The Segond's fracture is described as a cortical avulsion of the lateral tibial plateau at the site of insertion of the middle third of the lateral capsular ligament. The Segond's fracture is usually associated with a tear of the Anterior Cruciate Ligament (ACL) and it is considered as an indirect radiological sign of complete rupture of the ACL. However there are no studies investigating the effect of a Segond's fracture on the kinematic of the knee especially on the rotatory instability and Pivot Shift (PS) phenomenon. The purpose of this study is to investigate the effect of a Segond's fracture on the kinematic of the knee with the use of navigation and the PS test. Ten whole fresh-frozen cadavers were used. A navigator (2.0 Orthopilot Navigation System, BBraun Aesculap, Tuttlingen, Germany) was used to measure maximum manual Anterior Tibial Translation (ATT) at 30°, 60° and 90° of flexion, maximum manual Internal Rotation (IR) and maximum manual External Rotation (ER) at 0°, 15°, 30°, 45° and 90° of flexion. All procedures were performed three times and the mean value taken as the final result in each case. Moreover a PS test was performed by the senior, most experienced, surgeon, and graded as mild (gliding), moderate (jerk) and severe (subluxation). Navigation measurements and PS tests were performed in each knee with ACL intact, after arthroscopic cutting of the entire ACL and after a Segond's fracure was produced by exposing the antero lateral compartment of the knee underneath the ileo-tibial tract. Statistical analysis was performed using ANOVA 1-way and MANOVA tests and value for statistical analysis was set at p<0.05Introduction
Methods
In total knee arthroplasty extramedullary tibial guides could not to be as accurate as requested in obtaining proper alignment perpendicular to the mechanical axis. The aim of this study was to determine the accuracy of an accelerometer-based system (KneeAlign 2; OrthAlign Inc, Aliso Viejo, California) as evaluated by post-op X-rays analysis. Between March 2012 and May 2012 thirty consecutive patients with primary gonarthrosis were selected for unilateral total knee arthroplasty (TKA) using a handheld surgical navigation system to perform the tibial resection.
Postoperatively, standing anteroposterior hip-to-ankle radiographs and lateral knee-to-ankle radiographs were performed to determine the varus/valgus alignment and the posterior slope of the tibial components relative to the mechanical axis in both the coronal and sagittal planes. The difference between the intraoperative reading of the tibial varus/valgus alignment and posterior slope provided by the system was compared to the radiographic measurements obtained postoperatively for each respective case. Differences were analysed via standard t test. The critical level of significance was set at P <0.05.Introduction
Methods
Manual postoperative CT calculation of anteversion and inclination of the acetabular cup can be inaccurate and depends on the observer's experience. The aim of this study is to describe and present a validation of a new CT-image-based dedicate software (EGIT) for calculation of the acetabular component placement. The software principle is based on a three-dimensional reconstruction of a patient's bones from anatomical data collected postoperatively on the patient's CT scan. 15 Patient to be operated for THR were enrolled in this study. All patients were evaluated with post operative CT-scan. Measurement of Cup positioning were performed with two different methods: a manual method, performed by an expert radiologist, and a software CT image based method. Statistical analysis was performed with Intraclass Correlation Coefficent to asses interobserver and intraobserver reliability. A paired T-test was used to detect differences between manual and software methods. The Intraclass Correlation Coefficient was excellent for both the intraobserver and interobserver reliability. As expected the ICC is higher in the interobserver case. A mean cup anteversion of 14.2 (S.D. ±6.9), mean inclination of 44.2 (S.D.± 5.8) are detected with EGIT by the expert surgeon; Mean Cup anteversion of 13.6 (S.D. ± 5.11), mean inclination of 43.3 (S.D.± 5.1) are detected with manual method by expert radiologist. No statistical difference have been found (P> 0.05). The EGIT software seems to be an easy, accurate and reproducible method to calculate acetabular cup positioning using standard post-operative CT scan in THA.
Septic arthritis after arthroscopic anterior cruciate ligament (ACL) reconstruction is a rare complication. In the literature, several different managements have been proposed. A total of 1232 ACL reconstruction procedures were performed from January 2001 and December 2008. Twelve patients (0.97%) had a post-operative infection. The average age at trauma was 24 years (range:16–43). Treatment included continuous irrigation of the knee (4 hour/day for 2 days) and parenteral and oral antibiotics subsequently for a mean of 7 weeks (range:4–12 weeks). The average time at follow-up was 38 months (range 6–54 months). Follow-up included International Knee Documentation Committee (IKDC) forms, radiographs, the Tegner and Lysholm scores and KT-1000 arthrometric evaluation. In all cases treatment of infection was successful. In no cases graft or hardware removal was needed. At final examination pivot shift was negative in 10/12 patients and 1+ in 2/12 patients. In all cases the Lachman was negative. The mean postoperative Tegner score was 7.2 (range 5–9), the mean Lysholm score was 98.3 (range 69–100). 10/12 patients were graded as Group A and 2/12 patients as group B using the IKDC. The mean postoperative manual maximum KT-1000 side to side difference was 2.3 (range1–4), with 10 patients between 0 and 3 mm and 2 between 3 and 5 mm. No significative bone tunnel enlargement was found. The described treatment gives reliable results. There were no recurrences of septic arthritis or bone infection. No further surgeries were required. The graft can be retained during treatment of septic arthritis after ACL reconstruction.
The KT1000 is widely accepted as a tool for the instrumented measurement of the anteroposterior tibial translation. The aim of this study is to compare the data obtained with the KT1000 in ACL deficient knees with the data obtained using a navigation system during “in vivo” ACL reconstruction procedures and to validate the accuracy of the KT1000. An ACL reconstruction was performed using computer aided surgical navigation (Orthopilot, B-Braun, A esculap, Tuttlingen, Germany) in thirty patients. Antero-posterior laxity measurements were obtained for all patients using KT1000 arthrometer (in a conscious state and under general anesthesia) and during surgery using the navigation system, always at 30° of knee flexion. The mean AP translation was 14±4 mm and 15,6±3,8 using the KT1000 in conscious and under general anesthesia respectively (p=0.02) and 16,1±3,7 mm using navigation. Measurements with the KT1000 under general anesthesia were not different to those obtained “in vivo” with the navigation system (p=0,37). In conclusion this study validates the accuracy of the KT1000 to exactly calculate AP translation of the tibia, in comparison with the more accurate measurements obtained using a navigation system.
