Objectives. The goal of this study is to investigate the relation between indicators of osteoporosis (i.e., bone mineral density (BMD), and Cortical Index (CI)) and the complexity of a fracture of the
Aims. Resection of the
We investigated the functional outcome in patients
who underwent reverse shoulder replacement (RSR) after removal of
a tumour of the
In this study, we describe a morphological classification
for greater tuberosity fractures of the
Abstract. Reverse shoulder arthroplasty (RSA) is being increasingly used for complex, displaced fractures of the
We reviewed the results of sixteen patients with three and four part proximal humerus fractures treated with the Locking
Aims. The aim of this study was to analyze the results of reverse shoulder
arthroplasty (RSA) in patients with type 1 sequelae of a fracture
of the
Fractures and nonunions of the
Aims. Restoring the pre-morbid anatomy of the
Abstract. Background. Fractures
Bone loss secondary to primary or metastatic lesions of the
Fractures of the
The morphology of the proximal part of the humerus varies largely. Morphometric features characterizing the three-dimensional geometry of the
The
Introduction: The treatment of fractures of the
We have studied the three-dimensional geometry of the
Aim. The aim of this study was to analyze our results using a modular endoprosthetic replacement system (MUTARS) for bone tumours of the
Although new locking plates allows for secure fixation of osteoporotic fractures in the
Aims. A pragmatic multicentre randomised controlled trial (PROFHER)
was conducted in United Kingdom National Health Service (NHS) hospitals
to evaluate the clinical effectiveness and cost effectiveness of
surgery compared with non-surgical treatment for displaced fractures
of the
Introduction: Locking plates and screws have been developed to increase stability of internal fixation in osteoporotic bone. The anatomic design should also facilitate the fracture’s reduction in complex cases. The aim of this study was analyse the results of locking plates used for fractures of the
Fractures of the
Introduction: The treatment of fractures of the
Patients with pain and loss of shoulder function
due to nonunion of a fracture of the proximal third of the humerus may
benefit from reverse total shoulder replacement. This paper reports
a prospective, multicentre study, involving three hospitals and
three surgeons, of 35 patients (28 women, seven men) with a mean
age of 69 years (46 to 83) who underwent a reverse total shoulder
replacement for the treatment of nonunion of a fracture of the
We studied 100 patients who had undergone endoprosthetic replacement of the
Title. 3D distribution of cortical bone thickness in the
Objectives. The objective of this study was to perform a meta-analysis of all randomised controlled trials (RCTs) comparing surgical and non-surgical management of fractures of the
Fractures of the
In 45 patients we assessed the functional results and complications for three different reconstructive procedures after resection of primary tumors of the
Aims. The aims of this study were to estimate the cost of surgical
treatment of fractures of the
Introduction: Management of displaced comminuted fractures of the
Purpose: Primary bone tumours located in the upper limb are mainly found in the proximal portion of the humerus. Tumour resection raises difficult situations due to the sacrifice of the cuff tendons. We propose a decision making scheme for determining the best reconstruction strategy. Material and methods: This retrospective analysis was based on 35 cases (19 massive prostheses, ten composite prostheses, three inverted prostheses and three composite arthrodeses). All the clinical and radiographic data were reviewed to examine function, active motion, pain, and use of the upper limb in everyday activities. Results: Massive humeral prostheses provided a technically simple solution but produced mediocre functional results: painless shoulder without active motion, but preservation of elbow and forearm function. Composite humeral prostheses (prosthesis + allograft) did not, in our experience provide any gain in function compared with massive prostheses. Allografts were resorbed after four to five years. Composite arthrodesis with allograft and vascularised fibular graft provided a mobile shoulder with a useful amplitude and a pain free joint. Results persisted. The inverted Delta prostheses (Grammont) covered with allografts and with preservation of the rotator cuff tendons offered an interesting alternative with functional results superior to arthrodesis and similar to those with shoulder prostheses implanted for degenerative disease. The persistence of the glenoid anchorage remains uncertain. Conclusions: We use the following scheme for reconstruction of the
