Impact of sugammadex and neostigmine on outcome after major orthopaedic surgery: A population-based analysis

BACKGROUND

Residual neuromuscular blockade after surgery remains a major concern given its association with pulmonary complications. However, current clinical practices with and the comparative impact on perioperative risk of various reversal agents remain understudied.

OBJECTIVE

We investigated the use of sugammadex and neostigmine in the USA, and their impact on postoperative complications by examining national data.

DESIGN

This population-based retrospective study used national Premier Healthcare claims data.

SETTING AND PARTICIPANTS

Patients undergoing total hip/knee arthroplasty (THA, TKA), or lumbar spine fusion surgery between 2016 and 2019 in the United States who received neuromuscular blocking agents.

INTERVENTION

The effects of sugammadex and neostigmine for pharmacologically enhanced reversal were compared with each other and with controls who received no reversal agent.

MAIN OUTCOMES

included pulmonary complications, cardiac complications, and a need for postoperative ventilation. Mixed-effects regression models compared the outcomes between neostigmine, sugammadex, and controls. We report odds ratios (OR) and 95% confidence intervals (CI). Bonferroni-adjusted P values of 0.008 were used to indicate significance.

RESULTS

Among 361 553 patients, 74.5% received either sugammadex (20.7%) or neostigmine (53.8%). Sugammadex use increased from 4.4% in 2016 to 35.4% in 2019, whereas neostigmine use decreased from 64.5% in 2016 to 43.4% in 2019. Sugammadex versus neostigmine or controls was associated with significantly reduced odds for cardiac complications (OR 0.86, 95% CI, 0.80 to 0.92 and OR 0.83, 95% CI, 0.78 to 0.89, respectively). Both sugammadex and neostigmine versus controls were associated with reduced odds for pulmonary complications (OR 0.85, 95% CI, 0.77 to 0.94 and OR 0.91, CI 0.85 to 0.98, respectively). A similar pattern of sugammadex and neostigmine was observed for a reduction in severe pulmonary complications, including the requirement of invasive ventilation (OR 0.54, 95% CI, 0.45 to 0.64 and OR 0.53, 95% CI, 0.46 to 0.6, respectively).

CONCLUSIONS

Population-based data indicate that sugammadex and neostigmine both appear highly effective in reducing the odds of severe life-threatening pulmonary complications. Sugammadex, especially, was associated with reduced odds of cardiac complications.

The impact of multimodal analgesia in coronary artery bypass graft surgery-a population-based analysis

OBJECTIVE

Multimodal pain management aims to concurrently target several pain pathways for improved treatment efficacy and recovery. We investigated associations between multimodal analgesia use and postoperative complications, length of hospital stay (LOS), and opioid consumption among patients undergoing coronary artery bypass graft surgery.

METHODS

This retrospective cohort study included 349,940 adult patients undergoing elective coronary artery bypass graft surgery (January 2006 to December 2019), from the national Premier Healthcare claims dataset. The study intervention was multimodal analgesia, defined as opioid use with the addition of nonopioid analgesic modalities. These included, nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 inhibitors, paracetamol/acetaminophen, neuraxial anesthesia, steroids, gabapentin/pregabalin, and ketamine. Analgesic management was stratified into 4 categories: opioids only and multimodal analgesia with the addition of 1, 2 or ≥3 nonopioid analgesic modalities. Mixed-effects regression models measured associations between multimodal analgesia and postoperative complications, LOS, and opioid consumption measured in milligram oral morphine equivalents.

RESULTS

Multimodal analgesia was associated with a beneficial dose response pattern. With increasing nonopioid analgesic modalities added to opioid analgesia, a stepwise decrease in complication risk was consistently observed, eg, with the addition of 1, 2, or ≥3 nonopioid modalities the odds for any complication decreased by 8% (odds ratio [OR], 0.92; confidence interval [CI], 0.90-0.94), 17% (OR, 0.83; CI, 0.81-0.86), and 22% (OR, 0.78; CI 0.69-0.79), respectively. This stepwise pattern was consistent in respiratory, cardiac, and renal complications individually. Similarly, LOS decreased stepwise with added analgesic modalities.

CONCLUSIONS

These nationally representative data indicate that enhanced pain management by multiple pain pathways is associated with significant reductions in postoperative complications and shortened patient recovery.

The Perioperative Use of Benzodiazepines for Major Orthopedic Surgery in the United States

BACKGROUND

Despite numerous indications for perioperative benzodiazepine use, associated risks may be exacerbated in elderly and comorbid patients. In the absence of national utilization data, we aimed to describe utilization patterns using national claims data from total hip/knee arthroplasty patients (THA/TKA), an increasingly older and vulnerable surgical population.

METHODS

We included data on 1,863,996 TKAs and 985,471 THAs (Premier Healthcare claims data, 2006-2019). Benzodiazepine utilization (stratified by long- and short-acting agents) was assessed by patient- and health care characteristics, and analgesic regimens. Given the large sample size, standardized differences instead of P values were utilized to signify meaningful differences between groups (defined by value >0.1).

RESULTS

Among 1,863,996 TKA and 985,471 THA patients, the utilization rate of benzodiazepines was 80.5% and 76.1%, respectively. In TKA, 72.6% received short-acting benzodiazepines, while 7.9% received long-acting benzodiazepines, utilization rates 68.4% and 7.7% in THA, respectively. Benzodiazepine use was particularly more frequent among younger patients (median age [interquartile range {IQR}]: 66 [60-73]/64 [57-71] among short/long-acting compared to 69 [61-76] among nonusers), White patients (80.6%/85.4% short/long-acting versus 75.7% among nonusers), commercial insurance (36.5%/34.0% short/long-acting versus 29.1% among nonusers), patients receiving neuraxial anesthesia (56.9%/56.5% short/long-acting versus 51.5% among nonusers), small- and medium-sized (≤500 beds) hospitals (68.5% in nonusers, and 74% and 76.7% in short- and long-acting benzodiazepines), and those in the Midwest (24.6%/25.4% short/long-acting versus 16% among nonusers) in TKA; all standardized differences ≥0.1. Similar patterns were observed in THA except for race and comorbidity burden. Notably, among patients with benzodiazepine use, in-hospital postoperative opioid administration (measured in oral morphine equivalents [OMEs]) was substantially higher. This was even more pronounced in patients who received long-acting agents (median OME with no benzodiazepines utilization 192 [IQR, 83-345] vs 256 [IQR, 153-431] with short-acting, and 329 [IQR, 195-540] with long-acting benzodiazepine administration). Benzodiazepine use was also more frequent in patients receiving multimodal analgesia (concurrently 2 or more analgesic modes) and regional anesthesia. Trend analysis showed a persistent high utilization rate of benzodiazepines over the last 14 years.

CONCLUSIONS

Based on a representative sample, 4 of 5 patients undergoing major orthopedic surgery in the United States receive benzodiazepines perioperatively, despite concerns for delirium and delayed postoperative neurocognitive recovery. Notably, benzodiazepine utilization was coupled with substantially increased opioid use, which may project implications for perioperative pain management.

Early failure of an uncemented femoral stem, as compared to two other stems with similar design, following primary total hip arthroplasty performed with direct anterior approach

INTRODUCTION

An increased risk of early femoral component loosening has been reported using the direct anterior approach (DAA) compared with other common surgical approaches. However, long-term data are scarce. The purpose of this study is: (1) to determine the incidence of early femoral loosening in a high volume, single surgeon's practice utilising the DAA approach; and (2) to examine the effect of stem design and type of coating on aseptic loosening in the early and mid-term postoperative period.

