T. Muneta et al., ANTERIOR KNEE LAXITY AND LOSS OF EXTENSION AFTER ANTERIOR CRUCIATE LIGAMENT INJURY, American journal of sports medicine, 24(5), 1996, pp. 603-607
This study was performed to examine the relationship between knee exte
nsion loss and the length of time after injury. We also wanted to comp
are anterior laxity in anterior cruciate ligament-injured knees in the
early and late stages of injury. Loss of knee extension was measured
in 81 patients with anterior cruciate ligament injury using lateral ra
diography with the injured leg relaxed and elevated. Extension loss wa
s defined as the difference in maximal extension angle between the inj
ured and uninjured knees. Average loss of extension was 3.6 degrees in
the 17 knees in which the anterior cruciate ligament had been torn 3
weeks or less before examination (the acute injury group) and 0.6 degr
ees in the 64 knees in which the anterior cruciate ligament had been t
orn more than 3 weeks before examination (the chronic injury group). T
he extension loss in the acutely injured knees was significantly great
er compared with that in the uninjured knees and in the chronically in
jured knees. Arthrometric measurements using the KT-1000 arthrometer w
ere reliable to diagnose an acute tear. There was no correlation betwe
en the degree of extension loss and arthrometric anterior knee laxity
measurements. In 12 patients, the initial extension deficit in the ear
ly stage of injury significantly resolved with time, and manual maximu
m arthrometric measurements of anterior knee laxity improved spontaneo
usly with time.