Immediate and six-week effects of wearing a knee sleeve following anterior cruciate ligament reconstruction on knee kinematics and kinetics: a cross-over laboratory and randomised clinical trial.

BACKGROUND: Elastic knee sleeves are often worn following anterior cruciate ligament reconstruction (ACLR) but their effects on movement patterns are unclear. AIM: To determine the immediate and six-week effects of wearing a knee sleeve on biomechanics of the knee during a step-down hop task. METHODS: Using a cross-over design, we estimated sagittal plane knee kinematics and kinetics and stance duration during a step-down hop for 31 participants (age 26.0 [SD 6.6] years, 15 women) after ACLR (median 16 months post-surgery) with and without wearing a knee sleeve. In a subsequent randomised clinical trial, participants in the 'Sleeve Group' (n = 9) then wore the sleeve for 6 weeks at least 1 h daily, while a 'Control Group' (n = 9) did not wear the sleeve. We used statistical parametric mapping to compare (1) knee flexion/extension angle and external flexion/extension moment trajectories between three conditions at baseline (uninjured side, unsleeved injured side and sleeved injured side); (2) within-participant changes for knee flexion angles and external flexion/extension moment trajectories from baseline to follow-up between groups. We compared discrete flexion angles and moments, and stance duration between conditions and between groups. RESULTS: Without sleeves, knee flexion was lower for the injured than the uninjured sides during mid-stance phase. When wearing the sleeve on the injured side, knee flexion increased during the loading phase of the stance phase. Discrete initial and peak knee flexion angles increased by (mean difference, 95% CIs) 2.7° (1.3, 4.1) and 3.0° (1.2, 4.9), respectively, when wearing the knee sleeve. Knee external flexion moments for the unsleeved injured sides were lower than the uninjured sides for 80% of stance phase, with no change when sleeved. The groups differenced for within-group changes in knee flexion trajectories at follow-up. Knee flexion angles increased for the Control group only. Stance duration decreased by 22% for the Sleeve group from baseline to follow-up (-89 ms; -153, -24) but not for the Controls. CONCLUSIONS: Application of knee sleeves following ACLR is associated with improved knee flexion angles during hop landing training. Longer term (daily) knee sleeve application may help improve hop stance duration, potentially indicating improved hop performance. TRIAL REGISTRATION: The trial was prospectively registered with the Australia New Zealand Clinical Trials Registry No: ACTRN12618001083280, 28/06/2018. ANZCTR.

Fat Is Consistently Present within the Plantar Muscular Space of the Human Foot-An Anatomical Study.

Background and Objectives: The foot comprises of active contractile and passive connective tissue components, which help maintain stability and facilitate movement during gait. The role of age- or pathology-related degeneration and the presence of fat within muscles in foot function and pain remains unclear. The existence of fat has to date not been quantified or compared between individuals according to age, sex, side or subregion. Materials and Methods: 18 cadaveric feet (mean age 79 years) were sectioned sagittally and photographed bilaterally. Fat in the plantar muscular space of the foot (PMSF) was quantified through the previously validated manual fat quantification method, which involved observing photographs of each section and identifying regions using OsiriX. Fat volume and percentage was calculated using a modified Cavalieri's method. Results: All feet had fat located within the PMSF, averaging 25.8% (range, 16.5-39.4%) of the total PMSF volume. The presence of fat was further confirmed with plastination and confocal microscopy. Conclusions: These findings suggest that fat within the PMSF is a consistent but highly variable finding in elderly cohorts. Fat within the foot muscles may need to be considered a norm when comparing healthy and non-healthy subjects, and for therapeutic interventions to the foot. Further work is required to understand in detail the morphological and mechanical presence of fat in the foot, and compare these findings with pathological cohorts, such as sarcopenia. Additionally, future work should investigate if fat may compensate for the degeneration of the intrinsic muscles of the foot, with implications for both the use of orthotics and pain management.

Immediate and 6-week effects of wearing a knee sleeve following anterior cruciate ligament reconstruction: a cross-over laboratory and randomised clinical trial.

