Injured Shoulders Research Articles

Human Shoulder Response to Lateral Impact in Intermediate Loading Conditions Between High-Velocity, Short-Duration and Low-Velocity, Long-Duration.

The EuroSID-2re (ES-2re) Anthropomorphic Test Device (ATD) commonly known as the crash test dummy is also used in the military domain to assess the risk of injury of armored vehicles occupants from lateral impact. The loading conditions range from low velocity - long duration impacts (4 m/s - 50 ms) similar to the automotive domain, to high velocity - short duration impacts (28 m/s - 3 ms) corresponding to cases where the panel deforms under an explosion. The human shoulder response to lateral impact was investigated at bounds of the loading condition spectrum previously mentioned, and also at intermediate conditions (14 m/s - 9 ms) in previous studies. The aim of the current study is to provide additional insight at the intermediate loading conditions which are not found in the literature. Eight pure lateral shoulder impact tests were performed on Post Mortem Human Subjects (PMHS) using an 8.1 kg rigid impactor at velocities ranging from 3.3 m/s to 8.8 m/s with the duration ranging from 25 ms to 35 ms. The PMHS were instrumented with accelerometers attached to the sternum, and the upper thoracic spine (T1 vertebra). Strain gages were glued onto the right and left clavicles and ribs 2 to 6. The shoulder force was measured at the interface with the impactor and the impact was filmed by high speed cameras (5000 fps) to track the YZ displacements of the impactor, T1 vertebra, and sternum in the laboratory frame. Three shoulders out of the eight sustained AIS 2 injuries which included a clavicle fracture. The impactor forces ranged from 1200 to 4600 N. The PMHS accelerations ranged from 44 to 163 g at the sternum, and from 17 to 60 g at the T1 vertebra. The analysis of the strain gage signals revealed that the clavicle fractures occurred at the beginning of the impact and coincided with a peak force. An estimate of the acromion-to-shoulder compression (Cmax) was computed. It ranged from 0% to 15% for the non-injured shoulders, and from 19% to 28% for the injured shoulders. This new PMHS test series will be used in a future work to develop a shoulder injury criterion for the ES-2re ATD that is relevant for the whole loading conditions spectrum of the military domain.

Clinical effectiveness of surgical treatment with polyester tapes and temporary K-wires on complete acromioclavicular dislocation.

Ideal treatment of acute acromioclavicular joint (ACJ) dislocation remains unresolved. We evaluated ACJ reconstruction using polyester tapes and temporary Kirschner wire (KW) and presented clinical and radiological outcomes. Patients were retrospectively evaluated and classified according to Rockwood classification, clinical and sportive characteristics. Constant Score (CS) and ACJ joint instability (ACJI) score were collected. Zanca's, Alexander, axillary, standard, and stress AP views were collected. Radiographic coracoclavicular distance (CCd) of healthy and injured shoulders was measured pre-operatively, at 3months and at minimum 2-year follow-up. Heterotopic ossifications and clavicular osteolysis were evaluated. Influence of patients' characteristics and AC joint type on clinical and radiological outcomes were determined. Sixteen patients (13 type V and 3 type III ACJ dislocation) reached the end of follow-up (mean 2.4years; range 22-72months). Mean CS was 99.63 (range 96-100), while the mean ACJI score was 96.19 (range 85-100). The CCd of the treated shoulder was comparable with the healthy shoulder at 3months and at last follow-up; moreover, there was no difference in CCd scores at 3months and at 2years. CCd scores were lower in sedentary patients compared with physically active (sporty) patients. Heterotopic ossifications were observed in three patients. No osteolysis was reported. This technique provides good results with few complications and should be considered as an effective method to treat ACJ acute dislocation. CCd scores correlate with overuse factors but not with other clinical scores.

Effect of Cryotherapy on Proprioception and Throwing Accuracy In the Dominant Shoulder among Female Recreational Players

Throwing is one of the most complex activities within all athletic activity. The integrity of the receptors responsible for movement and proprioception with neural pathways plays a important role in maximizing the shoulder mobility in throwing skill. After an acute shoulder injury in sport, an athlete may return to practice or competition following a cryotherapy treatment to the injured shoulder. To find the effect of Cryotherapy on proprioception and throwing efficiency of shoulder in recreational players. 10 female basketball players will be selected as per the inclusion and exclusion criteria. The procedures were explained and an informed consent statement was obtained from the participants. Crushed ice with terry towels were employed to all the players included to the study. Treatment duration was 15 minutes, immediately at the end of the treatment, the post-test documentation on throwing efficiency was documented. Throwing performance index was used to assess the Functional ability of the shoulder joint. Paired t-test was used to compare in mean values of pre-test and post-test. There was a statistically significant changes obtained in the throwing accuracy after 15 minutes of cryotherapy application.

