Reliability of knee joint range of motion and circumference measurements after total knee arthroplasty: does tester experience matter?
OBJECTIVE
Two of the most utilized outcome measures to assess knee joint range of motion (ROM) and intra-articular effusion are goniometry and circumference, respectively. Neither goniometry nor circumference of the knee joint have been examined for both intra-tester and inter-tester in patients with total knee arthroplasty (TKA). The purpose of this study was to determine the intra-tester and inter-tester reliability of active and passive knee joint ROM and circumference in patients with TKA when administered by physiotherapists (testers) with different clinical experience.


METHODS
The design was an intra-tester, inter-tester and intra-day reliability study. Nineteen outpatients (10 females) having received a TKA were examined by an inexperienced and an experienced physiotherapist. Following a standardized protocol, active and passive knee joint ROM and circumference measurements were obtained using a universal goniometer and a tape measure, respectively. To establish reliability, intraclass correlation coefficients (ICC(2,1)) and smallest real difference (SRD) were calculated.


RESULTS
The knee joint ROM and circumference measurements were generally reliable (ICC > 0.8) within and between physiotherapists (except passive knee extension). Changes in knee joint ROM of more than 6.6 degrees and 10 degrees (except active knee flexion) and knee joint circumference of more than 1.0 cm and 1.63 cm represent a real clinical improvement (SRD) or deterioration for a single individual within and between physiotherapists, respectively. Generally, the experienced tester recorded larger knee joint ROM and lower circumference values than that of the inexperienced tester.


CONCLUSIONS
In clinical practice, we suggest that repeated knee goniometric and circumferential measurements should be recorded by the same physiotherapist in individual patients with TKA. Tester experience appears not to influence the degree of reliability.
Jakobsen
Thomas Linding
TL
Department of Physiotherapy, Copenhagen University Hospital at Hvidovre, Copenhagen, Denmark. tlj26@hotmail.com
Christensen
Malene
M
Christensen
Stine Sommer
SS
Olsen
Marie
M
Bandholm
Thomas
T
D000368:Aged; D053587:Arthrometry, Articular / Q000592:standards*; D019645:Arthroplasty, Replacement, Knee / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results