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Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 21 - 21
1 Oct 2020
Amstutz HC Le Duff MJ
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Background

Hip resurfacing arthoplasty (HRA) showed promising early and mid-terms results at the beginning of the new millennium. Adverse local tissue reactions associated with metal debris considerably slowed down the implantation of HRA which use is now limited to a few specialized centers. The long term success of this procedure, however, is still largely unknown. This study aimed to provide the clinical results of a series of 400 consecutive HRA with a minimum follow-up of 20 years.

Methods

All patients treated with Conserve®Plus HRA between November 1996 and November 2000 were retrospectively selected and 355 patients (400 hips) were included. The clinical results of this series was previously reported in 2004 at a follow up of 2 to 6 years[1]. There were 96 women (27%) and 259 men (73%). Mean age at surgery was 48.2 ± 10.9 years. Long-term survivorship was assessed with Kaplan-Meier survival estimates. UCLA hip scores and SF-12 quality of life scores were collected at follow-up visits. Radiographic positioning of the acetabular component was assessed with the computation of the contact patch to rim (CPR) distance. Radiolucencies about the metaphyseal stem and around the acetabular component were recorded to assess the quality of the component fixation.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 29 - 29
1 Oct 2020
Mont MA
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Introduction

With the widespread legalization of cannabis across the United States, well-powered studies evaluating the impact of cannabis use disorder on outcomes following primary total hip arthroplasty are warranted. Therefore, the aim of this study was to determine whether cannabis use disorder has an effect on patients who undergo primary hip arthroplasty in terms of: 1) hospital lengths of stay (LOS); 2) medical complications; 3) implant-related complications; and 4) costs of care.

Methods

Using an administrative database, patients who underwent primary total hip arthroplasty and had cannabis use disorder were matched to a cohort who did not in a 1:5 ratio by age, sex, and various medical comorbidities. This yielded 44,154 patients; 7,361 who had cannabis use disorder and 36,793 who did not. Variables for analysis included postoperative LOS, 90-day medical complications, 2-year implant-related complications, and 90-day costs of care. Mann-Whitney-U tests were used to compare LOS and costs. Multivariate logistic regression analyses were used to calculate the odds ratios (ORs) of developing complications. A p-value less than 0.005 was considered statistically significant.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 7 - 7
1 Oct 2020
Webb ML Scanlon CM Kerbel Y Evangelista P Kamath A Nelson CL
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Introduction

The long-term survival of modern ceramic-ceramic bearings in young active patients with osteonecrosis undergoing total hip arthroplasty (THA) is unknown. A previously published study of this series at 5-year follow-up demonstrated an extremely high activity level. The purpose of this study is to examine whether this very high activity level is associated with ceramic-on-ceramic THA failure at long-term follow-up.

Methods

This is a retrospective review of a single-surgeon at an academic medical center between years 2003–2010. Inclusion criteria were consecutive series of ceramic-on-ceramic articulations in patients younger than 50 with a diagnosis of osteonecrosis. Median follow-up was 12.4 years (range 10–17). Data was collected via mail, telephone, and e-mail surveys. Exclusion criteria included deceased prior to follow-up. Preoperative and postoperative Western Ontario and McMaster University Arthritis Index (WOMAC) and University of California at Los Angeles Activity scores (UCLA) were collected. Student t-tests were used as appropriate.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 11 - 11
1 Oct 2020
Wells JE Young WH Levy ET Fey NP Huo MH
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Purpose

Patients with acetabular dysplasia demonstrate altered biomechanics during gate and other activities. We hypothesized that these patients exhibit a compensatory increase in the anterior pelvic tilt during gait.

Materials & Methods

Twelve patients were included in this prospective radiographic and gait analysis study prior to the PAO. All were women. The mean age was 27 years (+/− 8 yrs). Tonnis grade was zero in nine, and one in three hips. All patients performed multiple one-minute walking trials on the level, the incline, and the decline treadmill surfaces in an optical motion capture lab. Anterior pelvic tilt is reported in (+), while the posterior pelvic tilt is reported in (–) values.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 31 - 31
1 Oct 2020
Chalmers BP Lebowitz J Chiu Y Joseph A Padgett D Bostrom M Della Valle AG
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Introduction

Due to the opioid epidemic, our service developed a cultural change highlighted by decreasing discharge opioids after lower extremity arthroplasty. However, concern of potentially increasing refill requests exists. As such, the goal of this study was to analyze whether decreased discharge opioids led to increased postoperative opioid refills.

Methods

We retrospectively reviewed 19,428 patients undergoing a primary hip or knee arthroplasty at a single institution from 2016–2019. Patients that underwent secondary procedures within that timeframe were excluded. Two-thousand two-hundred and forty-one patients (12%) were on narcotics preoperatively or had chronic pain syndrome. Two reductions in routine discharge narcotics were performed over this timeframe. First, 8,898 patients routinely received 750 morphine milligram equivalents (MMEs). After the first reduction, 4,842 patients routinely received 520 MMEs. After a second reduction, 5,688 patients routinely received 320 MMEs. We analyzed refill rates, refill MMEs, and whether discharge MMEs were associated with refill MMEs in a multivariate model.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 33 - 33
1 Oct 2020
Bostrom MPG
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Introduction

Patients with aseptic loosening, a cause of failure in uncemented total joint arthroplasty (TJA), often present with fibrous tissue at the bone-implant interface.1 In this study, we characterize the presence of neutrophil extracellular traps (NETs) in the intramedullary fibrotic membrane of aseptic loosening patients. We further explore the role of NETs, mediated by peptidyl arginine deiminase (PAD4), in peri-implant fibrosis and osseointegration failure through a murine model of unstable tibial implantation.2–4

Methods

Peri-implant membrane was retrieved from five patients during total hip revision surgery and analyzed for the presence of NETs (citH3+ with extracellular DNA) via immunofluorescence. A Ti-6Al-4V implant was inserted in an oversized drill-hole in the right proximal tibia of 8-week-old C57BL/6J and PAD4 knockout mice (n=3 per group). Fourteen days later, all mice were euthanized, and implanted tibias were dissected. Fibrosis and osseointegration at the bone-implant interface were assessed by micro-computed tomography (microCT) and hematoxylin and eosin (H&E) staining. H&E samples were scored blindly by the investigator and another observer for signs of poor (score=0) to excellent osseointegration (score=3) using a rubric established in our lab.


Background

Direct anterior approach (DAA), total hip arthroplasty (THA, performed with the patient in the supine position, creates a unique opportunity to do bilateral THA under one anesthesia. Previous studies evaluating this option are limited by small sample size or lack of control group. The purpose of this study is to compare early clinical outcomes of simultaneous bilateral, unilateral and staged bilateral DAA-THA.

Methods

Using an institutional registry database, we reviewed 3977 DAA-THA performed in 3334 patients at minimum 90-days follow up. A single surgeon performed all surgeries. Simultaneous bilateral DAA-THA group included 512 hips in 256 patients, unilateral DAA-THA group 2691 hips and staged bilateral DAA-THA group 774 hips in 387 patients. We reviewed 90-day postoperative complications, readmissions, length of stay, and rate of home discharge between all three groups.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 5 - 5
1 Oct 2020
Gorman H Jordan E Varady NH Hosseinzadeh S Smith S Chen AF Mont M Iorio R
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Introduction

A staging system has been developed to revise the 1994 ARCO classification for ONFH. The final consensus resulted in the following 4-staged system: stage I—X-ray is normal, but either magnetic resonance imaging or bone scan is positive; stage II—X-ray is abnormal (subtle signs of osteosclerosis, focal osteoporosis, or cystic change in the femoral head) but without any evidence of subchondral fracture, fracture in the necrotic portion, or flattening of the femoral head; stage III—fracture in the subchondral or necrotic zone as seen on X-ray or computed tomography scans. This stage is further divided into stage IIIA (early, femoral head depression ≤2 mm) and stage IIIB (late, femoral head depression >2 mm); and stage IV—X-ray evidence of osteoarthritis with accompanying joint space narrowing, acetabular changes, and/or joint destruction. Radiographs, magnetic resonance imaging (MRI), and computed tomography (CT) scans may all be involved in diagnosing ONFH; however, the optimal diagnostic modality remains unclear. The purpose of this study was to identify: 1) how ONFH is diagnosed at a single academic medical center, and 2) if CT is a necessary modality for diagnosing/staging OFNH.

Methods

The EMR was queried for the diagnosis of ONFH between 1/1/2008–12/31/2018 at a single academic medical center. CT and MRI scans were reviewed by the senior author and other contributors. The timing and staging quality of the diagnosis of ONFH were compared between MRI and CT to determine if CT was a necessary component of the ONFH work-up.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 10 - 10
1 Oct 2020
Moskal JT
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Background

The use of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in recent years. This is in part due to the proposed benefits of a faster early recovery and a lower risk of dislocation. The purpose of this study is to understand the dislocation rate in a non-selective, consecutive cohort of patients undergoing THA via the DAA including those at high risk for instability due to spinopelvic pathology.