The Effect of Adipose-derived Mesenchymal Stem Cells on Healing of Massive Chronic Rotator Cuff Tear in Rodent Model

Objectives:Mesenchymal stem cells (MSCs) may promote restoration of the structure and function of the injured tendon-bone interface of the healing rotator cuff following repair. As compared to acute tears, chronic massive rotator cuff tears are a challenging healing microenvironment, with degenerative changes present in the muscle, tendon, and bone. Therefore, the purpose of this study was to explore the efficacy of MSCs in restoring the tendon-bone interface following repair of massive chronic rotator cuff tears in a rodent model.Methods:Adipose-derived mesenchymal stem cells (ADSCs) were isolated from inguinal fat of adult Lewis rats (n= 8) and expanded to passage 2 (P2). To induce degenerative changes in a rat modeling a massive chronic rotator cuff tear, the supraspinatus and infraspinatus tendons were transected bilaterally near their bony insertion and the corresponding muscle bellies were injected with 2.5 U botulinum toxin A (botox). Eight weeks later, tendons were repaired with or without augmentation at the tendon-bone interface. In particular, there were 5 groups ; (1) no repair (defect), (2) repair, (3) repair + fibrin, (4) repair + fibrin + ADSCs, (5) repair + fibrin + ADSCs + TGF-β3 (n=12 shoulders per condition). An equivalent cohort of animals received acute tendon transection (without botox injection) and immediate repair with or without augmentation. At 4 weeks following repair, animals were euthanized and the shoulders were harvested for analysis of bone morphometry, histology, and mechanical properties. Bone morphometry of the humeral head including; bone mineral density, bone volume percentage, and trabeculae number, thickness, and spacing was determined using micro-computed tomography. Statistical analyses included 2-way ANOVA with Tukey post-hoc tests. Analyses of histology and mechanical properties are ongoing.Results:ADSCs at P2 demonstrated a spindle-shaped morphology and were capable of forming colonies (Fig. 1A) and undergoing trilineage differentiation (Fig. 1B). Compared to healthy and acutely injured shoulders, muscles in the chronic condition exhibited atrophy, fibrosis, and fatty infiltration, with corresponding reductions in wet weights (Fig. 1C). All groups in the acute and chronic conditions possessed significantly reduced bone mineral density and bone volume percentage compared to healthy controls (p < 0.05), while only groups in the chronic condition exhibited compromised trabecular number and spacing. (p < 0.05). Augmentation of repairs with ADSCs (with or without TGF-β3) in the chronic condition significantly increased bone mineral density over defect controls (p < 0.05).Conclusion:Two-tendon transection and chemical paralysis of rotator cuff muscles in a rodent model mimics the degenerative changes seen in human shoulders, including decrements in bone quality. The efficacy of ADSCs in restoring structure and function of the tendon-bone interface likely depends on tear chronicity and size and may have greater benefit in chronic tears, as suggested by improvements in parameters of bone morphometry. This study will help further clarify the involvement of adult stem cell therapy in enhancing healing of the rotator cuff enthesis in the setting of degenerative tissue. Future studies would investigate the potential of adult stem cells to promote muscle regeneration in chronic rotator cuff tears and augment structural healing at the enthesis.

