[Back pain : State of the art and guidelines]. / Rückenschmerz : Aktuelle Entwicklungen und Leitlinien.

Pain in general and back pain in particular are associated with a variety of pathological, clinical, and sociocultural factors. There are numerous clinical and therapeutic treatment as well as imaging-options available and comprehensive knowledge is required to meet the individual clinical needs of those affected. This requires a high degree of interdisciplinary cooperation. In addition, back pain is covered differently by various numbers of insurance companies. Imaging methods, including the example of periradicular image-assisted interventions, are presented with regard to their indication and efficiency. The existing guidelines and evaluation recommendations with different structural and targeted approaches are discussed in addition to extensive legal aspects in the literature. In addition, the structured reports and the certificated curricula of the AG Bildgebende Verfahren des Bewegungsapparates (Working Group "Imaging Procedures of the Musculoskeletal System") of the Deutsche Röntgengesellschaft ("German Society of Radiology") are recommended for the quality assurance.

[Surgery of sepsis in orthopedics and trauma - A highlight : Current survey by the section for bone and soft tissue infections of the German Society for Orthopedics and Trauma]. / Septische Chirurgie in OuU ­ ein Schlaglicht : Aktuelle Umfrage der DGOU-Sektion Knochen- und Weichteilinfektionen.

Surgery of sepsis in trauma surgery and orthopedics is attracting increasingly more attention due to the rising presence of multidrug-resistant pathogens and the increasing number of operative interventions. Despite extensive experience over decades neither the symptoms nor the treatment strategies have been evaluated and it has become obvious that a scientific investigation of this complex topic is necessary for optimization of patient care under economically sound conditions. The aim of this article is to give a snapshot from German healthcare institutions for trauma surgery and orthopedics to answer some questions on this topic from the section for bone and soft tissue infections (SeKuWi) of the German Society for Orthopedics and Trauma (DGOU) in cooperation with the German Society for Hospital Hygiene (DGKH).

[Revision arthroplasty : Histopathological diagnostics in periprosthetic joint infections]. / Revisionsendoprothetik : Infektionsdiagnostik und Histopathologie.

BACKGROUND: Histopathological differences in synovia and synovial-like interface membrane (SLIM) patterns can be used to differentiate periprosthetic particle-induced reactions, bacterial infections (bacterial synovitis and osteomyelitis), mechanical-induced tissue alterations, adverse reactions to implant material, and arthrofibrosis (SLIM consensus classification). AIM: Because of differences in treatment the diagnosis of a bacterial implant infection is very important. Histopathological tests and scoring systems are important diagnostic tools in identifying deep implant infections in patients with unclear clinical history as well as radiographic and laboratory studies. RESULTS: Modern enzyme PCR-based methods, histochemical- and immune-histopathological techniques (CD3,CD15, CD68) are useful in identifying specific and nonspecific infections, as well as differentiating postsurgical changes from recurrent infections in patients with a spacer. In all histopathological scoring systems for bacterial infection, quantifying the number of neutrophil granulocytes in a defined number of high power fields is crucial. DISCUSSION: Neutrophil granulocytes can be detected through histochemical methods and more specifically by immune-histopathological techniques and by various quantification systems (histopathological scores) leading to the diagnosis of bacterial peri-implant infection. One important function of histopathology, apart from diagnosing infection, is to rule out other mechanisms of implant failure, such as tumor infiltrations, particle-induced reactions, and adverse reactions to implant materials.

[CD15 focus score for diagnostics of periprosthetic joint infections : Neutrophilic granulocytes quantification mode and the development of morphometric software (CD15 quantifier)]. / CD15-Fokus-Score zur Diagnostik der periprothetischen Gelenkinfektion : Neutrophile-Granulozyten-Quantifizierungs-Modus und Entwicklung einer morphometrischen Software ("CD15-Quantifier").

