gms | German Medical Science

Objectives/Interrogation: The aim of the study was to investigate the effectiveness of the use of a vascularized pedicle bone graft of distal radius for scaphoid nonunions with osteonecrosis and its validity in correcting bone deformity too, even if the quality of the donor bone is not macroscopically so high as that used in free bone graft flaps.

Methods: We treated 12 patients, suffering of established scaphoid nonunion, with a VBG of the distal radius. All presented a scaphoid nonunion associated with proximal pole osteonecrosis; 8 of them presented a carpal collapse too.

An interposition palmar-based wedge graft was used in 8 cases and an inlay graft in 4 cases.

Functional outcome was assessed with DASH questionnaire, PWRE score, modified Mayo Wrist Score. Mean outcome measures of pain, range of motion and grip strength were evaluated. Time to return to daily activity was also recorded.

Radiological assessment was performed at the last follow-up visit with conventional X-rays and Computer Tomography scans, evaluating bone union and presence of osteoarthritis, measuring revised carpal height ratio, lateral intrascaphoid and radio-lunate angles.

Results and Conclusions: At an average follow-up of 7 years mean DASH score was 5, mean PRWE score was 16,4, mean MWS was 80,5. Mean VAS pain score was 2,7. Flexion-extension arc of the wrist averaged 73,7 % of the uninjured side; radial-ulnar inclination arc averaged 83 % of the uninjured side. Grip strength averaged 89,6 % of the unaffected hand. Return to previous activity averaged 6 months.

At the radiological evaluation bone union was obtained in 100% of cases, with a mean union time of 5 months. Ectopic ossification was present in 2 cases. Mean carpal height ratio was 1,55, mean lateral intrascaphoid angle was 21°, mean radio-lunate angle was 6,09°. There were signs of degenerative changes at the radio-scaphoid joint, confined to the radial styloid region, in only 2 cases; both benefited from a radial stiloidectomy. No sign of arthritic progression was detected at final follow-up.

We consider VBG a good method to increase the proportion of healed fractures in higher risk patients. We demonstrated that this technique is also valid in correcting bone deformity.

The advantages of these procedures are their relative technical ease compared with other methods of vascularised bone transfer (free flaps), the ability to limit dissection to a single surgical incision, the possibility to obtain additional nonvascularized cancellous graft, if needed, from the same harvest site.