Application of the method of anatomic coracoclavicular ligament reconstruction for distal clavicle fractures

Objective: To assess the clinical results of the method of anatomic coracoclavicular ligament reconstruction for distal clavicle fractures. Methods: From August 2013 to January 2015, the super image system was used to measure the CT data of 16 patients suffering distal clavicle fractures before operation in Department of Orthopaedics , the First Affiliated Hospital of Nanjing Medical Univerisity. The fractures' morphological features and acromioclavicular dislocation degree were assessed. By referring to the data collected by the my research group on Chinese people's coracoclavicular ligament, the injuries of the coracoclavicular ligament were estimated, which was then to verify the actual injuries detected during operation. Coracoclavicular ligament reconstruction was performed on patients and screws or suture anchors fixing small bone blocks was used as an adjuvant therapy. Clinical and radiological follow-up was at 1, 3, 6 and 12 months after the procedure. The clinical outcomes were assessed pre- and postoperatively with Constant Scores. Anteroposterior radiographs for the bilateral acromioclavicular joints were obtained immediately after surgery and every follow-up.To compare the reduction maintenance, coracoclavicular distances of the injured shoulders were measured in preoperative and postoperative standard radiographs. Results: All patients received satisfactory fracture and acromioclavicular joint reduction. The average follow-up period was (12.6±3.9) months (ranging from 6 to 22 months). Fractures healed six months after the operation. The coracoclavicular distances increased from (7.8±1.4)mm at one month follow-up to (7.9±1.2)mm at the final follow-up (P>0.05), which could be considered as no difference statistically. The constant score significantly increased from (49.1±4.4) at one month follow-up to (93.8±2.1) at the final evaluation (P<0.001). Obvious loss of acromioclavicular joint reduction was not observed after the operation. Coracoid process and calvicle fractures did not appear. Fractures healed well and shoulder joints also functioned well. Patients' lives and work went back to normal. Conclusion: Accompanied by ligament injuries, distal clavicle fractures is different from middle fractures. Coracoclavicular ligament injury is a major cause of the acromioclavicular joint instability, and the focus of the surgery. Therefore, the application of the double-bundle coracoclavicular ligament reconstruction is a feasible method to treat distal clavicle fractures, displaying satisfying clinical results.

Palmaris longus tendon versus iliotibial tract fascia graft for coracoclavicular ligament reconstruction combined with hook plate fixation in treatment of acromioclavicular joint dislocation

Objective To compare the clinical outcomes of palmaris longus tendon(PLT)and iliotibial tract fascia graft(ITFG)for coracoclavicular ligament(CCL)reconstruction combined with hook plate fixation in the treatment of acromioclavicular joint(AGJ)dislocation. Methods A retrospective study was conducted to evaluate the outcomes of 68 patients with ACJ dislocation of Rockwood type Ⅲ and above who had been treated in our department with CCL reconstruction using PLT or ITFG in addition to hook plate fixation from January 2008 to January 2014. They were 57 males and 11 females, with an average age of 36. 1 years(range, from 19 to 55 years). The patients were divided into 2 groups according to their grafts used in CCL reconstruction: 36 cases in PLT group and 32 in ITFG group. They were firstly treated with CCL reconstruction followed by hook plate fixation. The hook plates were removed at 6 months after operation. The acromioclavicular and coracoclavicular distances were measured on the postoperative anteroposterior radiographs of the injured shoulders. The outcomes were assessed at the final follow-ups according to Constant-Murley shoulder score and Karlsson criteria. The 2 groups were compatible without significant differences in preoperative general data(P> 0. 05). Results The 68 patients were followed up for an average of 18 months(range, from 16 to 22 months). The acromioclavicular and coracoclavicular distances measured in PLT group at 12 months after operation were significantly larger than those measured in ITFG group(P 0. 05). Conclusion In the treatment of ACJ dislocation of Rookwood type Ⅲ and above, CCL reconstruction using ITFG may lead to better radiographic outcomes than that using PLT, though the 2 grafts lead to similar functional recovery of the injured shoulders. Key words: Acromioclavicular joint; Dislocations; Ligament; Reconstructive surgical procedures

Concomitant intra-articular glenohumeral injuries in displaced fractures of the lateral clavicle