BACKGROUND: The aim of this project was to devise a quantification method for neutrophils within a single focal point through the development of a CD15 focus score which enables bacterial infections in synovial-like interface membranes (SLIM) to be diagnosed. METHODS: In this study a histopathological classification of 91 SLIM removed during revision surgery from the hips (n = 59) and knees (n = 32) was performed. Neutrophils were identified immunohistochemically by means of a CD15-specific monoclonal antibody. The quantitative evaluation of CD15-positive neutrophils (CD15Ne) used the principle of maximum focal infiltration (focus) together with an assessment of a single focal point (0.3 mm(2)). This immunohistochemical approach made it possible to develop the CD15 quantifier software, which automatically quantifies CD15Ne. RESULTS: The SLIM cases with positive microbiological findings (n = 47) had significantly (p < 0.001, Mann-Whitney U-test) more CD15Ne/focal point than cases with negative microbiological findings (n = 44). A count of 50 CD15Ne/focal point was identified as the optimum threshold when diagnosing periprosthetic joint infections (PJI) using the CD15 focus score. If the microbiological findings are used as a gold standard, the diagnostic sensitivity is 0.83, and the specificity is 0.864 with a positive predictive value (PPV) of 0.87, a negative predictive value (NPV) of 0.83, an accuracy of 0.846 and an area under the curve (AUC) of 0.878. The evaluation of findings for the preparations using the CD15 quantifier software (n = 31) deviated by an average of 12 cells from the histopathological evaluation findings (CD15 focus score). Above a cell count of 62, the CD15-quantifier needs on average 32 s less than the pathologist. CONCLUSION: The immunohistochemical CD15 focus score has a high diagnostic value and allowed the development of the CD15 quantifier software. This provides an automated procedure, which shortens the mentally tiring and time-consuming process of microscopic cell counting and thus makes a contribution towards the standardization of tools for diagnosing PJI.

Clinical and pathological nodal staging score for urothelial carcinoma of the bladder: an external validation.

PURPOSE: Radical cystectomy (RC) and pelvic lymph node dissection (LND) are standard treatments for muscle-invasive urothelial carcinoma of the bladder. Lymph node staging is a prerequisite for clinical decision-making regarding adjuvant chemotherapy and follow-up regimens. Recently, the clinical and pathological nodal staging scores (cNSS and pNSS) were developed. Prior to RC, cNSS determines the minimum number of lymph nodes required to be dissected; pNSS quantifies the accuracy of negative nodal staging based on pT stage and dissected LNs. cNSS and pNSS have not been externally validated, and their relevance for prediction of cancer-specific mortality (CSM) has not been assessed. METHODS: In this retrospective study of 2,483 RC patients from eight German centers, we externally validated cNSS and pNSS and determined their prediction of CSM. All patients underwent RC and LND. Median follow-up was 44 months. cNSS and pNSS sensitivities were evaluated using the original beta-binominal models. Adjusted proportional hazards models were calculated for pN0 patients to assess the predictive value of cNSS and pNSS for CSM. RESULTS: cNSS and pNSS both pass external validation. Adjusted for other clinical parameters, cNSS can predict outcome after RC. pNSS has no independent impact on prediction of CSM. The retrospective design is the major limitation of the study. CONCLUSIONS: In the present external validation, we confirm the validity of both cNSS and pNSS. cNSS is an independent predictor of CSM, thus rendering it useful as a tool for planning the extent of LND.

[Bone infections]. / Knocheninfektionen.

Even in recent traumatology and orthopedic surgery infectious diseases of the bone (i.e. osteomyelitis) and it's surrounding tissues remain serious complications. The therapy is demanding and oftenly does not lead to a complete restitutio ad integrum. In order to create the optimal treatment one has to have a profound knowledge about the "state of the art" therapy of bone infections and the basic phases: Reassurance of the local infection (bone and surrounding tissues) and reconstruction of the bone and surrounding tissues. The local infection treatment is based on the consequent surgical eradication of infected tissue. In addition (as a supportive therapy) antibiotics have to be applied according to the local and systemic response of the patient to the infection. Also further supportive methods like hyperbaric oxygenation may be taken into consideration. The following paper provides an overview of diagnostic features and the different surgical procedures as well as the current literature in order to reach the above mentioned goals.

