PRINCIPLES OF HAND SURGERY AND SURGICAL APPROACHES TO THE HAND AND WRIST

Even in emergency surgery, the surgeon usually has time
to examine the extremity carefully to determine the severity of
involvement of the skin, vessels, nerves, tendons, and skeleton. He or
she can then plan the anticipated surgical procedure, which, after
cleansing and debridement, might call for a skin graft or repair of
lacerated radial, ulnar, and digital arteries and nerves. Through
clinical examination and radiographs, the physician can evaluate the
skeletal structures and plan for reduction and internal fixation of
subluxations, dislocations, and fractures.

For severe injuries, paralytic conditions, and some
disease entities, staged surgical repair and reconstructive procedures
may be indicated. In these cases, a sequence of

surgical procedures can be planned and, in most cases, can be discussed with the patient and relatives before surgery.

The primary requirement in hand surgery is the
restoration of the position of function, nutrition, sensibility,
motion, and good skin cover. The ends of the digits should have
noncicatricial touch surfaces. The thumb should oppose the fingers, and
the hand should open and close for the functions of pinch, hook, and
grasp. The wrist should usually be in an extended position or
occasionally in a straight position, and the fingers should be flexed
partially at the metacarpophalangeal, proximal interphalangeal, and
distal interphalangeal joints. The priorities of reconstruction are, in
order of their importance, artery, skin, bone and nerve, and tendon.

For elective surgical procedures, advise patients to
discontinue any medications (aspirin, nonsteroidal antiinflammatory
drugs) that may increase perioperative bleeding at least 4 days before
surgery. Patients on warfarin should be under supervision by an
internist, who should be consulted regarding management.

Position a standard operating table so that a hand table
can be attached to it. The distal end should have a stable,
perpendicular appendage that extends to the floor. When fluoroscopy is
needed, use a radiolucent table without legs that interfere with
positioning of the fluoroscope. Always choose a table supported by legs
when using a microscope, otherwise the operative field will drift out
of focus as weight is placed on and taken off the table. With the
patient in a comfortable supine position, abduct the extremity to 90°
and place it on the table. Arrange the overhead lights opposite each
other in line with the hand table so that neither surgeons’ nor nurses’
heads obstruct the focused light. The stools on which the surgeon and
the assistant sit opposite from each other should be firm and stable,
and their height should be adjustable. Both the surgeon and the
assistant must be comfortably erect, with their forearms resting on the
hand table.

A tourniquet is mandatory for almost all hand surgery.
As Bunnell said, “A jeweler can’t repair a watch in a bottle of ink,
and neither can we repair a hand in a pool of blood” (6). A bloodless field allows very small vessels and nerves to be seen and dissected with accuracy and minimal trauma.

Formerly, Esmarch bandages were used as tourniquets, and
tourniquet palsy was not uncommon. Likewise, with the use of blood
pressure cuffs that were not monitored by a mercury manometer or
equipped with protective safety devices, false pressure readings, which
sometimes masked extremely high pressures, remained undetected. The
tourniquet gauge should, therefore, be checked and calibrated at least
daily and the figures recorded (24). The
calibration of many newer tourniquets is more stable and reliable.
Become familiar with the one you are using and be confident that the
pressure readings are accurate. Until a time of 2 hours was established
by Wilgis as a safe period for a tourniquet to remain in place,
tourniquet palsy was common (25).

The choice of anesthesia for each procedure, other than a local block, is made by the anesthesiologist (17,23).
Discuss with the anesthesiologist the patient’s concerns and wishes,
the estimated length of the operation, and the length of time the
tourniquet will be in place. For most children, for apprehensive
adults, and for extensive procedures and patients requiring surgery
elsewhere on the body, general anesthesia is usually preferable. A
general anesthetic may also be necessary because infection or neoplasm
may contraindicate regional anesthesia.

