The goal of reconstructive hand surgery is return of normal function,
including pain-free movement, normal active and passive range of
motion, premorbid strength, and intact sensation. Yet the process
of incising, dissecting, and sewing is associated with significant
scarring and pain. Scarring is especially troublesome in the hand,
since it leads to stiffness, ligamental tightening, and arthritis. As
a result, any procedure in the hand that minimizes postoperative
scarring or pain will contribute to an improved result.
Surgical care in the past decade has been revolutionized by the
introduction and incorporation of minimally invasive surgical techniques.
Laparoscopies and thoracoscopies have permitted the resection of
hollow and solid organs through 1 cm incisions, reducing the need
for laparotomies and thoracotomies. Likewise, urologists have employed
cystoscopy for evaluation and treatment of bladder and kidney disorders,
while orthopedic surgeons have used arthroscopy to similar effective ends
in the knee, ankle, elbow, and shoulder.
Two areas of hand surgery incorporate minimally invasive techniques:
Wrist arthroscopy has expanded the options for evaluating the chronically
painful wrist, and endoscopic carpal tunnel release (ECTR) provides
a less invasive method than open release for decompressing the median
nerve. While ECTR theoretically allows for a faster recovery, it
may in fact offer only limited advantages.
Diagnostic wrist arthroscopy was first successfully used in 1970.
Over the past 3 decades, it has taken its place among traditional
imaging techniques as a low-morbidity method for evaluating chronic wrist
pain. As the hardware for examining the wrist has become more sophisticated
and as hand surgeons have become more familiar with the arthroscopic
view of the wrist, increasingly aggressive attempts have been made
to use the arthroscope to treat as well as to diagnose wrist problems.
Diagnostic wrist arthroscopy is a useful technique to evaluate
patients with wrist pain, whether chronic or acute. In patients
with chronic pain, this technique can be used to augment information offered
by plain radiographs, CT, MRI, or wrist arthrography. It can confirm
an uncertain diagnosis or be used to reevaluate a patient who has
failed other treatments. In contrast, patients with acute symptoms—such
as those suffering from mechanical wrist pain—may complain
of pain localized over the joint, catching and popping sensations,
and relief with rest. Here, the wrist can be manipulated during
arthroscopy to localize the source of the symptoms. In general,
the technique is useful for evaluating articular cartilage, ligaments,
the triangular fibrocartilage complex (TFCC), and the synovium. Interestingly,
diagnostic wrist arthroscopy may provide too comprehensive an examination.
Only some of the lesions that are visualized during an examination may
be responsible for a patient’s symptoms. The hand surgeon
must critically correlate arthroscopic findings with the patient’s
examination to arrive at the appropriate diagnosis.
Therapeutic wrist arthroscopy is useful for the treatment of
ligament tears, TFCC lesions, articular cartilage lesions, subtle distal
radius and carpus fractures, dorsal wrist ganglions, removal of
isolated carpal bones up to and including the proximal carpal row,
and disorders of the distal radioulnar joint. It is useful also
in the management of lesions arising from rheumatoid arthritis.
It has been successfully used in completing synovectomies, proximal
row carpectomies in the case of scaphoid nonunion or scapholunate
collapse, radial styloidectomy, and isolated symptomatic chondral
Equipment for diagnostic wrist arthroscopy includes an apparatus
for elevating and distracting the wrist, an arthroscopic telescope,
a video camera, a fluid infusion system, and both manual and powered
Either general or regional anesthesia may be used. A tourniquet
is placed at the mid arm to provide a blood-free field during the
operation. The distal forearm, wrist, and hand are prepared into
the operative field. Traction is applied to the hand, usually via
sterile finger traps, and a distraction force is applied across
Individual skin incisions are then made at standard portal sites
determined by the goal of the operation. Portal sites are described
according to their relationship with the radius and ulna, the carpal bones,
and the extensor tendons. The relationship to the extensor tendons
is indicated by listing the extensor compartments on either side
of the incision. Typical portals include the 3–4 radiocarpal, through
which the scaphoid and lunate facets can be visualized; the 4–5
radiocarpal, through which the TFCC and the ulnocarpal ligaments
can be seen; and the 6R radiocarpal, through which the extensor
carpi ulnaris tendon and ulnar wrist are approached. The midcarpal joint
is approached through any of three portals, including the midcarpal
ulnar, the midcarpal radial, and the scaphotrapezial-trapezoid.
