Neural Drive and Motor Unit Characteristics of the Serratus Anterior in Individuals With Scapular Dyskinesis.

OBJECTIVE: Scapular dyskinesis is one of the causes of shoulder disorders and involves muscle weakness in the serratus anterior. This study investigated whether motor unit (MU) recruitment and firing property, which are important for muscle exertion, have altered in serratus anterior of the individuals with scapular dyskinesis. METHODS: Asymptomatic adults with (SD) and without (control) scapular dyskinesis were analyzed. Surface electromyography (sEMG) waveforms were collected at submaximal voluntary contraction of the serratus anterior. The sEMG waveform was decomposed into MU action potential amplitude (MUAPAMP), mean firing rate (MFR), and recruitment threshold. MUs were divided into low, moderate, and high thresholds, and MU recruitment and firing properties of the groups were compared. RESULTS: High-threshold MUAPAMP was significantly smaller in the SD group than in the control group. The control group also exhibited recruitment properties that reflected the size principle, however, the SD group did not. Furthermore, the SD group had a lower MFR than the control group. CONCLUSIONS: Individuals with scapular dyskinesis exhibit altered MU recruitment properties and lower firing rates of the serratus anterior; this may be detrimental to muscle performance. Thus, it may be necessary to improve the neural drive of the serratus anterior when correcting scapular dyskinesis.

Efficacy of head postural correction program on craniovertebral angle, scapular position, and dominant hand grip strength in forward head posture subjects: A randomized controlled trial.

OBJECTIVE: Forward head posture (FHP) is a common postural disorder that alters shoulder function. This study examined the efficacy of a corrective program involving postural correction exercises (PCEs), scapular stabilization exercises (SSEs), and kinesiotaping (KT) on improving craniovertebral angle (CVA), scapular position, and dominant hand grip strength (HGS) in individuals with FHP. METHODS: Sixty subjects (8 males and 52 females, 18-40 years old) were randomly allocated into four equal groups: Group A: received PCEs only, Group B: received PCEs and SSEs, Group C: received PCEs and KT, Group D: received PCEs, SSEs and KT. All subjects received treatment for 4 weeks (4 times/week) and postural advice. Outcome measures included cranio-vertebral angle (CVA), scapular position using Lateral Scapular Slide Test and dominant HGS using a CAMRY dynamometer that were assessed at baseline and 4 weeks post intervention. RESULTS: Comparing all groups post training revealed that there were statistically significant increases (p < 0.05) in all measured variables (CVA, scapular position and dominant HGS) in favor of group (D). CONCLUSION: Combination of PCEs, SSEs and KT interventions has achieved the best gains in terms of CVA, dominant HGS and regaining optimal scapular position in FHP subjects.

Investigating scapula positioning in individuals with non-specific lower back pain: A preliminary study.

INTRODUCTION: Low back pain (LBP) is an economic and physically disabling burden on individuals and society. With 70% of cases classed as non-specific, there is a need for further research into the causes and consequences associated. The involvement of postural balance in musculoskeletal conditions is gaining increasing interest in research and health practice. However, there is a lack of literature surrounding LBP and posture in distal segments of the body. OBJECTIVE: The current study investigated scapula positioning in those with non-specific LBP. METHODS: Scapula angle of rotation, scapula protraction, and scapula elevation were assessed in nine participants with chronic non-specific LBP and compared with that of nine asymptomatic controls (aged 18-60 years). The degree of pelvic tilt was assessed across both groups as a secondary outcome measure. RESULTS: No difference was identified between the two sample groups for scapula angle of rotation (p = 0.707), protraction (p = 0.755), or elevation (p = 0.691). Anterior pelvic tilt was greater in those with LBP (p = 0.046), supporting previous literature. CONCLUSION: The findings for the scapula position are novel, given that research in this field is limited. It is concluded that there is no change in scapula positioning in those with non-specific LBP, but there is an increased anterior pelvic tilt.

Evaluation of a method to quantify posture and scapula position using biplanar radiography.

