Faculty Bibliography

One-stage and two-stage revision strategies are the two main options for treating established chronic peri-prosthetic joint infection (PJI) of the hip; however, there is uncertainty regarding which is the best treatment option. We aimed to compare the risk of re-infection between the two revision strategies using pooled individual participant data (IPD). Observational cohort studies with PJI of the hip treated exclusively by one- or two-stage revision and reporting re-infection outcomes were retrieved by searching MEDLINE, EMBASE, Web of Science, The Cochrane Library, and the WHO International Clinical Trials Registry Platform; as well as email contact with investigators. We analysed IPD of 1856 participants with PJI of the hip from 44 cohorts across four continents. The primary outcome was re-infection (recurrence of infection by the same organism(s) and/or re-infection with a new organism(s)). Hazard ratios (HRs) for re-infection were calculated using Cox proportional frailty hazards models. After a median follow-up of 3.7 years, 222 re-infections were recorded. Re-infection rates per 1000 person-years of follow-up were 16.8 (95% CI 13.6-20.7) and 32.3 (95% CI 27.3-38.3) for one-stage and two-stage strategies respectively. The age- and sex-adjusted HR of re-infection for two-stage revision was 1.70 (0.58-5.00) when compared with one-stage revision. The association remained consistently absent after further adjustment for potential confounders. The HRs did not vary importantly in clinically relevant subgroups. Analysis of pooled individual patient data suggest that a one-stage revision strategy may be as effective as a two-stage revision strategy in treating PJI of the hip.

BACKGROUND:The advent of highly cross-linked polyethylene (HCLPE) has significantly improved total hip arthroplasty survivorship. HCLPE has been shown to improve wear properties in midterm outcomes when compared to traditional polyethylene liners; however, there is a paucity of studies evaluating long-term outcomes. In addition, there is concern that wear rates may accelerate as the implant ages. Thus, the aims of this study are to report on the longest-to-date follow-up of a specific first-generation HCLPE liner and to determine whether there is a change in the annual wear rate over time. METHODS:Forty hips in 38 patients which were previously reported on in a midterm study were included in this long-term follow-up study. Patients in this cohort all received total hip arthroplasty between March 1999 and August 2004 using the Crossfire HCLPE liner. Annual wear rates (mm/y) were calculated for this cohort. Patients were contacted and asked about complications or revision procedures they may have had since the index procedure. RESULTS:Clinical follow-up averaged 12.9 years with a range of 7-18 years. The average follow-up duration was 12.5 years with a range of 10-17 years. Linear wear was found to be 0.056 ± 0.036 mm/y. Osteolysis was not observed in any of the patients with greater than 10-year radiographic follow-up. Furthermore, only 1 patient required revision surgery following a mechanical fall. CONCLUSION/CONCLUSIONS:Our study demonstrates the long-term wear rates associated with HCLPE liners continue to match rates published in midterm studies. Previously, we have reported that this cohort had an average annual wear rate of 0.05 mm/y over 10 years. This most recent report demonstrates a similar wear rate with up to 18-year follow-up.

AIMS/OBJECTIVE:The routine use of dual-mobility (DM) acetabular components in total hip arthroplasty (THA) may not be cost-effective, but an increasing number of patients undergoing THA have a coexisting spinal disorder, which increases the risk of postoperative instability, and these patients may benefit from DM articulations. This study seeks to examine the cost-effectiveness of DM components as an alternative to standard articulations in these patients. PATIENTS AND METHODS/METHODS:A decision analysis model was used to evaluate the cost-effectiveness of using DM components in patients who would be at high risk for dislocation within one year of THA. Direct and indirect costs of dislocation, incremental costs of using DM components, quality-adjusted life-year (QALY) values, and the probabilities of dislocation were derived from published data. The incremental cost-effectiveness ratio (ICER) was established with a willingness-to-pay threshold of $100 000/QALY. Sensitivity analysis was used to examine the impact of variation. RESULTS:In the base case, patients with a spinal deformity were modelled to have an 8% probability of dislocation following primary THA based on published clinical ranges. Sensitivity analysis revealed that, at its current average price ($1000), DM is cost-effective if it reduces the probability of dislocation to 0.9%. The threshold cost at which DM ceased being cost-effective was $1180, while the ICER associated with a DM THA was $71 000 per QALY. CONCLUSION/CONCLUSIONS:These results indicate that under specific clinical and economic thresholds, DM components are a cost-effective form of treatment for patients with spinal deformity who are at high risk of dislocation after THA. Cite this article: Bone Joint J 2018;100-B:1297-1302.

