Recent findings in both basic studies and clinical studies have led to the improvement of the outcome of anterior cruciate ligament (ACL) reconstruction. However, graft failure occasionally occurs, resulting in the need for revision ACL reconstruction. Some technical difficulties exist which are specific to revision surgery. In this paper, we describe our methods for evaluating patients with failed ACL reconstruction in order to investigate the mechanism of failure to improve future preoperative planning. 6 patients consisting of 5 males and 1 female, with an average age of 24 years (ranging from 20 to 31 years) were studied. The average time from primary to revision ACL surgery was 48 months (ranging from 18 to 72 months). All patients who underwent revision ACL surgery were studied postoperatively (all with harvested contralateral patellar tendon grafts). We also reviewed stability (Lachman test, Pivot shift test) and recurvatum, and performed radiographic examination.
Lachman test was-(nagative) in 5 cases and ± in 1 case after the patients resumed their regular sports activity. After revision ACL reconstruction, the findings were-(negateve) in 3 cases and ± in 3 cases. Pivot shift test was-(negative) in 6 cases after the patients resumed their regular sports activity. After revision ACL reconstruction, the findings were-(negative) in 4 cases and ± in 2 cases.
The recurvatum was 15° in 1 case and 5° in 1 case.
The side to side difference in the anterior laxity was 2.2mm measured with Telos SE after the patients resumed their regular sports activity. After revision ACL reconstruction, it was 2.5mm.
From the magnetic resonance imaging (MRI) findings, low signal intensity was observed in 2 cases, intermediate intensity in 3 cases and high signal intensity in 1 case after the patients resumed their regular sports activity. After revision ACL reconstruction, low signal intensity was observed in 1 case while intermediate intensity was observed in 5 cases.
The failure cases were due to sports. In addition, 1 case had inadequate rehabilitation.
The Lysholm Knee Scores were 94.2 after the patients resumed their regular sports activity, 90.5 after revision ACL reconstruction.
The main causes of failed ACL reconstruction were sports related re-injuries. In order to reduce the occurrence of such sports related re-injuries, proper attention should be paid to such factors as: notch impingement, general joint laxity and inadequate rehabilitation.
