The effect of radioscapholunate fusion on wrist movement and the subsequent effects of distal scaphoidectomy and triquetrectomy

Radiocarpal Fusion: Indications, Technique, and Modifications

Degenerative disorders of the wrist may affect isolated joints and inhibit normal functions of the wrist secondary to pain and stiffness. These processes that affect only the radiocarpal joint may be secondary to posttraumatic osteoarthritis, primary osteoarthritis, or rheumatoid arthritis. Radiocarpal wrist arthrodesis may help preserve some of the native wrist kinematics while alleviating pain and improving the range of motion. However, the surgeon must ensure that the patient's pathologic process primarily affects the radiocarpal articulations while relatively sparing the midcarpal articulations. Depending on the location of the pathology, isolated radiolunate or radioscapholunate arthrodesis have been described to preserve some motion in the midcarpal joint. To maximize motion in the midcarpal joint after radiocarpal arthrodesis, techniques for distal scaphoid and triquetrum excision have been described. We report patient outcomes for various techniques and describe our preferred technique for radioscapholunate arthrodesis using distal scaphoid excision.

The Biomechanical Effects of Simulated Radioscapholunate Fusion With Distal Scaphoidectomy, 4-Corner Fusion With Complete Scaphoidectomy, and Proximal Row Carpectomy Compared to the Native Wrist

PURPOSE

To determine the effect of simulated radioscapholunate fusion with distal scaphoid excision (RSLF+DSE), 4-corner fusion with scaphoidectomy (4-CF), and proximal row carpectomy (PRC) on the wrist's range of motion (ROM), contact pressure, and contact force in a cadaveric model.

METHODS

Ten freshly frozen cadaveric wrists were tested under 4 sequential conditions: native wrist, RSLF+DSE, 4-CF, and PRC. The simulated fusions were performed using two 1.6-mm Kirschner wires. The ROM in the flexion-extension and radioulnar deviation planes was evaluated. Contact area, contact pressure, and contact force were measured at the scaphocapitolunate joint for the RSLF+DSE simulation and radiocarpal joint for the 4-CF and PRC simulations. Mechanical testing was performed using a 35-N uniaxial load and pressure-sensitive film.

RESULTS

The RSLF+DSE and 4-CF groups had a decreased wrist arc ROM compared with the native wrist. The PRC group had a greater wrist arc ROM compared with the RSLF+DSE and 4-CF groups, but compared to the native wrist, it demonstrated a mildly decreased wrist arc ROM. The carpal pressure and contact force were significantly increased in the RSLF+DSE, 4-CF, and PRC groups compared with those in the native wrist. The RSLF+DSE group had the smallest increase in the carpal pressure and contact force, whereas the PRC group had the greatest increase.

CONCLUSIONS

Our study validates previous findings that PRC is motion-conserving but has the greatest contact force, whereas RSLF-DSE and 4-CF may cause a decrease in the ROM but have lower contact forces.

CLINICAL RELEVANCE

Understanding the underlying native wrist biomechanics and alterations following different surgical treatments may assist hand surgeons in their clinical decision making for the treatment of stage II scapholunate advanced collapse.

Biomechanical Effects of Radioscapholunate Fusion With Distal Scaphoidectomy and Triquetrum Excision on Dart-Throwing and Wrist Circumduction Motions

PURPOSE

Distal scaphoid and triquetrum excisions can improve the range of wrist motion after radioscapholunate (RSL) fusion, but little is known about the kinematics of dart-throwing and global circumduction motions. We hypothesized that these excisions could increase the range of motion without causing midcarpal instability.

METHODS

Seven fresh-frozen cadaver upper extremities were mounted on a testing apparatus after isolation and preloading of the tendons of the flexor carpi radialis, flexor carpi ulnaris, extensor carpi radialis, and extensor carpi ulnaris. Sequential loadings of the flexor carpi ulnaris and extensor carpi radialis simulated active dart-throwing motion. Passive circumferential loading produced the wrist circumduction motion. We measured the range of wrist motions with an electromagnetic tracking system in 4 experiments: intact, simulated RSL fusion, RSL fusion with distal scaphoid excision, and RSL fusion with distal scaphoid and total triquetrum excisions. To evaluate midcarpal stability, we conducted passive mobility testing of the distal carpal row in the radial, volar, ulnar, and dorsal directions.

