Is the Iliac Wing Curved Inward in Patients with Developmental Dysplasia of the Hip?

Background

There is a paucity of studies on the iliac curvature in developmental dysplasia of the hip (DDH). Here, we examined the iliac curvature in DDH using three-dimensional computed tomography.

Methods

We allocated cases with a center-edge angle of < 20° to the DDH group (55 cases) and cases with a center-edge angle of > 25° to the control group (57 cases) and measured the straight line (line A) between the anterior and posterior superior iliac spines. We examined which part of the iliac bone line A passes through and classified the results into 4 categories (type A, inside the iliac bone; type B, through the iliac bone; type C, outside the iliac bone; and type D, both inside and outside the iliac bone) to evaluate the iliac wing curvature. After measuring the area and internal surface of the iliac wing using line A, we examined the correlation between these values, the interspinous distance, the superior iliac angle, and the center-edge angle.

Results

Distributions of the four types were compared between the two groups; there was no significant difference. The length of the portion of line A inside the ilium and the area formed by line A and the iliac wing, which shows the degree of iliac wing curvature, were not significantly different between the groups. There were no correlations between these values and the center-edge angle; however, there were weak positive correlations among the interspinous distance, the superior iliac angle, and the center-edge angle.

Conclusions

The inward nature of the iliac bone in patients with DDH is mainly due to the internal rotation of the entire iliac bone and less likely due to the curvature of the iliac bone.

Alkaptonuria with rapidly destructive arthropathy of the hip: A case report and literature review

Alkaptonuria-related rapidly destructive arthropathy of the hip joint has not been reported in detail with both imaging and histopathological findings in the literature. We, herein, presented the case of a 79-year-old male patient who suddenly started experiencing marked right hip pain. Radiography showed that the femoral head was spherical; however, after 3 months, approximately half of the femoral head was destroyed despite there being almost no change in the acetabulum. Radiographs of the spine also showed fusion between multiple vertebrae. Significant osteoporosis was observed on roentgenography, together with decreased bone density. Urinary gas chromatography-mass spectrometry analysis revealed that a large amount of homogentisic acid was excreted. During total hip arthroplasty, gray and muddy contents were observed in the joint capsule, and the surface of the destroyed femoral head was black. Histopathologically, granulomatous foci containing fragmented bone and cartilage debris were found in the bone marrow space of the joint surface, and the cartilage tissue was pigmented brownish black. The patient was subsequently diagnosed with ochronotic hip joint destruction. The present case report is the first to demonstrate rapidly destructive coxopathy associated with alkaptonuria using both imaging and histopathological findings. These findings clearly show that severe hip joint destruction defined as rapidly destructive hip arthropathy can occur in a very short time period for patients with alkaptonuria.

Sensitive quantification of free pazopanib using ultra-high performance liquid chromatography coupled to tandem mass spectrometry and assessment of clinical application

Pazopanib is widely used to treat renal cell carcinomas and soft tissue tumors in Japan. Although several reports demonstrated the usefulness of therapeutic drug monitoring (TDM) of pazopanib, those studies measured only total pazopanib concentration. For drugs with high protein binding rates such as pazopanib, measuring free concentrations may be clinically more useful than measuring total concentrations. In this study, we aimed to develop a high-throughput method for quantification of free pazopanib in human plasma using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). Free pazopanib was separated by ultrafiltration. After a simple solid-phase extraction step using a 96-well plate, pazopanib was analyzed by UHPLC-MS/MS in positive electrospray ionization mode. The novel method fulfilled the requirements of the US Food and Drug Administration guidelines for assay validation, and the lower limit of quantification was 0.05 ng/mL. The calibration curve was linear over the concentration range of 0.05-50 ng/mL. The average recovery rate was 66.9 ± 2.1% (mean ± SD). The precision was below 7.02%, and accuracy was within 10.60% across all quality control levels. Matrix effect varied between 44.4% and 60.4%. This assay was successfully applied to measure trough free pazopanib concentrations in three patients treated with pazopanib for soft tissue tumors. We succeeded to develop a novel high-throughput UHPLC-MS/MS method for quantification of free pazopanib in human plasma. This method can be applied to TDM for patients receiving pazopanib in the clinical setting.

