Relationship between the Arthroscopic Findings and Pathology of Greater Trochanteric Pain Syndrome.

In recent publications on greater trochanteric pain syndrome (GTPS), the pathology receiving the most attention has been gluteus medius muscle tendinous injury, and surgical techniques such as gluteus medius tendon repair and their outcomes for GTPS have been reported. In our department-related facilities, arthroscopic surgeries are routinely performed for the patients with recalcitrant GTPS. A total of 51 patients were diagnosed with GTPS. Surgical treatment was carried out 22 patients (24 joints; 4 males and 18 females; mean age at surgery of 52.0 years). Arthroscopic findings confirmed bursitis in all 24 joints. In all cases, debridement of the greater trochanter bursa provided rapid relief of greater trochanter pain. The Numerical Rating Scale showed significant improvement, from the preoperative mean of 7.8 (range, 6-10) to the postoperative day 7 mean of 1.6 (range, 0-3). The modified Harris Hip Score was significantly improved from the preoperative mean of 65.5 (range, 52.5-78.3) to the final follow-up (average 2.9 months) mean of 96.0 (range, 85.2-100). Fascial damage of the gluteus medius muscle was observed in 21 joints while only 2 patients had a gluteus medius tendinous injury. Greater trochanteric bursitis and fascia or muscle-fiber injury of the gluteus medius muscle are the most common pathologies in patients with lateral hip pain.

Characteristic imaging findings of tendinosis of the direct head of rectus femoris and their interpretation.

BACKGROUND: Tendinosis at the origin of the direct head of rectus femoris causing anterior hip pain is termed AIISpinitis, but no study has investigated its imaging findings. The aim of the present study was to determine the characteristic imaging findings of AIISpinitis and clarify their pathological significance. METHODS: We reviewed the preoperative imaging findings of 62 hips in 58 patients who had undergone endoscopy with a diagnosis of AIISpinitis. The origin of the direct head of rectus femoris was evaluated by ultrasound (US) and magnetic resonance imaging (MRI), and the positive rate of abnormal findings and their agreement with endoscopy regarding injury of the direct head of rectus femoris were measured. Signal changes in the fat pad around the anterior inferior iliac spine (AIIS fat pad) in MRI were compared with the pathological findings of that harvested endoscopically. RESULTS: Hypoechoic regions in US (53/62, 85%) and signal change in MRI (55/62, 89%) were observed with high frequency and corresponded with injury of the direct head of rectus femoris observed by endoscopy (58/62, 94%) (kappa coefficient, 0.43 [moderate agreement], 0.69 [good agreement] respectively). Hypoechoic regions had high sensitivity (85%) and specificity (86%) for AIISpinitis. Regarding the AIIS fat pad, punctate and completely hypo-intense change relative to normal fat corresponded to fibrosis and scar formation, respectively (weighted kappa coefficient, 0.51 [moderate agreement]). CONCLUSIONS: Hypoechoic regions on US which had high sensitivity and specificity; and signal change at the origin of the direct head of rectus femoris and hypo-intensity of the AIIS fat pad on MRI were characteristic findings of tendinosis of the direct head of rectus femoris. These findings correspond pathologically to injury of the direct head of rectus femoris and fibrosis or scar formation in the AIIS fat pad, respectively.

Osteosarcoma-initiating cells show high aerobic glycolysis and attenuation of oxidative phosphorylation mediated by LIN28B.