To detect concomitant intra-articular glenohumeral injuries, in acute displaced fractures of the lateral clavicle, initially missed due to unfeasible clinical evaluation of the acutely injured shoulder. All patients suffering from an acute displaced lateral clavicle fracture with indication to surgical treatment underwent diagnostic shoulder arthroscopy prior to open reduction and internal fixation. In case of therapy-relevant intra-articular glenohumeral injuries, subsequent surgical treatment was performed. Intra-articular injuries were found in 13 of 28 patients (46.4%) with initially suspected isolated lateral clavicle fracture. Additional surgical treatment was performed in 8 of 28 cases (28.6%). Superior labral anterior-posterior (SLAP) lesions were observed in 4 of 28 patients (14.3%; SLAP II a: 1; II b: 1; III: 1; and IV: 1). Lesions of the pulley system were found in 3 of 28 patients (10.7%; Habermeyer III°). One partial articular supraspinatus tendon avulsion lesion (3.6%) and one lesion of the subscapularis tendon (3.6%; Fox and Romeo II°) were observed. Traumatic concomitant glenohumeral injuries in lateral clavicle fractures seem to be more frequent than expected in general. Subsequent surgical treatment of these formerly missed but therapy-relevant injuries may increase functional outcome and reduce complication rate. IV.

Factors Expressed in an Animal Model of Anteroinferior Glenohumeral Instability.

Background:There is little information on the molecular factors important in healing and changes that occur in the glenoid labrum in response to injury. Using a novel animal model of acute anterior shoulder dislocation, this study characterizes the factors expressed in the glenoid labrum in response to injury and correlates their expression to glenohumeral stability.Purpose:To study the response of the glenoid labrum to injury both biomechanically and with immunohistochemical testing.Methods:An injury to the anteroinferior labrum was surgically induced in 50 male Lewis rats. Rats were sacrificed at 3, 7, 14, 28, or 42 days. Immunolocalization experiments were performed to localize the expression of growth factors and cytokines. For biomechanical testing, dynamic stiffness for anterior and posterior laxity, load to failure, stiffness, and maximum load were recorded. Statistical differences were determined at P < .05.Study Design:Descriptive laboratory study.Results:Expression of interleukin–1 beta (IL-1β), transforming growth factor–beta 1 (TGF-β1), matrix metalloproteinase 3 (MMP3), and matrix metalloproteinase 13 (MMP13) were increased in injured compared with uninjured specimens. Collagen III expression was increased early and decreased with time. Biomechanical testing verified instability by demonstrating increased anterior displacement and decreased stiffness in injured shoulders at all time points.Conclusion:This novel animal model of acute anterior shoulder dislocation showed increased expression of IL-1β, TGF-β1, MMP3, MMP13, and collagen III in the injured labral tissue at early time points. Increased anterior laxity and decreased stiffness and maximum load to failure were seen after anterior labral injury, supporting the model’s ability to re-create anterior glenohumeral instability. These data provide important information on the temporal changes occurring in a rat model of anterior glenohumeral dislocation.Clinical Relevance:Identification of factors expressed in the anterior capsule and glenoid labrum in response to injury may lead to the development of novel agents that can be used to augment glenoid labrum healing and ultimately improve both surgical and nonsurgical treatment of this common shoulder injury.

Through to You by Lauren Barnholdt (review)

Reviewed by: Through to You by Lauren Barnholdt Karen Coats Barnholdt, Lauren Through to You. Simon Pulse, 2014 [288p] Trade ed. ISBN 978-1-4424-3463-9 $17.99 E-book ed. ISBN 978-1-4424-3465-3 $10.99 Reviewed from galley Ad Gr. 7-10 So uptight that she worries about how uptight she is, Harper sees no value in making bad decisions. Penn is a known player both on and off the field, or at least he was until an injured shoulder dashed his dreams for a baseball scholarship. A bored flirtation on his part turns Harper’s head more than she’d like to admit, and before long both of them are involved in an off-again, on-again relationship neither saw coming. Penn’s horndog ways have honed his dating skills if not his ability to have a meaningful relationship, making it clear why an inexperienced girl like Harper would be swept off her feet, and her relative reserve in the face of his charm offensive likewise solves the puzzle of why he might be interested in her as a challenge. Other than that, they have little in common other than a fierce physical attraction, and all seems doomed until Penn finally learns to open up about his feelings and Harper forgives him for treating her so cavalierly as he worked out his own problems. Alternating narration between the two creates empathy with Penn, who, unbeknownst to Harper, is struggling with a dysfunctional family, and relatability for Harper, for whom the whole idea of having a boyfriend is new territory; each voice is distinctive and credible, adding dimension to Penn’s frustration and Harper’s insecurities. However, the plot and its fulfillment are absolutely formulaic, moving from one cliché of high school romance to another, making this run-of-the-genre-mill. Nonetheless, readers may enjoy watching Harper and Penn learn the rules of being a couple and getting a healthy dose of he-thought/she-thought insight along the way. Copyright © 2014 The Board of Trustees of the University of Illinois

