Faculty Bibliography

BACKGROUND:Revision total knee arthroplasty (rTKA) can be performed with isolated tibial, isolated femoral, and combined tibial and femoral component exchange for different indications. Replacement of only 1 fixed component in rTKA leads to shorter operative times and decreased complexity. We sought to compare functional outcomes and rates of rerevision in patients undergoing partial and full rTKA. METHODS:This retrospective study examined all aseptic rTKA patients with a minimum follow-up of 2 years in a single center between September 2011 and December 2019. Patients were divided into two groups: full rTKA (F-rTKA) if both components (femoral and tibial) were revised and partial rTKA (P-rTKA) if only 1 component was revised. A total of 293 patients (P-rTKA = 76, F-rTKA = 217) were included. RESULTS:P-rTKA patients had significantly shorter surgical time (109 ± 37 Versus. 141 ± 44 minutes, P < .001). At mean follow-up of 4.2 (range 2.2-6.2) years, rerevision rates did not significantly differ between groups (11.8 Versus. 16.1%, P = .358). Improvements in postoperative Visual Analogue Scale (VAS) pain and Knee Injury and Osteoarthritis Scale (KOOS), Joint Replacement scores were similar as well (P = .100 and P = .140, respectively). For patients undergoing rTKA due to aseptic loosening, freedom from rerevision due to aseptic loosening was similar between groups (100 Versus. 97.8%, P = .321). For patients undergoing rTKA due to instability, freedom from rerevision due to instability did not significantly differ as well (100 Versus. 98.1%, P = .683). In the P-rTKA cohort, freedom from all-cause and aseptic revision of preserved components was 96.1% and 98.7% at the 2-year follow-up. CONCLUSION:Compared to F-rTKA, P-rTKA yielded similar functional outcomes and implant survivorship with shorter surgical time. When indications and component compatibility allow for such a procedure, surgeons can expect good outcomes when performing P-rTKA.

INTRODUCTION/BACKGROUND:Previous studies have shown lower morbidity and mortality rates after total hip arthroplasty (THA) at academic teaching hospitals. This study sought to determine the relationship between hospital teaching status and patient-reported outcome measures (PROMs) following primary THA. METHODS:Using American Joint Replacement Registry data from 2012 to 2020, 4,447 primary, elective THAs with both preoperative and one-year postoperative Hip Disability and Osteoarthritis Outcome Score, Joint Replacement (HOOS, JR) scores were analyzed. The main exposure variable was hospital teaching status, with three cohorts: major teaching hospitals; minor teaching hospitals; and non-teaching hospitals. Mean preoperative and one-year postoperative HOOS, JR scores were compared. RESULTS:Preoperative HOOS, JR scores (non-teaching: 49.69±14.42 vs. major teaching: 47.68±15.10 vs. minor teaching: 42.46±19.19, P<0.001) were significantly higher at non-teaching hospitals than major and minor teaching hospitals, and these differences persisted at one-year postoperatively (87.40±15.14 vs. 83.87±16.68 vs. 80.37±19.27, P<0.001). Both preoperative and postoperative differences in HOOS, JR scores were less than the Minimum Clinically Important Difference (MCID) at both time points. In multivariate regressions, non-teaching and minor teaching hospitals had similar odds of MCID achievement in HOOS, JR scores compared to major teaching hospitals. CONCLUSION/CONCLUSIONS:Using the HOOS, JR score as a validated outcome measure, undergoing primary THA at an academic teaching hospital did not correlate with higher postoperative HOOS, JR scores or greater chances of MCID achievement in HOOS, JR scores compared to non-teaching hospitals. Further work is required to determine the most important factors that may lead to improvement in patient-reported outcomes following THA.

