Dual-Mobility versus Large Femoral Heads in Revision Total Hip Arthroplasty: Interim Analysis of a Randomized Controlled Trial.

BACKGROUND: This multicenter randomized controlled trial evaluated if dual-mobility bearings (DM) lower the risk of dislocation compared to large femoral heads (≥36 mm) for patients undergoing revision total hip arthroplasty (THA) via a posterior approach. METHODS: A total of 146 patients were randomized to a DM (n = 76; 46 mm median effective head size, range 36 to 59 mm) or a large femoral head (n = 70; twenty-five 36 mm heads [35.7%], forty-one 40 mm heads [58.6%], and four 44 mm heads [5.7%]). There were 71 single-component revisions (48.6%), 39 both-component revisions (26.7%), 24 reimplantations of THA after 2-stage revision (16.4%), seven isolated head and liner exchanges (4.8%), four conversions of hemiarthroplasty (2.7%), and 1 revision of a hip resurfacing (0.7%). Power analysis determined that 161 patients were required in each group to lower the dislocation rate from 8.4 to 2.2% (power = 0.8, alpha = 0.05). RESULTS: At a mean of 18.2 months (range, 1.4 to 48.2), there were three dislocations in the large femoral head group compared to two in the DM cohort (4.3 versus 2.6%; P = .67). One patient in the large head group and none in the DM group were successfully treated with closed reduction without subsequent revision. CONCLUSION: Interim analysis of this randomized controlled trial found no difference in the risk of dislocation between DM and large femoral heads in revision THA, although the rate of dislocation was lower than anticipated and continued follow-up is needed.

Non-ischaemic cardiomyopathy associated with elevated serum cobalt and accelerated wear of a metal-on-metal hip resurfacing.

A man in his late 30s developed non-ischaemic cardiomyopathy due to systemic cobalt toxicity associated with accelerated bearing surface wear from metal-on-metal hip resurfacing implanted in the previous 6 years. Following revision arthroplasty, the patient regained baseline cardiac function. Cobalt-induced cardiomyopathy is a grave condition that deserves early consideration due to potentially irreversible morbidity. We present this case to increase awareness, facilitate early detection and emphasise the need for research into the diagnosis and management of at-risk patients.

Preoperative Patient-Reported Outcomes Measurement Information System Global Health Scores Predict Patients Achieving the Minimal Clinically Important Difference in the Early Postoperative Time Period After Total Knee Arthroplasty.

INTRODUCTION: The patient-specific factors influencing postoperative improvement after total knee arthroplasty (TKA) are important considerations for the surgeon and patient. The primary purpose of this study was to determine which patient demographic factors influence the postoperative Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health (GH) scores. In addition, we aimed to compare the prognostic utility of preoperative PROMIS-GH scores and the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS-JR) in predicting postoperative improvement. METHODS: This retrospective cohort study of a consecutive series of patients who underwent primary, unilateral TKA analyzed prospectively collected KOOS-JR and PROMIS-GH surveys. PROMIS-GH includes physical health (PH) and mental health scores. Patient demographic and presurgical characteristics were evaluated for prognostic capability in predicting postoperative improvement in the PROMIS scores and achievement of the minimal clinically important difference (MCID). Receiver operating characteristic curves were used to understand the prognostic thresholds of the preoperative PROMIS score and KOOS-JR for predicting MCID achievement. RESULTS: A total of 872 patients were included. Although unadjusted analyses showed associations between patient demographic factors and PROMIS-PH scores, multivariable regression analysis for predictors of MCID achievement demonstrated that PROMIS-PH was the only significant preoperative variable. Receiver operating characteristic analysis revealed that the area under the curve of PROMIS-PH (0.70; 95% CI, 0.67 to 0.74) was less than that of the KOOS-JR (0.77; 95% CI, 0.73 to 0.81; P = 0.032). Sensitivity and specificity for achieving the MCID were maximized for preoperative PROMIS-PH scores of ≤ 38 (59% and 70%) and for preoperative KOOS-JR ≤ 51 (71% and 69%). CONCLUSIONS: Preoperative KOOS-JR and PROMIS-PH scores predict clinically meaningful improvement after TKA. The KOOS-JR has greater prognostic utility in the early postoperative period. LEVEL OF EVIDENCE: Level III, Prognostic Study.

