MORPHOLOGICAL STUDY OF THE MUSCLE- BONE INTERFACE IN MAN
Creators: name: Mustafa, Prof. Dr. Hesham N.
name: Dr. Mostafa Kamel Ibrahim El-Sayed, Prof.
name: Dr. Fouad Yehia Ahmed, Prof.
name: Prof. Dr. Hassan Mostafa Serry, Assistant
Publisher: name: figshare
Year: 2015
Subjects: classificationCode: 320220
subject: Pathology (excl. oral pathology)
classificationCode: 320307
subject: Oral medicine and pathology
classificationCode: 310299
subject: Bioinformatics and computational biology not elsewhere classified
classificationCode: 310201
subject: Bioinformatic methods development
classificationCode: 319999
subject: Other biological sciences not elsewhere classified
classificationCode: 310114
subject: Systems biology
classificationCode: 310112
subject: Structural biology (incl. macromolecular modelling)
classificationCode: 329999
subject: Other biomedical and clinical sciences not elsewhere classified
classificationCode: 310199
subject: Biochemistry and cell biology not elsewhere classified
classificationCode: 310911
subject: Animal structure and function

description: MORPHOLOGICAL STUDY OF THE MUSCLE- BONE INTERFACE IN MAN
The aim of the present study was to investigate the histological structure of the fleshy muscle-bone interface in selected limb muscles in man, as compared to that of the enthesis, in an attempt to clarify the way muscle fibers transmit their contractile force to adjacent bone. The muscle specimens were taken from biceps and tendocalcaneus as examples for the tendon-bone attachment (enthesis), from external intercostal, brachioradialis, and external oblique muscles as examples for the linear fleshy attachment, and from infraspinatus and brachialis as examples for the fleshy attachment over a wide area.
The muscle-bone interface specimens were collected form six formalin-fixed dissecting room elderly male cadavers with no gross pathology. The whole muscle-bone interface was extracted so that each specimen included the muscle and the underlying bone tissues. The specimens were fixed in 10% neutral buffered formol saline for one week, and then decalcified with 10% EDTA for about 4-6 weeks. Dehydrated in ascending grades of alcohols, cleared in xylol, and embedded in paraffin wax. Serial sections were cut at 8-µm thickness and stained with Haematoxylin and eosin, and Masson's trichrome.
In the present work, it was found that tendon-bone attachment of either biceps brachii or tendocalcaneus was formed of four zones; zone 1 (Z1) of dense connective tissue, zone 2 (Z2) of fibrocartilage, zone 3 (Z3) of calcified fibrocartilage, and zone 4 (Z4) of compact bone. Serrated basophilic line "tidemark" was usually seen between fibrocartilage and calcified fibrocartilage zones. Moreover, differences in the distribution and population of chondrocytes occurred between zone 2 (Z2) and zone 3 (Z3).
On the other hand, the muscle-bone interface of brachialis, infraspinatus, brachioradialis, and external intercostal muscles was noticed to be formed of three zones; zone 1 (Z1) of skeletal muscle tissue, zone 2 (Z2) of dense connective tissue, and zone 3 (Z3) of compact bone. The dense connective tissue zone interposed between the skeletal muscle fibers and the bone differed in its density and structure between the studied muscles. Moreover, some regions of the attachment site of the external oblique muscle were observed to include zones of fibrocartilage and calcified fibrocartilage so that a mixture of fibrocartilaginous and fibrous attachment could be identified.
From the above mentioned findings it was concluded that three patterns of muscle-bone interfaces could be described according to the number and types of histological zones; (1) the classical pattern of tendon-bone interface (enthesis) formed of the four zones, (2) the fleshy pattern of the muscle-bone interface characterized by absence of fibrocartilage, (3) the third pattern is an admixture of the previous two patterns. The present findings would be helpful in clinical practice; especially, for the choice of the suitable muscle for transplant.