Fluorodeoxyglucose Positron-Emission Tomography/Computed Tomography and Magnetic Resonance Imaging for Adverse Local Tissue Reactions near Metal Implants after Total Hip Arthroplasty: A Preliminary Report

Background

Plain computed tomography (CT) and magnetic resonance imaging (MRI) are useful for diagnosing adverse local tissue reactions after metal-on-metal total hip arthroplasty (THA), but metal artifacts can hamper radiological assessments near the implants. We sought to clarify the usefulness of 18F-fluorodeoxyglucose positron-emission tomography (18F-FDG-PET) CT and MRI in the periprosthetic region, which is difficult to assess after THA due to metal artifacts.

Methods

We performed preoperative 18F-FDG-PET/CT and 18F-FDG-PET/MRI, as well as plain CT and MRI, in 11 metal-on-metal THA patients who underwent revision surgery.

Results

Most patients showed high FDG uptake in the metal artifact areas and pseudotumors in the 18-F-FDG-PET/CT and 18-F-FDG-PET/MRI scans. Intraoperative intra-articular macroscopic and histopathological intra-articular granulation tissue findings were suggestive of adverse local tissue reaction.

Conclusions

The enhanced uptake in the metal artifact areas seemed to reflect adverse local tissue reaction. Therefore, 18F-FDG-PET/CT and 18-F-FDG-PET/MRI can be useful for the auxiliary diagnosis of adverse local tissue reactions after metal-on-metal THA.

Optimal intermittent administration interval of parathyroid hormone 1-34 for bone morphogenetic protein-induced bone formation in a rat spinal fusion model

INTRODUCTION

Both bone morphogenetic protein 2 (BMP-2) and teriparatide (parathyroid hormone [PTH] 1-34) are used to enhance bone healing. There is still no established opinion regarding the optimum dose and administration method. We investigated the optimal administration method for the combination of BMP-2 and PTH 1-34 in a rat spinal fusion model.

METHODS

Group I was implanted with a control carrier. Groups II, III, and IV were implanted with a carrier containing 3 μg of recombinant human BMP-2 (rhBMP-2). In addition, following implantation, PTH 1-34 injections were administered to Group III thrice a week (total, 180 μg/kg/week) and Group IV six times a week (total, 180 μg/kg/week). The rats were euthanized after 8 weeks, and their spines were explanted; assessed by manual palpation, radiographs, and high-resolution micro-computed tomography (micro-CT); and subjected to histological analysis. Serum markers of bone metabolism were also analyzed.

RESULTS

Manual palpation tests showed that the fusion rates in Groups III and IV were considerably higher than those in Group I. They also had higher radiographic scores than Group I and II. Micro-CT analysis revealed Tb.Th in the Group IV had higher values than that in the Group I, II, III with significant differences and Tb.Sp in the Group IV had lower values than that in the Group I, II, III with significant differences. Serum marker analysis revealed that Group IV had higher osteocalcin and lower tartrate-resistant acid phosphatase-5b than Group III. Histological analysis indicated that Group IV had enhanced trabecular bone structure.

CONCLUSIONS

Frequent administration of PTH may be better in making thicker and strengthening the trabecular bone structure in newly formed bone in the rat spinal fusion model using insufficient BMP-2.

Development of a High-Throughput Quantification Method for Pazopanib Using Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry and Its Clinical Application in Patients With Soft Tissue Tumors

BACKGROUND

Pazopanib is widely used to treat renal cell carcinomas and soft tissue tumors in Japan. Pazopanib has significant therapeutic efficacy but it is associated with frequent severe adverse effects. Therapeutic drug monitoring (TDM) may help to prevent adverse effects. A more convenient and rapid pazopanib assay is desirable for the application of TDM in clinical settings. In this study, the authors developed a high-throughput method for quantifying pazopanib in human plasma using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS).

METHODS

After a simple solid-phase extraction step using a 96-well plate, pazopanib was analyzed by UHPLC-MS/MS in the positive electrospray ionization mode.