Incidence of Pseudotumors in a Dual Modular Stem Construct With and Without Metal-on-Metal Bearing Surface.

BACKGROUND: The purpose of this study was to compare the incidence of pseudotumors in metal-on-metal (MoM) titanium modular neck hip arthroplasties to non-MoM modular neck hip arthroplasties. A secondary goal was to determine whether a correlation exists between elevated metal concentrations and pseudotumor incidence. METHODS: The data were collected and evaluated from 49 MoM joints and 26 non-MoM joints between the years 2012 and 2017. Hip ultrasonography was done after a minimum of 5 years postimplantation. Whole serum metal (titanium, cobalt, and chromium) concentrations were measured at the hip ultrasonography study. RESULTS: The average time elapsed between surgery and ultrasonography visit was 7.6 years. In the 49 patients with MoM joints, 22.4% (n = 11) had a pseudotumor. In the 26 patients with non-MoM joints, 9.1% of metal-on-polyethylene hips (n = 1) and 0% of ceramic-on-ceramic/polyethylene hips developed a pseudotumor. No significant statistical correlation was observed between serum metal concentrations and pseudotumor formation (P > 0.05). A significant correlation was observed of serum titanium concentration to pseudotumor size (P = 0.024). CONCLUSION: The incidence of pseudotumor formation in MoM total hip arthroplasties was more than five times the incidence associated with non-MoM bearings. The correlation between serum titanium concentration and pseudotumor size suggests that titanium levels may be a useful indicator for pseudotumor formation in patients with this particular titanium modular neck femoral implant. No notable correlation was observed between serum cobalt and chromium concentration and pseudotumor formation or size.

Echocardiographic Changes in the Context of Metal-on-Metal Versus Nonmetal-on-Metal Total Hip Arthroplasty.

BACKGROUND: The purpose of this study is to determine if there is a difference in echocardiographic results between patients with metal-on-metal (MoM) vs non-MoM total hip arthroplasty (THA) and to determine if a correlation exists between serum metal levels and echocardiographic outcomes. METHODS: Seventy-five patients with the same modular THA enrolled in this prospective cohort study, and 49 had MoM bearings. All patients had serum cobalt, chromium, and titanium levels drawn at 2 study visits with a transthoracic echocardiogram at the second visit. Serum metal concentrations and echocardiographic parameters were compared with 2-way t-tests. Multiple linear regression analyses identified any significant predictors of echocardiographic outcomes. RESULTS: Mean serum cobalt and chromium levels were significantly greater in the MoM group at both time-points (P < .001 and P < .05, respectively). Titanium levels were similar between groups (P > .05). MoM patients had significantly lower global longitudinal strain compared with the non-MoM group (18.4% vs 20.2%; P = .026). Serum cobalt concentration was found to be an independent predictor of tricuspid annular plane systolic excursion (P = .02). CONCLUSION: MoM THA bearings are associated with increased serum cobalt and chromium levels. Patients with MoM THAs had decreased global longitudinal strain, a measure of left ventricular function, but both groups remained within normal range. The clinical impact of the positive association between serum cobalt concentration and tricuspid annular plane systolic excursion, a marker of right ventricular function, deserves further study. These findings can reassure physicians and patients that metal-induced cardiomyopathy is not typical in the setting of MoM THA. LEVEL OF EVIDENCE: Level II, Prospective Cohort Study.

Patient-Reported Outcomes Measurement Information System (PROMIS) Global Health Short Forms Demonstrate Responsiveness in Patients Undergoing Knee Arthroplasty.