Introduction/objectives: The current study aims to add to the paucity of prior studies that have used a state's opioid registry to report detailed perioperative opioid use patterns and the effects of preoperative chronic opioid use among a consecutive cohort of total hip arthroplasty (THA) patients. Methods: A retrospective analysis on 256 consecutive patients who underwent a THA at our institution between February 2016 and June 2016 was performed. Two cohorts were involved in the study: THA patients who were deemed preoperative chronic opioid users and those who were not. Data on patients' opioid use histories 3 months prior to surgery and 6 months following surgery were collected using the state's prescription monitoring program. Variables that were compared between the two groups included baseline characteristics, as well as quality metrics. Results: Of the 256 patients, 54 (21.1%) patients were identified as chronic opioid users. The chronic users had a significantly higher prevalence of private insurance while the non-chronic users had a higher prevalence of worker's compensation insurance (p<0.001). Discharge disposition, value-based purchasing (VBP) costs, length of stay (LOS), emergency room visits, and postoperative office visits were similar between the two cohorts. Readmission rates, 30-day (p=0.031), 90-day (p=0.043), and 6-month (p=0.046), were significantly higher in the chronic opioid users cohort. Conclusion: The current study demonstrates that a substantial proportion of preoperative chronic opioid users continue to consume large amounts of opioids up to 6-months following THA surgery. Furthermore, preoperative chronic use is significantly associated with poorer quality outcomes, specifically with respect to readmission rates

Introduction/objectives: As surgeons, we have a moral obligation to address potentially preventable complications in an effort to improve total hip arthroplasty (THA) outcomes. The goal of this study is to identify and report potentially preventable causes for revision THA (rTHA). Methods: A retrospective review of 352 consecutive patients that underwent rTHA or re-revision THA from August 2015 to August 2017 was conducted. 138 of these were identified as primary to rTHA within a 5 year interval. Two adult reconstruction fellowship trained surgeons reviewed perioperative parameters and classified rTHA recipients into two categories: preventable rTHA and nonpreventable rTHA. Basic demographics, surgical characteristics for the primary THA (pTHA), and pre- and post-rTHA variables were analyzed. Results: Sixty (43.5%) rTHAs were deemed preventable. Of these rTHA recipients, 20 were male and 40 were female. Mean age at time of rTHA was 61.5 years and mean body mass index was 27.8 kg/m2. The following were identified as preventable reasons for rTHA: cup malpositioning (70%), instability (53%), intra-operative fracture (40%), history of spinal surgery/deformity (22%), aseptic loosening (20%), femoral component subsidence (15%), and other (18%). The most common bearing surface during pTHA was cobalt chrome on highly crosslinked polyethylene (40%). The most common femoral head size was 36mm (38%). Technology was used for assistance in 8.3% of pTHAs. Four patients (6.7%) underwent re-revision THA, three for instability and one for aseptic loosening. Conclusion: A high proportion (43.4%) of rTHA is potentially preventable. Furthermore, surgeons are responsible for carefully evaluating causes for rTHA and identifying new methods to address these issues