BACKGROUND: Rehabilitation following anterior cruciate ligament (ACL) reconstructions is based mainly on comprehensive progressive exercise programmes using a multi-dimensional approach. Elastic knee sleeves may be useful adjuncts to rehabilitation. The aim of this study was to determine the immediate and 6-week effects of wearing a knee sleeve on person-reported outcomes and function in participants who had undergone an ACL reconstruction and who had residual self-reported functional limitations. METHODS: Individuals with ACL reconstruction in the previous 6 months to 5 years were recruited. Immediate effects of a commercially-available elastic knee sleeve on single-leg horizontal hop distance were explored using a cross-over design. Following this first session, participants were randomised into a Control Group and a Sleeve Group who wore the sleeve for 6 weeks, at least 1 h daily. Outcome measures for the randomised clinical trial (RCT) were the International Knee Documentation Classification Subjective Knee Form (IKDC-SKF) score, the single-leg horizontal hop distance, and isokinetic quadriceps and hamstring peak torque. Linear mixed models were used to determine random effects. Where both limbs were measured at multiple time points, a random measurement occasion effect nested within participant was used. RESULTS: Thirty-four individuals (16 women) with ACL reconstruction completed the cross-over trial. Hop distance for the injured side during the sleeve condition increased by 3.6 % (95 % CI 0.4-6.8 %, p = 0.025). There was no evidence of differential changes between groups for the IKDC-SKF (Sleeve Group n = 15; Control Group n = 16; p = 0.327), or relative improvement in the injured side compared to the uninjured side for the physical performance measures (Sleeve Group n = 12, Control Group n = 12; three-way interaction p = 0.533 [hop distance], 0.381 [quadriceps isokinetic peak torque], and 0.592 [hamstring isokinetic peak torque]). CONCLUSIONS: Single-leg hop distance of the ACL reconstructed side improved when wearing a knee sleeve. Wearing the knee sleeve over 6 weeks did not lead to enhanced improvements in self-reported knee function, hop distance and thigh muscle strength compared to the control group. TRIAL REGISTRATION: The trial was prospectively registered with the Australia New Zealand Clinical Trials Registry No: ACTRN12618001083280 , 28 June 2018.

Wrist at risk? - Considerations derived from a novel experimental setup to assess torques during hip reaming with potential implications on the orthopedic surgeons' health.

Orthopedic surgeons endure high physical stresses when performing surgery, as large forces and torques are applied commonly. Occupational risks are consequently higher when compared to other surgical disciplines. One example is the reaming of the acetabula during total hip arthroplasty, using customized instruments. This surgery may predispose the surgeon to overuse-related wrist pathology. In this study, torques acting along the reaming tool were measured, and the resulting forces applied to the orthopedic surgeons' wrists were estimated based on the measured torque data from hip reaming. Different reamer sizes and tool velocities were analyzed to determine how both parameters may influence the torques applied at the surgeon's wrist. Using a highly standardized setup, torques were measured while the reamer was pushed into the acetabula to remove cartilage. Maximum torques and stoppage torques at blocking of the reamer were compared between feed rates and reamer sizes. Peak values of the maximum torques along the reamer axis averaged 1.5-1.8 Nm. No significant difference between maximum torques and reamer sizes was found. A significant difference in maximum torques was noted between feed rates with a large effect (p = 0.010; η2 = 0.214) and a large interaction effect (p = 0.017; η2 = 0.186). Based on this experimental setup, it can be hypothesized that the impulsive behavior of the torque when the milling tool reaches the subchondral lamella could potentially contribute to wrist pathology. These preliminary data warrant further study. Consequently, torque limiters should be implemented in reamers to minimize the risk of occupation-related pathology to the wrist.

The utility and benefit of a newly established postgraduate training course in surgical exposures for orthopedic and trauma surgery.

