A new muliticenter study which included researchers from the Mayo Clinic and St. Louis University looked at the very interesting question of whether Parkinson’s patients experienced better (or worse) outcomes depending on the length of their spine implant contruct.
The research term compared Parkinson’s patients who’d received short (1-3 level) constructs to long (>3 levels) constructs for thoracolumbar fusions. Their work is pending publication.
“A combination of two factors led to this work,” co-author Matthew Lindsey, M.D., told OTW. “First, there is a small amount of literature on patients with Parkinson’s who have spinal fusion, and most of it involves small case series. As a result the data is mixed about how best to treat them.”
“Second, we found that the database at the Mayo Clinic had enough patients that we could shed some light on the subject. We went in without preconceived notions, and it was enlightening.”
As for why there hasn’t been much work on the best way to treat these patients, Dr. Lindsey, an orthopedic surgeon at St. Louis University and in the U.S. Air Force, said to OTW, “It is a smaller, complex patient population who have a disease that is rare. All of this makes it so that substantive amounts of patients at one location are harder to come by.”
The researchers looked at all adult Parkinson’s patients who had posterior thoracolumbar fusion for deformity, degenerative, and traumatic indications at Mayo Clinic between 2017-2022 (n=92). Of these, 63 (68%) underwent short fusion and 29 (32%) had long fusion constructs.
The team found that short fusion constructs were more strongly associated with radiculopathy (51% vs 21%) while extended fusions had a higher indication of spinal deformity (41% vs 10%) or fracture (34% vs 8%) and were more likely to have decreased mobility prior to surgery (79.7% vs 53.9%).
Short constructs had a higher rate of listhesis (20% vs 0%) or stenosis (34.5% vs 4%) at the upper instrumented vertebra (UIV) or UIV +1, proximal screw loosening (13% vs 0%), proximal junctional complications (53% vs 12%) and proximal junctional failures (37% vs 8%). In-hospital complications, 90-day and 1-year mortality, reoperation rate, infection rate, progressive neurologic decline, and fusion rates were statistically similar between the two groups.
Regarding clinical outcomes, the team determined that the overall mortality rate was 2.2% at 90 days and 6.5% at 1 year. The rate of fusion among all cases was 72.9% at one year; major complications occurred in 20.6% of all cases.
Turning to radiographic outcomes, overall screw failure or loosening occurred in 19.1% of all cases [this occurred at a higher percentage in the lower instrumented levels than the upper instrumented levels (15% of cases vs 8.9% of cases)]. Overall reoperations occurred in 15 of the 92 patients (16.3%).
Dr. Lindsey, noting that their study appears to be the largest cohort study to date evaluating outcomes following thoracolumbar spinal fusion in Parkinson’s patients, told OTW, “What was not surprising was that we confirmed that this is a patient population with high risks of complications and morbidity.
“What was unusual was that paradoxically, patients with larger surgeries fared better in the long run while not having a higher rate of complications. By fared better, I mean that they had less rate of hardware failure, proximal and distal junctional failure, and peri implant stenosis.”
“This work sheds further light on how we should approach patients who need arthrodesis and also have Parkinson’s disease. It can help guide providers to choose levels with the long term outcomes and need for future surgeries in mind.”
“As with any retrospective work, a prospective work would allow for a more causative relationship. However, we hope to be able to compare cervical cases and identify Parkinson’s-specific metrics that might be predictive of fusion failure or success. Furthermore, a comparison of fusion vs decompression only would be another line of questioning that could be fruitful.”
