The June 2024 Shoulder & Elbow Roundup. 360. looks at: Reverse versus anatomical total shoulder replacement for osteoarthritis? A UK national picture; Acute rehabilitation following traumatic anterior shoulder dislocation (ARTISAN): pragmatic, multicentre, randomized controlled trial; acid for rotator cuff repair: a systematic review and meta-analysis of randomized controlled trials; Metal or ceramic humeral head total shoulder arthroplasty: an analysis of data from the National Joint Registry; Platelet-rich plasma has better results for long-term functional improvement and pain relief for lateral epicondylitis: a systematic review and meta-analysis of randomized controlled trials; Quantitative fatty infiltration and 3D muscle volume after nonoperative treatment of symptomatic rotator cuff tears: a prospective MRI study of 79 patients; Locking plates for non-osteoporotic proximal humeral fractures in the long term; A systematic review of the treatment of primary acromioclavicular joint osteoarthritis

Aims. The prevalence of osteoarthritis (OA) associated with instability of the shoulder ranges between 4% and 60%. Articular cartilage is, however, routinely assessed in these patients using radiographs or scans (2D or 3D), with little opportunity to record early signs of cartilage damage. The aim of this study was to assess the prevalence and localization of chondral lesions and synovial damage in patients undergoing arthroscopic surgery for instablility of the shoulder, in order to classify them and to identify risk factors for the development of glenohumeral OA. Methods. A total of 140 shoulders in 140 patients with a mean age of 28.5 years (15 to 55), who underwent arthroscopic treatment for recurrent glenohumeral instability, were included. The prevalence and distribution of chondral lesions and synovial damage were analyzed and graded into stages according to the division of the humeral head and glenoid into quadrants. The following factors that might affect the prevalence and severity of chondral damage were recorded: sex, dominance, age, age at the time of the first dislocation, number of dislocations, time between the first dislocation and surgery, preoperative sporting activity, Beighton score, type of instability, and joint laxity. Results. A total of 133 patients (95%) had synovial or chondral lesions. At the time of surgery, shoulders were graded as having mild, moderate, and severe OA in 55 (39.2%), 72 (51.4%), and six (4.2%) patients, respectively. A Hill-Sachs lesion and fibrillation affecting the anteroinferior glenoid cartilage were the most common findings. There was a significant positive correlation between the the severity of the development of glenohumeral OA and the patient’s age, their age at the time of the first dislocation, and the number of dislocations (p = 0.004, p = 0.011, and p = 0.031, respectively). Conclusion. Synovial inflammation and chondral damage associated with instability of the shoulder are more prevalent than previously reported. The classification using quadrants gives surgeons more information about the chondral damage, and could explain the pattern of development of glenohumeral OA after stabilization of the shoulder. As the number of dislocations showed a positive correlation with the development of OA, this might be an argument for early stabilization. Cite this article: Bone Joint J 2024;106-B(10):1125–1132

Aims. Reverse total shoulder arthroplasty (rTSA) can be used in complex cases when the glenoid requires reconstruction. In this study, a baseplate with composite bone autograft and a central trabecular titanium peg was implanted, and its migration was assessed for two years postoperatively using radiostereometric analysis (RSA). Methods. A total of 14 patients who underwent a rTSA with an autograft consented to participate. Of these, 11 had a primary rTSA using humeral head autograft and three had a revision rTSA with autograft harvested from the iliac crest. The mean age of the patients was 66 years (39 to 81). Tantalum beads were implanted in the scapula around the glenoid. RSA imaging (stereographic radiographs) was undertaken immediately postoperatively and at three, six, 12, and 24 months. Analysis was completed using model-based RSA software. Outcomes were collected preoperatively and at two years postoperatively, including the Oxford Shoulder Score, the American Shoulder and Elbow Score, and a visual analogue score for pain. A Constant score was also obtained for the assessment of strength and range of motion. Results. RSA analysis showed a small increase in all translation and rotational values up to six months postoperatively, consistent with settling of the implant. The mean values plateaued by 12 months, with no evidence of further migration. In four patients, there was significant variation outside the mean, which corresponded to postoperative complications. There was a significant improvement in the clinical and patient-reported outcomes from the preoperative values to those at two years postoperatively (p < 0.001). Conclusion. These findings show, using RSA, that a glenoid baseplate composite of a trabecular titanium peg with autograft stabilizes within the glenoid about 12 months after surgery, and reinforce findings from a previous study of this implant/graft with CT scans at two years postoperatively, indicating that this type of structural composite results in sound early fixation. Cite this article: Bone Joint J 2023;105-B(8):912–919