Osteosarcoma (OS) is a highly malignant bone tumor and the prognosis for non-responders to chemotherapy remains poor. Previous studies have shown that human sarcomas contain sarcoma-initiating cells (SIC), which have the characteristics of high tumorigenesis and resistance to chemotherapy. In the present study, we characterized SIC of a novel OS cell line, screened for SIC-related genes, and tried to regulate the proliferation of OS by metabolic interference. Initially, we established a new human OS cell line (OS13) and isolated clones showing higher tumorigenesis as SIC (OSHIGH ) and counterpart clones. OSHIGH cells showed chemoresistance and their metabolism highly depended on aerobic glycolysis and suppressed oxidative phosphorylation. Using RNA-sequencing, we identified LIN28B as a SIC-related gene highly expressed in OSHIGH cells. mRNA of LIN28B was expressed in sarcoma cell lines including OS13, but its expression was not detectable in normal organs other than the testis and placenta. LIN28B protein was also detected in various sarcoma tissues. Knockdown of LIN28B in OS13 cells reduced tumorigenesis, decreased chemoresistance, and reversed oxidative phosphorylation function. Combination therapy consisting of a glycolysis inhibitor and low-dose chemotherapy had antitumor effects. In conclusion, manipulation of glycolysis combined with chemotherapy might be a good adjuvant treatment for OS. Development of immunotherapy targeting LIN28B, a so-called cancer/testis antigen, might be a good approach.

Feasibility and efficacy of gemcitabine and docetaxel combination chemotherapy for bone and soft tissue sarcomas: multi-institutional retrospective analysis of 134 patients.

BACKGROUND: Bone and soft tissue sarcomas (BSTS) are rare malignant tumors. Recently, the combination of gemcitabine and docetaxel (GD) was shown to have activity as second-line setting in BSTS. However, the efficacy as first-line and adjuvant settings and precise profiles of adverse events in Japanese patients are not known yet. In the present study, the feasibility and efficacy of GD in patients with BSTS were investigated. METHODS: Patients with BSTS treated with GD in our institutions were retrospectively analyzed. Information regarding clinical features, adverse events, and outcome was collected and statistically studied. Factors related to survival were analyzed using log-rank test and Cox proportional hazard regression method. RESULTS: A total of 134 patients were analyzed. GD was carried out as adjuvant setting in 9, first-line in 23, second-line in 56, and third-or-greater line in 46 patients. The response rate (RR) for all patients was 9.7%. RR for the patients treated as adjuvant or first-line setting was 18.8%, whereas that as second-or-greater line was 6.9%. The median progression-free survival (PFS) and overall survival (OS) of all patients were 4.8 (95% CI 3.5-6.1) and 16.4 (95% CI 9.8-22.9) months, respectively. Survival tended to be better in the patients treated as first-line than in those treated as second-or-greater line. Multivariate analysis demonstrated that history of prior chemotherapy (p = 0.046) and response to GD (p = 0.009) was significantly associated with PFS and OS, respectively. The leucopenia and neutropenia were the most frequent adverse events, and grade 3 or 4 leucopenia and neutropenia were observed in 69.4 and 72.4% of the patients. Grade 2 or 3 pneumonitis was observed in one (0.7%) and four (3.0%) patients, respectively. All the patients with pneumonitis had experienced prior chemotherapy and/or radiotherapy. CONCLUSIONS: GD used as both first- and second/later line is effective chemotherapy for a proportion of patients with advanced BSTS. Higher response rate and better outcome was achieved in chemotherapy-naïve patients. This regimen is associated with high incidence of severe hematological toxicity, as well as the risk of severe pneumonitis, especially in pre-treated patients. GD is promising for further analysis by phase III study for the patients with BSTS.

Hip morphology influences the pattern of articular cartilage damage.