INTRODUCTION/BACKGROUND:The optimal administration of dexamethasone for postoperative pain management and recovery following primary, elective total joint arthroplasty (TJA) remains unclear. This study aimed to evaluate the effect of a second intravenous (IV) dose of dexamethasone on postoperative pain scores, inpatient opioid consumption, and functional recovery after total hip arthroplasty (THA) and total knee arthroplasty (TKA). METHODS:A retrospective review was conducted of 2,256 primary elective THA, and 1,951 primary elective TKA between May 2020 and April 2021. Patients who received two perioperative doses (2D) of dexamethasone 10 mg IV were propensity-matched 1:1 to a control group who received one perioperative dose (1D). Primary outcomes were opiate consumption as morphine milligram equivalences (MMEs), postoperative pain as Verbal Rating Scale (VRS) pain scores, and functional status assessed by the Activity Measure for Post-Acute Care (AM-PAC) scores. RESULTS:The 2D THA and 2D TKA cohorts consumed significantly less opiates at the 24 to 48 hour and 48 to 72 hour intervals. The 2D TKA cohort had significantly lower total opiate consumption compared to the 1D TKA cohort. Compared to the 1D cohorts, the 2D THA cohort and 2D TKA cohorts had significantly lower pain scores at the 48 to 60 hour interval; additionally, the 2D TKA cohort had significantly lower pain scores in the 36 to 48 hour interval. AM-PAC scores did not differ between cohorts for both TKA and THA at any interval. CONCLUSION/CONCLUSIONS:The administration of a second perioperative dexamethasone dose significantly decreased opioid consumption in the immediate postoperative period. Inpatient opioid administration can be significantly reduced while maintaining comparable functional recovery and superior pain control.

BACKGROUND:Revision total hip arthroplasty (rTHA) is a costly procedure, and its prevalence has been steadily increasing over time. This study aimed to examine trends in hospital cost, revenue, and contribution margin (CM) in patients undergoing rTHA. METHODS:We retrospectively reviewed all patients who underwent rTHA from June 2011 to May 2021 at our institution. Patients were stratified into groups based on insurance coverage: Medicare, government-managed Medicaid, or commercial insurance. Patient demographics, revenue (any payment the hospital received), direct cost (any cost associated with the surgery and hospitalization), total cost (the sum of direct and indirect costs), and CM (the difference between revenue and direct cost) were collected. Changes over time as a percentage of 2011 numbers were analyzed. Linear regression analyses were used to determine the overall trend's significance. Of the 1,613 patients identified, 661 were covered by Medicare, 449 by government-managed Medicaid, and 503 by commercial insurance plans. RESULTS:Medicare patients exhibited a significant upward trend in revenue (P < .001), total cost (P = .004), direct cost (P < .001), and an overall downward trend in CM (P = .037), with CM for these patients falling to 72.1% of 2011 values by 2021. CONCLUSION/CONCLUSIONS:In the Medicare population, reimbursement for rTHA has not matched increases in cost, leading to considerable reductions in CM. These trends affect the ability of hospitals to cover indirect costs, threatening access to care for patients who require this necessary procedure. Reimbursement models for rTHA should be reconsidered to ensure the financial feasibility of these procedures for all patient populations.

BACKGROUND:Different approaches for total hip arthroplasty (THA) may offer advantages in regard to achieving same-day-discharge (SDD) success. METHODS:We retrospectively identified patients aged ≥ 18 years who underwent elective primary THA from 2015 to 2020 who were formally enrolled in a single institution's SDD program. A total of 1,127 and 207 patients underwent THA via direct anterior approach and posterior approach, respectively, were included. Cohorts were assigned based on approach. The primary outcome was failure-to-launch, defined as hospital stay extending past 1 midnight. Secondary outcomes included Forgotten Joint Score-12, Hip Disability and Osteoarthritis Outcome Score for Joint Replacement, 90-day readmission and revision rate, and surgical time. Patient-reported outcomes were collected at 3 and 12 months. RESULTS:After controlling for demographic differences, posterior approach patients had higher rates of failure-to-launch (12.1% versus 5.9%, P = .002) and longer surgical times (99 versus 80 minutes; P < .001) compared to direct anterior approach patients. The cohorts had similar readmission (1.7% versus 1.4%; P = .64) and revision rates (1% versus 1%; P = .88). The magnitude of improvement in Hip Disability and Osteoarthritis Outcome Score for Joint Replacement scores from preoperative to 12 months was similar between cohorts (35.3 versus 34.5; P = .42). The differences in outcome scores between cohorts at each time point were not considered clinically significant. CONCLUSION/CONCLUSIONS:Our analysis suggests that patient selection and surgical approach may be important for achieving SDD. Surgical approach did not significantly impact readmission or revision rates nor did it have a meaningful impact on patient-reported outcomes in the first year after surgery.

