Hallux Rigidus

Definition

Osteoarthritis of the MTPJ

  • ↓ dorsiflexion of the Great Toe

Aetiology

  • Idiopathic
    • Most common
    • Repetitive trauma & DJD
  • Local trauma
  • OCD
  • Crystal arthropathy
  • Inflammatory arthropathy

Theories

  • long first metatarsal ( Mortons foot)
  • dorsiflexed first metatarsal

History

  • Pain
    • on walking
    • especially on slopes or rough ground
    • painful pushoff
    • worse without shoes
      • cf. hallus valgus which has relief when bare foot

Examination

  • Shoe
    • Shoe wear shows lateral wear
  • Look
    • Hallux straight
    • joint ­ bulk
    • Callosity under medial side of distal phalanx
  • Gait
    • Walks with poor toe off
    • excessive lateral weight bearing
    • absent 1st rocker
  • Feel
    • Areas of tenderness
  • Move
    • Decreased dorsiflexion
      • due to impingement on the dorsomedial osteophytes
    • Decreased plantarflexion
      • due to tethering of capsule over the osteophytes & traction on the dorsomedial n to hallux
    • compensatory hyperextension at the IPJ

Investigations

Xrays

  • Weight bearing A-P radiographs
    • joint space narrowing
    • lateral osteophyte formation
  • Lateral
    • Dorsal osteophytes
    • joint space narrowing

Treatment

Non-Operative :

  • Aimed at limitation of MTPJ motion
  • Shoes
    • Rocker Bottom shoe
    • Rigid sole with steel shank
    • large toe box

Operative:

  • Moberg Extension Osteotomy :
    • Dorsal closing wedge osteotomy of the PP to improve the dorsiflexion arc
      • often combined with Cheilectomy
    • Indications
      • young patients
      • minimal Osteoarthritis
      • >30° dorsiflexion
  • Cheilectomy:
    • Removal of dorsal 1/3 of MT head with the dorsal osteophyte to improve dorsiflexion
    • Should remove osteophytes from base of PP & early ROM
    • Indications
      • Mild – moderate pain
    • Disadvantages:
      • Recurrence of pain
    • Technique
      • Dorsal approach
      • Through extensor hood on either side of joint
      • Capsulotomy, synovectomy
      • Excision of dorsal osteophyte & dorsal 20-30% of metatarsal head
        • most common error is to remove dorsal exostosis in line with dorsal surface of the metatarsal rather than remove dorsal 20% to 30% of bone
      • Excision of lateral spurs
      • Restore 60-70° of dorsiflexion
        • Large portion of ROM will be limited post-op
  • Arthrodesis:
    • Indications
      • Severe Osteoarthritis
      • Failed cheilectomy
    • Position
      • 15o of valgus
      • 30°DF with respect to 1st MT
        • 15° with respect to floor
      • if too much DF
        • then get pain & callosity over the IPJ
      • If too straight
        • get pain at tip of hallux
    • Disadvantages
      • Transfer metatarsalgia
      • Compensatory IPJ Osteoarthritis
      • Malposition
      • Limitation of footwear
      • Non union
  • Kellers Excisional Arthroplasty:
    • Indications
      • Older patients with low demands
    • Disadvantages
      • Problems with cosmesis & metatarsalgia
  • Arthroplasty:
    • NO
    • Limited by Silicone synovitis