PURPOSE: The aim of this study was to obtain data on chondral damage and compare the damage patterns of various hip disorders. METHODS: Data were collected at 100 consecutive arthroscopies, and chondral lesions were recorded on anatomic articular maps divided into different anatomical zones. This geographic zone method made it possible to analyze the ICRS grade and location in relation to the hip morphology. RESULTS: The distribution and degree of the chondral defects showed a hip morphology-specific pattern. On the acetabular side, there were high incidences of full-thickness defects in the anterior-superior zone and the middle superior zone in patients with femoroacetabular impingement (FAI) (zone 2: 25.4 % grade 3, 35.5 % grade 4; zone 3: 20.3 % grade 3, 37.2 % grade 4) and borderline dysplasia (zone 2: 31.2 % grade 3, 12.5 % grade 4; zone 3: 18.7 % grade 3, 25 % grade 4). However, in patients with joint laxity, partial-thickness defects were dominant (zone 2: 50 % grade 1, 15 % grade 2; zone 3: 40 % grade 1). In patients with acetabular dysplasia, full-thickness defects extended even to the posterior superior zone (zone 4: 80 % grade 4). On the femoral head side, the incidence of full-thickness cartilage injuries was high in patients with FAI and borderline dysplasia compared to those with joint laxity and acetabular dysplasia. CONCLUSION: Evaluation of chondral damage using the geographic zone method showed that the pattern of cartilage damage was influenced by hip morphology. Understanding of hip disorder-specific chondral damage patterns may be useful for the development of arthroscopic classification of hip disorders and may lead to the establishment of treatment guidelines. LEVEL OF EVIDENCE: Diagnostic study, Level III.

[Neurolymphomatosis of the sciatic nerve diagnosed by FDG-PET/CT].

Neurolymphomatosis is a rare manifestation of malignant lymphoma. The involvement of peripheral nerves has mostly been described as dissemination of a systemic lymphoma. In contrast, primary peripheral nerve lymphoma is extremely rare. A 68-year-old man presented in January 2014 with a sensory disturbance in the left lower extremity. There were no obvious findings on MRI or CT that could account for his symptoms. After 1 year of symptomatic treatment, the patient was managed conservatively for an additional year. However, his symptoms worsened. FDG-PET/CT showed high FDG uptake in the left sciatic nerve. Biopsy of the lesion revealed diffuse large B cell lymphoma.

[Treatment Outcomes of Adult-Onset Ewing Sarcoma: A Single-Center Retrospective Study of Five Cases].

UNLABELLED: We report the treatment outcomes of 5 cases of adult-onset Ewing sarcoma(ES)managed between 2011 and 2014. We examined prognostic factors including the primary lesion, tumor size, metastatic status, and serum LDH levels. RESULTS: The locations of the primary lesions included the limbs in 1 case and the trunk in 4; the cases in the trunk had a worse prognosis than that in the limbs. Tumor size was greater than 8 cm in only 1 patient, who also displayed evidence of metastases at presentation and high LDH levels. All the patients received chemotherapy consisting of alternating vincristine, doxorubicin, and cyclophosphamide(VDC)and etoposide and ifosfamide(IE). Surgery was selected for the treatment of 4 patients, and radiotherapy was administered to 1 patient for local treatment of the tumor. A median follow-up duration of 31.6 months revealed the 2-year overall survival rate and progression-free survival rate to be 80.0%. CONCLUSIONS: The prognosis of patients with adult-onset ES is poor; however, combined modality therapy, including VDC-IE, was demonstrated to improve the outcome of patients in the present study. Nevertheless, the patient with tumor size exceeding 8 cm, metastasis, and high LDH levels, relapsed 1 year after treatment, as reported previously. Further investigation is required to clarify the factors affecting prognosis in adults, and to develop effective therapies for patients with a poor prognosis.

Prognostic impact of CD109 expression in myxofibrosarcoma.

BACKGROUND: CD109, a TGF-ß co-receptor, is reported to be preferentially expressed during the early stages of tumorigenesis in several carcinoma types. Myxofibrosarcoma is one of the most common soft-tissue sarcomas found in elderly patients. This study aimed to elucidate the impact of CD109 expression in myxofibrosarcoma on prognosis and recurrence. METHODS: Immunohistochemical staining for CD109 was performed on archival specimens from 37 patients. The Fisher exact test was used to evaluate association between CD109 expression and other clinicopathological features. Survival analysis was performed using Kaplan-Meier curves, and the prognostic significance was evaluated using the log-rank test. Multivariate analysis of factors was performed using Cox regression analysis. RESULTS: CD109 overexpression was significantly associated with surgical stage and distant metastasis (P = 0.00499, and 0.011, respectively). The frequency of CD109 overexpression was approximately 10% and CD109 overexpression was significantly associated with decreased overall survival (P = 0.004). Five-year overall survival rates 77% and 0% for CD109-negative and CD109-positive patients, respectively. In multivariate analysis, CD109 overexpression was the only independent risk factor for poor outcome (P = 0.02; hazard ratio, 10.64; 95% confidence interval, 1.47-76.91). CONCLUSIONS: Immunohistochemical CD109 expression in myxofibrosarcoma was associated with poor prognosis.

