Malignant transformation in chronic osteomyelitis: recognition and principles of management

Latent Chronic Osteomyelitis Presenting Decades After Initial Trauma: A Case Report and Literature Review

Osteomyelitis is an inflammatory bone process secondary to infection, and often presents as a chronic, recurrent illness, posing diagnostic and treatment challenges. It is frequently the result of previous inadequate treatment or undiagnosed acute infection. Clinical suspicion, thorough evaluation, laboratory studies, and advanced imaging modalities such as magnetic resonance imaging (MRI) and computed tomography (CT) play crucial roles in diagnosis. Treatment typically entails a combination of antibiotics and surgical debridement to eliminate infection and facilitate bone healing. In this report, we present a rare case involving a 64-year-old male who presented with new-onset pain in the right femur decades after experiencing a complicated femur fracture and forearm crush injury. Imaging studies revealed evidence of chronic osteomyelitis, leading to a diagnosis of latent infection. The patient underwent a comprehensive evaluation, including clinical examination, imaging studies, laboratory tests, and bone biopsy, confirming the diagnosis. This case of latent osteomyelitis highlights the clinical presentation, diagnostic modalities, and treatment strategies employed in managing this challenging condition.

Chronic osteomyelitis risk is associated with NLRP3 gene rs10754558 polymorphism in a Chinese Han Population

BACKGROUND

Single nucleotide polymorphisms (SNPs) in the nucleotide-binding domain leucine-rich repeat protein-3 (NLRP3) gene are reported to be linked to many inflammatory disorders. However, uncertainty persists over the associations between these SNPs and susceptibilities to chronic osteomyelitis (COM). This study aimed to investigate potential relationships between NLRP3 gene SNPs and the risks of developing COM in a Chinese Han cohort.

METHODS

The four tag SNPs of the NLRP3 gene were genotyped in a total of 428 COM patients and 368 healthy controlsusing the SNapShot technique. The genotype distribution, mutant allele frequency, and the four genetic models (dominant, recessive, homozygous, and heterozygous) of the four SNPs were compared between the two groups.

RESULTS

A significant association was found between rs10754558 polymorphism and the probability of COM occurence by the heterozygous model (P = 0.037, odds ratio [OR] = 1.541, 95% confidence interval [CI] = 1.025-2.319), indicating that rs10754558 may be associated with a higher risk of developing COM.In addition, possible relationship was found between rs7525979 polymorphism and the risk of COM development by the outcomes of homozygous (P = 0.073, OR = 0.453, 95% CI = 0.187-1.097) and recessive (P = 0.093, OR = 0.478, 95% CI = 0.198-1.151) models, though no statistical differences were obtained.

CONCLUSIONS

Outcomes of the present study showed, for the first time, that rs10754558 polymorphism of the NLRP3 gene may increase the risk of COM development in this Chinese Han population, with genotype CG as a risk factor. Nonetheless, this conclusion requires verification from further studies with a larger sample size.

Squamous Cell Carcinoma Arising in Chronic Osteomyelitis: A Rare Presentation

BACKGROUND

Malignant transformation of chronic osteomyelitis is extremely rare. Squamous cell carcinoma (SCC) is the most frequently reported malignancy, with a latency period of 20-50 years after the onset of osteomyelitis.

CASE PRESENTATION

A 61-year-old man presented with recurrent discharge from the left distal thigh 30 years after open femur fracture. Histopathology showed SCC arising from chronic osteomyelitis with bone invasion. The patient initially declined amputation but eventually consented to transfemoral amputation after symptom recurrence.

TREATMENT AND OUTCOME

Intraoperative frozen section was utilized to determine the level of amputation.

CONCLUSIONS

This case highlights the importance of definitive surgical treatment with amputation for SCC arising in chronic osteomyelitis, even after initial patient refusal. Recurrence should prompt the reconsideration of amputation.