BACKGROUND: The Patient-Reported Outcomes Measurement Information System (PROMIS) is an alternative to legacy outcome metrics. We investigated the relationship between Knee Injury and Osteoarthritis Outcomes Score for Joint Replacement (KOOS-JR) and PROMIS Global Health forms of Physical Health (PH) and Mental Health (MH) in knee arthroplasty patients. METHODS: This is a retrospective cohort study of knee arthroplasty patients from December 2017 through April 2019 who had surveys collected preoperatively and postoperatively. We excluded patients undergoing revision surgery. Outcome scores were analyzed for responsiveness, effect size index (ESI), minimal clinically important difference (MCID), and correlation with each other through 12 months postoperatively. RESULTS: A total of 875 patients were included. Floor and ceiling effects were 0% for PROMIS-PH. Postoperative PROMIS-PH and KOOS-JR scores significantly correlated with one another and increased from baseline at each postoperative time point (P < .001 for all). PROMIS-MH did not change between time points (P > .05). PROMIS-PH showed moderate responsiveness at 1 and 3 months (ESI >0.2) and excellent responsiveness at 6 and 12 months (ESI >0.8), whereas KOOS-JR was responsive at all time points (ESI >0.8). The MCID of PROMIS-PH correlated significantly with KOOS-JR, and a preoperative PROMIS-PH score of less than 32.5 predicted achieving MCID with 97% specificity. CONCLUSION: PROMIS global health forms are a valid metric which capture patient outcomes and correlate with KOOS-JR scores after knee arthroplasty. Although KOOS-JR may be more responsive in the early postoperative time period, both measures show excellent responsiveness at 6 and 12 months after knee arthroplasty.

Veterans Undergoing Total Hip and Knee Arthroplasty: 30-day Outcomes as Compared to the General Population.

INTRODUCTION: The Veterans Affairs (VA) health system is vital to providing joint replacement care to our retired service members but has come under recent scrutiny. The purpose of this study was to compare the short-term outcomes after total hip arthroplasty (THA) and total knee arthroplasty (TKA) between the VA cohort and the general cohort. METHODS: We retrospectively reviewed 10.460 patients with primary THA and TKA from the Veterans Affairs Corporate Data Warehouse. As a control group, we queried the American College of Surgeons-National Surgical Quality Improvement Program database and identified 58,820 patients with primary THA and TKA over the same time period. We compared length of stay, mortality rates, 30-day complication rates, and 30-day readmissions. We performed a multivariate logistic regression analysis to identify the independent effect of the VA system on adverse outcomes. RESULTS: Veterans are more likely to be men (93% versus 41%, P < 0.001) and have increased rates of medical comorbidities (all P < 0.001). The rate of short-term complications (all P < 0.001) were all higher in the VA cohort. When controlling for demographics and medical comorbidities, VA patients were more likely to have a readmission (P < 0.001), prolonged length of stay > 4 days (P < 0.001), and experience a complication within 30 days (P < 0.001). DISCUSSION: Despite controlling for higher rates of medical comorbidities, VA patients undergoing primary THA and TKA had poorer short-term outcomes than the civilian cohort. Additional research is needed to ensure our veteran cohort is appropriately optimized and address the discrepancy with the outcomes of the civilian.

Periprosthetic Fractures of the Distal Femur: Is Open Reduction and Internal Fixation or Distal Femoral Replacement Superior?

BACKGROUND: The purpose of this study is to compare open reduction and internal fixation (ORIF) to distal femoral replacement (DFR) for treatment of displaced periprosthetic distal femur fractures. METHODS: We identified 72 patients with minimum 2-year follow-up following a displaced periprosthetic distal femur fracture: 50 were treated with ORIF and 22 with DFR. Outcomes were assessed with multivariate regression analysis and include Knee Society Scores (KSS), infection rates, revision incidence, and mortality. RESULTS: Patients treated with DFR had a higher Charlson comorbidity index (5.2 vs 3.8; P = .006). The mean postoperative KSS were similar between groups, but the Knee Society Functional Scores were higher in the ORIF group (P = .01). Six ORIF patients (12%) and 3 DFR patients (14%) underwent a revision surgery (P = .1). In the ORIF group, 3 revisions were associated with periprosthetic infection, and 3 revisions occurred for aseptic nonunion. In the DFR group, 1 infection was treated with irrigation and debridement, and 2 cases of patellar maltracking resulted in 1 liner exchange with soft tissue release and 1 femoral revision for malrotation. More patients in the ORIF group required repeat revisions, with twice as many total revisions (P < .001). Six ORIF patients and 7 DFR patients died within 2 years (P = .26). CONCLUSION: The Knee Society Functional Score favored ORIF, but the total incidence of revision was higher in the ORIF cohort. Given the high mortality and the substantial risk of reoperation in both groups, additional studies are needed regarding the prevention of and optimal treatment for patients with periprosthetic distal femur fractures.