PURPOSE/OBJECTIVE:Sagittal spinal deformity (SSD) patients utilize pelvic tilt (PT) and their lower extremities in order to compensate for malalignment. This study examines the effect of hip osteoarthritis (OA) on compensatory mechanisms in SSD patients. METHODS:Patients ≥ 18 years with SSD were included for analysis. Spinopelvic, lower extremity, and cervical alignment were assessed on standing full-body stereoradiographs. Hip OA severity was graded by Kellgren-Lawrence scale (0-4). Patients were categorized as limited osteoarthritis (LOA: grade 0-2) and severe osteoarthritis (SOA: grade 3-4). Patients were matched for age and T1-pelvic angle (TPA). Spinopelvic [sagittal vertical axis (SVA), T1-pelvic angle, thoracic kyphosis (TK), pelvic tilt (PT), lumbar lordosis (LL), pelvic incidence minus lumbar lordosis (PI-LL), T1-spinopelvic inclination (T1SPi)] and lower extremity parameters [sacrofemoral angle, knee angle, ankle angle, posterior pelvic shift (P. Shift), global sagittal axis (GSA)] were compared between groups using independent sample t test. RESULTS:136 patients (LOA = 68, SOA = 68) were included in the study. SOA had less pelvic tilt (p = 0.011), thoracic kyphosis (p = 0.007), and higher SVA and T1Spi (p < 0.001) than LOA. SOA had lower sacrofemoral angle (p < 0.001) and ankle angle (p = 0.043), increased P. Shift (p < 0.001) and increased GSA (p < 0.001) compared to LOA. There were no differences in PI-LL, LL, knee angle, or cervical alignment (p > 0.05). CONCLUSIONS:Patients with coexisting spinal malalignment and SOA compensate by pelvic shift and thoracic hypokyphosis rather than PT, likely as a result of limited hip extension secondary to SOA. As a result, SOA had worse global sagittal alignment than their LOA counterparts. These slides can be retrieved under Electronic Supplementary Material.

Introduction/objectives: Cemented dual mobility cups combined with outer porous cups allows for optimal bony purchase by the outer porous metal shell and a more ideal anatomic orientation by the cemented inner dual mobility cup. The purpose of this study is to report on the clinical outcomes of this novel construct. Methods: A retrospective review of a single center's revision THA cases from January 1st, 2016 to July 1st, 2017 was conducted. Patients that received this novel construct were included. Demographic data including age, gender, body mass index (BMI), American Anesthesiology Society (ASA) score, smoking history, and calculated Charlson Comorbidity Index (CCI) was collected. Surgical details including reason for revision THA, time in years from primary THA, outer shell size, dual mobility cup size, and additional fixations was collected. Outcome information on radiographic assessment for implant fixation, infections, re-operations, periprosthetic fractures, and dislocations was collected. Results: Sixteen patients met the inclusion criteria for the study of which 9 were females and 7 were males. The average age at the time of THA was 61.1 years with an average follow-up of 5.9 months. Conclusion: Our study demonstrates encouraging results with the use of this novel construct in preventing instability after THA as evidenced by the absence of any dislocation or implant loosening. Although this study is limited by the lack of long-term follow-up and sample size, our novel construct shows promising short-term results. Moreover, as the majority of dislocations occur within the first 3 months, we believe that this construct may present as a new technique to solve the challenge of recurrent dislocation and instability following revision THA

Introduction/objectives: An understanding of patient characteristics associated with persistent-chronic opioid use after total joint arthroplasty (TJA) will allow surgeons to better manage these patients. Our study aims to identify risk factors among preoperative chronic opioid users who continue to chronically use narcotics after total hip arthroplasty (THA). Methods: A retrospective analysis was performed on 256 THA recipients using the state's mandated opioid monitoring program to identify preoperative chronic opioid users. Chronic users were stratified into two cohorts based on their use 6 months after surgery: 1) persistent-chronic, and 2) previous chronic users. Patient demographics and relevant histories were abstracted and comparatively assessed between the cohorts. In addition, an analysis was performed to calculate which preoperative opioid dose was most predictive of chronic use. Results: Within the study population, 54 patients were identified as preoperative chronic opioid users. Of these, 13 (24.1%) were identified as persistent-chronic users 6 months following surgery. Specific characteristics associated with a higher likelihood of persistent-chronic opioid use included: male gender, ASA score >2, and Medicare as a payer type. A 33 mg/day morphine-equivalent dose consumption prior to surgery was most predictive for persistent chronic opioid use. Conclusion: Our study demonstrates that patients who are male, have an ASA >2, and use Medicare are at greater risk for persistent chronic opioid use. Thus, given the poor outcomes associated with chronic opioid use, these findings may help guide surgeons' clinical decision-making process when encountering patients with a history of opioid use

