Vet Comp Orthop Traumatol 2020; 33(06): 417-427
DOI: 10.1055/s-0040-1715476
Original Research

Radiographic and Biomechanical Assessment of Three Implant Designs for Canine Cementless Total Hip Replacement

1  Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
,
Kristian J. Ash
1  Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
,
2  Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York, United States
,
Mark A. Miller
2  Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York, United States
,
Kenneth A. Mann
2  Department of Orthopedic Surgery, SUNY Upstate Medical University, Syracuse, New York, United States
,
Gretchen M. VanDeventer
1  Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
,
Dominick M. Valenzano
1  Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
,
Robert Hart
3  Department of Orthopedic Surgery, Animal Medical Center, New York, New York, United States
,
Mitsunori Kayano
4  Department of Veterinary Medicine, Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan
,
Kei Hayashi
1  Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, United States
› Author Affiliations
Funding None.

Abstract

Objective The aim of this study was to evaluate the relationship between radiographic fit/fill measurements and biomechanical performance of three canine cementless total hip implant designs using an in vitro biomechanical testing protocol that replicates compression and torsion.

Study Design Eighteen (six/group) canine cadaveric femurs were implanted with one of three cementless total hip implant designs: (1) collarless, (2) collared or (3) lateral bolt stems. Femoral length, canal flare index (CFI), canal fill, stem fit, stem level and stem angle were measured as independent variables. Biomechanical performance was tested using physiological, non-destructive gait loading (loading protocols) and destructive testing (failure protocols).

Results During loading protocols, compressive stiffness was influenced by stem level (p < 0.05) and torsional stiffness was influenced by stem level and CFI for collarless stems (p < 0.05). During failure protocols, peak load was influenced by mediolateral (ML) stem angle (p < 0.05) and CFI (p < 0.01) for collarless stems and CFI for lateral bolt stems (p < 0.05). Peak torque was influenced by ML stem angle, craniocaudal stem angle and CFI for collarless stems (p < 0.05) and average ML fill for collared stems (p < 0.05).

Conclusion Biomechanical performance of collarless stems in cementless hip arthroplasty is more impacted by radiographic fit/fill than lateral bolt and collared stems. As a result, collarless stems may be more dependent on preoperative fit and intraoperative precision.

Author Contribution

N.J.W. and K.J.A. contributed to conception of study, study design, data acquisition, data analysis, interpretation of results and drafting of the submitted manuscript. N.R.O. and M.A.M. contributed to conception of study, study design and the acquisition, analysis and interpretation of biomechanical data. K.A.M. contributed to the conception, design and analysis and interpretation of data for biomechanical testing. G.M.V. and R.H. contributed to conception of study and implantation of stems. K.J.A. contributed to implantation of stems. D.M.V. contributed to study design and interpretation of data. M.K. contributed to analysis and interpretation of data. K.H. contributed to conception of study, study design and interpretation of data. All authors revised and approved the submitted manuscript.




Publication History

Received: 07 November 2019

Accepted: 23 June 2020

Publication Date:
24 September 2020 (online)

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