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Table 1 Primary and secondary outcome parameters

From: Clinical and radiological effect of medialized cortical bone trajectory for lumbar pedicle screw fixation in patients with degenerative lumbar spondylolisthesis: study protocol for a randomized controlled trial (mPACT)

Outcome parameters Assessments
Primary outcome parameter Oswestry Disability Index (ODI) at 2-year follow up to measure degenerative lumbar spondylolisthesis-related disability [8]
Secondary outcome parameter Questionnaire - Timed “Up and Go” test (TUG) [12] - Beck depression inventory (BDI) [10] - Changes in physical and mental health captured by the Short Form (SF)-12v2 [9] - Core outcome measure index (COMI) [30, 31], patient-orientated outcome questionnaire including - visual analog scale (VAS) for back and leg pain - patient’s satisfaction - work disability - social disability - Pain relief on 100-mm VAS for back pain and leg pain - PainDetect Questionnaire (PD-Q) [11] - EuroQoL 5-Dimension (EQ-5D) [9]
Intraoperative - loss of blood (LOB) - amount of blood transfusion - operative time - length of wound incision - type of wound closure
Various - duration of hospitalization - device-related complications - surgery-related complications - re-operations - adverse events (AE), severe adverse events (SAE)
Health care contacts
Pain medication usage
Hospital costs
Radiological evaluation - MRI [13,14,15,16, 32] - x-ray evaluation (antero-posterior, lateral, flexion and extension, standing for overall sagittal alignment and differences in lordosis) - CT scan (overall fusion rate, rate of radiological and/or symptomatic adjacent segment disease, rate of pedicle and/or cage system implant failures)
Serum markers (CRP, leukocytes, TNF-α, IL-6)
  1. The primary study endpoint is the difference in Oswestry Disability Index between treatment groups at 2 years after surgery
  2. MRI magnetic resonance imaging, CT computed tomography, CRP C-reactive protein