Aims. Vascular compromise due to arterial injury is a rare but serious complication of a proximal humeral fracture. The aims of this study were to report its incidence in a large urban population, and to identify clinical and radiological factors which are associated with this complication. We also evaluated the results of the use of our protocol for the management of these injuries. Methods. A total of 3,497 adult patients with a proximal humeral fracture were managed between January 2015 and December 2022 in a single tertiary trauma centre. Their mean age was 66.7 years (18 to 103) and 2,510 (72%) were female. We compared the demographic data, clinical features, and configuration of those whose fracture was complicated by vascular compromise with those of the remaining patients. The incidence of vascular compromise was calculated from national population data, and predictive factors for its occurrence were investigated using univariate analysis. Results. A total of 18 patients (0.5%) had a proximal humeral fracture and clinical evidence of vascular compromise, giving an annual incidence of 0.29 per 100,000 of the population. Their mean age was 68.7 years (45 to 92) and ten (56%) were female. Evidence of a mixed pattern neurological deficit (brachial plexus palsy) (odds ratio (OR) 380.6 (95% CI 85.9 to 1,685.8); p < 0.001), complete separation of the proximal shaft from the humeral head with medial displacement (OR 39.5 (95% CI 14.0 to 111.8); p < 0.001), and a fracture-dislocation (OR 5.0 (95% CI 1.6 to 15.3); p = 0.015) were all associated with an increased risk of associated vascular compromise. A policy of reduction and fixation of the fracture prior to vascular surgical intervention had favourable outcomes without vascular sequelae. Conclusion. The classic signs of distal ischaemia are often absent in patients with proximal injuries to major vessels. We were able to identify specific clinical and radiological ‘red flags’ which, particularly when present in combination, should increase the suspicion of a fracture with an associated vascular injury, and facilitate early diagnosis and appropriate combined orthopaedic and vascular intervention. Cite this article: Bone Joint J 2024;106-B(8):842–848

Aims. To systematically review the predominant complication rates and changes to patient-reported outcome measures (PROMs) following osteochondral allograft (OCA) transplantation for shoulder instability. Methods. This systematic review, following PRISMA guidelines and registered in PROSPERO, involved a comprehensive literature search using PubMed, Embase, Web of Science, and Scopus. Key search terms included “allograft”, “shoulder”, “humerus”, and “glenoid”. The review encompassed 37 studies with 456 patients, focusing on primary outcomes like failure rates and secondary outcomes such as PROMs and functional test results. Results. A meta-analysis of primary outcomes across 17 studies revealed a dislocation rate of 5.1% and an increase in reoperation rates from 9.3% to 13.7% post-publication bias adjustment. There was also a noted rise in conversion to total shoulder arthroplasty and incidence of osteoarthritis/osteonecrosis over longer follow-up periods. Patient-reported outcomes and functional tests generally showed improvement, albeit with notable variability across studies. A concerning observation was the consistent presence of allograft resorption, with rates ranging from 33% to 80%. Comparative studies highlighted similar efficacy between distal tibial allografts and Latarjet procedures in most respects, with some differences in specific tests. Conclusion. OCA transplantation presents a promising treatment option for shoulder instability, effectively addressing both glenoid and humeral head defects with favourable patient-reported outcomes. These findings advocate for the inclusion of OCA transplantation in treatment protocols for shoulder instability, while also emphasizing the need for further high-quality, long-term research to better understand the procedure’s efficacy profile. Cite this article: Bone Jt Open 2024;5(7):570–580

