No Difference in the Rate of Periprosthetic Joint Infection in Patients Undergoing the Posterolateral Compared to the Direct Anterior Approach.

BACKGROUND: There remains inconsistent data about the association of surgical approach and periprosthetic joint infection (PJI). We sought to evaluate the risk of reoperation for superficial infection and PJI after primary total hip arthroplasty (THA) in a multivariate model. METHODS: We reviewed 16,500 primary THAs, collecting data on surgical approach and all reoperations within 1 year for superficial infection (n = 36) or PJI (n = 70). Considering superficial infection and PJI separately, we used Kaplan-Meier survivorship to assess survival free from reoperation and a Cox Proportional Hazards multivariate models to assess risk factors for reoperation. RESULTS: Between direct anterior approach (DAA) (N = 3,351) and PLA (N = 13,149) cohorts, rates of superficial infection (0.4 versus 0.2%) and PJI (0.3 versus 0.5%) were low and survivorship free from reoperation for superficial infection (99.6 versus 99.8%) and PJI (99.4 versus 99.7%) were excellent at both 1 and 2 years. The risk of developing superficial infection increased with high body mass index (BMI) (hazard ratio [HR] = 1.1 per unit increase, P = .003), DAA (HR = 2.7, P = .01), and smoking status (HR = 2.9, P = .03). The risk of developing PJI increased with the high BMI (HR = 1.04, P = .03), but not surgical approach (HR = 0.68, P = .3). CONCLUSION: In this study of 16,500 primary THAs, DAA was independently associated with an elevated risk of superficial infection reoperation compared to the PLA, but there was no association between surgical approach and PJI. An elevated patient BMI was the strongest risk factor for superficial infection and PJI in our cohort. LEVEL OF EVIDENCE: III, retrospective cohort study.

Effect of anterior approach compared to posterolateral approach on readiness for discharge and thrombogenic markers in patients undergoing unilateral total hip arthroplasty: a prospective cohort study.

INTRODUCTION: The direct anterior approach (DAA) for total hip arthroplasty (THA) is considered less invasive than the posterolateral approach (PLA), possibly leading to earlier mobilization, faster recovery, and lower levels of thrombogenic markers. The purpose of the current study was to prospectively compare readiness for discharge, rehabilitation milestones, markers of thrombosis and inflammation at 6 weeks postoperatively between DAA and PLA. METHODS: A total of 40 patients (20 anterior and 20 posterolateral) were prospectively enrolled. Readiness for discharge, length of stay (LOS), and related outcomes were additionally documented. Blood was drawn at baseline, wound closure, 5-h post-closure, and 24-h post-closure for assays of interleukin-6 (IL-6), PAP (plasmin anti-plasmin), a marker of fibrinolysis, and PF1.2 (Prothrombin fragment 1.2), a marker of thrombin generation. RESULTS: Compared to the PLA group, the DAA group was ready for discharge a mean 13 h earlier (p = 0.03), while rehabilitation milestones were met a mean 10 h earlier (p = 0.04), and LOS was 13 h shorter (p = 0.02) on average. Pain scores at all study timepoints and patient satisfaction at 6 weeks were similar (p > 0.05). At 24 h postoperatively, PAP levels were 537.53 ± 94.1 µg/L vs. 464.39 ± 114.6 µg/L (p = 0.05), and Il-6 levels were 40.94 ± 26.1 pg/mL vs. 60.51 ± 33.0 pg/mL (p = 0.03), in DAA vs. PLA, respectively. CONCLUSIONS: In the immediate postoperative period, DAA patients were ready for discharge before PLA patients. DAA patients had shorter LOS, a lower inflammatory response, and higher systemic markers of fibrinolysis. However, these differences may not be clinically significant. Future studies with larger study populations are warranted to confirm the validity and significance of these findings. LEVEL OF EVIDENCE: Level II, Therapeutic Study.

