Treatment of radiocarpal degenerative osteoarthritis by radioscapholunate arthrodesis: long-term follow-up

Radioscapholunate arthrodesis is the treatment of choice for symptomatic, degenerative radioscapholunate osteoarthritis. We report on three patients after radioscapholunate arthrodesis with a follow-up of 22-28 years. There were no short-term postoperative complications; range of motion and strength were stable. All three patients showed radiological evidence of progressive, but clinically asymptomatic midcarpal osteoarthritis. The conversion rate for radioscapholunate to panarthrodesis of the wrist is reported at 31% with follow-ups of more than five years, invariably due to either non-union, or progressive, symptomatic midcarpal osteoarthritis. Primary excision of the distal pole of the scaphoid during radioscapholunate arthrodesis probably plays an important role in avoiding these conditions in the long-term. This measure allows a residual range of motion more than previously believed; considering that the dart thrower's motion is the physiological axis of wrist motion.     

Simulated radioscapholunate fusion alters carpal kinematics while preserving dart-thrower's motion

PURPOSE: Midcarpal degeneration is well documented after radioscapholunate fusion. This study tested the hypothesis that radioscapholunate fusion alters the kinematic behavior of the remaining lunotriquetral and midcarpal joints, with specific focus on the dart-thrower's motion. METHODS: Simulated radioscapholunate fusions were performed on 6 cadaveric wrists in an anatomically neutral posture. Two 0.060-in. carbon fiber pins were placed from proximal to distal across the radiolunate and radioscaphoid joints, respectively. The wrists were passively positioned in a custom jig toward a full range of motion along the orthogonal axes as well as oblique motions, with additional intermediate positions along the dart-thrower's path. Using a computed tomography-based markerless bone registration technique, each carpal bone's three-dimensional rotation was defined as a function of wrist flexion/extension from the pinned neutral position. Kinematic data was analyzed against data collected on the same wrist prior to fixation using hierarchical linear regression analysis and paired Student's t-tests. RESULTS: After simulated fusion, wrist motion was restricted to an average flexion-extension arc of 48 degrees , reduced from 77 degrees , and radial-ulnar deviation arc of 19 degrees , reduced from 33 degrees . The remaining motion was maximally preserved along the dart-thrower's path from radial-extension toward ulnar-flexion. The simulated fusion significantly increased rotation through the scaphotrapezial joint, scaphocapitate joint, triquetrohamate joint, and lunotriquetral joint. For example, in the pinned wrist, the rotation of the hamate relative to the triquetrum increased 85%. Therefore, during every 10 degrees of total wrist motion, the hamate rotated an average of nearly 8 degrees relative to the triquetrum after pinning versus 4 degrees in the normal state. CONCLUSIONS: Simulated radioscapholunate fusion altered midcarpal and lunotriquetral kinematics. The increased rotations across these remaining joints provide one potential explanation for midcarpal degeneration after radioscapholunate fusion. Additionally, this fusion model confirms the dart-thrower's hypothesis, as wrist motion after simulated radioscapholunate fusion was primarily preserved from radial-extension toward ulnar-flexion.     

Radiocarpal fusion

Limited wrist fusion is a common and often effective method of treatment for many painful wrist conditions. When post-traumatic, inflammatory and noninflammatory arthritis affects only the articular surfaces of the proximal carpal joint, a limited radiocarpal fusion can be considered. Specific indications are painful arthritis following distal radial fractures, rheumatoid arthritis with ulnar shift of the carpus, scapholunate instability with radioscaphoid arthritis, and stage IV Kienbock's disease. It is necessary for the midcarpal joint surfaces to be essentially normal. Either a radioscapholunate or radiolunate fusion can be performed, depending on the underlying condition. Up to 70 degrees of wrist flexion-extension can be obtained after a radioscapholunate fusion. Keys to a successful postoperative result are proper alignment of the scaphoid and lunate, use of bone graft or bone graft substitute and careful positioning of internal fixation devices. Evidence of radiographic union is usually seen by eight weeks. Nonunion rates are quoted to be from 10 to 20%.     

