Adult posttraumatic osteomyelitis of the tibia

Evaluation and Management of Pelvic Osteomyelitis in Stage IV Pressure Injuries: A Multidisciplinary Collaborative Approach

Managing pelvic osteomyelitis (POM) in the setting of stage IV pressure injuries requires multidisciplinary evaluation as well as patient and caregiver engagement and is complicated by the lack of high-evidence data to guide best practices. In this review, we describe our approach to pressure injury and POM evaluation and management through multidisciplinary collaboration and highlight areas of future research that are necessary to enhance patient outcomes, reduce healthcare costs, and improve the quality of life of those affected by POM.

A retrospective study of the anterolateral thigh perforator flap in the treatment of chronic osteomyelitis of the leg with skin defects

Background

As a chronic inflammatory process, chronic osteomyelitis is caused by bacterial infections that lead to bone destruction. This disease is more common in patients with open fractures and those undergoing multiple surgical procedures after trauma. We aimed to provide a comprehensive overview and critical assessment of the therapeutic efficacy of the anterolateral thigh (ALT) perforator flap in the management of chronic osteomyelitis with dermatologic and soft tissue imperfections localized in the lower extremity.

Methods

A retrospective analysis involving a cohort of 16 patients who underwent ALT perforator flap reconstruction for the management of chronic osteomyelitis in the calf region that manifested with integumentary deficiencies was conducted.

Results

During the follow-up period spanning from 4 months to 2 years, all 16 patients who underwent ALT perforator flap transplantation exhibited flap viability. Among these cases, 15 patients made a full recovery from the infection and 1 patient had partial survival. Among the 15 cases, 2 patients developed vascular crisis (owing to venous thrombosis during surgical exploration). One patient had a relapse of the disease 1-year post-surgery. The success rate of this surgical method was 15/16, and the surgical complications included flap crisis, flap necrosis, delayed wound healing, and recurrence of infection.

Conclusion

The ALT perforator flap, which can cover bone and soft tissues and effectively control infections, can be applied to the treatment of chronic osteomyelitis of the lower limbs with skin defects. Overall, the muscle flap fills the dead space and medullary cavity and skin flap covers the skin defect.

Infection rates and risk factors with magnetic intramedullary lengthening nails

Introduction

Surgical site infection (SSI) related to magnetic intramedullary lengthening nails (MILNs) can lead to delayed consolidation or loss of limb function, resulting in deleterious effects to a patient's quality of life. With the rise of MILNs, we sought to determine the incidence rate and risk factors for infection during limb lengthening with MILNs.

Methods

We reviewed a consecutive series of patients who underwent femoral and/or tibial lengthening with an MILN at a single institution between 2012 and 2020 (n = 420). SSI was defined according to CDC-NHSN criteria (including superficial and deep infections) with postoperative surveillance time of 12 months. Demographic, health metrics, comorbidities, limb- and surgery-related factors, were assessed as potential risk mediators of SSI.

Results

Incidence of SSI was 3.3 % (14/420). This was divided into superficial (0.5 %,2/420) and deep (2.9 %, 12/420) infections. Of deep infections, 75 % (9/12) were osteomyelitis. Of the 14 limbs that developed SSI, 57 % (8/14) had a history of prior external fixation in the same limb and 38 % (5/14) had a previous infection of the same limb. A subanalysis of patients with a history of prior external fixation in the same bone was associated with SSI, as compared to those without previous external fixation. None of the surgery-related infection risk factors reached statistical significance.

Discussion and conclusion

The total incidence of infection with MILNs was 3.3 % at 24 months follow-up. The risk of deep infection was 2.9 %. Patients with a history of previous external fixation and prior infection show an independent association with increased rate of infection recurrence in the same bone. These patients could be considered a high-risk group for developing deep tissue infection. Potential algorithms include prolonged oral antibiotics after MILN insertion or simultaneous injection of absorbable antibiotic at the time of the nail insertion.

A modified induced membrane 2-stage technique using a thoracodorsal artery perforator free flap followed by vascularized or non-vascularized free fibular transfer for the treatment of complex bone infection with concomitant severe soft tissue lesion-A case series of 9 cases

Treatment of post-traumatic complex bone infection is very challenging. The two principal bone reconstruction approaches are the single-stage vascularized bone graft technique and the two-stage induced membrane technique (IMT). Here we introduce a modified 2-stage induced membrane technique (MIMT) for complex long bone infection with a major bone defect and a concomitant severe soft tissue lesion. The 2-stage procedure consists of bone debridement, placement of a PMMA spacer and soft tissue reconstruction with a thoracodorsal artery perforator free flap ("Tdap") at stage 1. At stage 2, the thoracodorsal artery perforator flap is elevated and a fibular strut graft (either vascularized of non-vascularized) is placed for bone reconstruction. We retrospectively analyzed the extents of lower extremity, long bone, post-traumatic bone infection treated via MIMT from 2008 to 2020. There were nine such cases (eight males) of mean age 59.8 (range 31 to 79) years. The osteomyelitis durations ranged from 3 to 360 months (mean 53 months). The cortical bone defect sizes was ranged from 9 to 14 cm (mean10.7 cm). All skin resurfacing employed Tdap. Vascularized fibular grafts were placed in six patients and non-vascularized grafts were placed in three. The fibular graft size ranged from 12.5 to 19 cm (mean 16.2 cm). Non-vascularized iliac bone grafts served as the fibula docking sites. Unfortunately, all patients suffered complications before bone union was achieved. One case of plate stress fracture and one case of screw fracture required plate and screw change. In three cases of cellulitis, one resolved by use of intravenous antibiotics, others required plate and screw removal. Wound disruption required re-suture and distal skin flap partial necrosis was covered by perforator-based island flap. One case of fibular stress fracture needed cast for 4 weeks. A peroneal nerve palsy patient recovered spontaneously. Bone union was achieved after 6 months in five patients and after 8 months in three (mean 6.9 months). All patients were able to walk unaided. The follow-up period ranged from 2 to 14 years (mean 6.2 years). MIMT saves the limbs in cases with difficult post-traumatic bone infection. It is valid treatment option for complex bone infections with severe soft tissue lesions. However, even with this technique potential complication must be considered.

Treatment of chronic osteomyelitis with antibiotic-impregnated polymethyl methacrylate (PMMA) - the Cierny approach: is the second stage necessary?

Background

Chronic osteomyelitis is a challenge for orthopedic surgeons. Most patients with osteomyelitis receive two-stage management according to Cierny-Mader. The first stage includes radical debridement and insertion of an antibiotic-impregnated cement spacer (ACS) (beads, rods, nails, or blocks) into the bone defect. The second stage is performed 6–8 weeks later, when the spacer is removed and a cancellous autograft is placed within the bone defect. The possibility of ACS as definitive management for osteomyelitis, avoiding the second stage, is presented.

Methods

Sixteen patients with osteomyelitis received radical debridement and insertion of an ACS in all forms into the bone defect as a definitive management. In 8 patients, the tibia was infected, 4 had femur infection, 2 humerus, 1 fibula, and 1 ankle. The mean age at the time of the first stage of reconstruction was 49 years (range, 13–71 years). According to the Cierny-Mader classification, 1 patient was C-M IA, another was IB, 7 IIIA, 6 IIIB, and 1 was 4A. All B hosts had systemic illnesses. The mean follow-up period was 6 years (1.5–16 years).