In 42 elderly patients, 33 women and nine men with a mean age of 72 years, we treated displaced fractures of the
The aim of the study was to assess the medium term outcome for complex proximal humeral fractures treated with the long proximal humeral internal locking system (PHILOS) plate fixation. All patients who had long PHILOS plate fixation of proximal humerus fractures with metaphyseal or diaphyseal extension over a three year period at our institution were included in the study. Patients had their case notes and radiographs reviewed. Patients were also contacted to assess functional outcome using the Visual Analogue Scale (VAS) for pain, DASH, Oxford shoulder score (OSS) and Stanmore Percentage of Normal Shoulder Assessment (SPONSA). Out of an initial cohort of 34 patients, 1 died, 2 patients had unrelated illnesses resulting in them being unable to complete the assessment and 6 were lost to follow-up, leaving 25 patients (74%) for review. All patients had proximal humeral fractures with metaphyseal or diaphyseal extension requiring long plate osteosynthesis. One patient had the procedure for non union following initial treatment with an intra medullary nail and the rest were acute injuries. The patients were followed up after a mean of 27 months (range 11–60). The length of plate used varied from 5 to 12 holes for the shaft region. There was 1 wound infection. 3 patients had non unions which required bone grafting and revision internal fixation. At final follow-up, mean pain was 3.6 (95% Confidence Interval 2.5–4.8) with only 4 patients having residual pain greater than 5 on the VAS scale. Mean DASH score was 41.2 (95% CI 32.0–50.4), mean OSS was 29.1 (95% CI 24.3–33.9) and mean SPONSA was 63.9% (95% CI 50.8–77.2) The long PHILOS plate appears to represent a good treatment option for complex proximal humerus fractures with favourable medium term results and few complications.
We treated 34 consecutive articular fractures of the
Introduction and Objectives: This study analyses the results of our experience in reconstruction of high-grade sarcomas of the
Introduction. Proximal humeral fracture occurs most frequently in elderly and usually unite within 12 weeks. Malunion is more common than nonunion. And even if nonunion occurs, we usually treat it by the blade plate. Norris et al. reported hemiarthroplasty is indicated for severe degenerative changes of the articular surface, osteonecrosis of the humeral head, or osteopenia severe enough to jeopardize fixation in order patients. Therefore, it is not common that hemiarthroplasty is used for primary treatment of the proximal humeral pseudoarthrosis. We report a case of
Reconstruction of the shoulder joint following resection of the
Aim: To describe a new surgical technique for the reconstruction of complex fractures of the
Introduction. Fractures of the
In
Introduction: Treatment of proximal humeral fractures is still controversial. Conservative treatment may result in malunion and shoulder stiffness. We present our experience with displaced or comminuted fractures of the
We present the results of treatment of complicated comminutive fractures and fracture dislocations of the
There is more than one option for
Fractures of
The operative treatment of fractures of the
Introduction: Three and four part fractures and fracture dislocations of the
The classification of complex fractures of the
Purpose of the study: The reversed total shoulder prosthesis is one of the treatments currently proposed for excentered glenoid osteoarthritic degeneration with massive rotator cuff tears. In light of the mediocre or at best highly variable results obtained with osteosynthesis or humeral arthroplasty for four-fragment fractures of the
The use of a Shoulder Hemiarthroplasty for the treatment of
Endoprosthetic replacement of the
Failed internal fixation of a fracture of the
proximal humerus produces many challenges with limited surgical options.
The aim of this study was to evaluate the clinical outcomes after
the use of a reverse shoulder arthroplasty under these circumstances.
Between 2007 and 2012, 19 patients (15 women and four men, mean
age 66 years; 52 to 82) with failed internal fixation after a proximal
humeral fracture, underwent implant removal and reverse shoulder arthroplasty
(RSA). The mean follow-up was 36 months (25 to 60). The mean American
Shoulder and Elbow Score improved from 27.8 to 50.1 (p = 0.019).
