Anatomy of Master Knot of Henry: A morphometric study on cadavers

Abstract

Objective: The objective of this study was to evaluate the features offlexor hallucis longus (FHL), flexordigitorum longus (FDL) andflexor digitorum accessorius (FDA) muscles with relevance to the tendongrafts and to reveal the location of Master Knot of Henry (MKH).Methods: Twenty feet from ten formalinŞxed cadavers were dissected, which were in the inventory ofAnatomy Department of Medicine Faculty, Mersin University. The location of MKH was identiŞed. Interconnections of FHL and FDL were categorized. According to incision techniques, lengths of FHL andFDL tendon grafts were measured. Attachment sites of FDA were assessed.Results: MKH was 12.61± 1.11 cm proximal to Şrst interphalangeal joint, 1.75 ± 0.39 cm below tonavicular tuberosity and 5.93± 0.74 cm distal to medial malleolus. The connections of FHL and FDL wereclassiŞed in 7 types. Tendon graft lengths of FDL according to medial and plantar approaches were6.14± 0.60 cm and 9.37 ± 0.77 cm, respectively. Tendon graft lengths of FHL according to single, doubleand minimal invasive incision techniques were 5.75± 0.63 cm, 7.03 ± 0.86 cm and 20.22 ± 1.32 cm,respectively. FDA was found to be inserting to FHL slips in all cases and it inserted to various surfaces ofFDL. Conclusion: The exact location of MKH and slips was determined. Two new connections not recorded inliterature were found. It was observed that the main attachment site of FDA was the FHL slips. Thesurgical awareness of connections between the FHL, FDL and FDA, which participated in the formation oflongflexor tendons of toes, could be important for reducing possible loss of function after tendontransfers postoperatively.