Modified Clavien-Dindo-Sink Classification System for operative complications in adult spine surgery.

OBJECTIVE: Currently there is no standardized mechanism to describe or compare complications in adult spine surgery. Thus, the purpose of the present study was to modify and validate the Clavien-Dindo-Sink complication classification system for applications in spine surgery. METHODS: The Clavien-Dindo-Sink complication classification system was evaluated and modified for spine surgery by four fellowship-trained spine surgeons using a consensus process. A distinct group of three fellowship-trained spine surgeons completed a randomized electronic survey grading 71 real-life clinical case scenarios. The survey was repeated 2 weeks after its initial completion. Fleiss' and Cohen's kappa (κ) statistics were used to evaluate interrater and intrarater reliabilities, respectively. RESULTS: Overall, interobserver reliability during the first and second rounds of grading was excellent with a κ of 0.847 (95% CI 0.785-0.908) and 0.852 (95% CI 0.791-0.913), respectively. In the first round, interrater reliability ranged from good to excellent with a κ of 0.778 for grade I (95% CI 0.644-0.912), 0.698 for grade II (95% CI 0.564-0.832), 0.861 for grade III (95% CI 0.727-0.996), 0.845 for grade IV-A (95% CI 0.711-0.979), 0.962 for grade IV-B (95% CI 0.828-1.097), and 0.960 for grade V (95% CI 0.826-1.094). Intraobserver reliability testing for all three independent observers was excellent with a κ of 0.971 (95% CI 0.944-0.999) for rater 1, 0.963 (95% CI 0.926-1.001) for rater 2, and 0.926 (95% CI 0.869-0.982) for rater 3. CONCLUSIONS: The Modified Clavien-Dindo-Sink Classification System demonstrates excellent interrater and intrarater reliability in adult spine surgery cases. This system provides a useful framework to better communicate the severity of spine-related complications.

Formal Radiologist Interpretations of Intraoperative Spine Radiographs Have Low Clinical Value.

STUDY DESIGN: Retrospective cohort. OBJECTIVE: To evaluate the clinical relevance, usefulness, and financial implications of intraoperative radiograph interpretation by radiologists in spine surgery. SUMMARY OF BACKGROUND DATA: Due to rising health care costs, spine surgery is under scrutiny to maximize value-based care. Formal radiographic analysis remains a potential source of unnecessary health care costs, especially for intraoperative radiographs. MATERIALS AND METHODS: A retrospective cohort analysis was performed on all adult elective spine surgeries at a single institution between July 2020 and July 2021. Demographic and radiographic data were collected, including intraoperative localization and post-instrumentation radiographs. Financial data were obtained through the institution's price estimator. Radiographic characteristics included time from radiographic imaging to completion of radiologist interpretation report, completion of radiologist interpretation report before the conclusion of surgical procedure, clinical relevance, and clinical usefulness. Reports were considered clinically relevant if the spinal level of the procedure was described and clinically useful if completed before the conclusion of the procedure and deemed clinically relevant. RESULTS: Four hundred eighty-one intraoperative localization and post-instrumentation radiographs from 360 patients revealed a median delay of 128 minutes between imaging and completion of the interpretive report. Only 38.9% of reports were completed before the conclusion of surgery. There were 79.4% deemed clinically relevant and only 33.5% were clinically useful. Localization reports were completed more frequently before the conclusion of surgery (67.2% vs. 34.4%) but with lower clinical relevance (90.1% vs. 98.5%) and clinical usefulness (60.3% vs. 33.6%) than post-instrumentation reports. Each patient was charged $32 to $34 for the interpretation fee, cumulating a minimum total cost of $15,392. CONCLUSIONS: Formal radiographic interpretation of intraoperative spine radiographs was of low clinical utility for spine surgeons. Institutions should consider optimizing radiology workflows to improve timeliness and clinical relevance or evaluate the necessity of reflexive consultation to radiology for intraoperative imaging interpretation to ensure that value-based care is maximized during spine surgeries. LEVEL OF EVIDENCE: 3.

Characterizing Negative Online Reviews of Spine Surgeons.

