Clinical features and treatment outcomes of dedifferentiated and grade 3 chondrosarcoma: A multi-institutional study.

Chondrosarcoma is the second most common primary malignant bone tumor. In this multicenter study, we sought to evaluate the disease-specific survival (DSS) and disease-free survival (DFS), and prognostic factors in patients with dedifferentiated chondrosarcoma (DDCS) or grade 3 chondrosarcoma (G3CS) in Japan. We retrospectively investigated the treatment outcomes and prognostic factors in 62 patients with DDCS and 19 patients with G3CS at 15 institutions participating in the Japanese Musculoskeletal Oncology Group. We also clarified significant clinicopathological factors for oncological outcomes. In surgery for primary lesions aimed at cure, a histologically negative margin (R0) was obtained in 93% (14/15) of patients with G3CS and 100% (49/49) of patients with DDCS. The 5-year DSS was 18.5% in patients with DDCS and 41.7% in patients with G3CS (p = 0.13). Local control was obtained in 80% (12/15) and 79.6% (39/49) of patients with G3CS and DDCS in the primary lesion after surgery with a wide surgical margin, respectively. In multivariate analysis, stage and no treatment/palliative treatment for the primary lesion were independent prognostic factors for DSS of DDCS, and age and no treatment/palliative treatment for DSS of G3CS. The 5-year DFS rate was 22.8% in 26 patients with DDCS who did not receive adjuvant chemotherapy, and 21.4% in 14 patients who received adjuvant chemotherapy. The prognosis of DDCS remains poor, although R0 resection was carried out in most cases. Effective and/or intensive chemotherapeutic regimens or agents should be considered or developed for patients with high-grade chondrosarcoma, particularly for those with DDCS.

Giant cell tumor of bone - Analysis of 213 cases involving extra-craniofacial bones.

We elucidated clinicopathological characteristics of giant cell tumor of bone (GCTB) in Japan, and significant clinicopathological factors for predicting local recurrence. Clinicopathological profiles of 213 patients with GCTB (100 male, 113 female) involving extra-craniofacial bones were retrieved. Pathological slides obtained at the initial surgery were reviewed. Fourteen pathological and five clinical features were statistically analyzed to disclose prognostic significance. Patient age ranged from 12-80 years (Average 38.7). Long bones were most frequently affected (86.4%), especially around the knee (62.9%). Histological features are basically similar to those previously reported. Within a follow-up period (24-316 months, average 106.1 months), the local recurrence rate is 29.1%. Metastasis has occurred in 9 patients. Cox regression analysis of representative clinicopathological features shows that younger age, higher mitotic count, smaller zones of stromal hemorrhage, considerable vascular invasion and absence of ischemic necrosis are significant predictors for local recurrence. Initial operative method (curettage) is a significant risk factor in univariate analysis but not by multivariate analysis (P = 0.053). Denosumab administration increases risk but not significantly (P = 0.053). Histone 3.3 G34W immunopositivity is not significant for predicting local recurrence.

Benign metastasizing leiomyoma in femur and thigh with a history of uterine leiomyoma: A case report and literature review.

Benign metastasizing leiomyoma (BML) is a rare disease that is characterized by well-differentiated smooth muscle tumors occurring extrauterine site in women with a history of uterine leiomyoma. The lung is the most common metastatic site for BML. A 48-year-old woman, who had histories of laparoscopic myomectomy and transabdominal total hysterectomy, visited an orthopedics complaining of a mass in her left thigh and difficulty in walking. Magnetic resonance imaging (MRI) and fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography revealed multiple mass lesions in her both thighs and left femur as well as both lungs. She was referred to our hospital for further examination. We diagnosed her tumors as BML according to histopathological analysis of tumor specimen. The left thigh tumor was resected and the treatment with gonadotropin releasing hormone agonist regressed the size of the residual tumors by approximately 30%. BML should be considered when multiple soft tissue tumors are found in women with a history of leiomyomas.

The feasibility of iodine-supported processing for titanium with different surfaces.

