An update on imaging of tarsal tunnel syndrome.

Tarsal tunnel syndrome (TTS) is an entrapment neuropathy of the tibial nerve (TN) within the tarsal tunnel (TT) at the level of the tibio-talar and/or talo-calcaneal joints. Making a diagnosis of TTS can be challenging, especially when symptoms overlap with other conditions and electrophysiological studies lack specificity. Imaging, in particular MRI, can help identify causative factors in individuals with suspected TTS and help aid surgical management. In this article, we review the anatomy of the TT, the diagnosis of TTS, aetiological factors implicated in TTS and imaging findings, with an emphasis on MRI.

Psoriatic Onycho-Pachydermo-Periostitis.

Psoriatic onycho-pachydermo-periostitis (POPP) is an unfamiliar and poorly recognised condition first described in 1989 by Fournie et al. It is a variant of psoriatic arthritis comprising the triad of onycholysis, soft tissue thickening and radiographically apparent periostitis. Whilst typically affecting the great toe, any of the digits of the hands and feet may be affected. A 'drumstick' appearance to the digits of the foot is the most common clinical presentation and can be extremely painful. Nail changes are another hallmark of POPP and can be mistakenly diagnosed as fungal infection leading to lengthy periods of incorrect treatment. In this article, we will outline the clinical presentation, imaging features, pathogenesis and treatment options for POPP. Currently, the existence of POPP is not widely known. Awareness of this unusual condition will allow early appropriate treatment and can aid in the diagnosis of indeterminate seronegative disease.