Results

No patient exhibited radiographic evidence of excessive bone loss. Signs of recurrence of osteomyelitis were not noted in any of the patients, and no fractures had occurred by the last follow-up.

Conclusion

Our study suggests that a proportion of patients with planned retention of ACS appear to function well without requiring further surgical intervention, especially in elderly or vulnerable patients.

How Successful Is Antibiotic Treatment for Superficial Surgical Site Infections After Open Fracture? A Fluid Lavage of Open Wounds (FLOW) Cohort Secondary Analysis

BACKGROUND

Although many studies report the incidence and prevalence of surgical site infections (SSIs) after open fractures, there is limited information on the treatment and subsequent outcomes of superficial SSIs in patients with open fractures. Additionally, clinical studies describing the factors that are associated with persistent infection after nonoperative treatment with antibiotics for patients with superficial SSIs are lacking.

QUESTIONS/PURPOSES

Therefore, we asked: (1) What proportion of patients with superficial SSIs after open fracture treatment developed persistent infection after nonoperative treatment (that is, treatment with antibiotics alone)? (2) What risk factors are associated with SSIs that do not resolve with nonoperative (antibiotic) treatment? As a secondary objective, we planned to analyze the microbiological information about participants wound cultures, when these were available, and the proportion of positive cultures for patients whose SSIs were not resolved by antibiotics alone.

METHODS

This is a secondary analysis of the Fluid Lavage of Open Wounds (FLOW) trial dataset. The FLOW trial included 2445 patients with operatively managed open fractures. FLOW participants who had a nonoperatively managed superficial SSI diagnosed in the 12 months post-fracture were included in this analysis. Superficial SSIs were diagnosed in 168 participants within 12 months of their fracture. Of these, 83% (139) had their superficial SSI treated with antibiotics alone. Participants were grouped into two categories: (1) 97 participants whose treatment with antibiotics alone resolved the superficial SSI and (2) 42 participants whose treatment with antibiotics alone did not resolve the SSI (defined as undergoing surgical management or the SSI being unresolved at latest follow-up [12-months post-fracture for the FLOW trial]). Of the participants whose treatment with antibiotics alone resolved the SSI, 92% (89 of 97) had complete follow-up, 6% (6 of 97) were lost to follow-up before 12 months, 1% (1 of 97) withdrew consent from the study before 12 months, and 1% (1 of 97) experienced mortality before 12 months. Of the participants whose treatment with antibiotics alone did not resolve the SSI, 90% (38 of 42) had complete follow-up, 7% (3 of 42) were lost to follow-up before 12 months, and 2% (1 of 42) withdrew consent from the study before 12 months. A logistic binary regression analysis was conducted to identify factors associated with persistent infection despite superficial SSI antibiotic treatment. Based on biologic rationale and previous evidence, we identified a priori 13 potential factors (corresponding to 14 levels) to be included in the regression model.

RESULTS

The antibiotic treatment resolved the superficial SSI in 70% (97 of 139) of patients and did not resolve the SSI in 30% (42 of 139). After controlling for potential confounding variables, such as age, fracture severity, and time from injury to initial surgical irrigation and débridement, superficial SSIs diagnosed later in follow-up were associated with antibiotics not resolving the SSI (odds ratio 1.05 [95% CI 1.004 to 1.009] for every week of follow-up; p = 0.03). Sex, fracture pattern, and wound size were not associated with antibiotics not resolving the SSI.

CONCLUSIONS

Our secondary analysis of prospectively collected FLOW data suggests that antibiotics alone can be an appropriate treatment option when treating superficial SSIs after an open fracture wound, especially when promptly diagnosed. Further research with longer follow-up time is needed to better identify the natural history of superficial SSIs and possibly some dormant or subclinical infections to help clinicians in the treatment decision-making process.

LEVEL OF EVIDENCE

Level III, therapeutic study.

MRI Diagnosis for Post-Traumatic Osteomyelitis of Extremities Using Conventional Metal-Artifact Reducing Protocols: Revisited

RATIONALE AND OBJECTIVES

To assess the diagnostic power of MR imaging features for post-traumatic osteomyelitis (PTOM) of the extremities with metal implants using a 3.0-T machine with conventional metal-artifact reducing (MAR) protocols.

MATERIALS AND METHODS

Between December 2012 and September 2016, 261 consecutive patients underwent MRI for clinical suspicion of PTOM in the appendicular skeleton at our hospital. A total of 72 enrolled patients with metal implants were divided into two groups, one with surgical, histologic, or microbiologic proven to be PTOM, and the other proven not to be PTOM. Their MR images were reviewed by two musculoskeletal radiologists who qualitatively analyzed various findings regarding PTOM, and concluded diagnosis of PTOM or without PTOM for each patient. All MR images were obtained using conventional MAR protocols.

RESULTS

The sensitivity, specificity, positive and negative predictive values, and accuracy of MR diagnosis by two observers were 55%/38%, 81%/93%, 67%/40%, 73%/78%, and 71%/71%, respectively. Among the findings, T1 low signal intensity, medullary location, confluent pattern, typical features (concurrence of T1 low signal intensity, medullary, and confluent patterns), heterogeneous or no enhancement, and cortical destruction were statistically significant by univariate analysis (p<0.05). Among these features, only medullary involvement was significant by multivariate analysis (p = 0.007). Medullary involvement and no enhancement pattern were significant by step-wise discrimination analysis. Interobserver correlation was moderate with a weighted kappa value of 0.512 (confidence interval: 0.3-0.723).

CONCLUSION

The overall accuracy for diagnosis of PTOM of the extremities using 3.0-T MRI with conventional metal-artifact reduction parameters was 71%. The strongest diagnostic MR imaging feature was medullary involvement of T1 low signal intensity. PTOM of the extremities can be accurately diagnosed with a 3.0-T MR machine using conventional MAR protocols.

Bacterial resistance trends among intraoperative bone culture of chronic osteomyelitis in an affiliated hospital of South China for twelve years

Background

The purpose of this study was to gather temporal trends on bacteria epidemiology and resistance of intraoperative bone culture from chronic ostemyelitis at an affiliated hospital in South China.

Method

Records of patients with chronic osteomyelitis from 2003 to 2014 were retrospectively reviewed. The medical data were extracted using a unified protocol. Antimicrobial susceptibility testing was carried out by means of a unified protocol using the Kirby-Bauer method, results were analyzed according to Clinical and Laboratory Standards Institute definitions.

Result

Four hundred eighteen cases met our inclusion criteria. For pathogen distribution, the top five strains were Staphylococcus aureus (27.9%); Pseudomonas aeruginosa (12.1%); Enterobacter cloacae (9.5%); Acinetobacter baumanii (9.0%) and Escherichia coli (7.8%). Bacterial culture positive rate was decreased significantly among different year-groups. Mutiple bacterial infection rate was 28.1%. One strain of Staphylococcus aureus was resistant to linezolid and vancomycin. Resistance of Pseudomonas aeruginosa stains to Cefazolin, Cefuroxime, Cefotaxime, and Cefoxitin were 100% nearly. Resistance of Acinetobacter baumanii stains against Cefazolin, Cefuroxime were 100%. Ciprofloxacin resistance among Escherichia coli isolates increased from 25 to 44.4%. On the contrary, resistance of Enterobacter cloacae stains to Cefotaxime and Ceftazidime were decreased from 83.3 to 36.4%.

