J Wrist Surg 2017; 06(04): 307-315
DOI: 10.1055/s-0037-1602849
Scientific Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Microstructure of the Distal Radius and Its Relevance to Distal Radius Fractures

Gregory Ian Bain
1   Department of Orthopaedic Surgery, Flinders University, Adelaide, South Australia, Australia
,
Simon Bruce Murdoch MacLean
1   Department of Orthopaedic Surgery, Flinders University, Adelaide, South Australia, Australia
,
Tom McNaughton
2   School of Medicine, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
,
Ruth Williams
3   Adelaide Microscopy, Medical School, The University of Adelaide, Adelaide, South Australia, Australia
› Author Affiliations
Further Information

Publication History

15 June 2016

07 April 2017

Publication Date:
10 May 2017 (online)

Abstract

Background There is a paucity of information on the microstructure of the distal radius, and how this relates to its morphology and function.

Purpose This study aims to assess the microanatomical structure of the distal radius, and relate this to its morphology, function, and modes of failure.

Methods Six dry adult skeletal distal radii were examined with microcomputed tomography scan and analyzed with specialist computer software. From 3D and 2D images, the subchondral, cortical, and medullary trabecular were assessed and interpreted based on the overall morphology of the radius.

Results The expanded distal radial metaphysis provides a wide articular surface for distributing the articular load. The extrinsic wrist ligaments are positioned around the articular perimeter, except on the dorsal radial corner. The subchondral bone plate is a 2 mm multilaminar lattice structure, which is thicker below the areas of the maximal articular load. There are spherical voids distally, which become ovoid proximally, which assist in absorbing articular impact. It does not have Haversian canals. From the volar aspect of the lunate facet, there are thick trabecular columns that insert into the volar cortex of the radius at the metaphyseal–diaphyseal junction. For the remainder of the subchondral bone plate, there is an intermediate trabecular network, which transmits the load to the intermediate trabeculae and then to the trabecular arches. The arches pass proximally and coalesce with the ridges of the diaphyseal cortex.

Conclusion The distal radius morphology is similar to an arch bridge. The subchondral bone plate resembles the smooth deck of the bridge that interacts with the mobile load. The load is transmitted to the rim, intermediate struts, and arches. The metaphyseal arches allow the joint loading forces to be transmitted proximally and laterally, providing compression at all levels and avoiding tension. The arches have a natural ability to absorb the impact which protects the articular surface. The distal radius absorbs and transmits the articular impact to the medullary cortex and intermediate trabeculae. The medullary arches are positioned to transmit the load from the intermediate trabeculae to the diaphysis.

Clinical Relevance The microstructure of the distal radius is likely to be important for physiological loading of the radius. The subchondral bone plate is a unique structure that is different to the cancellous and cortical bone. All three bone types have different functions. The unique morphology and microstructure of the distal radius allow it to transmit load and protect the articular cartilage.

 
  • References

  • 1 Marble HC. History of hand surgery. In: Flynn JE. , ed. Hand Surgery. Baltimore, MD: Williams & Wilkins; 1966: 1-10
  • 2 Chappard C. Microarchitecture assessment of human trabecular bone: description of methods [in French]. 2012; 28 (12) 1111-1115
  • 3 Singh M, Nagrath AR, Maini PS. Changes in trabecular pattern of the upper end of the femur as an index of osteoporosis. J Bone Joint Surg Am 1970; 52 (03) 457-467
  • 4 Currey J. Bones: Structure and Mechanics. Princeton, NJ: Princeton University Press; 2002
  • 5 Currey JD. Bone architecture and fracture. Curr Osteoporos Rep 2005; 3 (02) 52-56
  • 6 Currey JD. How well are bones designed to resist fracture?. J Bone Miner Res 2003; 18 (04) 591-598
  • 7 Melone Jr CP. Distal radius fractures: patterns of articular fragmentation. Orthop Clin North Am 1993; 24 (02) 239-253
  • 8 Mandziak DG, Watts AC, Bain GI. Ligament contribution to patterns of articular fractures of the distal radius. J Hand Surg Am 2011; 36 (10) 1621-1625
  • 9 Bain GI, Alexander JJ, Eng K, Durrant A, Zumstein MA. Ligament origins are preserved in distal radial intraarticular two-part fractures: a computed tomography-based study. J Wrist Surg 2013; 2 (03) 255-262
  • 10 Zumstein MA, Hasan AP, McGuire DT, Eng K, Bain GI. Distal radius attachments of the radiocarpal ligaments: an anatomical study. J Wrist Surg 2013; 2 (04) 346-350
  • 11 Francis A. Introducing Structures: A Textbook for Students of Civil and Structural Engineering, Building, and Architecture. Oxford, United Kingdom: Pergamon Press; 1980
  • 12 Andermahr J, Lozano-Calderon S, Trafton T, Crisco JJ, Ring D. The volar extension of the lunate facet of the distal radius: a quantitative anatomic study. J Hand Surg Am 2006; 31 (06) 892-895
  • 13 Kinney JH, Ladd AJ. The relationship between three-dimensional connectivity and the elastic properties of trabecular bone. J Bone Miner Res 1998; 13 (05) 839-845
  • 14 Troy KL, Grabiner MD. Off-axis loads cause failure of the distal radius at lower magnitudes than axial loads: a finite element analysis. J Biomech 2007; 40 (08) 1670-1675
  • 15 Ural A. Prediction of Colles' fracture load in human radius using cohesive finite element modeling. J Biomech 2009; 42 (01) 22-28
  • 16 Nalla RK, Stölken JS, Kinney JH, Ritchie RO. Fracture in human cortical bone: local fracture criteria and toughening mechanisms. J Biomech 2005; 38 (07) 1517-1525
  • 17 Roth L. Understanding Architecture: Its Elements, History, and Meaning. Boulder, CO: Westview Press; 2007
  • 18 Lewis R. Colles fracture-causative mechanism. Surgery 1950; 27 (03) 427-436
  • 19 Nalla RK, Kinney JH, Ritchie RO. Mechanistic fracture criteria for the failure of human cortical bone. Nat Mater 2003; 2 (03) 164-168
  • 20 Bala Y, Bui QM, Wang X-F. , et al. Trabecular and cortical microstructure and fragility of the distal radius in women. J Bone Miner Res 2015; 30 (04) 621-629
  • 21 Nilsson M, Ohlsson C, Sundh D, Mellström D, Lorentzon M. Association of physical activity with trabecular microstructure and cortical bone at distal tibia and radius in young adult men. J Clin Endocrinol Metab 2010; 95 (06) 2917-2926
  • 22 Greenspan SL, Perera S, Recker R. , et al. Changes in trabecular microarchitecture in postmenopausal women on bisphosphonate therapy. Bone 2010; 46 (04) 1006-1010
  • 23 Lochmüller E-M, Kristin J, Matsuura M. , et al. Measurement of trabecular bone microstructure does not improve prediction of mechanical failure loads at the distal radius compared with bone mass alone. Calcif Tissue Int 2008; 83 (04) 293-299