Chronic Scapholunate Instability

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Chronic Scapholunate Instability Powered By Docstoc
					 SLAC & SNAC wrists
Management & Results


                Satyam Patel
           January 19th, 2007
                   Overview
•   Definitions
•   Natural history
•   Treatment Options
•   Results
                  Definition
• SLAC = Scapho-Lunate Advanced
  Collapse
• SNAC = Scaphoid Nonunion
  Advanced Collapse
• PRC = proximal row carpectomy
• 4CF = 4 corner (Capito-Hamate-
  Lunate-Triquetrum) Fusion
                 Natural History
• Ligament disruption
   – Scapholunate
   – Radioscaphoid
                Natural History
• Scaphoid flexes abnormally
                   Natural History
• Increased contact
   – Proximal pole + scaphoid fossa
   – Distal pole + radial styloid



   – Arthritic changes
                  Natural History
• DISI deformity develops
   – Lunate and triquetrum extend
                  Natural History
• Capitate migrates into
  scapholunate interval

• Midcarpal arthritis at
  capitolunate articulation
                       Natural History
• SLAC wrist
   – Scapholunate advanced collapse

   – Constellation of findings
       •   DISI
       •   Radioscaphoid arthritis
       •   Midcarpal arthritis
       •   Sparing of radiolunate joint
       •   Carpal collapse
                  Natural History
• SLAC wrist
  – Scapholunate advanced
    collapse
                                        Radioscaphoid
     • I radial styloid + distal pole
       scaphoid
     • II scaphoid fossa + proximal
       pole                             Midcarpal
     • III capitolunate
                     Natural History
• SLAC wrist
   – Scapholunate advanced collapse

      • I radial styloid + distal pole scaphoid
      • II scaphoid fossa + proximal pole
      • III capitolunate
                  Natural History
• SLAC wrist
  – Scapholunate advanced
    collapse

     • I radial styloid + distal pole
       scaphoid
     • II scaphoid fossa + proximal
       pole
     • III capitolunate
             SNAC - Natural History
• Scaphoid nonunion leads to a series of degenerative changes
  that are similar to SLAC.
• In general
   – 1 decade after fracture - scaphoid nonunion cystic changes
   – 2 decades - radioscaphoid degeneration
   – 3 decades - pancarpal arthritis
• Stage I - radial styloid - scaphoid joint
• Stage II - degeneration of radioscaphoid and scaphocapitate
  joints
• Stage III - capitolunate degeneration
• (proximal radioschaphoid and radiolunate joints are relatively well
  preserved)
               Treatment Options
• Relevant factors
   – Patient age
   – Activity Level
   – State of Degeneration
                  Treatment Options
• Conservative
   –   Activity modification
   –   Splinting
   –   Steroid injection
   –   NSAIDs
                  Treatment Options
• Surgical
   –   PIN neurectomy
   –   Total or partial wrist arthrodesis
   –   Proximal row carpectomy
   –   Distraction arthroplasty
   –   Total wrist arthroplasty
      Biomechanical basis for treatment
     4-CF (+scaphoid excision)                    PRC

• Wrist motion occurs through        • Capitate articulates with
  preserved radiolunate and            lunate fossa
  ulnocarpal joints                  • Difference in arc of rotation
                                       between C & L allows for
• Including hamate and triquetrum      radial and ulnar deviation
  increases fusion rate without      • Preserving radio-scapho-
  sacrificing further motion           capitate ligament is important
• CI’s = radiolunate degeneration,     for stability (N.B. if doing
  ulnar carpal translation             styloidectomy)
    Irreducible Carpus And Arthritis
• RECALL:
• SLAC wrist
   – Scapholunate advanced collapse
      • I radial styloid + distal pole scaphoid
      • II scaphoid fossa + proximal pole
      • III capitolunate
        Irreducible Carpus And Arthritis
• I
      – Radial styloidectomy +/- scaphoid fixation & bone graft
• II
      – Proximal row carpectomy
      – 4 corner fusion +/- radial styloidectomy / scaphoid excision


• III
      – 4 corner fusion with scaphoid excision or arthrodesis
          • Proximal row carpectomy unsuitable due to midcarpal OA
       Irreducible Carpus And Arthritis
• I
      – Radial styloidectomy
         • Removes arthritic joint
         • Does not prevent progression to stage II and III
       Irreducible Carpus And Arthritis
• II
   – Proximal row carpectomy
        • Converts wrist into ball and socket joint
        • Mismatching radiocapitate joint allows translation
        • Removal of arthritic joints while motion maintained
       Irreducible Carpus And Arthritis
• II - SLAC wrist procedure
   –   Four corner fusion (capitate-lunate-hamate-triquetrum)
   –   Scaphoid excision
   –   Removes arthritic joints
   –   Makes use of preserved radiolunate joint
   –   Higher loss of motion, strength maintained
    Irreducible Carpus And Arthritis
• III
   – SLAC wrist procedure
        • Proximal row carpectomy not suitable due to midcarpal
          arthritis
 Indications for total wrist arthrodesis
• Diffuse arthritic change (capitate or lunate fossa
  involved)
• Motion less than 30 / 30

• Contraindication = if wrist dorsiflexion is required
  for tenodesis (e.g. tetraplegic patients)
                PRC - Technique
• Longitudinal incision through
  EPL sheath
• Capsulotomy
• Excise lunate first
• Then triquetrum and scaphoid
  via sharp dissection to preserve
  ligaments.
• +/- radial styloidectomy
• Dorsal capsular repair
• 2-3/52 in cast
                  PRC - variations
•   Pre-op arthroscopy to evaluate condition of cartilage
•   Temporary internal fixation with K-wires
•   dorsal capsule interposition
•   Radial styloidectomy
•   Proximal capitate excision (?)

