Understanding the ligamentum teres of the hip: a histological study

OBJECTIVE To perform a histological study describing the microstructure of the ligamentum teres of the hip, with special emphasis on the presence of nerve bundles. Our study aims to correlate the microstructure of the ligamentum teres with its postulated functions, allowing greater understanding of its role within the hip joint. METHODS Fresh specimens excised intra-operatively in 11 patients undergoing open hip procedures were preserved in formalin and sent to the laboratory for histological analysis by our collaborating pathologist. The specimens were sectioned and stained, and examined under the microscope to look at their microstructure. In addition, a novel staining technique was employed to detect neural elements within the individual specimens . RESULTS The ligamentum teres is composed predominantly of a connective tissue matrix of collagen fibers, fibrous and adipose tissue, with an overlying layer of investing synovium. In addition, there are blood vessels of various sizes surrounded by a layer of encircling fat. In all specimens examined, there were nerve bundles of various shapes and sizes, regardless of the age of the patient. CONCLUSION The ligamentum teres has both mechanical and biological functions within the hip joint and should no longer be considered a developmental vestige. Where possible, any surgical procedures around the hip joint should aim to limit damage to this structure to minimize any potential loss of function. Level of Evidence Basic Science Study.