Magnetic Resonance Arthrogram Outperforms Standard Magnetic Resonance Imaging 2 Weeks After First Shoulder Dislocation for Labral Tear Diagnosis.

PURPOSE: To determine the comparative accuracy and precision of routine magnetic resonance imaging (MRI) versus magnetic resonance (MR) arthrogram in measuring labral tear size as a function of time from a shoulder dislocation. METHODS: We retrospectively evaluated consecutive patients who underwent primary arthroscopic stabilization between 2012 and 2021 in a single academic center. All patients completed a preoperative MRI or MR arthrogram of the shoulder within 60 days of injury and subsequently underwent arthroscopic repair within 6 months of imaging. Intraoperative labral tear size and location were used as standards for comparison. Three musculoskeletal radiologists independently interpreted tear extent using a clock-face convention. Accuracy and precision of MR labral tear measurements were defined based on location and size of the tear, respectively. Accuracy and precision were compared between MRI and MR arthrogram as a function of time from dislocation. RESULTS: In total, 32 MRIs and 65 MR arthrograms (total n = 97) were assessed. Multivariate analysis demonstrated that intraoperative tear size, early imaging, and arthrogram status were associated with increased MR accuracy and precision (P < .05). Ordering surgeons preferred arthrogram for delayed imaging (P = .018). For routine MRI, error in accuracy increased by 3.4° per day and error in precision increased by 2.3° per day (P < .001) from time of injury. MR arthrogram, however, was not temporally influenced. Significant loss of accuracy and precision of MRI compared with MR arthrogram occurred at 2 weeks after an acute shoulder dislocation. CONCLUSIONS: Compared with MR arthrogram, conventional MRI demonstrates time-dependent loss of accuracy and precision in determining shoulder labral tear extent after dislocation, with statistical divergence occurring at 2 weeks. LEVEL OF EVIDENCE: Level II, retrospective radiographic diagnostic study.

Defining Critical Humeral Bone Loss: Inferior Craniocaudal Hill-Sachs Extension as Predictor of Recurrent Instability After Primary Arthroscopic Bankart Repair.

BACKGROUND: The glenoid track concept for shoulder instability primarily describes the medial-lateral relationship between a Hill-Sachs lesion and the glenoid. However, the Hill-Sachs position in the craniocaudal dimension has not been thoroughly studied. HYPOTHESIS: Hill-Sachs lesions with greater inferior extension are associated with increased risk of recurrent instability after primary arthroscopic Bankart repair. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: The authors performed a retrospective analysis of patients with on-track Hill-Sachs lesions who underwent primary arthroscopic Bankart repair (without remplissage) between 2007 and 2019 and had a minimum 2-year follow-up. Recurrent instability was defined as recurrent dislocation or subluxation after the index procedure. The craniocaudal position of the Hill-Sachs lesion was measured against the midhumeral axis on sagittal magnetic resonance imaging (MRI) using either a Hill-Sachs bisecting line through the humeral head center (sagittal midpoint angle [SMA], a measure of Hill-Sachs craniocaudal position) or a line tangent to the inferior Hill-Sachs edge (lower-edge angle [LEA], a measure of Hill-Sachs caudal extension). Univariate and multivariate regression were used to determine the predictive value of both SMA and LEA for recurrent instability. RESULTS: In total, 176 patients were included with a mean age of 20.6 years, mean follow-up of 5.9 years, and contact sport participation of 69.3%. Of these patients, 42 (23.9%) experienced recurrent instability (30 dislocations, 12 subluxations) at a mean time of 1.7 years after surgery. Recurrent instability was found to be significantly associated with LEA >90° (ie, Hill-Sachs lesions extending below the humeral head equator), with an OR of 3.29 (P = .022). SMA predicted recurrent instability to a lesser degree (OR, 2.22; P = .052). Post hoc evaluation demonstrated that LEA >90° predicted recurrent dislocations (subset of recurrent instability) with an OR of 4.80 (P = .003). LEA and SMA were found to be collinear with Hill-Sachs interval and distance to dislocation, suggesting that greater LEA and SMA proportionally reflect lesion severity in both the craniocaudal and medial-lateral dimensions. CONCLUSION: Inferior extension of an otherwise on-track Hill-Sachs lesion is a highly predictive risk factor for recurrent instability after primary arthroscopic Bankart repair. Evaluation of Hill-Sachs extension below the humeral equator (inferior equatorial extension) on sagittal MRI is a clinically facile screening tool for higher-risk lesions with subcritical glenoid bone loss. This threshold for critical humeral bone loss may inform surgical stratification for procedures such as remplissage or other approaches for at-risk on-track lesions.

Pseudoparesis and pseudoparalysis in the setting of massive irreparable rotator cuff tear: demographic, anatomic, and radiographic risk factors.