Comparison of Harris Hip Scores and Revision Rates in Metal-on-Metal Versus Non-Metal-on-Metal Total Hip Arthroplasty.

INTRODUCTION: This study compares functional outcome scores and revision rates between metal-on-metal (MoM) and non-MoM total hip arthroplasty patients. METHODS: A cohort of 75 patients who underwent implantation of the same dual modular hip arthroplasty between the years of 2004 and 2010 was enrolled. Patients were subsequently evaluated in 2015 to 2017 for joint revision history and functionality, as measured by the Harris hip score (HHS). Patients requiring a revision arthroplasty were not included in the HHS analysis. RESULTS: A total of 49 patients had MoM implants (65.3%), and 26 patients had non-MoM implants (34.8%). At a mean follow-up of 7.6 years, 10.2% (5/49) of MoM prostheses required revision, whereas 3.8% (1/26) of non-MoM prostheses required revision (P = 0.334). The mean HHS in the MoM cohort was 89.8, compared with 88.1 in the non-MoM cohort (P = 0.69). CONCLUSION: HHSs were not notably different between cohorts. The MoM cohort had three times as many revisions as the non-MoM cohort, but given the numbers available, this difference did not reach significance. Given the clinical importance of these revision data, further study is warranted to determine survivorship of the MoM versus non-MoM total hip arthroplasty at long-term follow-up.

Physical Therapy on Postoperative Day Zero Following Total Knee Arthroplasty: A Randomized, Controlled Trial of 394 Patients.

BACKGROUND: Surgeons have increasingly emphasized early mobilization as a way to facilitate discharge following total knee arthroplasty (TKA). The purpose of this study was to determine whether starting formal physical therapy (PT) the afternoon of postoperative day (POD) 0, instead of starting PT the morning of POD 1, could shorten hospital length of stay (LOS). METHODS: Patients undergoing elective TKA with a planned minimum 1-night hospital stay were randomized to start formal PT the afternoon following surgery or the morning of POD 1. LOS in hours was the primary outcome. An a priori sample size calculation suggested that 394 patients were required to show a 4-hour difference between groups. RESULTS: Out of 394 patients enrolled and randomized, 378 (95.9%) completed the study. The observed difference in hospital LOS was not large enough to be of clinical significance (intention-to-treat analysis: median of 32.0 hours for POD 0 PT vs 31.0 hours for POD 1 PT, P = .65; as-treated analysis: median of 31.0 hours for POD 0 PT vs 32.0 hours for POD 1 PT, P = .12). Similarly, the observed differences in satisfaction with inpatient PT (10.0 vs 10.0, P = .77), patient-reported readiness for discharge at time of discharge (10.0 vs 10.0, P = .97), and POD 0 pain (3.3 vs 4.0, P = .79) were not large enough to be of clinical significance. CONCLUSION: While PT on the day of surgery has been suggested as one method to facilitate discharge following TKA, this randomized trial did not demonstrate clinically meaningful differences in hospital LOS or patient satisfaction when PT is initiated on the day of surgery vs on the morning after surgery.

