Arm Dominance Research Articles

Quantifying the Impact of C7 Spinal Nerve Harvest on Spontaneous, Patient-Initiated Movement of the Donor Upper Extremity.

Transfer of a healthy C7 spinal nerve is a tool for upper extremity reanimation in patients with severe brachial plexus injury (BPI). Its use remains controversial owing to concern for neurological injury to the donor arm. Utilizing wearable motion-sensor technology, we aimed to quantify donor arm morbidity after C7 spinal nerve harvest in patients with pan-BPI, reporting both the time and magnitude of donor arm movement in a real-world setting compared to healthy controls. Seventeen patients who underwent contralateral C7 (CC7) transfer for traumatic pan-BPI at least 2 years prior were compared to 14 healthy controls. Each participant wore an accelerometer on both arms for 7 consecutive days. The vector time (VT), or time of movement measured in hours/day, and the vector magnitude (VM), or magnitude of arm movement measured as a single vector magnitude per second, were collected and compared between groups. The correlation between VT and VM and time from C7 spinal nerve harvest was also calculated. At mean 7.7 years after C7 spinal nerve harvest, there was no difference between donor and control arms for VT (5.76±1.55] vs 5.45±1.22 hours, P = 0.56) or VM (2242236±753853 vs 1919223±579723 activity counts, P = 0.20), regardless of donor arm dominance. The C7 harvest cohort used the injured arm 53% of the time and with 27% of the power of the donor arm. There was no significant difference in time or magnitude of arm movement between donor arms and the arms of healthy controls.

Preoperative inter-arm differences and normative-based thresholds for lymphedema in Chinese breast cancer patients: Insights from a large cohort study

ObjectiveEarly detection and diagnosis of lymphedema are crucial for effective treatment and prevention of its progression. Normative-based diagnostic thresholds can enhance diagnostic accuracy in the absence of preoperative measurements. This study aimed to investigate preoperative inter-arm differences and the associated factors, as well as to determine normative-based thresholds for lymphedema in Chinese breast cancer patients. MethodsThis study utilized baseline data from a large cohort of Chinese breast cancer patients. Bilateral arm circumferences were measured at the wrist and at 10 cm intervals proximally up to 40 cm. Arm volumes were calculated using the truncated cone formula. Paired t test, repeated measures analysis of variance, and regression analysis were performed. ResultsA total of 1707 breast cancer patients were included. Paired t tests showed that the dominant arm circumferences and volumes were significantly larger than those of the nondominant arm (P < 0.001). Regression analysis and repeated measures analysis of variance revealed that hand dominance was the influencing factor of inter-arm differences (P < 0.05). Normative-based thresholds determined by two standard deviations above the mean inter-arm volume ratio were 1.057 for the dominant arm and 1.079 for the nondominant arm. ConclusionsThe absolute and relative normative-based thresholds for Chinese breast cancer patients differed slightly from the commonly used diagnostic criteria and those reported in Western populations and among Chinese healthy women. The normal variability and asymmetry associated with arm dominance underscore the importance of preoperative baseline assessments. Implementing normative-based diagnostic thresholds can facilitate more accurate lymphedema diagnosis when preoperative measurements are unavailable. Trial registrationRegistration No. ChiCTR2200057083.

Poster 155: An Ultrasound and Clinical Evaluation in Patients Following Treatment for Proximal Humerus Fractures: Reverse Versus Anatomical Total Shoulder Arthroplasty

Objectives: Anatomic Total Shoulder Arthroplasty (ATSA) and Reverse Total Shoulder Arthroplasty (RTSA) are both viable treatment options for complex proximal humerus fractures. With its principal role as an abductor and internal rotator in a native joint, the subscapularis potentially plays an important functional and stability role postoperatively. Although less studied in RTSA, studies have found that failure of subscapularis repair is associated with anterior instability, and decreased range of motion (ROM), strength, and outcome scores following ATSA. The purpose of our study is to evaluate and compare the postoperative clinical, radiographic, and patient-reported outcomes following subscapularis reattachment in patients treated with either ATSA or RTSA. Methods: Sixty-eight consecutive patients with proximal humeral fractures were prospectively enrolled in the study between June 2015 and May 2020 (RTSA = 40; TSA = 28). Ultrasound scans of the subscapularis were performed postoperatively, and the subscapularis muscle cross-sectional area (iSMCSA) and contralateral subscapularis muscle cross-sectional area (cSMCSA) were measured. The ratio of the 2 values (iSMCSA/cSFCSA) was utilized to standardize values. Patient-reported outcomes (PROs) and ROM were evaluated at the final follow-up. Results: Demographically, there was no significant difference between age, arm dominance, surgical laterality, diabetes, or hypertension between the patient groups (Table 1). The RTSA group demonstrated higher PROs compared to TSA patients: Constant Score (p = .0007), Quick Dash (p = .0005), and ASES score (p = .09). ROM was better in the RTSA cohort, with statically significant values with internal rotation (p = .022 abduction), external rotation (p = .02 adduction and p = .01 abduction), abduction (p = 0.02), and forward flexion (p = .003). Radiographic ultrasound findings illustrated greater reduction in size of the subscapularis in the TSA cohort when compared to the contralateral, nonoperative subscapularis (40% vs 27%; p = 0.002). Reduction of subscapularis size of &gt;35% occurred in 2 RTSA (7%) and 8 TSA patients (44%) (p = 0.01) (Table 2). Conclusions: Subscapularis repair following RTSA demonstrated better results compared to subscapularis repair following TSA, providing better PROs and ROM. Subscapularis muscle tissue decreased 50% more in the ATSA versus RTSA patients (40% vs 27%). Subscapularis condition demonstrated no correlation with functional outcome in RTSA.