A natural history of untreated chronic osteomyelitis of the tibia over 20 years, with evolving squamous cell carcinoma: a case report

Squamous cell carcinoma (SCC) is a rare but potentially life-threatening complication of chronic osteomyelitis. Whilst there have been over 100 cases of chronic osteomyelitis with malignant transformation reported in the literature between 1999 and 2020, this is the first case report to document transformation with 20 years of concordant imaging and clinical review.

bcl-2 and p53 as novel biomarkers for predicting malignant transformation in chronic osteomyelitis

PURPOSE

To find whether B-cell lymphoma 2 (bcl-2) and p53 proteins could be used as parameters to detect malignant transformation of chronic osteomyelitis. We also attempted to determine whether they could be used to differentiate between secondary squamous cell carcinoma (SCC) resulting from chronic osteomyelitis, and primary cutaneous squamous cell carcinoma.

METHODS

Retrospective study was conducted during 5 years period, resulting in 7 patients in each group: secondary squamous cell carcinoma arising from chronic osteomyelitis, primary cutaneous squamous cell carcinoma, and chronic osteomyelitis patients. Immunohistochemistry staining with bcl-2 and p53 was performed with the pathologist blinded to the sample groups.

RESULTS

Contingency coefficient test was performed to assess the correlation between the biomarker status (bcl-2 and p53) and the case groups. Significant moderate correlations of bcl-2 and p53 were found between groups of chronic osteomyelitis and squamous cell carcinoma arising from chronic osteomyelitis in terms of malignant transformation (p = 0.005 for bcl-2 and p = 0.031 for p53). Insignificant correlations of bcl-2 and p53 expression were found between primary cutaneous squamous cell carcinoma and secondary squamous cell carcinoma arising from chronic osteomyelitis group (p = 0.577).

CONCLUSIONS

The expression of bcl-2 and p-53 is significantly correlated with chronic osteomyelitis malignant transformation into squamous cell carcinoma.

Vancomycin-Loaded, Nanohydroxyapatite-Based Scaffold for Osteomyelitis Treatment: In Vivo Rabbit Toxicological Tests and In Vivo Efficacy Tests in a Sheep Model

The treatment for osteomyelitis consists of surgical debridement, filling of the dead space, soft tissue coverage, and intravenous administration of antimicrobial (AM) agents for long periods. Biomaterials for local delivery of AM agents, while providing controllable antibiotic release rates and simultaneously acting as a bone scaffold, may be a valuable alternative; thus, avoiding systemic AM side effects. V-HEPHAPC is a heparinized nanohydroxyapatite (nHA)/collagen biocomposite loaded with vancomycin that has been previously studied and tested in vitro. It enables a vancomycin-releasing profile with an intense initial burst, followed by a sustained release with concentrations above the Minimum Inhibitory Concentration (MIC) for MRSA. In vitro results have also shown that cellular viability is not compromised, suggesting that V-HEPHAPC granules may be a promising alternative device for the treatment of osteomyelitis. In the present study, V-HEPHAPC (HEPHAPC with vancomycin) granules were used as a vancomycin carrier to treat MRSA osteomyelitis. First, in vivo Good Laboratory Practice (GLP) toxicological tests were performed in a rabbit model, assuring that HEPHAPC and V-HEPHAPC have no relevant side effects. Second, V-HEPHAPC proved to be an efficient drug carrier and bone substitute to control MRSA infection and simultaneously reconstruct the bone cavity in a sheep model.

Premalignant Conditions of Bone

Development of malignancy is a multifactorial process, and there are multitude of conditions of bone that may predispose patients to malignancy. Etiologies of malignancy include benign osseous conditions, genetic predisposition, and extrinsic conditions. New-onset pain or growth in a previously stable lesion is that should concern for malignant change and should prompt a diagnostic workup for malignancy.

Squamous Cell Carcinoma Arising from Chronic Osteomyelitis in the Extremities: Treatment Approach and Oncological Outcomes-A Systematic Review of the Literature

Aims

In chronic osteomyelitis-derived squamous cell carcinoma, what are the demographic and clinical variables, risk factors associated with worse outcomes, and results of treatment modalities used?