Regional anesthesia in the form of supraclavicular,
axillary, brachial, and peripheral nerve blocks is very satisfactory
for many procedures involving the upper extremity. Preoperative and, if
necessary, intraoperative sedation may be used to keep the patient from
moving and to lessen discomfort from the tourniquet.

Intravenous anesthesia using 1% lidocaine solution and
two tourniquets on the arm, when administered by a competent
anesthesiologist, is satisfactory for many surgical procedures on the
hand that take no longer than 1 ½ hours. The three main problems with
this technique are tourniquet pain, oozing at the surgery site, and
risk of systemic anesthetic toxicity from cuff failure.
Re-exsanguination 15 to 20 minutes after injection of the local
anesthetic by firm reapplication of a sterile Esmarch bandage, followed
by complete release and immediate reinflation of the double cuff
tourniquet provides a better surgical field with improved tourniquet
tolerance (18).

With proper preoperative sedation and, if necessary,
intravenous sedation, an arm tourniquet is generally well tolerated for
half an hour or longer. Many procedures can be performed simply with
local anesthesia or a digital block. Some clinical anesthesia is
produced almost immediately with a 1% solution of plain lidocaine
hydrochloride, but the full effect takes 3 to 7 minutes and lasts about
an hour (20). Avoid local anesthetics with
epinephrine for procedures on the hand. Injection in or close to an
artery can result in ischemic necrosis of digits.

The hand surgeon requires special instruments that are
often more delicate than those required for most other surgical
procedures. Small knife blades, such as Bard-Parker #15 and #11; small
Adson forceps; pointed, curved, and straight scissors; osteotomes and
chisels; ronguers and small bone cutters; probes; hemostats; curets;
gouges; tendon strippers; sharp hook and blade retractors; needles;
sutures; and ligatures are indispensable for hand surgery. Other
special instruments, various hand holders (including those made of
malleable lead), hand and motorized

drills, special sutures, and small needles should be available in the operating suite before starting a procedure.

Many hand surgeons routinely use 2.5 × to 4.5 ×
magnifying glasses or loupes when dissecting. With magnification, the
planes between diseased and normal tissue are immediately apparent.
Likewise, the small branches of the digital nerves and arteries are
seen and protected easily. Operating loupes have been designed on one
of three basic types of magnification systems: simple, compound
(galilean), and prismatic. For discussion of the fundamental optical
principles and terminology, and a concise description of various loupes
available on the market, the reader is referred to Baker and Meals’
article (1).

Those who perform microvascular surgery need a variety
of microsurgical instruments, as well as a double-headed or
triple-headed binocular microscope with electric foot controls that
allows 6 × to 15 × magnification. Learn, practice, and develop the
technical skills of operating with microscopic magnification in the
microsurgery laboratory; only after gaining this experience can the
skill be applied to patients.

Although vaccination against hepatitis B virus is now
available, there is no vaccination against either the hepatitis C virus
or the human immunodeficiency virus (HIV). Take care to avoid injury to
the surgical team by needle sticks (27).
Although the incidence of glove puncture varies with the type of
surgery, it is suggested that, on average, 5.6 injuries occur per 100
procedures (9). Double surgical gloves
significantly protect the surgeon against needle perforations, but they
impair comfort, sensitivity, and dexterity (instrument and tissue
handling) during operations (26). Each surgeon
must individually deliberate whether the price of perceived impairment
of sensation and dexterity is worth the benefit of extra protection
against injury.

Each hand surgeon and operating facility should
establish a standardized routine for preparation of the skin and
draping, thereby ensuring that each patient receives the same careful
attention to detail that is necessary for successful hand surgery. If
the surgical procedure is an elective one, caution the patient at the
time of scheduling to avoid scratches and abrasions to the hand and the
entire extremity for 2 weeks before surgery. Advise patients who are
manual laborers and who are accustomed to having grease and dirt on
their hands to scrub their hands with a detergent solution twice daily
for several days before surgery.