The effect of self-identified arm dominance on exercising forearm hemodynamics and skeletal muscle desaturation.

The human forearm model is commonly employed in physiological investigations exploring local vascular function and oxygen delivery; however, the effect of arm dominance on exercising forearm hemodynamics and skeletal muscle oxygen saturation (SmO2) in untrained individuals is poorly understood. Therefore, the purpose of this study was to explore the effect of self-identified arm dominance on forearm hemodynamics and SmO2 in untrained individuals during submaximal, non-ischemic forearm exercise. Twenty healthy individuals (23±4 years, 50% female; 80% right-handed) completed three-minute bouts of supine rhythmic (1 second contraction: 2 second relaxation duty cycle) forearm handgrip exercise at both absolute (10kg; 98N) and relative (30% of maximal voluntary contraction) intensities in each forearm. Beat-by-beat measures of forearm blood flow (FBF; ml/min), mean arterial blood pressure (MAP; mmHg) and flexor digitorum superficialis SmO2 (%) were obtained throughout and averaged during the final 30 seconds of rest, exercise, and recovery while forearm vascular conductance was calculated (FVC; ml/min/100mmHg). Data are Δ from rest (mean±SD). Absolute force production did not differ between non-dominant and dominant arms (97±11 vs. 98±13 N, p = 0.606) whereas relative force production in females did (69±24 vs. 82±25 N, p = 0.001). At both exercise intensities, FBFRELAX, FVCRELAX, MAPRELAX, and the time constant tau for FBF and SmO2 were unaffected by arm dominance (all p>0.05). While arm dominance did not influence SmO2 during absolute intensity exercise (p = 0.506), the non-dominant arm in females experienced an attenuated reduction in SmO2 during relative intensity exercise (-14±10 vs. -19±8%, p = 0.026)-though exercise intensity was also reduced (p = 0.001). The present investigation has demonstrated that arm dominance in untrained individuals does not impact forearm hemodynamics or SmO2 during handgrip exercise.

Clinical and radiological outcome following arthroscopic Latarjet with cerclage FiberTape fixation with a minimum 1-year follow-up

The rates of implant-related complications are significant following the Latarjet procedure using metal screws in patients with recurrent shoulder dislocation and bone loss. The purpose of this study is to evaluate the short-term outcome following the arthroscopic Latarjet procedure using cerclage FiberTape (Arthrex, Naples, FL, USA) combined with remplissage and capsulolabral repair. It was hypothesized that performing the procedure with cerclage FiberTape would provide sturdy fixation, comparable to the conventional method of using metal screws, while averting hardware-related complications attributed to the latter in published literature. A prospective study was performed in a single institution between 2020 and 2022, with all surgeries performed by a single fellowship-trained shoulder surgeon who has ample experience in performing arthroscopic screw Latarjet procedures. Patient demographics, number of dislocations before surgery, arm dominance, ligamentous laxity, type of sporting activity, Instability Severity Index Score, and percentage of bone loss on the glenoid and humeral sides were recorded. The patients were followed up with visual analog scale, American Shoulder and Elbow Surgeons score, Rowe score, and Walch-Duplay score preoperatively and postoperatively. The coracoid graft position, healing, and remodeling were assessed with computed tomography scans at 3 months postoperatively. Minimum clinical follow-up was for a period of one year. Overall, 10 patients (all males, average age 28±8.8 years) were operated on with an arthroscopic Latarjet procedure using cerclage FiberTape. The minimum follow-up period was 12 months, and the mean follow-up was 13.2 months. The median and individual visual analog scores during arm motion, American Shoulder and Elbow Surgeons scores, Rowe scores, and Walch-Duplay scores improved in the follow-up period. Computed tomography scans at 3 months showed flushed graft position in 5 patients, medial graft position in two patients, and three patients showed graft nonunion with migration. Out of 10 patients, seven had good graft union in follow-up scans. None of the patients required revision surgery. All three patients with graft nonunion were kept under follow-up beyond the study period for recurrence of instability. Our study demonstrated that arthroscopic Latarjet using cerclage FiberTape fixation combined with remplissage and capsulolabral repair resulted in high rate of graft loosening and migration (30%). Nonetheless, patients in whom the coracoid graft had united, as well as those in whom it had not, all had good to excellent functional and clinical outcomes, no complications, and did not require any revision surgery.