Prospective Evaluation of the Posterior Tissue Envelope and Anterior Capsule After Anterior Total Hip Arthroplasty.

BACKGROUND: Femoral exposure for direct anterior approach (DAA) total hip arthroplasty (THA) invariably requires posterior soft tissue releases. Released posterior structures cannot be repaired. The purpose of this study is to describe the frequency and anatomic consequences of DAA THA posterior soft tissue releases and to compare the appearance of the anterior capsule between a group of patients who had capsulotomy and repair versus capsulectomy. METHODS: Thirty-two DAA THA patients underwent metal artifact reduction sequence magnetic resonance imaging at discharge and 1-year follow-up. Seventeen had underwent capsulotomy and repair and 15 capsulectomy. A radiologist blinded to intraoperative data scored each metal artifact reduction sequence magnetic resonance imaging. Anterior capsular integrity, status of the piriformis and conjoint tendons, and muscle atrophy were graded. Descriptive statistics were performed to analyze results. RESULTS: Immediately postoperatively, 75% of piriformis tendons were intact and 38% of conjoined tendons were intact. At 1 year, 97% had an intact piriformis and conjoined tendon, although many were in continuity through scar with the capsule. The posterior capsule directly contacted bone in all patients. At 1 year, none of the patients who underwent capsulotomy with repair had persistent anterior capsule defects, while 27% in the capsulectomy group had persistent defects. CONCLUSION: Posterior capsule and conjoined tendon releases were commonly performed during DAA THA, yet continuity with bone was frequently achieved at 1 year. In this study, capsulotomy with repair resulted in no anterior capsular defects when compared with capsulectomy. These results may support improved THA stability observed after DAA with capsular repair despite posterior soft tissue releases. LEVEL OF EVIDENCE: Level III, prospective cohort study.

Outcomes of Acetabular Reconstructions for the Management of Chronic Pelvic Discontinuity: A Systematic Review.

BACKGROUND: A number of articles have been published reporting on the clinical outcomes of various acetabular reconstructions for the management of chronic pelvic discontinuity (PD). However, no systematic review of the literature has been published to date comparing the outcome and complications of different approaches to reconstruction. METHODS: The US National Library of Medicine (PubMed/MEDLINE) and EMBASE were queried for publications from January 1980 to January 2019 using keywords pertinent to total hip arthroplasty, PD, acetabular dissociation, clinical or functional outcomes, and revision total hip arthroplasty or postoperative complications. RESULTS: Overall, 18 articles were included in this analysis (569 cases with chronic PD). The overall survival rate of the acetabular components used for the treatment of chronic PD was 84.7% (482 of 569 cases) at mid-term follow-up, whereas the most common reasons for revision were aseptic loosening (54 of 569 hips; 9.5%), dislocations (45 of 569 hips; 7.9%), periprosthetic joint infection (30 of 569 hips; 5.3%), and periprosthetic fractures (11 of 569 hips; 1.9%). Both pelvic distraction technique (combined with highly porous shells) and custom triflanges resulted in less than 5% failure rates (96.2% and 95.8%, respectively) at final follow-up. Also, highly effective in the treatment of PD were cup-cages and highly porous shells with and/or without augments with 92% survivorship free of revision for aseptic loosening for both reconstruction methods. Inferior outcomes were reported for conventional cementless shells combined with acetabular plates (72.7%) as well as ilioischial cages and reconstruction rings (66.7% and 60.6% survivorship, respectively). CONCLUSION: The current literature contains moderate quality evidence in support of the use of custom triflange implants and pelvic distraction techniques for the treatment of chronic PD, with a less than 5% all-cause revision rate and low complication rates at mean mid-term follow-up. Cup-cages and highly porous shells with or without augments could also be considered for the treatment of PD because both resulted in greater than 90% survival rates. Finally, there is still no consensus regarding the impact of different types of acetabular reconstruction methods on optimizing the healing potential of PD, and further studies are required in this area to better understand the influence of PD healing on construct survivorship and functional outcomes with each reconstruction method.

