OSTEONEOGENESIS AND ITS INFLUENCING FACTORS DURING TREATMENT WITH THEILIZAROV METHOD

The radiographs of 57 patients who had undergone 58 callus distraction s and 13 epiphyseal distractions were evaluated. During the course of treatment, the density of the distraction areas on radiographs was mea sured in total and along the medial, lateral, ventral, and dorsal marg ins using a digital radiograph processing system. The densities of the whole distraction length were correlated to the following parameters: age of patient, start of distraction after corticotomy, mean distract ion speed, mean amount of weight load during the period of distraction and consolidation, location of corticotomy (distal femoral metaphysis versus the proximal tibial one), and diclofenac medication. Except fo r the location of corticotomy and the diclofenac medication, the densi ty was influenced by all these parameters. Age of the patient and weig ht load were the most important parameters. Patients with leg shorteni ng caused by poliomyelitis and a patient with a shortened leg after am niotic strangulation showed a slower rise of the density trend curve o n radiographs than the other patients. When comparing the different re gional density curves, a significant gradual density decrease could be observed from the medial to the lateral side in the femur, from later al to medial in the tibia, and from the dorsal to the ventral side in both bones. The respective differences between lateral and medial dens ity, and between dorsal and ventral density, were significantly higher in cases of callus distraction than in cases in which epiphyseal dist raction had been used. The amount of bone regeneration varied regional ly primarily because of the inhomogeneous soft tissue covering of the bone and the impairment of its local blood supply by the surgical expo sure for the corticotomy. The clinical relevancy of the various parame ters for osteoneogenesis is discussed in this article.