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Archives of Orthopaedic and Trauma Surgery

, Volume 139, Issue 8, pp 1069–1074 | Cite as

The influence of screw length on predicted cut-out failures for proximal humeral fracture fixations predicted by finite element simulations

  • James W. A. Fletcher
  • Markus Windolf
  • Leonard Grünwald
  • R. Geoff Richards
  • Boyko Gueorguiev
  • Peter VargaEmail author
Trauma Surgery

Abstract

Background

The aim of this study was to identify the effect of screw length on predictions of fixation failure in three-part proximal humeral fractures using a finite element-based osteosynthesis modelling toolkit.

Methods

A mal-reduced unstable three-part AO/OTA 11-B3.2 fracture with medial comminution was simulated in forty-two digitally processed proximal humeri covering a spectrum of bone densities and fixed with the PHILOS plate using three distal and six proximal locking screws. Four test groups were generated based on the screw tip to joint surface distance (TJD), with all proximal screws being shortened from 4 mm TJD to be 8, 12 or 16 mm TJD. Average bone strains around the screw tips, correlating with biomechanical cyclic cut-out-type failure, were evaluated in three physiological loading protocols representing simple shoulder motions. Six further groups were tested, where five of the proximal screws were inserted to 4 mm TJD and the sixth screw to 8 mm TJD.

Results

Exponential increases in the predicted risk of fixation failure were seen with increased tip-to-joint distances (p < 0.001). When one of the proximal screws was placed 8 mm from the joint, with the remaining five at 4 mm distance, significant increases (p < 0.001) were registered in the strains around the screw tips in all except the two superior screws. This effect was maximal around the calcar screws (p < 0.001) and for lower density samples (p < 0.001).

Conclusions

These results suggest that longer screws provide reduced risk of cut-out failure, i.e. distalisation and/or varisation of the head fragment, and thus may decrease failure rates in proximal humeral fractures treated with angular stable plates. These findings require clinical corroboration and further studies to investigate the risk of screw perforation.

Keywords

Proximal humerus fracture Locking plate fixation PHILOS plate Fixation failure Screw length Finite element analysis 

Notes

Funding

This study was performed with the assistance of the AO Foundation via the AOTRAUMA Network (Grant No.: AR2013_01).

Compliance with ethical standards

Conflict of interest

The authors are not compensated and there are no other institutional subsidies, corporate affiliations, or funding sources supporting this work unless clearly documented and disclosed.

