Bone infection associated with pressure sores: a clinical study

Pressure sores are common complications in patients with spinal injuries or cerebrovascular accidents. The management of pressure sores requires prolonged hospitalization and repeated surgical interventions with a high recurrence rate. Particularly osteomyelitis following initial pressure sores persistently complicates wound healing and recovery. Furthermore, it may also ultimately result in serious sepsis; thus an early diagnosis of osteomyelitis in pressure sore patients is crucial along with appropriate surgical and antibiotic therapy. Although many diagnostic methods were reported, there is no single 'gold' standard for early diagnosis of pressure sore-associated osteomyelitis. Authors reviewed pre-operative CBC, plain X-ray, Tc-99m bone scan, and post-operative biopsy results in 37 patients who had received surgical treatment for pressure sores in a 5-year period from September 1991 to August 1996. Based on these reviews, authors compared and analyzed the sensitivity and specificity in diagnosing osteomyelitis.The results were as follows: 1. Of 37 patients studied, 25 cases were confirmed histologically as osteomyelitis. Ischial region revealed the highest incidence of pressure sore-related osteomyelitis(78%, 14 out of 18 cases) while the regional incidence was as following in descending order : ischial, sacral, and greater trochanteric area. 2. Tc-99m bone scan had superior sensitivity(100%) and specificity(83%) to other pre-operative studies in diagnosing osteomyelitis.In conclusion, authors suggest that Tc-99m bone scan is the best diagnostic method because of its high sensitivity and specificity if osteomyelitis is clinically suspected in pressure sore patients. And in case the test result is positive, agressive surgical bone resection and appropriate antibiotic therapy based on bacterial culture from deep bone specimen should be combined to prevent complications or recurrences.

Secondary behavior changes of fibroblast functions induced by conditioned medium of silicone-sensitized murine lymphocytes

Fibrous capsular contracture has been considered as a major side effect of breast silicone implant. The etiology of fibrous capsular contracture has not been fully determined. In the present study, we tried to determine the indirect effect of immune system in fibroblast function which plays a major role in fibrous capsular contracture. For preparation of conditional medium of lymphocytes, mouse (ICR) splenocytes were cultured for one day. Two kinds of conditioned medium, silicone conditioned medium (SCM) and silicone free normal conditioned medium (NCM), were prepared from splenocyte cell suspension cultured on silicone gel coated surface and naked surface, respectively. Mouse fibroblasts (NIH 3T3) were cultured in usual culture dish. Conditioned medium of 25% concentration was added. On day 2 after innoculation, cell number, thymidine incorporation and proline uptake of fibroblasts were measured. The results were as follow; 1) There was no difference of fibroblast number by cultivation in SCM of splenocytes compared with that in fresh medium(FM). 2)There was significant increase of DNA synthesis of fibroblasts in SCM compared with that in FM (p < 0.001). 3) There was significant increase of collagen synthesis of fibroblasts in SCM compared with that in FM (p < 0.01) and in NCM (p <0.001). 4) The functional activities of DNA and collagen synthesis mediated by same number of fibroblast were calculated to be significantly increased in SCM compared with that in NCM and in FM (p < 0.001). In conclusion, fibroblasts cultured in SCM had a higher potential to synthesize macromolecules such as collagen and DNA. We can postulate that SCM may contain certain amount of unknown growth stimulant of fibroblasts, which is produced by silicone gel sensitized murine splenocytes.