The mean Simple Shoulder Test score improved from 0.7 to 3.2 (p
= 0.020), and the mean visual analogue scale for pain improved from
6.8 to 4.3 (p = 0.012). Mean forward flexion improved from 58.7°
to 101.1° (p <
0.001), mean abduction from 58.7° to 89.1° (p
= 0.012), mean external rotation from 10.7° to 23.1° (p = 0.043)
and mean internal rotation from buttocks to L4 (p = 0.034). A major
complication was recorded in five patients (26%) (one intra-operative
fracture, loosening of the humeral component in two and two peri-prosthetic
fractures). A total of 15 patients (79%) rated their outcome as
excellent or good, one (5%) as satisfactory, and three (16%) as
unsatisfactory. . An improvement in outcomes and pain can be expected when performing
a RSA as a salvage procedure after failed internal fixation of a
fracture of the
Purpose of this study is to examine the long-term follow-up in prosthesis reconstruction after
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
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
The poor results using non locked plates in the treatment of more part fractures of the
Purpose of the study: Osteosynthesis procedures proposed for fractures of the
The results of proximal humeral replacement following trauma are substantially worse than for osteoarthritis or rheumatoid arthritis. The stable reattachment of the lesser and greater tuberosity fragments to the rotator cuff and the restoration of shoulder biomechanics are difficult. In 1992 we developed a prosthesis designed to improve fixation of the tuberosity fragments in comminuted fractures of the
The surgical treatment of three- and four-part fractures of the
Aim: Displaced intrarticular fractures and fracture-dislocations of the
We assessed the intermediate functional results of eight patients after wide resection of the
Three and four part fractures of the
Many two-part fractures of the
Purpose: Collapse or necrosis of the head of the humerus after fracture of the
We have undertaken a five-year prospective study of 126 translated two-part fractures of the
Objective: To evaluate the outcome of open reduction and internal fixation of displaced proximal humerus fractures using a new locking plate. Design: Prospective. Setting: Level I university center. Patients: Twenty-eight women and 22 men (mean age, 62.9 ± 19.l years). Twenty-nine patients were 65 years of age or older (mean age, 76.8 years). Fractures were classified according to AO/OTA as 11-A2 (n=3), A3 (n=12), B1 (n=4), B2 (n=18), B3 (n=1), C1 (n=1), and C2 (n=11). Mean follow-up was 19.8 months (range, 12 to 39 months). Intervention: Open reduction and internal fixation with a
The medial periosteal hinge plays a key role in fractures of the head of the humerus, offering mechanical support during and after reduction and maintaining perfusion of the head by the vessels in the posteromedial periosteum. We have investigated the biomechanical properties of the medial periosteum in fractures of the
Purpose: The purpose of this study is to analyze the anatomo-radiological results, the clinical results, and complications of minimally displaced fractures of the
Introduction. Stress shielding of bone around the stem components of total shoulder replacement (TSR) implants can result in bone resorption, leading to loosening and failure. Titanium is an ideal biomaterial for implant stems; however, it is much stiffer than bone. Recent advances in additive manufacturing (AM) have enabled the production of parts with complex geometries from titanium alloys, such as hollow or porous stems. The objective of this computational study is to determine if hollow titanium stems can reduce stress shielding at the
Introduction. There is considerable uncertainty about the optimal treatment of displaced four-part fractures of the
There is a specific type of displaced four-part fracture of the
Purpose: The purpose of this study was to determine factors predictive of tumour recurrence, or refracture, following curettage as treatment for pathological fracture of the
Purpose: Nonunion of the surgical neck of the humerus can occur after orthopaedic or poorly-adapted surgery after displaced subtuberosity or cephalotuberosity fracture. The purpose of this study was to report functional and radiographic outcome after treatment with shoulder prosthesis. Material and methods: Twenty-two patients who had a non-constrained shoulder prosthesis were included in this retrospective multicentric study. Mean age was 70 years and mean follow-up was 45 months (range 2 – 9 years). The initial fracture had two fragments in six patients and was a three-fragment fracture involving the head and the tubercle in thirteen and a four-fragment fracture in three. Orthopaedic treatment was given in ten cases and surgical osteosynthesis was used in twelve. Time from fracture to implant insertion was 20 months. The deltopectoral approach was used for 21 humeral implants and one total shoulder arthroplasty (glenohumeral degeneration). The tuberosities were fixed to the cemented humeral stem and a crown of bone grafts were placed around the nonunion of the surgical neck. All patients were reviewed after a minimum of two years and assessed with the Constant score and x-rays. Results: The absolute Constant score improved from 23 reoperatively to 39 postoperatively with an anterior elevation of 53° to 63°. Pain score (from 3 to 9, p = 0.001) and external rotation (from 13° to 28°, p = 0.01) were significantly improved. Forty-five percent of the patients were satisfied and 55% were dissatisfied. The type of initial treatment, type of initial fracture, and time before implantation of the prosthesis did no affect final outcome. The complication rate was 36% (eight patients), and led to five revision procedures. The radiographic work-up disclosed six cases of persistent nonunion of the greater tuberosity, two proximal migrations of the prosthesis, and one humeral loosening. Conclusion: Outcome of shoulder prosthesis for sequela after fracture of the
