High Yield Topics

Nonunion of Fractures

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Ovid: 5-Minute Orthopaedic Consult

Editors: Frassica, Frank J.; Sponseller, Paul D.; Wilckens, John H.
Title: 5-Minute Orthopaedic Consult, 2nd Edition
> Table of Contents > Nonunion of Fractures

Nonunion of Fractures
Simon C. Mears MD, PhD
Melanie Kinchen MD
Basics
Description
  • Presence of a postfracture defect in a
    long bone beyond a reasonable expected healing date, or if no
    radiographic progression of healing is noted
  • If internal fixation is used to stabilize a fracture, a race exists between fracture healing and hardware failure.
  • Children, because of their active healing
    potential, rarely develop a nonunion unless other predisposing
    conditions are present (1).
  • Classification (2):
    • Atrophic nonunion:
      • Often poor blood supply
      • When visualized on radiographs, often show poor bone quality with tapered edges
      • Often occur in osteoporotic bone
    • Hypertrophic nonunions:
      • Good blood supply
      • Most go on to heal if adequate stabilization can be achieved.
Epidemiology
Incidence
  • The incidence depends on the fracture type.
    • 13% of tibial fractures (3)
    • 4–11% of clavicle fractures, depending on location (4)
    • Tibial shaft, femoral neck, and scaphoid
      fractures are at high risk for nonunion because they have a more
      tenuous blood supply than other bones, which often is damaged with the
      injury.
Risk Factors
  • Poor nutritional status
  • Poor bone quantity and quality
  • Suppressed immune system
  • Presence of bone infection may contribute to development of a nonunion.
  • Smoking (5)
  • Poor soft-tissue envelope
  • Vascular compromise
  • NSAID use
  • Open fractures
  • Poor fracture reduction
  • Distal tibia fractures
Etiology
  • Injury-related causes include segmental bone loss, extensive soft-tissue damage, and loss of adequate blood supply.
  • Treatment-related factors include quality of reduction, amount of distraction, and length of immobilization.
  • Inadequate fracture stabilization is a common cause of fracture nonunion.
Diagnosis
Signs and Symptoms
History
  • Patients have a history of a fracture that continues to be painful.
  • The patient may have broken hardware.
  • Pain often occurs after use of the limb.
Physical Exam
  • Patients have continued tenderness at the fracture site.
  • Motion of the bony fragments may or may not be evident.
Tests
Imaging
  • Radiography:
    • Plain AP and lateral radiographs, to determine the presence of callus formation
    • Serial radiographs, to ensure callus progression
  • CT:
    • Excellent at revealing nonunion
    • In many fractures, the fracture plane is difficult to see on plain radiographs because of overlap of the bone fragments.
  • Bone scans, to help determine whether
    increased blood flow and subsequently increased bone turnover is
    present at the fracture site
  • MRI is useful when hardware is not present.
Pathological Findings
  • Thick fibrous tissue with areas of uncalcified callus formation
  • A synovial pseudarthrosis or false joint may develop with excessive motion.
Differential Diagnosis
  • Delayed union, characterized by some
    tenderness and motion at the fracture site with variable amounts of
    callus present after a period in which most fractures would be healed
    clinically
  • Painful hardware
  • Posttraumatic arthritis
Treatment
General Measures
  • Most nonunions are treated with surgical intervention.
  • Aggressive treatment of delayed union can help prevent nonunion and hardware breakage.
  • Nonoperative interventions:
    • Bone stimulators (electrical or ultrasound)
    • Smoking cessation
    • Discontinuation of NSAIDs
    • Use of weightbearing casts or functional braces
Surgery
  • Surgical treatment of nonunions is
    determined by type of host, soft-tissue coverage, precise location of
    the nonunion, type of nonunion, and previous fracture treatment.
  • Patients with severe medical compromise, poor soft-tissue coverage, or poor vascular supply may be candidates for amputation.
  • Hypertrophic nonunion should be treated
    with rigid fixation of the nonunion, which may require revision of the
    internal fixation.
  • Nonunion of long-bone fractures with intramedullary nails may be treated with nail dynamization or exchange nailing.
    • Reaming the canal provides local bone graft and allows for placement of a larger diameter nail (6).
  • Bypass or wave plating allows for fixation and bone grafting (7).
  • For tibial nonunions, bracing may be combined with fibular osteotomy (8).
  • Well-stabilized atrophic nonunions are treated with bone grafting.
    • Bone graft may be autograft, allograft, or synthetic.
    • The fracture nonunion should be exposed and curetted, and the bone ends should be burred back to bleeding, viable bone.
    • Bone graft material then is packed into the nonunion.

