Anterior Femur Research Articles

Does Kinematic Alignment and Flexion of a Femoral Component Designed for Mechanical Alignment Reduce the Proximal and Lateral Reach of the Trochlea?

BackgroundKinematically aligned total knee arthroplasty uses a femoral component designed for mechanical alignment (MA) and sets the component in more internal, valgus, and flexion rotation than MA. It is unknown how much kinematic alignment (KA) and flexion of the femoral component reduce the proximal and lateral reach of the trochlea; two reductions that could increase the risk of abnormal patella tracking. MethodsWe simulated MA and KA of the femoral component in 0° of flexion on 20 3-dimensional bone models of normal femurs. The mechanically and kinematically aligned components were then aligned in 5°, 10°, and 15° of flexion and downsized until the flange contacted the anterior femur. The reductions in the proximal and lateral reach from the proximal point of the trochlea of the MA component set in 0° of flexion were computed. ResultsKA at 0° of flexion did not reduce the proximal reach and reduced the lateral reach an average of 3 mm. Flexion of the MA and KA femoral component 5°, 10°, and 15° reduced the proximal reach an average of 4 mm, 8 mm, and 12 mm, respectively (0.8 mm/degree of flexion), and reduced the lateral reach an average of 1 mm and 4 mm regardless of the degree of flexion, respectively. ConclusionArthroplasty surgeons and biomechanical engineers striving to optimize patella tracking might consider developing surgical techniques to minimize flexion of the femoral component when performing KA and MA total knee arthroplasty to promote early patella engagement and consider designing a femoral component with a trochlea shaped specifically for KA.

Management of the knees in arthrogryposis.

Arthrogryposis is defined as limited range of motion in three or more joints in two or more body parts. This article will describe treatment options for the arthrogrypotic knee. In all types of arthrogryposis, and in both extension and flexion deformities, very early treatment is favorable. Just after birth, traction and mobilization followed by serial casting could often greatly improve the range of motion. In the hyperextended knee, surgical lengthening of the extensor apparatus may be needed. Flexion deformities could be improved with temporary physeal arrest of the anterior distal femur by fixing two-hole plates over the physis on both sides of patella. The plates will result in a constrained growth of the anterior physis, and thus a very slow extension of the knee, which will give the nerves and vessels time to adjust. Pterygium, webbing of the knee joint, is a special subgroup that in selected mild cases could be treated with extensive surgical release of the webbing and orthotics. Arthrogrypotic knees can be treated with early reduction and maintenance with orthotics.

Proposed Referential Index to Resect Femoroacetabular Cam-Type Impingement During Arthroscopy Using a Cadaveric Hip Model

To establish a reference index for the simple identification of the optimum resection point for cam-type impingement on arthroscopy. Twelve cadaveric left hips with a 20° to 40° center-edge angle, without osteoarthritis, were examined (mean age, 85 ± 10.1 years). The pelvis was fixed such that the anterior pelvic plane and femur were parallel to the table. The resection line for impingement was first defined on the femoral head surface 5 mm distal to the acetabular labrum, from the 9-o'clock (anterior) to 12-o'clock (superior) position. Next, we measured the hip flexion angle necessary for the head-neck junction to reach the resection line. After positioning the wire on the femoral head surface along the resection line from the 9- to 12-o'clock area of the femoral head, we measured the targetalpha angle on radiographs at 0°, 15°, 30°, 45°, and 60° of hip flexion using the frog-leg 45/45/30 view (45° of flexion, 45° of abduction, and 30° of external rotation) and Dunn 45 view (45° of flexion, 20° of abduction, and neutral rotation). The mean hip flexion angle at which the head-neck junction reached the resection line was 31° ± 4.6°. For 0°, 15°, 30°, 45°, and 60° of hip flexion, the mean targetalpha angle was 75.5° ± 5.5°, 65.3° ± 5.6°, 56.3° ± 5.8°, 49.0° ± 6.6°, and 42.6° ± 5.8°, respectively, using the frog-leg 45/45/30 view and 75.0° ± 6.0°, 65.8° ± 6.2°, 57.2° ± 7.3°, 50.7° ± 6.9°, and 44.2° ± 5.8°, respectively, using the Dunn 45 view. There were no significant differences between the 2 radiographic techniques (P= .82, P= .84, P= .76, P= .57, and P= .52, respectively). A description of the degree of hip flexion during cam resection can affect the final alpha angle when using the labrum as a reference for resection. The described index allows systematic navigation of cam lesions during arthroscopy for femoroacetabular impingement patients using the hip flexion angle.