RESULTS

Radioscapholunate fusion decreased the dart-throwing motion to a mean of 46% of the baseline value; distal scaphoid and triquetrum excisions increased the mean arc to 50% and 62%, respectively. Radioscapholunate fusion diminished the wrist circumduction to a mean of 43% of the baseline value, which increased to a mean of 58% and 74% after distal scaphoid and triquetrum excision, respectively. A significant increase in radial deviation was noted after distal scaphoid excision, and subsequent triquetrum excision significantly increased motion in the ulnar-palmar direction. Regarding midcarpal stability, dorsal translation significantly increased after distal scaphoid and triquetrum excisions.

CONCLUSIONS

Distal scaphoid and triquetrum excision after RSL fusion improved both dart-throwing and circumduction motions, but dorsal midcarpal instability occurred.

CLINICAL RELEVANCE

Subsequent carpal excisions may improve short-term outcome by increasing motions in a RSL-fused wrist; however, a potential risk of midcarpal instability should be considered.

In-vivo three-dimensional motion analysis of the wrist during dart-throwing motion after midcarpal fusion and radioscapholunate fusion

We recorded the dart-throwing motion and basic motion tasks in patients following radioscapholunate fusion and midcarpal fusion with a three-dimensional motion capture system in vivo, using digital infrared cameras to track the movement of reflective skin markers on the hand and forearm. During the dart-throwing motion, 20 healthy volunteers showed a median range of motion of 107°. As expected, patients had significantly reduced wrist range of motion during basic motion tasks and dart-throwing motion compared with the healthy controls, except for ulnar flexion occurring in the dart-throwing motion in patients treated by midcarpal fusion and radial deviation after midcarpal fusion or radioscapholunate fusion. In addition, patients who had undergone radioscapholunate fusion had significantly reduced range of motion during dart-throwing motion compared with patients after midcarpal fusion.

Radioscapholunate fusion for posttraumatic osteoarthritis with consecutive excision of the distal scaphoid and the triquetrum: A comparative study

The aim of this study was to assess the clinical and radiographic outcomes after radioscapholunate (RSL) fusion for posttraumatic osteoarthritis. This was a retrospective, dual-center study of all patients who underwent RSL fusion between 1995 and 2015 for posttraumatic radiocarpal osteoarthritis. Patients were assessed at the final review to determine clinical (pain, wrist range of motion and strength), self-reported (QuickDASH, PRWE and MWS scores) and radiological (degenerative osteoarthritis in the scaphotrapeziotrapezoid (STT) or midcarpal joint and radiocarpal fusion) outcomes. We analyzed three groups: RSL fusion alone, RSL fusion with distal scaphoid excision (DSE) and RSL fusion with DSE and triquetrum excision (TE). Eighty-five patients were included; 10 were lost to follow-up and 11 required conversion to total wrist fusion before the final review. Finally, 64 patients had both clinical and radiographic evaluations. The mean follow-up was 9.1 years (range 1-21.4). RSL fusion alone was performed in 29 patients, RSL fusion with DSE in 23 and RSL fusion with DSE and TE in 12. At the final follow-up, the three groups did not differ in their pain or wrist motion. Overall, 47 (73%) patients were satisfied or very satisfied with the procedure. DSE significantly decreased STT osteoarthritis and radiocarpal non-union. The total wrist osteoarthritis rate after RSL fusion was 55%. RSL fusion is an effective procedure to preserve some motion in wrists with posttraumatic radiocarpal osteoarthritis. DSE prevents STT osteoarthritis by removing bony impingement and increases the fusion rate. LEVEL OF EVIDENCE: Level IV, Case series, Therapeutic studies.

[Palmar radioscapholunate arthrodesis with distal scaphoidectomy]

OBJECTIVE

Radioscapholunate (RSL) arthrodesis with distal scaphoidectomy using an angular stable plate and palmar access in post-traumatic or degenerative osteoarthritis limited to the radiocarpal joint.

INDICATIONS

Osteoarthritis limited to the radiocarpal joint with intact mediocarpal joint after malunited intra-articular distal radius fractures, rheumatoid osteoarthritis, scapholunate advanced collapse (SLAC) up to stage II.

