Strain shielding in distal radius after wrist arthroplasty with a current generation implant: An in vitro analysis

Complications after total wrist arthroplasty

We reviewed the incidence and management of complications after total wrist arthroplasty, as reported in the literature, with so-called fourth-generation implants and other recent designs. While early intraoperative and postoperative complications, including fractures, tendon lacerations, infection, nerve compression, tendonitis, stiffness and chronic regional pain syndrome, had an acceptable incidence, late complications, such as periprosthetic osteolysis and implant loosening, occurred more frequently. Implant survival at 10 years was in the range of 70%-80% in most publications. Several of the implants have been modified or withdrawn. Instability and dislocation were frequent after a pyrocarbon spacer. Failed arthroplasties can be salvaged by revision arthroplasty or total wrist arthrodesis. Revision arthroplasty has a lower survival rate than primary arthroplasty and does not clearly offer important significant advantages over total wrist arthrodesis in terms of patient-reported outcome measures. Further development of prosthetic design, new materials and more knowledge on patient-related risk factors are needed.

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.

The optimal strategy for 3D-printed uncemented endoprosthesis for the bone defect reconstruction of the distal radius, based on biomechanical analysis and retrospective cohort study

INTRODUCTION

Prosthetic reconstruction after resecting giant cell tumor of bone (GCTB) of the distal radius has been proposed. However, this is generally associated with various complications. To improve the functional outcomes, we designed a three-dimensional (3D)-printed uncemented endoprosthesis. Meanwhile, using finite-element analysis and clinical observation, an optimization strategy was explored.

MATERIALS AND METHODS

We retrospectively analyzed patients with Campanacci III or recurrent GCTB of the distal radius who underwent 3D-printed uncemented endoprosthesis reconstruction. Clinically, according to the different palmar tilts of the endoprosthesis, patients were divided into the biological angle (BA) group and the zero-degree (ZD) group. We recorded and evaluated the differences in functional outcomes and complications between the two groups. Biomechanically, four 3D finite-element models (normal and customized endoprostheses with three different implemented palmar tilts) were developed.

RESULTS

We analyzed 22 patients (12 males and 10 females). The median follow-up period was 60 (range, 19-82) months. Of the 22 patients, 11 patients were included in the BA group and the remaining 11 patients were in the ZD group. Both groups showed no significant differences in the range of motion, Mayo score, and disabilities of the arm, shoulder, and hand scores postoperatively. The subluxation rate was significantly lower in the ZD group than in the BA group. The biomechanical results showed similar stress and displacement distribution patterns in the normal and prosthetic reconstruction models. Additionally, the endoprosthesis with 0° palmar tilt showed better biomechanical performance.

CONCLUSION

3D-printed uncemented endoprosthesis provides acceptable midterm outcomes in patients undergoing distal radius reconstruction. Optimizing the design by decreasing the palmar tilt may be beneficial for decreasing the risk of wrist joint subluxation.

Salvage of Failed Distal Radius Open Reduction Internal Fixation With Long-Stem Total Wrist Arthroplasty

A 70-year-old woman was referred to hand surgery after a late failure of ORIF. She subsequently failed a primary total wrist arthroplasty and underwent a revision arthroplasty with a custom implant when her pain and wrist function failed to resolve. The patient reported improved functionality of her left wrist at 2 weeks after revision arthroplasty. At 3 years after surgery, she performed daily activities without pain or difficulty.

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: A 10-Year Follow-Up

PURPOSE

To assess long-term implant survival in total wrist arthroplasty (TWA), comparing 4 different implants.

METHODS

In a prospective cohort of 124 patients, 136 TWAs were evaluated 5 years and 10 years after surgery. The TWAs were implanted between 2005 and 2009. The primary outcome was implant survival. Survival analysis was performed with revision and radiographic loosening as the final end point. Revision was defined as exchange of whole or parts of the prosthesis. Implant loosening was assessed using radiographic examination at the 5-year and 10-year follow-up. Secondary outcome measures included wrist range of motion, hand grip strength, visual analog scale (VAS) pain scores, and patient-related outcome measures, including Disabilities of the Arm, Shoulder, and Hand (DASH), Patient-Rated Wrist Evaluation (PRWE), and Canadian Occupational Performance Measure (COPM).

RESULTS

Total cumulative implant survival was 92% with revision as the primary end point. When including a nonrevised radiographic loose implant as a failure, total implant survival was 75%. Radiographic loosening differed significantly between the implants with a range in frequency from 0% to 37.5%. At the 10-year follow-up, assessing the nonrevised TWAs, range of motion was preserved compared with preoperative values. Significant improvement was recorded for hand grip strength, VAS pain scores, and patient-related outcome measures at the 10-year follow-up compared with preovperative values.

CONCLUSIONS

High 10-year implant survival was found when defining the primary end point as revision of any cause. When including radiographic loosening of the implant in the survival analysis, implant survival was considerably lower. However, radiographic loosening does not seem to correlate with changes in secondary outcome measures, questioning the need for revision surgery in these cases.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

My personal experience with arthroplasties in the hand and wrist over the past four decades

I summarize my changing views and practices of arthroplasty in hand surgery over the past four decades. I recommend simple resection of the trapeziectomy for advanced arthritis of the first carpometacarpal joint, silicone implants for the metacarpophalangeal joints and the proximal interphalangeal joints, and the total wrist arthroplasty for advanced wrist arthritis and collapse. I also outline technical tips of these procedures.