Is tendon transfer surgery a functional reconstructive procedure rather than a cosmetic one for a patient with a chronic Z deformity of the thumb due to rupture of the extensor pollicis brevis (EPB) tendon?

Tendon Transfer Surgery for Chronic Z Deformity of the Thumb Due to EPB Rupture

Tendon transfer surgery for a chronic Z deformity of the right thumb secondary to extensor pollicis brevis (EPB) tendon rupture should be considered a functional reconstructive procedure rather than a cosmetic one, as it aims to restore essential thumb function and improve quality of life.

Functional Impact of Thumb Extensor Tendon Ruptures

• Rupture of the extensor pollicis brevis tendon leads to a Z deformity of the thumb that significantly impairs hand function, particularly thumb extension, which is critical for grip, pinch, and overall hand dexterity 1.
• The chronic nature of the deformity (3 years duration) suggests established functional limitations that affect activities of daily living and quality of life 2.
• Thumb extension is essential for functional hand use, and its loss represents a true functional deficit rather than merely a cosmetic concern 3.

Evidence Supporting Functional Reconstruction

• Tendon transfer procedures for thumb extensor tendon ruptures provide excellent long-term clinical results for restoring thumb extension function, with studies showing restoration of grip and pinch strength to 95% and 92% of the unaffected side, respectively 1.
• In cases of chronic rupture where direct repair is not possible, tendon transfer is the treatment of choice for anatomic reconstruction to restore functional thumb motion 2.
• Surgical reconstruction of extensor tendon injuries of the thumb is considered functionally necessary when there is lack of active extension in the metacarpophalangeal and interphalangeal joints 3.

Surgical Approaches and Functional Outcomes

• Several surgical techniques are available for reconstructing thumb extensor function:

  • Transfer of the extensor carpi radialis brevis tendon to the extensor pollicis longus provides excellent long-term clinical results for restoring thumb extension 1.
  • Transfer of the extensor indicis proprius tendon is considered a reference standard technique for chronic EPL ruptures 4.
  • In cases of combined EPB and EPL ruptures, transfer of the extensor indicis proprius for EPL and accessory abductor pollicis longus for EPB can restore thumb motion and enable resumption of activities of daily living 2.

• Functional outcomes after tendon transfer surgery include:

  • Full thumb extension capability 1
  • Restoration of grip and pinch strength 1
  • Return to previous employment in 97% of patients 4
  • Resumption of activities of daily living 2

Comparison to Other Reconstructive Procedures

• Similar to tendon transfer surgery for the thumb, other tendon transfer procedures in the hand and foot are also considered functional rather than cosmetic:
  • Strabismus surgical management is offered to eliminate diplopia and create a field of single binocular vision, which is considered functional rather than cosmetic 5.
  • Surgical release of pseudosyndactyly in the foot is performed to reduce pain on walking and allow shoes to be worn, which are functional outcomes 5.

Conclusion and Recommendation

• The decision to perform tendon transfer surgery should be based on functional assessment rather than cosmetic considerations 1, 2.
• The chronic Z deformity of the thumb due to EPB rupture represents a true functional deficit that warrants reconstructive intervention 3.
• The goal of surgery should be to restore thumb extension function, improve grip and pinch strength, and enhance the patient's ability to perform activities of daily living 1, 4, 2.