Isocentric 3-Dimensional C-Arm Imaging of Component Alignments in Total Knee Arthroplasty With Potential Intraoperative and Postoperative Applications

An intraoperative imaging tool for total knee arthroplasty could help avoid poor clinical outcomes related to malalignment. We investigated the feasibility of using isocentric (ISO-C) fluoroscopic imaging for this purpose. Three-dimensional ISO-C and computed tomographic (CT) images were acquired from 6 cadaveric specimens implanted with standard knee arthroplasty components and analyzed to determine rotational alignments. In comparison with standard CT measures, the ISO-C–based measures had overall accuracies (determined as root mean square error) of 0.8° and 1.3° and corresponding SDs of 1.3° and 1.4° for the femoral and tibial components, respectively. With ISO-C imaging, it is possible to measure rotational alignment in knee arthroplasty with accuracy and repeatability comparable with CT. Isocentric imaging has strong potential as an intraoperative tool to accurately align arthroplasty components.     

Accelerometer-Based,Portable Navigation vs Imageless,Large-Console Computer-Assisted Navigation in Total Knee Arthroplasty : A Comparison of Radiographic Results

Computer-assisted surgery (CAS) systems improve alignment accuracy in total knee arthroplasty (TKA) but have not been widely implemented. Eighty knees underwent TKA using an accelerometer-based, portable navigation device (KneeAlign 2; OrthAlign Inc, Aliso Viejo, California), and the radiographic results were compared with 80 knees performed using a large-console, imageless CAS system (AchieveCAS; Smith and Nephew, Memphis, Tennessee). In the KneeAlign 2 cohort, 92.5% of patients had an alignment within 3° of a neutral mechanical axis (vs 86.3% with AchieveCAS, P < .01), 96.2% had a tibial component alignment within 2° of perpendicular to tibial mechanical axis (vs 97.5% with AchieveCAS, P = .8), and 94.9% had a femoral component alignment within 2° of perpendicular to the femoral mechanical axis (vs 92.5% with AchieveCAS, P < .01). The mean tourniquet time in the KneeAlign 2 cohort was 48.1 ± 10.2 minutes vs 54.1 ± 10.5 minutes in the AchieveCAS cohort (P < .01). Accelerometer-based, portable navigation is as accurate as large-console, imageless CAS systems in TKA.     

Soft Tissue Releases Affect the Femoral Component Rotation Necessary to Create a Balanced Flexion Gap During Total Knee Arthroplasty

The structures that were released to balance the extension gap were recorded during 1500 consecutive TKA procedures, and the amount of femoral component external rotation (ER) necessary to balance the flexion gap was measured with a tensiometer. The amount of ER necessary to balance the flexion gap significantly decreased as more medial structures were released (1 structure = 4.7°, 2 = 4.1°, 3 = 2.8°, 4 or more = 1.1°, P < 0.012), whereas significantly greater ER was necessary when three or more lateral structures were released (1 structure = 5.3°, 2 = 5.5°, 3 or more = 8.6°, P < 0.03). Soft tissue releases affected the amount of femoral component ER necessary to balance the flexion gap, bringing into question the ability of techniques utilizing bony landmarks to properly align the femoral component in rotation.     

Intraoperative Measurements of Femoral Anterior Tangent (FAT) Line for Determining the Rotational Alignment of Femoral Component of Total Knee Arthroplasty

Previously, we reported using CT images that the anterior surface of the femur immediately proximal to the trochlea and its tangent line (femoral anterior tangent line; FAT line) could be used as a good index of the femoral rotation. In this study, we developed a jig that allowed us to measure the FAT line during surgery, and we examine the relation between preoperative and intraoperative measurement values. The results indicated that the average intraoperative measurement value of the ‘surgical’ FAT line was 9.8° ± 3.2° internally rotated using surgical transepicondylar axis reference. This value significantly correlated to preoperative FAT line/clinical transepicondylar axis angle. These findings demonstrated that FAT line is a useful index for appropriate rotational alignment of femoral component, both before and during TKA.     

CT三维重建下探讨BSSRO术舌侧水平截骨线与骨劈开效果的关系

目的:应用CT三维重建来探讨双侧下颌骨矢状劈开截骨术舌侧水平截骨线与骨劈开效果的关系,为下颌骨矢状劈开截骨术舌侧水平截骨位置的选择提供指导。方法:选择17例双侧下颌骨前突患者(34例),经过下颌骨矢状劈开截骨术,术后应用三维重建观测水平截骨线及劈开效果。结果:只有10.87%的劈开结果理想(符合Hunsuck描述),54.35%的劈开效果较理想,32.61%的穿过了下颌管,4.35%穿过了其它部位。劈开的效果直接受水平截骨位置的影响(P<0.01)。结论:三维CT在评价下颌骨矢状劈开截骨术效果方面是有效的工具,为下颌骨矢状劈开截骨术选择舌侧水平截骨线位置提供重要数据,并能降低不良劈开的发生率。     

A Multi-Planar CT-Based Comparative Analysis of Patient-Specific Cutting Guides With Conventional Instrumentation in Total Knee Arthroplasty

Patient specific guides (PSGs) are postulated to improve the alignment of components in total knee arthroplasty. Three hundred consecutive total knee arthroplasties performed with either conventional (CON) (n = 185) or Visionaire PSG (n = 115) were evaluated with a CT protocol for coronal limb alignment, coronal and sagittal alignment of individual components and femoral component rotation. There was no statistically significant difference between the two groups in any of the above parameters. In addition, no difference was found in total operative time. PSGs do not offer any benefit over conventional guides in terms improving the coronal alignment of the limb or alignment of individual components.     

