Effect of cisplatin chemotherapy on extracortical tissue formation in canine diaphyseal segmental replacement

Osseointegration Pharmacology: A Systematic Mapping Using Artificial Intelligence

Clinical performance of osseointegrated implants could be compromised by the medications taken by patients. The effect of a specific medication on osseointegration can be easily investigated using traditional systematic reviews. However, assessment of all known medications requires the use of evidence mapping methods. These methods allow assessment of complex questions, but they are very resource intensive when done manually. The objective of this study was to develop a machine learning algorithm to automatically map the literature assessing the effect of medications on osseointegration. Datasets of articles classified manually were used to train a machine-learning algorithm based on Support Vector Machines. The algorithm was then validated and used to screen 599,604 articles identified with an extremely sensitive search strategy. The algorithm included 281 relevant articles that described the effect of 31 different drugs on osseointegration. This approach achieved an accuracy of 95%, and compared to manual screening, it reduced the workload by 93%. The systematic mapping revealed that the treatment outcomes of osseointegrated medical devices could be influenced by drugs affecting homeostasis, inflammation, cell proliferation and bone remodeling. The effect of all known medications on the performance of osseointegrated medical devices can be assessed using evidence mappings executed with highly accurate machine learning algorithms.

The influence of Cisplatin-based chemotherapy on the osseointegration of dental implants: An in vivo mechanical and histometrical study

OBJECTIVES

To evaluate the effect of Cisplatin on bone repair and mineralization around implants and on the mechanical properties of bone tissue.

MATERIALS AND METHODS

Forty-three Wistar rats were randomly divided into two groups: Cisplatin (CIS, medication) and control (CTL, placebo solution), administered once a week for 4 weeks. After 4 weeks, implants were installed in both tibiae metaphysis. After 30 and 60 days, the animals were sacrificed and their femurs and tibiae were removed. Femurs were subjected to mechanical tests and tibiae for removal torque, arrangement and distribution of collagen fibers, morphometrical analyses (bone tissue in contact with the implant surface [BIC] and areal fraction between implant threads occupied by bone tissue [BAFO]) and scanning electron microscopy to calcium and calcium/phosphorus analysis. Data were analyzed by ANOVA or MANOVA, and Tukey or Games-Howell post hoc tests, respectively (α = 0.05).

RESULTS

The CTL specimens had significantly higher values (0.0001 ≤ p≤0.036) of strength (N), removal torque (N/cm² ), %BIC, and %BAFO than CIS specimens, being their best results at day 60. No significant differences were found among the groups regarding the values of deformation, percentage of calcium, and calcium/phosphorus ratio. In CIS groups, there was a reduction in the organization of collagen at the bone/implant interface, resulting in a trabecular bone with thin trabeculae and birefringent collagen and irregular arrangement.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Cisplatin interfered negatively in the repair and mineralization around dental implants, as well as on the quality of the bone tissue, mainly in the period of 30 days after the implant placement.

Limb-salvage treatment of en-block resected distal femoral tumors with endoprosthesis of all-polyethylene tibial component: a 9-year follow-up study

OBJECTIVE

To evaluate the medium-term outcome of limb-salvage surgery using all-polyethylene tibial endoprosthetic replacement following en-block resection for distal femoral tumors.

METHODS

Forty-nine patients with distal femoral tumor were treated between June 2006 and June 2012. The follow-up period was 6-110 months (average 53.4 months). The prosthetic survival was analyzed using the Kaplan-Meier method. The classification of failure of limb salvage after reconstructive surgery for bone tumors was adapted. Limb function was evaluated with the scoring system of the Musculoskeletal Tumor Society (MSTS).

