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.

Short-Term Indwelling Foley Catheters Do Not Reduce the Risk of Postoperative Urinary Retention in Uncomplicated Primary THA and TKA: A Randomized Controlled Trial.

BACKGROUND: The purpose of this randomized controlled trial was to determine whether a short-term Foley catheter (inserted in the operating room and removed upon arrival to the orthopaedic floor) would reduce the risk of postoperative urinary retention (POUR) in patients undergoing primary total hip (THA) and total knee arthroplasty (TKA). METHODS: Three hundred and eighty-eight patients undergoing inpatient primary TKA (n = 228) or THA (n = 160) with spinal anesthesia were randomized to receive a short-term Foley catheter (n = 194) or no Foley (n = 194). There were 143 male and 245 female patients. The primary outcome was POUR, defined as requiring ≥2 straight catheterizations or the placement of an indwelling urinary catheter when indicated by retention of ≥450 mL on bladder scans. Secondary outcomes included urinary tract infections (UTIs) within 3 weeks and the need for ≥1 straight catheterization. A power analysis determined that 194 patients per group were required to detect a 7% minimal clinically important difference in POUR rates at 80% power and alpha of 0.05. Intention-to-treat and as-treated analyses were performed (2 patients received the non-allocated treatment). Outcomes were compared between the groups using univariate and multivariate analyses, with alpha < 0.05. RESULTS: Nine patients developed POUR: 4 in the short-term Foley group and 5 in the control group (2.1% versus 2.6%; p = 1.00). Of those who developed POUR, 8 were male and 1 was female (88.9% versus 11.1%; p = 0.002). Twenty-four patients required ≥1 straight catheterization: 10 in the Foley group and 14 in the control group (5.2% versus 7.2%; p = 0.40). Four patients developed UTIs: 3 in the Foley group and 1 in the control group (1.5% versus 0.5%; p = 0.62) on intention-to-treat analysis, and 4 in the Foley group and none in the control group (2.1% versus 0.0%; p = 0.12) on as-treated analysis. CONCLUSIONS: The use of a short-term Foley catheter inserted in the operating room and removed on arrival to the orthopaedic floor does not decrease the rate of POUR. LEVEL OF EVIDENCE: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Intra-articular corticosteroid injections are associated with a dose-dependent risk of total knee arthroplasty at 5 years.

PURPOSE: Intra-articular corticosteroid injections (CSI) are used commonly for the non-operative management of patients with knee pain. Recent literature has raised concern for chondrotoxicity of CSI. The purpose of the present study is to evaluate for any dose-dependent association between CSI in non-osteoarthritic knees and subsequent total knee arthroplasty (TKA). METHODS: The Pearl Diver database identified patients with a diagnosis of knee pain without concomitant osteoarthritis who were administered CSI over a 2-year period. Patients were compared to matched and unmatched cohorts. The primary endpoint was the incidence of TKA at 5 years. Multivariable regression analysis was used to assess CSI quantity as an independent risk factor. RESULTS: 49,443 of 986,162 (5.0%) Patients diagnosed with knee pain without concomitant knee osteoarthritis who received at least one CSI were identified. At 5 years, there was a higher incidence of TKA in the matched injection cohort relative to the non-injection matched cohort (0.26 vs 0.13%; p < 0.001) and unmatched cohort (0.26 vs. 0.10%, p < 0.001). The quantity of CSI corresponded with an increased probability of TKA at 5 years; one injection: 0.22% (OR 1.23, 95% CI [0.87-1.74], p = 0.236); two injections: 0.39% (OR 1.98 CI [1.06-3.67], p = 0.03, three or more injections: 0.49% (OR 3.22 CI [1.60-6.48], p = 0.001). The average time to TKA after one CSI was 3.03 ± 2.29 years. This time was nearly halved with three CSI (1.78 ± 0.80 years, p < 0.001). CONCLUSIONS: Intra-articular corticosteroid injections in patients without knee osteoarthritis at the time of injection are associated with a dose-dependent risk of TKA at 5 years. CSI may not be as benign of a treatment modality as previously thought.

