Simple measurements in assessing muscle performance after an ACL reconstruction

Area of Science:

• Orthopedics
• Sports Medicine
• Rehabilitation Science

Background:

• Anterior cruciate ligament (ACL) reconstruction is a common orthopedic procedure.
• Assessing functional recovery and muscle performance post-ACL reconstruction is crucial for patient outcomes.
• Isokinetic strength testing is a gold standard but can be resource-intensive.

Purpose of the Study:

• To evaluate the validity of simple lower extremity muscle performance tests.
• To compare one-legged hop distance and thigh circumference measurements with isokinetic strength testing.
• To assess these measures 5-9 years after ACL reconstruction using a bone-patellar tendon-bone (BTB) autograft.

Main Methods:

• 86 patients underwent testing an average of 7 years post-ACL reconstruction.
• Evaluated one-legged hop for distance and thigh circumference (15 cm proximal to joint line).
• Compared results with isokinetic strength testing and clinical scores (IKDC, Lysholm, Marshall).

Main Results:

• Isokinetic knee extension strength deficit was 10% at 60°/sec; flexion deficits were smaller and not significant.
• Strength deficits correlated significantly with one-legged hop performance.
• Thigh atrophy correlated significantly with isokinetic strength deficits in knee extension and flexion.

Conclusions:

• One-legged hop testing demonstrates good correlation with isokinetic strength testing after ACL reconstruction, particularly for knee extension.
• The one-legged hop test is a practical, equipment-free method recommended for functional muscle performance evaluation post-ACL reconstruction.
• Thigh atrophy measurement is also a simple, valuable adjunct to hop testing, especially when isokinetic testing is unavailable.