| BackgroundWith the development of modern medicine, great progress has been made in the treatment of osteomyelitis in terms of both conception and practice. Yet, the complexity of the condition, the long treatment cycle, and the high rate of recurrence and disability still incur great economic and mental burdens to the patients and their families. The treatment of osteomyelitis remains a clinical challenge on the part of clinicians and needs further study.The general steps of clinical treatment of osteomyelitis include debridement,stabilization of the affected limb, filling of the dead cavity and closure of the wound. At the same time, bacterial culture is required for appropriate selection of sensitive antibiotics for the treatment of infection. In some serious cases, the function of the affected limb has to be reconstructed. For instance, large segmental bone defects have to be reconstructed by using the bone elongation technique. Debridement is a necessary step for the treatment of osteomyelitis, but debridement may cause soft tissue defects in addition to the bone defects.Clinically, bone defects are usually treated with autogenous bone grafting, artificial bone grafting and/or bone elongation, and soft tissue defects are usually covered with flaps. But in some patients with poor health conditions, those without much availability of flaps, or those with flap rejection, there are not many therapeutic methods that can help. Open bone grafting may provide a new technique to shed light on the treatment of osteomyelitis.However, open bone grafting needs further improvement because of a long time for wound closure, a long treatment cycle, and a long waiting time before the patient can resume normal work and return to society. Since advent of the negative pressure drainage technology, researchers have made useful explorations. However, the basic theory and clinical experience of this technique need further improvement, including the specific mode of operation. In the present study, we put forward a tentative idea of using cancellous bone grafts and one-stage grafting with the help of vacuum assisted closure for the treatment of chronic osteomyelitis, and evaluated the surgical outcome by observing the bone cell activity, revascularization level and healing time of wounds in patients with chronic posttraumatic osteomyelitis, on the basis of our previous clinical experience and with reference to the literature.Objective1. We observed the bone cell activity, revascularization level and healing time of wounds in three groups: Group A where patients received cancellous bone grafting therapy,Group B where patients received cancellous bone grafting with vacuum assisted closure,and Group C where patients received cancellous bone grafting and one-stage skin grafting with vacuum assisted closure, and compared the therapeutic outcomes between the three groups with respect to the soft tissue and bone defects.2. We studied and summarized the clinical effect of cancellous bone grafting and one-stage skin grafting for the treatment of chronic osteomyelitis with vacuum assisted closure through the analysis of the clinical cases.Methods1. A soft tissue and bone defect model was established in 60 New Zealand white rabbits. They were equally randomized to three groups. In group A, operation was performed on the right hind limb for cancellous bone grafting, and the wounds were conventionally dressed postoperatively. In Group B, operation was performed on the right hind limb for cancellous bone grafting, negative pressure dressing on postoperative day 4,and vacuum assisted closure on postoperative day 7. In Group C, operation was performed on the right hind limb for cancellous bone grafting, one-stage skin grafting, negative pressure dressing on postoperative day 4, vacuum assisted closure on postoperative day7.Limb X-ray examinations were performed 1, 2, 4 and 8 weeks after operation. Five rats were sacrificed in each group. Specimens of the transplanted cancellous bone were prepared into cell suspensions and paraffin-enbedded. Cell suspension was stained by trypan blue to observe the ratio of viable cells. Paraffin-embedded, HE and immunohistochemically stained histological sections were observed for CD34 antibody.microvessel density was analyzed quantitatively in each group.2. Wound healing was observed and recorded in the experimental rabbits that survived more than 4 weeks, except those killed at 1 and 2 weeks. The wound healing time was recorded and analyzed statistically.(Wound area was small and the wound healing time of each group was not longer than 4 weeks in the pre experiment).3. Data of patients with chronic osteomyelitis who were admitted and treated in General Hospital of Jinan Military Command Region between February 2011 and August2013 were reviewed and analyzed retrospectively. Of them, 16 patients underwent the operation of cancellous bone grafting and one-stage skin grafting with vacuum assisted closure( group A), and 19 patients underwent the operation of cancellous bone grafting Objectivewith vacuum assisted closure( group B). The gender, age, course of disease, osteomyelitis type, bleeding volume, operation time, bone volume, wound size, wound healing time,bone healing time and other aspects of the patients in the two groups were analyzed statistically.Results1. X-ray examinations showed that the fracture line was clear and no osteotylus was formed 1 week after operation; the fracture line was blurred and only a little osteotylus was formed 2 weeks after operation; the fracture line almost disappeared and a large amount of osteotylus was formed 4 weeks after operation; the fracture line disappeared and osteotylus got good plasticity 8 weeks after operation. The wound healing time of was(21.8±2.7)days in Group A, vs.