2015 ISAKOS Biennial Congress ePoster #1332

Can Muscle Strength Recovery Predict the Recovery of Dynamic Lower Limb Control During Single Leg Squatting After Anterior Cruciate Ligament Reconstruction?

Shizuka Sasaki, Hirosaki, Aomori JAPAN
Eiichi Tsuda, Prof., Hirosaki, Aomori JAPAN
Yuji Yamamoto, MD, Hirosaki, Aomori JAPAN
Shugo Maeda, MD, Hachinohe, Aomori JAPAN
Takuya Naraoka, MD, Fujinomiya, Shizuoka JAPAN
Yuka Kimura, MD, Hirosaki, Aomori JAPAN
Yasuyuki Ishibashi, MD, Hirosaki, Aomori JAPAN

Department of Orthopaedic Surgery, Hirosaki University Graduate School of Medicine, Hirosaki, Aomori, JAPAN

FDA Status Not Applicable

Summary: This study indicated that recovery of dynamic lower limb control was not predicted from muscle strength recovery after anterior cruciate ligament reconstruction.

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Abstract:

Background

Secondary anterior cruciate ligament (ACL) injury after reconstructive surgery is one of the problems that have been still unsolved. Although recovery of lower limb muscle strength has been used as an indicator for timing of return to sports, safety criteria for return to sports has not been determined yet. The purpose of this study was to determine the relationship between recovery of dynamic lower limb control and muscle strength recovery after ACL reconstruction.

Materials And Methods

Twenty six males and 58 females who had primary ACL reconstruction were divided into 3 groups according to postoperative period (3-5, 6-8, and 9-12 months). The coronal and sagittal views during single-leg squatting were recorded using digital video cameras. The lower limb control in the coronal view was defined as limb angle (LA) that was angle between the lines formed from the marker on the anterior superior iliac spine to patella and that formed from the patella to ankle joint. In the sagittal view, knee flexion angle was defined as angle between the line formed from the marker on the greater trochanter to patella and that formed from patella to ankle joint, and the amount of change in knee flexion angle from standing to maximum knee flexion phase was defined as knee flexion ROM (KFR). Isokinetic knee flexor and extensor muscle strength was measured with Cybex 6000, and muscle strength of injured side normalized by that of uninjured side was defined as index of muscle strength recovery. The difference among three groups in LA, KFR and muscle strength recovery, and the relationship between lower limb control and muscle strength recovery was analyzed statistically.

Results

LA and KFR in the injured side were 163.3 ± 8.5° and 58.6 ± 10.7° in the 3-5 months group, 163.0 ± 8.5° and 55.4 ± 13.8° in the 6-8 months group and 159.6 ± 10.7° and 61.0 ± 11.4° in the 9-12 months group. There was no significant difference among three groups in either LA or KFR. Muscle strength recovery index of knee flexor and knee extensor were 0.83 ± 0.16 and 0.65 ± 0.15 in the 3-5 months group, 0.91 ± 0.16 and 0.74 ± 0.21 in the 6-8 months group and 0.92 ± 0.10 and 0.92 ± 0.14 in the 9-12 months group. There was no significant difference among three groups in knee flexor muscle strength recovery. The knee extensor muscle strength of 9-12 months groups was higher than that of 3-5 and 6-8 months group (p < 0.001 and < 0.001). LA was not correlated with muscle strength, while KFR was correlated with knee extensor muscle strength (r = 0.22, p = 0.041).

Conclusions

Although lower limb muscle strength recovered after ACL reconstruction, LA and KFR did not show significant differences among three groups. Only knee extensor muscle strength recovery showed a weak correlation with KFR, and it was indicated that recovery of lower limb control was not predicted from muscle strength recovery.