Contribution of revision amputation vs replantation for certain digits to functional outcomes after traumatic digit amputations: A comparative study based on multicenter prospective cohort

Development and external validation of a prediction model for digit replantation failure after traumatic amputations based on a prospective multicenter cohort

BACKGROUND

Failure of digit replantation after traumatic amputation is difficult to predict. The authors aimed to develop a prognostic model to better identify factors that better predict replantation failure following traumatic digit amputation.

MATERIALS AND METHODS

In this multicenter prospective cohort, the authors identified patients who had received digit replantation between 1 January 2015 and 1 January 2019. Univariable and multivariable analyses were performed successively to identify independently predictive factors for failure of replanted digit. To reduce overfitting, the Bayesian information criterion was used to reduce variables in the original model. Nomograms were created with the reduced model after model selection. This model was then internally validated with bootstrap resampling and further externally validated in validation cohort.

RESULTS

Digit replantation was failed in 101 of 1062 (9.5%) digits and 146 of 1156 digits (12.6%) in the training and validation cohorts, respectively. The authors found that six independent prognostic variables were associated with digit replantation failure: age, mechanism of injury, ischemia duration, smoking status, amputation pattern (complete or incomplete), and surgeon's experience. The prediction model achieved good discrimination, with concordance indexes of 0.81 (95% CI: 0.76-0.85) and 0.70 (95% CI: 0.65-0.74) in predicting digit failure in the training and validation cohorts, respectively. Calibration curves were well-fitted for both training and validation cohorts.

CONCLUSIONS

The proposed prediction model effectively predicted the failure rate of digit replantation for individual digits of all patients. It could assist in selecting the most suitable surgical plan for the patient.

Is Replantation Associated With Better Hand Function After Traumatic Hand Amputation Than After Revision Amputation?

BACKGROUND

Replantation is an established treatment for traumatic upper extremity amputation. Only a few studies, however, have assessed the patient-reported outcomes of replantation, and the findings of these studies have been conflicting.

QUESTIONS/PURPOSES

(1) Is replantation associated with better hand function than revision amputation? (2) Is replantation associated with better health-related quality of life, less painful cold intolerance, and more pleasing hand esthetics than revision amputation after a traumatic hand amputation?

METHODS

In this retrospective, comparative study, we collected the details of all patients who sustained a traumatic upper extremity amputation and were treated at the study hospital. Between 2009 and 2019, we treated 2250 patients, and we considered all patients who sustained a traumatic amputation of two or more digital rays or a thumb as potentially eligible. Based on that, 15% (334 of 2250) were eligible; a further 2% (8 of 334) were excluded because of a subsequent new traumatic amputation or bilateral amputation, and another 22% (72 of 334) refused participation, leaving 76% (254 of 334) for analysis here. The primary outcome was the DASH score. Secondary outcomes included health-related quality of life (EuroQOL-5D [EQ-5D-5L] Index), painful cold intolerance (the Cold Intolerance Symptom Severity score), and hand esthetics (the Michigan Hand Questionnaire aesthetic domain score). The minimum follow-up time for inclusion was 18 months. Patients were classified into two treatment groups: replantation (67% [171 of 254], including successful replantation in 84% [144 of 171] and partially successful replantation in 16% [27 of 171], in which some but not all of the replanted tissue survived), and revision (complete) amputation (33% [83 of 254], including primary revision amputation in 70% [58 of 83] and unsuccessful replantation followed by secondary amputation in 30% [25 of 83]). In this cohort, replantation was performed if possible, and the reason for choosing primary revision amputation over replantation was usually an amputated part that was too severely damaged (15% [39 of 254]) or was unattainable (2% [4 of 254]). Some patients (3% [8 of 254]) refused to undergo replantation, or their health status did not allow replantation surgery and postoperative rehabilitation (3% [7 of 254]). Gender, age (mean 48 ± 17 years in the replantation group versus 50 ± 23 years in the revision amputation group; p = 0.41), follow-up time (8 ± 4 years in the replantation group versus 7 ± 4 years in the revision amputation group; p = 0.18), amputation of the dominant hand, smoking, extent of tissue loss, or presence of arterial hypertension did not differ between the groups. Patients in the replantation group less frequently had diabetes mellitus (5% [8 of 171] versus 12% [10 of 83]; p = 0.03) and dyslipidemia (4% [7 of 171] versus 11% [9 of 83]; p = 0.04) than those in the revision group and more often had cut-type injuries (75% [129 of 171] versus 60% [50 of 83]; p = 0.02).

