Pascal Poilvache

Rotational landmarks and sizing of the distal femur in total knee arthroplasty.

In 100 knees undergoing a total replacement, the angles between the tangent line of the posterior condylar surfaces, the anteroposterior axis as described by Whiteside, the transepicondylar line, and the trochlear line were measured. Also measured were the sulcus angle, the transepicondylar width, the height of the condyles, and the thickness of the various cuts. Radiologic measurements made were: the mechanical angle, the hip center-femoral shaft angle, the transcondylar angle, and the tibial plateau-tibial shaft angle. The mean values of these measurements were calculated, and comparisons were made according to gender and the mechanical axis using the Students t test. Correlations between the various measurements were calculated. The transepicondylar axis was found to be a reliable landmark to properly rotate the femoral component, and was easier to locate at surgery than the anteroposterior axis. In trochlear dysplasia and in some valgus knees, relying on the anteroposterior axis can induce an excessive external rotation of the femoral component, and the opposite can happen in some varus knees. The anterior extent of the condyles is highly variable in arthritic knees, and cannot be used to orient the prosthesis. The ratio between the transepicondylar width and the height of the condyles is constant, but some narrow femora could require narrower implants to avoid medial-lateral overhang of the femoral component.

Anatomy of the epicondyles of the distal femur: MRI analysis of normal knees.

Knowledge of precise anatomic landmarks and relationships of the distal femur can be helpful in knee surgery, especially primary and revision total knee arthroplasty. We analyzed 104 consecutive routine knee magnetic resonance imaging studies to define useful landmarks and relationships. The epicondyles are described, and the relationship of the epicondyles to the joint line is defined in multiple planes. Some significant gender differences were noted. The distance from the epicondyles to the joint line correlates with the transepicondylar width of the distal femur. This information can be helpful in determining appropriate joint line position intraoperatively. The posterior condylar angle averaged 3.11 degrees for all patients, and a tendency for the posterior condylar angle to increase with age was noted, but further study of this tendency is needed.

Synovial fluid levels of tumor necrosis factor alpha and oncostatin M correlate with levels of markers of the degradation of crosslinked collagen and cartilage aggrecan in rheumatoid arthritis but not in osteoarthritis.

OBJECTIVE To compare synovial fluid (SF) levels of oncostatin M (OSM), tumor necrosis factor alpha (TNFalpha), and interleukin-6 (IL-6) in patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and to determine which correlate best with SF levels of antigenic keratan sulfate (Ag KS), a marker of aggrecan catabolism, and pyridinium crosslinks, markers of the degradation of mature collagen molecules. METHODS SF was drawn from the knee joints of patients with RA (n = 31) or OA (n = 31). Levels of Ag KS, D-pyridinoline (D-Pyr), pyridinoline (Pyr), OSM, TNFalpha, and IL-6 were measured by enzyme-linked immunosorbent assay. RESULTS RA patients had higher median SF levels of OSM, TNFalpha, IL-6, and Pyr, but a lower median level of D-Pyr, than OA patients. In both groups, IL-6 levels correlated positively with those of OSM and TNFalpha. However, the correlation between levels of OSM and TNFalpha was only significant in the RA group. Ag KS and Pyr levels correlated positively in RA but not in OA. The correlation between TNFalpha and Ag KS was positive in RA and negative in OA. Further, in RA, OSM and IL-6 levels correlated strongly with Pyr and Ag KS levels but not with D-Pyr levels, while there were no strong correlations in OA for OSM or IL-6 levels with Pyr, Ag Ks, or D-Pyr levels. CONCLUSION This in vivo study suggests that TNFalpha and other proinflammatory cytokines are involved in the up-regulation of the coordinated degradation of cartilage aggrecan and collagen in RA. Further, OSM may act synergistically with other proinflammatory cytokines in up-regulating the production of metalloproteinases by chondrocytes in rheumatoid joints.

Spiral CT arthrography of the knee: technique and value in the assessment of internal derangement of the knee.

Abstract. Computed tomography imaging has achieved excellent multiplanar capability and submillimeter spatial resolution due to the development of the spiral acquisition mode and multidetector row technology. Multidetector spiral CT arthrography (CTA) yields valuable information for the assessment of internal derangement of the joints. This article focuses on the value of spiral CTA of the knee in the assessment of the meniscus, anterior cruciate ligament, and hyaline cartilage lesions. Advantages and disadvantages of spiral CTA with respect to MR imaging are presented.

Serum levels of hyaluronan, antigenic keratan sulfate, matrix metalloproteinase 3, and tissue inhibitor of metalloproteinases 1 change predictably in rheumatoid arthritis patients who have begun activity after a night of bed rest.

OBJECTIVE To evaluate whether and how moderate physical activity following a night of rest influences serum levels of matrix metalloproteinase 3 (MMP-3), tissue inhibitor of metalloproteinases 1 (TIMP-1), antigenic keratan sulfate (Ag KS), and hyaluronan (HA) in 10 normal subjects and 38 patients with rheumatoid arthritis (RA). METHODS Blood was obtained from 20 RA patients before they arose from a nights sleep, and again 1 and 4 hours after they had begun to perform moderate physical activity. Another 18 RA patients remained in bed and blood was sampled at the same time periods. Serum levels of MMP-3, TIMP-1, Ag KS, and HA were measured by enzyme-linked immunosorbent assay. Clinical activity was evaluated by the Lansbury index. RESULTS Both in normal subjects and in RA patients who did not remain in bed throughout the period of blood sampling, levels of HA, Ag KS, and MMP-3 increased significantly during the first hour after the subjects arose: the increase in HA and Ag KS correlated with the Lansbury index in the RA group. Three hours later, levels of Ag KS had dropped to baseline values in both groups of subjects. Levels of HA remained significantly and moderately elevated in the RA group but not in the control group, while levels of MMP-3 did not drop significantly in either group. In contrast, levels of HA, Ag KS, and MMP-3 did not change significantly in RA patients who had remained in bed. Unlike the other markers, the levels of TIMP-1 remained unchanged at the different time periods in all 3 groups studied. CONCLUSION Significant changes in serum levels of some metabolic markers occur during the first hour after one arises from a night of sleep, especially in patients with RA. Measurement of the magnitude of these changes at different times in individual patients provides very different information about metabolic changes occurring in joint tissue than does measurement of the level of the markers at a single time point, as is usually currently reported.

