text not published at authors' request.

Objective: To compare multi surgeon reliability of the classification systems of H. A. King and R.W. Coonrad and to analyse controversial classified curve patterns. Design: Three scoliosis surgeons and one orthopedic fellow were presented the AP radiographs of seventy adolescent idiopathic scoliosis patients. All reviewers assigned a type to each curve according to the classification systems of H. A. King [1] and R. W. Coonrad [2]. Subjects: Interobserver agreement and intraobserver reproducibility were tested. Kappa coefficients were used to test reliability. Between the observers, the divergent assignments to curve patterns were analysed in quantitative as well as in qualitative terms. An error analysis was performed. Results: For King’s classification, paired comparisons revealed a mean interobserver kappa coefficient of 0.45, and for Coonrad’s classification system 0.38, respectively. According to Svanholm et al., these values indicate poor reliability in terms of interobserver agreement. Error analyses for both classification systems revealed that the reason for poor reproducibility is disagreement on structural upper thoracic and structural lumbar curves among the observers. Conclusion: Neither King’s nor Coonrad’s method appear to have sufficient interobserver reliabilty. In order to improve reliability we recommend unequivocal description of structural stigmata of upper thoracic and lumbar curves.

Instruments used in surgery which rotate or vibrate at a high frequency can produce potentially contaminated aerosols. Such tools are in use in cemented hip revision arthroplasties. We aimed to measure the extent of the environmental and body contamination caused by an ultrasound device and a high-speed cutter. On a human cadaver we carried out a complete surgical procedure including draping and simulated blood flow contaminated with Staphylococcus aureus (ATCC 12600). After cemented total hip arthroplasty, we undertook repeated extractions of cement using either an ultrasound device or a high-speed cutter. Surveillance cultures detected any environmental and body contamination of the surgical team. Environmental contamination was present in an area of 6 x 8 m for both devices. The concentration of contamination was lower for the ultrasound device. Both the ultrasound and the high-speed cutter contaminated all members of the surgical team. The devices tested produced aerosols which covered the whole operating theatre and all personnel present during the procedure. In contaminated and infected patients, infectious agents may be present in these aerosols. We therefore recommend the introduction of effective measures to control infection and thorough disinfection of the operating theatre after such procedures.

For assessment of total knee arthroplasty outcome, various scoring systems have been introduced. The current study assessed the interobserver correlation of four commonly used total knee arthroplasty outcome scores. One hundred eighteen total knee arthroplasties were investigated by two independent observers, using the Hungerford score, the Hospital for Special Surgery score, the Knee Society score, and the Bristol score. Each score consisted of three subscores: pain, knee, and function. For the highest interobserver correlation was computed for the Bristol score (interobserver correlation coefficient, 0.88). For knee range of motion, flexion contracture, and extension lag there was high interobserver correlation (interobserver correlation coefficient > 0.8 each). For walking distance and walking aids, there also was a high interobserver correlation (interobserver correlation coefficient > 0.7 each). For clinical assessment of total knee arthroplasty, pain should be measured on a four-step system, the knee should be assessed by measurement of range of motion, extension lag, and flexion contracture, and function should be measured on a separate score assessing walking distance and walking aids.

Zusammenfassung Die Hauptindikation zur operativen Behandlung von idiopathischen Skoliosen und Scheuermann-Kyphosen ist die Kosmetik. Allerdings sind auch Schmerzen bei Skoliosepatienten häufiger zu finden, und bei hochgradigen Deformitäten eine Einschränkung der Lungenfunktion, besonders wenn schwere Skoliosen bereits im Alter von 5 Jahren bestanden (“early onset”). Skoliosen unter 30° nehmen im Erwachsenenalter nicht zu, jene zwischen 50° und 75° werden in den 40 Jahren nach Wachstumsabschluss um durchschnittlich 25° zunehmen. Bei juvenilen Kyphosen ist die Progression im Erwachsenenalter nicht gut dokumentiert. Ziel der operativen Behandlung ist es, die Progression zu stoppen, das Wachstum der Wirbelsäule zu lenken, oder eine Korrektur und Fusion zu erzielen durch Instrumentation und Knochentransplantate. Das wird erreicht durch die Korrekturprinzipien der Kompression, Distraktion, Derotation und Translation. Die zur Korrektur angewandten Kräfte werden durch Verankerungsteile (Pedikelschrauben, Wirbelkörperschrauben, Haken, sublaminäre Drahtcerclagen) auf die Wirbelsäule übertragen. Je höher die Korrekturkräfte sind, desto höher ist die erreichte Korrektur, desto höher ist aber auch das Risiko der Fraktur und des Ausrisses von Implantaten. Durch Mobilisation kann die Steife reduziert werden, und es kann bei gleichen Kräften eine bessere Korrektur erzielt werden. Die besten Mobilisationstechniken sind die Bandscheibenexzision, die Entfernung der Wirbelgelenke und Techniken zur Mobilisation des Thorax.

