Table 2.

Triplane Hallux Valgus Classification and Treatment (Anatomic Based).

Classification	Anatomic Findings	MTP Joint Status	Author’s Preferred Treatment
Type 1	Increased HVA and IMA No first metatarsal pronation on radiographs Sesamoids may be subluxed	No clinical or radiographic evidence of DJD	Transverse plane corrective procedure ± distal soft tissue procedures
Type 2a	Increased HVA and IMA First metatarsal pronation on AP and sesamoid radiographs No sesamoid subluxation	No clinical or radiographic evidence of DJD	Triplane first tarsometatarsal (TMT) arthrodesis ± distal soft tissue procedures
Type 2b	Increased HVA and IMA First metatarsal pronation on AP and sesamoid radiographs With sesamoid subluxation	No clinical or radiographic evidence of DJD	Triplane first TMT arthrodesis + lateral release ± Akin’s osteotomy
Type 3	Increased HVA and IMA >20 degrees metatarsus adductus angle	No clinical or radiographic evidence of DJD	Triplane first TMT arthrodesis + second and third metatarsal transverse plane correction
Type 4	Increased HVA and IMA ± first metatarsal pronation	Clinical and/or radiographic evidence of DJD	First MTP arthrodesis

Abbreviations: DJD, degenerative joint disease; HVA, hallux valgus angle; IMA, intermetatarsal angle; MTP, metatarsophalangeal.