Analyzing shoulder kinematics is challenging as the shoulder is comprised of a complex group of multiple highly mobile joints. Unlike at the elbow or knee which has a primary flexion/extension axis, both primary shoulder joints (glenohumeral and scapulothoracic) have a large range of motion (ROM) in all three directions. As such, there are six degrees of freedom (DoF) in the shoulder joints (three translations and three rotations), and all these parameters need to be defined to fully describe shoulder motion. Despite the importance of glenohumeral and scapulothoracic coordination, it's the glenohumeral joint that is most studied in the shoulder. Additionally, the limited research on the scapulothoracic primarily focuses on planar motion such as abduction or flexion. However, more complex motions, such as internally rotating to the back, are rarely studied despite the importance for activities of daily living. A technique for analyzing shoulder kinematics which uses 4DCT has been developed and validated and will be used to conduct analysis. The objective of this study is to characterize glenohumeral and scapulothoracic motion during active internal rotation to the back, in a healthy young population, using a novel 4DCT approach. Eight male participants over 18 with a healthy shoulder ROM were recruited. For the dynamic scan, participants performed internal rotation to the back. For this motion, the hand starts on the abdomen and is moved around the torso up the back as far as possible, unconstrained to examine variability in motion pathway. Bone models were made from the dynamic scans and registered to neutral models, from a static scan, to calculate six DoF kinematics. The resultant kinematic pathways measured over the entire motion were used to calculate the ROM for each DoF. Results indicate that anterior tilting is the most important DoF of the scapula, the participants all followed similar paths with low variation. Conversely, it appears that protraction/retraction of the scapula is not as important for internally rotating to the back; not only was the ROM the lowest, but the pathways had the highest variation between participants. Regarding glenohumeral motion, internal rotation was by far the DoF with the highest ROM, but there was also high variation in the pathways. Summation of ROM values revealed an average glenohumeral to scapulothoracic ratio of 1.8:1, closely matching the common 2:1 ratio other studies have measured during abduction. Due to the unconstrained nature of the motion, the complex relationship between the glenohumeral and scapulothoracic joints leads to high variation in kinematic pathways. The shoulder has redundant degrees of freedom, the same end position can result from different joint angles and positions. Therefore, some individuals might rely more on scapular motion while others might utilize primarily humeral motion to achieve a specific movement. More analysis needs to be done to identify if any direct correlations can be drawn between scapulothoracic and glenohumeral DoF. Analyzing the kinematics of the glenohumeral and scapulothoracic joint throughout motion will further improve understanding of shoulder mechanics and future work plans to examine differences with age

A fracture of the tuberosity is associated with 16% of anterior glenohumeral dislocations. Manipulation of these injuries in the emergency department is safe with less than 1% risk of fracture propagation. However, there is a risk of associated neurological injury, recurrent instability and displacement of the greater tuberosity fragment. The risks and outcomes of these complications have not previously been reported. The purpose of this study was to establish the incidence and outcome of complications associated with this pattern of injury. We reviewed 339 consecutive glenohumeral dislocations with associated greater tuberosity fractures from a prospective trauma database. Documentation and radiographs were studied and the incidence of neurovascular compromise, greater tuberosity fragment migration and intervention and recurrent instability recorded. The mean age was 61 years (range, 18–96) with a female preponderance (140:199 male:female). At presentation 24% (n=78) patients had a nerve injury, with axillary nerve being most common (n=43, 55%). Of those patients with nerve injuries 15 (19%) did not resolve. Greater tuberosity displacement >5mm was observed in 36% (n=123) of patients with 40 undergoing acute surgery, the remainder did not due to comorbidities or patient choice. Persistent displacement after reduction accounted for 60 cases, later displacement within 6 weeks occurred in 63 patients. Recurrent instability occurred in 4 (1%) patients. Patient reported outcomes were poor with average EQ5D being 0.73, QDASH score of 16 and Oxford Shoulder Score of 41. Anterior glenohumeral dislocation with associated greater tuberosity fracture is common with poor long term patient reported outcomes. Our results demonstrate there is a high rate of neurological deficits at presentation with the majority resolving spontaneously. Recurrent instability is rare. Late tuberosity fragment displacement occurs in 18% of patients and regular follow-up for 6 weeks is recommended to detect this