[Infectious bone diseases]. / Infektiöse Knochenerkrankungen.

Bacterial infection of the bone is a severe disease with complications, potentially including long-term physical disability. The diagnosis and therapy of osteomyelitis include several elements: histopathology, microbiology, radiologic imagining, as well as antibiotic and surgical therapy. Histopathologists differentiate between acute osteomyelitis (infiltration of cancellous bone with neutrophil granulocytes); specific osteomyelitis (epithelioid-like granulomatous inflammation, tuberculosis, mycotic infections); primary/secondary chronic osteomyelitis (lymphocytic infiltration); and special forms of chronic osteomyelitis (varying histomorphology, Brodie abscess, SAPHO syndrome). Another important task in the histopathological diagnosis of inflammatory bone diseases is to differentiate osteomyelitis from malignant entities (sarcoma, lymphoma). Therefore, biopsy samples should be of sufficient size for safe diagnosis. Clinical information and imaging as well as interdisciplinary teamwork between radiologists, microbiologists, orthopedic surgeons and pathologists is mandatory to verify these diagnoses.

[Ligament healing results after type C pelvic ring fractures. Results of triangular vertebropelvic support]. / Ligamentäre Ausheilungsergebnisse nach Beckenringfrakturen Typ C. Ergebnisse der triangulären vertebropelvinen Abstützung.

BACKGROUND: Posterior pelvic ring fractures are often associated with injuries of lumbopelvic soft tissue structures. The aim of this prospective MR study was to examine whether ruptured iliolumbal ligaments could be diagnosed in types B and C pelvic ring fractures. The influence of triangular lumbopelvic stabilization (TLPS) was also investigated with respect to stiffening of the lumbopelvic region. MATERIAL AND METHODS: Using a 1.5 Tesla MRI, 20 patients with types B and C fractures were examined to identify ruptured iliolumbal ligaments. In a retrospective study of 30 patients previously stabilized with a TLPS, pain scores, clinical instability testing and measuring of the segmental dislocation in extension, flexion and lateral flexion based on x-rays were also investigated. RESULTS: Of the patients 3 (1 type B, 2 type C fractures) had incompletely ruptured iliolumbal ligaments. In five patients pain intensity and localization could be significantly correlated with clinical instability of the lumbopelvic region, segmental hypermobility and instability. CONCLUSION: Pelvic ring fractures types B and C can be associated with ruptured iliolumbal ligaments. Lumbopelvic instability can be correlated with early implant loosening of TLPS.

[Carcinoma metastasis in cutaneous osseous metaplasia. Differential diagnosis of osseous tumor metaplasia]. / Carcinommetastase in cutaner ossärer Metaplasie. Differentialdiagnose ossärer Tumormetaplasien.

The formation of metastases in heterotopic ossifications is a very rare finding. The example of a 63-year old male who underwent Billroth II procedure because of recurrent duodenal ulcers 30 years ago and median laparotomy of the upper abdomen because of blunt abdominal trauma 9 years ago shows the formation of metastasis of a carcinoma found in the gastroenteral anastomosis in a focus of heterotopic ossification, which was located in the scar of the upper abdominal laparotomy.

[Corrective arthrodesis in isolated post-traumatic malalignment of the subtalar joint]. / Die Korrekturarthrodese bei isolierten posttraumatischen Fehlstellungen im Subtalargelenk.

Between 1990 and 1995, 27 patients with posttraumatic disorders of the subtalar joint were treated by correcting fusion. Preoperatively 24 patients (88.89%) suffered from pain; 15 (55.56%) had a walking range below 100 m. Seven patients were unable to work in their original profession. After an average period of 13.85 months postoperatively the patients were examined again. At this time 18 (66.67%) had no or minimal pain; 19 (70.37%) had no claudication. According to the score of Angus and Skuginna, in 81.48% of patients the result of the correcting arthrodesis was successful; according to Kitaoka's clinical rating system for ankle-hindfoot, midfoot, hallux and lesser toes, the average postoperative score was 75.8 points.