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/CONCLUSIONS: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.

BACKGROUND:Concerns have been voiced regarding how surgical approach impacts risk of dislocation after total hip arthroplasty (THA). This study investigated how surgical approach impacts rate, direction, and timing of dislocations following THA. METHODS:We conducted a retrospective review of 13,335 primary THAs from 2011 to 2020 and identified 118 patients with prosthetic hip dislocation. Patients were stratified into cohorts by surgical approach used during primary THA. Patient demographics, index THA acetabular cup positioning, number, direction, timing of dislocations, and subsequent revisions were collected. RESULTS:Dislocation rate differed significantly between posterior approach (PA), direct anterior approach (DAA), and laterally-based approach (LA) (1.1 versus 0.7% versus 0.5%, P = .026). Rate of hips dislocating anteriorly was lowest in the PA group (19.2%) compared to LA (50.0%) and DAA groups (38.2%, P = .044). There was no difference in rate of hips dislocating posteriorly (P = .159) or multidirectional (P = .508) instability; notably 58.8% of dislocations in the DAA cohort occurred posteriorly. There were no differences in dislocation timing or revision rate. Acetabular anteversion was highest in the PA cohort compared to DAA and LA (21.5 versus 19.2 versus 11.7 degrees, P = .049). CONCLUSION:After THA, patients in the PA group had a slightly higher dislocation rate compared to the DAA and LA groups. The PA group had a lower rate of anterior dislocation and nearly 60% of DAA dislocations occurred posteriorly. However, with no differences in other parameters including revision rates or timing, our data suggests surgical approach may impact dislocation characteristics to a lesser degree than previous studies have suggested.

INTRODUCTION/BACKGROUND:Despite the excellent outcomes associated with primary total hip arthroplasty (THA), implant failure and revision continue to burden the healthcare system. The use of computer-assisted navigation (CAN) offers the potential for more accurate placement of hip components during surgery. While intraoperative CAN systems have been shown to improve outcomes in primary THA, their use in the context of revision total hip arthroplasty (rTHA) has not been elucidated. We sought to investigate the validity of using CAN during rTHA. METHODS:A retrospective analysis was performed at an academic medical institution identifying all patients who underwent rTHA using CAN from 2016-2019. Patients were 1:1 matched with patients undergoing rTHA without CAN (control) based on demographic data. Cup anteversion, inclination, change in leg length discrepancy (ΔLLD) and change in femoral offset between pre- and post-operative plain weight-bearing radiographic images were measured and compared between both groups. A safety target zone of 15-25° for anteversion and 30-50° for inclination was used as a reference for precision analysis of cup position. RESULTS:Eighty-four patients were included: 42 CAN cases and 42 control cases. CAN cases displayed a lower ΔLLD (5.74 ± 7.0 mm vs 9.13 ± 7.9 mm, p = 0.04) and greater anteversion (23.4 ± 8.53° vs 19.76 ± 8.36°, p = 0.0468). There was no statistical difference between the proportion of CAN or control cases that fell within the target safe zone (40% vs 20.9%, p =  0.06). Femoral offset was similar in CAN and control cases (7.63 ± 5.84 mm vs 7.14 ± 4.8 mm, p = 0.68). CONCLUSION/CONCLUSIONS:Our findings suggest that the use of CAN may improve accuracy in cup placement compared to conventional methodology, but our numbers are underpowered to show a statistical difference. However, with a ΔLLD of ~ 3.4 mm, CAN may be useful in facilitating the successful restoration of pre-operative leg length following rTHA. Therefore, CAN may be a helpful tool for orthopedic surgeons to assist in cup placement and LLD during complex revision cases.

