Differentiating Nutrient Artery Canals of the Femur versus Fracture Lines in Patients with Total Hip Arthroplasty on Plain Radiographs

BACKGROUND

Nutrient artery canals of the femur are often visible on plain radiographs as radiolucent lines which may mimic fracture lines. The purpose of this study was to distinguish nutrient artery canals from fracture lines on plain radiographs.

MATERIALS AND METHODS

Ninety-three patients (102 hips) with an average age of 65.6 years were included in the study. We retrospectively analyzed nutrient artery canals of the femur on pre and postoperative anteroposterior (AP) and cross-table lateral (CTL) hip radiographs in patients with cementless total hip arthroplasty. The shape, number, location, direction of obliquity, length of nutrient artery canal, and the distance between the tip of the greater trochanter and the proximal end of the nutrient artery canal were measured.

RESULTS

Nutrient artery canals were determined in 54 hips (53.0%) on preoperative radiographs. The numbers of nutrient artery canals were entirely found to be one for each hip. The nutrient artery canals of the femur were the most frequently seen in the cortex on CTL radiographs with 32 hips (31.4%), whereas nutrient artery canals were not seen at all in the cortex on AP radiographs. All nutrient artery canals in the cortex on CTL radiographs coursed upward obliquely. Comparing to fracture lines, nutrient artery canals show less radiolucency, smaller diameter, and blunted ends in both the cortex and medullary cavity, show sclerotic walls in the cortex and have the less straight course in the medullary cavity.

CONCLUSIONS

Based on the results of this study, there are clearly distinguishable differences between nutrient artery canals of the femur and fracture lines on plain radiographs.

Spinal Accessory Nerve Injury Induced by Manipulation Therapy: A Case Report

Spinal accessory nerve (SAN) injury mostly occurs during surgical procedures. SAN injury caused by manipulation therapy has been rarely reported. We present a rare case of SAN injury associated with manipulation therapy showing scapular winging and droopy shoulder. A 42-year-old woman visited our outpatient clinic complaining of pain and limited active range of motion (ROM) in right shoulder and scapular winging after manipulation therapy. Needle electromyography and nerve conduction study suggested SAN injury. Physical therapy (PT) three times a week for 2 weeks were prescribed. After a total of 6 sessions of PT and modality, the patient reported that the pain was gradually relieved during shoulder flexion and abduction with improved active ROM of shoulder. Over the course of 2 months follow-up, the patient reported almost recovered shoulder ROM and strength as before. She did not complain of shoulder pain any more.

Reference Value for Infrapatellar Branch of Saphenous Nerve Conduction Study: Cadaveric and Clinical Study

Objective

To determine the optimal stimulation and recording site for infrapatellar branch of saphenous nerve (IPBSN) conduction studies by a cadaveric study, and to confirm that obtained location is practically applicable to healthy adults.

Methods

Twelve lower limbs from six cadavers were studied. We defined the optimal stimulation site as the point IPBSN exits the sartorius muscle and the distance or ratio were measured on the X- and Y-axis based on the line connecting the medial and lateral poles of the patella. We defined the optimal recording site as the point where the terminal branch met the line connecting inferior pole of patella and tibial tuberosity, and measured the distance from the inferior pole. Also, nerve conduction studies were performed with obtained location in healthy adults.

Results

In optimal stimulation site, the mean value of X-coordinate was 55.50±6.10 mm, and the ratio of the Y-coordinate to the thigh length was 25.53%±5.40%. The optimal recording site was located 15.92±1.83 mm below the inferior pole of patella. In our sensory nerve conduction studies through this location, mean peak latency was 4.11±0.30 ms and mean amplitude was 4.16±1.49 µV.

Conclusion

The optimal stimulation site was located 5.0–6.0 cm medial to medial pole of the patella and 25% of thigh length proximal to the X-axis. The optimal recording site was located 1.5–2.0 cm below inferior pole of patella. We have also confirmed that this location is clinically applicable.

Quantitative Measurement of Muscle Atrophy and Fat Infiltration of the Supraspinatus Muscle Using Ultrasonography After Arthroscopic Rotator Cuff Repair

Objective

To investigate the utility of ultrasonography to objectively examine morphological changes (i.e., muscle atrophy and fatty infiltration) of the supraspinatus muscle.

