It is a small cone-shaped anatomical space located between the talus and the calcaneus, open towards the external aspect of the foot in front of the lateral malleolus. Inside there is an interosseous ligament, proprioceptive nerve branches and synovial tissue. It is one of the regulators of rearfoot stability and, when it becomes inflamed or unstable after sprains, the clinical picture discussed on this page appears.

The acute sprain affects mainly the anterior peroneo-talar ligament; the tarsal sinus syndrome is the late consequence: pain in the external aspect, sensation of instability and synovitis inside the sinus. Many times both pictures coexist: there is lateral laxity plus internal synovitis of the sinus. Magnetic resonance imaging is the test that best differentiates them and guides the treatment (Lektrakul N, et al. 2001).

It depends on the phase. In mild cases, well controlled with insoles, proprioception and functional bandaging, many patients maintain a reduced activity without worsening. In acute phases with frank synovitis and daily pain, it is advisable to reduce volume and intensity or rest for a few weeks to avoid chronification of the injury. The rule of thumb: if pain limits you, listen to your foot and be guided by the assessment.

In a significant proportion of patients, yes. Custom-made stabilizing insoles, combined with a proprioception and peroneal strengthening program, control the instability and allow the synovitis to subside. If you have had the condition for a long time or the MRI shows very established synovitis, it is likely that insoles alone will not be sufficient and will have to be combined with infiltration or arthroscopy.

The medication (corticosteroid, platelet-rich plasma or hyaluronic acid) is injected directly into the sinus of the tarsus under ultrasound guidance. The needle enters the external aspect of the ankle guided in real time to deposit the product in the exact site. It is ambulatory, lasts a few minutes and, in many patients, it also serves as a diagnostic test: if the pain disappears after the infiltration, we confirm the origin of the condition.

The available literature is heterogeneous, but agrees that a majority of patients with tarsal sinus syndrome respond to well-designed conservative treatment (insoles + proprioception ± infiltration). Helgeson (2009) and other authors describe favorable responses avoiding surgery in a notable proportion of cases. Arthroscopic surgery is reserved for patients who do not respond after several months of correctly applied conservative treatment.

Tarsal sinus arthroscopy is performed through millimetric portals, so scars are practically imperceptible and the risk of adhesions or stiffness is low compared to open surgery. Like any intervention, it is not free of risks (infection, nerve injury of sensitive branches, residual pain), but in trained hands they are rare. We detail risks and expectations in the preoperative consultation.

With corticosteroid, we recommend 48-72 hours of very reduced activity and progressive reincorporation to training during the first week. With PRP, the protocol is somewhat more conservative: 7-10 days of reduced load and 3-6 weeks to return to previous performance, depending on the sport. The idea is not to “cover” the pain with the infiltration and return to the injury stimulus immediately: the improvement that the infiltration provides must be used to rehabilitate.

Yes, the most effective measure is the correct and complete rehabilitation of the initial sprain: 4-6 weeks of guided proprioception, peroneal strengthening and progressive return to sport. A stabilizing insole during the first months post-sprain and a functional bandage on return to practice add security. Most of the tarsal sinus syndromes that we see in consultation come from sprains treated only with rest and anti-inflammatory medication, without specific rehabilitation.