Cierny-mader Type Ⅳ Osteomyelitis Treated With Aggressive Debridement And Induced Membrane Technique:Clinical Outcome And Influencing Factors Research

BackgroundCierny-Mader(C-M) type Ⅳ chronic osteomyelitis represents a complex clinical challenge with permeation of extensive bone and soft tissue involvement.Aggressive debridement through viable tissue margin includes en bloc resection improves the odds of eradication of infection,which creates challenging large bone and soft tissue loss in treating this type of osteomyelitis.This critical segmental bone defect typically management with distraction osteogenesis,vascularized bone grafts or permanent acrylic spacers after debridement.However,these techniques for reconstruction of significant bone loss are associated with lengthy healing and unpredictable complications,or they use methods that are complicated or poorly tolerated.The induced membrane(Masquelet)technique,involving the placement of a polymethylmethacrylate(PMMA)spacer in the defect with subsequent bone grafting,has achieved good results in the management of large defects.The induced membrane is highly vascularized and secretes several growth factors,including VEGF and BMP-2.Furthermore,extracts from the membrane have been shown to stimulate bone marrow cell proliferation and differentiation of progenitor cells to the osteoblast lineage.These factors combine to facilitate successful consolidation of simple cancellous bone graft within an induced membrane and present length-independent in reconstructing segmental bone defect.The procedure potential as an alternative reconstruction method for segmental bone defects due to type Ⅳ chronic osteomyelitis.And which was scarcely reported in literature.Apart from the biological advantages illustrated in literature,the antibiotic impregnated PMMA spacer may offers other advantages in treatment of post-osteomyelitis skeletal reconstruction,including therapeutic benefits eluting local adjuvant antibiotics and increase mechanical stable for fracture fixation and soft tissue healing.More over,considering the profile of severe infection and poor soft tissue,the impact on the treatment and healing,including optimal range for grafting,fixed way,type of bone graft and patients age,all was unclear and need further research and discussion.We hypothesized that functional outcome and a high control rate can be obtained in treating type Ⅳ chronic osteomyelitis with this method,and related factors also would track back to host-related variables.Objectives1.The purpose of this study was to assess the clinical efficacy of C-M type Ⅳ chronic osteomyelitis treated with newly staged methods of aggressive debridement and induced membrane technique.2.A secondary objective was to determine clinical characteristics and related factors with this staged treatment protocol.Methods1.From January 2012 to January 2014,36 consecutive adult patients of C-M type Ⅳ chronic osteomyelitis were treated by this staged method in our clinical center with a minimum of 2-years follow-up.30 men and 6 women;average age: 41 years(range: 21– 68),Infections of the femur and tibia were 19 and 16 cases respectively,with one having a fibula infection.Clinical outcome of treatment in terms of infection cure,time of bone union,complications,end-state mobility and lower limb’s function activity score,occupational state with follow-up.2.The clinical and imaging results were retrospectively analyzed.The related factors involved in the bone union time,lower limb’s function activity score were compared using an independent t-test,and in the occurrence of complications were analyzed with a Fisher’ test.Results1.Five patients had a second debridement and eight needed a local flap transfer to cover the wound in the first stage.Patients formed a mean of 5.5 cm(range: 2–10.9)segmental bone defect after debridement;Systemic antibiotics was a mean of 2 weeks(range: 1–6 weeks)and the mean interval from debridement to bone grafting was 12 weeks(range: 6–36 weeks).Sixteen patients had autograft and twenty had autograft mixed allograft in the second stage.2.The mean follow-up time was 29.5 months(range: 24–45).No patients required amputation.Bone union was achieved in all patients with a mean of 5.9 months(range: 4–8 months)and all were able to walk independently.Clinical eradication of osteomyelitis was achieved in 35(97%)patients.The only relapse was 65 year old male combined with MRSA infection and diabetes.Who had second debridement and permanent acrylic spacers for reconstruction.Now the patient can walk independently and had no relapse.Complications included 7 patients suffered with joint stiffness,and 4 was noted with minor pain in final follow up.Patients returned to a mean of 82%(46.3%–100%)lower extremity function,and 31patients(86%)returned to work.3.Bone union time and lower limb’s functional activity score was not significantly related to length of bone defect,type of bone graft,or spacer-placing time(p > 0.05).Bone union time was more associated with the infection site and age(p < 0.05).In addition,patients advanced in age were more likely to sustain pain(p < 0.05),and stiffness was mainly attributed to the limb’s long-term immobilization prior to treatment(p < 0.05).Conclusions1.Staged methods of aggressive debridement and induced membrane technique seems to be a simple,reliable and effective for the treatment of C-M type Ⅳ chronic osteomyelitis.It cures infection through thorough debridement,also simply,rapidly repair bone defect and save limb’s function.2.Advanced age and poor soft tissue envelope may have adverse affects and are relative contraindications.Appropriate anti-infective therapy and restore good soft tissue coverage after debridement is the key point in order to make a success outcome.Also the combined assessment and management of such patients with a plastic surgeon are advocated.The optimal time for bone graft and preferable skeletal stabilization requires further discussion.