INTRODUCTION: Limited data exist on specialty surgical cadaver courses for graduates, their skill gain, and whether the course contents are transferable to other surgical disciplines. AIM: We present the details on the establishment of a specialist trauma and orthopedics approach course, and explore educational and career outcomes from this program. METHODS: A 3-day surgical approach course was developed, including a dissection program utilizing Thiel embalmed cadavers. The course was accredited with the local orthopedics association. Participants were assessed by survey on acquired surgical knowledge, skill, decision-making, confidence, and on self-development and effect on career. RESULTS: Thirty-one participants successfully completed the courses over 3 years. Increases in surgical skill, knowledge, surgical decision-making and confidence were reported. Skills and confidence also positively impacted on other surgical disciplines. Courses rated highly for learning outcomes; comments highlighted usefulness, applicability, and practicing opportunities, while also impacting positively on career opportunities. CONCLUSION: Surgical courses have shown being useful for the acquisition of skills, knowledge, confidence and decision-making, with a positive impact on confidence and decision-making. This information is relevant to future participants, benefactors, surgical programs, and tertiary institutions who want to establish specialist surgical courses.

In Silico Pelvis and Sacroiliac Joint Motion: Refining a Model of the Human Osteoligamentous Pelvis for Assessing Physiological Load Deformation Using an Inverted Validation Approach.

Introduction. Computational modeling of the human pelvis using the finite elements (FE) method has become increasingly important to understand the mechanisms of load distribution under both healthy and pathologically altered conditions and to develop and assess novel treatment strategies. The number of accurate and validated FE models is however small, and given models fail resembling the physiologic joint motion in particular of the sacroiliac joint. This study is aimed at using an inverted validation approach, using in vitro load deformation data to refine an existing FE model under the same mode of load application and to parametrically assess the influence of altered morphology and mechanical data on the kinematics of the model. Materials and Methods. An osteoligamentous FE model of the pelvis including the fifth lumbar vertebra was used, with highly accurate representations of ligament orientations. Material properties were altered parametrically for bone, cartilage, and ligaments, followed by changes in bone geometry (solid versus 3 and 2 mm shell) and material models (linear elastic, viscoelastic, and hyperelastic isotropic), and the effects of varying ligament fiber orientations were assessed. Results. Elastic modulus changes were more decisive in both linear elastic and viscoelastic bone, cartilage, and ligaments models, especially if shell geometries were used for the pelvic bones. Viscoelastic material properties gave more realistic results. Surprisingly little change was observed as a consequence of altering SIJ ligament orientations. Validation with in vitro experiments using cadavers showed close correlations for movements especially for 3 mm shell viscoelastic model. Discussion. This study has used an inverted validation approach to refine an existing FE model, to give realistic and accurate load deformation data of the osteoligamentous pelvis and showed which variation in the outcomes of the models are attributed to altered material properties and models. The given approach furthermore shows the value of accurate validation and of using the validation data to fine tune FE models.

Effects of Cutting the Sacrospinous and Sacrotuberous Ligaments.

The sacrospinous (SS) and sacrotuberous (ST) ligaments form a complex at the posterior pelvis, with an assumed role as functional stabilizers. Experimental and clinical research has yielded controversial results regarding their function, both proving and disproving their role as pelvic stabilizers. These findings have implications for strategies for treating pelvic injury and pain syndromes. The aim of the present simulation study was to assess the influence of altered ligament function on pelvis motion. A finite elements computer model was used. The two-leg stance was simulated, with the load of body weight applied via the fifth lumbar vertebra and both femora, allowing for nutation of the sacroiliac joint. The in-silico kinematics were validated with in-vitro experiments using the same scenario of load application following SS and ST transection in six human cadavers. Modeling of partial or complete ligament failure caused significant increases in pelvis motion. This effect was most pronounced if the SS and ST were affected with 164% and 182%, followed by the sacroiliac and iliolumbar ligaments with 123% and 147%, and the pubic ligaments with 113% and 119%, for partial and complete disruption, respectively. Simultaneous ligament transection multiplied the effects on pelvis motion by up to 490%. Unilateral ligament injury altered the motion at the pelvis contralaterally. The experiments presented here provide strong evidence for the stabilizing role of the SS and ST. A fortiori, the instability resulting from partial or complete SS and ST injury merits consideration in treatment strategies involving these ligaments as important stabilizers. Clin. Anat. 32:231-237, 2019. © 2018 Wiley Periodicals, Inc.

In-silico pelvis and sacroiliac joint motion-A review on published research using numerical analyses.