BACKGROUND: The reduction of microbial infections can substantially improve the success of implant surgery. The iodine-supported implants that were developed by us for infection prevention were featured at the recent International Consensus Meeting on Musculoskeletal Infection and were partly incorporated into the consensus guidelines. For future clinical application, we examined (1) whether iodine can be added to metals with different surface roughness, (2) differences in surface roughness before and after processing, and (3) the effect of sterilization on the iodine content. METHODS: Four Ti-6Al-4V metals were prepared with different surface roughness values by polishing, blasting and plasma spraying. Before and after processing, the surface structure of metals was observed using a scanning electron microscope and stylus instruments. Before and after sterilization, iodine contents were measured by X-ray fluorescence spectroscopy. RESULTS: After processing, sufficient iodine contents with an antimicrobial effect were detected for each metal. These iodine contents decreased after sterilization but were higher than the lowest content of iodine observed to have an antimicrobial effect in a previous study, indicating that the antimicrobial effect persists even after sterilization. After processing, surface roughness was greater for polishing metal. With general surface processing, iodine processing was possible. CONCLUSIONS: Our results indicated that surface roughness is affected by the processing method and that the iodine content should be set according to the sterilization method. Considering these factors, iodine processing can be used for clinical applications.

Early stage and small medial osteochondral lesions of the talus in the presence of chronic lateral ankle instability: A retrospective study.

BACKGROUND: In chronic lateral ankle instability (CLAI), the instability of the ankle joint results in repeated microtrauma to the articular cartilage. How the lesion condition or stage is affected by the presence of lateral instability in medial osteochondral lesions of the talus (OLT) is unclear. We aimed to examine whether CLAI is associated with the size and staging of medial OLT on radiographs, magnetic resonance (MR) images, and arthroscopy. METHODS: Forty-five patients with medial OLTs in 45 ankles were reviewed. Radiographs were assessed for damage and lesion classification. The tibio-talar tilting angle (TTA) was measured. The patients were divided into two groups: the CLAI group and the stable group. The lesion classification on radiographs, MR images, and arthroscopy, and size on MR images were statistically compared. RESULTS: The CLAI group had a mean TTA of 8.15 ± 3.41°, whereas the stable group had a mean TTA of 2.24 ± 1.64°. The CLAI group had a lower clinical score than the stable group at the initial visit to our clinic. The CLAI group presented with lesions of significantly shorter longitudinal and transverse diameters. Stages of medial OLT on radiographs, MR images, and arthroscopic evaluation were earlier in the CLAI group than those in the stable group. CONCLUSIONS: Patients with CLAI presented in the early stages of OLT and had significantly smaller lesions than those without CLAI. The patients without CLAI may be selected for surgery at an early phase.

Risk factors for surgical site infection after malignant bone tumor resection and reconstruction.

BACKGROUND: Use of an implant is one of the risk factors for surgical site infection (SSI) after malignant bone tumor resection. We developed a new technique of coating titanium implant surfaces with iodine to prevent infection. In this retrospective study, we investigated the risk factors for SSI after malignant bone tumor resection and to evaluate the efficacy of iodine-coated implants for preventing SSI. METHODS: Data from 302 patients with malignant bone tumors who underwent malignant bone tumor resection and reconstruction were reviewed. Univariate analyses were performed, followed by multivariate analysis to identify risk factors for SSI based on the treatment and clinical characteristics. RESULTS: The frequency of SSI was 10.9% (33/302 tumors). Pelvic bone tumor (OR: 4.8, 95% CI: 1.8-13.4) and an operative time ≥ 5 h (OR: 3.4, 95% CI: 1.2-9.6) were independent risk factors for SSI. An iodine-coated implant significantly decreased the risk of SSI (OR: 0.3, 95% CI: 0.1-0.9). CONCLUSION: The present data indicate that pelvic bone tumor and long operative time are risk factors for SSI after malignant bone tumor resection and reconstruction, and that iodine coating may be a promising technique for preventing SSI.

Mesenchymal hamartoma of the chest wall in a 10-year-old girl mimicking malignancy: a case report.

We herein report a rare case of mesenchymal hamartoma of the chest wall in a 10-year-old girl. She complained of chest pain and was diagnosed with a large chest wall tumor originating from the left fourth rib. Malignancy such as osteosarcoma or chondrosarcoma could not be ruled out with imaging studies. Therefore, we performed a core needle biopsy assisted by thoracoscopy, which revealed no malignancy. Therefore, extended resection with chest wall reconstruction was unnecessary, and thoracoscopy-assisted tumor excision with only the removal of the involved fourth rib was performed without chest wall reconstruction. The postoperative course was satisfactory with no thoracic deformity and no recurrence.

Iodine-supported titanium implants have good antimicrobial attachment effects.