BACKGROUND: Recent studies have stated the relevance of having new parameters to quantify the position and orientation of the scapula with patients standing upright. Although biplanar radiography can provide 3D reconstructions of the scapula and the spine, it is not yet possible to acquire these images with patients in the same position. METHODS: Two pairs of images were acquired, one for the 3D reconstruction of the spine and ribcage and one for the 3D reconstruction of the scapula. Following 3D reconstructions, scapular alignment was performed in two stages, a coarse alignment based on manual annotations of landmarks on the clavicle and pelvis, and an adjusted alignment. Clinical parameters were computed: protraction, internal rotation, tilt and upward rotation. Reproducibility was assessed on an in vivo dataset of upright biplanar radiographs. Accuracy was assessed using supine cadaveric CT-scans and digitally reconstructed radiographs. FINDINGS: The mean error was less than 2° for all clinical parameters, and the 95 % confidence interval for reproducibility ranged from 2.5° to 5.3°. INTERPRETATION: The confidence intervals were lower than the variability measured between participants for the clinical parameters assessed, which indicates that this method has the potential to detect different patterns in pathological populations.

Scapular Elevation Sign - A New Sign in Evaluation of Thoracic Outlet Syndrome.

Background: We noted that patients with thoracic outlet syndrome (TOS) have elevation of the ipsilateral scapula and named this the scapular elevation sign (SES). The aim was to determine the prevalence of SES in a normal cohort, compare SES with other provocative tests and to determine the treatment effect on SES. Methods: First, normal asymptomatic subjects were prospectively assessed to determine the prevalence of SES in a normal cohort. Second, patients with TOS were retrospectively examined for the presence of SES and four provocative tests: supraclavicular pressure, scalene test, elevated arm stress test (EAST) and the military brace manoeuvre. All patients were initially treated non-surgically. Surgery was offered to patients with persistent symptoms at 6 months. Patients were re-examined for the presence of the SES after treatment. Results: The prevalence of SES in our normal cohort was 4% (2/53). Our study cohort included 20 patients with TOS. The SES was positive in 18 patients (90%). Supraclavicular pressure was positive in 11 (55%), scalene test in 13 (65%), EAST in 9 (45%) and military brace manoeuvre in 11 patients (55%). Following non-surgical treatment, six patients had symptom resolution, three had improvement, nine persistent symptoms and two were lost to follow-up. The SES was positive in one out of six patients with symptom resolution, two out of three patients with improvement and in all nine patients with persistent symptoms. Patients with persistent symptoms underwent surgery with symptom resolution in eight and improvement in one patient. The SES remained positive in two patients after surgical treatment. Conclusions: The SES is simple and sensitive, does not rely on variations in performance of the test and suitable for diagnosis and assessment of outcomes of TOS. Level of Evidence: Level III (Diagnostic).

Scapula alata, a rare complication after minimally invasive repair of pectus excavatum.

A male patient in his early 30s underwent minimally invasive repair of pectus excavatum. According to standard Nuss bar procedure, a 30-degree thoracoscope was introduced through a right midaxillary 10 mm trocar in the 4th intercostal space. Two bars and five stabilisers were placed in a retromuscular position. After discharge, the patient experienced right upper back pain requiring prolonged opioid usage for three months and right scapular winging limiting functional activities. After conservative treatment with physiotherapy for 11 months, the patient still suffered from residual scapula alata with pain and muscle weakness. On suspicion of long thoracic nerve neuropraxia related to the thoracoscope placement, an electromyogram was conducted 16 months following surgery, revealing mild polyphasic potentials of the serratus anterior muscle without abnormal muscle unit action potential. After extended conservative therapy for another year, physical examination 28 months after surgery showed almost complete resolution of scapular winging.

Scapula fractures: functional anatomy, clinical assessment and management.