METHODS

A retrospective review of 1650 consecutive patients (1800 hips) who underwent total hip arthroplasty (THA) using the DAA between August 2011 and December 2017 was conducted at our institution. 3 types of uncemented femoral stems (Quadra-S, Avenir, TwinSys), with similar design, but different coating, were implanted. Patients were evaluated clinically and radiologically at 4 weeks, 3 months, 1 year, and annually thereafter.

RESULTS

After a mean follow-up of 46.4 months, the total incidence of revision for aseptic loosening was 0.44% (n = 8). All loose stems were Quadra-S, failing to achieve osseointegration, for an overall incidence of 0.96% (p = 0.002). None of the other stems were loose. Radiolucent lines around the proximal stem portion were visible in 75 Quadra-S stems (4.1%) on radiographs taken at 1 year postoperatively and continued to deteriorate at the latest follow-up.

CONCLUSIONS

In this specific cohort of patients, the increased rate of femoral stem aseptic loosening was implant-related and was attributed only to a specific type of femoral stem (Quadra-S). No relation to other factors was proven suggesting that the surface characteristics of this femoral stem and the lack of bioactive coating are responsible for the observed early femoral failures. These findings should be confirmed by additional registry work and larger population sample sizes are needed to evaluate the prosthesis performance after implantation through the DAA.

Low-Dose Perioperative Corticosteroids Can Be Administered Without Additional Morbidity in Patients Undergoing Bilateral Total Knee Replacement: A Retrospective Follow-up Study of a Randomized Controlled Trial

Background: Short-term benefits of perioperative corticosteroid injections (CSIs) for bilateral total knee replacement (BTKR) include suppressed inflammation, improved knee motion, and reduced pain. Very little is known about the long-term benefits, complications, and safety of corticosteroids administered in the perioperative period. Purpose: We sought to compare 3-year follow-up outcomes of BTKR patients who received perioperative CSI with those who received placebo. We hypothesized that there would be no statistically significant differences in functional outcomes or adverse events based on whether or not CSIs were administered in the perioperative period. Methods: We conducted a retrospective review of chart and registry data of BTKR patients from a prior randomized controlled trial to compare outcomes in patients who received hydrocortisone vs placebo injections after BTKR (ClinicalTrials.gov: NCT01399268 and NCT01815918). Outcomes were compared at 6 and 12 weeks and at 1, 2, and 3 years. The Knee Injury and Osteoarthritis Outcome Scores (KOOS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used to evaluate clinical outcomes. Cochran-Mantel-Haenszel tests were used to compare the risk of complications between treatments after adjustment for trial. When possible, summary relative risk estimates were calculated using the Mantel-Haenszel method. Results: No BTKR patients in the treatment group developed an infection. The risk of complications did not increase in patients who received CSI compared with those who received placebo. Patients in the CSI group experienced greater reductions in pain and stiffness, though these results were not statistically significant. There were no statistically significant differences in the KOOS-Symptoms, KOOS-Activities of Daily Living, KOOS-Sports, KOOS-Quality of Life, or WOMAC Function scores. Conclusions: Low-dose corticosteroids can be administered in selected patients who undergo BTKR without increasing the risk of adverse events. At 3-year follow-up, administration of low-dose corticosteroids did not result in superior clinical outcomes scores when compared with placebo.

Do trabecular metal and cancellous titanium implants reduce the risk of late haematogenous infection? An experimental study in rabbits

AIM

This study evaluated the late resistance to haematogenous contamination by microbial pathogens of implants and bone-implant interface and the development of late clinical infection when cementless components with different surface or structural properties are implanted.

MATERIAL AND METHODS

50 adult male New Zealand white rabbits were divided into 5 groups of 10 animals each. In Group A smooth titanium, in Group B grit blasted titanium, in Group C HA-coated titanium, in Group D trabecular metal and in group E cancellous titanium rods were implanted in the right proximal tibia. Four weeks later, 1 ml of inoculum of a standardised CA-MRSA strain (3 × 10⁸ cfu/ml) was injected through a femoral artery catheter (groups B, C, D, E) while in group A, 1 ml of sterile saline was injected in a similar way (control group). Subjects were killed 8 weeks after the initial procedure and 3 samples of each tibial specimen were subjected to conventional cultures and PCR studies.

RESULTS

The number of the specimens (conventional cultures and PCR studies) contaminated by the standardized pathogen was as follows: Group A: 0/10, Group B: 7/10, Group C: 6/10, Group D; 5/10 and Group E: 5/10. Comparing the number of colony form units isolated from the implant samples, Group B (GB titanium) showed statistically significantly higher values (Mann-Whitney test) compared to Group C (p = 0.044), Group D (p = 0.040) and Group E (p = 0.038). Local active infection was observed in 6 animals: 3 in Group B; 1 in Group C, 1 in Group D, and 1 in Group E.

CONCLUSIONS

Modern cementless implants (trabecular metal and cancellous titanium) showed a lower risk of implant contamination and late clinical haematogenous infection.

Bilateral Total Knee Arthroplasty and In-Hospital Opioid Dispension: A Population-Based Study

BACKGROUND

There is paucity of data regarding opioid dispension in patients undergoing bilateral total knee arthroplasty (BTKA). Our aim is to compare in-hospital opioid dispension between BTKA and unilateral TKA (UTKA) and to identify other factors associated with opioid dispension in the BTKA and UTKA cohorts.

METHODS

Patients receiving elective TKA from 2006 to 2016 were retrospectively extracted from the Premier Healthcare Database. The effect of interest was bilateral TKA. Our primary outcome was in-hospital opioid dispension in oral morphine equivalents. Univariable statistics between study variables and TKA type were obtained. A multilevel logistic regression model was run for the outcome of high opioid dispension.

RESULTS

A total of 1,029,120 patients were included. Among these, 14,469 (1.4%) underwent a BTKA. Within the 10-year period studied, there was a decrease in opioid dispension in both groups. Logistic regression analysis showed that patients treated with BTKA had 1.68 times higher odds for high opioid dispension compared to UTKA patients (odds ratio = 1.68; 95.5% confidence interval = 1.62, 1.75; P < .0001). White race, longer length of stay, Charlson/Deyo index, type of insurance, rural location, general anesthesia, peripheral nerve block use, and patient-controlled analgesia were also associated with high opioid dispension. Conversely, a more recent year of surgery, female gender, older age, and administration of nonsteroidal anti-inflammatory drugs and cyclooxygenase-2 inhibitors were associated with lower odds for high opioid dispension.

CONCLUSION

BTKA patients have increased odds for higher in-hospital opioid dispension compared to UTKA recipients. Utilization and prescribing habits should be examined to determine the optimal approach to opioid prescription in BTKA patients compared to UTKA.

Thirty-Day Outcomes After Bilateral Total Hip Arthroplasty in a Nationwide Cohort

Background

Approximately 42% of patients with end-stage osteoarthritis have bilateral disease. Although bilateral total hip arthroplasty (THA) is physiologically demanding, certain patients may benefit from simultaneous rather than staged bilateral procedures. This study examines the intraoperative differences and 30-day outcomes in patients receiving bilateral THA compared with those who underwent unilateral THA.

