Clinical analysis of the acromial height-measuring device combined with new-type clavicular hook plate and standard clavicular hook plate in the treatment of Neer type II distal clavicle fractures.

BACKGROUND: Distal clavicular fracture is a shoulder joint injury that is common in clinical settings and is generally surgically treated using the clavicular hook plate technique with a confirmed curative effect. However, symptoms, such as shoulder abduction limitation, shoulder discomfort, and postoperative joint pain, may occur in some patients. To overcome these problems, after a previous study we developed an acromial height-measuring device and a new type of clavicular hook plate. This study aimed to investigate whether an acromial height-measuring device combined with an improved new-type clavicular hook plate can better reduce the incidence of complications and improve postoperative function. To provide patients with better treatment effects, an acromion gauge and clavicular hook plate are used. METHODS: A retrospective analysis was performed on 81 patients with distal clavicular fractures admitted to our hospital. They were divided into experimental and control groups according to different plates, and the Constant-Murley score, visual analogue scale score, incidence of acromion osteolysis, and incidence of subacromial impingement syndrome were compared. RESULTS: Compared with the standard clavicular hook plate, the acromial height-measuring device combined with the new-type clavicular hook plate in the treatment of distal clavicle fractures has a lower incidence of subacromial impingement syndrome with better postoperative functional recovery and quality of life. CONCLUSIONS: We considered the acromial height-measuring device combined with the new clavicular hook plate to be a safe and promising alternative to distal clavicular fractures.

Posteroinferior relevant scapular neck offset in reverse shoulder arthroplasty: key player for motion and friction-type impingement in a computer model.

BACKGROUND: Range of motion (ROM) and prevention of notching remain a challenge for reverse shoulder arthroplasty (RSA). Both may be affected by the morphology of the scapula. The purpose of this study was to define anteroinferior (a) and posteroinferior (p) relevant scapular neck offset (RSNO) and to examine the hypothesis that pRSNO is significantly smaller than aRSNO, and influences rigid body motion (RBM). Adapting glenosphere implantation strategies may therefore be of value. MATERIAL AND METHODS: In this computer model study, we used deidentified computed tomographic scans of 22 patients (11 male and 11 female; mean age: 72.9 years) with massive cuff tears without joint space narrowing. Eight RSA glenoid configurations were tested with a constant neck-shaft angle (145°). Two baseplate types (25 mm; 25 + 3 mm lateralized) and 4 glenospheres (GS) (36 mm; 36 +2 mm of eccentricity; 39 mm; 39 + 3 mm) were used. RSNO was defined as the standardized measurement of the horizontal distance from the inferior extent of the GS to the bony margin of the scapula after baseplate positioning (flush to inferior glenoid extent; neutral position: 0° inclination and 0° version-both software computed). RESULTS: There was a highly significant difference between pRSNO and aRSNO for both genders (P < .001). pRSNO was always smaller than aRSNO. pRSNO was strongly correlated with external rotation (ERO: 0.84) and extension (EXT: 0.74) and moderately correlated with global ROM (GROM: 0.68). There was a moderately strong correlation between aRSNO and internal rotation (IRO: 0.69). pRSNO was strongly correlated with aRSNO, EXT, ERO, IRO, adduction (ADD) and GROM (0.82, 0.72, 0,8, 0.71, 0.82, 0.76) in female patients and with EXT and ERO (0.82, 0.89) in male patients. The median pRSNO allowing for at least 45° ERO and 40° EXT was 14.2 mm for men and 13.8 mm for women. For all patients and models, pRSNO ≥14 mm increased EXT, ERO, and GROM significantly compared with pRSNO <14 mm (P < .001). The combination of lateralization and inferior overhang (eccentricity) led to the most significant increase of pRSNO for each GS size (P < .001). CONCLUSION: This is one of the first RSA modeling studies evaluating nonarthritic glenoids of both genders. The lateral scapular extent to glenoid relationship is asymmetric. pRSNO is always smaller than aRSNO for both genders and was a critical variable for EXT and ERO, demonstrating additional strong correlation with aRSNO, IRO, ADD, and GROM in female patients. pRSNO ≥14 mm was a safe value to prevent friction-type impingement. Combining increased glenosphere size, lateralization, and inferior overhang gives the best results in this computer-simulated setting.

