Reverse dorsolateral proximal phalangeal island flap: Long-term results.

OBJECTIVES: This study aims to present long-term follow-up results of the reverse dorsolateral proximal phalangeal island flap designed for reconstruction of large fingertip and pulp defects. METHODS: We examined 18 patients who underwent reverse dorsolateral proximal phalangeal island flap surgery to address ≥2.5 cm fingertip and pulp defects. Mean follow-up was 84.4 months. Sensitivity assessments were conducted using the Semmes-Weinstein monofilament and 2-point discrimination tests. Additionally, we evaluated finger joint active range of motion, complications and cold intolerance. RESULTS: Mild venous congestion was observed in 5 flaps. Significant differences were observed in 2-point discrimination and Semmes-Weinstein monofilament tests between the injured and contralateral sides, specifically in the flaps, the dorsal side of the middle phalanx, and the donor site. The flap's mean static 2-point discrimination was 8.3 mm. Restricted distal interphalangeal joint extension was observed in 2 cases. Total active motion with the flap was good or excellent in the injured fingers, but with a significant difference between injured and contralateral fingers. Additionally, 42% of the injured fingers exhibited hook nail deformity, and 2 patients reported cold intolerance. Despite these issues, most patients has high scores for the appearance and satisfaction aspects of the Michigan Hand Outcomes Questionnaire. CONCLUSION: In moderate or larger fingertip defects, the reverse dorsolateral proximal phalangeal island flap serves as an alternative for reconstructing both fingertip and pulp issues. However, this option involves sacrificing some sensation in the dorsum of the middle phalangeal finger and the donor area. LEVEL OF EVIDENCE: IV, therapeutic study.

Expression changes of nerve cell adhesion molecules L1 and semaphorin 3A after peripheral nerve injury.

The expression of nerve cell adhesion molecule L1 in the neuronal growth cone of the central nervous system is strongly associated with the direction of growth of the axon, but its role in the regeneration of the peripheral nerve is still unknown. This study explored the problem in a femoral nerve section model in rats. L1 and semaphorin 3A mRNA and protein expressions were measured over the 4-week recovery period. Quantitative polymerase chain reaction showed that nerve cell adhesion molecule L1 expression was higher in the sensory nerves than in motor nerves at 2 weeks after injury, but vice versa for the expression of semaphorin 3A. Western blot assay results demonstrated that nerve cell adhesion molecule L1 expression was higher in motor nerves than in the sensory nerves at the proximal end after injury, but its expression was greater in the sensory nerves at 2 weeks. Semaphorin 3A expression was higher in the motor nerves than in the sensory nerves at 3 days and 1 week after injury. Nerve cell adhesion molecule L1 and semaphorin 3A expressions at the distal end were higher in the motor nerves than in the sensory nerves at 3 days, 1 and 2 weeks. Immunohistochemical staining results showed that nerve cell adhesion molecule L1 expression at the proximal end was greater in the sensory nerves than in the motor nerves; semaphorin 3A expression was higher in the motor nerves than in the sensory nerves at 2 weeks after injury. Taken together, these results indicated that nerve cell adhesion molecules L1 and semaphorin 3A exhibited different expression patterns at the proximal and distal ends of sensory and motor nerves, and play a coordinating role in neural chemotaxis regeneration.