A synoptic review of the genus Stagmomantis (Mantodea: Mantidae).

Stagmomantis is a remarkable genus within the Mantodea, being relatively species-rich and geographically widespread. Yet, the number of species within the genus remains curiously unresolved. The present synoptic review surveys the literature on Stagmomantis to identify named species for which scientific consensus exists, as well as to summarize basic biological information for each species, including geographic distribution, morphological features, and sex-specific biometric data. The review identifies 23 consensus taxa within Stagmomantis: 22 separate species, with one of these species, S. montana, split into two subspecies (S. m. montana and S. m. sinaloae). The review indicates morphological features that may prove to be diagnostic for a given species, particularly when examined in conjunction with male genitalia. Such features include dark spots on the anterior femur (S. amazonica, S. centralis, S. marginata, S. nahua, S. venusta, S. vicina), spines or denticulations on the anterior coxa (S. colorata, S. montana montana, S. parvidentata, S. theophila), and dark bands on abdominal tergites (S. californica, S. colorata, S. domingensis). Color variation of certain features with respect to body coloration, such as stigma coloration and body and leg markings, requires more attention. Information on life history, reproduction, and ecology are summarized, particularly for temperate populations of S. carolina and S. limbata. While the 23 consensus taxa represent a robust appraisal of the existing literature, some taxonomic uncertainties remain. The status of two species are somewhat unclear (S. marginata and S. tolteca), calling for taxonomic evaluation. Furthermore, proposed within-genus groupings deserve examination, as do possible subdivisions within some species (e.g., S. limbata, S. parvidentata). Information on basic morphology and biometry remains incomplete for nearly all species. Extreme examples are S. amazonica, S. costalis, and S. paraensis, for which females have not been described. Live animal research on life history, behavior, and ecology is needed for all species, with the possible exceptions of S. carolina and S. limbata. By reconciling species assignments and consolidating biological information for the 23 consensus taxa, this synoptic review promises to guide subsequent systematic and phylogenetic investigations of the genus Stagmomantis.

Prevalence of MRI-detected mediopatellar plica in subjects with knee pain and the association with MRI-detected patellofemoral cartilage damage and bone marrow lesions: data from the Joints On Glucosamine study

BackgroundThe mediopatellar plica is a synovial fold representing an embryonic remnant from the developmental process of the synovial cavity formation in the knee. We aimed to examine the frequency of MRI-detected mediopatellar plica and its cross-sectional association with MRI-detected cartilage damage and bone marrow lesions (BMLs) in the patellofemoral joint (PFJ) in a cohort of subjects with knee pain.Methods342 knees with chronic frequent knee pain were evaluated for MRI-detected mediopatellar plica (type A, B or C according to the modified Sakakibara classification). Cartilage damage (scored 0 to 6) and BMLs (scored 0 to 3) were semiquantitatively assessed in four subregions of the PFJ on MRI. Hoffa-synovitis and effusion-synovitis were graded 0 to 3. Patellar length ratio (PLR), lateral patellar tilt angle (LPTA), bisect offset (BO), and sulcus angle (SA) were measured on MRI. The presence of mediopatellar plica and its association with cartilage damage and BMLs in the PFJ was assessed using logistic regression after adjusting for age, gender, body mass index, PLR, LPTA, BO, SA, and Hoffa- and effusion-synovitis.Results163 (47.7%) knees exhibited mediopatellar plica (76 (22.2%) type A, 69 (20.2%) type B, and 18 (5.3%) type C) on MRI. Significant cross-sectional associations of MRI-detected mediopatellar plica and cartilage damage were observed for the medial patella (adjusted odds ratio (aOR) 2.12, 95% CI 1.23-3.64 for all types combined, and aOR 4.20, 95% CI 1.92-9.19 for type B lesion), but not for the anterior medial femur or the lateral PFJ. No associations were found between the presence of MRI-detected mediopatellar plica and BMLs in any patellofemoral subregion.ConclusionOn MRI, types A and B mediopatellar plicae were commonly observed in this cohort of subjects with knee pain. MRI-detected mediopatellar plica was cross-sectionally associated with higher likelihood of the presence of MRI-detected medial patellar cartilage damage after adjustment for confounders.