Methods

Thirty-four patients were prospectively enrolled in this study. The degrees of muscle atrophy and fat infiltration were measured using ultrasonography 3–4 months after arthroscopic supraspinatus tendon repair. Shoulder function (i.e., shoulder active range of motion, visual analogue scale, and constant score) was examined. Using the symmetricity of the muscles in the human body, the degrees of morphological changes of the supraspinatus muscle were quantitatively measured. The associations between the morphological changes of the supraspinatus muscle and shoulder function were identified.

Results

There were statistically significant differences in the cross-sectional area (CSA) and echogenicity between the surgery and non-surgery sides (p<0.001). The CSA ratio, which represents the degree of muscle atrophy, was associated with shoulder forward flexion, external rotation, and constant score; however, the echogenicity ratio, which represents the degree of fat infiltration, was not associated with shoulder function after surgery.

Conclusion

This study demonstrated that shoulder function could be predicted by evaluating the morphological changes of the supraspinatus muscle using ultrasonography and that objective evaluation is possible through quantitative measurement using the symmetricity of the human body.

Changes in coronal alignment of the ankle joint after high tibial osteotomy

PURPOSE

The purpose of this study was to investigate changes in coronal alignment of the ankle joint after HTO. Our hypothesis was that ankle joint orientation may become more parallel or less parallel to the ground after HTO, and this change may affect ankle symptoms.

METHODS

Eighty-six knees were retrospectively analysed after HTO for varus osteoarthritis. Preoperative and follow-up whole-leg radiographs were taken. The hip-knee-ankle (HKA) angle and medial proximal tibial angle (MPTA) were measured to evaluate coronal alignment of the knee. Tibial plafond inclination (TPI), talar inclination (TI), talar tilt (TT), and lateral distal tibial angle (LDTA) were measured to evaluate coronal alignment of the ankle. Patients were divided into two groups: those who exhibited a decrease in the absolute value of TPI and TI after HTO (group A) and those who exhibited an increase in the absolute value of TPI or TI after HTO (group B). Clinical outcomes of the knee and ankle were evaluated pre- and postoperatively.

RESULTS

Mean TPI and TI changed from 6.9° ± 3.6° and 8.0° ± 3.8° to 2.8° ± 3.1° and 3.9° ± 3.0° in group A (P < 0.001 for both) and from -1.3° ± 3.7° and 0.6° ± 4.5° to -6.0° ± 4.2° and -4.6° ± 5.9° in group B (P = 0.018 for both). VAS for ankle pain did not change significantly after HTO (n.s.) in group A, whereas those of group B increased significantly after HTO (P = 0.014).

CONCLUSION

Ankle joint orientation becomes more parallel or less parallel to the ground after HTO. Smaller preoperative HKA and LDTA result in a more valgus ankle joint orientation after HTO. Ankle symptoms were affected by coronal alignment changes of the ankle after HTO.

LEVEL OF EVIDENCE

III.

Myopericytoma around the knee: mimicking a neurogenic tumour

Myopericytoma is a rare, usually benign soft tissue tumour that arises most commonly in the dermis and subcutaneous soft tissue of the lower extremities. In this article, we present an unusual case of myopericytoma occurring in the deep soft tissue around the knee that mimicked a neurogenic tumour. Myopericytoma can be confused with neurogenic tumour when located in deep soft tissue and adjacent to nerve bundles. Preoperative MRI and colour Doppler ultrasound may help differentiate myopericytoma from neurogenic tumour by revealing the hypervascular nature of the tumour.

Influence of Mixed Solvent on the Electrochemical Property of Hybrid Capacitor

The hybrid capacitors (2245 size, cylindrical type) were prepared by using activated carbon cathode and Li4Ti5O12 anode. In order to improve the cell operation at high temperature range, propylene carbonate (PC) was used in combination with acetonitrile (AN) with volume ratio of 7:3, 5:5, and 3:7, respectively. We investigated the electrochemical behavior of the hybrid capacitors that enabled cell operation with stability at high temperature. The organic electrolyte of hybrid capacitor containing PC and AN with a volume ratio 7:3 intended to exhibit highly reversible cycle performance with good capacity retention at 60 degrees C after 2200 cycles. From this study, it has been found that the very strong influence of the solvent nature on the characteristics of hybrid capacitor, and the difference in performance associated with the two solvents.

A Postaxial Polydactyly with a Partial Duplication of the Fifth Metatarsal Without a Supernumerary Digit. Is Excision of the Duplicated Metatarsal Necessary?