Fractures of the scapula are rare injuries, accounting for 3-5% of all shoulder girdle fractures. They are frequently the result of high energy trauma and often present with concurrent and life-threatening injuries to adjacent structures, leading to significant morbidity and mortality. Patients presenting with scapula fractures must receive a thorough and systematic clinical assessment as directed by national trauma guidelines. Appropriate imaging is essential in delineating fracture morphology and should at the very least include anteroposterior, anteroposterior oblique (Grashey) and axillary or scapula 'Y' view of the shoulder. Computed tomography imaging with three-dimensional reconstruction allows better delineation of the fracture morphology and helps with surgical planning. A lack of randomised controlled trials comparing the efficacy of conservative and operative management of scapula fractures has resulted in limited consensus for surgical indications. Nevertheless, most extra-articular fractures can be managed conservatively while intra-articular fractures of the glenoid frequently require surgical fixation.

A Morphometric Study of Glenoid Cavity of Scapula in Bangladeshi Population.

This cross-sectional descriptive purposive study was conducted among 150 (70 right and 80 left) fully ossified dry human scapulae of Bangladeshi people from January 2019 to December 2019 in the Department of Anatomy, Mymensingh Medical College, Mymensingh. Shape of the glenoid cavity was observed as pear, oval or inverted comma shape. Morphometric parameters such as length and breadth of glenoid cavity were measured by digital Vernier slide calipers. In this study, 19.13% cases were found inverted comma shaped, 35.65% cases were oval and 45.22% cases were pear shaped. The mean±SD length of glenoid cavity was 37.5±3.61 mm and 36.19±3.68 mm on right and left sided scapulae respectively and mean±SD breadth was 23.6±2.73 mm on right and 23.42±2.75 mm on left side respectively. Mean±SD glenoid cavity index was 62.89±4.39 on right and 64.61±4.74 on left sided scapulae. Morphometric analysis of glenoid fossa of scapula might help clinicians in shoulder and its associated diseases.

Biomechanical Characteristics of Glenosphere Orientation Based on Tilting Angle and Overhang Changes in Reverse Shoulder Arthroplasty.

Background: Glenoid position and inclination are important factors in protecting against scapular notching, which is the most common complication that directly affects the longevity of reverse shoulder arthroplasty (RSA). This study aimed to investigate the biomechanical characteristics of glenosphere orientation, comparing neutral tilt, inferior overhang with an eccentric glenosphere at the same placement of baseplate, and inferior tilt after 10° inferior reaming in the lower part of the glenoid in RSA. Methods: Nine cadaveric shoulders were tested with 5 combinations of customized glenoid components: a centric glenosphere was combined with a standard baseplate (group A); an eccentric glenosphere to provide 4-mm inferior overhang than the centric glenosphere was combined with a standard baseplate (group B); a centric glenosphere was combined with a wedge-shaped baseplate tilted inferiorly by 10° with the same center of rotation (group C); an eccentric glenosphere was attached to a wedge-shaped baseplate (group D); and 10° inferior reaming was performed on the lower part of the glenoid to apply 10° inferior tilt, with a centric glenosphere secured to the standard baseplate for simulation of clinical tilt (group E). Impingement-free angles for adduction, abduction, forward flexion, external rotation, and internal rotation were measured. The capability of the deltoid moment arm for abduction and forward flexion, deltoid length, and geometric analysis for adduction engagement were evaluated. Results: Compared with neutral tilt, inferior tilt at the same position showed no significant difference in impingement-free angle, moment arm capability, and deltoid length. However, group D resulted in better biomechanical properties than a central position, regardless of inferior tilt. Group E demonstrated a greater range of adduction, internal and external rotation, and higher abduction and forward flexion capability with distalization, compared to corresponding parameters for inferior tilt with a customized wedge-shaped baseplate. Conclusions: A 10° inferior tilt of the glenosphere, without changing the position of the baseplate, had no benefit in terms of the impingement-free angle and deltoid moment arm. However, an eccentric glenosphere had a significant advantage, regardless of inferior tilt. Inferior tilt through 10° inferior reaming showed better biomechanical results than neutral tilt due to the distalization effect.

