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Unstable Fractures


- Displaced Extra-Articular Fractures 

- Spiral oblique of Proximal Phalanx: 
- is inherently unstable, and requires internal fixation 
- reduction can be obtained 
- attempt 2 or 3 K wires; 

- Transverse Frx at Neck of Proximal Phalanx: 
- common in children 
- "Booby - trap - fracture" 
- angulation is between 60 and 90 deg. (apex volar); 
- reduction is easy to obtain but difficult to maintain; 

- Angulation & Deforming Forces: 
- unstable frx of the proximal phalanx typically present w/ volar angulation; usually about 30 deg; 
- proximal fragment is flexed by the bony insertion of interossei into base of the proximal phalanx; 
- although there are no tendons inserting on the distal fragment, it tends to be pulled into hyperextension by the central slip acting on the base of the middle phalanx; 
- once the stability of the proximal phalanx is lost, there is an accordion like collapse at the fracture site, aggravated by further pull on the extensor hood by the extrinsic muscles; 

- Acceptable Reduction: 
- if allowed to unite with 25 deg or more of volar angulation, digital motion will be impaired, as extensor mechanism becomes shortened leading to a loss of full extension at the PIP joint;

- Non Operative Treatment: 
- when casting these fractures, ensure that there is an adequate amount of MP joint flexion, i.e. > 60 deg of flexion

- Operative Treatment: