One-level open vs. minimally invasive transforaminal lumbar interbody fusion: a systematic review and advanced meta-analytic assessment of prospective studies with at least two years follow-up.

PURPOSE: To determine whether the open or the minimally invasive transforaminal lumbar interbody fusion (O-TLIF, MI-TLIF) is the favored treatment, we provide first meta-analyses using prospective studies with at least two years follow-up only and present the clinical relevance of statistical results for the first time. METHODS: After a systematic review of six databases, we conducted 10 meta-analyses of randomized controlled trials (RCTs) and 10 meta-analyses of eligible prospective studies (EPSs) to compare fusion rate, patient-reported outcome measures (back pain (B-VAS), leg pain, Oswestry Disability Index (ODI)), for the first time safety outcome measures as operative and postoperative complications per case, and the perioperative outcome measures estimated blood loss (EBL), operation time and length of hospital stay (LOS). The clinical relevance was assessed by overall effect sizes (OESs) of statistically significant meta-analytic results. RESULTS: In our meta-analyses of RCTs, MI-TLIF is statistically significantly superior in ODI, EBL and LOS, with clinically meaningful OESs only in EBL and LOS. In meta-analyses of EPSs, MI-TLIF is statistically significantly superior in B-VAS, postoperative complications per case, EBL and LOS, all with clinically meaningful OESs except for B-VAS. The meta-analyses of remaining outcome measures present statistically nonsignificant results. In a descriptive analysis of complications, postoperative wound infections predominate in O-TLIF and hardware malposition in MI-TLIF. CONCLUSION: After at least two years, O-TLIF and MI-TLIF can be considered equally efficacious, which simplifies surgeons' decision between both treatments, however, with the safety outcome measure postoperative complications per case and the perioperative outcome measures EBL and LOS in favor of MI-TLIF. LEVEL OF EVIDENCE I: Well conducted meta-analyses, systematic reviews, or RCTs with a low risk of bias.

Advanced meta-analyses comparing the three surgical techniques total disc replacement, anterior stand-alone fusion and circumferential fusion regarding pain, function and complications up to 3 years to treat lumbar degenerative disc disease.

PURPOSE: The purpose of our meta-analyses is to find the most appropriate surgical technique treating lumbar degenerative disc disease (DDD). Spinal fusion is the conventional treatment for lumbar DDD. Total disc replacement (TDR) has been developed to avoid negative effects of fusions by preserving functionality. To our knowledge, there is no evaluation comparing meta-analytically the clinical results of three different surgical techniques with same inclusion and exclusion criteria for treating DDD. METHODS: The surgical techniques TDR, anterior lumbar interbody fusion (ALIF) and circumferential fusion (CFF) are pairwise meta-analytically compared. Primary outcomes are pain measured by the Visual Analogue Scale (VAS) and function measured by the Oswestry Disability Index (ODI). Secondary outcomes are the mean number of complications per case (MNOC) at surgery and follow-up and the overall MNOC. RESULTS: In our systematic search, we found finally six prospective studies with the minimum follow-up of two years: four randomized controlled trials and two cohort studies. In VAS and ODI, TDR is proved to be superior to ALIF and CCF (p < 0.05), whereat ALIF is more effective than CFF without statistical significance. CFF presents the best result in complications with the lowest overall MNOC (0.1), followed by TDR (1.2) and ALIF (1.5). CONCLUSION: According to our meta-analyses, we regard TDR to be the most appropriate surgical technique treating DDD, followed by ALIF. Further studies with a longer follow-up are needed using the same methodical approach to strengthen the VAS and ODI results and to explain the discrepant result to complications.

Severe back pain in elite athletes: a cross-sectional study on 929 top athletes of Germany.

PURPOSE: The cross-sectional study evaluates the incidence, localization, treatment, and influencing factors of back pain (BP) in Germany's elite athletes. METHODS: An online questionnaire was sent out to 3564 top athletes. We used the VAS to identify the intensity of BP and SPSS for statistical analyses. RESULTS: 929 athletes responded. 514 (55.3%) had BP within the last 12 months, mainly located in the lumbar spine (n = 293, 56.1%). The average pain intensity was 5.75/10. Back-affecting exercise and additional burdens (e.g. at their place of work) did not increase the intensity of BP. When dividing the athletes into two groups according to the BP intensity, BP did not correlate with gender, age or BMI. CONCLUSION: At least every tenth athlete suffers temporarily from low BP at a level at which spine surgery could be the only option to relieve the pain. BP occurs independently of back-affecting training and additional stress. Further evaluation is needed to identify factors for avoiding severe BP in top athletes.

Infection Prevention and the Protective Effects of Unidirectional Displacement Flow Ventilation in the Turbulent Spaces of the Operating Room.

