Posterior Tibial Slope in Patients Undergoing Anterior Cruciate Ligament Reconstruction With Patellar Tendon Autograft: Analysis of Subsequent ACL Graft Tear or Contralateral ACL Tear

Abstract

Background: Reports on greater posterior tibial slope (PTS) and its relationship to subsequent anterior cruciate ligament (ACL) injury show conflicting results; it has not been studied much in patients after ACL reconstruction with patellar tendon autograft (PTG). Hypothesis: Patients who suffered a subsequent ACL injury would have a larger PTS than patients who did not suffer a subsequent injury after primary or revision ACL reconstruction. Study Design: Cohort study; Level of evidence, 3. Methods: Patients received primary (n = 2439) or revision (n = 324) ACL reconstruction with PTG and were followed prospectively to determine the rate of graft tear and contralateral ACL tear. The PTS was measured preoperatively on digital lateral view radiographs. Intersecting lines were drawn along the medial tibial plateau and posterior tibia; the value of the acute angle at the lines’ intersection was then subtracted from 90° to obtain the PTS. This procedure was completed by a clinical assistant with an intrarater reliability of 0.89. Chi-square analysis and t tests were used to determine the differences between rate of tears and measurements between groups. A threshold of PTS ≥10° was used for analysis. Results: The mean follow-up time was 11.6 ± 4.0 years. After primary surgery, the mean PTS in patients with graft tears was 5.4°± 3.1° versus 4.8°± 2.9° for patients without a tear ( P = .041). The mean PTS was 4.9°± 3.4° for patients with contralateral tears (not statistically significantly different than the no-tear group; P = .80). Furthermore, patients with primary reconstruction with PTS ≥10° had a statistically significantly higher rate of graft tear (9.7%) than patients with PTS ≤9° (4.8%) ( P = .003), but not a higher rate of contralateral tear. Among patients undergoing revision surgery, there were no statistically significant differences between the graft tear, contralateral tear, and no-tear groups with relation to PTS ≥10°. Conclusion: After primary ACL reconstruction, patients with PTS >10° had a higher rate of subsequent graft tear but not a higher rate of contralateral tear. With revision surgery, there was no significant association between PTS and the rate of subsequent tear. Therefore, caution should be exercised when considering more radical interventions, such as osteotomy, to prevent retear in patients with high PTS.

Posterior Tibial Slope in Patients With Torn ACL Reconstruction Grafts Compared With Primary Tear or Native ACL: A Systematic Review and Meta-analysis

“…There were also 2 studies that used the anterior tibial cortex 19 , 97 and 3 studies that used the posterior tibial cortex for their measurement techniques. 43 , 44 , 86 …”

“… 58 , 104 Others have shown that patients with graft rupture after previous ACL reconstruction (ACLR) have greater PTS than those undergoing primary ACLR. 72 , 86 To protect reconstruction grafts from variations in PTS, some authors advocate the use of slope reducing, anterior closing-wedge high tibial osteotomy. 22 , 24 , 27 …”

Femoral and Tibial Bony Risk Factors for Anterior Cruciate Ligament Injuries Are Present in More Than 50% of Healthy Individuals

“…More recently, some authors have shown that patients with posterior tibial slope .10°had a higher rate of subsequent graft tear, leading the investigators to consider osteotomy in these cases to prevent retear. 27 All of these anatomic parameters may play a role in the pathogenesis of ACL tears; however, it should be noted that ''normal'' differences exist according to sex and ethnicity. For example, the intercondylar notch is wider in men than in women, 6,17,20,28,30 which may explain the higher prevalence of ACL injuries in women.…”

“…More recently, some authors have shown that patients with posterior tibial slope >10° had a higher rate of subsequent graft tear, leading the investigators to consider osteotomy in these cases to prevent retear. 27…”

Clarifying the structure of repeated serious injuries on female rugby players

“…Shelborne 11 suggested that female players had relatively high frequency of knee injuries, and knee surgery took time to recover. In recent years, serious injuries in female players have also been reported.…”