Summary & Overview
CPT 0594T: Humerus Lengthening with Adjustable Intramedullary Nail
CPT code 0594T represents a specialized orthopedic surgical procedure for humeral lengthening using an adjustable intramedullary nail. The procedure involves surgically dividing the humerus, inserting a telescoping or distractible nail into the intramedullary canal of the two segments, and using an external controller to gradually extend the device, permitting new bone formation and progressive lengthening. Imaging and device management related to alignment and lengthening adjustments are included with the procedure. Nationally, this code captures a relatively uncommon but clinically significant limb reconstruction technique used for congenital limb-length discrepancies, posttraumatic shortening, or reconstructive needs.
Key payers addressed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise policy and coverage context, typical sites of service, and clinical framing that clarify when the procedure is billed and how it is categorized for claims processing. The report also outlines common modifiers seen with complex orthopedic surgeries, identifies areas where payer policies commonly vary, and provides benchmarks and implementation considerations for coding accuracy and documentation. Data not available in the input for associated taxonomies, specific ICD-10 diagnoses, related codes, and detailed payer policy language are noted as unavailable.
Billing Code Overview
CPT code 0594T describes a surgical limb-lengthening procedure of the humerus in which the surgeon performs an osteotomy (divides the humerus into two segments) and implants specially designed intramedullary nails. The implanted nail is adjustable and can be gradually distracted with an external controller to promote new bone formation in the gap, resulting in progressive humeral lengthening. Imaging performed before and after alignment assessments, lengthening adjustments, and other device management tasks are included with this procedure.
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Service type: Surgical limb-lengthening with internal adjustable intramedullary device
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Typical site of service: Inpatient or outpatient hospital surgical setting or ambulatory surgery center where orthopedic operative procedures and intraoperative/immediate postoperative imaging are performed
Clinical & Coding Specifications
Clinical Context
A 17-year-old adolescent with a congenital limb-length discrepancy of the humerus undergoes humeral lengthening using an internal, motorized, intramedullary nail (CPT 0594T). Preoperative evaluation includes history and physical, radiographic planning (standing and comparative upper-extremity radiographs, CT or ultrasound if indicated), and surgical consent. In the operating room under general anesthesia, the orthopedic surgeon performs a controlled osteotomy of the humerus, inserts the telescoping intramedullary device, and confirms alignment and fixation with intraoperative fluoroscopy. Postoperative care includes inpatient recovery or ambulatory observation depending on stability, serial outpatient clinic visits for device activation (external controller adjustments), regular radiographic assessment of regenerate bone formation and alignment, and device management including potential minor adjustments or imaging. Typical lengthening occurs over weeks to months with scheduled distraction sessions and graduated rehabilitation (physical and occupational therapy) to maintain joint range of motion and neurovascular monitoring. Indications include congenital shortening, post-traumatic shortening, or skeletal dysplasia affecting humeral length and function. Typical site of service is an ambulatory surgical center or hospital outpatient department for the index procedure, with follow-up visits in clinic and periodic imaging in radiology.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 | Increased procedural services | Use when work or resources substantially exceed typical for 0594T (document rationale). |
51 | Multiple procedures | Use when 0594T is billed on the same date as additional unrelated procedures. |
52 | Reduced services | Use when 0594T is partially performed or limited. |
53 | Discontinued procedure | Use when 0594T is started but aborted due to unforeseen circumstances. |
62 | Two surgeons | Use when two surgeons with distinct skills concurrently perform portions of 0594T. |
66 | Surgical team | Use when a surgical team report is required for complex lengthening cases. |
78 | Unplanned return to OR for related procedure during the postoperative period | Use when patient returns to OR for complications related to 0594T. |
80 | Assistant surgeon | Use when an assistant surgeon provides intraoperative technical assistance. |
81 | Minimum assistant surgeon | Use when minimal assistance is required for 0594T. |
82 | Assistant surgeon (when qualified resident unavailable) | Use when an assistant is needed and a qualified resident is not available. |
RT | Right side | Use to identify procedures performed on the right humerus. |
TG | Telehealth consultation (general behavioral health) | Not typically applicable; included when telehealth preoperative or postoperative consults fit payer rules. |
QX | Service performed by PA with physician present (modifiers QX/QK/QY are used in some payer systems) | Use when a physician assistant provides part of the service under required supervision per payer rules. |
QY | Service performed by PA under comprehensive supervision | Use when billing reflects physician oversight per payer policy. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207X00000X | Orthopedic Surgery | Primary specialty performing humeral lengthening and intramedullary device placement. |
207L00000X | Hand Surgery | Involvement for distal humerus/upper-extremity function and rehabilitation planning. |
208U00000X | Physical Medicine & Rehabilitation | Postoperative management, functional recovery, and therapy coordination. |
2080P0206X | Physical Therapist (PT) | Provides outpatient range-of-motion and strengthening therapy during lengthening. |
207K00000X | Plastic and Reconstructive Surgery | Occasionally involved for soft-tissue considerations during complex reconstructions. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
M21.643 | Acquired deformity, right upper arm | May indicate acquired humeral shortening or deformity addressed by lengthening. |
M21.642 | Acquired deformity, left upper arm | Same relevance for left-sided humeral deformity requiring lengthening. |
Q72.0 | Congenital shortening of upper limb | Direct congenital indication for humeral lengthening procedures. |
M84.463A | Pathological fracture, right humerus, initial encounter for fracture | Post-traumatic or pathological fractures with resulting shortening may lead to lengthening. |
M84.462A | Pathological fracture, left humerus, initial encounter for fracture | As above for left side. |
Q77.4 | Achondroplasia | Skeletal dysplasia that can present with limb-length discrepancy treatable with lengthening. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
20690 | Removal of implant; deep (e.g., buried intramedullary device), requiring operative incision | May be performed after consolidation to remove the intramedullary lengthening device. |
77002 | Fluoroscopic guidance for needle placement (single procedure); < specific fluoroscopy codes vary > | Intraoperative fluoroscopy and alignment confirmation are integral to 0594T (use appropriate fluoroscopy guidance CPT as documented). |
99024 | Postoperative follow-up visit, normally included in global period (sometimes used by payers for unrelated visits) | Routine postoperative follow-up and device management visits after 0594T are typically part of the global period; use only per payer policy for unrelated services. |
20660 | Closed treatment of displaced extra-articular fracture or epiphyseal separation, with manipulation; with or without anesthesia | Related as a potential prior procedure for traumatic indications; may occur before or instead of lengthening in acute fractures. |
21076 | Distraction osteogenesis procedure, mandibular (separate example of distraction technique) | Conceptually related as a distraction osteogenesis code in another anatomic region; not billed with 0594T but useful for coding parallels and payer discussions. |