Postaxial polydactyly of the foot is one of the most common congenital malformations. Only a few cases of postaxial polydactyly with a partial duplication of the fifth metatarsal without a supernumerary digit have been reported, and both metatarsal heads were united to form a common joint with the proximal phalanx in all of those cases. We present a rare case of postaxial polydactyly with a partial duplication of the fifth metatarsal characterized by dual metatarsal heads and an extra proximal phalanx bud, without a supernumerary digit.

A validation study for estimation of femoral anteversion using the posterior lesser trochanter line: an analysis of computed tomography measurement

The aim of this study was to introduce a simple and reliable intraoperative reference guide to reproduce the normal femoral anteversion during total hip arthroplasty (THA). We hypothesized that the posterior lesser trochanter line (PLTL) could be a useful guide for estimating femoral anteversion during THA. We conducted a study of 56 men (112 hips) to evaluate the relationship between the PLTL and the femoral anteversion using computed tomography scans. The mean femoral anteversion was 9.0° ± 8.1° (range, -16.2° to 32.9°). The PLTL angle correlated (r(2) = 0.12, P < 0.05) with the femoral anteversion. We found a constant relationship between the PLTL and femoral anteversion, and the PLTL may be used as a guide for estimating the femoral stem anteversion during femoral stem fixation.

Comparison of the predictive power of the LODS and APACHE II scoring systems in a neurological intensive care unit

OBJECTIVE

A prospective study to compare the power of the Logistic Organ Dysfunction System (LODS) and the Acute Physiology and Chronic Health Evaluation II (APACHE II) scoring systems to predict survival, in patients admitted to the neurological intensive care unit (NICU).

METHODS

Clinical data from 521 consecutive NICU patients were collected during the first 24 h of admission and were used to compare the predictive power of both scoring systems.

RESULTS

The observed mortality rate was 10.0% compared with predicted mortality rates of 7.2% and 4.8% according to LODS and APACHE II, respectively. Both scoring systems had excellent discrimination but LODS had superior calibration.

CONCLUSION

The LODS scoring system was more stable than the APACHE II scoring system in the NICU setting.

Contact pressure in the wrist during computer mouse work

This study investigated the relationship between computer mouse work and contact pressure around the pisiform. Commonly performed mouse work was simulated using 3 different-shaped mice with 3 forearm positions. When typical mouse work was performed, the contact pressure on the pisiform area was evaluated using a digital pressure sensor and compared with that of the thenar area. Six mouse tasks were simulated. Results indicate that mouse users should avoid wrist-snap dragging and resting their wrist on the edge of the desk to minimize the pressure concentration on the pisiform area.

Reliability of a PowerPoint method for wear measurement after total hip arthroplasty: a retrieval study using 3-dimensional laser scanning

The purpose of this study was to evaluate the reliability of the PowerPoint (PP) (2007 Version; Microsoft, Redmond, Wash) method for measuring polyethylene liner wear after total hip arthroplasty. Seventeen retrieved polyethylene liners were included in this study. Wear volumes were calculated using the PP, the Dorr and Wan, and 3-dimensional (3D) laser scanning methods. Spearman correlation coefficients for wear volume results indicated strong correlations between the PP and 3D laser scanning methods (range, 0.89-0.93). On the other hand, Spearman correlation analysis revealed only moderate correlations between the Dorr and Wan and 3D laser scanning methods (range, 0.67-0.77). The PP method can be used to monitor linear wear after total hip arthroplasty and could serve as an alternative method when computerized methods are not available.

Loss of PTEN induces microtentacles through PI3K-independent activation of cofilin

