[Status quo of facet joint replacement]. / Status quo des Facettengelenkersatzes.

This review, regarding facet joint replacement, includes the presentation of six different implant systems from five US firms and one Swiss company. The implant systems are introduced for motion retaining replacement of the lumbar facet joints. Biomechanical and clinical results are included as far as they have been available from an Internet search, publications,oral and poster presentations, and from companies directly. At the beginning anatomical, biomechanical, and clinical data of the natural facet joints are presented. Basic principles of the high morbidity in that topographical region and at the same time for an artificial replacement of the facet joints are derived from the data. An implant classification and the available results of these implants are the basis for this article, which presents the actual situation of the treatment method for motion retaining replacements of facet joints, which have been in general clinical use since 2005. Clinical studies are not yet finalized and there are not enough clinical data; therefore, no binding recommendations for treatment with artificial facet joints are possible.

[Metal/metal--a new (old) hip bearing system in clinical evaluation. Prospective 7-year follow-up study]. / Metall/Metall--eine neue (alte) Gleitpaarung künstlicher Hüftgelenke in der klinischen Bewährungsprobe. Prospektive Verlaufsbeobachtung über 7 Jahre.

The problems of wear debris of bearing systems containing polyethylene used in hip arthroplasty have led to an increased trend to hard on hard bearing surfaces. Based on our own good experiences with the cementless Zweymüller-Alloclassic system, we implanted the same system with metal-on-metal bearing surfaces (Metasul) in 100 cases between October 1993 and November 1994. In order to record potential side effects, specific questioning and a clinical and radiological survey were carried out before surgery and in regular intervals thereafter. Up to date almost all of the patients have had good and excellent results with an average of more than 90 points in the Harris hip score (47.8 before surgery). There were no cases of revision surgery as a result of aseptic loosening. Two revisions were performed for other reasons (change of the insert, deep infection). No disadvantageous phenomena related to Metasul in the surrounding tissue were found on macroscopic and histologic investigation. The radiological examination did not show any specific signs pertaining to the use of a metal-on-metal bearing system. We also have no grounds to suppose that there are systemic reactions due to chromium or cobalt ions. Up to now, the new metal-on-metal bearing system in connection with a proven hip arthroplasty system has lived up to clinical expectations. With regard to less wear debris, it is justified to implant it in younger patients as well. Other open questions, in particular the possibly improved long-term results, have to be answered by continuation of the study.

Injury prophylaxis in paragliding.

OBJECTIVES: To show trends in paragliding injuries and derive recommendations for safety precautions for paraglider pilots on the basis of accident statistics, interviews, questionnaires, medical reports, and current stage of development of paragliding equipment. METHODS: All paragliding accidents in Germany have to be reported. Information on 409 accidents was collected and analysed for the period 1997-1999. RESULTS: There was a substantial decrease in reported accidents (166 in 1997; 127 in 1998; 116 in 1999). The number of accidents resulting in spinal injuries was 62 in 1997, 42 in 1998, and 38 in 1999. The most common cause of accident was deflation of the glider (32.5%), followed by oversteering (13.9%), collision with obstacles (12.0%), take off errors (10.3%), landing errors (13.7%), misjudgment of weather conditions (4.9%), unsatisfactory preflight checks (4.9%), mid-air collisions with other flyers (2.2%), accidents during winching (2.2%), and defective equipment (0.5%). Accidents predominantly occurred in mountain areas. Fewer than 100 flights had been logged for 40% of injured pilots. In a total of 39 accidents in which emergency parachutes were used, 10 pilots were seriously injured (26%) and an additional three were killed (8%). CONCLUSIONS: Injuries in paragliding caused by unpredictable situations can be minimised by (a) using safer gliders in the beginner or intermediate category, (b) improving protection systems, such as padded back protection, and (c) improving pilot skills through performance and safety training.

[Basic principles of successful implantation of the SB Charité model LINK intervertebral disk endoprosthesis]. / Grundlagen einer erfolgreichen Anwendung der LINK Zwischenwirbel-Endoprothese Modell SB Charité.