Conclusions

From 2003 to 2014, positive rate of intraoperative bone culture of chronic osteomyelitis was decreased; the proportion of Staphylococcus aureus was decreased gradually, and our results indicate the importance of bacterial surveilance studies about chronic osteomyelitis.

Osteomyelitis Complicating Sacral Pressure Ulcers: Whether or Not to Treat With Antibiotic Therapy

The treatment of osteomyelitis in patients with stage IV sacral pressure ulcers is controversial. We conducted a systematic literature review and did not find evidence of benefit of antibacterial therapy in this setting without concomitant surgical debridement and wound coverage. Furthermore, many patients with chronically exposed bone do not have evidence of osteomyelitis when biopsied, and magnetic resonance imaging may not accurately distinguish osteomyelitis from bone remodeling. The goal of therapy should be local wound care and assessment for the potential of wound closure. If the wound can be closed and osteomyelitis is present on bone biopsy, appropriate antibiotic therapy is reasonable. We find no data to support antibiotic durations of >6 weeks in this setting, and some authors recommend 2 weeks of therapy if the osteomyelitis is limited to cortical bone. If the wound will not be closed, we find no clear evidence supporting a role for antibiotic therapy.

Chronic Osteomyelitis - Bacterial Flora, Antibiotic Sensitivity and Treatment Challenges

Background:

Chronic osteomyelitis is a catastrophic sequel of delayed diagnosis of acute osteomyelitis.

Objectives:

The objectives of the study were to determine bacterial flora and antibiotic sensitivity, and to evaluate the outcome of an aggressive surgical approach to chronic osteomyelitis.

Methods:

This is a single surgeon, prospective cohort study on 30 consecutive patients with clinically and radiologically diagnosed chronic osteomyelitis presented to a hospital. We prospectively recorded demographic, clinical, radiological features, treatment protocol, microbiologic results of culture and sensitivity. The main treatment outcome measures were clinical signs of eradication of infection.

Results:

Microbiologic results showed that Gram-negative and mixed flora accounts for more than half of chronic osteomyelitis cases while Staphylococcus aureus was a dominating single pathogen (39%). We detected a high resistance rate to common antibiotics, e.g. 83% of S. aureus isolates were resistant to oxacillin (MRSA). The mean duration of bone infection was 4.2 years (3 months to 30 years) and the mean number of operations was 1.5 (1-5) . The mean follow-up was 15 months (12-18 months). Infection was eradicated in 95% (21 out of 22) treated by a single procedure and in all patients (n=8) by double procedure.

Conclusion:

Presented the high rate of MRSA strains is alarming and calls for updating of the antibiotic therapy guidelines in the country. Good results in treatment of chronic osteomyelitis can be achieved by a single-stage protocol including radical debridement combined with systemic and topical antibiotic.

The psychological impact of external fixation using the Ilizarov or Orthofix LRS method to treat tibial osteomyelitis with a bone defect

OBJECTIVE

To examine the psychological impact of external fixation for a tibial bone defect due to osteomyelitis, and to compare the Orthofix limb reconstruction system (LRS) with the Ilizarov external fixator.

MATERIALS AND METHODS

The SCL-90-R questionnaire was administered at four different time points (before surgery, while patients wore the external fixation device, when the device was removed, and two to three months after). The scores at the four time points were compared, as were the two different methods of external fixation (Orthofix LRS vs. Ilizarov).

RESULTS

The patients experienced a significant adverse impact on their mental health, with the worst outcomes at Time 2 (while wearing the external fixator), but with some negative effects still present even several months after removal of the fixation device. Although the Orthofix LRS and Ilizarov groups showed similar mental health scores at Time 1 (preoperatively) and Time 3 (upon removal of the fixation device), the Orthofix LRS was associated with better scores, specifically in the Hostility (Time 2), Phobic Anxiety (Time 2), Psychoticism (Times 2 and 4), and Other (Time 2) sub-scores, as well as the total score (Times 2 and 4).

CONCLUSIONS

Although both Ilizarov and Orthofix LRS fixation resolved the bone defects, external fixation had a negative impact on the patients' mental health, which persisted even after removal of the devices. Although both methods led to negative effects on the patients' mental, the impact of the Orthofix LRS was less severe.

Adaptive and Pathological Reshuffling in the Venous Wall in Special Hemodynamic Conditions-Acquired Arteriovenous Fistula

Hemodialysis and peritoneal dialysis are the two possible choices in chronic renal disease in the uremic stage. Native arteriovenous fistula is susceptible to complications, some posing vital risk and requiring prompt treatment. We present the case of a patient undergoing hemodialysis on native AVF. An aneurism developed progressively on the arterialized cephalic vein. The AVF was abolished by closing the arteriotomy with a venous patch and excising the aneurismal venous segment. The pathology exam of the surgical specimen showed unequal vessel wall thickness due to hyperplasia of the media and subintimal space, with calcifications within the hyperplastic media.

Case Presentation of Soft Tissue Defect after Bimalleolar Fracture Osteosynthesis

A 59-year-old patient presented in the ER with wound dehiscence and skin necrosis on the right ankle, with osteosynthesis implant visible, after open reduction and fixation with plate and screws, performed abroad, 16 days prior to the presentation, for a bimalleolar fracture. The patient was admitted to the plastic surgery department, where surgical debridement of the necrotic tissue was initially performed. Postoperatively, the patient was treated with Negative-pressure wound therapy (VAC dressing) and Platelet rich plasma (PRP) therapy. Upon obtaining granulation tissue without signs of infection, a sural fasciocutaneous flap was performed to cover the skin defect. Proper graft integration and healing was observed.

Outcomes of cement beads and cement spacers in the treatment of bone defects associated with post-traumatic osteomyelitis

Background

Cement spacers (Masquelet technique) have traditionally been used for the treatment of segmental bone defects. However, no reports have used cement spacers for the treatment of small/partial segmental bone defects associated with osteomyelitis and compared the outcomes with cement beads.

Methods

We retrospectively analysed 40 patients with post-traumatic osteomyelitis of the tibia who underwent treatment, which was performed in two stages. In the first stage, thorough debridement was performed, and bone defects were filled with either antibiotic-impregnated cement beads (bead group, 18 patients) or spacers (spacer group, 22 patients). In the second stage, the cement beads or spacers were removed (for the spacer group, the induced membrane formed by the spacer was preserved) and the bone defects were filled with cancellous autografts.

Results

All patients in the bead group had small/partial segmental bone defects after debridement, while 3 patients in the spacer group had large/segmental bone defects.

The mean volume of bone defects of the spacer group (40.4 cm³) was significantly larger than that of the bead group (32.4 cm³). The infection control rate (88.9%,16/18 vs 90.9%, 20/22), bone healing time (8.5 months vs 7.5 months) and complication rates (22.2%, 4/18 vs 27.2%, 6/22) were comparable between bead group and spacer group.

Conclusion

The results of this study suggest that cement spacers may have an infection control rate comparable to cement beads in the treatment of bone defects associated with post-traumatic osteomyelitis. Furthermore, cement spacers could be used for the reconstruction of small/partial segmental bone defects as well as for large/segmental bone defects, whereas cement beads were not suitable for the reconstruction of large/segmental bone defects.

