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.

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.

Introduction:

TTC fusion for the salvage of failed TARs with significant bone loss using a hindfoot nail and femoral head allograft has been reported in a number of small series. We present our experience of this procedure.

Background

Evaluation of outcomes and satisfaction following hallux valgus (HV) surgery is usually retrospective and rarely uses patient-reported outcome measures (PROMs).

Introduction

Ankle replacement is now common in the UK.

In a tertiary referral NHS practice, between 1997–2011 we implanted two types of cementless mobile bearing total ankle replacements (TAR).

Introduction

In 1927, Lambrinudi described a variant triple fusion for the treatment of paralytic “drop foot”. This involved closing wedge osteotomies and fusion to correct the deformities predominantly caused by Polio. The eradication of Polio has seen a shift in its use to the correction of other complex hind foot deformities. The technique has relevance in modern Orthopaedics for other neurological and degenerate conditions. There have been few published series of this technique since 1927.

We describe a series of 14 complex corrective triple arthrodeses to illustrate the power of Lambrinudi's concepts. We believe Lambrinudi's original description has relevance in terms of modern day complex hindfoot deformity correction.