RESULTS

Complications were observed in six cases (12.2%). Four suffered infection around the prosthesis, of which two cases were treated with debridement, drainage, and antibiotics without removal of the prosthesis, and the other two cases underwent amputation. Two cases were identified as radiographically loose at 7 year follow-up and did not require revision surgery. One patient underwent amputation due to local recurrence. Failure of limb salvage occurred in nine cases (18.4%), of which two cases were of type 1A, two cases of type 2B, three cases of type 4A, one case of type 4B, and one case of type 5A. The mean MSTS score was 84.3%. Twelve cases died due to distant metastases (24.5%), and the average survival time for these patients was 13.5 months. Thirty-seven patients survived (75.5%), for whom the average follow-up time was 66.3 months and the 5-year prosthetic survival rate was 88.2%.

CONCLUSION

The outcome of medium-term and long-term clinical follow-up was satisfactory. All-polyethylene tibial endoprosthetic replacement following en-block resection can be an alternative method of limb salvage for distal femoral tumors.

Dental Implants in Patients Receiving Chemotherapy: A Meta-Analysis

PURPOSE

To test the null hypothesis of no difference in the implant failure rates, postoperative infection, and marginal bone loss for patients being rehabilitated by dental implants and being versus not being submitted to chemotherapy, against the alternative hypothesis of a difference.

METHODS

An electronic search without time or language restrictions was undertaken in May 2014 in PubMed/MEDLINE, Web of Science, Cochrane Oral Health Group Trials Register plus hand-searching. Eligibility criteria included clinical human studies, either randomized or not.

RESULTS

Nine publications were included. The results suggested that the insertion of dental implants in patients submitted or not submitted to chemotherapy did not affect the implant failure rates (risk ratio 1.02, 95% confidence interval 0.56-1.85; P = 0.95). Because of lack of enough information, meta-analyses for the outcomes "postoperative infection" and "marginal bone loss" were not performed.

CONCLUSION

These results cannot suggest that the insertion of dental implants in patients submitted to chemotherapy may or may not affect the implant failure rates, because of a limited number of published studies, most of them characterized by a low level of specificity and dealing with a limited number of cases without a control group. The reliability and validity of the data collected and the potential for biases and confounding factors are some of the shortcomings of the present study.

Effects of cisplatin chemotherapy on the osseointegration of titanium implants

PURPOSE

The effect of chemotherapy on the osseointegration of dental implants has received less interest compared with radiotherapy. Thus, the aim of the current study was to investigate the effect of cisplatin chemotherapy on the osseointegration of dental implants in a rabbit model.

MATERIALS AND METHODS

Sixteen New Zealand White rabbits were randomly assigned to two groups of treatment of either cisplatin at 2.5 mg/kg/week for 4 weeks (n = 8) or placebo (n = 8), in which the first dose was administered 2 days prior to the surgical procedure. Each rabbit received one titanium dental implant inserted in the right distal femoral condyle. Four rabbits from each group were sacrificed 4 and 8 weeks after implant insertion. Osseointegration of the dental implants was analysed using micro-computed tomography and histomorphometric evaluation.

RESULTS

Analysis of micro-computed tomography data and histomorphometric data showed that the osseointegration parameters, including the ratio of bone volume to total volume (BV/TV) and bone-implant contact (BIC%) for the cisplatin group, were significantly lower compared to the control group at 4 and 8 weeks. (P ≤ 0.05).

CONCLUSION

Cisplatin chemotherapy had a negative effect on the osseointegration of dental implants when inserted throughout the chemotherapeutic regimens in a rabbit model.

Classification of failure of limb salvage after reconstructive surgery for bone tumours : a modified system Including biological and expandable reconstructions

Previous classification systems of failure of limb salvage focused primarily on endoprosthetic failures and lacked sufficient depth for the effective study of the causes of failure. In order to address these inadequacies, the International Society of Limb Salvage (ISOLS) formed a committee to recommend revisions of the previous systems. The purpose of this study was to report on their recommendations. The modifications were prepared using an earlier, evidence-based model with subclassification based on the existing medical literature. Subclassification for all five primary types of failure of limb salvage following endoprosthetic reconstruction were formulated and a complementary system was derived for the failure of biological reconstruction. An additional classification of failure in paediatric patients was also described. Limb salvage surgery presents a complex array of potential mechanisms of failure, and a complete and precise classification of types of failure is required. Earlier classification systems lacked specificity, and the evidence-based system outlined here is designed to correct these weaknesses and to provide a means of reporting failures of limb salvage in order to allow the interpretation of outcome following reconstructive surgery.

