Biomechanical comparison of screw-based zoning of PHILOS and Fx proximal humerus plates

Background Treatment of proximal humerus fractures with locking plates is associated with complications. We aimed to compare the biomechanical effects of removing screws and blade of a fixed angle locking plate and hybrid blade plate, on a two-part fracture model. Methods Forty-five synthetic humeri were divided into nine groups where four were implanted with a hybrid blade plate and the remaining with locking plate, to treat a two-part surgical neck fracture. Plates’ head screws and blades were divided into zones based on their distance from fracture site. Two groups acted as a control for each plate and the remaining seven had either a vacant zone or blade swapped with screws. For elastic cantilever bending, humeral head was fixed and the shaft was displaced 5 mm in extension, flexion, valgus and varus direction. Specimens were further loaded in varus direction to investigate their plastic behaviour. Results In both plates, removal of inferomedial screws or blade led to a significantly larger drop in varus construct stiffness than other zones. In blade plate, insertion of screws in place of blade significantly increased the mean extension, flexion valgus and varus bending stiffness (24.458%/16.623%/19.493%/14.137%). In locking plate, removal of screw zones proximal to the inferomedial screws reduced extension and flexion bending stiffness by 26–33%. Conclusions Although medial support improved varus stability, two inferomedial screws were more effective than blade. Proximal screws are important for extension and flexion. Mechanical consequences of screw removal should be considered when deciding the number and choice of screws and blade in clinic

Shoulder hemiarthroplasty for fractures of the proximal humerus

Proximal humeral fractures were managed with primary hemiarthroplasty in 57 patients, 53 women (93%) and 4 men (7%) aged 51–87 years (mean 72.2). The mean follow-up period was 52 months (range 12–98), and the mean Constant score was 59.2 (range 38–76). Patients were very satisfied (n = 19); satisfied (n = 32) or dissatisfied with the outcome (n = 5). One patient required early revision surgery. Surgical treatment of three- and four-part fractures of the proximal humerus with hemiarthroplasty is a safe and effective approach, the outcome of which appears to be related to the quality of the anatomical reconstruction of the tuberosities

Treatment of glenohumeral instability in rugby players

Rugby is a high-impact collision sport, with impact forces. Shoulder injuries are common and result in the longest time off sport for any joint injury in rugby. The most common injuries are to the glenohumeral joint with varying degrees of instability. The degree of instability can guide management. The three main types of instability presentations are: (1) frank dislocation, (2) subluxations and (3) subclinical instability with pain and clicking. Understanding the exact mechanism of injury can guide diagnosis with classical patterns of structural injuries. The standard clinical examination in a large, muscular athlete may be normal, so specific tests and techniques are needed to unearth signs of pathology. Taking these factors into consideration, along with the imaging, allows a treatment strategy. However, patient and sport factors need to be also considered, particularly the time of the season and stage of sporting career. Surgery to repair the structural damage should include all lesions found. In chronic, recurrent dislocations with major structural lesions, reconstruction procedures such as the Latarjet procedure yields better outcomes. Rehabilitation should be safe, goal-driven and athlete- specific. Return to sport is dependent on a number of factors, driven by the healing process, sport requirements and extrinsic pressures

Lack of fifth anchoring point and violation of the insertion of the rotator cuff during antegrade humeral nailing: pitfalls in straight antegrade humeral nailing.

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

Acetylsalicylic acid–silicone oil suspension for proliferative vitreoretinopathie: First results of Austrian clinical multicentre study

BACKGROUND: A new surgical method of intravitreal tamponade with silicone oil suspended with acetylsalicylic acid (AS) was investigated for safety and efficiency in the treatment of proliferative vitreoretinopathie. The study was designed as a prospective randomized, controlled double-blind Multicentre Study. METHODS: A standard three-port pars plana vitrectomy was performed in 29 eyes of 29 patients. In case a natural lens was present simultaneous phacoemulsification was obligatory. The control group received standard therapy vitreous tamponade with pure 5000centistoke silicone oil while the silicone oil was suspended with AS to a concentration of 0.2 mg/ml in the study group. After 6 months follow up the tamponade was removed in all eyes. RESULTS: The safety of AS SiO could be demonstrated: the AS SiO was well tolerated and stayed clear during the study period of 6 months. The clinical examination revealed no signs of local or systemic adverse effects in the study eyes. The visual acuities were well matched before inclusion into the study and there was no evidence of significant differences during the follow up period and in final visual outcome between the two groups. The rate of redetachments defined as the primary outcome parameter was the same for both groups. CONCLUSIONS: Acetylsalicylic acid delivery by intravitreal silicone oil in the human eye was shown a safe method that may offer a delivery route for other antiproliferative agents into the posterior pole.HINTERGRUND: Eine neue Form der intravitrealen Tamponade mit einer Suspension aus Azetyl-Salizylsäure und Silikonöl (AS SiO) wurde einer klinischen Prüfung unterzogen. Die Studie wurde als doppelt-blinde, randomisierte, multizentrische, prospektive Studie konzipiert, um die Sicherheit und Effektivität von AS SiO als Glaskörpertamponade bei proliferativer Vitreoretinopathie (PVR) zu evaluieren. METHODE UND PATIENTEN: Insgesamt 29 Augen von 29 Patienten mit einer PVR Grad C wurden in der Studie entweder einer Pars-Plana Vitrektomie mit anschließender AS-SiO- oder reiner SiO-Tamponade unterzogen. Die Azetyl-Salizylsäure-Konzentration der Suspension betrug 0,2 mg/ml und es wurde in beiden Gruppen jeweils 5000centistoke Silikonöl verwendet. Bei Phakie war zeitgleich eine Operation der Linse obligatorisch, um eventuell AS-SiO-bedingte Linsentrübungen zu vermeiden. Nach 6 Monaten wurde die Tamponade bei allen Patienten entfernt. Im Fall noch vorliegender Traktionen oder instabiler Verhältnisse war eine Retamponade mit reinem SiO natürlich möglich. ERGEBNISSE: Die Sicherheit von AS SiO konnte nachgewiesen werden. Es wurde in allen Augen gut toleriert und die Suspension blieb transparent innerhalb der Beobachtungszeit von 6 Monaten. Die klinische Untersuchung ergab keine Hinweise einer lokalen oder systemischen Toxizität. Die Visuswerte beider Gruppen unterschieden sich nicht signifikant sowohl präoperativ als auch postoperativ. Auch in Bezug auf die Rate der Reablationes, dem Hauptzielkriterium der Studie, waren beide Gruppen gleichwertig. SCHLUSSFOLGERUNG: Die Azetyl-Salizylsäure- und Silikonöl-Suspension (AS SiO) repräsentiert eine sichere und effektive Tamponade im Rahmen der PVR-Behandlung. Zusätzlich beweist sie, dass es möglich ist, mittels Silikonöl Medikamente in den posterioren Augenabschnitt zu verabreichen, wobei hier vor allem der Transfer antiproliferativer Substanzen interessant ist