DESIGN: Retrospective review. OBJECTIVE: Characterize negative reviews of spine surgeons in the United States. SUMMARY: Physician rating websites significantly influence the selection of doctors by other patients. Negative experiences are impacted by various factors, both clinical and nonclinical, geography, and practice structure. The purpose of this study was to evaluate and categorize negative reviews of spine surgeons in the United States, with a focus on surgical versus nonsurgical reviewers. METHODS: Spine surgeons were selected from available online professional society membership directories. A search for reviews was performed on Healthgrades.com, Vitals.com, and RateMDs.com for the past 10 years. Free response reviews were coded by complaint, and qualitative analysis was performed. χ 2 and Fisher exact tests were used to compare categorical variables, and multiple comparisons were adjusted with Benjamini-Hochberg correction. A binary logistic regression model was performed for the top three most mentioned nonclinical and clinical complaint labels. A P -value <0.05 was considered statistically significant. RESULTS: A total of 16,695 online reviews were evaluated, including 1690 one-star reviews (10.1%). Among one-star reviews, 64.7% were written by nonsurgical patients and 35.3% by surgical patients. Nonclinical and clinical comments constituted 54.9% and 45.1% of reviews, respectively. Surgeons in the South had more "bedside manner" comments (43.3%, P <0.0001), while Northeast surgeons had more "poor surgical outcome" remarks compared with all other geographic regions (14.4%, P <0.001). Practicing in the South and Northeast were independent predictors of having complaints about "bedside manner" and "poor surgical outcome," respectively. CONCLUSION: Most one-star reviews of spine surgeons were attributed to nonsurgical patients, who tended to be unsatisfied with nonclinical factors, especially "bedside manner." However, there was substantial geographic variation. These results suggest that spine surgeons could benefit from focusing on nonclinical factors (bedside manner), especially among nonoperative patients, and that regional nuances should be considered in delivering spine care. LEVEL OF EVIDENCE: Level- 5.

Margin convergence vs. superior capsular reconstruction for massive irreparable rotator cuff tears: outcomes are equivalent unless there is preoperative pseudoparesis.

BACKGROUND: Margin convergence (MC) and superior capsular reconstruction (SCR) are common treatment options for irreparable rotator cuff tears in younger patients, although they differ in associated costs and operative times. The purpose of this study was to compare range of motion, patient-reported outcomes (PROs), and reoperation rates following MC and SCR. We hypothesized superior outcomes after SCR relative to MC regarding functional outcomes, subjective measures, and reoperation rates. METHODS: This was a multicenter retrospective review of 59 patients from 3 surgeons treating irreparable rotator cuff tears with either MC (n = 28) or SCR (n = 31) and minimum 1-year follow-up from 2014-2019. Visual analog scale (VAS) for pain, Subjective Shoulder Value (SSV), active forward flexion (FF), external rotation (ER), retear rate, and conversion rate to reverse shoulder arthroplasty were evaluated. t tests and χ2 tests were used for continuous and categorical variables, respectively (P < .05). RESULTS: Baseline demographics, range of motion, and magnetic resonance imaging findings were similar between groups. Average follow-up was 31.5 months and 17.8 months for the MC and SCR groups, respectively (P < .001). The MC and SCR groups had similar postoperative FF (151° ± 26° vs. 142° ± 38°; P = .325) and ER (48° ± 12° vs. 46° ± 11°; P = .284), with both groups not improving significantly from their preoperative baselines. However, both cohorts demonstrated significant improvements in VAS score (MC: 7.3 to 2.5; SCR: 6.4 to 1.0) and SSV (MC: 54% to 82%; SCR: 38% to 87%). There were no significant differences in postoperative VAS scores, SSV, and rates of retear or rates of conversion to arthroplasty between the MC and SCR groups. In patients with preoperative pseudoparesis (FF < 90°), SCR (n = 9) resulted in greater postoperative FF than MC (n = 5) (141° ± 38° vs. 67° ± 24°; P = .002). CONCLUSION: Both MC and SCR demonstrated excellent postoperative outcomes in the setting of massive irreparable rotator cuff tear, with significant improvements in PROs and no significant differences in range of motion. Specifically for patients with preoperative pseudoparesis, SCR was more effective in restoring forward elevation. Further long-term studies are needed to compare outcomes and establish appropriate indications.

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.