The influence of chemotherapy on bone mineral density, quantitative ultrasonometry and bone turnover in pre-menopausal women with breast cancer

INTRODUCTION

The effects of doxorubicin/cyclophosphamide (A/C; 6 cycles) chemotherapy on bone mineral density (BMD), quantitative ultrasonography (QUS) and bone turnover markers in pre-menopausal women with oestrogen receptor-negative breast cancer (BC) were compared with age-matched controls.

METHODS

Among 106 women (BC=53, controls=53), BMD (spine and hip), QUS (calcaneus and phalanges) and bone marker levels were measured at baseline, 6 and 12 months. Correlations between parameters were determined by Spearman's rho.

RESULTS

All BC patients became amenorrhoeic after chemotherapy and remained so for the duration of treatment. BC patients had significant bone loss at all sites (P.005) and significant increases in bone turnover (P.05). There were significant correlations between BMD, QUS and bone markers (P.05).

CONCLUSIONS

Results confirm A/C's deleterious influence on bone health in pre-menopausal women with BC and established QUS's utility for monitoring bone effects. Large-scale longitudinal studies are needed to further understand and prevent bone changes following chemotherapy.

Bioactive glass granules as extender of autogenous bone grafting in cementless intercalary implant of the canine femur

BACKGROUND AND AIMS

Ceramic bone graft substitutes have a potential to be used as replacement of allogeneic bone grafting and, under optimal distribution of particle size, they may even provide mechanical support. The current study examined the efficacy of bioactive glass granules as an extender of autogenous bone grafting in a segmental bone replacement model of the canine femur.

MATERIAL AND METHOD

A 16 mm long segment of the femur shaft was bilaterally replaced with an intercalary titanium implant in eight animals. The implant had cementless grooved proximal and distal stems. In one leg, the peri-implant space was packed with composite graft consisting of a mixture of bioactive glass granules and autogenous bone graft in proportion of 50:50. In the opposite leg, the peri-implant space was treated with autogenous bone graft alone. After surgery, unlimited functional loading was allowed. The outcome was evaluated at three months.

RESULTS

Eight out of sixteen autografted implants and seven out of sixteen composite-grafted implants were radiographically incorporated and clinically stable at three months. In the paired comparison, the proximal components of composite-grafted implants showed lower maximum load under torsional testing (p = 0.068), less new bone in the longitudinal grooves of the stems (p = 0.036) and lower affinity of new bone to implant surface (p = 0.046). The distal components of the two sides showed a similar trend for less new bone in the grooves and lower bone affinity of new bone in the distal composite-grafted components.

CONCLUSIONS

The current study suggests that supplementation of periprosthetic bone graft with bioactive ceramic particles may not help to promote healing of cementless implants under high dynamic loading conditions.

Experience with cemented large segment endoprostheses for tumors

Published reports dealing with tumor prosthesis have yet to establish a clear advantage of using either cemented or cementless implants. We examined the outcome and complications with modular cemented implants in 135 patients identified from our database to strengthen the argument for routine use of cemented constructs. The minimum followup was 1.4 months (mean, 57 months; median, 47 months; range, 1.4-157 months). The majority of patients (104) had sarcoma. The complications included: 11 infections, three of which underwent amputation and one a stem revision; eight local recurrences, five of which underwent amputation; three hip dislocations; and three incidents of shoulder instability. One periprosthetic femur fracture was stabilized operatively. There was no aseptic loosening or stem fracture. The 5-year survival rates for distal femoral and proximal humeral replacements were 84% and 70%; the 10-year survival rates were 79% and 59%. The 5-year survival rates for proximal femur and proximal tibia replacements were 78% and 37%. Average Musculoskeletal Tumor Society 1987 scores and Toronto Extremity Salvage Scores were 21.5 and 73% for proximal femur, 28.1 and 67% for distal femur, and 21 and 78% for proximal humerus. The survival of the endoprostheses related to site of bone resection. Cemented constructs of modern design in the context of tumor surgery provide good short-term results.

