Preventing Structural Damage in Early Psoriatic Arthritis

Investigators hypothesize that TNFi is superior to SC MTX in preventing structural damage in early, treatment-naïve PsA, assessed using HR-pQCT. The study aims to ascertain: \- The effect of SC MTX and TNFi (adalimumab biosimilar) on erosion and enthesiophyte progression in early PsA by HR-pQCT. Participants will be: * Randomized in a 1:1 ratio to either the SC MTX group or the TNFi group. * HR-pQCT of MCPJ 2-4 will be performed at baseline, week 24, and one year. The primary outcome is the comparison of change in erosion volume over MCPJ 2-4 across 48 weeks between the SC MTX group (group 1) and the TNFi group (group 2), assessed by HR-pQCT.