Comparison of Different Tourniquet Release Times in Bunion Surgery

Evaluation of Post-operative Swelling and Functional Outcomes in Relation to Pneumatic Tourniquet Use Pattern in Bunion Surgery

Patients listed for hallux valgus/hallux rigidus correction surgery will be randomised to one of two treatment groups. Group 1 (standard care) will have the calf tourniquet released after wound closure. Group 2 will have the tourniquet removed five minutes before wound closure. Participants will have the volume of their operated foot measured pre-operatively and post-operatively at six weeks and three months.

Pneumatic tourniquets provide the benefits of better visualisation and decreased blood loss, but can also cause metabolic changes due to ischemia and compressive damage due to pressure. Surveys of foot and ankle surgeons demonstrates prevalent use of tourniquets in their clinical practice, with various patterns of use differing amongst the surgeons.

Bunion surgery is one of the most common surgical procedures in foot surgery. It involves correcting the hallux valgus deformity through a combination of various osteotomy, fusion, or soft tissue procedures. Swelling after any surgery is common, but particularly so after foot surgery as gravity causes fluid to collect in the foot. With regards to recovery after surgery, patients are advised to expect to be off work for between 6-8 weeks for a sedentary occupation, and between 12-14 weeks for heavy work. Although patients have low pain levels, the foot remains swollen for an average of 3-6 months after surgery. It is usually the swelling that prevents patients from getting in to normal footwear to be able to return to work sooner.

Bunion surgery is usually performed under a calf-tourniquet to create a bloodless surgical field and ensure less surgical bleeding, thereby reducing surgical time. However, use of tourniquets can lead to more swelling, increased post-operative pain and challenges in rehabilitation - all of which may affect recovery after bunion surgery. Prolonged duration of tourniquet use has been shown to cause post-operative wound healing complications, potentially attributable to local inflammation and tissue hypoxia. It is known from the studies for knee replacement surgery that tourniquet use can lead to decreased range of motion after surgery in early stage.

This study will be a randomised controlled trial with two study groups. The control group will have surgery with the tourniquet remaining in situ until the wound is closed. The intervention group will have the tourniquet released after surgery, but closure will be delayed by five minutes.

Inclusion Criteria:

• Patients having hallux valgus or hallux rigidus
• Able to give informed consent
• Able to return for follow-up

Exclusion Criteria:

• Patients with symptomatic peripheral vascular disease
• Patients with known peripheral oedema from any cause
• Patients who will also require lesser toe correction as part of the procedure
• Active smokers