I. Introduction
A. Wrist arthroscopy may be performed for diagnostic purposes alone.
B. Arthroscopic treatment is appropriate for multiple conditions, including those listed below.
II. Conditions Treated With Arthroscopy
A. Triangular fibrocartilage complex (TFCC) tear
1. The Palmer classification system (
Table 1) describes acute TFCC tears by location.
a. Ulnar or dorsal/ulnar tears (1B) are the most amenable to arthroscopic repair because of good blood supply.
b. Volar distal (1C) and radial (1D) tears are commonly debrided, although repair techniques exist.
c. Central tears (1A) are avascular; thus, debridement is recommended.
2. The central two thirds of the TFCC may be debrided without affecting distal radioulnar joint (DRUJ) stability.
B. Ligament injury
1. The gold standard for the identification of scapholunate (SL) and lunotriquetral (LT) ligament injuries is arthroscopy.
2. Debridement alone or together with pinning may be efficacious in patients with partial ligament tears without dissociation.
C. Ulnocarpal impaction
1. This condition may be associated with a chronic, central TFCC tear (Palmer type 2).
2. The distal aspect of the ulna may be removed arthroscopically to prevent impaction.
D. Distal radius fracture
1. Arthroscopic evaluation of distal radius fractures can aid in fracture reduction.
2. Arthroscopy allows for evaluation through a midcarpal portal of the SL ligament, the LT ligament, and the TFCC (all commonly injured at the time of distal radius fracture).
E. Scaphoid fracture—Arthroscopic evaluation through a midcarpal portal allows confirmation of an anatomic reduction at the time of fixation (percutaneous).
F. Chondral lesion/loose body
1. The evaluation and treatment of small chondral defects may be accomplished with arthroscopy.
2. Loose bodies may be removed with the arthroscope.
G. Wrist ganglion
1. Wrist ganglia are known to originate at the SL ligament dorsally and either the radiocarpal or scaphotrapeziotrapezoid joints volarly.
2. Even if the stalk of the dorsal ganglion is not identified, arthroscopic excision has a low recurrence rate.
H. Arthrosis
1. Early wrist arthritis (scapholunate advanced collapse [SLAC] wrist pattern) at the styloscaphoid joint can be treated by arthroscopic styloidectomy.
2. This procedure is typically combined with additional treatment of the SLAC or scaphoid non-union advanced collapse (SNAC) wrist.
[Table 1. Palmer Classification of Type 1 (Acute) TFCC Tears]
[
Figure 1. The standard wrist arthroscopy portals.]
I. Pisotriquetral arthrosis
1. Arthrosis may be treated with pisiform excision.
2. This can performed in an open fashion. Alternatively, in some patients, the pisiform can be identified and excised arthroscopically.
J. Synovitis (inflammatory or idiopathic)
1. An arthroscopic evaluation and synovectomy may be performed.
2. Although this treatment option rarely provides a long-term cure, it may improve symptoms and delay disease progression.
K. Infection—Arthroscopic debridement and irrigation is straightforward.
III. Patient Setup
A. Positioning—Supine, using a traction tower, with 10-lb traction to fingers.
B. Equipment—30° small joint (2.7-mm) arthroscope.
C. Skin markings—Key landmarks are marked after finger traction has been applied.
1. Lister tubercle
2. Extensor carpi ulnaris (ECU)
3. DRUJ
4. Scaphoid
5. Lunate
IV. Portals
A. Named for their relationship to dorsal compartments, these named portals reference entry into the radiocarpal joint (Figure 1).
B. Portals are created by skin incision and hemostat dissection through soft tissues and capsule. A blunt trochar is then placed into the joint.
1. 3-4 portal
a. It is located 1 cm distal to the Lister tubercle.
b. The superficial branch of the radial nerve averages 16 mm (5 to 22 mm) from the 3-4 portal.
2. 6R portal
a. It is located just radial to the ECU tendon.
b. The dorsal sensory branch of the ulnar nerve averages 8 mm (0 to 14 mm) from the 6R portal.
3. 4-5 portal—Slightly more radial than the 6R portal.
4. The following radiocarpal portals are less commonly used because they present a higher risk of neurovascular injury:
a. 1-2 portal—High risk of injury to the superficial branch of the radial nerve.
b. 6U portal—High risk of injury to the dorsal sensory branch of the ulnar nerve.
5. Radial and ulnar midcarpal portals—Approximately 1 cm distal to the 3-4 portal and the 4-5 portal. Useful for evaluation/visualization of adequacy of scaphoid reduction.
6. DRUJ portals—1 cm proximal to the 4-5 radiocarpal portal.
V. Complications
A. Arthroscopy of the wrist is typically safe, with minor and transient complications.
B. Nerve injury
1. Related to portal placement or suture of the TFCC
2. Typically affects the dorsal sensory branch of the radial or ulnar nerve
C. Infection is uncommon.
D. ECU tendinitis—May be related to portal placement or suture knot after TFCC repair.
E. Tendon injury—Improper portal placement may result in tendon injury.
F. Metacarpophalangeal joint pain
1. Typically caused by overdistraction
2. Transient
G. Wrist stiffness—Uncommon complication of uncertain etiology.
Top Testing Facts
1. Ulnar and dorsal-ulnar TFCC tears are amenable to repair because of good blood supply.
2. Evaluation of congruence of scaphoid fracture reduction is done through radial and ulnar midcarpal portals.
3. The superficial branch of the radial nerve averages 16 mm (5 to 22 mm) from the 3-4 portal.
4. The dorsal sensory branch of the ulnar nerve averages 8 mm (0 to 14 mm) from the 6R portal.
5. The 1-2 portal carries a high risk of injury to the superficial branch of the radial nerve, and the 6U portal carries a high risk of injury to the dorsal sensory branch of the ulnar nerve.
Bibliography
Geissler WB, Freeland AE, Weiss AP, Chow JC: Techniques of wrist arthroscopy. Instr Course Lect 2000;49:225-237.
Gupta R, Bozentka DJ, Osterman AL: Wrist arthroscopy: Principles and clinical applications. J Am Acad Orthop Surg 2001;9:200-209.
Palmer AK: Triangular fibrocartilage complex injuries: A classification. J Hand Surg [Am] 1989;14:594-606.