Alex M. Meyers, Mark E. Baratz, and Thomas Hughes
DEFINITION
Proximal row carpectomy (PRC) involves removal of the proximal carpal row (scaphoid, lunate, and triquetrum).
PRC has been described as a treatment option for a number of pathologic conditions:
Scaphoid nonunion advanced collapse (SNAC) wrist
Scapholunate advanced collapse (SLAC) wrist
Kienböck disease
Chronic or missed perilunate dislocation
Scaphoid osteonecrosis or Preiser disease
Wrist deformity or contracture
ANATOMY
The proximal row of the wrist consists of three bones: scaphoid, lunate, and triquetrum.
The proximal row moves as a single unit through intercarpal ligamentous attachments and bony congruity.
The proximal row flexes with radial deviation and extends with ulnar deviation.
The capitate, in the distal row, articulates with the lunate.
The proximal capitate articular surface is relatively, although not completely, congruous with the lunate facet of the radius.
PATHOGENESIS
A number of pathologies may eventually result in wrist degeneration requiring PRC. Patients experience progressive pain and limitation in motion, often requiring PRC to improve symptoms.
SNAC and SLAC
Stage I: Degenerative changes along the radial half of the radioscaphoid articulation. In SNAC wrists, the degenerative changes are typically limited to the articulation between the distal scaphoid fragment and the radius.
Stage II: Degenerative changes involving the entire radioscaphoid articulation (FIG 1). In SNAC wrists, the articulation between the proximal scaphoid fragment and the radius is preserved, and instead stage II degeneration occurs in the scaphocapitate joint.
Stage III: Degenerative changes at the capitolunate joint. The radiolunate joint is spared.
Kienböck disease
Stage I: Normal plain radiographs with wrist pain and positive MRI finding
Stage II: Sclerosis without collapse of the lunate
Stage IIIa: Lunate collapse without instability
Stage IIIb: Lunate collapse with carpal instability
Stage IV: Fixed carpal instability with pan-carpal degenerative changes
Missed perilunate dislocation
Scaphoid osteonecrosis (Preiser disease)
Congenital or spastic wrist and hand flexion contractures may be so severe that a PRC allows deformity correction that tendonlengthening procedures alone would be unable to correct.
PATIENT HISTORY AND PHYSICAL FINDINGS
It is important to seek the cause of the wrist degeneration.
Mechanical wrist pain is aggravated by use and relieved by rest. The history must support this for the proposed treatment to be successful.
The history defines the patient's symptoms, level of severity, and progression over time, as well as any previous attempts at treatment.
Limited and painful wrist motion with diminished grip strength tends to be a common denominator regardless of the initial source of pathology.
Normal range of motion: wrist extension, 70 degrees; wrist flexion, 75 degrees; radial deviation, 20 degrees; ulnar deviation, 35 degrees
Normal grip strength: Mean grip for males is 103 to 104 for the dominant extremity and 92 to 99 for the nondominant extremity. Mean grip for females is 62 to 63 for the dominant extremity and 53 to 55 for the nondominant extremity.
Radioscaphoid joint line tenderness on palpation implies radioscaphoid arthritis.
Swelling over the dorsal and dorsoradial aspects of the wrist can be associated with radiocarpal and intercarpal arthritis. Most often dorsoradial wrist swelling will be visible and palpable in cases of SLAC and SNAC.
FIG 1 • Intraoperative photograph showing wear at the dorsal half of the scaphoid fossa seen with SLAC wrist, as indicated by the black arrow. Cartilage integrity is preserved in the lunate fossa, as indicated by the red arrow.
IMAGING AND OTHER DIAGNOSTIC STUDIES
Plain radiographs assist with making the underlying diagnosis (eg, SNAC wrist, SLAC wrist, Kienböck disease).
The surgeon should evaluate the articular facets and surfaces, specifically of the proximal capitate and lunate facet of the radius.
The surgeon should evaluate for other sources of limited wrist motion, diminished grip strength, and pain (eg, thumb carpometacarpal arthritis, scapholunate instability without degenerative changes, fracture).
Although MRI may assist in making the underlying diagnosis (eg, Kienböck disease, Preiser disease, scaphoid avascular necrosis) and evaluating the joint surfaces, it is rarely used.
