Graft Survivorship After Anterior Cruciate Ligament Reconstruction Based on Tibial Slope

Abstract

Background: Increased tibial slope (TS) is believed to be a risk factor for anterior cruciate ligament (ACL) tears. Increased TS may also promote graft insufficiency after ACL reconstruction. Purpose: To delineate the relationship between TS and single as well as multiple graft insufficiencies after ACL reconstruction. Study Design: Cohort study; Level of evidence 3. Methods: We retrospectively identified 519 patients who had sustained ACL graft insufficiency after primary or revision ACL reconstruction (1 graft insufficiency, group A; 2 graft insufficiencies, group B; and ≥3 graft insufficiencies, group C). In addition, a subgroup analysis was conducted in 63 patients who received all surgical interventions by 2 specialized high-volume, single-center ACL surgeons. TS was measured by an observer with >10 years of training using lateral knee radiographs, and intrarater reliability was performed. Multiple logistic and univariate Cox regression was used to assess the contribution of covariates (TS, age, sex, and bilateral ACL injury) on repeated graft insufficiency and graft survival. Results: The study included 347 patients, 119 female and 228 male, who were 24 ± 9 years of age at their first surgery (group A, n = 260; group B, n = 62; group C, n = 25). Mean TS was 9.8°± 2.7° (range, 3°-18°). TS produced the highest adjusted odds ratio (1.73) of all covariates for repeated graft insufficiency. A significant correlation was found between TS and the number of graft insufficiencies ( r = 0.48; P < .0001). TS was significantly lower in group A (9.0°± 2.3°) compared with group B (12.1°± 2.5°; P < .0001) and group C (12.0°± 2.6°; P < .0001). A significant correlation was seen between the TS and age at index ACL tear ( r = −0.12; P = .02) as well as time to graft insufficiency ( r = −0.12; P = .02). A TS ≥12° had an odds ratio of 11.6 for repeated ACL graft insufficiency. Conclusion: The current results indicate that patients with a markedly increased TS were at risk of early and repeated graft insufficiency after ACL reconstruction. Because the TS is rarely accounted for in primary and revision ACLR, isolated soft tissue procedures only incompletely address recurrent graft insufficiency in this subset of patients.

Controversies in ACL revision surgery: Italian expert group consensus and state of the art

“…A high success rate of ACL revision in association with tibial opening osteotomy is reported in the literature, in particular if a concomitant reduction of the slope is performed [ 24 , 25 ]. An increased tibial slope (> 12°) is regarded as a risk factor for not only a first ACL injury but also early failure after ACL reconstruction, due to the excessive tension on the graft [ 10 ].…”

“…Many studies have identified some risk factors for revACLr, such as male sex, young age, and elevated body mass index as well as an early return to sport and pivoting sport after the reconstruction. However, traumatic re-injury is only the tip of the iceberg; there are also many technical factors, such as tunnel malpositioning, inadequate graft fixation, graft choice for primary reconstruction, insufficient anterolateral structures, and an elevated/excessive posterior tibial slope [ 7 – 10 ].…”

Simultaneous Correction of Varus Deformity and Posterior Tibial Slope by Modified Hybrid Closed-Wedge High Tibial Osteotomy

“… 13 Among several parameters, a large posterior tibial slope has been proven to be one of the strongest risk factors for ACL injuries, as well as graft tear and insufficiency after ACL reconstruction due to increased strain in the ACL and increased anterior tibial translation in ACL-deficient knees. 1 , 2 Therefore, in cases with ACL deficiency involving a large posterior tibial slope, especially in revision cases, anterior closing-wedge osteotomy has been performed as a slope-reducing osteotomy concomitant with ACL reconstruction, and satisfactory clinical outcomes with restored knee stability and graft-failure prevention have been reported. 3 , 4 , 5 However, in such chronic ACL deficiency cases, MM injuries as well as medial compartment OA often are also present, and simultaneous varus and slope correction would be required.…”

“…A large posterior tibial slope has been proven to be a risk factor for anterior cruciate ligament (ACL) injuries 1 as well as graft tear and insufficiency after ACL reconstruction. 2 Therefore, in cases of ACL deficiency involving a large posterior tibial slope, especially revision cases, anterior closing-wedge osteotomy as a slope-reducing osteotomy with concomitant ACL reconstruction is considered. 3 , 4 , 5 However, in such chronic ACL deficiency cases, medial meniscus (MM) injuries and medial compartment osteoarthritis (OA) often also are present, and simultaneous varus and slope correction would be required.…”

Effect of Anterior Tibial Closing Wedge Osteotomy on Coronal Tibial Alignment in Relation to Preoperative Medial Proximal Tibial Angle and Wedge Height

“…8,11,13,28 Patients with >12° of PTS, measured according to the proximal anatomic axis, are at high risk for further ACL injuries. 2,7,22,29…”