A Rare Case of Congenital Absence of Flexor Digitorum Profundus in the Index Finger.

Congenital anomalies of the flexor tendons in the human hand are rare, and those of the flexor digitorum profundus tendon (FDPt) are even rarer. Our search of the literature unearthed only eleven studies, with only one other report of absent FDPt in the index finger. This study presents a case of a 19-year-old male with congenital absence of FDPt in the index finger, discovered incidentally while seeking treatment for post-burn flexion contractures in the ring and little finger. The girth of the distal phalange was reduced compared to that of the opposite finger, and the distal digital crease was absent. Magnetic resonance imaging confirmed the diagnosis, with no compensatory tendon anomalies. The patient underwent release of post-burn flexion contractures with multiple Z-plasties and refused treatment for the index finger. These anatomic variants may cause misinterpretation during the evaluation of a patient with injuries. This case focuses on the need for thorough preoperative assessment.