Factors Predict Which Patients Crossover to Surgery for Spondylolisthesis

Peer Reviewed

Patients who prefer surgery for spondylolisthesis, have a greater Oswestry Disability Index (ODI) score, are married, and do not have joint problems were more likely to crossover to surgery after initially being randomized to nonoperative care in a prospective multicenter trial. Identifying which patients are likely to crossover to surgery may aid in patient counseling and provide more cost-effective treatments, the study authors noted in the May 8 issue of JBJS Open Access.

mature man thinks about spondylolisthesis treatment optionsSeveral factors are associated with patients deciding to undergo spine surgery to treat spondylolisthesis. Photo Source: 123RF.com.“This study speaks to the importance of ‘knowing one’s patient’ as a treating physician,” said lead author Peter G. Passias, MD, Assistant Clinical Professor of Orthopaedic Surgery at New York University School of Medicine, New York, NY. “We generally speak of outcomes in absolute terms without giving much deference to the entire social network, health state, and preferences. Historically, we have looked at radiographic factors and imaging findings such as degree of listhesis and severity of stenosis as the gold standard for indicating surgical management. These very focal analyses neglect the preferences of the patient and do not take into account the surrounding comorbidities and social network of patients.”

“Specifically, in our study, we saw that some patients have already reached the conclusion through their own thought processes that surgery is the right option,” Dr. Passias continued. “Whether this is related to personal failures with nonoperative approach, self-research, or conversations with peers, is unknown. But it is clear matching patient preferences with their treatment arm is a major influencing factor for outcomes. Similarly, patients with other significant musculoskeletal or neurological issues, such as joint osteoarthritis, may not have as their priority to address their spinal-related symptoms first. And lastly, possession of an adequate social support system, the most common being through marriage, is critical to allow patients to be comfortable with undergoing a surgical recovery.”

Study Design

The researchers retrospectively reviewed data from 145 patients (average age, 65.6 years; 68% female) with degenerative spondylolisthesis who were initially randomized to nonoperative care when enrolled in a prospective study between 2000 and 2005. Of this group, 80 patients (55%) later crossed over to surgery (standard posterior laminectomy with or without bilateral single-level fusion) during an 8-year follow-up period.

Fifty-five patients who crossed over to surgery did so within 6 months after enrollment and constituted an early surgery subgroup. The remaining 25 patients who crossed over to surgery after 6 months constituted a late surgery subgroup.

Characteristics of Patients Who Crossed Over to Spondylolisthesis Surgery

Patients who crossed over to surgery were significantly younger than those in the nonoperative cohort (63.6 years versus 68.1 years; P=0.009). However, there were no other significant differences in terms of race, sex, comorbidities (eg, osteoporosis, hypertension, diabetes), or spondylolisthesis-related diagnoses (eg, presence of pseudoclaudication, neurological deficits, stenosis levels/severity). The surgery cohort was more likely to have undergone epidural or facet injections before crossing over to surgery (58% versus 38%; P=0.035).

Patients who crossed over to surgery were more likely to be very dissatisfied with symptoms (P=0.035) and more likely to “probably” or “definitely” prefer surgery (P<0.001). Similarly, patients in the nonoperative cohort were significantly more likely to “probably” or “definitely” prefer nonoperative treatment (P<0.001).

Independent Predictors of Crossover to Spondylolisthesis Surgery

In a Cox proportional hazards model adjusted for demographic predictors of crossover, the greatest independent predictor of crossover was patient preference for surgery (hazard ratio [HR], 4.33). Even patients who responded “not sure” regarding preference were nearly 4 times (HR, 3.75) more likely to crossover to surgery than those who preferred nonoperative treatment.

Other independent predictors of crossover were greater ODI score (HR, 1.01 per point) and marital status listed as married (HR, 1.76). In contrast, joint problems were associated with a lower risk for crossover to surgical care (HR, 0.63).

“Our findings are novel in that they determine that issues such as patient preference, greater ODI score, marriage, and lack of major joint problems are perhaps more important than previously determined imaging findings and classic symptoms,” Dr. Passias said.

The lack of association between spinal stenosis and listhesis severity and crossover to surgery “is surprising but also intuitively understood by spine surgeons since we often see patients with severe slip and stenosis who are doing well clinically and do not go on to surgery,” commented SpineUniverse Editorial Board member Dwight S. Tyndall, MD, FAAOS. This information can be used when counseling patients about treatment options, he said.

“Of the patient characteristics that did predict crossover, desire for surgery and greater ODI make sense. The correlation with marital status and no joint problems are very interesting,” said Dr. Tyndall of DrSpine.com and an orthopaedic spine surgeon at Orthopaedic Specialists of Northwest Indiana, Munster, IN. “Is it possible that these predictive findings have more to do with patient desire to be more active—ie, if a patient is married and has no joint issues, they may be more likely to want to enjoy an active lifestyle and, hence, are more like to move on to surgery.”

“Although not predictive, the patients who crossed over to surgery were younger, which might also indicate a desire for a more active lifestyle and, therefore, the desire for surgical treatment,” Dr. Tyndall added. “Also, the authors raised the issues that it is possible that some patients who were assigned to the nonoperative group and crossed over to surgery might have had an already confirmation bias towards surgery which lead them to crossover to the surgical treatment,” Dr. Tyndall noted.

Spine Surgery Linked to Improved Patient-Reported Outcomes Measures

At 8-year follow-up, mean scores on all patient-reported outcome measures (PROMS) included in the analysis were significantly improved in the surgery group versus the nonoperative group. For example, Short Form 36 (SF-36) bodily pain score improved by 34.2 points in the surgery group compared with 15.1 points in the nonoperative group (P<0.001), and significantly greater improvements in SF-36 physical functioning, mental component summary, and physical component summary were found in the surgery versus nonoperative groups (P<0.001 for all comparisons). Scores on the ODI group were reduced by 26 points versus 9 points in the surgery and nonoperative groups, respectively (P<0.001), and significant improvements in favor of surgery were found on the Stenosis Bothersomeness Index.

No significant differences in these PROMS were found for patients in the early versus late surgery subgroups.

“Patients who have delayed surgery and eventually crossover maintain superior outcomes,” Dr. Passias said. “This is consistent with the Spine Patient Outcomes Research Trial (SPORT) trial findings in general.”1

Dr. Tyndall noted that the greater long-term improvement in health-related quality of life found in the surgical group “can also be an important point in counselling patients regarding going on to surgery.”

Matching Patient Goals to Surgery-Related Potential for Improvement

“The major goal of surgery in treating degenerative spondylolisthesis is to improve symptoms, functional capacity, and achieve patient satisfaction,” Dr. Passias continued. “All of these goals need to be considered, and it is important to match the goals of the patient with that of the surgery-related potential for improvement. For instance, a patient who can take only a few steps before surgery but can then walk a block may be very content with their result, while a patient who can walk a mile prior to surgery with pain and has reduced pain following surgery but doesn’t achieve greater walking capacity may also be satisfied.”

Dr. Passias has no relevant disclosures. He is a consultant for Medicrea, Terumo, and Royal Biologics.

Dr. Tyndall has no relevant disclosures.

Updated on: 07/23/19
Continue Reading
Patterns in Back Pain Over Time: Who Recovers and Who Persists?
Peter G. Passias, MD, FAAOS
Assistant Clinical Professor of Orthopaedic Surgery
New York University School of Medicine
Dwight S. Tyndall, MD, FAAOS
Orthopaedic Spine Surgeon
Orthopaedic Specialists of Northwest Indiana

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