Page 17 - Delaware Medical Journal - November 2016
P. 17
SCIENTIFIC ARTICLE
TABLE I: Subject Characteristics at Baseline (pre-op)
DESCRIPTIVES
SURGICAL APPROACH
LATERAL
POSTERIOR
P Value
Mean
SD
Mean
SD
Height (cm)
173
9
171
9
0.32
Weight (kg)
89
21
83
20
0.29
BMI (kg/m2)
29
5
28 6
6
0.51
Age (years)
59
6
68*
7
<0.01
Sex (male/female)
13/8
19/23
TABLE I
* = a significant P value <0.05 that shows significant difference between the groups
extension testing, the subject was seated on a dynamometer
Three trials were completed with a one-minute rest between each trial. Subjects were verbally encouraged to achieve maximum effort. The trial with the maximal force was recorded in Newtons and converted to kg then normalized to the subject’s body weight in kg.
Data Analysis
The primary analysis for this study was change in outcomes between the pre-operative and one-year time points. A repeated- measures analysis of variance (ANOVA) was performed for each variable. Time (pre-operative and one-year time points) were entered as the repeated measure and surgical approach
was entered as the between-group factor. In the presence of a
were performed for each group separately to determine if changes occurred over time. Follow-up independent samples T-tests were also performed to identify differences between groups at each time point. Descriptive data of means and standard deviations were reported for all three time points: pre-operative, three months after THA and one year after THA, although the three- month time point was not included in the longitudinal statistical analysis. Comparisons between groups for age, sex, height, weight, and BMI were evaluated at the pre-operative session.
RESULTS
Sixty-three subjects were included in this analysis (42 posterior, 21 lateral; Figure I). Demographic variables between the groups age (p<0.001). The Posterior group had a mean age of 68 while the Lateral group had an average age of 59 (Table I).
strength on the operated side (p=0.025). Follow-up independent t-tests revealed that there was no difference between groups at difference between groups at the one-year time point (Figure
II) with the posterior group being 31 percent stronger (p=0.018). Follow-up paired t-tests revealed a 0.023 percent body weight (15.8 percent) increase in strength for the posterior group group (p=0.256) by one year.
(Table II); however, all other variables with the exception of
hip abductor strength on the non-operated side and pain on the
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