Main Article Content
Flexor zone II amputations in single fingers, especially the index, historically have had poor functional outcomes. Due to this, summary evidence often lists replantation of these injuries as a relative or an absolute contraindication. This manuscript re-evaluates these recommendations in view of current evidence.
Current survival rates for flexor zone II injuries vary based on mechanism with sharp mechanisms having greater survival than crush and avulsion injuries. The impact of smoking on replant survival has mixed evidence with recent evidence suggesting a dose-response relationship. Active range of motion outcomes have not improved significantly since the often quoted Urbaniak and Ross studies with average active range of motion ranging from 109º - 155º varying by mechanism of injury and repair type. Index injuries impose less quadriga effect on neighboring digits. Sensation outcomes are particularly important for index replantation with functional bypass occurring below a yet to be established threshold. Workers’ compensation involvement is a significant risk factor for poor patient reported outcomes. Subjective measures, such as the DASH score, varies with time since injury, traumatic vs therapeutic amputation and correlates poorly with objective outcomes. Worker’s compensation, litigation, and manual labor vocations experienced delayed return to work. Secondary ray amputations experienced poorer subjective outcomes and delayed return to work.
It is hoped that this paper will help medical students establish a clear understanding of the relevant measures of hand function. Moreover, to be aware of the current literature informing clinical decision-making regarding replantation of flexor zone II injuries of the index.