Shoulder Laxity Among Badminton Players: Instrumented Measurement Comparing Arm Dominance, Gender and Years of Play

Shoulder Laxity Among Badminton Players: Instrumented Measurement Comparing Arm Dominance, Gender and Years of Play

Rates of subacromial notching are low following reverse shoulder arthroplasty with a 135° inlay humeral component and a lateralized glenoid

BackgroundLateralization in reverse shoulder arthroplasty (RSA) decreases bony impingement and improves rotational range of motion, but has been theorized to increase the risk of subacromial notching (SaN). The purpose of this study was to evaluate the presence of SaN following RSA and its relationship with lateralization with a 135° inlay humeral component. The secondary purpose was to assess the association of SaN with functional outcomes. MethodsA retrospective review was performed from a multicenter prospectively collected database on patients who underwent primary RSA from 2015-2021. All RSAs were performed with a 135° inlay humeral component. SaN was defined as bony erosion with sclerotic margins on the undersurface of the acromion on final follow-up radiographs not present preoperatively. Postoperative implant positioning (inclination, distalization, and lateralization) were evaluated on minimum 1 year postoperative radiographs. Regression analyses were performed on implant and clinical variables to assess for risk factors. A separate analysis was performed to determine the association of SaN with clinical outcomes. ResultsSaN was identified in 13 out of 442 shoulders (2.9%). Age, sex, body mass index, smoking status, diabetes mellitus, arm dominance had no relationship with SaN. Neither glenoid sided lateralization nor humeral offset were associated with SaN risk. Other implant characteristics such as distalization, glenosphere size, and postoperative inclination did not influence SaN risk. The presence of SaN did not affect patient reported outcomes (PROs) (ASES: p = 0.357, VAS: p = 0.210) or range of motion. ConclusionThe rate of SaN is low and not associated with glenoid or humeral prosthetic lateralization when using a 135° inlay humeral component. When SaN occurs, it is not associated with functional outcomes or range of motion at short term follow-up.

Impact of Arm Dominance and Location on Detecting Electrotactile Stimuli During Voluntary Motor Activation in Older Adults.

Activation-related sensory gating is important for sensorimotor control, filtering signals irrelevant to a task. Literature on brain lateralization suggests that motor activation patterns during sensorimotor control differ depending on arm dominance. Whether the lateralization effect extends to how sensory signals modulate during voluntary sensorimotor control remains unaddressed. We compared tactile sensory gating during voluntary motor activation between the arms of older adults. Eight right-arm dominant participants received a single-pulse, 100 μs square-wave electrotactile stimulus at their testing arm's fingertip or elbow. We identified at both arms the threshold at which the electrotactile stimulus was detected when participants were at rest (baseline) and isometrically flexing about the elbow to 25% and 50% of their maximum voluntary torque. Results reveal a difference in the detection threshold at the fingertip (p 0.001) between the arms, yet not the elbow (p = 0.264). Additionally, results demonstrate that greater isometric flexion about the elbow yields increased detection thresholds at the elbow (p = 0.005), yet not the fingertip (p = 0.069). However, the changes in detection threshold during motor activation did not significantly differ between the arms (p = 0.154). The findings regarding an impact of arm dominance and location on tactile perception are important when considering sensorimotorhaptic perception and training, including post-unilateral injury.

Risk Factors for Glenoid Bone Loss in the Setting of Posterior Glenohumeral Instability.

Posterior instability has been reported to account for up to 24% of cases of shoulder instability in certain active populations. However, there is a paucity of data available regarding the risk factors associated with posterior glenoid bone loss. To characterize the epidemiology of, and risk factors associated with, glenoid bone loss within a cohort of patients who underwent primary arthroscopic shoulder stabilization for isolated posterior-type glenohumeral instability. Cross-sectional study; Level of evidence, 3. This was a retrospective analysis of patients who underwent primary arthroscopic shoulder stabilization for posterior-type instability between January 2011 and December 2019. Preoperative magnetic resonance arthrograms were used to calculate posterior glenoid bone loss using a perfect circle technique. Patient characteristics and revision rates were obtained. Bone loss (both in millimeters and as a percentage) was compared between patients based on sex, age, arm dominance, sports participation, time to surgery, glenoid version, history of trauma, and number of anchors used for labral repair. Included were 112 patients with a mean age of 28.66 ± 10.07 years; 91 patients (81.25%) were found to have measurable bone loss. The mean bone loss was 2.46 ± 1.68 mm (8.98% ± 6.12%). Significantly greater bone loss was found in athletes versus nonathletes (10.09% ± 6.86 vs 7.44% ± 4.56; P = .0232), female versus male patients (11.17% ± 6.53 vs 8.17% ± 5.80; P = .0212), and patients dominant arm involvement versus nondominant arm involvement (10.26% ± 5.63 vs 7.07% ± 6.38; P = .0064). Multivariate regression analysis identified dominant arm involvement as an independent risk factor for bone loss (P = .0033), and dominant arm involvement (P = .0024) and athlete status (P = .0133) as risk factors for bone loss >13.5%. At the conclusion of the study period, 7 patients had experienced recurrent instability (6.25%). The findings of this study are in alignment with existing data suggesting that posterior glenoid bone loss is highly prevalent in patients undergoing primary arthroscopic stabilization for posterior-type shoulder instability. Our results suggest that patients with dominant arm involvement are at risk for greater posterior glenoid bone loss. Athlete status and dominant arm involvement were identified as independent risk factors for bone loss >13.5%.

