Ulnar longitudinal deficiency - a unique case series from the Indian subcontinent.

Purpose: Ulnar Longitudinal Deficiency (ULD) is a sporadic congenital difference affecting the upper-limb. There is a lack of information on this condition in the Indian subcontinent population, hence the importance of documenting ULD in this region and highlighting the novelty. This retrospective case-series aimed to describe the manifestations of ULD and document its unique presentation pattern in the South Asian population.

Methods: We made a comprehensive assessment of medical records for all the patients from 2008 to 2023. We assessed and documented the demographic details, clinical features, and radiographic images of the upper-limb and associated investigations for other clinical presentations. Patients were grouped based on standard elbow, forearm, and hand classifications.

Results: We documented a total of 68 hands in 55 patients. We observed consanguinity among parents in eight (15%) patients with family-history of other deformities in five patients (9%). Most of our patients presented during the second to fifth year of age (35%). Fourteen (25%) of them presented after ten years. The most common pattern of the presentation was Aplasia of the Ulna, either partial or complete (17 each - 50% of limbs), fixed elbow deformity (28 limbs - 41.1%), absent first web-space affecting 27 (39.7%) limbs, and absent ulnar two fingers with 20 (29.4%) limbs. We observed radial-side deficiency of the hand in 46 (67.6%) patients. 62.3% (43/69) of the surgeries were done for hand deformity.

Conclusion: Key features observed were the presence of consanguinity among parents, late presentation after the first decade, majority having radial-side hand defects and half presenting with elbow stiffness and ulnar aplasia.