T. Akisue et al., Evaluation of healing of the injured posterior cruciate ligament: Analysisof instability and magnetic resonance imaging, ARTHROSCOPY, 17(3), 2001, pp. 264-269
Purpose: Knees with an acute posterior cruciate ligament (PCL) injury and s
oft endpoint on posterior drawer test often develop less instability and a
firm endpoint at later follow-up. This type of healing is rarely seen in th
e acutely injured anterior cruciate ligament (ACL) and seems to be a. uniqu
e feature of healing fur PCL injury. The purpose of this study was to explo
re the healing process of the injured by means of instability measurement a
nd magnetic resonance imaging (MRI). Type of study: Consecutive sample. Met
hods: Forty-eight acute PCL deficient knees were followed up and evaluated.
We evaluated the detection of a so-called firm endpoint using a posterior
drawer test. We also determined the degree of posterior sag and categorized
them as 3 grades. Quantitative assessment of total anteroposterior (AP) tr
anslation of the tibia with a KT-1000 knee arthrometer (MedMetric, San Dieg
o, California) was performed by manual maximum AP drawer test with the knee
flexed 700. The continuity of the PCL was evaluated with sagittal and coro
nal T1- and T2-weighted MRIs. Results: Thirty-three (69%) cases exhibited a
so-called firm endpoint with a posterior drawer test. These cases showed s
tatistically less total AP translation (mean, 7.0 mm) in KT-1000 evaluation
, compared with 15 cases without an endpoint (mean, 11.9 mm). In addition,
36 cases (75%) with continuous low-intensity MRI showed statistically less
AP translation (mean 7.6 mm), compared with 12 cases (mean 11.4 mm) with di
srupted PCL image. Conclusions: These results suggest that a high percentag
e of acutely injured PCLs are likely to develop somewhat slack but continuo
us ligament-like tissue, and this continuous PCL-like tissue might function
as a posterior restraint of the tibia to certain extent. The elongated but
continuous PCL might paltry explain the relatively favorable prognosis of
this injury.