Carpal Component Research Articles

Total wrist arthroplasty with the Freedom® prosthesis: a short-term follow-up.

We retrospectively reviewed our series of primary total wrist arthroplasty with the Freedom® prosthesis. The primary outcome measure was revision, and secondary measures included radiographic loosening, pain, complications, movement range, grip strength and patient-reported measures. We reviewed 12 implants in 11 patients (mean age 59 years, range 45-80) with a mean radiological and clinical follow-up of 2.7 and 3 years, respectively. One radial component failed to integrate and was revised at Day 84. Four carpal components demonstrated areas of lucency. There was a statistically significant reduction in pain, and total flexion-extension increased. Despite high patient satisfaction on a ten-point visual analogue scale score (mean 8.7 out of 10), the mean patient-rated wrist evaluation, Quick Disabilities of the Arm, Shoulder and Hand and Patient Evaluation Measure scores were 52, 55 and 53, respectively. The Freedom® implant reduced pain and preserved wrist movement in our patients; however, annual surveillance is recommended due to the high incidence of early carpal component lucency.Level of evidence: IV.

Long-term outcomes of the Universal 2 total wrist replacement: revision and loosening at 10 years and beyond.

The aim of this study was to ascertain the long-term revision rates of the Universal 2 wrist prosthesis in a previously published cohort of patients with rheumatoid arthritis. The time to, and reasons for revision were determined. Radiographs were analysed to determine whether loosening had occurred in the long-term according to the Wrightington zonal classification of loosening. Seventy-eight wrists from the original cohort of 85 wrists could be identified for analysis. The longest follow-up was 16 years and 29 wrists had follow-up beyond 10 years. Seventeen wrists had been revised or were on the waiting list for revision, an overall revision rate of 22%. The 10-year survivorship was 78%. Long-term revision was commonly for periprosthetic loosening with pain and component subsidence. In those with more than 10-year follow-up, significant lucency was seen in 16 carpal components and 15 radial components. Explant analysis showed significant polyethylene wear and we postulate this is the principal reason for component loosening.Level of evidence: IV.

Total Wrist Replacement: State of the Art, Challenges and Pitfalls: A Comparative Review

Background Total wrist replacement (TWR) as motion-preserving procedure continues to be critically discussed in the literature, although the complication rates have been significantly reduced with the current 3rd generation designs compared with older types. Possible reasons for this are often also a lack of knowledge about the currently available evidence, the complication management, and the lack of practical experience by the surgeons. Methods Based on an extended review of literature and own experience, the aim of this article is to give practicable insights for the clinician on: (1) biomechanical fundamentals, (2) differences in design, survivorship and functional outcome between the recent types, (3) possible pitfalls, and (4) failures and salvage options. Results The goal of TWR is that the overall wrist motion is maintained respectively improved despite it works with a locked midcarpal joint. Regarding survivorship and functional outcome the Maestro is (was) being superior over all other types that is (was) based on features in design. There is no scientific evidence as to why the Maestro was withdrawn from the marketplace by the company. For assessment of instability and/or impingement the use of dynamic radiographs is recommended. The problem of TWR is unchanged failure of the carpal components primarily based on mechanical dysbalance, and secondarily followed by metal and/or polyethylene wear, but surgical revision of asyptomatic periprosthetic osteolysis without safe radiagraphic signs of loosening is only required in not more than 20% of cases. For a failed TWR, revision TWR or conversion to total wrist arthrodesis are viable salvage options. Conclusions The knowledge about recent evidence and features in design of the available types, exact assessment of radiographic findings, presence of technical skills by the surgeons, and observance of the patient's expectations are the basic requirements for a successful TWR.

A randomized controlled trial comparing two modern total wrist arthroplasties : improved function with stable implants, but high complication rates in non-rheumatoid wrists at two years.