BACKGROUND: The primary purpose of this study was to identify demographic, anatomic, and radiographic risk factors for active forward elevation (AFE) <90° in the setting of massive, irreparable rotator cuff tear (miRCT). The secondary purpose was to identify characteristics differentiating between patients with pseudoparalysis (AFE <45°) and pseudoparesis (AFE >45° but <90°). METHODS: This was a retrospective case-control study reviewing patients with miRCTs at a single institution between January 12, 2016 and November 26, 2020. Patients were separated into 2 cohorts based on presence or absence of preoperative AFE <90° with maintained passive range of motion. Demographics, RCT pattern, and radiographic parameters were assessed as risk factors for AFE <90°. A secondary analysis was conducted to compare patients with pseudoparalysis and pseudoparesis. RESULTS: There were 79 patients in the AFE <90° cohort and 50 patients in the control cohort. Univariate analysis confirmed significant differences between the AFE <90° and control cohort in age (71.9 ± 11.0 vs. 65.9 ± 9.1 years), arthritis severity (34.2% vs. 16.0% grade 3 Samilson-Prieto), acromiohumeral distance (AHD; 4.8 ± 2.7 vs. 7.6 ± 2.6 mm), fatty infiltration of the supraspinatus (3.3 ± 0.9 vs. 2.8 ± 0.8) and subscapularis (2.0 ± 1.2 vs. 1.5 ± 1.0), and proportion of subscapularis tears (55.7% vs. 34.0%). On multivariate analysis, age (odds ratio [OR] 1.08, P = .014), decreased AHD (OR 0.67, P < .001), severe arthritis (OR 2.84, P = .041), and subscapularis tear (OR 6.29, P = .015) were independent factors predictive of AFE <90°. Secondary analysis revealed tobacco use (OR 3.54, P = .026) and grade 4 fatty infiltration of the supraspinatus (OR 2.22, P = .015) and subscapularis (OR 3.12, P = .042) as significant predictors for pseudoparalysis compared to pseudoparesis. CONCLUSIONS: In patients with miRCT, increased age, decreased AHD, severe arthritis, and subscapularis tear are associated with AFE <90°. Furthermore, patients with AFE <90° tend to have greater supraspinatus and subscapularis fatty infiltration. Lastly, among patients with AFE <90°, tobacco use and grade 4 fatty infiltration of the supraspinatus and subscapularis are associated with pseudoparalysis compared with pseudoparesis.

Criteria-based return to sport testing after open Latarjet reveals residual deficits and can be utilized for sports clearance with excellent outcomes at mean 3.6 year follow-up: A small case series of competitive athletes.

OBJECTIVE: The purpose of this study was to assess the use of a criteria-based return to sport (CBRTS) test to evaluate readiness for return to play (RTP) in competitive athletes that underwent open Latarjet. DESIGN: Retrospective case series. METHODS: Ten competitive athletes (mean age 19.9 years) treated with open Latarjet for recurrent glenohumeral instability underwent CBRTS testing at a mean of 5.3 months postoperatively. Testing consisted of four components: 1. isometric strength, 2. isokinetic strength, 3. endurance, and 4. function. Patients failing 0 or 1 component of the test were cleared to RTP. Patients failing multiple components underwent additional deficit-based rehabilitation. RESULTS: Of the 10 patients that tested, 4 passed their overall CBRTS test and were cleared to RTP. The remaining 6 patients failed the overall CBRTS test. Seven patients (70%) failed at least one section of the strength testing, two patients (20%) failed endurance testing, and two patients (20%) failed functional testing. At final follow-up (mean 3.6 years), 1 patient had recurrent instability (10%) and 9 patients returned to play (90%). CONCLUSIONS: CBRTS testing may be clinically useful for return to play clearance decisions after open Latarjet procedure, as it can reveal deficits that may not be identified with time-based clearance alone.

Dual Versus Single Plate Fixation of Displaced Midshaft Clavicle Fractures: A Cost-Effectiveness Analysis.

BACKGROUND: Prior studies have highlighted lower rates of reoperation if fixation of a displaced midshaft clavicle fracture is performed with dual plating (DP) compared with single plating (SP). Despite higher initial costs associated with the DP construct, the observed reduction in secondary surgeries compared with the SP construct may make it a more cost-effective treatment option. The objective of this study was to assess the cost-effectiveness of DP compared with SP in patients with operatively indicated displaced midshaft clavicle fractures. METHODS: We developed a decision tree to model the occurrence of postoperative complications (acute hardware complications, wound healing issues, deep infection, nonunion, and symptomatic hardware) associated with secondary surgeries. Complication-specific risk estimates were pooled for both plating techniques using the available literature. The time horizon was 2 years, and the analysis was conducted from the health-care payer's perspective. The costs were estimated using direct medical costs, and the benefits were measured in quality-adjusted life-years (QALYs). We assumed that DP would be $300 more expensive than SP initially. We conducted probabilistic and 1-way sensitivity analyses. RESULTS: The model predicted reoperation in 6% of patients in the DP arm compared with 14% of patients in the SP arm. In the base case analysis, DP increased QALYs by 0.005 and costs by $71 per patient, yielding an incremental cost-effectiveness ratio (ICER) of $13,242 per QALY gained. The sensitivity analysis demonstrated that the cost-effectiveness of DP was driven by the cost of the index surgery, risk of symptomatic hardware, and nonunion complications with SP and DP. At a willingness-to-pay threshold of $100,000 per QALY gained, 95% of simulations suggested that DP was cost-effective compared with SP. CONCLUSIONS: When indicated, operative management of displaced midshaft clavicle fractures using DP was found to be cost-effective compared with SP. Despite its higher initial hardware costs, DP fixation appears to offset its added costs with greater health utility via lower rates of reoperation and improved patient quality of life. LEVEL OF EVIDENCE: Economic and Decision Analysis Level II . See Instructions for Authors for a complete description of levels of evidence.