Introduction. The standard treatment of proximal humerus fractures includes pre-contoured metal plates and up to nine cortical and trabecular screws. Frequent failures are reported, especially in case of poor bone quality. The scope of this study was to assess the strength of an innovative reconstruction technique (Cement-and-screws) based on a commercial plate, with a reduced number of screws compared to the standard, and with the injection of a beta-TCP additivated acrylic bone cement (Cal-Cemex, Tecres, Italy). The focus was on a four-fragment fracture of the
In fractures of
Purpose: Proximal humeral fractures are a commonplace injury, especially in the elderly population. Management is not always straightforward, and is particularly challenging when bone quality is poor. In recent years, locking plates have become available for the internal fixation of many types of fractures, including those of the
For any fracture classification, a high level of intraobserver reproducibility and interobserver reliability is desirable. We compare the consistency of the AO and Neer classifications for proximal humerus fractures with an assessment of the digitised radiographs of 100 fractures by 10 orthopaedic surgeons and 5 radiologists using the General Electric Picture Archiving and Communications System (PACS), allowing manipulation of the image. This process repeated 1 month later. Reproducibility and reliability moderate for both the AO and Neer systems. Reproducibility using the AO/ ASIF system was slightly greater. The assessor’s level of experience and specialty did affect accuracy. The ability to electronically manipulate images does not improve reliability and their sole use in describing these injuries and comparing similarly classified fractures from different centres is not recommended. Fractures of the
To identify mechanisms of failure in plate and nail fixation in proximal humerus fractures. 5% of the proximal humerus fractures need surgical fixation, which is carried out, principally, by open reduction and internal fixation or closed reduction and intramedullary nailing. Fixation failure remains a problem. This study answers the mode of failure of these implants regardless of the fracture personality. In-vitro testing of
We present a retrospective study of 125 patients with an impacted valgus fracture (B1.1) of the
Secure fixation of displaced proximal fractures of the humerus is a challenging problem. A total of 32 patients with acutely displaced three- or four-part proximal fractures of the humerus were treated by open reduction and internal fixation using the proximal humeral internal locking system (PHILOS) plate. There were 23 women and nine men with a mean age of 59.9 years (18 to 87). Data were collected prospectively and the outcomes were assessed using the Constant score. The mean follow-up was for 11 months (3 to 24). In 31 patients (97%) the fracture united clinically and radiologically at a mean of 10 weeks (8 to 24). The mean Constant score at final review was 66.5 (30 to 92). There was no significant difference in outcome when comparing patients aged more than 60 years (18 patients) with those aged less than 60 years (14 patients) (t-test, p = 0.8443). There was one case each of nonunion, malunion and a broken screw in the elderly population. This plate provides an alternative method of fixation for fractures of the
The Purpose: To compare clinical results of proximal humerus fractures following internal fixation with proximal humeral locked plate versus conservative treatment. Materials and Methods: 25 patients sustained 3-part fractures of the
Untreated 3- and 4-part fractures of the
Introduction. A review of the literature showed a discrepancy between biomechanical and clinical studies on fracture fixation failure in patients with poor bone quality. The objective of the present study is to assess the influence of local bone status on complications after surgical treatment of proximal humerus fractures. Methods. A prospective cohort study was initiated in 2007. The inclusion criteria were closed displaced fractures of the
Purpose: With the advent of the locking precontoured
In primary malignant bone tumours, the “en – block” excision with the sacrifice of soft tissues causes a functional deficit of the interested limb. There are many possibilities for reconstruction after a wide resection of the
We evaluated the biomechanical properties of two different methods of fixation for unstable fractures of the
A reduced retroversion angle of the humeral head may predispose to recurrent anterior shoulder dislocation and may also be a factor in persistent instability after soft-tissue repair. We performed rotational osteotomy of the
