2025 ISAKOS Biennial Congress ePoster
Association Between Pivot-Shift Like Phenomenon In The Contralateral Uninjured Knee And Residual Pivot-Shift Phenomenon After Anterior Cruciate Ligament Reconstruction
Naosuke Nagata, MD, Kobe, Hyogo JAPAN
Kanto Nagai, MD, PhD, Kobe, Hyogo JAPAN
Yuta Nakanishi, MD, PhD, Kobe, Hyogo JAPAN
Kyohei Nishida , MD, PhD, Kobe, Hyogo JAPAN
Yuichi Hoshino, MD, PhD, Kobe, Hyogo JAPAN
Tetsuya Yamamoto, MD, PhD, Kobe, Hyogo JAPAN
Noriyuki Kanzaki, MD, PhD, Kobe, Hyogo JAPAN
Takehiko Matsushita, MD, PhD, Kobe, Hyogo JAPAN
Ryosuke Kuroda, MD, PhD, Kobe, Hyogo JAPAN
Kobe university graduate school of medicine, Kobe, Hyogo, JAPAN
FDA Status Not Applicable
Summary
Patients with pivot-shift like phenomenon in the contralateral uninjured knee were more likely to have residual pivot-shift phenomenon postoperatively than those without pivot-shift like phenomenon, suggesting that the laxity of the contralateral uninjured knee may be associated with residual pivot-shift phenomenon after ACL reconstruction.
ePosters will be available shortly before Congress
Abstract
Introduction
In patients with anterior cruciate ligament (ACL) injury, the pivot-shift like phenomenon is sometimes observed in the contralateral uninjured knee, but its relationship to postoperative knee stability of the ACL reconstructed knee is unclear. The purpose of this study was to investigate the relationship between the pivot-shift like phenomenon in the contralateral uninjured knee and postoperative knee stability after ACL reconstruction.
Methods
Patients who underwent hardware removal approximately 1 year after primary ACL reconstruction were included. Patients with history of contralateral knee injury were excluded. The pivot-shift test was performed on both knees preoperatively under general anesthesia and quantified posterior tibial translation (PTT, mm) and posterior tibial acceleration (PTA, m/s2) during the pivot-shift test using an electromagnetic sensor system (EMS) in both surgeries. Positive pivot-shift like phenomenon in the contralateral uninjured knee was defined as the presence of a wave indicating posterior tibial translation during the pivot-shift test. Patients were allocated into the “positive group” and “negative group” according to the presence or absence of the pivot-shift like phenomenon in the contralateral uninjured knee. Postoperative residual pivot-shift phenomenon after ACL reconstruction was defined as PTT greater than 2 mm. Patient background, the incidence of postoperative residual pivot-shift phenomenon, and pre- and postoperative PTT and PTA were compared between positive and negative group. The correlation between postoperative PTT/PTA on the ACL reconstructed knee and PTT/PTA on the contralateral uninjured knee was also evaluated in the positive group.
Results
In total, 92 patients were included in this study (25.7±11.7 years, male/female: 43/49). 28 patients (30.4%) were in the positive group and 64 (69.6%) were in the negative group. There was no significant difference in the patient demographics between positive and negative groups. The postoperative residual pivot-shift phenomenon was significantly more common in the positive group (14/28 patients; 50.0%) than the negative group (15/64 patients; 23.4%) (p=0.009). The positive group showed significantly greater preoperative PTT on the ACL reconstructed knee compared to the negative group (positive group: 7.8 ± 7.0 mm, negative group: 3.9 ± 3.3 mm; p<0.001). The postoperative PTT on the ACL reconstructed knee was significantly higher in the positive group compared to the negative group (2.2±1.8 mm, 1.4±2.4 mm; p=0.006). In the positive group, postoperative PTA on ACL reconstructed knee was positively correlated with PTA on the contralateral uninjured knee (r=0.38, p=0.035).
Discussion
Patients with a positive pivot-shift like phenomenon in the contralateral uninjured knee were more likely to have postoperative residual pivot-shift phenomenon compared to those with a negative pivot-shift like phenomenon in the contralateral knee, suggesting that the laxity of the contralateral uninjured knee may be associated with residual pivot-shift phenomenon after ACL reconstruction. Moreover, patients with a positive pivot-shift like phenomenon in the contralateral uninjured knee had greater preoperative PTT during the pivot-shift test in the ACL-injured knee than those with a negative pivot-shift like phenomenon in the contralateral uninjured knee, suggesting that physiological anterolateral rotatory knee laxity may be related to preoperative knee instability in ACL-injured knees.