Comparing the Safety and Outcome of Simultaneous and Staged Bilateral Total Knee Arthroplasty in Contemporary Practice: A Systematic Review of the Literature.

BACKGROUND: Although a variety of studies have assessed the outcomes of simultaneous bilateral total knee arthroplasty (BTKA) and staged BTKA, there remains no definitive conclusion regarding the superiority of one technique in terms of safety. METHODS: The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried utilizing keywords pertinent to BTKA, simultaneous and staged, and clinical or functional outcomes. In order to examine the contemporary relevant literature, studies published prior to 2009 were excluded from our search. RESULTS: In total, 19 articles met the inclusion criteria and were included in this analysis. The overall quality of the studies included in this review was rated as moderate. Seven of the 19 studies reported no significant differences between the 2 groups in regards to baseline clinical and demographic characteristics (comorbidity index, American Society of Anesthesiologists grade, preoperative clinical subjective scores). Nearly all from these 7 studies with comparable initial characteristics documented no significant differences in the overall complication rates between the 2 groups in addition to no difference in mortality rate, cardiac complications, revision rate, thromboembolic events, and functional outcomes. CONCLUSION: In contemporary studies involving comparable baseline demographics (including comorbidity index, American Society of Anesthesiologists grade), there was moderate evidence to show that simultaneous BTKA is as safe as the staged BTKA.

Preoperative Physical Therapy Education Reduces Time to Meet Functional Milestones After Total Joint Arthroplasty.

BACKGROUND: As length of stay decreases for total joint arthroplasty, much of the patient preparation and teaching previously done in the hospital must be performed before surgery. However, the most effective form of preparation is unknown. This randomized trial evaluated the effect of a one-time, one-on-one preoperative physical therapy education session coupled with a web-based microsite (preopPTEd) on patients' readiness to discharge from physical therapy (PT), length of hospital stay, and patient-reported functional outcomes after total joint arthroplasty. QUESTIONS/PURPOSES: Was this one-on-one preoperative PT education session coupled with a web- based microsite associated with (1) earlier achievement of readiness to discharge from PT; (2) a reduced hospital length of stay; and (3) improved WOMAC scores 4 to 6 weeks after surgery? METHODS: Between February and June 2015, 126 typical arthroplasty patients underwent unilateral TKA or THA. As per our institution's current guidelines, all patients attended a preoperative group education class taught by a multidisciplinary team comprising a nurse educator, social worker, and physical therapist. Patients were then randomized into two groups. One group (control; n = 63) received no further education after the group education class, whereas the intervention group (experimental; n = 63) received preopPTEd. The preopPTEd consisted of a one-time, one-on-one session with a physical therapist to learn and practice postoperative precautions, exercises, bed mobility, and ambulation with and negotiation of stairs. After this session, all patients in the preopPTEd group were given access to a lateralized, joint-specific microsite that provided detailed information regarding exercises, transfers, ambulation, and activities of daily living through videos, pictures, and text. Outcome measures assessed included readiness to discharge from PT, which was calculated by adding the number of postoperative inpatient PT visits patients had to meet PT milestones. Hospital length of stay (LOS) was assessed for hospital discharge criteria and 6-week WOMAC scores were gathered by study personnel. At our institution, to meet PT milestones for hospital discharge criteria, patients have to be able to (1) independently transfer in and out of bed, a chair, and a toilet seat; (2) independently ambulate approximately 150 feet; (3) independently negotiate stairs; and (4) be independent with a home exercise program and activities of daily living. Complete followup was available on 100% of control group patients and 100% patients in the intervention group for all three outcome measures (control and intervention of 63, respectively). RESULTS: The preopPTEd group had fewer postoperative inpatient PT visits (mean, 3.3; 95% confidence interval [CI], 3.0-3.6 versus 4.4; 95% CI, 4.1-4.7; p < 0.001) and achieved readiness to discharge from PT faster (mean, 1.6 days; 95% CI, 1.2-1.9 days versus 2.7 days; 95% CI, 2.4-3.0; p < 0.001) than the control group. There was no difference in hospital LOS between the preopPTEd group and the control group (2.4 days; 95% CI, 2.1-2.6; p = 0.082 versus 2.6 days; 95% CI, 2.4-2.8; p = 0.082). There were no clinically relevant differences in 6-week WOMAC scores between the two groups. CONCLUSIONS: Although this protocol resulted in improved readiness to discharge from PT, there was no effect on LOS or WOMAC scores at 6 weeks. Preoperative PT was successful in improving one of the contributors to LOS and by itself is insufficient to make a difference in LOS. This study highlights the need for improvement in other aspects of care to improve LOS. LEVEL OF EVIDENCE: Level II, therapeutic study.

