Medical Case Management: Old vs. New Injuries

Pre-existing conditions are among the trickiest variables in Medical Case Management. Many injured workers come into claims with past injuries, chronic health issues, or degenerative joint disease, which can overlap with new injuries. Independent Medical Exams (IMEs) and Utilization Review (UR) are often used to help distinguish between pre-existing and work-related conditions, but without clear separation, claims can spiral into inflated medical costs, delayed recoveries, and frequent disputes.

A 2025 Workers’ Compensation Research Institute (WCRI) study, Degenerative and Comorbid Conditions in Workers’ Compensation, found degenerative disc disease appears in about 33% of claims where back nerves are injured, and osteoarthritis in 36% of shoulder injury claims. Claims with one or more conditions incurred significantly higher medical payments and longer temporary disability durations than claims without them.

That’s where case managers step in. Acting as both investigators and advocates, they help adjusters determine what portion of care is legitimately related to the work incident vs. part of a pre-existing condition. Getting that separation right early protects both recovery progress and claim defensibility.

Challenge of Overlap in Medical Case Management

In medical case management, one of the earliest hurdles is recognizing that what a worker reports as “new pain” often includes elements of long-standing health issues. Here’s what complicates that overlap:

• Undiagnosed pre-existing conditions: For example, degenerative disc disease, osteoarthritis, or metabolic conditions like diabetes may have been present but asymptomatic until a new injury triggers symptoms. In the WCRI study, about 21.9% of claims had exactly one comorbidity, and 7.2% had three or more. Those comorbidities correlated with higher costs and longer time off work.
• Shared symptom patterns: Pain, stiffness, and limited range of motion could stem from both old and new damage. A worker’s description, such as “my back always hurts a bit, but after this fall it’s worse”, may mask the pre-existing baseline.
• Degenerative changes in diagnostic imaging: MRIs, X-rays, and other imaging often show wear and tear, even in asymptomatic workers. Those findings can be confusing in the context of a new injury unless medical case management digs into the history.
• Function vs. pathology: Sometimes, pre-existing pathology doesn’t cause impairment until something new tips the scale. Case managers must distinguish what is a new functional limitation vs. what was already limiting the worker’s ability, which influences what treatments are claim-worthy.

Example:

Consider a worker who slips at work and injures their shoulder. Imaging reveals both a rotator cuff tear and underlying osteoarthritis. In this case, the arthritis may have been pre-existing and asymptomatic, while the tendon tear is directly linked to the workplace injury and therefore compensable. Treatment for the tear would typically fall under the claim, while care for the arthritis may not. Medical case management plays a key role in sorting out these nuances through medical history, provider input, and, when necessary, independent medical exams or utilization review to ensure the right care is authorized for the right condition.

Investigating Pre-Existing vs. New Injuries in Medical Case Management

In medical case management, separating a true work-related injury from a pre-existing condition is a structured process. Case managers act as investigators, piecing together medical history, clinical evidence, and functional impact to draw a defensible line between old and new. Here’s how it typically unfolds:

1. Medical History and Prior Records

Case managers start by gathering a detailed medical history. That includes chart reviews, pharmacy records, and, when possible, past diagnostic imaging. According to the CDC, 6 in 10 U.S. adults have a chronic condition and 4 in 10 have multiple, which means many injured workers walk into claims with health baggage. Knowing what existed before the work incident is the baseline for credible decisions.

Example:

A worker with diabetes develops a foot ulcer after a workplace accident. The accident caused the wound, but the diabetes slows healing. Medical case management clarifies which treatments are related to the work injury (wound care) vs. those stemming from the chronic condition (long-term glucose control).

2. Symptom Timeline

One of the most powerful tools case managers use is the timeline of symptoms. Did the worker report pain immediately after the incident, or were symptoms delayed? Did they already have restrictions before the injury? Linking symptoms directly to the accident helps clarify what’s new versus what’s longstanding.

Example:

After a lifting injury, a worker reports low back pain. Review of prior records shows they sought care for similar pain six months earlier. That doesn’t automatically exclude compensability, but it provides context for case managers and treating providers to distinguish baseline pain from acute aggravation.

3. Diagnostic Evidence

Diagnostic imaging is often where disputes begin. Many MRIs show degenerative changes in people with no symptoms at all. In fact, research published in the American Journal of Neuroradiology found about 37% of 20-year-olds already show signs of disc degeneration on imaging, even without back pain. By age 50, that number rises above 80%.