Evaluating the role of subacromial impingement in rotator cuff tendinopathy: development and analysis of a novel rat model.

BACKGROUND: Subacromial impingement of the rotator cuff caused by variations in acromial anatomy or altered glenohumeral kinematics leads to inflammation and degeneration of the rotator cuff, ultimately contributing to the development of tendinopathy. However, the underlying cellular and molecular changes in the impinged tendon remain poorly understood. Because the rat is an accepted model for rotator cuff studies, we have developed a rat model to study rotator cuff tendinopathy. METHODS: Forty-four adult male Sprague-Dawley rats were allocated to one of 4 study groups: intact control group (group 1, n = 11); bilateral subacromial surgical clip placement to induce supraspinatus impingement for 2 weeks (group 2, n = 11), 4 weeks (group 3, n = 11), and 8 weeks (group 4, n = 11). Bilateral shoulder specimens were harvested for biomechanical testing, histology, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. RESULTS: Radiography confirmed that all microvascular clips remained in stable position in the subacromial space. Gross inspection of supraspinatus tendon specimens in the impingement groups revealed changes in tendon morphology at the enthesis and midsubstance. Biomechanical evaluation demonstrated decreased supraspinatus tendon failure force and tissue stiffness at all time points compared with control tendons. Semiquantitative scoring of histologic specimens demonstrated significant, persistent tendinopathic changes over 8 weeks. qRT-PCR analysis of impinged tendon specimens demonstrated upregulation of gene expression for Col3 and Mmp14 in the impingement groups compared with control groups. In muscle samples, significant upregulation was seen in the expression of genes that are commonly associated with muscle atrophy (MuRF1 and Ube2b) and fatty infiltration (Fabp4, Pparg2, and Klf15). CONCLUSION: This new rat subacromial impingement model creates cellular and molecular changes consistent with the development of rotator cuff tendinopathy. The results of this study may serve as a baseline for future investigation.

Shoulder impingement: various risk factors for supraspinatus tendon tear: A case group study.

ABSTRACT: A total of 680 cases of monolateral shoulder pain and functional impairment were included, and Chi-Squared tests was incorporated to test for possible associations.No relation between impingement syndrome and potential risk factors was found, such as presence of down slopping (P = .083), presence of ossification acromiale (P  = .102), presence of calcific tendinitis (P  = .144), types of acromion (I [P = .600], II [P = .536], III [P = .633] and IV [P = .832]) and grade of acromioclavicular degenerative changes (mild [P = .077], moderate [P = .111], and severe [P = .700]). However, a significant relationship was uncovered between impingement syndrome and risk factors such as gender (X2 = 7.004, df = 1, P = .08) (where females were more prone), history of shoulder dislocation (X2 = 19.440, df = 1, P = .001), presence of supraspinatus tendon tear or tendinopathy (X2 = 69.344, df = 1, P = .001) and supraspinatus complete tear (X2 = 13.593, df = 1, P = .001). A significant relationship was found between the type of supraspinatus pathology and factors such as gender (female more prone) (X2 = 34.719, df = 3, P = .01), presence of down slopping (X2 = 57.765, df = 3, P = .01), history of shoulder dislocation (X2 = 148.880, df = 3, P = .001), type III of the acromion (X2 = 12.979, df = 3, P = .005), presence of acromioclavicular generative changes mild (X2 = 76.408, df = 3, P = .001) and moderate (X2 = 29.697, df = 3, P = .001), and acromiohumeral distance of ≤3 mm (X2 = 18.915, df = 3, P = .001), 3.1 to 6 mm (X2 = 13.212, df = 3, P = .004), and 9.1-12 mm (X2 = 15.066, df = 3, P = .002). Overall, the Magnetic Resonance Imaging results yielded high sensitivity for detecting full-thickness supraspinatus tears.Considering the findings, this study may help radiologists understand the salient risk factors and identify which factors are mainly responsible for supraspinatus tendon tears and the respective grade of tear (articular partial, bursal partial, complete, or tendinopathy).

Open plate fixation versus nailing for humeral shaft fractures: a meta-analysis and systematic review of randomised clinical trials and observational studies.

