Reliability of radiographic landmarks in medial patello-femoral ligament reconstruction in relation to the anatomical femoral torsion.

PURPOSE: Anatomically correct graft positioning at the femoral insertion site is a key factor in surgical reconstruction of the medial patello-femoral ligament (MPFL). Basically there are two techniques to define this point in fluoroscopy during surgery. The role of the anatomical femoral torsion on the accuracy and reproducibility of both procedures has not been clarified. METHODS: Twenty human anatomical leg specimens were dissected. The femoral insertion of the MPFL was marked by two K-wires. The position of the ligament insertion was determined fluoroscopically in the true lateral view as used in routine clinical practice. The anatomical MPFL insertion was compared to the radiographic landmarks which were recommended by two previous studies. The anatomical femoral torsion of the specimens was assessed by computed tomography scans. RESULTS: In true lateral view fluoroscopy, the mean distance of the femoral MPFL insertion was -0.2 mm distal to the vertical reference line intersecting the posterior point of Blumensaat's line. In the anteroposterior direction, the mean distance was -2.0 mm posterior to the femoral cortex reference line. There was no correlation between anatomical femoral torsion and the distance of the femoral MPFL insertion to the posterior cortex. CONCLUSIONS: The results of this study strongly recommend use of a vertical line intersecting the most posterior point of Blumensaat's line as a reference to identify the MPFL insertion in the craniocaudal direction. In the anteroposterior direction, the femoral MPFL insertion showed distinctive variation and was found -2.0 mm posterior to the femoral cortex reference line without being influenced by the anatomical femoral torsion.

Sex estimation using the femur of Austrians born in the 19th to the middle of the 20th century.

Sex estimation of human bones or bone fragments is crucial for the identification process of unknown bodies. Regional differences and secular changes lead to ever changing osteometric standards for different populations. This study provides femoral dimensions of Austrians born between 1822 and 1949 and evaluates the discriminating power of sex estimation functions developed by discriminant analyses. Depending on the state of preservation up to 127 femora of adult individuals (72 females and 55 males) were measured. The following means and standard variations were obtained: Maximum length (male: 449.7 ± 16.7 mm, female: 413.9 ± 16.3 mm), head circumference (148.5 ± 7.8 vs. 133.8 ± 6.4 mm), vertical (46.9 ± 2.4 vs. 41.9 ± 2.1 mm), transverse (46.3 ± 2.4 vs. 41.5 ± 2.0 mm), and maximum head diameter (47.0 ± 2.3 vs. 42.0 ± 2.1 mm), as well as sagittal (28.3 ± 2.2 vs. 26.2 ± 1.8 mm), transverse (27.9 ± 2.5 vs. 26.1 ± 2.0 mm), and maximum midshaft diameter (29.2 ± 2.1 vs. 27.3 ± 1.6 mm) and finally condylar width (79.6 ± 4.6 vs. 71.9 ± 3.8 mm). The (cross-validated) discriminant analysis for single measurements showed that the best classification is obtained using femur head dimensions, with correct sexing rates between 84.8 % for the circumference and 87.8 % for the maximum diameter. The maximum length achieved a similarly high rate of correct classification with 86.5 %, whereas the rate for the condylar width (80.6 %) was somewhat lower. The potential of midshaft dimensions for sex estimation was substantially weaker (62.3 to 70.8 %). With regard to a multivariate analysis, a stepwise selection procedure favoured a combination of maximum length and vertical head diameter with 90.1 % being correctly classified. A combination of maximum length, maximum head diameter and maximum midshaft diameter resulted in an even higher rate of 91.5 %. These Austrian standards may provide additional possibilities for sexing unknown bodies and skeletal remains born in the 19(th) to the middle of the 20(th) century.