Nail Surgery- Important points listed below
- Nail matrix
- Proximal nail matrix forms superficial (dorsal) surface of nail plate
- Distal nail matrix forms deep (ventral) surface of nail plate; lunula is distal 1/3 matrix
- Distal matrix surgery better for nail appearance than proximal matrix surgery as defect of nail plate less noticeable on undersurface of nail plate
- Nail bed
- Surgery of nail bed rarely causes permanent nail plate dystrophy but may cause mild onycholysis
- Nail bed: no subcutaneous tissue underneath it (dermis sits directly on periosteum)
- Anesthesia
- Inject either as digital block and/or wing block
- Digital block: 2% plain lidocaine, superficial with volume <1–1.5 ml on each side of digit (total 3 ml per digit)
- Useful procedures: punch biopsy (± prior nail avulsion), lateral longitudinal excision, elliptical excision in nail bed or nail matrix
- Biopsy
- Procedures should be oriented properly for healing to be optimal with minimal scarring
- Matrix: biopsy along horizontal axis
- Nail bed: biopsy along vertical or longitudinal axis
- Biopsies should be taken down to level of periosteum (undermine at same level)
- Preferable for excision to be ≤ 3 mm; suture if possible, but ≤ 3 mm does not need suture
- When biopsing pigmented band, specimen must be taken from nail matrix, where pigment generated (matrix exploration); matrix w/ highest risk of scarring so choose distal matrix if possible; unusually melanoma can start in nail bed and spread to matrix
- Excision
- Elliptical excision should be in horizontal direction in matrix and vertical in nail bed
- Nail matrix excision/repair results in thinner nail plate due to the fact that nail plate thickness is proportional to length of matrix
- Avulsion
- Nail avulsion can be partial or total and may be performed either distally or proximally
- Procedure allows for exploration of nail bed and matrix for tumors and subsequent biopsy if needed
- Distal technique: Freer septum elevator used to loosen nail plate from attachment to nail bed, matrix, proximal and lateral nail folds by inserting into hyponychium toward the matrix
- Proximal technique: Freer septum elevator inserted at the proximal nail fold
- Partial nail avulsion: often used in longitudinal melanonychia involving lateral ¼ nail plate or if patient with ingrown toenai
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