RESULTS

The novel method fulfilled the requirements of the US Food and Drug Administration and the European Medicines Agency guidelines for assay validation, and the lower limit of quantification was 0.5 mcg/mL. The calibration curves were linear over the concentration range of 0.5-100 mcg/mL. The average recovery rate was 102.0% ± 3.9% (mean ± SD). The precision was below 5.0%, and the accuracy was within 12.0% for all quality control levels. Matrix effect varied between 90.9% and 97.1%. This assay was successfully applied to TDM of pazopanib trough concentrations in 3 patients treated with the drug for soft tissue tumors.

CONCLUSIONS

The authors succeeded in developing a novel high-throughput UHPLC-MS/MS method for quantifying pazopanib in human plasma. This method can be applied to TDM of patients receiving pazopanib in clinical settings.

Comparison of Cup Setting Angle Accuracy between Computed Tomography-Based and Computed Tomography-Free Navigation in the Same Patients with Crowe's Classification I or II Hip Dysplasia

Backgroud

In total hip arthroplasty, the cup setting angle may affect the postoperative results. In recent years, both computed tomography-based navigation and computed tomography-free (imageless) navigation have been reported to produce high accuracy in cup installation; however, no direct comparison between these two methods has been performed. The present study aimed to directly compare the cup installation angle accuracy between computed tomography-based navigation and computed tomography-free navigation in patients with Crowe's classification stage I or II dysplastic osteoarthritis and to examine the factors affecting the cup installation accuracy.

Methods

Using both navigation systems for the same technique, primary total hip arthroplasty was performed by the same surgeon in 36 patients. A cup was installed using computed tomography-based navigation, and the installed cup was measured again using computed tomography-free navigation. We compared the error between the target angle and the intraoperative installation angle for each navigation method by performing statistical analyses.

Results

For computed tomography-based navigation, errors in the inclination and the anteversion angles compared to the target angle were 3.14° ± 1.55° and 1.47° ± 0.99°, respectively. For computed tomography-free navigation, the inclination and anteversion angle errors were significantly larger, i.e., 6.84° ± 4.78° and 5.43° ± 5.22°, respectively (p < 0.01). The inclination and anteversion angles of computed tomography-free navigation were correlated, and there were no significant factors influencing the error.

Conclusions

Computed tomography-based navigation is more accurate for cup installation than computed tomography-free navigation. When using computed tomography-free navigation, it is necessary to add technical schemes before and during surgery to improve the cup installation accuracy.

The benzylisoquinoline alkaloids, berberine and coptisine, act against camptothecin-resistant topoisomerase I mutants

DNA replication inhibitors are utilized extensively in studies of molecular biology and as chemotherapy agents in clinical settings. The inhibition of DNA replication often triggers double-stranded DNA breaks (DSBs) at stalled DNA replication sites, resulting in cytotoxicity. In East Asia, some traditional medicines are administered as anticancer drugs, although the mechanisms underlying their pharmacological effects are not entirely understood. In this study, we screened Japanese herbal medicines and identified two benzylisoquinoline alkaloids (BIAs), berberine and coptisine. These alkaloids mildly induced DSBs, and this effect was dependent on the function of topoisomerase I (Topo I) and MUS81-EME1 structure-specific endonuclease. Biochemical analysis revealed that the action of BIAs involves inhibiting the catalytic activity of Topo I rather than inducing the accumulation of the Topo I-DNA complex, which is different from the action of camptothecin (CPT). Furthermore, the results showed that BIAs can act as inhibitors of Topo I, even against CPT-resistant mutants, and that the action of these BIAs was independent of CPT. These results suggest that using a combination of BIAs and CPT might increase their efficiency in eliminating cancer cells.

Iliac anatomy in women with developmental dysplasia of the hip: Measurements using three-dimensional computed tomography

Background

We aimed to clarify the iliac anatomy in developmental dysplasia of the hip using three-dimensional computed tomography.

Methods

The distance between two points along each anatomical portion of the ilium, including the acetabular center, were compared between patients in the dysplasia and control groups.

Results

There were no significant differences in the upper part of the ilium between the groups. However, three distances that included the acetabular center were significantly shorter in the dysplasia group than in the control group.

Conclusions

Our study suggests that bone dysplasia occurs in the ilium near the acetabulum, not in the iliac wings.

