Abnormal knee mobility and meniscal injury.

Stress radiography for anteroposterior mobility of the knees was performed in 17 patients who had undergone medical meniscectomy and 10 patients who had undergone lateral meniscectomy. Sixteen of the patients were also tested for valgus-varus mobility. An increase in varus mobility following medical meniscectomy was primarily attributed to compression of the medical compartment space. No increase in anteroposterior mobility was found in the knees that had undergone meniscectomy compared with the uninjured contralateral knees. Anterior and total anteroposterior mobility were bilaterally greater in patients with medial meniscectomy compared with lateral meniscectomy. Furthermore, for the patients with medial meniscectomies anterior as well as total mobility were bilaterally greater than values obtained in 28 normal knees. We conclude that idiopathic anteroposterior hypermobility seems to predispose to injury of the medical meniscus. Perhaps individuals with generalized joint laxity should be warned against participating in contact sports.