Radiologic Approach to Musculoskeletal Infections

Imaging is often used to establish a diagnosis of musculoskeletal infections and evaluate the full extent and severity of disease. Imaging should always start with radiographs, which provide an important anatomic overview. MRI is the test of choice in most musculoskeletal infections because of its superior soft tissue contrast resolution and high sensitivity for pathologic edema. However, MRI is not always possible. Alternative imaging modalities including ultrasound scan, computed tomography, and radionuclide imaging may be used. This article reviews the individual imaging modalities and discusses how specific musculoskeletal infections should be approached from an imaging perspective.

Global Forum: The Burden of Bone and Joint Infections: A Growing Demand for More Resources

The rate and severity of septic complications following joint replacement surgery and the incidence of posttraumatic infections are projected to increase at a faster pace because of a tendency to operate on high-risk patients, including older patients, patients with diabetes, and patients who are immunocompromised or have comorbidities. Musculoskeletal infections are devastating adverse events that may become life-threatening conditions. They create an additional burden on total health-care expenditures, and can lead to functional impairment, long-lasting disability, or even permanent handicap, with the inevitable social and economic burdens. The scientific community should take a more active role to draw public attention to the plight of hundreds of thousands of people across the globe who experience complications, become disabled, and, in some cases, die, and it should highlight what could be achieved if the global community takes decisive steps to improve access, early detection, and appropriate care. However, mitigating the adverse personal, clinical, and socioeconomic effects of these conditions requires increasing financial resources provided by both governments and funding organizations. Furthermore, a targeted action plan from the providers and the professional societies should be put in place so that the burden created by bone and joint infections is included in the agenda for global health-care priorities.

Two stage management of Cierny-Mader type IV chronic osteomyelitis of the long bones

INTRODUCTION

Cierny-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 large bone and soft tissue loss in treating this type of osteomyelitis. The potentially large defects increase reconstruction problems with traditional reconstruction technique. The newly staged induced membrane technique presents length-independent, potential as an alternative reconstruction method for segmental bone defects due to type IV chronic osteomyelitis. The purpose of this study was to assess the result and related factors of C-M type IV chronic osteomyelitis treated with staged methods of aggressive debridement and induced membrane technique.

METHODS

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. The clinical and imaging results were retrospectively analyzed.

RESULTS

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 5.5cm (range: 2-10.9) segmental bone defect; Sixteen patients had autograft and twenty had autograft mixed allograft in the second stage. The mean follow-up time was 29.5 months (range: 24-45). No patients required amputation. Bone union was achieved in all patients. Clinical eradication of osteomyelitis was achieved in 35 (97%) patients, 35 (97%) patients were able to walk independently, and 31patients (86%) returned to work. Patients returned to a mean of 82% (46.3%-100%) lower extremity function. Bone union time was not dependent on the length of bone defect, but associated with the infection site (p=0.005) and age (p=0.005).

CONCLUSIONS

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. Advanced age and poor soft tissue envelope may have adverse affects and are relative contraindications. The combined assessment and management of such patients with a plastic surgeon are advocated.

Infected hardware after surgical stabilization of rib fractures: Outcomes and management experience

BACKGROUND

Surgical stabilization of rib fracture (SSRF) is increasingly used for treatment of rib fractures. There are few data on the incidence, risk factors, outcomes, and optimal management strategy for hardware infection in these patients. We aimed to develop and propose a management algorithm to help others treat this potentially morbid complication.

METHODS

We retrospectively searched a prospectively collected rib fracture database for the records of all patients who underwent SSRF from August 2009 through March 2014 at our institution. We then analyzed for the subsequent development of hardware infection among these patients. Standard descriptive analyses were performed.

RESULTS

Among 122 patients who underwent SSRF, most (73%) were men; the mean (SD) age was 59.5 (16.4) years, and median (interquartile range [IQR]) Injury Severity Score was 17 (13-22). The median number of rib fractures was 7 (5-9) and 48% of the patients had flail chest. Mortality at 30 days was 0.8%. Five patients (4.1%) had a hardware infection on mean (SD) postoperative day 12.0 (6.6). Median Injury Severity Score (17 [range, 13-42]) and hospital length of stay (9 days [6-37 days]) in these patients were similar to the values for those without infection (17 days [range, 13-22 days] and 9 days [6-12 days], respectively). Patients with infection underwent a median (IQR) of 2 (range, 2-3) additional operations, which included wound debridement (n = 5), negative-pressure wound therapy (n = 3), and antibiotic beads (n = 4). Hardware was removed in 3 patients at 140, 190, and 192 days after index operation. Cultures grew only gram-positive organisms. No patients required reintervention after hardware removal, and all achieved bony union and were taking no narcotics or antibiotics at the latest follow-up.

CONCLUSIONS

Although uncommon, hardware infection after SSRF carries considerable morbidity. With the use of an aggressive multimodal management strategy, however, bony union and favorable long-term outcomes can be achieved.

LEVEL OF EVIDENCE

Therapeutic study, level V.

Trends in the epidemiology of osteomyelitis: a population-based study, 1969 to 2009

BACKGROUND

The epidemiology of osteomyelitis in the United States is largely unknown. The purpose of this study was to determine long-term secular trends in the incidence of osteomyelitis in a population-based setting.

METHODS

The study population comprised 760 incident cases of osteomyelitis first diagnosed between January 1, 1969, and December 31, 2009, among residents of Olmsted County, Minnesota. The complete medical records for each potential subject were reviewed to confirm the osteomyelitis diagnosis and to extract details on anatomical sites, infecting organisms, etiological risk factors, and outcomes.

RESULTS

The overall age and sex-adjusted annual incidence of osteomyelitis was 21.8 cases per 100,000 person-years. The annual incidence was higher for men than for women and increased with age (p < 0.001). Rates increased with the calendar year (p < 0.001) from 11.4 cases per 100,000 person-years in the period from 1969 to 1979 to 24.4 per 100,000 person-years in the period from 2000 to 2009. The incidence remained relatively stable among children and young adults but almost tripled among individuals older than sixty years; this was partly driven by a significant increase in diabetes-related osteomyelitis from 2.3 cases per 100,000 person-years in the period from 1969 to 1979 to 7.6 cases per 100,000 person-years in the period from 2000 to 2009 (p < 0.001). Forty-four percent of cases involved Staphylococcus aureus infections.

CONCLUSIONS

The reasons for the increase in osteomyelitis between 1969 and 2009 are unclear but could comprise a variety of factors, including changes in diagnosing patterns or increases in the prevalence of risk factors (e.g., diabetes) in this population.

Protein antigens increase the protective efficacy of a capsule-based vaccine against Staphylococcus aureus in a rat model of osteomyelitis

Staphylococcus aureus is an invasive bacterial pathogen, and antibiotic resistance has impeded adequate control of infections caused by this microbe. Moreover, efforts to prevent human infections with single-component S. aureus vaccines have failed. In this study, we evaluated the protective efficacy in rats of vaccines containing both S. aureus capsular polysaccharides (CPs) and proteins. The serotypes 5 CP (CP5) and 8 CP (CP8) were conjugated to tetanus toxoid and administered to rats alone or together with domain A of clumping factor A (ClfA) or genetically detoxified alpha-toxin (dHla). The vaccines were delivered according to a preventive or a therapeutic regimen, and their protective efficacy was evaluated in a rat model of osteomyelitis. Addition of dHla (but not ClfA) to the CP5 or CP8 vaccine induced reductions in bacterial load and bone morphological changes compared with immunization with either conjugate vaccine alone. Both the prophylactic and therapeutic regimens were protective. Immunization with dHla together with a pneumococcal conjugate vaccine used as a control did not reduce staphylococcal osteomyelitis. The emergence of unencapsulated or small-colony variants during infection was negligible and similar for all of the vaccine groups. In conclusion, addition of dHla to a CP5 or CP8 conjugate vaccine enhanced its efficacy against S. aureus osteomyelitis, indicating that the inclusion of multiple antigens will likely enhance the efficacy of vaccines against both chronic and acute forms of staphylococcal disease.