Ligamentum teres injury is associated with the articular damage pattern in patients with femoroacetabular impingement.

PURPOSE: The objective of this study was to investigate the association between ligamentum teres injury and the hip joint cartilage damage pattern in patients with femoroacetabular impingement. METHODS: We compared articular cartilage damage between ligamentum teres-intact and-ruptured hips. Data were collected for 77 consecutive patients with femoroacetabular impingement who underwent hip arthroscopy. The locations of the chondral lesions were recorded on anatomic articular maps using the geographic zone method. The patients were divided into 2 groups (ligamentum teres-intact and-injured groups), and the incidence and degree of cartilage injury were compared between the 2 groups by use of the Mann-Whitney U test. RESULTS: In patients with ligamentum teres injury, chondral damage extended to the middle-inferior area of the acetabulum (7.6% [grade 1] in ligamentum teres-intact group and 66.6% [grade 1, 12.1%; grade 2, 42.4%; grade 3, 12.1%] in ligamentum teres-injured group, P < .01) and the apex of the femoral head (anterior apex: 7.1% [grade 1, 3.8%; grade 2, 3.3%] in intact group and 42.4% [grade 1, 30.3%; grade 2, 12.1%] in injured group, P < .01; middle apex: 7.6% [grade 1, 3.8%; grade 2, 3.8%] in intact group and 63.5% [grade 1, 42.4%; grade 2, 18.1%; grade 3, 3.0%] in injured group, P = .04; posterior apex: 7.6% [grade 1, 3.8%; grade 2, 3.8%] in intact group and 42.4% [grade 1, 30.3%; grade 2, 12.1%] in injured group, P < .01). CONCLUSIONS: This study showed the association between ligamentum teres injury and articular cartilage damage in the inferior middle part of the acetabulum and the apex of the femoral head in patients treated for femoroacetabular impingement. LEVEL OF EVIDENCE: Level IV, case-control study.

SYT-SSX breakpoint peptide vaccines in patients with synovial sarcoma: a study from the Japanese Musculoskeletal Oncology Group.

In the present study, we evaluated the safety and effectiveness of SYT-SSX-derived peptide vaccines in patients with advanced synovial sarcoma. A 9-mer peptide spanning the SYT-SSX fusion region (B peptide) and its HLA-A*2402 anchor substitute (K9I) were synthesized. In Protocols A1 and A2, vaccines with peptide alone were administered subcutaneously six times at 14-day intervals. The B peptide was used in Protocol A1, whereas the K9I peptide was used in Protocol A2. In Protocols B1 and B2, the peptide was mixed with incomplete Freund's adjuvant and then administered subcutaneously six times at 14-day intervals. In addition, interferon-α was injected subcutaneously on the same day and again 3 days after the vaccination. The B peptide and K9I peptide were used in Protocols B1 and B2, respectively. In total, 21 patients (12 men, nine women; mean age 43.6 years) were enrolled in the present study. Each patient had multiple metastatic lesions of the lung. Thirteen patients completed the six-injection vaccination schedule. One patient developed intracerebral hemorrhage after the second vaccination. Delayed-type hypersensitivity skin tests were negative in all patients. Nine patients showed a greater than twofold increase in the frequency of CTLs in tetramer analysis. Recognized disease progression occurred in all but one of the nine patients in Protocols A1 and A2. In contrast, half the 12 patients had stable disease during the vaccination period in Protocols B1 and B2. Of note, one patient showed transient shrinkage of a metastatic lesion. The response of the patients to the B protocols is encouraging and warrants further investigation.