Recurrent Instability After Arthroscopic Bankart Repair in Patients With Hyperlaxity and Near-Track Lesions.

Background: Recurrent anterior shoulder instability after arthroscopic Bankart repair presents a challenging clinical problem, with the primary stabilization procedure often portending the best chance for clinical success. Purpose: To determine if capsuloligamentous laxity affects failure (recurrent dislocation, subluxation, and/or perceived instability symptoms) after arthroscopic Bankart repair in patients with near-track lesions (ie, those with smaller distance to dislocation [DTD]). Study Design: Case-control study; Level of evidence, 3. Methods: The authors retrospectively reviewed consecutive patients who underwent primary arthroscopic Bankart repair for recurrent anterior glenohumeral instability at a single institution between 2007 and 2019 and who had at least 2 years of follow-up data. Patients with glenoid bone loss >20%, off-track lesions, concomitant remplissage, or rotator cuff tear were excluded. Capsuloligamentous laxity, or hyperlaxity, was defined as external rotation >85° with the arm at the side and/or grade ≥2 in at least 2 planes with the shoulder at 90° of abduction. Near-track lesions were defined as those with a DTD <10 mm. Results: Included were 173 patients (mean age, 20.5 years; mean DTD, 16.2 mm), of whom 16.8% sustained a recurrent dislocation and 6.4% had recurrent subluxations (defined as any subjective complaint of recurrent instability without frank dislocation), for an overall recurrent instability rate of 23.1%. The rate of revision stabilization was 15.6%. The mean time to follow-up was 7.4 years. Independent predictors of recurrent instability were younger age (P = .001), smaller DTD (P = .021), >1 preoperative instability episode (P < .001), and the presence of hyperlaxity during examination under anesthesia (P = .013). Among patients with near-track lesions, those with hyperlaxity had a recurrent instability rate almost double that of patients without hyperlaxity (odds ratio, 34.1; P = .04). The increased rate of failure and recurrent dislocation in the near-track hyperlaxity cohort remained elevated, even in patients with no bone loss. Conclusion: Capsuloligamentous shoulder laxity was a significant independent risk factor for failure after primary arthroscopic Bankart repair without remplissage and was more predictive of failure in patients with versus without near-track lesions.

Dual Mini-Fragment Plate Fixation of Midshaft Clavicle Fractures Reduces Risk of Reoperation Compared With Single-Plate Fixation Techniques.

BACKGROUND: Recent studies have highlighted dual plating as a method of reducing high rates of postoperative complication after operative management of displaced midshaft clavicular fractures. However, few studies have reliably characterized reoperation rates and magnitude of risk reduction achieved when using dual versus anterior and superior single-plate techniques. HYPOTHESIS: There would be lower rates of reoperation among patients who underwent open reduction and internal fixation (ORIF) of displaced midshaft clavicular fractures via dual plating. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This was a retrospective analysis of patients who underwent ORIF for a displaced midshaft clavicular fracture between 2010 and 2021 at a level 1 trauma center with a minimum 12-month follow-up. Patients were separated into 3 cohorts based on fixation type: (1) orthogonal dual mini-fragment plate fixation, (2) superior plate fixation, and (3) anterior plate fixation. Data on patient characteristics, fracture pattern, and reoperations were documented. All-cause reoperation rates and hazard ratio (HR) estimates of dual, superior, and anterior plating were calculated using a multivariate multilevel mixed-effects parametric survival model. Significant confounders including high-risk fracture morphology and smoking status were controlled for in the final model. RESULTS: A final cohort of 256 patients was identified with mean follow-up of 4.9 ± 3.8 years. In total, 101 patients underwent superior plating, 92 underwent anterior plating, and 63 underwent dual plating. Overall, 31 reoperations took place (18 in superior, 12 in anterior, 1 in dual plating) among 22 patients. Major contributors to reoperation included symptomatic hardware (n = 11), nonunion (n = 8), deep infection (n = 7), and wound dehiscence (n = 2). Superior plating revealed the highest reoperation rate of 0.031 per person-years, followed by anterior plating with 0.026 per person-years and dual plating with 0.005 per person-years. Overall, single plating (either anterior or superior placement) had a nearly 8-fold greater risk of reoperation than dual plating (HR, 7.62; 95% CI, 1.02-56.82; P = .048). Further broken down by technique, superior plating had an 8-fold greater risk of reoperation than dual plating (HR, 8.36; 95% CI, 1.10-63.86; P = .041), but anterior plating did not demonstrate a statistically significant difference compared with dual plating (HR, 6.79; 95% CI, 0.87-52.90; P = .068). CONCLUSION: Dual-plate fixation represents an excellent treatment for displaced midshaft clavicular fractures, with low rates of nonunion and reoperation. When compared with single locked superior or anterior plate fixation, dual mini-fragment plate fixation has a nearly 8-fold lower risk of reoperation.

Remplissage reduces recurrent instability in high-risk patients with on-track Hill-Sachs lesions.