BACKGROUND: Unidirectional displacement flow (UDF) ventilation systems in operating rooms are characterized by a uniformity of velocity ≥80% and protect patients and operating room personnel against exposure to hazardous substances. However, the air below the surgical lights and in the surrounding zone is turbulent, which impairs the ventilation system's effect. AIM: We first used the recovery time (RT) as specified in International Organization for Standardization 14644 to determine the particle reduction capacity in the turbulent spaces of an operating room with a UDF system. METHODS: The uniformity of velocity was analyzed by comfort-level probe grid measurements in the protected area below a hemispherical closed-shaped and a semi-open column-shaped surgical light (tilt angles: 0°/15°/30°) and in the surrounding zone of a research operating room. Thereafter, RTs were calculated. RESULTS: At a supply air volume of 10,500 m3/h, the velocity, reported as average uniformity ± standard deviation, was uniform in the protected area without lights (95.8% ± 1.7%), but locally turbulent below the hemispherical closed-shaped (69.3% ± 14.6%), the semi-open column-shaped light (66.9% ± 10.9%), and in the surrounding zone (51.5% ± 17.6%). The RTs ranged between 1.1 and 1.7 min below the lights and 3.5 ± 0.28 min in the surrounding zone and depended exponentially on the volume flow rate. CONCLUSIONS: Compared to an RT of ≤20 min as required for operating rooms with mixed dilution flow, particles here were eliminated 12-18 times more quickly from below the surgical lights and 5.7 times from the surrounding zone. Thus, the effect of the lights was negligible and the UDF's retained its strong protective effect.

Meta-analyses comparing spine simulators with cadavers and finite element models by analysing range-of-motion data before and after lumbar total disc replacement.

BACKGROUND: Range-of-motion (ROM) data generated by the in vitro test methods of spine simulators with cadavers (SSCs) and finite element models (FEMs) are used alternatively and complementarily for in vitro evaluations. AIM OF REVIEW: Our purpose is to compare exemplary segmental ROM data from SSCs and FEMs before and after ball-and-socket total disc replacement (bsTDR) to determine whether the two test methods provide the same data for the same evaluation subjects. KEY SCIENTIFIC CONCEPTS OF REVIEW: We performed 70 meta-analyses (MAs) and 20 additional comparative analyses based on data from 21 SSC studies used for 39 MAs and 16 FEM studies used for 31 MAs. Only fifty-nine percent (n = 23/39) of SSC MAs show a restored ROM after bsTDR, whereas in FEM MAs, the ROM is restored in ninety percent (n = 28/31). Among the analyses comparing data from the same spinal segments, motion directions and bsTDR, SSC and FEM data are significantly different in ten percent (n = 2/20). According to our results, data generated by SSCs and FEMs cannot be used as alternative and complementary data without restriction. The quality of the evaluation methods itself as well as potential technical reasons for the discrepant results were not our evaluation target. Further SSC and FEM data should be compared using the same approach.

Clinical efficacy and compatibility of allogeneic avital tissue transplants sterilized with a peracetic acid/ethanol mixture.

In the course of the past 20 years a quantity of approximately 60,000 allogeneic avital tissue grafts sterilized with the peracetic acid-ethanol method (PES) were transplanted successfully. Based on a retrospective report of clinical experience of the years 1997-2001 on the overall scope of tissue grafts manufactured by the Tissue Banks of the University Hospital Charité and the German Institute for Cell and Tissue Replacement, the clinical efficacy and side effects of 18.3% (3.087/16.823) of all transplants were studied. Cancellous (1.601/3.087) and cortical (291/3.087) bone transplants as well as amnion (1.027/3.087) constituted the greatest part. In 91% of the examined patients (2.369/2.592) tissue integration ratios ranging from good up to very well could be observed. The transplant function of defect replacement or of a spacer respectively could be obtained for all types of tissue. The clinical effect caused by the transplant resulted in more than 99% of the transplants in primary integration or in the desired aim of the therapy (defect replacement, stabilization in case of palliative operations, etc.). In less than 1% (9/2.592) of cases a secondary healing occurred for cancellous bone transplantations or, revisional operations became necessary. In all cases severe side effects, in particular transmission of infectious diseases or transplant rejections, were not observed.

Indications for lumbar total disc replacement: selecting the right patient with the right indication for the right total disc.