The scope of the LINK SB Charité Artificial Disc is to replace degeneratively changed, symptomatic intervertebral discs and to restitute the fundamental functions of the lumbar mobile segment. Biomechanical static- and dynamic test results as well as postoperative controls of a patient-group with uniform indications are presented. The options of an intervertebral disc replacement with the SB Charité Artificial Disc are discussed. For the evaluation of segmental stability, comparative static examinations of the range of motion of cadaveric lumbar segments prior to and after the implantation of the artificial disc were carried out. The stress-dependent mechanical response to directional static load on implanted SB Charité Discs in neutral position, extension and flexion was examined under different testing-conditions in order to gain results on changes of surfaces, durability and sustain of functionality. Restitutable changes to the UHMWPE sliding core, prognosed definite deformations of the sliding core after 5 and 10 years, and the functionality of the UHMWPE sliding cores after stress were examined using dynamic compression tests. Our clinical results refer to 20 patients, who received a mono- (n = 14) or bisegmental (n = 6) implantation of a SB Charité Artificial Disc following a postnucleotomy-syndrome. Comparison of the ranges of motion in cadaveric segments with and without a SB Charité Artificial Disc reflected a significantly higher mobility in cases with an implanted prosthesis only in axial rotation. Other movements showed similar ranges of motion in native segments and in segments with prosthesis. The UHMWPE sliding cores showed tolerable changes during maximal static compression in neutral position and extension. The 7.5 mm sliding cores showed changes beyond normal deformations on compression in maximal flexion. None the less it may be concluded that in vivo these sliding cores also retain their mechanical integrity. Most of the 7.5 mm and 9.5 mm high sliding cores showed a regeneration of 50% compared to maximal deformation. All the tested UHMWPE sliding cores reflected continued articulation despite plastic deformation. Predictions for a period of 5 and 10 years state that extreme loads of 4.5 kN would lead to a reduction in the height of the sliding cores of less than 8%. There was no failure of the sliding cores due to delamination or extreme coldflow. The Oswestry-Score amounted to 24% (0-56) in the postoperative controls 46 months (6 months-13 years) postoperatively. In pain analysis 5 patients (25%) were pain free, 14 patients (70%) reported a pain reduction and 1 patient (5%) had no pain relief compared to preoperatively. 15 (83%) of 18 patients had no leg pain anymore after implantation of the SB Charité Artificial Disc. 14 (93%) of 15 patients had a negative leg raising test. 2 of 5 patients recovered from their motor symptoms. The segmental saggital total range of motion was 6.8 degrees (0-20) and in cases of bisegmental implantation 5.8 degrees (0-14) in the second disc segment. Those neighboring segments with the best function showed a range of motion of 6.8 degrees (2-15). The stated general and specific complications (n = 9) had a definite influence on the results of the postoperative control in one patient and a questionable influence in another patient. Based on biomechanical static and dynamic testing, the SB Charité Artificial Disc is suited to replace the fundamental functions of the lumbar intervertebral disc. Patients suffering from a postnucleotomy-syndrome can be rendered pain free with the implantation of this prosthesis.

[Influencing factors of the patella alignment in TKR and operative soft tissue management]. / Einflussfaktoren auf die Patellaführung in der Knieendoprothetik und operatives Weichteilmanagement.

UNLABELLED: The patella has a crucial effect on the postoperative result after TKR, as complication statistics demonstrate. What factors influence the patella alignment and through which surgical steps can it be centred? METHOD: Reviewing the findings from publications ranging from 1983 to 2000 and our own operative experience, we tried to establish all factors that could influence patella alignment after TKR. RESULTS: A complex overview is given about the dependency of the patella alignment on the design of the prosthesis, the soft tissue and bone preparation and the implantation technique, together with suggestions for intraoperative management for patella centralisation. CONCLUSION: To avoid any patella pathologies, it is of crucial importance to have comprehensive knowledge and to follow the described surgical steps strictly for patella centralisation, including the extensor mechanism. This is essential to achieve a satisfying functional result after TKR.

[Postoperative analgesic effect after intra-articular morphine or ropivacaine following knee arthroscopy - a prospective randomized, doubleblinded study]. / Postoperative analgetische Wirksamkeit intraartikulärer Morphin- oder Ropivacaingabe nach Kniegelenkarthroskopie - Prospektive randomisierte Doppelblindstudie.

INTRODUCTION: Recent studies for postoperative pain relief after arthroscopy by intraarticular morphine or bupivacaine showed controversial results. The aim of the study was to evaluate the analgesic effect of intraarticular morphine and ropivacaine. METHODS: 135 patients were randomized into 9 groups (n=15) after standardized knee-arthroscopy. They received either 1 mg or 5 mg morphine or 150 mg ropivacaine or a combination of 5 mg morphine and 75 mg ropivacaine. Drains were opened either after 10 or 30 minutes. A control-group received isotonic saline. Pain was assesed 1 h and 4 h after surgery, at 8 pm on the day of the operation and at 8am and 4 pm the following two days by a VAS scale. Tramadol consumption as rescue medication was registred. RESULTS: Ropivacaine showed the best pain relief after surgery. After 24 h the pain intensity approximated in all groups and after 48 h there was no difference. Tramadol consumption was highest in the control group and lowest in the ropivacaine group (p<0,05). Ropivacaine showed better pain reduction than morphine. An influence of the time, when drains were opened, could only be demostrated for the 75 mg ropivacain combination group. CONCLUSION: Intraarticular ropivacaine following elective knee-arthroscopy reduces postoperative analgetic consumption significantly and improves patient comfort.