Antibiotics for treating chronic osteomyelitis in adults

BACKGROUND

Chronic osteomyelitis is generally treated with antibiotics and surgical debridement but can persist intermittently for years with frequent therapeutic failure or relapse. Despite advances in both antibiotic and surgical treatment, the long-term recurrence rate remains around 20%. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To determine the effects of different systemic antibiotic treatment regimens for treating chronic osteomyelitis in adults.

SEARCH METHODS

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (October 2012), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2012, Issue 9), MEDLINE (January 1948 to September Week 4 2012), EMBASE (January 1980 to 2012 Week 40), LILACS (October 2012), the WHO International Clinical Trials Registry Platform (June 2012) and reference lists of relevant articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs addressing the effects of different antibiotic treatments given after surgical debridement for chronic osteomyelitis in adults.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened papers for inclusion, extracted data and appraised risk of bias in the included trials. Where appropriate, we pooled data using the fixed-effect model.

MAIN RESULTS

We included eight small trials involving a total of 282 participants with chronic osteomyelitis. Data were available from 248 participants. Most participants were male with post-traumatic osteomyelitis, usually affecting the tibia and femur, where recorded. The antibiotic regimens, duration of treatment and follow-up varied between trials. All trials mentioned surgical debridement before starting on antibiotic therapy as part of treatment, but it was unclear in four trials whether all participants underwent surgical debridement.We found that study quality and reporting were often inadequate. In particular, we judged almost all trials to be at moderate to high risk of bias due to failure to conceal allocation and inadequate follow-up.Four trials compared oral versus parenteral route for administration of antibiotics. There was no statistically significant difference between the two groups in the remission at the end of treatment (70/80 versus 58/70; risk ratio (RR) 1.04, 95% confidence interval (CI) 0.92 to 1.18; four trials, 150 participants). There was no statistically significant difference between the two groups in the remission rate 12 or more months after treatment (49/64 versus 44/54; RR 0.94, 95% CI 0.78 to 1.13; three trials, 118 participants). There was also no significant difference between the two groups in the occurrence of mild adverse events (11/64 versus 8/54; RR 1.08, 95% CI 0.49 to 2.42; three trials, 118 participants) or moderate and severe adverse events (3/49 versus 4/42; RR 0.69, 95% CI 0.19 to 2.57; three trials, 91 participants). Superinfection occurred in participants of both groups (5/66 in the oral group versus 4/58 in the parenteral group; RR 1.08, 95% CI 0.33 to 3.60; three trials, 124 participants).Single trials with few participants found no statistical significant differences for remission or adverse events for the following four comparisons: oral only versus parenteral plus oral administration; parenteral plus oral versus parenteral only administration; two different parenteral antibiotic regimens; and two different oral antibiotic regimens. No trials compared different durations of antibiotic treatment for chronic osteomyelitis, or adjusted the remission rate for bacteria species or severity of disease.

AUTHORS' CONCLUSIONS

Limited and low quality evidence suggests that the route of antibiotic administration (oral versus parenteral) does not affect the rate of disease remission if the bacteria are susceptible to the antibiotic used. However, this and the lack of statistically significant differences in adverse effects need confirmation. No or insufficient evidence exists for other aspects of antibiotic therapy for chronic osteomyelitis.The majority of the included trials were conducted over 20 years ago and currently we are faced with a far higher prevalence of bacteria that are resistant to many of the available antibiotics used for healthcare. This continuously evolving bacterial resistance represents another challenge in the choice of antibiotics for treating chronic osteomyelitis.

Clinical course, complication rate and outcome of segmental resection and distraction osteogenesis after chronic tibial osteitis

INTRODUCTION

Radical segmental resection and subsequent distraction osteogenesis are considered the gold standard in the treatment of chronic tibial osteitis. We investigated the clinical course of treatment, particularly with respect to patients' quality of life, and the complication rate associated with this technique.

METHODS

In this prospective case series, 25 patients (22 men, 3 women, average age: 46 years) with chronic post-traumatic tibial osteitis were managed operatively from 2006 to 2009. Standardised treatment included bacterial eradication by segmental resection, bone transport using Ilizarov apparatus, and docking manoeuvre. The follow-up rates during bacterial eradication, bone transport, post docking, and complete osseous consolidation were 100% while follow-up two years after completed consolidation was 76%. The main outcome measurements consisted of the quality of life (Medical Outcomes Study 36-Item Short Form Health Survey (SF-36 score)) and the virtual analogue scale (VAS) of pain during the five stages of therapy. Additionally, all complications and difficulties were documented.

RESULTS

The average defect size was 5.3 cm (range: 3-13). The healing index was 57 days per cm transport (range: 18-172). The overall treatment time averaged 93 weeks (range: 38-183). Patients suffered 22 minor and 13 major complications including one amputation. The average complication rate per patient consisted of 0.88 minor and 0.52 major complications. After the period of bone transport, the physical and mental component summary scores increased continuously. After completed consolidation, the average mental summary score was comparable to a normal collective.

CONCLUSIONS

Distraction osteogenesis is challenging for both the patient and the surgeon. The arduous and demanding nature of the clinical course subjects the patient to considerable mental and physical stress. Thankfully, the average physical and mental status of health continues to improve during the clinical course of treatment. The 2-year success rate of the distraction osteogenesis in an infected tibia is 96%.

[Osteomyelitis in adults. Diagnostic principles and therapeutic strategies]

This review focuses on the presentation of the diagnostic and therapeutic principles for treatment of chronic osteomyelitis of long bones in adults. Early detection of the offending bacteria is a crucial step which has to be performed with tissue and fluids from the depth of the wound. Superficial samples and swaps from fistulas should be avoided and are not considered to be representative. Chronic osteomyelitis is characterized by necrotic and nonvascularized bony tissue which represents one of the most relevant sources for recurrence infection. Appropriate therapy includes radical excision of the diseased bone and infected scar tissue, closure of the wound with well-vascularized (muscle) flaps, stabilization, and administration of adequate antibiotics.

In vitro and in vivo analysis of a biodegradable poly(lactide-co-glycolide) copolymer capsule and collagen composite system for antibiotics and bone cells delivery

The authors investigated poly(lactide-co-glycolide) (PLGA) capsule and collagen composite system for antibiotics and bone cells delivery to treat infected bone defects. Poly(lactide-co-glycolide) was mixed with vancomycin and hot compressing molded to form an antibiotic capsule. Rabbit mesenchymal stem cells (MSCs) were entrapped in collagen gel phase and dispersed throughout the void volume of capsule. In vitro study, the composite systems were cultured in complete or osteogenic medium for 21 days. The profiles of vancomycin released from the systems were evaluated using the high-performance liquid chromatography method. Relative activity of vancomycin against Staphylococcus aureus was determined by an antibiotic disk diffusion method. The expression of osteogenic gene was determined by reverse-transcription polymerase chain reaction. The alkaline phosphatase activity and calcium level of the MSCs were assessed. Analytical results demonstrated that the concentrations of vancomycin eluted from the composite system were above the minimal inhibitory concentration for 21 days. Sample inhibition zone was 10 to 24 mm, and the relative activity was 17.6% to 100%. mRNA of Cbfa1 and osteocalcin were detected, and increased alkaline phosphatase activity and calcium levels were noted. In in vivo investigation, the PKH 26-labeled MSCs and composite systems were implanted in the distal femoral cavities of four rabbits. The local concentration of vancomycin was above the minimal inhibitory concentration for 56 days. Sample inhibition zone was 9 mm to 24 mm, and the relative activity was 11.8% to 100%. Implanted PKH 26-labeled MSCs were identified in the newly formed bony trabeculae in specimens at 2 and 4 months after implantation. The results offer a potential approach to meet clinical requirements in the treatment of infected bone defects.

