Recovery in horizontal gait after hip
resurfacing vs. total hip arthroplasty at
6-month follow-up – a RCT study
C. Jensen 1, P. Aagaard 2, S. Overgaard 1
Orthopaedic Research Unit – Dept. of Orthopaedic Surgery and Traumatology, Odense, Denmark
2 Institute of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark
1
Results
Methods
Forty-three patients were randomized into either
S-THA or R-THA. Three-dimensional gait data
were collected at self-selected normal and
maximal walking speed. Primary outcome was
gait speed while secondary outcomes comprised
selected
temporospatial
and
kinematic
parameters obtained during horizontal walking.
Explorative outcome was the relationship
between hip and knee muscle strength (MVC)
and horizontal gait function in THA patients. Data
was collected pre-operatively, 8 and 26 weeks
post-surgery.
FIGURE 1: Gait speed self-selected normal (A) and maximal (B) walking speed, mean ± 95% C.I.
2.2
R-THA
S-THA
1.4
p=.36
1.2
Age at surgery, yrs
55 (6.2)
57 (5.1)
Gender, F:M
3:16
7:11
Operated, L:R
13:6
11:7
Leg length, m
.86 (.03)
.88 (.06)
Follow-up, weeks
8.7 (1.0)
8.2 (1.0)
Follow-up, weeks
24.5 (1.4)
24.4 (0.8)
*
8 weeks
p=.03
1.6
p=.06
*
1.4
1.2
p=.71
Preoperatively
1.8
1.0
26 weeks
Preoperatively
8 weeks
26 weeks
FIGURE 2: Temporospatial gait parameters at self-selected normal walking speed, mean ± 95% C.I.
1.8
160
(B)
(A)
1.7
150
1.6
140
1.5
1.4
p=.82
1.3
p=.32
1.2
1.0
120
Preoperatively
8 weeks
100
26 weeks
50
50
45
*
40
*
p=.79
p=.54
35
30
130
p=.67
110
1.1
Single Support [% GC]
Characteristic
R-THA
(n=18)
Gait Speed [m/s]
1.6
(C)
S-THA
(n = 19)
S-THA
2.0
1.8
1.0
R-THA
(B)
2.0
TABLE 1: Baseline characteristics, mean (SD)
No significant difference between groups
(A)
2.2
Cadence [step/min]
Standard total hip arthroplasty (S-THA) is the
established surgical treatment for patients older
than 65 years with progressive osteoarthritis.
However, implant survivorship curves decline
more rapidly in patients younger than 50 years.
Resurfacing hip arthroplasty (R-THA) has
therefore been suggested as an alternative for
younger more active patients. Walking ability is
one of the most common and useful outcome
measures used in hip replacement patients, and
the ability to safely ambulate is considered a
prerequisite for discharge from most orthopedic
facilities. Improvements in walking ability and
kinematics have been suggested after hip
resurfacing, but no study has objectively
assessed this aspect in a randomized clinical
trial.
The present data could not provide evidence to
support the hypothesis that resurfacing total hip
arthroplasty should lead to a superior recovery
in gait and hip kinematics compared to standard
total hip arthroplasty in younger hip arthritis
patients. Maximal isolated leg muscle strength
was a predictor of horizontal gait performance,
and thus provides an important and valid
functional outcome measure for individuals
undergoing total hip arthroplasty.
Preoperatively
8 weeks
26 weeks
Double Support [% GC]
Background
Conclusion
There was no effect of treatment on horizontal
self-selected normal gait speed. However, an
effect of treatment was observed on maximal
walking speed where S-THA subjects walked
faster than the R-THA subjects (P = 0.03, Fig.1).
No differences in the recovery of temporospatial
parameters were observed between treatment
groups (Fig. 2). Also, peak hip flexion and peak
hip adduction angles recorded during the stance
phase were similar in both groups (Table 2). The
explorative outcome analysis of the study
showed that maximal isometric knee and hip
muscle
strength
(MVC)
were
positively
associated with gait speed, step length and
cadence during maximal walking (R2= 0.13-0.37,
P < .05) (Not-shown)
Gait Speed [m/s]
To test the hypothesis that (i) a superior
recovery in gait would be observed following
resurfacing total hip arthroplasty (R-THA)
compared to standard total hip arthroplasty (STHA) and (ii) to investigate the hypothesized
relationship between mechanical hip and knee
muscle performance (MVC) and horizontal gait
function in patients with total hip replacement
Stride Length [m]
Purpose
Preoperatively
8 weeks
p=.13
26 weeks
(D)
40
30
20
p=.25
p=.18
10
0
Preoperatively
8 weeks
26 weeks
TABLE 2: Kinematic gait parameters during the stance phase at self-selected normal speed, mean (SD)
Gait parameter
Side
Operated
Peak Hip Flexsion [deg]
Non-operated
Operated
Peak Hip Adduction [deg]
Non-operated
Pre-surgery
Time
8 wks post-surgery
26 wks post-surgery
R-THA
31 (6.4)
33 (5.5)
34 (4.8)
S-THA
31 (6.3)
33 (6.5)
34 (6.9)
R-THA
36 (6.0)
36 (6.7)
36 (5.5)
S-THA
33 (5.5)
36 (6.8)
35 (5.7)
R-THA
6 (3.5)
5 (3.8)
5 (2.5)
S-THA
9 (4.1)
7 (3.4)
8 (4.0)
R-THA
7 (4.4)
6 (5.8)
7 (3.6)
S-THA
9 (4.0)
9 (4.6)
9 (4.6)
Treatment
No significant difference between groups at any time points