2015 ISAKOS Biennial Congress ePoster #1322

The Predictors Associated With the Restoration of the Knee Extensor Strength in Athletes During the Early Postoperative Phase After Anatomic ACL Reconstruction - A Multiple Logistic Regression Analysis

Kyohei Nishida, MD, Pittsburgh, pennsylvania UNITED STATES
Daisuke Araki, MD, PhD, Kobe, Hyogo JAPAN
Takehiko Matsushita, MD, Kobe, Hyogo JAPAN
Yuya Ueda, PT, Kobe, Hyogo JAPAN
Tomoyuki Matsumoto, MD, PhD, Kobe, Hyogo JAPAN
Koji Takayama, MD, PhD, Kobe, Hyogo JAPAN
Masahiro Kurosaka, MD, Kobe, Hyogo JAPAN
Ryosuke Kuroda, MD, PhD, Kobe, Hyogo JAPAN

The Predictors Associated with the Restoration of the Knee Extensor Strength in Athletes during the Early Postoperative Phase after Anatomic ACL Reconstruction - A Multiple Logistic Regression analysis, Kobe, Hyogo, JAPAN

FDA Status Not Applicable

Summary: The male, the strength of the muscle peak torque at 60º/s of knee extensor before surgery, the fewer knee pain at the measurement could predict better recovery, and the continuous rehabilitation for 6 months was also indicated as a predictor relative to the 3 months and no rehabilitation groups.

Rate:

Abstract:

Background

It has been reported that the 85% recovery of knee extensor muscle strength relative to contralateral knees was crucial to securely return to competitive sports after anterior cruciate ligament (ACL) reconstruction. However, few studies have investigated the factors influencing the postoperative muscle recovery. Therefore, the purpose of this study was to examine the predictors associated with the restoration of knee extensor muscle strength in athletes during the early postoperative phase after anatomic ACL reconstruction using a multiple logistic regression analysis.

Methods

Two hundred and ten patients (129 male and 81 female) with unilateral ACL deficiency were included in this study. All patients were playing sports at the competitive level (Tegner activity score 7 or above). Quadriceps muscle strength were quantitatively measured using Myoret (RZ450, Kawasaki Heavy Industries Co., Japan) before surgery and 6 months postoperatively. Based on the isokinetic peak torque of knee extensor muscle at 60 º/s (% ratio of contralateral normal knee) at postoperative 6-months follow-up, all patients were separated into two groups. Considering the percentage peak torque of the operated knee, the patients higher than 85% were categorized as Group A, and those lower than 85% as Group B. To determine the predictors for Group A, a logistic regression model was built with the sex, the isokinetic peak torque of knee extensor muscle at 60º/s before surgery, the knee pain on measurements, and the continuous rehabilitation periods in the outpatient clinic (no rehabilitation, 3 months rehabilitation, 6 months rehabilitation).

Results

Ninety-nine patients categorized into Group A and 151 patients into Group B. According to the multiple logistic regression analysis, the male (Odds Ratio (OR) =2.27, 95% Confidence Interval (CI) =1.18-4.55), the higher strength of the isokinetic muscle peak torque of the knee extensor at 60 º/s before operation (OR=1.03, 95%CI=1.01-1.04), and lower knee pain on measurement (OR=3.70, 95%CI=1.42-11.56) predicted the higher restoration of the knee extensor muscle strength. Regarding the period of rehabilitation, the continuous 6 months rehabilitation was higher than no rehabilitation (OR=4.17, 95%CI=1.39-14.29), and 3 months rehabilitation (OR=2.33, 95%CI=1.05-5.56).

Conclusion

The predictors associated with the better restoration of knee extensor muscle strength in athletes after anatomic ACL reconstruction were demonstrated. The male, the strength of the muscle peak torque at 60º/s of knee extensor before surgery, the fewer knee pain at the measurement could predict better recovery. Regarding the period of rehabilitation, the continuous rehabilitation for 6 months was also indicated as a predictor relative to the 3 months and no rehabilitation groups.