PURPOSE: This meta-analysis compares open reduction and internal fixation with a plate (ORIF) versus nailing for humeral shaft fractures with regard to union, complications, general quality of life and shoulder/elbow function. METHODS: PubMed/Medline/Embase/CENTRAL/CINAHL was searched for observational studies and randomised clinical trials (RCT). Effect estimates were pooled across studies using random effects models. Results were presented as weighted odds ratio (OR) or risk difference (RD) with corresponding 95% confidence interval (95% CI). Subgroup analysis was performed stratified for study design (RCTs and observational studies). RESULTS: Eighteen observational studies (4906 patients) and ten RCT's (525 patients) were included. The pooled effect estimates of observational studies were similar to those obtained from RCT's. More patients treated with nailing required re-intervention (RD 2%; OR 2.0, 95% CI 1.0-3.8) with shoulder impingement being the most predominant indication (17%). Temporary radial nerve palsy secondary to operation occurred less frequently in the nailing group (RD 2%; OR 0.4, 95% CI 0.3-0.6). Notably, all but one of the radial nerve palsies resolved spontaneously in each groups. Nailing leads to a faster time to union (mean difference - 1.9 weeks, 95% CI - 2.9 to - 0.9), lower infection rate (RD 2%; OR 0.5, 95% CI 0.3-0.7) and shorter operation duration (mean difference - 26 min, 95% CI - 37 to - 14). No differences were found regarding non-union, general quality of life, functional shoulder scores, and total upper extremity scores. CONCLUSION: Nailing carries a lower risk of infection, postoperative radial nerve palsy, has a shorter operation duration and possibly a shorter time to union. Shoulder impingement requiring re-intervention, however, is an inherent disadvantage of nail fixation. Notably, absolute differences are small and almost all patients with radial nerve palsy recovered spontaneously. Satisfactory results can be achieved with both treatment modalities.

Influential factors of subacromial impingement syndrome after hook plate fixation for acromioclavicular joint dislocation: A retrospective study.

ABSTRACT: Subacromial impingement syndrome (SIS) after hook plate fixation for acromioclavicular joint (AC) dislocation was the most common complication. However, the researches on its' influential factors were rare. The purpose of this study was to identify the risk factors by analyzing the influencing factors of postoperative SIS and minimize the incidence of SIS in clinical surgery.We retrospectively analyzed the prospectively collected data from 330 consecutive patients with AC joint dislocation between August 2014 and August 2017 at our institute. The SIS was presented as the dependent variable at the last follow-up when the internal fixation was removed. The independent variables included age, gender, body-mass index (BMI), smoking status, alcohol consumption, type of injury, Rockwood Classification, site of injury, operation time, injury-to-surgery, the distance between the hook body and the acromion (DBA), the depth of hook tip (DHT), the distance between the hook plate and the humeral head (DHH), the distance between the acromion and the humeral head (DAH), the hook plate angle (AHP) and acromial shape. Logistic regression analysis was performed to identify independent influential factors of SIS.A total of 312 cases were included and 18 cases were lost. The follow-up rate was 94.5%. In without SIS group, there were 225 cases (123 males and 102 females). In with SIS group, a total of 87 cases were included (56 males and 31 females). The incidence of SIS was 27.8%. DHT (OR = 9.385, 95% CI = 4.883 to 18.040, P < .001) and DBA (OR = 2.444, 95% CI = 1.591 to 3.755, P < .001) were the significant independent risk factor for SIS of AC dislocation treat with hook plate. DAH (OR = 0.597, 95% CI = 0.396 to 0.900, P = .014) and acromial shape with flat and straight (OR = 0.325, 95% CI = 0.135 to 0.785, P = .012) were also independent factors of SIS, but they were all protective.The SIS had a high incidence in fixation of clavicular hook plate for AC dislocation. DHT and DBA were two independent risk factors, DAH and acromial shape with flat and straight were two independent protective factors for SIS. In clinical surgery, we should avoid risk factors to reduce the incidence of SIS.

To explore the reasonable selection of clavicular hook plate to reduce the occurrence of subacromial impingement syndrome after operation.