Rotator Cuff Weakness Is Not a Risk Factor for First-Time Anterior Glenohumeral Instability

Background:Shoulder instability is a common problem in young athletes and can lead to pain and decreased ability to participate in high-level activities. Little is known about the modifiable risk factors for glenohumeral joint instability.Hypothesis:Isometric shoulder strength at baseline would be a modifiable risk factor associated with subsequent first-time anterior instability events.Study Design:Cohort study.Methods:Study participants were freshmen entering the United States Military Academy in June 2006. All participants completed bilateral isometric strength evaluations with a hand-held dynamometer at baseline upon entry into the study. Variables measured included internal and external rotation at 0° (IR0, ER0) and internal and external rotation at 45° of abduction (IR45, ER45). All subjects were followed for subsequent glenohumeral joint instability events until graduation in May 2010. Independent t tests were used to analyze the data.Results:Baseline strength data were available for 1316 shoulders with no prior history of instability, of which 26 went on to have an acute first-time anterior shoulder instability event while the individuals were at the academy. There were no significant differences in mean strength between shoulders that did not go on to develop instability (uninjured; n = 1290) and those that did develop anterior instability (injured; n = 26). The mean strength values in pounds of force for uninjured and injured shoulders, respectively, were as follows: IR0 (49.80 vs 49.29; P = .88), ER0 (35.58 vs 33.66; P = .27), IR45 (47.38 vs 46.93; P = .88), and ER45 (40.08 vs 38.98; P = .59).Conclusion:No association was found between isometric shoulder strength measures at baseline and subsequent first-time anterior glenohumeral joint instability within the high-risk athletic population studied in this prospective cohort.

Kinesthetically guided reaching accuracy in individuals with a history of traumatic anterior shoulder dislocation

Background: The purpose of the study was to investigate whether individuals with a history of traumatic anterior shoulder dislocation show larger reaching errors than those with healthy shoulders and to determine if they implement different reaching strategies to protect the injured shoulder. Methods: Ten people with a history of traumatic anterior shoulder dislocation and 15 with healthy shoulders volunteered for this study. After viewing targets in space, participants pointed with the unconstrained arm to remembered target locations in space without visual guidance. Nine different targets were located in various planes and heights. Endpoint reaching errors were determined by comparing the finger endpoint position without visual guidance to the target location. Shoulder rotation angle at the endpoint was also compared between groups. Results: Participants with injured shoulders were able to point voluntarily to visually specified targets as accurately as participants with healthy shoulders (1 cm difference). However, participants with injured shoulders showed less shoulder external rotation (average 12° difference) at the target location when compared with healthy shoulders. This difference was consistent over a large range of target locations. Conclusion: Individuals with a history of traumatic anterior shoulder dislocation have sufficient kinesthetic information about their upper limb orientation to point accurately to visually specified targets in space. However, individuals with injured shoulders acquired a new motor strategy to reach with less shoulder external rotation, presumably to protect the injured shoulder from recurrent injuries.

Treatment of Osteopenic or Non-united Fractures of the Humerus with Structure Bone Allograft and Non-locking Plates

Background: Treatment of osteopenic or non-united fractures of the humerus are difficult to achieve optimum mechanical stabilization before bone union. This report presents the clinical experience of structure bone allograft augmentation plus non-locking plates fixation for these complex fractures. Patients and methods: Twenty-four patients with osteopenic or non-united fractures of the humerus (thirteen proximal humerus and eleven humeral shaft fractures) were selected and treated with structure bone allograft augmentation and non-locking internal fixation. All patients were followed and evaluated using shoulder-joint range of motion, the American Shoulder and Elbow Surgeons (ASES) scale and radiographic examination for fracture union assessment. Results: The mean duration of follow-up was 45.3 months. The average time from surgery to the date of radiographic union was 3.6 months (range, 2.5-4.5 months). Twenty-three patients showed radiographically bony union. The total union rate was 95.8%. The average injured shoulder forward flexion was 120 degrees, the external rotation averaged 42 degrees and the internal rotation averaged to the 12th thoracic vertebra. The ASES score improved from an average of 37 preoperatively to 85 postoperatively. One patient had the complication of persistent non-union and loss of reduction. Conclusions: Structure bone allograft can be used as a strong adjuvant mechanical support for internal fixation for the weakened osteopenic humeral fractures. Through rigid fixation and good stabilization, this method can provide an effective treatment for the management of severely osteopenic or non-united fractures of the humerus.