Loss of PTEN tumor suppressor enhances metastatic risk in breast cancer, although the underlying mechanisms are poorly defined. We report that homozygous deletion of PTEN in mammary epithelial cells induces tubulin-based microtentacles (McTNs) that facilitate cell reattachment and homotypic aggregation. Treatment with contractility-modulating drugs showed that McTNs in PTEN(-/-) cells are suppressible by controlling the actin cytoskeleton. Because outward microtubule extension is counteracted by actin cortical contraction, increased activity of actin-severing proteins could release constraints on McTN formation in PTEN(-/-) cells. One such actin-severing protein, cofilin, is activated in detached PTEN(-/-) cells that could weaken the actin cortex to promote McTNs. Expression of wild-type cofilin, an activated mutant (S3A), and an inactive mutant (S3E) demonstrated that altering cofilin phosphorylation directly affects McTNs formation. Chemical inhibition of PI3K did not reduce McTNs or inactivate cofilin in PTEN(-/-) cells. Additionally, knock-in expression of the two most common PI3K-activating mutations observed in human cancer patients did not increase McTNs or activate cofilin. PTEN loss and PI3K activation also caused differential activation of the cofilin regulators, LIM-kinase1 (LIMK) and Slingshot-1L (SSH). Furthermore, McTNs were suppressed and cofilin was inactivated by restoration of PTEN in the PTEN(-/-) cells, indicating that both the elevation of McTNs and the activation of cofilin are specific results arising from PTEN loss. These data identify a novel mechanism by which PTEN loss could remodel the cortical actin network to facilitate McTNs that promote tumor cell reattachment and aggregation. Using isogenic MCF-10A PTEN(-/-) and PIK3CA mutants, we have further demonstrated that there are clear differences in activation of cofilin, LIMK and SSH between PTEN loss and PI3K activation, providing a new evidence that these mutations yield distinct cytoskeletal phenotypes, which could have an impact on tumor biology.

The analgesic effect of remifentanil on prevention of withdrawal response associated with the injection of rocuronium in children: no evidence for a peripheral action

Remifentanil pre-treatment has been reported to decrease the incidence of rocuronium injection-associated withdrawal movement. This study was designed to explore the site of action of remifentanil for reducing withdrawal response during rocuronium injection in children. Ninety-six paediatric patients were randomly assigned to three groups. After induction of anaesthesia with 5 mg/kg 2.5% thiopental sodium, 2 ml saline (placebo group) or 0.5 microg/kg remifentanil (group R), was injected intravenously 1 min before 0.6 mg/kg rocuronium. In a third group (group R'), the venous retention of 0.5 microg/kg remifentanil was maintained for 30 s followed by tourniquet release and injection of 0.6 mg/kg rocuronium. Withdrawal response was graded using a four-point scale. The incidence of withdrawal movement after rocuronium administration was 94%, 22% and 81% in the placebo, R, and R' groups, respectively. This study demonstrated that the pre-treatment effect of remifentanil for reducing rocuronium-associated withdrawal response occurs mainly through a central action.

Metastatic breast tumors express increased tau, which promotes microtentacle formation and the reattachment of detached breast tumor cells

The cytoskeletal organization of detached and circulating tumor cells (CTCs) is currently not well defined and may provide potential targets for new therapies to limit metastatic tumor spread. In vivo, CTCs reattach in distant tissues by a mechanism that is tubulin-dependent and suppressed by polymerized actin. The cytoskeletal mechanisms that promote reattachment of CTCs match exactly with the mechanisms supporting tubulin microtentacles (McTN), which we have recently identified in detached breast tumor cells. In this study, we aimed to investigate how McTN formation is affected by the microtubule-associated protein, tau, which is expressed in a subset of chemotherapy-resistant breast cancers. We demonstrate that endogenous tau protein localizes to McTNs and is both necessary and sufficient to promote McTN extension in detached breast tumor cells. Tau-induced McTNs increase reattachment of suspended cells and retention of CTCs in lung capillaries. Analysis of patient-matched primary and metastatic tumors reveals that 52% possess tau expression in metastases and 26% display significantly increased tau expression over disease progression. Tau enrichment in metastatic tumors and the ability of tau to promote tumor cell reattachment through McTN formation support a model in which tau-induced microtubule stabilization provides a selective advantage during tumor metastasis.

Pseudoaneurysm of the popliteal artery complicating medial opening wedge high tibial osteotomy

The popliteal artery is vulnerable to injury during surgeries performed around the knee joint. Pseudoaneurysm of the popliteal artery following a high tibial osteotomy is rare. Few case reports describe the development of this complication after a lateral closing wedge high tibial osteotomy. Our patient underwent an uneventful medial opening wedge high tibial osteotomy and autogenous bone grafting fixed with dual plating for medial osteoarthritis of the knee. The procedure was performed under tourniquet control, which was released only once after the wound closure. Postoperatively, the dressing was soaked, and a large volume of hemorrhagic collection was present in the suction drain. The patient experienced decreased sensation over the sole, which was successfully treated conservatively with medication. Other clinical parameters like motor function and distal pulses were normal. The patient was discharged after 2 weeks. Two days later, the patient presented with pain and numbness over the entire lower limb and a pulsatile swelling in the popliteal fossa. A femoral angiogram revealed a pseudoaneurysm arising from the popliteal artery just below the osteotomy site. Open vascular surgery with resection of the pseudoaneurysm and end-to-end anastomosis using contralateral saphenous vein interposition graft was performed. During the vascular surgery, a pinhead-sized tear was clearly identified on the anterior wall of the popliteal artery, which may have occurred while using the oscillating saw during opening wedge high tibial osteotomy. Careful placement of retractors around the osteotomy site during sawing and flexing the knee to displace the popliteal artery away are recommended to prevent this complication. To our knowledge, this is the first report of a popliteal artery pseudoaneurysm occurring after a medial opening wedge high tibial osteotomy.

