Study Finds Chronic Steroid Use Greatly Increases Risk of Deadly Blood Clots After Complex Spine Surgery

Patients on long-term steroids face nearly three times the risk of developing life-threatening blood clots after complex spine surgery, according to a Houston Methodist-led study that's already changing practice and potentially saving lives.

The researchers found that patients taking long-term corticosteroids were 2.7 times more likely to develop deep vein thrombosis (DVT) or pulmonary embolism (PE) within 30 days of surgery than those not on steroids.

“Blood clots are among the most dangerous complications in all of surgery, particularly in spine surgery,” said Dr. Comron Saifi, an orthopedic spine surgeon at Houston Methodist Hospital and the study’s primary investigator. “Pulmonary embolisms can be fatal, but spine surgeons can’t routinely use aggressive blood thinners because of the risk of epidural bleeding, which can cause paralysis. So we have to walk a very fine line.”

The study, published recently in the Journal of Bone and Joint Surgery, analyzed outcomes from more than 7,400 patients across 600 hospitals, the largest investigation to date of venous thromboembolism (VTE) risk in complex spine surgery.

The findings have already led Dr. Saifi to change how he manages patients who take chronic steroids.

“If someone’s on long-term steroids, I’m more aggressive with anticoagulation,” said Dr. Saifi. “I now give subcutaneous heparin starting on postoperative day one, and I have a much lower threshold for ordering imaging if there’s even a hint of a clot. That’s a direct change in my practice based on this research.”

Balancing risks

Thromboembolic prevention is one of the most challenging problems in spine surgery because of the delicate balance involving the risks of pulmonary embolisms and epidural bleeding — especially for patients undergoing complex deformity corrections such as scoliosis or kyphosis.

“These patients are often older adults whose spines have collapsed over time due to arthritis,” Dr. Saifi said. “They come to us in constant, debilitating pain after exhausting all nonsurgical options."

Surgery can be life-changing, but it carries significant risk. Because of that risk, the success of spinal deformity surgery depends as much on meticulous perioperative management as it does on the operation itself.

Surgeons rely on carefully coordinated protocols before, during and after surgery to reduce complications and protect patients during a long and vulnerable recovery.

“Knowing which patients are at the highest risk allows us to be more precise and proactive,” Dr. Saifi said. “If we understand the risk factors, we can tailor our protocols to prevent complications before they happen.”

The new findings have already led Dr. Saifi to change how he manages patients who take chronic steroids.

“If someone’s on long-term steroids, I’m more aggressive with anticoagulation,” he said. “I now give subcutaneous heparin starting on postoperative day one, and I have a much lower threshold for ordering imaging if there’s even a hint of a clot. That’s a direct change in my practice based on this research.”

Surprise results

When Dr. Saifi presented the findings at a national meeting of spine surgeons, the reaction was notable.

“Everyone was surprised to hear that steroids were by far the strongest risk factor — higher than BMI, operative time or other medical conditions.”

The discovery highlights the power of large-scale data analysis to uncover hidden risks that smaller studies may miss. By pooling thousands of cases, Dr. Saifi and his collaborators were able to quantify a rare but serious complication with clear implications for patient care.

For Houston Methodist, the study exemplifies how physician-led research translates into safer, more effective surgical practices.

“Ultimately, it’s about improving outcomes,” said Dr. Saifi. “Every time we learn something that lets us protect even one more patient, it makes the research worth it.”