Normative Values of Isometric Shoulder Strength Among Healthy Adults.

Normative data is useful for comparing measured values of strength with population norms and can avoid the issues associated with limb symmetry index. The available normative shoulder strength values are limited by constraints on research designs and variability in subject groups which prevents this data being successfully extrapolated to the greater population. The purpose of this study was to establish normative isometric strength values for various movements of the shoulder that are specific to function and rotator cuff strength. A secondary goal of this study was to analyze the effect of age, gender, weight, height, activity level and arm dominance on shoulder strength. Observational cohort study. Subjects in four age groups (20-29, 30-39, 40-49, 50-59) were included in this study-200 males (40.0 ± 11.6 years, 179.1 ± 6.5 cm, 81 ± 13.0 kg) and 200 females (40.1 ± 11.5 years, 165.3 ± 7.4sm, 64.4 ± 11.6 kg). Bilateral isometric strength measurements were taken with a handheld dynamometer testing seven shoulder movements. Tables of normative strength data were constructed. Multivariate analyses were performed to analyze the effects of age, gender, weight, height and activity level on isometric shoulder strength. Men were stronger than women (p<0.001). Age was not associated with most strength measures with the exception of dominant arm abduction (p<0.004), non-dominant arm abduction (p<0.028) and non-dominant arm scapular plane abduction (p<0.004) which had a negative association with strength. Weight was positively associated with strength (p<0.001). Activity level was positively associated with all strength measures (p<0.05) except dominant sided abduction (p=0.056). There were no statistically significant differences between dominant and non-dominant sides. This normative data may be useful to the clinician, as it permits a standard against which to compare shoulder strength for various age groups. Clinicians can have confidence that the uninvolved limb, if symptom free, can be used as an adequate benchmark for strength measures. Level 3©The Author(s).

Poster 161: Musculoskeletal Adaptations to Baseball Pitching Differ Markedly Between Righthand Dominant Versus Lefthand Dominant Pitchers

Objectives: Musculoskeletal adaptations on the dominant arm of baseball pitchers are typically (1) a gain in glenohumeral external rotation (ER) range of motion (ROM), (2) a loss of glenohumeral internal rotation (IR) ROM, (3) posterior shoulder tightness, (4) weakness in the empty can test, and (5) increased IR strength. The purpose of this study was to determine if these adaptations differed between righthand dominant (RHD) versus lefthand dominant (LHD) pitchers. Based on recent work it was hypothesized that ROM adaptations would be less apparent in LHD pitchers, but strength adaptations would not differ between RHD and LHD pitchers. Methods: Shoulder ROM and strength were measured in 327 baseball pitchers in preseason screening (91 were tested on more than one season, 418 player-seasons, 322 RHD vs. 96 LHD). There were 157 youth pitchers (age 11-15 yr) 146 adolescent pitchers (age 16-17 yr) and 115 adult pitchers (age 18-24 yr). ER ROM, IR ROM and posterior shoulder ROM (Tyler test) were measured with a digital level. Empty can, ER, IR and scapular retraction strength were measured with a hand-held dynamometer. Differences between the dominant and nondominant arms, between RHD and LHD pitchers, and between age groups, were assessed using mixed model analysis of variance (mean and SD reported). Results: ROM Adaptations RHD pitchers had 11±10° more ER ROM on the dominant versus nondominant arm (P&lt;0.001) but LHD pitchers had no ER ROM difference (0±10°, P=0.685). The difference in ER ROM between RHD and LHD pitchers (P&lt;0.001) was unaffected by age (P=0.829). IR ROM loss on the dominant versus nondominant arm for RHD pitchers (10±11°) was greater (P&lt;0.001) than for LHD pitchers (5±10°). This difference was apparent for youth pitchers (RHD 9±9° vs. LHD 1±9°, P&lt;0.001) and adolescent pitchers (RHD 12±10 vs. LHD 5±11°, P&lt;0.001) but not for adult pitchers (RHD 9±14° vs. LHD 8±10°, P=0.863; RHD vs. LHD by Age Group P=0.040). Total ROM (ER+IR ROM) adaptations also differed between RHD and LHD pitchers (P&lt;0.001) and this effect was more apparent in the adult pitchers (Age Group by RHD vs. LHD P=0.027): RHD adult pitchers had a 4±15° gain in total ROM on the dominant side (P=0.007) while LHD adult pitchers had a 7±10° loss in total ROM on the dominant side (P=0.002). Posterior shoulder tightness on the dominant side was affected by arm dominance and age (P=0.038); for youth and adolescent pitchers there was no difference between RHD and LHD pitchers (youth RHD 6±13° vs. LHD 10±11°, P=0.156; adolescent RHD 5±10° vs. LHD 8±15°) but for adult pitchers, posterior shoulder tightness was greater for RHD versus LHD pitchers (6±8° vs. 1±11°, P=0.032). Strength Adaptations For the empty can test, RHD pitchers were weaker on the dominant versus nondominant arm (5±15%, P&lt;0.001) while there was no difference between the dominant and nondominant arms for LHD pitchers (3±16% stronger on dominant side P=0.100; RHD vs. LHD P&lt;0.001). For IR strength, RHD pitchers were stronger on the dominant arm (7±17%, P&lt;0.001) while there was no difference between the dominant and nondominant arms for LHD pitchers (2±21% P=0.360; RHD vs. LHD P=0.032). By contrast, for scapular retraction strength, LHD pitchers were stronger on the dominant arm (6±19%, P=0.007) while there was no difference between the dominant and nondominant arms for RHD pitchers (0±15% P=0.723; RHD vs. LHD P=0.003). Dominant versus nondominant ER strength was not different between RHD and LHD pitchers (P=0.323). Conclusions: The typical strength and ROM adaptations seen in baseball pitchers were mostly absent, or diminished, in LHD pitchers, but with some age dependent effects for ROM. Adult RHD pitchers had IR ROM loss and posterior shoulder tightness, but paradoxically adult LHD pitchers had IR ROM loss without associated posterior shoulder. The opposite was the case for youth and adolescent pitchers, with LHD pitchers having posterior shoulder tightness in the absence of IR ROM loss. Differences in strength adaptations between RHD and LHD pitchers have not been reported previously. Epidemiological studies examining the role of strength and ROM in injury risk for baseball pitchers have not previously accounted for differences between lefthanded and righthanded pitchers.

