Background: Many surgeons recommend weight loss for patients with obesity before total joint arthroplasty (TJA), but few studies have evaluated weight loss interventions. This study compared weight loss using a remote dietitian and a mobile application (app) with weight loss using standard care for patients with severe obesity before TJA. Methods: This multicenter randomized controlled trial included 60 subjects with a body mass index (BMI) of 40 to 47 kg/m 2 who had been scheduled for primary total hip or knee arthroplasty from September 2019 to January 2023. The mean age was 61 years, 67% were women, and the mean BMI was 44 kg/m 2 . The control subjects (n = 29) received standard care; the intervention subjects (n = 31) completed video calls with dietitians and used a mobile app for 12 weeks preoperatively. Weights and surveys were collected at baseline and 12 weeks, with 87% follow-up. Weight loss, patient-reported outcomes, complications, revisions, and reoperations were compared. The mean follow-up was 1.8 years. Results: The intervention subjects lost more weight (−4.1 versus −2.1 kg, p = 0.22) and had larger decreases in BMI (−1.4 versus −0.9 kg/m 2 , p = 0.36 than the controls, but not significantly so. The intervention subjects had higher odds of achieving a BMI of <40 kg/m 2 (odds ratio = 1.9, p = 0.44), but not significantly so. There were no significant differences in the mean change in the Hip disability and Osteoarthritis Outcome Score, the Knee injury and Osteoarthritis Outcome Score, or the Lower Extremity Activity Scale score. At baseline, only 11% had seen a dietitian in the last 3 months. Most subjects (83%) felt that video calls were helpful. There were no differences in complications between the groups; there was a patellar fracture in the control group and a deep venous thromboembolism in the intervention group. Conclusions: A preoperative weight loss intervention using a dietitian and a mobile app was feasible and viewed favorably among patients. Remote dietitians and mobile apps may address gaps in access to obesity treatment before TJA. While the intervention subjects lost more weight and were more likely to achieve a BMI of <40 kg/m 2 , the differences were not significant. More intensive interventions may be needed to achieve enough weight loss for clinically important improvements in TJA. Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.
Precision or Pitfall? Evaluating the Accuracy of ICD-10 Coding for Cemented Total Hip Arthroplasty
Background: The International Statistical Classification of Diseases and Related Health Problems, 10th Revision, Procedure Coding System (ICD-10-PCS) was adopted in the U.S. in 2015. Proponents of the ICD-10-PCS have stated that its granularity allows for a more accurate representation of the types of procedures performed by including laterality, joint designation, and more detailed procedural data. However, other researchers have expressed concern that the increased number of codes adds further complexity that leads to inaccurate and inconsistent coding, rendering registry and research data based on ICD-10-PCS codes invalid and inaccurate. We aimed to determine the accuracy of the ICD-10-PCS for identifying cemented fixation in primary total hip arthroplasty (THA). Methods: We retrospectively reviewed all cemented primary THAs performed at 4 geographically diverse, academic medical centers between October 2015 and October 2020. Cemented fixation was identified from the ICD-10-PCS coding for each procedure. The accuracy of an ICD-10-PCS code relative to the surgical record was determined by postoperative radiograph and chart review, and cross-referencing with institution-level coding published by the American Joint Replacement Registry (AJRR) was also performed. Results: A total of 552 cemented THA cases were identified within the study period, of which 452 (81.9%) were correctly coded as cemented with the ICD-10-PCS. The proportion of cases that were correctly coded was 187 of 260 (72%) at Institution A, 158 of 185 (85%) at Institution B, 35 of 35 (100%) at Institution C, and 72 of 72 (100%) at Institution D. Of the 480 identified cemented THA cases at 3 of the 4 institutions, 403 (84%) were correctly reported as cemented to the AJRR (Institution A, 185 of 260 cases [71%]; Institution B, 185 of 185 [100%]; and Institution C, 33 of 35 [94%]). Lastly, of these 480 identified cemented THA cases, 317 (66%) were both correctly coded with the ICD-10-PCS and correctly reported as cemented to the AJRR. Conclusions: Our findings revealed existing discrepancies within multiple institutional data sets, which may lead to inaccurate reporting by the AJRR and other registries that rely on ICD-10-PCS coding. Caution should be exercised when utilizing ICD-10 procedural data to evaluate specific details from administrative claims databases as these inaccuracies present inherent challenges to data validity and interpretation.