BACKGROUND: The purpose of this study was to compare recurrent instability rates between patients with on-track Hill-Sachs lesions who underwent arthroscopic labral repair (ALR) alone and those who underwent ALR with remplissage (ALR-R). Our hypothesis was that ALR-R would decrease the rate of recurrent instability, especially among patients at high risk of recurrent instability after ALR, such as contact athletes with near-track Hill-Sachs lesions. METHODS: We performed a multicenter, retrospective analysis of patients aged 14-50 years with on-track Hill-Sachs lesions who underwent ALR-R or ALR without remplissage between January 2014 and December 2019 with minimum 2-year follow-up. The exclusion criteria included prior ipsilateral shoulder surgery, >15% glenoid bone loss (GBL), off-track Hill-Sachs lesion, concomitant shoulder procedure, and connective tissue disorder. Age, sex, follow-up, and contact sports participation were recorded. GBL, Hills-Sachs interval (HSI), glenoid track, and distance to dislocation (DTD) were determined from preoperative magnetic resonance imaging scans. Affected-shoulder range of motion, Western Ontario Shoulder Instability Index scores, Subjective Shoulder Value scores, and recurrent dislocation and/or revision surgery status were also collected. A subgroup analysis was performed on "high-risk" patients (defined as participants in contact sports with DTD <10 mm) from each cohort. RESULTS: The ALR-R cohort included 56 patients, and the ALR cohort included 127. ALR-R patients had greater GBL (P = .004) and a greater HSI (P < .001). In the ALR-R cohort, only 1 patient (1.8%) had a recurrent dislocation and there were no revision operations. In comparison, in the ALR cohort, 14 patients (11.0%) had recurrent dislocations (P = .040) and 8 (6.3%) underwent revision operations (P = .11). Univariate analysis showed that remplissage protected against recurrent dislocation (P = .040) whereas younger age (P = .004), contact sports participation (P = .001), and increased GBL (P = .048) were associated with recurrent dislocation. Multivariate analysis showed that HSI (P = .001) and contact sports participation (P = .002) predicted recurrent dislocation. Among high-risk patients, only 1 patient (4.2%) in the ALR-R group had a recurrent instability event vs. 6 (66.7%) in the ALR group (P < .001). The high-risk ALR-R subgroup also had significantly better final Western Ontario Shoulder Instability Index (P = .008) and Subjective Shoulder Value (P = .001) scores than the high-risk ALR subgroup. CONCLUSIONS: Anterior shoulder instability patients with on-track Hill-Sachs lesions have lower recurrent dislocation rates after ALR plus remplissage when compared with ALR alone. This is especially true for high-risk patients, such as contact athletes with a DTD <10 mm.

Outpatient shoulder arthroplasty in the COVID-19 era: 90-day complications and risk factors.

BACKGROUND: With the COVID-19 pandemic placing an increased burden on health care systems, shoulder arthroplasties are more commonly being performed as outpatient procedures. The purpose of this study was to characterize the 90-day episode-of-care complications of consecutive shoulder arthroplasties defaulted for outpatient surgery without using a prior algorithm for patient selection and to assess for their risk factors. We hypothesized that outpatient shoulder arthroplasty would be a safe procedure for all patients, regardless of patient demographics and comorbidities. METHODS: A retrospective review of consecutive patients who underwent planned outpatient anatomic or reverse total shoulder arthroplasty between March 2020 and January 2022 with 3-month follow-up was performed. All patients were scheduled for outpatient surgery regardless of medical comorbidities. Patient demographics; pre/postoperative patient-reported outcomes including visual analog scale, subjective shoulder value, and American Shoulder and Elbow Surgeons score; pre/postoperative range of motion; and complications were collected from medical chart review. Multivariate logistic regression was used to identify predictors of the following outcomes: 1. Unplanned overnight hospital stay, 2. 90-day unplanned emergency department (ED)/clinic visit, 3. 90-day hospital readmission, 4. 90-day complications requiring revision. RESULTS: One hundred twenty-seven patients (47% male, 17% tobacco users, 18% diabetics) with a mean age 69 ± 9 years were identified, of whom 92 underwent reverse total shoulder arthroplasty and 35 underwent anatomic total shoulder arthroplasty. All patient-reported outcomes and range of motion were significantly improved at 3 months. There were 15 unplanned overnight hospital stays (11.8%) after the procedure. Within 90 days postoperatively, there were 17 unplanned ED/clinic visits (13.4%), 7 hospital readmissions (5.5%), and 4 complications requiring revision (3.1%). Factors predictive of unplanned overnight stay included age above 70 years (odds ratio [OR], 36.80 [95% confidence interval [CI], 2.20-615.49]; P = .012), tobacco use (OR, 12.90 [95% CI, 1.23-135.31]; P = .033), and American Society of Anesthesiologists status of 3 (OR, 13.84 [95% CI, 1.22-156.57]; P = .034). The only factor predictive of unplanned ED/clinic visit was age over 70 years old (OR, 7.52 [95% CI, 1.26-45.45]; P = .027). No factors were predictive of 90-day hospital readmission or revision. CONCLUSION: Outpatient shoulder arthroplasty is a safe procedure with excellent outcomes and low rates of readmissions and can be considered as the default plan for all patient undergoing shoulder arthroplasty. Patients who are above 70 years of age, use tobacco, and have ASA score of 3, however, may be less suitable for outpatient arthroplasty and should be counseled regarding the higher risk of unplanned overnight hospitalization.