CONTRAINDICATIONS

Mediocarpal osteoarthritis, poor patient compliance, SLAC from stage III, osteitis.

SURGICAL TECHNIQUE

The palmar RSL arthrodesis is performed using the palmar approach between the flexor carpi radialis tendon and the radial artery. After releasing the pronator quadratus muscle, a longitudinal capsulotomy is performed and the radiocarpal joint is inspected. After correction of a volar or dorsal intercalated segmental instability of the lunate, the lunate is temporarily fixed to the scaphoid using a K-wire. The distal quarter of the scaphoid and the palmar rim of the distal radius is resected and the cartilage between the scaphoid, lunate and distal radius is removed. The scaphoid and lunate are temporarily fixed to the distal radius using K‑wires. Under image intensifier control the angular stable low-profile plate (e.g., volar 2.5 Trilock RSL Fusion plate [Medartis® Aptus® Basel, Switzerland]) is fixed to the distal radius in the long-leg hole. The scaphoid and lunate are fixed distally with two screws each. The carpus is pushed distally using a Codeman distractor and the cancellous bone graft is impacted. Finally, the shaft is fixed with angular stable screws.

POSTOPERATIVE MANAGEMENT

Immobilization using a plaster cast or thermoplastic short-arm orthosis for 5 weeks. After 2 weeks, the orthosis can be removed during hand therapy with active wrist and finger exercises. Normal activities permitted after 12 weeks.

RESULTS

Palmar RSL arthrodesis and distal scaphoidectomy using angular stable plate fixation shows a high union rate and pain relief while maintaining good residual mobility of the wrist.

Radioscapholunate Fusion for Radiocarpal Osteoarthritis: Prognostic Factors of Clinical and Radiographic Outcomes

Background  Radioscapholunate (RSL) fusion is a surgical option to manage radiocarpal osteoarthritis. Many authors upgrade the procedure by adding distal scaphoid excision with or without excision of the triquetrum. Our objective was to identify the prognostic factors for good clinical and radiographic outcomes of RSL arthrodesis. Purpose  Distal scaphoid excision improves both scaphotrapeziotrapezoidal osteoarthritis and radiocarpal fusion, and excision of the triquetrum is not critical to achieving satisfactory outcomes. Methods  In this retrospective and bicentric investigation, all wrists were managed with RSL fusion for posttraumatic radiocarpal osteoarthritis. A total of 85 patients were included and evaluated at the revision by clinical (pain, wrist motion, and strength), functional (Disabilities of the Arm, Shoulder, and Hand questionnaire, Patient-Related Wrist Evaluation score, and Modified Mayo Wrist Score), and radiological (scaphotrapeziotrapezoidal, midcarpal osteoarthritis, and radiocarpal nonunion) examinations. We assessed prognostic factors for clinical and radiographic (osteoarthritis and nonunions) outcomes. Results  The average follow-up was 9.1 years (1-21.4). Work-related accidents adversely impacted the clinical outcomes, and distal scaphoid excision significantly improved them and decreased scaphotrapeziotrapezoidal osteoarthritis and nonunion. Neither distal scaphoid excision nor excision of the triquetrum influenced midcarpal osteoarthritis. Radiocarpal fusion was significantly promoted by memory staples and bone grafting. Discussion  Distal scaphoid excision should be preferred to improve the functional results while decreasing scaphotrapeziotrapezoidal osteoarthritis and radiocarpal nonunion rates. Excision of the triquetrum appears to be an alternative to radioulnar resection-arthroplasty to solve ulnocarpal impaction syndrome. Strict surgical procedure must be observed to promote RSL fusion combining solid bone fixation and the use of bone graft. Level of evidence  This is a level IV, case series, retrospective series.

Triquetrum Excision in Radioscapholunate Arthrodesis for Posttraumatic Radiocarpal Osteoarthritis With Ulnar Impaction Syndrome

Dependent on fracture type, concomitant carpal injuries, and operative treatment, distal radius fractures can lead to symptomatic radiocarpal osteoarthritis. In addition, radial shortening can cause ulnar impaction syndrome. Radiocarpal arthrodesis and ulnar shortening osteotomy are known and frequently applied surgical procedures for each of those pathologies. There are limited data concerning treatment options for a combined disorder. The presented technique in this article demonstrates that radioscapholunate arthrodesis with distal pole scaphoidectomy and total triquetrum excision successfully treats both symptomatic radiocarpal osteoarthritis and ulnar impaction syndrome without further surgery on the ulna.

