What Are the Implications of Alternative Alpha Thresholds for Hypothesis Testing in Orthopaedics?

Randomized Controlled Trial of Irrigation-Coupled Bipolar Electrocautery Versus Tourniquet in Total Knee Arthroplasty

Background

Recovery from total knee arthroplasty remains arduous for some patients, prompting interest in perioperative management. While tourniquet use is not associated with longer-term outcomes, its effect on quadriceps strength in the immediate postoperative window is unknown.

Methods

A single-center, double-blind, randomized controlled trial of 66 patients undergoing primary total knee arthroplasty from 2019 to 2022 was performed to compare the use of an irrigation-coupled bipolar device (ICBD) and no tourniquet (ICBD group, N = 34) to tourniquet use with no ICBD (tourniquet group, N = 32). Groups were similar with respect to age, sex, and obesity. The primary outcome was quadriceps strength at 2 weeks, measured using a handheld dynamometer and standardized to the contralateral side. Knee Injury and Osteoarthritis Outcome Score for Joint Replacement was measured with the difference from baseline serving as a secondary outcome. Comparisons were performed using the Student's t-test.

Results

Only 28 patients, 14 in each group, had primary outcome data. At 2-weeks, quadriceps strength was higher in the ICBD group compared to the tourniquet group (83% vs 70%), though not statistically significant (P = .16). There was no difference between the ICBD and tourniquet groups in Knee Injury and Osteoarthritis Outcome Score for Joint Replacement changed at 2-weeks (13 vs 10, P = .37) or 6-weeks (16 vs 17, P = .76).

Conclusions

Tourniquet use was associated with a small but not statistically significant difference in quadriceps strength at 2 weeks that may justify further study given the loss of power here. There can be limitations to conducting randomized controlled trials that are important for early-career investigators to consider and that were magnified due to COVID-related restrictions in the present study, which we discuss.

Level of Evidence

Level II.

Nutritional Laboratory Studies Prior to Total Knee Arthroplasty: Practice Versus Publication

BACKGROUND

Recent emphasis has been placed on nutritional status assessment prior to total knee arthroplasty (TKA), including multiple American Academy of Orthopaedic Surgeons publications recommending specific laboratory studies; however, the frequency with which surgeons obtain these laboratory studies remains unclear. We sought to assess the incidence of ordering nutritional laboratory studies in the 90 days prior to TKA, utilizing data from a large administrative claims database.

METHODS

With use of the PearlDiver database, we identified 557,670 patients undergoing primary TKA from 2011 to 2020 with a metabolic panel or blood cell count claim within 90 days prior to TKA. We then determined the incidence of prealbumin, transferrin, vitamin D, and zinc laboratory tests claimed 90 days prior to TKA. Associations between claims and the year of surgery, patient demographics, and clinical characteristics were assessed by comparing proportions and chi-square testing.

RESULTS

Nutritional laboratory studies were infrequently claimed within 90 days prior to TKA, with studies for prealbumin being performed in 2.2% of patients; transferrin, 1.9%; vitamin D, 10.2%; and zinc, 0.2%. From 2011 to 2020, there was a moderate but steady increase in the proportion of patients with claims for prealbumin (change from 0.8% in 2011 to 3.4% in 2020; p < 0.001), transferrin (0.8% to 2.7%; p < 0.001), and vitamin D (7.6% to 9.4%; p < 0.001) laboratory tests but there was less of a change for zinc (0.1% to 0.2%; p < 0.001). There were weak-to-absent associations of age, gender, obesity, diabetes, and anemia with laboratory claims.

CONCLUSIONS

Despite multiple publications and recommendations, nutritional laboratory studies are infrequently ordered prior to TKA. Although there has been a slight increase in the use of nutritional laboratory studies over the past decade, patient factors such as gender and obesity were not associated with this increase. Understanding current practice patterns may help target future areas for improvement.

LEVEL OF EVIDENCE

Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Novel machine-learning analysis of SARS-CoV-2 infection in a subclinical nonhuman primate model using radiomics and blood biomarkers

