Although Taekwondo is becoming an increasingly popular sport, there is a lack of reliable epidemiologic data on Taekwondo injuries. To perform an epidemiologic study on the variety of types of injury in professional and amateur Taekwondo athletes and to find a relation between Taekwondo style, skill level, weight-class and warm-up routine and the occurrence of injuries, we analysed the injury data using a 7-page questionnaire from a total of 356 Taekwondo athletes who were randomly selected. Overall, we registered a total of 2,164 injuries in 356 athletes. Most traumas were contusions and sprains in the lower extremities. Professional Taekwondo athletes have an increased risk of injury in comparison to recreational athletes. Taekwondo style, weight class and tournament frequency have an influence on the athlete's injury profile. Warm-up routines were found to have a positive effect on injury rates. Overall, Taekwondo may be considered a rather benign activity, if injuries during Taekwondo tournaments can be avoided. If not, Taekwondo can result in serious musculoskeletal problems.

Patellofemoral complications are among the most common causes for revision surgery in total knee arthroplasty. So far no quantitative assessment has been made of the femoral and tibial malalignment or the positioning of the patellar component and the type of patellofemoral complication or failure. In particular, no comparative studies are available that include patients with and without patellofemoral failure in respect to the above-mentioned parameters when implant material, implant design, and fixation technique were identical. Between 1985 and 1992, 171 MG I total knee arthroplasties were performed. Since 1999, 20% of all the implanted MG I knee arthroplasties (all with metal-backed patellar component) had to be revised. Of those 34 patients, 18 were pair matched with 18 control patients based on the criteria of sex, body mass index, and age. The only difference in the control group was that they did not suffer any malfunction of the patellofemoral mechanism. To assess the patella component localization, conventional AP radiographs, patellar merchant view radiographs in 30 degrees, and CT scans were performed. This study has demonstrated a significant difference for the thickness of the patellar component and a trend regarding the rotational malalignment of the tibial component. Potential causes for the malrotation and guidelines to prevent rotational malalignment are discussed.

Patella fractures are rare and account for approximately 1% of all fractures. They are classified regarding their localization (proximal, distal) and appearance. The aim of any treatment is reconstruction of the extensor mechanism and joint surface. If dislocation and cartilage steps are less than 2 mm, conservative treatment may be indicated. Operative treatment is only necessary if a dislocation is more than 2 mm or when the extensor mechanism is unstable. Depending on the shape of the fracture, tension band wiring, interfragmentary screw fixation and combinations are the main techniques. Because patellectomy has functionally the worst result it should be avoided. Sleeve fractures (children) need exact reconstruction of the joint surface. In elderly patients conservative treatment or surgical patella-enclosing wiring techniques for stabilization are the best options due to low bone quality.

Hypophosphatemic diabetes, a rare metabolic disease, presents in children, young adults as well as in elderly patients. In this report we describe the case of a 43-year-old woman with known hypophosphatemic diabetes who complained of severe knee pain after several osteotomies of the lower extremities. The patient was treated with bilateral total knee arthroplasty. The immediate post-operative outcome was good but showed deterioration at 12-month follow-up with decreased range of motion due to ligament stiffness. Knee arthroplasty in patients with hypophosphatemic diabetes remains a challenge for the orthopaedic surgeon. Arthroplasty can be recommended in severe knee pain; however, pre-operative interventions should be considered to prevent post-operative complications.