Knowledge of the premorbid glenoid shape and the morphological changes the bone undergoes in patients with glenohumeral arthritis can improve surgical outcomes in total and reverse shoulder arthroplasty. Several studies have previously used scapular statistical shape models (SSMs) to predict premorbid glenoid shape and evaluate glenoid erosion properties. However, current literature suggests no studies have used scapular SSMs to examine the changes in glenoid surface area in patients with glenohumeral arthritis. Therefore, the purpose of this study was to compare the glenoid articular surface area between pathologic glenoid cavities from patients with glenohumeral arthritis and their predicted premorbid shape using a scapular SSM. Furthermore, this study compared pathologic glenoid surface area with that from virtually eroded glenoid models created without influence from internal bone remodelling activity and osteophyte formation. It was hypothesized that the pathologic glenoid cavities would exhibit the greatest glenoid surface area despite the eroded nature of the glenoid and the medialization, which in a vault shape, should logically result in less surface area. Computer tomography (CT) scans from 20 patients exhibiting type A2 glenoid erosion according to the Walch classification [Walch et al., 1999] were obtained. A scapular SSM was used to predict the premorbid glenoid shape for each scapula. The scapula and humerus from each patient were automatically segmented and exported as 3D object files along with the scapular SSM from a pre-operative planning software. Each scapula and a copy of its corresponding SSM were aligned using the coracoid, lateral edge of the acromion, inferior glenoid tubercule, scapular notch, and the trigonum spinae. Points were then digitized on both the pathologic humeral and glenoid surfaces and were used in an iterative closest point (ICP) algorithm in MATLAB (MathWorks, Natick, MA, USA) to align the humerus with the glenoid surface. A Boolean subtraction was then performed between the scapular SSM and the humerus to create a virtual erosion in the scapular SSM that matched the erosion orientation of the pathologic glenoid. This led to the development of three distinct glenoid models for each patient: premorbid, pathologic, and virtually eroded (Fig. 1). The glenoid surface area from each model was then determined using 3-Matic (Materialise, Leuven, Belgium). Figure 1. (A) Premorbid glenoid model, (B) pathologic glenoid model, and (C) virtually eroded glenoid model. The average glenoid surface area for the pathologic scapular models was 70% greater compared to the premorbid glenoid models (P < 0 .001). Furthermore, the surface area of the virtual glenoid erosions was 6.4% lower on average compared to the premorbid glenoid surface area (P=0.361). The larger surface area values observed in the pathologic glenoid cavities suggests that sufficient bone remodelling exists at the periphery of the glenoid bone in patients exhibiting A2 type glenohumeral arthritis. This is further supported by the large difference in glenoid surface area between the pathologic and virtually eroded glenoid cavities as the virtually eroded models only considered humeral anatomy when creating the erosion. For any figures or tables, please contact the authors directly

Massive irreparable rotator cuff tears often lead to superior migration of the humeral head, which can markedly impair glenohumeral kinematics and function. Although treatments currently exist for treating such pathology, no clear choice exists for the middle-aged patient demographic. Therefore, a metallic subacromial implant was developed for the purpose of restoring normal glenohumeral kinematics and function. The objective of this study was to determine this implant's ability in restoring normal humeral head position. It was hypothesized that (1) the implant would restore near normal humeral head position and (2) the implant shape could be optimized to improve restoration of the normal humeral head position. A titanium implant was designed and 3D printed. It consisted of four design variables that varied in both implant thickness (5mm and 8mm) and curvature of the humeral articulating surface (high constraint and low constraint. To assess these different designs, these implants were sequentially assessed in a cadaver-based biomechanical testing protocol. Eight cadaver specimens (64 ± 13 years old) were loaded at 0, 30, and 60 degrees of glenohumeral abduction using a previously developed shoulder simulator. An 80N load was equally distributed across all three deltoid heads while a 10N load was applied to each rotator cuff muscle. Testing states included a fully intact rotator cuff state, a posterosuperior massive rotator cuff tear state (cuff deficient state), and the four implant designs. An optical tracking system (Northern Digital, Ontario, Canada) was used to record the translation of the humeral head relative to the glenoid in both superior-inferior and anterior-posterior directions. Superior-Inferior Translation. The creation of a posterosuperior massive rotator cuff tear resulted in significant superior translation of the humeral head relative to the intact cuff state (P=0.016). No significant differences were observed between each implant design and the intact cuff state as all implants decreased the superior migration of the humeral head that was observed in the cuff deficient state. On average, the 5mm low and high constraint implant models were most effective at restoring normal humeral head position to that of the intact cuff state (-1.3 ± 2.0mm, P=0.223; and −1.5 ± 2.3mm, P=0.928 respectively). Anterior-Posterior Translation. No significant differences were observed across all test states for anterior-posterior translation of the humeral head. The cuff deficient on average resulted in posterior translation of the humeral head, however, this was not statistically significant (P=0.128). Both low and high constraint implant designs were found to be most effective at restoring humeral head position to that of the intact cuff state, on average resulting in a small anterior offset (5mm high constraint: 2.0 ± 4.7mm, P=1.000; 8mm high constraint: 1.6 ± 4.9mm, P=1.000). The 5mm high constraint implant was most effective in restoring normal humeral head position in both the superior-inferior and anterior-posterior directions. The results from this study suggest the implant may be an effective treatment for restoring normal glenohumeral kinematics and function in patients with massive irreparable rotator cuff tears. Future studies are needed to address the mechanical efficiency related to arm abduction which is a significant issue related to patient outcomes

