BackgroundPostoperative infection associated with implants remains a serious complication in orthopedic surgery. Several biomaterial surface treatments have been proposed as a means of reducing the incidence of implant-associated infections. In this study, a clinical trial was performed using an iodine-supported titanium that suppresses the microbial activities.MethodsA total of 222 patients with postoperative infection or compromised status were treated using iodine-supported titanium implants. The mean age of the patients was 49.4 years (range 5–85 years). One hundred twenty-seven patients were male and 95 were female. In 158 patients, iodine-supported implants were used to prevent infection, such as compromised hosts and conditions, and in 64 patients to treat active infection. White blood cell (WBCs) and C-reactive protein (CRP) levels were measured pre- and postoperatively in all patients. To confirm whether iodine from the implant affected physiological functions, thyroid hormone levels in the blood were examined. Both examinations were conducted sequentially for a year. Radiological evaluations were performed regularly after the operation. The chronological changes of the iodine amount were evaluated using half pins removed after completion of external fixation.ResultsThe mean follow-up period was 18.4 months (range 3–44 months). Acute infection developed in three tumor cases among the 158 patients on preventive therapy. All three recovered without removal of the implants. Infection was cured in all 64 patients with infection. Median WBC levels were in the normal range, and median CRP levels returned to <0.5 within 4 weeks after surgery. Abnormalities of thyroid gland function were not detected. None of the patients experienced loosening of the implants. There were two patients with mechanical implant failure, which was treated by re-implantation. Excellent bone ingrowth and ongrowth were found around all hip and tumor prostheses. One year later, the amount of iodine on external fixation pins remained about 20–30 %.ConclusionsIodine-supported titanium implants can be very effective for preventing and treating infections after orthopedic surgery. Cytotoxicity and adverse effects were not detected.

Deep infection remains a serious complication in orthopedic implant surgery. In order to reduce the incidence of implant-associated infections, several biomaterial surface treatments have been proposed. This study focused on evaluating the antibacterial activity of iodine-supported titanium (Ti-I 2 ) and impact on post-implant infection, as well as determining the potential suitability of Ti-I 2 as a biomaterial.External fixation pins were used in this experiment as trial implants because it was easy to make the septic models.The antibacterial activity of the metal was measured using a modification of the Japanese Industrial Standards method. Activity was evaluated by exposing the implants to Staphylococcus aureus or Escherichia coli and comparing reaction of pathogens to the Ti-I 2 versus the stainless steel and titanium controls. The Ti-I 2 clearly inhibited bacterial colonization more than the control metals. In addition, cytocompatibility was assessed by counting the number of colonies that formed on the metals. The three metals showed the same amount of fibroblast colony formation.Japanese white rabbits were used as an in vivo model. Three pins were inserted into both femora of six rabbits for histological analysis. Pin sites were inspected and graded for infection and inflammation. Fewer signs of infection and inflammatory changes were observed in conjunction with the Ti-I 2 pins. Furthermore, osteoconductivity of the implant was evaluated with osteoid formation surface of the pin. Consecutive bone formation was observed around the Ti-I 2 and titanium pins, while little osteoid formation was found around the stainless steel pins. These findings suggest that Ti-I 2 has antimicrobial activity and cytocompatibility.Therefore, Ti-I 2 substantially reduces the incidence of implant infection and shows particular promise as a biomaterial.

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In 1999, we developed a technique for biological reconstruction after excision of a bone tumour, which involved using autografts of the bone containing the tumour treated with liquid nitrogen. We have previously reported the use of this technique in 28 patients at a mean follow up of 27 months (10 to 54). In this study, we included 72 patients who underwent reconstruction using this technique. A total of 33 patients died and three were lost to follow-up, at a mean of 23 months (2 to 56) post-operatively, leaving 36 patients available for a assessment at a mean of 101 months 16 to 163) post-operatively. The methods of reconstruction included an osteo-articular graft in 16, an intercalary in 13 and, a composite graft with prosthesis in seven. Post-operative function was excellent in 26 patients (72.2%), good in seven (19.4%), and fair in three (8.3%) according to the functional evaluation system of Enneking. No recurrent tumour occurred within the grafts. The autografts survived in 29 patients (80.6%), and the rates of survival at five and ten years were 86.1% and 80.6 %, respectively. Seven of 16 osteo-articular grafts (44%) failed because of fracture or infection, but all the composite and intercalary grafts survived. The long-term outcomes of frozen autografting, particularly using composite and intercalary grafts, are satisfactory and thus represent a good method of treatment for patients with a sarcoma of bone or soft tissue.