BACKGROUND:Modern fluted titanium-tapered stems (FTTS) have been increasingly utilized to achieve primary stability in conversion and revision total hip arthroplasty with major femoral bone loss. This study sought to determine the radiographic and clinical outcomes of a monoblock FTTS in patients who had major femoral bone loss. METHODS:A multicenter retrospective observational study of all total hip arthroplasty patients who received a monoblock FTTS who had up to 5-year radiographic follow-up was conducted. Only patients with femoral Paprosky classifications of IIIa, IIIb, and IV were included. Eighty-one monoblock FTTS were examined. Median clinical follow-up was 29 months (range, 18 to 58). Stem subsidence and loosening were assessed on most recent radiographs. All-cause revisions and stem survivals were assessed. RESULTS:Median subsidence was 1.4 millimeters (mm) (range, 0 to 15.0). Sixteen (23.9%) and 3 (4.5%) stems had subsidence greater than 5 and 10 mm, respectively. All stems not acutely revised appeared stable, without evidence of loosening, at latest follow-up. Ten hips (12.3%) required reoperations. Of these, only 5 (6.2%) stems were removed; 4 due to periprosthetic joint infection and 1 for surgical exposure during acetabular revision. Kaplan-Meier analyses yielded an all-cause stem survivorship of 95.1% at 2-years and 87.1% at 4-years. Stem survivorships excluding septic causes was 98.8% at both 2 and 4 years. CONCLUSION/CONCLUSIONS:Monoblock FTTS in complex femoral reconstruction cases showed encouraging clinical and radiographic results in patients who had severe femoral bone loss at median 29 months follow-up.

INTRODUCTION/BACKGROUND:Arthrofibrosis remains a common cause of patient dissatisfaction and reoperation after total knee arthroplasty (TKA). Losartan is an angiotensin receptor blocker (ARB) with inhibitory effects on transforming growth factor beta, previously implicated in tissue repair induced fibrosis, and has been studied to prevent stiffness following hip arthroscopy. This study aimed to evaluate pre- and postoperative range of motion (ROM) and the incidence of manipulation under anesthesia (MUA) following primary TKA in patients taking Losartan preoperatively for hypertension. MATERIALS AND METHODS/METHODS:A retrospective review of 170 patients from 2012 to 2020 who underwent a primary, elective TKA and were prescribed Losartan at least three months prior to surgery. All patients who were prescribed Losartan and had a preoperative and postoperative ROM in their chart were included and were matched to a control group of patients who underwent TKA and had no Losartan prescription. ROM, MUA, readmissions, reoperations, and revisions were assessed using chi-square and independent sample t tests. RESULTS:Seventy-nine patients met the inclusion criteria. Preoperative ROM was similar between patients on Losartan and the control group (103.59° ± 16.14° vs. 104.59° ± 21.59°, respectively; p = 0.745). Postoperative ROM and ΔROM were greater for patients prescribed Losartan (114.29° ± 12.32° vs. 112.76° ± 11.65°; p = 0.429 and 10.57° ± 14.95° vs. 8.17° ± 21.68°; p = 0.422), though this difference did not reach statistical significance. There was no difference in readmission, rate of manipulation for stiffness, or all-cause revision rates. CONCLUSION/CONCLUSIONS:In this study, we found that the use of Losartan did not significantly improve postoperative ROM, reduce MUA or decrease revision rates. Further prospective studies using Losartan are required to elucidate the potential effects on ROM and incidence of arthrofibrosis requiring MUA. LEVEL III EVIDENCE/METHODS:Retrospective cohort study.