Criteria-based return-to-sport testing helps identify functional deficits in young athletes following posterior labral repair but may not reduce recurrence or increase return to play.

Background: The purpose of this study was to compare recurrent instability and return to play (RTP) in young athletes who underwent clearance to full activity based on a validated return-to-sport (RTS) test to those who underwent time-based clearance following primary posterior labral repair. Methods: This was a retrospective review of athletes with posterior shoulder instability who underwent primary arthroscopic posterior labral repair from 2012 to 2021 with minimum 1-year follow-up. Patients who underwent RTS testing at a minimum of 5 months postoperatively were compared to a historic control cohort of patients who underwent time-based clearance. Results: There were 30 patients in the RTS cohort and 67 patients in the control cohort (mean follow-up 32.1 and 38.6 months, respectively). Of the 30 patients who underwent RTS testing, 11 passed without failing any sections, 10 passed while failing 1 section, and 9 failed the RTS test by failing 2+ sections. No differences were found between the RTS and control cohort in the incidence of recurrent instability (6.7% vs. 9.0%), overall RTP (94.7% vs. 94.3%), RTP at the same level as before injury (84.2% vs. 80.0%), recurrent pain/weakness (23.3% vs. 25.4%), or revision surgery (0% vs. 3.0%), respectively. Discussion: While RTS testing in young athletes after posterior labral repair did not reduce recurrence or improve return to play compared to time-based clearance, two-thirds of athletes who underwent testing failed at least 1 section, indicating some functional deficit. Thus, RTS testing may help guide postoperative rehabilitation following posterior stabilization.

Dynamic Changes in Lumbar Spine Kinematics During Gait May Explain Improvement in Back Pain and Disability in Patients With Hip-Spine Syndrome.

STUDY DESIGN: Prospective cohort. OBJECTIVE: Determine if total hip arthroplasty (THA) changes lumbar spine kinematics during gait in a manner that explains the improvements in back pain seen in patients with hip-spine syndrome. SUMMARY OF BACKGROUND DATA: For patients with hip-spine syndrome, improvements in both hip and back pain have been demonstrated after THA; however, the exact mechanism of improvement in back pain remains unknown, as no corresponding changes in lumbar spine static radiographic parameters have been identified. METHODS: Thirteen patients with severe, unilateral hip osteoarthritis scheduled to undergo THA with concomitant back pain and disability were tested at baseline and 6 months after THA. Harris Hip Score (HHS) and Oswestry Disability Index questionnaires were completed; the static orientation of the spine and pelvis were measured on standing radiographs, and lumbar spine kinematics were measured during treadmill walking using a validated measurement system that matched subject-specific bone models created from CT scans to dynamic biplane radiographs. RESULTS: After THA, both the Oswestry Disability Index (36.3-11.3, P <0.001) and Harris Hip Score (55.7-77.9, P <0.001) improved; however, there were no changes in static intervertebral or pelvis orientation. During gait after THA, the overall lumbar spine (L1 to L5) was less lordotic from heel strike to contralateral toe off ( P <0.001), the L4 and L5 vertebra were less anteriorly tilted by 3.9° ( P =0.038) from midstance to contralateral heel strike and by 3.9° ( P =0.001) during stance, respectively. CONCLUSION: The decreased anterior tilt of the 2 lowest lumbar vertebrae and the corresponding loss of lumbar lordosis may reduce facet loading during the stance phase of gait after THA. This change in lumbar spine kinematics during gait is a potential mechanism to explain the observed improvements in back pain and disability after THA. LEVEL OF EVIDENCE: 4.

Validation of dynamic biplane radiography and three-dimensional model-based tracking for evaluation of dynamic thumb kinematics.

