Infection almost anywhere in a patient's hand makes its back swell, but pus seldom collects there. On the rare occasions when it does collect on the dorsum, it is usually subcutaneous, and only occasionally in the subaponeurotic space under his extensor tendons (B, Fig. 8-1). If localized tenderness persists for more than 48 hours, don't wait for fluctuation. Drain it through a longitudinal incision over the point of greatest tenderness.
THE COMMONEST CAUSE OF SWELLING ON THE DORSUM IS INFECTION IN THE PALM Fig. 8-6 INCISIONS FOR HAND INFECTIONS. Incisions for the finger tips are shown in Figs. 8-2 and 8-3. Some infections don't have fixed incisions (the volar surfaces of the proximal and middle phalanges, the superficial palmar space, and the dorsum of the hand), so these are not illustrated. A, to D, the remaining incisions for more serious hand infections, have been numbered, and most of them are shown here.
Incisions 1 for web space infections. Alternative incisions 2 and 3 for a middle palmar space infection. Alternative incisions 4 and 5 for a thenar space infection. Incision 6 for pus in the space of Parona (proximal to the flexor retinaculum and deep to the flexor tendons).
There are several alternative incisions for tendon sheaths: The lateral ones 7. The transverse palmar ones 8 (shown in Fig. 8-7). The zig-zag palmar ones 9; 9a the first part, and 9b the second part if necessary. Incisions 7 and 8 are for less severe infections, and incisions 9 for more severe ones.
Incision 10 divides the flexor retinaculum. Incisions 11 or 12 drain the radial bursa.
E, the tendon sheaths, the radial and ulnar bursae, the lumbrical muscles, and the flexor retinaculum.
F, the incision for dividing the flexor retinaculum (10). On the ulnar side of the retinaculum the palpable landmarks are the pisiform and the hook of the hamate. On the radial side you can feel the tubercle of the scaphoid and, more deeply, the tuberosity of the trapezium (see also Fig. 27-14a).
G, a cross section of the finger. The digital nerves are at the ''edges' of the palmar surfaces, so don't incise there. Either incise towards the middle of the palmar surfaces or laterally towards the dorsum as shown by the arrows. E, and F, after Grant's ''Method of Anatomy', (9th edn. 1975 edited by JV Basmajian). Williams and Wilkins, with kind permission.