DIFFERENTIAL DIAGNOSIS
Triangular fibrocartilage complex or distal radioulnar joint pathology
Extensor carpi ulnaris, flexor carpi ulnaris, flexor carpi radialis tendinitis
De Quervain tenosynovitis
First carpometacarpal arthritis
Scapholunate or lunotriquetral instability without degenerative changes
Midcarpal arthritis
SURGICAL MANAGEMENT
Regardless of the initial source of pathology when considering treatment via PRC, the integrity of the articular cartilage and the congruity between the proximal capitate and the lunate facet of the radius are critical. This determination is often made intraoperatively.
Indications
SLAC and SNAC wrist degeneration: stage I, II, or III (only if the degenerative changes at proximal capitate are limited to thinning or minor fissuring)
Kienböck disease (stage III and IV)
Chronic or missed perilunate dislocations
Scaphoid osteonecrosis (Preiser disease)
Wrist deformity or contracture
Contraindications
Active inflammatory arthritis (rheumatoid arthritis). PRC may be used for inflammatory arthritis patients with “burnt-out” disease (those without active tenosynovitis).
Advanced degenerative changes at the proximal articular surface of the capitate or lunate facet of the radius
Ulnar carpal translation or subluxation of the radiocarpal joint
Relative contraindications
Heavy laborers
Young (less than 35 years) active patients (controversial)7
Preoperative Planning
Plain radiographs of the wrist should be reviewed. The surgeon should scrutinize the location of degenerative changes, should know the amount of radial styloid beaking (and potential need for radial styloidectomy), and should note any previous fractures or hardware (may need to be removed).
The surgeon should discuss and obtain consent for alternative procedures from the patient (ie, if one should find excessive degenerative changes at the capitate, one might proceed with intercarpal arthrodesis).
Regional anesthesia, general anesthesia, or a combination of the two (for postoperative analgesia) is suitable.
Positioning
The patient is supine with the arm on a radiolucent armboard.
A nonsterile tourniquet preset at 250 mm Hg is on the upper arm.
The shoulder, elbow, and hand are positioned such that the hand rests in pronation at the center of the armboard (if a dorsal approach is planned).
TECHNIQUES
INCISION AND EXPOSURE
Make a dorsal longitudinal skin incision over the fourth dorsal compartment or a transverse incision across the dorsal wrist crease just distal to the tubercle of Lister.
The longitudinal incision is more extensile and versatile.
The transverse incision tends to be more cosmetic.
Expose the extensor retinaculum.
Maintain full-thickness flaps when elevating soft tissues off the extensor retinaculum to minimize the risk of damage to the radial and ulnar sensory nerves (TECH FIG 1A).
Look for the distal extent of the posterior interosseous nerve (PIN) in the proximal portion of the incision on the radial floor of the fourth compartment. Perform a PIN neurectomy after coagulating the accompanying vessels.
Incise the extensor retinaculum in line with extensor pollicis longus (EPL) with scissors and transpose the EPL radially, dorsal to the retinaculum.
Incise the radial septum of the fourth dorsal compartment and expose the wrist capsule by retracting the fourth compartment extensor tendons ulnarly and the EPL and radial wrist extensor tendons radially.
Create a distally based “inverted-U” capsular flap by first incising the wrist capsule transversely over the radiocarpal joint (from radial to ulnar) and then, at the margins, extending the incision distally (TECH FIG 1B).
Making a U-shaped capsular hood provides flexibility should one elect to add a dorsal capsular interposition arthroplasty in the setting of mild midcarpal arthrosis.
The dorsal branch of the radial artery is radial to the second compartment, so take care at the radial aspect of the capsulotomy.
Inspect the articular cartilage on the proximal capitate and lunate facet of the radius for any degenerative changes.
If the cartilage is in good condition, proceed with PRC; if not, consider alternative procedures (TECH FIG 1C).
TECH FIG 1 • A. Superficial branches of the radial nerve and the dorsal cutaneous branch of the ulnar nerve. The dorsal branch of the radial artery is in danger deeper in the dissection as the wrist joint capsule is incised. B.Intraoperative photograph showing the distally based U-shaped dorsal capsular flap. This flap is centered over the capitate. The radial margin is just adjacent to the ulnar border of the extensor carpi radialis brevis tendon. The proximal margin is taken directly off the dorsal lip of the radius. (Red arrow points to distal articular surface of the hamate; the triquetrum has not yet been removed. Black arrow points to the dorsal lip of scaphoid fossa.) The ulnar margin is just radial to the extensor digiti minimi. C. Wear on the ulnar aspect of the head of the capitate is visualized in this case. (Arrowpoints to a cartilage defect on the capitate head.) Arthrosis affecting the non-weight-bearing portion of the capitate does not preclude the use of a proximal row carpectomy but one may want to include a capsular interposition. This is usually employed in older, lower-demand individuals.
