Talocalcaneal coalition in dry bones: An observational descriptive morphological study.

Dr. Vidulatha  Kuppurathinam; Dr. Sundar  Gurunathan; Dr. Sangeetha   Kuthalingam

doi:10.51168/sjhrafrica.v6i12.2316

Authors

Dr. Vidulatha Kuppurathinam Associate professor, Department of Anatomy, Coimbatore medical college, Coimbatore, Tamil Nadu, India
Dr. Sundar Gurunathan Associate Professor, Department of Anatomy, Government Vellore Medical College, Vellore, Tamil Nadu
Dr. Sangeetha Kuthalingam Assistant Professor, Department of Anatomy, Coimbatore Medical College, Coimbatore, Tamil Nadu

DOI:

https://doi.org/10.51168/sjhrafrica.v6i12.2316

Keywords:

Talocalcaneal coalition, Tarsal coalition, Calcaneum, Talus, Subtalar joint, Flatfoot, Dry bone, Anatomy, Foot biomechanics

Abstract

Background:
Tarsal coalition is an abnormal union between two or more tarsal bones and may be fibrous, cartilaginous, or osseous. Among its variants, talocalcaneal coalition (TCC) is one of the most common and is clinically significant because progressive ossification can restrict subtalar joint mobility and alter foot biomechanics, often becoming symptomatic after skeletal maturity.

Aim:
To determine the occurrence, type, and morphological characteristics of talocalcaneal coalition in dry human tali and calcanei.

Materials and Methods:

This observational descriptive study examined 150 dry calcanei and 150 dry tali obtained from the Department of Anatomy, Coimbatore Medical College. Intact bones from both sides were included irrespective of age and sex, while damaged or eroded specimens were excluded. Each specimen was evaluated by visual inspection and morphometric assessment for evidence of talocalcaneal fusion, facet involvement, bony bridges, traction spurs, and obliteration of the subtalar joint space.

Results:
Talocalcaneal coalition was identified in two talus–calcaneum pairs, one right and one left, representing 1.33% of the examined dry bone sample. Both were osseous coalitions. The left-sided specimen showed complete synostosis predominantly involving the middle subtalar facet with extension into the anterior facet, resulting in obliteration of the subtalar joint space and associated traction spur formation. The right-sided specimen demonstrated complete medial fusion at the middle facet with incomplete lateral osseous bridging and a small residual unfused gap, along with traction spurs and an indistinct middle facet.

Conclusion:
Osseous talocalcaneal coalition was uncommon in this dry bone series but consistently involved the middle subtalar facet with possible anterior facet extension. Such coalitions are clinically relevant, as they may contribute to rigid flatfoot, restricted subtalar movements, recurrent ankle sprains, and peroneal muscle spasm.

Recommendations:
Routine emphasis on subtalar facet morphology should be incorporated into anatomical teaching and radiological training.

Author Biographies

Dr. Vidulatha Kuppurathinam , Associate professor, Department of Anatomy, Coimbatore medical college, Coimbatore, Tamil Nadu, India

is an Associate Professor in the Department of Anatomy, Coimbatore Medical College, affiliated with The Tamil Nadu Dr. M.G.R. Medical University. She completed her MBBS (1996–2001) at Coimbatore Medical College and later earned her MD in Anatomy (2012–2015) from Madurai Medical College. With 10 years of teaching experience, including 8 years of postgraduate teaching, she is dedicated to fostering effective learning in medical education. Her academic interests center on innovative teaching strategies and anatomical research, and she remains passionate about advancing scientific knowledge through active research and student mentorship.

Dr. Sundar Gurunathan , Associate Professor, Department of Anatomy, Government Vellore Medical College, Vellore, Tamil Nadu

is the First Author and serves as an Associate Professor of Anatomy at Government Vellore Medical College, affiliated with The Tamil Nadu Dr. M.G.R. Medical University. He completed his MBBS (April 2001) at IRT Perundurai Medical College and obtained his MD in Anatomy (October 2015) from Sri Manakula Vinayagar Medical College, Puducherry. With 13 years of teaching experience, Dr. Sundar is committed to simplifying anatomical concepts through clear language and illustrative line diagrams. His academic interests focus on enhancing anatomy education, integrating visual learning tools, and promoting meaningful understanding among medical students.

Dr. Sangeetha Kuthalingam, Assistant Professor, Department of Anatomy, Coimbatore Medical College, Coimbatore, Tamil Nadu

(ORCID: 0009-0005-6784-7331) is the 3rd Author and currently serves as an Assistant Professor of Anatomy at Coimbatore Medical College, affiliated with the Tamil Nadu Dr. M.G.R. Medical University. She completed her MBBS (2008) at Fr. Muller Medical College, Mangalore, and earned her MD in Anatomy (2019) from PSG Institute of Medical Sciences & Research, Coimbatore. With 6 years of teaching experience, she is passionate about guiding students and exploring anatomical concepts that support accurate clinical diagnosis. Her academic interests include applied anatomy, medical education, and research aimed at enhancing the clinical relevance of foundational anatomical sciences.

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