Lateralization and distalization shoulder angles do not predict outcomes in reverse shoulder arthroplasty for cuff tear arthropathy

BACKGROUND

In reverse shoulder arthroplasty (RSA), there are a plethora of measurements regarding implant lateralization and distalization to optimize the center of rotation. Two specific measurements known as the "lateralization shoulder angle" (LSA) and "distalization shoulder angle" (DSA) have been the recent focus of studies to assess their association with RSA and postoperative function. The aim of this study was to evaluate the prognostic clinical value of the LSA and DSA in a large cohort of patients with cuff tear arthropathy (CTA) who were treated with different RSA systems.

METHODS

Two local shoulder arthroplasty registries were reviewed for all RSA patients documented to have undergone a radiologic assessment and complete 2-year follow-up examination. The main inclusion criterion was primary RSA in patients with CTA. Patients with either a complete teres minor tear, os acromiale, or acromial stress fracture reported between the time of surgery and the 24-month follow-up were excluded. Five RSA implant systems with 4 neck-shaft angles (NSAs) were assessed. The Constant score, Subjective Shoulder Value, and range of motion at 2 years were correlated with both the LSA and DSA assessed on 6-month anteroposterior radiographs. Linear and parabolic univariable regressions were calculated for both shoulder angles, for each prosthesis system, and for the entire patient cohort.

RESULTS

Between May 2006 and November 2019, there were a total of 630 CTA patients who had undergone primary RSA. Of this large cohort of patients, 270 were treated with the Promos Reverse prosthesis system (NSA, 155°); 44, Aequalis Reversed II (NSA, 155°); 62, Lima SMR Reverse (NSA, 150°); 25, Aequalis Ascend Flex (NSA, 145°); and 229, Univers Revers (NSA, 135°). The mean LSA was 78° (standard deviation [SD], 10°; range, 6°-107°), and the mean DSA was 51° (SD, 10°; range, 7°-91°). The average Constant score at 24 months' follow-up was 68.1 points (SD, 13 points; range, 13-96 points). Neither the linear nor parabolic regression calculations for the LSA or DSA revealed significant associations with any of the clinical outcomes.

CONCLUSION

Different patients may achieve different clinical outcomes despite having identical LSA and DSA values. There is no association between angular radiographic measurements and 2-year functional outcomes after RSA.

Neck pain in rounded shoulder posture: Clinico-radiologic correlation by shear wave elastography

AIM

The frequency of neck pain increases in adolescents and young adults. Using smart phones and computers for a long time causes posture disorders such as rounded shoulder (RSP) and forward head postures, and these posture disorders cause neck pain. The aim of the study is to analyse the correlation between shoulder and neck angles and the stiffness of the upper trapezius and pectoralis minor muscles in patients with RSP.

METHOD

Patients with neck pain examined by shear wave elastography were screened retrospectively. Patients with RSP were determined. Of these patients, whose had evaluated for shoulder and neck angles with a smart phone-based photogrammetric method were assigned. Patients with a history of operation/trauma, connective tissue or neurological disease were excluded. A total of 39 female patients were included in the study. Age, height, weight, elastography measurements, cervical and shoulder angles were noted. Obtained data were statistically analysed with SPSS 22.0 program.

RESULTS

Cervical and shoulder angles of the patients were 52.2 ± 3.8 and 57.91 ± 9.4, respectively. The stiffness of the right and left upper trapezius muscles and right and left pectoralis minor muscles were 42.5 ± 14.1, 47.1 ± 17.1, 20.5 ± 8.0 and 17.9 ± 8.4, respectively. In multiple regression analysis, it was observed that the stiffness of the left upper trapezius muscle was positively correlated with the shoulder angle.

CONCLUSION

The upper trapezius muscle stiffness increased in RSP. It can reveal the relationship between RSP and neck pain.

Shoulder moments and angles during single and combined manual material handling tasks

Shoulder musculoskeletal disorders due to manual material handling tasks are common workplace injuries. Here we investigated the difference in shoulder biomechanics (moments and angles) between a single task of removing a box from a shelf (or depositing a box on a shelf) and the equivalent part of a combined task that consisted of removing, carrying and depositing boxes; that is, a single removing [depositing] task was compared with the removing [depositing] part of a combined task. We found that the peak and cumulative shoulder moments were larger during the single-task paradigm than during the equivalent part of the combined task by 26.3 and 25.5%, respectively. The two paradigms also differed in terms of shoulder angles. It is likely that the main contributors to this overestimation were differences between the single and combined tasks in terms of the lever arm (i.e. horizontal distance), the shoulder angle, and the task duration. Practitioners' Summary: We investigated shoulder moments during single and combined manual material handling tasks. Shoulder moments were found to be smaller during combined tasks. Practitioners should consider that analysing combined tasks using estimations based on single tasks could result in an overestimation of 26.3 and 25.5% in peak and cumulative shoulder moments, respectively.Abbrevaitions: MSDs: musculoskeletal disorders; MMH: manual material handling; LMM: linear mixed model.

