Background: The efficacy of standard compression style staples with use in scaphoid fractures has been established. Memory shape alloys possess unique biochemical properties that make them of particular interest with use in bone fixation. The purpose of this study is to determine the effectiveness of memory shape Nitinol staples for scaphoid fractures using parameters of incidence of non-union, postoperative complications, length of immobilization, recovery time, and functional ROM.
Methods: This is a single surgeon retrospective chart review study. There were 10 charts reviewed from 5/05 to 10/07 that assessed the application of memory shape staples for the fixation of scaphoid fractures. Both acute and non-union scaphoid fractures were treated. The patients were all male ranging from 15-43 years of age. Vascularized bone graft was used in 6 of the 10 patients; cancellous bone graft was used in 2 of the 10 patients. Demineralized bone substitute was used in the other 2 patients and at the bone graft donor sites. The staples used in this study were OSStaple by Biomedical Enterprise located in San Antonio, TX.
Results: Of the charts reviewed, one patient showed evidence of postoperative scaphoid non-union. The average length of immobilization in at least a thumb spica splint was two months. Postoperative complications assessed were infection, formation of hematoma, and dislodgement of the staple. None of the patients experienced postoperative complications. Functional ROM allowing for efficient, pain-free ADLs and full duty work status was achieved in 9 patients. One patient did not return for follow up.
Conclusions: The authors' data supports the use of memory shape Nitinol staples for use in scaphoid fractures. Patient outcomes using Nitinol staples are comparable to patient outcomes using standard compression style staples and superior to conservative treatment. From a surgeon standpoint, however, the memory shape staple offers an advantage over the standard compression screws with improved ease of application especially with use of bone graft