Abstract
Aims: Whether the harvesting of Hamstring graft for ACL reconstruction results in compromised knee flexion strength and proprioception, and hence knee function?
Methods: A prospective study, approved by the local Ethics committee, was undertaken to assess the function and strength of the knee joint in patients who had ACL reconstruction performed using a four-strand Hamstring graft. The contra lateral knee acted as control. 28 knee joints were studied with mean follow up 70.1 weeks (range 52–156). All operated knees received an extensive set regime of pre and post-operative physiotherapy. Assessment tools were Biodex dynamometry and stabilometery for hamstring and quadriceps strength and proprioception, clinical examination, Laxometer arthrometry for measured anterior draw. The knee function was assessed using a questionnaire incorporating International knee documentation committee (IKDC) proforma, Lysholm 2 score and Tegner’s activity scale.
Results: Objective assessment using Biodex dynamometer pre-operatively showed that mean peak flexion torque was 67.86 N-m (SD± 24) in the involved knee and 76.1 N-m (SD± 22.2) in the healthy knee. Following reconstruction (mean 70.1 weeks post-op), mean peak flexion torque around the knee joint was 69.8 N-m (SD± 20.6) and 76.2 N-m (SD ±22.1) in the operated and non-operated knee (control) respectively. Flexion torque in the operated knee was as good as the control and not significantly different from the pre-operative levels.
Mean Flexion: Extension ratio around the knee joint was 53.9% in the operated and 53.2% in non-operated sides. Mean stability index, measured using open eye stabilometery, was 3.5 (SD±2.4) on the operated and 3.1 (SD±1.8) on the non-operated side, with no significant difference demonstrable.
The mean age of patients was 28.3 (range 18–44) years. Mean IKDC score following reconstruction was 74.8 (range 49–100), SD±18.5. There was significant improvement in pre and post reconstruction mean Lysholm 2 and Tegner’s activity scores (p< 0.01). Subjective function of the knee on a scale of 0–10 improved from pre-operative 3.1 to post-operative 7.7 (p< 0.01). Arthrometry at 25-degree flexion and 130 N force using Laxometer showed mean anterior laxity 5.3mm on the operated side and 3.1 on the healthy side (side to side difference 2.2mm).
Conclusion: The function of the knee improved significantly following ACL reconstruction both objectively and subjectively. The harvesting of Hamstring as a graft neither compromises the flexion torque nor the proprioception around the knee joint.
The abstracts were prepared by Mr Roger Smith. Correspondence should be addressed to him at the British Association for Surgery of the Knee, c/o BOA, Royal College of Surgeons of England, 35–43 Lincoln’s Inn Fields, London WC2A 3PN.