Formerly, it was customary to shave the entire
extremity, but it has been shown that this is unnecessary and, in fact,
may do more harm than good. Shaving should be limited to the site of
the proposed incisions and is done in the operating room immediately
before final skin preparation. The nails should be cleansed and
trimmed, and polish should be removed before the patient enters the
operating room.

After the patient and the extremity are properly
positioned, scrub the hand and forearm for 10 minutes with a sterile
povidone-iodine solution from the tips of the nails to the upper arm,
where the pneumatic tourniquet is in position. Then dry the extremity
with sterile towels and paint it with povidone-iodine. Povidone-iodine
stains the digits and obscures the evaluation of capillary flow in
patients whom the vascular status must be assessed intraoperatively
(e.g., replants, revascularizations). Consider an alternative scrub
solution like chlorhexidine or hexachlorophene, particularly in these
situations. Next, apply sterile drapes and stockinette to the hand and
forearm. Cover the hand table with a waterproof drape to prevent
contamination of the drapes should they become wet during the
procedure. Then exsanguinate or elevate the extremity and request that
the tourniquet be inflated. Take a seat, usually on the axillary side
of the patient, and cut the stockinette to expose the hand.

The basic aim of hand surgery is to restore function and
cosmesis to the greatest extent possible within the shortest, safest
period of time. In acute injuries, this can often be done by thorough
cleansing and debridement of the wound, followed by primary repair of
nerve, bone, and tendon injuries. However, in some severe and
mutilating injuries, the primary object of treatment is to obtain
healing of the skin and subcutaneous tissues and skeletal stabilization
without intercurrent wound infection. These injuries often mandate
delayed wound closure and a further delay in the repair of tendons and
nerves. For each injury or reconstructive procedure, formulate a basic
plan, which may consist of one or more stages (12,13).

The time required for the induration of tissues that
follows each injury and surgical procedure to subside is variable and
must be anticipated. It is best to wait until all inflammatory signs
have subsided, the danger of infection is past, the tissues are soft
and supple, and the joints are flexible. During this waiting period,
proper positioning, encouragement of active motion, and the use of
corrective splinting help to prevent permanent stiffness.

Make surgical incisions so that they offer the best
possible exposure, protection of important structures, and healing with
minimal scar. For some conditions, they should parallel the flexion
creases in the fingers, palm, and wrist. Zigzag incisions described by
Bruner or the traditional Bunnell incision in a midlateral location are
often most appropriate (4,5). On the dorsum, curved and S-shaped
incisions are often appropriate for the fingers, metacarpal area, and
wrist. Transverse incisions are often used at the level of the wrist.
See Table 37.1 and Table 37.2 and the approaches described later in this chapter.

Sharp dissection with the aid of loupes or magnifying
glasses, Bard-Parker #15 and #11 blades, and small curved Littler
scissors is essential for the atraumatic technique that has been
championed by Bunnell and his disciples.

Obtain hemostasis with small hemostats and a bipolar
cautery unit, both during the surgical procedure and just before wound
closure, when the tourniquet is deflated. Then, irrigate the wound with
Ringer’s or normal saline solution before you close the skin.
Injections of 0.25% bupivacaine (Marcaine) into the subcutaneous as
well as deep tissues at this point decreases the amount of analgesics
needed for immediate postoperative pain control.

Primary skin closure is appropriate for most surgical
procedures and some sharp traumatic wounds. Interrupted 5-0 nylon
sutures are usually used for closure of surgical wounds of the hand. An
occasional subcutaneous absorbable suture allows removal of the skin
sutures at the end of 1 week. If necessary, Steri-Strips can then be
applied, thereby eliminating cross-hatch suture scars. For young
children, always use small absorbable sutures to obviate the need for
suture removal.

The following article, entitled “Who Should Do Surgery
of the Hand?” was published as an editorial in 1961 and is as relevant
today as it was then (14). It is reprinted by permission of Surgery, Gynecology & Obstetrics.