BACKGROUND: Computational models of the human pelvis have become highly useful tools to assess mechanisms of injury, diagnostics and treatment options. The purpose of this systematic literature review was to summarize existing pelvic computer models, to assess their comparability and the measures taken for experimental validation. METHODS: Research on virtual simulations of the posterior pelvis and sacroiliac joint available from the ISI Web of Knowledge, PubMed and Scopus databases available until January 2018 were included. FINDINGS: From a total of 3938 articles, 33 studies matched the criteria. Thirteen studies reported on experimental biomechanics, of which seven were parametric. Thirteen studies focused on pelvic injury and surgery, three were clinical case reports. One study assessed the effects of lumbar surgery on the sacroiliac joint, three studies on diagnostics and the non-surgical treatment of the sacroiliac joint. The mode of load application, geometry, material laws and boundary conditions varied vastly between the studies. The majority excluded the lumbosacral transition as part of pelvic biomechanics, and used isotropic linear elastic material properties. Outcomes of the analyses were reported inconsistently with negative impact on their comparability, and validation was commonly conducted by literature with varying agreement of the loading conditions. INTERPRETATION: Comparability and validation are two major issues of present computational biomechanics of the pelvis. These issues diminish the transferability of the in-silico findings into real-life scenarios. In-vitro cadaveric models remain the realistic standard to account for the present computational analyses which simplify the complex nature of musculoskeletal tissues of the pelvis.

Physiological in vitro sacroiliac joint motion: a study on three-dimensional posterior pelvic ring kinematics.

The sacroiliac joint (SIJ) is a well-known source of low back and pelvic pain, of increasing interest for both conservative and surgical treatment. Alterations in the kinematics of the pelvis have been hypothesized as a major cause of SIJ-related pain. However, definitions of both the range and the extent of physiological movement are controversial, and there are no clear baseline data for pathological alterations. The present study combined a novel biomechanical setup allowing for physiological motion of the lumbosacral transition and pelvis without restricting the SIJ movement in vitro, combined with optical image correlation. Six fresh human pelvises (81 ± 10 years, three females, three males) were tested, with bodyweight-adapted loading applied to the fifth lumbar vertebra and both acetabula. Deformation at the lumbopelvises was determined computationally from three-dimensional image correlation data. Sacroiliac joint motion under the loading of 100% bodyweight primarily consisted of a z-axis rotation (0.16°) and an inferior translation of the sacrum relative to the ilium (0.32 mm). Sacroiliac joint flexion-extension rotations were minute (< 0.02°). Corresponding movements of the SIJ were found at the lumbosacral transition, with an anterior translation of L5 relative to the sacrum of -0.97 mm and an inferior translation of 0.11 mm, respectively. Moreover, a flexion of 1.82° was observed at the lumbosacral transition. Within the innominate bone and at the pubic symphysis, small complementary rotations were seen around a vertical axis, accounting for -0.10° and 0.11°, respectively. Other motions were minute and accompanied by large interindividual variation. The present study provides evidence of different SIJ motions than reported previously when exerted by physiological loading. Sacroiliac joint kinematics were in the sub-degree and sub-millimeter range, in line with previous in vivo and in vitro findings, largely limited to the sagittal rotation and an inferior translation of the sacrum relative to the ilium. This given physiological loading scenario underlines the relevance of the lumbosacral transition when considering the overall motion of the lumbopelvis, and how relatively little the other segments contribute to overall motion.

Pelvic orthosis effects on posterior pelvis kinematics An in-vitro biomechanical study.

The sacroiliac joint (SIJ) is a well-known source of low back pain, with increasing interest for both conservative and surgical treatment. Alterations in pelvis kinematics are hypothesized as a contributor to SIJ pain and pelvic orthoses one treatment option, but their effects on the pelvis are poorly understood. Alterations in movement patterns induced by the application of pelvic orthoses were determined in five human cadaveric pelvises. Deformations were obtained from the lumbosacral transition and the bilateral SIJ, using digital image correlation and a customized routine to compute the movements within the pelvis. Significant alterations were found for the movements at the SIJ, in particular a vast increase in axial (x-axis) rotation, accompanied by increased inferior (y-) translation of the sacrum relative to the ilium. Movement patterns at the lumbosacral transition changed, causing increases in axial rotation and decreased inferior translation of L5 relative to S1. Using a physiologic mode of load application gives novel insights into the potential effects of pelvic orthoses. The results of these in-vitro experiments vary markedly from previous experiments with loading limited to two or less axes. Furthermore, the influence of pelvic orthoses on the lumbosacral transition warrants further investigation.