Utility of Diagnostic Tests Before Reimplantation in Patients Undergoing 2-Stage Revision Total Joint Arthroplasty
Introduction: Periprosthetic joint infection (PJI) is a devastating complication after total joint arthroplasty (TJA), with treatment failure occurring in 12% to 28% after 2-stage revision. It is vital to identify diagnostic tools indicative of persistent infection or treatment failure after 2-stage revision for PJI. Methods: The Cochrane Library, PubMed (MEDLINE), and EMBASE were searched for randomized controlled trials and comparative observational studies published before October 3, 2021, which evaluated the utility of serum/plasma biomarkers (erythrocyte sedimentation rate [ESR], C-reactive protein [CRP], interleukin-6 [IL-6], fibrinogen, D-dimer), synovial biomarkers (white blood cell [WBC] count, neutrophil percentage [PMN %], alpha-defensin [AD], leukocyte esterase [LE]), tissue frozen section, tissue culture, synovial fluid culture, or sonicated spacer fluid culture indicative of persistent infection before the second stage of 2-stage revision for PJI or treatment failure after 2-stage revision for PJI. Results: A total of 47 studies including 6,605 diagnostic tests among 3,781 2-stage revisions for PJI were analyzed. Among those cases, 723 (19.1%) experienced persistent infection or treatment failure. Synovial LE (sensitivity 0.25 [0.10-0.47], specificity 0.99 [0.93-1.00], positive likelihood ratio 14.0 [1.45-135.58]) and serum IL-6 (sensitivity 0.52 [0.33-0.70], specificity 0.92 [0.85-0.96], positive likelihood ratio 7.90 [0.86-72.61]) had the highest diagnostic accuracy. However, no biomarker was associated with a clinically useful negative likelihood ratio. In subgroup analysis, synovial PMN %, synovial fluid culture, serum ESR, and serum CRP had limited utility for detecting persistent infection before reimplantation (positive likelihood ratios ranging 2.33-3.74; negative likelihood ratios ranging 0.31-0.9) and no utility for predicting failure after the second stage of 2-stage revision. Conclusions: Synovial WBC count, synovial PMN %, synovial fluid culture, serum ESR, and serum CRP have modest sensitivity and specificity for predicting persistent infection during the second stage of 2-stage revision, suggesting some combination of these diagnostic tests might be useful before reimplantation. No biomarker or culture accurately predicted treatment failure after reimplantation. Level of Evidence: Level III . See Instructions for Authors for a complete description of levels of evidence.
Cooled Radiofrequency Ablation Compared with a Single Injection of Hyaluronic Acid for Chronic Knee Pain
Background: Knee osteoarthritis is a painful and sometimes debilitating disease that often affects patients for years. Current treatments include short-lasting and often repetitive nonsurgical options, followed by surgical intervention for appropriate candidates. Cooled radiofrequency ablation (CRFA) is a minimally invasive procedure for the treatment of pain related to knee osteoarthritis. This trial compared the efficacy and safety of CRFA with those of a single hyaluronic acid (HA) injection. Methods: Two hundred and sixty subjects with knee osteoarthritis pain that was inadequately responsive to prior nonoperative modalities were screened for enrollment in this multicenter, randomized trial. One hundred and eighty-two subjects who met the inclusion criteria underwent diagnostic block injections and those with a minimum of 50% pain relief were randomized to receive either CRFA on 4 genicular nerves or a single HA injection. One hundred and seventy-five subjects were treated (88 with CRFA and 87 with HA). Evaluations for pain (Numeric Rating Scale [NRS]), function (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), quality of life (Global Perceived Effect [GPE] score and EuroQol-5 Dimensions-5 Level [EQ-5D-5L] questionnaire), and safety were performed at 1, 3, and 6 months after treatment. Results: Demographic characteristics did not differ significantly between the 2 study groups. A total of 158 subjects (76 in the CRFA group and 82 in the HA group) completed the 6-month post-treatment follow-up. In the CRFA group, 71% of the subjects had ≥50% reduction in the NRS pain score (primary end point) compared with 38% in the HA group (p < 0.0001). At 6 months, the mean NRS score reduction was 4.1 ± 2.2 for the CRFA group compared with 2.5 ± 2.5 for the HA group (p < 0.0001). The mean WOMAC score improvement at 6 months from baseline was 48.2% in the CRFA group and 22.6% in the HA group (p < 0.0001). At 6 months, 72% of the subjects in the CRFA group reported improvement in the GPE score compared with 40% in the HA group (p < 0.0001). Conclusions: CRFA-treated subjects demonstrated a significant improvement in pain relief and overall function compared with subjects treated with a single injection of HA. No serious adverse events related to either procedure were noted, and the overall adverse-event profiles were similar. Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.
Definition of Successful Infection Management and Guidelines for Reporting of Outcomes After Surgical Treatment of Periprosthetic Joint Infection