Measuring ulnar variance: A comparison of techniques

Steyers, Curtis M.; Blair, W. Frank

doi:10.1016/0363-5023(89)90175-5

Cited by 194 publications

(125 citation statements)

References 16 publications

Supporting

Mentioning

111

Contrasting

Unclassified

Order By: Relevance

“…Ulnar variance describes the length of the ulna relative to the radius [4]. In the present study, the ulnar variance was assessed by the method of perpendiculars, which is a simple and reproducible method with good inter-and intraobserver reliability [12]. The interclass correlation coefficients demonstrated excellent interobserver and intraobserver reliability in our study.…”

Section: Discussionmentioning

confidence: 51%

See 1 more Smart Citation

Can Ulnar Variance Be Used to Detect Overstuffing After Radial Head Arthroplasty?

Moon

Hong

Bither

et al. 2013

Clin Orthop Relat Res

View full text Add to dashboard Cite

Background Overstuffing of the radiocapitellar joint during metallic radial head arthroplasty has been reported to cause loss of elbow flexion, capitellar erosion, and earlyonset 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.

show abstract

Section: Discussionmentioning

confidence: 51%

“…The ulnar variance, or relative positions of the distal radius and ulna, has been used to assess the radioulnar relationship in the wrist [4,12]. This parameter has been used not only for evaluation of wrist diseases such as Kienbock's disease, but also in surgical procedures to correct radial length.…”

Section: Introductionmentioning

confidence: 99%

Can Ulnar Variance Be Used to Detect Overstuffing After Radial Head Arthroplasty?

Moon

Hong

Bither

et al. 2013

Clin Orthop Relat Res

View full text Add to dashboard Cite

show abstract

“…1). Ulnar variance was measured as the distance between a line perpendicular to the longitudinal axis through the distal ulnar aspect of the radius and the distal cortical rim of the ulna [3,16]. In order to correct for angulation of the distal radius fragment, we had to adjust the perpendicular line through the distal ulnar aspect of the radius.…”

Section: Calibrated Measurementsmentioning

confidence: 99%

“…Steyers and colleagues compared various methods for measuring ulnar variance including the project-a-line technique, the method of concentric circles, and the method of perpendiculars and found that the method of perpendiculars was most reliable for both intraobserver and interobserver comparisons [16].…”

Section: Introductionmentioning

confidence: 99%

Measurement of Ulnar Variance on Uncalibrated Digital Radiographic Images

Vries

Souer

Zurakowski

et al. 2009

Hand (New York, N,Y.)

View full text Add to dashboard Cite

Uncalibrated digital radiographs used in multicenter trials hinder quantitative measures such as articular step and ulnar variance. This investigation tested the reliability of alternative measures of ulnar variance that are scaled to the length of the capitate. A sample of 30 sets of radiographs from patients enrolled in a prospective study of operative treatment of fractures of the distal radius were blinded and randomized. Five observers measured the ulnar variance (UV) and longitudinal length of the capitate (CH) on two separate occasions with greater than 2 weeks between measurements. During each measurement session, the observers made the measurements on both a calibrated and a noncalibrated workstation. The ratio of the ulnar variance to the length of capitate was calculated (UV/CH ratio). Paired t tests were used to compare two rounds of measurements for both methods. Intra-and interobserver reliability was assessed by the Pearson product-moment correlation coefficients. The ratios were compared using analysis of variance with a Bonferroni correction. The intraobserver reliability was excellent for each of the three variables (UV, CH, UV/CH ratio) for each workstation. The interobserver reliability of the UV/CH ratios obtained for each workstation was moderate to excellent as judged by the Pearson correlations between observers. The BlandAltman method indicated a mean difference in UV/CH between calibrated and uncalibrated measurement techniques of 0.002 with limits of agreement of −0.11 to 0.11. Measurements of ulnar variance that are scaled to the length of the capitate may be useful measures of deformity in studies that utilize uncalibrated digital radiographs.

show abstract

“…We used the following criteria, for good radiocarpal alignment which were con- Relative ulnar length (mm) 4 ( 3) 1 (2) 3 (2) a volar dislocation sidered to be physiological: a radiocarpal angle between 10" volarly or 10" dorsally, a radial inclination of 20"-30", and an ulnar variance of -2 to +3 mm (Friberg andLundstrom 1976, Steyers andBlair 1989). If at least 1 of the 3 radiological parameters was not in the physiological range, the result was considered a malunion.…”

Section: Radiographic Assessmentmentioning

confidence: 99%