Pre-operative selective arterial embolization as a neoadjuvant therapy for proximal humerus giant cell tumor of bone: radiological and histological evaluation.

The management of giant cell tumor of the proximal humerus that extends to the joint is challenging. Here, we report a case of proximal humerus giant cell tumor with cortical bone destruction extending to the shoulder joint. Pre-operative selective arterial embolization induced peripheral tumor ossification. Subsequently, the lesion was removed by intralesional curettage, and the cavity was filled with cement. Macroscopically, the inner wall of the cavity was found to be lined with a thick fibrous membrane. Histologically, massive fibrosis and resultant remodeling of the destroyed cortical bone were induced, which was consistent with the peripheral ossification on the plain radiograph. We believe that selective arterial embolization can be an effective neoadjuvant therapy for giant cell tumors of the extremities, especially for tumors with large cortical defects or joint involvement.

Endoscopic Resection for Iliopectineal Bursitis Associated With Developmental Dysplasia of the Hip.

Iliopectineal bursitis usually develops subsequent to other hip pathologies and can often be treated conservatively. However, when conservative treatment fails or the enlarged bursa causes pain or compression of the surrounding neurovascular structures, surgery may be required. Most previous studies have described open surgeries, and reports on endoscopy are very limited. We present a case of iliopectineal bursitis associated with developmental dysplasia of the hip (DDH) that was successfully treated endoscopically. A 16-year-old female with a one-year history of right inguinal pain was referred to our department. She was diagnosed with a hip ganglion and treated with needle aspiration nine times by her previous doctor. Radiographs revealed bilateral DDH without narrowing of the joint space. Magnetic resonance imaging revealed a distinct mass in the deep layer of the iliopsoas muscle, and communication between the mass and the hip joint was observed on ultrasonography. Endoscopic debridement and resection were performed based on the diagnosis of iliopectineal bursitis. We partially debrided the medial side of the rectus femoris muscle toward the deep layer and resected the bursa. We observed a burst of concentrated content from the bursa and confirmed the disappearance of the mass by intraoperative ultrasonography. The postoperative course was good, and there were no functional restrictions or symptom recurrence at two-year postoperatively. Endoscopic resection for repetitive iliopectineal bursitis without an intraarticular procedure does not induce hip instability in patients with DDH and is a minimally invasive cosmetic procedure, and superior to open surgery, especially in young women.

Revision total hip arthroplasty due to pain from hypersensitivity to cobalt-chromium in total hip arthroplasty.

We report a case with hypersensitivity to CoCr in total hip arthroplasty coupled with conventional polyethylene and CoCr femoral head. The patient complained of left hip pain and systemic fever, and computed tomography imaging revealed a periprosthetic cystic lesion, so we performed revision total hip arthroplasty using a titanium stem and ceramic head and highly crosslinked polyethylene. Hip pain and cystic lesion disappeared 3 years after revision surgery.

Bone and/or joint attachment is a risk factor for local recurrence of myxofibrosarcoma.

BACKGROUND: Myxofibrosarcoma is characterized by a high local recurrence rate despite optimal surgical treatment. The definition of prognostic factors for recurrence offers high-risk patients a closer follow-up and a multidisciplinary therapeutic approach. METHODS: A cohort of 23 patients treated for primary myxofibrosarcoma was retrospectively analyzed. The patients (sex and age), tumors (size, stage, tumor location, bone and/or joint attachment), radiological findings (abnormal signal extension in MRI), histological findings (FNCLCC grade and microscopic extension along the muscle fascia), and treatment (surgical margin) characteristics were included in univariate prognostic factor analysis. RESULTS: After a median follow-up of 63.3 months (range 15-191), the overall recurrence rate was 34.7%. Median time between initial surgery and recurrence was 24.8 months (range 8-52). Inadequate surgical margins (p = 0.026) and bone and/or joint attachment (p = 0.001) were associated with an increased recurrence rate. CONCLUSION: For the further improvement of local recurrence-free survival of patients with myxofibrosarcoma, accurate diagnosis of the tumor extension and adequate planning for the surgical margin should be focused on in cases with bone and/or joint attachment.

