Concomitant ligamentous and meniscal injuries in floating knee.

BACKGROUND To identify and characterize the concomitant ligamentous and meniscal injuries in floating knee. METHODS A total of 37 cases of floating knee were enrolled. Arthroscopic or open surgical examination of the knee, Lachman test, posterior drawer's test, and varus and valgus stress tests under anesthesia were carried out to determine the incidence of knee injury. RESULTS Through arthroscopic and open surgical examinations, a medial meniscal tear was detected in 14 (37.8%) cases and a lateral meniscal tear in 11 (29.7%). Twenty-one (56.8%) patients had anterior cruciate ligament (ACL) injury including complete injury in 6 and incomplete injury in 15 cases. Three (8.1%) patients had posterior cruciate ligament (PCL) tear, including complete injury in 1 and incomplete injury in 2. Varus and valgus stress tests revealed that 10 (27.0%) and 7 (18.9%) patients had medial and lateral collateral ligament (MCL and LCL) laxity, respectively. Lachman test showed positive in 8 (21.6%) cases. Posterior drawer test showed positive in 3 (8.1%) cases. Twenty-six (70.3%) patients had knee ligamentous injuries. ACL injury was the most common ligamentous injury. ACL injury in 15 (71.4%) cases was associated with meniscal injury, including medial meniscal injury in 9 (42.9%) and lateral meniscal injury in 6 (28.6%). CONCLUSION Physicians should pay attention to the concomitant ligamentous and meniscal injuries in floating knee. Careful clinical examination with aid of arthroscopic examination is helpful for the early diagnosis and treatment of these injuries.