CARPECTOMY
Precisely ensure the anatomy and which bones are to be removed.
Consider intraoperative fluoroscopy if there is any question.
Note the location of the radioscaphocapitate ligament at the waist of the scaphoid. Protect it and the other volar extrinsic ligaments while removing the proximal carpal row.
Avoid iatrogenic injury to the cartilaginous surfaces of the capitate head and lunate facet of the radius.
Osteotomize the scaphoid at its waist with a straight osteotome to facilitate scaphoid excision.
Place the osteotome such that it parallels the flexor carpi radialis tendon to minimize the risk of transection (TECH FIG 2A,B).
The distal pole of the scaphoid is particularly difficult to remove (especially with SNAC wrist deformities).
Consider using a threaded Kirschner wire (0.062 inch) or a large threaded Steinmann pin (5/32 inch) as a joystick to control the bone to be removed (TECH FIG 2C). Try to create tension between the proximal carpal bones during dissection (a combination of no. 15 blade; Beaver blade; periosteal, Freer, or Carroll elevator; and small straight or curved curettes is valuable; TECH FIG 2D).
If possible, remove the carpal bones whole rather than piecemeal. This facilitates removal when possible and ensures that no portions are left behind (TECH FIG 2E).
TECH FIG 2 • A,B. The appropriate location for the scaphoid osteotomy. C. A large threaded pin inserted into the lunate is used to facilitate resection. D. An elevator placed in the lunotriquetral joint and then levered against the triquetrum helps strip the volar capsule off the lunate. E. Resected lunate.
ASSESSMENT OF REDUCTION AND IMPINGEMENT
Once the proximal row is removed, seat the capitate into the lunate facet on the radius to evaluate congruity.
Check for impingement between the trapezium and radial styloid with extreme radial deviation.
The trapezium has been shown to be volar to the styloid, making impingement less common than once thought.
If radial-sided impingement is a concern, proceed with a radial styloidectomy.
RADIAL STYLOIDECTOMY
See Chapter HA-86.
Elevate the tendons of the second and then the first extensor compartments off the radial styloid through the same dorsal incision.
Take care to avoid injuring the dorsal branch of the radial artery just radial to the second dorsal compartment.
The styloidectomy can be performed from proximalradial to distal-ulnar with a straight osteotome (remove no more than 5 to 7 mm) (TECH FIG 3).
TECH FIG 3 • The amount of radial styloid that is removed and the direction of the osteotomy. The origin of the radioscaphocapitate ligament is carefully preserved.
WOUND CLOSURE
Close the capsule with nonabsorbable 2-0 suture.
Plain radiographs or fluoroscopic images should be obtained in AP and lateral planes to ensure that the capitate is seated in the lunate fossae.
While uncommon, radiocarpal subluxation is possible with a PRC.
Maintenance of the volar ligaments (especially the radioscaphocapitate, which is most at risk during removal of the scaphoid) minimizes any risk of radiocarpal instability after PRC.
Close the retinaculum with nonabsorbable 3-0 suture, leaving the EPL superficial to the retinaculum.
Consider placing a drain in the subcutaneous tissues, to be removed in 24 to 48 hours.
Close the skin with a 3-0 nonabsorbable running subcuticular Prolene stitch with “rescue loops” to facilitate removal at 10 to 14 days.
Cover the incision with nonadherent gauze.
Fashion a sugar-tong splint over a bulky dressing.
Keep the fingers and the thumb free proximal to the metacarpophalangeal joints.
Hold the wrist at neutral or slight extension (10 degrees).
PROXIMAL ROW CARPECTOMY WITH INTERPOSITION ARTHROPLASTY
If mild to moderate chondral changes are noted on the capitate head, a PRC may still be indicated with the addition of an interpositional arthroplasty between the capitate head and lunate fossae.
Use the previously created distally based inverted Ushaped capsular flap as the interpositional material.
Place three simple stitches (2-0 PDS) connecting the dorsal capsular flap to the palmar capsule.