Giant cell tumor of the sacrum treated with selective arterial embolization.

Giant cell tumor of the sacrum is extremely difficult to manage. Standard treatments, including surgery and radiation, are associated with significant complications and recurrence rates. In this manuscript, we report an early clinical result of a case of giant cell tumor of the sacrum successfully managed with selective arterial embolization. A 56-year-old woman underwent selective embolization for management of giant cell tumor of the sacrum. Radiologically, massive shrinkage of the extraosseous mass and increased peripheral ossification were obvious. Clinically, rapid pain relief was achieved and gait disability recovered. At final follow-up 28 months after completion of treatment, she retained normal activity in daily life. We stress the effectiveness of selective arterial embolization as a less invasive and less complicated primary treatment of giant cell tumors of the sacrum.

HLA-A*0201-restricted CTL epitope of a novel osteosarcoma antigen, papillomavirus binding factor.

BACKGROUND: To develop peptide-based immunotherapy for osteosarcoma, we previously identified papillomavirus binding factor (PBF) as a CTL-defined osteosarcoma antigen in the context of HLA-B55. However, clinical application of PBF-based immunotherapy requires identification of naturally presented CTL epitopes in osteosarcoma cells in the context of more common HLA molecules such as HLA-A2. METHODS: Ten peptides with the HLA-A*0201 binding motif were synthesized from the amino acid sequence of PBF according to the BIMAS score and screened with an HLA class I stabilization assay. The frequency of CTLs recognizing the selected PBF-derived peptide was determined in peripheral blood of five HLA-A*0201+ patients with osteosarcoma using limiting dilution (LD)/mixed lymphocyte peptide culture (MLPC) followed by tetramer-based frequency analysis. Attempts were made to establish PBF-specific CTL clones from the tetramer-positive CTL pool by a combination of limiting dilution and single-cell sorting. The cytotoxicity of CTLs was assessed by 51Cr release assay. RESULTS: Peptide PBF A2.2 showed the highest affinity to HLA-A*0201. CD8+ T cells reacting with the PBF A2.2 peptide were detected in three of five patients at frequencies from 2 x 10-7 to 5 x 10-6. A tetramer-positive PBF A2.2-specific CTL line, 5A9, specifically lysed allogeneic osteosarcoma cell lines that expressed both PBF and either HLA-A*0201 or HLA-A*0206, autologous tumor cells, and T2 pulsed with PBF A2.2. Five of 12 tetramer-positive CTL clones also lysed allogeneic osteosarcoma cell lines expressing both PBF and either HLA-A*0201 or HLA-A*0206 and T2 pulsed with PBF A2.2. CONCLUSION: These findings indicate that PBF A2.2 serves as a CTL epitope on osteosarcoma cells in the context of HLA-A*0201, and potentially, HLA-A*0206. This extends the availability of PBF-derived therapeutic peptide vaccines for patients with osteosarcoma.

Prognostic impact and immunogenicity of a novel osteosarcoma antigen, papillomavirus binding factor, in patients with osteosarcoma.