Aims. Conservative treatment of moderately displaced proximal humeral head fractures yields good clinical results, but secondary fragment displacement may occur. Identification of those fractures at risk of displacement may influence initial decision-making. Methods. A total of 163 shoulders in 162 patients with conservatively treated isolated proximal humeral fractures were included. The fractures occurred between January 2015 and May 2018. The mean age of the patients was 69 years (26 to 100) and the mean follow-up was 144 days (42 to 779). The fractures were classified according to Neer. Scores for osteoporosis (Tingart, Deltoid Tuberosity Index (DTI)) and osteoarthritis (OA) of the glenohumeral joint were assessed. Translation of the head on follow-up radiographs of more than 10 mm was defined as displacement. Eccentric head index (EHI) describes the offset of the humeral head centre in relation to the diaphyseal axis. The ratio was estimated on anteroposterior (AP) and Neer views. Medial hinge was considered intact if the medial cortex proximal and distal to the fracture was in line on AP view. Results. Secondary fracture displacement occurred in 41 patients (25.2%). Clinical risk factors were alcohol abuse (odds ratio (OR) 6.8; 95% confidence interval (CI) 1.3 to 36; p = 0.025) and previously diagnosed osteoporosis (OR 4.6; 95% CI 0.6 to 34; p = 0.136). Age (OR 1.1; 95% CI 1.0 to 1.1; p = 0.003) and sex (OR 0.9; 95% CI 0.3 to 2.8; p = 0.867) were not independent factors. Radiological risk factors were OA grade 3 (OR 16.4; 95% CI 0.25 to 37.6; p = 0.107) and osteoporosis with the DTI (OR 10; 95% CI 0.8 to 250; p = 0.031) being more predictive than the Tingart score (OR 2.3; 95% CI 0.8 to 4.7; p = 0.041). A high EHI (AP/Neer > 0.4, OR 18.9; 95% CI 2.1 to 30.9/3.0; 95% CI 1.1 to 8.0; p = 0.002/p = 0.033) and a disrupted medial hinge (OR 3.7; 95% CI 1.1 to 12.6; p = 0.039) increased the risk of secondary displacement significantly. Neer classification had no influence. Conclusion. During conservative treatment, a quarter of patients showed secondary fracture displacement of at least 10 mm. Patients with alcohol abuse, severe OA, and osteoporosis are at risk. Newly defined EHI and disrupted medial hinge are relevant predictors for secondary displacement. Cite this article: Bone Joint J 2020;102-B(7):881–889

Aims. The aim of this study was to evaluate the clinical and radiological outcomes of locking plate fixation, with and without an associated fibular strut allograft, for the treatment of displaced proximal humeral fractures in elderly osteoporotic patients. Patients and Methods. We undertook a retrospective comparison of two methods of fixation, using a locking plate without an associated fibular strut allograft (LP group) and with a fibular allograft (FA group) for the treatment of these fractures. The outcome was assessed for 52 patients in the LP group and 45 in the FA group, with a mean age of 74.3 years (52 to 89), at a mean follow-up of 14.2 months (12 to 19). The clinical results were evaluated using a visual analogue scale (VAS) score for pain, the Constant score, the American Shoulder and Elbow Surgeons (ASES) score, and the range of movement. Radiological results were evaluated using the neck-shaft angle (NSA) and humeral head height (HHH). Results. The mean forward elevation in the LP and FA groups was 125.3° (. sd. 21.4) and 148.9° (. sd. 19.8), respectively (p = 0.042), while other clinical factors showed no statistically significant differences between the groups. The changes in NSA and HHH immediately after the operation and at final follow-up were significantly better in the FA group than in the LP group (p = 0.015 and p = 0.021, respectively). Conclusion. For comminuted proximal humeral fractures in osteoporotic patients, locking plate fixation with a fibular strut allograft shows satisfactory short-term results with respect to humeral head support and maintenance of reduction, and may reduce the incidence of complications associated with fixation using a locking plate alone. Cite this article: Bone Joint J 2019;101-B:260–265