The Effect of Radioscapholunate Fusion With and Without Distal Scaphoid and Triquetrum Excision on Capitolunate Contact Pressures

PURPOSE

To determine the effects of motion-increasing modifications to radioscapholunate (RSL) arthrodesis on capitolunate contact pressure in cadaveric wrist specimens.

METHODS

Ten fresh-frozen cadaveric wrists were dissected of all superficial soft tissue, potted in polymethyl-methacrylate, and the carpus exposed via a ligament-sparing capsulotomy. An RSL arthrodesis was simulated using 2 2.4-mm distal radius plates with locking screws. The distal scaphoid pole and triquetrum were removed with an osteotome and rongeur, respectively. Contact area, pressure, and force were measured in the capitolunate joint during the application of a 35-N uniaxial load using pressure-sensitive film. Measurements were obtained before and after simulated RSL fusion, following distal scaphoidectomy and after triquetrectomy.

RESULTS

The combination of RSL fusion with distal scaphoid excision (DSE) increased contact forces in the capitolunate joint by 50% over controls. An RSL fusion, and RSL fusion with DSE and triquetrum excision (TE), exhibited intermediate levels of contact force between controls and RSL fusion with DSE. Capitolunate contact pressures were similar between all experimental groups. Contact area in the capitolunate joint increased by 43% after RSL fusion with DSE over intact specimen controls. Lastly, contact area in wrists with RSL fusion, and RSL fusion with DSE and TE, were elevated, but not significantly different from intact controls.

CONCLUSIONS

A DSE performed at the time of RSL fusion results in increased midcarpal joint contact force and area, with resultant contact pressures unchanged. Triquetrectomy, which has been previously shown to improve range of motion, did not increase contact forces in the capitolunate joint.

CLINICAL RELEVANCE

If a surgeon is contemplating performing an RSL arthrodesis with DSE, we recommend adding a triquetrectomy to improve motion because this does not add to the potentially deleterious effects of increased midcarpal contact force.

Radioscapholunate fusion with triquetrum and distal pole of scaphoid excision: long-term follow-up

The purpose of this study was to assess the long-term outcomes of radioscapholunate fusion, with and without distal pole of scaphoid excision and excision of the triquetrum. These compromised three operative groups. Seventeen patients were identified with a minimum of 10 years follow-up, with a mean of 15 years (range 10-19). Fifteen of the 17 patients were satisfied with their outcome. Two were converted to total wrist fusion. The mean outcomes scores were; pain visual analogue scale score 2.1/10, Quick Disabilities of the Arm, Shoulder, and Hand 29 and Modified Mayo Wrist score 60. Patients with excision of the triquetrum had a mean radial-ulnar arc increase of 10° compared with the other two groups, but this was not statistically significant. The mean space for the scaphocapitate joint was 1.7 mm and lunocapitate joint was 1.3 mm at latest follow-up. Close adherence to the indications and surgical technique provided a sustainable good clinical outcome. Patients who obtained a good result at 2 years were likely to achieve a good long-term outcome.

LEVEL OF EVIDENCE

IV.

Clinical and radiological outcomes following radioscapholunate fusion

INTRODUCTION

Radioscapholunate (RSL) fusion is typically performed following wrist trauma. It addresses the pain caused by radiocarpal osteoarthritis but reduces the wrist's mobility. The objective of this study was to determine the long-term clinical and radiological outcomes of this procedure.

MATERIALS AND METHODS

This was a retrospective study of all wrists operated for RSL fusion in our surgery unit over a 12-year period. The clinical analysis consisted of joint amplitudes, grip strength, pain (VAS) and functional scores (PRWE, QuickDash, Mayo Wrist Score). The radiological analysis focused on bone fusion and the presence of midcarpal osteoarthritis.