Distance to Dislocation and Recurrent Shoulder Dislocation After Arthroscopic Bankart Repair: Rethinking the Glenoid Track Concept.

BACKGROUND: The "distance to dislocation" (DTD) calculation has been proposed as 1 method to predict the risk of recurrent dislocation after arthroscopic Bankart repair for an "on-track" shoulder. Rates of recurrent dislocation at specific DTD values are unknown. HYPOTHESIS: Among patients with "on-track" shoulder lesions who underwent primary arthroscopic Bankart repair, the rate of recurrent dislocation would increase as DTD values decrease. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: We performed a retrospective analysis of 188 patients with "on-track" shoulder lesions who underwent primary arthroscopic anterior labral repair between 2007 and 2019, with a minimum 2-year follow-up. Glenoid bone loss, Hill-Sachs interval, glenoid track, and DTD were determined from preoperative magnetic resonance imaging scans. The rate of recurrent dislocation was determined at 2-mm DTD intervals. Univariate and multivariate regression analyses were used to evaluate the relationship between recurrent dislocation, patient characteristics, and bone loss variables. A multivariate regression model was created to predict the probability of failure at continuous DTD values. A subgroup analysis of failure rate based on collision sports participation was also performed. RESULTS: A total of 29 patients (15.4%) sustained recurrent dislocations. Patient age (P = .046), multiple dislocations (P = .03), glenoid bone loss (P < .001), Hill-Sachs interval length (P < .001), and DTD (P < .001) were all independent predictors of failure. As the DTD decreased, the rate of recurrent dislocation increased. Below a DTD threshold of 10 mm, the recurrent dislocation rate increased exponentially. Up to a threshold of 24 mm, the failure rate for collision athletes remained >12.3%, independent of the DTD. Conversely, the failure rate among noncollision athletes decreased steadily as the DTD increased. CONCLUSION: For "on-track" shoulder lesions, as the DTD approached 0 mm ("off-track" threshold), the risk of recurrent dislocation after arthroscopic Bankart repair increased significantly. Below a DTD threshold of 10 mm, the risk of failure increased exponentially. The risk of recurrent dislocation for collision sports athletes remained elevated at higher DTD values than for noncollision athletes.

Arthritis Severity and Medical Comorbidities Are Prognostic of Worse Outcomes Following Arthroscopic Rotator Cuff Repair in Patients With Concomitant Glenohumeral Osteoarthritis.

Purpose: To assess demographic factors, comorbidities, radiographic variables, and injury patterns as potential prognostic indicators of poor functional and patient-reported outcomes following arthroscopic rotator cuff repair in patients with concomitant glenohumeral osteoarthritis. Methods: A retrospective review of consecutive patients with glenohumeral osteoarthritis who underwent arthroscopic supraspinatus repairs between 2013 and 2018 with a minimum of 1-year follow up was performed. Demographic variables included age, tobacco use, alcohol use, diabetes, sex, hypercholesterolemia, and body mass index while injury patterns included partial- versus full-thickness tear, bicep tendon involvement, and osteoarthritis severity. Multivariate linear regression was used to identify independent predictors of visual analog pain scale (VAS), subjective shoulder value (SSV), and American Shoulder and Elbow Surgeons (ASES) score as well as active range of motion (ROM) in forward flexion (FF) and external rotation (ER). Binary logistic regression was used to identify predictors of repair failure as well as postoperative strength in FF and ER. Results: In total, 91 patients (mean age 61.48 ± 9.4 years) were identified with an average follow up of 26.3 ± 5.7 months. Repair failures occurred in 9.9% (9/91 patients) of the total cohort. Postoperative outcomes were significantly improved with regards to visual analog pain scale, subjective shoulder value, ASES score, ROM in FF, FF strength, and external rotation strength compared with preoperative baseline. Obesity (P = .023) and diabetes (P = .010) were significant independent predictors of greater pain scores postoperatively. Obesity (P = .029) and tobacco use (P = .007) were significant predictors of lower ASES scores postoperatively. Finally, moderate-to-severe osteoarthritis was a significant risk factor for poor ROM and strength in FF postoperatively compared to mild osteoarthritis (P = .029). No variables were predictive of repair failure. Conclusions: Tobacco use, obesity, and diabetes are associated with worse pain and patient-reported outcomes following arthroscopic rotator cuff repair in the context of glenohumeral OA. In addition, moderate-to-severe OA is associated with worse strength and forward flexion compared to those with mild OA. Level of Evidence: Level III, retrospective cohort study.

Hip kinematics in healthy adults during gait and squatting: Sex differences and asymmetry revealed through dynamic biplane radiography.