Vitamin D3 Supplementation Prior to Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: The purpose of this randomized controlled trial was to determine if a one-time dose of vitamin D3 prior to total knee arthroplasty improves function and patient-reported outcomes, while decreasing complications. METHODS: One hundred seven patients undergoing primary total knee arthroplasty were randomized to receive 50,000 international units vitamin D3 (57 patients) or placebo (50 patients) on the morning of surgery. Power analysis determined 45 patients were required in each cohort to detect a minimal clinically important difference of 6 points in the functional component of the 2011 version of the Knee Society Score (KSS), assuming an alpha of 0.05 and power of 80%. KSS and a Timed Up and Go Test (TUGT) were measured preoperatively and at 3 and 6 weeks postoperatively. RESULTS: There was no difference in improvement of KSS at 3 weeks (+4.8 points vitamin D3 versus +3.0 points placebo; P = .6) or 6 weeks (+14.5 points vitamin D3 versus +12.4 points placebo; P = .5) from baseline. There was no difference in change in TUGT at 3 weeks (+1.2 seconds vitamin D3 versus +0.6 seconds placebo; P = .6) or 6 weeks (-0.3 seconds vitamin D3 versus -0.9 seconds placebo; P = .6) from baseline. There were 4 complications in the placebo cohort within the first 90 days postoperatively and 5 complications in the vitamin D3 cohort (P = 1.0). CONCLUSION: Supplementation with 50,000 international units vitamin D3 on the day of surgery failed to demonstrate statistical significant differences in functional KSS, TUGT times, or complications in the early postoperative period compared to placebo. LEVEL OF EVIDENCE: Level I, therapeutic study.

Early Results of a Randomized Controlled Trial of Partial Versus Total Knee Arthroplasty.

BACKGROUND: Debate still exists regarding the benefits of unicompartmental (UKA) versus total knee arthroplasty (TKA) for the treatment of medial compartment osteoarthritis. The purpose of this randomized trial is to compare the early outcomes of UKA versus TKA. METHODS: One-hundred and seven candidates for UKA were randomized at two centers; 57 candidates received UKA and 50 received TKA. Six-week and 6-month outcome measures including Knee Injury and Osteoarthritis Outcome Score, Joint Replacement (KOOS, JR), Knee Society Score (KSS), Forgotten Joint Score (FJS), and VR-12 global health scores were obtained. No demographic or baseline patient reported outcome (PRO) differences were present suggesting successful randomization (P > .05). RESULTS: UKA demonstrated shorter operative times (UKA = 65 minutes, TKA = 74 minutes; P < .001) and length of stay (UKA = 0.7 nights, TKA = 1.2 nights; P < .01). At 6 weeks, there were no differences in KOOS, JR (P = .755), KSS (P = .754), FJS (P = .664), or PRO change from preoperative scores (P = .468). There were three surgical complications within 90 days in each group. The duration of opioid consumption (UKA = 33.8 days, TKA = 28.5 days; P = .290) and return to work (UKA = 57.1 days, TKA = 47.3 days; P = .346) did not differ between groups. CONCLUSION: Data suggest no clinically significant differences between UKA and TKA in the early postoperative period in regards to patient-reported outcome measures, duration of opioid use, or return to work. Patients undergoing UKA can anticipate a shorter length of stay and greater early range of motion. All-cause short-term complications may be more prevalent with TKA.

Malseating of modular dual mobility liners.

AIMS: Prior studies have identified that malseating of a modular dual mobility liner can occur, with previous reported incidences between 5.8% and 16.4%. The aim of this study was to determine the incidence of malseating in dual mobility implants at our institution, assess for risk factors for liner malseating, and investigate whether liner malseating has any impact on clinical outcomes after surgery. METHODS: We retrospectively reviewed the radiographs of 239 primary and revision total hip arthroplasties with a modular dual mobility liner. Two independent reviewers assessed radiographs for each patient twice for evidence of malseating, with a third observer acting as a tiebreaker. Univariate analysis was conducted to determine risk factors for malseating with Youden's index used to identify cut-off points. Cohen's kappa test was used to measure interobserver and intraobserver reliability. RESULTS: In all, 12 liners (5.0%), including eight Stryker (6.8%) and four Zimmer Biomet (3.3%), had radiological evidence of malseating. Interobserver reliability was found to be 0.453 (95% confidence interval (CI) 0.26 to 0.64), suggesting weak inter-rater agreement, with strong agreement being greater than 0.8. We found component size of 50 mm or less to be associated with liner malseating on univariate analysis (p = 0.031). Patients with malseated liners appeared to have no associated clinical consequences, and none required revision surgery at a mean of 14 months (1.4 to 99.2) postoperatively. CONCLUSION: The incidence of liner malseating was 5.0%, which is similar to other reports. Component size of 50 mm or smaller was identified as a risk factor for malseating. Surgeons should be aware that malseating can occur and implant design changes or changes in instrumentation should be considered to lower the risk of malseating. Although further follow-up is needed, it remains to be seen if malseating is associated with any clinical consequences. Cite this article: Bone Jt Open 2021;2(10):858-864.

Similar 90-day outcomes among inpatient and outpatient arthroplasties : a single-surgeon matched cohort analysis.

