# Unusual Anastomosis between Branches of the Ulnar Nerve (Kaplan Type Anastomotic Variant) – Case Report

## TL;DR

This case report describes a rare anatomical variation of the ulnar nerve, known as the Kaplan anastomosis, with an unusual loop formation near the pisiform bone.

## Contribution

The paper presents a previously unreported anatomical variation of the ulnar nerve with a unique looping structure.

## Key findings

- A Kaplan-type anastomosis was identified with an unusual loop conformation between ulnar nerve branches.
- The anatomical variation was located in strict relation to the pisiform bone in a left upper limb.
- This case highlights the clinical and surgical relevance of such rare nerve variations.

## Abstract

The Kaplan anastomosis is a rare communication originally described between the superficial and dorsal branches of the ulnar nerve, distal to the ulnar tunnel, and in strict relation with the pisiform bone. It reveals, by its particular location, a formation of high clinical-surgical expressiveness. In this paper, we describe a Kaplan-type communication from a left upper limb with an unusual loop conformation between branches of the ulnar nerve in the pisiform bone.

A anastomose de Kaplan é uma rara comunicação originalmente descrita entre os ramos superficial e dorsal do nervo ulnar, distal ao túnel ulnar e em estreita relação com o osso pisiforme. O que revela, pela sua particular localização, uma formação de alta expressividade clínico-cirúrgica. Neste trabalho, uma comunicação do tipo Kaplan, porém, ainda não relatada, é descrita a partir de um membro superior esquerdo com uma inusual conformação em alça, ou um
looping
, entre ramos do nervo ulnar, no osso pisiforme.