Takashi Mihara

Study of Pin Track Infection During Use of External Fixatioin System

The external fixation system is used for the treatment of fracture, limb lengthening, deformity corrections, etc. Some complications are however seem, of which one especially serious one is pin track infection. In order to reduce pin track infection, we develop a new postoperative dressing method details of which and the infection rate are reported in the following.Since use of the external fixation system from 1995, postoperative pin site care has been performed basically by cleaning the affected part twice a week, then the pins and the skin around the pin sites were disinfected with hibitane pledget while removing secreta and eschar. After disinfecting the affected limb and the entire external fixator using hibitane spray, and filling with univalve gauze, the affected area and the external fixation system were convered with a sponge pad at the same time, and made airtight with bandages.Pin track infection was observed in 1 out of 24 cases (4.2%), which had a open femoral shaft fracture. Results show that above method helps prevent pin track infection.

Clinical Use of Absorbable Screws for Posterior Dislocation of Acetabular fracture

5 patients with posterior rim acetabular fractures were treated with absorbable screws. Open reduction and internal fixation were performed on these patients due to the instability of the fracture following closed reduction. All 5 patients healed without complications and showed good results, indicating that the absorbable screws provided sufficient stability for the fixation of this type of fracture. In addition, the absorbable implants did not require removal and produced no artifacts in postoperative CT and 3-DCT images, permitting excellent analysis of the fracture aligment and union. These results indicate that the absorbable screws may be a viable alternative to metalic implants for the treatment of unstable posterior rim acetabular fractures.

Treatment Using the Ultrasonic Surgical System for Hard Tissue

The advantages and limitations of the ultrasonic surgical system in spinal surgery are disccused in this report.We used SUMISONIC ME-24000, which transmits ultrasonic vibrations (maximum vibration 2400times/sec, maximum amplitude 200μm) to the horn tip. Since the horn tip is very thin, accurate, precise cutting and resection of hard tissue is possible using a light touch.Cool water is discharged by the horn tip, minimizing heat gererated from cutting, and also washs away dissolved tissue.It was very useful in spinal surgery, especially in surgical decompression of spinal cord of OPLL and OYL.The risk of damage to soft tissue appears to be very low, in comparison with surgiairtome.