The objective of this proof of concept study was to explore whether some total hip arthroplasty (THA) patients with well-functioning implants achieve normal sagittal plane hip kinematics during walking gait. Sagittal plane hip kinematics were recorded in eleven people with well-functioning THA (71 ± 8 years, Oxford Hip Score = 46 ± 3) and ten healthy controls (61 ± 5 years) using a three-dimensional motion capture system as they walked over-ground at a self-selected velocity. THA patients were classified as high- or low-functioning (HF and LF, respectively) depending on whether the mean absolute difference between their sagittal plane hip kinematics was within one standard deviation of the control group (5.4°) or not. Hedge's g effect size was used to compare the magnitude of the difference from the control group for the HF and LF THA groups.Abstract
Objectives
Methods
Orthopaedic surgical hoods rely on an intrinsic fan to force clean external air over the wearer and allow potentially contaminated and expired air to flow down and away from the surgical field. Carbon dioxide (CO2) is produced through aerobic metabolism and can potentially accumulate inside the hood. Levels above 2500ppm have been shown to affect cognitive and practical function in flight simulator studies. Maximum Health and Safety Executive (HSE) 8-hour exposure limit is 5000ppm There is a paucity of data on real-world CO2 levels experienced during arthroplasty surgery whilst wearing a hood. CO2 levels were continuously recorded during 31 elective arthroplasties, both primary and revision. Data was collected for surgeon and assistant. Data was recorded at 0.5Hz throughout the procedure utilising a Bluetooth CO2 detector, worn inside a Stryker Flyte™ surgical helmet worn with a toga gown. Four surgeons contributed real time data to the study. This data was augmented with experimental data, investigating varying fan speeds and activity levels. Median operative duration was 82 minutes (range 36–207). The average CO2 level across all procedures was 2952ppm, with 22 of the cases having a mean above 2500ppm, but none having a mean above 5000ppm. For each procedure, the time spent above 2500 and 5000 ppm was calculated, with the average being 68.4 % and 5.6% respectively. The experimental data demonstrated higher CO2 levels with lower fan speed, and at higher activity levels, and levels exceeding 15000 ppm during gentle exercise. During operative cases, low fan speed cases did have a marginally higher mean CO2 value than high fan speed (3033.02 and 2903.56 respectively) but the small numbers of cases (n=10) where this data was captured limit the relevance of this difference. The use of surgical helmets for elective orthopaedic surgery, can results in CO2 levels regularly rising to a point which may affect cognitive function. This study recommends the use of a higher fan speed where possible to minimise the risk of such CO2 levels, and recommends further research in this area.
The objective of this study was to determine the kinematic factor(s) underlying the reduction in walking velocity displayed by total hip arthroplasty (THA) patients in comparison to healthy controls during walking gait. Eleven patients with well-functioning THA (71 ± 8 years, Oxford Hip Score = 46 ± 3) and ten healthy controls (61 ± 5 years) participated within this study. Sagittal plane lower limb kinematics were captured using a 10 camera Qualisys motion capture system, sampling at 200Hz, as participants walked overground at a self-selected pace. Bivariate linear regression was used to explore the relationship between walking velocity and a number of kinematic variables in a deterministic manner. Kinematic variables significantly associated with walking velocity were compared between THA and healthy groups utilising independent samples t-tests.Abstract
Objectives
Methods