Methods

We performed a retrospective review of a large prospectively collected single institution database assessing all patients undergoing THA via the DAA between 2011 and 2017. The primary outcome measure was dislocation at minimum two-year follow-up. We then stratified patients by known risk factors for dislocation including spinopelvic pathology and performed an in-depth analysis of those patients who had a dislocation event.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 14 - 14
1 Oct 2020
Gu Y Madurawe C Kim W Pierrepont J Shimmin A Lee G
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Introduction

The prevalence of the various patterns of spinopelvic abnormalities that increase the risk for prosthetic impingement is unknown. While prior surgery or lumbar fusion are recognized as a risk factors for postoperative dislocation, many patients presenting for THA do not have obvious radiographic abnormalities. The purpose of this study is to determine the prevalence of large posterior pelvic tilt (PPT) when standing, stiff lumbar-spine (SLL) and spino-pelvic sagittal imbalance (SSI) in patients undergoing primary THA.

Methods

A consecutive series of 1592 patients (56% female) over 2 years underwent functional analysis of spinopelvic mobility using CT, standing, and flexed seated lateral radiographs as part of pre-operative THA planning. The average age was 65 (20–93). We investigated the prevalence of these 3 validated spinopelvic parameters known to increase the risk for impingent and correlated them to the patient's age and gender using Chi squared analysis. Finally, the risk of flexion and extension impingement was modeled for each patient at a default supine cup orientation (DSCO) of 40°/20° (±5°).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 18 - 18
1 Oct 2020
Nunley RM Barrack RL Lawrie CM
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Introduction

Modular dual mobility (MDM) prostheses are increasingly utilized for total hip arthroplasty (THA) to mitigate the risk of postoperative instability in high risk patients. Short-term reports on clinical outcomes are favorable but there are few studies on young active patients. This study quantified proximal femoral stress shielding and metal ion release in MDM combined with modern cementless stem design in young active patients.

Methods

This was a prospective study of patients between 18 and 65 years of age, with a body mass index (BMI) < 35 kg/m2 and University of California at Los Angeles (UCLA) activity score > 6, who received a modular cobalt-chromium acetabular liner, highly crosslinked polyethylene mobile bearing, and cementless titanium femoral stem for their primary THA. DEXA scans were performed at 6 weeks postoperatively as a baseline, then again at 6 months, 1 year, 2 years and 5 years postoperatively as were metal ions.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 23 - 23
1 Oct 2020
Bechtold D Schwabe M Lawrie C Clohisy JC
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Introduction

The direct anterior approach (DAA) for total hip arthroplasty (THA) has gained popularity in recent years. Potential advantages over other surgical approaches include less postoperative pain, fewer postoperative precautions, and quicker early recovery. It is most commonly performed in the supine position with traction tables or table mounted bone hooks to facilitate exposure. In this study, we describe a reproducible surgical technique for DAA THA in the lateral decubitus position with use of standard THA equipment and report on our results and learning curve.

Methods

A prospectively collected hip repository was queried for all primary THA DAA performed in the lateral position by a single surgeon over a 4-year period from the surgeon's first case utilizing the technique. Retrospective chart review was performed to identify complications and revisions. Modified Harris Hip Score (mHHS) was collected pre-operatively and again at 1-year post-operative. Radiographic parameters including were measured on the 1-year postoperative radiographs.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 44 - 44
1 Oct 2020
Fehring TK Kavolus J Cunningham D Eftekhary N Ting N Griffin W Seyler T
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Introduction

Debridement, antibiotics, and implant retention (DAIR) for acute prosthetic hip infection is a popular low morbidity option despite less than optimal success rates. We theorized that the delay between DAIR and explantation in failed cases may complicate eradication due to biofilm maturation and entrenchment of bacteria in periprosthetic bone. We ask, what are the results of two-stage reimplantation after a failed DAIR versus an initial two-stage procedure?

Methods

114 patients were treated with 2-stage exchange for periprosthetic hip infection. 65 were treated initially with a 2-stage exchange, while 49 underwent an antecedent DAIR prior to a 2-stage exchange. Patients were classified according to MSIS host criteria. Failure was defined as return to the OR for infection, a draining sinus, or systemic infection.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 45 - 45
1 Oct 2020
Jacobs JJ McCarthy SM Hall DJ Levine BR Lundberg HJ Pourzal R
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Introduction

Total hip replacement failure due to fretting-corrosion remains a clinical concern. We recently described that damage within CoCrMo femoral heads can occur either by mechanically-dominated fretting processes leading to imprinting (via rough trunnions) and surface fretting (via smooth trunnions), or by a chemically-dominated etching process along preferential corrosion sites, termed “column damage”. These corrosion sites occur due to banding of the alloy microstructure. Banding is likely caused during thermo-mechanical processing of the alloy and is characterized by local molybdenum depletion. It was the objective of this study to quantify material loss from femoral heads with severe corrosion, identify the underlying damage modes, and to correlate the damage to the alloy's microstructure.

Methods

105 femoral heads with a Goldberg score 4 were evaluated. Coordinate measuring machine data was used to compute material loss and visualize damage features. Time in situ and stem alloy were identified. Metallographic samples were produced for each case. Grain size and banding were identified using light-microscopy. Mann-Whitney tests were conducted to compare material loss between groups.


Introduction

In the United States, cementless femoral fixation remains the dominant mode of fixation for femoral neck fractures, despite strong worldwide registry data that supports cemented fixation. The reason for this discrepancy remains unknown, controversial and often difficult to compare due to multiple variables. The purpose of this study was to evaluate a matched cohort of patients undergoing arthroplasty for femoral neck fractures and assess outcomes of revisions, periprosthetic fractures and mortality.

Methods

This is an exact matched cohort study. Cemented fixation cases were exact matched to cementless fixation cases in a 1:1 fashion based on age, sex and Charlson Comorbidity Index (CCI). Outcome variables included: revision for periprosthetic fracture; all cause revision and mortality at any time point; all cause revision and mortality within 1-year and within 90-days. The primary independent variable was femoral fixation (cemented, cementless) and covariates included race (black, white, other), ethnicity (hispanic, non-hispanic), teaching status (minor, major, nonteaching) and bedsize (1–99, 100–399, >=400). Chi-square tests and multivariable logistic regression models were used for statistical analysis.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 55 - 55
1 Oct 2020
Barnes CL
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Introduction

Recent literature has sought to quantify pre-operative work associated with total joint arthroplasty. These studies have utilized surveys or self-reported time logs to estimate the Pre-op Optimization Work (POW) completed by the surgical team. The purpose of this study was to objectively quantify POW associated with total hip arthroplasty (THA) using electronic medical record (EMR) activity audit logs.

Methods

Retrospective analysis of EMR activity for 4 arthroplasty surgeons and their clinical staff was collected for 100 consecutive THA cases (25 per surgeon). Clinical informatics data was generated using EMR activity audit logs for pre-THA activity. Every action and mouse-click within a patient's chart was recorded for each team member. The time between mouse-clicks was calculated and summed for each user. Times exceeding five minutes without activity were assumed to reflect inactivity and excluded. Descriptive statistics were used to estimate the POW associated with THA preparation.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 35 - 35
1 Oct 2020
Roof MA Yeroushalmi D Aggarwal VK Meftah M Schwarzkopf R
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Introduction

Previous reports have investigated the correlation between time to revision hip arthroplasty (rTHA) and reason for revision, but little is known regarding the impact of timing on outcomes following rTHA. The purpose of this study is to evaluate the effect of time to rTHA on both indication and outcomes of rTHA.

Methods

This retrospective observational study reviewed patients who underwent unilateral, aseptic rTHA at an academic orthopedic specialty hospital between January 2016 and April 2019 with at least 1-year of follow-up. Patients were early revisions if they were revised within 2 years of primary THA (pTHA) or late revisions if revised after greater than 2 years. Patient demographics, surgical factors, and post-operative outcomes were compared between the groups. Post-hoc power analysis was performed (1-β=0.991).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 28 - 28
1 Oct 2020
Schwenk ES Kasper VP Torjman MC Austin MS Brown SA Hozack WJ
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Introduction

Early ambulation after total hip arthroplasty (THA) predicts early discharge. Spinal anesthesia is preferred but can delay ambulation, especially with bupivacaine. Mepivacaine, an intermediate-acting local anesthetic, could enable earlier ambulation than bupivacaine. We hypothesized that patients who received mepivacaine would ambulate earlier than those who received hyperbaric bupivacaine or isobaric bupivacaine for primary THA.

Methods

This was a randomized, double-blind controlled trial of patients undergoing primary THA. Patients were randomized 1:1:1 to mepivacaine 52.5 mg, hyperbaric bupivacaine 11.25 mg, or isobaric bupivacaine 12.5 mg for spinal anesthesia. The primary outcome measure was ambulation between 3–3.5 hours. Secondary outcomes included return of motor and sensory function, postoperative pain, opioid consumption, urinary retention, transient neurological symptoms, intraoperative muscle tension, length of stay and 30-day readmissions. A priori power analysis required 44 patients per group. After testing for normality (Shapiro-Wilk test), continuous data were analyzed using analysis of variance (ANOVA) or Kruskal-Wallis, as appropriate, and categorical data were analyzed with chi square.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 42 - 42
1 Oct 2020
Yang J Olsen AS Serino J Terhune EB Della Valle CJ
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Introduction

The proportion of arthroplasties performed in the ambulatory setting has increased substantially. However, concerns remain regarding whether same-day discharge may increase the risk of complications. The purpose of this study was to compare 90-day outcomes between inpatients and patients having surgery at an ambulatory surgery center (ASC).