SUMMARY OF BACKGROUND DATA: As with any surgery, care should be taken to determine patient selection criteria for lumbar TDR based on safety and optimizing outcome. These goals may initially be addressed by analyzing biomechanical implant function and early clinical experience, ongoing evaluation is needed to refine indications. OBJECTIVE: The purpose of this work was to synthesize information published on general indications for lumbar TDR. A secondary objective was to determine if indications vary for different TDR designs. METHODS: A comprehensive literature search was conducted to identify lumbar TDR articles. Articles were reviewed and patient selection criteria and indications were synthesized. RESULTS: With respect to safety, there was good agreement in the literature to exclude patients with osteopenia/osteoporosis or fracture. Risk of injury to vascular structures due to the anterior approach was often addressed by excluding patients with previous abdominal surgery in the area of disc pathology or increased age. The literature was very consistent on the primary indication for TDR being painful disc degeneration unresponsive to at least 6 months of nonoperative care. Literature investigating the impact of previous spine surgery was mixed; however, prior surgery was not necessarily a contra-indication, provided the patient otherwise met selection criteria. The literature was mixed on setting a minimum preoperative disc height as a selection criterion. There were no publications investigating whether some patients are better/worse candidates for specific TDR designs. Based on the literature a proposal for patient selection criteria is offered. CONCLUSIONS: Several TDR indications and contra-indications are widely accepted. No literature addresses particular TDR design being preferable for some patients. As with any spine surgery, ongoing evaluation of TDR outcomes will likely lead to more detailed general and device design specific indications.

In vivo deformation, surface damage, and biostability of retrieved Dynesys systems.

STUDY DESIGN: Retrospective retrieval analysis. OBJECTIVE: To evaluate wear, deformation and biodegradation within retrieved polycarbonate urethane (PCU) components of Dynesys systems. SUMMARY OF BACKGROUND DATA: The Dynesys Dynamic Stabilization System (Zimmer Spine) consists of pedicle screws (Ti alloy), polycarbonate urethane (PCU) spacers, and a polyethylene-terephthalate cord. METHODS: Seventeen retrieved (mean implantation: 2.5 years, range: 0.7-7.0 years) and 2 exemplar implant systems were available. Reasons for revision were persistent pain (16/17), infection (1/17), and/or screw loosening (11/17), with 1/17 case of implant migration. Optical microscopy, microCT, and scanning electron microscopy were conducted to evaluate PCU spacer wear and deformation. Attenuated total reflectance Fourier transform infrared spectroscopy was used to assess spacer surface chemical composition. RESULTS: Retrieved spacer components exhibited permanent bending deformation (mean: 4.3°, range: 0.0°-15.8°). We observed evidence of PCU spacer contact with pedicle screws, cords, and surrounding bony structures (74/75, 69/75, and 51/75 spacers, respectively). Relatively infrequent damage modes included PCU fracture (1/75 spacers) or cracking (2/75 spacers), as well as pedicle screw fracture (3/103 screws). PCU degradation products were identified in 10/75 spacers, which represented retrievals having significantly longer implantation times (mean: 4.3 years, range: 1.0-7.0 years). Of these spacers, 8/10 had degradation peaks identified along the side of the spacer where the material would have been in contact with bodily fluid. CONCLUSION: PCU spacers from retrieved Dynesys systems exhibited permanent deformation, focal regions of in vivo wear and surface damage. Chemical changes associated with PCU biodegradation were associated with longer-term retrievals. The most frequently observed complication was pedicle screw loosening, with 3 incidences of screw breakage in 2 patients. These retrieval data provide a crucial basis for developing in vitro tests to simulate in vivo damage and degradation of posterior dynamic motion preservation implants. Longer-term retrievals, as well as retrievals that include more recent design features (e.g., HA coating), will be useful to provide a greater context for the clinical implications of our short-term observations.

Frisbee - the first artificial cervical disc of 3RD generation / Frisbee - o primeiro disco cervical artificial de 3ª geração / Frisbee - el primer disco cervical artificial de 3ra generación

OBJECTIVE: The current cervical disc arthroplasty is limited by postoperative facet joint arthritis, heterotopic ossification and segmental kyphosis. The total Frisbee disc, which has an upper convex/concave non-spherical surface and a lower flat sliding surface, is a new approach for improved outcomes. Prior to clinical application, safety and suitability tests are required. METHODS: The Frisbee is the first 3rd generation disc according to a new classification of total disc because it can precisely mimic the segmental ROM, including the soft limitation of axial rotation. The ISO 18192-1 test was carried out to determine the rate of wear debris. A FE model was used to assess the safety of prosthetic components. In the sagittal plane several variables to determine the most favorable lordotic angle were evaluated. RESULTS: Two angled prosthetic plates are safer than one sliding angled core to prevent the displacement. The lordosis of 7° of the Frisbee leads to kyphosis of no more than 2° without reduction of the ROM. The wear rate of the Frisbee is five times smaller compared to an FDA-approved disc with a spherical sliding surface. CONCLUSIONS: Based on the test results, the clinical application of Frisbee can now be studied. The postoperative kyphosis observed with other devices is not an issue with the Frisbee design. Physiological ROM is combined with the significant reduction of wear debris. For these reasons the Frisbee has the potential to provide a better balanced segmental loading reducing the degeneration of the joint surface and heterotopic ossification. .