Methods

Patients undergoing THA were selected from the National Surgical Quality Improvement Program database from 2008 to 2015. Patients were selected according to those with primary and concurrent coding for Current Procedural Terminology 27130. Thirty-day complications were recorded, and multivariate analyses were performed to determine whether concurrent THA was a risk factor for poor outcomes.

Results

A total of 97,804 patients and 587 patients who underwent unilateral and bilateral THA, respectively, were identified. Patients who underwent bilateral procedures were younger (57.3 vs 64.6 years, P < .001), were of lower body mass index (29.2 vs 30.2, P < .001), and had fewer comorbidities than patients who underwent unilateral procedures. Length of stay was not increased for bilateral recipients (3.13 vs 2.93 days, P = .308), although fewer were discharged to home (62.8% vs 77.6%, P < .001). The bilateral recipients required postoperative transfusions at a higher rate (29.8% vs 10.9%, P < .001) and had an increased incidence of deep wound infections on univariate analysis (1.2% vs 0.3%, P = .002). There was no increased risk of superficial infection, medical complications, or thromboembolic events for the bilateral cohort.

Conclusions

Although bilateral THA recipients are younger with fewer preoperative comorbidities, bilateral THA is associated with an increased rate of transfusion in a nationwide setting. With this knowledge, specific interventions should be instituted to target these procedure-specific risks.

Periacetabular osteotomy using an imageless computer-assisted navigation system: a new surgical technique

Periacetabular osteotomy (PAO) is an effective surgical treatment for hip dysplasia. The goal of PAO is to reorient the acetabulum to improve joint stability, lessen contact stresses and slow the development of hip arthrosis. During PAO, the acetabulum is repositioned to adequately cover the femoral head. PAO preserves the weight-bearing posterior column of the pelvis, maintains the acetabular blood supply and retains the hip abductor musculature. The surgical technique needed to perform PAO is technically demanding, with correct repositioning of the acetabulum the most important—and challenging—aspect of the procedure. Imageless navigation has proven useful in other technically challenging surgeries, although its use in PAO has not yet been investigated. We have modified the standard technique for PAO to include the use of an imageless navigation system to confirm acetabular fragment position following osteotomy. Here, we describe the surgical technique and discuss the potential of this modified technique to improve patient-related outcomes.

Surgical approach does not affect deep infection rate after primary total hip arthroplasty

BACKGROUND

There is a concern for higher rates of wound complications and a potentially increased periprosthetic joint infection (PJI) risk after total hip arthroplasty (THA) with the direct anterior approach (DAA) compared to the posterolateral approach (PLA). Our purpose was to compare PJI risk after THA with the DAA or the PLA and to identify risk factors for PJI after primary THA.

METHODS

Clinical characteristics of patients treated in our institution with primary DAA or PLA THA between 1/2010 and 12/2015 were retrospectively reviewed. The respective deep PJI rates were calculated. A logistic regression model was constructed to determine a potential difference in the PJI risk between the 2 groups, and risk factors for hip PJI in all patients.

RESULTS

During the period studied, there were 1,182 DAA THAs and 18,853 PLA THAs. The PJI rate was 0.25% for the DAA group and 0.31% for the PLA group (p = 1.0). The DAA was not associated with a significantly increased risk for PJI compared to the PLA. Compared to younger patients, older patients had lower PJI risk; patient discharge to home was also associated with lower PJI risk compared to other discharge disposition; longer length of stay was associated with higher PJI risk compared to shorter length of stay.

CONCLUSION

The DAA is equally safe compared the PLA with respect to PJI risk. Younger age, discharge to facilities other than home and increased length of stay increase the risk for deep PJI after primary THA.

Same-Day Surgery Does Not Increase the Manipulation Under Anesthesia and Reoperation Rates for Stiffness Following Bilateral Total Knee Arthroplasty

BACKGROUND

There is a paucity of data on the incidence of stiffness and need for subsequent manipulation under anesthesia (MUA) and reoperation following same-day bilateral total knee arthroplasty (BTKA). We compared the rates of at least 1 MUA, bilateral knee involvement, single and multiple MUA rates, and stiffness-related reoperation rates between patients undergoing same-day, same-admission staged, and staged within 1 year BTKA in a tertiary institution.

METHODS

We analyzed institutional data for 3175 same-day (group A), 153 same-admission staged (group B), and 1226 staged within 1 year BTKA patients (group C) from 1998 to 2009. Several variables, including patient demographics, comorbidity profile, Charlson-Deyo index, and range of motion at different time points, were tabulated. Follow-up was minimum 1 year after first MUA. Univariate analyses were performed using the Wilcoxon rank-sum or Kruskal-Wallis test, and Fisher exact or the chi-square test for continuous and categorical variables, respectively. The Cochran-Armitage trend test was used to check the bilateral knee involvement rate across groups.

RESULTS

Overall, 2.2% (98/4554) of BTKA patients required MUA. The rate of at least 1 MUA was similar across groups but the percentage of bilateral knee involvement was higher in group A. The single MUA rate was comparable among groups. Both no revision and revision reoperation rates were similar among the manipulated groups.

CONCLUSION

Same-day BTKA was not associated with increased incidence of single or multiple MUA and stiffness-related reoperation rates. These findings may facilitate preoperative counseling in patients with symptomatic bilateral knee disease, eligible for same-day BTKA.

Anaesthetic care of patients undergoing primary hip and knee arthroplasty: consensus recommendations from the International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) based on a systematic review and meta-analysis

BACKGROUND

Evidence-based international expert consensus regarding anaesthetic practice in hip/knee arthroplasty surgery is needed for improved healthcare outcomes.

METHODS

The International Consensus on Anaesthesia-Related Outcomes after Surgery group (ICAROS) systematic review, including randomised controlled and observational studies comparing neuraxial to general anaesthesia regarding major complications, including mortality, cardiac, pulmonary, gastrointestinal, renal, genitourinary, thromboembolic, neurological, infectious, and bleeding complications. Medline, PubMed, Embase, and Cochrane Library including Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, NHS Economic Evaluation Database, from 1946 to May 17, 2018 were queried. Meta-analysis and Grading of Recommendations Assessment, Development and Evaluation approach was utilised to assess evidence quality and to develop recommendations.

RESULTS

The analysis of 94 studies revealed that neuraxial anaesthesia was associated with lower odds or no difference in virtually all reported complications, except for urinary retention. Excerpt of complications for neuraxial vs general anaesthesia in hip/knee arthroplasty, respectively: mortality odds ratio (OR): 0.67, 95% confidence interval (CI): 0.57-0.80/OR: 0.83, 95% CI: 0.60-1.15; pulmonary OR: 0.65, 95% CI: 0.52-0.80/OR: 0.69, 95% CI: 0.58-0.81; acute renal failure OR: 0.69, 95% CI: 0.59-0.81/OR: 0.73, 95% CI: 0.65-0.82; deep venous thrombosis OR: 0.52, 95% CI: 0.42-0.65/OR: 0.77, 95% CI: 0.64-0.93; infections OR: 0.73, 95% CI: 0.67-0.79/OR: 0.80, 95% CI: 0.76-0.85; and blood transfusion OR: 0.85, 95% CI: 0.82-0.89/OR: 0.84, 95% CI: 0.82-0.87.

CONCLUSIONS

Recommendation: primary neuraxial anaesthesia is preferred for knee arthroplasty, given several positive postoperative outcome benefits; evidence level: low, weak recommendation.

