2025 ISAKOS Biennial Congress ePoster
The Relationship Between Knee Stability After ACL Reconstruction and Anterior Tibial Subluxation
Hibiki Kakiage, MD, Maebashi, --お選びください-- JAPAN
Kazuhisa Hatayama, MD, PhD, Maebashi, Gunma JAPAN
Satoshi Nonaka, MD, Maebashi, Gunma JAPAN
Masanori Terauchi, MD, Gunma-Ken JAPAN
HIrotaka Chikuda, MD, PhD, Maebashi, Gunma JAPAN
Gunma Medical University, Maebashi, Gunma, JAPAN
FDA Status Not Applicable
Summary
Knee instability after ACL reconstruction was associated with larger pre- and postoperative ATS, younger age, medial meniscus injury, ramp lesions, and postoperative rotational instability.
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Abstract
Background
Anterior tibial subluxation (ATS) in knee extension is seen in anterior cruciate ligament (ACL) injured knees. It has been reported that preoperative ATS adversely affects postoperative anterior stability and risks early graft failure. The purpose of this study was to investigate the association between knee stability after ACL reconstruction and ATS.
Methods
A total of 113 patients who underwent primary ACL reconstruction at our hospital were included. Patients with ACL injury of the contralateral knee were excluded. Preoperatively, all patients were taken lateral radiographs in full extension of both knees to evaluate ATS. ATS was measured the distance between a perpendicular line to femoral condyles and tibial condyles with respect to the medial tibial plateau to one decimal place. The SSD of anterior translation using Telos Stress devise at 20 degrees at 1 year postoperatively, and the two groups were compared: those with 3 mm or more (F group) and those with less than 3 mm (S group). We investigated whether age, height, weight, gender, time from injury to surgery, posterior tibia slope (PTS) and hyperextension angle from lateral radiographs in knee extension, SSD in ATS, meniscal tear, mechanism of injury, pivot shift test at 1 year postoperatively. The student t test and the chi-square test were used to compare the two groups. P values <.05 were considered significant. All statical analyses were performed using SPSS software.
Results
There were 36 patients in the F group and 76 in the S group. Preoperative ATS was significantly larger in F group (2.5 ± 2.0mm) than in S group (1.3 ± 1.5mm) (p=0.002). Postoperative ATS was also significantly larger in F group (1.7 ± 2.5mm) than in S group (0.4 ± 1.9mm) (p=0.003). Age was significantly lower in F group (25.4 ± 11.2 vs. 31.2 ± 14.0, p=0.015), and medial meniscus injury (67% vs. 36%, p=0.002), ramp lesion (47% vs. 25%, p=0.008), and pivot shift test (0.28 ± 0.5 vs. 0.05 ± 0.3, p=0.001) were significantly larger in F group. ROC analysis showed an AUC of 0.690, and the cut-off value of preoperative ATS was 1.85mm.
Discussion
Present study showed that knee instability after ACL reconstruction was associated with larger pre- and postoperative ATS, younger age, medial meniscus injury, ramp lesions, and postoperative rotational instability. Clinically, it may be important to perform appropriate meniscal repair at the time of ACL reconstruction to avoid causing increased forces in the ACL graft and reduce postoperative ATS after ACL reconstruction. Patients with a combination of risk factors may need to be considered for additional lateral procedures such as ALL reconstruction or LET.