To analyze the short-term outcome of two types of total wrist arthroplasty (TWA) in terms of wrist function, migration, and periprosthetic bone behaviour. A total of 40 patients suffering from non-rheumatoid wrist arthritis were enrolled in a randomized controlled trial comparing the ReMotion and Motec TWAs. Patient-rated and functional outcomes, radiological changes, blood metal ion levels, migration measured by model-based radiostereometric analysis (RSA), bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), complications, loosening, and revision rates at two years were compared. Patient-Rated Wrist and Hand Evaluation (PRWHE) scores, abbreviated version of the Disabilities of the Arm, Shoulder and Hand questionnaire scores, and pain improved similarly and significantly in both groups. Wrist motion improved significantly in the Motec group only, and forearm rotation in the ReMotion group only. Cobalt (Co) and chromium (Cr) blood ion levels were significantly higher in the metal-on-metal (MoM) Motec group than in the metal-on-polyethylene (MoP) ReMotion group. Mean total translation was 0.65 mm (95% confidence interval (CI) 0.26 to 1.12) and 0.27 mm (95% CI 0.14 to 0.47) for the ReMotion carpal and radial components, and 0.32 mm (95% CI 0.22 to 0.45) and 0.26 mm (95% CI 0.20 to 0.34) for the Motec metacarpal and radial components, respectively. Apart from dorsal and volar tilts, which were significantly higher for the radial ReMotion than for the Motec component, no significant differences in absolute migration occurred. BMD around the radial components never returned to baseline. Almost one-third of patients required reoperation due to complications. Two ReMotion implants were revised to Motec TWAs due to carpal component loosening, and three Motec MoM articulations were revised to metal-on-polyether ether ketone due to painful synovitis. Both implants provided matched function and were stable at short-term follow-up, but with a high complication rate. This procedure should be restricted to specialist centres undertaking prospective analysis until its role is clarified.Cite this article: Bone Joint J2022;104-B(10):1132-1141.

In vivo articular contact pattern of a total wrist arthroplasty design

Total wrist arthroplasty (TWA) designs suffer from relatively high complication rates when compared to other arthroplasties. Understanding the contact pattern of hip and knee replacement has improved their design and function; however, the in vivo contact pattern of TWA has not yet been examined and is thus the aim of this study. We hypothesized that the center of contact (CoC) is located at the geometric centers of the carpal component and radial component in the neutral posture and that the CoC moves along the principal arcs of curvature throughout primary anatomical motions. Wrist motion and implant kinematics of six patients with the Freedom® total wrist implant were studied during various tasks using biplanar videoradiography. The location of the CoC of the components was investigated by calculating distance fields between the articular surfaces. We found the CoC at the neutral posture was not at the geometric centers but was located 3.5 mm radially on the carpal component and 1.2 mm ulnarly on the radial component. From extension to flexion, the CoC moved 10.8 mm from dorsal to volar side on the carpal component (p < 0.0001) and 7.2 mm from volar to dorsal on the radial component (p = 0.0009). From radial to ulnar deviation, the CoC moved 12.4 mm from radial to ulnar on the carpal component (p < 0.0001), and 5.6 mm from ulnar to radial on the radial component (p = 0.009). The findings of this study may eventually improve TWA success by advancing future designs through a more accurate understating of their kinematic performance in vivo.

Total Wrist Arthroplasty Alignment and Its Potential Association with Clinical Outcomes.

Purpose There is a lack of quantitative research that describes the alignment and, more importantly, the effects of malalignment on total wrist arthroplasty (TWA). The main goal of this pilot study was to assess the alignment of TWA components in radiographic images and compare them with measures computed by three-dimensional analysis. Using these measures, we then determined if malalignment is associated with range of motion (ROM) or clinical outcomes (PRWHE, PROMIS, QuickDash, and grip strength). Methods Six osteoarthritic patients with a single type of TWA were recruited. Radiographic images, computed tomography images, and clinical outcomes of the wrists were recorded. Using posteroanterior and lateral radiographs, alignment measurements were defined for the radial and carpal components. Radiographic measurements were validated with models reconstructed from computed tomography images using Bland-Altman analysis. Biplanar videoradiography (<1mm and <1 degree accuracy) was used to capture and compute ROM of the TWA components. Linear regression assessed the associations between alignment and outcomes. Results Radiographic measures had a 95% limit-of-agreement (mean difference ± 1.96 × SD) of 3 degrees and 3mm with three-dimensional values, except for the measures of the carpal component in the lateral view. In our small cohort, wrist flexion-extension and radial-ulnar deviation were correlated with volar-dorsal tilt and volar-dorsal offset of the radial component and demonstrated a ROM increase of 3.7 and 1.6 degrees per degree increase in volar tilt, and 10.8 and 4.2 degrees per every millimeter increase in volar offset. The carpal component's higher volar tilt was also associated with improvements in patient-reported pain. Conclusions We determined metrics describing the alignment of TWA, and found the volar tilt and volar offset of the radial component could potentially influence the replaced wrist's ROM. Clinical Relevance TWA component alignment can be measured reliably in radiographs, and may be associated with clinical outcomes. Future studies must evaluate its role in a larger cohort.

