Association among neuromuscular and anatomic measures for patients with knee osteoarthritis.
OBJECTIVE
To investigate neuromuscular and anatomic factors involved in varus gonarthrosis by identifying measures associated with degenerative changes.


METHODS
Descriptive study. Individual measures that explained substantial portions of the variability in ratings of knee joint-degenerative changes in patients with knee medial compartment osteoarthritis.


METHODS
Outpatient orthopedic clinic and biomechanics and muscular assessment laboratory.


METHODS
Volunteer sample of 20 subjects (age range, 59 +/- 9 yr) with no history of neurologic disease.


METHODS
Not applicable.


METHODS
We assessed degenerative changes, varus alignment, standing balance, and knee proprioception. Weight-bearing radiographs were used to assess the extent of degenerative changes and the degree of varus alignment. Single-limb standing balance control was assessed through tests performed on a force platform. Knee proprioception was assessed with an isokinetic dynamometer, using a joint angle replication test.


RESULTS
Forward-stepwise multiple linear regression indicated that the extent of degenerative changes could be best predicted from a linear combination of the independent variables, varus alignment, and standing balance (R =.80, F(2,17) = 14.81, p =.0002). Sixty-four percent of the variability in ratings of degenerative changes was explained by alignment and standing balance measures (37% by varus alignment, 27% by standing balance). Alignment and balance measures were poorly correlated (r =.12, p =.63), further suggesting that they provided different information about gonarthrosis.


CONCLUSIONS
Although varus alignment is widely accepted as a clinically important factor in gonarthrosis, and is the focus of many treatment efforts, our results suggest that objective measures of standing balance are also important. As a result, the potential impact of rehabilitation to improve the control of standing balance should be further evaluated in this patient population.
Birmingham
T B
TB
Faculties of Health Sciences, University of Western Ontario, London, Ont, Canada. tbirming@julian.uwo.ca
Kramer
J F
JF
Kirkley
A
A
Inglis
J T
JT
Spaulding
S J
SJ
Vandervoort
A A
AA
D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000534:rehabilitation; D004856:Postural Balance; D011434:Proprioception; D011859:Radiography