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Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_10 | Pages 6 - 6
1 Jun 2023
Watts D Bye D Nelson D Chase H Nunney I Marshall T Sanghrajka A
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Introduction

Derotation osteotomies are commonly performed in paediatric orthopaedic and limb reconstruction practice. The purpose of this study was to determine whether the use of a digital inclinometer significantly improves the accuracy in attaining the desired correction.

Materials & Methods

We designed an electronic survey regarding derotation femoral osteotomy (DFO) including methods of intra-operative angular correction assessment and acceptable margins of error for correction. This was distributed to 28 paediatric orthopaedic surgeons in our region. A DFO model was created, using an anatomic sawbone with foam covering. 8 orthopaedic surgeons each performed two 30-degree DFOs, one using K-wires and visual estimation (VE), and the other using a Digital Inclinometer (DI). Two radiologists reported pre and post procedure rotational profile CT scans to assess the achieved rotational correction.


The Bone & Joint Journal
Vol. 102-B, Issue 7 | Pages 904 - 911
1 Jul 2020
Sigmund IK Dudareva M Watts D Morgenstern M Athanasou NA McNally MA

Aims

The aim of this study was to evaluate the diagnostic value of preoperative serum CRP, white blood cell count (WBC), percentage of neutrophils (%N), and neutrophil to lymphocyte ratio (NLR) when using the fracture-related infection (FRI) consensus definition.

Methods

A cohort of 106 patients having surgery for suspected septic nonunion after failed fracture fixation were studied. Blood samples were collected preoperatively, and the concentration of serum CRP, WBC, and differential cell count were analyzed. The areas under the curve (AUCs) of diagnostic tests were compared using the z-test. Regression trees were constructed and internally cross-validated to derive a simple diagnostic decision tree.


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XVIII | Pages 76 - 76
1 May 2012
Silikas N Watts D Batra GS
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Despite the increasing use on uncemented implants, cement continues to be used for hip and knee replacement in both primary and revision cases. Whilst the exact clinical relevance of reducing cement porosity, and thereby increasing its strength, is unclear in such applications, successive generations of mixing and implanting have all concentrated on reducing the amount of air in cement.

The aim of the present study was to elucidate whether the use of a power tool mixing device could reduce cement porosity more than the use of mixing under vacuum conditions alone. Furthermore, we determined if variability in cement porosity could also be reduced with power tool mixing compared with hand mixing under vacuum conditions. Cement was mixed in three different ways in a Stryker cement mixing cartridge. For group 1, cement was mixed by hand with no vacuum. For group 2, cement was mixed manually under vacuum. For group 3, cement was mixed under vacuum using the Stryker Revolution system. For all three groups, cement was stored and mixed at the same temperature and humidity. To study cement porosity, we used 3-dimensional computerised microtomography, a technique which has previously been used by other investigators. Porosity for the sample in group 1 was 9.4%, and for groups 2 and 3, mean sample porosity was 1.8% (SD 1.3) and 1.1% (SD 1.0) respectively. The large difference in porosity between group 1 and the other groups was evident on visual examination. These pores were absent when vacuum was applied. This confirms the results of several studies that have shown significant cement porosity under non-vacuum mixing conditions, even when there is strict adherence to mixing methods. Under vacuum conditions, using the Stryker Revolution system, further small reduction in cement porosity was achieved compared with manual mixing. Both Groups 2 and 3 showed variations in porosity between specimens from the same batch (intra-batch) and between batches (inter-batch). Individual specimens also demonstrated regional variations in internal porosity. Whilst the absolute reduction in overall porosity was small between the two groups (0.7%), the results favoured mixing using a rotary power tool. In addition the Revolution device was of great benefit from an ergonomic perspective. It enabled low porosity specimens to be mixed with greater ease, homogeneity and reproducibility than with manual mixing. Using the Revolution device was operator independent and involved less effort. This is likely to be of benefit in the operating room. In current practice, staff members often do not work with the same surgical team on a repeated basis, so the surgeon is likely to get greater cement consistency with such a device. It is likely to be easier to mix cement well for less experienced members of the surgical scrub team. Whilst an experience operator may be able to produce a mix of cement with very low porosity by manual mixing, it is still likely to be higher than one mixed using a power assisted device. Also, since porosity of following is related to cement working time, greater reproducibility will aid the surgeon when timing insertion of components, provided other environmental conditions remain constant.