Proximal-distal shift of the center of rotation in a total wrist arthroplasty is more than twice of the healthy wrist.

Reproduction of healthy wrist biomechanics should minimize the abnormal joint forces that could potentially result in the failure of a total wrist arthroplasty (TWA). To date, the in vivo kinematics of TWA have not been measured and it is unknown if TWA preserves healthy wrist kinematics. Therefore, the purpose of this in vivo study was to determine the center of rotation (COR) for a current TWA design and to compare its location to the healthy wrist. The wrist COR for six patients with TWA and 10 healthy subjects were calculated using biplane videoradiography as the subjects performed various range-of-motion and functional tasks that included coupled wrist motions. An open-source registration software, Autoscoper, was used for model-based tracking and kinematics analysis. It was demonstrated that the COR was located near the centers of curvatures of the carpal component for the anatomical motions of flexion-extension and radial-ulnar deviation. When compared to healthy wrists, the COR of TWAs was located more distal in both pure radial deviation (P < .0001) and pure ulnar deviation (P = .07), while there was no difference in its location in pure flexion or extension (P = .99). Across all coupled motions, the TWA's COR shifted more than two times that of the healthy wrists in the proximal-distal direction (17.1 vs 7.2 mm). We postulate that the mismatch in the COR location and behavior may be associated with increased loading of the TWA components, leading to an increase in the risk of component and/or interface failure.

A Minimum 5-Year Longitudinal Study of a New Total Wrist Arthroplasty in Patients With Rheumatoid Arthritis

To evaluate the longitudinal clinical outcomes using a new semiconstrained wrist prosthesis for the treatment of severe rheumatoid arthritis of the wrist. Twenty patients with rheumatoid arthritis (20 wrists) underwent total wrist arthroplasty with the prosthesis in a clinical trial. The preoperative Larsen classification was grade IV in 16 wrists and grade V in 4 wrists. Assessments were performed before surgery, 1.5 years after surgery, and at final follow-up (≥ 5 years after surgery) using the visual analog scale for pain, Figgie wrist score, Japanese version of the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire, and plain radiographs. At final follow-up, no patient had wrist pain. The preoperative flexion-extension arc at final follow-up was similar to the preoperative range. The mean 1.5-year postoperative Figgie score was significantly improved and was unchanged at final follow-up. The DASH score significantly improved from before surgery to 1.5 years after surgery; the DASH score was improved further at final follow-up, but not significantly. Five of the 19 wrists evaluated had radiographic findings indicating carpal component loosening at final follow-up; however, all patients with the loosening were asymptomatic and had not undergone revision surgery. Total wrist arthroplasty using this wrist prosthesis leads to favorable clinical outcomes regarding pain relief and retained range of wrist motion. Therapeutic IV.

Kinematic Accuracy in Tracking Total Wrist Arthroplasty With Biplane Videoradiography Using a Computed Tomography-Generated Model.