4. Daily Activities and Functional Status

Medical case management examines not only scans and medical history but also how the injury affects function. Case managers examine whether the incident created a meaningful change in the worker’s daily functioning, like a sudden loss of ability to perform routine tasks. Objective functional changes are often a better indicator of new injury than imaging alone.

5. Provider Collaboration

Case managers frequently coordinate with treating physicians, specialists, and therapists to reconcile differing opinions. If questions remain unresolved, escalation to independent medical exams or utilization review provides an external check to ensure defensibility.

When to Escalate to Independent Medical Exams or Utilization Review

Even the most thorough medical case management can hit a wall. Sometimes the medical record review, symptom timeline, and provider collaboration don’t fully resolve the question of whether an injury is pre-existing or new. That’s when escalation becomes critical. Case managers rely on two key tools: independent medical exams and utilization review.

Independent medical exams provide a neutral, outside opinion when credibility or objectivity is at stake. Case managers typically recommend an IME when:

• Causation is disputed: For example, an injured worker claims a torn rotator cuff is from a workplace fall, but records show shoulder complaints years earlier.
• Treatment plans don’t align with evidence-based medicine: For instance, prolonged opioid therapy for a soft tissue injury raises red flags.
• Multiple providers disagree: Conflicting reports can stall claim resolution, and independent medical exams help establish a clear direction.

The value is in defensibility. A 2024 survey by the WCRI found that claims involving contested causation take 42% longer to resolve than those without disputes. A well-documented IME can shorten timelines by clarifying medical facts and reducing litigation risk.

On the other hand, utilization review focuses on the appropriateness of care, not causation. Case managers should escalate to UR when:

• Proposed treatments exceed clinical guidelines: For example, extended chiropractic care beyond evidence-based duration limits.
• Cost-intensive interventions are requested: Advanced imaging, injections, or surgeries often require UR to confirm medical necessity.
• Medication concerns arise: According to the National Council on Compensation Insurance, prescription drug costs account for about 14% of Workers’ Compensation medical spending. UR ensures prescribing stays aligned with formularies and clinical best practices.

The decision to request an IME or UR is about credibility, compliance, and cost containment. Case managers who escalate at the right time can prevent unnecessary disputes, reduce downstream litigation, and support faster, more defensible outcomes.

Why the Distinction Matters in Medical Case Management

Drawing a clear line between pre-existing conditions and new injuries is what turns complex claims into credible, cost-contained outcomes. When case managers connect the dots across medical records, psychosocial factors, and treatment history, they help ensure claims are both clinically accurate and defensible. This is where medical case management proves its value: protecting injured workers from unnecessary delays while safeguarding insurers from inflated costs or disputes.

By knowing when to rely on provider records, when to escalate to independent medical exams, and when to integrate utilization review, case managers play a pivotal role in keeping claims grounded in fact, not assumption. The result is stronger defensibility, reduced litigation risk, and more trust across all stakeholders, from claimants to attorneys to insurers.

Pre-existing conditions don’t have to derail a claim. With the right approach, case managers can separate the old from the new, the noise from the evidence, and turn what could be a costly dispute into a clear, credible resolution.

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Check out our sources:

American Journal of Neuroradiology. Systematic Literature Review of Imaging Features of Spinal Degeneration in Asymptomatic Populations. American Society of Neuroradiology, 2015, www.ajnr.org/content/36/4/811.

Centers for Disease Control and Prevention. Chronic Diseases in America. CDC, 23 May 2023, www.cdc.gov/chronic-disease/about/index.html.

National Council on Compensation Insurance. Workers Compensation Prescription Drug Study 2023 Update. NCCI, 2023, www.ncci.com/SecureDocuments/II_Insights/Pages/II_CompDrug.aspx.

Workers’ Compensation Research Institute. Degenerative and Comorbid Conditions in Workers’ Compensation. WCRI, 2025, www.wcrinet.org/reports/degenerative-and-comorbid-conditions-in-workers-compensation.

Workers’ Compensation Research Institute. Contested Causation in Workers’ Compensation Claims. WCRI, 2024, www.wcrinet.org/reports/contested-causation-in-workers-compensation-claims.