Methods

Among a single-surgeon cohort of 721 patients who underwent arthroplasty at a free-standing ASC, 611 (84.7%) were matched one-to-one to inpatients based on age, gender, American Society of Anesthesiologists (ASA) score, and Body Mass Index (110 patients could not be adequately matched). The cohort included 208 total hip arthroplasties (34.0%), 196 total knee arthroplasties (32.1%), 178 unicompartmental knee arthroplasties (29.1%), 25 hip resurfacings (4.1%), two revision hip arthroplasties (0.3%) and two revision knee arthroplasties (0.3%). Post-operative outcomes including readmissions, reoperations, unplanned clinic visits, emergency department visits, and complications were compared. Complications were classified as either major (i.e. death, periprosthetic joint infection, pulmonary embolism) or as minor (i.e. delayed wound healing, rashes, urinary retention).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 48 - 48
1 Oct 2020
Kayani B Onochie E Patel V Begum F Cuthbert R Ferguson D Bhamra JS Sharma A Bates PD Haddad FS
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Background

There remains a paucity of clinical studies on the effects of coronavirus on perioperative outcomes, with no existing trials reporting on risk factors associated with increased risk of postoperative mortality in these patients. The objectives of this study were to assess perioperative complications and identify risk factors for increased mortality in patients with coronavirus undergoing surgery.

Methods

This multicentre cohort study included 340 coronavirus negative patients versus 82 coronavirus positive patients undergoing surgical treatment for neck of femur fractures across nine NHS hospitals within Greater London, United Kingdom. Predefined study outcomes relating to patient demographics, fracture configuration, operative treatment, perioperative complications and mortality were recorded by observers using a standardised data collection proforma. Univariate and multivariate analysis were used to identify risk factors associated with increased risk of mortality.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 32 - 32
1 Oct 2020
Yang J Terhune EB DeBenedetti A Della Valle CJ Gerlinger TL Levine BR Nam D
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Introduction

Wound complications following revision total hip arthroplasty (THA) are associated with an increased risk of superficial and deep infections. Closed incision negative-pressure therapy (ciNPT) has been reported to decrease this risk. This study's purpose was to assess if ciNPT decreases the rate of wound complications following revision THA versus a conventional, silver-impregnated dressing.

Methods

This was a single center, randomized controlled trial of patients undergoing both septic and aseptic revision THA. Patients received either ciNPT or a silver-impregnated dressing (control) for 7 days. Wound complications within 90 days of the procedure were recorded, including: surgical site infection (SSI), periprosthetic joint infection (PJI), prolonged drainage greater than 5 days, erythema requiring antibiotics, and hematoma formation. An a priori power analysis determined 201 patients per cohort were necessary to demonstrate a 10% decrease in wound complication rate.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 39 - 39
1 Oct 2020
Lygrisse K Tang A Hutzler L Schwarzkopf R Bosco J Davidovitch R Slover J
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Background

The Comprehensive Care for Joint Replacement (CJR) model was implemented in April-2016 to standardize cost and improve quality of care for two of the most commonly billed inpatient procedures for Medicare patients, total knee and total hip arthroplasty. The purpose of this study is to compare one institution's predicted savings and losses under the CJR model with actual savings and losses after two years of implementation and discuss new methods to maintain savings.

Methods

Using our institution's data, we calculated the mean cost per episode of care. We calculated the percent reduction in target price and percent savings or losses per case for the CJR and Bundle Payment Care Initiative (BPCI) for each Medicare Severity Diagnosis Related Group (MS-DRG) using mean cost per episode and CJR and BPCI target prices. We compared the target prices, annual savings, and losses per episode of care for both CJR and BPCI. All CJR savings, projected and actual, were computed by comparing CJR savings to that of 2018 BPCI savings.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 40 - 40
1 Oct 2020
Girbino KL Klika AK Barsoum WK Rueda CAH Piuzzi NS
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Introduction

With the removal of total hip arthroplasty (THA) from the Centers for Medicare & Medicaid Services (CMS) inpatient-only list, understanding predictors of length of stay (LOS) after THA is critical. Thus, we aimed to determine the influence of patient- and procedure-related risk factors as predictors of >1-day LOS after THA.

Methods

A prospective cohort of 5,281 patients underwent primary THA between January 2016 and April 2019. Risk factors increased LOS were categorized as patient-related (demographics, smoking status, baseline Veterans RAND 12 Item Health Survey Mental Component Summary score [VR-12 MCS], Charlson Comorbidity Index [CCI], surgical indication, baseline Hip Injury and Osteoarthritis Outcome Score [HOOS] pain subscore and baseline HOOS physical function shortform (HOOS-PS), range of motion, and predicted discharge disposition) or procedure-related (hospital site, surgeon, approach, day of surgery, and surgery start time). By using the Akaike information criterion (AIC) and internally-validated concordance probabilities (C-index) for discriminating a 1-day LOS from a >1-day LOS, we compared performance between a patient-related risk factors only model and a model containing both patient- and procedure-related risk factors.


Background

Dislocation is a common complication following total hip arthroplasty (THA), and accounts for a high percentage of subsequent revisions. The purpose of this study was to develop a convolutional neural network (CNN) model to identify patients at high risk for dislocation based on postoperative anteroposterior (AP) pelvis radiographs.

Methods

We retrospectively evaluated radiographs for a cohort of 13,970 primary THAs with 374 dislocations over 5 years of follow-up. Overall, 1,490 radiographs from dislocated and 91,094 from non-dislocated THAs were included in the analysis. A CNN object detection model (YOLO-V3) was trained to crop the images by centering on the femoral head. A ResNet18 classifier was trained to predict subsequent hip dislocation from the cropped imaging. The ResNet18 classifier was initialized with ImageNet weights and trained using FastAI (V1.0) running on PyTorch. The training was run for 15 epochs using ten-fold cross validation, data oversampling and augmentation.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 15 - 15
1 Oct 2020
Howarth WR Dannenbaum J Murphy S
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Introduction

The effect of spine-pelvis position and motion on hip arthroplasty function has been increasingly appreciated in the past several years. Some authors have stressed the importance of using precision technologies for component placement while others have advocated the use of dual mobility articulations or large bearings and lateralized liners in patients with fused lumbar spines. The current study assesses the prevalence of stiff and fused spines in an elective total hip arthroplasty population.

Methods

One hundred and forty-nine patients undergoing elective total hip arthroplasty were assessed preoperatively with CT (computed tomography) and functional radiographs for the purpose of CT based planning and intraoperative navigation of total hip arthroplasty (HipXpert System, Surgical Planning Associates, Inc., Boston, MA). The functional radiographs included standing and sitting lateral images (EOS Imaging, SA, Paris, France). Patients were assessed for supine, standing and sitting pelvic tilt (PT) and change in sacral slope (SS). Spine stiffness was defined by a change in sacral slope (SS) of less than or equal to 10 degrees on the standing to sitting lateral radiographs according to Luthringer et al JOA 2019.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 16 - 16
1 Oct 2020
Anderson LA Wylie J Erickson JA Peters CL
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Introduction

Periacetabular osteotomy (PAO) is the preferred treatment for symptomatic acetabular dysplasia in adolescents and young adults. There remains a lack of consensus regarding whether intra-articular work such as labral repair or improvement of femoral offset should be performed at the time of PAO or addressed subsequent to PAO if symptoms warrant. The purpose of this review was to determine the rate of subsequent hip arthroscopy (HA) in a contemporary PAO cohort with no intra-articular work performed at the time of PAO.

Methods

From June 2012 to September 2019, 272 Rectus Sparing PAOs were performed and followed for a minimum of one year (mean 4.6 years). The average age was 24 (range 14–44) and 87% were female. The average BMI was 25 and average length of hospital stay was 2.9 days. Patients were evaluated at last follow-up with PROMIS PF-CAT, pain and mental health scores. Clinical records were reviewed for complications or subsequent surgery. Pre and post-operative radiographs were reviewed for change in the following acetabular parameters: LCEA, ACEA, AI, and the alpha-angle was obtained from preoperative radiographs. Patients were cross-referenced from the two largest hospital systems in our area to determine if subsequent HA was performed. Descriptive statistics and logistic regression were used to analyze risk factors for HA.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 19 - 19
1 Oct 2020
Roedel GG Sveom DS Garvin KL
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Introduction

THA for patient's 50 years and younger is a procedure at high risk for complications and failure because of the high level of activity of this population. Highly cross linked polyethylene (HXLPE) has greatly improved the durability of the implant because of the improved wear characteristics. Few studies have followed this population into the second decade and therefore the purpose of this investigation was to evaluate the clinical outcome for the patients 5o years of age and younger at a minimum of 15 years. The second purpose was to evaluate the radiographic findings secondary to wear or mechanical failure of the implant.