Total wrist arthroplasty (TWA) for improving the functionality of severe wrist joint pathology has not had the same success, in parameters such as motion restoration and implant survival, as hip, knee, and shoulder arthroplasty. These other arthroplasties have been studied extensively, including the use of biplane videoradiography (BVR) that has allowed investigators to study the in vivo motion of the total joint replacement during dynamic activities. The wrist has not been a previous focus, and utilization of BVR for wrist arthroplasty presents unique challenges due to the design characteristics of TWAs. Accordingly, the aims of this study were (1) to develop a methodology for generating TWA component models for use in BVR and (2) to evaluate the accuracy of model-image registration in a single cadaveric model. A model of the carpal component was constructed from a computed tomography (CT) scan, and a model of the radial component was generated from a surface scanner. BVR was acquired for three anatomical tasks from a cadaver specimen. Optical motion capture (OMC) was used as the gold standard. BVR's bias in flexion/extension, radial/ulnar deviation, and pronosupination was less than 0.3 deg, 0.5 deg, and 0.6 deg. Translation bias was less than 0.2 mm with a standard deviation of less than 0.4 mm. This BVR technique achieved a kinematic accuracy comparable to the previous studies on other total joint replacements. BVR's application to the study of TWA function in patients could advance the understanding of TWA, and thus, the implant's success.

Surgical technique: about a new total and isoelastic wrist implant (Prosthelast®).

This study describes a new total wrist implant (Prosthelast®) designed to reduce the risk of distal migration of the carpal component. The Prosthelast® implant consists in a one-block radial implant replacing the metaphysis and the articular surface fixed to a radial elastic centromedullar wire and a carpal component in titanium with an articular condylar surface in polyethylene. We operated on five patients (three male patients and two female patients) and followed them up for 12months on average. Two of the patients presented with rheumatoid arthritis of the wrist, and an ulnar osteotomy (Darrach procedure) was carried out at the same time of the arthroplasty. All clinical variables improved postoperatively (Quick DASH score, pain score, range of motion) except from wrist flexion which was reduced. No patients underwent revision surgery. Two patients presented with a periprosthetic radiolucent loosening around the radial component, but no implant migration was observed. Overall, the preliminary results of our case series show that the new Prosthelast® implant presents comparable short-term results to those described in the literature. We will follow up the patients to verify that long-term results are as satisfactory as the short-term results.

Survivorship of Revision Wrist Replacement.

Purpose This study aims to report the 5-year survivorship of revision wrist arthroplasties and to report midterm clinical and radiological results. Materials and Methods All patients receiving a revision wrist arthroplasty in our unit between January 1, 1997 and October 31, 2010 were identified, and clinical notes retrospectively analyzed for Quick Disabilities of the Arm, Shoulder and Hand (quickDASH), Patient Evaluation Method (PEM), Patient-Rated Wrist Evaluation (PRWE), the range of movement, and visual analog score (VAS). In cases where patient review had not occurred within the past year, they were invited for assessment, and this data was included in the analysis. Plain radiographs were analyzed for loosening of each component. The 5-year survival was plotted using Kaplan-Meier analysis. Results Of the 19 patients identified, 1 was lost to follow-up and therefore excluded from all analyses. Mean age at revision wrist arthroplasty was 55.8 years and the mean time from primary to revision wrist arthroplasty was 6.7 years. At revision arthroplasty, 7 patients received the Biaxial implant (DePuy, Inc., Warsaw, IN) and 11 received the Universal II implant (Integra, Inc., Plainsboro, NJ). The 5-year implant revision survivorship was 83%. Depending on the variable of interest, clinical data were available for either three, four or five patients. At final follow-up (mean: 10.4 years), mean visual analog score was 2.9, mean quickDASH 57, mean PEM 49, mean PRWE 61, and mean arc of flexion/extension was 26 degrees. Radiological data were available for 12 patients, with evidence of gross loosening present in around 60% of the carpal components and 50% of the radial components at mean 6.7 years. Conclusion Revision wrist replacement implant survival is acceptable, but the majority of the surviving implants are radiologically loose. It is not clear at this time whether they are better or worse than a fusion after a failed primary wrist arthroplasty. Clinical Relevance It is reasonable to offer revision wrist arthroplasty in selective cases, but regular clinical and radiological follow-up is recommended.

Universal 2 Wrist Arthroplasty in Rheumatoid Arthritis.