Aims. In patients with a rotator cuff tear, tear pattern and tendon involvement are known risk factors for the development of pseudoparalysis of the shoulder. It remains unclear, however, why similar tears often have very different functional consequences. The present study hypothesizes that individual shoulder anatomy, specifically the moment arms (MAs) of the rotator cuff (RC) and the deltoid muscle, as well as their relative recruitment during shoulder abduction, plays a central role in pseudoparalysis. Materials and Methods. Biomechanical and clinical analyses of the pseudoparalytic shoulder were conducted based on the ratio of the RC/deltoid MAs, which were used to define a novel anatomical descriptor called the Shoulder Abduction Moment (SAM) index. The SAM index is the ratio of the radii of two concentric spheres based on the centre of rotation of the joint. One sphere captures the humeral head (numerator) and the other the deltoid origin of the acromion (denominator). A computational rigid body simulation was used to establish the functional link between the SAM index and a potential predisposition for pseudoparalysis. A retrospective radiological validation study based on these measures was also undertaken using two cohorts with and without pseudoparalysis and massive RC tears. Results. Decreased RC activity and improved glenohumeral stability was predicted by simulations of SAM indices with larger diameters of the humeral head, being consequently beneficial for joint stability. Clinical investigation of the SAM index showed significant risk of pseudoparalysis in patients with massive tears and a SAM < 0.77 (odds ratio (OR) 11). Conclusion. The SAM index, which represents individual biomechanical characteristics of shoulder morphology, plays a determinant role in the presence or absence of pseudoparalysis in shoulders with massive RC tears

Aims. The aim of this study was to explore why some calcar screws are malpositioned when a proximal humeral fracture is treated by internal fixation with a locking plate, and to identify risk factors for this phenomenon. Some suggestions can be made of ways to avoid this error. Methods. We retrospectively identified all proximal humeral fractures treated in our institution between October 2016 and October 2018 using the hospital information system. The patients’ medical and radiological data were collected, and we divided potential risk factors into two groups: preoperative factors and intraoperative factors. Preoperative factors included age, sex, height, weight, body mass index, proximal humeral bone mineral density, type of fracture, the condition of the medial hinge, and medial metaphyseal head extension. Intraoperative factors included the grade of surgeon, neck-shaft angle after reduction, humeral head height, restoration of medial support, and quality of reduction. Adjusted binary logistic regression and multivariate logistic regression models were used to identify pre- and intraoperative risk factors. Area under the curve (AUC) analysis was used to evaluate the discriminative ability of the multivariable model. Results. Data from 203 patients (63 males and 140 females) with a mean age of 62 years (22 to 89) were analyzed. In 49 fractures, the calcar screw was considered to be malpositioned; in 154 it was in the optimal position. The rate of malpositioning was therefore 24% (49/203). No preoperative risk factor was found for malpositioning of the calcar screws. Only the neck-shaft angle was found to be related to the risk of screw malpositioning in a multivariate model (with an AUC of 0.72). For the fractures in which the neck-shaft angle was reduced to between 130° and 150°, 91% (133/46) of calcar screws were in the optimal position. Conclusion. The neck-shaft angle is the key factor for the appropriate positioning of calcar screws when treating a proximal humeral fracture with a locking plate. We recommend reducing the angle to between 130° and 150°. Cite this article: Bone Joint J 2020;102-B(12):1629–1635