Cemented rotating hinge endoprosthesis for limb salvage of distal femur tumors

We retrospectively ascertained the outcomes and complications with a cemented rotating hinge implant. Implant failure was defined as amputation of the affected limb and revision of part or all of the components. We included 77 consecutive distal femoral replacements performed between 1989 and 2004. The mean age was 42 years (range, 12-87 years) and the mean length of followup was 52 months (range, 1.5-157 months). Five-year implant survival was 84% and 10-year survival was 79%. There were 67 bone sarcomas, two soft tissue sarcomas and eight metastatic carcinomas. At followup, 54 patients had no evidence of disease, 16 were alive with disease, and seven were dead from disease. Six patients had deep infection, two of which required amputations. There were five local recurrences; three needed amputation and two soft-tissue excisions only. Three patients sustained a tibial bearing fracture and one required replacement of loose bumper. No revision was performed for stem loosening, stem fracture, or bushing wear. Musculoskeletal Tumor Society 1987 scores averaged 30 and Toronto Extremity Salvage Scores averaged 77.6 at latest followup. Cemented endoprosthesis is a reliable procedure after resection of the distal femur for tumors.

LEVEL OF EVIDENCE

Therapeutic study, level IV (case series).

Autoclaved tumor bone for reconstruction: an alternative in developing countries

The options for reconstruction after excision of skeletal tumors include reimplanting the autoclaved tumor-bearing bone. We asked whether such bone will survive and unite with normal bone and whether the local tumor recurrence rate increases after its use. We ascertained the functional outcome (Musculoskeletal Tumor Society score) and complications in 19 patients. After wide excision, the bony segment was autoclaved at 120 degrees for 10 minutes and reimplanted at the original defect with intramedullary nails and compression plates. Twelve of our 19 patients were available for followup. The autoclaved segment united with the normal bone in 11 of the 12 patients. No patients had fracture or resorption of the autoclaved segment. Two patients had local tumor recurrence in nearby soft tissues, apparently unrelated to the autoclaved bone. The mean functional score was 70%. Complications included fatigue failure of the nail in one patient, superficial infection in three patients, and deep infection in two patients. Reconstruction with autoclaved tumor-bearing bone is a simple and effective tool in limb salvage. This technique is a cost-effective alternative for developing countries circumventing complications of prosthetic and allograft reconstruction.

The effect of multidrug chemotherapy on bone graft augmented prosthesis fixation

Use of combination adjuvant chemotherapies have improved the disease free survival rate of tumor patients significantly. However, studies have shown that chemotherapeutic agents have negative effects on bone graft incorporation and fixation of porous-coated prostheses needed for reconstruction of bone defects after wide resection of malignant tumors. Unilateral resection of a 6-cm segment of the femoral diaphysis and reconstruction with a porous-coated segmental prosthesis was performed in eight mixed-breed dogs under perioperative chemotherapy with doxorubicin, cisplatin, and ifosfamide. Eight strips of autogenous cortical bone were evenly placed around the junctions between the femur and the prosthetic surface. Autogenous cancellous bone was placed under and between the strips of cortical bone. Two cycles of the chemotherapy were given preoperatively, and three cycles postoperatively. The animals were followed for 12 weeks, with sequential assessments of weight-bearing and radiographic evaluation. Biomechanical, histological, and microradiographic analyses of the retrieved specimens were performed. Doxorubicin, cisplatin, and ifosfamide combination chemotherapy showed a significant effect on new bone formation as seen in reduced callus size and lower ultimate strength of extracortical fixation. However, the onlay corticocancellous grafting method provided better biologic fixation of the prosthesis compared with fixation without any bone grafting under non-chemotherapy condition in a previous study. Extracortical bone grafting is an effective modality for implant fixation even under intensive chemotherapy.