Carpal tunnel syndrome in childhood: report of five new cases.

Carpal tunnel sybdrome is a condition rarely ecountered during the growth period. We decribe five new cases in two large Belgain university hospials. One case concerned a 2-year old child suffering from disseminated angiomatosis, an association not previously reported. Another case of mild severity corresponded to the classic association of trigger fingers and carpal tunnel syndrome. The third case was posttarumatic, and the last two cases were of the familial type that preciously has been reported in four families. We discuss these observarions and briefly review the literature.

Validation of the Ottawa knee rules in an emergency teaching centre.

Abstract. Our objective was to determine the value of the Ottawa knee rules when applied by users with different levels of clinical training. We used a prospective patient survey by the medical students and surgery residents of a European university trauma centre. The study group consisted of 261 eligible patients who presented with acute knee trauma during a 6-month period. Radiography or follow-up was obtained for each patient. Data were separately analysed according to the degree of qualification of the initial examiner. The Ottawa knee rules had a sensitivity and a negative predictive value of 1.00. Variable degree of medical competence of the users did not alter the accuracy of the rules. Application of the rules would have reduced knee radiography requests by 25%. The Ottawa knee rules remain highly sensitive when applied by medical users with different levels of qualification, such as encountered in a teaching setting.

The patella in total knee replacement: technical aspects on the femoral side

Abstract. The influence of femoral component positioning on patellar tracking is critical. The various possibilities of modifying the position of the femoral component relative to the distal femoral epiphysis are analyzed, and the ideal positioning in the medio-lateral, antero-posterior, and proximal-distal directions is described. Special emphasis is placed on the rotational positioning of the femoral component.

Surgical Treatment of Intra-articular Knee Venous Malformations: When and How?

Background: To assess the efficacy of surgical treatment of intra-articular knee venous malformations (VM). Methods: Between 1998 and 2010, 8 children (mean age: 12.3 y) underwent surgical resection of their vascular malformation (7 venous and 1 capillary venous) involving the knee joint. The lesion was diffuse in 6 cases and well-demarcated in 2 cases. All children were suffering from knee pain and had recurrent hemarthroses. Color-Doppler ultrasonography, magnetic resonance imaging, computed tomography scan, and blood test were performed preoperatively. Preoperative and postoperative physical examination, clinical symptoms, and orthopaedic evaluation were retrospectively reviewed. Surgery consisted in arthrotomy with total excision of the vascular malformation for the 2 well-demarcated lesions and synovectomy with squeezing of the surrounding vascular malformation for 5 diffuse lesions. One patient with an extensive venous malformation associated with severe localized intravascular coagulopathy and mild hemophilia A had undergone synovectomy by knee arthroscopy. Results: Immediate postoperative follow-up was uneventful in 6 patients, whereas 2 patients with diffuse vascular malformation and coagulopathy suffered from postoperative hemarthroses, delaying their rehabilitation. After a mean follow-up of 5.1 years, persistence of the VM within the joint was observed in the 6 initially diffuse lesions. The 2 well-demarcated lesions showed no evidence of disease at latest follow-up. Four patients with preoperative chondropathy and functional impairment were not substantially improved regarding their range of knee motion at latest follow-up, whereas the 4 others were free of symptoms. Only 1 patient presented a recurrent hemarthroses after a 5-year-symptom-free period and had to be reoperated. Patients without preoperative chondropathy recovered normal knee function mobility. Conclusions: This retrospective study highlights the importance of early surgery in patients with intra-articular venous malformation, even if asymptomatic, to prevent joint impairment. For well-demarcated lesions, total resection by arthrotomy can provide definitive healing without resuming of symptoms. Although diffuse lesions treated by synovectomy still persist in the joint, treatment avoids recurrence of hemarthroses and, therefore, protects the cartilage from further erosion. Level of evidence: Level IV—cases series.

2108 Genou : imagerie des lesions ligamentaires, des ligamentoplasties et de leurs complications

Objectifs pedagogiques Familiariser l’auditeur aux images de lesions ligamentaires, des ligamentoplasties et de leurs complications ; permettre la conduite de l’examen et son interpretation. Resume L’expose comprend un rappel des techniques (RX, arthro-TDM, IRM) disponibles, de leurs limites, des incidences, sequences ou plans de coupe, de l’anatomie des principaux ligaments, de breves notions cliniques et principes therapeutiques. L’imagerie des lesions ligamentaires est detaillee, avec accent sur les difficultes et questions du clinicien (lesion complete ou partielle, recente ou ancienne, lesions meniscales, osseuses, cartilagineuses associees). L’etude de l’imagerie des plasties aborde les criteres de reussite chirurgicale, les malpositions et complications. Conclusion Le contenu de ce cours va de la lesion elementaire aux associations lesionnelles, de la lesion a son traitement, de la reparation chirurgicale a ses complications.