Effects of scapular treatment on chronic neck pain: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Chronic neck pain (CNP) is a common public health problem that affects daily living activities and quality of life. There is biomechanical interdependence between the neck and scapula. Studies have shown that shoulder blade function might be related to chronic neck pain. We therefore evaluated the effects of scapular targeted therapy on neck pain and function in patients with CNP. METHODS: Databases, including MEDLINE (via PubMed), EMBASE (via Ovid), Ovid, Web of Science, and Scopus, were systematically searched for randomized controlled trials published in English investigating treatment of the scapula for CNP before July 16, 2023. RESULTS: A total of 313 participants were included from 8 RCTs. Compared with those in the control group, the intervention in the scapular treatment group exhibited greater improvement in pain intensity (standardized mean difference (SMD) = 2.55; 95% CI = 0.97 to 4.13; P = 0.002), with moderate evidence. Subgroup analysis for pain intensity revealed a significant difference between the sexes, with only the female population (SMD = 6.23, 95% CI = 4.80 to 7.65) showing better outcomes than those with both sexes (SMD = 1.07, 95% CI = 0.57 to 1.56) (p < 0.00001). However, moderate evidence demonstrated no improvement in neck disability after scapular treatment (SMD of 0.24[-0.14, 0.62] of Neck Disability Index or Northwick Park Neck Pain Questionnaire). No effect of scapular treatment was shown on the pressure pain threshold (PPT). The cervical range of motion (CROM) and electromyographic activity of neck muscles could not be conclusively evaluated due to limited support in the articles, and further study was needed. However, the patient's head forward posture appeared to be corrected after scapular treatment. CONCLUSION: Scapular therapy was beneficial for relieving pain intensity in patients with CNP, especially in women. Head forward posture might also be corrected with scapular therapy. However, scapular therapy may have no effect on the PPT or neck disability. However, whether scapular therapy could improve CROM and cervical muscle activation in patients with CNPs had not been determined and needed further study.

Management of Bone Loss in Posterior Glenohumeral Shoulder Instability: Current Concepts.

¼ Posterior glenohumeral instability is relatively uncommon compared with anterior instability, but is becoming an increasingly recognized and surgically managed shoulder pathology.¼ Soft-tissue stabilization alone may not be sufficient in patients who present with substantial bone loss to the posterior glenoid and/or the anterior humeral head.¼ For posterior glenoid defects, posterior glenoid osteoarticular augmentation can be used, and posterior glenoid opening wedge osteotomy can be considered in cases of posterior instability with pathologic retroversion.¼ For humeral head lesions, several surgical treatment options are available including subscapularis transposition into the humeral head defect, autograft or allograft reconstruction, humeral rotation osteotomy, and shoulder arthroplasty.

Superior scapular location: An overlooked albeit frequent finding in elastofibroma dorsi.

PURPOSE: To explore the frequency of superior scapular elastofibroma dorsi in a large patient series with elastofibroma dorsi. METHODS: 136 chest CTs from January 2016 to July 2022 reporting elastofibroma dorsi were retrospectively analyzed. Three radiologists assessed the number, size, and location of elastofibroma dorsi. Continuous variables underwent two-tailed t-tests with p < 0.05. Inter-observer agreement was assessed by using Cohen's Kappa values. RESULTS: In 136 patients (mean age, 75.9 +/- 9.8 years; 117 female), 330 elastofibroma dorsi were found. Six (4.4 %) patients had single, 87 (64 %) double, 22 (16.2 %) triple and 21 (15.4 %) quadruple lesions. All single and double lesions were in the inferior scapular regions. 43 (31.6 %) patients had superior scapular lesions in addition to inferior scapular elastofibroma dorsi. Inferior scapular elastofibroma dorsi was significantly larger than superior scapular elastofibroma dorsi. The probability of a right superior lesion was significantly higher in patients with a larger right inferior lesion. Inter-observer agreement was very good for experienced radiologist (κ = 94.1) and good for other radiologists (κ = 79.4 and κ = 78). CONCLUSION: In contrast to current belief, superior scapular elastofibroma dorsi accompanying the typical inferior scapular lesions is not uncommon and can even manifest bilaterally. To the best of our knowledge, this is the first case series reporting prevalence of quadruple elastofibroma dorsi.