Histopathological Osteomyelitis Evaluation Score (HOES) - an innovative approach to histopathological diagnostics and scoring of osteomyelitis.

BACKGROUND: Treatment and diagnosis of osteomyelitis are still a challenging problem for surgeons, microbiologists and histopathologists. A direct microbiological detection of bacteria in tissues is still gold standard, but it is not always successful for example in chronic osteomyelitis and/or when an antibiotic treatment has already been started or in cases of low virulent bacteria. The goal of this study was to define diagnostic criteria of osteomyelitis, the inflammatory regression of osteomyelitis ("osteomyelitis score") under specific therapy by the correlation of histopathological and microbiological and clinical standard tests. METHODS: In this retrospective analysis patients with medical history and clinically clear signs of bacterial infection and osteomyelitis underwent surgery between 01.01.2013 and 31.12.2012. Their formal consent was given. Tissue samples were taken during surgery according to defined criteria including surgical interventions. Histopathological diagnosis was carried out by conventional techniques based on defined criteria of bacterial infection in connective tissue, peri-implant membrane and bone. These results were carried out in tables by numbers representing the histopathological criteria of acute osteomyelitis (A1 to A3) as well as the chronic criteria (C1 and C2) in a semiquantitative way (scale 0 to 3). On the other hand a notational, graduated histopathological report was performed. Preoperative clinical diagnosis, perioperative macroscopic diagnosis, histopathological and microbiological findings were correlated. RESULTS: Histopathological samples of 52 surgical interventions based on the preoperative diagnosis "osteomyelitis" (AOM, ECOM or COM) were included. 37 times preoperatively signs of a chronic osteomyelitis (COM), 10 times preoperatively acute osteomyelitis (AOM) was diagnosed. Another 5 patients were preoperatively diagnosed as acute exacerbated osteomyelitis (ECOM). The correlation of the histopathological infection including the inflammatory activity and microbiological detection of bacteria was 57%. The correlation between preoperative diagnosis and histopathological findings was 68%. CONCLUSION: The relatively small 68% correlation between clinical preoperative and histopathological diagnosis and 57% correlation between preoperative clinical diagnosis and microbiological findings indicates: Clinical findings are not sufficient for the diagnosis "osteomyelitis".Clinical findings are not sufficient for the differentiation between AOM, ECOM and COM.Histopathological analysis is the critical factor for the diagnosis ("osteomyelitis") and differential diagnosis (AOM vs. COM).Histopathological analysis represents the basis for further treatment.HOES facilitates the classification of the histopathological findings.HOES is a sufficient tool for the treating physician in order to define the further treatment.

[Classification of haematogenous and post-traumatic osteomyelitis]. / Klassifikation der Osteomyelitis und Osteitis.

A classification of osteomyelitis must reflect the complexity of the disease and, moreover, provide conclusions for the treatment. The classification is based on the following eight parameters: source of infection (OM [osteomyelitis]/OT [post-traumatic OM]), anatomic region, stability of affected bone (continuity of bone), foreign material (internal fixation, prosthesis), range of infection (involved structures), activity of infection (acute, chronic, quiescent), causative microbes (unspecific and specific bacteria, fungi) and comorbidity (immunosuppressive diseases, general and local). In the long version of the classification, which was designed for scientific studies, the parameters are named by capital letters and specified by Arabic numbers, e.g., an acute, haematogenous osteomyelitis of a femur in an adolescent with diabetes mellitus, caused by Staphylococcus aureus, multi-sensible is coded as: OM2 Lo33 S1a M1 In1d Aa1 Ba2a K2a. The letters and numbers can be found in clearly arranged tables or calculated by a freely available grouper on the internet (www.osteomyelitis.exquit.net). An equally composed compact version of the classification for clinical use includes all eight parameters, but without further specification. The above-mentioned example in the compact version is: OM 3 S a Ba2 K2. The short version of the classification uses only the first six parameters and excludes causative microbes and comorbidity. The above mentioned example in the short version is: OM 3 S a. The long version of the classification describes an osteomyelitis in every detail. The complexity of the patient's disease is clearly reproducible and can be used for scientific comparisons. The for clinical use suggested compact and short versions of the classification include all important characteristics of an osteomyelitis, can be composed quickly and distinctly with the help of tables and provide conclusions for the individual treatment. The freely available grouper (www.osteomyelitis.exquit.net) creates all three versions of the classification in one step.