Methods

A systematic review was performed using PubMed and EMBASE. Articles were evaluated for inclusion and exclusion criteria, and for quality analysis. PRISMA guidelines were applied. Demographic and clinical data and therapeutic approaches were presented narratively and in descriptive statistics registered at PROSPERO.

Results

Most patients were male (40/49), trauma was the most common etiology (27/36), and about half of all SCC were in the tibia (25/48). Amputation was the main definitive treatment (42/47). Adjuvant treatments were not analyzed. Well-differentiated SCC accounted for 58.3% (21/36) of all tumors. Bone invasion was described in 82.8% (24/29); recurrence, in 7.7% (3/39); and metastasis, in 7.7% (3/39). Recurrence and metastasis occurred more frequently when bone invasion was present (p = 0.578 and p = 0.646, respectively). SCC with lymph node involvement showed a higher tendency to metastasize (p = 0.377). Compared with limb salvage, amputation was associated with a tendency for less recurrence (p = 0.312) and longer survival (p = 0.219).

Conclusions

COM-derived SCC mostly occurs after trauma and is usually located in the tibia. Bone invasion is common, and patients predominantly undergo amputation. This treatment is associated with a trend toward higher survival, compared to limb salvage.

Management of Squamous Cell Carcinoma in Chronic Osteomyelitis: Our Experience, Review of the Literature and Role of MRI in Differential Diagnosis

Background. The authors describe a series of patients with chronic osteomyelitis associated with squamous cell carcinoma, whilst analyzing its incidence in chronic osteomyelitis, surgical options for treatment and focusing on the role of MRI in differential diagnosis. Methods. The authors reviewed 73 cases of chronic osteomyelitis (CO) treated in their department between 1995 and 2019. Six of these patients (8.2%) had a malignant degeneration in squamous cell carcinoma (SCC). All cases with malignancy were evaluated with preoperative gadolinium-enhanced MRI. Results. In this series, the authors observed an incidence rate of 8.2% (6 cases out of 73); all patients were male with a mean age of 63.5 years. The mean time between the occurrence of chronic osteomyelitis and the diagnosis of squamous cell carcinoma was 36 years (range: 21–66). The treatment consisted of amputation in five patients and limb salvage with vascularized fibula autograft in one case. Conclusions. MRI played a key role in the differential diagnosis between infected and tumoral tissue, and was found to be crucial during follow-up. Amputation is the treatment of choice in extended tumoral involvement of bone and soft tissue.

Squamous cell carcinoma complicating chronic osteomyelitis: A systematic review and case series

INTRODUCTION

Squamous cell carcinoma (SCC) is a rare but serious complication of chronic osteomyelitis. This study aimed to determine an optimum approach to diagnosis and management.

METHODS

A systematic review was performed using Medline, Embase, CINAHL and Web of Science, from 1999-present. Additional cases, meeting the eligibility criteria, were added from our hospital database. Patient demographics (age, gender, co-morbidities), osteomyelitis diagnosis (location, duration), diagnosis of SCC (method, imaging, extent of disease) and management (amputation versus wide local excision versus palliation) as well as outcome at one and five years were collected.

RESULTS

Nineteen studies involving 106 patients met strict inclusion criteria. All published studies were case reports or case series. Chronic osteomyelitis had been present for a mean of 31 years (range 3-67) prior to SCC diagnosis. SCC was most commonly treated by amputation (81%). A poorer outcome occurred in those with metastatic disease (p = 0.006 at one year; p = 0.032 at five years), an incidental diagnosis at surgery for osteomyelitis (p = 0.052; p = 0.021) and SCC after pelvic osteomyelitis (p < 0.001; p = 0.002).

CONCLUSIONS

SCC should be suspected in all cases of chronic osteomyelitis with skin changes, particularly if the duration of sinus drainage exceeds 3 years. Histological biopsy for malignancy should be taken in all suspected cases, as well as routinely during excision of osteomyelitis when chronic skin changes are present. Staging computed tomography (CT) scanning is recommended to guide adjunctive therapy. Amputation, where possible, may be considered as the definitive surgical management, after discussion with the patient.

