The influence of compression on the healing of experimental tibial fractures.

PURPOSE Experimental studies of the effects of various mechanical conditions and stimuli on bone healing have disclosed an improvement potential in bone fracture mineralization and biomechanical properties. We therefore evaluated the effect of a clinically practicable application of a mechanical compressive interfragmentary stimulus on the healing of experimental tibial diaphyseal fractures. METHODS Sixty Male rats received a standardized tibial shaft osteotomy stabilized with a unilateral external fixator with a zero interfragmentary distance, and then randomly assigned to the compression (N=20), control (N=20) or distraction (N=20) group. From days 4 to day 14, the external fixator was either tightened (compression group) or loosened (distraction group) once daily to gradually induce a total axial displacement of the external fixator pin clamps of 1.25 mm. Evaluation at 30 and 60 days post-osteotomy included radiography, dual-energy X-ray absorptiometry (DXA), quantitative CT and mechanical testing. RESULTS All fractures healed radiographically with sparse callus. At 60 days, the compression and control groups exhibited significantly less amount of mineralized callus in terms of DXA measured callus area and bone mineral content (BMC) compared to the distraction group. These groups also demonstrated a smaller volume of low-mineralized bone tissue (callus) and a larger volume of highly mineralized bone tissue (cortical bone) measured by QCT than in the distraction group. Both mechanical strength and stiffness was significantly higher in the compression and control groups than in the distraction group at 60 days. DISCUSSION Compression did not enhance fracture healing in terms of mineralization, bending strength, or stiffness at the time of union, compared with the control condition. The compression and control groups exhibited improved healing in terms of mechanical strength and stiffness and a more mature callus mineralization compared with the distraction group.

[1]  R. Brumback,et al.  Management of open grade III tibial fractures. , 1987, The Orthopedic clinics of North America.

[2]  G A Ilizarov,et al.  The tension-stress effect on the genesis and growth of tissues: Part II. The influence of the rate and frequency of distraction. , 1989, Clinical orthopaedics and related research.

[3]  G A Ilizarov,et al.  The tension-stress effect on the genesis and growth of tissues. Part I. The influence of stability of fixation and soft-tissue preservation. , 1989, Clinical orthopaedics and related research.

[4]  E. Chao,et al.  External skeletal fixation of canine tibial osteotomies. Compression compared with no compression. , 1985, The Journal of bone and joint surgery. American volume.

[5]  E Y Chao,et al.  Effects of axial dynamization on bone healing. , 1993, The Journal of trauma.

[6]  B. Mckibbin,et al.  The biology of fracture healing in long bones. , 1978, The Journal of bone and joint surgery. British volume.

[7]  S. Nork.  Initial Fracture Management and Results , 2005, Journal of orthopaedic trauma.

[8]  David S. Chang.  Biomechanics in the musculoskeletal system: Manohar M. Panjabi and Augustus A. White III. Philadelphia, Churchill Livingstone, 2001, 224 pp., $65.00 , 2002 .

[9]  O. Reikerås,et al.  Role of the fibula in lower leg fractures: An in vivo investigation in rats , 2008, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[10]  A. Ekeland,et al.  Methods for testing the mechanical properties of the rat femur. , 1978, Acta orthopaedica Scandinavica.

[11]  T. Einhorn.  The Science of Fracture Healing , 2005, Journal of orthopaedic trauma.

[12]  Gavriil A. Ilizarov,et al.  The Tension-Stress Effect on the Genesis and Growth of Tissues , 1992 .

[13]  J Kenwright,et al.  Controlled mechanical stimulation in the treatment of tibial fractures. , 1989, Clinical orthopaedics and related research.

[14]  E. Chao,et al.  Comparison of osteotomy healing under external fixation devices with different stiffness characteristics. , 1984, The Journal of bone and joint surgery. American volume.

[15]  J Kenwright,et al.  The role of fixator frame stiffness in the control of fracture healing. An experimental study. , 1993, Journal of biomechanics.

[16]  A. White,et al.  Comparison of cyclic loading versus constant compression in the treatment of long-bone fractures in rabbits. , 1981, The Journal of bone and joint surgery. American volume.

[17]  C. Court-Brown,et al.  External fixation for type III open tibial fractures. , 1990, The Journal of bone and joint surgery. British volume.

[18]  L. Claes,et al.  Influence of size and stability of the osteotomy gap on the success of fracture healing , 1997, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[19]  P. Giannoudis,et al.  Damage control: extremities. , 2004, Injury.

[20]  T. Einhorn.  Bone strength: The bottom line , 1992, Calcified Tissue International.

[21]  P. Schneider,et al.  Preparation and characterization of calibration standards for bone density determination by micro-computed tomography. , 2007, The Analyst.

[22]  L. Claes,et al.  Temporary distraction and compression of a diaphyseal osteotomy accelerates bone healing , 2008, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[23]  J L Cunningham,et al.  Strain Rate and Timing of Stimulation in Mechanical Modulation of Fracture Healing , 1998, Clinical orthopaedics and related research.

[24]  B. Rydevik,et al.  An external fixation method and device to study fracture healing in rats , 2003, Acta orthopaedica Scandinavica.

[25]  Lutz Claes,et al.  Shear movement at the fracture site delays healing in a diaphyseal fracture model , 2003, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.

[26]  T. Matsushita,et al.  Comparison of cyclic compression, cyclic distraction and rigid fixation. Bone healing in rabbits. , 1998, Acta orthopaedica Scandinavica.

[27]  O. Reikerås,et al.  External fixation compared to intramedullary nailing of tibial fractures in the rat , 2009, Acta orthopaedica.

[28]  A. Ekeland,et al.  Mechanical properties of fractured and intact rat femora evaluated by bending, torsional and tensile tests. , 1981, Acta orthopaedica Scandinavica.

[29]  C. Krettek,et al.  Effect of mechanical stability on fracture healing--an update. , 2007, Injury.

[30]  S M Perren,et al.  The influence of cyclic compression and distraction on the healing of experimental tibial fractures , 2004, Journal of orthopaedic research : official publication of the Orthopaedic Research Society.