[Superinfected epidermal inclusion cyst of the thigh with development of squamous cell carcinoma--case report of a rare complication]. / Superinfektion einer epidermalen Inklusionszyste des Oberschenkels mit Ausbildung eines Plattenepithelkarzinoms--Fallbericht einer seltenen Komplikation.

Epidermal cysts (atheroma) are the most common benign tumours of the skin with ubiquitous localisation all over the body. However, rupture of the atheroma and formation of an inclusion cyst with additional superinfections are frequently seen. Malignant transformations have rarely been reported. Presented here is the unusual case of a 65-year-old woman with multiple atheromas and a distinctive tumour of the upper limb. Imaging diagnostics showed malignant deformation. Contrary to the imaging findings the histological/microbiological examination showed an enormous superinfected and ruptured epidermoid cyst with multiple abscess formation in the ventral upper limb. Radical surgical restoration with salvage of the limb was frustrated because of honey-combed anterior soft tissue and the changing bacterial spectrum. After resection of the complete ventral compartment, remission was realised approximately. In the follow-up there was a recurring infection with spontaneous fistula formation that histologically impressed as a squamous cell carcinoma. After proximal ablation of the upper limb, total rehabilitation of the infection as well as the malignoma could be achieved.

Revised histopathological consensus classification of joint implant related pathology.

This extended classification of joint implant related pathology is a practical histopathologic classification based on defined morphological criteria covering the complete spectrum of pathohistologic changes in periprosthetic tissues. These changes may occur as a consequence of endoprosthetic replacement of large joints and may lead to a reduction in the prosthesis survival rate. We describe the established consensus classification of the periprosthetic membrane, in which aseptic and septic prosthetic loosening can be subdivided into four histological types, as well as histopathological criteria for additional significant pathologies including endoprosthetic-associated arthrofibrosis, particle-induced immunological, inflammatory and toxic mechanisms (adverse reactions), and bone tissue pathologies. These characteristic tissue alterations and their relationships are summarized in the extended classification. Since particle heterogeneity in periprosthetic tissue is high and particle identification is a necessary part of diagnosis, the identification of different types of particles is described in the histopathological particle algorithm. The morphological qualities of prosthetic material particles and the demarcation between abrasion and non-abrasion endogenous particles are also summarized. This feasible classification which is based on low cost standard tissue processing and examination and on well-defined diagnostic criteria is a solid platform for the histological diagnosis of implant associated pathologies providing a stable and reproducible tool for the surgical pathologist. Since this classification is suitable for standardized histopathological diagnostics, it might also provide a useful data set for joint arthroplasty registers, particularly for registers based on so-called routine data.

Wound irrigation within the surgical treatment of osteomyelitis.

The basic treatment of osteomyelitis remains even today the surgical debridement in combination with a wound irrigation by lavage systems. Next to a comprehensive knowledge of the surgical techniques a profound knowledge of the lavage systems, the rinsing solutions used and the philosophies of revision programs are a must. In this article the typical hardware of modern lavage systems is analysed, their advantages and disadvantages are pointed out. In addition we investigate the value of common antiseptic wound irrigation solutions for their use in osteomyelitis therapy. Finally the two basic philosophies of wound revision and irrigation in the course of osteomyelitis therapy are presented and discussed.