Purpose The aim of this study was to evaluate the mid- to long-term outcomes and complications in patients affected by rheumatic diseases treated with the Universal 2 (U2) total wrist arthroplasty (TWA). Methods We reviewed, in a retrospective, noncontrolled cohort study, 22 patients affected by rheumatoid arthritis (RA), who underwent U2 total wrist replacement between March 2003 and January 2014 for the treatment of 23 rheumatoid wrists with the aim of obtaining the remission of pain and a range of motion (ROM) useful for daily activities, according to the patients' demands, as an alternative to total wrist arthrodesis. The cohort of patients included 20 females and 2 males, with a mean age of 54.9 years. Residual pain, preoperative ROM, postoperative ROM increases, grip strength, radiographic changes, long-term complications, and reasons for revision or failures were evaluated. Results In this study, 22 patients were evaluated at a mean follow-up of 82.3 months (range: 2-12 years). All patients had good or complete pain relief, the mean visual analogue scale pain score was 0.82. The mean grip strength improved and postoperatively was 11 kg (Jamar). The mean total ROM of flexion-extension was 72.3 degrees; radial-ulnar deviation 24.9 degrees. The mean QuickDASH score of 49 and patient rate wrist/hand evaluation of 41.7 a revision surgical procedure in six cases (26%): in two cases, a carpal component revision procedure and in four cases, total implant failures requiring either conversion to a Swanson spacer or wrist joint fusion. Conclusion TWA provides pain relief, preserves motion, and improves function in severe degenerative RA. Our results at a mid- to long-term follow-up with the U2 prosthesis were encouraging and represent, when indicated, a valid alternative to fusion which is less appealing for RA patients. Level of Evidence Level of evidence is therapeutic IV.

Disillusioning midterm results after UNI 2 total wrist arthroplasty in RA Patients

Total wrist arthroplasty attempts to produce a stable, pain free joint. Avoidance of arthrodesis is a strong impetus. Early results of the Universal total wrist arthroplasty KMIy in wrist arthritis were at least as encouraging as were reports with other implants. The five to ten year outcomes showed a 45% revision rate with arthrodesis rate below 10%. Our question was wether results withstand over time. Material and method Between 2002 and 2012, 12 rheumatoid patients all but one female had cementless UNI 2 total wrist arthroplasty - the only implant used by a single surgeon - on 14 wrists, average age of 68, 55 years (range 37–84 y.). Indication was panarthritis of the carpus with Simmen Grade I and II without major bone loss intact tendons without active synovitis or infection. No patient was dependent on walking aids. At follow-up average 6.9 years the only question was on the status of the implant whether radiological and mechanical stable or not. Two patients were lost to follow-up due to death for other medical reasons. Results During the follow-up 9 wrists or 75% of the surviving got clinically symptomatic with increasing pain, local swelling and radiovolar drift of the carpus. There was in any instance polyethylene wear accentuated on the radius, synovitis and secondary carpal tunnel syndrome. After an average of 5 years revision rate rose markedly. Radiologic and mechanical loosening of the carpal component was seen 7 times. Surgery - twice there was only the change of the polyethylene component necessary. Three times the carpal component had to be changed in combination with cancellous bone adjunct. Finally, 4 revisions ended in arthrodesis, two of those in first revision. At present, two more patients with three implants are due to reoperation. Thus, arthroplasty showed complication in 75% and mobility was lost in 33% of the surviving. Discussion Early results of the universal total wrist arthroplasty KMIy in rheumatoid arthritis were encouraging. Midterm results show an array of problems focussing on the carpal component. These studies generally sum up degenerative, posttraumatic and rheumatoid arthritis cases. To our knowledge ours is the only focusing on RA patients only. The majority of publications delude oneself to believe in total wrist arthroplasty in this category of patients. The authors own experience is much more deceiving. In our department total wrist arthroplasty in rheumatoid patients is no longer the treatment of choice.

