Chronicity of Anterior Cruciate Ligament Deficiency, Part 2: Radiographic Predictors of Early Graft Failure

Abstract

Background:Accumulating evidence suggests that long-term anterior cruciate ligament (ACL) deficiency can give rise to an abnormal tibiofemoral relationship and subsequent intra-articular lesions. However, the effects of chronic ACL deficiency (ACLD) on early graft failure after anatomic reconstruction remain unclear.Hypothesis:We hypothesized that patients with long-term ACLD lasting more than 5 years would have a greater rate of early graft failure due to insufficient intraoperative reduction of the tibia and that the preoperative and immediately postoperative abnormal tibiofemoral relationship in the sagittal plane, such as anterior tibial subluxation (ATS), would correlate with the graft status on postoperative magnetic resonance imaging (MRI).Study Design:Cohort study; Level of evidence, 3.Methods:A total of 358 patients who had undergone anatomic ACL reconstruction with hamstring grafts were divided into 5 groups based on chronicity of ACLD: (1) 0 to 6 months, (2) 6 months to 1 year, (3) 1 to 2 years, (4) 2 to 5 years, and (5) longer than 5 years. Preoperatively and immediately postoperatively, lateral radiographs in full extension were taken in all patients to evaluate the tibiofemoral relationship, specifically with regard to ATS, space for the ACL (sACL), and extension angle. All patients underwent MRI at 6 months to reveal graft status. Groups with a high rate of graft failure were further analyzed to compare demographic and radiographic factors between the intact and failure subgroups, followed by multivariate logistic regression analysis to identify predisposing factors.Results:Graft failure without trauma was observed in 4 (1.8%), 0 (0%), 1 (3.7%), 3 (9.7%), and 8 patients (17.7%) in groups 1, 2, 3, 4, and 5, respectively. Of the 76 patients in groups 4 and 5, significant differences were noted between the failure and intact subgroups in preoperative ATS (4.9 vs 2.4 mm, respectively; P < .01), side-to-side differences in sACL (sACL-SSD) (4.7 vs 1.9 mm, respectively; P < .01), extension deficit (4.4° vs 1.3°, respectively; P < .01), and chondral lesions (P = .02), while postoperative ATS and sACL-SSD showed no differences. Multivariate logistic regression analysis revealed that of these factors, preoperative sACL-SSD could be a risk factor for early graft failure (odds ratio, 3.2; 95% CI, 1.37-7.46).ConclusionEarly graft failure at 6 months increased in patients with ACLD longer than 2 years. In this population, preoperative sACL-SSD was the most significant risk factor for early graft failure on MRI. However, immediately postoperative radiographic measurements had no effect on graft failure rates.

Side-to-side anterior tibial translation on monopodal weightbearing radiographs as a sign of knee decompensation in ACL-deficient knees

“…The originality of the present study is the assessment of ATT under monopodal weightbearing conditions, which reflect physiological knee loading during activities of daily living better than passive MRI measurements in a supine position. Despite this obviousness, MRI has progressively replaced weightbearing radiographs to measure ATT in recent decades [14, 22, 32, 37]. Although these MRI studies have showed some interesting aspects of the natural history of ACL‐injured and reconstructed knees, one may question the clinical impact of these findings obtained under passive loading conditions.…”

“…The concept of passive ATT was re‐introduced in recent studies using MRI examination [14, 25, 37] or stress radiographs [38]. Several studies have demonstrated that an increased passive ATT was associated with the chronicity of the ACL rupture [22, 32], multiple ACL graft failures [13, 31], major knee laxity [20, 30] and worse clinical outcomes [21, 29]. Together, these observations have led to the development of the concept of sagittal decompensation of ACL‐deficient knees over time.…”

Comparison of Side-to-Side Difference in Posterior Tibial Slope in Knees With Acute Versus Chronic Anterior Cruciate Ligament Deficiency

“… 17 The association of increased ATT with the chronicity of ACL rupture was reported previously. 20 , 22 , 29 In a 2022 study, Macchiarola et al 20 compared the ACL-deficient knees of their patients with the unaffected side and found that exposure for >4 years and the presence of meniscal injury were associated with a higher ATT on monopodal weightbearing lateral radiographs. A comparison of PTS measurement with the contralateral intact knee was also questioned, and the mean PTS was 0.6° higher in the ACL-deficient knee (10.2° vs 9.6°) without a significant difference.…”

Anatomical rectangular tunnels identified with the arthroscopic landmarks result in excellent outcomes in ACL reconstruction with a BTB graft

“…In this case, the time from injury to surgery was more than 3 years (218 weeks) and bilateral meniscectomy was performed due to unrepairable tears of the bilateral menisci. Recent studies have also shown that a medial meniscal deficiency and a chronic ACL deficiency for more than 2 years were risk factors for graft failure in the early postoperative terms after anatomic ACLR [29, 45]. Tanaka et al recommended a decelerated rehabilitation programme to prevent the early graft failure in such cases with a chronic ACL deficiency [45].…”

“…Recent studies have also shown that a medial meniscal deficiency and a chronic ACL deficiency for more than 2 years were risk factors for graft failure in the early postoperative terms after anatomic ACLR [29, 45]. Tanaka et al recommended a decelerated rehabilitation programme to prevent the early graft failure in such cases with a chronic ACL deficiency [45]. Conversely, two cases with the anterior knee laxity of − 2 and − 3 mm showed a loss of extension of 3°–5°.…”