Introduction. For anatomical reconstruction in shoulder arthroplasty, it is important to understand normal glenohumeral geometry. Unfortunately, however, the details of the glenohumeral joint in Asian populations have not been sufficiently evaluated. There is a racial difference in body size, and this difference probably results in a difference in glenohumeral size. The purpose of this study was to evaluate three-dimensional geometry of the glenohumeral joint in the normal Asian population and to clarify its morphologic features. Methods. Anthropometric analysis of the glenohumeral joint was performed using computed tomography scans of 160 normal shoulders from healthy volunteers in age from 20 to 40 years. Using OsiriX MD, Geomagic Studio, and AVIZO software, the dimensions of humeral head width, humeral head diameter, glenoid height, glenoid width, and glenoid diameter were analyzed three-dimensionally (Figure 1). In diameter analyses, the humeral head was assumed to be a sphere and the glenoid was to fit a sphere (Figure 2–3). Sex differences in height, humeral length, humeral head width, humeral head diameter, glenoid height, glenoid width, and glenoid diameter were compared using Mann-Whitney U tests. The correlations between sides and among the respective parameters in the glenohumeral dimensions were evaluated with Spearman rank correlation tests. The significance level was set at 0.05 for all analyses. Results. Average height and humeral length of the volunteers were 164.7 ± 9.7 cm and 29.1 ± 1.8 cm respectively. The normal Asian glenohumeral joint has average humeral head width of 41.4 ± 3.7 mm, humeral head diameter of 42.9 ± 3.6 mm, glenoid height of 31.5 ± 2.8 mm, glenoid width of 23.1 ± 2.4 mm, and glenoid diameter of 62.0 ± 6.8 mm. The humeral head and glenoid were significantly larger in males than in females (p<0.001 in all analyses). The average radius difference between the glenoid and the humeral head was 9.6 ± 2.8 mm, and there was no sex difference (p=0.359). The average ratio of the glenoid radius to the humeral head radius was 144.9% ± 12.2%, and the ratio was significantly larger in females than in males (p=0.026). The glenohumeral size was well correlated between the two sides, and there were direct correlations among the heights, humeral length, humeral head size, and glenoid size (p<0.001 in all analyses). Conclusions. The present study revealed that the values of glenohumeral dimensions were uniform in both males and females with a strong correlation between the dominant shoulder and the nondominant shoulder. Since there are direct correlations among height, humeral length, and the size of the glenohumeral joint, we can also predict the glenohumeral size of patients from their respective heights. The present results would be useful to determine the size of implants and to improve clinical outcomes of shoulder arthroplasty for glenohumeral joints of Asian patients. The size of the Asian glenohumeral joint was obviously smaller than that reported in the past literature including black and Caucasian populations. Some shoulder prostheses that are designed in Europe or America and are widely used worldwide could be oversized for small females

Aims. Frozen shoulder is a common, painful condition that results in impairment of function. Corticosteroid injections are commonly used for frozen shoulder and can be given as glenohumeral joint (GHJ) injection or suprascapular nerve block (SSNB). Both injection types have been shown to significantly improve shoulder pain and range of motion. It is not currently known which is superior in terms of relieving patients’ symptoms. This is the protocol for a randomized clinical trial to investigate the clinical effectiveness of corticosteroid injection given as either a GHJ injection or SSNB. Methods. The Therapeutic Injections For Frozen Shoulder (TIFFS) study is a single centre, parallel, two-arm, randomized clinical trial. Participants will be allocated on a 1:1 basis to either a GHJ corticosteroid injection or SSNB. Participants in both trial arms will then receive physiotherapy as normal for frozen shoulder. The primary analysis will compare the Oxford Shoulder Score (OSS) at three months after injection. Secondary outcomes include OSS at six and 12 months, range of shoulder movement at three months, and Numeric Pain Rating Scale, abbreviated Disabilities of Arm, Shoulder and Hand score, and EuroQol five-level five-dimension health index at three months, six months, and one year after injection. A minimum of 40 patients will be recruited to obtain 80% power to detect a minimally important difference of ten points on the OSS between the groups at three months after injection. The study is registered under ClinicalTrials.gov with the identifier NCT04965376. Conclusion. The results of this trial will demonstrate if there is a difference in shoulder pain and function after GHJ injection or SSNB in patients with frozen shoulder. This will help provide effective treatment to patients with frozen shoulder. Cite this article: Bone Jt Open 2023;4(3):205–209