RESULTS

This surgery procedure was performed on 48 wrists. Of these, 34 patients were available for review, including 6 who had subsequently undergone total wrist fusion after the RSL procedure. The average follow-up was 53 months. Flexion/extension and radioulnar deviation were 56° and 30°, respectively. Grip strength in the operated wrist was 71% of the contralateral wrist. The mean pain level was 3 out of 10. The PRWE, QuickDash and Mayo Wrist Score were 35.7, 44.5 and 57.2, respectively. Seventy-nine percent of patients were satisfied with the outcome. The fusion rate was 71%, the midcarpal osteoarthritis rate was 64% and the STT osteoarthritis rate was 46%.

DISCUSSION

Reduced wrist range of motion in patients who have undergone RSL fusion helps to preserve satisfactory function in the majority of patients; however, the functional outcome scores point to some hindrance in day-to-day activities. Nonunion occurred in nearly one-quarter of patients and appears to be preventable by excision of the distal pole of the scaphoid (DPS). Midcarpal osteoarthritis develops in most wrists over the long-term and appears to be inevitable.

CONCLUSION

RSL fusion is a palliative procedure that preserves some of the wrist's mobility. However, it is a difficult procedure that has a significant nonunion rate. Excision of the DPS may contribute to lowering the nonunion rate.

Volar Radioscapholunate Arthrodesis and Distal Scaphoidectomy After Malunited Distal Radius Fractures

PURPOSE

The purpose of this study was to assess range of motion (ROM), pain, and incidence of radiographic degenerative joint disease (DJD) after volar radioscapholunate (RSL) arthrodesis and distal scaphoidectomy (DSE) following malunited distal radius fractures (DRF).

METHODS

Fourteen patients with malunited DRF and DJD limited to the radiocarpal joint underwent RSL arthrodesis and DSE between 2006 and 2014. These were retrospectively analyzed both clinically and radiologically. Eleven patients with a mean follow-up of 63 months (range, 30-97 months) were included in the final analysis because 1 was unavailable and 2 had died. The outcome was evaluated using parameters of pain, ROM, grip strength, nonunion rate, and DJD of the adjacent joints. In addition, self-assessment by patients was registered on the Disability of the Arm, Shoulder and Hand score, Patient-Rated Wrist Evaluation score, and Michigan Hand Outcomes Questionnaire. To investigate DJD and union, a computed tomography (CT) scan at the final follow-up visit was performed.

RESULTS

All patients showed union and no midcarpal DJD in the CT scans at final follow-up. The mean ROM in extension was 53°, flexion 42°, supination 81°, pronation 85°, radial deviation 10° and ulnar deviation 25°. The ROM in extension, extension/flexion arc, and supination improved significantly after surgery. Patients achieved a mean of 80% of grip strength compared with the other hand.

CONCLUSIONS

Volar angular stable plate RSL arthrodesis with resection of the distal scaphoid pole is a safe and effective method for treating malunited DRF. This leads to an improved ROM and low pain level.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Application of a three-dimensional computational wrist model to proximal row carpectomy

A three-dimensional (3D) computational model of the wrist examined the biomechanical effects of the proximal row carpectomy (PRC), a surgical treatment of certain wrist degenerative conditions but with functional consequences. Model simulations, replicating the 3D bony anatomy, soft tissue restraints, muscle loading, and applied perturbations, demonstrated quantitatively accurate responses for the decreased motions subsequent to the surgical procedure. It also yielded some knowledge of alterations in radiocarpal contact force which likely increase contact pressure as well as additional insight into the importance of the triangular fibrocartilage complex and retinacular/capsular structures for stabilizing the deficient wrist. As better understanding of the wrist joint is achieved, this model could serve as a useful clinical tool.

International Federation of Societies for Surgery of the Hand 2013 Committee's report on wrist dart-throwing motion

This report updates information on wrist dart-throwing (DT) motion, based on the most recent research published on the kinematics, kinetics, and clinical applications of DT motion. A wide range of DT planes exists. "Pure" DT motion is done along an oblique plane that intercepts the coronal and sagittal planes at the zero position, and occurs almost exclusively at the midcarpal joint with near zero scaphoid and lunate motion. "Functional" DT motion such as a hammering is done along an oblique plane that is almost parallel to the pure DT plane, but that has an offset toward the dorsal side. Functional DT rotation has greater scaphoid and lunate motion compared with pure DT motion. Midcarpal arthrodesis adversely affects DT motion compared with radiocarpal arthrodesis. During a DT motion, the mean and peak tendon forces of the flexor carpi ulnaris and the extensor carpi radialis longus were the greatest among wrist motors. By performing a task along the plane of DT motion, the scapholunate (SL) joint was stable and SL ligament elongation was minimal in healthy subjects. However, a more recent study of patients with SL dissociation revealed that DT exercises applied tensile forces on the SL ligament and induced an SL gap.