Poster 207: Chronic Adaptations of the Ulnar Nerve in Professional Baseball Pitchers

Objectives: The presence of ulnar neuropathy in baseball pitchers is a poor prognostic factor of successful return to play and may adversely impact outcomes after ulnar collateral ligament reconstruction (UCLR). Screening programs to identify negative ulnar nerve adaptations in throwing athletes can help minimize injury risk, individualize treatment programs, and optimize rehabilitation. Ultrasound provides the advantage of viewing structural adaptations prior to the onset of symptoms, an important factor in identifying potential injuries in advance. However, it is currently unclear how the ulnar nerve adapts chronically in professional baseball pitchers. Therefore, the primary purpose of this study was to compare ulnar nerve ultrasound characteristics between the throwing (dominant) and non- throwing control (non-dominant) elbows in professional pitchers, with a secondary purpose of comparing ultrasound characteristics between subluxing and non-subluxing ulnar nerves. The authors hypothesized that ulnar nerve area and echogenicity (i.e. brightness) would be increased in the throwing elbow. Methods: All healthy professional baseball pitchers from a single organization underwent bilateral ultrasound examination at the beginning of the 2022 Minor League Baseball spring training. Ultrasound examination was done by a musculoskeletal radiologist (**) for imaging and subsequent quantification of the ulnar nerve properties, as well as to identify ulnar nerve subluxation. ImageJ software was utilized to measure ulnar nerve area, echogenicity (i.e. brightness), and circularity by one investigator (**) who was blinded to subluxation findings and arm dominance. Comparison of ulnar nerve ultrasound characteristics were performed between: dominant vs. non-dominant elbows, subluxing vs. non- subluxing dominant elbows, and between all (dominant and non-dominant) subluxing vs. non-subluxing elbows. Results: Overall, 74 male professional baseball pitchers (age: 22.5 ± 2.4 years; professional experience: 1.7 ± 1.5 years) were enrolled. There was a trend toward statistical significance for echogenicity bilaterally (dominant: 137 optical density vs. non-dominant: 128 optical density, p=0.053), while area (0.2 mm2 vs. 0.2 mm2, p=0.767) and circularity (0.67 vs. 0.69, p=0.165) did not differ bilaterally (Table 1). There were no demographic differences between pitchers with subluxing vs. non-subluxing dominant ulnar nerves, including similar years of professional experience and similar Beighton hypermobility scores between groups (Table 2). Echogenicity was significantly lower in subluxing dominant ulnar nerves compared to non-subluxing dominant ulnar nerves (128 optical density vs. 142 optical density, p=0.020). Echogenicity remained significantly lower in subluxing ulnar nerves after evaluating all subluxing vs. non-subluxing elbows (121 optical density vs. 138 optical density, p=0.001) (Table 3). Ulnar nerve area and circularity did not differ based on ulnar nerve subluxation. Conclusions: There was a trend towards the ulnar nerve of the throwing elbow having increased echogenicity relative to the non-throwing elbow, suggesting that echogenicity may play a role in the chronic adaptations of the ulnar nerve. Nerve echogenicity also differed based on ulnar nerve subluxation, however further research is necessary to determine why this difference exists and the potential direction of causality. [Table: see text][Table: see text][Table: see text]