Adult calcaneal osteitis: incidence, etiology, diagnostics and therapy.

Calcaneal osteomyelitis presents a complicated situation. The specific anatomy of the os calcis and its surrounding soft tissues plays an important role in the planning and realization of the procedures needed in order to eradicate the osteomyelitic focus. The calcaneus represents a spongious bone; a fact that supports the developement of an osteomyelitis. It is the strongest bone of the foot and is highly important for the biomechanical features of physiological walking. The surrounding soft tissues are thin and contain various important anatomical structures. These might be damaged during the treatment of the osteomyelitis. In addition the vascularization of the os calcis is delicate and may be compromized during the surgical osteomyelitis treatment. Calcaneus osteomyelitis may be classified based on the routes of infection into exogenous and endogenous forms. Additionally from the clinical point of view acute and chronic forms may be distinguished from an early and a late infection. Exogenous calcaneal osteomyelitis mostly is the result of an infection with S. aureus. The treatment is equal to the therapy in other locations and based on: Eradication of the bone infectionSanitation of the soft tissue infectionReconstruction of bone and soft tissue Especially the preservation and restoration of the soft tissue is important. Thus plastic surgical procedures play an essential role. The main object of treatment is the preservation of a biomechanical functioning foot. This may be impossible due to the local situation. Calcanectomy or even below knee amputation may be needed in those cases.

[Imaging diagnostics of osteitis, osteomyelitis and joint infections]. / Bildgebende Diagnostik bei Osteitis/Osteomyelitis und Gelenkinfekten.

Imaging diagnostics and surgical treatment of bone and joint infections are of paramount interest. The main purpose of our survey is to give a detailed overview about methods, indications, image criteria and efficiency of imaging diagnostics as a state of the art presentation. In conclusion we attempt to give some recommendations for clinical scenarios and diagnostic procedures concerning bone and joint infections. This paper has been prepared under the patronage of the AG Septische Chirurgie of the Deutsche Gesellschaft für Unfallchirurgie in Germany. It is our aim to update the paper with respect to the technical and clinical improvements and to publish it again after a number of years.

[Risk Assessment in the Therapy for Osteomyelitis using Immunological Parameters]. / Risikoeinschätzung bei der Therapie der Osteitis anhand immunologischer Parameter.

PROBLEM: The treatment of osteomyelitis is based on the surgical eradication of the septic focus and the additional administration of antibiotics (local and/or systemic). In some cases the course of the therapy may be prolonged without any obvious reason in terms of the quality of the surgical treatment, virulence and type of bacteria or the co-morbidities. ISSUE: Can these patients at risk be detected by immunological assessments? Will these immunological features lead to a more individualised therapeutic strategy? PATIENTS: 20 patients suffering from chronic osteomyelitis of the lower extremity were included in our study. Group 1: 15 patients showed a prolonged course of the disease and/or an abnormal high rate of surgery. These courses could not be correlated with the bacterial spectrum or the co-morbidities. Group 2: 5 patients showed a clinical course as expected. METHODS: Blood samples of all patients were analysed by immunological methods: lymphocytes were analysed by using 8 colour flow cytometry. CD4/8 ratio and double negative T cells were calculated. T cell response to recall antigens was determined by elispot testing. RESULTS: In group 1 double negative T cell and cytotoxic T cell counts were significantly lower in comparison to group 2. This was not the case for T cells and T helper cells. In ROC analysis, area under the curve (AUC) analysis revealed best discrimination by double negative T cells (0.88). At a cut-off of 60 double negative T cells/µL, discrimination of septic complications revealed 100 % specificity and 87 % sensitivity. In elispot testing, reactivity to tetanus toxoid established best results (AUC 0.76). CONCLUSION: The analysis of the above data shows that the detection of higk-risk patients during the therapy for osteomyelitis based on immunological features seems to be possible. Further studies are needed to verify the data collected from our pilot study.