Methods

Between October 1999 and December 2005, 105 THAs were performed in 95 patients (53 female, 42 male) age 50 years and younger (mean 42 years; range 20–50). Ten patients (10 hips) were lost to follow-up or deceased. The remaining 95 hips and 85 patients were followed for a minimum of 15 years (mean of 16.8, range 15–20.5) for analysis. HXLPE (Longevity, Zimmer Biomet) was the acetabular bearing for all hips. Radiographs were evaluated for radiolucent lines and osteolysis.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 20 - 20
1 Oct 2020
Engh CA Ho H Bhal V Housman LR Masonis JL Noble JW Hopper RH Su EP
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Introduction

The BIRMINGHAM HIP Resurfacing is a metal-on-metal (MOM) hip implant system approved by the US FDA in 2006. The approval required a multicenter, prospective, post-approval study (PAS). Our purpose is to report the current minimum 10-year results.

Methods

253 patients (280 hips) had surgery between October 2006 and December 2009 at one of 5 sites. We report revisions, survivorship, EQ-5D, Harris Hip Score (HHS), radiographic findings, and metal levels including cobalt (Co) and chromium (Cr). The mean age at surgery was 51 years, 74% male, BMI 28, osteoarthritis 95%. 243 (87%) of hips have known outcome or 10-year minimum follow-up (fup). Prior to 10 years, 5 patients died, 20 hips were revised, and 37 hips did not complete 10-year fup.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 22 - 22
1 Oct 2020
Kraus KR Dilley JE Ziemba-Davis M Meneghini RM
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Introduction

While additional resources associated with direct anterior (DA) approach total hip arthroplasty (THA) such as fluoroscopy, staff, and special tables are well recognized, time consumption is not well studied. The purpose of this study was to analyze anesthesia and surgical time in DA and posterior approach THA in a large healthcare system across multiple facilities and surgeons.

Methods

3,155 unilateral primary THAs performed via DA or posterior approaches between 1/1/2017 and 06/30/2019 at nine hospitals and ambulatory surgery centers (ASC) in a large metropolitan healthcare system were retrospectively reviewed. All surgeons were experienced and beyond learning curves. 247 cases were excluded to eliminate confounds. Operating room (OR) in and out times and surgical times were collected via EMR electronic and manual data extraction with verification. Multivariate statistical analyses were utilized with p<0.05 significant.


Background

The acknowledged benefit of the direct anterior (DA) approach is early functional return. Most surgeons in the U.S. use cementless femoral replacement given the negative track record of some cemented designs. However, delayed osseointegration of a femoral stem typically seen in older patients with poor bone quality will delay recovery, diminishing the benefits of the DA approach. Registry studies have shown a higher revision rate and complications in this patient population leading to a renewed interest in cemented fixation.

Questions posed

To achieve the functional benefits of the DA approach and the fixation benefits of cemented replacement, this study combined the 2 techniques posing the following questions:1) Does the limited access of the DA approach adversely affect the cement technique? 2) Does such a cementing technique reduce the incidence of cementless complications?


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 26 - 26
1 Oct 2020
Hamilton WG Robertson RN Cororaton AD Ho H Hopper RH
Full Access

Introduction

The rise of the anterior approach (AA) in primary surgery has led to enthusiasm for using this approach in revision surgery, especially because head and liner exchanges have been accompanied by a high dislocation rate when the posterior approach (PA) is used. The aim of this study was to compare the institutional dislocation rate comparing the PA and AA in isolated head and liner exchange.

Methods

A retrospective institutional database query was done to identify all aseptic head and liner exchanges between the years 2010- June, 2020. 186 hips were identified with an average age of 64.8+/−10.8 yrs (27.9–87.6) and average BMI of 28.7+/−6.3 kg/m2 (16.2–52). The reason for revision was polyethylene wear and osteolysis in 105 hips (56.5%), adverse tissue reaction to metal on metal (MOM) in 43 hips (23.1%), and recurrent instability in 38 hips (20.4%). The approach used for the revision surgery was PA in 128 hips (68.8%) and AA in 58 hips (31.2%). The mean follow-up for this cohort is 1.9±2 yrs (0.0–8.6).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 50 - 50
1 Oct 2020
Kraay MJ Bigach SD Rimnac CM Moore RD Kolevar MP Adavi P
Full Access

Introduction

The purpose of this study was to evaluate the long term changes in bone mineral density (BMD) following implantation of a low-modulus composite femoral component designed to closely match the stiffness of the proximal femur and minimize stress shielding. Specifically, we asked: 1) How does BMD in the proximal femur change with time and with Gruen zone location; 2) Does BMD in the proximal femur stabilize after two years of implantation?

Methods

We retrospectively reviewed a subgroup of sixteen patients who had preoperative and postoperative DEXA scans in an FDA multi-center prospective trial of this composite stem. Five of these sixteen patients returned for long-term DEXA scans at a mean 22.0 years post-op (range 21.2–22.6 years). BMD in the 7 Gruen zones at final follow-up was compared to immediate post-operative and 2-year follow-up values. Percentage change was calculated and change in BMD was plotted against time from immediate post-operative measurements to each subsequent follow-up.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 57 - 57
1 Oct 2020
Rueda CAH
Full Access

Introduction

The association between preoperative opioid use and adverse outcomes after total hip arthroplasty (THA) has been reported. However, a quantitative assessment used to evaluate the combined effect of controlled substance use and define a threshold for adverse outcomes after THA has not been established. The current study aimed to identify the association between the NarxCare Score (NCS) (indicative of controlled substance use) and length of stay (LOS), discharge disposition, 90-day emergency department (ED) visits, readmission, and reoperation after primary THA, necessary to identify a preoperative NCS threshold for adverse outcomes.

Methods

A total of 2,787 THAs (57.3% female; mean age: 64.3±11.14 years; NCS range: 0–800) were performed between November 2018-January 2020 at an integrated healthcare system with preoperative NCSs. Outcomes assessed included LOS, discharge disposition, 90-day ED visits, readmission (all-cause, procedure and non-procedure-related) and reoperation. The association between NCS category (in 100-point increments) and was analyzed through multivariate logistic regression accounting for risk factors.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 1 - 1
1 Oct 2020
Clohisy J Haddad FS
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The unparalleled events of the year 2020 continue to evolve and challenge the worldwide community on a daily basis. The COVID-19 pandemic has had a major impact on all aspects of our lives, and has caused major morbidity and mortality around the globe. The impact of COVID-19 on the practice of orthopedic surgery has been substantial with practice shutdowns, elective surgery restrictions, heightened utilization of telemedicine platforms and implementation of precautionary measures for in-person clinic visits. During this transition period the scholarly and educational pursuits of academic surgeons have been de-emphasized as the more immediate demands of clinical practice survivorship have been the priority. This unavoidable focus on clinical practice has heightened the importance of orthopedic subspecialty societies in maintaining an appropriate level of attention on research and educational activities. Under the outstanding presidential leadership of Robert Barrack, MD, The Hip Society adapted to the profound challenges of 2020, and maintained strong leadership in the realms of education and research. The recent 2020 summer meeting of the Hip Society was a testimonial to the resilience and dedication of the Society members to ongoing innovation in research and education. Due to travel and social distancing restrictions the 2020 summer meeting was transitioned from an in-person to a virtual meeting format. Dr Barrack and Program Chair Dr John Clohisy assisted with oversight of the meeting, while Olga Foley and Cynthia Garcia ensured the success of the meeting with remarkable planning and organization. These collaborative efforts resulted in an organized, well-attended, high level scientific meeting with engaging discussion and a remarkable virtual conference environment.

The Bone & Joint Journal is very pleased to partner with The Hip Society to publish the proceedings of this very unique virtual meeting. The Hip Society is based in the United States and membership is granted to select individuals for leadership accomplishments in education and research related to hip disease. The Society is focused on the mission of advancing the knowledge and treatment of hip disorders to improve the lives of patients. The vision of the Hip Society is to lead in the discovery and dissemination of knowledge related to disorders of the hip. The annual closed meeting is one of the most important events of the society as this gathering highlights timely, controversial and novel research contributions from the membership.

The top research papers from The Hip Society meeting will be published and made available to the wider orthopedic community in The Bone & Joint Journal. This partnership with The Bone & Joint Journal enhances the mission and vision of The Hip Society by international dissemination of the meeting proceedings. Given the far-reaching circulation of The Bone & Joint Journal the highest quality work is available to an expanding body of surgeons, associated healthcare providers and patients. Ultimately, this facilitates the overarching Hip Society goal of improving the lives of our patients.

The 2020 virtual Hip Society meeting was characterized by outstanding member attendance, high quality paper presentations and robust discussion sessions. The meeting was held over two days and encompassed 58 open paper presentations divided into ten sessions with moderated discussions after each session. All papers will be presented in this issue in abstract form, while selected full papers passing our rigorous peer review process will be available online and in The Bone & Joint Journal in a dedicated supplement in 2021.