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.

Incidence, indications, outcomes, and survivorship of stems in primary total knee arthroplasty.

PURPOSE: The indications, incidence, outcomes, and survivorship of stems in primary total knee arthroplasty (TKA) are lacking in the contemporary literature. Our hypothesis is stems in primary TKA would result in worse outcomes and survivorship. METHODS: All primary TKAs between 2007 and 2011 with 2-year follow-up were identified. Revision TKA or UKA conversion was excluded. Demographic information (age, sex, race, BMI, primary diagnosis, and Charlson-Deyo comorbidity index), outcome measures including KOOS and WOMAC, and any revisions were identified from the registry. A 2:1 matched cohort of non-stemmed/stemmed primary TKA patients was created to compare revision rates and outcomes at baseline and 2 years post-TKA. Subgroup analyses of long versus short stems, 1 versus 2 stems, and cemented versus hybrid stem fixation were completed. Two-sample t tests and Chi-square tests were used to compare conventional and stemmed TKA groups. RESULTS: The registry review included 13,507 conventional TKA and 318 stemmed TKA resulting in an incidence of 2.3 % in primary TKA. The mean follow-up was approximately 49 months in both groups. No difference was found in revision rates between stemmed TKA (2.5 %) and conventional TKA (2.2 %). Patients with post-traumatic arthritis had an odds ratio of 10.5 (95 % CI 1.2-15.3) of receiving stems. Stem length did not affect revision rates. Patients with two stems had worse KOOS and WOMAC scores at baseline which equalized to single-stem patients at 2 years. CONCLUSIONS: The use of stems may provide a survival benefit in complex primary TKA over the short term and no adverse effect on patient outcomes or satisfaction. LEVEL OF EVIDENCE: III.

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.

Duloxetine and Subacute Pain after Knee Arthroplasty when Added to a Multimodal Analgesic Regimen: A Randomized, Placebo-controlled, Triple-blinded Trial.

BACKGROUND: Duloxetine is effective for chronic musculoskeletal and neuropathic pain, but there are insufficient data to recommend the use of antidepressants for postoperative pain. The authors hypothesized that administration of duloxetine for 15 days would reduce pain with ambulation at 2 weeks after total knee arthroplasty. METHODS: In this triple-blinded, randomized, placebo-controlled trial, patients received either duloxetine or placebo for 15 days, starting from the day of surgery. Patients also received a comprehensive multimodal analgesic regimen including neuraxial anesthesia, epidural analgesia, an adductor canal block, meloxicam, and oxycodone/acetaminophen as needed. The primary outcome was the pain score (0 to 10 numeric rating scale) with ambulation on postoperative day 14. RESULTS: One hundred six patients were randomized and analyzed. On day 14, duloxetine had no effect on pain with ambulation; mean pain was 3.8 (SD, 2.3) for placebo versus 3.5 (SD, 2.1) for duloxetine (difference in means [95% CI], 0.4 [-0.5 to 1.2]; P = 0.386). Symptoms potentially attributable to duloxetine discontinuation at study drug completion (nausea, anxiety) occurred among nine patients (duloxetine) and five patients (placebo); this was not statistically significant (P = 0.247). Statistically significant secondary outcomes included opioid consumption (difference in mean milligram oral morphine equivalents [95% CI], 8.7 [3.3 to 14.1], P = 0.002 by generalized estimating equation) over the postoperative period and nausea on day 1 (P = 0.040). There was no difference in other side effects or in anxiety and depression scores. CONCLUSIONS: When included as a part of a multimodal analgesic regimen for knee arthroplasty, duloxetine does not reduce subacute pain with ambulation.

