Abstract: The invention provides surgical methods, devices, apparatus, and systems for supporting the thumb of a patient after basal joint arthroplasty. The embodiments of the invention comprise at least one index metacarpal anchor, at least one thumb metacarpal anchor, at least one sling for positioning the thumb metacarpal anchor relative to the index metacarpal anchor, and at least one anchor washer for tightening and securing the sling(s) without the need to tie the suture(s) components of the sling(s) into knots. Index and thumb metacarpal anchors comprise at least one bone-engaging element for engaging the respective metacarpal. The anchor washer may incorporate one or more sling-engagement mechanisms.