Advertisement for orthosearch.org.uk
Results 1 - 5 of 5
Results per page:
Applied filters
Content I can access

Include Proceedings
Dates
Year From

Year To
Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXI | Pages 184 - 184
1 May 2012
G. NS P. W D. M K. JM
Full Access

Background

Current treatments for the prevention of thromboembolism include heparin and low-molecular weight heparins (LMWHs). A number of studies have suggested that long term administration of these drugs may adversely affect osteoblasts and therefore, bone metabolism. Xarelto(tm) (Rivaroxaban) is a new anti-thrombotic drug for the prevention of venous thromboembolism in adult patients undergoing elective hip and knee replacement surgery. The aim of this in vitro study was to investigate the possible effects of rivaroxaban on osteoblast proliferation, function, matrix mineralisation and gene expression compared to enoxaparin, a commonly used LMWH.

Methods

Primary human osteoblast cultures were treated with varying concentrations of rivaroxaban (0.013, 0.13, 1.3 and 13 μg/ml) or enoxaparin (0.1, 1.0 and 10 international units/ml). The effect of each drug on osteoblast function and matrix mineralisation was evaluated by measuring alkaline phosphatase activity and calcium deposition, respectively. The MTS assay was used to assess the effect of drug treatments on cell proliferation. Changes in osteocalcin, Runx2 and BMP-2 messenger RNA (mRNA) expression following drug treatments were measured by real-time polymerase chain reaction (PCR).


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXI | Pages 25 - 25
1 May 2012
Y-M. K S. G D. S A. K P. M H.S. G D M
Full Access

Pseudotumours (soft-tissue masses relating to the hip joint) following metal-on-metal hip resurfacing arthroplasty (MoMHRA) have been associated with elevated serum and hip aspirate metal ion levels, suggesting that pseudotumours occur when there is increased wear. This study aimed to quantify the wear of implants revised for pseudotumours and a control group of implants revised for other reasons of failure.

A total of 30 contemporary MoMHRA implants in two groups were investigated: (1) 8 MoMHRA implants revised due to pseudotumour; (2) 22 MoMHRA implants revised due to other reasons of failure. The linear wear of retrieved implants was measured using a Taylor-Hobson Roundness machine. The average linear wear rate was defined as the maximum linear wear depth divided by the duration of the implant in vivo.

In comparison with the non-pseudotumour implant group, the pseudotumour implant group was associated with: (1) significantly higher median linear wear rate of the femoral component: 8.1 um/year (range 2.75-25.4 um/year) vs. 1.97 um/year (range 0.82-13.00 um/year), p=0.002; and (2) significantly higher median linear wear rate of the acetabular component: 7.36 um/year (range 1.61-24.9 um/year) vs. 1.28 um/year (range 0.18-3.33 um/year), p=0.001. Wear on the acetabular cup components in the pseudotumour group always involved the edge, indicating edge-loading of the bearing.

Significantly greater linear wear rates of the MoMHRA implants revised due to pseudotumour support the in vivo elevated metal ion concentrations in patients with pseudotumours. This study is the first to confirm that pseudotumour occurs when there is increased wear at the MoM articulation. Furthermore, edge-loading may be the dominant wear generation mechanism in patients with pseudotumour.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXI | Pages 105 - 105
1 May 2012
M. H G. T D. B D. M G. A
Full Access

Introduction

Varus positioning of cemented ‘composite beam’ stems is associated with increased risks of aseptic loosening and stem fracture. We investigated whether the incidence of varus malalignment of the Exeter polished, double taper design in a multicentre prospective study adversely affected outcome after total hip replacement (THR).

Materials & Methods

A multicentre prospective study of 1189 THR was undertaken to investigate whether there is an association between surgical outcome and femoral stem malalignment. The primary outcome measure was the change in the Oxford hip score (OHS) at five years. Secondary outcomes included the rate of dislocation and revision, stem subsidence, quality of cementing. 938 (79.89%) were followed-up at five years.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXI | Pages 18 - 18
1 May 2012
D. M A.W.G. K R. S A.H. D N.B. S
Full Access

Patients undergoing total knee arthroplasty (TKA) experience significant post-operative pain. We report the results of a new comprehensive patient care plan to manage peri-operative pain, enable early mobilisation and reduce length of hospital stay in TKA.

A prospective audit of 1081 patients undergoing primary TKA during 2008 and 2009 was completed. All patients followed a planned programme including pre-operative patient education, pre-emptive analgesia, spinal/epidural anaesthesia with propofol sedation, intra-articular soft tissue wound infiltration, post-operative high volume intermittent ropivacaine boluses with an intra-articular catheter and early mobilisation. The primary outcome measure was the day of discharge from hospital. Secondary outcomes were verbal rating pain scores on movement, time to first mobilisation, nausea and vomiting scores, urinary catheterisation for retention, need for rescue analgesia, maximum flexion at discharge and six weeks post-operatively, and Oxford score improvement.

The median day of discharge to home was post-operative day four. Median pain score on mobilisation was three for first post-operative night, day one and two. 35% of patients ambulated on the day of surgery and 95% of patients within 24 hours. 79% patients experienced no nausea or vomiting. Catheterisation rate was 6.9%. Rescue analgesia was required in 5% of cases. Median maximum flexion was 85° on discharge and 93° at six weeks post-operatively. Only 6.6% of patients had a reduction in maximum flexion (loss of more than 5°) at six weeks. Median Oxford score had improved from 42 pre-operatively to 27 at six weeks post-operatively. The infection rate was 0.7% and the DVT and PE rates were 0.6% and 0.5% respectively.

This multidisciplinary approach provides satisfactory post-operative analgesia allowing early safe ambulation and discharge from hospital. Anticipated problems did not arise, with early discharge not being detrimental to flexion achieved at six weeks and infection rates not increasing with the use of intra-articular catheters.


Introduction

Rolando type base of thumb metacarpal fractures are potentially debilitating injuries, which can be difficult to manage because of their inherent instability. Malunion is associated with stiffness, pain and weakness of pinch grip. We aimed to assess the outcome of a simple technique for the treatment of this fracture using the principle of ligamentotaxis, with a static, 2-pin external fixator spanning the trapeziometacarpal joint. We present the results and functional outcomes of this technique.

Methods

A consecutive series of 8 patients (7 males, 1 female) with Rolando type intra-articular fractures of the base of the first metacarpal was retrospectively reviewed. All cases were performed by the senior author using a static, 2-pin Mini-Hoffman external fixator. Case notes and radiographs were reviewed, and patients' functional outcome assessed using the Quick Disability of Arm, Shoulder and Hand (Quick DASH) scoring system. Mean age of the group was 32.8 years (range 18.1-52.3 years). Mean follow-up was 2.7 years (range 3.5 months to 6.0 years).