Original articleFit of current glenoid component designs: An anatomic cadaver study*,**
Introduction
Despite the improved longevity and performance of newer shoulder prostheses, the fixation of the glenoid component remains the greatest challenge in total shoulder arthroplasty.The literature indicates that glenoid loosening represents one third of all reported complications and is the most common indication for revision.4, 5, 7, 11, 12 The interaction between the underlying osseous support of the glenoid and the component's shape and size can affect fixation longevity.1–3 By increasing the surface contact between the glenoid component/cement and underlying cortical bone and minimizing the amount of component that is unsupported, load transfer can be improved and loosening forces reduced.6, 10, 13
The purpose of this study was to template actual cadaver glenoids with currently available prosthetic glenoid components in order to assess the degree of fit provided by these various component designs and sizes.
Section snippets
Materials and methods
Four hundred twelve skeletal scapulae that had intact glenoid surfaces were provided on loan from the American Museum of Natural History in New York. The scapulae were from individuals with a mean age of 58 years (range, 24–87 years); 89% were from men, and 11% were from women. The gross appearance of the glenoid surfaces was first qualified as pear-shaped or elliptical. The scapulae were placed in an articulated holder to position the glenoid at a set orientation and reproducible distance, and
Results
Of the 412 glenoids, 71% were classified as pear-shaped and 29% as elliptical. The mean maximum height was 37.9 mm (range, 31.2–50.1 mm; SD, 2.7 mm), and the mean maximum width was 29.3 mm (range, 22.6–41.5 mm; SD, 2.4 mm); the glenoids from women were approximately 10% smaller than those from men. Eighty-five percent of all measured glenoids ranged from 34 to 42 mm high and 24 to 32 mm wide. The mean height-to-width ratio was 1.3 (SD, 0.07), which is similar to findings in a previous study.2
Discussion
The poorest direction for optimal fit of all prostheses was directly superior. This was a result of the height-to-width ratios of the components. Because the various components had height-to-width ratios ranging from 1.3 to 1.6, compared with 1.3 for the glenoids themselves, fitting the components to match the glenoid width often created overhang in the height.
The relative component shapes also influenced fit. The more ovoid designs, such as the Biomodular, Cofield 2, Kirschner/Neer, and Global
References (14)
- et al.
Mechanical testing of shoulder prostheses and recommendations for glenoid design
J Shoulder Elbow Surg
(2000) - et al.
Glenoid loosening in total shoulder arthroplasty
J Arthroplasty
(1988) Glenohumeral translation after total shoulder arthroplasty
J Shoulder Elbow Surg
(1992)- et al.
Total shoulder arthroplasty with the Neer prosthesis: long-term results
J Shoulder Elbow Surg
(1997) - et al.
Total shoulder arthroplasty with the Neer prosthesis: Long-term results
J Shoulder and Elbow.
(1997) - et al.
An anthropometric evaluation of the glenoid: implications in the design and fixation of a shoulder prosthesis
- et al.
Edge displacement and deformation of glenoid components in response to eccentric loading
J Bone Joint Surg Am
(1992)
Cited by (37)
The study of 2-dimensional computed tomography scans of the glenoid anatomy in relation to reverse shoulder arthroplasty in the Southern Chinese population
2021, JSES InternationalCitation Excerpt :We compared our data with those reported in previous cadaveric and radiologic studies. Most of the studies, especially the earlier studies, were on Caucasian and African-American patients.2–4,6,7,9,12,21,25,27–30,41,43,47 Similar to these studies, we found most glenoids in our study were pear-shaped, whereas the remaining was elliptical.3,21,43
Functional Anatomy of the Shoulder?
2017, Orthopaedic Physical Therapy Secrets: Third EditionA glenoid reaming study: How accurate are current reaming techniques?
2014, Journal of Shoulder and Elbow SurgeryAddressing glenoid bone deficiency and asymmetric posterior erosion in shoulder arthroplasty
2013, Journal of Shoulder and Elbow SurgeryCitation Excerpt :Prosthetic design and surgical considerations related to glenoid anatomy are based on numerous studies focusing on the glenoid height, width, inclination, and version (Tables I and II).7,8,35,43,47
Effect of glenoid implant design on glenohumeral stability: An experimental study
2012, Clinical BiomechanicsCitation Excerpt :The eigenvectors of the matrix were then used to define the principal axes of the glenoid. Referring to the global shape of the glenoid (Checroun et al., 2002), the first axis (x-axis) corresponded to the anterior–posterior axis, the second axis (y-axis) was aligned to the inferior–superior axis and the third axis (z-axis) was normal to the X–Y plane. The center of the humeral head (GH) was projected on this at each increment of arm elevation.
The safe zone for avoiding suprascapular nerve injury during shoulder arthroscopy: An anatomical study on 500 dry scapulae
2011, Journal of Shoulder and Elbow SurgeryCitation Excerpt :Nevertheless, these findings demonstrate the great variability in the distances that can be found among the whole population. Previous studies analyzed the possible differences existing in the anatomy of the scapula in males and females;18,24 in particular, they focused on glenoid characteristics7,8,14,20 reporting conflicting results. Based on our findings, we support the idea that there are anatomical differences between the scapulae in males and females7,8,14,18,24; in particular, referring to the posterosuperior (E) and posterior (F) distances, we observed, respectively, an increase in the mean values of 0.31 cm and 0.03 cm in the males with respect to the females.
- *
Sponsored by a grant from the National Orthopaedic Surgery Fellows Foundation.
- **
Reprint requests: Fred J. Kummer, PhD, 301 E 17th St, New York, NY 10003 (E-mail: [email protected]).