RECOMMENDATION

neuraxial anaesthesia is recommended for hip arthroplasty given associated outcome benefits; evidence level: moderate-low, strong recommendation. Based on current evidence, the consensus group recommends neuraxial over general anaesthesia for hip/knee arthroplasty.

TRIAL REGISTRY NUMBER

PROSPERO CRD42018099935.

Nonmodular Stems Are a Viable Alternative to Modular Stems in Revision Total Hip Arthroplasty

BACKGROUND

Nonmodular and modular femoral stems have been associated with complications after revision total hip arthroplasty (rTHA). As such, the ideal femoral component for rTHA remains undecided. This study aims to report outcomes of titanium, tapered-fluted, modular and nonmodular femoral components in rTHA.

METHODS

From January 1, 2013 to September 30, 2017, all rTHAs using modular or nonmodular femoral stems were identified. Demographic data including age, gender, and American Society of Anesthesiologists scores were collected. Surgical details including operative time and implant cost were also collected. Clinical outcomes including length of stay, dislocation, infection, fracture, reoperation, and re-revision were collected. Statistical analysis was performed using chi-square test and Student's t-test for all categorical and continuous variables, respectively.

RESULTS

One hundred forty-six rTHA cases (103 modular and 43 nonmodular) were identified with an average follow-up of 29 months (range 3-59 months). Nonmodular stems had a significantly lower cost when compared to modular implants (modular stems 120.8% higher cost; P < .001). The surgical time of nonmodular components was significantly greater (193 minutes vs 163 minutes; P = .029). There were no differences observed in any other surgical details or clinical outcomes assessed, including length of stay (P = .323), rate of re-revision of the femoral implant (P = .389), rate of re-operation (P = .383), and postop complications (P = .241), including infection (P = .095), dislocation (P = .778), and fracture (P = .959).

CONCLUSIONS

Nonmodular components provide encouraging clinical results with significantly lower costs compared to modular implants in rTHA. The use of titanium, tapered-fluted, nonmodular components may offer a more cost-effective approach to rTHA compared to their modular counterparts.

Perioperative impact of sleep apnea in a high-volume specialty practice with a strong focus on regional anesthesia: a database analysis

Background and objectives

Obstructive sleep apnea (OSA) is a risk factor for adverse postoperative outcome and perioperative professional societies recommend the use of regional anesthesia to minimize perioperative detriment. We studied the impact of OSA on postoperative complications in a high-volume orthopedic surgery practice, with a strong focus on regional anesthesia.

Methods

After Institutional Review Board approval, 41 766 cases of primary total hip and knee arthroplasties (THAs/TKAs) from 2005 to 2014 were extracted from institutional data of the Hospital for Special Surgery (approximately 5000 THAs and 5000 TKAs annually, of which around 90% under neuraxial anesthesia).

The main effect was OSA (identified by the International Classification of Diseases, ninth revision codes); outcomes of interest were cardiac, pulmonary, gastrointestinal, renal/genitourinary, thromboembolic complications, delirium, and prolonged length of stay (LOS). Multivariable logistic regression models provided ORs, corresponding 95% CIs, and p values.

Results

Overall, OSA was seen in 6.3% (n=1332) of patients with THA and 9.1% (n=1896) of patients with TKA. After adjustment for relevant covariates, OSA was significantly associated with 87% (OR 1.87, 95% CI 1.51 to 2.30), 52% (OR 1.52, 95% CI 1.13 to 2.04), and 44% (OR 1.44,95% CI 1.31 to 1.57) increased odds for pulmonary gastrointestinal complications, and prolonged LOS, respectively. The odds for other outcomes remained unaltered by OSA diagnosis.

Conclusion

We showed that, even in a setting with almost universal regional anesthesia use, OSA was associated with increased odds for prolonged LOS, and pulmonary and gastrointestinal complications. This puts forward the question of how effective regional anesthesia is in mitigating postoperative complications in patients with OSA.

In-Hospital Morbidity and Postoperative Revisions After Direct Anterior vs Posterior Total Hip Arthroplasty

BACKGROUND

The direct anterior approach (DAA) offers the potential for less soft tissue insult, improved early recovery, and reduced dislocation rates. However, complications are associated with the DAA, particularly during the learning curve. We compare the DAA learning curve experience with the posterior approach regarding in-hospital complications and revision rate.

METHODS

We evaluated systemic and local in-hospital complications associated with primary unilateral cementless THAs from January 1, 2010 to December 31, 2012 in 4249 patients through a posterior approach and 289 patients through a DAA. All procedures were performed consecutively by high-volume surgeons who use a single approach in a nonselective manner. The DAA was performed by surgeon transitioning from the posterior approach, thus incorporating the learning curve. Demographics were comparable. Revision procedures were captured through a minimum 4-year follow-up. Analyses compared complication and revision rates.

RESULTS

The DAA group demonstrated shorter length of stay, procedure time, lower blood transfusion rate, and increased discharge to home rate. Local and major systemic in-hospital complications were rare and comparable between groups. The minor systemic complication rate was significantly greater for the posterior group (10.9% posterior vs 6.2% DAA, P < .05). Revision rate was significantly greater for the posterior group (2.7% posterior vs 0.7% DAA, P < .032). The incidence of revision for dislocation was 1.5% for the posterior approach vs 0.4% for the DAA.

CONCLUSION

There was an increased rate of in-hospital minor systemic complications and overall revision, predominantly due to instability, after THA by the posterior approach, in comparison with the DAA.

Rate and Risk Factors for Periprosthetic Joint Infection Among 36,494 Primary Total Hip Arthroplasties

BACKGROUND

As periprosthetic joint infections (PJIs) can have tremendous health and socioeconomic implications, recognizing patients at risk before surgery is of great importance. Therefore, we sought to determine the rate of and risk factors for deep PJI in patients undergoing primary total hip arthroplasty (THA).

METHODS

Clinical characteristics of patients treated with primary THA between January 1999 and December 2013 were retrospectively reviewed. These included patient demographics, comorbidities (including the Charlson/Deyo comorbidity index), length of stay, primary diagnosis, total/allogeneic transfusion rate, and in-hospital complications, which were grouped into local and systemic (minor and major). We determined the overall deep PJI rate, as well as the rates for early-onset (occurring within 2 years after index surgery) and late-onset PJI (occurring more than 2 years after surgery). A Cox proportional hazards regression model was constructed to identify risk factors for developing deep PJI. Significance level was set at 0.05.

RESULTS

A deep PJI developed in 154 of 36,494 primary THAs (0.4%) during the study period. Early onset PJI was found in 122 patients (0.3%), whereas late PJI occurred in 32 patients (0.1%). Obesity, coronary artery disease, and pulmonary hypertension were identified as independent risk factors for deep PJI after primary THA.

CONCLUSION

The rate of deep PJIs of the hip is relatively low, with the majority occurring within 2 years after THA. If the optimization of modifiable risk factors before THA can reduce the rate of this complication remains unknown, but should be attempted as part of good practice.

Perioperative Morbidity of Same-Day and Staged Bilateral Total Hip Arthroplasty

BACKGROUND

Management strategies for bilateral hip degenerative disease include same-day or staged bilateral total hip arthroplasty (THA), but information on outcomes remains sparse. We sought to describe in-hospital complications and blood transfusion rates after same-day and staged bilateral THAs at different time intervals and to assess risk factors for these events.

