Using Projective IRT to Evaluate the Effects of Multidimensionality on Unidimensional IRT Model Parameters.

The application of unidimensional IRT models requires item response data to be unidimensional. Often, however, item response data contain a dominant dimension, as well as one or more nuisance dimensions caused by content clusters. Applying a unidimensional IRT model to multidimensional data causes violations of local independence, which can vitiate IRT applications.

Nucleus Pulposus Allograft Supplementation in Patients with Lumbar Discogenic Pain: Initial 6-month Outcomes from a Prospective Clinical Pilot Study.

Background: Preventing disc degeneration remains a clinical challenge; patients experiencing chronic lumbar discogenic pain have limited treatment options. Minimally invasive intradiscal procedures such as allogeneic nucleus pulposus (NP) injection have the potential to fill the treatment gap between failed conservative care and spine surgery.

Objectives: Our study sought to evaluate the magnitude and durability of improvement in back function in patients with chronic lumbar discogenic pain followed for 6 months after a single intradiscal injection of minimally manipulated, off-the-shelf processed NP allograft (VIA Disc NP®, VIVEX Biologics, Inc.

Pain After Lower Limb Amputations: Insights from the Heidelberg Amputation Registry.

: The experience of unpleasant sensory phenomena after lower limb amputations (LLAs), including phantom limb pain (PLP), phantom limb sensation (PLS), and residual limb pain (RLP), impacts global healthcare and adversely affects outcomes post-amputation. This study aimed to describe the distribution of PLP, PLS, and RLP among patients with LLAs registered in the Heidelberg Amputation Registry. The primary objective was to determine the prevalence of sensory abnormalities across different amputation levels and causes.