الفهرس 
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Abstract
The carpal scaphoid bone is known to play a key role in the function of the wrist. Therefore, pathologic abnormalities of the scaphoid may have serious consequences. Scaphoid fractures account for 2-7% of all fractures, 69% of all carpal injuries that are commonly seen in the young and healthy population, they are second in frequency only to distal radius fractures, and typically a cousequences of fall on the outstretched hand .
Scaphoid delayed union is a difficult surgical problem facing the orthopedic surgeons, and continue to be problem sequalae. Scaphoid fractures fail to heal because of micro-motion and shearing forces at the fracture site results in fibrous tissue formation and a failure of bone healing , also there are biological and clinical factors contribute to the development of delayed union then nonunion including the degree of fracture displacement, the fragile vascular supply of the scaphoid, and its complex architecture also variable patient symptoms such as minimal pain and swelling, compliance with immobilization, lack of medical and radiological diagnosis, and delays in treatment .
The ability to treat scaphoid delayed union has improved dramatically. The degree of collapse can be accurately assessed in waist fractures using lateral radiographs and more better by sagittal images on CT scan, the fracture require reduction and bone grafting to reestablish the normal geometry of the scaphoid. Magnetic resonance imaging helps evaluate whether or not avascular necrosis is present in the proximal pole.
The surgical options for the delayed union of the scaphoid are many and each has its own advantages and drawbacks .
In this study , the results of cancellous bone grafting from the distal radius were evaluated in twenty patients with internal fixation by Herbert screw in nineteen of them , their mean age was 24 years (19-32 years), there were 19 males and one female, mean ,there were 19 patients with waist fracture and one patient with distal pole fracture pattern.
All patients progressed to union in average time 12.4 weeks (range of 8-20 weeks) with pain free motion during daily activities in 90 % of patients . all patients returned to their preinjury work . There were no wound infection or hypertrophic scar in any patients .
The results were evaluated according to modified Mayo wrist score system ,excellent in 12 patients (60%), good in 6 patients (30%), fair in 2 patients (10%) with no poor results .
Conclusion:
Delayed union of scaphoid fractures is a challenging problem facing the Orthopedic surgeons and is often difficult to heal even after prolonged immobilization.
This study highlights the need for surgical interference in cases of delayed union of scaphoid fractures, the surgery provides the chance for reduction to reestablish the normal geometry of scaphoid and also bone grafting.
The policy of open reduction and internal fixation by cannulated screws with the use of cancellus bone grafting is recommended if the state of union is doubt.
Recommendation:
To achieve clinical and radiological union the following principles have been previously proposed:
(i) preservation of the blood supply;
(ii) bone grafting to achieve the original bony alignment and correct any humpback deformity;
(iii) stable internal fixation and correction of carpal instability; and
(iv) the treatment of scaphoid fractures before the development of degenerative change .