The James A. Rand Young Investigator's Award: Large Opioid Prescriptions Are Unnecessary After Total Joint Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: The purpose of this randomized controlled trial is to determine whether the quantity of opioid pills prescribed at discharge is associated with the number of opioid pills consumed or unused by patients after primary hip and knee arthroplasty within 30 days after discharge. METHODS: A total of 304 opioid-naïve patients were randomized to receive either 30 or 90 5-mg oxycodone immediate-release (OxyIR) pills at discharge. Daily opioid consumption, number of unused pills, and pain scores were calculated for 30 days with a patient-completed medication diary. Statistical analysis involved t-test, rank-sum, chi-squared tests, and multiple linear regression with alpha = 0.05. RESULTS: Of the 304 patients randomized, 161 patients were randomized to receive 30 pills and 143 to receive 90. In the first 30 days after discharge, the median number of unused pills was 15 in the 30 group vs 73 in the 90 group (P < .001). Within 90 days of discharge, 26.7% of the 30 group and 10.5% of the 90 group requested a refill (P < .001), leading to a mean of 777.1 ± 414.2 morphine equivalents vs 1089.7 ± 536.4 prescribed (P < .0001). There was no difference between groups in mean morphine equivalents consumed. Regression analysis demonstrated that being prescribed 90 OxyIR pills was independently associated with taking more OxyIR pills (P = .028). There was no difference in pain scores within the first 30 days and in patient-reported outcome scores at 6 weeks postoperatively. CONCLUSION: Prescribing fewer OxyIR pills is associated with a significant reduction in unused opioid pills and decreased opioid consumption with no increase in pain scores and no difference in patient-reported outcomes. LEVEL OF EVIDENCE: Level I. Randomized controlled trial.

Utilizing the Time Trade-Off, Standard Gamble, and Willingness to Pay Utility Measures to Evaluate Health-Related Quality of Life Prior to Knee or Hip Arthroplasty.

BACKGROUND: Time trade-off, standard gamble, and willingness to pay assess the number of years, risk of death, and income a patient would give up for perfect health. These questions were used to evaluate the impact knee arthritis, hip arthritis, or failed total knee (TKA) or hip arthroplasty (THA) has on patients' health-related quality of life prior to surgery. METHODS: Three hundred sixty patients including 176 undergoing primary TKA, 127 undergoing primary THA, 31 undergoing revision TKA, and 26 undergoing revision THA were assessed. Time trade-off and standard gamble were converted to utility scores with 1.0 suggesting perfect health and 0 suggesting preference for death rather than living in current state. Willingness to pay is the percentage of yearly income that a patient would pay for perfect health. RESULTS: The mean time trade-off, standard gamble, and willingness to pay scores were 0.74, 0.83, and 0.32 without significant difference between procedures with the numbers available for study (P = .16, .31, and 0.41, respectively). Increasing body mass index was correlated with decreasing time trade-off scores (P = .014). CONCLUSION: Patients scheduled for primary or revision THA and TKA would accept an average 17% risk of death, lose 2.6 years of an additional 10-year life expectancy, and pay 32% of their income for perfect health. The time trade-off (0.74) was similar to patients with history of acute myocardial infarction (0.74) or minor stroke (0.72) and worse than those with chronic hepatitis C (0.83) or human immunodeficiency virus/acquired immunodeficiency syndrome infection (0.86). These data highlight the high value that patients place on adult reconstructive procedures.

Inpatient Versus Outpatient Arthroplasty: A Single-Surgeon, Matched Cohort Analysis of 90-Day Complications.

BACKGROUND: Although some prior work supports the safety of same-day arthroplasty performed in a hospital, concerns remain when these procedures are performed in a free-standing ambulatory surgery center. The purpose of this study is to compare 90-day complication rates between matched cohorts that underwent inpatient vs outpatient arthroplasty at an ambulatory surgery center. METHODS: A single-surgeon cohort of 243 consecutive patients who underwent outpatient arthroplasty was matched with 243 inpatients who had the same procedure. One-to-one nearest-neighbor matching with respect to gender, age, American Society of Anesthesiologists Score, and body mass index was utilized. The 486 primary arthroplasties included 178 unicondylar knees (36.6%), 146 total hips (30.0%), 92 total knees (18.9%), and 70 hip resurfacings (14.5%). Ninety-day outcomes including reoperation, readmission, unplanned clinic or emergency department visits, and major and minor complications were compared using a 2-sample proportions test. RESULTS: The 2 cohorts were similar in distribution of demographic variables, demonstrating successful matching. The inpatient and outpatient cohorts both had readmission rates of 2.1% (P = 1.0). With the number of subjects studied, there were no statistically significant differences in rates of major complications (2.1% vs 2.5%, P = 1.0), minor complications (7.0% vs 7.8%, P = .86), reoperations (0.4% vs 2.1%, P = .22), emergency department visits (1.6% vs 2.5%, P = .52), or unplanned clinic visits (3.3% vs 5.8%, P = .19). CONCLUSION: This study suggests that arthroplasty procedures can be performed safely in an ambulatory surgery center among appropriately selected patients without an increased risk of complications.

Synovial Fluid Alpha-Defensin Is an Adjunctive Tool in the Equivocal Diagnosis of Periprosthetic Joint Infection.

BACKGROUND: Synovial fluid alpha-defensin has shown to be a reliable diagnostic test for the diagnosis of periprosthetic joint infection (PJI), but its use in equivocal cases has yet to be established. The purpose of this study was to determine the reliability of alpha-defensin testing in patients, where the diagnosis of PJI was unclear. METHODS: A consecutive series of 41 synovial aspirations by a single surgeon that were sent for alpha-defensin testing in equivocal cases of PJI were retrospectively reviewed. Indications for alpha-defensin testing included recent antibiotic use, borderline synovial fluid cell count, and differential, suspected culture-negative infection, and suspected false-positive culture. PJI was diagnosed using the Musculoskeletal Infection Society (MSIS) criteria. RESULTS: Of the 39 aspirations in 32 patients included in the study, there were 33 (85%) knee and 6 (15%) hip samples. Eleven (28%) samples met MSIS criteria for PJI. Of the 23 samples that had recent antibiotic use (6 MSIS positive, 17 negative), alpha-defensin results confirmed the correct MSIS diagnosis in 19 (83%) samples. Of the 11 samples in which alpha-defensin testing was performed for a borderline cell count (3 MSIS positive, 8 negative), alpha-defensin confirmed the MSIS diagnosis in 10 of 11 (91%) samples. Finally, among the 5 samples with suspected false-positive or false-negative cultures (2 MSIS positive, 3 negative), alpha-defensin confirmed the correct diagnosis in 3 (60%) samples. The overall sensitivity, specificity, negative predictive value, and positive predictive value of synovial alpha-defensin were 82%, 82%, 92%, and 64%, respectively. CONCLUSION: In patients for whom the diagnosis of PJI is unclear because of recent antibiotic use, equivocal laboratory findings, or suspected false-negative or false-positive cultures, synovial fluid alpha-defensin can provide an additional data point to assist the clinician in determining whether PJI is present but is prone to false-positive results in this challenging population.

Single-dose lidocaine spinal anesthesia in hip and knee arthroplasty.

BACKGROUND: With the increasing interest in fast recovery and outpatient joint arthroplasty, short-acting local anesthetic agents and minimal narcotic use are preferred. Lidocaine is a fast-onset, short-duration local anesthetic that has been used for many years in spinal anesthesia. However, lidocaine spinal anesthesia has been reported to have a risk of transient neurologic symptoms (TNSs). The purpose of this study is to determine the safety and efficacy of single-dose lidocaine spinal anesthesia in the setting of outpatient joint arthroplasty. METHODS: We performed a prospective study on 50 patients who received lidocaine spinal anesthesia in the setting of outpatient hip and knee arthroplasty. All patients received a single-shot spinal injection, with 2% isobaric lidocaine along with titrated propofol sedation. We evaluated demographic data, length of motor blockage, time to ambulation, time to discharge readiness, patient-reported symptoms of TNS. RESULTS: Of the 50 patients studied, 11 had total hip arthroplasty, 33 total knee arthroplasty, 5 unicompartmental knee arthroplasty, and 1 underwent isolated polyethylene liner exchange in a total knee arthroplasty. The average total duration of motor blockade was 2.89 hours (range 1.73-5.17, standard deviation 0.65). Average time from postanesthesia care unit to return of motor function was 0.58 hours (range 0-1.5, standard deviation 0.48). None of the patients reported TNS. CONCLUSIONS: Isobaric lidocaine spinal anesthesia appears to be a safe and effective regimen for outpatient hip and knee arthroplasty. All patients were discharged on the day of surgery with isobaric lidocaine spinal injection. There were no reports of TNSs.