T2 Mapping and Functional Outcome of Patients With Medial Knee Osteoarthritis After the Use of Unloader Bracing

Introduction: Osteoarthritis (OA) is a debilitating and costly disease, affecting 27 million Americans and costing over $60 billion annually. Most clinical treatments are aimed at minimizing pain and maintaining quality of life as opposed to altering disease processes. Unloader knee braces improve mechanical alignment and provide a non-invasive, conservative form of treatment for patients with mild to moderate OA. However, previous studies have not identified a quantifiable, sustained benefit to this treatment. The purpose of this study was to evaluate the effect of unloader bracing on patients with unicompartmental, medial knee OA using quantitative T2 mapping MRI in attempt to elucidate whether bracing results in physiological articular cartilage changes. Methods: Seven patients with Kellgren-Lawrence grade 1 or 2 OA of the medial compartment (4 males, 3 females) were scanned at baseline and following a 3-month period of unloader knee bracing. All knees were imaged at 3.0 Tesla in the sagittal plane using a Discovery MR750 scanner and an 8-channel transmit-receive knee coil. Cartilage was manually segmented in five regions of interest (ROIs) in the medial femur using OsiriX: medial anterior femur (MAF), medial central femur (MCF), medial posterior femur (MPF), medial anterior tibia (MAT), medial posterior tibia (MPT). T2 fit maps were generated and T2 relaxation times were measured preand post-bracing. Patients completed a daily bracing diary to document the amount of time for which the brace was worn, along with the Knee Osteoarthritis Outcome Score (KOOS) and Visual Analog Scale (VAS) questionnaires at baseline and at 3-months follow-up. Braces also included iButton technology, which acquired temperature readings every 20 minutes to objectively document hours of brace-wear. Results: According to bracing diaries, braces were worn for an average of 35.7 hours per week versus 28.1 hours according to the iButton sensor. Daily bracewear was also overestimated by patient diaries versus the iButton sensor (5.09 vs. 4.15 hrs per day). The average T2 relaxation time of articular cartilage of the medial femur pre-bracing was 35.88 ±4.24 ms versus 40.54±4.77 ms post-bracing (p=0.150). In the medial tibia, the average T2 relaxation time of cartilage was 40.97±5.11ms pre-bracing vs. 38.49±5.87 ms post-bracing (p=0.814). There were no significant results when the regions were further subdivided (MAF, MCF, MPF, MAT, MPT). Improvements were seen in the VAS pain score (2.4 pre-bracing vs. 1.2 post-bracing) as well as the KOOS pain, daily living, function, and quality of life sub-scores following the bracing period, however these results did not reach statistical significance (p>0.05). International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports Medicine 9 th Biennial ISAKOS Congress • May 12-16, 2013 • Toronto, Canada ISAKOS

Evaluation of patellofemoral joint in ADVANCE® Medial-pivot total knee arthroplasty

ADVANCE Medial Pivot (MP) (Wright Medical) total knee arthroplasty (TKA) was established to replicate normal tibio-femoral knee joint kinematics, however, its influence on the patello-femoral (PF) joint is unclear. The purpose in this study was to assess the PF joint conditions in Advance MP TKA, via radiography and three-dimensional image-matching software. Ten subjects with osteoarthritis were treated with the ADVANCE MP TKA. Pre-operatively and one month after surgery, skyline views at 30, 60, and 90° of flexion were taken, and patella shift and tilt were measured. With 2D-3D registration techniques using software, implant orientations were matched with the pre-operative CT and changes in the anterior part of the femoral prosthesis, condylar twist angle (CTA) for femoral rotation, and tibial rotation were evaluated. The relationships between morphological and rotational changes were evaluated. There were significant differences in patella tilt at 60° and patella shift at all angles between pre- and post-operation (p < 0.05). No correlation was found between morphological changes in the anterior femur with patella tilt and shift. A positive correlation between postoperative CTA and patella shift at 90° was found (p < 0.05); however, no correlation was found between rotational alignment of the tibial component and patella tilt and shift. ADVANCE MP TKA changed patello-femoral joint kinematics, compared to that found before surgery. The kinematic features were mainly due to the design concepts for tibio-femoral joint motion, indicating the difficulty to reproduce normal patello-femoral joint kinematics after TKA.