The first session of the meeting focused on issues related to complex primary THA and osteonecrosis of the femoral head. Dr Gross presented on the conversion of hip fusion to THA in 28 patents at a mean 7 years. He reported a high clinical success rate, yet complications of heterotopic ossification and neurologic injury were relatively common. Consideration of heterotopic ossification prophylaxis and the selective use of a constrained liner were recommended. Dr Pagnano summarized the use of various contemporary porous acetabular components in 38 hips in the setting of prior pelvic radiation. The mean follow-up was 5 years and 10 year survivorship was 100% with all implants radiographically fixed. Dr Bolognesi's study demonstrated that THA in solid organ transplant patients is associated with higher risk for facility placement, transfusions and readmissions. This patient population also has increased mortality risk (4.3% risk at 1 year) especially lung transplant patients. The second group of papers focused on femoral head osteonecrosis. Dr Iorio presented single center data demonstrating that CT scan was a useful adjunct for diagnosis in the staging work-up for cancer, yet was not useful for ARCO staging and treatment decision-making. On the basic science side, Dr Goodman utilized a rabbit model of steroid-induced femoral head osteonecrosis to determine that immunomodulation with IL-4 has the potential to improve bone healing after core decompression. The session was concluded by Dr Nelson's study of ceramic-on-ceramic THA in 108 osteonecrosis patients. The median 12 year results were outstanding with marked increases in PROs, maintenance of high activity levels, and a 3.7% revision rate.

In the second session attention was directed to THA instability and spinopelvic mobility. Dr Sierra presented a machine learning algorithm for THA dislocation risk. Two modifiable variables (anterior/lateral approach, elevated liner) were most influential in minimizing dislocation risk. Dr Taunton's study demonstrated a deep learning artificial intelligence model derived from postoperative radiographs to predict THA dislocation risk. High sensitivity and negative predictive value suggest that this model may be helpful in assessing postoperative dislocation risk. In reviewing a large single-center, multiple surgeon cohort of 2,831 DAA procedures, Dr Moskal noted a very low dislocation rate (0.45%) at minimum 2 years. Importantly, spinopelvic pathology or prior spinal instrumentation was not associated with an increased dislocation risk (0.30%). Dr Huo and colleagues analyzed pelvic tilt during functional gait in patients with acetabular dysplasia. They detected variable pelvic tilt on different surfaces with the data suggesting that patients with more anterior pelvic tilt while standing tend to have greater compensatory posterior pelvic tilt during gait. Dr Lamontagne reported on the sagittal and axial spinomobility in patients with hip OA, and highlighted reductions in pelvic tilt, pelvic-femoral-angle, lumbar lordosis and seated maximal trunk rotation when compared to controls. Dr Dennis showed that differences in spinopelvic mobility may explain the variable accuracy of acetabular version measurements on the cross-table lateral radiographs. Dr Gwo-Chin presented on a comprehensive functional analysis of 1,592 patients undergoing THA and observed that spinopelvic abnormalities are not infrequent (14%) in THA patients. Consistent with these findings Dr Murphy and collaborators identified a low prevalence of previous spinal instrumentation (1.5%), yet a high prevalence of spine stiffness (27.6%) in 149 patients undergoing THA.

Session three highlighted various aspects of treating hip disease in young patients. Dr Peters investigated the need for subsequent hip arthroscopy in 272 patients treated with an isolated PAO. Only 4.8% of these patients required subsequent arthroscopy calling into question the routine use of combined arthroscopy and PAO. Three papers addressed questions related to THA in young patients. Dr Berend's study of 2532 hips demonstrated that high activity level was not associated with an increased risk of midterm aseptic or all cause failure. Dr Nunley presented on 43 young patients with an average age of 52 years treated with a cementless stem and modular dual mobility articulation. Stress shielding was minimal and no concerning metal ion release detected. Dr Garvin summarized minimum 15 year data of THA with highly cross-linked polyethylene in patient less than 50 years. These hips performed exceptionally well with no mechanical loosening or radiographic osteolysis. Dr Engh examined 10 year results of the Birmingham Hip Resurfacing implant and reported a 92.9 % overall survivorship, with males less than 55 years achieving a 98.3% survivorship. The session was concluded by long-term data on the Conserve Plus hip resurfacing arthroplasty. Dr Amstutz presented an impressive dataset depicting an 83.1% 20 year survivorship for this early resurfacing cohort.

Direct anterior approach total hip arthroplasty was the focus of session four. Dr Meneghini reported on the anesthesia and surgical times of direct anterior and posterior approaches from a large healthcare system database. These data suggested longer OR and surgical times for the DAA both in the inpatient and ASC environments. Dr Clohisy introduced the technique and early outcomes of lateral decubitus position DAA. In a learning curve experience of 257 hips. 96% of acetabular components were in the Lewinneck safe zone, the aseptic revision rate was 0.9% and there were no dislocations. Dr Beaule analyzed femoral stem cement mantle with the DAA and posterior approaches by comparing two matched cohorts. Stem alignment and cement mantle quality were equivalent with both approaches. Similarly, Dr Emerson demonstrated technical feasibility and fewer cemented femoral stem failures when compared to cementless stems in a series of 360 DAAs THAs. The final paper of the session presented by Dr Hamilton examined the impact of surgical approach on dislocation after isolated head and liner exchange. Neither the posterior nor the anterior approach was superior in reducing the dislocation rate for these high dislocation risk procedures.

The fifth session explored contemporary topics related to anesthesia and pain management. Dr Byrd opened the session with a comparative study evaluating general versus spinal anesthesia for hip arthroscopy. This preliminary study was provoked by the desire to minimize aerosolized exposure early in the COVID-19 pandemic by transitioning to spinal anesthesia. Both anesthetic methods were effective. Dr Austin presented a randomized, double-blind controlled trial comparing spinal anesthetic with mepivacaine, hyperbaric bupivacaine and isobaric bupivacaine. Mepivacaine patients ambulated earlier and were more likely to be discharged the same day. Dr Mont provided a very timely study on the effects of “cannabis use disorder” and THA outcomes. This administrative database study of 44,154 patients revealed this disorder to be associated with longer hospital stays, increased complications rates and higher costs. Dr Bedair investigated whether a highly porous acetabular component submerged in an analgesic solution could enhance perioperative pain management. Interestingly, this novel strategy was associated with a reduction of postoperative pain scores and opioid consumption in 100 experimental patients compared to 100 controls. The concluding paper of the session by Dr Della Valle examined whether decreased discharge opioids led to increased postoperative opioid refills. A large single-center study of 19,428 patients detected a slight increase (5%) in opioid refills but a reduction in total refill morphine milligram equivalents.

The final, sixth session of day one considered various challenging aspects of revision hip arthroplasty. Dr Nam started the session with review of preliminary results from a randomized control trial comparing closed incision negative-pressure therapy with a silver-impregnated dressing for wound management in 113 hips undergoing revision arthroplasty. Unlike previous reports, the negative pressure therapy was associated with a higher reoperation rate for wound-related complications. Dr Bostrom highlighted the potential clinical impact of basic biological interventions by establishing the presence of Neutrophil Extracellular Traps (NETS) in fibrotic tissue from human aseptic loosening specimens and in a murine model of unstable tibial implantation. NET inhibition in the murine model prevented the expected tibial implant osseointegration failure. Dr Lombardi presented early 3.3 year clinical results of a highly porous Ti6al4v acetabular component in complex primary and revision arthroplasty. Survivorship for aseptic loosening was 96.6 % and 95.3% for the primary and revision cases, respectively. Dr Schwarzkopf and colleagues explored the impact of time to revision arthroplasty on clinical outcomes. Analysis of 188 revision cases revealed early revisions (less than 2 years from primary) were associated with worse outcomes, longer hospitalizations and higher reoperation rates. Mid-term results for modular dual mobility implants in revision arthroplasty were reviewed by Dr Lachiewicz who reported on 126 hips at a mean 5.5 years. 11% of hips dislocated and the 6 year survival was 91%. An outer head diameter of 48mm or greater was associated with a lower risk of dislocation. Dr Berry concluded the session by discussing the outcomes of treating the challenging problem of interprosthetic femur fractures. A single-center study of 77 cases treated over 32 years demonstrated a 79% success rate free of reoperation at 2 years with 95% of patients being ambulatory.

The second day commenced with the seventh session evaluating recent strategies to improve short-term THA outcomes. Dr Bozic and colleagues investigated the association of quality measure public reporting with hip/knee replacement outcomes. Annual trend data from 2010–2011 and 2016–2017 indicate that hospital-level complication and readmission rates decease after the start of public reporting, yet it is difficult to prove a direct effect. Dr Slover reviewed his institutions experience with the Comprehensive Care for Joint Replacement (CJR) model and emphasized that lower CJR target prices make it increasingly difficult for programs to meet target price thresholds. Cost saving strategies including same day discharge and reduction of home health services may result in smaller losses of positive margins. Dr Barsoum reported on the influence of patient and procedure-related risk factors of length of stay after THA. Patient-related risk factors provided substantial predictive value yet procedure-related risk factors (hospital site and surgical approach) remain the main drivers of predicting length of stay. Dr Hozack reviewed an impressive, single surgeon cohort of 3,977 DAA THAs and analyzed adverse events and 90 day perioperative outcomes. Simultaneous bilateral DAA THA was comparable with unilateral or staged bilateral procedures in regards to complications, readmission rate and home discharge rate but with an increased risk of transfusion. To examine the risk of complications with outpatient joint arthroplasty, Dr Della Valle performed a single-surgeon matched cohort analysis comparing outpatient and inpatient hip and knee arthroplasties. Outpatient procedures were not associated with an increased risk of any postoperative complications and actually experienced fewer emergency department visits.