The fibrinogen levels on admission is a predictive marker of the contrast extravasation on enhanced computed tomography in sacral fracture

Sacral fracture is the most frequent posterior injury among unstable pelvic ring fractures and is prone to massive hemorrhage and hemodynamic instability. Contrast extravasation (CE) on computed tomography (CT) is widely used as an indicator of significant arterial bleeding. However, while CE is effective to detect significant arterial bleeding but negative result cannot completely rule out massive bleeding. Therefore, additional factors help to compensate CE for the prediction of early hemodynamically unstable condition.We evaluated the risk factors that predict CE on enhanced computed CT in patients with sacral fractures. Patients were classified into 2 groups: CE positive on enhanced CT of the pelvis [CE(+)] and CE negative [CE(-)]. We compared age, sex, injury severity score (ISS), systolic blood pressure (sBP), type of sacral fracture based on Denis classification, platelet (PLT), base excess, lactate, prothrombin time-international normalized ratio, hemoglobin (Hb), activated partial thromboplastin time, D-dimer, and fibrinogen between the 2 groups.A total of 82 patients were treated for sacral fracture, of whom 69 patients were enrolled. There were 17 patients (10 men and 7 women) in CE(+) and 52 patients (28 men and 24 women) in CE(-). Age, ISS, and blood transfusion within 24 hours were significantly higher in the CE(+) group than in the CE(-) group (P = .023, P < .001, P < .001). sBP, Hb, PLT, fibrinogen were significantly lower in the CE(+) group than in the CE(-) group (P < .001, P < .001, P < .001, P < .001). D-dimer and lactate were higher in the CE(+) group than in the CE(-) group (P = .036, P < .001) with significant differences. On multivariate analysis, the level of fibrinogen was an independent predictor of CE(+). The area under the curve value for fibrinogen was 0.88, and the optimal cut-off value for prediction was 199 mg/dL.The fibrinogen levels on admission can predict contrast extravasation on enhanced CT in patients with sacral fractures. The optimal cut-off value of fibrinogen for CE(+) prediction in sacral fracture was 199 mg/dL. The use of fibrinogen to predict CE(+) could lead to prompt and effective treatment of active arterial hemorrhage in sacral fracture.

Gait analysis of a patient who underwent complete resection of the patella and quadriceps femoris for soft tissue sarcoma

The knee extension mechanism including the quadriceps femoris muscles and patella plays a crucial role in the stance phase of a normal gait cycle. We performed gait analysis of a patient who had undergone complete resection of the knee extension mechanism. An 8-month-old boy developed infantile fibrosarcoma of the right knee and underwent resection of the quadriceps femoris muscles, patella, and patellar tendon. The gait analysis performed at 8 years of age demonstrated that he could maintain the knee joint extension position during the stance phase. Increased muscle activities in the hamstring and gastrocnemius were observed. The results suggest that the hamstring and gastrocnemius muscles might play a role in maintaining the knee extension position during the stance phase. We suggest the importance of reinforcing these muscles in rehabilitation for patients who lost the knee extension mechanism.

Effect of age and sex on femoral curvature in the Japanese population: three-dimensional computed tomography findings

Age- or sex-related differences in femoral curvature affect the onset of trauma or degenerative diseases of the hip joints. This study aimed to investigate femoral curvature in detail in Japanese individuals using three-dimensional computed tomography, evaluate its effects on the position of proximal femur, and assess differences in femoral curvature according to age and sex. We measured sagittal and coronal femoral bowing in 40 elderly (mean age 85.2 years) and 40 adult (mean age 30.1 years) Japanese individuals using computed tomography. In adult individuals, the radii of the femoral curvatures of the distal end and shaft in the coronal planes were significantly smaller in women than in men. In contrast, no significant difference was observed in femoral curvature between the sexes in the elderly group. Furthermore, the radius of femoral curvature was significantly smaller in elderly individuals than in adult individuals, regardless of the sex and location of the measurement. The highest point of the greater trochanter of the femoral head center was 7.3 ± 5.6 mm in the elderly group and 2.2 ± 4.6 mm in the adult group (p < 0.05). Thus, the femoral curvature varies with age and sex in Japanese individuals. In addition, the femoral curvature could cause positional changes in the proximal femur, such as the highest point of the greater trochanter. Therefore, further studies investigating the biomechanical effects of these morphological changes are warranted.