BACKGROUND: We have developed iodine-supported titanium implants, which were shown to have good anti-bacterial effects for Methicillin-sensitive Staphylococcus aureus (MSSA) in our past basic research. However, PJI can be caused by various bacteria including MRSA, Pseudomonas aeruginosa, MSSE, and fungus. The purpose of this study was to investigate whether these implants also have good antibacterial attachment effects for MRSA, P. aeruginosa, MSSE, and fungus. METHODS: Ti-6Al-4V titanium plates were either left untreated (Ti), treated with oxide film on the Ti surface by anodization (Ti-O), or treated with an iodine coating on oxidation film (Ti-I). The antibacterial activity of the TiI was measured by experimental methods according to Japanese Industrial Standard (JIS) protocols. Implants in this study were exposed to MRSA (ATCC43300), P. aeruginosa (ATCC27853), MSSE (ATCC35984), and Candida Albicans (ATCC10231). Colonies were counted immediately after the bacteria attached to the metal surface and again after 24 h incubation. The difference in the number of bacteria on each metal plate was statistically investigated and an antibacterial activity value was calculated. An effective antibacterial active value of more than 2.0 was judged to be effective according to JIS protocol. RESULTS: No countable viable bacteria were observed on the Ti-I surface. For all bacteria there was a significant difference in the mean number of viable bacteria between Ti-I and Ti or Ti-O. Antibacterial activity value in Ti-I and Ti-O was more than 5.9 and 3.6 respectively for MRSA, more than 2.8 and zero for P. aeruginosa, more than 4.3 and zero for MSSE, and more than 4.7 and zero for C. Albicans. CONCLUSIONS: This study showed that iodine-supported titanium implants have good antimicrobial attachment effects for MRSA, P. aeruginosa, MSSE, and C. Albicans. Iodine-supported titanium implants could have great potential as innovative antibacterial implants that can prevent early onset periprosthetic joint infection.

Treadmill Running in Established Phase Arthritis Inhibits Joint Destruction in Rat Rheumatoid Arthritis Models.

Exercise therapy inhibits joint destruction by suppressing pro-inflammatory cytokines. The efficacy of pharmacotherapy for rheumatoid arthritis differs depending on the phase of the disease, but that of exercise therapy for each phase is unknown. We assessed the differences in the efficacy of treadmill running on rheumatoid arthritis at various phases, using rat rheumatoid arthritis models. Rats with collagen-induced arthritis were used as rheumatoid arthritis models, and the phase after immunization was divided as pre-arthritis and established phases. Histologically, the groups with forced treadmill running in the established phase had significantly inhibited joint destruction compared with the other groups. The group with forced treadmill running in only the established phase had significantly better bone morphometry and reduced expression of connexin 43 and tumor necrosis factor α in the synovial membranes compared with the no treadmill group. Furthermore, few cells were positive for cathepsin K immunostaining in the groups with forced treadmill running in the established phase. Our results suggest that the efficacy of exercise therapy may differ depending on rheumatoid arthritis disease activity. Active exercise during phases of decreased disease activity may effectively inhibit arthritis and joint destruction.

Limb saving surgery for Ewing's sarcoma of the distal tibia: a case report.

BACKGROUND: Ewing's sarcoma is a primary malignant tumor of bone occurring mostly in childhood. Few effective reconstruction techniques are available after wide resection of Ewing's sarcoma at the distal end of the tibia. Reconstruction after wide resection is especially difficult in children, as it is necessary to consider the growth and activity of the lower limbs. CASE PRESENTATION: A 12-year-old Japanese boy had presented with right lower leg pain at age 8 years. Imaging examination showed a bone tumor accompanied by a large extra-skeletal mass in the distal part of his tibia. The tumor was histologically diagnosed as Ewing's sarcoma. The patient received chemotherapy, followed by wide resection. Reconstruction consisted of a bone transport method involving external fixation of Taylor Spatial Frame. To prevent infection after surgery, the external fixation pin was coated with iodine. One year after surgery, the patient showed poor consolidation of bone, so iliac bone transplantation was performed on the extended bones and docking site of the distal tibia. After 20 months, tibia formation was good. Three years after surgery, there was no evidence of tumor recurrence or metastases; bone fusion was good, and he was able to run. CONCLUSIONS: The bone transport method is an effective surgical method of reconstruction after wide resection of a bone tumor at the distal end of the tibia, if a pin can be inserted into the distal bone fragment. Coating external fixation pins with iodine may prevent postoperative infection.