#6345 HIGH BRACHIAL ARTERY BIFURCATION AND CLINICAL IMPLICATIONS UPON HEMODIALYSIS VASCULAR ACCESS PLANNING

Abstract Background and Aims Preoperative ultrasound mapping provides information about overall vessel, caliber, flow and anatomic variations, useful for hemodialysis (HD) vascular access planning. High bifurcation of the brachial artery (HBBA) is one of such variations, established early upon fetal development. Its implications in arteriovenous HD access creation are fairly unknown. The present work aims to characterize the prevalence and demographic characteristics of patients presenting with HBBA and study its impact upon HD vascular access planning, construction and patency. Method We developed a retrospective study focusing on 457 patients accessed from 2018 to 2021. Demographic data and presence of HBBA were registered as well as vessel diameter and peak systolic velocities (PSV) for brachial and radial arteries. Theoretical feasibility for each specific access (i.e., radiocephalic, brachiocephalic, brachiobasilic and prosthetic fistulae, according to ultrasound evaluation), final choice of access and 30-day patency were also gathered. Categorical variables are presented as frequencies and percentages and continuous variables as means and standard deviations or medians and interquartile ranges, as appropriate. Logistic regressions were adjusted considering sex, race, arm dominance and HBBA as independent variables. Results From a total of 457 patients, 193 (42,2%) were women and 264 (57,8%) were men. Mean age was 65,4 ±15,3 years. 383 (83,8%) were caucasian and 427 (93,4%) were right-handed. High bifurcation of the brachial artery was present on both arms of 6 (1,3%) patients, only one arm on 62 (13,6%) and on none of the remaining 389 (85,1%) patients. We found an association between being non-caucasian and presenting with HBBA (27% vs 12,5%, p-value = 0,01) but not with sex or arm dominance. Considering all patients, female sex was associated with smaller radial artery diameter, (2,0 ± 0,7 mm vs 2,2 ± 0,6 mm, p &amp;lt; 0,01). HBBA was not associated with a significant difference on arterial diameters (adjusted for sex and race) and there were also no significant differences when comparing dominant vs non-dominant arms. We found no association between HBBA and the theoretical feasibility of a raciocephalic fistula but rather with the choice of arteriovenous graft as the only possible access (26,5% vs 19,5%, p-value = 0,044). A total of 379 (77,0%) patients proceeded to vascular access construction: 59 (15,6%) radiocephalic fistulas, 229 (60,4%) brachiocephalic fistulas, 31 (8,2%) brachiobasilic fistulas and 60 (15,8%) arteriovenous grafts were created, with no differences between HBBA and non-HBBA groups. There was, however, an association between non-caucasian patients and the choice for a more proximal access (p = 0,001) as well as the need for surgical or angiographic reintervention within 45 days after access creation (11 (5%) vs 6 (17,6%), p-value = 0,002). Conclusion Our study suggests that presenting with HBBA is not necessarily associated with lower quality vessels and less distal access construction. However, this variation seems to be more frequent among non-caucasians, who appear to receive more proximal accesses, in greater need for early intervention than their counterparts. Further investigation is necessary to understand if apart from diameter or PSV, HBBA could influence other determinants of access placement choice, such as distance from brachial artery to cephalic or basilic vein or risk of distal hypoperfusion syndrome.

Effects of Arm Dominance and Decision Demands on Change of Direction Performance in Handball Players.

This field study investigated the effect of unilateral dominance (handedness of players) on the change of direction speed in a specific cutting manoeuvre with a ball (in the direction of the throwing arm vs. against the direction of the throwing arm) in team handball. In addition, the effect of a cutting manoeuvre in response to an immediate stimulus compared to one planned in advance on the movement speed was analysed. Forty participants (22 male, 18 female, Mage 23 years) performed change of direction actions to the left and the right side (the direction of the throwing arm vs. against the direction of the throwing arm) under planned and reactive (light as visual stimuli) conditions. Change of direction speed was measured post-hoc by video-analyses. The results showed two effects. First, the decision demand in reaction to a visual stimulus reduced the speed in the change of direction compared to the planned action. Second, participants performed their action faster in the direction of the throwing arm than against it. The results replicate the effects of decision demands of previous studies and regardless of the reaction to the stimuli being unspecific, further studies could investigate if specific training can reduce the speed loss due to decision demands. The lateral speed differences of cutting manoeuvres of handball players have been analysed for the first time in this study. This effect could have several causes (e.g., coordination, power, motivation) which should be investigated in future studies in more detail.

Patterns of limitations in activities of daily living, sleep, and pain in the early postoperative period following total shoulder arthroplasty: a prospective study.

The aim of this study is to investigate the pattern of changes in activities of daily living (ADLs), sleep disturbance, and pain in the early postoperative period following a total shoulder arthroplasty (TSA). Prospective data on patterns of limitation in ADLs, sleep disturbance, and pain were collected from patients undergoing elective TSA preoperatively and at specific time points postoperatively (2, 6, and 12 weeks). At each time point, patients were asked regarding the major limitation affecting their shoulder. Limitations in ADLs and sleep disturbances were scored on a 3-point scale (0=unable to do, 3=no difficulty) modeled after the ADL which require active external rotation score and visual analog scale scores were used for pain. Patient responses were analyzed with respect to patient factors (demographics, arm dominance, function of opposite arm, and ambulation status), and living situation (alone, or with caregiver). Shoulder pain (43%) and inability to perform ADLs (38%) were the 2 most commonly reported limitations prior to undergoing TSA. Patients noticed progressive improvements in pain with 37% reductions in visual analog scale scores at 2 weeks and 67% reduction at 3 months. At 2 weeks after TSA, sleep disturbances were the most disabling issue in 33% of the cohort, with considerable improvements (104%) in sleep scores at 3 months compared to pre-op. The ADLs involving forward elevation and working at the waist level improved considerably between 6 weeks and 3 months, but activities involving rotation including reaching behind the back, across the chest, and use of strength showed mild improvements by 3 months. This prospective study demonstrates the chronology of improvements in pattern of limitations experienced by patients with respect to pain, sleep, and ADLs in the early postoperative period after TSA. Majority of patients can expect to have 2/3 resolution of pain, improved sleep, and improvement in ADLs involving forward elevation and waist level function by 3 months.