Detection of the physiological response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is challenging in the absence of overt clinical signs but remains necessary to understand a full subclinical disease spectrum. In this study, our objective was to use radiomics (from computed tomography images) and blood biomarkers to predict SARS-CoV-2 infection in a nonhuman primate model (NHP) with inapparent clinical disease. To accomplish this aim, we built machine-learning models to predict SARS-CoV-2 infection in a NHP model of subclinical disease using baseline-normalized radiomic and blood sample analyses data from SARS-CoV-2-exposed and control (mock-exposed) crab-eating macaques. We applied a novel adaptation of the minimum redundancy maximum relevance (mRMR) feature-selection technique, called mRMR-permute, for statistically-thresholded and unbiased feature selection. Through performance comparison of eight machine-learning models trained on 14 feature sets, we demonstrated that a logistic regression model trained on the mRMR-permute feature set can predict SARS-CoV-2 infection with very high accuracy. Eighty-nine percent of mRMR-permute selected features had strong and significant class effects. Through this work, we identified a key set of radiomic and blood biomarkers that can be used to predict infection status even in the absence of clinical signs. Furthermore, we proposed and demonstrated the utility of a novel feature-selection technique called mRMR-permute. This work lays the foundation for the prediction and classification of SARS-CoV-2 disease severity.

Are Oblique Views Necessary? A Review of the Clinical Value of Oblique Knee Radiographs in the Acute Setting

Introduction: The purpose of this study was to assess the added clinical value of oblique knee radiographs four-view (4V) compared to orthogonal anteroposterior (AP) and lateral radiographs in a two-view (2V) series. Methods: We obtained 200 adult, 4V knee radiographs in 200 patients in the ED and randomly divided them into two groups with 100 series in each group. Ten reviewers — three musculoskeletal radiologists and seven orthopedic surgeons — performed radiograph analyses. These reviewers were randomly divided evenly into group one and group two. Reviewers were blinded to patient data and first reviewed 2V radiographs (AP/lateral) only, and then reviewed 4V radiographs, including AP/lateral, and two additional oblique views for the same patients at least four weeks later. Acute pathology identification and the need for further imaging was assessed for all reviewers, and clinical decision-making (operative vs nonoperative treatment, need for admission, need for additional imaging) was assessed only by the seven orthopaedic surgeon reviewers. Results: Mean sensitivity for pathology identification was 79% with 2V and 81% with 4V (P =0.25). Intra-observer kappa value was 0.81 (range 0.54-1.00). Additional oblique radiographs led orthopaedic reviewers to change their treatment recommendations in 62/329 patients (18.84%) (P <0.001). Eight of 329 radiographic series were identified as “critical misses.” (2.43%) (P =0.004), when pathology was reported as normal or reviewers recommended nonoperative treatment on 2V radiographs but changed their recommendation to operative management after the addition of oblique radiographs. The number needed to treat (NNT) for any treatment change and for “critical misses” was 83 and 643, respectively. Conclusion: Although the addition of oblique radiographs may improve a clinician’s ability to identify subtle pathologic findings not identified on 2V, it rarely leads to significant changes in treatment recommendations. Given the high NNT, limiting the usage of these oblique radiographs in the general patient population may reduce costs without significantly affecting patient care.

National Trends Show Declining Use of Arthroscopic Subacromial Decompression Without Rotator Cuff Repair

PURPOSE

The goal of this study was to investigate trends in the United States for arthroscopic subacromial decompression (aSAD) and open SAD (oSAD) with and without rotator cuff repair (RCR) between 2010 and 2018.

METHODS

The PearlDiver Mariner claims database was queried using CPT codes for open and arthroscopic subacromial decompression and rotator cuff repair. Patient cohorts were developed for those undergoing aSAD or oSAD between 2010 and 2018, then segmented by whether RCR was performed simultaneously. Annual incidence was analyzed, as were associated diagnosis codes, and concomitant shoulder-associated procedures performed on the same day.

RESULTS

The PearlDiver Mariner dataset from 2010 to 2018 included 186,932 patients that underwent aSAD, while 9,263 patients underwent oSAD. The total incidence of aSAD declined from 118.0 to 71.3 per 100,000 (39.6% decrease) (P < .001). This change was due primarily to a decreasing incidence of aSAD performed without RCR, which declined from 66.3 to 25.5 per 100,000 (61.5% decrease) (P < .001). During the same period, the incidence of aSAD combined with RCR remained relatively stable, from 51.7 to 45.8 per 100,000 (11.5% decrease) (P = .27). The overall incidence of oSAD declined from 7.1 to 2.2 per 100,000 (68.1% decrease) (P < .001).

CONCLUSIONS

The overall rate of aSAD has declined in recent years, primarily due to a large decrease in the incidence of aSAD without RCR as an isolated treatment for rotator cuff disorders.

CLINICAL RELEVANCE

Prior studies have demonstrated a rising incidence of SAD; however, high-level clinical evidence and clinical practice guidelines have challenged its efficacy. It is important for orthopaedic surgeons to understand evolving national trends in management among their peers.