Proximal row carpectomy (PRC) is a reliable alternative to arthrodesis for treating wrist arthritis. This motion-preserving reconstructive procedure involves removing the scaphoid, lunate, and triquetrum, effectively converting the wrist’s complex joint into a simple hinge.
The procedure has faced significant criticism for altering the normal wrist anatomy, potentially impairing strength and movement, causing improper redistribution of joint load, leading to subsequent radiocapitate arthritis, and producing unpredictable outcomes. Conversely, many researchers have documented satisfactory motion preservation, maintained grip strength, effective pain relief, and high patient satisfaction. Multiple mid- and long-term follow-up studies have shown that proximal row carpectomy is a dependable procedure, with results comparable to other reconstructive and salvage wrist surgeries.
The wrist enables intricate interactions among a series of anatomical structures, each contributing to the stability and mobility of the radiocarpal joint. Several factors contribute to the precise mechanism of wrist function, and a traumatic disruption of any link in this anatomical chain alters carpal mechanics, leading to predictable and progressive joint degeneration.
Scaphoid pathology is often the primary driver of wrist arthritis development. As the joint contact area decreases, load distribution becomes more irregular, and shear forces develop.
The proximal row of carpal bones functions as an intercalated segment between the distal radius and the distal carpal row. Disruption of the intercarpal ligament in the proximal row leads to wrist instability. Injuries to the scapholunate interosseous ligament and the external ligament complex allow the lunate to extend, resulting in dorsal intercalated segment instability.
The resulting palmar flexion of the scaphoid alters load distribution across the radioscaphoid joint, increases contact pressure, and ultimately leads to degenerative changes. This sequential progression of arthritis is known as scapholunate advanced collapse (SLAC) of the wrist.
Another form of scaphoid pathology associated with wrist arthritis results from nonunion or malunion following a scaphoid fracture. This arthritic condition also follows a predictable pattern, known as scaphoid nonunion advanced collapse (SNAC).
Indications for proximal row carpectomy include:
Relative contraindications for proximal row carpectomy are:
Proximal row carpectomy can be performed using an open technique or an arthroscopic technique.
The patient is positioned supine with the affected upper extremity on a radiolucent hand table. The surgical time is typically less than 2 hours, and regional anesthesia or general anesthesia is sufficient for this procedure. A well-padded tourniquet is placed around the upper arm, and the wrist is suspended with 10 to 15 pounds of traction on a traction tower. The tourniquet is inflated, but additional exsanguination is not required. After distraction is applied, the dorsal side of the wrist is palpated for landmarks, and portals are created. The 3-4 portal is routinely used as the primary viewing portal.
Instruments required for performing an arthroscopic proximal row carpectomy:
The 2.7 mm arthroscope is inserted after the radiocarpal joint is insufflated with saline. A 6-R outflow portal is created under direct visualization at the prestyloid recess. A mechanical pump maintains constant intra-articular pressure and flow. The joint is examined routinely, with special attention to the lunate fossa of the distal radius. The volar extrinsic ligaments are identified and preserved throughout the procedure—particularly the radioscaphocapitate ligament, as it plays an essential role in stabilizing the new joint and preventing volar dislocation and ulnar translocation of the distal carpal row. The ulnar extrinsic ligaments and the triangular fibrocartilage complex are identified as the arthroscope is directed ulnarly.
To assess the integrity of the proximal surface of the capitate, the midcarpal joint is visualized. If the quality of this cartilage surface is questionable, an alternative procedure is considered (e.g., four-corner fusion, capitolunate arthrodesis, proximal row carpectomy with interposition arthroplasty, or wrist arthrodesis). Visualization of the midcarpal joint is achieved by establishing a radial midcarpal portal, located approximately 1 cm distal to the 3-4 portal.
Once the surgeon is satisfied with the condition of the cartilage surfaces of the proximal capitate and lunate fossa, the first step in performing the proximal row carpectomy is to remove the scapholunate and lunotriquetral ligaments using a shaver or radiofrequency probe. This step is performed through the 4-5 portal, the 6-R portal, or both. The lunate core is then removed using a burr. Care is taken not to damage the proximal capitate or lunate fossa, which is achieved by leaving an eggshell rim of the lunate. This remaining lunate shell is then morcellized with a pituitary rongeur under direct visualization or image intensification.
