Copyright © 2009 by The Journal of Bone and Joint Surgery, Inc.
Commentary & Perspective
Commentary & Perspective by
J. Lawrence Marsh, MD*,
University of Iowa Hospitals and Clinics, Iowa City, Iowa
Posted November 2009
Surgeons are familiar with treating fracture nonunion with a variety of external
fields, such as electrical stimulation and low-intensity ultrasound1.
However, a major weakness in the literature is a lack of studies that directly
compare these noninvasive techniques with surgical stabilization with or without
grafting. Most surgeons in the United States will not be familiar with higher-intensity-ultrasound
extracorporeal shock-wave therapy for treating nonunion, since it is FDA-approved
in the musculoskeletal system for only the treatment of chronic heel pain and
lateral epicondylitis2,3. Clinical studies from Europe and elsewhere
have suggested that extracorporeal shock-wave therapy effectively heals nonunions
in a high percentage of patients, particularly those with a hypertrophic nonunion4-6.
Just as is the case with studies of other external fields for treating fracture
nonunions, extracorporeal shock-wave therapy has not previously been directly
compared with surgical treatment.
In their randomized controlled trial, Cacchio et al. found that extracorporeal
shock-wave therapy was as effective as surgery for healing fracture nonunion.
At six months after treatment, more than 70% of nonunions in patients treated
with extracorporeal shock-wave therapy had healed, which was similar to the result
in the surgical group, and, in both extracorporeal shock-wave groups, more than
90% of nonunions in enrolled patients were healed by two years. The strength
of this study, in addition to the randomized design, was the fact that the radiographic
outcomes were assessed by radiologists not directly involved with other aspects
of the study and that these assessments were found to be reliable and reproducible.
Patients were not enrolled unless their radiographs, which were assessed by two
independent radiologists, had failed to demonstrate progress toward union for
at least six months following treatment. This increases confidence that the majority
of the nonunions would not have healed without intervention and decreases the
concern about the lack of an untreated control group.
Interestingly, the data also showed that the patients who received extracorporeal
shock-wave therapy had quicker relief of pain and return to function than the
surgical patients had, as reflected by significantly better pain and function
scores at three and six months after treatment. These early differences were
not seen at twelve and twenty-four months because the pain decreased and function
improved in the surgically treated patients. It is unlikely that this finding
is explained by earlier healing in the extracorporeal shock-wave therapy groups,
and the authors suggest that it might be from a direct effect of extracorporeal
shock-wave therapy on pain mechanisms. If these results were to hold true in
other studies, better pain relief and improved function in the early months after
treatment would be important advantages of treating fracture nonunion with extracorporeal
shock-wave therapy.
This study was only powered to detect a 30% healing-rate difference between
groups. A much smaller difference than this would be clinically significant.
However, the near equivalence between groups at all three time points in this
study and a nearly 95% healing rate at two years in the extracorporeal shock-wave
therapy group that received an energy flux density of 0.40 mJ/mm2 decrease
the concern about lack of power to detect important differences. The authors
acknowledged that the healing assessments by the radiologists were not completely
blinded, since changes in hardware and other postoperative changes that would
be visible on radiographs would identify many of the patients in the surgical
group.
More important than concerns about the study design is uncertainty of how
these results will generalize to other practice environments, assuming that extracorporeal
shock-wave therapy were made more widely available for the treatment of nonunion.
There are important disadvantages to the extracorporeal shock-wave therapy protocol
as it was applied in this study. The authors enrolled patients with atrophic
nonunions, but the large number lost to follow-up and the failures in the extracorporeal
shock-wave therapy groups, combined with previous reports in the literature,
suggest that extracorporeal shock-wave therapy is not very effective for the
treatment of an atrophic nonunion. Similar to the result of treatment with other
noninvasive techniques, malalignment is not corrected, making the extracorporeal
shock-wave technique most applicable only for patients with a well-aligned nonunion.
Patients with infection or broken hardware were not enrolled. Finally, the extracorporeal
shock-wave therapy treatment was intensive in several ways. There were four extracorporeal
shock-wave therapy treatments over four weeks, each requiring the use of regional
anesthesia. All fractured limbs were immobilized for six to twelve weeks, and,
if the nonunion was in a lower extremity, a long leg cast was applied. Many surgeons
would argue, and at least some patients would agree, that this intensive treatment
program should not be considered "conservative."
Despite these disadvantages, for selected patients with a nonunion, a nonoperative
treatment option that results in similar healing time, faster return to function,
and quicker relief of pain than what can be expected after surgery would be a
welcome addition. Patients with a history of infection, poor quality of local
soft tissues, and appreciable medical comorbidities would be particularly good
candidates. Further study might identify effective but less intensive treatment
protocols for extracorporeal shock-wave therapy. For instance, a minimally invasive
surgical stabilization technique could be combined with extracorporeal shock-wave
therapy to achieve union with earlier function and without the need for the immobilization
used in this study.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.
References
1. Nelson FR, Brighton CT, Ryaby J, Simon BJ, Nielson JH, Lorich DG, Bolander M, Seelig J. Use of physical forces in bone healing. J Am Acad Orthop Surg. 2003;11:344-54.
2. U.S. Food and Drug Administration: OrthospecTM Extracorporeal Shock Wave Therapy - P040026. 2005 Apr 1. http://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/DeviceApprovalsandClearances/Recently-ApprovedDevices/ucm078648.htm. Accessed 2009 Oct 6.
3. U.S. Food and Drug Administration: SONOCUR® - P010039. 2002 Jul 19. ttp://www.fda.gov/MedicalDevices/ProductsandMedicalProcedures/DeviceApprovalsandClearances/Recently-ApprovedDevices/ucm083389.htm. Accessed 2009 Oct 6.
4. Rompe JD, Rosendahl T, Schollner C, Theis C. High-energy extracorporeal shock wave treatment of nonunions. Clin Orthop Relat Res. 2001;387:102-11.
5. Schaden W, Fischer A, Sailler A. Extracorporeal shock wave therapy of nonunion or delayed osseous union. Clin Orthop Relat Res. 2001;387:90-4.
6. Wang CJ, Chen HS, Chen CE, Yang KD. Treatment of nonunions of long bone fractures with shock waves. Clin Orthop Relat Res. 2001;387:95-101.
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