Neurosurgery Coding Alert

Check with payer for conservative therapies they might require before surgery.

To determine if a patient requires a revision or replacement of a total disc arthroplasty (TDA), the surgeon will need to perform tests to confirm that a revision/replacement is necessary.

They’ll also have to try more conservative treatments before most payers will approve a complex revision/replacement surgery. As a coder, your job is to make sure you document and code all these services correctly.

Check out part 1 of our two-part series designed to help you get a handle on coding for spinal prosthetic device procedures.

Surgeon Performs History and Exam First

To determine if a patient requires a revision or replacement of a TDA, the physician evaluates clinical evaluation findings, targeted imaging modalities, and diagnostic tests.

The process begins with an in-depth clinical history and physical examination. The physician focuses on specific red flags and patterns of clinical failure. These red flags include the following:

• Symptom profile: These could include recurrent, persistent, or worsening neck/arm pain (cervical) or back/leg pain (lumbar). The physician evaluates whether the pain is mechanical (worse with motion/sitting) or radicular (nerve compression).
• Neurological examination: This is an assessment for new or progressive numbness, tingling, weakness, or signs of myelopathy (spinal cord compression, such as clumsy hand movements or gait imbalance).
• Mechanical incompetence: The patient may report an abnormal clicking, grinding sensation, or a feeling that the spine is out of place during movement.

You’ll code these services with the appropriate evaluation and management (E/M) code depending on encounter specifics.

Imaging Tests Pinpoint Revision/Replacement Spot

Imaging is crucial to definitively confirm that the failure of the previously placed device needs a revision or replacement. The tests the surgeon will use to decide on revision/replacement include the following:

• Dynamic X-rays (flexion-extension views): This is the baseline test. It helps the physician identify implant migration, subsidence (sinking into the vertebral bone), malpositioning, severe regional deformity (like kyphosis), or segmental instability.
• CT scan: CT provides high-resolution 3D visualization of the bone-implant interface. The physician uses it to look for failed osseointegration (the bone failing to bond to the metal endplates), periprosthetic osteolysis (bone loss around the device), vertebral fractures, heterotopic ossification (abnormal bone bridging that fuses the joint), and facet joint arthropathy.
• MRI: This test is used primarily to evaluate the spinal cord, nerve roots, and surrounding soft tissues. It helps detect incomplete initial decompression, new soft tissue herniations, or adjacent segment disease.
  • Make note: Stainless steel or certain cobalt-chromium implants can cause severe metal artifacts that obscure MRI diagnostics, sometimes requiring specialized artifact-reduction software or a titanium implant profile.

Rule out Other Causes Before Surgery

Before proceeding to a highly complex revision surgery, the surgeon must systematically rule out other pain generators and underlying pathologies that might be causing the patient’s symptoms. The surgeon could perform these services for the rule out process:

• Infection workup: An infection (such as from Cutibacterium acnes) is a frequent culprit behind device loosening and failed integration. The physician will order laboratory blood tests, including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), along with a complete blood count (CBC).
• Diagnostic injections (facet blocks or medial branch blocks [MBBs]): If imaging shows facet joint degradation adjacent to or at the index level, the surgeon may perform a targeted facet joint block. If the injection temporarily relieves the pain, it confirms that the facet joints, rather than the artificial disc itself, are the primary pain generators, which may alter the surgical revision strategy.
• Metabolic/bone density testing: If implant collapsing or loosening is detected, the surgeon may order a dual-energy X-ray absorptiometry (DEXA) to evaluate for underlying osteoporosis or osteopenia, which would impact whether the device can be replaced with another arthroplasty or if it must be converted to a spinal fusion instead.

Keep in mind that most payers require six to 12 weeks of conservative therapy via treatments such as physical therapy (PT), nonsteroidal anti-inflammatory drugs (NSAIDs), or epidural steroid injections to determine the pain location/cause before proceeding with a major surgery.

Consider This Clinical Example

The case: A 48-year-old patient underwent a single-level cervical TDA at C5-C6 two years ago for degenerative disc disease and radiculopathy. The patient did well initially, with resolution of their arm pain. However, over the last six months, they developed progressive, deep mechanical posterior neck pain, recurrent radiating left-sided arm numbness, and decreased range of motion.

Orders: Imaging via X-rays, CT, and MRI reveals that the superior component of the artificial disc has subsided (sank approximately 3 mm) into the C5 vertebral body, without evidence of bone degeneration.

Surgeon actions: The surgeon concludes that the patient’s acute radiculopathy and mechanical failure are driven strictly by the structural malposition/migration of the implant rather than biological bone failure. Because the surrounding bone stock remains perfectly robust, dense, and uncompromised, the segment does not require permanent fusion. The patient remains an ideal candidate for motion-preservation therapy. The surgeon decides to perform a revision to explant the migrated device and insert a new, properly centered cervical artificial disc. The patient agrees to the procedure and will schedule with the front office.

Coding: On the claim, you’ll report the following:

• 99214 (Office or other outpatient visit for the evaluation and management of an established patient, which requires a medically appropriate history and/or examination and moderate level of medical decision making. When using total time on the date of the encounter for code selection, 30 minutes must be met or exceeded.) for the E/M
• T84.328A (Displacement of other bone devices, implants and grafts, initial encounter) appended to 99214 to represent the displacement of the patient’s cervical artificial disc.

(Be on the lookout for part 2 of this story in Revenue Cycle Insider next month, which will feature documentation strategies and a real-world example of a TDA replacement/revision.)

Jessica Sullivan, CPC, COBGC, COSC, Consultant,
Pinnacle Enterprise Consulting Services (PERCS)