The next step is fragmentation of the scaphoid and triquetrum using an osteotome and burr under image intensification, followed by gradual fragment removal with a pituitary rongeur while working through the 3-4 or 4-5 portal. The surgeon can ensure easier removal and better protection of the articular cartilage by first burring and fragmenting these carpal bones.
After the entire proximal carpal row has been removed, the wrist is examined under image intensifier control. Special attention is given to the area of the radial styloid to ensure there is no impingement with the trapezium. Some surgeons recommend a moderate styloidectomy. Although we rarely perform this part of the procedure, it is quite simple to perform with image intensifier assistance.
If desired, a posterior interosseous neurectomy can be performed through a separate 1.5 cm incision directly on the ulnar side of Lister’s tubercle. The fourth extensor compartment is opened on its radial side, and 1 cm of the nerve is resected using bipolar electrocautery. The fourth compartment is repaired with absorbable suture, and all wounds are closed with 4-0 nylon monofilament suture.
Initially, patients are placed in a short arm plaster splint. Between 7 and 10 days after surgery, the portal sutures are removed, and immobilization is continued with a thermoplastic short arm splint for an additional 3 weeks. After 4 weeks, the splint is removed, and gentle range-of-motion exercises are initiated. Strengthening begins approximately 8 weeks after surgery.
Arthroscopic proximal row carpectomy carries several potential complications, including:
Proximal row carpectomy is performed as follows:
Make a transverse incision on the dorsum of the wrist, 5 to 10 mm distal to the radiocarpal joint, extending from the dorsal side of the ulnar styloid to the radial styloid. Deepen the incision to the extensor retinaculum, preserving the sensory branches of the radial and ulnar nerves. Ligate and divide the superficial veins.
Divide the retinaculum longitudinally on the radial and ulnar sides of the extensor digitorum communis tendons. Avoid damaging the extensor pollicis longus tendon as it courses diagonally through the wound.
Expose the dorsum of the proximal carpal row through two longitudinal incisions in the capsule—one in the interval between the extensor digitorum communis and extensor carpi ulnaris tendons, and another between the extensor carpi radialis brevis and extensor digitorum communis tendons.
If the capitate articular surface is eroded, create a distally based capsular flap by connecting the parallel capsular incisions with a transverse incision proximally, near the dorsum of the distal radial articular surface. (The extensor pollicis longus tendon traverses this area diagonally and can be retracted medially or laterally as needed.)
Expose the lunate by elevating the wrist capsule beneath the extensor digitorum communis tendon. Insert a threaded pin into the lunate, apply traction to the bone through the pin, and excise the bone by dividing its capsular attachments with sharp, pointed scissors. A small, angled rongeur is also helpful. Carefully fragment the lunate with a small bone cutter, osteotome, or saw to facilitate removal.
Insert the pin into the triquetrum and excise it similarly. (The lunate and triquetrum are excised first to create more space for the more difficult removal of the scaphoid.)
Through the more radial of the two capsular incisions, excise the ulnar fragment of the scaphoid first, followed by the radial fragment. Dissect close to this fragment to avoid injuring the radial artery.
Align the capitate with the lunate fossa. If necessary, use a Steinmann pin to stabilize the capitate. If the palmar radiocapitate ligament is preserved, this may be unnecessary. Achieve hemostasis if needed, then close the wound in layers. Apply a sugar-tong splint with the hand and wrist in a functional position.
The wrist is immobilized in a sugar-tong plaster splint in slight extension and with the hand in a functional position for 2 to 3 weeks. If a Steinmann pin was used, it is removed after approximately 4 weeks. Active finger movement is encouraged shortly after surgery and continued throughout convalescence. Once the soft tissues have healed, active wrist motion is gradually increased. Active grip strengthening exercises are of utmost importance.
