Clavicular hook plates have been used over the last decade in the treatment of lateral clavicular fractures with good rates of union reported throughout the literature. Fewer studies have reported the functional outcome of these patients and some have reported potential soft tissue damage post plate removal. We aimed to review the functional outcomes alongside union rates in patients treated with hook plates for lateral clavicular fractures. In this retrospective case series, 21 patients with traumatic lateral third clavicular fractures were included. 15 had Neer type II fractures, 4 Neer type III fractures, 1 patient had a Neer type I fracture and 1 radiograph was not able to be classified. All patients were treated with clavicular hook plates at the same district general hospital by five experienced surgeons between March 2010 and February 2015 adhering to the same surgical protocol. All patients had standard physiotherapy and post operative follow up. Plates were removed when radiological union was achieved in all but one patient who had the plate removed before union was achieved due to prolonged non-union. Patients were followed up post plate removal and evaluated clinically using the Oxford Shoulder Score. Their post plate radiographs were assessed by an independent radiologist and bony union documented. 21 patients were included. Mean age was 40 (range 14–63) with a male:female ratio of 17:4. Mean follow up was 5 months post injury (1–26 months). The hook plate remained in situ for a mean time of 4.3 months (2–16 months). One patient developed a post-operative wound infection treated with antibiotics, 2 patients developed adhesive capsulitis, one patient had not achieved bony union prior to hook plate removal at 16 months, however did achieve union 2 months post plate removal, two patients required revision plating. All patients achieved bony union eventually with good alignment and no displacement of the acromioclavicular joint seen on the most recent post operative radiographs. Post plate removal Oxford Shoulder Scores indicated good shoulder function with a mean score of 41.5 (maximum score possible 48 and the range of scores for our cohort was 30–47). Our data would support the use of hook plates in the treatment of lateral clavicular fractures. All patients achieved union eventually with good alignment and this was reflected in the good functional outcome scores. This study is limited in its small cohort and short-term follow up. More research is required to examine the long term consequences of hook plate surgery in a larger patient population

Summary Statement. This study examined the fixation stiffness of 13 tibial and 12 femoral Salter-Harris fracture fixation methods, and determined that screws and screws+ k-wires methods provided the highest stability. In situations where k-wire use is unavoidable, threaded k-wires are preferable. Introduction. Salter-Harris fractures of the proximal tibia and distal femur are common in pediatric patients that present to orthopedic surgeons. Salter-Harris type I fractures are characterised by breaks that extend only through the physis while Salter-Harris II fractures are the most common, accounting for 85% of Salter-Harris fractures, and extend past the growth plate, exiting through the metaphyseal bone. Fixation of these fracture types can be accomplished using a variety of methods including the use of Kirschner wires, cannulated screws, and a combination of both materials. Stability of fracture fixation is of utmost importance as persistent motion at the fracture margin leads to deformity. The purpose of this study is to analyze the biomechanical efficacy of various fixation methods used to stabilise Salter-Harris I and II fracture patterns in both the proximal tibia and distal femur. Stiffness, the primary gauge of efficacy, will be tested in flexion and extension, varus and valgus movement, and internal and external rotation and will be compared to determine the optimal fixation method. Materials and Methods. This study utilised 39 tibia and 36 femur 4. th. generation synthetic bones (Model 3401 and 3403, Pacific Research Laboratories Inc.) The synthetic bones were fractured and fixated to model Salter-Harris fractures and common fixation methods. Fixation methods used employed 6.5mm cannulated screws, 4.5mm cannulated screws, 2mm smooth K-wires, and 2mm threaded K-wires. Tibias were fractured according to Salter-Harris I, valgus Salter-Harris II, and flexion Salter-Harris II patterns with 13 different fixation methods. Femurs were fractured according to Salter-Harris I and Salter-Harris II patterns with 12 different fixation methods. Testing was performed in three orientations, flexion/extension, varus/valgus, and internal/external rotation, on a materials testing machine (Model 8874, Instron, Norwood, MA) and cyclic displacement tests were performed using Wavematrix software. These displacement tests recorded the torque required to reach an angulation of ±5° for 10 cycles. From this data, the rotational stiffness of the loading phases for each cycle was determined. Statistical analysis was performed to compare construct stiffness and differences between groups using analysis of variance. Results. Results show superior fixation for threaded k-wires in both femoral and tibial Salter-Harris I fractures. Methods utilizing transverse screws were least optimal for the fixation of femoral Salter-Harris II fractures, while a combination of k-wires and screws or the use of oblique screws was more effective. Fixation utilizing a combination of k-wires and screws yielded greater stiffness in valgus and flexion tibial Salter-Harris II fractures. Internal and external rotational stiffness values were low for all fixation methods and no significant variance existed for internal and external rotational stiffnesses in most fracture patterns. Discussion/Conclusion. Based on the results and statistical analysis, we believe that significant variance exists between most of the studied fixation methods for each fracture type. Fixation methods utilizing screws and a combination of screws and k-wires would provide optimal stability. In situations where the use of k-wires is unavoidable, threaded k-wires are preferable