Tibial Nonunions Clinical Presentation

Updated: Oct 17, 2018
  • Author: Minoo Patel, MBBS, PhD, MS, FRACS; Chief Editor: Thomas M DeBerardino, MD  more...
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Presentation

Classification

The Weber-Cech classification is the one most widely used for tibial nonunions. [13]  In this system, fractures are classified according to radiographic appearance, which correlates with the fracture biology, as follows:

  • Hypertrophic nonunions - These are tibial nonunions that show prolific callus formation; they are vascular and have excellent healing potential, given the right environment; these nonunions result from inadequate immobilization of the fracture
  • Atrophic nonunions - These are characterized by an absence of callus and atrophic bone ends, which may be tapered and osteopenic or sclerotic; bone vascularity is deficient, and the bone has poor healing potential; a special subgroup of atrophic nonunions consists of those that form a fibrous capsule around a freely mobile nonunion; this cavity is filled with a viscous fluid, creating the appearance of a joint, and is referred to as a tibial pseudarthrosis
  • Normotrophic nonunions - These are nonunions that share the characteristics of both atrophic and hypertrophic nonunions; the bone ends have moderate healing potential

Determining whether evidence of infection is present at the nonunion site is critical.

Paley and Herzenberg classified nonunions into three categories according to clinical mobility, as follows:

  • Stiff (< 5º mobility)
  • Partially mobile (5-20º mobility)
  • Flail (>20º mobility)

The Paley-Herzenberg categories are roughly correlated with the three Weber-Cech categories.

Congenital pseudarthrosis of the tibia is a unique condition observed in children. [14, 15, 16]  Neurofibromatosis and fibrous dysplasia are predisposing factors, though some congenital tibial pseudarthroses are idiopathic. The pathology seems to lie in the periosteum.