Primary clear cell sarcoma of the femur: a unique case with RT-PCR and direct sequencing confirmation of EWSR1/ATF1 fusion gene

Background

It is very rare for clear cell sarcomas (CCS) to arise in the bone. During diagnosis, it is important to distinguish primary CCS of bone from bone metastasis of melanoma because this difference fundamentally changes the therapeutic options. Recently, characteristic fusion genes of CCS have been detected using reverse transcription polymerase chain reaction (RT-PCR) or direct sequencing which allowed to distinguish CCS from melanoma. However, there was no study applying these analyses with positive results. In this case, we describe the use of fusion gene analysis to diagnose a primary CCS of the bone.

Case presentation

A 36-year-old male presented with a four-months history of left knee pain. Magnetic resonance imaging showed a lesion in the left femoral medial epicondyle. Histological examination of the biopsy specimen revealed proliferating oval or rounded cells. These cells had clear cytoplasm arranged in fascicles or compact nests with frequent deposits of brown pigment. Furthermore, immunohistochemistry analysis revealed that tumor cells were positive for S-100 protein, HMB-45, Melan-A, and SOX10. It stained negative for CD34 and BRAF v600e. Conclusively, detection of the EWSR1/ATF1 fusion gene using RT-PCR and direct sequencing confirmed that the lesion was a primary CCS of the bone. Wide-margin resection and reconstruction with a tumor endoprosthesis were performed.

Conclusions

Herein, we diagnosed a rare case of primary CCS of the bone by detecting EWSR1/ATF1 fusion gene using RT-PCR and direct sequencing. Since fluorescence-in situ hybridization (FISH) and RT-PCR could show false positive by mainly due to technical problems, it is better to perform direct sequencing to confidently diagnose the tumor as a primary CCS especially at very rare site such as bone.

Effectiveness of 18F-fluoro-deoxyglucose Positron Emission Tomography/Computed Tomography and Magnetic Resonance Imaging to Detect Iliopsoas Tendonitis after Total Hip Arthroplasty: A Case Report

Disorders involving artificial joints are difficult to evaluate due to metal artifacts hindering plain computed tomography (CT) or magnetic resonance imaging (MRI). In the current case study 18F-fluoro-deoxyglucose positron emission tomography (18F-FDG-PET)/CT and MRI were used to confirm iliopsoas tendonitis within the metal artifact area following total hip arthroplasty (THA). The patient was a 61-year-old woman who developed hip pain on flexion of the ipsilateral hip after THA. Imaging studies were performed to evaluate for iliopsoas tendonitis due to impingement with the cup. Assessment of the iliopsoas muscle near the artificial joint was difficult due to the metal artifact on plain CT and MRI. Imaging using 18F-FDG-PET/CT and 18F-FDG-PET/MRI showed uptake along the iliopsoas muscle. Therefore, revision was performed to resolve iliopsoas tendon impingement, and the preoperative pain resolved. The result of the current case study suggest 18F-FDG-PET/CT or 18F-FDG-PET/MRI will be useful to detect iliopsoas tendonitis within metal artifact areas after THA.

Analysis of reciprocal changes in upper cervical profiles after posterior spinal fusion with the simultaneous double rod rotation technique for adolescent idiopathic scoliosis

BACKGROUND

The relationship between postoperative change of cervical lordotic alignment and restoration of thoracic kyphosis with adolescent idiopathic scoliosis (AIS) is still controversial. We investigated reciprocal changes in the sagittal profiles of the upper and middle-lower cervical spinal segments after posterior spinal fusion with the simultaneous double rod rotation technique (SDRRT) for AIS.

HYPOTHESIS

Occiput-C2 and C2-C7 sagittal profiles of patients with AIS could change significantly after surgical adequate increase of thoracic kyphosis with SDRRT.

