We retrospectively reviewed 409 ultrasound studies performed on 384 patients referred with lateral hip pain in both a native hip and post THA.
One-hundred and eleven patients were excluded including patients with bilateral symptoms,
bilateral THR and patients with imaging unavailable for review.
A total of 273 patients were therefore included in the study.
Mean age was 59.7 years (range 14-96,
SD 15.0) and there was a female (n = 211,
77.3%) predominance.
One hundred and seven (39.2%) patients had a THA.
Findings on ultrasound are detailed in table 1.
The range of measurements on the normal asymptomatic side in our study population are detailed in table 2.
Table 1: Ultrasound findings in patients with symptoms in THA and native hip.
Ultrasound finding
|
THA (n=107)
|
Native hip (n=166)
|
Tendinopathy
|
68 (63.6%)
|
76 (45.8%)
|
Subgluteal bursitis
|
19 (17.8%)
|
34 (20.5%)
|
Trochanteric bursitis
|
47 (43.9%)
|
34 (20.5%)
|
Table 2: Femoral offset,
global offset,
trochanteric impingement distance and abductor lever arm in the healthy,
unaffected hip.
Measurement
|
Mean (mm) ± SD
|
Range(mm)
|
Femoral offset
|
50.0 ± 8.7
|
22.4-76.5
|
Global offset
|
82.3 ± 10.9
|
40.1-116.1
|
Trochanteric Impingement Distance
|
41.2 ± 8.6
|
13.8-63.1
|
Abductor lever arm
|
66.6 ± 8.9
|
45.0-98.4
|
Mean FO,
GO,
ALA and TID in the symptomatic native hip and THA are detailed in tables 3 and 4 respectively. There was no statistically significant difference between FO,
GO,
ALA and TID and findings of gluteal tendinopathy,
subgluteal bursitis and trochanteric bursitis on ultrasound in native hips or THA (tables 3 and 4).
Table 3: Measurements of femoral offset,
global offset,
trochanteric impingement distance and abductor lever arm in the symptomatic native hip with ultrasound findings of subgluteal bursitis,
trochanteric bursitis and tendinopathy (presented as mean (mm) ± standard deviation (SD).
Measurements in the normal asymptomatic native hip have been included for reference.
|
Normal
|
Subgluteal bursitis
|
Trochanteric bursitis
|
Tendinopathy
|
Femoral offset (mm)
|
50.0±8.7
|
47.6±6.9 (p=0.59)
|
47.9±7.1 (p=0.79)
|
48.7±8.8 (p=0.34)
|
Global offset (mm)
|
82.3±10.9
|
80.8±9.4 (p=0.94)
|
80.9±8.6 (p=0.82)
|
81.9±9.6 (p=0.09)
|
Trochanteric impingement distance (mm)
|
41.2±8.6
|
42.1±8.5 (p=0.88)
|
41.6±9.7 (p=0.51)
|
41.5±8.4 (p=0.22)
|
Abductor lever arm (mm)
|
66.6±8.9
|
64.9±7.3 (p=0.66)
|
65.9±8.6 (p=0.67)
|
65.9±9.1 (p=0.48)
|
Table 4: Measurements of femoral offset,
global offset,
trochanteric impingement distance and abductor lever arm in the symptomatic hip post THA with ultrasound findings of subgluteal bursitis,
trochanteric bursitis and tendinopathy (presented as mean (mm) ± standard deviation (SD).
Measurements in the normal asymptomatic native hip have been included for reference.
|
Normal
|
Subgluteal bursitis
|
Trochanteric bursitis
|
Tendinopathy
|
Femoral offset (mm)
|
50.0±8.7
|
50.2±8.4 (p=0.98)
|
53.1±9.9 (p=0.54)
|
52.2±9.3 (p=0.42)
|
Global offset (mm)
|
82.3±10.9
|
83.7±9.7 (p=0.65)
|
84.5±9.9 (p=0.96)
|
84.1±10.2 (p=0.49)
|
Trochanteric impingement distance (mm)
|
41.2±8.6
|
37.0±10.8 (p=0.48)
|
37.9±10.7 (p=0.74)
|
38.8±9.9 (p=0.32)
|
Abductor lever arm (mm)
|
66.6±8.9
|
64.1±9.9 (p=0.96)
|
67.6±9.9 (p=0.35)
|
65.8±10.0 (p=0.10)
|
There was almost perfect inter-observer agreement for TID (ICC 0.81,
95% CI 0.70-0.89) and substantial agreement for ALA (ICC 0.68,
95% CI 0.50-0.80).
There was moderate inter-observer agreement for both FO and GO measurements (ICC 0.50,
95% CI 0.29-0.67 and ICC 0.56,
95% CI 0.38-0.72 respectively).