Aims. Fixation of osteoporotic proximal humerus fractures remains challenging even with state-of-the-art locking plates. Despite the demonstrated biomechanical benefit of screw tip augmentation with bone cement, the clinical findings have remained unclear, potentially as the optimal augmentation combinations are unknown. The aim of this study was to systematically evaluate the biomechanical benefits of the augmentation options in a humeral locking plate using finite element analysis (FEA). Methods. A total of 64 cement augmentation configurations were analyzed using six screws of a locking plate to virtually fix unstable three-part fractures in 24 low-density proximal humerus models under three physiological loading cases (4,608 simulations). The biomechanical benefit of augmentation was evaluated through an established FEA methodology using the average peri-screw bone strain as a validated predictor of cyclic cut-out failure. Results. The biomechanical benefit was already significant with a single cemented screw and increased with the number of augmented screws, but the configuration was highly influential. The best two-screw (mean 23%, SD 3% reduction) and the worst four-screw (mean 22%, SD 5%) combinations performed similarly. The largest benefits were achieved with augmenting screws purchasing into the calcar and having posteriorly located tips. Local bone mineral density was not directly related to the improvement. Conclusion. The number and configuration of cemented screws strongly determined how augmentation can alleviate the predicted risk of cut-out failure. Screws purchasing in the calcar and posterior humeral head regions may be prioritized. Although requiring clinical corroborations, these findings may explain the controversial results of previous clinical studies not controlling the choices of screw augmentation

Antegrade nailing of proximal humeral fractures using a straight nail can damage the bony insertion of the supraspinatus tendon and may lead to varus failure of the construct. In order to establish the ideal anatomical landmarks for insertion of the nail and their clinical relevance we analysed CT scans of bilateral proximal humeri in 200 patients (mean age 45.1 years (. sd. 19.6; 18 to 97) without humeral fractures. The entry point of the nail was defined by the point of intersection of the anteroposterior and lateral vertical axes with the cortex of the humeral head. The critical point was defined as the intersection of the sagittal axis with the medial limit of the insertion of the supraspinatus tendon on the greater tuberosity. The region of interest, i.e. the biggest entry hole that would not encroach on the insertion of the supraspinatus tendon, was calculated setting a 3 mm minimal distance from the critical point. This identified that 38.5% of the humeral heads were categorised as ‘critical types’, due to morphology in which the predicted offset of the entry point would encroach on the insertion of the supraspinatus tendon that may damage the tendon and reduce the stability of fixation. We therefore emphasise the need for ‘fastidious’ pre-operative planning to minimise this risk. Cite this article: Bone Joint J 2014;96-B:249–53

Objectives. This investigation sought to advance the work published in our prior biomechanical study (Journal of Orthopaedic Research, 2016). We specifically sought to determine whether there are additional easy-to-measure parameters on plain radiographs of the proximal humerus that correlate more strongly with ultimate fracture load, and whether a parameter resembling the Dorr strength/quality characterisation of proximal femurs can be applied to humeri. Materials and Methods. A total of 33 adult humeri were used from a previous study where we quantified bone mineral density of the proximal humerus using radiographs and dual-energy x-ray absorptiometry (DEXA), and regional mean cortical thickness and cortical index using radiographs. The bones were fractured in a simulated backwards fall with the humeral head loaded at 2 mm/second via a frustum angled at 30° from the long axis of the bone. Correlations were assessed with ultimate fracture load and these new parameters: cortical index expressed in areas (“areal cortical index”) of larger regions of the diaphysis; the canal-to-calcar ratio used analogous to its application in proximal femurs; and the recently described medial cortical ratio. Results. The three new parameters showed the following correlations with ultimate fracture load: areal cortical index (r = 0.56, p < 0.001); canal-to-calcar ratio (r = 0.38, p = 0.03); and medial cortical ratio (r = 0.49, p < 0.005). These correlations were weaker when compared with those that we previously reported: mean cortical thickness of the proximal diaphysis versus ultimate fracture load (r = 0.71; p < 0.001); and mean density in the central humeral head versus ultimate fracture load (r = 0.70; p < 0.001). Conclusion. Simple-to-measure radiographic parameters of the proximal humerus reported previously are more useful in predicting ultimate fracture load than are areal cortical index, canal-to-calcar ratio, and medial cortical ratio. Cite this article: J. G. Skedros, C. S. Mears, W. Z. Burkhead. Ultimate fracture load of cadaver proximal humeri correlates more strongly with mean combined cortical thickness than with areal cortical index, DEXA density, or canal-to-calcar ratio. Bone Joint Res 2017;6:1–7. DOI: 10.1302/2046-3758.61.BJR-2016-0145.R1

