the manufacturing characteristics of polyethylene acetabular liners on the survival of cementless and hybrid total hip arthroplasty (THA).

Methods

Prospective cohort study using linked National Joint Registry (NJR) and manufacturer data. The primary endpoint was revision for aseptic loosening. Cox proportional hazard regression was the primary analytical approach. Manufacturing variables included resin type, crosslinking radiation dose, terminal sterilization method, terminal sterilization radiation dose, stabilization treatment, total radiation dose, packaging, and face asymmetry. Total radiation dose was further divided into G1 (no radiation), G2 (> 0 Mrad to < 5 Mrad), G3 (≥ 5 Mrad to < 10 Mrad), and G4 (≥ 10 Mrad).


The Bone & Joint Journal
Vol. 102-B, Issue 1 | Pages 82 - 89
1 Jan 2020
Coenders MJ Mathijssen NMC Vehmeijer SBW

Aims

The aim of this study was to report our experience at 3.5 years with outpatient total hip arthroplasty (THA).

Methods

In this prospective cohort study, we included all patients who were planned to receive primary THA through the anterior approach between 1 April 2014 and 1 October 2017. Patient-related data and surgical information were recorded. Patient reported outcome measures (PROMs) related to the hip and an anchor question were taken preoperatively, at six weeks, three months, and one year after surgery. All complications, readmissions, and reoperations were registered.


The Bone & Joint Journal
Vol. 101-B, Issue 12 | Pages 1585 - 1592
1 Dec 2019
Logishetty K Rudran B Cobb JP

Aims

Arthroplasty skills need to be acquired safely during training, yet operative experience is increasingly hard to acquire by trainees. Virtual reality (VR) training using headsets and motion-tracked controllers can simulate complex open procedures in a fully immersive operating theatre. The present study aimed to determine if trainees trained using VR perform better than those using conventional preparation for performing total hip arthroplasty (THA).

Patients and Methods

A total of 24 surgical trainees (seven female, 17 male; mean age 29 years (28 to 31)) volunteered to participate in this observer-blinded 1:1 randomized controlled trial. They had no prior experience of anterior approach THA. Of these 24 trainees, 12 completed a six-week VR training programme in a simulation laboratory, while the other 12 received only conventional preparatory materials for learning THA. All trainees then performed a cadaveric THA, assessed independently by two hip surgeons. The primary outcome was technical and non-technical surgical performance measured by a THA-specific procedure-based assessment (PBA). Secondary outcomes were step completion measured by a task-specific checklist, error in acetabular component orientation, and procedure duration.


The Bone & Joint Journal
Vol. 101-B, Issue 12 | Pages 1578 - 1584
1 Dec 2019
Batailler C Weidner J Wyatt M Pfluger D Beck M

Aims

A borderline dysplastic hip can behave as either stable or unstable and this makes surgical decision making challenging. While an unstable hip may be best treated by acetabular reorientation, stable hips can be treated arthroscopically. Several imaging parameters can help to identify the appropriate treatment, including the Femoro-Epiphyseal Acetabular Roof (FEAR) index, measured on plain radiographs. The aim of this study was to assess the reliability and the sensitivity of FEAR index on MRI compared with its radiological measurement.

Patients and Methods

The technique of measuring the FEAR index on MRI was defined and its reliability validated. A retrospective study assessed three groups of 20 patients: an unstable group of ‘borderline dysplastic hips’ with lateral centre edge angle (LCEA) less than 25° treated successfully by periacetabular osteotomy; a stable group of ‘borderline dysplastic hips’ with LCEA less than 25° treated successfully by impingement surgery; and an asymptomatic control group with LCEA between 25° and 35°. The following measurements were performed on both standardized radiographs and on MRI: LCEA, acetabular index, femoral anteversion, and FEAR index.