Mid- to long-term clinical outcome of giant cell tumor of bone treated with calcium phosphate cement following thorough curettage and phenolization.

BACKGROUND AND OBJECTIVES: Giant cell tumors of bone (GCTB) are intermediate and locally aggressive bone tumor. Calcium phosphate cement (CPC) is a bone void filler used in orthopaedic surgery. This study investigated the clinical outcome of GCTB treated with thorough curettage, phenolization, and CPC. METHODS: We investigated 26 patients with at least 36 months of follow-up. The mean age and follow-up were 37 years (range: 19-63) and 87 months (range: 38-169), respectively. Radiological outcomes including consolidation of CPC to the surrounding bone, cortical bone defect remodeling, and clinical outcomes were investigated. RESULTS: The consolidation of CPC to the surrounding bone was excellent in 22 cases (84.6%), good in three (11.5%), and acceptable in one (3.8%). Local recurrence occurred in three cases (11.5%). Pulmonary metastasis occurred in one case (3.8%). Cortical bone defect remodeling appeared in 22 cases (84.6%). The mean Musculoskeletal Tumour Society score was 28.7 (95.7%). Osteoarthritis, chronic synovitis, and fracture were observed in one case each (3.8%), which were managed conservatively. CONCLUSIONS: Phenolization did not prevent the consolidation of CPC to the bone. CPC provided biological interface and long lasting stability without internal fixation, with comparable complication rates to other published series.

Treadmill Running Ameliorates Destruction of Articular Cartilage and Subchondral Bone, Not Only Synovitis, in a Rheumatoid Arthritis Rat Model.

We analyzed the influence of treadmill running on rheumatoid arthritis (RA) joints using a collagen-induced arthritis (CIA) rat model. Eight-week-old male Dark Agouti rats were randomly divided into four groups: The control group, treadmill group (30 min/day for 4 weeks from 10-weeks-old), CIA group (induced CIA at 8-weeks-old), and CIA + treadmill group. Destruction of the ankle joint was evaluated by histological analyses. Morphological changes of subchondral bone were analyzed by µ-CT. CIA treatment-induced synovial membrane invasion, articular cartilage destruction, and bone erosion. Treadmill running improved these changes. The synovial membrane in CIA rats produced a large amount of tumor necrosis factor-α and Connexin 43; production was significantly suppressed by treadmill running. On µ-CT of the talus, bone volume fraction (BV/TV) was significantly decreased in the CIA group. Marrow star volume (MSV), an index of bone loss, was significantly increased. These changes were significantly improved by treadmill running. Bone destruction in the talus was significantly increased with CIA and was suppressed by treadmill running. On tartrate-resistant acid phosphate and alkaline phosphatase (TRAP/ALP) staining, the number of osteoclasts around the pannus was decreased by treadmill running. These findings indicate that treadmill running in CIA rats inhibited synovial hyperplasia and joint destruction.

Inhibition of biofilm formation on iodine-supported titanium implants.

PURPOSE: We have developed iodine-supported titanium implants that suppress microbial activities and conducted in vivo and in vitro studies to determine their antimicrobial properties. METHODS: The implants were Ti-6Al-4 V titanium implants either untreated (Ti), treated with oxide film on the Ti surface by anodization (Ti-O), or treated with an iodine coating on oxidation film (Ti-I). The strain of bacteria used in this study was Gram-positive Staphylococcus aureus strain ATCC 25923. We analyzed the antibacterial attachment effects in vivo by using rats. The attachment bacteria on the implant surface were evaluated using a spread-plate method assay. A biofilm study was performed in vitro. The biofilm formed after bacterial attachment was qualitatively studied with fluorescence microscopy (FM) and scanning electron microscopy (SEM). Also, the formed biofilm was quantitatively studied with a spread-plate method assay. RESULTS: In vivo analysis of antimicrobial attachment effects showed that the mean viable bacterial number was significantly lower on Ti-I than Ti or Ti-O surfaces. In the in vitro biofilm study, FM and SEM images showed thick and mature biofilm formation on Ti and Ti-O and thin, small biofilm formation on Ti-I. A quantitative biofilm analysis found a significant difference in the number of viable bacteria between Ti-I and Ti or Ti-O. CONCLUSIONS: This study showed that iodine-supported implants have a good antibacterial attachment effect and inhibit biofilm formation and growth. Iodine-supported implants may have great potential as innovative antibacterial implants that can prevent implant related infection in orthopaedic surgery.