A novel phased-concept course for the delivery of anatomy and orthopedics training in medical education.

Integration of anatomy and clinical teaching is a theoretical ideal, yet there is a worldwide paucity of such amalgamation. These teaching models provide support for medical trainees, an important element in Germany where orthopedic intern numbers have declined and anecdotal evidence suggests disinterest in orthopedics. The aim of the study was to develop an integrated anatomy-surgical course for undergraduate medical training, assess the model developed, and explore how medical students perceive orthopedics as a career. The course was to deliver medical anatomy and clinical orthopedic training, focusing on interdisciplinary teaching and learning, vertical integration of clinical knowledge and skills, and professional interaction. Survey evaluation of the course and students' perceptions of orthopedic careers was performed, including Likert-type responses rating variables of interest. A phased-concept program of five courses, each optional and under one-week in duration, was developed parallel to the undergraduate medical program. Delivered by anatomists and surgeons, courses included biomechanics, advanced dissection, surgical approaches, casts and implants, and sports medicine. Course data indicate positive support for course format, stimulation of interest, and high clinical relevance. Students are generally interested in surgery, and identify hierarchy, lawsuits, bureaucracy and physical stress as barriers to orthopedic careers. This novel phased-concept successfully delivers combined anatomy and surgery training in a vertically-integrated format while addressing students' clinical and professional skills. The format facilitates an appreciation of potential career options in orthopedics, while fostering professional skills during medical training. Barriers to careers in orthopedics can now be addressed in future courses. Anat Sci Educ 10: 372-382. © 2016 American Association of Anatomists.

Pelvic Belt Effects on Health Outcomes and Functional Parameters of Patients with Sacroiliac Joint Pain.

INTRODUCTION: The sacroiliac joint (SIJ) is a common source of low back pain. However, clinical and functional signs and symptoms correlating with SIJ pain are widely unknown. Pelvic belts are routinely applied to treat SIJ pain but without sound evidence of their pain-relieving effects. This case-control study compares clinical and functional data of SIJ patients and healthy control subjects and evaluates belt effects on SIJ pain. METHODS: 17 SIJ patients and 17 healthy controls were included in this prospective study. The short-form 36 survey and the numerical rating scale were used to characterize health-related quality of life in patients in a six-week follow-up and the pain-reducing effects of pelvic belts. Electromyography data were obtained from the gluteus maximus, biceps femoris, rectus femoris and medial vastus. Alterations of muscle activity, variability and gait patterns were compared in patients and controls along with the belts' effects in a dynamic setting when walking. RESULTS: Significant improvements were observed in the short-form 36 survey of the SIJ patients, especially in the physical health subscores. Minor declines were also observed in the numerical rating scale on pain. Belt-related changes of muscle activity and variability were similar in patients and controls with one exception: the rectus femoris activity decreased significantly in patients with belt application when walking. Further belt effects include improved cadence and gait velocity in patients and controls. CONCLUSIONS: Pelvic belts improve health-related quality of life and are potentially attributed to decreased SIJ-related pain. Belt effects include decreased rectus femoris activity in patients and improved postural steadiness during locomotion. Pelvic belts may therefore be considered as a cost-effective and low-risk treatment of SIJ pain. TRIAL REGISTRATION: ClinicalTrials.gov NCT02027038.

Teaching surgical exposures to undergraduate medical students: an integration concept for anatomical and surgical education.