[Acetabular component implantation in coxarthrosis due to dysplasia after high congenital hip dislocation]. / Zur Pfannenimplantation bei Dysplasiecoxarthrosen nach angeborener hoher Hüftluxation.

A total of 71 (25-110) months after primary total hip replacement, 17 patients with high congenital hip dislocation and false iliac acetabulum were clinically and radiologically assessed. Twenty-one threaded cups were placed, 16 at the site of the true acetabulum, one at the site of the acetabular rim and four at the site of the false acetabulum. The Harris hip score increased from 37.1 (20.2-55.5) points preoperatively to 84.7 (67.4-97.7) points postoperatively. Radiologically there were no signs of cup migration. It can be concluded that even complicated dysplastic hips can be treated successfully by total hip replacement, without prior ileofemoral distraction or additional acetabular augmentation.

A multicenter retrospective study of the clinical results of the LINK SB Charité intervertebral prosthesis. The initial European experience.

OBJECTIVE: This study is a multicenter, retrospective review of the initial clinical results of an artificial disc replacement, the LINK SB Charité intervertebral prosthesis. METHODS: Independent analysis by chart review included patient demographics, surgical data, and a comparison of presurgical to follow-up data. Data were analyzed from 93 patients (average age = 43.0 +/- 7.3) in whom a total of 139 Model III prostheses (Waldemar Link GmbH & Co, Hamburg, Germany) were implanted. RESULTS: The predominant diagnostic indication for the disc was degenerative disc disease (52.4%). The L4-L5 and L5-S1 levels comprised 87.1% of all levels implanted. The average follow-up was 11.5 +/- 8.4 months. After disc implantation, a significant proportion of the patient sample experienced pain relief (P < 0.05). Improvements were also noted in pain intensity, walking distance, lumbar mobility, and the percentage of patients showing a positive SLR or neurological weakness. No difference in work status after disc implantation could be detected. Device failure, migration, or dislocation occurred in 6 of 93 (6.5%) patients. CONCLUSIONS: This study represents the largest multicenter case series of any functional artificial disc implantation. Carefully controlled, prospective studies that compare disc implantation and fusion are warranted.

[Intervertebral disk endoprosthesis--development and current status]. / Bandscheibenendoprothetik--Entwicklungsweg und gegenwärtiger Stand.

The clinical use of SB endoprosthesis and new international models and research results have increased the importance of functional intervertebral disc prosthetics as an alternative method to certain fusion operations. An analysis of the development of intervertebral disc prostheses and special problems regarding this development will be discussed.

Noninvasive diagnosis of cruciate ligament damage with particular reference to computed tomography with arthrography.

Computed tomography (CT) with arthrography, a method not requiring anesthesia, has worked well in cruciate ligament damage diagnosis, particularly in the detection of PCL damage and in differentiation between ACL and PCL lesions. Evidence has been produced of its superior accuracy by comparison, in the study of 40 patients, among clinical findings, findings obtained from initial radiography, and diagnostic data produced by CT alone. Reference is also made to false interpretations in the context of clinical examination and CT.

Biomechanics of the SB Charité lumbar intervertebral disc endoprosthesis.

The SB Charité intervertebral disc prostheses consist of two metal end-plates and an interposed polyethylene slide core. These were subjected to static and dynamic testing in a servohydraulic test rig. When embedded in polypropylene, the prostheses were found to function adequately under a high static load, and under a lighter dynamic load for a long time. When tested in a cadaveric vertebral segment, a large end-plate surface area proved to be of critical importance in preventing collapse of the prosthesis into the vertebral body.

[An alternative treatment strategy in lumbar intervertebral disk damage using an SB Charité modular type intervertebral disk endoprosthesis]. / Eine alternative Behandlungsstrategie beim lumbalen Bandscheibenschaden mit der Bandscheiben-endoprothese Modulartyp SB Charité.

At the Department of Orthopedics, Humboldt University School of Medicine, Charité Hospital, the three-piece disk endoprosthesis SB Charité of the modular type, which works according to the low-friction principle, has been developed combining the advantages of a beneficial effect on the patient's complaints by simultaneous distraction in the vertebral segment, and of achieving movement within the physiological range. So far, this disk endoprosthesis consisting of two cover plates made of implantat steel or titanium sheet, which are fixed without cement, as well as a moveable polyethylene sliding core being vertically adjustable, has been implanted in sixteen patients. The therapeutic results show that it is possible with this method to replace the nucleus pulposus, thus providing, in addition to conventional nucleotomy and segment fusion, another therapeutic alternative for lumbar disk lesions.