METHODS

We retrospectively reviewed administrative data for 3785 patients treated with same-day bilateral (n = 1946; group A) and staged bilateral THA within (1) 0-3 months apart (n = 328; group B); (2) 3-6 months apart (n = 703; group C); and (3) 6-12 months apart (n = 808; group D), between 1999 and 2014. We recorded demographics, the Charlson-Deyo comorbidity index and in-hospital local and systemic (minor and major) complications. Complication and blood transfusion rates among groups were compared. A logistic regression model was developed to identify risk factors for major complications.

RESULTS

Local complications were rare. Minor complications were less frequent in group A (P < .001). Major complications were more frequent in group D (P = .012). Group A had higher overall (P < .001) and allogeneic blood transfusion rates (P < .001) compared with the staged groups. Staged procedures within 6-12 months apart vs same-day bilateral THA, older age, Charlson-Deyo index ≥2 vs 0, and earlier vs recent admission year were associated with higher adjusted odds for major complications.

CONCLUSION

Same-day bilateral THA in a high-volume joint replacement center may be a safe option for younger and healthier patients, given the relatively low incidence of adverse events reported in this study.

Dislocation following total hip arthroplasty using dual mobility acetabular components: a systematic review

AIMS

The aim of this systematic review was to report the rate of dislocation following the use of dual mobility (DM) acetabular components in primary and revision total hip arthroplasty (THA).

MATERIALS AND METHODS

A systematic review of the literature according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines was performed. A comprehensive search of Pubmed/Medline, Cochrane Library and Embase (Scopus) was conducted for English articles between January 1974 and March 2016 using various combinations of the keywords "dual mobility", "dual-mobility", "tripolar", "double-mobility", "double mobility", "hip", "cup", "socket". The following data were extracted by two investigators independently: demographics, whether the operation was a primary or revision THA, length of follow-up, the design of the components, diameter of the femoral head, and type of fixation of the acetabular component.

RESULTS

In all, 59 articles met our inclusion criteria. These included a total of 17 908 THAs which were divided into two groups: studies dealing with DM components in primary THA and those dealing with these components in revision THA. The mean rate of dislocation was 0.9% in the primary THA group, and 3.0% in the revision THA group. The mean rate of intraprosthetic dislocation was 0.7% in primary and 1.3% in revision THAs.

CONCLUSION

Based on the current data, the use of DM acetabular components are effective in minimising the risk of instability after both primary and revision THA. This benefit must be balanced against continuing concerns about the additional modularity, and the new mode of failure of intraprosthetic dislocation. Longer term studies are needed to assess the function of these newer materials compared with previous generations. Cite this article: Bone Joint J 2017;99-B(1 Supple A):18-24.

Periprosthetic Infection Recurrence After 2-Stage Exchange Arthroplasty: Failure or Fate?

BACKGROUND

Two-stage exchange arthroplasty remains the preferred method for treating a chronic periprosthetic joint infection (PJI) in North America. However, infection recurrence may occur. Previously, recurrent infections have been classified as persistent (same isolated pathogen) or new (different pathogen identified). We sought to determine (1) recurrence rates among patients with chronic hip and knee PJI, treated with 2-stage exchange arthroplasty; (2) risk factors for infection recurrence; and (3) risk factors for developing persistent vs new infection.

METHODS

We retrospectively reviewed clinical characteristics of patients with chronic hip and knee PJI, treated with 2-stage revision between January 1998 and March 2014. Minimum follow-up was 24 months. Two multivariate logistic regression models were constructed to determine independent predictors for infection recurrence and persistence.

RESULTS

In total, 548 patients were identified (283 men, 265 women). Forty-eight had a recurrent infection (8.76%). Men had 54.8% lower odds of PJI recurrence than women (odds ratio [OR] = 0.452; 95% confidence interval [CI], 0.235-0.869). Patients with heart disease had 109% higher odds of infection recurrence than patients without heart disease (OR = 2.09; 95% CI, 1.097-3.081). The risk of infection recurrence was 119% higher in patients with psychiatric disorders than in patients without psychiatric disorders (OR = 2.19; 95% CI, 1.011-4.761). Patients with recurrent knee PJI had 84.6% lower odds of persistent infection (OR = 0.154; 95% CI, 0.034-0.696) compared to hip PJI. Patients with heart disease had 5-fold increased odds for persistent PJI (OR = 5.068; 95% CI, 1.38-22.56).

CONCLUSION

Female gender, heart disease, and psychiatric disorders increase the risk of hip and knee PJI recurrence. Patients with PJI of the hip and with heart disease are at higher risk of infection persistence.

Total Knee Arthroplasty Using Cementless Porous Tantalum Monoblock Tibial Component: A Minimum 10-Year Follow-Up

BACKGROUND

Cementless fixation in total knee arthroplasty (TKA) was introduced to improve the longevity of implants but has yet to be widely adopted because of reports of higher failure rates in some series. The cementless tantalum monoblock tibial component, in contrast, has shown successful short-term results, but long-term survivorship with this design is still lacking. The purpose of this study was to investigate the minimum 10-year clinical and radiographic results of the cementless tantalum monoblock tibial component in primary TKA.

METHODS

From March 2002 to March 2005, 33 patients (33 knees) underwent primary TKA with a cementless tantalum monoblock tibial component. All patients were followed clinically and radiographically for a minimum of 10 years (mean 11.5 years, range 10-13 years). No patients were lost to follow-up. The underlying diagnosis that led to the primary TKA was primary osteoarthritis in 31 knees and post-traumatic osteoarthritis in 2 knees.

RESULTS

None of the components was revised. At a minimum 10-year follow-up, the survivorship with reoperation for any reason as end point was 96.9%. With tibial component revision for aseptic loosening or osteolysis as the end point survivorship was 100%. There was no radiographic evidence of tibial component loosening, subsidence, osteolysis, or migration at the time of the latest follow-up. The mean Knee Society knee scores improved from 56 points preoperatively to 93 points at the last clinical visit.

CONCLUSION

The porous tantalum tibial monoblock component demonstrated excellent clinical and radiographic outcomes with no component revisions for aseptic loosening at a minimum follow-up of 10 years.

Risk Assessment for Chronic Pain and Patient Satisfaction After Total Knee Arthroplasty

The estimated prevalence of patients who report minor or no improvement of their symptoms and pain after total knee arthroplasty (TKA) remains high, ranging from 5% to 40%. The authors sought to determine whether chronic pain and functional health are related to specific variations in demographic data, surgical techniques, or radiographic pre- and postoperative findings. They also sought to identify independent risk factors for persistent moderate-to-severe chronic pain after TKA. A total of 273 patients who underwent primary TKA from October 2007 to March 2010 with a minimum follow-up of 1 year were identified from electronic medical records. A questionnaire to identify persistent postoperative pain (36-item Short Form Health Survey [SF-36]) was mailed to these patients. Linear regression and logistic regression were used to identify predictors for SF-36 and chronic pain, respectively. Thirty-nine percent of patients reported persistent pain after TKA, with a median average pain score of 3 out of 10 and worst pain score of 5 out of 10. Independent risk factors for persistent pain are the length of the operative procedure (odds ratio [OR]=1.013), medical history of diabetes mellitus (OR=0.430), presence of preoperative flexion contracture (OR=1.089), and patellofemoral joint overstuffing (OR=0.915). Persistent postoperative pain is a common finding after TKA. Nonmodifiable risk factors could be used for risk stratification, whereas modifiable risk factors could be used as a clinical guidance for modification of some aspects of existing surgical techniques.