Introduction/objectives: Routine use of DM may not be a cost-effective measure, but an increasing number of THA candidates have coexisting spinal disorders, substantially increasing their risk for instability. This study seeks to expand our understanding of the cost-effectiveness of dual mobility components as an alternative to standard articulations in this high-risk dislocation population. Methods: A state-transition Markov model with expectedvalue decision analysis was used to evaluate the costeffectiveness of DM cups for high-risk patients who would be at high risk for dislocation within one year of their index THA. Direct and indirect costs of dislocation, incremental DM cost ($1000), quality-adjusted life years (QALY) values and dislocation probabilities were derived from published data. Results: Spine fusion patients were modelled to have a 15% probability of dislocation following primary THA based on published clinical ranges. A hypothetical reduction of 5% in probability of dislocation was deemed clinically plausible with the addition of a DM implant. Under these model parameters, sensitivity analysis was used to identify scenarios for which DM would be cost effective. For example, if the probability of dislocation is 15% with traditional bearings, then the use of DM is cost-effective if it reduces the dislocation risk to 10% and costs less than $640 (Figure 1). However, at its current average selling price ($1000), it would only be cost-effective if it reduces the probability of dislocation from 15% to 7% in this population. Conclusion: Dislocation is a significant complication and spine fusion patients have been shown to be at high risk. Our results indicate that under specific conditions DM cups are cost-effective for this high risk spine fusion population

Introduction/objectives: Diagnosis and treatment of patients with coexisting hip and spine pathologies can be challenging. Patients with sagittal spinopelvic deformity utilize pelvic tilt (PT) and their lower extremities in order to compensate for malalignment. In patients with lower extremity osteoarthritis (OA), these compensatory mechanisms can be compromised, leading to further disability. Methods: Patients > 18 years with SSD [SVA > 50mm, PT > 25degree, or TK > 60degree] were included for analysis. Spinopelvic, lower extremity, and cervical alignment were assessed on standing full-body stereoradiographs. Hip OA severity was graded by Kellgren-Lawrence scale (0-4). Propensity score matching was used to control for age and T1 pelvic angle (TPA). Patients were categorized as limited OA (LOA: grade 0-2) and severe OA (SOA: grade 3-4). Results: A total of 997 patients (LOA=929, SOA=68) were identified meeting inclusion criteria. After PSM, 136 patients (SOA: n=68, LOA n=68) were included in the study. SOA had less PT (17.8degree+/-12.6degree vs 22.6degree+/-8.4degree, p=0.011), TK (42.5degree+/-21.2degree vs 52.3degree+/-20.2degree, p=0.007), higher SVA (71.6 mm+/-47.1 vs 40.7 mm+/-43.9, p<0.001) and T1Spi (+2.3degree+/-6.4degree vs -2.6degree+/-5.5degree, p<0.001) than LOA. SOA also had a lower SFA (194.3degree+/-12.4degree vs 202.4degree+/-9.5degree, p<0.001) and AA (5.9degree+/-3.5degree vs 7.2degree+/-3.6degree, p=0.043), increased P.Shift (49.7mm+/-39.5 vs 19.7mm+/-28.4; p<0.001) and increased GSA (7.7degree+/-4.5degree vs 5.0degree+/-4.0degree, p< 0.001) compared to LOA. There was no difference in PI, PI-LL mismatch, LL, KA or cervical alignment (p >0.05). Conclusion: Patients with coexisting spinal malalignment and severe hip OA compensate by pelvic shift and thoracic hypokyphosis rather than pelvic tilt, likely as a result of limited hip extension