A new technique for the treatment of displaced fractures of the
The purpose of this study is to evaluate the results of the treatment of displaced greater-tuberosity fractures by open reduction and stable fixation with heavy non absorbable sutures and early passive motion. Thirty-six patients, 21 male (average age 50 years) and 15 female (average age 62 years) underwent open reduction and internal fixation for a displaced greater-tuberosity fracture of the
Background: The purpose of the presented study was to evaluate the longterm outcome of surgically treated complex fractures of the
A consecutive series of 31 displaced fractures of the
Minimally displaced paediatric proximal humerus fractures (PHFs) can be reliably managed non-operatively, however there is considerable debate regarding the appropriate management of severely displaced PHFs, particularly in older children and adolescents with limited remodelling potential. The purpose of this study was to perform a systematic review to answer the questions: “What are the functional and quality-of-life outcomes of paediatric PHFs?” and “What factors have been associated with a poorer outcome?” A review of Medline and EMBASE was performed on 4th July 2021 using search terms relevant to PHFs, surgery, non-operative management, paediatrics and outcomes. Studies including ≥10 paediatric patients with PHFs, which assessed clinical outcomes by use of an established outcome measure, were selected. The following clinical information was collected: participant characteristics, treatment, complications, and outcomes. Twelve articles were selected, including four prospective cohort studies and eight retrospective cohort studies. Favourable outcome scores were found for patients with minimally displaced fractures, and for children aged less than ten years, irrespective of treatment methodology or grade of fracture displacement. Older age at injury and higher grade of fracture displacement were reported as risk factors for a poorer patient-reported outcome score. An excellent functional outcome can be expected following non-operative management for minimally displaced paediatric PHFs. Prospective trials are required to establish a guideline for the management of severely displaced PHFs in children and adolescents according to fracture displacement and the degree of skeletal maturity.
We report a retrospective review of outcome after shoulder hemiarthroplasty for proximal humerus fractures. All patients managed with shoulder hemiarthroplasty for proximal humerus fractures between 1997 and 2008 were included. Clinical notes were reviewed and surviving patients completed postal Oxford Shoulder Score (OSS) questionnaires. Results were analysed to assess whether there was a difference in outcome for those above the age of 70 years. A total of 96 patients were treated during this period. Female to male ratio was 3.36:1 with mean age 72 ± 9.6 (45–93) years at time of fracture. At time of review 30.2% of patients were dead. Two patients were lost to follow-up after discharge. Complete case notes were available in 68 patients. Response rate to the OSS was 67.2%. There were 20 patients below 70 years and 48 patients above 70 years of age. The ASA grade was II in 60% of patients. Mean follow-up was 52 months. There were 2 in hospital post-operative deaths due to medical complications. Mean OSS was 27 (3–47) of a maximum of 48, with no significant difference between groups. Overall complication rate was 27.9%, with no significant difference between groups. Ten year survival was 96.9% overall with no significant difference between groups. There appears to be no significant difference in functional outcome, complication rate, or implant survival between patients below or above the age of 70 years treated with primary hemiarthroplasty for fracture of the
Purpose of the study: The
Fractures of the
We present a series of 18 consecutive cases of primary reverse total shoulder arthroplasty for irreparable proximal humerus fractures in patients over 70. Failure of tuberosity union and poor cuff function leads to unsatisfactory results in over half the patients with hemiarthroplasty. Reverse total shoulder arthroplasty does not depend upon a functional rotator cuff and requires little formal rehabilitation. Patients over 70 with irreparable proximal humerus fractures treated with a reverse total shoulder arthroplasty were included in this study. Only primary arthroplasties were included. Reverse arthroplasties for failed hemiarthroplasties were excluded. All arthroplasties were performed using either a deltoid split direct lateral (superior) approach or the antero-lateral MacKenzie approach. The SMR reverse total shoulder prothesis was implanted in all cases using a press-fit glenoid base plate and glenosphere, and press-fit or cemented humerus stem. Tuberosity repair was attempted in 10 cases. The supraspinatus was excised from the greater tuberosity. Patients were allowed self-mobilisation after two weeks in a sling. Patients were recruited and followed up per ethics approved protocol. Outcome measures used were range of motion, dislocation and revision rates radiological signs of loosening and glenoid notching, DASH