Beeinflussung biomechanischer Eigenschaften lumbaler Bewegungssegmente durch unterschneidende Spinalkanaldekompression und dynamische Implantate

Die Unterschneidende Dekompression (UD) fuehrt postoperativ haeufig zu lumbaler Segmentinstabilitaet. Betroffene Bewegungssegmente (BS) werden fusioniert oder mit dynamischen Implantaten (DI) stabilisiert. Diese biomechanische Arbeit stellt den Einfluss der UD und den Effekt von DI (Wallis (DIW) und Dynesys (DID)) auf den Bewegungsumfang (Range of Motion = ROM) humaner, lumbaler BS (n=21) dar. Im Pure-Moment-Verfahren (5 Nm) wurden ROM und Neutrale Zone (NZ) in Flexion-Extension (FE), Lateralflexion (LF) und axialer Rotation (AR) fuer vier Zustaende bestimmt: 1) Nativ, 2) UD, 3) UD + DIW 4) UD + DID. Fazit: Die Implantation von DI nach UD erzielt eine signifikante Abnahme der ROM in allen Ebenen. Die FE wird durch beide DI stark eingeschraenkt. Zusaetzlich zur FE fuehrt DID zu einer erheblichen Begrenzung der LF. Die AR wird zwar von beiden DI signifikant eingeschraenkt, jedoch nicht klinisch relevant

Results of advanced core decompression in patients with osteonecrosis of the femoral head depending on age and sex—a prospective cohort study

Background Core decompression is a common surgical technique to treat osteonecrosis of the femoral head. The aim of this study is to evaluate the effect of the parameters “age” and “sex” on the outcome of this type of treatment. Methods A prospective cohort study was performed. Eighty-six osteonecrotic hips with a mean follow-up of 32.5 months (± 24.8) after advanced core decompression were analysed regarding age- and sex-dependent treatment failure. Additionally, the modified Harris Hip Score and Numeric Rating Scale were compared regarding the parameters age and sex. Results The mean hip survival of the male participants was 51.3 months (39.4% treatment failure), whereas females presented a longer, thus not significant, mean survival of 61.4 months (30% therapy failure; p = 0.48). The further evaluation revealed significantly better survival in the patients aged < 40 years (mean survival 66.09 months, 16% treatment failure) in comparison to those aged ≥ 40 years (mean survival 50.14 months, 46% therapy failure; p = 0.03). The modified Harris Hip Score and Numeric Rating Scale results of patients whose treatment did not fail during the study period were similar, irrespective of the patient’s sex or age. Conclusions The study shows that the number of therapy failures is significantly higher in older patients, with 40 years of age marking the borderline. Patients’ sex does not seem to affect the outcome of treatment, and postoperative clinical scores appear to be identical with individuals not affected by therapy failure. Since age and sex are unalterable parameters, the study helps to provide valuable predictions regarding the chances of long-term hip survival after treatment of osteonecrosis

Evaluation of intra- and interobserver reliability in the assessment of the ‘critical trochanter angle’

Background: The recently described 'critical trochanter angle' (CTA) is a novel parameter in the preoperative risk assessment of stem malalignment in total hip arthroplasty. As its reproducibility needs to be evaluated, the given study aims to investigate intra- and interobserver reliability. It is hypothesized that both analyses justify the clinical use of the CTA. Methods: A total of 100 pelvic radiographs obtained prior to total hip arthroplasty were retrospectively reviewed by four observers with different levels of clinical experience. The CTA was measured twice by each observer at different occasions in the previously described technique. Intra- and interobserver reliability was evaluated using intraclass correlation coefficients (ICC) with confidence intervals (CI) and the Bland-Altman approach. Results: The mean CTA in both measuring sequences was 20.58° and 20.78°. The observers' means ranged from 17.76° to 25.23°. Intraobserver reliability showed a mean difference of less than 0.5° for all four observers (95% limit of agreement: - 7.70-6.70). Intraobserver ICCs ranged from 0.92 to 0.99 (CI 0.88-0.99). For interobserver variation analysis, ICCs of 0.83 (CI 0.67-0.90) and 0.85 (CI 0.68-0.92) were calculated. Conclusion: Analyses concerning intra- and interobserver reliability in the assessment of the CTA showed 'very good' and 'good' results, respectively. In view of these findings, the use of the CTA as an additional preoperative parameter to assess the risk of intraoperative stem malalignment seems to be justified

Development of Open Backend Structures for Health Care Professionals to Improve Participation in App Developments: Pilot Usability Study of a Medical App

BACKGROUND: Efficient digitization in medicine still is in its infancy but undeniably has great potential for current and future challenges in health care. Thus far, the rollout of medical apps has not resulted in widespread use of smartphones in the German health care sector-the reasons for this have not been clarified so far. Nevertheless, the lack of user involvement in the development process and content creation might contribute to low acceptance of these products. OBJECTIVE: This study aims to outline an approach to involve medical expertise without any coding knowledge for developing medical app content and functions. METHODS: An end user-operable backend was built. Its usability was evaluated using a usability evaluation test protocol. The results of the usability tests were evaluated by the app development team, and the usability test was repeated for optimizing backend usability. In total, 40 criteria to measure the ease of app usage were defined a priori. The usability test comprised 20 tasks that had to be fulfilled. Usability tasks were analyzed for completion, dropout, and test duration. Due to the COVID-19 pandemic, digital videoconferencing platforms (Zoom and QuickTime Player) were used to complete usability questionnaires. Finally, several backend-based apps for several specialties (infectiology, plastic and reconstructive surgery, and orthopedics) were developed by health care professionals as prototypes. RESULTS: Initial usability testing was conducted with 5 participants (4 men and 1 woman; mean age 39.2, SD 5.97 years). All of them could complete the assigned backend tasks with only a few workflow interruptions and some minor errors. After usability optimization, the workflow completion time decreased from 5.03 minutes to 3.50 minutes, indicating a time saving. The basic backend structure was clear to all test users and the handling was intuitive to learn. Some minor errors in the backend occurred during the test rounds. The apps developed using the aforementioned approach are in clinical use as a proof of concept. CONCLUSIONS: Backends offering operability for medical professionals might have great potential for app development in the mobile health sector. Sophisticated and time-saving usability are pivotal for the acceptance of medical software, as illustrated by the backend-based apps presented herein, which are in clinical use as a proof of concept. Basic interventions are essential and sufficient for adequate usability optimization. Practicable, well-structured software usability evaluation is possible based on the usability evaluation test protocol

