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Official Description

Opponensplasty; hypothenar muscle transfer

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

Opponensplasty is a surgical procedure aimed at restoring thumb abduction, particularly in patients who have experienced median nerve damage. This condition often results in a loss of function in the thumb, which is critical for grasping and pinching movements. The procedure involves various techniques, one of which includes the transfer of the hypothenar muscles, a group of three muscles located in the palm that primarily control the motion of the little finger. These muscles include the abductor digiti minimi, the flexor digiti minimi, and the opponens digiti minimi. By mobilizing and transferring these muscles to the thumb's muscles and tendons, the surgeon aims to re-establish the ability to abduct the thumb effectively. Other techniques for opponensplasty may involve the transfer of different tendons, such as the palmaris longus or superficialis tendon, each with its specific procedural steps and anatomical considerations. The choice of technique depends on the individual patient's condition and the extent of nerve damage, with the ultimate goal of improving hand function and quality of life.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

Opponensplasty is indicated for patients who have suffered from median nerve damage, leading to impaired thumb abduction. The procedure is particularly relevant for individuals experiencing significant functional limitations in hand movements, which can affect daily activities and overall quality of life. The following conditions may warrant the performance of opponensplasty:

  • Median Nerve Injury - Damage to the median nerve resulting in loss of thumb function.
  • Thumb Abduction Deficiency - Inability to properly abduct the thumb, impacting grip and pinch strength.
  • Previous Surgical Interventions - Cases where prior surgeries have not restored adequate thumb function.

2. Procedure

The procedure of opponensplasty involves several critical steps to ensure the successful transfer of the hypothenar muscles to restore thumb abduction. The following outlines the procedural steps:

  • Step 1: Incision - An incision is made over the ulnar aspect of the wrist to access the hypothenar muscles and surrounding structures.
  • Step 2: Mobilization of Hypothenar Muscles - The three hypothenar muscles, namely the abductor digiti minimi, flexor digiti minimi, and opponens digiti minimi, are carefully mobilized to prepare for transfer.
  • Step 3: Transfer to Thumb - The mobilized hypothenar muscles are then transferred to the muscles and tendons of the thumb, ensuring proper alignment and tension to restore thumb abduction.
  • Step 4: Suturing - The transferred muscles are sutured securely to the appropriate anatomical structures in the thumb to facilitate functional movement.
  • Step 5: Closure - The incision is closed in layers to promote healing, and the surgical site is dressed appropriately.

3. Post-Procedure

After the completion of the opponensplasty procedure, patients typically undergo a recovery period that may involve immobilization of the thumb to allow for proper healing of the transferred muscles. Physical therapy may be recommended to enhance rehabilitation and restore function gradually. Patients are monitored for any signs of complications, such as infection or improper healing, and follow-up appointments are scheduled to assess the success of the procedure and the restoration of thumb abduction. The overall recovery time can vary based on individual circumstances and adherence to post-operative care instructions.

Short Descr HAND TENDON/MUSCLE TRANSFER
Medium Descr OPPONENSPLASTY HYPOTHENAR MUSC TR
Long Descr Opponensplasty; hypothenar muscle transfer
Status Code Active Code
Global Days 090 - Major Surgery
PC/TC Indicator (26, TC) 0 - Physician Service Code
Multiple Procedures (51) 2 - Standard payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 2 - Payment restriction for assistants at surgery does not apply to this procedure...
Co-Surgeons (62) 1 - Co-surgeons could be paid, though supporting documentation is required...
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator Hospital Part B services paid through a comprehensive APC
ASC Payment Indicator Surgical procedure on ASC list in CY 2007; payment based on OPPS relative payment weight.
Type of Service (TOS) 2 - Surgery
Berenson-Eggers TOS (BETOS) P5B - Ambulatory procedures - musculoskeletal
MUE 1
CCS Clinical Classification 160 - Other therapeutic procedures on muscles and tendons
51 Multiple procedures: when multiple procedures, other than e/m services, physical medicine and rehabilitation services or provision of supplies (eg, vaccines), are performed at the same session by the same individual, the primary procedure or service may be reported as listed. the additional procedure(s) or service(s) may be identified by appending modifier 51 to the additional procedure or service code(s). note: this modifier should not be appended to designated "add-on" codes (see appendix d).
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
LT Left side (used to identify procedures performed on the left side of the body)
RT Right side (used to identify procedures performed on the right side of the body)
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Pre-1990 Added Code added.
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