Dynamic biplane radiography (DBR) in conjunction with model-based tracking (MBT) has provided a suitable mechanism for biomechanical assessment of many joints but has not yet achieved widespread use at the thumb and wrist. The purpose of this work is to determine the accuracy of DBR with markerless MBT for the evaluation of thumb and wrist joint kinematics. Three 0.6 mm stainless steel beads were implanted into each trapezium, scaphoid, first metacarpal, and radius of three cadaveric upper extremities. Each specimen was manipulated in thumb abduction/adduction, thumb flexion/extension, wrist radioulnar deviation, and wrist flexion/extension while synchronized biplane radiographs were collected at 100 Hz. Specimen-specific 3D bone models were created from CT scans. MBT was performed by optimizing the correlation between digitally reconstructed radiographs, created from the volumetric CT-based bone models, and the biplane radiographs. Joint kinematics and joint space were calculated and compared between the "gold standard" bead-based tracking and markerless MBT. The MBT system accuracy (RMS error) in measuring bone position for the static and dynamic trials was 0.25 mm and 0.58 mm, respectively. The overall MBT system accuracy in measuring dynamic joint kinematics was 1.3 mm in translation and 5.0° in rotation. The MBT system accuracy in measuring dynamic joint space was 0.4 mm. DBR with MBT is a non-invasive and accurate method that can be utilized for kinematic analysis of the thumb and wrist.

Magnetic Resonance Imaging-Measured Cross-Sectional Area of the Median Nerve.

Purpose: The size of the median nerve may serve as a useful parameter to predict carpal tunnel syndrome (CTS) in a subset of patients. The purpose of this study was to evaluate magnetic resonance imaging-based measurements of median nerve cross-sectional area (CSA) to examine trends between patient subgroups and CSA that may assist in predicting the individuals who are most likely to develop CTS symptoms. Methods: A retrospective chart review of 1,273 wrist magnetic resonance images was performed, and the images were analyzed to evaluate the median nerve CSA at the level of the pisiform and the hook of hamate. The age, sex, height, weight, and body mass index (BMI) of the patients were collected from their medical records. Results: The median nerve size correlated with patient BMI. Additionally, patients with CTS had larger median nerves at the hook of hamate and pisiform than those without CTS. When subdividing patients on the basis of BMI, obese patients with CTS had larger median nerve CSA at the pisiform than those without CTS. Conclusions: This study demonstrated that increased BMI is associated with increased median nerve CSA at the hook of hamate and pisiform in patients with or without CTS. Additionally, patients with CTS had larger median nerve CSA than those without CTS. Measurements at these locations may help predict individuals who are likely to experience median nerve impingement. Type of study/level of evidence: Prognostic III.

Implant characteristics affect in vivo shoulder kinematics during multiplanar functional motions after reverse shoulder arthroplasty.

The purpose of this study was to determine how implant characteristics affect in vivo shoulder kinematics after reverse shoulder arthroplasty (RSA). Kinematics of the affected upper limb were measured in 32 participants during five motions (scapular plane abduction, hand-to-head, hand-to-back, internal/external rotation at 90° abduction, and circumduction) using optical motion capture. Shoulder abduction, plane of elevation, and internal/external rotation range of motion (ROM), peak angles, and continuous kinematics waveforms were calculated for each motion. Multiple regression was used to identify associations between kinematics and implant characteristics of lateralization, humeral retroversion, glenosphere size, glenosphere tilt, glenoid eccentricity, and implant neck-shaft angle (135° or 145°). Less humeral retroversion was associated with greater shoulder rotation ROM (p = 0.036) and greater plane of elevation ROM (p = 0.024) during circumduction, while less eccentricity was associated with more posterior plane of elevation during hand-to-back (p = 0.021). The 145° implant was associated with greater internal/external shoulder rotation ROM (p < 0.001), greater internal shoulder rotation (p = 0.002), and greater plane of elevation ROM (p = 001) during the hand-to-back. The 145° implant was also associated with more internal/external rotation ROM (p = 0.043) during shoulder rotation and more abduction ROM during circumduction (p = 0.043). During the hand-to-back motion, individuals having 135° neck-shaft angle implants were more abducted from 21 to 51% of the motion and were less internally rotated from 70 to 100% of the motion, while more lateralization was associated with less internal rotation from 90 to 100% of the motion. Retroversion and implant neck-shaft angle are the primary implant characteristics associated with in vivo shoulder kinematics during complex motions after RSA.

Common animal models lack a distinct glenoid labrum: a comparative anatomy study.

