The activities of 210Po and 210Pb in cigarette smoked in Tunisia.

In this study, the activity concentration of polonium 210 in cigarette for Tunisian consumers was investigated by alpha spectrometry. After chemical digestion of tobacco, 210Po was extracted, auto-deposited on disc and measured. The activity of 210Pb was assessed after radioactive equilibrium was achieved. The activity levels of 210Po ranged between 7.8 ± 0.3 and 17 ± 0.5 mBq per cigarette with an average of 12.9 ± 0.4 mBq per cigarette. Effective doses per year due to cigarette smoking were calculated assuming that 22% of the 210Pb and 210Po in tobacco were retained in the lungs of the smokers. It is concluded that for a smoker in Tunisia, the average effective dose is about 90.6 ± 3.3 µSv per year for a cigarette consumption of one pack of cigarettes per day. This value is somewhat lower than 106.4 ± 5.3 µSv per year estimated as the mean global effective dose from smoking.

Opening the medial tibiofemoral compartment by pie-crusting the superficial medial collateral ligament at its tibial insertion: a cadaver study.

BACKGROUND: Arthroscopic treatment of tears in the middle and posterior parts of the medial meniscus can be difficult when the medial tibiofemoral compartment is tight. Passage of the instruments may damage the cartilage. The primary objective of this cadaver study was to perform an arthroscopic evaluation of medial tibiofemoral compartment opening after pie-crusting release (PCR) of the superficial medial collateral ligament (sMCL) at its distal insertion on the tibia. The secondary objective was to describe the anatomic relationships at the site of PCR (saphenous nerve, medial saphenous vein). MATERIAL AND METHOD: We studied 10 cadaver knees with no history of invasive procedures. The femur was held in a vise with the knee flexed at 45°, and the medial aspect of the knee was dissected. PCR of the sMCL was performed under arthroscopic vision, in the anteroposterior direction, at the distal tibial insertion of the sMCL, along the lower edge of the tibial insertion of the semi-tendinosus tendon. Continuous 300-N valgus stress was applied to the ankle. Opening of the medial tibiofemoral compartment was measured arthroscopically using graduated palpation hooks after sequential PCR of the sMCL. RESULTS: The compartment opened by 1mm after release of the anterior third, 2.3mm after release of the anterior two-thirds, and 3.9mm after subtotal release. A femoral fracture occurred in 1 case, after completion of all measurements. Both the saphenous nerve and the medial saphenous vein were located at a distance from the PCR site in all 10 knees. DISCUSSION: PCR of the sMCL is chiefly described as a ligament-balancing method during total knee arthroplasty. This procedure is usually performed at the joint line, where it opens the compartment by 4-6mm at the most, with some degree of unpredictability. PCR of the sMCL at its distal tibial insertion provides gradual opening of the compartment, to a maximum value similar to that obtained with PCR at the joint space. The lower edge of the semi-tendinosus tendon is a valuable landmark for PCR of the distal sMCL.

Minimally invasive posterior approach in the popliteal fossa for semitendinosus and gracilis tendon harvesting: an anatomic study.

INTRODUCTION: Harvesting the semitendinosus (ST) and gracilis (GR) tendons at the anteromedial side of the knee may be hampered by a conjoint tendon insertion on the tibial metaphysis and an accessory bundle between the ST and the medial gastrocnemius. Locating and sparing the terminal branches of the saphenous nerve are difficult on an anteromedial approach. The principal objective of the present anatomic study was to assess the feasibility of ST and GR harvesting from a minimally invasive posterior approach in the popliteal fossa. The secondary objective was to analyze the risk of saphenous nerve branch lesion during harvesting. METHOD: Ten cadaver knees, free of scarring, were used. The whole body was positioned supine. The tendons were located in the popliteal fossa with the knee in 30° flexion. A mini-incision was performed in the fossa. The ST and GR tendons were located, and retrograde followed by anterograde stripping was performed. Tendon lengths and diameters were measured. The knees were then dissected to check for saphenous nerve branch lesions (anterior, infrapatellar and posterior branches). RESULTS: The GR and ST tendons were respectively located at 14.4 and 24 mm from the medial edge of the knee. In 90% of cases, there was an accessory ST bundle toward the medial gastrocnemius muscle, 26 mm below the posterior edge. Tendons could be harvested without deviation of the stripper. Knee dissection did not find any saphenous nerve branches, these being protected by the sartorius fascia. DISCUSSION: Posterior ST and GR tendon harvesting in the popliteal fossa is reliable and reproducible. It allows easy sectioning of the accessory ST bundle, without deviation during retrograde stripping. Unlike anterior harvesting, which leads to a rate of saphenous branch lesion of 50-78%, posterior harvesting protects the nerve branches by keeping away from the sartorius. LEVEL OF EVIDENCE: Level 4.