PATIENTS AND METHODS

Twenty-seven consecutive patients with AIS treated with the SDRRT were retrospectively reviewed. We investigated the following parameters preoperatively, postoperatively, and at the 2-year follow-up: the Cobb angles of main thoracic curves; C7 sagittal vertical axis; thoracic kyphosis (TK) from T5 to T12; lumbar lordosis from L1 to S1; chin-brow vertical angle; McGregor's slope; occiput to C2 Cobb angle (O-C2angle); C2-C7 Cobb angle (C2-C7angle); T1-slope; and C2-C7 sagittal vertical axis. Additionally, the Scoliosis Research Society questionnaire was completed preoperatively and at the 2-year follow-up. Patients were categorized according to preoperative TK (T5-T12) into hypokyphotic (TK<20°) and normo-hyperkyphotic (TK≧20°) groups. To assess the effect of corrective surgery on sagittal profiles, we investigated correlations among the changes in sagittal parameters.

RESULTS

The mean preoperative TK was 6.1±3.7° in the Hypokyphotic group and 23.5±4.7° in the Normo-hyperkyphotic group (p<0.001), which was significantly improved postoperatively (22.3±4.4° and 26.1±2.6°, respectively; p=0.02) and at the 2-year follow-up (23.0±6.3° and 26.8±5.0°, respectively; p=0.04). The mean preoperative C2-C7angle reflected kyphosis (7.4±9.8°) in the Hypokyphotic group, and, in contrast, lordosis (-8.8±6.8°) in the Normo-hyperkyphotic group (p<0.001), which improved toward greater lordosis postoperatively (-3.7±5.8° and -14.8±5.1°, respectively; p<0.001) and at the 2-year follow-up (-5.1±4.4° and -15.3±6.4°, respectively; p<0.001). On the other hand, the mean preoperative O-C2angle was -20.5±6.5° in the Hypokyphotic group and -13.1±2.8° in the Normo-hyperkyphotic group (p=0.002), which was significantly changed postoperatively (-12.6±6.4° and -7.7±4.3°, respectively; p=0.04) and at the 2-year follow-up (-13.1±6.3° and -7.9±4.3°, respectively; p=0.04). ΔC2-C7 was negatively correlated with ΔT5-T12 (r=-0.298) and ΔO-C2angle (r=-0.332).

DISCUSSION

Lordotic reciprocal alignment changes in the C2-C7angle can occur after adequate restoration of TK. The O-C2angle compensates the C2-C7angle for a maintained horizontal gaze. O-C2 and C2-C7 sagittal profiles of patients with AIS changed significantly after corrective surgery with SDRRT.

LEVEL OF EVIDENCE

IV, Case-series.

Reference values for the locomotive syndrome risk test quantifying mobility of 8681 adults aged 20-89 years: A cross-sectional nationwide study in Japan

BACKGROUND

The locomotive syndrome risk test was developed to quantify the decrease in mobility among adults, which could eventually lead to disability. The purpose of this study was to establish reference values for the locomotive syndrome risk test for adults and investigate the influence of age and sex.

METHODS

We analyzed 8681 independent community dwellers (3607 men, 5074 women). Data pertaining to locomotive syndrome risk test (the two-step test, the stand-up test, and the 25-question geriatric locomotive function scale [GLFS-25]) scores were collected from seven administrative areas of Japan.

RESULTS

The reference values of the three test scores were generated and all three test scores gradually decreased among young-to-middle-aged individuals and rapidly decreased in individuals aged over 60 years. The stand-up test score began decreasing significantly from the age of 30 years. The trajectories of decrease in the two-step test score with age was slightly different between men and women especially among the middle-aged individuals. The two physical test scores were more sensitive to aging than the self-reported test score.

CONCLUSION

The reference values generated in this study could be employed to determine whether an individual has mobility comparable to independent community dwellers of the same age and sex.

Finite Element Analysis of Stress Distribution in Flat and Elevated-Rim Polyethylene Acetabular Liners

Backgroud

No study has compared flat and elevated-rim polyethylene liners in terms of stress distribution on the bearing surface. The purpose of this study was to investigate the difference in stress distribution between flat and elevated-rim polyethylene liners.

Methods

A stress analysis was performed by using the 3-dimensional finite element method. The cup was placed at an open angle of 20°, the flat liner and the liner with a 10° elevation was placed at inclination angles of 80°, 70°, and 60°.