Once abnormalities are identified, therapeutic wrist arthroscopy
can be used to effect repairs. Partial ligament tears and tears
of the TFCC can be debrided arthroscopically using knife blades
and motorized shavers. Carpal bone resections can be completed with
miniature osteotomes and powered saw blades.
Operations employing diagnostic and therapeutic wrist arthroscopy
typically result in less swelling, less postoperative pain, and
less stiffness than comparable open wrist procedures. There is a
concomitant earlier return to function and work. Therapeutic wrist
arthroscopy even of dorsal wrist ganglia, the most superficial of
wrist abnormalities, is followed by fewer—or no more—recurrences
than the open technique.
The rate of complications associated with diagnostic and therapeutic
wrist arthroscopy is estimated to be 2% and is due to a
variety of causes. The continuous traction necessary to properly
distract the wrist can cause problems, including ligamental strain
at the MCP joints with concomitant joint edema and stiffness and
stretching of peripheral nerves. Establishment of the operative portals
can damage articular cartilage, ligaments, tendons, cutaneous nerves, the
radial artery, and cutaneous and deep veins. Such injuries include
abrasions, contusions, lacerations, and transections. A high proportion
of complications of therapeutic wrist arthroscopy are associated
with inadequate relief of symptoms or a diminished return of function.
A now less common complication of therapeutic wrist arthroscopy
results from the fluid infusion. Forearm compartment syndromes have
resulted from extravasation of infusion fluid during endoscopic
repair of distal radius fractures; this problem is now avoided by
circumferential compression of the forearm during the procedure.
Endoscopic release of the transverse carpal ligament is an increasingly
popular method of treating carpal tunnel syndrome. Advocates of
the procedure claim that it is associated with decreased postoperative
morbidity and earlier return to work. Others caution that there
is little if any short-term difference between endoscopic and open
carpal tunnel release, no long-term difference, and that endoscopic
carpal tunnel release is associated with an increased likelihood
of significant nerve injury.
Endoscopic carpal tunnel release is easier to perform in patients
with larger wrists. Ease of access to the carpal tunnel correlates
with the wrist circumference and the height and age of patients.
Surgeons should be aware that the procedure is likely to be more
difficult in small patients with small wrists and are advised to
maintain a lower threshold for conversion to the open technique
to avoid neurologic complications.
Absolute contraindications to endoscopic carpal tunnel release
include masses in the carpal canal and other space-occupying lesions,
abnormalities in canal anatomy, and wrist stiffness that precludes
In the United States, most surgeons use one of two techniques—either
Chow or Agee. The two differ primarily in the number of incisions,
or portals, needed to gain access. The Chow technique, first described
in 1989, employs two portals, while the Agee technique requires
Either operation can be performed under local anesthesia with
a brachial tourniquet. An initial transverse incision is made proximal
to the wrist flexion crease between the palmaris longus and flexor carpi
ulnaris tendons. The space between the transverse carpal ligament and
the flexor tendons is defined with a dissector. In the Agee procedure,
the endoscope is advanced under the transverse carpal ligament,
radial to the hook of the hamate along the axis of the ring finger.
The ligament is incised along its entire length, with care taken
to avoid the Guyon canal and the superficial palmar arch. In the
Chow operation, a second transverse incision is made just distal
to the transverse carpal ligament along the axis of the ring finger.