To develop peptide-based immunotherapy for osteosarcoma, we previously identified papillomavirus binding factor (PBF) as a cytotoxic T lymphocytes (CTL)-defined osteosarcoma antigen in the context of human leukocyte antigen (HLA)-B55. In the present study, we analyzed the distribution profile of PBF in 83 biopsy specimens of osteosarcomas and also the prognostic impact of PBF expression in 78 patients with osteosarcoma who had completed the standard treatment protocols. Next, we determined the antigenic peptides from PBF that react with peripheral T lymphocytes of HLA-A24(+) patients with osteosarcoma. Immunohistochemical analysis revealed that 92% of biopsy specimens of osteosarcoma expressed PBF. PBF-positive osteosarcoma conferred significantly poorer prognosis than those with negative expression of PBF (P = 0.025). In accordance with the Bioinformatics and Molecular Analysis Section score, we synthesized 10 peptides from the PBF sequence. Subsequent screening with an HLA class I stabilization assay revealed that peptide PBF A24.2 had the highest affinity to HLA-A24. CD8(+) T cells reacting with a PBF A24.2 peptide were detected in eight of nine HLA-A24-positive patients with osteosarcoma at the frequency from 5 x 10(-7) to 7 x 10(-6) using limiting dilution/mixed lymphocyte peptide culture followed by tetramer-based frequency analysis. PBF A24.2 peptide induced CTL lines from an HLA-A24-positive patient, which specifically killed an osteosarcoma cell line that expresses both PBF and HLA-A24. These findings suggested prognostic significance and immunodominancy of PBF in patients with osteosarcoma. PBF is the candidate target for immunotherapy in patients with osteosarcoma.

Prognostic implication of SYT-SSX fusion type in synovial sarcoma: a multi-institutional retrospective analysis in Japan.

The prognostic implication of SYT-SSX fusion type in synovial sarcomas is still controversial. The aim of this study is to clarify the prognostic impact of fusion type, in association with other clinical factors, in patients with synovial sarcoma in Japan. Data on 108 SYT-SSX fusion transcript-positive patients with synovial sarcoma, treated in 11 tertiary referral cancer centers in Japan, were retrospectively analyzed. The following parameters were examined for their potential prognostic impact: SYT-SSX fusion type, patient age at presentation, sex, primary tumor location, tumor size, histological subtype, histological grade, treatment modalities and disease stage at presentation. Among the patients with localized disease at presentation, 5-year overall survival (OS) for SYT-SSX1 and -2 subgroups were 84.4 and 74.9%, respectively (P=0.244). Five-year metastasis-free survival (MFS) rates were 67.8% for SYT-SSX1 and 68.5% for SYT-SSX2 (P=0.949). Univariate survival analyses for 91 patients with localized disease at presentation showed that tumor size was the only significant prognostic factor for OS (P=0.0033) and MFS (P=0.0029) and the histological grade was marginally significant for MFS (P=0.0785), whereas the SYT-SSX fusion type and other variables were not. Multivariate survival analyses further indicated that tumor size was the most significant independent prognostic factor for OS and MFS and the histological grade was also significant for MFS. In conclusion, the SYT-SSX fusion type is not a significant prognostic factor unlike tumor size, followed by histological grade for patients with localized synovial sarcoma in Japan.

Cup-neck impingement due to the malposition of the implant as a possible mechanism for metallosis in metal-on-metal total hip arthroplasty.

The metal-on-metal bearing total hip prosthesis is expected to reduce the risk of debris-related osteolysis. However, several reports demonstrated that the socket-stem impingement in the metal-on-metal prosthesis due to the implant malposition results in titanium wear debris and secondary metallosis. In this article, we presented a case of massive metallosis due to metal-on-metal impingement. A 60-year woman had severe hip pain due to fracture of the greater trochanter. We planned a revision of the metal-on-metal inlay. Intraoperatively, the trochanteric bursa and joint space were found to be stained black. Black stained granulation tissue was observed between the femoral stem and the great trochanter. Intraoperatively, notching was noticed on both the posteroinferior aspect of the neck of the femoral component and the anterior aspect of the metal liner and polyethylene core. The notch corresponded to the position of impingement between the socket and the femoral neck during the maximum extension of the hip. To clarify the mechanism of cup-neck impingement, the alignment of the prosthesis and pelvic tilt were evaluated. The cup was placed in too much anteverted position. In addition, increased posterior tilt of pelvis in the standing position made the anteversion of the acetabular cup more significant, which enhanced the cup-neck impingement during the gait. Careful attention is necessary for implant alignment and pelvic tilt especially in metal-on-metal-bearing total hip arthroplasty.