Sinus Tarsi Syndrome

Normal Anatomy Articulation of the talus and calcaneus (subtalar joint) across anterior, middle and posterior facets Stability provided by various ligaments Extrinsic Calcaneofibular ligament Deltoid ligament Intrinsic Talocalcaneal ligament Interosseuous ligament Cervical ligaments

Normal Anatomy Space between the talus and calcaneus is the sinus tarsi space This space is filled with connective and adipose tissue richly innervated with mechanoreceptors and free nerve endings Important for proprioception Inferior extensor retinaculum lies over the lateral aspect of the sinus tarsi

Pathology Instability of the subtalar joint due to laxity or rupture of the intrinsic ligaments of the subtalar joint Instability results in excessive supination and pronation movements Increases the stress through the sinus tarsi tissues resulting in synovitis, fibrotic tissue and chronic inflammation

Mechanism of Injury Traumatic Single or repeated ankle sprains damage Sudden stop after a jump or fall

Subjective Examination Deep anterolateral ankle pain History of single or repeated ankle sprain trauma Reports a feeling of instability Aggravated by walking over uneven ground, stepping off a curb or running or sprinting activities Cutting and jumping on firm surfaces

Objective Examination Pain on palpation of the sinus tarsi Pain over the sinus tarsi at end range plantarflexion with foot supination Subtalar instability Pain with rotational movements during single leg standing

Further Investigation Lidocaine injection Broden stress view X-rays Stress fluoroscopy MRI

Management Goal is to restore stability to the subtalar joint Treatment is similar to lateral ligament sprains and often treated at the same time

Conservative Reduce pain and inflammation Orthotics NSAID’s Ice Massage Restore Normal Range of Movement Ankle Joint mobilisation Joint manipulation Restore Normal Muscle Activation Evertors Invertors Intrinsic Foot Muscles Restore Dynamic Stability Proprioceptive Training Sport Specific Training

Plan B Synovectomy of the subtalar joint Ligamentous reconstruction

References Helgeson, K. (2009). "Examination and Intervention for Sinus Tarsi Syndrome." N Am J Sports Phys Ther 4(1): 29-37.