A prospective clinical study of the results of prosthetic ligament replacement of the ACL with the Gore-Tex polytetrafluoroethylene prosthesis was undertaken. Thirty-three (80%) of 41 patients were available at a minimum 36 month followup (mean, 48 months; range, 36 to 62). Kaplan-Meier survival analysis revealed an 82% probability of survival of the polytetrafluoroethylene ligament at the 48 month followup. When compared to the same data at a minimum 24 month followup, the results appeared to have deteriorated somewhat over time. Three possible "predictors" of failure at later followup were identified: preoperative subjective symptoms of swelling, subjective symptoms of giving way at 2 years, and an increased anterior drawer sign at 2 years.

The aim of this study was to evaluate the clinical outcome of freeze-dried compared to fresh frozen allograft tissue used as a substitute for a ruptured ACL of the knee. In addition, the incidence of any graft rejection phenomena was recorded. Forty-one patients with ACL deficient knees underwent reconstructive surgery using a patellar bone-tendon-bone allograft that had been freeze-dried (Group 1, N = 14) or fresh frozen (Group 2, N = 27). All patients underwent the same implant technique and rehabilitation program. Followup ranged from 24 to 36 months. The evaluation consisted of subjective, objective, and instrumented laxity testing (KT-1000, MEDmetric, San Diego, CA; and Genucom, FARO Medical Technologies, Inc., Montreal, Canada). There were 31 males and 10 females. Eleven (79%) patients in Group 1 thought their knee was "normal" or "improved," and 25 (93%) in Group 2 thought the same. In addition, 10 (71%) patients in Group 1 denied any "giving way," compared to 26 (96%) in Group 2. The mean Lysholm knee score in Group 1 was 86/100 (range, 22 to 100) compared to 92/100 (range, 59 to 100). Clinical examination included the Lachman test and tests for anterior drawer sign and pivot shift. Postoperatively, Group 1 patients had the following results: Lachman test--seven Grade 0, six Grade 1, one Grade 2; anterior drawer sign--eight Grade 0, five Grade 1, one Grade 2; and pivot shift--seven Grade 0, five "trace," and two "present."(ABSTRACT TRUNCATED AT 250 WORDS)