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Journal Club

May 2010

Extracorporeal Shock-Wave Therapy Compared to Surgery for Hypertrophic Long-Bone Nonunions

• Authors: Angelo Cacchio, Lucio Giordano, Olivo Colafarina, Jan D. Rompe, Emanuela Tavernese, Francesco Ioppolo, Stefano Flamini, Giorgio Spacca, Valter Santilli
  
• Institution: Department of Physical Medicine and Rehabilitation and the Division of Orthopaedic Surgery, Department of Surgery, ‘‘San Salvatore’’ Hospital of L’Aquila; the Physical Medicine and Rehabilitation Center, Nomentana Hospital, Rome; and the Department of Physical Medicine and Rehabilitation, School of Medicine, ‘‘La Sapienza’’ University, Rome, Italy
  
• Journal: J Bone Joint Surg Am. 2009;91:2589-97

No external source of funding

Abstract link

Introduction

• ECSW has been investigated as treatment for non-union
• No prospective RCT has been performed comparing ECSW directly to surgery
• ECSW thought to work by way of microfracture that induces healing reaction and vascularity
• Aims
  • Compare ECSW to surgery
  • Ascertain differences between two different ECSW generators

Methodology

• Prospective three-arm RCT between Oct 2001 - Sep 2004
• Two separate shock-wave devices and one surgery arm
• Non-union was fracture with no progression of healing for 1 month for at least 6 months
• Inclusion criteria
  • Long-bone non-union and skeletal maturity
  • Both hypertrophic and atrophic
• Exclusion criteria
  • Bone tumours, pathological fractures, infected non-unions, breakage of fixation, implanted pacemaker, blood coagulation disorders, use of anti-coagulants, pregnancy
• Treatment
  • Computer generated list for randomisation Shock-Wave Therapy
    • 4 sessions 1 week apart
    • 4000 impulses applied to fracture site
    • All patients underwent regional nerve block
    • Limb immobilised for 6-12/52
    • NSAID's and ice-packs for 3/7 following Rx
    • Returned to pre-op WB status 3/7 after Rx
    • Two different generators used
      • Differing energy flux density
  • Surgical Therapy
    • Removal of implant, decortication of fracture site, refreshing of fracture site, recanalizing the medullary canal, reducing and fixing fracture site
    • Autogenous bone graft in 12 patients
    • Ex-fix in 7 patients
• Outcome Measures
  • Xray
    • AP/Lat Xrays assessed before Rx and at 3,6,12,24 months post Rx
      • Radiologists were blinded to nature of intervention
    • Primary end point
      • 4 cortical union
  • Secondary end points
    • Functional and pain scores
    • DASH
    • LEFS
    • Self-rated pain score
    • Patient satisfaction assessed
    • Offered surgical Rx at 6/12
      • None accepted
• Statistical Analysis
  • Worst-case scenario intention to treat principle for those that did not complete Rx or follow-up
  • 2-sided Chi-square test for union
  • Significance set a 5%
  • Two-way analysis of variance for secondary end-points
  • Power calculation for sample size
  • 35 patients per group for difference of 30% in each group

Results

• 126 patients
  • 92 hypertrophic
  • 34 atrophic
  • 15 lost to follow-up
    • 11 of which were atrophic non-union
  • 42 in each arm
    • Group A - ECSW low energy flux
    • Group B - ECSW high energy flux
    • Group C - Surgery
• High inter and intraobserver correlation for radiographic measures
• Results
  • All patients returned to work
    • 19% upper limb and 30% lower limb on reduced activity
    • Adverse effects
      • ECSW
        • Local complication in 27% (haematoma that resolved in 4-6/7)
      • Surgery
        • 4.8% infection rate (2 patients)
        • 1 radial nerve neuropraxia - resolved within 4/12
  • Xrays
    • No difference between 3 groups
      • Healed At six months
        • 70% of the nonunions in Group 1,
        • 71% of the nonunions in Group 2,
        • 3% of the nonunions in Group 3
  • Clinical Outcomes
    • 3 and 6 months after treatment
      • two shock-wave groups were significantly better than those in the surgical group (p < 0.001).
    • 12 and 24 months
      • no differences among the three groups
      • except DASH score
        • which differed significantly between Groups 1 and 3 (p = 0.038)
        • and between Groups 2 and 3 (p = 0.021) at twelve months.

Discussion

• Previous studies report success rates of ECSW of between 41-91%
• Higher for hypertrophic compared to atrophic
• Union rates similar
• Functional and pain scores better in first 6/12
• ? Related to hyperstimulation analgesia
• Some in vitro studies suggest the lower the energy flux of the ECSW generator the greater the proliferation of osteoblast-like cells

Pros of Study

• Study design
• RCT partial blinded
• Comparison between gold-standard and new treatment
• Clear inclusion/exclusion criteria

Cons of Study

• High rate of atrophic union patient drop-out
• Cannot adequately blind radiologists to treatment
• Did not discuss what treatment options the patients that did not unite underwent
  • ? Whether ECSW made surgery more difficult due to scarring
• Unclear regarding weight-bearing status and immobilisation
  • Appear to be contradictory
• Unclear on immobilisation following surgical treatment