Implant retention after acute and hematogenous periprosthetic hip and knee infections: Whom, when and how?

Periprosthetic joint infections (PJI) of the hip and the knee are grossly classified as early post-operative, acute hematogenous and late chronic infections. Whereas two-stage exchange arthroplasty is the standard of care in North America for treating chronic infections, irrigation and debridement (I and D) with retention of implants has been used in an attempt to treat the other two types of PJIs. The rationale of this approach is that a PJI may be eradicated without the need of explanting the prostheses, as long as it has not transitioned into a chronic state. With the present paper, we review current evidence regarding the role of I and D with implant retention for treating PJIs of the hip and the knee. While a very wide range of success rates is reported in different studies, a short period of time between initiation of symptoms and intervention seems to play a prominent role with regards to a successful outcome. Moreover, pathogens of higher virulence and resistance to antibiotics are associated with a poorer result. Specific comorbidities have been also correlated with a less favorable outcome. Finally, one should proceed with serial I and Ds only under the condition that a predefined, aggressive protocol is applied. In conclusion, when treating a PJI of the hip or the knee, all the above factors should be considered in order to decide whether the patient is likely to benefit from this approach.

Same-Day Surgery Does Not Increase Deep Infection Risk in Bilateral Total Hip Arthroplasty Patients

BACKGROUND

Patients with bilateral hip disease may undergo same-day or staged bilateral total hip arthroplasty (THA). Our purpose was to compare the odds and identify risk factors for deep periprosthetic joint infection (PJI) among patients undergoing same-day vs staged bilateral THA (within 1 year or more than 1 year apart).

METHODS

Administrative data for patients subjected to same-day and staged bilateral THA between January 1999 and December 2013 were retrieved. Patients with subsequent PJI were identified. Mean follow-up was 112.6 months (range, 23-201). A logistic regression model was constructed to determine differences in odds for infection between groups and risk factors for PJI.

RESULTS

We identified 1808 patients treated with same-day bilateral THA, 2082 patients treated with staged THAs within 1 year, and 2760 patients treated with staged THAs more than 1 year apart. Patients treated with same-day procedures had similar odds for PJI compared to those treated with staged THAs within 1 year (odds ratio [OR] = 0.632, 95% confidence interval [CI] [0.203, 1.962]), or more than 1 year apart (OR = 1.391, 95% CI [0.516, 3.746]). Women had 66.1% lower odds for PJI than men (OR = 0.339, 95% CI [0.16, 0.72]). Patients with inflammatory arthritis had 632% higher odds for PJI than patients with degenerative arthritis (OR = 7.321, 95% CI [1.912, 28.028]). Allogeneic transfusion was associated with 166% higher odds for PJI (OR = 2.661, 95% CI [1.198, 5.911]).

CONCLUSION

Same-day bilateral THA is not associated with increased odds for PJI compared to staged procedures. Male gender, inflammatory etiology, and allogeneic transfusion are significant risk factors for PJI in patients undergoing same-day or staged bilateral THA.

Multiple Irrigation and Debridements for Periprosthetic Joint Infections: Facing a Necessity or Just Prolonging the Inevitable?

Irrigation and debridement (I&D) may be a viable option in selected cases of periprosthetic joint infections (PJI). Our aim was to investigate the role of multiple I&Ds. Among 141 patients with PJI treated with I&D in our institution, 19 were subjected to additional procedures. Their clinical characteristics were retrospectively reviewed and compared to the remaining patients treated with a single I&D. The probability of treatment failure (removal of implants) was not significantly different among the two groups. The interval between serial I&Ds was a significant factor determining outcomes. Patients treated with multiple I&Ds had a significantly higher prevalence of peripheral vascular disease. The decision to proceed with repeat of I&D should be made with caution.

Medial Unicondylar Knee Arthroplasty Improves Patellofemoral Congruence: a Possible Mechanistic Explanation for Poor Association Between Patellofemoral Degeneration and Clinical Outcome

The purpose was to determine the effect of medial fixed bearing unicondylar knee arthroplasty (UKA) on postoperative patellofemoral joint (PFJ) congruence and analyze the relationship of preoperative PFJ degeneration on clinical outcome. We retrospectively reviewed 110 patients (113 knees) who underwent medial UKA. Radiographs were evaluated to ascertain PFJ degenerative changes and congruence. Clinical outcomes were assessed preoperatively and postoperatively. The postoperative absolute patellar congruence angle (10.05 ± 10.28) was significantly improved compared with the preoperative value (14.23 ± 11.22) (P = 0.0038). No correlation was found between preoperative PFJ congruence or degeneration severity, and WOMAC scores at two-year follow up. Pre-operative PFJ congruence and degenerative changes do not affect UKA clinical outcomes. This finding may be explained by the post-op PFJ congruence improvement.

Risk Factors for Recurrence of Periprosthetic Knee Infection

We retrospectively reviewed 110 patients who underwent two-stage revision surgery in order to identify potential risk factors for recurrence of periprosthetic infection. We found that patients with inflammatory arthritis (P=0.0125), perioperative hematoma formation (P=0.0422), wound dehiscence (P=0.042), and those who are chronic Staphylococcus carriers (P=0.0177) were associated with an increased incidence of re-infection. The duration of intravenous antibiotic therapy less than 6 weeks was associated with a reduced risk of reinfection to greater than 6 weeks (P=0.03). Multivariate analysis indicated that wound dehiscence (odds ratio [OR], 5.119; 95% confidence interval [CI], 1.367-19.17), and Staphylococcus carriers (OR, 11.419; 95% CI, 1.376-94.727) are significant predictors of recurrence (P=0.0153 and 0.0241, respectively).

Irrigation and debridement for periprosthetic infections of the hip and factors determining outcome

PURPOSE

Our purpose was to identify the success rate and factors predicting outcome of irrigation and debridement (I&D) in patients with deep periprosthetic joint infection (PJI) of the hip.

METHODS

We retrospectively reviewed clinical characteristics of patients with deep PJI after primary/revision total hip arthroplasty (THA) between January 2000 and May 2013 treated with I&D. Implant retention was the outcome of interest. Sixty patients (29 men and 31 women; mean age 64.9 years) were identified. Mean follow-up was 59 months (range, 12-168).

RESULTS

The implants were retained in 42 patients (70%). Failure of I&D treatment correlated with duration of symptoms >five days (p <0.001) and obesity [body mass index (BMI) ≥ 30)] (p = 0.0289). Treatment outcome was affected by the type of pathogen (p = 0.0482), with patients with methicillin-resistant staphylococci having significantly lower odds of success.

CONCLUSIONS

I&D can be a feasible option in THA patients presenting with acute deep PJI. Duration of symptoms >five days, isolation of methicillin-resistant staphylococci and obesity should be taken into consideration in pre-operative decision making.

Perioperative morbidity and mortality of same-admission staged bilateral TKA

BACKGROUND

Controversy continues regarding the optimal timing of surgery for patients with symptomatic bilateral degenerative knee arthritis who are not considered eligible for same-day bilateral TKA (BTKA).

QUESTIONS/PURPOSES

We compared (1) 30-day mortality; (2) rates of in-hospital complications; and (3) blood transfusion rates between patients undergoing same-admission staged BTKA and patients undergoing BTKA staged within 1 year in a highly specialized center where specific guidelines have been implemented for same-day BTKA patient selection.