Radioscapholunate arthrodesis for advanced degenerative radiocarpal osteoarthritis

Degenerative joint disease affecting the radioscaphoid and radiolunate articulations while sparing the midcarpal joint may be best treated by a radioscapholunate arthrodesis. Limited wrist fusions have been shown to reliably improve pain and maintain some wrist motion. However, nonunion rates have been reported to be relatively high with traditional forms of fixation such as multiple Kirschner wires or cannulated screws. We report a technique of using two angled 2.4-mm distal radius plates to provide locking plate stabilization for radioscapholunate fusions. Our technique also features careful preparation of the planned fusion sites and the use of iliac crest bone graft. We have not had any instances of nonunion or delayed union with this technique thus far.     

Radioscapholunate arthrodesis

Although RSL fusion is a viable option for isolated radiocarpal arthritis, the enthusiasm for this procedure should be tempered with the reality that kinematics of the wrist is not entirely suited for independent midcarpal flexion and extension [10]. Limited wrist flexion and extension is expected following a successful RSL arthrodesis. The effects of imposed abnormal kinematics are further shown by the high incidence of RSL nonunions, occurrence of scaphoid fractures, and postoperative deterioration of the midcarpal joint [15,22]. In a young patient with posttraumatic arthritis or rheumatoid arthritis limited to the radiocarpal joint, however, RSL arthrodesis remains a viable alternative to complete wrist arthrodesis if the midcarpal joint is normal. Internal fixation with plates and screws and distal scaphoid excision are technical alternatives to consider when an RSL arthrodesis is performed.     

Treatment of radiocarpal degenerative osteoarthritis by radioscapholunate arthrodesis and distal scaphoidectomy

PURPOSE: The purpose of this study was to assess wrist pain, range of motion, and the presence of radiographic midcarpal degenerative joint disease (DJD) in patients who had a distal scaphoidectomy in association to a radioscapholunate (RSL) arthrodesis and to compare these findings with prior studies of patients with only an RSL fusion. METHODS: Sixteen patients with radiocarpal DJD treated by RSL arthrodesis and distal scaphoidectomy were evaluated retrospectively for pain relief and range of motion at an average follow-up period of 37 months (range, 12-84 mo). Radiographs were assessed for the presence of secondary radiographic midcarpal DJD. RESULTS: Complete pain relief was obtained in 10 patients, 3 patients complained of slight pain during strenuous loading, and 3 patients had occasional pain with regular activities. The average postoperative ranges of motion were 32 degrees of flexion, 35 degrees of extension, 14 degrees of radial deviation, and 19 degrees of ulnar deviation. Two patients exhibited secondary midcarpal DJD. These results are significantly better compared with those previously published about RSL arthrodesis alone in terms of residual pain and decrease of wrist radial deviation and flexion. CONCLUSIONS: Patients who require an RSL arthrodesis for the treatment of severe localized radiocarpal DJD appear to have less pain and to retain more flexion and radial deviation if the distal scaphoid is excised concomitantly. This associated procedure also may help prevent secondary midcarpal DJD.     

Kinematics of the midcarpal and radiocarpal joint in flexion and extension: an in vitro study

PURPOSE: To apply carpal kinematic analysis using noninvasive medical imaging to investigate the midcarpal and radiocarpal contributions to wrist flexion and extension in a quasidynamic in vitro model. METHODS: Eight fresh-frozen cadaver wrists were scanned with computed tomography in neutral, full flexion, and full extension. Body-mass-based local coordinate systems were used to track motion of the capitate, lunate, and scaphoid with the radius as a fixed reference. Helical axis motion parameters and Euler angles were calculated for flexion and extension. RESULTS: Minimal out-of-plane carpal motion was noted with the exception of small amounts of ulnar deviation and supination in flexion. Overall wrist flexion was 68 degrees +/- 12 degrees and extension was 50 degrees +/- 12 degrees. In flexion, 75% of wrist motion occurred at the radioscaphoid joint, and 50% occurred at the radiolunate joint. In extension, 92% of wrist motion occurred at the radioscaphoid joint, and 52% occurred at the radiolunate joint. Midcarpal flexion/extension between the capitate and scaphoid was 0 degrees +/- 5 degrees in extension and 10 degrees +/- 13 degrees in flexion. Midcarpal flexion/extension between the capitate and lunate was larger, with 15 degrees +/- 11 degrees in extension and 22 degrees +/- 19 degrees in flexion. CONCLUSIONS: The capitate and scaphoid tend to move together. This results in greater flexion/extension for the scaphoid than the lunate at the radiocarpal joint. The lunate has greater midcarpal motion between it and the capitate than the scaphoid does with the capitate. The engagement between the scaphoid and capitate is particularly evident during wrist extension. Out-of-plane motion was primarily ulnar deviation at the radiocarpal joint during flexion. These results are clinically useful in understanding the consequences of isolated fusions in the treatment of wrist instability.     