and Constant scores. Results were compared to another series of cases of reverse shoulder arthroplasty for sequelae of trauma and failed hemiarthroplasties, as well as a series of primary hemiarthroplasties. At an average follow-up of 30 months (minimum 12 months) all patients were satisfied with their results. Average forward elevation was 132 deg. and abduction 108 deg. There was not deterioration of movement at 12 or 24 months. No patient had ongoing pain. The average constant score was 62. There was no evidence of humeral stem loosening apart from one case of early subsidence in a press fit stem. Eleven cases showed glenoid notching, four Nerot grade 1, six Nerot grade 2 and one Nerot grade 3. All notching had stabilised after 12 months. There were no cases of dislocation. No case needed revision, or awaits revision. All cases were pain-free at last review. Overall results for this group of primary reverse arthroplasties for fractures was much better than for reverse arthroplasties for sequelae of trauma. The results were also better than for primary hemiarthroplasties. Irreparable three and four part fractures of the
Aims: The evaluation of blood supply of the humeral head in displaced 4-part Òvalgus impactedÒ fractures of the
We evaluated the impact of stereo-visualisation of three-dimensional volume-rendering CT datasets on the inter- and intraobserver reliability assessed by kappa values on the AO/OTA and Neer classifications in the assessment of proximal humeral fractures. Four independent observers classified 40 fractures according to the AO/OTA and Neer classifications using plain radiographs, two-dimensional CT scans and with stereo-visualised three-dimensional volume-rendering reconstructions. Both classification systems showed moderate interobserver reliability with plain radiographs and two-dimensional CT scans. Three-dimensional volume-rendered CT scans improved the interobserver reliability of both systems to good. Intraobserver reliability was moderate for both classifications when assessed by plain radiographs. Stereo visualisation of three-dimensional volume rendering improved intraobserver reliability to good for the AO/OTA method and to excellent for the Neer classification. These data support our opinion that stereo visualisation of three-dimensional volume-rendering datasets is of value when analysing and classifying complex fractures of the
Purpose: Optimal fixation for comminuted proximal humerus fractures is controversial. Complications using locked plates have been addressed by anatomic reduction or medial cortical support. The current study measured relative mechanical contributions of varus malalignment and medial cortical support. Method: Forty synthetic humeri were divided into three groups, osteotomized, and fixed at 0, 10, and 20 degrees of varus malreduction with locked
Introduction: The goal of this study is to report the clinical and radiographic results of 2 types of implants used to treat 3 and 4 parts fractures of the
Purpose: We compared three fixation systems for proximal fractures of the humerus to elaborate a rigid extra-medullary implant: the basket plate. This novel implant allows fixation of the tubercles with a claw system associated or not with a central cephalic locking screw. The objectives of this study were: check the resistance of the prototype, evaluate the contributions of the claws, and the usefulness of locking. Material and methods: This was a prototype experimental study comparing a commonly used implant (Maconor2 plate) with the new implant using two series of static mechanical tests (Instrum). The tests were performed on 20 DMO-frozen anatomic specimens using the four-fragment fracture model. An implant was assigned to five groups of randomly selected specimens. The first tests (three groups) were axial compression tests mimicking abduction in the plane of the scaphoid. We analysed the overall mechanical behaviour of the implant and evaluated the locking system. The second tests (two groups) were traction tests. We analysed the behaviour of the fixed tuberosities. The mechanical resistance of the assemblies was noted as the limit load on the force: deformation curve and as the rigidity of the slope. Results: The first tests showed that the implant was improved by the locking system and had better overall mechanical characteristics than the compared implant, although the difference was not statistically significant. The better hold in the tubercles provided by the claws was expected after the first tests and confirmed by the second tests, but the difference was not significant. Discussion: The prototype improved with the locking system presented mechanical resistance equivalent to the compared model. The usefulness of locking could not be demonstrated but was considered to improve tolerance to loading by better force distribution. The contribution of the claws was not demonstrated statistically although the results are in line with early hopes. The present findings and data in the literature on shoulder biomechanics suggest that the tests should be conducted on a larger number of specimens to demonstrate a statistically significant difference. The tested series was too small. Conclusion: Comparison of mechanical resistance with theoretical data on forces applied to the