Chemotherapy decreases epiphyseal strength and increases bone fracture risk

To establish the effect of three frequently used chemotherapeutic agents in childhood cancer on the skeleton, growing male Wistar rats were studied. Treatment with doxorubicin, methotrexate, and cisplatin reduces the proximal tibial growth plate shear strength because of a decreased surface area and maximum shear stress. After treatment the bone fracture risk of the tibia and femur is increased because of decreased bending resistance. Doxorubicin and cisplatin reduce the maximum shear stress of the proximal tibial growth plate, none of the chemotherapeutic agents inhibit bone mineralization. These effects are caused by treatment-induced malnutrition and the accompanying weight reduction and a direct effect of the chemotherapeutic agents on the skeleton. The current study confirmed the importance of preventing malnutrition during chemotherapeutic treatment in view of possible skeletal complications. During followup of children treated with chemotherapy, attention should be given to signs and symptoms suggestive of such complications.

Healing of autologous bone in a titanium mesh cage used in anterior column reconstruction after total spondylectomy

STUDY DESIGN

Autologous bone inside a titanium mesh cage, used as an anterior strut in a reconstruction after total spondylectomy, was histologically examined in a postmortem specimen.

OBJECTIVES

To determine whether the autologous bone inside the titanium mesh cage attained fusion and remodeling in a combined reconstruction, consisting of an anterior titanium mesh cage with posterior multilevel instrumentation, after total spondylectomy.

SUMMARY OF BACKGROUND DATA

There are few previous reports on the histologic analysis of the bone inside a titanium mesh cage when it is used clinically as an anterior column support in a spinal fusion. Attaining biologic bony fusion is desirable for long-term stability after total spondylectomy.

METHODS

A postmortem specimen from a 16-year-old boy with Ewing's sarcoma at T6, who died of lung metastasis 16 months after total spondylectomy and combined reconstruction, was analyzed.

RESULTS

Histologic examination revealed many viable cells and normal lamella of trabecular bone formation in the grafted bone inside the mesh. Consecutive trabecular cancellous bony fusion between the grafted bone and the adjacent vertebral bodies was achieved.

CONCLUSION

Remodeling and fusion of the grafted bone inside the titanium mesh cage was observed. Combined reconstruction using an anterior titanium mesh cage with posterior multilevel instrumentation after total spondylectomy makes it possible to achieve biologic fusion of the bone inside the mesh cage with the adjacent vertebral bodies.

Effect of cisplatin on bone transport osteogenesis in dogs

OBJECTIVE

To document effects of cisplatin on regenerate bone formation during the distraction and consolidation phases of bone transport osteogenesis.

ANIMALS

10 skeletally mature hounds.

PROCEDURES

Bone transport osteogenesis was performed to reconstruct a 3-cm defect in the radius of each dog. Five dogs were randomly selected to receive cisplatin (70 mg/m2, IV, q 21 d for 4 cycles), and 5 were administered saline (0.9% NaCl) solution. Bone mineral density was measured by use of dual-energy x-ray absorptiometry (DEXA) on days 24, 55, and 90 after surgery. Dogs were euthanatized 90 days after surgery. Histomorphometry was performed on nondecalcified sections of regenerate bone. Bone mineral density and histomorphometric indices of newly formed bone were compared between groups.

RESULTS

Densitometric differences in regenerate bone mineral density were not detected between groups at any time period. Cisplatin-treated dogs had decreased mineralized bone volume, decreased percentage of woven bone volume, decreased percentage of osteoblast-covered bone, increased porosity, and increased percentage of osteoblast-covered surfaces, compared with values for control dogs. Lamellar bone volume and osteoid volume did not differ significantly between groups.