Subperiosteal inflammatory pseudotumor mimicking primary malignant bone tumor: A case report.

We report a case of IgG4-positive inflammatory pseudotumor mimicking malignant bone tumor. Biopsy revealed no tumor cells. Surgical excision was performed and an abscess developing beneath the periosteum was observed with Streptococcus constellatus. Preoperative serum IgG4 value of 120 mg/dl normalized postoperatively to 80.6 mg/dl. It was difficult to distinguish inflammatory pseudotumor from sarcoma because it developed under the periosteum. In such cases, it is important to measure blood IgG4 values and perform tissue staining and culturing.

Clinical relevance of peroxisome proliferator-activated receptor-gamma expression in myxoid liposarcoma.

BACKGROUND: Peroxisome proliferator-activated receptor gamma (PPARγ) is a ligand-activated transcription factor that belongs to the nuclear hormone receptor superfamily. PPARγ is essential in adipocyte differentiation from precursor cells. Its antitumorigenic effects are reported in certain malignancies; however, its effects in liposarcoma are unclear. METHODS: We analyzed PPARγ expression using immunohistochemistry (IHC) in 46 patients with myxoid liposarcoma [MLS; median age, 47 years (range, 14-90 years) and mean follow-up period, 91 months (range, 13-358 months)]. PPARγ mRNA expression levels were measured by quantitative reverse transcription polymerase chain reaction. Further, we evaluated the correlation of PPARγ expression with clinical outcomes. RESULTS: We found that the metastasis-free survival rate was significantly higher in lower PPARγ expressers [34 patients with labeling index (LI) <50 %] than in higher expressers (12 patients with LI ≥50 %; p = 0.01). Cox multivariate analysis revealed that a higher PPARγ level was an independent predictor of metastasis (relative risk = 6.945, p = 0.026). Furthermore, using 28 fresh MLS specimens, we confirmed an increased PPARγ mRNA expression level in the higher LI group (p = 0.001). CONCLUSIONS: In this study, higher PPARγ expression in MLS was a risk factor associated with distant metastasis; therefore, it would be a novel prognostic marker for MLS. Further analyses will help to understand the correlation between PPARγ expression and tumor malignancy in liposarcoma.

The outcomes of reconstruction using frozen autograft combined with iodine-coated implants for malignant bone tumors: compared with non-coated implants.

OBJECTIVE: We perform reconstruction using frozen tumor bone treated by liquid nitrogen after excision of malignant bone tumors. To prevent post-operative infection, we use iodine-coated implants that we developed. The purpose of this study is to compare the outcome of reconstruction using frozen autograft with non-coated implants (group N) and iodine-coated implants (group I). METHODS: Sixty-two patients were included in group N. The mean age was 31.9 ± 2.3 years. A total of 20 patients died and two were lost to follow-up, averaging 20.0 ± 2.9 months post-operatively, leaving 40 patients available for an assessment at a mean of 79.1 ± 5.8 months post-operatively. There were 38 patients in group I. The mean age was 29.8 ± 3.9 years. The mean follow-up period was 32.1 ± 3.0 months. All patients were alive at the latest follow-up. Survival of frozen bone was determined by Kaplan-Meier analysis. RESULTS: In group N, survival of frozen bone was 80.7 ± 6.0% and 57.4 ± 10.2% at 5 and 10 years, respectively. Complications were encountered in 31 of 62 patients (50.0%), including deep infection in 10 (16.1%), fracture in 11 (17.7%), local soft-tissue recurrence in 6 (9.7%) and bone absorption in 4 (6.5%). In group I, survival of frozen bone was 86.7 ± 6.3% at 5 years. Complications were encountered in 8 of 38 patients (21.1%), including deep infection in one (2.6%), fracture in four (10.5%), local soft-tissue recurrence in two (5.3%) and bone absorption in one (2.6%). There was a significantly lower infection rate in group I (P = 0.032). CONCLUSION: Reconstruction using frozen autograft combined with iodine-coated implants for patients with malignant bone tumor is very useful method in which good limb function can be gained with minimized risk of infection.

Hindfoot alignment at one year after total knee arthroplasty.

PURPOSE: It 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. METHODS: The 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. RESULTS: In 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. CONCLUSIONS: HFA 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 EVIDENCE: III.

Magnetic resonance angiography evaluation of the bone tunnel and graft following ACL reconstruction with a hamstring tendon autograft.