Reconstruction of osteomyelitis defects

Reconstruction of large skeletal defects secondary to osteomyelitis remains a challenging problem. Osteomyelitis can result from a variety of etiologies; most often, it is a consequence of trauma to a long bone. Despite advances in antibiotic therapy, treatment of chronic osteomyelitis requires adequate surgical debridement, which can often lead to large soft tissue and bone loss. Free vascularized bone can be used to reconstruct large skeletal defects greater than 6 cm or bone defects of smaller size that failed to heal with nonvascularized bone grafting. The length, cortical strength, and anatomic configuration of the free vascular fibular graft make it an ideal bone graft to bridge extremity defects, and it can be transferred with skin, fascia, and muscle to fill soft tissue defects in the recipient site.

Treatment of long bone intramedullary infection using the RIA for removal of infected tissue: indications, method and clinical results

Treatment of intramedullary infections of long bones is based upon the principles of surgical debridement, irrigation, fracture site stabilization, soft tissue coverage, and antibiotic administration. Reaming of the medullary canal is an essential component of surgical debridement because it removes intramedullary debris and infected bone surrounding the removed intramedullary device and within the intramedullary canal. The Reamer-Irrigator-Aspirator (RIA) has distinct features that appear to be beneficial for management of intramedullary infections. It allows reaming under simultaneous irrigation and aspiration, which minimizes the residual amount of infected fluid and tissue in the medullary canal and the propagation of infected material. The disposable reamer head is sharp, which combined with the continuous irrigation may attenuate the increased temperature associated with reaming and its potential adverse effects on adjacent endosteal bone. The disadvantage of the RIA is increased cost because of use of disposable parts. Potential complications can be avoided by detailed preoperative planning and careful surgical technique. The RIA should be used with caution in patients with narrow medullary canals and in infections involving the metaphysis or a limited part of the medullary canal. Reaming of the canal is performed with one pass of the RIA under careful fluoroscopic control. Limited information is available in the literature on the results of the RIA for management of intramedullary infections of long bones; however preliminary results are promising. The RIA device appears to be an effective and safe tool for debridement of the medullary canal and management of intramedullary infections of the long bones. Further research is needed to clarify the exact contribution of the RIA in the management of these infections.

Efficacy of moxifloxacin compared to teicoplanin in the treatment of implant-related chronic osteomyelitis in rats

Treatment of implant-related chronic osteomyelitis is often difficult and usually consists of implant removal, extensive surgical debridement, and prolonged antibiotic use. This study was performed to assess the efficacy of moxifloxacin compared to a glycopeptide, teicoplanin in chronic implant-related methicillin-sensitive Staphylococcus aureus (MSSA) osteomyelitis. The left femoral medullar cavities of 60 Wistar male rats were contaminated with 100 µl of 10(8) cfu/ml methicillin-sensitive S. aureus (ATCC 29213) and Kirschner wires were placed into the medulla of the femur. After 6 weeks, rats were randomly divided into five groups. In two groups, the Kirschner wires were removed. Experimental groups were as follows: group 1: contaminated, Kirschner wire inside, received teicoplanin; group 2: contaminated, Kirschner wire removed, received teicoplanin; group 3: contaminated, Kirschner wire inside, received moxifloxacin; group 4: contaminated, Kirschner wire removed, received moxifloxacin; group 5: contaminated, Kirschner wire inside, no antibiotics (control group). Groups 1 and 2 received teicoplanin (20 mg/kg once daily), whereas groups 3 and 4 received moxifloxacin (10 mg/kg twice daily) intraperitoneally for 28 days. At the end of the treatment, animals were sacrificed by inhalation anesthesia with ether and femora were retrieved and bacterial counts (cfu/g) were determined. Bacterial counts in all study groups were significantly reduced relative to the control. The decrease of bacterial counts was more prominent in group 4 compared to group 1 (p = 0.001) and group 2 (p = 0.003). Moxifloxacin therapy is an effective alternative to teicoplanin for chronic implant-related MSSA osteomyelitis.

Local antibiotic delivery with bovine cancellous chips

Infected bone defects and osteomyelitis are encountered frequently in trauma cases. Currently, the standard of care for osteomyelitis cases is prolonged systemic antibiotic therapy and implantation of antibiotic carrier beads. However, this method requires a secondary surgery to remove the beads after the infection has cleared. In the present study a common bone void filler was investigated for its ability to be infused with an antibiotic. This study demonstrates that the xenograft material tested can be loaded with gentamicin and release clinically relevant levels of the drug for at least 14 days in vitro allowing for the inhibition of bacterial growth on the graft. This study also demonstrates that the levels of gentamicin released did not have an adverse effect on primary osteoblast cell proliferation or ability to generate alkaline phosphatase. This bone void filler may represent a viable alternative to current methods of local antibiotic delivery in orthopedic applications.

[Chronic osteitis of the lower extremities. An interdisciplinary treatment concept]

INTRODUCTION

The purpose of this investigation was the retrospective analysis of patients with delayed infections, chronic posttraumatic osteitis of the lower extremities and free-flap coverage after radical debridement of bone and soft tissue.

METHODS

From the time period 1994-2003 a total of 22 patients including 4 females and 18 males were investigated. In 16 patients treatment was carried out on the lower leg and in 6 patients the foot was treated with subsequent free-flap coverage. In 14 cases the latissimus dorsi muscle was used, in 5 cases the gracilis muscle, in 2 cases parascapula flaps were used and in 1 case the serratus anterior muscle. The average age of the patients was 43 years (range 17-63 years) and grouping was according to the HOST classification. Functional outcome was evaluated by a standardized questionnaire (Funktionsfragebogen Hannover FFbH-OA 2,0), quality of life and social reintegration by non-standardized questionnaires.

RESULTS

In the cases investigated the following results could be achieved: full leg activity 55%, leg pain while walking 73%, special footwear 68%, normal gait 55%, positive quality of life and social reintegration 55%, port activities 36% and reemployment 45%.

CONCLUSION

According to the results of this study the quality of life of patients with chronic osteitis of the lower leg is in general satisfying. In order to improve quality management and cost reduction in public health an interdisciplinary treatment concept of plastic and orthopedic surgeons should be established for complex fracture management as this is the most effective tool in treating chronic osteitis.