PURPOSE: Development and validation of an animal model of labral healing would facilitate translation of novel surgical and biological strategies to improve glenolabral healing. The purpose of this study was to characterize the anatomic and histological properties of the shoulder labrum in rat, rabbit, dog, pig, goat, and humans. Given the demonstrated similarities in size and structural morphology in other joints, it was hypothesized that the goat glenoid with surrounding capsulolabral complex would most closely resemble that of humans in terms of dimensions and structure, as observed grossly and histologically. METHODS: Cadaveric glenohumeral joints from rats (n = 8), New Zealand white rabbits (n = 13), Mongrel dogs (n = 9), Spanish goats (n = 10), Yorkshire pigs (n = 10), and humans (n = 9) were freshly harvested. Photographs were taken of the glenoid with its surrounding capsulolabral complex. Linear dimensions of the glenoid articular surface were measured. It was determined where the capsulolabral complex was continuous with, or recessed from, the articular glenoid surface. The glenoid was divided into 6 equal segments radiating out toward 12, 2, 4, 6, 8, and 10 o'clock positions. Samples were sectioned and stained with Safranin O/Fast green and Mallory Trichrome. Insertion of the capsulolabral tissue onto the glenoid was qualitatively assessed and compared with gross morphology. RESULTS: Dimensions of the goat glenoid most closely paralleled dimensions of the human glenoid. A capsulolabral complex was continuous with the glenoid surface from ~ 9 to 12 o'clock in the rats, 7 to 12 o'clock in rabbits, 5 to 12 o'clock in the dogs, and 9 to 12 o'clock in goats, 6 to 12 o'clock in pigs, and 2 to 8 o'clock in humans. In contrast to humans, no other species demonstrated an organized fibrocartilaginous labrum either macroscopically or histologically. CONCLUSION: The animals in the present study did not possess a discrete fibrocartilaginous labrum by gross or histological evaluation, as directly compared to humans. While models using these animals may be acceptable for examining other shoulder pathologies, they are not adequate to evaluate labral pathology. LEVEL OF EVIDENCE: Basic Science Study; Anatomy and Histology; Cadaveric Animal Model.

Glenoid Radius of Curvature and Humeral Head Volume Are Associated With Postoperative Dislocation After Arthroscopic Bankart Repair.

PURPOSE: To measure bony morphologic parameters and identify their association with arthroscopic Bankart repair failure. METHODS: This was a retrospective comparative study. The inclusion criteria were primary arthroscopic Bankart repair, no prior shoulder surgery, traumatic cause, and had a Bankart (soft tissue and bony) lesion evident on magnetic resonance imaging (MRI). The exclusion criteria were posterior labral pathology, multidirectional instability, connective tissue disorder, rotator cuff pathology, and those who underwent concomitant shoulder procedures. Patients who had a postoperative redislocation (unstable group) were compared with matched patients who did not (stable group). Data were obtained by chart review and from preoperative MRI. Comparisons were made using the Student t test, Fisher exact test, or χ2 test. Statistical significance was defined as P < .05. Inter-rater reliability was measured between reviewers. RESULTS: A total of 45 patients experienced a postoperative dislocation and were matched to 90 patients without a postoperative dislocation. There were no differences in demographic and radiographic variables. The radius of curvature (ROC) of the glenoid was larger (shallower) in the unstable group (23.6 mm vs 22.6 mm, P = .05). The humeral head volume (HHV) trended higher in the unstable group (68.9 mL vs 62.9 mL, P = .06). The glenoid volume was not significantly different. A greater percentage of patients with a glenoid ROC of 24.5 mm or greater (62.1% vs 26.4%, P = .0003) and an HHV of 80 mm3 or greater (60.8% vs 28.9%, P = .003) experienced a redislocation compared with patients without these factors. Patients with a glenoid ROC of 24.5 mm or more and an HHV of 80 mm3 or more had greater than 4 times the odds of redislocation (odds ratio, 4.56; 95% confidence interval, 1.44-14.43; P = .0098). Strong inter-rater reliability was found for the HHV, glenoid volume, glenoid ROC, and humeral head ROC measurements (r = 0.94, r = 0.88, r = 0.89, and r = 0.95, respectively). CONCLUSIONS: This study shows that large ROC (shallow) glenoids in conjunction with large humeral heads may predispose patients to failure after arthroscopic Bankart repair. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.

Labral Morphology and Number of Preoperative Dislocations Are Associated With Recurrent Instability After Arthroscopic Bankart Repair.