Beeinflussung biomechanischer Eigenschaften lumbaler Bewegungssegmente durch unterschneidende Spinalkanaldekompression und dynamische Implantate

Die Unterschneidende Dekompression (UD) fuehrt postoperativ haeufig zu lumbaler Segmentinstabilitaet. Betroffene Bewegungssegmente (BS) werden fusioniert oder mit dynamischen Implantaten (DI) stabilisiert. Diese biomechanische Arbeit stellt den Einfluss der UD und den Effekt von DI (Wallis (DIW) und Dynesys (DID)) auf den Bewegungsumfang (Range of Motion = ROM) humaner, lumbaler BS (n=21) dar. Im Pure-Moment-Verfahren (5 Nm) wurden ROM und Neutrale Zone (NZ) in Flexion-Extension (FE), Lateralflexion (LF) und axialer Rotation (AR) fuer vier Zustaende bestimmt: 1) Nativ, 2) UD, 3) UD + DIW 4) UD + DID. Fazit: Die Implantation von DI nach UD erzielt eine signifikante Abnahme der ROM in allen Ebenen. Die FE wird durch beide DI stark eingeschraenkt. Zusaetzlich zur FE fuehrt DID zu einer erheblichen Begrenzung der LF. Die AR wird zwar von beiden DI signifikant eingeschraenkt, jedoch nicht klinisch relevant

Transforaminal lumbar interbody fusion with expandable cages: Radiological and clinical results of banana-shaped and straight implants

Purpose: Expandable titanium transforaminal lumbar interbody fusion (TLIF) devices are a relatively new group of implants allowing restoration of lumbar lordosis (LL) and thus improvement of sagittal alignment. The purpose of our study is to compare clinical and radiological results of two different expandable TLIF devices. Materials and Methods: In a retrospective study, patients who underwent TLIF surgery with a banana-shaped or straight TLIF cage in our spine center were analyzed. Primary outcome was change of disc height (DH), segmental lordosis angle (SLA), and lumbar lordotic angle (LLA). Moreover, basic patients parameters and cage subsidence were evaluated. Results: Sixty-one patients were studied (33 banana-shaped and 28 straight cages). DH changed in the banana group from 4.8 mm (standard deviation SD 2.5) to 10.4 (SD 2.4) and in the straight cage group from 6.2 mm (SD 2.5) to 9.6 mm (SD 1.7). The difference was statistically significant (P = 0.03). In addition, SLA correction was higher in the banana group with 5.8° (SD 5.0)–3.7° (SD 3.6), but not significant. LLA improved in the straight group with 5.2 (SD 6.4) compared to 3.7° (SD 5.8) in the banana group. We found subsidence in four patients (6.6%) in the banana-shaped group and nine cases (14.8%) in the other group. Conclusions: Expandable titanium implants show similar improvements in restoring segmental and global lordosis. Banana-shaped expandable cages offer higher potency restoring the intervertebral DH and show less rates of subsidence compared to straight expandable cages

Bone Substitutes in Orthopaedic Surgery: Current Status and Future Perspectives

AbstractBone replacement materials have been successfully supplied for a long time. But there are cases, especially in critical sized bone defects, in which the therapy is not sufficient. Nowadays, there are multiple bone substitutes available. Autologous bone grafts remain the “gold standard” in bone regeneration. Yet, donor-site morbidity and the available amount of sufficient material are limitations for autologous bone grafting. This study aimed to provide information about the current status in research regarding bone substitutes. We report on the advantages and drawbacks of several bone substitutes. At the end, we discuss the current developments of combining ceramic substitutes with osteoinductive substances.</jats:p

Functional Knee Performance Differences in Handball are Depending on Playing Class

AbstractHandball is one of the most traumatic sports. The knee is the most commonly injured joint. To prevent knee injuries, optimal functional knee stability is of great importance. Nevertheless, there is still no consensus about objective criteria for knee function. Depending on playing class, injury rates seem to differ. The purpose of this study was to evaluate knee function in handball depending on playing class and to establish reference data for functional knee stability. 261 handball players (25.1±5.8 years) performed a functional test including two- and one-legged stability assessments, jump tests, speed and agility analysis. Except for balance, differences between playing classes were detected in all tests with superior performance of high-class players (Germany’s 1st (“Oberliga”) and 2nd (“Verbandsliga”) non-elite playing class). High-class players achieved significant better results in jumping height (p≤0.011–0.029), relative power per body weight in the two-legged counter movement jump (p≤0.023) and speed and agility tests (p≤0.001). This study illustrates the relevance of playing class specific screening. Sports and playing class-specific databases will help to identify individual deficits and strengths in order to prevent injury and increase performance. Moreover, objective criteria for return to sports can be established.</jats:p