Clinical characteristics, treatment, and prognosis of squamous cell carcinoma arising from extremity chronic osteomyelitis: a synthesis analysis of one hundred and seventy six reported cases

PURPOSE

Squamous cell carcinoma (SCC) arising from extremity chronic osteomyelitis (COM) has not been well-understood due to its low prevalence. This study aimed to synthesize the cases recently published to clarify their clinical characteristics, treatment, and prognosis.

METHODS

PubMed, Embase, and Cochrane Library databases were searched for English literature reporting cases diagnosed of SCC originating from extremity COM between January 1, 1990, and September 30, 2019. The National Institutes of Health (NIH) assessment tool was used to evaluate the quality of reports included, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was applied to summarize the quality of available evidence. The data synthesized for analysis were clinical features, treatment strategy, and incidences of local recurrence, metastasis, all-cause, and SCC-related deaths. In addition, potential factors that might have influenced treatment efficacy and prognosis of SCC were also investigated.

RESULTS

Included for this analysis were 60 studies of 176 patients (a male-to-female ratio of 6.7). COM mostly occurred following trauma (73%), the tibia was the most frequent site (61%), and a sinus tract was the most common symptom (61%). The mean duration from COM to SCC was 27 years. Positive rate of pathogen culture was 90%, with 73% being polymicrobial. Limb amputation was performed in 80.5% of the patients. Incidences of local recurrence, metastasis after treatment, all-cause, and SCC-related mortalities were 16.7%, 12%, 31.1%, and 12.6%, respectively. Patients with local lymphadenopathy at diagnosis had significantly higher risks of local recurrence (P = 0.01), SCC-related (P = 0.02), and all-cause deaths (P = 0.01) than those without. Patients with moderately-to-poorly differentiated SCC types had significantly higher risks of local recurrence (P = 0.01) and all-cause death (P = 0.02) than those with a well-differentiated type.

CONCLUSIONS

SCC arising from extremity COM favoured males and the tibia. Although limb amputation was the mainstay of treatment, the overall incidences of local recurrence, metastasis, and SCC-related death exceeded 10%. Patients with local lymphadenopathy at diagnosis of SCC and those with moderately-to-poorly differentiated SCC types should be followed up closely.

TRIAL REGISTRATION

CRD42020154221.

Carcinogenesis and precancerosis transformation of chronic osteomyelitis: 6 cases report and literature review

BACKGROUND

Malignant transformation is a rare and late complication of chronic osteomyelitis. This study presented the results of six cases of carcinogenesis and precancerosis transformations arising from chronic osteomyelitis.

METHODS

Patients who were diagnosed as chronic osteomyelitis and treated in our division were retrospectively retrieved from electronic case system of our hospital. A total of six cases of chronic osteomyelitis patients, confirming with pathological results were included. Not only the characteristics and causes of chronic osteomyelitis, but also time from diagnosis to malignancy, histological types, therapeutic choices and results of treatment were fully incorporated to further study this disease.

RESULTS

All 6 cases with chronic osteomyelitis included in the study were male, with average age of 55.67 year-old (ranging from 48 to 66). The average time from onset of osteomyelitis to carcinomatous change was 31 years (ranging from 9 to 50). Two thirds of patients had explicit infection source of trauma, whereas the rest cases had no obvious culprits before osteomyelitis emerging. All 3 patients diagnosed as carcinoma were performed with proximal limb amputation, but therapy strategies varied in the remaining 3 patients in precancerosis stage. After amputation, 1 patient had carcinoma relapsed at the lower portion of his femur.

CONCLUSION

Although carcinomatous degeneration exists as a rare complication in chronic osteomyelitis, some suspicious conditions such as failure treatment of refractory ulcer and bulking of cauliflower-like mass should be taken cautiously. Early diagnosis and proximal amputation are essential for prognosis and clinical results.