Over a seven-year period we treated a consecutive series of 58 patients, 20 men and 38 women with a mean age of 66 years (21 to 87) who had an acute complex anterior fracture-dislocation of the proximal humerus. Two patterns of injury are proposed for study based upon a prospective assessment of the pattern of soft-tissue and bony injury and the degree of devascularisation of the humeral head. In 23 patients, the head had retained capsular attachments and arterial back-bleeding (type-I injury), whereas in 35 patients the head was devoid of significant soft-tissue attachments with no active arterial bleeding (type-II injury). Following treatment by open reduction and internal fixation, only two of 23 patients with type-I injuries developed radiological evidence of osteonecrosis of the humeral head, compared with four of seven patients with type-II injuries. A policy of primary treatment by open reduction and internal fixation of type-I injuries is justified, whereas most elderly patients (aged 60 years or over) with type-II injuries are best treated by hemiarthroplasty. The best treatment for younger patients (aged under 60 years) who sustain type-II injuries is controversial and an individualised approach to their management is advocated

Fractures of the proximal humerus can lead to malalignment of the humeral head, necrosis and post-traumatic osteoarthritis. In such cases surface replacement might be a promising option. A total of 28 shoulders with glenohumeral arthritis subsequent to a fracture underwent surface replacement arthroplasty of the humeral head in patients with a mean age of 60 years (35 to 83). On the basis of the inclination of the impacted head, post-traumatic arthritis was divided into three types: type 1, an impacted fracture of the head in an anatomical position (seven cases); type 2, a valgus impacted fracture (13 cases); type 3, a varus impacted fracture (eight cases). The outcome was measured by means of the Constant score. According to the Boileau classification of the sequelae of fractures of the proximal humerus, all 28 patients had a final result of intra-capsular category 1. The mean Constant score for the 28 shoulders increased from 23.2 points (2 to 45) pre-operatively to 55.1 points (20 to 89) at a mean of 31 months (24 to 66) post-operatively. Valgus impacted fractures had significantly better results (p < 0.039). Surface replacement arthroplasty can provide good results for patients with post-traumatic osteoarthritis of the shoulder. Their use avoids post-operative complications of the humeral shaft, such as peri-prosthetic fractures. Further surgery can be undertaken more easily as the bone stock is preserved

A review of the pathology, mechanism, and operative treatment of recurrent dislocation of the shoulder, based on an analysis of 180 cases, with 159 operations, is presented. From this analysis the following conclusions have been made and appear to be substantiated:. 1. The pathology comprises two important elements: (a) anterior detachment of the glenoid labrum from the bone margin of the glenoid, associated with some degree of stripping of the anterior part of the capsule from the front of the neck of the scapula, found in 87 per cent. of cases examined adequately at operation; (b) defect or flattening of the posterolateral aspect of the articular surface of the head of the humerus which engages with the glenoid cavity when the arm is in external rotation and abduction; this defect is demonstrated most readily in antero-posterior radiographs taken with the humerus in 60 to 70 degrees of internal rotation and was shown to be present in 82 per cent. of cases which had been subjected to adequate radiographic examination. 2. The frequency of the humeral head defect has been under-estimated in the past, because of the difficulty of demonstrating it, particularly when the defect is small. 3. Either type of lesion alone may predispose to recurrence of the dislocation. 4. Both types of lesion are often present in the same shoulder. When this is the case the tendency to redislocation is great. 5. The initial dislocation, which results in the development of one or both these persistent structural abnormalities, may be due to very different types of injury, the commonest of which is a fall on the outstretched hand. The factor common to all these injuries is a resultant force acting on the humeral head in the direction of the anterior glenoid margin. 6. In the treatment of recurrent dislocation of the shoulder joint the Nicola operation is unreliable, and it may be associated with a recurrence rate as high as 36 per cent. It is believed that continued instability after this operation is usually due to the presence of a defect of the humeral head. 7. Operative treatment should aim at repairing, or nullifying, the effects of both types of lesion. For anterior detachment of the labrum this involves either suturing the labrum back to the glenoid margin, or constructing some form of anterior buttress, fibrous or bony: for humeral head defects it necessitates some procedure designed to limit external rotation, thus preventing the defect from coming into engagement with the glenoid cavity. Such limitation of external rotation does not constitute a significant disability