Biocompatibility of a polymeric implant for the treatment of osteomyelitis

We evaluated the biocompatibility of an injectable gelling polymeric device for the controlled release of gentamicin sulfate in the treatment of invasive bacterial infections in bone of male Wister rats. The biodegradable delivery carrier, poly(sebacic-co-ricinoleic-ester-anhydride), designated as p(SA:RA), was injected, with and without gentamicin, into the tibial canal. Rats were killed 3 weeks later. The tibiae were processed histologically, leaving the injectable polymer in situ. The local tissue reaction to the polymer with or without antibiotic consisted mainly of mild reactive fibroplasia/fibrosis and mild to moderate increased reactive bone formation. At this stage, no evidence for any active inflammatory response to the polymer was seen. Thus, the injection of p(SA:RA) was well tolerated and did not induce any signs of a progressive inflammatory reaction.

Antibiotics for treating chronic osteomyelitis in adults

BACKGROUND

Chronic osteomyelitis is generally treated with antibiotics and surgical debridement but can persist intermittently for years with frequent therapeutic failure. Despite advances in both antibiotics and surgical treatment, the long-term recurrence rate remains at approximately 20% to 30%.

OBJECTIVES

To determine the effects of different systemic antibiotic treatment regimens for treating chronic osteomyelitis in adults.

SEARCH STRATEGY

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (October 2008), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2008, Issue 3), MEDLINE (January 1966 to October 2008), EMBASE (January 1980 to October 2008), LILACS (October 2008) and reference lists of relevant articles.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials addressing the effects of different antibiotic treatments given after surgical debridement for chronic osteomyelitis in adults.

DATA COLLECTION AND ANALYSIS

Two authors independently screened papers for inclusion, extracted data and appraised the quality of included trials. Where appropriate, we pooled data using the fixed-effect model.

MAIN RESULTS

We included eight small trials (257 participants in total, with data available from 228). Study quality was often inadequate: in particular, concealment of allocation was not confirmed and there was an absence of blinding of outcome assessment. The antibiotic regimens, duration of treatment and follow-up varied between trials. Five trials compared oral versus parenteral antibiotics. There was no statistically significant difference between the two groups in the remission rate 12 or more months after treatment (risk ratio 0.94, 95% confidence interval 0.78 to 1.13; 3 trials). Antibiotic treatment for osteomyelitis was associated with moderate or severe adverse events in 4.8% of patients allocated oral antibiotics and 15.5% patients allocated parenteral antibiotics (risk ratio: 0.40, 95% confidence interval 0.13 to 1.22; 4 trials). Single trials with very few participants found no statistical significant differences for remission or adverse events for the following three comparisons: parenteral plus oral versus parenteral only administration; two oral antibiotic regimens; and two parenteral antibiotic regimens. No trials compared different durations of antibiotic treatment for chronic osteomyelitis, or adjusted the remission rate for bacteria species or severity of disease.

AUTHORS' CONCLUSIONS

Limited evidence suggests that the method of antibiotic administration (oral versus parenteral) does not affect the rate of disease remission if the bacteria are sensitive to the antibiotic used. However, this and the lack of statistically significant differences in adverse effects need confirmation. No or insufficient evidence exists for other aspects of antibiotic therapy for chronic osteomyelitis.

Treatment of long bone osteomyelitis with a mechanically stable intramedullar antibiotic dispenser: nineteen consecutive cases with a minimum of 12 months follow-up

BACKGROUND

Antibiotic cement beads are the most common system of local antibiotic delivery. Unfortunately, bead strings do not give mechanical support to the fracture site, stability being fundamental in osteomyelitis treatment. Local treatment associated with bone stability should improve the results in posttraumatic osteomyelitis. The objective of this article is to present our experience in the treatment of long bone osteomyelitis using an intramedullary, mechanically stable antibiotic dispenser.

METHOD

We present a retrospective review of a consecutive series of patients with a long bone osteomyelitis treated using an intramedullary, mechanically stable antibiotic dispenser. The dispenser used with a T-95 chest tube filled with poly(methyl methacrylate) + antibiotic (vancomycin, gentamycin, or both, tobramycin or imipenem; depending on culture results) and with a metal center (Ender nail).

RESULTS

Fifteen patients were men and three were women, with an average age of 37 years (range, 18-52 years). In four cases, treatment involved the femur and in 15 the tibia. Positive cultures were obtained from each patient. Methicillin-resistant Staphylococcus aureus was isolated in 17 cases. The intramedullary dispenser was removed between 6 and 76 weeks after surgery. Success was defined as negative cultures after dispenser removal. Follow-up period was between 10 and 54 months. Negative cultures were obtained from intramedullary reaming after dispenser removal in all but one patient who could not finish treatment because of local intolerance to antibiotic treatment. None of the 17 patients presented an infection recurrence.

CONCLUSION

The combination of local antibiotic treatment with bone segment stability showed acceptable results in our short series of patients. Further investigation on locked intramedullary antibiotic dispensers providing improved stability will help us learn about this difficult clinical scenario.

In vitro evaluation of a fibrin gel antibiotic delivery system containing mesenchymal stem cells and vancomycin alginate beads for treating bone infections and facilitating bone formation

Bone infection and defects are two major problems that occur in the course of treating posttraumatic open bone fractures and osteomyelitis for which local antibiotic delivery is efficacious. Further, hemostasis is an essential treatment after removal of infected bones. Herein we report a new antibiotics delivery system made of vancomycin alginate beads embedded in a fibrin gel (Vanco-AB-FG) to treat bone infections, with the addition of bone marrow-derived mesenchymal stem cells (BMMSCs) seeded in the fibrin gel to promote bone formation. The proliferation of BMMSCs was measured under different conditions of three-dimensional (3D) gel or monolayer, with or without Vanco-AB; cells were labeled by enhanced green fluorescence protein, and their morphology and distribution were observed. The alkaline phosphatase (ALP) activity, real-time RT-PCR, and von Kossa staining were used for determining the osteogenic differentiation of BMMSCs. The concentrations of vancomycin resulting from the antibiotic delivery were determined; the antibiotic activity was evaluated by an assay with standard Staphylococcus aureus (ATCC 25923) as a biological target. The results showed that for Vanco-AB-FG, vancomycin concentrations remained above the breakpoint sensitivity for 22 days. The 3D culture within the gel and the addition of Vanco-AB affected the cell behavior. The morphology of BMMSCs within the 3D gel was different from that in monolayer. The proliferation of the cells within the 3D gel was lower than that in monolayer in early stage, but in later stage the number of BMMSCs in Vanco-AB-FG was similar to that in monolayer. The ALP activity was higher in the 3D gel, and the addition of Vanco-AB slightly increased ALP activity. The osteogenic gene expression levels of ALP, osteopontin, and alpha1 chain of collagen I were higher in the 3D gel than those in monolayer, and additional Vanco-AB could also increase their expression. The von Kossa staining showed that the deposition of mineralization was observed in both the 3D gel and monolayer cultures, but the mineralization nodule size in monolayer was bigger and the number of them in 3D gel was greater. In conclusion, this system could be an alternative treatment for bone infections and defects.

Treatment of osteomyelitis in rats by injection of degradable polymer releasing gentamicin

We evaluated the potential of an injectable degradable polymer-poly(sebacic-co-ricinoleic-ester-anhydride) containing gentamicin for the treatment of osteomyelitis. Osteomyelitis of both tibiae was induced in 13 female Fischer rats by injecting a suspension containing approximately 105 (CFU)/ml of S. aureus into the tibial medullar canal. Three weeks later both tibiae were X-rayed, drilled down the medullar canal, washed with 50 microl gentamicin solution (80 mg/2 ml) and then injected with 50 microl P(SA-RA)+gentamycin 20% w/v to the right tibia and 50 microl P(SA-RA) without gentamicin to the left tibia. After an additional 3 weeks, the rats were sacrificed, and radiographs of the tibiae were taken. Histopathological evaluation of the tibiae was done in a blinded manner. X-ray radiographs showed that all tibiae developed changes compatible with osteomyelitis in 3 weeks. Histological evaluation revealed significant differences between right and left tibiae in 10 rats. In the left tibia moderate intramedullary abscess formation occurred. In most treated tibiae typical changes included the absence (or minimal grade only) of abscesses. The treated group developed significantly less intramedullary abscesses; the p value was 0.028. Locally injected degradable polymer releasing gentamicin proved to be efficient histologically in the treatment of osteomyelitis.