METHODS

We analyzed institutional data for 149 patients undergoing same-admission staged and 1557 patients undergoing staged BTKA diagnosed with bilateral knee idiopathic osteoarthritis from 1998 to 2011. Although patients in both groups presented with bilateral knee disease, same-admission staged patients had more medical comorbidities and did not qualify for same-day BTKA. Specifically, patients with coronary artery disease with inducible ischemia, congestive heart failure, advanced chronic obstructive pulmonary disease, uncontrolled diabetes, peripheral vascular disease, renal failure, morbid obesity, history of venous thromboembolism, or those who were older than 75 years were not considered eligible for same-day BTKA. Patient demographics and Deyo comorbidity index were tabulated. The groups were similar in age, but same-admission staged patients were more likely to be male and had a higher overall comorbidity burden. The complications were categorized into systemic (medical) and local (orthopaedic). Furthermore, the systemic complications were subcategorized into major (required complex surgical or medical intervention or were deemed life-threatening) and minor (necessitated additional observation or required medical treatment), depending on their severity. Regression models were conducted to examine the association between surgery type and development of complications.

RESULTS

There was no difference in 30-day mortality between the groups (0% versus 0.06%; p=0.754). There was no difference in the local complication rates (0.7% versus 0.8%; p=1.000). However, multivariable regression analysis adjusting for age, sex, and Deyo comorbidity index showed that same-admission staged patients were three and two times more likely than staged to develop a minor (odds ratio [OR], 3.02; 95% confidence interval [CI], 1.25-3.25; p=0.004) and major (OR, 2.02; 95% CI, 2.09-4.37; p<0.001) complication, respectively. The same-admission group experienced more acute postoperative anemia (11% versus 3%; p<0.001) and blood transfusions (93% versus 54%; p<0.001).

CONCLUSIONS

These results suggest that patients who are not appropriate candidates for same-day BTKA as a result of increased overall comorbidity burden may be better served by undergoing staged BTKA within 1 year rather than same-admission staged because of the associated higher perioperative morbidity observed in the same-admission BTKA group.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Trends in same-day bilateral total knee arthroplasty

Between 2000 and 2009 demographics, comorbidity, complications, and 30-day mortality following same-day BTKA (SBTKA) in two high-volume institutions were obtained. Two 5-year periods were created to facilitate trend analysis. The percentage of SBTKA decreased by 36.2% in the latter period. A decline in mean age reflected mainly by a 50% decrease in patients >75 years was observed. The average LOS decreased (5.7 vs. 4.5 days). Overall, selected patients were healthier in the second period. The prevalence of CAD and obesity decreased, whereas hypercholesteremia increased. The overall complication rate decreased by 55.5%; reduction in cardiac adverse events and acute posthemorrhagic anemia was observed. The rate of PE and 30-day mortality was unchanged with time. A need for more selective preoperative screening for potential candidates of SBTKAs is indicated.

Infection following simultaneous bilateral total knee arthroplasty

Between 2000 and 2009, demographics, clinical characteristics, and infection details were compared among patients undergoing simultaneous BTKA (SBTKA), staged or UTKA. 2825 (16%) patients underwent SB, 1151 (6%) staged, and 13,983 (78%) UTKA. The overall infection rate following SBTKA (0.57%) was lower compared to staged (1.39%) or UTKA (1.1%) (P=0.01). The in-hospital infection rate was lower for the SB group (0.28% vs. 0.96% vs. 0.69%, respectively, P=0.01). The rate of late infections was comparable between the groups (0.32% vs. 0.43% vs. 0.43%, respectively, P=0.72). The rate of superficial infection was lower in the simultaneous cohort (0.28% vs. 1.04% vs. 0.87%; P=0.003). The overall rate of deep infection and reoperation for infection was similar among the groups. Among patients with late infection, age, gender, comorbidity score, time to infection, and most common organism isolated were not significantly different between the groups. Among infected patients after SB or staged TKA, 3 SB patients (18.75%), and 3 staged (20%) had bilateral involvement (P=1.0). Staged patients had more 2nd side infections, while simultaneous patients had more 1st side infections (P=0.02). Regression analysis showed that UTKA patients were 2.5 times more likely to develop in-hospital infection compared to SBTKA, while staged patients were almost 3.4 times more likely. Each additional hospital day increased the risk of late infection by 11.3%. SBTKA demonstrates an advantage over staged and maintains the safety profile of unilateral approaches with respect to infectious complications.

In-hospital surgical site infections after primary hip and knee arthroplasty--incidence and risk factors

Data of hospitalizations for THA or TKA were analyzed for each year between 1998 and 2007 from the National Inpatient Sample. Demographics, comorbidities, incidence of morbidity and mortality, length of hospital stay (LOS), and overall cost were compared for infected and non-infected patients. Perioperative SSI rates were 0.36% for THA and 0.31% for TKA (412,356 and 784,335 patient entries, respectively). Patients with SSI had a significantly higher overall comorbidity burden, higher perioperative mortality rates, longer length of stay, and higher complication rates. Average cost of in-hospital care was double for SSI versus non-SSI patients. Independent risk factors for perioperative SSI included male gender, minority race, a diagnosis for cancer, liver disease, coagulopathies, fluid and electrolyte disorders, congestive heart failure, and pulmonary circulatory disease. Data relied on coded information and could not differentiate between superficial or deep infection, or capture patients readmitted for SSI, and therefore may have underestimated the true incidence of SSI.

Ten- to 15-year clinical and radiographic results for a compression molded monoblock elliptical acetabular component

The aim of this study was to report the long-term results from a previously published midterm follow-up of a titanium monoblock, elliptical acetabular component. A total of 258 primary total hip arthroplasties (212 patients) with a monoblock, acetabular component were followed up for a mean period of 11.1 years (10-15). Average yearly wear rate was 0.08 mm/y (0.0009-0.32). Acetabular radiolucencies were present in 6 hips (2.4%); all were nonprogressive and present in acetabular zone I. Acetabular osteolysis was present in 5 patients (5 hips, 1.9%); all cups were stable. Four acetabular components were revised, 3 because of recurrent instability. No acetabular components were revised for polyethylene wear or dissociation, acetabular osteolysis, loosening, or deep infection. This monoblock design demonstrates excellent long-term survival and low rate of osteolysis.

An algorithmic approach to mechanical hip pain

BACKGROUND

As our understanding of hip pathology evolves, the focus is shifting toward earlier identification of hip pathology. Therefore, it is vitally important to elucidate intra-articular versus extra-articular pathology of hip pain in every step of the patient encounter: history, physical examination, and imaging.

QUESTIONS/PURPOSES

The objective was to address the following research questions: (1) Can an algorithmic approach to physical examination of a painful non-arthritic hip provide a more accurate diagnosis and improved treatment plan? (2) Does an anatomical layered concept of clinical diagnosis improve diagnostic accuracy? (3) What are the diagnostic tools necessary for the accurate application of a four-layer (osteochondral, inert, contractile, and neuromechanical) diagnosis?

METHODS

An unrestricted computerized search of MEDLINE was conducted. Different terms were used in various combinations.