Osteosarcoma is the most common primary malignancy of bone. Although outcomes of patients with osteosarcoma have improved since the introduction of chemotherapy, outcomes of metastatic or unresectable osteosarcomas are still unsatisfactory. To improve osteosarcoma outcomes, the development of novel systemic therapies for osteosarcoma is needed. Since the 1880s, various immunotherapies have been utilized in patients with osteosarcoma and some patients have shown response to the treatment. Based on recent studies about the role of the immune system in malignancies, immunotherapies including immune modulators such as interleukin-2 and muramyl tripeptide, dendritic cells, immune checkpoint inhibitors, and engineered T cells have been utilized in patients with malignancies. Although there are limited reports of immunotherapies for osteosarcoma, immunotherapy is thought to be a promising treatment option for treating osteosarcomas. In this review, an overview of various immunotherapies for osteosarcoma is provided and their potential as adjuvant therapies is discussed.

Abstract:The most frequent complication in external fixation is pin tract infection. In order to reduce the incidence of implant-associated infection, many published reports have looked at preventing bacterial adhesion by treating the pin surface. This study aimed to evaluate the antibacterial activity of a Titanium-Copper (Ti-Cu) alloy on implant infection, and to determine the potential use of the Ti-Cu alloy as a biomaterial. Two forms of Ti-Cu alloys were synthesized: one with 1% Cu and the other with 5% Cu. For analyzing infectious behavior, the implants were exposed to Staphylococcus aureus and Escherichia coli. The reaction of pathogens to the Ti-Cu alloys was compared with their reaction to stainless steel and pure titanium as controls. Both Ti-Cu alloys evidently inhibited colonization by both bacteria. Conversely, cytocompatibility studies were performed using fibroblasts and colony formation on the metals was assessed by counting the number of colonies. Ti-1% Cu alloy showed no difference in the number of colonies compared with the control. External fixator pins made of Ti-Cu alloys were evaluated in a rabbit model. The tissue-implant interactions were analyzed for the presence of infection, inflammatory changes and osteoid-formation. Ti-1% Cu alloy significantly inhibited inflammation and infection, and had excellent osteoid-formation.. Copper blood levels were measured prior to surgery and at 14 days post-operatively. Pre-operative and post-operative blood copper values were not statistically different. Overall, it was concluded that Ti-Cu alloys have antimicrobial activity and substantially reduce the incidence of pin tract infection. Ti-1% Cu alloy shows particular promise as a biomaterial.

The aim of this study was to determine how alendronate (ALN) alters cartilage degeneration and periarticular bone quality in a rabbit anterior cruciate ligament transection (ACLT) model of osteoarthritis (OA). Thirty rabbits underwent an ACLT on the left knee and a sham operation on the right knee. Fifteen rabbits received weekly subcutaneous injections of ALN (0.14 mg/kg) and 15 rabbits (the control [cont] group) received saline. Animal knees were divided into four groups: cont/sham, cont/ACLT, ALN/sham, and ALN/ACLT. Histological, radiological, and immunohistochemical indices were evaluated for each group. Bone volume ratios by microcomputed tomography showed that ALN prevented periarticular bone loss. Histologically, the cont/ACLT group had significantly worse cartilage damage than the cont/sham group 12 weeks after the surgery. However, the ALN/ACLT group had mild cartilage degeneration compared with that of the ALN/sham group. Immunohistochemical analysis showed that ALN suppressed the expression of matrix metalloproteinase-13, interleukin-1b, type-X collagen, vascular endothelial growth factor, and receptor activator of nuclear factor kB ligand in OA cartilage. ALN had a chondroprotective effect in an experimental rabbit model of OA. ß

PurposeIt has previously been found that valgus hindfoot alignment (HFA) improves 3 weeks following total knee arthroplasty (TKA) for varus knee osteoarthritis (OA). In the present study, HFA was evaluated prior to TKA, as well as 3 weeks and 1 year following TKA. Using these multiple evaluations, the chronological effects of TKA on HFA were investigated.MethodsThe study included 71 patients (73 legs) who underwent TKA for varus knee OA. Radiograph examinations of the entire limb and hindfoot were performed in the standing position prior to TKA, as well as 3 weeks and 1 year following TKA. The varus–valgus angle was used as an indicator of HFA in the coronal plane. Patients were divided into two groups according to the preoperative varus–valgus angle: a hindfoot varus group (varus–valgus angle <76°) and a hindfoot valgus group (varus–valgus angle ≥76°). The changes in the varus–valgus angle were evaluated and compared in both groups.ResultsIn the hindfoot valgus group, the mean ± standard deviation varus–valgus angle significantly declined from 80.5 ± 3.1° prior to TKA to 78.6 ± 3.7° 3 weeks following TKA and 77.1 ± 2.7° 1 year following TKA. However, in the hindfoot varus group, the mean varus–valgus angle prior to TKA (72.7 ± 2.6°) did not differ significantly from the mean varus–valgus angles 3 weeks (72.3 ± 3.3°) or 1 year (73.5 ± 3.0°) following TKA.ConclusionsHFA improved chronologically in legs with hindfoot valgus as a result of the alignment compensation ability of the hindfoot following TKA. However, no improvement was noted in legs with hindfoot varus because the alignment compensation ability of the hindfoot had been lost. The patients with hindfoot varus should be attended for ankle pain in the outpatient clinic after TKA.Level of evidenceIII.