BACKGROUND: Acromioclavicular joint dislocation is a shoulder joint injury common in the clinical setting and is generally surgically treated with clavicular hook plate technique with confirmed curative effect. However, symptoms such as shoulder abduction limitation, shoulder discomfort and joint pain postoperatively may occur in some patients. Therefore, this study aimed to explore whether the existing clavicular hook plate can be reasonably selected to reduce the incidence of subacromial impingement syndrome (SIS) and provide a reference for clinical diagnosis and treatment. MATERIALS AND METHODS: Patients with SIS admitted from March 2018 to June 2020 were selected as the experimental group and asymptomatic patients postoperatively, as the control group. The hook end depth and acromial height of the hook plate used in patients were recorded, and the difference between them was calculated. RESULTS: The difference between the hook plate depth and acromial height was 7.500±1.912 mm and 6.563±1.537 mm in the experimental and control groups, respectively, with statistically significant difference (t=3.021, P=0.006). A difference of >0.6 mm as a grouping index is required to perform a single factor analysis, with statistically significant difference (t=3.908, P=0.048). CONCLUSIONS: The occurrence of SIS after placing the clavicular hook plate may be related to the difference between its depth and the acromial height. A difference of >6 mm may be a factor affecting the occurrence of SIS. Pre-imaging measurement of the acromial height can provide suggestions for selecting the type of hook plate intraoperatively.

The clinical anatomy of variations of the pectoralis minor.

Shoulder pathology is a very common medical presentation and can be due to anatomical variations. Therefore, knowledge of variants is important for the clinician treating patients with such complaints so that misdiagnosis is minimized and iatrogenic injury prevented. A review of the literature was performed of the variant anatomy of the pectoralis minor muscle. The aim of this review is to better inform clinicians who might treat patients with shoulder pathology so that if identified, variants of the pectoralis minor muscle are better appreciated.

Assessment of Mitochondrial Dysfunction in a Murine Model of Supraspinatus Tendinopathy.

BACKGROUND: The purpose of this study was to assess mitochondrial dysfunction in a murine model of supraspinatus tendinopathy. METHODS: Eighty-four mice (168 limbs) were included in the study. Supraspinatus tendinopathy was induced by inserting a microsurgical clip in the subacromial space of 63 mice bilaterally (126 limbs). Forty-two of these limbs were harvested at 4 weeks postoperatively, 42 underwent clip removal at 4 weeks after the initial procedure and were harvested at 2 weeks, and 42 underwent clip removal at 4 weeks and were harvested at 4 weeks. Forty-two limbs in the remaining 21 mice did not undergo surgical intervention and were utilized as the control group. Outcomes included biomechanical, histological, gene expression, superoxide dismutase (SOD) activity, and transmission electron microscopy (TEM) analyses. RESULTS: Radiographs confirmed stable clip position in the subacromial space at 4 weeks. Biomechanical testing demonstrated a 60% decrease in failure force of the supraspinatus tendons at 4 weeks compared with the control group. The failure force gradually increased at 2 and 4 weeks after clip removal. Histological analysis demonstrated inflammation surrounding the tendon with higher modified Bonar scores at 4 weeks after clip placement followed by gradual improvement following clip removal. The expression of mitochondrial-related genes was decreased at 4 weeks after clip placement and then significantly increased after clip removal. SOD activity decreased significantly at 4 weeks after clip placement but increased following clip removal. TEM images demonstrated alterations in morphology and the number of mitochondria and cristae at 4 weeks after clip placement with improvement after clip removal. CONCLUSIONS: Mitochondrial dysfunction appears to be associated with the development of tendinopathy. CLINICAL RELEVANCE: Mitochondrial protection may offer a potential strategy for delaying the development of tendinopathy and promoting tendon healing.

Anatomical variations of the acromial and coracoid process: clinical relevance.

