Treatment Outcomes of Traumatic Upper Extremity Amputations

Traumatic upper extremity amputations are relatively rare injuries that can have a long-term influence on the daily lives of patients due to reduced functional capacity and pain. Treatment options for upper extremity amputations include the restoration of the vitality and function of amputated tissue (replantation) and surgical revision amputation (completion of the amputation) in which non-viable injured tissue is debrided and the soft tissue defect is covered. In subtotal amputation, reconstruction surgery is termed revascularization. Although replantation is the established treatment option in upper extremity amputations, there is, nevertheless, conflicting evidence regarding the benefits of replantation when compared with revision.

Accordingly, the rationale of this dissertation was to evaluate the treatment outcomes of traumatic upper extremity amputations. Secondary aims were to analyze the rates of replantation and revascularization operations and the validity of the patient-reported outcome measurement QuickDASH Outcome Measure (QuickDASH) instrument in the assessment of patients after traumatic upper extremity amputation. Study I focused on assessing the incidence rates of replantation and revascularization operations. In studies II and III, we evaluated patients who have undergone traumatic upper extremity amputation. Study IV aimed to evaluate the concurrent validity of the QuickDASH compared to the full Disabilities of Arm, Shoulder, and Hand (DASH) Outcome Measure instrument.

Study I was based on data from the Finnish National Hospital Discharge Register (NDHR), which includes information from all Finnish hospitals. The inclusion criterion for study I was a traumatic amputation, or amputation-in-continuity, of any part of the upper extremity treated with emergency replantation or revascularization between the years 1998 and 2016 in Finland. For studies II, III, and IV, we screened and reviewed 2250 patients who had sustained a traumatic upper extremity amputation and were treated at Tampere University Hospital between 2009 and 2019. For study II, we included all patients who had an amputation of two or more digits proximal to the distal interphalangeal joint or in the thumb proximal to the interphalangeal joint. Exclusion criteria were a subsequent new traumatic amputation or bilateral amputation. For study III, the inclusion criterion was a traumatic amputation injury at or proximal to the carpus. For study IV, the inclusion criterion was a traumatic upper extremity amputation. Patients with single-finger amputations or incomplete DASH answers were excluded. Using these criteria and after patient consent, 2434 patients were included in study I, 254 patients in study II, 31 patients in study III, and 292 patients in study IV.

In study I, the primary outcome was the number of operations with the adjusted incidence rate. In studies II and III, the primary outcome was the score of the DASH. The secondary outcomes included health-related quality of life with EuroQol 5-Dimension 5-Level (EQ-5D-5L) and EuroQol visual analogue scale (EQ-VAS); cold intolerance with the Cold Intolerance Symptom Severity (CISS) questionnaire; and appearance with the Michigan Hand Outcomes Questionnaire (MHQ) aesthetic domain. In study IV, the primary outcome was the mean difference between DASH and QuickDASH scores.

The average number of replantation and revascularization operations performed per year nationwide was 128, which corresponds to 2.4 operations per 100 000 person-years. We compared the treatment outcomes of replantation (n=171) and revision (n=83) in hand amputations. After controlling for potential confounding variables such as age, sex, accident type, extent of tissue loss before treatment, and accident of the dominant hand, we found no evidence of better functionality (DASH), superior health-related quality of life (EQ-5D-5L and EQ-VAS), improved cold intolerance (CISS), or a more pleasing hand aesthetic (MHQ aesthetic domain) following replantation compared to revision amputation. After traumatic proximal amputation, patients reported significant disability, indicated by the DASH score, after replantation (n=20) and revision amputation (n=11). The mean difference between the DASH and QuickDASH was minor and the correlation between total scores was very strong.

The findings of this dissertation study reveal that the rates of emergency replantation and revascularization operations in upper extremity injuries have remained constant over the last decades. Moreover, our results did not indicate a superior outcome for replantation of an amputated thumb or two or more digits when compared to revision (completion) amputation. The absence of benefits from replantation surgery was not due to the unsatisfactory results of replantation but because there was only minor disability after revision (completion) amputation. However, our findings highlight the significant effect of proximal upper extremity amputation on the daily life of patients, even after a technically successful replantation. For future studies, our validation results support the use of the QuickDASH instead of the complete DASH when evaluating disability andsymptoms in severe traumatic conditions.