Background

Calcaneal osteomyelitis remains a difficult condition to treat with high rates of recurrence and below knee amputation; particularly in cases of severe soft tissue destruction.

Background

Masses are not uncommon in the foot and ankle. Most of these masses are benign, often leading clinicians to underestimate their potential for malignancy.

Background

The treatment of chronic calcaneal osteomyelitis is a challenging and increasing problem because of the high prevalence of diabetes mellitus and operative fixation of heel fractures. In 1931, Gaenslen reported treatment of hematogenous calcaneal osteomyelitis by surgical excision through a midline, sagittal plantar incision. We have refined this approach to allow successful healing and early mobilization in a modern series of complex patients with hematogenous, diabetic, and postsurgical osteomyelitis.

Introduction

Primary ankle arthroplasty (TAR) is increasingly used to treat end-stage ankle arthritis. Reported revision rates of TAR vary from 8.5% to 11.1% at 9 years. Revision surgery remains technically challenging with options ranging from simple joint debridement to tibio-talar-calcaneal fusion. The efficacy of these procedures remains unclear and there is no consensus on optimal revision options.

Background

Open or arthroscopic ankle fusion (AAF) is a successful operative treatment for end-stage ankle arthritis. Evidence suggest that AAFs have better outcomes. In addition to the operative technique other patient-factors can influence outcomes. The most significant complication of ankle fusion is a non-union. To better understand the risk factors related to this we undertook a retrospective investigation of primary AAFs.

Tendinopathy can commonly occur around the foot and ankle resulting in isolated rupture, debilitating pain and degenerative foot deformity. The pathophysiology and key cells involved are not fully understood. This is partly because the dense collagen matrix that surrounds relatively few resident cells limits the ability of previous techniques to identify and target those cells of interest. In this study, we apply novel single cell RNA sequencing (CITE-Seq) techniques to healthy and tendinopathic foot/ankle tendons. For the first time we have identified multiple sub-populations of cells in human tendons. These findings challenge the view that there is a single principal tendon cell type and open new avenues for further study. Healthy tendon samples were obtained from patients undergoing tendon transfer procedures; including tibialis posterior and FHL. Diseased tendon samples were obtained during debridement of intractable Achilles and peroneal tendinopathy, and during fusion of degenerative joints. Single cell RNA sequencing with surface proteomic analysis identified 10 sub-populations of human tendon derived cells. These included groups expressing genes associated with fibro-adipogenic progenitors (FAPs) as well as ITGA7+VCAM1- recently described in mouse muscle but, as yet, not human tendon. In addition we have identified previously unrecognised sub-classes of collagen type 1 associated tendon cells. Each sub-class expresses a different set of extra-cellular matrix genes suggesting they each play a unique role in maintaining the structural integrity of normal tendon. Diseased tendon harboured a greater proportion of macrophages and cytotoxic lymphocytes than healthy tendon. This inflammatory response is potentially driven by resident tendon fibroblasts which show increased expression of pro-inflammatory cytokines. Finally, identification of a previously unknown sub-population of cells found predominantly in tendinopathic tissue offers new insight into the underlying pathophysiology. Further work aims to identify novel proteins targets for possible therapeutic pathways.

Background:

Avascular necrosis (AVN) of the talus is a painful condition caused by trauma, steroids, alcoholism and haematological disorders. It is difficult to treat and at present there is insufficient evidence in favour of any particular strategy. The aim of operative therapy should be to relieve symptoms, maintain the normal architecture of the talus and treat associated arthritis. Small case series have described early core decompression, retrograde tibiotalocalcaneal arthrodesies and open tibio-calcaneal arthrodesis. Open procedures risk further talar collapse by disrupting its blood supply, and tibiotalocalcanal fusion sacrifices both the ankle and subtalar joints. The hypothesis is that arthroscopic ankle fusion relieves symptoms of AVN talus while preserving the subtalar joint and preventing further collapse.

Introduction:

Vitamin D plays an important role in bone turnover. Deficiency (including borderline deficiency, or insufficiency) has a known association with fractures and has been linked to delayed or nonunion of fractures. We therefore routinely test vitamin D in cases of nonunion. Noting a high rate of vitamin D deficiency in this group, we instituted a policy to routinely screen for and treat vitamin D deficiency in both post-operative and pre-operative patients. We hypothesised that, in the post-operative patients, levels would correlate with rates of union.

Background:

Calcaneal osteotomy is an established technique in correcting hind foot deformity. Patients have traditionally received an open osteotomy through Atkins lateral approach. In order to reduce the rate of wound complications associated with the Atkins approach, a minimally invasive surgical (MIS) technique has been adopted since 2011. This uses a low-speed, high-torque burr to perform the same osteotomy under radiographic guidance. The results of the new MIS technique, including post-operative complication rates, are compared to the standard open approach.