Kinematic Analysis of 2-Point and 3-Point Jump Shot of Elite Young Male and Female Basketball Players

Basketball shooting is one of the most important offensive skills in basketball. Winning or losing a game mostly depends on the shooting effectiveness. The study aims to compare the selected kinematic variables of 2-point (2-pt) and 3-point (3-pt) jump shots (after making a cut and receiving the ball) and ascertain the differences between elite male under 16 and 18 (U16M, U18M) and female under 16 and 18 (U16F, U18F) basketball players. Overall, forty-eight young male and female basketball players participated in the study. 3D motion analysis using an inertial suit with the addition of utilizing a smart ball was performed for assessing the 2-pt and 3-pt shooting techniques. Players in male categories shot for 2-pt with a higher center of mass difference in the vertical direction (U16M 5.7 cm, U18M 3.9 cm vs. U16F 1.4 cm, U18F 0.6 cm), with higher release shoulder angle (U16M 110.9, U18M 113.8 vs. U16F 103, U18F 105), and with a higher entry angle of the ball (U16M 34, U18M 32 vs. U16F 30, U18F 30) when compared to female categories (p < 0.001). In the 3-pt shooting, there were differences between male and female categories in the shoulder angle when releasing the ball (p < 0.001). In the players shooting speed, there were differences between U16M vs. U18F (0.95 ± 0.1 vs. 0.88 ± 0.1; p = 0.03) and U16F vs. U18F (0.96 ± 0.06 vs. 0.88 ± 0.1; p = 0.02) players. Male categories shot 3-pt shots with a smaller center of mass difference in the horizontal direction when compared to 2-pt shots (p < 0.001). The entry angle was higher in successful shooting attempts compared to unsuccessful shooting attempts when shooting for 3-pt (p = 0.02). Player shooting speed was higher in all categories (except U18F) when shooting for 3-pt (p < 0.001). It appears that performers show difference in kinematic variables based on distance from the basket. Basketball coaches and players should work to minimize the kinematic differences between 2-pt and 3-pt shooting and to optimize the shooting technique.

Effects of adjustments to wheelchair seat to back support angle on head, neck, and shoulder postures in subjects with cerebral palsy

A wheelchair is usually a source of mobility for people with moderate to severe cerebral palsy, who are unable to walk. They spend long periods of time sitting in their wheelchair, which can affect their head and neck alignment. Opening the seat to back support angle of the wheelchair can modify realignment of body segments and improve posture. Aims: To examine the effect of seat to back support angle adjustments on head, neck, and shoulder postural alignment in people with cerebral palsy. Methods: Nine participants with cerebral palsy who use a wheelchair for mobility sat in a research wheelchair. Sagittal head angle (SHA), cervical angle (CVA), and shoulder angle (SA) from photographs were examined using the Coach's Eye device during three different seat to back support angles of the wheelchair (90°, 100°, 110°). Results: There were significant differences in mean SHA and CVA among the different seat to back support angles (p < .001). However, there was no significant difference in mean SA. Conclusion: Head (SHA) and (CVA) alignment was closest to neutral posture with seat to back support angles set at 110°. Thus, adjusting the wheelchair back support to a 110º would provide the most appropriate sagittal head and cervical angle for this population.

Validity and reliability of wheelchair sitting posture measures using Coach's Eye in abled subjects

People in wheelchairs spend a long time in the sitting position and often incur alignment problems resulting in neck and back pain. This study: (1) assessed the validity/reliability of Coach's Eye (CE) smart device application, (2) examined the effect of seat to back support angle adjustments on head, neck, and shoulder posture in the sitting position, and (3) compared changes in cervical rotation at each back support angle. Abled subjects sat in a wheelchair with back support angles positioned at 90°, 100°, and 110°. CE, as well as ImageJ software, was used to analyze three angles: sagittal head angle (SHA), cervical angle (CVA), and shoulder angle (SA). There were highly significant differences for CVA and SA (p < 0.001) among the three seat to back support angles. Validity of CE was examined by correlating CE with ImageJ scores. CE had high validity for all angles (r = 0.99, 0.98, 0.99 respectively, p < 0.001). Inter-rater reliability for SHA, CVA, and SA was high (intraclass correlation coefficient [ICC] ranged from 0.95 to 0.99). Head (CVA) and shoulder (SA) alignment was closest to neutral posture with back support angles set at 110° and 90°, respectively.