Custom 3D-Printed Implants for Critical-Sized Bone Defects in Foot and Ankle Surgery: A Multicentre Collaborative Study

J Mangwani, A See, L Houchen-Wolloff, 3D custom made multicentre collaborative

Introduction: The treatment of critical-sized bone defects in foot and ankle surgery remains challenging. Traditional methods, such as bone transport, bulk allograft, vascularized bone graft, and Masquelet procedures carry risks including multiple surgeries, donor site morbidity, infection, and non-union. Recently, custom 3D-printed implants have emerged, offering improved anatomical compatibility, eliminating the need for tissue harvesting, and often requiring only a single operation. This study aims to present the largest UK series of custom 3D-printed implants in foot and ankle
surgery.

Methods: A retrospective multicentre collaborative study was conducted in 10 NHS Trusts. Demographic, surgical and radiographic variables were recorded including: age; sex; side; type of operation; complications; and postop imaging at 6 weeks, 3 months, 6 months and 12 months. Baseline characteristics were described for demographic variables. Categorical variables were expressed as frequencies and percentages.

Results: Data was collected on a total of 34 patients. The mean age of patients was 54 years (range 29 to 83). 68% of patients were men. Avascular necrosis was the most common indication for surgery (35%) followed by trauma (21%), total ankle replacement failure (21%), infection (12%), Charcot arthropathy (6%) and AVN and infection (3%). The most common operation performed was a fusion augmented with a truss (44%) and 91% of patients had a combination of regional and general anaesthetic. All patients had an ASA grade of less than 4. Of the patients that had follow-up imaging, the implants were reported intact by 94% at 6 weeks, 78% at 3 months, 68% at 6 months and 67% at 12 months.

Discussion: This is the largest case series of custom-made foot and ankle implants in the UK to date. The clinical and radiographic outcomes at one year Follow-up are satisfactory. Further work is required to assess long term implant survivorship.