CPT® Code 0594T

Official Description

Osteotomy, humerus, with insertion of an externally controlled intramedullary lengthening device, including intraoperative imaging, initial and subsequent alignment assessments, computations of adjustment schedules, and management of the intramedullary lengthening device

Common Language Description

The procedure described by CPT® Code 0594T involves an osteotomy of the humerus, which is a surgical operation that entails cutting the bone to correct deformities or to facilitate limb lengthening. This specific procedure utilizes an externally controlled intramedullary lengthening device, which is implanted within the medullary canal of the humerus. The device is designed to gradually lengthen the bone through a process known as distraction osteogenesis, where the bone is slowly separated to allow new bone tissue to form in the gap created. This technique is particularly beneficial in cases of trauma or congenital deformities, providing a method for limb reconstruction. The average duration for the lengthening process is approximately 70 days, with a typical distraction rate of 0.72 mm per day, translating to about 13 days for each centimeter of lengthening. Different methods can be employed for the insertion of the lengthening device, including antegrade and retrograde approaches, which may utilize either electromotorized or magnetically activated devices. The antegrade approach involves making an incision on the anterolateral aspect of the shoulder to access the humeral canal, while the retrograde approach, which is often preferred for its protective benefits to the rotator cuff, requires the patient to be positioned supine with the elbow flexed. In both approaches, careful dissection and the use of protective sleeves are critical to ensure the integrity of surrounding soft tissues and to facilitate the osteotomy. Postoperatively, the lengthening process is initiated within 5 to 8 days, utilizing an external controller to manage the rate of distraction, while ongoing assessments and adjustments are made to ensure proper alignment and device function throughout the lengthening period.

1. Indications

The procedure described by CPT® Code 0594T is indicated for the following conditions:

Trauma - This procedure is performed to address bone length discrepancies resulting from traumatic injuries to the humerus.
Deformity Correction - It is utilized in cases where there is a need to correct congenital or acquired deformities of the humerus.

2. Procedure

The procedure involves several critical steps to ensure successful osteotomy and lengthening of the humerus:

Step 1: Patient Positioning and Incision - The patient is positioned supine for the retrograde approach, with the elbow flexed to facilitate access to the humerus. An incision is made to allow for the insertion of the intramedullary device.
Step 2: Accessing the Humeral Canal - For the antegrade approach, an anterolateral transdeltoid incision is made, and the supraspinatus tendon is split along its fibers. A protective steel sleeve is inserted through the split tendon to safeguard the soft tissues during the reaming process.
Step 3: Osteotomy Preparation - Careful dissection is performed to expose the bone, with predrilling conducted through a small lateral incision. Soft tissue protectors and a drill guide may be utilized to ensure safe completion of the osteotomy using a drill and chisel.
Step 4: Insertion of the Lengthening Device - The lengthening nail is placed within the humeral canal using intraoperative imaging to ensure accurate positioning. This step is crucial for the effectiveness of the lengthening process.
Step 5: Initiation of Lengthening - After 5 to 8 days post-surgery, the lengthening process begins. The external controller is used to initiate distraction at a maximum rate of approximately 1/3 mm three times a day, allowing for gradual bone lengthening.
Step 6: Ongoing Management and Assessments - Throughout the lengthening period, alignment assessments and management of the intramedullary lengthening device are conducted. Weekly distraction calculations and adjustments are performed under clinical supervision, utilizing calibrated radiographs of the osteotomy site to monitor progress until the desired lengthening is achieved.

3. Post-Procedure

Post-procedure care involves monitoring the patient for any complications and ensuring proper alignment of the humerus during the lengthening process. Patients are typically advised on the use of the external controller for lengthening and may require follow-up visits for alignment assessments and adjustments. The expected recovery includes a gradual increase in limb length, with careful observation of the osteotomy site through imaging to confirm successful bone regeneration and alignment. Rehabilitation may be necessary to restore function and strength in the affected limb following the completion of the lengthening process.

Short Descr	OSTEOT HUM XTRNL LNGTH DEV
Medium Descr	OSTEOT HUM INSJ XTRNL CTRLD IMED LNGTH DEVICE
Long Descr	Osteotomy, humerus, with insertion of an externally controlled intramedullary lengthening device, including intraoperative imaging, initial and subsequent alignment assessments, computations of adjustment schedules, and management of the intramedullary lengthening device
Status Code	Carriers Price the Code
Global Days	YYY - Carrier Determines Whether Global Concept Applies
PC/TC Indicator (26, TC)	0 - Physician Service Code
Multiple Procedures (51)	0 - No 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)	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	Device-intensive procedure added to ASC list in CY 2008 or later; paid at adjusted rate.
Berenson-Eggers TOS (BETOS)	none
MUE	2