Prospective Randomized Trial of the Efficacy of Continuous Passive Motion Post Total Knee Arthroplasty: Experience of the Hospital for Special Surgery.

Conflicting evidence has created substantial controversy regarding the use of continuous passive motion (CPM) in the in-patient setting post total knee arthroplasty (TKA). A total of 109 patients were randomly assigned to two groups, CPM or no CPM, applied after TKA. All patients received the same physical therapy protocol (3 sessions per day), with the only exception being the CPM. Both groups had a knee flexion of 115° at 6 weeks and 120° at 3 months, with no significant differences (P=0.69 and P=0.41, respectively). Length of stay was significantly less for the group who did not receive CPM. The use of CPM had no clinically relevant benefits with respect to AROM, clinical outcomes or discharge disposition and was associated with a cost of $235.50 per TKA.

The modern Burch-Schneider antiprotrusio cage for the treatment of acetabular defects: is it still an option? A systematic review.

BACKGROUND: A number of papers have been published about the clinical performance of modern rough-blasted titanium Burch-Schneider antiprotrusio cages (BS-APCs) for the treatment of acetabular bone defects. However, no systematic review of the literature has been published to date. METHODS: The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried for publications using keywords pertinent to Burch-Schneider antiprotrusio cage, revision THA, and clinical outcomes. RESULTS: 8 articles were found to be suitable for inclusion in the present study in which 374 cases (370 patients) had been treated with modern BS-APCs. Most acetabular bone defects were type 3 according to the Paprosky classification (type 2C: 18.1%, 3A: 51%, and 3B: 28.9%). The overall re-revision rate for the 374 acetabular reconstructions with modern BS-APCs was 11.5% (43 cases). The short-term survival rate of the modern BS-APC construct was 90.6% (339 out of 374 cases), while the mid-term survival rate was 85.6% (320 out of 374 cases), and the long-term survival rate 62% (54 out of 87 cases). The most common reasons for revision were aseptic loosening (5.6%), periprosthetic joint infection (3.8%), dislocation (2.7%), and acetabular periprosthetic fracture (1.9%). CONCLUSIONS: There was moderate quality evidence to show that the use of modern rough blasted titanium BS-APCs in cases of acetabular bone loss has an unacceptably high failure rate (38%). Given that antiprotrusio cages do not provide any biological fixation, we would not recommend the routine use of modern BS-APCs in complex revision THA cases. By contrast, the satisfactory short- to mid-term outcome of modern BS-APCs in combination with their low cost compared to highly porous acetabular implants, make us feel that BS-APCs might still be used in selected elderly or low-demand patients without severe superomedial acetabular bone loss.

The validity of self-report as a technique for measuring short-term complications after total hip arthroplasty in a joint replacement registry.