Surgical treatment of displaced fractures of the greater tuberosity of the humerus

Objective To discuss the techniques and efficacy of surgical treatment of displaced fractures of the humeral greater tuberosity. Methods We reviewed the 20 patients who had been treated and followed up for displaced fractures of the humeral greater tuberosity in our institute between June 2006 and June 2011.They were 11 men and 9 women,aged from 30 to 69 years(average,49.6 years).The time intervals from injury to surgery ranged from one to 122 days (average,8.2 days).(Open surgery was performed for 17 patients,arthroscopy for 2 and open surgery plus arthroscopy for one.In open surgery the deltopectoral approach was adopted for 7 patients and the trans-deltoid approach for 10.Of the 7 fixation methods adopted,the cannulated screws were the most frequently used (in 11 cases).The functional outcomes of the injured shoulders were evaluated by the University of California at Los Angeles (UCLA) shoulder rating system.Results The patients obtained a mean follow-up of 13.6 months (range,6 to 51 months).The fractures all united 6 weeks postoperatively.By the UCLA system,the 7 patients in whom the deltopectoral approach was adopted scored an average of 28.4 points,the 10 patients in whom the trans-deltoid approach was adopted scored an average of 30.4 points,the 2 patients undergoing arthroscopy scored an average of 34.5 points,and the one undergoing open surgery plus arthroscopy scored 34 points.Ten cases were rated as excellent,3 as good and 7 as poor,with a good to excellent rate of 65.0％. Conclusions Open reduction and internal fixation is the mainstay treatment of displaced fractures of the greater tuberosity of the humerus.The trans-deltoid approach may be the most frequently used.The methods of internal fixation varied depending on the characteristics of the fracture.The arthroscopic indications for fractures of greatertuberosity are moderate fragments,proximal fracture line,little displacement and little comminution. Key words: Shoulder fractures; Humeral fractures; Surgical procedure; operative; Pain,postoperative

Acute surgical treatment of acromioclavicular dislocation type V with a hook plate: superiority to late reconstruction

Outcomes for patients with acromioclavicular joint dislocation, Rockwood type V, treated with acute or delayed hook plate surgery were investigated. Patients treated with a hook plate for acromioclavicular joint dislocation, Rockwood type V, were retrospectively evaluated 1 to 8 years after the injury. Of 41 patients, 37 were re-evaluated, 32 in person and 5 by telephone or letter. The acute surgery group comprised 22 patients operated on with a hook plate within 4 weeks after the injury. The delayed surgery group comprised 15 patients, with unacceptable pain or functional disability after a minimum of 4 months of conservative treatment, who were operated on with modified Weaver-Dunn procedure augmented with a hook plate. The evaluation was based on radiographs, registration of activity level, and shoulder function. The median Constant Score was 91 for the acute surgery group and 85 for the delayed surgery group (P=.097). The acutely treated patients had better outcomes according to the median Shoulder Pain and Disability Index (SPADI; P=.006), shortened version of the Disabilities of the Arm, Shoulder, and Hand (QuickDASH; P=.002), and Subjective Shoulder Value (P=.032). The acutely treated patients had less pain in their injured shoulder during rest (P=.014) and during movement (P=.005). There was a significant difference in subluxation between the groups in favor of the acute group, shown by weighted radiographs (P=.011), but no significant relation between subluxation on the weighted radiographs and the shoulder function according to Constant Score at follow-up (r(s)=.122, P=.619). Patients treated with acute surgery had a more satisfactory outcome than those with late surgery after failed conservative treatment.

