The aim of this study was to compare biomechanical properties of pre-contoured plate fixation using different screw fixation modes in a mid-shaft clavicle fracture model. Fourth generation biomechanical clavicle sawbones with a mid-shaft osteotomy were plated in one of three modes: nonlocking bicortical, locking bicortical and locking unicortical mode. The specimens were then tested to failure in four-point bending and pull-off tests.Aims
Methods
Damage Control techniques involve primary external fracture fixation to reduce the ‘second hit’ of surgery. This study used a large animal (ovine) trauma model to compare pathophysiological responses of primary external femoral fixation and intramedullary stabilisation. Under terminal anaesthesia bilateral femoral fractures and hypovolaemia were produced using a pneumatic ram. 24 sheep were randomised into 4 groups and monitored for 24 hours. Group 1 – Control; Group 2 – Trauma only; Group 3 – Trauma and external fixation; Group 4 – Trauma and reamed intramedullary stabilisation. Outcome measures: pulmonary embolic load (transoesophageal echocardiography); plasma coagulation markers; bronchoalveolar lavage differential cell counts (neutrophils, lymphocytes and macrophages). Total embolic load was significantly higher (p<0.001) in the intramedullary fixation group (median score 42 versus 20). All trauma groups had a significant increase (p < 0.05) in prothrombin time with a fall in antithrombin III and fibrinogen levels. No significant differences occurred between trauma groups with any coagulation or alveolar lavage marker. Intramedullary femoral fracture fixation produced a relatively higher pulmonary embolic load. However, the initial fracture fixation method did not affect any of the changes seen in the measured coagulation or inflammatory markers during the first 24 hours of injury.
Our purpose was to study the functional outcome and electrophysiologically to assess the axially nerve function in patients who have undergone surgery using a deltoid-splitting approach to treat complex proximal humeral fractures. This was a prospective observational study and was carried out in the Shoulder injury clinic at a university teaching hospital. Over a one-year period we treated fourteen locally-resident patients (median age 59 years) who presented with a three- or four-part proximal humeral fracture. All patients were treated using the extended deltoid-splitting approach, with open reduction, bone grafting and plate osteosynthesis. All patients were prospectively reviewed and underwent functional testing using the DASH, Constant and SF-36 scores as well as spring balance testing of deltoid power, and dynamic muscle function testing. At one year after surgery, all patients underwent EMG and nerve latency studies to assess axillary nerve function. Thirteen of the fourteen patients united their fractures without complications, and had DASH and Constant score that were good, with comparatively minor residual deficits on assessment of muscle power. Of these thirteen patients, only one had evidence of slight neurogenic change in the anterior deltoid. This patient had no evidence of anterior deltoid paralysis and her functional scores, spring balance and dynamic muscle function test results were indistinguishable from the patients with normal electrophysiological findings. One of the fourteen patients developed osteonecrosis of the humeral head nine months after surgery and had poor functional scores, without evidence of nerve injury on electrophysiological testing. Reconstruction through an extended deltoid-splitting approach provides a useful alternative in the treatment of complex proximal humeral fractures. The approach provides good access for reduction and implant placement and does not appear to be associated with clinically-significant adverse effects.