CPT 27100 External Oblique Transfer Reimbursement | OpenPayer

Summary & Overview

CPT 27100: External Oblique Transfer to Greater Trochanter

CPT code 27100 represents a surgical muscle-transfer procedure in which the external oblique is repositioned to the greater trochanter to restore hip abductor function in patients with paralysis. This reconstructive orthopedic technique is clinically important for improving gait stability and reducing Trendelenburg gait in affected patients. Nationally, the procedure is performed in specialized orthopedic and reconstructive surgery programs and may have implications for postoperative rehabilitation and long-term functional outcomes.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical context and typical sites of service, plus what payers commonly consider when evaluating coverage for complex reconstructive procedures. The publication summarizes available benchmarks where present, highlights relevant policy considerations affecting authorization and post-operative care, and outlines the clinical rationale for the procedure.

This summary is intended for clinicians, coding and billing professionals, and policy analysts seeking a concise briefing on CPT code 27100, including its clinical purpose, service setting, and the payer landscape that typically influences access and reimbursement processes.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 27100hip abductor reconstructionmuscle transferexternal obliqueorthopedic surgeryreconstructive surgeryoperative procedurebilling and coding

Billing Code Overview

CPT code 27100 describes a surgical procedure in which the provider transfers the external oblique muscle to the greater trochanter to compensate for paralyzed hip abductor muscles. The external oblique is the largest and most superficial muscle of the anterior abdominal wall.

Service Type: Surgical, muscle transfer for hip abductor reconstruction

Typical Site of Service: Inpatient or outpatient surgical setting (operating room)

Clinical & Coding Specifications

Clinical Context

A typical patient is an adult with chronic paralysis or severe weakness of the hip abductor mechanism (gluteus medius/minimus) after traumatic nerve injury, poliomyelitis sequelae, or iatrogenic sciatic nerve damage. The patient presents with a Trendelenburg gait, lateral hip instability, and pain or functional limitation despite conservative management (physical therapy, orthoses). Preoperative workup includes gait analysis, pelvic radiographs, MRI or electromyography to confirm abductor deficiency, and medical clearance.

In the operating room, an orthopedic or reconstructive surgeon performs a transfer of the external oblique muscle attachment to the greater trochanter to reconstitute lateral hip stability. The procedure typically requires general anesthesia, possible regional block for postoperative analgesia, and perioperative antibiotics. Postoperative care involves protected weight bearing, physical therapy for progressive strengthening, and routine wound and neurovascular checks. Follow-up visits include wound assessment, range-of-motion evaluation, and functional outcome assessments over months to determine gait improvement.

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use if work, time, or technical effort is substantially greater than typical for `27100`.

CPT 27181: Intertrochanteric Osteotomy for Slipped Femoral Epiphysis with Fixation

CPT-27110-ILIOPSOAS-TRANSFER-GREATER-TROCHANTER

CPT 27110: Iliopsoas Transfer to Greater Trochanter

CPT-27147-PELVIC-OSTEOTOMY-WITH-HIP-REDUCTION

CPT 27147: Pelvic Osteotomy with Hip Reduction

CPT-27146-PELVIC-OSTEOTOMY-ILIAC-ACETABULAR-INNOMINATE-BONE

CPT 27146: Pelvic Osteotomy — Iliac/Acetabular/Innominate Bone

CPT-27111-ILIOPSOAS-TRANSFER-FEMORAL-NECK-HIP-STABILITY

CPT 27111: Iliopsoas Transfer to Femoral Neck for Hip Stability

CPT-27179-FEMORAL-NECK-OSTEOTOMY-SLIPPED-EPIPHYSIS

CPT 27179: Femoral Neck Osteotomy for Slipped Femoral Epiphysis

CPT-27158-PELVIC-OSTEOTOMY-PEDIATRIC-HIP-RECONSTRUCTION

CPT 27158: Pediatric Pelvic Osteotomy for Hip Stabilization

CPT-27120-ACETABULOPLASTY-HIP-RECONSTRUCTION

CPT 27120: Acetabuloplasty, Surgical Reshaping of the Hip Socket

CPT-27105-PARASPINAL-MUSCLE-TRANSFER-TO-HIP-RECONSTRUCTIVE

CPT 27105: Paraspinal Muscle Transfer to Hip, Reconstructive Procedure

CPT-27178-CLOSED-REDUCTION-PERCUTANEOUS-PINNING-SLIPPED-FEMORAL-EPIPHYSIS

CPT 27178: Closed Reduction and Percutaneous Pinning for Slipped Femoral Epiphysis

Showing 1–10 of 30

Taxonomy Code	Specialty	Notes
207L00000X	Orthopedic Surgery	Primary specialty performing muscle transfer for hip abductor deficiency.
2080P0222X	Physical Medicine & Rehabilitation	Manages preoperative functional assessment and postoperative rehab.
2086S0122X	Reconstructive Plastic Surgery	Performs soft tissue transfers or complex reconstructions when indicated.
207K00000X	Neurological Surgery	Consulted when procedure relates to nerve injury management and reconstruction.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`G83.4`	Monoplegia of lower limb	Hip abductor paralysis requiring muscle transfer to restore lateral stability.
`G82.50`	Paraplegia, unspecified	When abductor dysfunction is part of broader lower-extremity paralysis impacting gait.
`M62.81`	Muscle weakness (generalized)	Localized severe abductor weakness may be an indication when focal.
`S34.0X9`	Unspecified injury of nerve root of lumbar and sacral spinal cord segment	Nerve injuries causing abductor paralysis that necessitate tendon/muscle transfer.
`M16.9`	Osteoarthritis of hip, unspecified	Secondary abductor insufficiency may accompany degenerative hip disease influencing surgical planning.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`20680`	Removal of implant; deep (e.g., buried wire, pin, screw, metal band, nail, rod or plate)	Performed if prior hardware removal is necessary before muscle transfer.
`27020`	Fasciotomy, hip region (e.g., compartment syndrome)	May be used when decompression of fascial compartments is required as part of exposure or management.
`27030`	Arthrotomy, hip; with biopsy	Performed if intra-articular inspection or biopsy is needed during the operative session.
`27096`	Open treatment of pelvic fracture, posterior ring, with internal fixation	Relevant when hip abductor deficiency follows pelvic fracture requiring concurrent stabilization.
`29827`	Arthroscopy, hip, surgical; with synovectomy, debridement/loose body removal (separate procedure)	Sometimes performed arthroscopically prior to or after open soft-tissue reconstruction when intra-articular pathology coexists.

OpenPayer