Two year follow-up comparing computer assisted versus freehand TKR on joint stability, muscular function and patients satisfaction.

Computer assisted (CAS) knee surgery has been established in clinical routine. There is still no study that investigates clinical outcome. Fifty patients who received a primary total knee replacement 2 years before were investigated. These patients were divided into two groups of matched-pairs; group A was operated in the freehand technique and group B with support of a computer system. We compared Womac score, Knee Society score, range of motion, leg alignment, knee stability and isokinetic muscle strength. We found similar results for WOMAC, Knee Society score and isokinetic muscle force. Stability and range of motion revealed slightly better values for the CAS group. A statistically significant difference could only be demonstrated for postoperative leg alignment. Two years after freehand versus computer assisted TKR we found slightly better values for range of motion and ligamentous stability. Only postoperative leg alignment was statistically better in the CAS group.

The computer-assisted sequential lateral soft-tissue release in total knee arthroplasty for valgus knees.

Soft-tissue management is a critical factor in total knee arthroplasty, especially in valgus knees. The stepwise release has been based upon surgeon's experience. Computer-assisted surgery has gained increasing scientific interest in recent times and allows the intraoperative measurement of leg axis and gap size in extension and flexion. We therefore aimed to analyse the effect of sequential lateral soft-tissue release and the resulting change in the a.p. limb axis on the one hand and the tibiofemoral gaps on the other hand in extension as well as in flexion in eight cadaveric knees. Measurements were obtained using a CT-free navigation system. In extension the highest increase compared to the previous release step was found for the first (iliotibial band, P = 0.002), second (popliteus muscle, P = 0.0003), third (LCL, 0.007) and the sixth (entire PCL, P = 0.001) release step. In 90 degrees flexion all differences of the lateral release steps were statistically significant (P < 0.004). Massive progression of the lateral gap in flexion was found after the second (popliteus muscle, P = 0.004) and third (LCL, 0.007) release step. Computer-assisted surgery allows measurement of the effect of each release step of the sequential lateral release sequence and helps the surgeon to better assess the result.

[Is there a correlation between the clinical, radiological and intrasurgical findings of osteoarthritis of the knee? A Prospective study on 103 patients]. / Korrelieren die klinischen, radiologischen und intraoperativen Befunde der Gonarthrose? Eine prospektive Studie an 103 Patienten.

AIM: The aim of this study was to compare the different diagnostic features (symptoms, physical examination, radiographic features and intraoperative findings) of osteoarthritis of the knee before total joint replacement and consequently relate them with each other. METHOD: Patients with primary osteoarthritis of the knee, who where accepted for total joint replacement in our clinic, were integrated in our study. The medical conditions were recorded by using the Womac score, the knee subscore (KS) of the Knee Society Clinical Rating System and a visual analogue scale (VAS). A physical examination was also performed. The radiological evaluation was performed by using standardised radiographs. Joint space narrowing, subchondral sclerosis, osteophytes, knee alignment and the Kellgren score were recorded. During surgery an orthopaedic specialist documented the progression of cartilage lesions using the classification of chondromalacia described by Outerbridge. The analysis of correlation was performed by using the Spearman correlation (SpK) coefficient. RESULTS: 103 patients were integrated in the study (mean age: 68 years, 70 women). No significant correlation could be found between the Womac score or VAS and the results of the radiological examination (SpK [Womac - Kellgren score]: - 0.04; SpK [VAS - Kellgren score]: 0.08). There was a significant correlation between the KS and the results of the radiological examination as well as the progression of the cartilage lesions, caused by the results of the physical examination documented in the KS (SpK [KS - Kellgren score]: - 0.39). The radiographic features, with the exception of subchondral sclerosis, showed a significant correlation with the degree of chondromalacia (SpK [Kellgren score - chondromalacia]: 0.43). The amount of osteophytes correlated the most with the cartilage lesions: SpK: 0.43. CONCLUSION: The knee subscore appears to be an efficient method for staging the clinical progression of osteoarthritis of the knee for clinical practice as well as for clinical trials. The Womac score especially serves to record the level of pain. We were able to confirm that the presence of osteophytes is the most significant radiographic feature of osteoarthritis of the knee. The Kellgren score turned out to be a reliable method for monitoring the radiographic progression of osteoarthritis of the knee.

[Prevention of deep vein thrombosis in total knee replacement--current status of therapy in orthopedie and trauma departments in Germany]. / Thromboseprophylaxe in der Knieendoprothetik. Stand der Therapie an deutschen orthopädisch-traumatologischen Kliniken.

INTRODUCTION: Symptomatic deep vein thrombosis is a serious complication after total knee arthroplasty, with a risk of about 4-5% despite prevention with herparin. Aim of the current study was to find out about the actual status of thrombosis prophylaxis in Germany after total knee replacement. MATERIAL AND METHODS: In a countrywide survey 470 German trauma and orthopaedic surgery departments were asked about their prophylactic procedures addressing deep vein thrombosis after total knee replacement. RESULTS: 98% perform prevention of thrombosis with low-molecular-weight heparin, 2% use unfractioned heparin. Low-molecular-weight heparin is applicated in standard doses in 48% and in 44% according to patient's weight. In 82% the prophylaxis is begun the night before surgery. The therapy is carried out for 4.7 weeks in mean. 96% use graduated compressions stocking as additional therapeutic option. CONCLUSION: Our survey shows that most of the surgeons perform prevention of deep vein thrombosis according to the official guidelines.

Two-year follow-up on joint stability and muscular function comparing rotating versus fixed bearing TKR.

Mobile and fixed bearing in total knee replacement are still discussed controversially. In a retrospective, matched-pair study, we investigated 40 patients with computer-assisted (BrainLAB) primary total knee replacement (PFC Sigma, DePuy) performed two years before. Twenty patients each received a mobile bearing and a fixed bearing. We compared Womac Score, Knee Society Score, postoperative ROM, fluoroscopic measurement of knee stability in flexion and extension and isokinetic muscle strength using a Biodex-3 dynamometer. Both groups showed similar results concerning WOMAC Score (total rotating bearing: 23.05; fixed bearing: 22.57), KSS (rotating bearing: 174.89; fixed bearing: 176.1). Isokinetic muscle force demonstrated statistically significant superior results for knee flexion in the rotating bearing group. Medio-lateral stability revealed statistically significant superior results for the rotating bearing compared to fixed bearing in extension (P>0.05). In flexion only lateral stability was superior (P>0.05). Two-year clinical follow-up after computer-assisted total knee replacement resulted in good clinical outcome with high patient satisfaction. Statistically significant better values for the rotating platform group were found for the medio-lateral stability in extension and the peak flexion torque.