Lateralising reverse shoulder arthroplasty using bony increased offset (BIO-RSA) or increasing glenoid component diameter: comparison of clinical, radiographic and patient reported outcomes in a matched cohort.

BACKGROUND: This study aims to compare the range of motion (ROM) of reverse shoulder arthroplasty lateralised by bony increased offset (BIO-RSA) using a standard 38-mm (mm) component to regular reverse shoulder arthroplasty (RSA) lateralised by using a 42-mm glenoid component. The secondary aims are to compare patient-reported and radiographic outcomes between the two groups. MATERIALS AND METHODS: All patients with a BIO-RSA and size 38 glenosphere were retrospectively identified and matched to patients with a regular RSA and size 42 glenosphere. Matched patients were invited for a follow-up visit. ROM was assessed as well as radiographic outcomes (lateralisation, distalisation, inferior overhang, scapular notching, heterotopic bone formation, radiolucency, stress shielding, bone graft healing and viability and complications) and patient-reported outcomes (subjective shoulder value, Constant score, American Shoulder and Elbow Surgeons, activities of daily living which require internal rotation, activities of daily living which require external rotation and a visual analogue scale for pain). Outcomes were compared between the two groups. RESULTS: In total, 38 BIO-RSAs with a size 38 glenosphere were matched to 38 regular RSAs with a size 42 glenosphere. Of the 76 matched patients, 74 could be contacted and 70 (95%) were included. At the final follow-up, there were no differences between the two groups in ROM, patient-reported outcomes or radiographic outcomes (p > 0.485). CONCLUSIONS: Using a larger glenosphere is a feasible alternative to BIO-RSA for lateralising RSA, providing comparable ROM, patient-reported and radiographic results, while potentially decreasing costs, operative time and complication rates.

Age Estimation Based on Computed Tomography Analysis of the Scapula.

Background and Objectives: Age estimation from skeletal remains and in living individuals is an important issue for human identification, and also plays a critical role in judicial proceedings for migrants. Forensic analysis of ossification centers is the main evaluation method for age estimation, and ossification degree can be determined using computed tomography analysis. The purpose of this study is to investigate the applicability of CT (computed tomography) in the analysis of left scapula ossification centers, for forensic age estimation in Turkish society. Materials and Methods: We analyzed six ossification centers of the left scapula and these ossification centers are the coracoid, subcoracoid, coracoid apex, acromial, glenoid, and inferior angle ossification centers. A pediatric radiologist analyzed these six ossification centers of the scapula by using a staging method defined by Schmeling et al. in 2004. Two months after the first assessment, 20 randomly selected cases was reanalyzed by the first observer and by another pediatric radiologist. Correlation between the age and ossification stage was assessed using Spearman's nonparametric correlation test. Linear regression analysis was performed using a backwards model. Cohen's kappa coefficient was used for evaluating interobserver and intraobserver variability. Results: In this retrospective study, 397 (248 male and 149 female) cases were evaluated. Ages ranged between 7.1 and 30.9. The mean age was 19.83 ± 6.49. We determined a positive significant correlation between the age and the ossification stages of ossification centers analyzed in both sexes. In each ossification center, except inferior angle, all of the stage 1 and 2 cases in both sexes were under 18 years old. Intraobserver and interobserver evaluations showed that reproducibility and consistency of the method was relatively good. Conclusions: The present study indicated that CT analysis of scapula ossification centers might be helpful in forensic age assessment of living individuals and dry bones.

Minimum 5-Year Clinical and Return-to-Sport Outcomes After Primary Arthroscopic Scapulothoracic Bursectomy and Partial Scapulectomy for Snapping Scapula Syndrome.