Glenohumeral dislocation is complicated with a greater tuberosity fracture in 16% of cases. Debate regarding the safety of closed reduction in the emergency department exists, with concerns over fracture propagation during the reduction manoeuvre. The study aim was to report the results of closed reduction, identify complications and define outcome for these injuries. 188 consecutive glenohumeral dislocations with a tuberosity fracture were identified from a prospective database from 2014–2017. 182 had an attempted closed reduction under appropriate sedation using standard techniques, five were manipulated in theatre due to contra-indications to sedation. Clinical, radiographic and patient reported outcomes, in the form of the QuickDASH and Oxford Shoulder Score (OSS), were collected. A closed reduction in the emergency department was successful in 162 (86%) patients. Two iatrogenic fractures of the proximal humerus occurred, one in the emergency department and one in theatre, representing a 1% risk. 35 (19%) of patients presented with a nerve lesion due to dislocation. Surgery was performed in 19 (10%) cases for persistent or early displacement (< 2 weeks) of the greater tuberosity fragment. Surgery resulted in QuickDASH and OSS scores comparable to those patients in whom the tuberosity healed spontaneously in an anatomical position (p=0.13). 18 patients developed adhesive capsulitis (10%). Glenohumeral dislocation with greater tuberosity fracture can be safely treated by closed reduction within the emergency department with a low risk of humeral neck fracture. Persistent or early displacement of the tuberosity fragment will occur in 10% of cases and is an indication for surgery

Aims: Although the glenohumeral joint is the most mobile articulation of the human body it is known to exhibit ball-and-socket-kinematics. Compression into the glenoid concavity keeps the humeral head centered. The purpose of this study was to determine the effects of joint position on glenohumeral stability through concavity-compression. Methods: Ten cadaver shoulders were tested. The glenoid was mounted horizontally onto a six-component load cell while the humerus was clamped to a vertically unconstrained slide. An x-y-stage translated the load cell with the glenoid underneath the humeral head in eight different directions. Compressive loads of twenty, forty and sixty Newtons were applied. The tests were repeated in 0, 30, 60 and 90 degrees of glenohumeral abduction with and without labrum. Translation distances and the forces resisting translation were recorded and the stability ratio calculated. Results: The average stability ratio was higher in hanging arm position than in glenohumeral abduction. With intact labrum the highest stability ratio was detected in inferior direction (59.8±7.7 percent), without labrum in superior direction (53.3±7.9 percent). In both conditions the anterior direction showed the lowest stability ratio (32.0±4.4 percent; 30.4±4.1 percent). Resection of the labrum resulted in a decrease in stability ratio of 9.6 ±1.7 percent. With increasing compressive load the stability ratio slightly decreased. Conclusions: Anterior shoulder dislocation may be facilitated by the lower stability in glenohumeral abduction and anterior direction. The labrum may not contribute as much as previously assumed to glenohumeral stability. Even moderate compressive forces are sufficient to provide stability through concavity-compression

Background. Rotator cuff atrophy evaluated with computed tomography scans has been associated with asymmetric glenoid wear and humeral head subluxation in glenohumeral arthritis. Magnetic resonance imaging has increased sensitivity for identifying rotator cuff pathology and has not been used to investigate this relationship. The purpose of this study was to use MRI to assess the association of rotator cuff muscle atrophy and glenoid morphology in primary glenohumeral arthritis. Methods. 132 shoulders from 129 patients with primary GHOA were retrospectively reviewed and basic demographic information was collected. All patients had MRIs that included appropriate orthogonal imaging to assess glenoid morphology and rotator cuff pathology and were reviewed by two senior surgeons. All patients had intact rotator cuff tendons. Glenoid morphology was assigned using the modified-Walch classification system (types A1, A2, B1, B2, B3, C, and D) and rotator cuff fatty infiltration was assigned using Goutallier scores. Results. 46 (35%) of the shoulders had posterior wear patterns (23 type B2s, 23 type B3s). Both the infraspinatus and teres minor independently had significantly more fatty infiltration in B2 and B3 type glenoids compared to type A glenoids (p<0.001). There was a greater imbalance in posterior rotator cuff muscle fatty atrophy in B2 and B3 type glenoids compared to type A glenoids (p<0.001). However, there was no difference in axial plane imbalance between B2 and B3 glenoids (p=1.00). There was increased amount fatty infiltration of the infraspinatus among B2 and B3-type glenoids compared to type A glenoids on multivariate analysis controlling for age and gender (p<0.001). Conclusions. These results identify significant axial plane rotator cuff muscle imbalances in B2 and B3-type glenoids compared to concentrically worn glenoids, favoring a relative increase in fatty infiltration of the infraspinatus and teres minor compared to the subscapularis in glenoids with patterns of posterior wear. For any figures or tables, please contact authors directly