Objectives. The bony shoulder stability ratio (BSSR) allows for quantification of the bony stabilisers in vivo. We aimed to biomechanically validate the BSSR, determine whether joint incongruence affects the stability ratio (SR) of a shoulder model, and determine the correct parameters (glenoid concavity versus humeral head radius) for calculation of the BSSR in vivo. Methods. Four polyethylene balls (radii: 19.1 mm to 38.1 mm) were used to mould four fitting sockets in four different depths (3.2 mm to 19.1mm). The SR was measured in biomechanical congruent and incongruent experimental series. The experimental SR of a congruent system was compared with the calculated SR based on the BSSR approach. Differences in SR between congruent and incongruent experimental conditions were quantified. Finally, the experimental SR was compared with either calculated SR based on the socket concavity or plastic ball radius. Results. The experimental SR is comparable with the calculated SR (mean difference 10%, . sd. 8%; relative values). The experimental incongruence study observed almost no differences (2%, . sd. 2%). The calculated SR on the basis of the socket concavity radius is superior in predicting the experimental SR (mean difference 10%, . sd. 9%) compared with the calculated SR based on the plastic ball radius (mean difference 42%, . sd. 55%). Conclusion. The present biomechanical investigation confirmed the validity of the BSSR. Incongruence has no significant effect on the SR of a shoulder model. In the event of an incongruent system, the calculation of the BSSR on the basis of the glenoid concavity radius is recommended. Cite this article: L. Ernstbrunner, J-D. Werthel, T. Hatta, A. R. Thoreson, H. Resch, K-N. An, P. Moroder. Biomechanical analysis of the effect of congruence, depth and radius on the stability ratio of a simplistic ‘ball-and-socket’ joint model. Bone Joint Res 2016;5:453–460. DOI: 10.1302/2046-3758.510.BJR-2016-0078.R1

Dislocation of the shoulder may occur during seizures in epileptics and other patients who have convulsions. Following the initial injury, recurrent instability is common owing to a tendency to develop large bony abnormalities of the humeral head and glenoid and a susceptibility to further seizures. Assessment is difficult and diagnosis may be missed, resulting in chronic locked dislocations with protracted morbidity. Many patients have medical comorbidities, and successful treatment requires a multidisciplinary approach addressing the underlying seizure disorder in addition to the shoulder pathology. The use of bony augmentation procedures may have improved the outcomes after surgical intervention, but currently there is no evidence-based consensus to guide treatment. This review outlines the epidemiology and pathoanatomy of seizure-related instability, summarising the currently-favoured options for treatment, and their results

