[Congenital knee dislocation in Larsen syndrome treated by arthroplasty].

A 59-year-old woman with bilateral congenital knee dislocation due to Larsen syndrome was treated by arthroplasty. To prevent neurovascular deficiency and major loss of bone substance, a continuous joint distraction was performed by unilateral external fixation. After a period of 25 days and a leg lengthening of 4.5 cm, a constrained total knee endoprosthesis was implanted. Both operations and their postoperative courses were free of complications. A previously planned lengthening of the Achilles tendon was unnecessary.