Glenohumeral chondrolysis is a devastating condition characterized by the rapid dissolution of glenohumeral cartilage and resultant joint destruction. Excessive intra-articular use of thermal heat, suture anchors that are prominent or loose, and the use of an intra-articular pain pump (IAPP) delivering local anesthetics have all been implicated as causative factors. Between November 2007 and February 2010, 29 patients presented with glenohumeral chondrolysis related to one or more of the causative factors noted above. Seventeen patients have been followed since their initial presentation, with the remainder presenting for evaluation only, at the suggestion of their attorneys. Of those 17 patients, 7 were male and mean age at the time of their index surgery was 28.6 years (range 15-55 years). Two patients developed chondrolysis as a result of prominent suture anchors and 15 as a result of an IAPP delivering bupivacaine. Two patients underwent placement of an IAPP following closed manipulation for adhesive capsulitis and 13 underwent IAPP placement following arthroscopic labrum repair or capsular plication using one to seven suture anchors. Onset of symptoms related to chondrolysis, such as increased pain, stiffness and crepitation, occurred at a mean 8 months (range 1-32 months) following the index procedure. Twelve of the 17 patients underwent one or more additional arthroscopic procedure, typically for debridement and chondroplasty, and in some cases, capsular release. A loose suture anchor was found in one joint at arthroscopy, which was removed. Eleven patients had radiographs documenting joint space obliteration at most recent follow-up or at the time of prosthetic shoulder arthroplasty. At most recent follow-up, 7 patients had undergone 3 total shoulder replacements and 4 humeral head resurfacing procedures. Four other patients were contemplating prosthetic shoulder arthroplasty. For those undergoing shoulder replacement, range of motion recovered modestly so that active forward elevation improved from 111° to 137° (p<0.05) and active abduction improved from 99° to 123° (p<0.05). Seven of the 12 patients presenting for evaluation only had also undergone prosthetic shoulder arthroplasty elsewhere by the time of their presentation, so that overall, 14 of 29 patients had undergone their first prosthetic shoulder replacement for chondrolysis within 25 months (range 9-54 months) of their index procedure. The onset of chondrolysis in two patients following the use of an IAPP after closed manipulation has not been reported previously. Post-arthroscopic glenohumeral chondrolysis (PAGCL) is a devastating condition that strikes young patients and frequently requires shoulder replacement surgery. The use of an intra-articular pain pump delivering local anesthetics is the principal causative factor for glenohumeral chondrolysis in most patients and should be abandoned

The aim of this study was to determine if the extent of the glenoid and humeral bone loss affects the rate of recurrent instability and the functional outcome following the Latarjet procedure. 161 patients underwent open Latarjet procedure during the period 2006–2015 (Mean age 30.0 years, 150t (93.2%) Male, 118 (73.3%) primary procedure). Functional outcome was measured using the Western Ontario Shoulder Instability Index (WOSI) and Quick Disabilities of the Arm, Shoulder and Hand (QuickDash) score at a mean of 4.7 years post-operatively. All patients underwent computed tomographic (CT) imaging pre-operatively. Using three-dimensional reconstruction, the glenoid bone loss, Hill-Sachs lesion and ‘Glenoid Track’ status was recorded. Radiographically-confirmed redislocation was rare (1.2%), but 18.5% (n=23/124) reported ongoing subjective shoulder instability. Fifty-two shoulders (32.3%) were classified as “Off-Track”. The median Quick DASH and WOSI scores were 2.27 (IQR 9.09; range 0–70.45) and 272.0 (IQR 546.5; range 0–2003), respectively. There were no significant differences observed between overall Quick DASH scores or WOSI scores for either On-Track or Off-Track groups (p=0.7 and 0.73, respectively). Subjective instability was not influenced by the degree of glenoid bone loss (p=0.82), the overall size of the Hill-Sachs lesion (p=0.80), or the presence of an ‘Off-Track’ lesion (p=0.84). Functional outcome and recurrent instability following the Latarjet procedure do not appear to be influenced by the extent of glenohumeral bone loss prior to surgery

The natural history of primary anterior glenohumeral dislocation in adolescent patients remains unclear and no consensus exists for management of these patients. The study objectives were to report the natural history following primary anterior glenohumeral joint dislocation in adolescent patients and to identify risk factors for repeat dislocation. We reviewed prospectively-collected clinical and radiological data of 133 adolescent patients (mean age 16.3 years (range 13–18); 115 male patients (86.5%)) diagnosed with primary anterior glenohumeral joint dislocation and managed nonoperatively from 1996 to 2008 at our institution (mean follow-up 95.2 months (range 1–215)). During follow-up, 102 (absolute incidence of 76.7%) patients experienced repeat dislocation. Median time interval between primary and repeat dislocation was 10 months (CI: 7.4 – 12.6). On survival analysis, 59% (CI: 51.2 – 66.8%) of patients remained stable one year following initial injury, 38% (CI: 30.2 – 45.8%) after two years, 21% (CI: 13.2- 28.8%) after five years, and 7% (CI: 1.1–12.9%) after 10 years. Neither age nor gender significantly predicted repeat dislocation during follow-up. In conclusion, adolescent patients with primary anterior glenohumeral joint dislocations have a high rate of repeat dislocation, which usually occurs within two years of initial injury, and these patients should be considered early for operative stabilisation

