Possible reflex pathway between medial meniscus and semimembranosus muscle: an experimental study in rabbits

Abstract

Meniscus is a well innervated tissue with four types of receptors. These receptors are mainly concentrated at the anterior and posterior horns. Although they are intended to be a part in reflex arc, this function has not been thoroughly evaluated. We hypothesized that electrical stimulation of the normal meniscus would elicit electromyographic activity of the hamstring muscle via the reflex arc. Five adult domestic male rabbits were used in this study. Under general anesthesia, knee arthrotomy and thigh dissection were done to expose medial meniscus and semimembranosus muscle. Menisci were stimulated by Teflon-coated bipolar needle electrodes. Needles were placed in the posterior horn of the medial menisci. Two Teflon-coated monopolar needle electrodes were placed in semimembranosus muscle. A four-channel electromyograph was used for recording. Two different potentials were recorded from the target muscle. The first response had a very short distal latency and its amplitude was changing in accordance with the strength of the stimulus, suggesting that this response was being elicited by direct muscle stimulation. The second delayed response with less amplitude also appeared in some traces. The latency and the amplitude of this second response were fairly stable stating that this delayed response was being generated by a reflex pathway and seen in all subjects.

The Basic Science of Human Knee Menisci

“…They contribute to load transmission, ¶¶ shock absorption, 10,49,94,96,170 stability, 51,100,101,109,155 nutrition, 23,24,84,141 joint lubrication, 102-104,141 and proprioception. 5,15,81,88,115,147 They also serve to decrease contact stresses and increase contact area and congruity of the knee. 91,172 …”

Magnetic Resonance Imaging of the Postoperative Meniscus

“…25 In the normal medial meniscus, mechanoreceptors may be crucial in a reflex arc that stimulates the semimembranosus to contract, including the segment that pulls the medial meniscus posterior horn posteriorly, thus preventing the meniscus from being trapped and injured with knee flexion. 26 By contrast, derangements and some surgeries involving the meniscus posterior horn may contribute to the inhibition of semimembranosus muscle activation and alter meniscus mobility, thus changing the internal joint forces. 27 In a subset of patients, symptoms of giving way or buckling of the knee may be due to an alteration in stretchreflex excitability rather than ligamentous laxity.…”

Arthroscopic Dissection of the Distal Semimembranosus Tendon: An Anatomical Perspective on Posteromedial Instability and Ramp Lesions

“…The authors demonstrated that electrical stimulation of the PHMM produced an electroneuromyography-verified response of the semimembranosus muscle. Subsequently, Akgun et al 11 . reported that mechanical stimulation of the posterior horn receptors during flexion or rotation of the rabbit knee joint also causes semimembranosus muscle contraction and therefore posterior translation of the medial meniscus.…”