There is a lack of data unaffected by soft tissue artifact describing bilateral symmetry and sex differences in hip kinematics in asymptomatic individuals during activities of daily living. This study aimed to identify sex-based differences and to quantify bilateral symmetry in continuous hip kinematics during walking and bodyweight squatting using biplane radiography. Twenty-four asymptomatic young adults (13 women, 11 men; age: 21.9 ± 2.2 years) performed treadmill walking and squatting while synchronized biplane radiographs of the hip were collected at 50 frames/s. Pelvis and proximal femur bone tissue were segmented from CT images and reconstructed into subject-specific 3D bone models. Femoroacetabular kinematics were determined using a validated volumetric model-based tracking technique that matched digitally reconstructed radiographs generated from the CT-based bone models to the biplane radiographs. Symmetry was calculated as the average absolute side-to-side difference (SSD) in kinematic waveforms for each participant. Sex-based and phase-based (eccentric vs. concentric squatting) kinematic variations were assessed using linear mixed model analysis. Women were 0.2 mm more anteriorly translated and 0.1 mm more inferiorly translated than men across the gait cycle (both p < 0.04), but no sex-based or phase-based kinematic differences during squatting were identified. The maximum SSD across all movements was up to 18.6° (internal-external rotation) and 1.0 mm (superior-inferior translation), respectively. Asymmetry in internal rotation, superior translation, and medial translation was greater during squatting than during walking (all p < 0.002). This study provides a reference dataset of healthy young adults for evaluating hip kinematics and symmetry in symptomatic cohorts or in individuals undergoing surgery or rehabilitation.

Using Simultaneous Confidence Bands to Calculate the Margin of Error in Estimating Typical Biomechanical Waveforms.

Studies of human movement usually collect data from multiple repetitions of a task and use the average of all movement trials to approximate the typical kinematics or kinetics pattern for each individual. Few studies report the expected accuracy of these estimated mean kinematics or kinetics waveforms for each individual. The purpose of this study is to demonstrate how simultaneous confidence bands, which is an approach to quantify uncertainty across an entire waveform based on limited data, can be used to calculate margin of error (MOE) for waveforms. Bilateral plantar pressure data were collected from 70 participants as they walked over 4 surfaces for an average of at least 300 steps per surface. The relationship between MOE and the number of steps included in the analysis was calculated using simultaneous confidence bands, and 3 methods commonly used for pointwise estimates: intraclass correlation, sequential averaging, and T-based MOE. The conventional pointwise approaches underestimated the number of trials required to estimate biomechanical waveforms within a desired MOE. Simultaneous confidence bands are an objective approach to more accurately estimate the relationship between the number of trials collected and the MOE in estimating typical biomechanical waveforms.

Emergence of heartbeat frailty in advanced age I: perspectives from life-long EKG recordings in adult mice.

The combined influences of sinoatrial nodal (SAN) pacemaker cell automaticity and its response to autonomic input determine the heart's beating interval variability and mean beating rate. To determine the intrinsic SAN and autonomic signatures buried within EKG RR interval time series change in advanced age, we measured RR interval variability before and during double autonomic blockade at 3-month intervals from 6 months of age until the end of life in long-lived (those that achieved the total cohort median life span of 24 months and beyond) C57/BL6 mice. Prior to 21 months of age, time-dependent changes in intrinsic RR interval variability and mean RR interval were relatively minor. Between 21 and 30 months of age, however, marked changes emerged in intrinsic SAN RR interval variability signatures, pointing to a reduction in the kinetics of pacemaker clock mechanisms, leading to reduced synchronization of molecular functions within and among SAN cells. This loss of high-frequency signal processing within intrinsic SAN signatures resulted in a marked increase in the mean intrinsic RR interval. The impact of autonomic signatures on RR interval variability were net sympathetic and partially compensated for the reduced kinetics of the intrinsic SAN RR interval variability signatures, and partially, but not completely, shifted the EKG RR time series intervals to a more youthful pattern. Cross-sectional analyses of other subsets of C57/BL6 ages indicated that at or beyond the median life span of our longitudinal cohort, noncardiac, constitutional, whole-body frailty was increased, energetic efficiency was reduced, and the respiratory exchange ratio increased. We interpret the progressive reduction in kinetics in intrinsic SAN RR interval variability signatures in this context of whole-body frailty beyond 21 months of age to be a manifestation of "heartbeat frailty."

Risk factors for complications and reoperation following operative management of displaced midshaft clavicle fractures.