RESULTS

After controlling for potential confounding variables such as age, injury type, extent of tissue loss before treatment, and accident of the dominant hand, replantation was not associated with better DASH scores than revision amputation (OR 0.82 [95% confidence interval (CI) 0.50 to 1.33]; p = 0.42). After controlling for potential cofounding variables, replantation was not associated with better EQ-5D-5L Index scores (OR 0.93 [95% CI 0.56 to 1.55]; p = 0.55), differences in Cold Intolerance Symptom Severity scores (OR 0.85 [95% CI 0.51 to 1.44]; p = 0.79), or superior Michigan Hand Questionnaire esthetic domain scores (OR 0.73 [95% CI 0.43 to 1.26]; p = 0.26) compared with revision amputation.

CONCLUSION

Replantation surgery was conducted, if feasible, in a homogenous cohort of patients who underwent amputation. If the amputated tissue was too severely damaged or replantation surgery was unsuccessful, the treatment resulted in revision (complete) amputation, which was not associated with worse patient-reported outcomes than successful replantation. These results contradict the assumed benefits of replantation surgery and indicate the need for credible evidence to better guide the care of these patients.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Replantation of digit-tip amputation caused by crush injuries with supermicrosurgery technique

PURPOSE

Digit-tip amputation caused by crush injury is a common emergency scenario, and the management is full of challenges. The objective of this study was to demonstrate the application of the supermicrosurgery technique in replantation procedures for complex digit-tip amputations resulting from crush injuries, while also assessing functional and aesthetic outcomes.

METHODS

We conducted a retrospective analysis of the data from 12 patients who underwent replantation of 15 digits in our department between July 2022 and June 2023. The outcomes of replantation, functional recovery (including return to work, cold tolerance, bone union, DASH score, VAS score, and two-point discrimination test), aesthetic results (including digit appearance, nail deformity, and pulp atrophy), and patient satisfaction were assessed.

RESULTS

The amputation of 7 digits occurred within Tamai zone I level, 8 digits within Tamai zone II level, while 4 digits occurred within Ishikawa zone I level, 3 digits within Ishikawa zone II level, 7 digits within Ishikawa zone III level, and 1 digit within Ishikawa zone IV level. The replanted digits all survived (100%) without any indications of arterial insufficiency or venous congestion. The follow-up procedures were conducted on all 12 patients, with an average duration of 9.6 months (range, 6 to 18 months). The fracture successfully underwent healing at 9.2 weeks (range, 8 to 13 weeks). The mean VAS score was 1.75 points (range 0 to 4 points), the mean two-point discrimination test result was 5.72 mm (range 4.0 to 7.0 mm), and the mean DASH score was 9.78 points (range 3.33 to 22.5 points). All patients demonstrated cold tolerance and successfully resumed their pre-injury occupational activities. The nail deformity was observed in one digit following replantation within Tamai zone I, and in three digits following replantation within Tamai zone II; moreover, eight digits exhibited varying degrees of pulp atrophy. All patients expressed satisfaction with both functional and aesthetic outcomes.

CONCLUSION

The successful replantation of digit-tip amputation caused by crush injury can be achieved through the application of supermicrosurgery technique, resulting in improved functional and aesthetic outcomes. Digit-tip replantation is a favorable and meaningful procedure with high patient satisfaction.

Functional outcome after digit replantation versus amputation

Background

The success of digit replantation is mainly based on survival rates. The functional outcome as well as the recovery of sensibility are essential parameters for judging the outcome after digit replantation but have been poorly assessed in previous studies.

Patients and methods

Forty-eight patients with 56 complete traumatic digit amputations occurring between 2008 and 2013 returned for a follow-up examination, the earliest being 6 months postoperatively. Each patient’s range of motion, fingertip-to-table distance, fingertip-to-palm distance, grip and pinch strengths, static two-point discrimination (2-PD), and Semmes–Weinstein monofilament (SWM) test level were assessed in order to compare functional outcome and recovery of sensibility between successful replantation (n = 19) and primary or secondary amputation (n = 37). Subjective assessments of the pain level and function of the upper extremity were performed using the numerical rating scale and the DASH score, respectively.

Results

Replanted digits achieved 58% of the median total range of motion of the corresponding uninjured digits. Grip and pinch strength were not significantly different after thumb or finger replantation or amputation. Recovery of sensibility was excellent after replantation, with a median static 2-PD of 5 mm and a reduction of pressure sensibility of two levels of the SWM test compared to the contralateral side. After amputation, the median static 2-PD was also very good, with a median value of 6 mm and a reduction of pressure sensibility of only one level according to the SWM test. There was significantly less pain after replantation at rest (p = 0.012) and under strain (p = 0.012) compared to patients after amputation. No significant differences were observed in the DASH score between the two groups.

Conclusion

Comparable functional results and sensory recovery but significantly less pain at rest and under strain can be expected after digit replantation when compared to digit amputation.

Level of evidence

IV.