Practical Tips to Improve Efficiency and Success in Upper Limb Replantation

Simultaneous or Delayed Free Tissue Transfer in Combination with Replantation Surgery

In hand and upper extremity replantation surgery, simultaneous free flap reconstruction restores the physiologic circulation to the amputated part, ensuring its survival, and promotes wound healing through anatomic restoration. Especially in digit replantation, an arterialized venous flap serves to reconstruct both vessel and soft tissue defects simultaneously. Delayed free flap reconstruction aims to enhance both functional improvement and cosmetic acceptance in a successfully replanted part using flaps that include functioning muscle, bone, joint, nerve, and soft tissue.

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 Outcomes in Upper Limb Replantation-A Systematic Review

Functionality after upper limb replantation is a decisive factor when considering the success of the intervention. Therefore, its evaluation is fundamental. The aim of this article was to conduct a systematic review of upper limb functions after replantation or reimplantation, seeking to identify reported functional outcomes as well as the level and mechanism of injury. To achieve this objective, a literature search was conducted in PubMed, ScienceDirect, Cochrane and Web of Science. Studies from the last 10 years which included patients with upper limb replantation and reported their functional outcomes were included. Out of 523 articles, 12 studies (n = 607) were finally included. DASH and CISS were the most commonly used assessments to report functional outcomes. In conclusion, functional outcomes after replantation are assessed using widely varying scales; therefore, due to this methodological variability, it is difficult to compare functional success between studies and further studies on functionality are needed to provide new data.

Outcomes of single digit replantation for amputation proximal to the flexor digitorum superficialis insertion: A systematic review with meta‐analysis

BACKGROUND

A single digit amputated proximal to the flexor digitorum superficialis (FDS) insertion is a relative contraindication to replantation. The aim of this study is to conduct a systematic review on replantation of these injuries to synthesize best available evidence on outcomes.

METHODS

This review was registered in PROSPERO under registration number CRD42021277305. A MEDLINE, CENTRAL, and EMBASE databases search yielded 1536 studies. Primary clinical studies on single digit replantation and functional outcome with at least 10 cases were included. Data on revision amputation and replantation distal to the FDS were collected as comparators. Data extracted included demographics, type of digit, level of injury, secondary surgeries, duration of sick leave, survival, function, and patient-reported outcomes. All studies were assessed using the Risk of Bias In Non-randomized Studies of Intervention (ROBINS-I) tool and data synthesis was completed using RevMan and Microsoft Excel.

RESULTS

Six studies representing 182 replanted single digits that were amputated proximal to the FDS insertion were included. The average PIPJ motion of replanted single digits was 50° in those amputated proximal to the FDS insertion compared to 82.5 in those amputated distal to the FDS. The average Michigan Hand Questionnaire (MHQ) score was 84.78 in replantation group versus 76.81 in the amputation group which was statistically significant (p < .00001). Mean Disability of Arm, Shoulder, and Hand Questionnaire (DASH) score was 12 in replantation group compared to 18.5 in amputation group, however this was not statistically significant (p = .17).

CONCLUSION

Few studies exist on outcomes of single digit replantations proximal to FDS insertion. Although range of motion is inferior in the replant group, this has increased since initial studies were performed, and patient satisfaction and patient reported outcomes are high. This is promising evidence for achieving reasonable outcomes in replantation of single digits amputated proximal to the FDS.

LEVEL OF EVIDENCE

Level III.

Survival Statistics of Digital Replantation in the UK

Background

Digital replantation is associated with a substantial risk of failure. There is considerable variation in survival rates globally, and the current data are limited by poor statistical methods and bias of selection, which limits its translation to Europe and the USA. We aimed to establish a more representative survival rate of digit replantation for western populations and evaluate espoused prognostic variables using robust statistical methodology.

Materials and Methods

Retrospective data were collected from 58 consecutive patients who underwent digital replantation following traumatic amputation in three tertiary care hand centres in the UK over seven years. The unit of analysis was the digit. Generalized linear modelling was used to estimate the odds ratio (OR) of digit survival.

Results

Forty-six of 68 replanted digits survived (68%). The typical replant candidate was a 40-year-old male manual worker. Digit survival was more likely with guillotine injuries (adjusted OR 25.5 [95% CI 5.60, 115]) and when intraoperative skeletal shortening was performed (adjusted OR 15.3 [95% CI 2.62, 89.5]). The age of the patient, seniority of the operating surgeon, and use of vein grafts was not associated with digit survival.

Conclusion

We provide robust data to show that guillotine amputations have more favourable survival rates, which can be further improved by skeletal shortening at the time of replantation. We suggest that research networks worldwide set up digit amputation registries to capture individual patient data on this uncommon injury.

Application of Cryopreservation Technique in the Preservation of Rat Limbs

OBJECTIVE

The aim of this study was to observe the physiologic and pathologic changes of severed fingers (limbs) under different storage conditions through animal experiments, and to screen out the best preservation conditions.

METHODS

Sixty healthy adult male Sprague-Dawley rats were selected and evenly divided into 4 preservation groups, including conventional low-temperature dry (CLTD), the University of Wisconsin (UW) solution, cryopreservation, and cryopreservation + UW solution preservation group. After harvesting the limbs, were preservated for 72 hours and 7 days, respectively. Then the limbs were thawed and replanted in situ. Sciatic nerves were collected for hematoxylin & eosin (H&E) staining and observed the changes in tissue morphology.

RESULTS

Replantation was successful in 11 of 15 rats (73%) in the cryopreservation + UW group, and the walking function of the 9 (82%) rats in cryopreservation + UW group were significantly better than that of the cryopreservation preservation group. Additionally, the H&E staining results shown that the CLTD group nerve bundles were morphologically damaged, and there were more acellular structures and tissue fragments; the UW group nerve bundles were less injured and the perineurium was more complete and more orderly. The nerve bundles in the cryopreservation group and the cryopreservation + UW group are tightly arranged, and the tissue morphology is regular. Compared with the cryopreservation + UW group, the completeness of the cryopreservation group was not sufficient.

CONCLUSIONS

The cryopreservation technology combined with the UW solution is a new and effective method for preservation of severed limbs.

Starfish Procedure

For those patients with partial hand level amputation who would benefit from myoelectric prosthetic digits for enhanced prehensile function, the Starfish Procedure provides muscle transfers, which allow for the generation of intuitively controlled electromyographic signals for individual digital control with minimal myoelectric cross-talk. Thoughtful preoperative planning allows for creation of multiple sources of high-quality myoelectric signal in a single operation, which does not require microsurgery, providing for wide applicability to hand surgeons of all backgrounds.