Approximately one third of all injuries requiring the
services of a physician or a surgeon, whether in the emergency
department of a metropolitan hospital or the office of a rural
practitioner, involve the hand. The physician administering the primary
treatment for such injuries has a great responsibility, since his
treatment determines, to a large extent, the final outcome.

All physicians must be taught the basic principles that
should govern the treatment of an injury to the hand. They must know
that it is important to protect wounds from contamination and infection
and that adequate help, facilities, and proper instruments must be
available before one starts to care for the injured hand. The
traumatized hand must be cleansed thoroughly but gently. When compared
with injuries of the arm, leg, or abdomen, the involved tissue of the
hand should be sparingly debrided. Whereas many wounds of the arms and
legs should be treated by delayed closure, almost all wounds of the
hand should be closed primarily and this closure must be without
tension. In some instances, the use of skin grafts is necessary to
avoid tension. When possible, fractures should be reduced and
immobilized at the time of the primary treatment. However, if the
physician is not trained to care adequately for the bone injury, less
harm will be done if the skin is closed, the hand is placed in a
position of moderate dorsiflexion of the wrist, moderate flexion of the
fingers, and moderate abduction and opposition of the thumb, and a
bulky dressing is applied to prevent edema. In such selected instances,
the fractures can be dealt with after the cutaneous wound has healed.
Even more important is the necessity to realize that severed nerves and
tendons do not require primary repair; less harm will be done under
unfavorable conditions by secondary repair of nerves and tendons after
the initial wound has healed. A surgeon who attempts primary suture of
a flexor tendon in its digital sheath should have had considerable
education, training, and experience in reconstructive surgical
treatment of the hand and should be capable of performing a tendon
graft.

Extensive, reparative, restorative, reconstructive, and
rehabilitative surgery of the hand should be carried out in hospitals
by surgeons well qualified and dedicated to this field of surgery. The
surgeon interested in treatment of the severely injured hand must be
educated to work in orthopedic surgery, plastic surgery, and
neurosurgery. He should have knowledge of dermatologic, circulatory,
paralytic and arthritic diseases which are prone to affect the hand. He
must be well versed in the most minute details of the surgical and
functional anatomy of the entire upper extremity. He must be versed in
rehabilitative procedures and trained in splinting and bracing. He must
be capable of teaching the patient how to prevent and overcome
stiffness of joints and how to co-ordinate muscles which formerly had
one function but after a tendon transfer have another function.

Above all, the surgeon who devotes much of his time to
surgery of the hand must teach medical students, interns, and residents
how to care properly for injuries which affect the hand. Many of the
principles established by such pioneers as Allen Kanavel, Sterling
Bunnell, and Sumner Koch are still basic and pertinent. It is important
that these principles be learned if crippling of the hand is to be
minimized.

Always think and strive to avoid being in the
predicament that results in pondering to yourself “if there were only
an operation that could undo the results of my last operation!”

There are essentially three approaches to the digit: the
dorsal approach, the midaxial approach, and the palmar approach. The
midaxial approach and the midlateral approach are similar, except that
the midaxial incision is dorsal to the midlateral. The midlateral
incision is made at the anatomic midpoint of the finger. The midaxial
incision is made at the connection of the centers of rotation of the
respective joints and is slightly dorsal to the midlateral because the
joints are dorsal to the rest of the soft tissues in the digit (flexor
tendons). The midaxial incision is more often used because it is right
over the bone and, on deep dissection, leaves the neurovascular
structures safely in the palmar flap.

There are two approaches to the hand: dorsal and palmar.
The dorsal approach exposes the extensor tendons, metacarpals (MP), and
carpometacarpal (CMC) joints, and the intrinsic muscle compartments.
The palmar approach exposes the flexor tendons and lumbricals,
neurovascular bundles, and Dupuytren’s disease.