Radiocarpal arthrodesis in the treatment of the rheumatoid wrist. A prospective midterm follow-up

This prospective study was performed to evaluate the clinical and radiological results of radiocarpal joint arthrodesis in the treatment of unstable Simmen group III and Larsen grade II or III rheumatoid wrists. Radiolunate arthrodesis was performed in 16 wrists and radioscapholunate arthrodesis in 7 wrists in 20 patients. When they were evaluated at a mean of 5.8 (range 3.5-9.8) years later, flexion was 29 degrees and extension 34 degrees , representing 67% and 92% of the preoperative values, respectively. Patient satisfaction was excellent, or good, for 20 wrists and satisfactory for 1 wrist. In two patients with poor satisfaction, arthritis progressed to the midcarpal joint and necessitated total arthrodesis of the wrist. Radiolunate joint arthrodesis, with inclusion of the scaphoid in the fusion if necessary, is a useful operation in the treatment of this degree of wrist disease as it produces a functional and pain-free wrist at the same time as preserving much of the mobility and bone stock.     

Results of four-corner arthrodesis using dorsal circular plate fixation

PURPOSE: Four-corner arthrodesis with scaphoid excision has been used to reduce pain and preserve functional range of motion for patients with radioscaphoid arthritis. Early results of 4-corner arthrodesis with scaphoid excision using dorsal circular plate fixation are compared with reported results in the literature. METHODS: We reviewed retrospectively the first 18 four-corner arthrodeses performed with this system by 4 hand surgeons. Two patients had revision surgery for nonunions before the study that were considered failures. Eight patients returned for final radiographs, objective examination, and functional questionnaire. The average follow-up period was 20 months (range, 13-33 mo). These results were compared with reported results in the literature using alternate fixation methods. RESULTS: Radiographic union was achieved in only 3 wrists. Range of motion was 46% that of the opposite normal wrist and grip strength compared with the opposite wrist was 56%. Five patients would have the procedure again and 6 of 8 have returned to their original employment. CONCLUSIONS: Four-corner arthrodesis with scaphoid excision using a circular internal fixation plate produced a high number of nonunions. Grip strength and range of motion results also were inferior to those reported in the literature.     

Capitolunate arthrodesis with scaphoid and triquetrum excision

A retrospective two-center outcome study was designed to evaluate the results of capitolunate arthrodesis with scaphoid and triquetrum excision mainly for scapholunate advanced collapse patterns of arthritis. Fourteen wrists in 14 patients were evaluated objectively by standard parameters and subjectively by the Short Musculoskeletal Functional Assessment at an average of 28 months after surgery (range, 14-51 months). All patients were men between the ages of 20 and 70 years (average, 49 years). Two patients had a painful nonunion and one had persistent pain despite conversion to a solid wrist arthrodesis. One patient had x-ray evidence of progressive radiolunate narrowing, but only occasional pain. Postoperative wrist flexion-extension arc was 53 degrees and radioulnar deviation arc was 18 degrees. Grip and pinch strengths were 71% and 75%, respectively, of the normal contralateral wrist. The results of our study indicate that capitolunate arthrodesis with scaphoid and triquetrum excision is comparable to other motion-preserving operative procedures for scapholunate advance collapse.     

Intercarpal fusion for the treatment of scaphoid nonunion.

Salvage of the ununited scaphoid may not always be feasible or advisable, hence the availability of a number of alternative techniques which prioritize restoration of pain relief and range of motion. The role of intercarpal fusion reflects the importance of midcarpal stabilization when the scaphoid is resected. While scaphocapitate and scaphocapitolunate fusions have been described, these techniques provide less pain relief than midcarpal fusion with scaphoid excision, and are associated with an increased risk of radioscaphoid arthritis. In this article, the author will address the rationale for, technique of, and outcome after midcarpal arthrodesis and scaphoid excision.     