Introduction and Objective. Only few studies have investigated the outcome of exercises in patients with glenohumeral osteoarthritis (OA) or rotator cuff tear arthropathy (CTA), and furthermore often excluded patients with a severe degree of OA. Several studies including a Cochrane review have suggested the need for trials comparing shoulder arthroplasty to non-surgical treatments. Before initiation of such a trial, the feasibility of progressive shoulder exercises (PSE) in patients, who are eligible for shoulder arthroplasty should be investigated. The aim was to investigate whether 12 weeks of PSE is feasible in patients with OA or CTA eligible for shoulder arthroplasty. Moreover, to report changes in shoulder function and range of motion (ROM) following the exercise program. Materials and Methods. Eighteen patients (11 women, 14 OA), mean age 70 years (range 57–80), performed 12 weeks of PSE with 1 weekly physiotherapist-supervised and 2 weekly home-based sessions. Feasibility was measured by drop-out rate, adverse events, pain and adherence to PSE. Patients completed Western Ontario Osteoarthritis of the Shoulder (WOOS) score and Disabilities of the Arm, Shoulder and Hand (DASH). Results. Two patients dropped out and no adverse events were observed. Sixteen patients (89%) had high adherence to the physiotherapist-supervised sessions. Acceptable pain levels were reported. WOOS improved mean 23 points (95%CI:13;33), and DASH improved mean 13 points (95%CI:6;19). Conclusions. PSE is feasible, safe and may improve shoulder pain, function and ROM in patients with OA or CTA eligible for shoulder arthroplasty. PSE is a feasible treatment that may be compared with arthroplasty in a RCT setting

Cementless surface replacement arthroplasty (CSRA) is an established treatment for glenohumeral osteoarthritis. Few studies however, evaluate its role in cuff tear arthopathy. The purpose of this study is to compare the outcomes of CSRA for both glenohumeral osteoarthritis and cuff tear arthopathy. 42 CSRA with the Mark IV Copeland prosthesis were performed for glenohumeral osteoarthritis (n=21) or cuff tear arthopathy (n=21). Patients were assessed with Oxford and Constant scores, patient satisfaction, range of motion and radiologically with plain radiographs. Mean follow-up and age was 5.2 years and 74 years in both groups. Functional outcomes were significantly higher in OA compared with CTA with OSS improving from 18 to 37.5 and 15 to 26 in both groups respectively. Forward flexion improved from 60° to 126° and 42° to 74° in both groups. Three patients in the CTA group had a deficient subscapularis tendon, two of whom dislocated anteriorly. Humeral head resurfacing arthroplasty is a viable treatment option for glenohumeral osteoarthritis. In patients with CTA, functional gains are limited. We suggest CSRA should be considered in low demand patients where pain is the primary problem. Caution should be taken in patients with a deficient subscapularis due to the high risk of dislocation

Purpose: Study experimental instability by ligament section leaving intact all the periarticular elements. Material and methods: Sixteen fresh cadaver shoulders were studied. Dissection was achieved via an axillary approach isolating the ligaments without muscle section. Instability was classified in five stages: 0) stable, 1) drawer and sulcus, 2) subluxation: the head crossed the glenoid border but remained in the plane of the glenoid, 3) reversible dislocation: the head was dislocated by returned spontaneously into place when the arm was left to hang along the body, 4) permanent dislocation. The ligaments were sectioned in the following order: 1) betrween 7h and 5h, 2) between 5h and 2h, 3) between 1h and 11h. Instability was tested with usual manœuvres: drawer, sulcus, hyperabduction test, provoked dislocation in elevation and maximal external rotation, downward pressure in the axis of the humerus. Results: Dissection of the ligaments produced class 1 instability in 0% of the shoulders, Section between 7h and 5h (anterior part of the inferior glenohumeral ligament) yielded class 2 instability in 12 cases, and class 3 instability in six. The hyperabduction test was positive in all shoulders. Section between 5h and 3h (middle glenohumeral ligament) produced class 3 instability in all the shoulders but never permanent dislocation. To obtain class 4 instabilty, section between 1h and 11h (superior glenohumeral ligament) was required. Section of the cuff was not necessary to obtain permanent dislocation. Discussion: The role of the superior glenohumeral ligament in the production of shoulder instability has not been detailed to date. Closure of the rotator interval, proposed by Nobuhar and by Field, corresponds to retightening this ligament. The function of the superior glenohumeral ligament should be taken into account during the treatment of shoulder instability