BACKGROUND: Snapping scapula syndrome (SSS) is a rare condition that is oftentimes debilitating. For patients whose symptoms are resistant to nonoperative treatment, arthroscopic surgery may offer relief. Because of the rarity of SSS, reports of clinical outcomes after arthroscopic SSS surgery are primarily limited to small case series and short-term follow-up studies. PURPOSE: To report minimum 5-year clinical and sport-specific outcomes after arthroscopic bursectomy and partial scapulectomy for SSS and to identify demographic and clinical factors at baseline associated with clinical outcomes at minimum 5-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients who underwent arthroscopic bursectomy and partial scapulectomy for SSS between October 2005 and February 2016 with a minimum of 5 years of postoperative follow-up were enrolled in this single-center study. Clinical outcome scores, including the 12-Item Short Form Health Survey (SF-12), American Shoulder and Elbow Surgeons (ASES) Shoulder Score, shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) score, Single Assessment Numeric Evaluation (SANE), and visual analog scale (VAS) score for pain, were collected at a minimum 5-year follow-up. Additionally, it was determined which patients reached the minimal clinically important difference. Bivariate analysis was used to determine whether baseline demographic and clinical factors had any association with the outcome scores. RESULTS: Of 81 patients eligible for inclusion in the study, follow-up was obtained for 66 patients (age 33.6 ± 13.3 years; 31 female). At a mean follow-up of 8.9 ± 2.5 years (range, 5.0-15.4 years), all of the outcome scores significantly improved compared with baseline. These included the ASES (from 56.7 ± 14.5 at baseline to 87.2 ± 13.9 at follow-up; P < .001), QuickDASH (from 38.7 ± 17.6 to 13.1 ± 14.6; P < .001), SANE (from 52.4 ± 21.2 to 82.7 ± 19.9; P < .001), SF-12 Physical Component Summary (from 39.7 ± 8.3 to 50.3 ± 8.2; P < .001), SF-12 Mental Component Summary (from 48.2 ± 11.7 to 52.0 ± 9.0; P = 0.014) and VAS pain (from 5.2 ± 2.1 to 1.4 ± 2.0; P < .001). The minimal clinically important difference in the ASES score was reached by 77.6% of the patients. Median postoperative satisfaction was 8 out of 10. It was found that 90.5% of the patients returned to sport, with 73.8% of the patients able to return to their preinjury level. At the time of final follow-up, 8 (12.1%) patients had undergone revision surgery for recurrent SSS symptoms. Older age at surgery (P = .044), lower preoperative SF-12 Mental Component Summary score (P = .008), lower preoperative ASES score (P = .019), and increased preoperative VAS pain score (P = .016) were significantly associated with not achieving a Patient Acceptable Symptom State on the ASES score. CONCLUSION: Patients undergoing arthroscopic bursectomy and partial scapulectomy for SSS experienced clinically significant improvements in functional scores, pain, and quality of life, which were sustained at a minimum of 5 years and a mean follow-up of 8.9 years postoperatively. Higher patient age, inferior mental health status, increased shoulder pain, and lower ASES scores at baseline were significantly associated with worse postoperative outcomes.

Complications and Reinterventions of Reverse Total Shoulder Arthroplasty in a Korean Population: 14-Year Experience in Reverse Shoulder Arthroplasty.

