Minimally invasive lumbar laminotomy has no functional benefits at six or 24 months compared with an open procedure

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Minimally invasive lumbar laminotomy offers no functional benefits at six or 24 months after surgery, compared with a traditional open procedure, according to a study published by The Spine Journal.

Comparative studies between open and minimally invasive surgical approaches for the treatment of spinal stenosis have largely focused on immediate postoperative parameters. As such, the authors, led by Chia-Liang Ang, Singapore General Hospital, Singapore, write, “It remains largely to be seen whether minimally invasive surgery for the treatment of spinal stenosis offers a sustained advantage over open procedures in terms of functionality, pain scores, and patient satisfaction.” The authors aimed to gather such functional data using a retrospective review of prospectively-collected data.

The study involved 113 patients with visual analogue scale scores for back and leg pain, Oswestry Disability Index (ODI) scores, the North American Spine Society score on neurogenic symptoms, and average Short Form Health Survey-36 (SF-36) score used as outcome measures.

From 2000–2008, 113 patients (30 open, 83 minimally invasive) underwent a one-level lumbar laminotomy with complete postoperative data available for analysis. Between the approaches, there were no differences in baseline demographic data or functional scores.

“This study found that minimally invasive techniques did not have any clear advantage in clinical outcomes and pain scores compared with open techniques at six and 24 months after surgery,” the authors report. At six and 24 months after surgery, there were no differences in improvement in back or leg pain, or improvement in ODI, neurogenic symptoms, or SF-36 scores. The minimally invasive group reported greater satisfaction with treatment at six months (p=0.009) but not at 24 months. Within the minimally invasive group, three patients (3.6%) experienced an inadvertent durotomy and two patients (2.4%) underwent fusion of the operated segment within 24 months.

“This retrospective study suggests that minimally invasive lumbar laminotomy gave no clear benefits in long-term functional or pain scores compared with an open approach,” write Ang and colleagues. “The minimally invasive group seemed to also be associated with higher rates of inadvertent durotomies and reoperation within two years. Although there is a suggestion of minimally invasive approaches being associated with greater satisfaction at six months, this effect was equalised at 24 months.”

“In any lumbar decompressive surgery, the purported advantages of a minimally invasive approach should be carefully weighed against potential complications,” write the authors. “For a relatively simple surgery such as laminotomy, the open approach remains a safe and straightforward option.”