Introduction The complex movement of scapula is significant for the support of the arm and the stability of the shoulder joint. Recent investigations showed an adaptation in scapula rhythm after total shoulder replacement with a big variability within subjects. The latter can change the loading pattern in the glenohumeral contact forces and affect the performance of shoulder prosthesis. Methods In this study, Newcastle shoulder model was used to simulate a total shoulder arthroplasty and investigate joint stability. The model describes the DELTA . ®. prosthesis; a reverse anatomy design with a socket component attached to the humeral head and a hemi-ball to the glenoid. Scapula kinematics data of 6 shoulders were recorded using a palpating technique. The subjects had a total shoulder replacement after severe rotator cuff damage. Standard and daily activities were then analysed. Results and Discussion Scapula kinematics data show an increased scapular lateral rotation, which influences the joint contact forces. Comparing contact forces on the Glenohumeral joint, results indicate that the scapula rhythm adaptation reduces the compressive forces and shifts the shear component more superiorly to the glenoid. The scapula rhythm data used in this study show a large variability, which also affect the loading results. This effect is more significant in “reaching tasks”, where high humeral elevation is required and joint contact loads are maximum. The anterior shear forces in these tasks can be as great as 19% of body weight. Conclusions The adaptation in scapulohumeral rhythm after a shoulder joint replacement has already been reported. The reason for this adaptation cannot be explained yet and may be pain related or due to muscle adaptation that takes place after the arthroplasty. This change in kinematics influences the loading pattern of the glenohumeral joint. In particular the increased shear forces must be taken into considered in prosthetic design

Purpose: Arthroscopic treatment of calcified tendinopathy is classically performed in two times: exploration of the glenohumeral joint followed by subacromial arthroscopy to evacuate the calcification. In our experience, glenohumeral arthroscopy has only exceptionally provided a diagnostic element. In addition, the principal complication of this procedure is retractile capsulitis which may be a secondary effect of glenohumeral aggression. We conducted a retrospective analysis to assess the effect of systematic exploration of the glenohumeral joint. Material and methods: Two homogeneous groups of patients were identified. Group 1 included 32 patients who had had glenohumeral arthroscopy then resection of the calcifications using a bursoscope. Group 2 included 32 patients whose treatment was limited to subacromial arthroscopy for resection. The preoperative Constant score (52 in group 1 and 54 in group 2), disease duration (34 and 40 months respectively), and localisation of the calcification were comparable for the two groups. Acromioplasty was not performed in these patients. All were reviewed at minimal follow-up of 6 months for assessment of the Constant score and a radiography study. Results: At last follow-up the mean Constant score was 70 in group 1; calcifications had disappeared in 84% of the cases and delay to recovery (total pain relief and return to work) was 11 months. There were 4 cases of postoperative capsulitis (12.5%). The mean Constant score was 79 in group 2; calcifications had disappeared in 78% of the cases and delay to recovery was 6.5 weeks (p = 0.0001). There was one case of retractile capsulitis (3%). In group 1, glenohu-meral arthroscopy did not lead to the discovery of specific elements except in two cases where it identified partial tear of the deep aspect of the supraspinatus. Acromioplasty was never performed. Discussion-Conclusion: Systematic glenohumeral arthros-copy is not warranted in patients undergoing treatment for calcified tendinopathy. The fact that glenohumeral exploration did not disclose any particular element and had no effect on healing and capsulitis rates favours the use of a subacromial approach alone