Acute infections after fracture repair: management with hardware in place

Managing infections in fractures treated with open reduction and internal fixation is an ongoing dilemma. Little published data exist to support the current practice of treating these infections with retained hardware, irrigation, débridement, and antibiotic suppression. We evaluated the effectiveness of this approach. We identified potential subjects from a central trauma database and selected them based on chart review and specific inclusion and exclusion criteria. We divided the patients into two groups. Patients achieving successful union with original hardware in place were considered as having successful results and patients who required hardware removal before healing were considered to have failed results. Data, including age, gender, tobacco use, diabetic status, site of fracture, Orthopaedic Trauma Association class, open grade, type of fixation, joint involvement, and organism, were gathered and compared between the groups by analysis of variance. Sixty-nine cases were available for analysis. Forty-seven (68%) were successful and 22 (32%) were unsuccessful. Average time to healing was 130 days. Most of the failures occurred within 120 days from the time of injury. Smoking was a major risk factor with a 3.7 times greater likelihood of procedures being unsuccessful per month than procedures among nonsmokers. Treating infected fractures with hardware in place is less successful than widely believed.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Reconstruction of segmental bone defects due to chronic osteomyelitis with use of an external fixator and an intramedullary nail. Surgical technique

BACKGROUND

Callus distraction over an intramedullary nail is a rarely used technique for the reconstruction of intercalary defects of the femur and tibia after radical débridement of chronic osteomyelitic foci. The aim of this study was to summarize our experience with distraction osteogenesis performed with an external fixator combined with an intramedullary nail for the treatment of bone defects and limb-shortening resulting from radical débridement of chronic osteomyelitis.

METHODS

Thirteen patients who ranged in age from eighteen to sixty-three years underwent radical débridement to treat a nonunion associated with chronic osteomyelitis of the tibia (seven patients) and femur (six patients). The lesions were classified, according to the Cierny-Mader classification system, as type IVA (nine) and type IVB (four). The resulting segmental defects and any limb-length discrepancy were then reconstructed with use of distraction osteogenesis over an intramedullary nail. Two patients required a local gastrocnemius flap. Free nonvascularized fibular grafts were added to the distraction site for augmentation of a femoral defect at the time of external fixator removal and locking of the nail in two patients. At the time of the latest follow-up, functional and radiographic results were evaluated with use of the criteria of Paley et al.

RESULTS

The mean size of the defect was 10 cm (range, 6 to 13 cm) in the femur and 7 cm (range, 5 to 10 cm) in the tibia. The mean external fixator index was 13.5 days/cm, the consolidation index was 31.7 days/cm, and the mean time to union at the docking site was nine months (range, five to sixteen months). At a mean follow-up of 47.3 months, eleven of the thirteen patients had an excellent result in terms of both bone and functional assessment. There were two recurrences of infection necessitating nail removal. These patients underwent revision with an Ilizarov fixator. Subsequently, the infection was controlled and the nonunions healed.

CONCLUSIONS

This combined method may prove to be an improvement on the classic techniques for the treatment of a nonunion of a long bone associated with chronic osteomyelitis, in terms of external fixation period and consolidation index. The earlier removal of the external fixator is associated with increased patient comfort, a decreased complication rate, and a convenient and rapid rehabilitation.

Cierny-Mader Type III chronic osteomyelitis: the results of patients treated with debridement, irrigation, vancomycin beads and systemic antibiotics

Cierny-Mader (C-M) Type III osteomyelitis is defined as a localised lesion with both medullary and cortical involvement that is stable mechanically after debridement. The treatment of C-M Type III osteomyelitisis is difficult and requires a precise protocol to achieve a disease-free long-term follow-up. We report here the results of our study on 26 patients (19 men and 7 women; average age: 34.7 years) with C-M Type III osteomylelitis who were treated with radical debridement, irrigation, vancomycin-impregnated custom-made beads and culture-specific systemic antibiotics. Those patients with metaphyseal involvement were treated with deroofing of the cortex and debridement by means of a "trough" (16 patients); those with diaphyseal involvement were treated with both intramedullary reaming and debridement from a trough (ten patients). Antibiotic cement rods were used as an additional therapy in five patients with diaphyseal involvement. Recurrence developed in three patients and was attributed to inadequate debridement; all three patients were treated again in the same manner with success. The mean follow-up is currently 3.6 years (range: 2-6 years). All of the patients have normal clinical, radiographic and laboratory parameters, and all are ambulatory and have returned to their pretreatment level of activity or better. We conclude that C-M Type III chronic osteomyelitis can be safely treated with this protocol.

Infection and musculoskeletal conditions: Osteomyelitis

Osteomyelitis can result from hematogenous or contiguous microbial seeding of the bone. Staphylococcus aureus is the most common infecting microorganism. Although any bone can potentially develop osteomyelitis, long-bone, vertebral, and foot osteomyelitis account for the majority of cases. Confirmatory diagnosis of osteomyelitis often depends on the results of a bone biopsy and bone cultures. Radiologic and laboratory studies are often helpful in leading to the diagnosis, determining the extent of the disease, and following up selected patients with osteomyelitis. Optimal therapy for osteomyelitis requires the collaboration of a multidisciplinary team of physicians. Debridement is often needed in contiguous osteomyelitis, whereas acute hematogenous and vertebral osteomyelitis can often be treated with a prolonged course of antimicrobial therapy.

Gentamicin extended release from an injectable polymeric implant

Gentamicin sulfate, a potent antibiotic agent, is currently used for treatment of osteomyelitis mainly by intravenous injection with a long-term indwelling catheter, local implant of antibiotic containing polymethylmethacrylate beads or calcium phosphate (bone cements). Searching for more effective treatments, this study was designed to evaluate biodegradable injectable gelling polymeric devices for the controlled release of gentamicin sulfate in the treatment of invasive bacterial infections. Gentamicin sulfate was incorporated in poly(sebacic-co-ricinoleic-ester-anhydride P(SA-RA)) paste at 10-20% w/w and its release in buffer solution was monitored. The in vitro activity of the formulations was determined against Staphylococcus aureus. A constant release of active gentamicin for over 28 days was found. The stability of the formulation was determined under different storage conditions. The formulations were stable to sterilization by gamma-irradiation and long term storage under freezing. The toxicity of the polymer and the formulations with gentamicin was examined by subcutaneous injection to rats. Four weeks after implantation, histopathological examination of the tissues surrounding the implant showed no inflammation. A preliminary study revealed positive effect of gentamicin containing P(SA-RA) on established osteomyelitis in a rat model. In conclusion this study suggests that poly(sebacic-co-ricinoleic-ester-anhydride) 3:7 loaded with 10%-20% gentamicin sulfate, might be used as an injectable biodegradable device for in situ treatment of osteomyelitis induced by S. aureus.