Computer Assisted Diagnosis and Treatment Planning of Femoroacetabular Impingement (FAI)

Femoroacetabular impingement (FAI) is a dynamic conflict of the hip defined by a pathological, early abutment of the proximal femur onto the acetabulum or pelvis. In the past two decades, FAI has received increasing focus in both research and clinical practice as a cause of hip pain and prearthrotic deformity. Anatomical abnormalities such as an aspherical femoral head (cam-type FAI), a focal or general overgrowth of the acetabulum (pincer-type FAI), a high riding greater or lesser trochanter (extra-articular FAI), or abnormal torsion of the femur have been identified as underlying pathomorphologies. Open and arthroscopic treatment options are available to correct the deformity and to allow impingement-free range of motion. In routine practice, diagnosis and treatment planning of FAI is based on clinical examination and conventional imaging modalities such as standard radiography, magnetic resonance arthrography (MRA), and computed tomography (CT). Modern software tools allow three-dimensional analysis of the hip joint by extracting pelvic landmarks from two-dimensional antero-posterior pelvic radiographs. An object-oriented cross-platform program (Hip2Norm) has been developed and validated to standardize pelvic rotation and tilt on conventional AP pelvis radiographs. It has been shown that Hip2Norm is an accurate, consistent, reliable and reproducible tool for the correction of selected hip parameters on conventional radiographs. In contrast to conventional imaging modalities, which provide only static visualization, novel computer assisted tools have been developed to allow the dynamic analysis of FAI pathomechanics. In this context, a validated, CT-based software package (HipMotion) has been introduced. HipMotion is based on polygonal three-dimensional models of the patient’s pelvis and femur. The software includes simulation methods for range of motion, collision detection and accurate mapping of impingement areas. A preoperative treatment plan can be created by performing a virtual resection of any mapped impingement zones both on the femoral head-neck junction, as well as the acetabular rim using the same three-dimensional models. The following book chapter provides a summarized description of current computer-assisted tools for the diagnosis and treatment planning of FAI highlighting the possibility for both static and dynamic evaluation, reliability and reproducibility, and its applicability to routine clinical use.

Tularemia in the Southeastern Swiss Alps at 1,700 m above sea level.

A 37-year-old man presented with a 4-day history of nonbloody diarrhea, fever, chills, productive cough, vomiting, and more recent sore throat. He worked for the municipality in a village in the Swiss Alps near St. Moritz. Examination showed fever (40 °C), hypotension, tachycardia, tachypnea, decreased oxygen saturation (90 % at room air), and bibasilar crackles and wheezing. Chest radiography and computed tomography scan showed an infiltrate in the left upper lung lobe. He responded to empiric therapy with imipenem for 5 days. After the imipenem was stopped, the bacteriology laboratory reported that 2/2 blood cultures showed growth of Francisella tularensis. He had recurrence of fever and diarrhea. He was treated with ciprofloxacin (500 mg twice daily, oral, for 14 days) and symptoms resolved. Further testing confirmed that the isolate was F. tularensis (subspecies holarctica) belonging to the subclade B.FTNF002-00 (Western European cluster). This case may alert physicians that tularemia may occur in high-altitude regions such as the Swiss Alps.

Tuberculosis Mortality and Living Conditions in Bern, Switzerland, 1856-1950.

BACKGROUND Tuberculosis (TB) is a poverty-related disease that is associated with poor living conditions. We studied TB mortality and living conditions in Bern between 1856 and 1950. METHODS We analysed cause-specific mortality based on mortality registers certified by autopsies, and public health reports 1856 to 1950 from the city council of Bern. RESULTS TB mortality was higher in the Black Quarter (550 per 100,000) and in the city centre (327 per 100,000), compared to the outskirts (209 per 100,000 in 1911-1915). TB mortality correlated positively with the number of persons per room (r = 0.69, p = 0.026), the percentage of rooms without sunlight (r = 0.72, p = 0.020), and negatively with the number of windows per apartment (r = -0.79, p = 0.007). TB mortality decreased 10-fold from 330 per 100,000 in 1856 to 33 per 100,000 in 1950, as housing conditions improved, indoor crowding decreased, and open-air schools, sanatoria, systematic tuberculin skin testing of school children and chest radiography screening were introduced. CONCLUSIONS Improved living conditions and public health measures may have contributed to the massive decline of the TB epidemic in the city of Bern even before effective antibiotic treatment became finally available in the 1950s.