Purpose:. The optimal degree of conformity between the glenoid and humeral components in cemented total shoulder arthroplasty (TSA) has not been established. Glenoid component stability is thought to be at risk due to the “rocking-horse” phenomenom, which, can lead to increased micromotion and loosening in response to humeral head edge loading. The goal of this biomechanical study is to investigate the influence of glenohumeral mismatch on bone-implant interface micromotion in a cemented glenoid implant model. Methods:. Twenty-Five cemented glenoid components (Affiniti, Tornier, Inc., Bloomington, MN, USA) were implanted in polyurethane foam biomechanics testing blocks. Five glenoid sizes, 40 mm, 44 mm, 48 mm, 52 mm and 55 mm (n = 5 per glenoid size), were cyclically tested according to ASTM Standard F-2028-08. A 44 mm humeral head (Affiniti, Tornier, Inc., Bloomington, MN, USA) was positioned centrally within the glenoid fixed to a materials testing frame (MTS Mini-Bionix II, Eden Prairie, MN, USA). Phase I testing (n = 3 per glenoid size) involved a subluxation test for determination of the humeral head translation distance which would be used for phase II cyclic testing. During cyclic loading, the humeral head was translated ± distance for 50,000 cycles at a frequency of 2 Hz, simulating approximately 5 years of device use. Glenoid compression, distraction, and superior-inferior glenoid translation were measured throughout testing via two differential variable reluctance transducers. Results:. Humeral head translation distance was identified as 0.55 mm, 1.09 mm, 2.32 mm, 3.82 mm, and 4.73 mm for each glenoid size, respectively (Figure 1). No significant difference was noted in 40 mm glenoids between cycle 1 and 50,000 for all parameters evaluated during testing (p > 0.05) (Figure 2). Conversely, a significant decrease in superior-inferior translation was present for 44 mm between cycle 1 and 50,000 (p = 0.010) (Figure 3). When analyzing all data from the first two smallest glenoid sizes, glenoid compression and translation both showed significantly increased micromotion with 40 mm glenoid sizes compared with the 44 mm glenoid size (p = 0.010 and p = 0.002, respectively). No significant difference was found with respect to glenoid distraction (p = 0.136). Conclusion:. The first phase of mechanical testing established the subluxation displacement of the humeral head against the glenoid for each prosthetic mismatch couple, which was larger for couples with greater glenohumeral mismatch. During cyclic testing, this displacement distance was covered in the same amount of time leading to differences in humeral head velocity and resultant stresses seen at the implant-cement-foam interfaces. A smaller mismatch in glenohumeral radius may lead to greater stress with shorter humeral translation compared to greater mismatch allowing for larger translations with lower resultant stresses. Data from our study will provide further clarification on the importance of glenohumeral mismatch on implant stability. Further studies are warranted to fully evaluate the impact and optimal amount radial mismatch for a clinical setting

Introduction and purpose: Neuropathy associated with syringomyelia is a relatively rare entity that predominantly affects the glenohumeral joint. It is characterized by joint destruction, which is in many cases severe and which requires a differential diagnosis from other severe conditions. The therapeutic options are based on maintaining function rather than on immobilization. We present our experience of treating this condition in 4 cases. Materials and methods: The cases were 4 females with a mean age of 53.25 years. One of the cases had both the glenohumeral and carpal joints affected. Only in one case was there a known history of syrinogomyelia associated with Arnold Chari disease, whereas in the other 3 the diagnosis of syringomyelia was established by studying the neuroarthropathy. Results: Two of the patients were treated by means of joint replacement (one total and the other partial) with a favorable postoperative evolution in the medium term. Acceptable pain control and joint balance were achieved. At the end of 5 and 2 years respectively, the total and partial prosthesis had to be revised due to aseptic loosening of the components and joint instability, respectively. The conservative treatment applied to the two remaining cases achieved a functional range of movement for activities of daily living and one of the cases was able to continue with their usual work activities. Conclusions: In spite of numerous sources in the literature that advise against joint replacement, there are very few documented cases and series that substantiate that recommendation. In the long run, in our experience joint replacement is not a satisfactory treatment for glenohumeral neuroarthropathy

Purpose. There is minimal information on outcome of glenohumeral debridement for treatment of shoulder osteoarthritis (OA). The purpose of this study was to examine the outcome of this procedure with or without acromioplasty /resection of clavicle in subjective perception of disability and functional range of motion and strength at one year following surgery. Method. Prospectively collected data of patients with advanced OA of the glenohumeral joint who were not good candidates for shoulder arthroplasty due to young age, high activity level, or desire to avoid major surgery at the time of assessment were included. Arthroscopic debridement included removal of loose bodies, chondral flaps, and degenerative tissue. Resection of the lateral end of the clavicle or acromioplasty was performed as clinically indicated for management of osteoarthritis of the Acromioclavicular (AC) joint or subacromial impingement respectively. Disability at 12 months following surgery was measured by the American Shoulder and Elbow Surgeons (ASES) assessment form, Constant-Murley score (CMS), strength, and painfree range of motion in four directions. Results. Sixty-seven patients (mean age= 57, SD: 15 (range: 25–87), range: 35–86, 35 females, 32 males) were included in analysis. The average symptom duration was 5 years. Fifteen (22%) patients had left shoulder involvement with 37 (55%) having right shoulder problem and 15(22%) reporting bilateral complaints. The right shoulder was operated on in 41 (61%) patients. Fifty two (78%) patients had an associated subacromial decompression [49 (73%) had acromioplasty and 27 (40%) had resection of the lateral end of the clavicle with some procedures overlapping]. Paired student t-tests showed a statistically significant improvement in scores of ASES and CMS (p<0.001) and painfree range of motion (p=0.02) at 1 year follow-up. However, no change was observed in strength (p>0.05). Conclusion. Arthroscopic debridement with or without acromioplasty /resection of the lateral end of the clavicle improves disability and painfree range of motion in patients suffering from osteoarthritis of glenohumeral joint at one year following surgery