Minimally invasive intraoperative stiffness measurement of lumbar spinal motion segments.

Objective: To test a new tiny-tipped intraoperative diagnostic tool that was designed to provide the surgeon with reliable stiffness data on the motion segment during microdiscectomy. A decrease in stiffness after nuclectomy and a measurable influence of muscle tension were assumed. If the influence of muscle tension on the motion segment could at least be ruled out, there should be no difference with regard to stiffness between women and men.

Influence of thread design on pedicle screw fixation. Laboratory investigation.

Object: The authors conducted a study to determine the thread properties that provide optimal screw fixation in cancellous bone, when screws of the same external screw diameter are used.

Methods: Three compliance engineering-certified screws in clinical use, all of the same external diameter and length, were compared in an axial pullout experiment with respect to advantageous thread properties. As test material, standardized Sawbone blocks with 3 different densities (0.

Prognosis of multifactorial outcome in lumbar discectomy: a prospective longitudinal study investigating patients with disc prolapse.

Objectives: Although previous research has shown that certain medical data and psychosocial factors predict postoperative pain, it remains unclear whether they also contribute to a more distinct outcome measure that is based on classification of self-reported outcome criteria. To assess the prognostic power of somatic, psychologic, and social predictors when evident outcome criteria of surgical treatment are investigated, this study used a prospective longitudinal design examining preoperative factors associated with outcome six months after lumbar discectomy.

Methods: Forty-eight out of 58 consecutive patients were included (60% male, 40% female, mean age 47 years).