Is the Hallux Valgus Congruent or Incongruent?

- Congruent Joint:
    - if there is no lateral subluxation, then the joint is congruent;
    - hallux valgus may be the result of lateral deviation of articular surface rather than subluxation of proximal phalanx on metatarsal head;
    - if joint is congruent, proximal phalanx can't be rolled around on metatarsal head to correct hallux valgus lesion;
    - therefore, to obtain correction extra-articular procedures are required so that the articular orientation is not changed;
          - extra-articular procedures include:
                 - Akin Procedure
                 - Chevron
                 - Mitchell Bunion Procedure
                 - Proximal MT Osteotomy
                 - Silver Procedure
          - intra-articular procedures such as the McBride Procedure are specifically contraindicated w/ a congruent joint;
                 - these will lead to Hallux stiffness;

- Incongruent Joint:
    - if lateral subluxation of proximal phalanx on metatarsal head is present, then joint is incongruent, meaning that proximal phalanx can be rolled medially on metatarsal head to achieve correction of deformity;
    - in this case, a distal soft tissue procedure that realigns MPJ such as the McBride Procedure can be used;
    - if the hallux valgus angle is < 30 & intermetatarsal angle is < 15 deg, then distal soft tissue procedure w/ proximal metatarsal osteotomy, is indicated;
    - some authors may choose to perform a chevron or Mitchell procedure, instead of a proximal metatarsal osteotomy;
          - however, if HVA is > 30 & IM angle is > 15 deg, then usually Chevron procedure cannot result in satisfactory correction;
          - some consider chevron contra-indicated w/ incongruent joint;
    - when hallux valgus angle is > 40 deg and / or IM angle is > 20 deg, Arthrodesis, gives best result

Original Text by Clifford R. Wheeless, III, MD.

Last updated by Data Trace Staff on Tuesday, September 4, 2012 1:47 pm