References

  1. 1.
    Brunner F, Sommer C, Bahrs C et al (2009) Open reduction and internal fixation of proximal humerus fractures using a proximal humeral locked plate: a prospective multicenter analysis. J Orthop Trauma 23(3):163–172CrossRefGoogle Scholar
  2. 2.
    Gupta AK, Harris JD, Erickson BJ et al (2015) Surgical management of complex proximal humerus fractures—a systematic review of 92 studies including 4500 patients. J Orthop Trauma 29(1):54–59CrossRefGoogle Scholar
  3. 3.
    Schnetzke M, Bockmeyer J, Porschke F, Studier-Fischer S, Grützner P-A, Guehring T (2016) Quality of reduction influences outcome after locked-plate fixation of proximal humeral type-C fractures. JBJS 98(21):1777–1785CrossRefGoogle Scholar
  4. 4.
    Sproul RC, Iyengar JJ, Devcic Z, Feeley BT (2011) A systematic review of locking plate fixation of proximal humerus fractures. Injury 42(4):408–413CrossRefGoogle Scholar
  5. 5.
    Beeres FJP, Hallensleben NDL, Rhemrev SJ, Goslings JC, Oehme F, Meylaerts SAG, Babst R, Schep NWL (2017) Plate fixation of the proximal humerus: an international multicentre comparative study of postoperative complications. Arch Orthop Trauma Surg 137(12):1685–1692CrossRefGoogle Scholar
  6. 6.
    Jabran A, Peach C, Ren L (2018) Biomechanical analysis of plate systems for proximal humerus fractures: a systematic literature review. Biomed Eng Online 17(1):47CrossRefGoogle Scholar
  7. 7.
    Gardner MJ, Weil Y, Barker JU, Kelly BT, Helfet DL, Lorich DG (2007) The importance of medial support in locked plating of proximal humerus fractures. J Orthop Trauma 21(3):185–191CrossRefGoogle Scholar
  8. 8.
    Krappinger D, Bizzotto N, Riedmann S, Kammerlander C, Hengg C, Kralinger FS (2011) Predicting failure after surgical fixation of proximal humerus fractures. Injury 42(11):1283–1288CrossRefGoogle Scholar
  9. 9.
    Kamer L, Noser H, Popp AW, Lenz M, Blauth M (2016) Computational anatomy of the proximal humerus: an ex vivo high-resolution peripheral quantitative computed tomography study. J Orthop Transl 4:46–56Google Scholar
  10. 10.
    Liew ASL, Johnson JA, Patterson SD, King GJW, Chess DG (2000) Effect of screw placement on fixation in the humeral head. J Shoulder Elb Surg 9(5):423–426CrossRefGoogle Scholar
  11. 11.
    Varga P, Grünwald L, Inzana JA, Windolf M (2017) Fatigue failure of plated osteoporotic proximal humerus fractures is predicted by the strain around the proximal screws. J Mech Behav Biomed Mater 75:68–74CrossRefGoogle Scholar
  12. 12.
    Varga P, Inzana JA, Gueorguiev B, Sudkamp NP, Windolf M (2018) Validated computational framework for efficient systematic evaluation of osteoporotic fracture fixation in the proximal humerus. Med Eng Phys 57:29–39CrossRefGoogle Scholar
  13. 13.
    Krappinger D, Roth T, Gschwentner M et al (2012) Preoperative assessment of the cancellous bone mineral density of the proximal humerus using CT data. Skelet Radiol 41(3):299–304CrossRefGoogle Scholar
  14. 14.
    DePuy Synthes Trauma (2016) PHILOS and PHILOS Long. Surgical techniqueGoogle Scholar
  15. 15.
    Varga P, Inzana JA, Gueorguiev B, Suedkamp NP, Windolf M (2018) Validated computational framework for efficient systematic evaluation of osteoporotic fracture fixation in the proximal humerus. Med Eng Phys 57:29–39CrossRefGoogle Scholar
  16. 16.
    Bergmann G, Graichen F, Bender A et al (2011) In vivo gleno-humeral joint loads during forward flexion and abduction. J Biomech 44(8):1543–1552CrossRefGoogle Scholar
  17. 17.
    Westerhoff P, Graichen F, Bender A et al (2009) In vivo measurement of shoulder joint loads during activities of daily living. J Biomech 42(12):1840–1849CrossRefGoogle Scholar
  18. 18.
    R (2013) A language and environment for statistical computing. R Foundation for Statistical Computing R: a language and environment for statistical computing. (eds) R Foundation for Statistical Computing. R Core Team, ViennaGoogle Scholar
  19. 19.
    Ponce BA, Thompson KJ, Raghava P et al (2013) The role of medial comminution and calcar restoration in varus collapse of proximal humeral fractures treated with locking plates. JBJS 95(16):e113CrossRefGoogle Scholar
  20. 20.
    Jung W-B, Moon E-S, Kim S-K, Kovacevic D, Kim M-S (2013) Does medial support decrease major complications of unstable proximal humerus fractures treated with locking plate? BMC Musculoskelet Disord 14(1):102CrossRefGoogle Scholar
  21. 21.
    Rangan A, Handoll H, Brealey S et al (2015) Surgical vs nonsurgical treatment of adults with displaced fractures of the proximal humerus: the PROFHER randomized clinical trial. JAMA 313(10):1037–1047CrossRefGoogle Scholar
  22. 22.
    Simpson AHRW, Howie CR, Norrie J (2017) Surgical trial design—learning curve and surgeon volume. Bone Jt Res 6(4):194–195CrossRefGoogle Scholar
  23. 23.
    Padegimas EM, Zmistowski B, Lawrence C, Palmquist A, Nicholson TA, Namdari S (2017) Defining optimal calcar screw positioning in proximal humerus fracture fixation. J Shoulder Elb Surg 26(11):1931–1937CrossRefGoogle Scholar
  24. 24.
    McMillan TE, Johnstone AJ (2018) Primary screw perforation or subsequent screw cut-out following proximal humerus fracture fixation using locking plates: a review of causative factors and proposed solutions. Int Orthop 42(8):1935–1942CrossRefGoogle Scholar
  25. 25.
    Knierzinger D, Buschbaum J, Konschake M, Richards RG, Blauth M, Windolf M (2017) Ex-vivo evaluation of a novel system for implant positioning assistance at the proximal humerus using angular stable plates. Kongress Deutsche Gesellschaft für Biomechanik, HannoverGoogle Scholar
  26. 26.
    Zysset PK, Dall’ara E, Varga P, Pahr DH (2013) Finite element analysis for prediction of bone strength. BoneKEy Rep 2:386CrossRefGoogle Scholar
  27. 27.
    Synek A, Chevalier Y, Baumbach SF, Pahr DH (2015) The influence of bone density and anisotropy in finite element models of distal radius fracture osteosynthesis: evaluations and comparison to experiments. J Biomech 48(15):4116–4123CrossRefGoogle Scholar
  28. 28.
    Chen YN, Chang CW, Lin CW et al (2017) Numerical investigation of fracture impaction in proximal humeral fracture fixation with locking plate and intramedullary nail. Int Orthop 41(7):1471–1480CrossRefGoogle Scholar
  29. 29.
    Kennedy J, Feerick E, McGarry P, FitzPatrick D, Mullett H (2013) Effect of calcium triphosphate cement on proximal humeral fracture osteosynthesis: a finite element analysis. J Orthop Surg 21(2):167–172CrossRefGoogle Scholar
  30. 30.
    Yang P, Zhang Y, Liu J, Xiao J, Ma LM, Zhu CR (2015) Biomechanical effect of medial cortical support and medial screw support on locking plate fixation in proximal humeral fractures with a medial gap: a finite element analysis. Acta Orthop Traumatol Turc 49:203–209Google Scholar
  31. 31.
    Diederichs G, Korner J, Goldhahn J, Linke B (2006) Assessment of bone quality in the proximal humerus by measurement of the contralateral site: a cadaveric analyze. Arch Orthop Trauma Surg 126(2):93–100CrossRefGoogle Scholar
  32. 32.
    Kathrein S, Kralinger F, Blauth M, Schmoelz W (2013) Biomechanical comparison of an angular stable plate with augmented and non-augmented screws in a newly developed shoulder test bench. Clin Biomech 28:273–277CrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  1. 1.AO Research Institute DavosDavosSwitzerland
  2. 2.Department for HealthUniversity of BathBathUK
  3. 3.Department of Traumatology and Orthopedic SurgeryKlinikum EsslingenEsslingenGermany

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