Morphometric feature description of the proximal ulna based on quantitative measurement: a key consideration for implant design

Abstract

Purpose To perform quantitative measurements of the anatomic morphology of the proximal ulna and establish the morphologic references based on Chinese for the surgical protocol and implant design. Methods The computed tomography data of 156 upper extremities were involved in this study. The ulna model was reconstructed in Mimics. Ten distance and 6 angle parameters were measured by 4 independent investigators with a new quantitative measurement method. The intraclass correlation coefficient was used to evaluate the measuring reliability. Gender and side differences of measured parameters were evaluated. Results Measurements showed a mean coronoid height of 15 mm, which was 42% of ulnar height with gender-specific differences (mean 16 mm in men and 14 mm in women, P < 0.001). A mean unsupported anteromedial facet width of 8 mm was 61% of the coronoid anteromedial facet. A larger opening angle correlates to a larger olecranon-diaphysis angle (P < 0.001) and larger coronoid height (P = 0.001). A mean proximal ulna dorsal angulation of 4.7° is present in 80% of models at an average of 52 mm distal to olecranon tip. The average proximal ulna varus angulation was 16° at a mean of 74 mm distal to the olecranon tip. Morphological features between the left and right sides were highly consistent. The ICC was between 0.789 and 0.978 for inter-observer and between 0.696 and 0.997 for intra-observer reliability. Conclusions The proximal ulna features variable morphology but minor side differences among individuals. Over half of the anteromedial facet was not supported by the proximal ulnar diaphysis, making the coronoid vulnerable to elbow trauma. Preconditioning or customized design of the ulnar plate in the clinical setting with the help of contralateral morphology may be a good choice.

Proximal ulna morphology in various pediatric population age groups: proximal ulna dorsal angulation (PUDA) and olecranon tip-to-apex (TTA) distance

“…As to TTA, mean value in age groups 0–10 years old (mean TTA 22.04 mm) and 11–14 years old (mean TTA 37.41 mm), were lower than in adults. On the other hand, in age group 15–18 years old mean TTA was 43.79 mm, comparable with values reported by Rouleau et al − 47 mm, Chapleau et al − 47 mm, Wang et al − 52 mm and Totlis et al − 86.3 mm [ 2 , 15 , 22 , 24 , 25 ].…”

“…As to TTA, in this study it was higher in males in all age subgroups, however, statistical significance was not reached. In studies of Totlis et al Wang et al and Rouleau et al, TTA was reported to be bigger in males, while Chapleau et al did not report TTA values for gender subgroups [ 2 , 15 , 22 , 24 , 25 ]. Many other characteristics of proximal ulna morphology were shown to be sex-dependent, for example length between the tip of olecranon and edge point (“height” of olecranon), varus angulation and olecranon length [ 12 , 22 ].…”

“…Authors commented on this suggesting that such result could be related to the fact that all included patients were prepubescent children [ 6 ]. In the literature concerning adult proximal ulna morphology, in the papers of Totlis et al Wang et al and Puchwein et al there were no gender-associated differences of PUDA [ 12 , 22 , 24 , 25 ]. Rouleau et al reported no significant difference in PUDA between genders on the right side, however, on the left side PUDA was bigger in males (4.6 degrees for females vs 6.6 degrees for males) [ 15 ].…”

Derotational distal femoral osteotomy improves subjective function and patellar tracking after medial patellofemoral ligament reconstruction in recurrent patellar dislocation patients with increased femoral anteversion: A systematic review and meta‐analysis

“…When disagreement occurred, a third senior orthopaedic surgeon was consulted for final consensus. The intraclass correlation coefficient was calculated in SPSS software (version 26.0, IBM) and was used to evaluate the reliability of the publication bias assessment [15].…”

Recurrent patellar dislocation patients with high‐grade J‐sign have multiple structural bone abnormalities in the lower limbs

“…The intraclass correlation coefficient (ICC) was calculated to assess the reliability of the measuring method adopted in this study. The PASS 15.0 (NCSS LLC) was applied to calculate the sample size for intraclass correlation analysis [2,23]. With approximately 90% certainty, it was found that a stable coefficient of consistency could be obtained with just 14 samples when three measurers independently measured the same set of parameters using the same method.…”