Explanation
A distal chevron osteotomy is an intra-articular or juxta-articular procedure intended for mild to moderate hallux valgus deformities (HVA <30°, IMA <13°). Advanced degenerative joint disease (hallux rigidus) of the first MTP joint is an absolute contraindication because realigning an arthritic joint will not relieve the patient's pain, and the surgical trauma may exacerbate stiffness. In such cases, arthrodesis or excisional arthroplasty is indicated. A congruent joint is a relative contraindication (requiring a strictly extra-articular correction to avoid making the joint incongruent), but DJD represents a hard stop for joint-sparing realignment.

**References:**
1. Coughlin MJ, Mann RA. 'Arthrodesis of the first metatarsophalangeal joint as salvage for the failed Keller procedure.' *The Journal of Bone and Joint Surgery (American)*. 1987;69(1):68-75.
2. *Mann's Surgery of the Foot and Ankle*, 9th Edition. Chapter: Hallux Valgus.