The eighth session covered various contemporary challenges in hip arthroplasty care. Dr Griffin began the session with an analysis of the timing of complications associated with two-stage exchange procedures for periprosthetic joint infection (PJI). Of the 189 hips included, 41.6% had a complication and the mortality was 14.1% at 2.5 years, highlighting the morbidity of this treatment method. Dr Fehring provided data assessing the fate of two-stage reimplantation after failed debridement, antibiotics and implant retention (DAIR) for a prosthetic hip infection. This analysis of 114 hips yielded concerning results demonstrating a 42.9% treatment failure of patients treated with a previous DAIR compared to a 12.3% failure rate in patients treated with an initial 2-stage procedure. Dr Jacobs reviewed the analysis of 106 femoral heads with severe corrosion and identified a chemically dominated etching process termed “column damage” to be a detrimental damage mode within CoCr femoral heads that is directly linked to banding within its microstructure. These data indicate that implant alloy microstructure must be optimized to minimize the release of fretting-corrosion products. Simon Mears presented retrospective data from 184 THAs with a dual modular femoral stem. A subgroup of hips with a modular, cobalt chromium femoral neck had a pseudotumor visualized in 15% with only 55% of these having elevated CoCr levels. These findings may support the use of routine follow-up MARS MRI for modular CoCr femoral neck prostheses. The final two studies explored timely issues related to viral illness and hip surgery. Dr Browne analyzed three large administrative databases to elucidate whether patients are at increased risk for viral illnesses following total joint replacement. The incidence of postoperative influenza after total joint replacement was not increased compared to patients not undergoing total joint replacement surgery suggesting that arthroplasty procedures may not heighten the risk of viral illness. In the final paper of the session Dr Haddad presented important data regarding perioperative complications in coronavirus positive patients undergoing surgical treatment of femoral neck fractures. In this multicenter cohort study from the United Kingdom 82 coronavirus positive patients were shown to have longer hospital stays, more critical care unit admissions, higher risk of perioperative complications and an increased mortality compared to 340 coronavirus negative patients.

The eighth session had two papers on alternative femoral stem designs and three presentations more focused on femoral fracture treatments. Dr Mihalko focused on the European and US experiences with the Metha femoral neck retaining stem. The US experience mirrored the encouraging results from Europe with a 94% all cause femoral survivorship and a 99.1% femoral aseptic loosening survivorship at 5 years. Dr Kraay summarized dual energy x-ray absorptiometry (DEXA) evaluation of 16 low modulus composite femoral components at long-term follow-up of a mean 22 years. The bone mineral density associated with the implant increased in Gruen zones 2–6 and showed limited decreases in zones 1 and 7. These data support the concept that a low modulus femoral stem may more effectively load the proximal femur. Dr Springer provided data from the American Joint Replacement Registry (AJRR) and by evaluating outcomes of exact matched cohorts of 17,138 patients treated with cementless or cemented femoral implants for femoral neck fractures. Cemented implants were associated with marked reduction in early revision and periprosthetic fractures. However, cemented fixation was associated with an increased mortality at 90 days and 1 year. Additional data from the AJRR was presented by Dr Huddleston who investigated the risk factors for revision surgery after arthroplasty in a cohort of 75,333 femoral neck fractures. THA when compared to hemiarthroplasty was associated with higher early and overall revision rates. Cementless femoral fixation and increased age were also associated with higher rates of any revision. Both of these studies from the AJRR suggest that further consideration should be given to femoral fixation preferences in the femoral neck fracture population. Dr Vail summarized his institution's experience with an interdisciplinary hip fracture protocol for patients undergoing arthroplasty for acute femoral neck fractures. His study compared 157 cases prior to protocol implementation with 114 patients treated after the protocol was established. The impact of the interdisciplinary protocol was impressive as evidenced by a reduced time to operative treatment, length of stay, complication rate and one-year mortality. All being achieved without an increase in readmissions or facility discharges.

The final session of the meeting addressed innovations in perioperative care of THA patients. Dr Barrack started the session with an interesting study examining the feasibility and patient preferences regarding telemedicine. A cross-sectional telephone survey of 163 arthroplasty patients indicated that 88% of patients use the internet and 94% own a device capable of videoconferencing. Nevertheless, only 18% of patients preferred a video visit over an in-person clinic visit due to concerns of inferior care. Dr Barnes quantified preoperative optimization work in 100 arthroplasty patients by using EMR activity logs and determined the surgical team spends an average 75 minutes per case on preoperative work activities. Dr Duwelius reported the early outcomes of primary THA with a smartphone-based exercise and educational platform compared to standard of care controls. A randomized control trial design with 365 patients demonstrated similar outcomes and non-inferiority of the smartphone platform relative to complications, readmissions, emergency room/urgent care visits. The association of controlled substance use with THA outcomes was assessed by Dr Higuera Rueda. A quantitative assessment using the NarxCare score identified 300 and above as a score associated with adverse outcomes after THA. Dr Macaulay reviewed data from a large retrospective study of 1,825 THAs indicating that discontinuation of intermittent pneumatic compression devices does not increase the risk of venous thromboembolism in standard risk patients being treated with 81mg ASA BID as prophylaxis. Dr Antoniou presented the final paper of the meeting investigating potential changes in patient health status as an indication for surgery over time. Data from this large systematic review of the literature found patients undergoing THA at similar health status to the past with no influence form patient age, gender, year of enrollment or geographic region.

As summarized above, the 2020 virtual Hip Society Summer Meeting was rich in scientific content, productive discussion and a collaborative spirit. This collective body of work will result in impactful scientific contributions and will serve as a foundation for future innovation and advancements in the treatment of hip disease.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 8 - 8
1 Oct 2020
Wyles CC Maradit-Kremers H Rouzrokh P Barman P Larson DR Polley EC Lewallen DG Berry DJ Pagnano MW Taunton MJ Trousdale RT Sierra RJ
Full Access

Introduction

Instability remains a common complication following total hip arthroplasty (THA) and continues to account for the highest percentage of revisions in numerous registries. Many risk factors have been described, yet a patient-specific risk assessment tool remains elusive. The purpose of this study was to apply a machine learning algorithm to develop a patient-specific risk score capable of dynamic adjustment based on operative decisions.

Methods

22,086 THA performed between 1998–2018 were evaluated. 632 THA sustained a postoperative dislocation (2.9%). Patients were robustly characterized based on non-modifiable factors: demographics, THA indication, spinal disease, spine surgery, neurologic disease, connective tissue disease; and modifiable operative decisions: surgical approach, femoral head size, acetabular liner (standard/elevated/constrained/dual-mobility). Models were built with a binary outcome (event/no event) at 1-year and 5-year postoperatively. Inverse Probability Censoring Weighting accounted for censoring bias. An ensemble algorithm was created that included Generalized Linear Model, Generalized Additive Model, Lasso Penalized Regression, Kernel-Based Support Vector Machines, Random Forest and Optimized Gradient Boosting Machine. Convex combination of weights minimized the negative binomial log-likelihood loss function. Ten-fold cross-validation accounted for the rarity of dislocation events.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 12 - 12
1 Oct 2020
Lamontagne M Catelli DS Cotter B Mazuchi FAS Grammatopoulos G
Full Access

Introduction

Spinopelvic mobility has been associated with THA outcome. To-date spine assessments have been made quasi-statically, using radiographs, in standing and seated positions but dynamic spinopelvic mobility has not been well explored. This study aims to determine the association between dynamic (motion analysis) and quasi-static (radiographic) sagittal assessments and examine the association between axial and sagittal spinal kinematics in hip OA patients and controls.

Methods

This is a prospective, IRB approved, cohort study of 12 patients with hip OA pre-THA (6F/6M, 67±10 years) and six healthy controls (3F/3M, 46±18 years). All underwent lateral spinopelvic radiographs in standing and seated bend-and-reach (SBR) positions. Pelvic tilt (PT), pelvic-femoral-angle (PFA) and lumbar lordosis (LL) angles were measured in both positions and the differences (Δ) in angles between SBR and standing were computed. All participants performed two dynamic tasks at the motion laboratory: seated maximal trunk rotation (STR) and seated bend and reach (SBR). Three-dimensional joint motion data were collected and processed by a 10-camera infrared motion analysis system (Vicon, Nexus 2.10, UK). Total axial and sagittal spine (mid-thoracic to lumbar) range of motion (ROM) were calculated for STR and SBR, respectively.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 30 - 30
1 Oct 2020
Bedair HS
Full Access

Introduction

Prosthetic designs that use porous metals possess an extremely high surface area and through capillary effect may potentially ‘absorb’ and later elute analgesic solution, serving as a surgical site drug depot. This study aimed to determine if a highly porous acetabular component submerged in an aqueous-based analgesic solution prior to implantation reduced postoperative pain scores and opioid consumption in the early post-operative period.