STUDY DESIGN:The assignment of idiopathic scoliosis curves to the curve types,1-6 to the lumbar spine modifier (A, B, or C), and to the sagittal thoracic modifier (-, N, +), as recently described by Lenke et al, was evaluated by five observers on two occasions. OBJECTIVE:To determine the intraobserver and interobserver reliabilities of Lenke's new system for classifying idiopathic scoliosis. SUMMARY OF BACKGROUND DATA:Lenke et al recently introduced a new system for classifying idiopathic scoliosis. METHODS:Preoperative standing long cassette coronal and sagittal radiographs as well as side-bending radiographs of 51 consecutive patients who underwent surgery for idiopathic scoliosis were labeled with the Cobb angles for all the curves. The center sacral vertical line was marked as the bisection of the proximal sacrum perpendicular to the true horizontal line. Five observers independently assigned a curve type, a lumbar spine modifier, and a sagittal thoracic modifier to each curve following the guidelines as described by Lenke et al. Assignment of the curves was repeated 3 weeks later, with the curves presented in a different order. Kappa coefficients were used to determine the interobserver and intraobserver reliabilities. RESULTS:All five reviewers agreed on the overall classification in 21 (41%) of the 51 patients. A mean kappa value of 0.62 was determined for interobserver reliability, and a mean kappa of 0.73 for intraobserver reliability. Determination of an upper thoracic curve as structural or nonstructural and assignment of a lumbar spine modifier were the main reasons for disagreement. CONCLUSIONS:Lenke's new classification system is more reliable than the older King classification, but proper classification of high thoracic and lumbar curves seems to be difficult.

The Robodoc total hip replacement procedure requires a wider exposure of the proximal femur, especially of the greater trochanter, than the standard procedure. Moreover, the leg must be placed in a rigid leg-holder apparatus to obtain fixation in maximal hip adduction and external rotation. This may impair the hip abductors and reduce hip abduction in the mid- and terminal stance phase of the cycle. In this study we compared patients after Robodoc and conventional total hip arthroplasty with three-dimensional gait analysis (VICON System, Oxford Metrics, Oxford, U.K.) to assess the kinematics of the pelvis and hip. 25 patients underwent total hip replacement by means of the Robodoc total hip arthroplasty system, 25 patients were treated with conventional total hip replacement, and 40 healthy volunteers served as controls. None of the patients undergoing total hip replacement, robotic or conventional, obtained normal kinematic gait patterns 6 months after surgery. However, the reduction in hip abduction did not differ significantly in patients undergoing robotic or conventional total hip arthroplasty, which suggests that the robotic procedure did not impair hip abductor function more than the conventional method.

Indication for operative treatment of idiopathic scoliosis and juvenile kyphosis is mainly cosmetic. There is also a higher incidence of pain in scoliosis patients, and reduced pulmonary function in severe deformity, especially in severe deformities present at the age of 5 years (early onset). Scoliotic curves of less than 30 degrees will not progress in adults, whereas curves of 50-75 degrees will further progress a mean of 25 degrees during 40 years. Progression in adults with juvenile kyphosis is not well documented. Operative treatment aims to stop progression, to control spinal growth, or to perform correction and fusion by spinal instrumentation and bone grafts. These goals can be achieved either by an anterior, a posterior, or a combined approach. Correction principles are compression, distraction, derotation and translation. The forces applied by correction are transferred by fixation devices (pedicle screws, anterior screws, hooks, sublaminar wires) to the spine. The higher correction forces are, the higher is the correction achieved, but also the risk of fracture and torn out implants. Mobilisation reduces rigidity and allows to achieve a better correction with equal forces. The best mobilisation techniques are disc excision, facet joint removal, and techniques to mobilise the thorax.

The ROBODOC system is a promising new method for removing cement with high-speed milling. Heat is generated during the milling process. This study was designed to measure temperatures in the cutting area, and to assess the risk of heat injury and the effectiveness of irrigation. We measured temperatures at the bone-cement cutting area in three experimental settings, two involving the proximal area comprising a cement mantle, and one the distal cement plug beneath the prosthesis. Without cooling facilities, a mean temperature of 94 degreesC was measured in proximal areas. However, this could effectively be reduced below 70 degreesC with irrigation. In the area of the distal cement plug, we measured a mean temperature of 172 degreesC without irrigation. In this area, the integrated irrigation system with an additional high-flow irrigation system could not guarantee cooling to an acceptable temperature of below 70 degreesC since the irrigation stream was impeded by the cutter in the narrow cavity. We need an integrated irrigation device that guarantees continuous cooling at the cutting interface in front of the cutter.