PURPOSE: To develop a method to measure capsule and labral volume on preoperative magnetic resonance imaging to predict surgical failure after primary Bankart repair. METHODS: A retrospective case-control study was conducted on patients undergoing primary anterior arthroscopic shoulder stabilization. Surgical failure was defined as a recurrent dislocation event. Cases were matched to controls based on age and sex in a 1:2 ratio. Preoperative magnetic resonance (MR) arthrograms were analyzed by 2 trained reviewers using Vitrea software to measure labral and capsular volume with a 3-dimensional model. Labral size was also qualitatively measured on axial images. A "diffusely small" labrum was defined as labral height less than the width of the glenoid tidemark cartilage. RESULTS: Of the 289 patients who had an arthroscopic Bankart repair from 2006 to 2015, 33 who had a postoperative dislocation met the inclusion criteria and were matched to 62 control patients who did not. There was no difference between groups with regard to age (P = .88), sex (P = .82), contact sport participation (P = .79), proportion of overhead athletes (P = .33), proportion of throwers (P = 1), surgical positioning in lateral decubitus (P = .18), or number of repair anchors used (P = .91). The average number of preoperative dislocations was significantly higher in the failure group (3.2 vs. 2.0, P < .0001). In patients with normal labrum morphology, the odds of having surgical failure increased by 26% for a 1-unit increase in the number of prior dislocations (odds ratio [OR] 1.26, 95% confidence interval [CI] 1.02 to 1.55). The case and control groups had similar labral and capsular volume as measured in Vitrea. The failure group had a significantly higher proportion of patients with a diffusely small labral morphology (47% vs. 17%, P = .03). Controlling for number of preoperative dislocations, the odds of having a diffusely small labral morphology was 3.2 times more likely in the case group than the control group (95% CI 1.259 to 8.188). Interrater reliability between 2 independent reviewers was excellent for measurement of capsule volume (r = 0.91) and good for measurement of labral volume (r = 0.74). CONCLUSIONS: This study presents a novel method of measuring labral and capsule volume with high interrater reliability. An increased number of recurrent dislocations prior to primary Bankart repair was associated with increased odds of recurrent instability after surgery. The OR for failure also increased with increasing number of preoperative dislocations. Diffusely small labral morphology was associated with having a postoperative redislocation. LEVEL OF EVIDENCE: III (case-control study).

Effects of pelvis-shoulders torsional separation style on kinematic sequence in golf driving.

The golfer's body (trunk/arms/club) can be modeled as an inclined axle-chain system and the rotations of its parts observed on the functional swing plane (FSP) can represent the actual angular motions closely. The purpose of this study was to investigate the effects of pelvis-shoulders torsional separation style on the kinematic sequences employed by the axle-chain system in golf driving. Seventy-four male skilled golfers (handicap ≤ 3) were assigned to five groups based on their shoulder girdle motion and X-factor stretch characteristics: Late Shoulder Acceleration, Large Downswing Stretch, Large Backswing Stretch, Medium Total Stretch, and Small Total Stretch. Swing trials were captured by an optical system and the hip-line, thorax, shoulder-line, upper-lever, club, and wrist angular positions/velocities were calculated on the FSP. Kinematic sequences were established based on the timings of the peak angular velocities (backswing and downswing sequences) and the backswing-to-downswing transition time points (transition sequence). The backswing and transition sequences were somewhat consistent across the groups, showing full or partial proximal-to-distal sequences with minor variations. The downswing sequence was inconsistent across the groups and the angular velocity peaks of the body segments were not significantly separated. Various swing characteristics associated with the separation styles influenced the motion sequences.

Effects of the golfer-ground interaction on clubhead speed in skilled male golfers.