In-vivo confirmation of the use of the dart thrower's motion during activities of daily living

The dart thrower's motion is a wrist rotation along an oblique plane from radial extension to ulnar flexion. We report an in-vivo study to confirm the use of the dart thrower's motion during activities of daily living. Global wrist motion in ten volunteers was recorded using a three-dimensional optoelectronic motion capture system, in which digital infra-red cameras track the movement of retro-reflective marker clusters. Global wrist motion has been approximated to the dart thrower's motion when hammering a nail, throwing a ball, drinking from a glass, pouring from a jug and twisting the lid of a jar, but not when combing hair or manipulating buttons. The dart thrower's motion is the plane of global wrist motion used during most activities of daily living. Arthrodesis of the radiocarpal joint instead of the midcarpal joint will allow better wrist function during most activities of daily living by preserving the dart thrower's motion.

RSL Fusion with Excision of Distal Scaphoid and Triquetrum: A Cadaveric Study

Radioscapholunate (RSL) fusion has been utilized for treatment of radiocarpal arthritis for patients with an intact midcarpal joint. This preserves midcarpal joint motion while alleviating pain. Dart thrower's motion (DTM), which has been emphasized recently, is mainly a midcarpal joint motion. Question A cadaveric study was designed to measure and compare the range of motion (ROM) of the human wrist before and after an RSL fusion, followed by distal scaphoid excision, and finally excision of the triquetrum. Methods Twelve embalmed adult cadaveric upper limbs were assessed. The wrist motion was measured with an electrogoniometer. Measurements of the flexion-extension plane and radial-ulnar deviation plane were obtained for baseline after capsulotomy, after simulated RSL fusion with memory staples, after distal scaphoidectomy, and after excision of the triquetrum. Results The effects of scaphoid and triquetrum excision were expressed as improvements in movement over that of the preceding step. RSL fusion alone resulted in a decrease of the flexion-extension (F-E) arc by 36% and the radioulnar deviation (R-U) arc by 30%. Excision of the distal scaphoid with RSL improved the F-E arc by 34% and the R-U arc by 34%. With excision of the triquetrum, the F-E arc improved further by 13% and the R-U arc by 21%. The ROM of the simulated RSL fusion with distal scaphoidectomy is improved with excising the triquetrum, mainly through an increase in ulnar deviation motion. RSL fusion with distal scaphoidectomy and triquetrectomy can be an alternative to total wrist arthrodesis for patients with an intact midcarpal joint.

Radioscapholunate arthrodesis with compression screws and local autograft

Radioscapholunate arthrodesis is performed for patients who experience pain and disability from radiocarpal arthritis. Initial reports from the 1980s demonstrated high nonunion rates and marginal clinical outcomes. Improvements in surgical technique and clearly defined indications have reduced nonunion rates and improved patient satisfaction. We present a technique using headless compression screws inserted through a dorsal approach, which optimizes hardware placement and incorporates local bone graft harvested from the insertion site to supplement the arthrodesis.

Load transfer through the radiocarpal joint and the effects of partial wrist arthrodesis on carpal bone behaviour: a finite element study

A finite element model of the wrist was developed to simulate mechanical changes that occur after surgery of the wrist. After partial arthrodesis, the wrist will experience altered force transmission during loading. Three different types of partial arthrodesis were investigated - radiolunate, radioscaphoid, and radioscapholunate - and compared with the healthy untreated wrist. The results showed that the compressive forces on the radiocarpal joint decreased compared with the untreated wrist with both radiolunate and radioscaphoid fusions. The load transmission through the midcarpal joints varied depending on arthrodesis type. The forces in the extrinsic ligaments decreased with the fusion, most noticeably in the dorsal radiotriquetral ligament, but increased in the dorsal scaphotriquetral ligament. From the results of the study it can be concluded that the radioscapholunate fusion shows the most biomechanically similar behaviour out of the three fusion types compared with the healthy wrist. The modelling described in this paper may be a useful approach to pre-operative planning in wrist surgery.