AIMS: The proportion of arthroplasties performed in the ambulatory setting has increased considerably. However, there are concerns whether same-day discharge may increase the risk of complications. The aim of this study was to compare 90-day outcomes between inpatient arthroplasties and outpatient arthroplasties performed at an ambulatory surgery centre (ASC), and determine whether there is a learning curve associated with performing athroplasties in an ASC. METHODS: Among a single-surgeon cohort of 970 patients who underwent arthroplasty at an ASC, 854 (88.0%) were matched one-to-one with inpatients based on age, sex, American Society of Anesthesiologists (ASA) grade, BMI, and procedure (105 could not be adequately matched and 11 lacked 90-day follow-up). The cohort included 281 total hip arthroplasties (THAs) (32.9%), 267 unicompartmental knee arthroplasties (31.3%), 242 primary total knee arthroplasties (TKAs) (28.3%), 60 hip resurfacings (7.0%), two revision THAs (0.3%), and two revision TKAs (0.3%). Outcomes included readmissions, reoperations, visits to the emergency department, unplanned clinic visits, and complications. RESULTS: The inpatient and outpatient groups were similar in all demographic variables, reflecting successful matching. The reoperation rate was 0.9% in both cohorts (p = 1.000). Rates of readmission (2.0% inpatient vs 1.6% outpatient), any complications (5.9% vs 5.6%), minor complications (4.2% vs 3.9%), visits to the emergency department (2.7% vs 1.4%), and unplanned clinic visits (5.7% vs 5.5%) were lower in the outpatient group but did not reach significance with the sample size studied. A learning curve may exist, as seen by significant reductions in the reoperation and overall complication rates among outpatient arthroplasties over time (p = 0.032 and p = 0.007, respectively), despite those in this group becoming significantly older and heavier (both p < 0.001) during the study period. CONCLUSION: Arthroplasties performed at ASCs appear to be safe in appropriately selected patients, but may be associated with a learning curve as shown by the significant decrease in complication and reoperation rates during the study period. Cite this article: Bone Joint J 2021;103-B(7 Supple B):84-90.

Understanding the difference between symptoms of focal cartilage defects and osteoarthritis of the knee: a matched cohort analysis.

PURPOSE: Comparing symptoms of patients with focal cartilage defects of the knee to those with knee osteoarthritis. METHODS: Prospectively maintained databases identified patients with focal cartilage defects (FCD group) who underwent osteochondral allograft transplantation and patients with osteoarthritis (OA group) undergoing arthroplasty. Patients between 18 and 55 years of age were included and matched based on age. Baseline patient demographics, symptoms, and patient-reported outcomes including the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement (KOOS JR), SF-12, and VR-12 questionnaires were recorded. Patient symptoms and individual responses of the KOOS JR were compared between groups. Regression analysis was used to evaluate the association between pre-operative factors that significantly differed between groups and the KOOS JR questionnaire. RESULTS: Sixty-four patients were included: 32 patients in each group. The FCD group had a significantly lower body mass index (BMI) (p = 0.04) and greater number of workers' compensation cases (p = 0.027) when compared to the OA group. Patients in the OA group complained more frequently of medial-sided pain (p = 0.02) and knee swelling (p = 0.003). The OA cohort also had greater pain with fully straightening the knee (p = 0.012), pain with standing upright (p = 0.016), and pain with rising from sitting (p = 0.003). Patients in the FCD group had greater KOOS JR outcome scores (51.5 ± 12.9 vs. 41.5 ± 20.5; p = 0.023). CONCLUSION: When compared to patients with focal cartilage defects, adults with knee osteoarthritis scheduled for knee arthroplasty have a more severe presentation of symptoms, particularly medial-sided pain, swelling of the knee, pain associated with straightening the knee, standing upright, and rising from sitting.

Atypical Subtrochanteric Femur Fracture and Hip Osteoarthritis Treated with a Revision Monoblock Stem and Strut Allograft: A Case Report.

CASE: A 73-year-old woman was diagnosed with a nondisplaced incomplete atypical bisphosphonate-related subtrochanteric femur fracture and ipsilateral hip osteoarthritis. She was treated with a total hip arthroplasty using a monoblock revision stem and a strut allograft to provide adjunctive mechanical and biological support. At the final follow-up, the patient had no pain, the stem was well fixed, and the allograft strut had incorporated; however, a persistent fracture line was noted. CONCLUSION: When an atypical femur fracture coexists with hip osteoarthritis, total hip arthroplasty may be a reasonable treatment option to address the fracture and concomitant hip osteoarthritis with a single surgical intervention. However, consideration should be given to using a stem with distal fixation and augmenting the construct with a strut allograft.