Related Experiment Video
Updated: Jul 17, 2026
Athymic Rat Model for Evaluation of Engineered Anterior Cruciate Ligament Grafts
Published on: March 26, 2015
Does transferred medial gastrocnemius flap help with knee extension during gait following proximal tibial
Dyuti Deepta Rano1, Love Kapoor2, Venkatesan Sampath Kumar1
1Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi 110029, India.
Introduction:
Patients undergoing proximal tibial endoprosthesis for bone tumors usually have a medial gastrocnemius flap for wound coverage, supposed to help in knee extension instead of normal flexor of the knee.
Objectives:
1. Does medial gastrocnemius flap participates in knee extension during normal gait? 2. What are the gait changes following proximal tibial endoprosthesis?
Materials & Methods:
This cross-sectional observational study included 52 patients who had proximal tibial endoprosthesis between January 2008 to January 2020 for bone tumours and regained maximum function with independent ambulatory capacity. Instrumented gait analysis was done according to Helen-Hayes protocol with a special surface EMG probe placed over the flap. Tc 99 m three-phase bone scan was used to evaluate flap viability.
Results:
Mean age was 27.92 ± 12.88 years and mean follow-up duration was 23.1 ± 4.2 months. Patients walked slower with mean velocity of 0.74 ± 0.23 m/s and mean cadence of 87.9 ± 10.3 steps/min. Mean knee flexion on the operated side was significantly decreased(89.42 ± 14.87° vs 125.38 ± 6.01°, p < 0.001). Mean swing time was significantly increased on the operated limb(0.56 ± 0.08 sec vs 0.46 ± 0.07 sec, p < 0.001) with consequent increase in mean single support phase on the normal limb(operated vs normal limb, 33.71 ± 5.05 % vs 40.81 ± 4.03 %, p < 0.001). Peak knee flexion in swing, total sagittal plane excursion, peak flexion loading response, peak knee extensor moment at early stance and peak ankle plantarflexion moment at stance decreased significantly on operated side. Electrical activity in the knee extensors decreased over the operated side. Bone scan confirmed flap viability in all.
Conclusion:
The medial gastrocnemius flap primarily provides successful soft tissue coverage but does not consistently adopt a functional role in knee extension during gait. Patients' walking patterns remain slower and asymmetrical but well compensated post-reconstruction, adopting a stiff-knee gait pattern with features of quadriceps avoidance.
