Introduction

Sinus tarsi syndrome was first described by O’Connor in 1958. It has historically been defined as persistent pain in the tarsal sinus secondary to trauma, mostly inversion ankle sprains, with an incidence of 70% among reported cases. There are no specific objective findings in this condition.

History & Physical examination

The exact aetiology is not clearly defined, but scarring and degenerative changes to the soft-tissue structure of the sinus tarsi are thought to be the most common cause of pain in this region. Walking on uneven terrain results in pain and a feeling of instability.

On clinical examination there is recognisable tenderness  on palpation by firm pressure over the lateral opening of the sinus tarsi. Relief of symptoms with injection of local anaesthetic directly into the sinus tarsi confirms the diagnosis.

Diagnostic imaging

Routine radiographs show no abnormalities. A MRI may reveal inflammation and fibrotic tissue in the sinus tarsi region.  

Surgical treatment

Conservative treatment is always the first treatment of choice. Conservative treatment consists of icing, balance and proprioceptive training, muscle strengthening exercises, bracing, taping and foot orthosis.  If it fails, surgical intervention can be a solution. The initial surgical treatment consists of synovectomy and fibrous tissue debridement.

Post-operative rehabilitation

The patient can be discharged the same day of surgery and weightbearing is allowed as tolerated. The patient is instructed to perform active dorsiflexion of the ankle to the neutral position (knee slightly bent). This exercise should be performed 2 or 3 days times per hour for the first days after surgery. The patient is instructed to elevate the foot when not walking to prevent edema. The dressing is removed 3 days post-operative. Normal walking without crutches at 4 - 5 days post surgery. Patients with limited range of motion are directed to a physiotherapist. Running can be started when range of motion is normal and in absence of swelling. This can on avarage be expected at 3 weeks post surgery. Sport resumption can on average be expected at 6 weeks post surgery. 

Recommended literature

Chapter  19.9.1 van Dijk, C.N., Ankle Arthroscopy: Techniques Developed by the Amsterdam Foot and Ankle School. 2014: Springer Berlin Heidelberg.