Place and tag all stitches into the dorsal capsule (passing from deep to superficial) and into the palmar capsule (passing from proximal to distal) before tying them down to the palmar capsule (TECH FIG 4A).
Loosely reapproximate the lateral margins of the dorsal flap to the residual dorsal capsule after interposing the dorsal capsule (TECH FIG 4B).
Postoperative management is not altered.
TECH FIG 4 • A. Sutures are passed in a mattress fashion through dorsal capsule, volar capsule, and then dorsal capsule to interpose the dorsal capsular flap between the capitate and lunate fossa. (Arrowpoints to the head of the capitate.) B. The dorsal capsule interposed between the capitate (shown above) and the radius (shown below) after the PDS sutures have been tied down.
POSTOPERATIVE CARE
PRC tends to be an outpatient procedure; an overnight stay may be necessary for postoperative pain or nausea.
A short splint is applied in the operating room with the wrist in neutral and the fingers and thumb free at the metacarpophalangeal joints.
Passive thumb and finger motion is encouraged immediately postoperatively, along with elevation and ice for the first 48 hours.
At the first postoperative follow-up visit (in 10 to 14 days) the splint is removed, plain wrist AP and lateral radiographs are obtained to ensure the capitate is located in the radial lunate facet, and sutures are removed.
At 2 weeks postoperatively, gentle active wrist extension and flexion and radioulnar deviation are added and a removable cock-up wrist splint or custom Orthoplast wrist splint is worn between exercises.
Scar massage can begin once the incision is healed.
Edema control may be necessary with compressive dressings.
The removable splint can be removed as the patient feels comfortable (typically in 3 to 4 weeks).
At 6 weeks, objective measurements of wrist extension, flexion, radioulnar deviation arcs, grip and pinch strength should be obtained.
Therapy is initiated if the patient seems to be struggling to regain wrist or finger motion.
At 3 months, full activities are encouraged.
OUTCOMES
A broad range in grip strength outcome has been reported postoperatively.
60% to 100% grip strength of the contralateral wrist (and a 20% to 30% increase in postoperative grip versus preoperative grip) can be expected.3,7
A decrease in postoperative wrist motion can be expected, as well as a decrease in flexion–extension by 20%, a decrease in radioulnar deviation by 10%,3 and a 72to 75degree arc of motion in flexion and extension.2,7
Satisfactory pain relief can be expected in 80% to 100% of patients.3,5
Return to work for manual laborers after PRC has been unpredictable, varying from 20% in one series3 to 85% in another.5
Age less than 35 years has been shown to be predictive of early failure with PRC.
COMPLICATIONS
Incomplete removal of the carpal bones (typically distal scaphoid)
Use of pins has been associated with pin site infections and rapid degenerative changes when placed through the radiocapitate articulation (because of this, pins are not routinely recommended as they once were).
Reflex sympathetic dystrophy
Excessive styloidectomy and compromise of the radioscaphocapitate ligament
Compromise of the radioscaphocapitate ligament can lead to ulnar carpal subluxation.
Conversely, failure to check intraoperatively for radialsided impingement may lead to radial-sided wrist pain postoperatively.
Damage to sensory nerves (radial sensory and dorsal ulnar branches)
Progressive arthritis
REFERENCES
1. Begley BW, Engber WD. Proximal row carpectomy in advanced Kienböck's disease. J Hand Surg Am 1994;19A:1016–1018.
2. Calandruccio JH. Proximal row carpectomy. J Am Soc Surg Hand 2001;1:112–122.
3. Culp RW. Proximal row carpectomy: a multicenter study. J Hand Surg Am 1993;18:19–25.
4. Nakamura R, Horii E, Watanabe K, et al. PRC vs. limited wrist arthrodesis for advanced Kienböck's disease. J Hand Surg Br 1998; 23:741–745.
5. Imbriglia JE, Broudy AS, Hagberg WC, et al. Proximal row carpectomy: clinical evaluation. J Hand Surg Am 1990;15:426–430.
6. Mathiowetz V, Kashman N, Volland G, et al. Grip and pinch strength: normative data for adults. Arch Phys Med Rehabil 1985;66: 69–74.
7. Stern PJ, Agabegi SA, Kiefhaber TR, et al. Proximal row carpectomy. J Bone Joint Surg Am 2004;86A:2359–2365.