Evaluation of Medial-Lateral Stability and Functional Outcome Following Total Knee Arthroplasty: Results of a Single Hospital Joint Registry

A precept of a successful total knee arthroplasty (TKA) would be a well balanced, stable knee. We analyzed the effects of medial-lateral (ML) stability on functional outcome at 2 years post-operatively. Prospectively collected Joint Registry data of all unilateral primary TKAs between 2004 and March 2008 were used. ML stability (Group 1: < 5°, Group 2: 6°–9°, Group 3: ≥ 10°) was assessed by 3 independent researchers. 1500 patients undergoing 1507 arthroplasties were divided into their various groups. Outcome assessment involved range of motion (ROM) and functional outcome, using the Knee Society Function Score (KSS), Oxford Knee Score (OKS) and SF-36 score. At 2 years, Group 1 patients reported significantly higher KSS (P < 0.001) and SF-36 scores. All groups had good post-operative ROM. A stable knee (ML stability < 5°) post TKA is likely associated with significantly better functional outcome.     

Active learning in Mental Health Nursing - use of the Greek Chorus,dialogic knowing and dramatic methods in a university setting

This article recounts a teaching method employed in a mental health module delivered in Ireland to international nursing students. In it the authors propose that there is a place for innovative teaching methods which combine active learning, dialogue, hard-fun and metacognition to stimulate student engagement and rich learning. We discuss an innovation ‘Movie-shoot’ which incorporated role-play with an analytical commentary by a Greek Chorus of nursing students. We argue this flexible teaching method enhanced active and rich learning, critical reflection and engagement and may be appropriate for use in nursing education.     

Skeletal Stability After Mandibular Counterclockwise Rotational Advancement for Correction of Skeletal Class II Deformity—A Systematic Review and Meta-analysis

ObjectivesThe aim of this systemic review was to compare surgical and postsurgical changes in the mandible after bilateral sagittal split osteotomy (BSSO) with counterclockwise (CCW) rotational advancement. A review of the current available dental literature regarding skeletal stability after mandibular CCW rotational advancement for skeletal Class II deformity was performed using a qualitative and quantitative analysis (meta-analysis).Material and MethodsFive databases were searched: PubMed, MEDLINE (Ovid), Science Direct, Scopus, and Web of Science. The systematic review and meta-analysis addressed the stability of BSSO CCW rotational advancement and the effect of the amount of CCW rotation on skeletal stability after BSSO advancement. Meta-analysis was performed only for studies reporting point B position in mm or mandibular plane angle in degrees before and after surgery and at follow-up.ResultsThe database search resulted in 284 articles after removal of duplicates, and an additional 3 articles were included from hand searches of the bibliographies of the selected articles and relevant reviews. Eight studies were included in the systematic review; all were retrospective case series, and all used rigid fixation. Only 1 study was of medium quality; all other studies were of low quality. Meta-analysis of 3 studies revealed a mean forward movement of 7.6 mm at point B (95% confidence interval [CI], 4.07 to 11.4), a mean downward movement of 2.6 mm (95% CI, −0.66 to 5.84), and a mean CCW rotation of mandibular plane of 4.3° (95% CI, −6.34 to −2.19) during surgery. After surgery, point B showed a mean backward movement of −0.18 mm (95% CI, −1.30 to 1.14), a mean upward movement of −0.5 mm (95% CI, −3.00 to 1.98), and a mean clockwise rotation of 0.1° (95% CI, −1.76 to 1.91).ConclusionsMeta-analysis showed mandibular CCW rotational advancement is a stable procedure, both horizontally and vertically. However, the conclusions are far from robust due to the small sample size and poor quality of the reviewed studies.     

Vascular changes caused by deep brain stimulation using double-dose gadolinium-enhanced brain MRI

We retrospectively analyzed the clinical data of 32 patients with medically intractable idiopathic Parkinson＇s disease who had undergone staged bilateral deep brain stimulation of the subtha-lamic nuclei from January 2007 to May 2011. The vascularture of the patients who received two deep brain stimulations was detected using double-dose gadolinium-enhanced brain MRI. The dimensions of straight sinus, superior sagittal sinus, ipsilateral internal cerebral vein in the tha- lamic branch and ipsilateral anterior caudate vein were reduced. These findings demonstrate that bilateral deep brain stimulation of the subthalamic nuclei affects cerebral venous blood flow.