      • P.277


    • The use of bone morphogenic protein 2 recently has been approved for tibial nonunion treatment (9).
    • The optimal bone graft material or bone morphogenic protein is unknown.
      • Factors to consider with the use of
        autograft include the need for a 2nd incision and the relative quality
        of the patient’s bone.
      • Some patients may not want to have a 2nd incision with its risk of pain or infection (10).
  • Femoral neck nonunions may be treated with realignment osteotomy or joint replacement.
  • Infected nonunion:
    • Treatment is challenging and requires
      débridement of the infection, fracture stabilization, removal of dead
      space, and soft-tissue coverage.
    • Plastic surgery reconstruction may be necessary, and multiple surgeries often are necessary (11).
  • Large bone defects may be managed with bone transport via an external fixation and the Ilizarov method (12).
Follow-up
Prognosis
  • 90% of nonunions are treated successfully with 1 surgery (13).
  • In 80% of nonunions, limb length and alignment are restored (13).
  • If infection is present, often >1 surgery is required.
Complications
  • Infection and osteomyelitis
  • Hardware failure
  • Continued nonunion
  • Pain
  • Malunion
  • Joint stiffness
  • Pain and infection at the bone graft donor site
Patient Monitoring
Serial radiographs are obtained once a month, to assess the development of callus.
References
1. Arslan H, Subasy M, Kesemenli C, et al. Occurrence and treatment of nonunion in long bone fractures in children. Arch Orthop Trauma Surg 2002;122:494–498.
2. McKee
MD. Aseptic non-union. In: Ruedi TP, Murphy WM, eds. AO Principles of
Fracture Management. New York: Thieme, 2000: 749–762.
3. Audige
L, Griffin D, Bhandari M, et al. Path analysis of factors for delayed
healing and nonunion in 416 operatively treated tibial shaft fractures.
Clin Orthop Relat Res 2005;438: 221–232.
4. Robinson
CM, Court-Brown CM, McQueen MM, et al. Estimating the risk of nonunion
following nonoperative treatment of a clavicular fracture. J Bone Joint Surg 2004;86A:1359–1365.
5. Adams CI, Keating JF, Court-Brown CM. Cigarette smoking and open tibial fractures. Injury 2001;32:61–65.
6. Pihlajamaki
HK, Salminen ST, Bostman OM. The treatment of nonunions following
intramedullary nailing of femoral shaft fractures. J Orthop Trauma 2002;16:394–402.
7. Ring
D, Jupiter JB, Quintero J, et al. Atrophic ununited diaphyseal
fractures of the humerus with a bony defect: treatment by wave-plate
osteosynthesis. J Bone Joint Surg 2000;82B: 867–871.
8. Sarmiento A, Burkhalter WE, Latta LL. Functional bracing in the treatment of delayed union and nonunion of the tibia. Int Orthop 2003;27:26–29.
9. Friedlaender
GE, Perry CR, Cole JD, et al. Osteogenic protein-1 (bone morphogenetic
protein-7) in the treatment of tibial nonunions. J Bone Joint Surg 2001;83A:S1-151–S1-158.
10. Giannoudis PV, Dinopoulos H, Tsiridis E. Bone substitutes: an update. Injury 2005;36:S20–S27.
11. Patzakis MJ, Zalavras CG. Chronic posttraumatic osteomyelitis and infected nonunion of the tibia: current management concepts. J Am Acad Orthop Surg 2005;13:417–427.
12. Rozbruch
SR, Weitzman AM, Watson JT, et al. Simultaneous treatment of tibial
bone and soft-tissue defects with the Ilizarov method. J Orthop Trauma 2006;20:197–205.
13. Rodriguez-Merchan EC, Forriol F. Nonunion: general principles and experimental data. Clin Orthop Relat Res 2004;419:4–12.
Miscellaneous
Codes
ICD9-CM
733.82 Nonunion fracture
Patient Teaching
Strict adherence to the recommendations of the
orthopaedic surgeon regarding activity and care of the fracture may
reduce the likelihood of developing a nonunion, particularly with
problematic fractures.
Prevention
Excellent reduction of fractures, smoking cessation, and aggressive treatment of delayed unions decrease nonunion rates.
FAQ
Q: How long does a nonunion take to heal?
A:
90% of nonunions are treated successfully with 1 surgical intervention,
and healing occurs over a 3–4-month period. Full rehabilitation with
muscle strengthening takes longer, because the patient often is
debilitated before treatment.

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