Evolution of total wrist arthroplasty

Since the first wrist implant in 1890 by Gluck in the form of an ivory prosthesis, the evolution of the prosthetic wrist has been sawtoothing. Abandoned in the late nineteenth century due to infectious complications, they reappeared after the Second World War. Several concepts have rubbed shoulders for decades. It flourished simple and lightweight silicone implants Swanson and complex and heavy metal prostheses Meuli kind. Silicone implants gave spectacular results in the early years but were abandoned due to siliconite and / or implant fracture. The metallic prostheses can be categorised into multiple implants or ball and socket, cemented or not, inverted or not, with or without polyethylene or retentive unconstrained. Several generations have been developed to reduce complications. However, regardless of the type of prosthesis, survival at 5 years did not exceed 50% mainly due to the loosening of the carpal component. This is what has led to the arrival of new total prostheses in the 2000s: the Remotion SBI ® and ™ Uni2 ® Integra ™. These new prostheses preserve the carpal bone stock and seem to have a better survival rate at 5 years than the previous generation. A new concept that is emerging in recent years, is the concept of unicompartmental prosthesis. Assuming that the loosening of the carpal component is the main problem of total prostheses, deletion avoids this complication. The mechanical stresses are lower than the hip, so therefore the theoretical risk in the radial carpal prosthesis is low. It is still too early to comment on the results. Nevertheless, the evolution of prosthetic wrist is not complete, as evidenced by the most recent implants.

Wear Particles and Osteolysis in Patients With Total Wrist Arthroplasty

To determine whether the amount of polyethylene debris in the interphase tissue between prosthesis and bone in patients with total wrist arthroplasty correlated with the degree of periprosthetic osteolysis (PPO); and to investigate the occurrence of metal particles in the periprosthetic tissue, the level of chrome and cobalt ions in the blood, and the possible role of infectious or rheumatoid activity in the development of PPO. Biopsies were taken from the implant-bone interphase in 13 consecutive patients with total wrist arthroplasty and with at least 3 years' follow-up. Serial annual radiographs were performed prospectively for the evaluation of PPO. We collected blood samples for white blood cell count, C-reactive protein, and metallic ion level. A radiolucent zone of greater than 2 mm was observed juxta-articular to the radial component in 4 patients and at the carpal component in 3. The magnitude of the radiolucent zone tended to level out over time. We observed subsidence of the implant in 3 patients on the carpal side and in none on the radial side. The amount of polyethylene and metallic debris was generally small and did not correlate with the width of the radiolucent zone. The blood levels of chrome and cobalt ions were normal. There was no evidence of infectious or rheumatoid activity. Polyethylene wear has been accepted as a major cause of osteolysis in total hip arthroplasty, and metallic debris has also been cited to be an underlying cause. However, our hypothesis that polyethylene debris correlated with the degree of PPO could not be confirmed. Also, metallic debris and infectious or rheumatoid activity did not correlate with PPO. Prognostic I.

Periprosthetic osteolysis after total wrist arthroplasty.

Background and Literature Review Periprosthetic osteolysis (PPO) after second- or third-generation total wrist arthroplasty (TWA), with or without evident loosening of the implant components, has previously been reported in the literature, but rarely in a systematic way. Purpose The purpose of this study was to analyze the prevalence, location, and natural history of PPO following a TWA and to determine whether this was associated with prosthetic loosening. Patients and Methods We analyzed 44 consecutive cases in which a RE-MOTION TWA (Small Bone Innovations Inc., Morrisville, PA, USA) had been done. Results We found significant periprosthetic radiolucency (more than 2 mm in width) at the radial component side in 16 of the cases and at the carpal component side in 7. It developed gradually juxta-articularly around the prosthetic components regardless of the primary diagnosis, and seemed to stabilize in most patients after 1-3 years. In a small percentage of the patients, the periprosthetic area of bone resorption was markedly larger. In general, radiolucency was not related to evident loosening of the implant components, and only five carpal components and one radial had subsided or tilted. Conclusion Periprosthetic loosening is frequent following a TWA. In our series it was not necessarily associated with implant loosening and seemed to stabilize within 3 years. Close and continued observation is, however, recommended. Level of Evidence Therapeutic IV.

Component alignment in total wrist arthroplasty: success rate of surgeons in their first cases.