BACKGROUND: Decreasing numbers of students are interested in starting a surgical career, posing substantial challenges to patient care in the next years. The anatomy course is one of the key subjects in medical training, especially in surgical disciplines. Innovative teaching concepts that integrate surgically relevant anatomy and manual dexterity might help boost student interest in surgery. METHODS: A preclinical workshop entitled "Surgical exposures" was developed. A team of anatomists and surgeons introduced the surgical exposures, demonstrating the procedures on Thiel-fixed body donors. Following this introduction, students practiced the exposures in an operating room-like manner. A six-point Likert scale was used to evaluate the workshop and to compare it to the first-year dissection course. RESULTS: The overall evaluation result for the surgical exposures was excellent, proving to be a significantly better result when compared to the first-year dissection course. The students were more satisfied with the teaching time invested by the peers and regarded the workshop as clinically highly relevant. Furthermore, they felt that questions were addressed better and that the overall atmosphere was better than in the gross anatomy course. Subject to criticism was the course size and practicing time in both cases. DISCUSSION: The surgical exposures workshop provides preclinical students with clinically relevant anatomy and manual dexterity. It may positively influence the decision to follow a surgical career. This course, however, requires extensive teaching resources. The given concept may help implement practical medical skills in the preclinical curriculum, strengthening the professional identity of surgeons and anatomists.

Pelvic belt effects on sacroiliac joint ligaments: a computational approach to understand therapeutic effects of pelvic belts.

BACKGROUND: The sacroiliac joint is a widely described source of low back pain. Therapeutic approaches to relieve pain include the application of pelvic belts. However, the effects of pelvic belts on sacroiliac joint ligaments as potential pain generators are mostly unknown. OBJECTIVES: The aim of our study was to analyze the influence of pelvic belts on ligament load by means of a computer model. STUDY DESIGN: Experimental computer study using a finite element method. METHODS: A computer model of the human pelvis was created, comprising bones, ligaments, and cartilage. Detailed geometries, material properties of ligaments, and in-vivo pressure distribution patterns of a pelvic belt were implemented. The effects of pelvic belts on ligament strain were computed in the double-leg stance. RESULTS: Pelvic belts increase sacroiliac joint motion around the sagittal axis but decrease motion around the transverse axis. With pelvic belt application, most of the strained sacroiliac joint ligaments were relieved, especially the sacrospinous, sacrotuberous, and the interosseous sacroiliac ligaments. Sacroiliac joint motion and ligament strains were minute. These results agree with validation data from other studies. LIMITATIONS: Assigning homogenous and linear material properties and excluding muscle forces are clear simplifications of the complex reality. CONCLUSIONS: Pelvic belts alter sacroiliac joint motion and provide partial relief of ligament strain that is subjectively marked, although minimal in absolute terms. These findings confirm theories that besides being mechanical stabilizers, the sacroiliac joint ligaments are likely involved in neuromuscular feedback mechanisms. The results from our computer model help with unraveling the therapeutic mechanisms of pelvic belts.

Finite element analysis of acetabular fractures--development and validation with a synthetic pelvis.

Acetabular fracture presents a challenging situation to trauma surgeons today due to its complexity. Finite element (FE) models can be of great help as they can improve the surgical planning and post surgery patient management for those with acetabular fractures. We have developed a non-linear finite element model of the pelvis and validated its fracture prediction capability with synthetic polyurethane pelves. A mechanical experiment was performed with the synthetic bones and fracture loads and patterns were observed for two different loading cases. Fracture loads predicted by our FE model were within one standard deviation of the experimental fracture loads for both loading cases. The incipient fracture pattern predicted by the model also resembled the actual pattern from the experiment. Although it is not a complete validation with human cadaver bones, the good agreement between model predictions and experimental results indicate the validity of our approach in using non-linear FE formulation along with contact conditions in predicting bone fractures.

Early results with the Genesis II Posterior Stabilized High Flexion knee prosthesis. A one year follow-up study.

The aim of this prospective study was to assess the range of motion (ROM) achieved with the Genesis II Posterior Stabilized High Flexion knee prosthesis. The ROM was compared with that of a historical study group with the standard PS insert and an identical study design. Sixty three patients with primary knee osteoarthritis (37 female, 26 male; average age: 67.0 years, average BMI 31.2) underwent primary cemented TKA with a PS high flex insert. The surgery was performed by one senior author using a mini-midvastus approach. During the follow-up no statistically significant difference in maximal flexion was found between 14 weeks (average flexion = 120 degrees, SD = 11.2) and 65 weeks postoperatively (average flexion = 122 degrees, SD = 8.9). The radiographic evaluation showed no influence of the implant positioning on the final flexion. Compared to the results obtained in a 5 year follow-up study of 100 cases in combination with the PS standard insert, the improvement in final flexion range found in this study did not appear not to be great enough to generally recommend the PS high flex insert in terms of a proven higher flexion result.