Impact of Operative Time on Adverse Events Following Primary Total Joint Arthroplasty.

BACKGROUND: Little is known regarding the impact of operative time on adverse events following arthroplasty. The present study tests for associations between a 15-minute increase in operative time and the occurrence of adverse events following primary total joint arthroplasty. METHODS: Patients undergoing primary total hip or knee arthroplasty during 2006-2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program. Operative time (as a continuous variable) was tested for association with perioperative outcomes using multivariate regression. All regressions were adjusted for differences in demographic, comorbidity, and procedural characteristics. RESULTS: A total of 165,474 patients met inclusion criteria. The mean (±standard deviation) operative time was 91.9 ± 32.5 minutes. Following adjustment for baseline characteristics, an increase in operative time by 15 minutes increased the risk of anemia requiring transfusion by 9% (95% confidence interval [CI] = 8%-10%, P < .001), wound dehiscence by 13% (95% CI = 8%-19%, P < .001), renal insufficiency by 9% (95% CI = 3%-14%, P < .001), sepsis by 10% (95% CI = 6%-14%, P < .001), surgical site infection by 9% (95% CI = 7%-12%, P < .001), and urinary tract infection by 4% (95% CI = 2%-6%, P < .001). Similarly, an increase in operative time by 15 minutes increased the risk of hospital readmission by 5% (95% CI = 4%-6%, P < .001) and of extended hospital length of stay (≥4 days) by 9% (95% CI = 8%-10%, P < .001). CONCLUSION: The present study suggests that greater operative time increases the risk for multiple postoperative complications following total joint arthroplasty. These data suggest that surgeons should consider steps to minimize operative time without compromising the technical components of the surgical procedure.

Formal Physical Therapy May Not Be Necessary After Unicompartmental Knee Arthroplasty: A Randomized Clinical Trial.

BACKGROUND: The purpose of this randomized clinical trial was to compare formal outpatient physical therapy (PT) and unsupervised home exercises after unicompartmental knee arthroplasty (UKA). METHODS: Fifty-two patients were randomized to 6 weeks of outpatient PT or an unsupervised home exercise program after UKA. The primary outcome was change in range of motion at 6 weeks with secondary outcomes including total arc of motion, Knee Society Score, Knee Injury and Osteoarthritis Outcome Score Jr, Lower Extremity Functional Scale, and Veterans Rands-12 score. RESULTS: Twenty-five patients received outpatient PT, 22 patients the self-directed exercise program, while 3 patients deviated from the protocol, 1 patient withdrew, and 1 patient was lost to follow-up. There was no difference in the change of range of motion (P = .43) or total arc of motion at 6 weeks (P = .17) between the groups and likewise no significant differences were found in any of the secondary outcomes. Two patients who crossed over from the unsupervised home exercise program to formal outpatient PT within the first 2 weeks postoperatively required a manipulation under anesthesia. CONCLUSIONS: Our results suggest self-directed exercises may be appropriate for most patients following UKA. However, there is a subset of patients who may benefit from formal PT.

Incidence, Risk Factors, and Clinical Implications of Pneumonia After Surgery for Geriatric Hip Fracture.

