A prior injury, arthritis, or old surgery doesn't end your workers' comp claim in Missouri. If a workplace accident significantly aggravated, accelerated, or worsened your condition, you may still be entitled to benefits for medical treatment, lost wages, and disability. Bur Oak Injury Law knows how insurers fight these claims — and how to beat them.
Pre-existing conditions affect over 60% of contested workers' compensation claims in Missouri — particularly cases involving prior back problems, joint degeneration, arthritis, prior neck injuries, and old surgeries. Insurance companies use prior medical history as their primary weapon to deny or minimize benefits, arguing that the current need for treatment is just the natural progression of a condition that was already there before the accident.
Missouri law does not let them off that easy. Under RSMo §287.020, a work injury that significantly aggravates a pre-existing condition is compensable — as long as the work-related injury was the prevailing factor causing the need for medical treatment or disability. That means the work accident must be the primary cause, outweighing all other contributing factors including the natural progression of the prior condition.
Understanding exactly what "prevailing factor" means — and how to prove it with medical records, physician opinions, and diagnostic imaging — is where pre-existing condition cases are won or lost.
Missouri insurance adjusters focus on one question in every pre-existing condition case: did the work accident cause a permanent change to the underlying condition, or just a temporary flare-up? The legal terms are aggravation and exacerbation — and they lead to opposite outcomes.
Proving aggravation rather than exacerbation requires strong medical documentation — ideally from the treating physician — that distinguishes the post-accident condition from the pre-accident baseline using objective findings like MRI results, functional capacity evaluations, and permanent restriction assessments. This is exactly where legal representation makes a measurable difference.
The following pre-existing conditions appear most frequently in contested Missouri workers' compensation claims. In each situation, the key legal question is whether the work injury was the prevailing factor in worsening the condition beyond its natural progression.
Missouri's Second Injury Fund (RSMo §287.220), overseen by the Missouri Department of Labor, provides supplemental compensation when a new work injury combines with a pre-existing disability to create a more serious overall disability than either condition would have produced alone.
The Second Injury Fund was designed to encourage employers to hire workers with disabilities by ensuring that if a second injury occurs, the employer's insurer is only responsible for the new injury — and the Fund covers the combined effect. In practice, navigating the Fund requires meeting specific statutory thresholds and presenting medical evidence that satisfies the Fund's liability standards for Permanent Total Disability.
Workers who had a pre-existing permanent partial disability of 50 weeks or more (or specific qualifying conditions) and then suffer a new work injury that, in combination, results in substantially greater disability than the new injury alone would cause.
Medical expenses, lost wages, and disability benefits beyond what the employer's workers' compensation insurance provides — up to and including Permanent Total Disability benefits when the statutory thresholds are met.
We analyze your pre-injury disability history, gather medical records, work with medical experts, and evaluate whether RSMo §287.220 applies — then pursue Fund benefits alongside the primary workers' compensation claim.
We start with a free consultation to understand how the accident occurred, what symptoms existed before the workplace injury, what changed after the work accident, and how your job duties contributed to the worsening condition. We analyze both pre-injury and post-injury medical records to map the difference — and identify where the insurance company's denial argument is weakest.
Strong evidence is critical when a claim involves prior health issues. We gather medical records, diagnostic imaging, witness statements, employment records, and physician opinions that separate the pre-existing condition from the aggravated condition. We work with treating physicians and, when needed, orthopedic specialists or occupational medicine experts to document that the work injury — not natural degeneration — was the prevailing factor.
We file the Claim for Compensation with the Missouri Division of Workers' Compensation and respond to the insurer's denial with medical records, legal arguments, and evidence supporting your right to benefits. We negotiate for fair settlement terms covering medical bills, authorized treatment, lost wages, disability benefits, and future care — and we evaluate Second Injury Fund eligibility at every stage.
If the insurer refuses a fair resolution, we take the case before an Administrative Law Judge at the Missouri Division of Workers' Compensation. If needed, we appeal to the Labor and Industrial Relations Commission and Missouri courts. Chris Miller administered the DWC before representing injured workers — he knows this process firsthand.
Case results depend on the facts, medical evidence, Missouri law, and the specific claim. These reflect the types of pre-existing condition matters we are prepared to handle.
Bur Oak Injury Law handles pre-existing condition workers' compensation claims for injured workers throughout central Missouri — including Columbia, Jefferson City, Fulton, Moberly, Sedalia, Mexico, Boonville, and surrounding communities. Whether you're dealing with a back injury aggravated by a workplace fall, arthritis worsened by repetitive job duties, or a denied claim where the insurer is pointing to prior medical conditions as the cause of your current disability, the Missouri prevailing factor standard applies uniformly across all counties. The process requires the same disciplined approach to medical documentation, expert opinions, and legal argument regardless of where in central Missouri the injury occurred. Chris Miller has handled these disputes before — as a DWC attorney reviewing them, and now as an advocate fighting for injured workers facing them.
When a workers' compensation claim involves a prior medical condition, insurance adjusters follow a predictable playbook. They order an Independent Medical Examination (IME) by a physician of their choosing — one who reviews prior medical records and concludes the current symptoms are the natural progression of the pre-existing condition, not the result of the workplace accident. They argue the work injury was merely an exacerbation, not an aggravation. They cite old X-rays, prior treatment notes, and documented pre-existing limitations to support a causation denial. They may also request an insurance meeting or recorded statement to build their case — do not agree to one without an attorney. Overcoming these arguments requires a treating physician who can articulate — in objective, documented terms — exactly what changed after the accident, why that change exceeds the expected progression of the prior condition, and why the work injury was the prevailing factor under Missouri law. Building that evidentiary record is what Bur Oak Injury Law does in every pre-existing condition case.
Don't let an insurer use your medical history to take away benefits Missouri law gives you. If a prior condition is being used to deny your claim, call Bur Oak Injury Law. Chris Miller reviews every pre-existing condition case personally — no handoffs, no associates.