PURPOSE: In this study, magnetic resonance angiography (MRA) was performed in the early phase after anterior cruciate ligament (ACL) reconstruction to analyse the changes in nutrient blood vessels and blood flow to the femoral and tibial tunnels and the intraosseous tendon grafts. METHODS: The subjects were 30 patients who underwent single-bundle ACL reconstruction with an autogenous hamstring tendon. MRA was performed at 2, 3, and 6 months postoperatively (n = 10 at each time point). The mean overall signal-to-noise ratios (SNRs) in the tunnel regions and in the region of the tendon graft were compared in each femur and tibia. RESULTS: Blood vessels from arteries reached the femoral and tibial tunnels 2 months postoperatively. The tunnel walls showed high signal intensity, while the intraosseous tendon grafts had lower intensity. SNRs showed significant differences between the femoral and tibial tunnels overall and the intraosseous tendon grafts. At 3 and 6 months postoperatively, the signal intensity of the tunnel walls was decreased significantly, while that of the intraosseous tendon grafts was also decreased, but not significantly. At these times, the SNRs of the femoral and tibial tunnels did not differ significantly, both overall and in the region of the intraosseous tendon grafts. CONCLUSION: Revascularization around the femoral and tibial tunnels occurred at 2 months postoperatively, with blood flow subsequently decreasing over time until 6 months. This revascularization may be involved in bone tendon healing and maturation of the tendon graft within the bone tunnels. Evaluations of revascularization by MRA may show the maturation stage of the graft and guide medical rehabilitation. LEVEL OF EVIDENCE: IV.

Differences in monthly variation, cause, and place of injury between femoral neck and trochanteric fractures: 6-year survey (2008-2013) in Kyoto prefecture, Japan.

BACKGROUND: The incidence of femoral neck and trochanteric fractures reportedly differ by age and regionality. We investigated differences in monthly variations of the occurrence of femoral neck and trochanteric fractures as well as place and cause of injury in the Kyoto prefecture over a 6-year period. METHODS: Fracture type (neck or trochanteric fracture), age, sex, place of injury, and cause of injury were surveyed among patients aged ≥ 65 years with hip fractures that occurred between 2008 and 2013 who were treated in 1 of 13 participating hospitals (5 in an urban area and 8 in a rural area). The proportion of sick beds in the participating hospitals was 24.7% (4,151/16,781). Monthly variations in the number of patients were investigated in urban and rural areas in addition to the entire Kyoto prefecture. Place of injury was classified as indoors or outdoors, and cause of injury was categorized as simple fall, accident, or uncertain. RESULTS: There were 2,826 patients with neck fractures (mean age, 82.1 years) and 3,305 patients with trochanteric fractures (mean age, 85.0 years). There were similarities in the monthly variation of the number of fractures in addition to the place and cause of injury between neck and trochanteric fractures. Indoors (approximately 74%) and simple falls (approximately 78%) were the primary place and cause of injury, respectively. The place of injury was not significantly different by fracture type with each age group. Significantly more patients with neck fracture had "uncertain" as the cause of injury than trochanteric fracture in all age groups. CONCLUSIONS: Based on the results of the present study, the injury pattern might not have a great effect on the susceptibility difference between neck and trochanteric fractures.

Metastasis of differentiated thyroid cancer in the subchondral bone of the femoral head: a case report.

BACKGROUND: Differentiated thyroid cancer (DTC) is relatively rare and can metastasize to both the lungs and bones. The great majority of bone metastases occur in red marrow regions where blood flow is high. Only one patient has been described with direct DTC metastasis to the subchondral bone of the femoral head. CASE PRESENTATION: The patient was a 68-year-old Japanese female who had presented with left hip joint pain at age 63 years. At age 51 years, she had been diagnosed with DTC and underwent partial excision. X-rays showed partial femoral head collapse, suggesting osteoarthritis or idiopathic necrosis of the left femoral head. Three years later, a (131) I whole-body scan showed accumulation in the left femoral head, resulting in a diagnosis of DTC metastasis to the left femoral head. Bipolar hip arthroplasty was performed. Examination of the excised femoral head resulted in a final diagnosis of metastasis of follicular thyroid cancer, which was limited histopathologically to the subchondral bone of the femoral head. CONCLUSION: Tumor metastasis to the subchondral bone of the femoral head is exceedingly rare. Overall survival of patients with bone metastasis is improved by complete resection. Differential diagnosis of patients with a previous history of DTC who present with femoral head collapse should include bone metastasis of DTC.