Ankle ligament injury is a common cause of injury to military recruits, and frequently implicated in failure to complete Royal Marines (RM) recruit training. A minority of patients at Commando Training Centre Royal Marines (CTCRM) with ankle ligament injury undergo arthroscopic ankle stabilisation surgery (Bostrum or Evans procedures). The decision to undertake surgery involves an assessment of functional benefit to the patient, medical and surgical risks, and cost-effectiveness. However, there is currently little data on the efficacy of surgery in enabling recruits to complete RM training.

To assess the number of RM recruits who completed recruit training following ankle stabilisation surgery and entered the trained strength.

A retrospective analysis of all patients at CTCRM who underwent surgery for ankle stabilisation was performed using healthcare records data. The primary outcome measure was completion of RM recruit training after surgery. 27 patients underwent surgical intervention for ankle instability between 2004 and 2015. Patients remaining in rehabilitation following their surgery were excluded, leaving 22 patients suitable for inclusion in the final analysis.

Of the eligible patients undergoing surgical intervention (n = 22), six patients – 27% – completed RM recruit training. Average time in rehabilitation 68 weeks. 10 patients underwent a Evans procedure and 9 underwent a brostum repair with 3 unknown.

Based on cumulative data spanning 11 years at CTCRM, operative intervention for ankle instability enables only a minority (27%) of patients to complete RM recruit training. Patients who undergo surgical intervention also undertake prolonged rehabilitation at a cost of £1850 per recruit per week. The poor rates of completing RM training following surgery, and the high costs of rehabilitation, have implications with regards to retaining recruits who sustain ankle injuries requiring surgical reconstruction.

Previous Anterior Cruciate Ligament (ACL) reconstruction is currently a bar from entry to the Royal Marines and Royal Navy, whilst the British Army allows recruits to join if asymptomatic 18 months post ACL reconstruction. However current Royal Marines policy is to rehabilitate recruits who sustain an ACL disruption in training. We retrospectively analysed the rehabilitation times and pass out rate of Royal Marines who had an ACL disruption during recruit training over an 8 year period.

12 recruits sustained an ACL disruption during recruit training in the study period, giving an incidence of around 1.5/1000 recruits. 9 Patients underwent ACL repairs in training, with 1 patient leaving and rejoining post repair and later successfully passed out. 2 patients were treated conservatively. Of the 12 ACL sustained in training 8/12 (67%) passed out. None of the patients treated conservatively passed out. The mean time out of training for successful recruits was 51.6 weeks (95% CI 13.1) mean rehabilitation time post ACL reconstruction for successful recruits was 36.7 weeks (95% CI 12.5). Mean time to discharge for unsuccessful recruits 63.2 weeks (95% CI 42.4). In the operative group 1/10 left due to failure to return to training and 1/10 left through unrelated reasons. Current costing for recruit training is £1800 per week per recruit.

ACL injuries are not common in Royal Marine Training, and reconstruction is not a bar to completing Royal Marine basic training. We estimate that it costs around £100,000 per-injured recruit, to maintain a policy of rehabilitating ACL injured recruits in Royal Marines training. Further research into the long-term employability or Royal Marines sustaining an ACL injury in training is required.