Journal of orthopaedic research : official publication of the Orthopaedic Research Society
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Hydroxyapatite is a synthetic bone graft, which is used for the treatment of bone defects and nonunions. However, it is a rather inert material with no or little intrinsic osteoinductive activity. Recombinant human osteogenic protein-1 (rhOP-1) is a very potent biological agent, that enhances osteogenesis during bone repair. ⋯ Although the differences were not significant, histological examination revealed that there was more often bony bridging of the defect in both combination groups and the autograft group than in the group with hydroxyapatite alone. Healing of bone defects, treated with porous hydroxyapatite, can be enhanced by the addition of rhOP-1 or autologous bone marrow. The results of these composite biosynthetic grafts are equivalent to those of autograft.
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Comparative Study
Development of an atrophic nonunion model and comparison to a closed healing fracture in rat femur.
Although most fractures heal, some fail to heal and become nonunions. Many animal models have been developed to study problems of fracture healing. The majority of nonunion models have involved segmental bone defects, but this may not adequately represent the biologic condition in which nonunions clinically develop. ⋯ The radiographical appearance of nonunion models was atrophic. This investigation showed pronounced differences between the experimental nonunions and standard closed fractures both histologically and biomechanically. In conclusion, we have developed a reproducible atrophic nonunion model in the rat femur that simulates the clinical condition in which there is periosteal disruption but no bone defect.
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Pedicle screws for spinal fixation risk neural damage because of the proximity between screw and nerve root. We assessed whether spinal somatosensory evoked potential (SSEP) could selectively detect pedicle-screw-related acute isolated nerve injury. Because pedicle screws are too large for a rat's spine, we inserted a K-wire close to the pedicle in 32 rats, intending not to injure the nerve root in eight (controls), and to injure the L4 or L5 root in 24. ⋯ SSEP monitoring provided reliable, useful diagnostic and intraoperative information about the functional integrity of single nerve-root injury. These findings are clinically relevant to acute nerve-root injury and pedicle-screw insertion. If a nerve-root irritant remains in place, a considerable neurologic deficit will occur.
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The etiology of local posttraumatic infection in the locomotor system depends on the amount, virulence and pathogenicity of the inoculated microorganisms and the local/systemic host damage due to the type and extent of the accident or iatrogenic trauma. The relative effect of these factors remains unclear. In particular, it is still unclear today whether--in presence of microorganisms--soft tissue damage and its pathophysiological consequences lead to infection after soft tissue trauma, or whether the bacterial contamination is the primarily cause for posttraumatic infection. The aim of the project was to gain information on the consequences of a soft tissue injury in terms of resistance to local infection. Since clinical populations are too heterogeneous, the problem was investigated in a standardized, reduced (no surgery or implants) experimental in vivo model. ⋯ The infection rate after a standardized closed soft tissue injury was significantly higher and the ID50 lower than without soft tissue trauma. Our results demonstrate that in presence of microorganisms it is not primarily the bacterial contamination but rather the soft tissue damage and its pathophysiological consequences resulting in decreased infection resistance that secondarily lead to infection.
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Comparative Study
Comparison of commonly used orthopaedic outcome measures using palm-top computers and paper surveys.
Measuring patient-perceived outcomes following orthopaedic procedures have become an important component of clinical research and patient care. General and disease-specific outcomes measures have been developed and applied in orthopaedics to assess the patients' perceived health status. Unfortunately, paper-based, self-administered instruments remain inefficient for collecting data because of: (a) missing data (b) respondent error, and (c) the costs to administer and enter data. ⋯ Administration of HRQL questionnaires using portable palm-top computer devices has the potential advantage of decreased cost and convenience. These data lend some support for the comparability of palm-top computers and paper surveys for outcomes measures widely used in the field of orthopaedic surgery. The present study identified the lack of reliability across modes of administration that requires further study in a randomized comparability trial. These mode effects are important for orthopaedic surgeons to appreciate before implementing innovative data-capture technologies in their practices.