2019 ISAKOS Biennial Congress ePoster #763
The Biomechanical Effect of ALL Reconstruction Augmented to ACL Reconstruction on ACL Deficient Knee with Gross Instability
Yusuke Kawanishi, Nagoya, Aichi JAPAN
Masahiro Nozaki, MD, PhD, Nagoya, Aichi JAPAN
Makoto Kobayashi, MD, PhD, Nagoya, Aichi JAPAN
Sanshiro Yasuma, MD, Nagoya, Aichi JAPAN
Masahito Yoshida, MD, PhD, Nagoya, Aichi JAPAN
Hiroto Mitsui, MD, PhD, Nagoya, Aichi JAPAN
Takanobu Otsuka, MD, PhD, Prof., Nagoya, Aichi JAPAN
Nagoya City University, Nagoya, Aichi, JAPAN
FDA Status Not Applicable
The purpose of this study was to evaluate the effect on instability of the pivot shift test quantitatively by performing ALL reconstruction for ACL deficient knee which showed gross instability, and it demonstrated that augmented ALL reconstruction to ACL reconstruction could contribute to a significant stabilizing effect on the rotational element in the instability of the pivot shift test.
Anterolateral ligament reconstruction (ALLR) for ACL injury patients with gross instability in the pivot shift test involved in residual instability after anterior cruciate ligament reconstruction (ACLR) has been reported. However, few studies have reported the effect of augmented ALLR to ACLR on instability in the pivot shift test. The purpose of this study was to evaluate the biomechanical effect of augmented ALLR to ACLR in ACL deficient knee with gross instability.
Nine patients (male: 6, female: 3, mean age: 29.8 ± 11.8 years) with unilateral ACL injury who showed grade 3 in the pivot shift test and underwent anatomical double-bundle ACLR using semitendinosus tendon autograft and ALLR using gracilis tendon autograft were included in this study. The patients were evaluated intraoperatively in the following sequence: (1) unaffected knee preoperatively (Intact); (2) affected knee preoperatively (ACLD); (3) affected knee after ACLR (ACLR); (4) affected knee after ACLR and ALLR (2R). In each sequence, we performed quantitative measurement of the pivot shift test using inertial sensors (MicroStone Corporation, Japan) which could measure tibial acceleration (Acceleration) and tibial external rotational angular velocity (ER angular velocity) in the pivot shift test. All measurements were performed intraoperatively under general anesthesia. For adjusting to individual differences in the original instability, the values of the ratio to Intact (ACLD/I, ACLR/I, 2R/I) were also evaluated. A repeated ANOVA was conducted to compare the values, followed by multiple comparison testing with Bonferroni’s test. Statistical significance was set at p value < 0.05.
The Acceleration ( m/s2) of Intact, ACLD, ACLR, and 2R was 6.5 ± 8.7, 32.8 ± 8.8, 5.9 ± 1.9, and 5.1 ± 2.3. The ER angular velocity (deg/s) of Intact, ACLD, ACLR, and 2R was 126.3 ± 60.9, 359.2 ± 110.4, 204.8 ± 56.5, and 155.1 ± 36.7. Acceleration between Intact and ACLR, between Intact and 2R showed no significant difference, while ER angular velocity between Intact and ACLR showed a significant difference (p < 0.05) and that between 2R and Intact no significant difference. The value of ACLD/I, ACLR/I, 2R/I in Acceleration was 8.5 ± 4.3, 1.4 ± 0.5, and 1.2 ± 0.5. The value of ACLD/I, ACLR/I, 2R/I in ER angular velocity was 3.1 ± 1.2, 1.8 ± 0.5, and 1.4 ± 0.4. The value between ACLR/I and 2R/I in Acceleration showed no significant difference, while that in ER angular velocity showed a significant difference (p < 0.05).
This study demonstrated that isolated ACLR improved AP acceleration to a status equivalent to unaffected knee, and ER angular velocity to a non-equivalent status, while additional ALLR improved ER angular velocity better to a status equivalent to unaffected knee. The results showed that augmented ALLR to ACLR could contribute to a significant stabilizing effect on the rotational element in the instability of the pivot shift test for ACL deficient knee which shows gross instability.