Positive predictive values in clinical screening for developmental dysplasia of the hip.

AIM: To establish the positive predictive value (PPV) of clinical hip examinations performed by referrers in the Danish screening programme for Developmental Dysplasia of the Hip (DDH) utilising three definitions of true positive DDH diagnosis. METHODS: We retrospectively identified 290 children (169 female) referred during a 4-year period to the orthopaedic outpatient clinic at our institution with a positive clinical hip examination. Positive predictive value was calculated for clinical hip examinations across three definitions of a true positive clinical hip examination for all referrers and subgroups consisting of general practitioners, midwives and paediatricians. The PPV for clinical hip examinations was calculated for paediatric orthopaedic surgeons using one of the three definitions. RESULTS: Positive predictive value of clinical hip examinations for all referrers were 5.4%, 3.6% and 1.8% with the definition of a true positive DDH diagnosis defined as clinical instability found by orthopaedic surgeon, ultrasound classification ≥Graf IIc or both definitions combined, respectively. Positive predictive value of clinical hip examinations performed by orthopaedic surgeons was 33.3% with a true positive clinical examination defined as an ultrasound classification ≥Graf IIc. CONCLUSION: We conclude that the positive predictive value of clinical hip examinations made by referrers in the Danish screening programme for DDH is low.

Risk factors for revision due to infection after primary total hip arthroplasty. A population-based study of 80,756 primary procedures in the Danish Hip Arthroplasty Registry.

BACKGROUND AND PURPOSE: There has been a limited amount of research on risk factors for revision due to infection following total hip arthroplasty (THA), probably due to low absolute numbers of revisions. We therefore studied patient- and surgery-related risk factors for revision due to infection after primary THA in a population-based setting. MATERIALS AND METHODS: Using the Danish Hip Arthroplasty Registry, we identified 80,756 primary THAs performed in Denmark between Jan 1, 1995 and Dec 31, 2008. We used Cox regression analysis to compute crude and adjusted relative risk (RR) of revision due to infection. Revision was defined as extraction or exchange of any component due to infection. The median follow-up time was 5 (0­14) years. RESULTS: 597 primary THAs (0.7%) were revised due to infection. Males, patients with any co-morbidity, patients operated due to non-traumatic avascular femoral head necrosis, and patients with long duration of surgery had an increased RR of revision due to infection within the total follow-up time. A tendency of increased RR of revision was found for patients who had received cemented THA without antibiotic and hybrid THA relative to patients with cementless implants. Hip diagnosis and fixation technique were not associated with risk of revision due to infection within 1 year of surgery (short-term risk). INTERPRETATION: We identified several categories of THA patients who had a higher risk of revision due to infection. Further research is required to explain the mechanism underlying this increased risk. More attention should be paid by clinicians to infection prevention strategies in patients with THA, particularly those with increased risk.

[Femur shaft fractures in infants should be considered despite no known trauma].

Femur shaft fractures in infants are rare and associated with abuse or fall from heights. The fracture is often easy to recognize on X-ray, however, the determination of the indication can be difficult. It is important to pay attention to pain signals from the extremity and the objective findings, such as a swollen and tight thigh. Early recognition of the fracture is of importance to the prognosis and to detection of possible violence resulting in battered child syndrome. Exploration for injuries of the extremities is of utmost necessity in these cases, despite the absence of trauma in the anamnesis.