• N.B. caution in pts < 35 y.o., rheumatoid patients
Technique

                    SLAC Wrist Procedure
        Four-Corner-Fusion With Scaphoid Excision
 •   Exposure as in PRC
 •   Scaphoid excision
 •   Radioscaphocapitate ligament preserved
 •   Joints decorticated
 •   ICBG or distal radius bone graft
 •   Lunate reduced to capitate (slight flexion)
 •   K-wires, staples, screws, “spider” plate
 •   Avoid silastic scaphoid (synovitis)
 •   6/52 – 8/52 cast
      Variations of 4 -corner fusion
• Use of k-wires vs. use of spider plate
   – Trade-off between increased fusion rate and incidence of
     dorsal impingement
   – P. Stern
• Excision of triquetrum (3 corner fusion / Capito-lunate
  fusion)
   – Better dorsiflexion in cadaveric study, no significant increase
     in ROM clinically thus far.
   – G. Bain, J. Calandruccio, R. Gelberman
                       Salvage
• Total wrist fusion
   – All arthritic joints fused
   – (radius - 3rd MC axis
     mandatory, others optional)
   – No motion / good strength
                             Results
• Limited fusions
   – STT
      • 14% nonunion (385 cases from multiple series)
      • Pain relief unpredictable
      • Add styloidectomy if impingement present
   – SL
      • 50% nonunion
   – SLC
      • 50% decrease in wrist motion
      • 4/11 required total wrist fusion
                          Results
Degenerative Arthritis of the Wrist : Proximal Row Carpectomy
  versus Scaphoid excision and four-corner arthrodesis.
  M. Cohen S. Kozin J. Hand Surg. 2001 26A:94-104

2 cohorts of 19 patients each largely stage 2 arthritis, most
   SLAC, 3 SNAC in one arm 6 in the other.
         - Early follow-up results (DASH, SF-36)
No significant differences in pain, grip strength, ROM
4CF group scored higher on mental-health component of SF-36 and
   retained a slightly greater radial-ulnar deviation arc.
                     Results
• Acta Orthop Belg 2006
  – Salvage procedures for degenerative osteoarthritis
    of the wrist due to advanced carpal collapse
  – 63 patients - 19 fused, PRC 26, scaphoidectomy
    +4CF 18
  – PRC significantly better (DASH =16)
  – No significant differences between 4CF and
    arthrodesis (DASH = 39, 45)
                    PRC - results
• Jorgenson 22 PRC cases over 20 years
• Increased ROM, subjective feeling of weakness

• Scand J Plast Reconstr Surg & Hand Surg 2006
      • 51 patients PRC between 1992 & 2002
        11% required arthrodesis (9 patients)
      • 34 returned to work (avg. 6/12)
      • F 66% E 73%                 RD 74% UD 76%
      • Grip 70%
    Results of 4CF & scaphoidectomy
•   Ashmead et. al
•   44/12     100 patients
•   E 32deg F 42deg (53%)
•   Grip strength 80%
•   78/85 satisfied (would undergo operation again)
•   3% nonunion rate
•   Dorsal impingement 13%
                         Results
• Wrist fusion
   – 85% total pain relief
   – 65% return to former occupation
             Hastings and Silver
            Summary: No Arthritis
• Reducible + adequate ligament
   – Reduction, repair, pinning


• Reducible + inadequate ligament
   – Soft tissue vs. bony procedure




• Irreducible
   – Treat as SLAC wrist vs. Limited fusion (STT)   Next page
               Summary: Arthritic Wrist
•   Stage I
     – Radial styloidectomy

•   Stage II
     – Proximal row carpectomy: maintain motion, fast recovery
     – Four corner fusion + scaphoidectomy : strength ?

•   SLAC III
     – Four corner fusion + scaphoidectomy

•   Salvage
     – Wrist fusion
     Irreducible Carpus Without Arthritis
• Why is it not reducible?                 • Limited carpal fusion
    – Fibrous tissue in joints                •Removes intraarticular
    – Deformed articular surfaces             block to reduction
    – Ligament shortening and laxity
                                              •Fixes reduced scaphoid
• Solution                                    position to carpus
    – Remove fibrous tissue from joints
                                              •Prevents further carpal
    – Remove deformed articular surfaces
                                              collapse
    – Remove lax / stiff ligaments
                                              •Spares uninvolved joints
  Irreducible Carpus Without Arthritis
• STT fusion + dorsolateral styloidectomy
• SL / SC / SLC fusion




• Without reduction of deformity, progression to SLAC wrist
• Results of limited wrist carpal fusions may not be good enough
  or predictable enough to justify using them -- safer option is to
  treat as SLAC wrist
Technique


                                            STT Fusion
 •   Transverse dorsal incision
 •   Retract superficial radial n. and v.
 •   Open retinaculum along EPL
 •   B/w ECRL and ECRB
 •   Open STT
 •   Open radioscaphoid joint
      – If arthritic go to SLAC wrist reconstruction
 •   Reduce scaphoid and fix to carpus
 •   Remove STT joint preserving height
 •   Distal radius graft
 •   3 x 0.045 K-wires across STT
                      Results
                PRC        SLAC
                           procedure
ROM             64%        45%
maintained
Grip strength   75%        75%
Pain relief     “good”     “good”
Satisfaction    “good”     “good”
Failure rate    20%, 0     0-7%, 30%   Krakauer et al, 1994
                                       Wyrick et al, 1995
                                       Tomaino et al, 1994

				
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