[Management of malignant wounds]

Malignant wounds arise either primary or secondary in the context of a malignant transformation of already existing wounds. A plethora of skin tumors, such as basal cell carcinoma, squamous cell carcinoma, melanoma, lymphoma as well as cutaneous metastases of other malignancies can ulcerate and be the cause of malignant wounds. Ulcerating tumors or metastases of the skin can however mimic chronic wounds from other causes and remain unrecognized over a longer period. In patients with chronic ulcerations, the correct and timely diagnosis is paramount. Based on this, the stage and disease-oriented treatment should be chosen in harmony with the wishes of the patient. In addition, general measures, such as atraumatic dressing changes to reduce pain and bleeding and the use of antiseptic dressing materials to prevent bacterial colonization and associated odors should be considered.

Positron emission tomography/computed tomography imaging appearance of benign and classic “do not touch” osseous lesions

BACKGROUND

Classic “do not touch” and benign osseous lesions are sometimes detected on ¹⁸-F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) studies. These lesions are often referred for biopsy because the physician interpreting the PET/CT may not be familiar with the spectrum of ¹⁸F-FDG uptake patterns that these lesions display.

AIM

To show that “do not touch” and benign osseous lesions can have increased ¹⁸F-FDG uptake above blood-pool on PET/CT; therefore, the CT appearance of these lesions should dictate management rather than the standardized uptake values (SUV).

METHODS

This retrospective study evaluated 287 independent patients with 287 classic “do not touch” (benign cystic lesions, insufficiency fractures, bone islands, bone infarcts) or benign osseous lesions (hemangiomas, enchondromas, osteochondromas, fibrous dysplasia, Paget’s disease, osteomyelitis) who underwent ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) at a tertiary academic healthcare institution between 01/01/2006 and 12/1/2018. The maximum and mean SUV, and the ratio of the maximum SUV to mean blood pool were calculated. Pearson’s correlations between lesion size and maximum SUV were calculated.

RESULTS

The ranges of the maximum SUV were as follows: For hemangiomas (0.95-2.99), bone infarcts (0.37-3.44), bone islands (0.26-3.29), enchondromas (0.46-2.69), fibrous dysplasia (0.78-18.63), osteochondromas (1.11-2.56), Paget’s disease of bone (0.93-5.65), insufficiency fractures (1.06-12.97) and for osteomyelitis (2.57-12.64). The range of the maximum SUV was lowest for osteochondromas (maximum SUV 2.56) and was highest for fibrous dysplasia (maximum SUV of 18.63). There was at least one lesion that demonstrated greater ¹⁸F-FDG avidity than the blood pool amongst each lesion type, with the highest maximum SUV ranging from 9.34 times blood pool mean (osteomyelitis) to 1.42 times blood pool mean (hemangiomas). There was no correlation between the maximum SUV and the lesion size except for enchondromas. Larger enchondromas had higher maximum SUV (r = 0.36, P = 0.02).

CONCLUSION

The classic “do not touch” lesions and classic benign lesions can be ¹⁸F-FDG avid. The CT appearance of these lesions should dictate clinical management rather than the maximum SUV.

Interleukin-1 Beta Gene Polymorphism rs16944 May Associate with Increased Susceptibility to Extremity Chronic Osteomyelitis in Chinese Han Population

Background

Previous studies had indicated that interleukin-1 beta (IL-1β) gene single nucleotide polymorphisms (SNPs) associate with different inflammatory diseases. However, potential links between these polymorphisms and susceptibility to extremity chronic osteomyelitis (COM) remain unclear. This study aimed to investigate relationships between IL-1β gene polymorphisms (rs16944, rs1143627, rs1143634, and rs2853550) and risks of developing extremity COM in Chinese Han population.

Methods

Altogether 233 extremity COM patients and 200 healthy controls were genotyped for the four tag SNPs of the IL-1β gene using the SNapShot genotyping method. Comparisons were performed regarding genotype distribution, mutant allele frequency, and four genetic models (dominant, recessive, homozygous, and heterozygous models) of the four SNPs between the two groups.

Results

Significant associations were identified between rs16944 polymorphism and the risk of developing COM by dominant model (P = 0.026, OR = 1.698, 95% CI 1.065-2.707) and heterozygous model (P = 0.030, OR = 1.733, 95% CI 1.055-2.847). Although no statistical differences were found of rs1143627 polymorphism between the two groups, there existed a trend that rs1143627 may be linked to an elevated risk of developing COM by outcomes of dominant (P = 0.061), homozygous (P = 0.080) and heterozygous (P = 0.095) models. However, no statistical correlations were found between rs1143634 and rs2853550 polymorphisms and susceptibility to COM in Chinese Han population.