The Bone & Joint Journal
Vol. 101-B, Issue 11 | Pages 1459 - 1463
1 Nov 2019
Enishi T Yagi H Higuchi T Takeuchi M Sato R Yoshioka S Nakamura M Nakano S

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.


The Bone & Joint Journal
Vol. 101-B, Issue 11 | Pages 1447 - 1458
1 Nov 2019
Chatziagorou G Lindahl H Kärrholm J

Aims

We investigated patient characteristics and outcomes of Vancouver type B periprosthetic fractures treated with femoral component revision and/or osteosynthesis.

Patients and Methods

The study utilized data from the Swedish Hip Arthroplasty Register (SHAR) and information from patient records. We included all primary total hip arthroplasties (THAs) performed in Sweden since 1979, and undergoing further surgery due to Vancouver type B periprosthetic femoral fracture between 2001 and 2011. The primary outcome measure was any further reoperation between 2001 and 2013. Cross-referencing with the National Patient Register was performed in two stages, in order to identify all surgical procedures not recorded on the SHAR.


The Bone & Joint Journal
Vol. 101-B, Issue 11 | Pages 1423 - 1430
1 Nov 2019
Wiik AV Lambkin R Cobb JP

Aims

The aim of this study was to assess the functional gain achieved following hip resurfacing arthroplasty (HRA).

Patients and Methods

A total of 28 patients (23 male, five female; mean age, 56 years (25 to 73)) awaiting Birmingham HRA volunteered for this prospective gait study, with an age-matched control group of 26 healthy adults (16 male, ten female; mean age, 56 years (33 to 84)). The Oxford Hip Score (OHS) and gait analysis using an instrumented treadmill were used preoperatively and more than two years postoperatively to measure the functional change attributable to the intervention.


The Bone & Joint Journal
Vol. 101-B, Issue 11 | Pages 1431 - 1437
1 Nov 2019
Harrison-Brown M Scholes C Ebrahimi M Field C Cordingley R Kerr D Farah S Kohan L

Aims

It is not known whether change in patient-reported outcome measures (PROMs) over time can be predicted by factors present at surgery, or early follow-up. The aim of this study was to identify factors associated with changes in PROM status between two-year evaluation and medium-term follow-up.

Patients and Methods

Patients undergoing Birmingham Hip Resurfacing completed the Veteran’s Rand 36 (VR-36), modified Harris Hip Score (mHHS), Tegner Activity Score, and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at two years and a minimum of three years. A change in score was assessed against minimal clinically important difference (MCID) and patient-acceptable symptom state (PASS) thresholds. Binary logistic regression was used to assess the relationship between patient factors and deterioration in PASS status between follow-ups.


The Bone & Joint Journal
Vol. 101-B, Issue 11 | Pages 1438 - 1446
1 Nov 2019
Kong X Chai W Chen J Yan C Shi L Wang Y

Aims

This study aimed to explore whether intraoperative nerve monitoring can identify risk factors and reduce the incidence of nerve injury in patients with high-riding developmental dysplasia.

Patients and Methods

We conducted a historical controlled study of patients with unilateral Crowe IV developmental dysplasia of the hip (DDH). Between October 2016 and October 2017, intraoperative nerve monitoring of the femoral and sciatic nerves was applied in total hip arthroplasty (THA). A neuromonitoring technician was employed to monitor nerve function and inform the surgeon of ongoing changes in a timely manner. Patients who did not have intraoperative nerve monitoring between September 2015 and October 2016 were selected as the control group. All the surgeries were performed by one surgeon. Demographics and clinical data were analyzed. A total of 35 patients in the monitoring group (ten male, 25 female; mean age 37.1 years (20 to 46)) and 56 patients in the control group (13 male, 43 female; mean age 37.9 years (23 to 52)) were enrolled. The mean follow-up of all patients was 13.1 months (10 to 15).


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_12 | Pages 30 - 30
1 Oct 2019
Antoniou J Gomes SK Zukor D Huk O Bergeron S Robbins SM
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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.