The aim of this study was to assess the probability of achieving a satisfactory alignment in the performance of a first wrist arthroplasty. The total wrist arthroplasties (ReMotion®) of 14 wrists of 7 corpses performed by 14 inexperienced surgeons were reviewed radiologically. Radial component alignment in the posteroanterior view (RCA-PA), radial component alignment in the lateral view (RCA-Lat), carpal component alignment in the posteroanterior view (CCA-PA) and carpal component alignment in lateral view (CCA-Lat) were measured. Mean RCA-PA angle was 9.6º, mean RCA-Lat angle 4.6º, mean CCA-PA angle 4.4º and mean CCA-Lat angle 10.1º. None of the arthroplasties had a satisfactory alignment. It is difficult for an inexperienced surgeon to achieve a correct component alignment in his/her first total wrist arthroplasty, especially in the carpal component. Therefore, we recommend that the position of the prosthesis is confirmed before securing it to the bone with the help of X-ray images.

AB0296 Outcomes of universal-2 total wrist arthroplasty: Our experience at wrightington hospital

BackgroundTotal Wrist Arthroplasty (TWA) for Rheumatoid Arthritis (RA) involving the wrist joint allows pain relief and preservation of the movements, when compared to the fusion. Universal-2® Total Wrist Arthroplasty is...

Five to Ten-Year Outcomes of the Universal Total Wrist Arthroplasty in Patients with Rheumatoid Arthritis

Implant arthroplasty of the wrist offers pain relief with preservation of motion to patients with rheumatoid arthritis, although few studies have investigated the long-term results of this procedure. The purpose of the present study is to report the prospective results of total wrist arthroplasty with use of the Universal wrist prosthesis in a consecutive series of patients with rheumatoid arthritis who were managed by a single surgeon. Twenty-four wrist arthroplasties in twenty patients with rheumatoid arthritis were followed prospectively. Nineteen wrists in fifteen patients were followed clinically and radiographically for a mean of 7.3 years (range, 5.0 to 10.8 years) after the index procedure. Outcome measures included the Disabilities of the Arm, Shoulder and Hand (DASH) score, wrist range of motion, and standard radiographic findings. The average DASH score improved from 62 points preoperatively to 40 points at the time of the latest follow-up. The mean wrist flexion and extension at the time of the latest follow-up were 42° and 20°, respectively, for a mean improvement in the total flexion-extension arc of 14°. A total of nine wrists (45%) in eight patients underwent revision surgery because of a loose carpal component at the time of the latest follow-up. One patient underwent wrist arthrodesis because of recurrent wrist instability. Two additional wrists in two patients had radiographic evidence of carpal component subsidence at the time of the latest follow-up. The implant survival rates at five and seven years for the original prosthetic components were 75% and 60%, respectively. The results for the Universal wrist prosthesis at a minimum of five years of follow-up include a high rate of failure, most often because of carpal component loosening, resulting in revision of ten (50%) of twenty wrists at the time of the latest follow-up (with the inclusion of one revision in a patient who died before five years). Patients with a stable prosthesis maintained a functional range of motion and had improvement in patient-reported outcome measures.

A new computed tomography-based radiographic method to detect early loosening of total wrist implants

Diagnosis of loosening of total wrist implants is usually late using routine radiographs. Switching modality to computed tomography (CT) should aid in early diagnosis. To propose and evaluate the accuracy of a new CT method for assessing loosening of the carpal component in total wrist arthroplasty. A protocol encompassing volume registration of paired CT scans of patients with unexplained pain in a prosthetically replaced wrist (used in clinical routine) is presented. Scans are acquired as a dynamic examination under torsional load. Using volume registration, the carpal component of the prosthesis is brought into spatial alignment. After registration, prosthetic loosening is diagnosed by a shift in position of the bones relative to the prosthesis. This study is a preclinical validation of this method using a human cadaverous arm with a cemented total wrist implant and tantalum markers. Seven CT scans of the arm were acquired. The scans were combined into 21 pairs of CT volumes. The carpal component was registered in each scan pair, and the residual mismatch of the surrounding tantalum markers and bone was analyzed both visually and numerically. The detection limit for prosthetic movement was less than 1 mm. The results of this study demonstrate that CT volume registration holds promise to improve detection of movement of the carpal component at an earlier stage than is obtainable with plain radiography.