Conclusions

To our knowledge, we reported for the first time that IL-1β gene rs16944 polymorphism may contribute to the increased susceptibility to extremity COM in Chinese Han population, with genotype of AG as a risk factor.

[Malignant transformation of chronic osteomyelitis: a case report]

La transformation maligne d’une ostéomyélite chronique est une complication rare et tardive qui survient le plus souvent au niveau des berges d’un trajet fistuleux avec extension et infiltration des tissus mous de voisinage et plus rarement une infiltration osseuse. Nous rapportons une observation. Il s’agit de Monsieur N.J. âgé de 67 ans, suivi pour une ostéomyélite chronique (OMC) du fémur droit fistulisée à la peau et évoluant depuis l’âge de 16 ans. Il s’est présenté actuellement pour des fistules productives, avec présence à l’imagerie d’une fracture pathologique sur une lésion ostéolytique de l’extrémité inférieure du fémur droit associé à une collection liquidienne mal limitée intra-médullaire étendue sur 8cm de grand axe. Une excision chirurgicale des fistules avec mise à plat de la collection et curetage de la cavité osseuse ont été réalisées. L’examen anatomopathologique a mis en évidence une prolifération tumorale maligne à type de carcinome épidermoïde différencié et kératinisant, infiltrant le trajet fistuleux avec extension au niveau des parties molles et infiltration de l’extrémité inférieure du fémur droit. Le bilan d’extension étant négatif, une désarticulation de la hanche a été pratiquée. Au dernier recule de deux ans, le patient va bien et ne présente pas de récidive locale ni de métastase à distance. La prise en charge initiale des ostéomyélites chroniques est primordiale pour prévenir les complications redoutables. En cas de transformation maligne et particulièrement en carcinome épidermoïde comme le cas de notre observation, l’amputation reste le traitement de choix pour prévenir les localisations secondaires.

Breast implant capsule-associated squamous cell carcinoma: a report of 2 cases

The use of prosthetic implants for breast augmentation has become commonplace. Although implants do not increase the risk of conventional mammary carcinoma, they are rarely associated with anaplastic large cell lymphoma. We report 2 cases of breast implant capsule-associated squamous cell carcinoma with poor clinical outcomes. Both patients (56-year-old woman and 81-year-old woman) had long-standing implants (>25 years) and presented with acute unilateral breast enlargement. In both cases, squamous cell carcinoma arose in (focally dysplastic) squamous epithelium-lined breast implant capsules and widely invaded surrounding breast parenchyma or chest wall. Neither patient had evidence of a primary mammary carcinoma or squamous cell carcinoma at any other anatomic site. Within 1 year, one patient developed extensive, treatment-refractory, locoregional soft tissue metastasis, and the second patient developed hepatic and soft tissue metastases and died of disease. There are 2 prior reported cases of implant-associated squamous cell carcinoma in the plastic surgery literature; one provides no pathologic staging or outcome information, and the second case was a capsule-confined squamous cell carcinoma. Together, all 4 cases share notable commonalities: the patients had long-standing breast implants and presented with acute unilateral breast pain and enlargement secondary to tumors arising on the posterior aspect of squamous epithelialized implant capsules. Because of both its rarity and its unusual clinical presentation, implant capsule-associated squamous cell carcinoma may be underrecognized. The aggressive behavior of the tumors in this series underscores the importance of excluding malignancy in patients with long-standing breast implants who present with acute unilateral breast pain and enlargement.

Chronic osteomyelitis: what the surgeon needs to know

Chronic osteomyelitis represents a progressive inflammatory process caused by pathogens, resulting in bone destruction and sequestrum formation.

It may present with periods of quiescence of variable duration, whereas its occurrence, type, severity and prognosis is multifactorial.