PURPOSE: The acromial and coracoid process morphology is of clinical relevance due to associations with functional limitations and shoulder pathology. Our objective was to describe the anatomical characteristics of the acromial and coracoid process using computed tomography (CT). METHODS: Descriptive, observational, transversal and retrospective study. A total of 155 CT of patients without shoulder pathology, of both genders, and indistinct age were evaluated and grouped by age: Group 1 < 25 years; group 2 25-40 years; group 3 > 40 years. The following parameters were evaluated: Acromial type (AcT), vertical coracoid distance (VCD), acromial tilt (AT), acromial projection (AP), critical shoulder angle (CSA), type of the subcoracoid outlet (TSO), and the area of the subcoracoid outlet (ASO). RESULTS: Statistically significant differences were found between men and women for VCD (14.44 ± 4.79 vs. 11.76 ± 4.00 mm; p < 0.001) and AP (3.66 ± 4.71 vs. 1.62 ± 4.99 mm; p < 0.05) as well as between age groups 1 and 3 for AT (35.08 ± 11.53 vs. 28.41 ± 6.60; p < 0.05) and ASO (398.99 ± 153.91 vs. 255.56 ± 124.58 mm2; p < 0.001). An unexpected high ASO variation was identified with 11% of S-shaped acromion and 1.3% clock-shaped TSO. CONCLUSION: The age group between 25-40 years had the most uniform distribution of data. There is a high morphological variability present in an asymptomatic population, which should be considered in the clinical assessment such as shoulder impingement syndrome.

The acromion-greater tuberosity impingement index: A new radiographic measurement and its association with rotator cuff pathology.

PURPOSE: Several radiographic parameters describe humeral head coverage by the acromion. We describe a new radiographic measurement, the acromion-greater tuberosity impingement index (ATI), and its ability to predict rotator cuff pathology. METHODS: The ATI was measured with magnetic resonance imaging (MRI) and X-ray analysis in 83 patients with rotator cuff pathology and 76 patients with acute rotator cuff tears. The lateral acromial angle (LAA), acromion type, the acromion index (AI) and the critical shoulder angle (CSA) were measured to assess their correlations with the ATI. Receiver operating characteristic (ROC) curves were used to predict degenerative rotator cuff pathology. The change in the ATI after acromion surgery was evaluated in both groups. RESULTS: According to the ROC curves, the ATI is a good predictor of degenerative rotator cuff pathology on both X-ray (cut-off, 0.865) and MRI (cut-off, 0.965). Patients with degenerative rotator cuff pathology had a significantly higher average ATI compared to the trauma group (p = 0.001 for X-ray and MRI). The degenerative group had a significantly lower LAA (p = 0.001) and a higher ratio of type III acromion (p = 0.035) than the trauma group. The ATI on X-ray was negatively related to the LAA and positively related to the AI, the CSA and acromion type (each p < 0.05). The ATI on MRI was negatively related to the LAA and positively related to the AI and acromion type (each p <0.05). More patients in the degenerative group than the trauma group needed acromioplasty or acromion decompression (p < 0.05). The ATI on MRI was significantly lower after acromion surgery compared to before surgery in both groups (p < 0.05). CONCLUSION: The ATI is a good predictor of degenerative supraspinatus tendon tears or subacromial impingement syndrome. The ATI on MRI is more accurate and can precisely guide acromion surgery.

Is antegrade nailing a proper option in 2- and 3-part proximal humeral fractures?

PURPOSE: To report our experience with antegrade short locked intramedullary nail for treatment of proximal humeral fractures and to review the current literature. MATERIALS AND METHODS: From January 2012 to July 2013, 41 patients affected by two and three-part proximal humeral fractures were treated with surgical internal fixation with short locked intramedullary nails. Outcome analysis included standard clinical follow-up, Constant shoulder score and plain radiographs. The mean follow-up was 30 months (range 24-42). Moreover, a review of the literature was carried out. RESULTS: The mean Constant shoulder score was 81.5, excellent functional outcomes in 24/38 patients. All the fractures healed in an average time of 3.7 months. Five patients underwent additional operations, complications included hardware penetration into the joint (n = 2), backed out screw (n = 1), shoulder impingement due to protrusion of the nail (n = 2) and superficial infection (n = 1). The literature review showed 530 patients affected by proximal humeral fracture and treated with intramedullary nail with mean age of 65 years, mean follow-up of 22.2 months and a Constant shoulder score of 72.9 points; the major complications reported were backing out of the screws, shoulder impingement and joint protrusion of the screws. CONCLUSIONS: Antegrade short locked intramedullary nail allows stable fixation, minimal soft tissue dissection, early mobilization of the shoulder and good outcomes. It is an efficacious therapeutic solution for 2- and 3-part proximal humeral fractures.