The Biomechanical Effect of Proximal Tumor Defect Location on Femur Pathological Fractures

The femur is the most common long bone affected by cancerous metastasis. Femoral tumor defects are known to induce pain and functional impairment in patients. Although prior studies exist evaluating the clinical and biomechanical effect of tumor defect size, no biomechanical studies have experimentally examined the risk of pathological fracture with respect to the anterior, posterior, medial, and lateral surfaces on which a proximal tumor defect is located on the femur. Circular tumor-like defects of 40-mm diameter were created proximally in the subtrochanteric region on the Anterior (n = 5), Posterior (n = 5), Medial (n = 5), and Lateral (n = 5) sides of 20 synthetic femurs. Intact femurs served as a control group (n = 4). Femurs were tested for lateral, "offset" torsional, and axial stiffness, as well as axial strength. Lateral stiffnesses (range, 121-162 N/mm) yielded no differences between groups (P = 0.069). "Offset" torsional stiffnesses (range, 135-188 N/mm) demonstrated that the Medial group was less stiff than the Intact, Anterior, and Lateral groups (P ≤ 0.012). Axial stiffnesses (range, 1057-1993 N/mm) showed that the Medial group was less stiff than the Intact group (P = 0.006). Axial strengths (range, 3250-6590 N) for the Medial group were lower than Anterior (P = 0.001) and Posterior (P = 0.001) specimens, whereas the Lateral group had a lower strength than Anterior specimens (P = 0.019). No other statistical differences were noted. Axial failure of Medial and Lateral specimens involved the tumor-like defect in 100% of cases, whereas 100% of Intact femurs and 80% of Anterior and Posterior femur groups failed only through the neck. In 2 of 3 test modes, the Medial tumor-like defect group resulted in statistically lower stiffness values compared with Intact femurs and had lower strength than Anterior and Posterior groups in axial failure.

Correlation of muscle function and bone strain in the hindlimb of the river cooter turtle (Pseudemys concinna)

During terrestrial locomotion, limb muscles must generate mechanical work and stabilize joints against the ground reaction force. These demands can require high force production that imposes substantial loads on limb bones. To better understand how muscle contractile function influences patterns of bone loading in terrestrial locomotion, and refine force platform equilibrium models used to estimate limb bone safety factors, we correlated in vivo recordings of femoral strain with muscle activation and strain in a major propulsive hindlimb muscle, flexor tibialis internus (FTI), of a species with a published model of hindlimb force production (river cooter turtles, Pseudemys concinna). Electromyography (EMG) recordings indicate FTI activity prior to footfall that continues through approximately 50% of the stance phase. Large EMG bursts occur just after footfall when the muscle has reached its maximum length and is beginning to actively shorten, concurrent with increasing compressive strain on the anterior femur. The FTI muscle shortens through 35% of stance, with mean fascicle shortening strains reaching 14.0 ± 5.4% resting length (L0 ). At the time of peak compressive strains on the femur, the muscle fascicles remain active, but fascicles typically lengthen until mid-stance as the knee extends. Influenced by the activity of the dorsal knee extensor femorotibialis, the FTI muscle continues to passively lengthen simultaneously with knee extension and a shift to tensile axial strain on the anterior femur at approximately 40% of stance. The near coincidence in timing of peak compressive bone strain and peak muscle shortening (5.4 ± 4.1% stance) indicates a close correlation between the action of the hip extensor/knee flexor, FTI, and femoral loading in the cooter hindlimb. In the context of equilibrium models of limb bone loading, these results may help explain differences in safety factor estimates observed between previous force platform and in vivo strain analyses in cooters.