The ‘gold standard’ for the diagnosis of chronic osteomyelitis is the presence of positive bone cultures and histopathologic examination of the bone.

Its management remains challenging to the treating physician, with a multidisciplinary approach involving radiologists, microbiologists with expertise in infectious diseases, orthopaedic surgeons and plastic surgeons.

Treatment should be tailored to each patient according the severity and duration of symptoms, as well as to the clinical and radiological response to treatment.

A combined antimicrobial and surgical treatment should be considered in all cases, including appropriate dead space management and subsequent reconstruction. Relapse can occur, even following an apparently successful treatment, which has a major impact on the quality of life of patients and is a substantial financial burden to any healthcare system.

Cite this article EFORT Open Rev 2016;1:128–135. DOI: 10.1302/2058-5241.1.000017.

In vitro and in vivo drug release and antibacterial properties of the novel vancomycin-loaded bone-like hydroxyapatite/poly amino acid scaffold

Antibiotic-loaded carriers were developed to fill cavities and locally deliver antibiotics following implantation. However, the most commonly used antibiotic carrier, polymethyl methacrylate (PMMA), has many disadvantages including that it does not promote bone regeneration or conduction. Vancomycin-loaded bone-like hydroxyapatite/poly amino acid (V-BHA/PAA) was successfully fabricated by a homogeneous method, certified as biosafe and known to promote osteogenesis. To evaluate its drug-release features, the quantity of the vancomycin in the elution was obtained every 2 days after in vitro simulated body fluid immersion. The drug concentration in the elution was determined to obtain the drug-release curve. The in vitro drug release was a three-phase process with two release peaks. Its antibacterial activity was evaluated in vitro using an antibacterial zone assay, antibacterial inhibition, and scanning electron microscopy (SEM) observation. Scaffolds of V-BHA/PAA were implanted into a rabbit model of chronic osteomyelitis. The antibacterial activity of the material was evaluated in vivo by gross observations, X-ray, and histological and ultrastructural observations. During the first 48 h, the vancomycin release was more rapid, followed by a period of sustained slow release. Use of V-BHA/PAA could achieve relatively long-term vancomycin delivery of 38 days in vitro and 42 days in vivo. V-BHA/PAA showed a significant and consistent bactericidal effect toward both Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in vitro and in vivo. Moreover, the bactericidal effect was stronger than that of vancomycin-loaded polymethyl meth acrylate (V-PMMA). The duration of the antibacterial effect of V-BHA/PAA toward both S. aureus and MRSA exceeded 28 days in vitro, while that of V-PMMA lasted only 14 days. The curative rate for V-BHA/PAA in the chronic osteomyelitis model was 75% for regular S. aureus and 66.67% for MRSA infection, which significantly exceeded that of V-PMMA (50% and 41.67%, respectively). Vancomycin released from the V-BHA/PAA scaffold was significantly superior to that delivered by V-PMMA.

Malignant transformation in chronic osteomyelitis

Introduction

Carcinomatous degeneration is a rare and late complication developing decades after the diagnosis of chronic osteomyelitis.

Objectives

To present the results from a retrospective study of six cases of squamous cell carcinoma arising from chronic osteomyelitis.

Methods

Six cases of chronic osteomyelitis related to cutaneous squamous cell carcinoma were identified. The cause and characteristics of the osteomyelitis were analyzed, as well as time up to malignancy, the suspicion signs for malignancy, the localization and histological type of the cancer, and the type and result of the treatment.

Results

The mean time between osteomyelitis onset and the diagnosis of malignant degeneration was 49.17 years (range: 32–65). The carcinoma resulted from tibia osteomyelitis in five cases and from femur osteomyelitis in one. The pathological examination indicated cutaneous squamous cell carcinoma in all cases. All the patients were staged as N0M0, except for one, whose lomboaortic lymph nodes were affected. The treatment consisted of amputation proximal to the tumor in all patients. No patient presented signs of local recurrence and only one had carcinoma metastasis.

Conclusion

Early diagnosis and proximal amputation are essential for prognosis and final results in carcinomatous degeneration secondary to chronic osteomyelitis.