Relationship Between Shoulder Impingement Syndrome and Thoracic Posture.

BACKGROUND: Shoulder impingement syndrome (SIS) is the most common form of shoulder pain and a persistent musculoskeletal problem. Conservative and invasive treatments, aimed at the shoulder joint, have had limited success. Research suggests shoulder function is related to thoracic posture, but it is unknown whether thoracic posture is associated with SIS. OBJECTIVE: The objective of this study was to investigate whether there is a relationship between SIS and thoracic posture. DESIGN: This was a case control study. METHODS: Thoracic posture of 39 participants with SIS and 39 age-, gender-, and dominant arm-matched controls was measured using the modified Cobb angle from a standing lateral radiograph. Thoracic range of motion (ROM) was also measured using an inclinometer. Between-group differences were compared using t tests. The relationship between thoracic posture and thoracic ROM was determined with linear regression. RESULTS: Twenty women and 19 men with SIS (mean age = 57.1 years, SD = 11.1) and 39 age-matched, gender-matched, and dominant arm-matched controls (mean age = 55.7years, SD = 10.6) participated. Individuals with SIS had greater thoracic kyphosis (mean difference = 6.2o, 95% CI 2.0-10.4) and less active thoracic extension (7.8o, 95% CI = 2.2-13.4). Greater thoracic kyphosis was associated with less extension ROM (ie, more flexion when attempting full extension: ß = 0.71, 95% CI = 0.45-0.97). LIMITATIONS: These cross-sectional data can only demonstrate association and not causation. Both radiographic measurements and inclinometer measurements were not blinded. CONCLUSION: Individuals with SIS had a greater thoracic kyphosis and less extension ROM than age- and gender-matched healthy controls. These results suggest that clinicians could consider addressing the thoracic spine in patients with SIS.

Mejoría clínica de tendinopatía de hombro tras modificaciones ergonómicas del puesto de trabajo de usuarios de ordenador / Clinical improvement of shoulder tendinopathy after ergonomic modifications of the workstation of computer users

INTRODUCCIÓN: A pesar de la baja evidencia de la relación entre la patología del hombro y el uso de ordenadores, algunos autores asocian dicha patología con el uso del ratón informático, su posición alejada del cuerpo o el espacio insuficiente en la mesa de trabajo. CASO CLÍNICO: Presentamos el caso de cuatro trabajadores que, en el transcurso del último año, se han dirigido espontáneamente al servicio médico manifestando dolor en el hombro que relacionaban con sus condiciones de trabajo y como se ha solucionado dicha clínica mediante la adaptación del puesto de trabajo, básicamente gracias a la introducción de un ratón inalámbrico que ha permitido el rediseño del puesto de trabajo. DISCUSIÓN: La imposibilidad de mover el ratón libremente debido a restricciones en el espacio de la mesa de trabajo y a la utilización de ratón más de 4 horas/día durante la jornada laboral se ha descrito como causa de patología a nivel de hombros. En otros casos también se asoció con un espacio insuficiente en la mesa de trabajo, tener el ratón alejado de la posición corporal o utilizarlo durante la mitad o más tiempo de la jornada laboral. Desde un punto de vista biomecánico el manguito de los rotadores es exigente para evitar fuerzas luxantes, lo que realiza mediante contracción excéntrica o fuerzas neutralizadoras de grupos antagonistas. El supraespinoso tiene un papel importante al inicio de la abducción con un ángulo de tracción máximo aproximadamente a 75°. Determinadas posiciones podrían influenciar su fatiga y/o proceso inflamatorio. CONCLUSIONES: Nuestra experiencia nos indica que una sencilla y asumible modificación de la posición del hombro durante la utilización del ratón ha sido útil para revertir cuadros clínicamente compatibles con tendinopatías a este nivel