The Biomechanical Effect of Notch Size, Notch Location, and Femur Orientation on Hip Resurfacing Failure

For hip resurfacing, this is the first biomechanical study to assess anterior and posterior femoral neck notching and femur flexion and extension. Forty-seven artificial femurs were implanted with the Birmingham hip resurfacing (BHR) using a range of notch sizes (0, 2, and 5 mm), notch locations (superior, anterior, and posterior), and femur orientations (neutral stance, flexion, and extension). Implant preparation was done using imageless computer navigation, and mechanical tests measured stiffness and strength. For notch size and location, in neutral stance the unnotched group had 1.9 times greater strength than the 5-mm superior notch group (4539 N versus 2423 N, p=0.047), and the 5-mm anterior notch group had 1.6 times greater strength than the 5-mm superior notch group, yielding a borderline statistical difference (3988 N versus 2423 N, p = 0.056). For femur orientation, in the presence of a 5-mm anterior notch, femurs in neutral stance had 2.2 times greater stiffness than femurs in 25° flexion (1542 N/mm versus 696 N/mm, p = 0.000). Similarly, in the presence of a 5-mm posterior notch, femurs in neutral stance had 2.8 times greater stiffness than femurs in 25° extension (1637 N/mm versus 575 N/mm, p = 0.000). No other statistical differences were noted. All femurs failed through the neck. The results have implications for BHR surgical techniques and recommended patient activities.

A new navigation system for minimally invasive total knee arthroplasty.

A computer-assisted navigation system to be used for total knee arthroplasties (TKAs) was reported to improve the accuracy of bone resection and result in precise implant placement, but the concomitant surgical invasion and time consumption are clinical problems. We developed a computed tomography (CT)-based navigation system (NNS) to be used for minimally invasive TKA. It requires only the reference points from a small limited area of the medial femoral condyle and proximal tibia through a skin incision to obtain optical images. Here we evaluated the usefulness and accuracy of the NNS in comparison with the commercially available BrainLAB image-free navigation system (BLS). In a clinical experiment, the registration times obtained with the NNS tended to be shorter than those obtained with the BLS, but not significantly so. The NNS group tended to be in the extended position in the sagittal plane of the distal femur within 3 degrees, and the BLS group showed rather flexed deviation in the sagittal plane of the anterior femur.

The Safe Zone for External Fixator Pins in the Femur

To define the anatomic "safe zone" for placement of external fixator half pins into the anterior and lateral femur. In 20 fresh-frozen hemipelvis specimens, the femoral nerve and all branches crossing the femur were dissected out to their final muscular locations. The location where the nerves crossed the anterior femur was measured from the anterior superior iliac spine and inferior margin of the lesser trochanter. The knee joint was then opened, and the distance from the superior reflection of the suprapatellar pouch to the last branch of the femoral nerve crossing the anterior femur was measured, defining the safe zone for anterior pin placement. The last branch of the femoral nerve crossed at an average distance from the anterior superior iliac spine of 174 ± 43 mm (range, 95-248 mm) and from the lesser trochanter at a distance of 58 ± 36 mm (range, 0-136 mm). The average distance from the proximal pole of the patella to the superior reflection of the suprapatellar pouch was 46.3 ± 13.1 mm (range, 20-74 mm). Using the linear distance between the last crossing femoral nerve branch and the superior reflection of the pouch, the average safe zone measured 199 ± 39.8 mm (range, 124-268 mm). The safe zone correlated with thigh length (r = 0.48, P = 0.03). All nerve branches terminated at their muscular origins without crossing lateral to a line from the anterior greater trochanter to the anterior aspect of the lateral femoral condyle. The safe zone for anterior external fixator half pin placement into the femur is on average 20 cm in length and can be as narrow as 12 cm. Anterior pins should begin 7.5 cm above the superior pole of the patella to avoid inadvertent knee joint penetration. Because the entire lateral femur is safely available for half pin placement, including distally, we recommend the use of alternative frame constructs with either anterolateral or lateral pins given the limitations and risks of anterior pin placement.