CONCLUSIONS AND CLINICAL RELEVANCE

Regenerate bone will form and remodel during administration of cisplatin. Results of histomorphometric analysis suggest that bone formation and resorption may be uncoupled in cisplatin-treated regenerate bone as a result of increased osteoclast activity or delayed secondary bone formation during remodeling. These histomorphometric differences were modest in magnitude and did not result in clinically observable complications or decreased bone mineral density as measured by use of DEXA.

Influence of chemotherapy on endosteal implant survival and success in oral cancer patients

Little is known about the effect of chemotherapy on the osseointegration and survival of endosteal dental implants. In a retrospective study, two groups of patients were compared: one group consisting of 30 oral cancer patients received postsurgical adjuvant chemotherapy with either cis- or carboplatin and 5-fluorouracil in three cycles and were treated subsequently with 106 dental implants placed in the mandible; the other group consisting of 17 patents suffering from oral cancer was prescribed with 54 dental implants placed in the mandible after oncological surgery. No patient was treated with radiotherapy. Twenty patients in the first group were successfully provided with a prosthetic superstructure (mean time of function: 35.8 months) compared to 16 patients in the second group (mean time of function: 36.2 months). The observation time was 10 years. A life-table analysis based on defined success parameters demonstrated no significant difference between implant survival in either group. It was concluded that chemotherapy with cis- or carboplatin and 5-fluorouracil was not detrimental to the survival and success of dental implants in the mandible.

Autogenous onlay grafting for enhancement of extracortical tissue formation over porous-coated segmental replacement prostheses

BACKGROUND

Prosthetic reconstruction with extracortical bone-bridging is an effective method of limb salvage after resection of a malignant or locally invasive benign bone tumor. Use of cancellous bone graft alone is less effective in achieving extracortical bone-bridging. The present study was performed to investigate the effects of a corticocancellous onlay graft on bone and soft-tissue formation over a porous-coated replacement prosthesis in the mid-diaphyseal region of canine femora.

METHODS

Bilateral resection of a six-centimeter segment of the femoral diaphysis and reconstruction with a porous-coated segmental prosthesis was performed in six mongrel dogs. In one limb (the experimental side), eight strips of corticocancellous bone were evenly placed around the junctions between the femur and the prosthetic surface. Cancellous bone was placed under and between the strips of cortical bone. No graft was used in the other limb (the control side). The animals were followed for twelve weeks, with sequential assessments of load-bearing and radiographic evaluation. Biomechanical, histological, and microradiographic analyses of the specimens were performed after death.

RESULTS

On the control side, load-bearing at four weeks postoperatively was significantly decreased compared with the preoperative value (p<0.05); no difference in these values could be detected on the experimental side. Both the area of the callus and the contact area between the bone and the prosthetic shoulder were greater on the experimental side (p<0.05). The mechanical stiffness and the maximum torque at failure of the extracortical bridging tissue across the junction between the bone and the prosthetic shoulder were eighteen (p<0.007) and five times greater (p<0.05), respectively, on the experimental side.

CONCLUSIONS

Extracortical bone-bridging was accomplished with corticocancellous onlay bone-grafting. Without bone-grafting, bone formed only occasionally. Bone-grafting also enhanced the formation of a soft-tissue capsule around the prosthesis.

Implant fixation by bone ingrowth

The term osseointegration referred originally to an intimate contact of bone tissue with the surface of a titanium implant; the term bone ingrowth refers to bone formation within an irregular (beads, wire mesh, casting voids, cut grooves) surface of an implant. The section dealing with the historical background describes the development of macroporous, microporous, and textured surfaces with an emphasis on the evolution of porous and textured metal surfaces. The principal requirements for osseointegration and bone ingrowth are systematically reviewed as follows: i) the physiology of osseointegration and bone ingrowth, including biomaterial biocompatibility with respect to cellular and matrix response at the interface; ii) the implant surface geometry characteristics; iii) implant micromotion and fixation modes; and iv) the implant-bone interface distances. Based on current methods of bone ingrowth assessment, this article comparatively reviews and discusses the results of experimental studies with the objective of determining local and systemic factors that enhance bone ingrowth fixation.