Abstract
Introduction Due to a higher risk for implant loosening, particularly of the distal component,
patients with physically demanding lifestyles are infrequently considered for total
wrist arthroplasty (TWA). A distal radius hemiarthroplasty may obviate the need for
the strict restrictions recommended for patients treated by TWA, thus providing another
surgical option for active patients with severe wrist arthritis, especially those
with articular degeneration of the lunate facet of the radius, capitate head, or combination
of both, who are not typically candidates for traditional motion-preserving procedures.
The purpose of this cadaver study was to evaluate the radiographic static alignment
of the wrist following distal radius hemiarthroplasty and after hemiarthroplasty combined
with proximal row carpectomy (PRC) to determine if these procedures should be further
considered for clinical application.
Materials and Methods Eight fresh-frozen cadaver limbs (age range, 43–82 years) with no history of rheumatoid
arthritis or upper extremity trauma were used. Radiodense markers were inserted in
the radius and hand. Posteroanterior (PA) fluoroscopic images with the wrist in neutral,
radial deviation, and ulnar deviation, and lateral images with the wrist in neutral,
flexion, and extension were obtained for each specimen before implantation, after
distal radius hemiarthroplasty, and after combined hemiarthroplasty and PRC.
Results On the PA images, the capitate remained within 1.42 and 2.21 mm of its native radial-ulnar
position following hemiarthroplasty and hemiarthroplasty with PRC, respectively. Lateral
images showed the capitate remained within 1.06 mm of its native dorsal-volar position
following hemiarthroplasty and within 4.69 mm following hemiarthroplasty with PRC.
Following hemiarthroplasty, capitate alignment changed 2.33 and 2.59 mm compared with
its native longitudinal alignment on PA and lateral films, respectively. These changes
did not reach statistical significance. As expected, significant shortening in longitudinal
alignment was seen on both PA and lateral films for hemiarthroplasty with PRC.
Conclusion A distal radius implant hemiarthroplasty with or without a PRC provides good static
alignment of the wrist in a cadaver model and thus supports the concept as potential
treatment alternatives for advanced wrist arthritis; however, combined hemiarthroplasty
with a PRC has more clinical relevance because it avoids the risk of proximal carpal
row instability and eliminates the commonly arthritic radioscaphoid joint.
Keywords
wrist arthroplasty - wrist hemiarthroplasty - wrist replacement - distal radius arthroplasty
- distal radius replacement