RISK FACTORS FOR DEVELOPING UPPER LIMB CELLULITIS AFTER BREAST CANCER TREATMENT

Cellulitis is one of the most important troubling complications of breast cancer treatment. Therefore, elucidating the risk factors for cellulitis in patients that have undergone breast cancer treatment is crucial. This is a retrospective medical record study among 523 patients who had received breast cancer treatment and were referred to the Lymphedema Clinic. Data on age, height, weight, BMI (body mass index), education level, arm dominance, history of previous surgery, axillary lymph node dissection, radiotherapy, and chemotherapy were noted. The time between operation and onset of lymphedema, duration of lymphedema, history of cellulitis, and number of cellulitis attacks were recorded. Circumference measurements were taken at four points on the upper limb. Univariate analysis showed that longer duration of lymphedema, larger circumference of the unaffected arm and larger circumference of the arm with lymphedema were associated with higher risk of cellulitis (p=0.008, p=0.007, p< 0.001, respectively). The incidence of cellulitis was higher in patients with lymphedema than patients who had no lymphedema (p< 0.001). Moreover, the frequency of cellulitis was higher in patients with lower education level (p=0.015). It was deter-mined that patients with cellulitis needed more compression garments (p< 0.001) and multi-layered bandage therapy (p< 0.001) than those without. Regression analysis revealed that presence of lymphedema (p=0.036), duration of lymphedema (p=0.048), radiotherapy (p=0.01) and educational level (0.019) are significantly associated with developing upper extremity cellulitis. It is important to consider these risk factors for the prevention and management of cellulitis in patients who undergo treatment for breast cancer. Early detection and treatment of lymphedema also remains essential for these patients.

Clinical Outcomes of Ulnar Collateral Ligament Surgery in Nonthrowing Athletes

Background: Ulnar collateral ligament (UCL) surgery continues to demonstrate excellent clinical outcomes and a high return-to-play (RTP) rate with a low complication rate. Recent studies have demonstrated similar clinical outcomes for baseball players who have undergone either UCL reconstruction or UCL repair. In comparison, few studies have assessed the clinical outcomes of UCL surgery for nonthrowing athletes. Purpose/Hypothesis: The primary objective of this study is to provide clinical outcomes of UCL surgery performed in nonthrowing athletes at a single institution with a minimum 2-year follow-up. Our hypothesis was that these patients would have similar clinical outcomes, complication rates, and RTP rates when compared with throwing athletes. Level of Evidence: Case series; Level of evidence, 4. Methods: From our longitudinal elbow registry, 40 nonthrowing athletes were identified who underwent UCL surgery (repair or reconstruction) between 2011 and 2019. Participant characteristics were recorded: age, sex, laterality, arm dominance, sport, level of competition, and type of surgery (UCL repair or reconstruction). Outcomes included RTP rate and average time, American Shoulder and Elbow Surgeons (ASES) scores, and complications. Results: From the 40 patients eligible for inclusion in this study with a minimum 2-year follow-up, 37 (93%) were successfully contacted: 16 male (43%) and 21 female (57%). Mean ± standard deviation age at the time of surgery was 18.0 ± 3.7 years. From the 37 technical procedures, 28 (76%) were UCL repairs and 9 (24%) were UCL reconstructions. For these patients, 15 (41%) had partial tears, 20 (54%) had complete tears, 1 (3%) had a medial epicondyle avulsion, and 1 (3%) had an unspecified pathology. Sports included football (n = 11), gymnastics (11), cheerleading (7), wrestling (4), volleyball (2), basketball (1), and acrobatics (1). Quarterbacks were excluded from the football patients, as quarterbacks are throwing athletes. Level of competition included high school (n = 26), college (8), professional (2), and youth sports (1). The RTP rate was 93% (26/28) at a mean 7.4 months for UCL repair and 100% (9/9) at a mean 10.0 months for UCL reconstruction. Mean ASES scores were 94.4 and 98.7 for UCL repair and reconstruction, respectively. Complications were low, with 2 patients in the UCL repair group requiring ulnar nerve transposition for ulnar nerve paresthesia. Conclusion: In nonthrowing athletes, patients undergoing UCL repair and UCL reconstruction show favorable outcomes at minimum 2-year follow-up. RTP and clinical outcomes are consistent with previous studies in baseball players as well as a parallel ongoing study conducted on non–baseball throwing athletes.

The Effect of Arm Dominance on Knee Joint Biomechanics During Basketball Block Shot Single-Leg Landing.

