Vibration
Perception Threshold and Hip Osteoarthritis in Multicenter Ostoearthritis Study

Background/Purpose:

It
is hypothesized that reduced sense of position in space leading to increased
impact force and unbalanced foot strike during gait contributes to osteoarthritis
(OA).  In previous work from the Multicenter Osteoarthritis Study (MOST), we
reported that high VPTs were associated with knee OA especially in men and
women aged 65 or greater.  However, the association of VPT and hip OA has not
been studied for a large population.  It is unclear whether sensory deficits
which are mostly distal can lead to hip OA.  We examined the association of
vibratory sense with radiographic hip OA in participants of MOST. 

Methods:

MOST
is a NIH funded longitudinal study that recruited participants at risk for knee
OA.  We carried out a cross sectional assessment of vibration perception
threshold (VPT) and hip OA at the 60 month exam. Using a protocol from knee OA
studies, we measured VPT at 3 anatomical bony sites: 1st MTP, tibial
tuberosity, and radial styloid.  VPT measures the voltage threshold at which a
subject senses vibration, thus a higher VPT threshold represents a greater
sensory deficit.  Long limb radiographs obtained at the same visit were read for
radiographic hip OA (RHOA) using criteria devised at UCSF that incorporated
features of modified Croft criteria.  Symptomatic hip OA (SHOA) was defined as
hips with pain and RHOA.  Persons with total knee replacements, total hip
replacements and diabetes were excluded from this analysis. 

Because
large differences in VPT exist between genders and age, men and women were evaluated
separately and divided into age subgroups: <65 years and ≥65 years. 
The unaffected hips of persons with unilateral RHOA may be intermediate in VPT
between hips with OA and normal hips without any radiographic knee OA, so a
limb-based analysis was performed with three hip groups:  1) RHOA; 2)
contralateral “normal” hip of unilateral RHOA; and 3) control hip (no RHOA in
either hip).  Statistical analysis entailed using linear regression with GEE to
compare VPT between groups adjusted for age, BMI, radiographic knee OA, and
accounting for the correlation between hips.

Results:

VPT
was assessed in 612 men and 930 women.  Of the 612 men, 72 hips were excluded from
analysis (missing RHOA status due to poor quality radiographs).  Of the 930
women, 99 hips were excluded.  For both men and women for all age groups, VPTs
were not higher for those with RHOA or SHOA compared to controls (results only
shown for men age < 65 years).  VPTs at the radial styloid on the non-OA side
for those with unilateral RHOA and SHOA were significantly lower than controls
for men age < 65 years.    

Conclusion:

In
MOST, RHOA was not associated with any meaningful alteration in VPT.