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.

Aim

Management of bone and joint infection can be technically complex and often requires a prolonged course of antibiotics. Traditionally, bone and joint infection management utilises nurse-led outpatient parenteral antibiotic therapy (OPAT) where adherence is unlikely to be an issue. However, with increasing evidence in favour of oral therapy, the question of adherence merits further consideration. We describe the adherence of both oral (PO) and self-administered intravenous (IV) antibiotics in the treatment of bone and joint infection using paper questionnaires (8-item Modified Morisky Adherence Score (MMAS)) and, in a subset of participants, electronic pill containers (Medication Event Monitoring Systems*).

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.

Summary Statement

This study examined the fixation stiffness of 13 tibial and 12 femoral Salter-Harris fracture fixation methods, and determined that screws and screws+ k-wires methods provided the highest stability. In situations where k-wire use is unavoidable, threaded k-wires are preferable.

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.

INTRODUCTION – Tuberosity fractures of the calcaneum are rare injuries. The traditional operative treatment involves open reduction and internal fixation with a tension band wire construct. We have developed a new technique of fixing these fractures with internal fixation using cannulated screws and a figure of eight wire. This paper describes the new technique outlining its advantages and compares the 2 methods of fixation biomechanically to determine their properties with respect to fracture fixation.

METHOD – 20 sections of bovine bone were taken to act as an experimental model for the calcaneum. They were osteotomised to create the posterior process fracture model. 10 were fixed using a traditional tension band wire construct and 10 were fixed using the cannulated screw and wire construct. Each construct was subjected to biomechanical testing to identify the stiffness, energy to failure and load to failure.

RESULTS – During loading the cannulated screw and wire constructs showed a significant increase in stiffness and energy to failure compared to the tension band wire constructs

CONCLUSION – The increased stability of the cannulated screw construct demonstrated by the testing offers biomechanical benefit over the traditional tension band wire construct. This, as well as the improved technical aspects of the cannulated screw fixation, may be beneficial for clinical use.

We have treated 17 patients with bone defects of the tibia by internal bone transport using a stacked Taylor Spatial Frame.

There were 12 cases of infected non unions, 2 cases of osteomyelitis, 1 case of acute traumatic bone loss, 1 case of non union in a patient with neurofibromatosis, and 1 case of pseudoarthrosis of the tibia.

The mean bone defect was 51.8mm (range 10–100mm).

Leg length has been restored to within 10mm in 16 cases and to within 15mm in one case. All patients have united.

Residual deformity at the docking site or regenerate was negligible in 4 patients and less than 5 degrees in any plane in the remaining 13 patients. There have been two cases of re-fracture which have united with conservative treatment and 1 case of partial peroneal nerve palsy which is recovering.

The use of a stacked Taylor Spatial Frame system is effective in mediating bone transport resulting in predictable regenerate, accurate docking and minimal induced bone deformity.

The aim of this study was to determine the outcome of total hip arthroplasty, with regard to dislocation, at our unit.

1727 primary total joint arthroplasties and 305 revision total hip arthroplasties were performed between 1993 and 1996 at our unit. We followed up 1567 of the primary hip arthroplasties and 284 of the revision hip arthroplasties at 8 to 11 years post surgery. Patients were traced by postal questionnaire, telephone interview or examination of case notes of the deceased.

The dislocation rates by approach were: 23 out of 555 (4.1%) for the posterior approach, 0 out of 120 (0%) for the Omega approach and 30 out of 892 (3.4%) for the modified Hardinge approach.

58.5% of dislocations after primary total hip arthroplasty were recurrent. The mean number of dislocations per patient was 2.81.

8.1% of revision total hip arthroplasties suffered dislocation. 70% of these became recurrent. The mean number of dislocations per patient was 2.87. The vast majority of dislocations occur within 3 months of surgery.

To our knowledge this is the largest multisurgeon audit of dislocation after total hip arthroplasty published in the United Kingdom. The follow-up of 8 to 11 years is longer than most comparable studies.

The effect of pre-operative pain, physical function, mental function and multiple patient factors on patient outcome following TKR was examined.

After informed consent, 105 patients undergoing primary TKR completed preoperative SF-36 and WOMAC questionnaires and a Knee Society Score (KSS) was determined. These scores were repeated at 12 months. Patient data studied included age, gender, BMI and significant comorbid conditions such as diabetes, cardiac disease, and COPD. Statistical analysis included a univariate analysis, followed by a bivariate analysis and multiple regression analysis.

All physical dimensions of the SF-36, WOMAC and KSS showed highly significant improvements after one year. The KSS improved to a mean of 94.8 (p< 0.000001). For patients greater than 65 years of age, postoperative physical function was returned to normative scores for age matched controls. For patients less than 65, physical function did not reach age matched controls even though similar improvements in physical function were seen. Patients with lower physical function scores (PCS) pre-operatively showed greater improvement postoperatively yet did not reach the same absolute level of function as patients who had higher preoperative physical function. The mean PCS for men increased from 35 to 42, while for women it increased from 29 to 42 (p=0.042). Preoperative mental function (MCS) was a strong predictor of postoperative physical function. Patients with low preoperative MCS and one or more comorbid conditions were 10.1 times more likely to have a poor outcome following TKR.

Knowledge of preoperative physical function, mental function, gender, age and comorbid conditions improves prediction of post-operative physical function after TKR. Patients at high risk for little improvement following TKR are those with low preoperative mental function (MCS< 50) in addition to one or more comorbid conditions. These patients can be identified during the pre-operative period.

Clinical use of glucocorticoids engenders deleterious changes in bone fragility and initiates apoptosis in osteoblasts and osteocytes. The pathways leading to corticosteroid-induced death in bone remain unclear. Similarly little is known about the effects of ‘bone sparing’ bisphosphonates on osteocytes in vivo. We investigated the effects of bisphosphonates (BPs) on dexamethasone (Dex)-induced apoptosis in the murine osteocyte cell line, MLO-Y4 and studied the putative pathways involved by intervention with inhibitors of signalling molecules, such as p42/44 MAPK and protein kinase A (PKA). Cells were preincubated with N- & non N-containing BPs and/or inhibitors before insult with Dex or H₂O₂ for 5 hrs. Apoptotic morphology was revealed by acridine orange staining. Activation of p42/44 was identified using Western blotting and in situ immunocytochemistry in the presence or absence of serum.

Both N- & non N-containing BPs were shown to protect against cell death. The addition of inhibitors of p42/44 and PKA blocked the action of Dex. H₂O₂-induced apoptosis was not blocked by BPs or by any of the inhibitors. Dex appeared to activate p42/44 only in serum supplemented cultures. These data suggest that glucocorticoid but not oxidant-induced osteocyte apoptosis involves activation of p42/44 and that bisphosphonate engendered cell rescue is brought about by inhibition of these MAPK’s. Studies using truncated BPs that lack anti-resorptive activity, and therefore do not interrupt bone remodelling showed that these BPs were also able to protect osteocytes from glucocorticoid-induced death. The ability of bisphosphonates to influence MAPK activation and cell death in the osteocyte opens up exciting possibilities for pharmaceutical intervention during age and steroid hormone related osteocyte loss.