Results

Compared with the 60° flat liner, the 80° and 70° flat liners showed higher stress at the liner edge. In the elevated-rim liner, the stress was high at the liner edge along the cup edge. When the von Mises equivalent stress was applied to each element of the liner, the high stress area (volume) was the largest for the 80° flat liner, second largest for the 80° elevated-rim liner, and third largest for the 70° flat liner. The average contact pressure also followed the same order.

Conclusions

Elevated-rim liners affect the stress distribution by increasing the area of contact. However, since elevated-rim liners exhibit high stress at the cup edge, they are likely to result in new problems including liner failure. These findings could aid surgeons in the selection of liners and determination of revision methods such as isolated liner exchange vs. acetabular cup revision for a well-fixed metal cup with a higher inclination angle in revision total hip arthroplasty.

Osteomyelitis of the Distal Phalanx of the Thumb due to Parvimonas micra and Fusobacterium nucleatum: A Case Report

We herein report a case of osteomyelitis of the distal phalanx of the thumb of a 55-year-old man caused by Parvimonas micra and Fusobacterium nucleatum. Osteomyelitis often occurs in long bones and rarely occurs in the bones of the fingers. In addition, osteomyelitis of the finger frequently occurs after trauma or surgery, and blood-borne infection is very rare. P. micra and F. nucleatum, normal flora of the oral cavity, are very rare pathogenic bacteria of osteomyelitis except in periodontal disease, and there are no previous reports regarding the occurrence of osteomyelitis due to P. micra and F. nucleatum in the finger bones.

Surrogate endpoints for overall survival in randomised controlled trials of localised osteosarcoma: A meta-analytic evaluation

Event-free survival (EFS) is considered the most reliable surrogate endpoint for overall survival (OS) in randomised controlled trials (RCTs) of adjuvant therapies for malignant tumours. However, the surrogacy of intermediate endpoints such as EFS for OS in trials of patients with osteosarcoma has not been investigated to date. In this study, we investigated the correlation between OS and intermediate endpoints in RCTs of localised osteosarcoma. A systematic search identified 20 relevant RCTs. The correlations between the surrogate endpoints and OS were evaluated using weighted linear regression analyses and by calculating the Spearman rank correlation coefficients (ρ). The strength of the correlation was determined by calculating the coefficient of determination (R2). A total of 5,620 patients were randomly assigned to 45 treatment arms in the eligible 20 RCTs. The correlation between the hazard ratios for EFS and OS was moderate (R2 = 0.456, ρ = 0.440); this correlation tended to be weaker for patients with localised osteosarcoma excluding the patients with metastases. Overall, the trial-level correlation between the surrogate endpoints and OS was not robust in RCTs of osteosarcoma published to date. Hence, the suitability of the intermediate endpoints as surrogates for OS could not be confirmed.

A meta-analytic evaluation of the correlation between event-free survival and overall survival in randomized controlled trials of newly diagnosed Ewing sarcoma

Background

In randomized controlled trials (RCTs) of adjuvant treatment for malignant tumors, event-free survival (EFS) is considered the most acceptable surrogate for overall survival (OS). However, even though EFS has repeatedly been selected as a primary endpoint in RCTs of Ewing sarcoma (ES), the surrogacy of EFS for OS has not been investigated. This study aimed to evaluate the correlation between EFS and OS in RCTs of chemotherapy for newly diagnosed ES using a meta-analytic approach.

Methods

We identified seven RCTs of newly diagnosed ES through a systematic review, and a meta-analysis was performed to evaluate the efficacy and adverse events associated with chemotherapy for previously untreated ES. The correlation between EFS and OS was investigated using weighted linear regression analysis and Spearman rank correlation coefficients (ρ). The strength of the correlation was evaluated using the coefficient of determination (R²).

Results

A total of 3612 patients were randomly assigned to 17 treatment arms in the eligible RCTs. The meta-analysis revealed that the hazard ratios for OS and EFS showed significantly better results in the experimental treatment groups with increasing toxicities. The correlation between the hazard ratios for EFS and OS was good (R² = 0.747, ρ = 0.683), and the correlation tended to be more favorable in cases of localized ES (R² = 0.818, ρ = 0.929).

