Rajasekaran 2013.

Methods	Singe‐centre RCT Setting: Department of Orthopaedics and Spine Surgery, Ganga Hospital, Coimbatore, Tamil Nadu Country: India Period: not reported
Participants	Number: 51 patients (28/23) Diagnosis: MRI exam correlating with typical neurogenic claudication symptoms due to degenerative lumbar canal stenosis Included: degenerative lumbar canal stenosis affecting 3 or less levels; typical neurogenic claudication symptoms; MRI demonstrating good clinical correlation; and failure of conservative methods of treatment for a minimum period of 6 months Excluded: spondylolisthesis with slip Meyerding grade 2 or greater; instability at the level of stenosis (as defined by > 3 mm translation or > 10° angular change on flexion extension lateral radiographs); concomitant symptomatic cervical or thoracic stenosis; comorbidities such as cardiopulmonary insufficiency; peripheral neuropathy; peripheral vascular disease, prior lumbar spine surgery; severe hip or knee disease Age (years): mean (SD) 57.3 (11.2)/54.5 (8.2)
Interventions	Group 1: lumbar spinous process splitting decompression. In the experimental group, the interspinous and supra spinous ligaments were cut longitudinally in line with the spinous processes, then decompression proceeded according to the conventional method Group 2: conventional midline decompression. In the conventional decompression group the overhanging portion of the proximal spinous process, the interspinous and the supraspinous ligaments were removed, and the ligamentum flavum and the distal half of the proximal lamina were excised. Facetal undercutting was performed as needed Follow‐up: 16 months
Outcomes	Pain: 10 cm VAS leg pain (neurogenic claudication) Disability: JOA Recovery Operation time Perioperative blood loss Complications Reoperations Length of hospital stay
Notes	Surgeon's experience: not reported Funding: "AO Spine India research grant and the Ganga Orthopaedic Research and Education Foundation funds were received in support of this work"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "the study was a prospective randomized controlled study" and "surgical treatment method for the patients was determined by an automated computer‐generated block randomization chart."
Allocation concealment (selection bias)	Unclear risk	Not mentioned.
Blinding of participants (performance bias) All outcomes	Unclear risk	No mention of any attempts to blind the participants.
Bliding of personnel/ care providers (performance bias)	High risk	The surgeon could not have been blinded to the intervention.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "patients outcomes were assessed by an independent observer who was blinded to the type of surgery that a particular patient has undergone."
Incomplete outcome data (attrition bias) All outcomes	Low risk	100% of the patients completed the follow‐up.
Intention‐to‐treat analysis (attrition bias)	Unclear risk	No information about intention‐to‐treat analysis.
Selective reporting (reporting bias)	Low risk	All expected outcomes were reported.
Group similarity at baseline (selection bias)	Low risk	Patients did not differ in their baseline characteristics, based on Tables 1, 2 and 4.
Co‐interventions (performance bias)	Low risk	Only the surgical technique differed between treatment groups.
Compliance (performance bias)	Low risk	Compliance in both treatment groups: 100% (surgery).
Timing of outcome assessment (detection bias)	Unclear risk	Quote: "the mean duration of follow‐up was 14.2 ± 2.9 months (12–16 mo)."
Other bias	Unclear risk	Quote: "AO Spine India research grant and the Ganga Orthopaedic Research and Education Foundation funds were received in support of this work."