Objectives. All-suture anchors are increasingly used in rotator cuff repair procedures. Potential benefits include decreased bone damage. However, there is limited published evidence for the relative strength of fixation for all-suture anchors compared with traditional anchors. Materials and Methods. A total of four commercially available all-suture anchors, the ‘Y-Knot’ (ConMed), Q-FIX (Smith & Nephew), ICONIX (Stryker) and JuggerKnot (Zimmer Biomet) and a traditional anchor control TWINFIX Ultra PK Suture Anchor (Smith & Nephew) were tested in cadaveric human humeral head rotator cuff repair models (n = 24). This construct underwent cyclic loading applied by a mechanical testing rig (Zwick/Roell). Ultimate load to failure, gap formation at 50, 100, 150 and 200 cycles, and failure mechanism were recorded. Significance was set at p < 0.05. Results. Overall, mean maximum tensile strength values were significantly higher for the traditional anchor (181.0 N, standard error (. se). 17.6) compared with the all-suture anchors (mean 133.1 N . se. 16.7) (p = 0.04). The JuggerKnot anchor had greatest displacement at 50, 100 and 150 cycles, and at failure, reaching statistical significance over the control at 100 and 150 cycles (22.6 mm . se. 2.5 versus 12.5 mm . se. 0.3; and 29.6 mm . se. 4.8 versus 17.0 mm . se. 0.7). Every all-suture anchor tested showed substantial (> 5 mm) displacement between 50 and 100 cycles (6.2 to 14.3). All-suture anchors predominantly failed due to anchor pull-out (95% versus 25% of traditional anchors), whereas a higher proportion of traditional anchors failed secondary to suture breakage. Conclusion. We demonstrate decreased failure load, increased total displacement, and variable failure mechanisms in all-suture anchors, compared with traditional anchors designed for rotator cuff repair. These findings will aid the surgeon’s choice of implant, in the context of the clinical scenario. Cite this article: N. S. Nagra, N. Zargar, R. D. J. Smith, A. J. Carr. Mechanical properties of all-suture anchors for rotator cuff repair. Bone Joint Res 2017;6:82–89. DOI: 10.1302/2046-3758.62.BJR-2016-0225.R1

We treated 47 patients with a mean age of 57 years (22 to 88) who had a proximal humeral fracture in which there was a severe varus deformity, using a standard operative protocol of anatomical reduction, fixation with a locking plate and supplementation by structural allografts in unstable fractures. The functional and radiological outcomes were reviewed. At two years after operation the median Constant score was 86 points and the median Disabilities of the Arm, Shoulder and Hand score 17 points. Seven of the patients underwent further surgery, two for failure of fixation, three for dysfunction of the rotator cuff, and two for shoulder stiffness. The two cases of failure of fixation were attributable to violation of the operative protocol. In the 46 patients who retained their humeral head, all the fractures healed within the first year, with no sign of collapse or narrowing of the joint space. Longer follow-up will be required to confirm whether these initially satisfactory results are maintained

Resurfacing of the humeral head is commonly used within the UK to treat osteoarthritis (OA) of the shoulder. We present the results of a small prospective randomised study of this procedure using the Global CAP prosthesis with two different coatings, Porocoat and DuoFix hydroxyapatite (HA). We followed two groups of ten patients with OA of the shoulder for two years after insertion of the prosthesis with tantalum marker beads, recording pain, Constant–Murley and American Shoulder and Elbow Surgeons (ASES) outcome scores, and using radiostereometric analysis to assess migration. The outcomes were similar to those of other series, with significant reductions in pain (p = 0.003) and an improvement in the Constant (p = 0.001) and ASES scores (p = 0.006). The mean migration of the prosthesis three months post-operatively was 0.78 mm (0.51 to 1.69) and 0.72 mm (0.33 to 1.45) for the Porocoat and DuoFix groups, respectively. Analysis of variance indicated that the rate of migration reached a plateau after three months post-operatively in both groups. At follow-up of two years the mean migration was 1 mm (. sd. 1 (0.25 to 3.32)); in the Porocoat group and 0.8 mm (. sd. 0.4 (0.27 to 1.45)) in the DuoFix HA group. Significant migration of the prosthesis was seen in one patient who had received an anterior humeral bone graft. This prosthesis was later revised after 2.7 years. The addition of a coating of HA to the sintered surface does not improve fixation of this prosthesis. Cite this article: Bone Joint J 2014;96-B:1077–81