INTRODUCTION: Despite the low evidence of the relationship between shoulder pathology and the use of computers, some authors associate this pathology with the use of the computer mouse, its position away from the body or insufficient space on the desk. CLINICAL CASE: We present the case of four workers who, during the last year, consulted medical services spontaneously, manifesting shoulder pain related to their working conditions and how this clinic has been solved by adapting the workplace, basically thanks to the introduction of a wireless mouse that allowed the redesign of the workplace. DISCUSSION: The inability to move the mouse freely due to restrictions in the space of the work table and the use of mice more than 4 hours / day during the workday has been described as a cause of shoulder pathology. In other cases, it was also associated with insufficient space on the work table, having the mouse away from body position or using it during half or more of the workday. From a biomechanical point of view the rotator cuff is demanding to avoid dislocating forces, which it does by means of eccentric contraction or neutralizing forces of antagonist groups. The supraspinatus plays an important role at the beginning of abduction with a maximum traction angle of approximately 75°. Certain positions may influence your fatigue and / or inflammatory process. CONCLUSIONS: Our experience indicates that a simple and acceptable modification of the position of the shoulder during the use of the mouse has been useful to improve events of clinical presentations like tendinopathies at this level

Three-dimensional scapular kinematics, shoulder outcome measures and quality of life following treatment for breast cancer - A case control study.

BACKGROUND: There are no conclusive results concerning changes in scapular kinematics associated with upper limb dysfunctions after breast cancer surgery. OBJECTIVE: To compare the three-dimensional (3-D) scapular kinematics during elevation of the arm between women after breast cancer surgery and controls. Shoulder range of motion (ROM), muscle strength, pain intensity, upper limb function, and quality of life were also assessed. METHODS: Forty-two women were assigned to two groups (surgery group, n = 21; control group, n = 21). 3-D scapular kinematics was collected during elevation of the arm in the scapular plane. ROM was assessed using a digital inclinometer, muscle strength using a manual dynamometer, pain with the Visual Analogue Scale (VAS), upper limb function with the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire and quality of life with the 36-item Short-Form Health Survey (SF36). RESULTS: The surgery group presented decreased scapular upward rotation at 120° of arm elevation in the scapular plane (p < .05; d = -0.88), decreased shoulder external rotation ROM and strength of shoulder abduction and external rotation when the affected side was compared to the non-affected side and control group. Moreover, the surgery group also reported higher pain, increased upper limb disability and poorer quality of life compared with healthy controls. CONCLUSION: Scapular upward rotation seems to be decreased at 120° of arm elevation in women following breast cancer surgery. In addition, shoulder external rotation ROM, abduction strength, external rotation strength, function, and quality of life are also impaired in these women. They also experienced pain during the studied movements.

Parameterization of proximal humerus locking plate impingement with in vitro, in silico, and in vivo techniques.

BACKGROUND: Locked plating of displaced proximal humeral fractures is common, but rates of subacromial impingement remain high. This study used a multidisciplinary approach to elucidate the relationships between common surgical parameters, anatomic variability, and the likelihood of plate impingement. METHODS: The experiment was completed in 3 phases. First, a controlled in vitro experiment was conducted to simulate impingement. Second, a dynamic in silico musculoskeletal model modeled changes to implant geometry, surgical techniques, and acromial anatomy, where a collision detection algorithm was used to simulate impingement. Finally, in vivo shoulder kinematics were recorded for 9 activities of daily living. Motions that created a high likelihood of impingement were identified. RESULTS: Of simulated impingement events, 73.9% occurred when the plate was moved proximally, and 84% occurred when acromial tilt was 20° or 25°. Simulations of impingement occurred at cross-body adduction angles between 10° and 50°. Impingement occurred at an average of 162.0° ± 14.8° abduction with 10 mm distal plate placement, whereas the average was 72.1° ± 11.4° with 10 mm proximal placement. A patient may encounter these shoulder angles when performing activities such as combing one's hair, lifting an object overhead, and reaching behind one's head. DISCUSSION AND CONCLUSION: Proximal implant placement and decreases in acromial tilt play major roles in the likelihood of impingement, whereas plate thickness and humeral head center of rotation should also be considered. Careful preoperative planning that includes these factors could help guide operative decision making and improve clinical outcomes.

Frozen shoulder or shoulder stiffness from Parkinson disease?