Background: There are few reports on the revision or reintervention of reverse total shoulder arthroplasty (RTSA) in South Korea. The purpose of this study was to evaluate the true incidence of complications and reintervention of RTSA and clinical and radiological outcomes based on our 14-year experience in RTSA in a Korean population. Methods: Between March 2008 and June 2022, 412 consecutive cases of RTSA were performed in 388 patients with an average age of 74.4 years at our institute. Excluding 23 patients lost to follow-up, 365 patients (373 shoulders including 8 bilateral cases) who underwent primary RTSA with more than 6 months of follow-up were enrolled in this study. We evaluated those who had complications or reintervention including revision RTSA for failed RTSA. Patient charts were reviewed, and clinical outcomes including clinical scores, complications, and reintervention and radiologic outcomes were evaluated at the last follow-up. Results: Among the 373 shoulders that underwent primary RTSA, complications were found in 50 patients (13.94%, 10 men and 40 women with a mean age of 75.9 ± 6.7 years [range, 51-87 years]). The causes of complications were as follows: 13 acromion, coracoid, or scapular spine fractures, 10 loosening (glenoid: 5, humeral stem: 5), 5 infections, 4 periprosthetic fractures, 2 instability, 2 neurologic complications, and 14 miscellaneous complications. Twenty patients (5.63%, 4 men and 16 women with a mean age of 74.2 ± 8.2 years [range, 51-87 years]) underwent reintervention. The interval to the first reintervention was 27.8 ± 23.1 months (range, 0.1-78 months). The causes of reintervention (20 cases) were 8 loosening (glenoid: 4, humeral stem: 4), 5 infections, 5 fractures, and 2 instability. Among them, 15 component revisions (4.02%) were performed. At the last follow-up, American Shoulder and Elbow Surgeons, University of California at Los Angeles, and Simple Shoulder Test scores were improved from 25.4, 12.4, and 1.6 preoperatively to 40.4, 16.2, and 3.2, respectively. Forward flexion (48° to 87°), abduction (52° to 79°), external rotation (18° to 22°), and internal rotation (buttock to L2) were improved. Conclusions: After primary RTSA in a Korean population, the complication, reintervention, and revision rates were 13.94%, 5.63%, and 4.02%, respectively. Careful evaluation of the complications and adequate treatments should be performed.

Neglected Sprengel's deformity in an 80-year-old female cadaver: a case report.

BACKGROUND: Sprengel's deformity is a congenital abnormality of the shoulder girdle. Because scapular retraction, such as the Green procedure, is usually performed during childhood to improve esthetics and shoulder function, Sprengel's deformity is rarely found in older patients. CASE PRESENTATION: We presented a unique case of a Japanese female cadaver with Sprengel's deformity at the age of 80 years. Anatomical dissection and radiological imaging revealed musculoskeletal anomalies associated with Sprengel's deformity, including Klippel-Feil syndrome, presence of an omovertebral bone, and absence of the trapezius muscle. In addition, bilateral cervical ribs were in contact with the brachial plexus. These anomalies may lead to numbness, pain, and limited range of motion of the neck and upper girdle with aging. CONCLUSIONS: Because most adult patients with Sprengel's deformity experience neck pain and limited movement of the shoulder, the presented case is a rare case of neglected Sprengel's deformity in an 80-year-old cadaver.

External handheld loads affect scapular elevation and upward rotation during shoulder elevation tasks.

Altered scapular kinematics is associated with shoulder pain. Resistance exercise is a common treatment; however, the effects of lifting an external load on scapular kinematics is limited. Understanding whether an external handheld load affects scapular kinematics in a healthy population can provide normal values utilized for comparison to individuals with shoulder pain. Currently, no studies have examined the effect of incrementally increased handheld loads. We defined the effects of varying external handheld loads on scapular kinematics during a shoulder elevation task. Healthy participants (n = 50) elevated their shoulder in the scapular plane over 4 trials. One trial of no loading (control) and 3 trials with incrementally increased external handheld loads. Scapular kinematic rotations and translations were measured during ascent and descent phases using 3D motion capture. Compared to no load, the highest external load during ascent increased scapular elevation [mean difference = 3.2 degrees (95%CI: 0.9, 5.4), p = 0.006], and during descent increased scapular elevation [mean difference = 3.9 degrees (95%CI: 2.8, 5.1), p < 0.001] and increased scapular upward rotation [mean difference = 4.5 degrees (95%CI: 2.4, 6.6), p < 0.001]. External handheld loads result in small increases in scapular elevation and scapular upward rotation. These results should be utilized as normal values to compare to individuals with shoulder pain.