Targeting novel microtentacles to reduce the adhesion of circulating tumor cells to blood vessel walls

Abstract #2044

Detached human breast tumor cell lines produce novel protrusions of the plasma membrane that promote reattachment of tumor cells to each other and extracellular matrix. We have termed these protrusions “microtentacles” due to clear mechanistic distinctions from either actin-based filopodia/invadopodia or tubulin-based cilia.&#x2028; &#x2028; Compelling in vivo studies show that a mechanism consistent with microtentacles is responsible for the attachment of circulating tumor cells to blood vessel walls. Human breast tumor cell lines that display a disorganized actin cortex and hallmarks of epithelial-to-mesenchymal transition produce higher frequencies and greater extension of microtentacles. Conversely, some current and proposed tumor drugs that target the cytoskeleton actually increase microtentacles. While many cancer therapies are directed against the process of cell division, it remains important to consider the effects of these drugs on the invasive characteristics of tumor cells. Our current research has determined that microtentacles are composed of coordinated filaments of vimentin and detyrosinated tubulin. Previous studies indicate that elevated levels of vimentin and detyrosinated tubulin in tumors predict poor patient outcome, although the specific mechanisms remain unclear. Time-lapse video microscopy also indicates that the rapid extension and dynamic motion of microtentacles relies on kinesin activation. Again, our results suggest that the kinesin responsible is a conventional kinesin, rather than the mitotic kinesins commonly targeted by cancer therapies. We propose that the independent roles of vimentin, detyrosinated tubulin and kinesin in tumor metastasis could result from their interdependent contributions to microtentacle formation. Since large epithelial tumor cells are often fragmented in narrow capillaries, we are targeting microtentacles to promote the fragmentation of circulating tumor cells in the capillaries of the lung. We are currently using time-lapse confocal microscopy of tumor cells circulating in intact blood vessels and whole-animal optical imaging to define therapies that reduce microtentacle-dependent adhesion of circulating breast tumor cells during metastasis.&#x2028; &#x2028; This image shows circulating tumor cells (red) adhering to the walls of an intact blood vessel (green).

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2044.

Ganglion cysts of the posterior cruciate ligament

Ganglion cysts of the posterior cruciate ligament (PCL) are uncommon lesions found incidentally on MRI and arthroscopy. Twenty patients (11 males and nine females) with the mean age of 35 years presenting with a variety of knee signs and symptoms were found to have PCL cysts on MRI. Out of these, thirteen patients (65%) had isolated symptomatic PCL cysts and seven patients had associated chondral and meniscal lesions. Eight out of the 20 patients (40%) gave a history of antecedent trauma. On arthroscopy, the majority of the cysts were situated at the midsubstance of the ligament with inter-cruciate distension and no involvement of the substance of the ligament. The content of the cysts varied with the majority having yellowish viscous fluid and three containing serous and bloody fluid. All cysts were successfully treated arthroscopically through standard anterior, posteromedial and posterolateral portals with no signs of recurrence on MRI at a mean followup of 24 months. PCL cysts may clinically mimic meniscal or chondral lesions and preoperatively, MRI is essential for the diagnosis of ganglion cysts arising from the PCL. Ganglion cysts of the PCL can be successfully treated arthroscopically using standard portals.

Express primer tool for high-throughput gene cloning and expression

High-throughput approaches for gene cloning and expression require the development of new nonstandard tools for molecular biologists and biochemists. We introduce a Web-based tool to design primers specifically for the generation of expression clones for both laboratory-scale and high-throughput projects. The application is designed not only to allow the user complete flexibility to specify primer design parameters but also to minimize the amount of manual intervention needed to generate a large number of primers for the simultaneous amplification of multiple target genes.