Degenerative arthritis of the wrist: proximal row carpectomy versus scaphoid excision and four-corner arthrodesis

Two cohort populations of 19 patients from separate institutions performing exclusively either a scaphoid excision and 4-corner arthrodesis (lunate, capitate, hamate, and triquetrum) or proximal row carpectomy (PRC) for scapholunate advanced collapse arthritis were compared. There were no preoperative differences with respect to age, gender, dominance, stage of arthritis, or preoperative measures of pain and function. The length of the follow-up period averaged 28 months for the 4-corner arthrodesis group compared with 19 months for the PRC patients. At the follow-up examination wrist motion revealed no significant differences in the flexion-extension arc, averaging 81 degrees in the PRC patients and 80 degrees following 4-corner arthrodesis, which was 62% and 58%, respectively, of the opposite wrist. The 4-corner arthrodesis patients maintained greater radial deviation and total percent radial-ulnar deviation of the wrist. Grip strength averaged 71% for the PRC group compared with 79% for the 4-corner arthrodesis patients. Pain relief was similar using a variety of measures and patient satisfaction was equivalent. Function was similar except that the 4-corner arthrodesis patients scored significantly higher on the mental health component of the short form-36 health status survey. No differences were seen on the physical health component or an outcome scale specifically designed for the wrist. Both PRC and scaphoid excision and 4-corner arthrodesis are motion-preserving options for the treatment of scapholunate advanced collapse arthritis with minimal subjective or objective differences in short-term follow-up evaluations.     

Midcarpal arthrodesis with complete scaphoid excision and interposition bone graft in the treatment of advanced carpal collapse (SNAC/SLAC wrist): operative technique and outcome assessment

Thirty-six patients with stage II or III SNAC and SLAC wrists were treated by midcarpal arthrodesis and complete scaphoid excision. When assessed at a mean follow-up of 25 months, pain was significantly reduced both under resting and stress conditions. The active range of motion was 54% of the contralateral wrist and grip strength was 65% of the non-operated hand. The mean DASH score was 28 points, the Mayo wrist score was 63 points, and the Krimmer wrist score was 68. Correlation of the wrist scores with the DASH values demonstrated a significant correlation. Our data demonstrate that midcarpal fusion with complete excision of the scaphoid is a reliable procedure for treating advanced carpal collapse.     

Changes in patterns of scaphoid and lunate motion during functional arcs of wrist motion induced by ligament division

PURPOSE: To determine the in vitro motion of the scaphoid and lunate during wrist circumduction and wrist dart-throw motions and to see how these motions change after the ligamentous stabilizers of the scaphoid and lunate are sectioned in a manner simulating scapholunate instability. METHODS: Twenty-one fresh-frozen cadaver forearms were moved through a dart-throw motion and a circumduction motion using a wrist joint simulator. Scaphoid and lunate motion were measured with the wrist ligaments intact and after sectioning of the scapholunate interosseous ligament, the scaphotrapezium ligament, and the radioscaphocapitate ligament. RESULTS: In the intact wrist the scaphoid and lunate moved more during circumduction than during the dart-throw motion. With ligamentous sectioning the scaphoid flexed more and the lunate extended more during both the circumduction and dart-throw motions. During the circumduction motion both before and after sectioning the global motion of the scaphoid was greater than that of the lunate. After sectioning the scaphoid motion increased and the lunate motion decreased. CONCLUSIONS: The scaphoid and lunate motions were observed to change remarkably after ligamentous sectioning. The observed changes in carpal motion correlate with the clinical observation that after ligamentous injury arthritic changes occur in the radioscaphoid joint and not in the radiolunate joint. Analysis of the injured wrist in positions that combine flexion-extension and radial-ulnar deviation may allow noninvasive diagnosis of specific wrist ligament injuries.     

An anatomic guide for arthroscopic visualization of the wrist capsular ligaments

Wrist arthroscopy allows examination of the palmar capsular wrist ligaments without extensive exposure. Arthroscopic examination of the wrist requires an accurate knowledge of the ligamentous anatomy as seen from inside the joint. In this study 13 fresh cadaver wrists were examined from the inside out to provide a visual guide for ligament identification during arthroscopy. The major palmar capsular ligaments seen from the inside of the wrist at the radiocarpal joint include the radioscaphoid, radioscaphocapitate, radiolunate, radioscapholunate, ulnolunate, ulnotriquetral ligaments, and the ulnar capsule. At the midcarpal joint, the scaphocapitate, radioscaphocapitate, triquetrocapitate, and triquetrohamate ligaments are identified palmarly. Dorsally, constant capsular structures at the radiocarpal joint are the radiolunate and radioulnotriquetral ligaments along with a prominent synovial fold.     