RESULTS

An algorithmic approach to physical examination of a painful nonarthritic hip, including history, physical examination (specific tests), and advanced imaging allow for better interpretation of debilitating intra- and extra-articular disorders and their effect on core performance. Additionally, it improves our understanding as to how underlying abnormal joint mechanics may predispose the hip joint and the associated hemipelvis to asymmetric loads. These abnormal joint kinematics (layer I) can lead to cartilage and labral injury (layer II), as well as resultant injury to the musculotendinous (layer III) and neural structures (layer IV) about the hip joint and the hemipelvis. The layer concept is a systematic means of determining which structures about the hip are the source of hip pathology and how to best implement treatment.

CONCLUSIONS

A clear understanding of the differential diagnosis of hip pain through a detailed and systematic physical examination, diagnostic imaging assessment, and the interpretation of how mechanical factors can result in such a wide range of compensatory injury patterns about the hip can facilitate the diagnosis and treatment recommendations.

Change in preoperative expectations in patients undergoing staged bilateral primary total knee or total hip arthroplasty

The objective of this study was to compare preoperative expectation scores between stages in patients with bilateral total knee arthroplasty (TKA) and total hip arthroplasty (THA) using intraclass correlation coefficients (ICCs). For patients with TKA (57), ICC was 0.449, indicating fair agreement between stages; expectations did not change for 31% of patients, whereas 40% had higher and 29% had lower expectations. For patients with THA (55), ICC was 0.663, indicating moderate agreement; expectations did not change for 42% of patients, whereas 38% had higher and 20% had lower expectations. In multivariable analyses controlling for first expectation score, second expectation score was associated with better Western Ontario McMaster Universities Osteoarthritis Index stiffness score for TKA and with worse Western Ontario McMaster Universities Osteoarthritis Index function score for patients with THA. For most patients, expectations changed between staged bilateral TKA and THA, but the direction of change was not uniform.

Meta-analysis of cause of death following total joint replacement using different thromboprophylaxis regimens

We performed a meta-analysis of modern total joint replacement (TJR) to determine the post-operative mortality and the cause of death using different thromboprophylactic regimens as follows: 1) no routine chemothromboprophylaxis (NRC); 2) Potent anticoagulation (PA) (unfractionated or low-molecular-weight heparin, ximelagatran, fondaparinux or rivaroxaban); 3) Potent anticoagulation combined (PAC) with regional anaesthesia and/or pneumatic compression devices (PCDs); 4) Warfarin (W); 5) Warfarin combined (WAC) with regional anaesthesia and/or PCD; and 6) Multimodal (MM) prophylaxis, including regional anaesthesia, PCDs and aspirin in low-risk patients. Cause of death was classified as autopsy proven, clinically certain or unknown. Deaths were grouped into cardiopulmonary excluding pulmonary embolism (PE), PE, bleeding-related, gastrointestinal, central nervous system, and others (miscellaneous). Meta-analysis based on fixed effects or random effects models was used for pooling incidence data. In all, 70 studies were included (99 441 patients; 373 deaths). The mortality was lowest in the MM (0.2%) and WC (0.2%) groups. The most frequent cause of death was cardiopulmonary (47.9%), followed by PE (25.4%) and bleeding (8.9%). The proportion of deaths due to PE was not significantly affected by the thromboprophylaxis regimen (PA, 35.5%; PAC, 28%; MM, 23.2%; and NRC, 16.3%). Fatal bleeding was higher in groups relying on the use of anticoagulation (W, 33.8%; PA, 9.4%; PAC, 10.8%) but the differences were not statistically significant. Our study demonstrated that the routine use of PA does not reduce the overall mortality or the proportion of deaths due to PE.

Epidural bleeding after ACL reconstruction under regional anaesthesia: a case report

Introduction

Epidural bleeding as a complication of catheterization or epidural catheter removal is often associated with perioperative thromboprophylaxis especially in adult reconstructive surgery.

Case presentation

We report on a case of a 19 years old male athlete that underwent anterior cruciate ligament reconstruction, receiving low molecular weight heparin for thromboprophylaxis and developed an epidural hematoma and subsequent cauda equina syndrome two days after removal of the epidural catheter. An urgent magnetic resonance imaging scan revealed an epidural hematoma from the level of L3 to L4. Emergent decompression and hematoma evacuation resulted in patient's significant neurological improvement immediately postoperatively.

Conclusion

A high index of clinical suspicion and surgical intervention are necessary to prevent such potentially disabling complications especially after procedures on a day-case basis and early patient's discharge.

Effect of transosseous application of low-intensity ultrasound at the tendon graft-bone interface healing: gene expression and histological analysis in rabbits

The present study investigates the effect of transosseous low-intensity pulsed ultrasound (LiUS) on the healing at tendon graft-bone interface, in molecular and histological level. The anterior cruciate ligament (ACL) in both knees of 52 New Zealand White rabbits was excised and replaced with the long digital extensor. A custom-made ultrasound transducer was implanted onto the medial tibial condyle, adjacent to the surface of the bone tunnel at both knees of the rabbits. The LiUS-treated right knees received 200-mus bursts of 1 MHz sine waves at a pulse repetition rate of 1 kHz and with 30 mW/cm(2) spatial-average temporal-average intensity for 20 min daily (study group), while the left knee received no LiUS (control group). Thirty-six rabbits were used to perform semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) analysis from both study and control groups for transforming growth factor-beta1 (TGF-beta1), biglycan and collagen I. RT-PCR products showed statistically significant upregulation of biglycan and collagen I gene expression in the study group, while TGF-beta1 gene expression exhibited a bimodal profile. Histological examination performed in 16 rabbits from both groups supported the findings of the molecular analysis, indicating a faster healing rate and a more efficient ligamentization process after ultrasound treatment. These findings suggest that transosseous application of LiUS enhances the healing rate of the tendon graft-bone interface, possibly by affecting the expression levels of genes significant for the tendon to bone healing process.

Novel model for studying hematogenous infection in an experimental setting of implant-related infection by a community-acquired methicillin-resistant S. aureus strain

The aim of this study is to establish a new experimental model of hematogenous implant-related infection (IRI) by a community-acquired methicillin-resistant S. aureus (CA-MRSA) strain. Cylindrical porous tantalum intramedullary implants were inserted in the proximal right tibia of 30 male white rabbits after administration of antibiotic prophylaxis. Four weeks later and without antibiotic prophylaxis, 20 animals received 1 ml of inoculum of two different concentrations (study groups A and B) of CA-MRSA strain through an ipsilatelar femoral artery catheter. The remaining 10 received normal saline instead (control group C). Surviving animals were sacrificed 4 weeks later. Sterile bone, bone marrow biopsies, and implants were harvested for culture and histological evaluation. Ten animals receiving 5 x 10(8)cfu/ml (group A) died within 48-72 h due to septic shock. Blood cultures were positive; histology demonstrated acute infection. Ten animals received bacterial load of 3 x 10(8)cfu/ml (group B) and all survived; two had negative Gram-stain and cultures but PCR and RT-PCR results demonstrated the viability of the microorganisms, while periprosthetic osteolysis and histological evaluation indicated subacute osteomyelitis; eight animals established periprosthetic infection, osteomyelitis, and septic arthritis documented by positive Gram-stain, cultures, subperiosteal reaction, and chronic infection on histology. Control group specimens demonstrated no signs of infection. Histopathological semiquantitative scoring was used to compare the three groups. Comparison of groups A and B with control group and between group A and B showed statistically significant difference (p < 0.05) in all parameters except for periosteal reaction between groups B and C (p = 0.354). This novel, reproducible experimental model will facilitate the study of hematogenous CA-MRSA IRIs.