Repair of Soft Tissue Defect of the Finger Using the Heterodigital Neurocutaneous Island Flap

At final follow-up, we measured the sensibility of the flaps using the Semmes-Weinstein monofilament test and the static 2-point discrimination test. The test points were at the center of the radial or ulnar portion of the pulp. The donor site, i.e. radial- or ulnar-dorsal aspect of the middle phalanx of the donor digit, was also evaluated. Each area was tested 3 times with a Discriminator (Ali Med, Dedham, MA). We stopped at 4mm as a limit of 2PD and considered this normal.

• the neurocutaneous island flap (Device), also known as dorsal digital island flap: The neurocutaneous island flap of the dorsal branch of the digital nerve can be used for repair the defects of the proximal and middle phalanxes of adjacent fingers.

Primary outcomes

• Discriminatory Sensation of the Flap [18 months to 24 months]: Discriminatory sensation of the flap is evaluated with the Static 2-point Discrimination Test. The test determines the minimal distance at which a subject can sense the presence of two needles. The modified American Society for Surgery of the Hand guidelines were used to stratify Discriminator measurements (excellent <6 mm; good 6-10 mm; fair 11-15 mm; poor >15 mm. The test point is at the center of the flap. Each area was tested 3 times with a Discriminator (Ali Med, Dedham, MA). Two out of 3 correct answers were considered proof of perception before proceeding to another lower value. We stop at 4mm as a limit of 2PD and considered this normal. These assessments take place at a single time point at the final follow-up.

Secondary outcomes

• Cold Intolerance [18 months to 24 months]: We access the cold intolerance of the injured and donor fingers using the self-administered Cold Intolerance Severity Score questionnaire10 that is rated into mild, moderate, severe, and extreme (0-25, 26-50, 51-75 and 76-100).

Sex: All, ages: 15 Years to 60 Years, accepts healthy volunteers

Inclusion Criteria:

* the soft tissue defects involving the middle phalanx, the proximal interphalangeal joint, or both;
* a defect greater than or equal to 2 cm in length;
* a patient between 15 and 60 years of age.

Exclusion Criteria:

* concomitant injuries to the dorsal skin of the middle phalanx of adjacent finger that precluded its use as donor site;
* injuries to the course of donor nerve branch;
* a defect less than 1.5 cm in length;
* a fingertip or pulp defect;
* a soft tissue defect of the thumb.

Participant flow

Outcome results

• Discriminatory Sensation of the Flap (Primary), Mean, mm: Surgical Flap 8.3 +/- 1.6
• Cold Intolerance (Secondary)

Adverse events

Time frame: One year

Limitations and caveats: The samples of our study are small, and the results may change as our experience grows.

• Results publication: Chen C, Zhang X, Shao X, Gao S, Wang B, Liu D. Treatment of a combination of volar soft tissue and proper digital nerve defects using the dorsal digital nerve island flap. J Hand Surg Am. 2010 Oct;35(10):1655-1662.e3. doi: 10.1016/j.jhsa.2010.07.011. PMID 20888502
• Results publication: Wang B, Zhao Y, Lu A, Chen C. Ulnar nerve deep branch compression by a ganglion: a review of nine cases. Injury. 2014 Jul;45(7):1126-30. doi: 10.1016/j.injury.2014.03.017. Epub 2014 Apr 3. PMID 24774037
• Results publication: Chen C, Tang P, Zhang L. Reconstruction of a soft tissue defect in the finger using the heterodigital neurocutaneous island flap. Injury. 2013 Nov;44(11):1607-14. doi: 10.1016/j.injury.2013.06.025. Epub 2013 Jul 18. PMID 23871427