Conclusions

Overall, the trial-level correlation between EFS and OS was good for newly diagnosed ES and was very good in cases of localized disease. EFS may be a useful endpoint in RCTs of ES chemotherapy, and it is worth verifying using individual patient data.

Analysis of the reciprocal changes in upper cervical profile and the risk factors for increasing cervical sagittal vertical axis after laminoplasty for ossification of the posterior longitudinal ligament of the cervical spine

OBJECTIVE

The purpose of this study was to elucidate the reciprocal changes in the upper cervical profile and the risk factors for increasing cervical sagittal vertical axis (cSVA) after laminoplasty for ossification of the posterior longitudinal ligament (OPLL) of the cervical spine.

PATIENTS AND METHODS

This retrospective study included thirty-nine consecutive patients (30 men and 9 women) with cervical OPLL who underwent cervical laminoplasty. We recorded the operative time, blood loss, Japanese Orthopaedic Association (JOA) score recovery rate. Radiological measurements were performed to analyze the following parameters: pre and 1- year postoperative chin-brow vertical angle (CBVA), McGregor's slope (McGS), occiput to C2 Cobb angle (O-C2 angle), C2-C7 Cobb angle (C2-C7 angle), T1-slope (T1S), C2-C7 sagittal vertical axis (cSVA) and calculated the change (Δ). Patients were divided into two groups according to ΔcSVA: positive (ΔcSVA ≥ 0) and negative (ΔcSVA < 0).

RESULTS

Postoperative O-C2 angle (P = 0.028), ΔO-C2 angle (P = 0.019), ΔC2-C7 angle (P = 0.030) and T1S (P = 0.009) diff ;ered between the two groups. ΔcSVA showed a positive correlation with ΔO-C2 (R = 0.365, P = 0.022) and T1S (R = 0.472, P = 0.002). ΔO-C2 showed a positive correlation with T1S (R = 0.478, P = 0.002) and a negative correlation with ΔC2-C7 (R=-0.443, P = 0.005). ΔC2-C7 showed a negative correlation with T1S (R=-0.415, P = 0.009). Stepwise multiple linear regression analysis showed that ΔcSVA increased by 0.757 mm for each T1 slope and increased by 0.905 mm for each ΔMcGS.

CONCLUSION

Increasing the lordosis in the O-C2 segment compensates for the loss of lordosis in the C2-C7 segment after cervical laminoplasty. Higher T1S is a risk factor for increasing cSVA after laminoplasty for OPLL of the cervical spine.

Comparison of cementless and cemented cups in revision total hip arthroplasty using a computed tomography-based navigation system

BACKGROUND

Studies comparing cementless and cemented cups are lacking, especially for revision total hip arthroplasty (THA). The aim of this study was to investigate and compare the differences in implant accuracy between two fixation methods in revision THA.

METHODS

We conducted a retrospective study of 85 hips in 70 patients who underwent revision THA using a computed tomography (CT)-based navigation system. Among these, 53 hips underwent cementless THA and 32 hips underwent cemented THA. We measured cup inclination and anteversion using the Kyocera two-dimensional-template with X-ray (Japan-Kyocera, Shiga, Japan) and stem anteversion with CT. We calculated the combined anteversion [cup anteversion+0.7×stem anteversion].

RESULTS

There were no significant differences between the two groups with respect to definitive cup inclination and anteversion. The mean deviations in the inclination and anteversion angle were 40.3 ± 4.3 and 19.6 ± 6.2° in the cementless group and 40.5 ± 3.3 and 17.1 ± 5.1° in the cemented group. There were 11 outliers with respect to the Lewinnek safe zone in the cementless group and two in the cemented group (P = 0.072). Although there was no statistically significant difference, the number of safe zone outliers in the cemented group was less than that in the cementless group.

CONCLUSION

We conclude that when using a navigation system for revision THA, high precision can be obtained for the cup placement angle with or without cement. However, it seems that a major error in the installation angle of the cup is less likely to occur when using a cemented cup than when using a cementless cup in revision THA with a navigation system.