Severity of scapholunate instability is related to joint anatomy and congruency

PURPOSE: To determine whether the bony architecture of the distal radius and proximal scaphoid have a role in stabilizing the scaphoid, and to determine whether a relationship between the bony geometry measurements and the amount of wrist constraint could be determined. METHODS: Eight cadaver wrists were tested in a wrist joint motion simulator. The level of scapholunate instability after sectioning the scapholunate interosseous, radioscaphocapitate, and the scaphotrapezium ligaments was determined and related to radiographic measurements of volar tilt, lateral tilt (ulnar tilt of the radioscaphoid fossa), the depth of the radioscaphoid fossa, and 6 radii of curvature measurements of the proximal scaphoid and distal radius. The force to dorsally dislocate the scaphoid out of the radioscaphoid fossa was computed. RESULTS: The radioscaphoid fossa and scaphoid curvatures were larger in those wrists that did not show gross instability after ligamentous sectioning in the wrist simulator. Similarly, those wrists with a deeper radioscaphoid fossa and greater volar tilt were also more stable. The force required to dislocate these wrists was greater than in those wrists that showed gross carpal instability. CONCLUSIONS: This study suggests that the bony anatomy of the radius and scaphoid have a role in stabilizing the carpus after ligament injury. The effect of ligament sectioning on producing carpal instability may be moderated by the bone geometry of the radiocarpal joint. This may explain why some people may have a tear of the scapholunate interosseous ligament but not present with clinical symptoms.     

Four-corner fusion and scaphoid excision using headless compression screws for SLAC and SNAC wrist deformities

Scapholunate advanced collapse and scaphoid nonunion advanced collapse wrist deformities are the most common causes of traumatic arthritis of the wrist. Four-corner fusion and scaphoid excision has proven to be an effective procedure for relieving pain and preserving range of motion in the wrist joint. Several methods for providing fixation of the midcarpal joint during fusion have been used, including K-wires, staples, and the Spider plate. K-wire fixation has proven effective, but requires a period of cast immobilization to protect the fusion mass. The Spider plate was promising, but has not been without complications. The development and improvements in cannulated headless compression screws has resulted in increased indications for their use, including fixation for 4-corner fusion. We review the technique and tips developed by the senior author over the last several years using headless compression screws for fixation of the midcarpal joint. Acutrak 2 Standard implants were used. This technique has allowed for early range of motion with reliable fusion rates.     

Management of the scaphoid during four-corner fusion-a cadaveric study

PURPOSE: To examine the effects of scaphoid retention, inclusion, and excision on wrist motion and radiolunate contact characteristics in a cadaveric model after simulated 4-corner fusion with rigid internal fixation. METHODS: Seven fresh-frozen cadaveric upper extremities were examined. For all surgical manipulations the motion was measured and contact characteristics were assessed using ultra-low prescale pressure-sensitive film. RESULTS: Compared with the intact specimen, simple 4-corner fusion with scaphoid retention led to a significant decrease in extension, radial deviation, and ulnar deviation, but no change in radiolunate contact characteristics. After 4-corner fusion there was no significant difference in motion or radiolunate contact characteristics between scaphoid retention and scaphoid inclusion. After 4-corner fusion scaphoid excision allowed significantly greater radial deviation compared with scaphoid retention and scaphoid inclusion. Compared with the intact specimen 4-corner fusion with scaphoid excision also led to a significant increase in radiolunate contact area and mean contact pressure. CONCLUSIONS: When performing 4-corner arthrodesis in the absence of radioscaphoid arthritis, scaphoid excision may improve motion at the cost of increased mean radiolunate contact pressure.     

Degenerative change in symptomatic scaphoid nonunion

A retrospective radiographic analysis of 64 patients with symptomatic scaphoid nonunions without previous surgical treatment was accomplished. The results showed a high frequency of degenerative changes occurring in a predictable sequence. For nonunions of 4 years duration, 75% of patients had radioscaphoid changes, and for those of 9 years duration 60% of the patients had midcarpal changes. The pattern of arthritis in scaphoid nonunion is that of scapholunate advanced collapse (SLAC) wrist resulting from rotary subluxation of the distal scaphoid fragment. The radius-proximal scaphoid fragment joint and the radiolunate joint were consistently spared from degenerative changes, even with severe arthritis. Instability was progressive and associated with an earlier onset of arthritis. Patients with symptomatic scaphoid nonunions appear to have a significant likelihood of arthritis developing.