Chapter 35 Table 35.1 Reverse first dorsal radial metacarpal flap (Moschella)
Reverse First Dorsal Radial Metacarpal Flap (Moschella)
Flap |
|
Tissue | Skin and subcutaneous tissue |
Course of the vessels | On the undersurface of the flap |
Dimensions | 3 × 1.5 cm |
Extensions and combinations | — |
Anatomy | Recurrent radial branch of the princeps pollicis artery; no identifiable vein |
Neurovascular pedicle | — |
Artery | — |
Veins | — |
Length and arc of rotation | — |
Diameter | — |
Nerve | — |
Surgical technique |
|
Preoperative examination and markings | Dorsal aspect of the first metacarpal; Doppler identification of the vessels and their course |
Flap design | Mark the defect size and include the cutaneous extension distally to facilitate skin closure of the donor site and rotation of the flap into the defect; the flap can be considered a “propeller” flap because it is rotated on an isolated vascular pedicle into an adjacent defect |
Patient position | Arm on hand table, with the hand pronated |
Dissection | Incise the flap circumferentially in the marked and required dimensions; dissection starts close to the paratenon of the abductor pollicis longus; the vessel that runs along the periosteum of the first metacarpal and has to be “peeled off” of the periosteum; dissect toward the pivot point, where the vessel exits from underneath; rotate the flap into the defect, and then close the skin without tension |
Advantages | Local flap with reliable blood supply when the vessel can be identified with a handheld Doppler |
Disadvantages | The vessel is very fragile and difficult to dissect |
Pearls and pitfalls |
|
Dissection | It may be necessary to leave a small dog-ear around the pivot point when the perforating vessel is not clearly visible |
Extensions and combinations | — |
Contouring and correction | Secondary contouring is rarely necessary |
Clinical applications | Dorsal defects of the thumb distal to the interphalangeal joint |