Experience of using anterior windowing of the femur in revision total hip arthroplasty

To discuss the clinical results of anterior windowing of the femur to remove the femoral component and cement in revision total hip arthroplasty. From September 1999 to May 2011, 31 revision cases received anterior windowing of the femur in operation. There were 12 male and 19 female, with the average age in operation was 61.8 years (from 40 to 83 years). The reason for revision included aseptic loosening in 12 cases, infection in 4 cases, breakage of femoral stem in 11 cases and acetabular liner wear in 4 hemi-arthroplasties. Nine cases were cemented and 22 were non-cemented for the primary stem. The position of the window located in the anterior femur with 6 cases of complete windowing from the proximal to the end of the stem. Another 25 cases received regional windowing just around the tip of the stem. In revisions, non-cemented rectangular revision stem were used for 27 cases and two-stage surgery were used for 4 infection cases. In all revisions, femoral stems and cement fragments were removed successfully and safely without any complications of fracture and perforation of new stems. All femur windows showed successfully union for average 14 weeks (12-18 weeks). There were some postoperative complications. One recurrent dislocation was treated using plaster external fixation for 8 weeks. One case with dislocation and fracture along with the window was revised by cerclage fixation. One periprosthetic fracture due to trauma was treated by cerclage fixation. The average Harris score of the hip improved to 83 points (75 to 90 points) at an average 5.5 years follow-up (0.5 to 12.0 years). Twenty six cases were completely followed up. Revision femoral stems were well-fixed without any subsidence or loosening. Anterior windowing of the femur is a proven technique which can be used to remove femoral stem and cement conveniently and safely without any fractures in revision total hip arthroplasty.

Three Femoral Fixation Devices for Anterior Cruciate Ligament Reconstruction: Comparison of Fixation on the Lateral Cortex Versus the Anterior Cortex

To evaluate the biomechanical properties of 3 anterior cruciate ligament (ACL) reconstruction femoral fixation devices in a porcine model with implantation on both the lateral femoral cortex and the anterior femoral cortex. ACL reconstructions with an 8-mm porcine tendon graft were performed on 48 porcine femurs with the EndoButton CL (Smith & Nephew, Andover, MA), ToggleLoc with ZipLoop technology (Biomet Sports Medicine, Warsaw, IN), or EZLoc (Biomet Sports Medicine). In 8 specimens for each implant, the femoral tunnel was drilled from the 10:30 surgical position out the lateral cortex. In another 8 specimens for each implant, the tunnel was drilled from the 10:30 position to a standardized anterior femoral surface. Cyclic testing was performed on an MTS testing machine (MTS, Eden Prairie, MN) from 50 N to 450 N for 2,000 cycles, followed by load-to-failure testing in specimens that survived. The cortical thickness and location of the implant exit were recorded. In the lateral femur group, 0 of the EZLoc devices, 2 of the ToggleLoc devices, and 3 of the EndoButtons completed cyclic testing. In the anterior femur group, 1 of the EZLoc devices, 5 of the ToggleLoc devices, and 5 of the EndoButtons completed cyclic testing (P = .012). In the anterior femur group, the ToggleLoc exhibited higher 2,000-cycle elongation (5.46 +/- 1 mm) than the EndoButton (3.55 +/- 0.6 mm) (P = .005). The EndoButton showed a higher first failure load (1,190.9 +/- 150.0 N) than the ToggleLoc (912.6 +/- 82.4 N) (P = .007). The anterior cortex (1.4 mm) was thinner than the lateral cortex (1.7 mm) (P = .0002). The EndoButton provided the strongest ACL femoral fixation with significantly less graft-implant elongation and significantly higher failure loads. It was also shown in a porcine model that implants on the anterior cortical surface perform better than those on the lateral surface. Increased cortical thickness, in the range tested, was not associated with improved implant performance in the porcine model. The EndoButton provided the best ACL femoral fixation of the devices tested.