This study evaluated concordance between self-reports and surgeon assessments of short-term complications. A total of 3976 primary total hip arthroplasty patients consented for an institutional registry (5/2007-12/2008); 3186 (80.1%) completed a 6-month survey; 137 (4.4%) reported deep venous thrombosis, pulmonary embolism, major bleeding, fracture, or dislocation. Patients reporting complications were called. Positive predictive values and 95% confidence intervals (95% CI) for patient self-report were measured, using surgeon assessment for comparison: pulmonary embolism, 88.9% (95% CI, 78.4%-99.4%); dislocation, 81.1% (95% CI, 75.9%-86.5%); fracture, 73.7% (95% CI, 63.8%-83.5%); deep venous thrombosis, 69.7% (95% CI, 61.9%-77.5%); major bleeding, 32.0% (95% CI, 19.4%-44.5%); any bleeding, 88.0% (95% CI, 75.3%-99.9%). Of 97 confirmed complications, 64.95% presented to outside institutions. Registry data on self-reported complications may overcome limitations of traditional methods, but data should be interpreted cautiously. Concordance was high for PE and dislocation but low for major bleeding.

Erratum to 'Adverse Reaction to Zirconia in a Modern Total Hip Arthroplasty With Ceramic Head' [Arthroplasty Today 6 (2020) 612-616].

[This corrects the article DOI: 10.1016/j.artd.2020.03.009.].

No Effect of Surgical Approach on Discharge Outcomes in Outpatient Total Hip Arthroplasty.

Background: The interest in ambulatory total hip arthroplasty (THA) has increased recently due to a national focus on value-based care and improved rapid recovery protocols. Purpose: We sought to determine if surgical approach had an effect on discharge outcomes in outpatient THA. Methods: We performed a retrospective cohort study examining patients who underwent unilateral THA at a single institution using a standardized perioperative care pathway who were discharged home within 24 hours. In total, we compared 106 patients who underwent THA using the direct anterior approach (ATHA) and 90 patients who underwent THA using the posterior approach (PTHA). Univariate and multivariable analyses were used to compare time to ambulation, length of surgery, readmissions, and 90-day complications. Results:Time to ambulation in the ATHA and PTHA groups was 3.9 hours and 4.1 hours, respectively, and time to discharge was 5.9 hours and 6.0 hours, respectively. Length of surgery was shorter in the ATHA group than in the PTHA group (78 minutes vs 86 minutes, respectively). Complications occurred in 3 patients (3%) in the ATHA group vs 4 patients (4%) in PTHA group. In both groups, early ambulation (within 5 hours) predicted earlier time to discharge. Surgical approach was not associated with time to ambulation or time to discharge on multivariable analysis. Conclusion: In this retrospective study, outpatient THA was feasible in a well-selected population of patients undergoing anterior or posterior approaches. Further study is warranted.

Is there a role for expectation maximization imputation in addressing missing data in research using WOMAC questionnaire? Comparison to the standard mean approach and a tutorial.

BACKGROUND: Standard mean imputation for missing values in the Western Ontario and Mc Master (WOMAC) Osteoarthritis Index limits the use of collected data and may lead to bias. Probability model-based imputation methods overcome such limitations but were never before applied to the WOMAC. In this study, we compare imputation results for the Expectation Maximization method (EM) and the mean imputation method for WOMAC in a cohort of total hip replacement patients. METHODS: WOMAC data on a consecutive cohort of 2,062 patients scheduled for surgery were analyzed. Rates of missing values in each of the WOMAC items from this large cohort were used to create missing patterns in the subset of patients with complete data. EM and the WOMAC's method of imputation are then applied to fill the missing values. Summary score statistics for both methods are then described through box-plot and contrasted with the complete case (CC) analysis and the true score (TS). This process is repeated using a smaller sample size of 200 randomly drawn patients with higher missing rate (5 times the rates of missing values observed in the 2,062 patients capped at 45%). RESULTS: Rate of missing values per item ranged from 2.9% to 14.5% and 1,339 patients had complete data. Probability model-based EM imputed a score for all subjects while WOMAC's imputation method did not. Mean subscale scores were very similar for both imputation methods and were similar to the true score; however, the EM method results were more consistent with the TS after simulation. This difference became more pronounced as the number of items in a subscale increased and the sample size decreased. CONCLUSIONS: The EM method provides a better alternative to the WOMAC imputation method. The EM method is more accurate and imputes data to create a complete data set. These features are very valuable for patient-reported outcomes research in which resources are limited and the WOMAC score is used in a multivariate analysis.