BACKGROUND: Little is known regarding the occurrence of pneumonia after hip fracture surgery. The purpose of this study is to determine the incidence, risk factors, and clinical implications of pneumonia after surgery for geriatric hip fracture. METHODS: The American College of Surgeons National Surgical Quality Improvement Program was used to retrospectively study geriatric patients undergoing surgery for hip fracture during 2006-2014. Independent risk factors for developing pneumonia within 30 days of surgery were identified using multivariate regression. RESULTS: Of the 29,377 patients meeting inclusion criteria, 13,736 (46.8%) underwent hemiarthroplasty, 9468 (32.2%) intramedullary fixation, 4294 (14.6%) plate and/or screw fixation, 1299 (4.4%) total joint arthroplasty, and 580 (2.0%) percutaneous fixation. In total 1191 patients developed pneumonia, an incidence of 4.1%. The strongest risk factors for pneumonia were male sex, older age (especially ≥90 years), low body mass index, and chronic obstructive pulmonary disease. Patients who developed pneumonia had a higher readmission rate (79.1% vs 8.2%, P < .001), a higher rate of sepsis (16.6% vs 1.7%, P < .001), and a higher mortality rate (29.2% vs 5.7%, P < .001). Among 1602 total mortalities, 348 (17.9%) occurred in patients with pneumonia. CONCLUSION: Pneumonia is a serious complication after geriatric hip fracture surgery, which increases the readmission and mortality risks. Evidence-based pneumonia prevention programs should be implemented among high-risk patients-males, patients ≥90 years, body mass index <18.5 kg/m2, and/or patients with chronic obstructive pulmonary disease-to decrease morbidity and mortality.

Serum Albumin Predicts Survival and Postoperative Course Following Surgery for Geriatric Hip Fracture.

BACKGROUND: Serum albumin level is the most well-established serum marker of malnutrition, with a serum albumin concentration <3.5 g/dL considered to be suggestive of malnutrition. The purpose of this study was to test if serum albumin level is associated with death, specific postoperative complications (e.g., pneumonia), length of hospital stay, and readmission following a surgical procedure for geriatric hip fracture. METHODS: A retrospective cohort study of geriatric patients (≥65 years of age) undergoing a hip fracture surgical procedure as part of the American College of Surgeons National Surgical Quality Improvement Program was conducted. Outcomes were compared between patients with and without hypoalbuminemia. All comparisons were adjusted for baseline and procedural differences between populations, and patients with missing serum albumin concentration were included in analyses using a missing data indicator. RESULTS: There were 29,377 geriatric patients undergoing a hip fracture surgical procedure who met inclusion criteria; of these patients, 17,651 (60.1%) had serum albumin available for analysis. The prevalence of hypoalbuminemia was 45.9%. Following adjustment for baseline and procedural characteristics, the risk of death was inversely associated with serum albumin concentration as a continuous variable (adjusted relative risk, 0.59 [95% confidence interval (CI), 0.53 to 0.65]; p < 0.001). In comparison with patients with normal albumin concentration, patients with hypoalbuminemia had higher rates of death (9.94% compared with 5.53% [adjusted relative risk, 1.52 (95% CI, 1.37 to 1.70); p < 0.001]), sepsis (1.19% compared with 0.53% [adjusted relative risk, 1.92 (95% CI, 1.36 to 2.72); p < 0.001]), and unplanned intubation (2.64% compared with 1.47% [adjusted relative risk, 1.51 (95% CI, 1.21 to 1.88); p < 0.001]). The mean length of stay (and standard deviation) was longer among patients with hypoalbuminemia at 5.67 ± 4.68 days compared with those without hypoalbuminemia at 4.99 ± 3.95 days; the adjusted difference was 0.50 day (95% CI, 0.38 to 0.63 day; p < 0.001). However, the rate of readmission did not differ (p = 0.054) between patients with hypoalbuminemia (10.91%) and those without hypoalbuminemia (9.03%); the adjusted relative risk was 1.10 (95% CI, 1.00 to 1.21). CONCLUSIONS: Hypoalbuminemia is a powerful independent risk factor for mortality following a surgical procedure for geriatric hip fracture. These data suggest that further investigation into postoperative nutritional supplementation is warranted to decrease the risk of complications. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.