OBJETIVO: A atual artroplastia de disco cervical é limitada pela artrite facetária pós-operatória, pela ossificação heterotópica e pela cifose segmentar. O disco Frisbee total, que tem face superior não-esférica convexo-côncava e face inferior plana e deslizante, é uma nova modalidade para melhores resultados. Antes da aplicação clínica, são necessários testes de segurança e adequação. MÉTODOS: O Frisbee é o primeiro disco de 3ª geração, de acordo com uma nova classificação de disco total, pois pode imitar precisamente a AM segmentar, incluindo a limitação suave da rotação axial. O teste ISO 18192-1 foi realizado para determinar a taxa de resíduos de desgaste. Um modelo de FE foi utilizado para avaliar a segurança dos componentes protéticos. No plano sagital, foram avaliadas diversas variáveis para determinar o ângulo de lordose mais favorável. RESULTADOS: Duas placas protéticas anguladas são mais seguras para evitar o deslocamento do que um núcleo angulado deslizante. A lordose de 7° do Frisbee leva a uma cifose de não mais de 2°, sem redução da AM. A taxa de desgaste do Frisbee é cinco vezes menor em comparação com um disco aprovado pela FDA, com superfície de deslizamento esférica. CONCLUSÕES: Com base nos resultados dos testes, a aplicação clínica do Frisbee pode, agora, ser estudada. A cifose pós-operatória, observada com outras próteses não constitui problema com o desenho do Frisbee. A AM fisiológica é combinada com a redução significativa dos detritos de desgaste. Por essas razões o Frisbee tem o potencial de fornecer uma carga segmentar mais equilibrada, reduzindo a degeneração da face articular e a ossi...

OBJETIVO: La actual artroplastia de disco cervical es limitada por la artritis facetaria posoperatoria, por la osificación heterotópica y por la cifosis segmentaria. El disco Frisbee total, que tiene faz superior no esférica, convexo-cóncava e faz interior plana y deslizante, es una nueva modalidad para mejores resultados. Antes de la aplicación clínica, se necesita de pruebas de seguridad y adecuación. MÉTODOS: El Frisbee es el primer disco de la tercera generación, de acuerdo con una nueva clasificación de disco total, pues puede imitar, con precisión, la AM segmentaria, incluyendo la limitación suave de la rotación axial. La prueba ISO 18192-1 fue realizada para determinar la tasa de residuos de desgaste. Un modelo de FE fue utilizado para evaluar la seguridad de los componentes protéticos. En el plano sagital, se evaluaron diversas variables para determinar el ángulo más favorable de lordosis. RESULTADOS: Dos placas protéticas anguladas son más seguras, para evitar el desplazamiento, que un núcleo angulado deslizante. La lordosis de 7mo del Frisbee lleva a una cifosis de no más de 2do, sin reducción de la AM. La tasa de desgaste del Frisbee es cinco veces menor en comparación con un disco aprobado por la FDA, con superficie esférica de deslizamiento. CONCLUSIONES: Con base en los resultados de las pruebas, la aplicación clínica del Frisbee puede ser estudiada en la actualidad. La cifosis posoperatoria, observada con otras prótesis, no es un problema con el diseño del Frisbee. La AM fisiológica se combina con la reducción significativa de los detritos de desgaste. Por esas razones, el Frisbee tiene el potencial para suministrar una carga segmentaria más equilibrada, reduciendo la degeneración de la fase articular y la osificación heterotópica. .

Optimal minimally traumatic approach for the SB Charité Artificial Disc.

The skin incisions and minimally traumatic approaches required for the optimal dissection of the intervertebral space and thereby for the correct implantation of the LINK SB Charité Artificial Disc are described.

[Iatrogenic "metalloma" (titanoma) caused by implant failure in "metal-backed" patellar joint surface replacement]. / Iatrogenes "Metallom" (Titanom) durch Implantatversagen bei "metal-backed" Patellagelenkflächenersatz.

Patellofemoral problems frequently provide the cause for revisions after total knee replacements (TKR). Problems with metal-backed patellae, in particular, have been reported on in the past, with a failure rate of 33%. As a result of implant failure, there is an increase of polyethylene and metallic wear, which eventually leads to a synovialitis and metallosis. We report a case of a iatrogenic induced metallosis of the knee joint resulting from failure of a metal-backed patella component with the formation of a substantial pseudotumor within the popliteal fossa. Intraoperatively, a browny-grey, knotted and hard structure was to be seen, which histologically imposed as a hyalinated scar tissue with black particular deposits. Energy dispersive X-ray microanalysis showed a high level of titanium within the intra- and extracellular deposits. In differential diagnosis these findings were postulated as "metalloma" (titanoma). In cases of periprosthetic pseudotumors, particular those with implant failure, a iatrogenic-induced metalloma should be considered.