Glenoid cartilage mechanical properties decrease after rotator cuff tears in a rat model

Rotator cuff repairs are commonly performed to reduce pain and restore function. Tears are also treated successfully without surgical intervention; however, the effect that a torn tendon has on the glenohumeral cartilage remains unknown. Clinically, a correlation between massive rotator cuff tears and glenohumeral arthritis has often been observed. This may be due to a disruption in the balance of forces at the shoulder, resulting in migration of the humeral head and subsequently, abnormal loading of the glenoid. Our lab previously demonstrated changes in ambulation and intact tendon mechanical properties following supraspinatus and infraspinatus rotator cuff tendon tears in a rat model. Therefore, the purpose of this study was to investigate the effects of supraspinatus and infraspinatus rotator cuff tears on the glenoid cartilage. Nine rats underwent unilateral detachment of the supraspinatus and infraspinatus tendons and were sacrificed after 4 weeks. Cartilage thickness significantly decreased in the antero-inferior region of injured shoulders. In addition, equilibrium elastic modulus significantly decreased in the center, antero-superior, antero-inferior, and superior regions. These results suggest that altered loading after rotator cuff injury may lead to damage to the joint with significant pain and dysfunction. Clinically, understanding the mechanical processes involved with joint damage will allow physicians to better advise patients.

Assessment of scapulohumeral rhythm for scapular plane shoulder elevation using a modified digital inclinometer

To develop a better understanding of scapulohumeral rhythm during scapular plane shoulder elevation. Thirteen healthy, college-aged subjects participated in this study. Subjects were free from any upper extremity, neck or back pathology. A modified digital inclinometer was utilized to measure scapular upward rotation of the subject's dominant shoulder. Upward rotation was measured statically as subjects performed clinically relevant amounts of shoulder elevation in the scapular plane. Testing order was randomized by arm position. Scapular upward rotation was assessed over the entire arc of motion and over a series of increments. The percent contributions to shoulder elevation for the scapula and glenohumeral joint were calculated. Scapulohumeral rhythm was assessed and represented the ratio of glenohumeral motion to scapulothoracic motion (glenohumeral elevation: scapular upward rotation). A one-way ANOVA was used to compare scapular upward rotation between elevation increments. Scapulohumeral rhythm for the entire arc of shoulder elevation was equal to a ratio of 2.34 :1 and ranged from 40.01:1 to 0.90:1 when assessed across the different increments of humeral elevation. Total scapular motion increased over the arc of shoulder elevation. The scapula contributed 2.53% of total motion for the first 30 degrees of shoulder elevation, between 20.87% and 37.53% for 30(o)-90(o) of shoulder elevation, and 52.73% for 90(o)-120(o) of shoulder elevation. Statistically significant differences in scapular upward rotation were identified across the shoulder elevation increments [F((3,48)) = 12.63, P = 0.0001]. Clinically, we must recognize the usefulness of the inclinometer in documenting the variable nature of scapulohumeral rhythm in healthy and injured shoulders.

Avaliação clínica e por ressonância magnética do ombro de pacientes lesados medulares

ObjectiveTo study the shoulder of this group of patients using magnetic resonance imaging to detect clinical and subclinical disorders and establish a rehabilitation program.MethodsNine patients with spinal cord injury followed in the Laboratory of Biomechanics and Rehabilitation of the Locomotive System at HC/UNICAMP were divided into two groups according to the presence of paraplegia and tetraplegia and were clinically assessed for correlation with the imaging exams.ResultsNormal results were found in 41% of the shoulders. Most common injuries were tendinopathy of the supraspinatus and acromioclavicular joint degeneration. Eighty percent of injured shoulders had combined lesions.ConclusionA great variety of causes of shoulder pain was identified in paraplegic and tetraplegic subjects. Routine clinical assessment and imaging studies of the shoulder may contribute to the evolution of rehabilitation and reduction of pain and musculoskeletal disorders. Level of Evidence II, Development of Diagnostic Criteria on Consecutive Patients, With Universally Applied Reference "Gold" Standard.

Locking plate versus nonsurgical treatment for proximal humeral fractures: better midterm outcome with nonsurgical treatment