(18.6±2.2) days in Group B, and(16.5±2.0) days in Group C.Analysis of variance showed a statistically significant difference between the groups, the SNK-q test showed that the differences among groups had statistical significance. No obvious necrosis was observed in 11 patients, partial necrosis in 4 patients, and complete necrosis in 5 patients. The wounds healed under the crust after necrosis of the skin.2. The ratio of viable cells in Group A was(16.6±2.1)% in the 1st week after surgery,vs.(24±2.2)% in Group B, and(24.4±2.1)% in group C. The results of analysis of variance showed significant differences in the ratio of viable cells between the groups. The results of SNK-q test showed statistically significant differences between Group A and B,and between Group A and C, but there was no statistically significant difference between Group B and C.The ratio of viable cells in Group A was(19.8±1.6) % in the 2nd week after surgery,vs.(30.6±2.5) % in Group B, and(31.8±4.3)% in Group C. The results of analysis of variance showed statistically significant difference in the ratio of viable cells between the groups. The results of SNK-q test showed statistically significant differences between Group A and B and between Group A and group C but there was no statistically significant difference between Group B and C.The ratio of viable cells in Group A was(25.2±3.7)% in the 4th week after surgery, vs.(37.6±4.3)% in Group B and(46.2±5.2)% in Group C. The results of analysis of variance showed statistically significant differences between the groups. The results of SNK-q test showed significant differences between any two groups.The ratio of viable cell in Group A was(49.2±4.1)% in the 8th week after surgery, vs.(68.2±6.8)% in Group B and(73.4±4.6)% in Group C. The results of analysis of varianceshowed statistically significant differences in the ratio of viable cells between the groups.The results of SNK-q test showed that there was statistically significant difference between Group A and B and between Group A and C but there was no statistically significant difference between Group B and C.3. In the 1st week after surgery, microvessel density in Group A was 7.8±1.9, vs.14.8±2.6 in Group B and 16.0±2.2 in Group C. There were statistically significant differences between the groups. There was statistical significance between Group A and B and between Group A and C,but there was no significant difference between Group B and C.In the 2nd week after surgery, microvessel density in group A was 16.2±1.9, vs.26.2±2.4 in Group B and 28.6±3.4 in Group C. There are statistically significant differences between the groups. There was statistical significance between Group A and B and between Group A and C,but there was no significant difference between Group B and C.In the 4th week after surgery, microvessel density in group A was 30.2±3.4, vs.47.6±2.5 in Group B and 52.8±4 in Group C. There are statistically significant differences between the groups. There was statistical significance between Group A and B and between Group B and C and between Group A and B.In the 8thweek after surgery, microvessel density in group A was 51.8±1.5, vs.52.8±3.0 in Group B and 55.2±2.9 in Group C. There were no statistically significant differences between the groups.4. All cases were followed up. IN goup of cancellous bone grafting and one-stage skin grafting with vacuum assisted closure, the mean follow-up time was 24(12~42) months;the mean time of the wound free of exudation was(32.3±8.1) days(22~56 days); the number of cases of grafting skin without obvious necrosis was 10; the wound healing time was 22~33 days; partial necrosis was in 4 cases; the wound healing time was 29 to 56 days;the number of cases with complete necrosis was 2, where the wound healing time was 36 and 40 days respectively; the wounds healed under the crust after necrosis of the skin; the mean time of bone healing was 4.6 ± 0.8 months(4~7 months). During one year follow-up period, no recurrence was found; the limb allowed full weight-bearing; external fixation was removed when the bone healed.In group of conventional open bone grafting, the mean follow-up time was 23.3months(12~39months); the mean time of wounds without exudation was 51.8 ± 8.6days(34~69days); the granulation tissue eventually covered the bone surface, then scarred and the wound healed; the mean time of bone healing was 7.2 ± 1.3 months(5~10months).During the one year follow-up period, no recurrence was observed in 17 cases; the limb allowed full weight-bearing; external fixation was removed when the bone healed. There were two cases of recurrence, where the wound healed well after operation, and the limb allowed partly weight-bearing when the patients were followed up again.There was a significant difference in wound and bone healing time between the two groups(P<0.05).Conclusions1. Vacuum assisted closure could improve the ratio of viable cells of transplanted cancellous bone, stimulate revascularization of the transplanted cancellous bone, indirectly promote bone healing, and shorten the wound healing time.2. Skin grafting did not affect the revascularization process of the cancellous bone and earlier wound closure increased the ratio of living cells of the bone graft and accelerated revascularization of the bone graft3. Necrosis of the skin graft did not affect the growth of granulation and could reduce the risk of invasion of external bacteria.4. Cancellous bone grafting and one-stage skin grafting with vacuum assisted closure is a revolutionary change as compared with conventional open bone grafting and expected to change from "open" to "closed with negative pressure", creating a favorable environment for the growth of the cancellous bone. One-stage skin grafting on cancellous bone is "physiological coverage" of the wound. With the help of VAC, the skin can survive,thus making the wound close earlier, shortening the bone healing time, and reducing the recurrence rate of osteomyelitis. As the operation is simple and wound management is convenient, this new technique warrants wider application to clinical practice. |
PDF Full Text Request