Free vascularised medial femoral condyle periosteal flaps in recalcitrant long bone non-union: a systematic review

Introduction In adults, treatment of recalcitrant long bone non-union is extremely challenging, with poorly vascularised and atrophic defects unresponsive to standard non-vascularised bone graft treatment. Recent studies have documented the use of free vascularised periosteal flaps to achieve union in refractory long bone fracture non-union, yet its use is not well established. This systematic review aims to assess the evidence for free vascularised periosteal flaps in recalcitrant long bone non-union. Materials and methods The MEDLINE®/PubMed ® and Embase databases were searched for the Medical Subject Heading (MeSH) terms periosteal flap/vascularised flap/long bone/non-union/non united fracture in accordance with the PRISMA guidelines. Bibliographies were scrutinised for additional articles. Results Pooled data from 14 studies met the inclusions criteria, comprising 137 cases of non-union, with 117 relating to long bone non-union. Pooled data indicated an overall 99% (116/117) successful union rate. All studies were of mid- to low-level evidence (Level III, IV and V). Only one study directly compared vascularised periosteal flaps to non-vascularised bone grafts, showing union rates of 100% versus 80% and faster time to union (2 versus 5.5 months). Conclusions Free vascularised periosteal flaps are promising with pooled data showing a 99% success rate in achieving union in refractory long bone non-union. This compares favourably with standard orthopaedic care consisting of revision fixation and non-vascularised bone graft union rates of approximately 80%. However, study design flaws should be addressed by validated outcome measures plus adequate blinding, and further comparative studies with greater patient numbers are required.