Jaw bone changes in rats after treatment with zoledronate and pamidronate

The aim of this study was to histopathologically evaluate the effects of pamidronate and zoledronate on the mandible in an animal model. Sixty female Sprague-Dawley rats were used in this study. Animals were divided into 6 groups (10 per group): control-1 (C1), injected with saline solution for 6 weeks; zoledronate-1 (ZA1), injected with zoledronate for 6 weeks; pamidronate-1 (PA1), injected with pamidronate for 6 weeks; control-2 (C2), injected with saline solution for 8 weeks; zoledronate-2 (ZA2), injected with zoledronate for 8 weeks; and pamidronate-2 (PA2), injected with pamidronate for 8 weeks. No dental procedures were performed on the animals. Rats were killed 2 days after the end of drug therapy, and the posterior and anterior mandible and femur of each rat were evaluated histopathologically. Histological examination revealed inflammation limited to the posterior mandible of the ZA2 and PA2 groups; the anterior mandible and femur were not affected. Soft tissue necrosis was evident in one rat in the ZA2 group. Specific, bisphosphonate-associated inflammatory bony and soft tissue changes were observed in the mandible, suggesting that these drugs may set the stage for altered healing associated with the development of bisphosphonate-related osteonecrosis of the jaw.

Descrição de novas espécies de Fidicinoides Boulard &amp; Martinelli (Hemiptera: Cicadidae) do Brasil

The examination of entomological collections of cicadas of several Brazilian institutions revealed three undescribed species in the genus Fidicinoides Boulard & Martinelli i.e., F. dolosa sp.n., F. carmenae sp.n. and F. rosabasalae sp.n. They are described and illustrated based on the male genitalia, the right anterior femur and the operculum.

Seven Cuts to the Perfect Total Knee

There are a total of 7 bone cuts in a typical total knee replacement (TKR): distal femur, anterior femur, posterior femur, anterior chamfer, posterior chamfer, tibia, and patella. Each of these cuts has its own special science, and each cut can affect the other cuts and potentially the outcome of the TKR. The distal femoral cut starts the overall alignment of the leg. Five degrees of valgus is cosmetically appealing, avoids excessive valgus, and prevents thighs from rubbing together. The anterior femoral cut sets femoral component rotation, which has effects on patellar tracking and gap balancing. In most knees, correct rotation is approximately 3 degrees of external rotation compared to the posterior condylar axis. An important exception is in valgus knees, where this could lead to accidental internal rotation. The posterior condyle cuts, with the tibial cut, determine the flexion gap. Injury to the medial collateral and posterior cruciate ligaments should be avoided. Anterior and posterior chamfer cuts must avoid these ligaments as well. The tibial cut is challenging. A 3 degrees posterior slope is most typical, and rotation is crucial. Internal rotation is a common error, affecting patellar tracking. Changing rotation on a sloped cut also adds varus or valgus. The patella cut should not be too deep. Component placement should tend medial and superior. If a lateral release is necessary, it should be done from inside-out, with preservation of the blood supply.

Phenetic Analysis of the Anisoptera (Insecta: Odonata) in Jeju Island, Korea, Based on Morphological Characters

This study was conducted from April 2002 to September 2007 to investigate the relationships of 27 species of Anisoptera which were collected in wetlands of Jeju Island, using a phenetic analysis of external morphological characters. The generated phenogram revealed the presence of two superfamilies within Anisoptera, Aeshnoidea and Libelluloidea. Moreover, the three groups, Aeshinidae, Libellulidae and Corduliidae, were clearly branched. As a result, the phenogram was similar to that of the ordinary systematic classification. The Aeshnidae was divided into Anax and Gynacantha, and Polycanthagyna and Aeschnophlebia. Three species of Anax (e.g., guttatus, parthenope and nigrofasciatus) presented to have very similar external morphological characteristics. Particularly, A. guttatus has confused its name, e.g., someone treated it as a synonym with A. parthenope due to the presence of very similar morphological characters. However, major differences were observed in the upper edge of the frons and the anterior femur in these species. Therefore, we obtained a conclusion that is more valid to classify A. guttatus as an independent species rather than as a synonym. The Libellulidae consisted of three subgroups. When the relationship of the genus Sympetrum were considered, the key characteristics were determined to be the patterns of the first lateral suture, the second lateral suture and the humeral suture. The Corduliidae was divided into Macromiinae and Cordulinae. Particularly, Somatochlora graeseri and S. clavata were confirmed to be unregistered species in Jeju Island.