BACKGROUND: Optimal management of a displaced midshaft clavicle fracture remains controversial. This study assessed demographic factors, fracture pattern, and surgical technique as potential predictors of surgical complications. Smoking, diabetes, obesity, polytrauma, high-energy mechanism, inpatient status, transverse or comminuted fractures, and single-plating technique were hypothesized to be associated with an increased risk of complications following clavicle fracture open reduction internal fixation (ORIF). METHODS: Consecutive patients with minimum 12-week follow-up from the trauma and sports medicine divisions at a single tertiary institution who presented with a midshaft clavicle fracture and underwent ORIF between 2007 and 2020 were retrospectively identified. Patient demographics, fracture pattern, plating technique, and postoperative complications were recorded. Postoperative complications were classified into major (reoperation) and minor (no reoperation) complications. Chi-squared statistics, Fisher's exact test, analysis of variance, Kruskal-Wallis test, and multivariate logistic regression modeling were utilized with a significance level set to P < .05. RESULTS: One hundred ninety-eight patients (average = 39.5 ± 14.6 years) were identified with an average follow-up of 9.1 ± 10.7 months. The cohort consisted of 155 males (78.3%), 62 smokers (31.3%), and 12 diabetics (6.1%). Injury characteristics revealed 80 transverse fractures (40.4%), 87 oblique fractures (43.9%), and 31 Z-type fractures (15.7%). Seventy-nine patients (39.9%) underwent superior plating, 72 (36.4%) underwent anterior plating, and 47 (23.7%) underwent dual plating. Overall, postoperative complications occurred in 47 patients (23.7%), 29 minor (14.6%) and 18 major (9.1%). Major complications requiring reoperation were symptomatic hardware, nonunion, deep infection, wound dehiscence, and broken hardware. Minor complications consisted of sensory deficit or paresthesia beyond peri-incisional numbness, superficial infections, postoperative pain and/or stiffness, and delayed union. Smoking status (P = .008), obesity (P = .009), and transverse or Z-type fractures (P = .002) were significant prognostic factors for overall complication risk. Only manual labor was predictive of minor complications (P = .019). Transverse or Z-type fractures and single plating were predictive of major complications (P = .004 and P = .008, respectively). No reoperations occurred in patients who underwent dual plating. Smokers (P = .027) with transverse/Z-type fractures (P = .022) were at the highest risk of reoperation with single plating. CONCLUSION: The overall rate of complications following ORIF of displaced midshaft clavicle fracture was 27.3%, with 9.1% requiring reoperation. Given relatively high complication rates, in instances when nonoperative vs. operative management is equivocal, nonoperative management should be strongly considered in obese patients, smokers, and patients who present with transverse or Z-type fracture. If operative management is indicated, use of dual plating may decrease reoperation rates.

Does Femoral Head Translation Vary by Sex and Side in Asymptomatic Hips During a Weightbearing Apprehension Test?

BACKGROUND: Hip microinstability is an increasingly recognized source of pain and dysfunction but has no agreed upon diagnostic criteria and the pathophysiology remains unclear. It has been suggested that pain associated with microinstability is caused by excess translation of the femoral head. Recent research indicates that single-plane femoral head translation can be reliably measured using dynamic ultrasonography during a supine clinical examination; however, the overall accuracy of that technique has not been established, and the range of femoral head translation values that are found in individuals with no history of surgery or symptomatic pathology is unknown. QUESTIONS/PURPOSES: (1) How much femoral head translation is present in native, uninjured hips during a weightbearing apprehension position for females and males? (2) How large is the side-to-side difference in hip translation and rotation within the same individual in females and males with no history of surgery or pain during the weightbearing apprehension position? (3) What differences exist in femoral head translation and rotation when comparing females to males? METHODS: Twenty-two young adults (11 males, 11 females; mean age 22 ± 2 years; BMI 22 ± 5 kg/m2) with no history of hip pain, no known hip injury, and who never had hip surgery participated in this study. High-resolution CT images of the femur and pelvis were acquired for each participant, and the bone tissue was segmented from the CT volume. Synchronized biplane radiographs were collected during a neutral standing trial and during a static weightbearing apprehension position in which the participant extended, externally rotated, and abducted at their back hip while standing with their feet split in the AP direction. A validated volumetric model-based tracking technique was used to match the patient-specific bone models to the biplane radiographs with an accuracy of 0.3 mm for translation and 0.8° for rotation. Translation of the center of the femoral head relative to the center of the acetabulum and rotation of the femur relative to the pelvis from neutral to the weightbearing apprehension position were calculated. Sex-based differences in hip kinematics were assessed by bivariate linear regression. RESULTS: The median (range) translation during the weightbearing apprehension position in females was 0.9 mm (0.2 to 2.7 mm), which was less than in the 1.3 mm (0.2 to 2.6 mm) translation found in males (median difference of 0.5 mm; p = 0.04). The median absolute side-to-side difference in translation during the pivot was 1.4 mm (0.1 to 3.8 mm) in females and 1.3 mm (0.1 to 4.4 mm) in males. CONCLUSION: These findings demonstrate that the femoral head translates the same under bodyweight loading as previously observed during supine exam, showing the inherent stability of the hip with no history of surgery or symptomatic pathology. This study also provides normal values for comparison with individuals who have suspected microinstability. Future directions for research include directly comparing biplane radiography to alternative imaging techniques, such as dynamic ultrasound, for identifying hip microinstability and identifying threshold values for symptomatic hip microinstability. LEVEL OF EVIDENCE: Level III, prognostic study.

Use of Ultrasound in Patients With Carpal Tunnel Syndrome: A Cost-Effective Solution to Reduce Delays in Surgical Care.