Since its introduction, there has been controversy about the use of locking plates in the treatment of proximal humeral fractures. Have they really improved the functional outcome after a proximal humeral fracture or should nonsurgical treatment have a more prominent role? In order to evaluate our hypothesis that nonsurgical treatment for proximal humerus fractures should be the first choice of treatment, a matched controlled cohort study was conducted to compare the midterm (>1 year) functional and radiologic outcome of a group of patients treated with a locking plate and a matched group of patients treated nonsurgically. Complications in each group of patients were evaluated. Through direct matching, 17 patients (1 bilateral fracture) treated with a locking plate were matched to 18 patients treated nonsurgically. Medical records and radiographs were reviewed retrospectively to obtain relevant patient related data and fracture type according to Neer classification (i.e. 2-, 3- and 4-part fractures). At the time of clinical follow-up, EQ-5D, American Shoulder and Elbow Surgeons (ASES) score, visual analog pain (VAS) pain and VAS satisfaction scores were completed. Active range of motion was tested. New radiographs were made to evaluate fracture healing, complications and, in the locking plate group, the position of the plate and screws. No significant differences were found in the characteristics of the patient groups. A significant difference in range of motion was found in favor of the nonsurgically treated patients. Results of ASES and patient satisfaction scores were also tending toward nonsurgical treatment. Furthermore, the complication rate was higher with locking plate treatment. Patients treated with a locking plate needed significantly more additional treatment on their injured shoulder (P = 0.005). This study's main limitation was the fact that the choice of initial fracture management was based on clinical judgement, as well as patient's fitness for surgery and therefore not randomized. By matching for fracture type this bias was largely overcome. Surgical treatment had a higher complication rate, requiring more additional treatment, which was often related to the initial surgery. Improving surgical technique could possibly lead to better outcomes for the surgically treated patients. In addition to the more favorable outcomes, nonsurgical treatment is also a more cost effective treatment. Nonsurgical treatment should have a more prominent role in the treatment of proximal humeral fractures.

Radiography of the acutely injured shoulder

Routine radiological examination of the acute shoulder has been unchanged in radiology departments for many years. At UCLH (University College London Hospitals, UK) this examination consists of two projections, an AP (antero-posterior) and an LS (lateral scapula). Following a review of the related literature and the possible advantages of an axial style projection, a study was performed to evaluate whether a new projection named modified trauma axial (MTA) shoulder projection could replace the existing LS projection in the routine examination of the acute shoulder. A retrospective analysis of 244 acute shoulder examinations over a 5-month period was performed. AP, LS and MTA projections were taken with paired AP and LS, and AP and MTA radiographs were reported separately. 97 traumatic abnormalities were reported using AP and MTA whilst only 64 abnormalities were reported using AP and LS views. The MTA projection demonstrated it was significant for evaluating articular surfaces of the humeral head and glenoid, defects in the humeral head, greater tuberosity fractures, glenoid fractures and fractures of the acromion. It was established that if the LS projection was replaced with the MTA view no traumatic pathologies would have been overlooked and in fact there was a 52% increase in traumatic abnormalities detected. Use of a chi-squared test demonstrated a highly significant difference in the number of traumatic abnormalities detected between the two pairs of projection combinations ( p = 0.0004). Based on this study and the examined literature the routine examination of the acutely injured shoulder is recommended to include the AP and MTA projections only.

Transacromial Extra-articular Knowles Pin Fixation Treatment of Acute Type V Acromioclavicular Joint Injuries

Type V acromioclavicular (AC) joint dislocations need surgical treatment. This report described a new transacromial extra-articular Knowles pin fixation method to treat this very unstable dislocations to analyze this treatment. The hypothesis is that the results would be improved. Thirteen consecutive patients with type V AC joint dislocations within 9 days of injuries were treated by open reduction transacromial extra-articular Knowles fixation, AC ligament repair, coracoclavicular (CC) ligament repair, CC augmentation sutures. All of them received postoperative arm sling supports for 3 weeks. The radiographic and clinical follow-up was at least 23 months. A modified Constant-Murley score was used for evaluation of bilateral shoulder functions. All AC ligaments were torn at the clavicle sides. All CC ligament were torn at the mid-substances. The anterior deltoid insertions and the superior-posterior trapezius insertions to the clavicles were torn. Radio-lucent zones around the pins 1 mm to 3 mm were noted in all patients before pin removal. Lateral pin migration 1 mm to 2 mm were noted in nine patients before pin removal. Nine patients had increase of CC distances 1 mm to 4 mm at follow-up. Six patients had CC space calcifications. The mean modified Constant-Murley score of the injured shoulders was 94.5 +/- 2.7, the mean score of the uninjured shoulders was 93.9 +/- 1.3, which was not statistically different. The transacromial extra-artocular Knowles pin fixation method is a reliable method to treat acute type V AC joint dislocations.