Issues
Pain and weakness
Humpback deformity / flexion deformity - alters wrist kinematics
Avascular necrosis
SNAC wrist (scaphoid nonunion advanced collapse) - radiocarpal OA
Risk factors
Displaced fractures
- systematic review of scaphoid fractures displaced > 1 mm
- operative versus non operative management
- nonunion rate of displaced fractures 4X nondisplaced fractures
- nonunion rate of displaced fractures treated with cast: 18%
- nonunion rate of displaced fractures treated with surgery: 1%
Proximal pole fractures
Chong et al J Plastic Surg Hand 2022
- meta-analyis of proximal third fractures
- nonunion rates 2 - 3X higher than waist fractures
- nonoperative nonunion: 18%
- operative nonunion: 6%
Grewal et al J Hand Surg Am 2016
- 53 proximal pole scaphoid fractures
- union rate 90%
- increased risk with comminuted / cysts / translation
Post scaphoid ORIF
Xray
Fibrous nonunion with minimal displacement and minimal resorption
Nonunion with significant displacement and bone resorption
Proximal pole nonunion with displacement and absorption
Nonunion with increased sclerosis proximal pole consistent with AVN
CT
Indication
- diagnose nonunion and identify size of cyst / defect
- identify humpback deformity
- helps to plan approach / size and shape of bone graft
Failure of fracture to unite at 3 months on CT scan
Nonunion with flexion / humpback deformity
Nonunion with flexion deformity
MRI
Indication
- look for signs of AVN
- look for associated ligamentous injury (i.e. SL ligament)
Low vascularity of scaphoid on T1 MRI consistent with AVN
Operative management
Options
Approach: Arthroscopic versus Open (dorsal v volar approach)
Fixation: single screw / double screw / volar plate
Vascularized versus non vascularized bone graft
Approach
| Arthroscopic | Open Dorsal | Open Volar |
|---|---|---|
| Minimal deformity |
Proximal pole nonunion
Waist nonunion with minimal deformity
|
Waist nonunion
Hunchback deformity correction |
Bone graft
| Non structural / Cancellous | Structural / Cortico-cancellous | Vascularized bone graft |
|---|---|---|
|
Minimal deformity
|
Deformity correction |
Nonunions
AVN |
Structural versus non structural bone graft
Hegazy et al J Hand Surg Am 2021
- RCT of 98 patients with unstable scaphoid nonunion without AVN
- corticocancellous structural iliac crest v cancellous only graft
- union rate 94% cancellous bone graft only but malunion rate 41%
- union rate 90% corticocancellous graft with malunion rate 18%
- patients with pre-existing deformity had better outcome scores with structural graft
Vascularized v non-vascularized bone graft
Duncumb et al Bone Joint J 2022
- systematic review of 7000 patients
- mean union rate non vascularized bone graft: 82%
- mean union rate vascularized bone graft: 89%
Non vascularized bone grafts
| Source | Matti-Russe inlay corticocancellous strut grafts | Fisk wedge graft |
|---|---|---|
|
Distal radius
|
No deformity | Hunchback deformity |
|
Iliac crest
|
Narrow rectangle placed into center of scaphoid | Volar triangular / trapezoidal grafts |
 |
  |
Iliac crest versus distal radius
Goyal et al Musculoskeletal Surg 2013
- RCT of 100 patients
- distal radius versus iliac crest
- no difference between two groups
Techniques
Vumedi volar approach distal radius cancellous bone graft
Vumedi iliac crest wedge graft
Vumedi volar approach distal radius bone graft
Minimally displaced waist nonunion with cancellous bone graft from distal radius
Wedge shaped corticocancellous iliac crest bone graft for deformity correction
Vascularized bone grafts
| Dorsal distal radius | Volar distal radius | Free |
|---|---|---|
|
1,2 intercompartmental supraretinacular artery (ICSRA) - branch radial artery - travels between 1st and 2nd extensor compartment
4,5 extensor compartment artery
|
Volar carpal artery
Pronator quadratus
|
Medial femoral condyle - harvested on medial genicular artery pedicle - pedicle sutured into radial artery
Revision nonunion
|
Vascularized bone grafts
Tsantes et al J Hand Microsurg 2019
- systematic review
- union rate 1/2 ICRSA: 86%
- volar radial bone graft: 94%
- free medial condyle graft: 89%
Volar techniques
Vumedi scaphoid plate + volar carpal artery
Vumedi medial femoral condyle pedicle graft
Dorsal techniques
| 4th extensor artery VBG | 1,2 ICSRA VBG |
|---|---|
|
Vumedi 4th extensor artery VBG
|
Youtube 1/2 ICSRA VBG |
 |
 |
Fixation
Screw versus K wire fixation
- RCT of 122 patients with unstable scaphoid nonunion without AVN
- multiple K wires v Herbert screw
- union rate K wires: 91%
- union rate Herbert screw: 88%
Single versus double screws
Vumedi proximal pole dorsal double screw video
Issue double screw
- ? increased stability
- increased cartilage damage from 2 screw insertion
- limited real estate
- increased risk of cartilage perforation
Scaphoid volar plates
Morgan et al J Hand Surg Eur 2021
- systematic review of volar plating scaphoid nonunion
- no difference in union rates compared to screws
- 21% plate removal - can impinge distally and proximally
Scaphoid waist nonunion techniques (volar approach)
| Cancellous bone graft | Structural bone graft | Vascularized bone graft |
|---|---|---|
|
Vumedi volar approach distal radius bone graft
|
Vumedi Russe inlay bone graft | Vumedi scaphoid plate + volar carpal artery |
|
Vumedi iliac crest wedge graft
|
Vumedi medial femoral condyle pedicle graft |
Proximal pole nonunion techniques / dorsal approach
| Cancellous bone graft | Vascularized bone graft |
|---|---|
| Vumedi proximal pole Lister's tubercle bone graft |
Vumedi 4th extensor artery VBG
|
|
|