PURPOSE: Currently, electrodiagnostic testing, which comprises electromyogram (EMG) and nerve conduction studies (NCS), is the most commonly used method for confirming the clinical diagnosis of carpal tunnel syndrome (CTS). Electromyogram and NCS can be costly, can require multiple visits, may induce anxiety, and may be painful for patients. The purpose of this study was to determine whether replacing EMG/NCS with ultrasound (US), performed by the treating surgeon, to diagnose CTS decreases time to surgery and the number of office visits. METHODS: We retrospectively reviewed a database that consisted of patients who presented to our department with numbness and/or tingling in the hand(s). We assessed the patients' histories for any subsequent carpal tunnel release, dates of diagnosis, dates of surgery, the number of CTS-related medical visits, and diagnostic methods employed. A fellowship-trained hand surgeon performed US examination, and the patients were referred for EMG/NCS testing. We collected data prior to surgery using the Boston Carpal Tunnel Questionnaire to evaluate symptom severity scale and functional status scale scores. We performed linear regression to assess differences in the time to surgery and the number of medical visits prior to carpal tunnel release. RESULTS: Patients who had the diagnosis confirmed by the surgeon using US (n = 34) underwent surgical intervention 3-4 weeks earlier, with 1.8 fewer medical visits on average than the number of medical visits for those who had their diagnosis confirmed using EMG/NCS (n = 98). CONCLUSIONS: If a confirmatory method for the diagnosis of CTS is required or desired by the treating surgeon, surgeon-conducted US might have an impact on the efficiency of care for patients with CTS. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Replacing Computed Tomography with "Rapid" Magnetic Resonance Imaging for Ventricular Shunt Imaging.

INTRODUCTION: Children with ventricular shunts undergo frequent neuroimaging, and therefore, radiation exposures, to evaluate shunt malfunctions. The objective of this study was to safely reduce radiation exposure in this population by reducing computed tomography (CT) and increasing "rapid" magnetic resonance imaging (rMRI-shunt) among patients warranting neuroimaging for possible shunt malfunction. METHODS: This was a single-center quality improvement study in a tertiary care pediatric emergency department (ED). We implemented a multidisciplinary guideline for ED shunt evaluation, which promoted the use of rMRI-shunt over CT. We included patients younger than 18 years undergoing an ED shunt evaluation during 11 months of the preintervention and 25 months of the intervention study periods. The primary outcome was the CT rate, and we evaluated the relevant process and balancing measures. RESULTS: There were 266 encounters preintervention and 488 during the intervention periods with similar neuroimaging rates (80.7% versus 81.5%, P = 0.8.) CT decreased from 90.1% to 34.8% (difference -55.3%, 95% confidence interval [CI]: -71.1, -25.8), and rMRI-shunt increased from 9.9% to 65.2% (difference 55.3%, 95% CI: 25.8, 71.1) during the preintervention and intervention periods, respectively. There were increases in the mean time to neuroimaging (53.1 min; [95% CI: 41.6, 64.6]) and ED length of stay (LOS) (52.3 min; [95% CI: 36.8, 67.6]), without changes in total neuroimaging, 72-hour revisits, or follow-up neuroimaging. CONCLUSIONS: Multidisciplinary implementation of a standardized guideline reduced CT and increased rMRI-shunt use in a pediatric ED setting. Clinicians should balance the reduction in radiation exposure with ED rMRI-shunt for patients with ventricular shunts against the increased time of obtaining imaging and LOS.

Body-mass index, blood pressure, diabetes and cardiovascular mortality in Cuba: prospective study of 146,556 participants.

BACKGROUND: Cardiovascular disease accounts for about one-third of all premature deaths (ie, age < 70) in Cuba. Yet, the relevance of major risk factors, including systolic blood pressure (SBP), diabetes, and body-mass index (BMI), to cardiovascular mortality in this population remains unclear. METHODS: In 1996-2002, 146,556 adults were recruited from the general population in five areas of Cuba. Participants were interviewed, measured (height, weight and blood pressure) and followed up by electronic linkage to national death registries until Jan 1, 2017; in 2006-08, 24,345 participants were resurveyed. After excluding all with missing data, cardiovascular disease at recruitment, and those who died in the first 5 years, Cox regression (adjusted for age, sex, education, smoking, alcohol and, where appropriate, BMI) was used to relate cardiovascular mortality rate ratios (RRs) at ages 35-79 years to SBP, diabetes and BMI; RR were corrected for regression dilution to give associations with long-term average (ie, 'usual') levels of SBP and BMI. RESULTS: After exclusions, there were 125,939 participants (mean age 53 [SD12]; 55% women). Mean SBP was 124 mmHg (SD15), 5% had diabetes, and mean BMI was 24.2 kg/m2 (SD3.6); mean SBP and diabetes prevalence at recruitment were both strongly related to BMI. During follow-up, there were 4112 cardiovascular deaths (2032 ischaemic heart disease, 832 stroke, and 1248 other). Cardiovascular mortality was positively associated with SBP (>=120 mmHg), diabetes, and BMI (>=22.5 kg/m2): 20 mmHg higher usual SBP about doubled cardiovascular mortality (RR 2.02, 95%CI 1.88-2.18]), as did diabetes (2.15, 1.95-2.37), and 10 kg/m2 higher usual BMI (1.92, 1.64-2.25). RR were similar in men and in women. The association with BMI and cardiovascular mortality was almost completely attenuated following adjustment for the mediating effect of SBP. Elevated SBP (>=120 mmHg), diabetes and raised BMI (>=22.5 kg/m2) accounted for 27%, 14%, and 16% of cardiovascular deaths, respectively. CONCLUSIONS: This large prospective study provides direct evidence for the effects of these major risk factors on cardiovascular mortality in Cuba. Despite comparatively low levels of these risk factors by international standards, the strength of their association with cardiovascular death means they nevertheless exert a substantial impact on premature mortality in Cuba.