The wrist is dorsiflexed, and a slotted cannula is advanced into
the proximal incision, deep to the transverse carpal ligament, and
out the distal incision. The endoscope is then used to visualize
the ligament while the knife divides it. The wounds are closed,
and the patient’s wrist placed in dorsiflexion.
Several studies have compared open versus endoscopic carpal tunnel
release, focusing on the incidence of recovery from symptoms, the
time span until the patient returns to work, and the incidence of
recurrence of symptoms. Overall, both techniques have equivalent
Many of the most convincing studies are prospective randomized
trials. One such study, comparing open and endoscopic carpal tunnel
release among 32 hands in 29 patients, found no difference in postoperative
recovery time or surgical result. The only significant difference noted
by the authors was transient numbness on the radial side of the
ring finger in three endoscopic carpal tunnel release patients.
In another study, the authors compared in a prospective randomized
manner the early outcome of carpal tunnel release using either a
conventional open carpal tunnel release procedure in 40 patients or
a two-portal endoscopic release in 56 patients. They found no statistically
significant difference between the groups in postoperative pain,
recovery from paresthesias, or time taken to return to work. However,
the endoscopic group demonstrated better grip strength recovery
at 1 and 3 months. No surgical complications were observed in either
Nonrandomized studies have supported this trend. An analysis
of 191 consecutive patients undergoing carpal tunnel release with
an average 2-year follow-up showed that none of the patients undergoing
open release had a recurrence, while 7% of patients undergoing
endoscopic release had recurrences. Another study observed a higher
incidence of incomplete release of the carpal tunnel with endoscopic
techniques than with standard open releases.
The factors identified with poor outcomes in endoscopic carpal
tunnel release are similar to those seen in open release. Less satisfactory
results were present in workers’ compensation cases; patients with
normal motor latencies on nerve conduction studies; patients with
preoperative hand weakness, widened two-point discrimination, myofascial
pain syndrome, or fibromyalgia; and patients involved in litigation,
those with multiple compressive neuropathies, and those with abnormal
Only a limited number of studies include a sufficient number
of patients to compare complication rates and type between endoscopic
and open carpal tunnel release. Overall, the types and rates of
complications between the two forms of release are similar. Nonetheless,
isolated but severe complications from endoscopic release over the
past decade tend to dramatize its risk.
The study by Boeckstyns and Sorensen is perhaps the most comprehensive
to date. These authors analyzed 54 published series of endoscopic
and open releases comprising 9516 and 1203 patients, respectively.
Irreversible nerve damage from the procedure occurred in 0.3% of
endoscopic and 0.2% of open releases, including such injuries
as transection of the median nerve. While reversible nerve injuries
were more common with endoscopic release than with open release
(4.4% versus 0.9%, respectively, among prospective
controlled and randomized studies), tendon lesions, reflex sympathetic
dystrophy, hematoma, and wound problems were equally common with
A less compelling analysis—a retrospective survey of hand
surgeons who had performed either open or endoscopic carpal tunnel
release over the preceding 5 years—found major complications
with both approaches, including median nerve lacerations, ulnar
nerve lacerations, digital nerve lacerations, vessel lacerations,
and tendon lacerations. While the authors could not reach a conclusion
about the rate of complications for one procedure versus the other,
their results demonstrate the potentially devastating sequelae of
carpal tunnel release even in experienced hands.
Carpal tunnel symptoms may persist or recur following either
open or endoscopic release. In patients who have persistent symptoms
following endoscopic release, many authors recommend open carpal tunnel
release as definitive therapy.
Beredjiklian PK et al: Complications of wrist
arthroscopy. J Hand Surg [Am] 2004;29:406.
Shih JT et al: Arthroscopically-assisted reduction of intra-articular
fractures and soft tissue management of distal radius. Hand Surg
Slutsky DJ: Wrist arthroscopy through a volar radial portal. Arthroscopy
Thoma A et al: A systematic review of reviews comparing the effectiveness
of endoscopic and open carpal tunnel decompression. Plast Reconstr