PURPOSE: To understand the role of camptocormia (increased kyphosis) and postural alteration in Parkinson's disease in the development of shoulder pathology, with a special concern for adhesive capsulitis and shoulder stiffness. METHODS: A preliminary online search was carried out, with combination of keywords including "Parkinson," "Shoulder stiffness," "Frozen shoulder," "Adhesive capsulitis," "Postural alteration," "Camptocormia". The retrieved papers were screened by title and abstract and those considered relevant to the aim of the review were read in full text and included. Relevant information were extracted and reported into text. RESULTS: Due to a severe impairment of posture, patients affected by PD show an increased thoracic kyphosis (camptocormia) and decreased mobility of the trunk that can yield a humeroacromial impingement syndrome and capsulitis, resulting in inflammation of the bursa, shoulder pain and reduction of movement. Furthermore, kinematic of the shoulder is allowed by the combined movement of the humerus, the scapula, the clavicle, the thoracic wall and thoracic spine. The thoracic spine and wall mobility are severely impaired in the parkinsonian patient, thus limiting the shoulder motion. CONCLUSION: The postural alteration observed in PD is the primum movens for shoulder pathology, since anterior tilt of the scapula, which occurs with the increment of thoracic kyphosis, yields to a subacromial impingement. A closed loop is then created, as the rigidity of the shoulder causes further alteration in the posture, which worsens the impingement syndrome and so on.

Scapular Notching in Reverse Total Shoulder Arthroplasty.

Scapular notching is a common radiographic finding occurring after reverse total shoulder arthroplasty, and it refers to an erosive lesion of the inferior scapular neck because of the impingement of the humeral implant during adduction. The clinical importance of notching is unclear, and the optimal treatment of severe notching is unknown. The incidence and severity of scapular notching is related to prosthetic design and surgical technique. Implant design factors include size, shape, and position of the glenosphere, inclination of the humeral neck-shaft angle, implant offset, and native scapular anatomy. Scapular notching may lead to deterioration of functional outcomes and glenoid implant loosening and failure. Lateral offset, inferior glenosphere overhang, and careful consideration of the presurgical glenoid morphology may help prevent scapular notching. Currently, there is limited evidence to direct the management of scapular notching, and further research is needed to elucidate optimal prevention and treatment strategies.

Radiological and biomechanical assessment of displaced greater tuberosity fractures.

PURPOSE: Greater tuberosity fractures are challenging lesions concerning decision-making. In order to improve our treatment algorithm, we developed a new method, which allows predicting a possible subacromial conflict on standard anteroposterior radiographs, considering not only the displacement of the fragment but also the width of the subacromial space. METHODS: The measurement technique consisted of drawing three concentric circles on true anteroposterior radiographs. The inner circle (radius Rh) perfectly matched the humeral head surface. The medial circle (radius Rt) was tangent to the greater tuberosity, and the outer circle (radius Ra) touched the undersurface of the acromion. The ratio Rt/Rh, which describes how much the greater tuberosity projects above the articular surface, and the relationship (Rt-Rh)/(Ra-Rh), which quantifies the space occupied by the greater tuberosity under the acromion, were calculated and called Greater Tuberosity Index and Impingement Index, respectively. Five dry humeri were used to assess the influence of rotation and abduction on the Greater Tuberosity Index. The radiographs of 80 shoulders without any osseous pathology were analyzed to obtain reference values for both indices. Finally, greater tuberosity fractures with different displacements were created in five cadaver specimens, and subacromial impingement was correlated with these parameters. RESULTS: On anteroposterior radiographs, the greater tuberosity was most prominent in neutral rotation, regardless of abduction. In shoulders without osseous pathology, the Greater Tuberosity Index and the Impingement Index averaged 1.15 (range 1.06-1.28) and 0.46 (range 0.21-0.67). In the biomechanical experiments, the Impingement Index was a better discriminator for subacromial impingement than the Greater Tuberosity Index. A fracture with a displacement corresponding to an Impingement Index of 0.71 or greater was associated with subacromial impingement. CONCLUSIONS: Reduction of a displaced greater tuberosity fragment should be considered if the Impingement Index is 0.7 or greater. The measurement method is simple and reliable and has the potential to be used for the assessment of subacromial impingement in other conditions.