Results after radioscapholunate arthrodesis with or without resection of the distal scaphoid pole

PURPOSE

To evaluate the differences between radioscapholunate (RSL) arthrodesis alone versus RSL arthrodesis with additional distal scaphoidectomy.

METHODS

We retrospectively evaluated 61 patients who were treated with RSL arthrodesis for painful posttraumatic osteoarthritis. Thirty patients had an RSL arthrodesis with additional resection of the distal scaphoid pole (group A), and 31 had RSL arthrodesis alone (group B). Six patients in group A and 8 in group B had the RSL arthrodesis converted to a complete wrist arthrodesis during follow-up. Those patients were excluded from the survey. Of the remaining 47 patients, 35 (20 from group A, 15 from group B) returned for a clinical and radiological examination at an average of 28 (range, 10-47) months after the index surgery. The results were rated by the Disabilities of the Arm, Shoulder, and Hand score and the modified Mayo Wrist Score. The patients' outcomes after RSL arthrodesis with or without distal scaphoidectomy were compared for pain, wrist motion, grip strength, nonunion rate, osteoarthritis of the adjacent joints, the Disabilities of the Arm, Shoulder, and Hand score and the modified Mayo Wrist Score.

RESULTS

Three patients with RSL arthrodesis alone showed a radioscaphoid nonunion. All arthrodeses in group A healed. In the clinical evaluation, there was no significant difference between groups A and B in the Disabilities of the Arm, Shoulder, and Hand score, the modified Mayo Wrist Score, grip strength, pain, or wrist motion. Assuming that wrist motion might be better in patients with a nonunion, the average wrist motion was recalculated after eliminating 3 patients with a radioscaphoid nonunion from group B. Radial deviation was then found to be significantly better in group A.

CONCLUSIONS

Additional distal scaphoidectomy with RSL arthrodesis seems to improve postoperative radial deviation of the wrist. The radioscaphoid nonunion rate is high with RSL arthrodesis alone. Distal scaphoidectomy appeared to increase the successful fusion rate of RSL arthrodeses. No significant effect on wrist extension, flexion, ulnar deviation, pain level, restriction in activities of daily living, or grip strength was noted.

Midcarpal hemiarthroplasty for wrist arthritis: rationale and early results

Midcarpal hemiarthroplasty is a novel motion-preserving treatment for radiocarpal arthritis and is an alternative to current procedures that provide pain relief at the expense of wrist biomechanics and natural motion. It is indicated primarily in active patients with a well-preserved distal row and debilitating arthritic symptoms. By resurfacing the proximal carpal row, midcarpal arthroplasty relieves pain while preserving the midcarpal articulation and the anatomic center of wrist rotation. This technique has theoretical advantages when compared with current treatment options (i.e., arthrodesis and total wrist arthroplasty) since it provides coupled wrist motion, preserves radial length, is technically simple, and avoids the inherent risks of nonunion and distal component failure. The KinematX midcarpal hemiarthroplasty has an anatomic design and does not disrupt the integrity of the wrist ligaments. We have implanted this prosthesis in nine patients with promising early results. The indications for surgery were as follows: scapholunate advanced collapse wrist (three), posttraumatic osteoarthritis (three), inflammatory arthritis (two), and Keinböck disease (one). Prospective data has been collected and the results are preliminary given the infancy of the procedure. The mean follow-up was 30.9 weeks (range: 16 to 56 weeks). The mean Mayo wrist score increased from 31.9 preoperatively to 58.8 (p < 0.05) and the mean DASH score improved significantly from 47.8 preoperatively to 28.7 (p < 0.05). There was a trend toward increased motion but statistical significance was not reached. Two patients required manipulation for wrist stiffness. There was no evidence of prosthetic loosening or capitolunate narrowing. The procedure is simple (average surgical time was 49 minutes) and maintains coupled wrist motion through preservation of the midcarpal articulation. The preliminary data show that it appears safe but considerably longer follow-up is required before conclusions can be drawn as to its durability, reliability, and overall success. The level of evidence for this study is therapeutic level IV (case series).