Isolated Spontaneous Atraumatic Avulsion of Lesser Trochanter of Femur-A Pathognomonic Sign of Malignancy in Adults? A Case Report and Review of Literature

Abstract

Introduction: Avulsion fractures of lesser trochanter (LT) of femur are generally seen following trauma with intertrochanteric or sub trochanteric fractures. Non-traumatic fractures of LT could oc-cur due to sudden violent contraction of the iliopsoas muscle that inserts on the LT; during vigorous exercise, or sudden pull involving flexion of hip. These are seen commonly in adolescents where the physis has not fused yet. Such a scenario in an adult patient most often or not leads to a diagnosis of an underlying malignancy or metastatic lesion.

Case report: A 60-year-old female patient, presented to the outpatient department of our institute with pain on walking, with no history of trauma. X-ray showed an incidental finding of avulsion of LT of femur. Magnetic resonance imaging showed a large intramedullary tumour in the metaphysis though she had no symptoms or signs of malignancy. On further evaluation, she was diagnosed with primary lung carcinoma with widespread metastasis. Biopsy from the proximal femur also revealed a metastatic lesion. She was given palliative treatment in the form of a proximal femoral nail after which she was started on chemoradiation.

Conclusion: A high index of suspicion of malignancy should be maintained in atraumatic fracture of LT in adults until proved otherwise. Lesser trochanter fracture.

Keywords: adults; lesser trochanter avulsion; metastasis; patho-logical fracture; tumour.

Figure 1

X-ray depicting lesser trochanter avulsion.

Figure 2

Magnetic resonance imaging depicting intramedullary tumour.

Figure 3

Positron emission tomography scan showing widespread metastasis.