The flexible Triac-Brace for conservative treatment of idiopathic scoliosis. An alternative treatment option?

The flexible Triac-Brace was developed to improve cosmetic appearance and wearing comfort. It was evaluated in this study with respect to primary curve correction in idiopathic scoliosis (IS). Twenty patients (15 girls, 5 boys, mean age: 12.5) with a diagnosis of IS were treated with the Triac-Brace. Lumbar curves showed an initial average Cobb angle of 26 degrees (SD = 9 degrees), thoracic curves of 25 degrees (SD = 7 degrees). After 6.2 weeks the primary curve correction was measured (Cobb). Further radiological follow-up was done every 6 months during the average wearing time of 15 months. Cosmesis and wearing comfort were assessed by a valid scoring system (Quality of Life Profile for Spine Deformities). We observed a primary correction of 41% in lumbar curves (n = 12) (significant, t-test), and 10% in thoracic curves (n = 17) (not significant, t-test). An increase in correction over time as reported by Veldhuizen et al was not seen. Curve progression was noted in five patients (average 12 degrees). The scores for cosmesis (4.2/5) and flexibility of the back (4.6/5) were high. Ninety percent of the patients reported a wearing time of 22-23 h. We do not recommend treatment of thoracic or double curves with the Triac-Brace. Larger studies are necessary to assess the effectiveness in lumbar curves. The improved wearing comfort is a potential advantage.

Comparison of operative time and accuracy using conventional fixed navigation cutting blocks and adjustable Pivotal cutting blocks.

Computer-assisted navigation in total knee arthroplasty has been shown to improve implant positioning and may lead to improved patient outcomes. The purpose of this study was to assess differences in time and accuracy using a navigation system with either a conventional (20 knees) or specially designed (20 knees) system of cutting blocks. The time needed for fixing and positioning the specially designed blocks averaged 2.9 minutes, compared to 6.4 minutes for the conventional blocks (p < 0.001). In the coronal plane, the mean angular difference between the instrument slot and the resected bone was smaller for the specially designed blocks than for the conventional blocks. This difference was significant for both the femoral (p = 0.007) and tibial (p = 0.028) cuts. These encouraging results show the need for further study of navigation in total knee arthroplasty.

CT-based and fluoroscopy-based navigation for cup implantation in total hip arthroplasty (THA).

The goal of using navigation systems in total hip arthroplasty (THA) is to minimise malpositioned components, increase range of motion, and decrease the risk of dislocation, which may result in long-term stability. The two systems used to navigate the acetabular component are CT-based and fluoroscopy-based. Between May 2001 and May 2002, surgery was performed on 153 patients using navigation systems for cup positioning. The CT-based system was used in 46 patients and fluoroscopy-based system in 107. The diagnoses were primary osteoarthritis in 120 of the patients, and secondary osteoarthritis following congenital and post-traumatic deformities in 33. The outcomes of the operations were investigated clinically and radiologically. Mean variation of the postoperative abduction angle to the preoperative planning was 2.7 (0-8) after CT-based navigation and 3.9 (0-9) after fluoroscopy-based navigation. After the first 30 surgeries with each system, the operating time was extended by 9 minutes using the CT-based system and by 13 minutes with the fluoroscopy-based system compared to hand implantation. Also, the preoperative planning using the CT-based system was more time-consuming. No additional planning was necessary with the fluoroscopy-based system was used. Both systems were accurate and provided an improved reproducible quality. The CT-based system provided a link between the preoperative planning and intraoperative placement of acetabular components. Only a minimal difference was noted when compared to the fluoroscopy-based procedure; however, the time-consuming set up remains a problem. The advantage in using the CT-based system is the three-dimensional feed back of anatomic landmarks, but a disadvantage is the time-consuming preoperative procedure (CT-scan, data transfer, planning). For this reason the CT-based method should be performed in cases of congenital and post-traumatic deformities. The fluoroscopy-based method is easier to handle in routine cases with normal anatomy or lesser deformities. Both systems present an excellent additional tool to improve reproducible quality in THA.