Methods

Using our IRB approved database, 200 consecutive opioid naïve primary THA patients operated on by a single surgeon at two institutions using the same acetabular component were identified. 100 patients had a standard volume/concentration of an analgesic cocktail soft-tissue injection at closure (control). 100 patients had their acetabular components submerged into the same cocktail prior to implantation (treatment) and the balance of the volume injected. Postoperative protocols were otherwise identical. Groups were compared for visual analog pain scores (VAS), opioid consumption, 1-year radiographic findings and surgical revision rates.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 36 - 36
1 Oct 2020
Hernandez NM Hinton ZW Wu CJ Lachiewicz PF Ryan SP Wellman SS
Full Access

Background

Modular dual mobility (MDM) acetabular components are often used to prevent dislocation in revision total hip arthroplasty (THA). As there is insufficient data on these components, the outcomes were evaluated in a cohort with a mean follow-up time of greater than five years.

Methods

Using the database of a single academic center, 126 revision THAs (117 patients) with one MDM were retrospectively reviewed. There were 94 hips in 88 patients with a mean follow-up time of 5.5 years. Survivorship analysis was performed with the endpoints of dislocation, reoperation for dislocation, cup revision for aseptic loosening, and cup revision for any reason. The secondary endpoints were perioperative complications and radiographic review.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 37 - 37
1 Oct 2020
Tibbo ME Limberg AK Gausden EB Huang P Perry KI Yuan BJ Berry DJ Abdel MP
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Introduction

The prevalence of ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) is rising in concert with life expectancy, putting more patients at risk for interprosthetic femur fractures (IPFF). Our study aimed to assess treatment methodologies, implant survivorship, and clinical outcomes of patients with IPFF.

Methods

77 patients treated for an IPFF from 1985–2017 at a single large referral center were reviewed. Prior to the fracture, at the hip/knee sites respectively 46 femurs had primary/primary, 21 had revision/primary, 3 had primary/revision and 7 had revision/revision components. Mean age and BMI were 74 years and 30 kg/m2, respectively. Mean follow-up after fracture treatment was 7 years.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 38 - 38
1 Oct 2020
Suter LG Yu H Zywiel MG Li L Lin Z Simoes JL Sheares KD Grady J Bernheim S Bozic K
Full Access

Introduction

Quality measures play a substantial role in the Centers for Medicare and Medicaid Services' hospital payment and public reporting programs. The purpose of this study was to assess whether public measurement of total hip and knee arthroplasty risk-standardized readmission (RSRRs) and complication rates (RSCRs) was temporally associated with decreasing rates of adverse outcomes among Medicare beneficiaries.

Methods

We evaluated annual trends in hospital-level risk-standardized complication and readmission rates in the fiscal years 2010–11 and 2016–17 for patients undergoing hospital-based inpatient hip/knee replacement procedures. We calculated hospital-level rates using the same measures and methodology used in public reporting. We examined annual trends in the distribution of hospital-level outcomes through density plots (similar to histograms).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 43 - 43
1 Oct 2020
Griffin WL Li K Cuadra M Otero J Springer B
Full Access

Introduction

Prosthetic joint infection (PJI) is an devastating complication after total hip arthroplasty (THA). The common treatment in the US is a two-stage exchange which can be associated with significant morbidity and mortality. The purpose of this study was to analyze complications in the treatment course of patients undergoing two-stage exchange for PJI THA and determine when they occur.

Methods

We analyzed all patients that underwent two-stage exchange arthroplasty for treatment of PJI after THA from January 2005 – December 2017 at a single institution. Complications were categorized as medical or surgical, divided into three intervals: (1) inter-stage, (2) early post-reimplantation (<90 days) and (3) late post-reimplantation (> 90 days). Minimum follow up was one year. Success was based on the Musculoskeletal Infection Society (MSIS) definition.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 47 - 47
1 Oct 2020
Quinlan ND Werner BC Novicoff WM Browne JA
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Introduction

Elective surgery elicits a systemic immune response and may result in immunosuppression in certain patients. It is currently unknown whether patients are at an increased risk for viral infection and associated illness in the immediate postoperative period following total joint arthroplasty. This question has become more important given the ongoing coronavirus disease 2019 (COVID-19) pandemic.

Methods

We analyzed 3 large administrative datasets (Medicare 5% and 100% standard analytic files, Humana claims database) to identify patients who underwent total knee arthroplasty (TKA) and total hip arthroplasty (THA) from 2005 to 2013. The influenza vaccination status of each patient was defined using the presence or absence of a code for vaccination. The incidence of a flu diagnosis was recorded in both vaccinated and unvaccinated patients at 1 month, 3 months, and 6 months following the date of surgery and was compared to a cohort of vaccinated patients who did not undergo surgery.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 49 - 49
1 Oct 2020
Mihalko WM Gehlert R Jove M
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Introduction

In Europe a femoral neck retaining stem (Metha, Aesculap Inc, Tuttlingen, Germany) has been reported with excellent midterm survivorship. We report on a US series and compare it to a review of reports in Europe over the past decade to determine if US experience matches that in Europe.

Methods

A review of published studies was performed on PubMed with search terms: Hip, replacement, arthroplasty, and Metha. We found four publications that met the criteria of reporting survivorship and reasons for revision surgery. The results from these four articles combined had 4179 THA with the Metha stem. After IRB approval three orthopaedic groups in the US were used to combine their experience over the last 11 years. These US sources had 824 surgeries performed between 2008–2019. We then reported on all revisions for comparison of survivorship.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 54 - 54
1 Oct 2020
Freiman S Schwabe M Pashos G Barrack RL Nunley R Adelani M Pascual-Garrido C Clohisy J Lawrie C
Full Access

Introduction

The purpose of the study was to determine access to and, ability to use telemedicine technology in an adult hip and knee reconstruction patient population and we seek to understand these patients' perceived benefits, risks and preferences of telemedicine.

Methods

We performed a cross-sectional telephone administered survey on patients scheduled to undergo primary THA and TKA by one of six surgeons at a single academic institution between March 23 and June 2, 2020.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 59 - 59
1 Oct 2020
Antoniou J
Full Access

Introduction

The number of total hip arthroplasties (THAs) performed per year is increasing for reasons that are not fully explained by a growing and aging population. The purpose of this study was to determine the role of patient health status as an indication for surgery and determine if patients are undergoing surgery at a better health status than in the past.

Methods

To examine how pre-operative functional health status has changed over time, a systematic review and meta-analysis of the Medline, Embase, and Cochrane databases was performed in accordance with the PRISMA guidelines. Health status was assessed using the physical component summary (PCS) score from the 36-item short-form (SF-36) health survey. Only primary procedures were included; revisions were excluded. Articles were screened by two independent reviewers with conflicts resolved by consensus with a third reviewer. Meta-regression analysis was performed to determine the effect of time, patient age, and gender. Subgroup analysis was performed to assess differences between countries.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 13 - 13
1 Oct 2020
Bracey DN Hegde V Shimmin AJ Jennings JM Pierrepont JW Dennis DA
Full Access

Introduction

Cross table lateral (CTL) radiographs are commonly used to measure acetabular component anteversion after total hip arthroplasty (THA). CTL measurements may differ by >10 degrees from CT scan measurements, but the reasons for this discrepancy are poorly understood. We compare anteversion measurements made on CTL radiographs and CT scans to identify spinopelvic parameters predictive of inaccuracy.

Methods

THA patients (n=47) with preoperative spinopelvic radiographic analysis and postoperative CT scans were retrospectively reviewed. Acetabular component anteversion was measured on post-operative CTL radiographs, and CT scans using 3D reconstructions of the pelvis. Patients were grouped by error (CTL-CT)>10° (n=11) or <10° (n=36), and spinopelvic mobility parameters were compared using t-tests. Correlation between error and mobility parameters was assessed with Pearson coefficient.


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 27 - 27
1 Oct 2020
Byrd JWT
Full Access

Introduction

With resumption of non-urgent surgery in May 2020, standard anesthesia for hip arthroscopy switched from general with endotracheal intubation (GA) to spinal (SA) in response to COVID-19 implications; reducing potential aerosolized exposure for patient and staff and reducing consumption of personal protective equipment (PPE). There are no studies that compare the attributes for these two anesthesia methods for hip arthroscopy; and thus, this was viewed as an opportunity to perform a comparative observational study on SA to a recent matched group of GA.

Methods

Beginning in May 2020, SA became the standard for hip arthroscopy. GA was used if the patient refused SA or had a history of previous lumbar spinal surgery, or body mass index (BMI) greater than 35. SA patients were carefully matched for age, gender and procedure to a recent previous GA population and compared for recovery room (RR) length of stay, entry and discharge visual analog scores (VAS), morphine mg equivalent (MME) usage, and untoward events. Additionally, SA and GA cases performed since May 2020 were compared for the length of time from entry to the operating room (OR) until the surgeon was able to perform an examination under anesthesia (EUA).