The latissimus dorsi creates a dynamic track for the inferior angle of the scapula during arm abduction in humans.

BACKGROUND: The importance of several scapulothoracic muscles, including trapezius and serratus anterior, in maintaining physiological scapula kinematics has been highlighted in the past. However, the relationship between the scapula and the latissimus dorsi muscle remains unclear. Our clinical surgical observation is that the latissimus dorsi does not directly attach but rather runs superficial to the inferior angle of the scapula. Based on this observation, we hypothesise that the latissimus dorsi creates a dynamic track on which the scapula glides under the muscle belly during elevation of the arm, creating the latissimus-scapula overlap (LSO). METHODS: All consecutive patients who had a whole-body computed tomography scan (CT) in case of polytrauma evaluation between 2018 and 2021, with complete depiction of the scapula and latissimus dorsi muscle, were analysed. 150 shoulders in 90 patients with arms up were matched according to their age (within five years), gender, and affected side with 150 shoulders in 88 patients with arms down. Patients with pathologies of the upper extremities or thorax that potentially could alter LSO measurements were excluded. LSO was calculated as a ratio of the measured area of the latissimus dorsi projection on the scapula and the total scapula area. RESULTS: The mean age of the 178 patients (48 females; 13 males) was 60 years. The arms-up group showed a significantly higher LSO than the arms-down group (19.9 ± 6.3% vs. 2.7 ± 2.2%; p < 0.0001). In the arms-up group, approximately one fifth of the scapula was overlapped inferiorly by the muscle belly of the latissimus dorsi, contrary to the almost non-existing LSO in the arms-down group. CONCLUSION: With arms up, humans show a significantly higher LSO in comparison to arms down indicating that the latissimus dorsi indeed creates a dynamic track on which the scapula is forced to travel during abduction of the arm. This finding of increased LSO during the elevation of the arm warrants further consideration of the role of the latissimus dorsi in scapula kinematics and potentially scapular dyskinesis. LEVEL OF EVIDENCE: Level two diagnostic study.

The Association between SLAP Lesions and Critical Shoulder Angle and Glenoid Depth.

PURPOSE OF THE STUDY: The critical shoulder angle (CSA) is formed by the combination of glenoid inclination and acromial index and has been shown related to rotator cuff tears and glenohumeral osteoarthritis. SLAP lesions today have an important place among bicipitolabral pathologies that cause intensive shoulder pain. We aimed to investigate the relationship between CSA and glenoid depth and SLAP lesions. MATERIAL AND METHODS: Between March 2017 and January 2022, 279 consecutive shoulder arthroscopy patients' MRI images were retrospectively examined. After the exclusion criteria, 191 patients were eligible. Patients with SLAP lesions (n=37) were assembled as the study group (Group 1), and patients with intact superior labrum (n=154) were named as the control group (Group 2). Critical shoulder angle (CSA) and glenoid depth measurements were performed using the preoperative MRI images. RESULTS: A total of 191 patients, of whom 84 were male (44%) were included. The mean age was 49.9±14.96 (range 18-79). There was a statistically signifi cant difference between the SLAP group (Group 1) and the control group (Group 2) in terms of CSA (p=0.032). The mean CSA was 31.66°±3.51° in Group 1 and 33.57° ±5.01° in Group 2. The cut-off value for CSA in patients with SLAP lesions was calculated as 32.85° and the area under the curve was 0.61, therefore a satisfactory association was observed between the groups. The mean glenoid depth was 4.32 ±1.25 mm in Group 1, and 4.39 ±0.32 mm in Group 2. There was no statistically signifi cant difference between the groups in terms of glenoid depth (p=0.136) and also no association between the glenoid depth and SLAP lesions was observed (cut-off=4.45 mm, AUC=0.32). CONCLUSIONS: Low CSA is associated with SLAP lesions, just as in glenohumeral osteoarthritis. Further prospective clinical studies are needed to enlighten the predisposing effect of CSA to SLAP lesions and the success of superior labral repairs. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.