TY - JOUR
T1 - Can ulnar variance be used to detect overstuffing after radial head arthroplasty?
AU - Moon, Jun Gyu
AU - Hong, Jin Ho
AU - Bither, Nitin
AU - Shon, Won Yong
PY - 2014/2
Y1 - 2014/2
N2 - Background: Overstuffing of the radiocapitellar joint during metallic radial head arthroplasty has been reported to cause loss of elbow flexion, capitellar erosion, and early-onset osteoarthritis. Although this is known, there is no agreed-on measurement approach to determine whether overstuffing has occurred. Questions/purposes: We therefore hypothesized that overlengthening the radial head during radial head arthroplasty changes the ulnar variance in the wrist. Methods: Seven cadaveric radii were implanted with radial head prostheses of increasing thickness. Each specimen was implanted successively with increasingly thick radial head prostheses measuring 2, 4, and 6 mm thicker than the native radial head, and radiographs were taken after implantation of each prosthesis. The ulnar variance with each prosthesis was measured using the method of perpendiculars. Results: The ulnar variance of the native and 2-mm (p = 0.04), 4-mm (p = 0.008), and 6-mm (p = 0.008) overly thick radial head prosthesis-implanted states decreased significantly with each incremental increase in prosthetic head thickness. Conclusions: Implantation of thicker radial head prostheses decreased the ulnar variance. Our results indicate ulnar variance could be used to detect overstuffing of radial head prostheses. Clinical Relevance: The simplicity and reliability of ulnar variance make it a potentially useful indicator of overlengthening after radial head arthroplasty.
AB - Background: Overstuffing of the radiocapitellar joint during metallic radial head arthroplasty has been reported to cause loss of elbow flexion, capitellar erosion, and early-onset osteoarthritis. Although this is known, there is no agreed-on measurement approach to determine whether overstuffing has occurred. Questions/purposes: We therefore hypothesized that overlengthening the radial head during radial head arthroplasty changes the ulnar variance in the wrist. Methods: Seven cadaveric radii were implanted with radial head prostheses of increasing thickness. Each specimen was implanted successively with increasingly thick radial head prostheses measuring 2, 4, and 6 mm thicker than the native radial head, and radiographs were taken after implantation of each prosthesis. The ulnar variance with each prosthesis was measured using the method of perpendiculars. Results: The ulnar variance of the native and 2-mm (p = 0.04), 4-mm (p = 0.008), and 6-mm (p = 0.008) overly thick radial head prosthesis-implanted states decreased significantly with each incremental increase in prosthetic head thickness. Conclusions: Implantation of thicker radial head prostheses decreased the ulnar variance. Our results indicate ulnar variance could be used to detect overstuffing of radial head prostheses. Clinical Relevance: The simplicity and reliability of ulnar variance make it a potentially useful indicator of overlengthening after radial head arthroplasty.
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U2 - 10.1007/s11999-013-3277-z
DO - 10.1007/s11999-013-3277-z
M3 - Article
C2 - 24030626
AN - SCOPUS:84893680549
VL - 472
SP - 727
EP - 731
JO - Clinical Orthopaedics and Related Research
JF - Clinical Orthopaedics and Related Research
SN - 0009-921X
IS - 2
ER -