The reliability of the patellotrochlear index on magnetic resonance imaging for measuring patellofemoral height.

BACKGROUND: The purpose of this study was to determine the inter- and intra-observer reliability of the patellotrochlear index (PTI) on magnetic resonance images (MRI) in patients with patellofemoral pain. The correlation between the PTI measured on MRI and the modified Insall-Salvati (MIS) ratio measured on radiographs was also assessed. METHODS: The PTI was assessed on MRI images and the MIS ratio on radiographs of 66 knees of 62 patients. Assessment was performed by two orthopaedic surgeons, one orthopaedic surgery registrar, two radiologists and one radiology registrar. Correlation coefficients, standard errors of measurement and limits of agreement were calculated for the PTI. To assess the association between the PTI and the MIS ratio, the Pearson's correlation coefficient was calculated. RESULTS: The PTI showed good interobserver reliability (intraclass correlation coefficient (ICC) 0.79; 95% confidence interval (CI) 0.73-0.85) and excellent intra-observer reliability (ICC 0.90; 95% CI 0.89-0.91). The standard error of measurement was 0.05 and limits of agreement with the mean ± 0.09. A very weak and not significant correlation was found between the PTI and the MIS (r = 0.02; P = 0.77). CONCLUSIONS: The PTI showed good interobserver reliability and excellent intra-observer reliability. In order to conclude which measurement method of assessing patellar height is truly the most reliable, future studies should investigate agreement parameters (standard error of measurement, limits of agreement) besides solely correlation coefficients. We found a very weak correlation between the PTI and the MIS which suggests that at least one index has poor validity. Future validity studies on indices to assess patellar height are necessary.

A decade of washing out common bile duct stones with papillary balloon dilatation as a one-stage procedure during laparoscopic cholecystectomy.

BACKGROUND: Laparoscopic cholecystectomy is the treatment of choice for the management of cholecystolithiasis. For the management of choledocholithiasis, a number of options exist. The effectiveness of washing out common bile duct stones with laparoscopic transcystic papillary balloon dilatation (LTPBD) in patients undergoing laparoscopic cholecystectomy (LC) as a one-stage procedure was evaluated. METHODS: Retrospectively, the files of 63 patients treated with LTPBD in a one-stage procedure undergoing laparoscopic cholecystectomy between December 1996 and December 2006 were studied. RESULTS: Fifty-three patients were treated successfully in a one-stage procedure, seven patients were treated in two steps with an endoscopic retrograde cholangiopancreatography (ERCP) postoperatively, and in three cases a conversion to open surgery was required. The median operation time was 128 min, and the median hospital stay was 4 days. No patients developed postoperative pancreatitis. In one case contrast leakage from the common bile duct was detected. It was the only complication directly related to the LTPBD. There were no postoperative deaths. CONCLUSIONS: We consider the wash out of common bile duct stones after LTPBD in a one-stage procedure to be an easy to do and safe operation with great results. Cooperation with an intervention radiologist and application of an angioplastic dilatation dotter balloon catheter are the keys to success in this procedure. In our hospital, it is the treatment of choice for choledocholithiasis associated with cholelithiasis.