Short-term coagulation complications following total knee arthroplasty: a comparison of patient-reported and surgeon-verified complication rates.

Data from 3278 patients from a prospective patient-centered total joint registry was used to investigate the rates of complications in the first 6 months following primary total knee arthroplasty. All patients reporting deep venous thrombosis (DVT), pulmonary embolism (PE), or major bleeding were identified through patient self-reporting. Complications were verified by a review of imaging records and direct communication with patients by a surgeon. Surgeon-verified rates of DVT, PE, and major bleeding were 1.52%, 0.49%, and 0.34%, respectively. When compared with the complication rates as reported by patients, concordance was 86.2% for DVT, 84.2% for PE, and 36.7% for major bleeding. More than half (54.5%) of the complications were diagnosed and treated at the original operative hospital, and 45.5% were diagnosed and treated at other institutions.

Can robotic technology mitigate the learning curve of total hip arthroplasty?

AIMS: Traditionally, acetabular component insertion during total hip arthroplasty (THA) is visually assisted in the posterior approach and fluoroscopically assisted in the anterior approach. The present study examined the accuracy of a new surgeon during anterior (NSA) and posterior (NSP) THA using robotic arm-assisted technology compared to two experienced surgeons using traditional methods. METHODS: Prospectively collected data was reviewed for 120 patients at two institutions. Data were collected on the first 30 anterior approach and the first 30 posterior approach surgeries performed by a newly graduated arthroplasty surgeon (all using robotic arm-assisted technology) and was compared to standard THA by an experienced anterior (SSA) and posterior surgeon (SSP). Acetabular component inclination, version, and leg length were calculated postoperatively and differences calculated based on postoperative film measurement. RESULTS: Demographic data were similar between groups with the exception of BMI being lower in the NSA group (27.98 vs 25.2; p = 0.005). Operating time and total time in operating room (TTOR) was lower in the SSA (p < 0.001) and TTOR was higher in the NSP group (p = 0.014). Planned versus postoperative leg length discrepancy were similar among both anterior and posterior surgeries (p > 0.104). Planned versus postoperative abduction and anteversion were similar among the NSA and SSA (p > 0.425), whereas planned versus postoperative abduction and anteversion were lower in the NSP (p < 0.001). Outliers > 10 mm from planned leg length were present in one case of the SSP and NSP, with none in the anterior groups. There were no outliers > 10° in anterior or posterior for abduction in all surgeons. The SSP had six outliers > 10° in anteversion while the NSP had none (p = 0.004); the SSA had no outliers for anteversion while the NSA had one (p = 0.500). CONCLUSION: Robotic arm-assisted technology allowed a newly trained surgeon to produce similarly accurate results and outcomes as experienced surgeons in anterior and posterior hip arthroplasty. Cite this article: Bone Jt Open 2021;2(6):365-370.

Cement-in-cement technique of the femoral component in aseptic total hip arthroplasty revision: A systematic review of the contemporary literature.

BACKGROUND: Clinical outcomes of cemented femoral stems revisions using the cement-in-cement technique in aseptic conditions after total hip arthroplasty have been widely described. METHODS: The US National Library of Medicine (PubMed/MEDLINE), EMBASE, and the Cochrane Database of Systematic Reviews were queried. RESULTS: Twelve articles were included (620 revision THA). Revision rate for complications related to the femoral side was 1.4% at mid-term follow-up (5.4 years). Periprosthetic femoral fracture rate was 1.1%, aseptic loosening of the femoral component 0.3%. CONCLUSIONS: Cement-in-cement revision technique of the femoral component is associated with a high mid-term success rates (98.6%) and is potentially less challenging than other revision techniques.