Severe Hip OA Patients More Likely to Undergo Spinal Reoperation After Lumbar Spine Fusion

The hip and spine are intricately connected: decreased motion in one leads to increased motion in the other to compensate. Consequently, hip osteoarthritis (OA) leads to decreased motion through the hip and increased motion — and pressure — through the lumbar spine. While many studies have established that a prior lumbar spinal fusion increases the risks of hip dislocation and revision following a total hip arthroplasty (THA), little is known about how the effects of hip OA impact outcomes following spinal fusion.

In one of the first studies to investigate the association between hip OA and reoperation rates following spinal fusion, Exponent authors Ekaterina Cleary, Edmund Lau, and Kevin Ong, along with co-authors, found that patients with severe hip OA at the time of primary lumbar fusion have an increased risk of revision spinal surgery. 

Specifically, in their publication, "Patients with Hip Osteoarthritis Have a Higher Rate of Spinal Reoperation Following Lumbar Spinal Fusion," they included more than 10,000 patients who were divided into two groups: those who underwent an elective THA within one year after primary lumbar fusion (indicating that they had severe hip OA at the time of lumbar fusion) and those who underwent lumbar fusion with no diagnosed hip OA and no THA during the study period. 

The authors determined that patients with severe hip OA were 61% more likely to undergo spinal reoperation at three years and 87% more likely to undergo spinal reoperation at five years than the patients in the control group. This increased risk of spinal reoperation may be due to increased stress placed on the spine by the decreased motion through the hip. Their results further support performing total hip arthroplasty (THA) before lumbar fusion in patients with dual degenerative diseases of the hip and lumbar spine.

From the publication: "Although many studies have been published on the effects of lumbar fusion and spinal degenerative disease on outcomes following THA, to our knowledge, the present study is the first to demonstrate the association between hip OA and reoperation rates following lumbar spinal fusion."