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_10 | Pages 52 - 52
1 Oct 2020
Huddleston JI De A Jaffri H Barrington JW Duwelius PJ Springer BD
Full Access

Introduction

Patients with FNF may be treated by either total hip arthroplasty (THA) or hemiarthroplasty (HA). Utilizing American Joint Replacement Registry (AJRR) data, we aimed to evaluate outcomes in FNF treatment.

Methods

Medicare patients with FNF treated with HA or THA reported to the AJRR database from 2012–2019 and CMS claims data from 2012–2017 were analyzed in this retrospective cohort study. “Early” was defined as less than 90 days from index procedure. A logistic regression model, including index arthroplasty, age, sex, stem fixation method, hospital size1, hospital teaching affiliation1, and Charlson comorbidity index (CCI), was utilized to determine associations between index procedure and revision rates.


Bone & Joint Open
Vol. 1, Issue 9 | Pages 594 - 604
24 Sep 2020
James HK Pattison GTR Griffin J Fisher JD Griffin DR

Aims

To develop a core outcome set of measurements from postoperative radiographs that can be used to assess technical skill in performing dynamic hip screw (DHS) and hemiarthroplasty, and to validate these against Van der Vleuten’s criteria for effective assessment.

Methods

A Delphi exercise was undertaken at a regional major trauma centre to identify candidate measurement items. The feasibility of taking these measurements was tested by two of the authors (HKJ, GTRP). Validity and reliability were examined using the radiographs of operations performed by orthopaedic resident participants (n = 28) of a multicentre randomized controlled educational trial (ISRCTN20431944). Trainees were divided into novice and intermediate groups, defined as having performed < ten or ≥ ten cases each for DHS and hemiarthroplasty at baseline. The procedure-based assessment (PBA) global rating score was assumed as the gold standard assessment for the purposes of concurrent validity. Intra- and inter-rater reliability testing were performed on a random subset of 25 cases.


The Bone & Joint Journal
Vol. 102-B, Issue 9 | Pages 1128 - 1135
14 Sep 2020
Khoshbin A Haddad FS Ward S O hEireamhoin S Wu J Nherera L Atrey A

Aims

The rate of dislocation when traditional single bearing implants are used in revision total hip arthroplasty (THA) has been reported to be between 8% and 10%. The use of dual mobility bearings can reduce this risk to between 0.5% and 2%. Dual mobility bearings are more expensive, and it is not clear if the additional clinical benefits constitute value for money for the payers. We aimed to estimate the cost-effectiveness of dual mobility compared with single bearings for patients undergoing revision THA.

Methods

We developed a Markov model to estimate the expected cost and benefits of dual mobility compared with single bearing implants in patients undergoing revision THA. The rates of revision and further revision were calculated from the National Joint Registry of England and Wales, while rates of transition from one health state to another were estimated from the literature, and the data were stratified by sex and age. Implant and healthcare costs were estimated from local procurement prices and national tariffs. Quality-adjusted life-years (QALYs) were calculated using published utility estimates for patients undergoing THA.


Aims

To investigate the effect of polyethylene manufacturing characteristics and irradiation dose on the survival of cemented and reverse hybrid total hip arthroplasties (THAs).

Methods

In this registry study, data from the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man (NJR) were linked with manufacturing data supplied by manufacturers. The primary endpoint was revision of any component. Cox proportional hazard regression was a primary analytic approach adjusting for competing risk of death, patient characteristics, head composition, and stem fixation.


Bone & Joint Open
Vol. 1, Issue 9 | Pages 530 - 540
4 Sep 2020
Arafa M Nesar S Abu-Jabeh H Jayme MOR Kalairajah Y

Aims

The coronavirus disease (COVID)-19 pandemic forced an unprecedented period of challenge to the NHS in the UK where hip fractures in the elderly population are a major public health concern. There are approximately 76,000 hip fractures in the UK each year which make up a substantial proportion of the trauma workload of an average orthopaedic unit. This study aims to assess the impact of the COVID-19 pandemic on hip fracture care service and the emerging lessons to withstand any future outbreaks.

Methods

Data were collected retrospectively on 157 hip fractures admitted from March to May 2019 and 2020. The 2020 group was further subdivided into COVID-positive and COVID-negative. Data including the four-hour target, timing to imaging, hours to operation, anaesthetic and operative details, intraoperative complications, postoperative reviews, COVID status, Key Performance Indicators (KPIs), length of stay, postoperative complications, and the 30-day mortality were compiled from computer records and our local National Hip Fracture Database (NHFD) export data.


Bone & Joint Open
Vol. 1, Issue 9 | Pages 512 - 519
1 Sep 2020
Monzem S Ballester RY Javaheri B Poulet B Sônego DA Pitsillides AA Souza RL

Aims

The processes linking long-term bisphosphonate treatment to atypical fracture remain elusive. To establish a means of exploring this link, we have examined how long-term bisphosphonate treatment with prior ovariectomy modifies femur fracture behaviour and tibia mass and shape in murine bones.

Methods

Three groups (seven per group) of 12-week-old mice were: 1) ovariectomized and 20 weeks thereafter treated weekly for 24 weeks with 100 μm/kg subcutaneous ibandronate (OVX+IBN); 2) ovariectomized (OVX); or 3) sham-operated (SHAM). Quantitative fracture analysis generated biomechanical properties for the femoral neck. Tibiae were microCT scanned and trabecular (proximal metaphysis) and cortical parameters along almost its whole length measured.


Bone & Joint Research
Vol. 9, Issue 9 | Pages 534 - 542
1 Sep 2020
Varga P Inzana JA Fletcher JWA Hofmann-Fliri L Runer A Südkamp NP Windolf M

Aims

Fixation of osteoporotic proximal humerus fractures remains challenging even with state-of-the-art locking plates. Despite the demonstrated biomechanical benefit of screw tip augmentation with bone cement, the clinical findings have remained unclear, potentially as the optimal augmentation combinations are unknown. The aim of this study was to systematically evaluate the biomechanical benefits of the augmentation options in a humeral locking plate using finite element analysis (FEA).

Methods

A total of 64 cement augmentation configurations were analyzed using six screws of a locking plate to virtually fix unstable three-part fractures in 24 low-density proximal humerus models under three physiological loading cases (4,608 simulations). The biomechanical benefit of augmentation was evaluated through an established FEA methodology using the average peri-screw bone strain as a validated predictor of cyclic cut-out failure.


Bone & Joint Open
Vol. 1, Issue 8 | Pages 500 - 507
18 Aug 2020
Cheruvu MS Bhachu DS Mulrain J Resool S Cool P Ford DJ Singh RA

Aims

Our rural orthopaedic service has undergone service restructure during the COVID-19 pandemic in order to sustain hip fracture care. All adult trauma care has been centralised to the Royal Shrewsbury Hospital for assessment and medical input, before transferring those requiring operative intervention to the Robert Jones and Agnes Hunt Orthopaedic Hospital. We aim to review the impact of COVID-19 on hip fracture workload and service changes upon management of hip fractures.

Methods

We reviewed our prospectively maintained trust database and National Hip Fracture Database records for the months of March and April between the years 2016 and 2020. Our assessment included fracture pattern (intrascapular vs extracapsular hip fracture), treatment intervention, length of stay and mortality.


Bone & Joint Open
Vol. 1, Issue 8 | Pages 443 - 449
1 Aug 2020
Narula S Lawless A D’Alessandro P Jones CW Yates P Seymour H

Aims

A proximal femur fracture (PFF) is a common orthopaedic presentation, with an incidence of over 25,000 cases reported in the Australian and New Zealand Hip Fracture Registry (ANZHFR) in 2018. Hip fractures are known to have high mortality. The purpose of this study was to determine the utility of the Clinical Frailty Scale (CFS) in predicting 30-day and one-year mortality after a PFF in older patients.

Methods

A retrospective review of all fragility hip fractures who met the inclusion/exclusion criteria of the ANZHFR between 2017 and 2018 was undertaken at a single large volume tertiary hospital. There were 509 patients included in the study with one-year follow-up obtained in 502 cases. The CFS was applied retrospectively to patients according to their documented pre-morbid function and patients were stratified into five groups according to their frailty score. The groups were compared using t-test, analysis of variance (ANOVA), and the chi-squared test. The discriminative ability of the CFS to predict mortality was then compared with American Society of Anaesthesiologists (ASA) classification and the patient’s chronological age.


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.


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.


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.


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 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 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.


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 27 - 27
1 Jul 2020
Wyatt M Whitehouse M Kieser D Frampton C Hooper G
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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.


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
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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 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
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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 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.


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
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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 11 - 11
1 Jul 2020
Magill P Hill J Bryce L Dorman A Hogg R Campbell C Benson G Beverland D
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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.


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


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.


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


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.


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.


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 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.


Full Access

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.


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.