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Official Description

Release of thenar muscle(s) (eg, thumb contracture)

© Copyright 2026 American Medical Association. All rights reserved.

Common Language Description

The thenar muscles are a group of intrinsic muscles located in the palm of the hand, specifically associated with the movement of the thumb. These muscles include the abductor pollicis brevis, flexor pollicis brevis, opponens pollicis, and adductor pollicis. They play a crucial role in the thumb's ability to perform various movements, such as opposition, flexion, and abduction. The origin of these muscles is from the flexor retinaculum and the carpal bones, while their insertion point is at the proximal phalanx of the thumb. The procedure described by CPT® Code 26508 involves the surgical release of one or more of these thenar muscles to alleviate thumb contracture, a condition that restricts the normal range of motion of the thumb. During the procedure, a surgical incision is made over the palm and proximal phalanx of the thumb to access the thenar muscles. The surgeon evaluates these muscles to identify which ones are contributing to the contracture. Once identified, the responsible muscle(s) are carefully cut to release the contracture, allowing for improved thumb mobility. After the release, the range of motion is assessed, and if necessary, further release may be performed. The procedure concludes with the closure of the incision in layers, followed by immobilization of the hand in a splint or cast to promote healing.

© Copyright 2026 Coding Ahead. All rights reserved.

1. Indications

The release of thenar muscle(s) is indicated for the treatment of thumb contracture, which may result from various conditions that lead to the tightening or shortening of the thenar muscles. This procedure is typically performed when conservative treatments have failed to restore normal thumb function and range of motion.

  • Thumb Contracture A condition characterized by the inability to fully extend or move the thumb due to the tightening of the thenar muscles.

2. Procedure

The procedure for the release of thenar muscle(s) involves several key steps to ensure effective treatment of thumb contracture.

  • Step 1: Incision The surgeon begins by making an incision over the palm and proximal phalanx of the thumb. This incision provides access to the thenar muscles that need to be evaluated and potentially released.
  • Step 2: Exposure and Evaluation Once the incision is made, the thenar muscles are carefully exposed. The surgeon evaluates these muscles to determine which specific muscle(s) are contributing to the contracture. This evaluation is critical for ensuring that the correct muscle(s) are targeted for release.
  • Step 3: Muscle Release After identifying the responsible muscle(s), the surgeon strategically cuts the muscle(s) to release the contracture. This step is essential for restoring normal function and range of motion to the thumb.
  • Step 4: Range of Motion Assessment Following the release, the surgeon assesses the range of motion of the thumb. This evaluation helps determine if additional release is necessary to achieve optimal mobility.
  • Step 5: Closure Once the procedure is complete, the incision is closed in layers to promote proper healing. This layered closure technique helps minimize scarring and supports the underlying structures.
  • Step 6: Immobilization Finally, the hand is immobilized in a splint or cast to protect the surgical site and facilitate recovery. This immobilization is crucial for ensuring that the thumb heals properly after the procedure.

3. Post-Procedure

After the release of the thenar muscle(s), patients are typically advised to follow specific post-procedure care instructions. This may include keeping the hand immobilized in a splint or cast for a designated period to allow for proper healing. Patients may also be instructed to avoid certain activities that could strain the thumb during the initial recovery phase. Follow-up appointments are essential to monitor healing progress and assess the range of motion. Physical therapy may be recommended to help restore strength and flexibility to the thumb as healing progresses.

Short Descr RELEASE THUMB CONTRACTURE
Medium Descr RELEASE THENAR MUSCLE
Long Descr Release of thenar muscle(s) (eg, thumb contracture)
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) 1 - 150% payment adjustment for bilateral procedures applies.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 0 - Payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
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).
58 Staged or related procedure or service by the same physician or other qualified health care professional during the postoperative period: it may be necessary to indicate that the performance of a procedure or service during the postoperative period was: (a) planned or anticipated (staged); (b) more extensive than the original procedure; or (c) for therapy following a surgical procedure. this circumstance may be reported by adding modifier 58 to the staged or related procedure. note: for treatment of a problem that requires a return to the operating/procedure room (eg, unanticipated clinical condition), see modifier 78.
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
AS Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery
F4 Left hand, fifth digit
F5 Right hand, thumb
FA Left hand, thumb
GC This service has been performed in part by a resident under the direction of a teaching physician
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
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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