The purposes of this study were to characterise the golfer-ground interactions during the swing and to identify meaningful associations between the golfer-ground interaction force/moment parameters and the maximum clubhead speed in 63 highly skilled male golfers (handicap ≤ 3). Golfers performed shots in 3 club conditions (driver, 5-iron and pitching wedge) which were captured by an optical motion capture system and 2 force plates. In addition to the ground reaction forces (GRFs), 3 different golfer-ground interaction moments (GRF moments, pivoting moments and foot contact moments) were computed. The GRF moment about the forward/backward (F/B) axis and the pivoting moment about the vertical axis were identified as the primary moments. Significant (p < 0.05) correlations of peak force parameters (all components in the lead foot and F/B component in the trail foot) and peak moment parameters (lead-foot GRF moment and trail-foot pivoting moment) to clubhead speed were found. The lead-foot was responsible for generating the GRF moment, while the trail foot contributed to the pivoting moment more. The instant the lead arm becomes parallel to the ground was identified as the point of maximum angular effort, and the loading onto the lead-foot near this point was critical in generating both peak moments.

Silicon Photomultipliers for Deep Tissue Cerenkov Emission Detection During External Beam Radiotherapy.

Cerenkov Emission (CE) during external beam radiation therapy (EBRT) from a linear accelerator (Linac) has been demonstrated as a useful tool for radiotherapy quality assurance and potentially other applications for online tracking of tumors during treatment delivery. However, some of the current challenges that are impacting the potential of CE are related to the limited detection sensitivity and the lack of flexible tools to fit into an already complex treatment delivery environment. Silicon photomultiplier (SiPM) solid-state devices are new promising tools for low light detection due to their extreme sensitivity that mirrors photomultiplier tubes and yet have a form factor that is similar to silicon photodiodes, allowing for improved flexibility in device design that may help in the process of wider clinical applicability. In this work, we assess the feasibility of using SiPMs to detect CE during EBRT from a Linac and contrast their performance with commercially available silicon photodiodes (PDs). We demonstrate the feasibility of the SiPM based probes for standard dosimetry measurements. We also demonstrate that CE optical signals can be detected from tissue depths about five times greater than that for standard probes based on PDs, making our SiPM probe an enabling technology of CE measurements, particularly for deep tissue applications.

Validity of the X-factor computation methods and relationship between the X-factor parameters and clubhead velocity in skilled golfers.

The purpose of this study was to assess the validity of the X-factor computation methods and to examine whether direct relationships exist between the X-factor parameters and the clubhead velocity in a group of skilled male golfers (n = 18, handicap = -0.6 +/- 2.1). Five driver trials were captured from each golfer using an optical motion capture system (250 Hz). Two plane-based methods (conventional vs. functional swing plane-based) and one Cardan rotation-based method (relative orientation) were used to compute select X-factor (end of pelvis rotation, top of backswing, ball impact (BI), and maximum), X-factor stretch (stretch and maximum stretch), and X-factor velocity (BI and maximum) parameters. The maximum clubhead velocity was extracted and normalized to golfer's body height to eliminate the effect of body size. A one-way repeated MANOVA revealed that the computation methods generated significantly different X-factor parameter values (p < 0.001). The conventional method provided substantially larger X-factor values than the other methods in the untwisting phase and the meaningfulness of select X-factor parameters generated by this method was deemed questionable. The correlation analysis revealed that the X-factor parameters were not directly related to the maximum clubhead velocity (both unnormalized and normalized).

Assessment of planarity of the golf swing based on the functional swing plane of the clubhead and motion planes of the body points.

The purposes of this study were (1) to determine the functional swing plane (FSP) of the clubhead and the motion planes (MPs) of the shoulder/arm points and (2) to assess planarity of the golf swing based on the FSP and the MPs. The swing motions of 14 male skilled golfers (mean handicap = -0.5 +/- 2.0) using three different clubs (driver, 5-iron, and pitching wedge) were captured by an optical motion capture system (250Hz). The FSP and MPs along with their slope/relative inclination and direction/direction of inclination were obtained using a new trajectory-plane fitting method. The slope and direction of the FSP revealed a significant club effect (p < 0.001). The relative inclination and direction of inclination of the MP showed significant point (p < 0.001) and club (p < 0.001) effects and interaction (p < 0.001). Maximum deviations of the points from the FSP revealed a significant point effect (p < 0.001) and point-club interaction (p < 0.001). It was concluded that skilled golfers exhibited well-defined and consistent FSP and MPs, and the shoulder/arm points moved on vastly different MPs and exhibited large deviations from the FSP. Skilled golfers in general exhibited semi-planar downswings with two distinct phases: a transition phase and a planar execution phase.