Coughlin's 1996 AAOS instructional course lecture systematically reviews hallux valgus pathoanatomy, radiographic grading, and operative decision-making. The central question: how do you match the right procedure to the right deformity based on severity and joint congruency? All three radiographic parameters — HVA, IMA, and sesamoid subluxation — are needed to classify deformity and guide surgical selection.
Every operative decision in hallux valgus surgery flows from two questions: What is the deformity grade (HVA, IMA, sesamoid subluxation), and is the MTP joint congruous?
Confirm congruency before choosing a procedure. A congruous MTP joint — whether mild or severe. Demands extra-articular correction. Applying a McBride-type soft-tissue realignment to a congruous joint is a setup for recurrence or arthrosis. This principle prevents one of the most common categories of hallux valgus surgical failure.
For chevron osteotomy, IMA 12° is the inflection point: satisfaction falls from 94% to 74% above it, and AVN risk climbs sharply if you add a lateral release. For moderate-to-severe subluxated deformity, the proximal crescentic osteotomy combined with distal soft-tissue reconstruction delivers 92% satisfaction. But requires stable screw fixation to avoid the 28% dorsiflexion malunion rate seen with pin-only constructs.
The hallux varus warning is practical: never excise the lateral sesamoid. Preserving it cuts the varus rate nearly in half, and many postoperative varus deformities under 10° are asymptomatic only because the sesamoid was left in place.
Coughlin's 1996 AAOS instructional course lecture systematically reviews hallux valgus pathoanatomy, radiographic grading, and operative decision-making. The central question: how do you match the right procedure to the right deformity based on severity and joint congruency? All three radiographic parameters — HVA, IMA, and sesamoid subluxation — are needed to classify deformity and guide surgical selection.
Every operative decision in hallux valgus surgery flows from two questions: What is the deformity grade (HVA, IMA, sesamoid subluxation), and is the MTP joint congruous?
Confirm congruency before choosing a procedure. A congruous MTP joint — whether mild or severe. Demands extra-articular correction. Applying a McBride-type soft-tissue realignment to a congruous joint is a setup for recurrence or arthrosis. This principle prevents one of the most common categories of hallux valgus surgical failure.
For chevron osteotomy, IMA 12° is the inflection point: satisfaction falls from 94% to 74% above it, and AVN risk climbs sharply if you add a lateral release. For moderate-to-severe subluxated deformity, the proximal crescentic osteotomy combined with distal soft-tissue reconstruction delivers 92% satisfaction. But requires stable screw fixation to avoid the 28% dorsiflexion malunion rate seen with pin-only constructs.
The hallux varus warning is practical: never excise the lateral sesamoid. Preserving it cuts the varus rate nearly in half, and many postoperative varus deformities under 10° are asymptomatic only because the sesamoid was left in place.