Single arm blocking is a key component of successful basketball defence. The player uses either their dominant or non-dominant arm to block the ball landing on a common leg. Understanding how the bio-physical loads of the landing leg change as a function of the blocking arm will provide insights into potential injury risk of the lower limb. The aim of this study was to investigate the effects of arm dominance on the biomechanical variables of injury risk of the lower limb, specifically the knee joint during the single-leg landing in female basketball players. Kinematic and kinetic data were collected from fourteen female basketball athletes (20.85 ± 1.35 years, 1.69 ± 0.06 m, 60.37 ± 7.75 kg), each performing three trials of a dominant arm and non-dominant block jump landing on the dominant leg. The results showed significantly higher anterior and medial ground reaction force, knee joint flexion and abduction and lateral knee force during the dominant arm landing (p < 0.05). These findings highlight potential injury risk and the need for the player to be more proficient at dominant arm block-shot landing. The player should aim to develop a larger landscape of technique to meet the demands of the game and facilitate a more effective and safer landing strategy.

Initial kinematic chain injuries increase hazard of subsequent arm injuries in professional baseball pitchers.

Currently, there are few studies that have evaluated the relationship between a lower extremity or trunk injury (kinematic chain) and subsequent arm injury. The purpose of this study was (1) to investigate the relationship between initial kinematic chain (lower extremity or trunk) injury and subsequent arm injury; and (2) to investigate the relationship between initial shoulder or elbow injury and subsequent arm injury. A 7-year prospective injury risk study was conducted with Minor League Baseball pitchers. Pitches, pitching appearances, athlete exposures (AEs), and arm injuries (≥1-day time loss) were documented throughout the season. Cox survival analyses with 95% confidence intervals (95% CIs) were performed. Confounders controlled for included age, body mass index, arm dominance, pitching role, previous arm injury, number of pitching appearances, and seasonal pitch load. A total of 297 pitchers participated (total player days=85,270). Arm injury incidence was 11.4 arm injuries/10,000 AEs, and kinematic chain incidence was 5.2 injuries/10,000 AEs. Pitchers who sustained a kinematic chain injury demonstrated a greater hazard (2.6 [95% CI: 1.2, 5.6], P=.019) of sustaining an arm injury. Pitchers who sustained an initial shoulder injury demonstrated a greater hazard (9.3 [95% CI: 1.1, 83], P=.047) of sustaining a subsequent shoulder or elbow injury compared with pitchers who sustained an initial elbow injury. Pitchers who sustained an initial lower extremity or trunk injury demonstrated an increased subsequent arm injury hazard compared with pitchers who did not. Pitchers who sustained an initial shoulder injury demonstrated a greater hazard of sustaining a subsequent arm injury compared with pitchers who sustained an initial elbow injury. However, this secondary analysis should be interpreted with caution. Clinicians should monitor risk with workload accumulation, which may be related to pitching compensatory strategies in a fatigued state. Pitchers who sustain a shoulder injury should be evaluated and perform both shoulder and elbow rehabilitation strategies before return to sport.

Including Modifiable and Nonmodifiable Factors Improves Injury Risk Assessment in Professional Baseball Pitchers.

To (1) evaluate an injury risk model that included modifiable and nonmodifiable factors into an arm injury risk prediction model in Minor League Baseball (MiLB) pitchers and (2) compare model performance separately for predicting the incidence of elbow and shoulder injuries. Prospective cohort. A 10-year MiLB injury risk study was conducted. Pitchers were evaluated during preseason, and pitches and arm injuries were documented prospectively. Nonmodifiable variables included arm injury history, professional experience, arm dominance, year, and humeral torsion. Modifiable variables included BMI, pitch count, total range of motion, and horizontal adduction. We compared modifiable, nonmodifiable, and combined model performance by R2, calibration (best = 1.00), and discrimination (area under the curve [AUC]; higher number is better). Sensitivity analysis included only arm injuries sustained in the first 90 days. In this study, 407 MiLB pitchers (141 arm injuries) were included. Arm injury incidence was 0.27 injuries per 1000 pitches. The arm injury model (calibration 1.05 [0.81-1.30]; AUC: 0.74 [0.69-0.80]) had improved performance compared to only using modifiable predictors (calibration: 0.91 [0.68-1.14]; AUC: 0.67 [0.62-0.73]) and only shoulder range of motion (calibration: 0.52 [0.29, 0.75]; AUC: 0.52 [0.46, 58]). Elbow injury model demonstrated improved performance (calibration: 1.03 [0.76-1.33]; AUC: 0.76 [0.69-0.83]) compared to the shoulder injury model (calibration: 0.46 [0.22-0.69]; AUC: 0.62 [95% CI: 0.55, 0.69]). The sensitivity analysis demonstrated improved model performance compared to the arm injury model. Arm injury risk is influenced by modifiable and nonmodifiable risk factors. The most accurate way to identify professional pitchers who are at risk for arm injury is to use a model that includes modifiable and nonmodifiable risk factors. J Orthop Sports Phys Ther 2022;52(9):630-640. Epub: 9 July 2022. doi:10.2519/jospt.2022.11072.