Guided Growth for Fixed Knee Flexion Deformity

Fixed knee flexion deformity (FKFD) is an insidious problem that may complicate the management of patients with neuromuscular compromise due to cerebral palsy, spina bifida, arthrogryposis, and other conditions. The energy costs associated with crouch gait may become prohibitive and, with the inexorable progression of fixed knee flexion, secondary pain may ensue as a result of fragmentation of the patella and/or tibial tubercle. Concomitant or compensatory flexion deformity of the hips and lumbar lordosis may develop, along with "pseudo equinus" of the ankles. Recommended treatments for FKFD have included bracing; physical therapy; and, in recalcitrant cases, distal femoral osteotomy, posterior release, or frame distraction. However, these latter modalities are fraught with potential complications including neurovascular damage, loss of fixation, undercorrection malunion, fracture, and recurrent deformity. Considering that FKFD is often bilateral, the complication risks for a given patient are doubled. In a previous study, the senior author reported successful hemiepiphysiodesis of the distal anterior femur using staples. However, further experience has demonstrated some of the limitations of stapling including relatively slow correction and occasional hardware migration. This led to the development of a more versatile and reliable solution using a pair of anterior tension band plates. In this retrospective clinical study, we are reporting this new technique of promoting gradual correction through guided growth of the distal femur, using a pair of anterior 8-plates. The correction is accomplished simultaneously and bilaterally, without immobilization, and may be combined with other operative procedures as indicated. We reviewed the charts, radiographs in a group of patients treated accordingly. In this group of 18 patients with 29 deformities, we noted correction averaging 1.3 degrees (range, 0.0 [1 patient]-4.8 degrees), with minimal complications. No inadvertent coronal plane deformities were created. Upon full correction, the plates were removed so as to avoid recurvatum. As an alternative to posterior capsulotomy or supracondylar extension osteotomy, we have found that guided growth is an effective and safe method of gradually correcting FKFD in growing children and adolescents. 4 (retrospective clinical series).

The effects of COX-1 and COX-2 inhibitors on prostaglandin synthesis and the formation of heterotopic bone in a rat model

Traumatic heterotopic ossification (HO) is a common clinical condition associated with various orthopedic procedures that involve injury to soft tissues near bone. In this study, we tested the hypothesis that the prophylactic effects of NSAID's in the treatment of HO are mediated via inhibition of the COX-2 enzyme. Here we describe a rat model that simulates HO in the human that was used to test the above hypothesis. Heterotopic ossification was surgically induced in the quadriceps by injury to the muscle and femoral periosteum and transplantation of donor bone marrow cells containing osteoprogenitors into the site of injury. HO was imaged and quantified by micro-CT scanning of femurs removed from sacrificed animals at 6 weeks post-injury, three-dimensional computer reconstructions of the scanned bones and computer-assisted morphometric analysis. Prostaglandin E(2) (PGE(2)) synthesis was quantified using an enzyme immunoassay system. The effects of a nonselective COX inhibitor or specific inhibitors of COX-1 or COX-2 following oral administration on the content of ectopic bone and PGE(2) were also measured. Micro-CT and histological analyses demonstrated that all of the femurs in operated limbs developed HO in the vastus lateralis muscle belly of the quadriceps close to the anterior femur. Only the COX-1,2 nonselective and COX-2 inhibitors significantly decreased HO formation (by about one-third in each case; P < 0.05). PGE(2) synthesis at the site of injury was increased 50- and 100-fold (to 25 ng/g tissue) within 1 and 7 days, respectively, post-injury with the levels declining to near baseline within 2 weeks of surgery. Both the COX-1,2 nonselective and COX-2 inhibitors significantly decreased PGE(2) levels to 25% of control HO levels within 24 h of the first administration, even at low dosages. The COX-1 inhibitor only produced the same effect after 1 week of administration. These findings suggest that although inhibitors of COX-2 or COX-1 reduced PGE(2) synthesis, only the COX-2 enzyme plays a role in the mechanism of traumatic HO.