ICD-10-PCS Billable Code

01S40ZZ

Reposition Ulnar Nerve to No Qualifier with No Device, Open Approach

Procedural Specifications

Clinical Axis Detail Definition
Section0 Medical and Surgical
Body System1 Peripheral Nervous System
OperationS Reposition
Body Part4 Ulnar Nerve
Approach0 Open
DeviceZ No Device
QualifierZ No Qualifier

Operation Definition

Moving to its normal location, or other suitable location, all or a portion of a body part

Procedure Overview

This family covers procedures that move a peripheral nerve back to its normal anatomical course, or to a different suitable location, without cutting across the nerve's continuity. A nerve can end up out of place from a traumatic injury, a compressive mass, scar tissue, or a congenital anomaly, and repositioning it relieves the resulting pain, numbness, or weakness by taking pressure off the nerve or restoring its natural path. Ulnar nerve transposition at the elbow for cubital tunnel syndrome is a familiar example, where the nerve is freed and rerouted in front of the medial epicondyle so it no longer catches or stretches with elbow motion.

Because the nerve itself is not removed, replaced, or rerouted to do another nerve's job, these operations are aimed purely at correcting the nerve's position, distinguishing them from repairs that restore a severed nerve's continuity.

Anatomy & Axis Detail

Ulnar Nerve

The ulnar nerve travels down the medial arm and passes behind the medial epicondyle of the humerus through the cubital tunnel, a shallow and unprotected groove that makes it prone to compression and repeated subluxation with elbow flexion. Repositioning here, commonly known as ulnar nerve transposition, is performed for cubital tunnel syndrome when conservative treatment fails or when the nerve is found to snap in and out of the groove with movement. The nerve is freed from the tunnel and relocated anterior to the epicondyle, either subcutaneously or beneath the flexor-pronator muscle mass, to remove it from the mechanical stress of elbow flexion and repetitive stretch. Because the nerve's course near the elbow is so exposed, this is one of the more frequently performed peripheral nerve repositioning procedures in upper extremity surgery.

Approach: Open

Open approach means the surgeon cuts through skin, mucous membrane, or other tissue layers to physically expose the target site to view before performing the procedure. It gives direct visualization and hands-on access, distinguishing it from Percutaneous approaches where instruments pass through a small puncture without exposing the site. Open is typical for procedures needing wide access, such as most laparotomies.

Coding & Documentation

Documentation needs to describe the nerve moved, the reason it was out of position (entrapment, tumor mass effect, dislocation, prior injury), and where it was relocated to. Operative notes for transposition procedures should make clear that the nerve was freed and rerouted, not decompressed in place, since a simple release of surrounding tissue without moving the nerve belongs to a different root operation. A common assignment error is coding an in-situ decompression (such as a straightforward carpal tunnel release) as Reposition when the nerve was only freed from surrounding tissue and not physically relocated - that scenario is Release, not Reposition. Coders should also confirm the body part value matches the specific nerve or plexus segment named in the note, since peripheral nerve values are granular by nerve name and laterality.

Commonly Confused With

ReleaseRelease (root operation N) is the most frequent point of confusion, since both procedures free a nerve from surrounding constricting tissue; the distinction is whether the nerve was actually moved to a new position afterward.
TransferTransfer is confused with Reposition because both involve relocating a body part, but Transfer moves a nerve segment to take over the function of a different body part, while Reposition simply relocates the nerve to serve its own original function.
RepairRepair is used instead when the nerve has been severed and the procedure restores its continuity rather than adjusting its course.