Purpose Paediatric orbital fractures are rare. Existing literature demonstrates wide variation in estimates of incidence, aetiology, management protocols and outcomes. Despite this, it is generally acknowledged that orbital fractures with entrapment of the extraocular muscles constitute a surgical emergency due to the potential for persistent diplopia secondary to muscle ischaemia and necrosis. Methods This retrospective study was conducted to determine the characteristics and outcomes of management of orbital fractures amongst the paediatric population. It involved patients presenting to a major trauma unit in London between 2010 and 2020. Results Thirteen patients with isolated orbital fractures presented to our unit in this period. The average age was 13 years. Surprisingly the predominant aetiology was interpersonal violence. The most common fracture pattern involved the orbital floor and medial wall. One medial wall fracture case was missed in the emergency department. Eight patients required surgical intervention due to diplopia caused by muscular entrapment of extraocular muscles; the final patient had a large defect resulting in enophthalmos requiring a large titanium plate. A transconjuctival approach was preferred for surgical access and resorbable sheet was used in the remaining cases. Five patients had nausea, vomiting or bradycardia associated with the oculocardiac reflex. Surgical intervention occurred within 24–48 h of injury in 6 cases. Resolution of diplopia occurred in 7 patients within 6 months. Conclusion Paediatric patients with orbital fractures should be assessed on the day of injury by a maxillofacial surgeon. Due to the risk of persistent diplopia, urgent surgical intervention in patients with entrapment of extraocular muscles should occur as soon as possible.

Ligament integrity is directly associated with ankle stability. Nearly 40% of ankle sprains result in chronic ankle instability, affecting biomechanics and potentially causing osteoarthritis. Ligament replacement could restore stability and avoid this degenerative pathway, but a greater understanding of ankle ligament behaviour is required. Additionally, autograft or allograft use is limited by donor-site morbidity and inflammatory responses respectively. Decellularised porcine grafts could address this, by removing cellular material to prevent acute immune responses, while preserving mechanical properties.This project will characterise commonly injured ankle ligaments and damage mechanisms, identify ligament reconstruction requirements, and investigate the potential of decellularised porcine grafts as a replacement material.Several porcine tendons were evaluated to identify suitable candidates for decellularisation. The viscoelastic properties of native tissues were assessed using dynamic mechanical analysis (DMA), followed by ramp to ‘sub-rupture’ at 1% strain/s, and further DMA. Multiple samples (n=5) were taken along the graft to assess variation along the tendon.When identifying suitable porcine tendons, a lack of literature on human ankle ligaments was identified. Inconsistencies in measurement methods and properties reported makes comparison between studies difficult.Preliminary testing on porcine tendons suggested there is little variation in viscoelastic properties along the length of tendon. Testing also suggested strain rates of 1%/s sub-rupture was not large enough to affect viscoelastic properties (no changes in storage or loss moduli or tanẟ). Further testing is underway to improve upon low initial sample numbers and confirm these results, with varying strain rates to identify suitable sub-rupture sprain conditions.This work highlights need for new data on human ankle ligaments to address knowledge gaps and identify suitable replacement materials. Future work will generate this data and decellularise porcine tendons of similar dimensions. Collagen damage will be investigated using histology and lightsheet microscopy, and viscoelastic changes through DMA.