Photon-counting detector (PCD) CT is an advanced CT technology introduced for clinical use in 2021. Multiple studies have shown the clinical benefits of this detector technology for musculoskeletal imaging, which include the rejection of electronic noise, increased calcium contrast-to-noise ratio, standardized CT numbers, decreased metal artifacts, and most notably, increased spatial resolution and decreased radiation dose. Attention is now shifting towards advancing quantitative imaging tasks, leveraging the ultra-high spatial resolution and the ability of PCD-CT to always acquire spectral information. Applications include improved detection and quantitation of gout/pseudo-gout and bone marrow edema. Bone mineral density and body composition can be estimated using phantom-less multi-energy 3D CT techniques, as well as with 2D CT localizer radiographs. Trabecular microarchitecture characterization, previously limited to extremity CT, is now possible in central skeletal sites using PCD-CT. Glycosaminoglycan imaging in the articular cartilage, previously possible only with advanced MRI techniques, can be achieved using spectral PCD-CT and ionic contrast media to measure cartilage health. Finally, quantitative dynamic CT imaging that combines spatial, temporal, spectral, and kinematic information can be achieved from a single PCD-CT scan of moving joints.