[Vacuum-assisted closure therapy for the treatment of skin and soft-tissue infections. Are wound specimens of use in planning secondary wound closure?]. / Vakuumtherapie bei Haut- und Weichgewebsinfektionen der Extremitäten. Nutzen des Wundabstrichs bei der Planung des sekundären Wundverschlusses?

AIM: Vacuum-assisted closure is used frequently for the treatment of skin and soft-tissue infections (SSTI) of the extremities. After debridement and repeated VAC dressing changes, the wounds are closed by secondary suture, split-thickness skin grafts or local flaps. However, no objective parameters describe the time point for secondary wound closure. Our thesis was that negative microbiological results from wound specimens can indicate the time for secondary wound closure. PATIENTS AND METHODS: 24 patients with SSTI of the extremities were treated by serial debridements and VAC therapy and analysed prospectively. Debridements were repeated until the wounds were macroscopically free from signs of infection (good granulation/no necrosis). During each revision specimens were taken for microbiological analysis. Moreover, number of revisions, bacterial cultures, type of wound closure and wound status after 3 years and 5 months on average after the last surgery were analysed. RESULTS: 6.3 revisions on average were performed until secondary wound closure was possible. In spite of the absence of macroscopic infection, bacteria were still found in tissue samples from 14 of 24 wounds. 6 wounds were free of bacteria for the first time right before wound closure, 3 wounds had become negative during the treatment. After 3.4 years on average, the wounds of all 18 patients available for examination had healed well and were free from signs of infection. CONCLUSION: Vacuum-assisted closure resulted in clean, good granulating wounds without necrosis. However, in more than half of the wounds bacteria persisted. This bacterial load had no correlation to wound healing and outcome after over 3 years. In conclusion, microbiological tissue samples are not suitable as indicator for the time point of secondary wound closure in SSTI.

[Vacuum-assisted closure therapy for the treatment of acute postoperative osteomyelitis]. / Vakuumtherapie bei akuter postoperativer Osteitis.

AIM: Vacuum-assisted closure is used frequently for the treatment of posttraumatic osteomyelitis of the extremities. After debridement and repeated VAC dressing changes, the wounds are closed by secondary suture, split-thickness skin grafts or local flaps. However, no objective parameters describe the time point for secondary wound closure. Our thesis was that negative microbiological results from bone specimens can indicate the time for secondary wound closure. Moreover, treatment course and clinical outcome after 3.4 years should be compared to those of other surgical approaches for acute postoperative osteomyelitis from the literature. PATIENTS AND METHODS: 43 patients with acute postoperative osteomyelitis of the extremities and the pelvis were treated by serial bone and soft tissue debridements and VAC therapy and analysed prospectively. Debridements were repeated until the wounds were macroscopically free from signs of infection (good granulation/no necrosis). During each revision a bone specimen was taken for microbiological analysis. Number of revisions, bacterial cultures, type of wound closure and recurrence of infection after 3 years and 5 months on average after the last surgery was analysed. RESULTS: 9.8 debridements on average were performed until eradication of infection and secondary wound closure. Despite the absence of macroscopic infection, bacteria were still found in bone samples from 15 of 43 patients. Three biopsies were free of bacteria for the first time right before wound closure, 25 samples had become negative during the treatment. Six recurrences (19.3 %) were noted after 3.4 years on average. Four patients from the group of negative bone biopsies (19 %) and two patients from the group of persisting bacteria before secondary closure (20 %) had a recurrence of infection. CONCLUSION: In about one third of the bone biopsies bacteria persisted. This bacterial load had no correlation to wound healing and rate of recurrence after over 3 years. In conclusion, microbiological bone samples are not suitable as an indicator for the time point of secondary wound closure. Compared to other treatment options in acute postoperative osteomyelitis from the literature (especially implantation of local antibiotics), no advantage of vacuum-assisted closure could be shown concerning number of debridements and rate of recurrences.