New method to estimate femoral head size from the trochanteric length of the femur.

INTRODUCTION: Preoperative planning is an important step before any joint replacement surgery. In developing countries standardised radiographs and planning tools might not be available but nevertheless hemiarthroplasties are performed in certain trauma cases. An equation should be devised to allow a preoperative estimation of the expected femoral head size dimensions in those situations. MATERIALS AND METHODS: 35 lower limbs of human cadavers were studied. The estimated femoral head (EFH) size of each femur was obtained by measuring the trochanteric length (TL) (in cm) and using the equation 'EFH = 16 + (0.7 × TL)'. The hip joint was dissected, and the actual size of the femoral head (AFH) was measured on the specimen. RESULTS: There was a correlation between the EFH and AFH (p = 0.0001). Accepting a range of ±3 mm the femoral head size was predicted correctly in 31 hips (89%), for ±4 mm in 33 hips (94%) and for ±5 mm in 35 hips (100%), respectively. CONCLUSIONS: A simple tape measurement and the equation Femoral head size = {16 + (0.7 × Trochanteric Length)} ±5 mm gives a rather reliable guess for the expected femoral head size. It might be useful as pre-operative planning tool if no standardised radiographs are available.

Spectrum of musculo-skeletal disorders in sickle cell disease in Lagos, Nigeria.

BACKGROUND: Sickle cell anemia (SCA) is a common genetic disease in Nigeria. Past studies from West Africa focused on isolated aspects of its medical and surgical presentations. To the best of our knowledge, the musculo-skeletal presentations amongst Nigerians with SCA have not been documented in a single all encompassing study. This work aims to prospectively document the musculo-skeletal disease burden among SCA patients. METHODS: In a prospective study of 318 consecutive patients with genotype-confirmed SCA at the Lagos University Teaching Hospital (LUTH), the musculo-skeletal pathologies, anatomic sites, grade of disease, age at presentation and management outcome were recorded over a one-year period. Data obtained were analyzed using Epi-Info software version 6.0. Data are presented as frequencies (%) and mean values (SD) as appropriate. RESULTS: The HbSS genotype occurred in 296 (93.0%), while 22 (7.0%) were HbSC. 100 (31.4%) patients with average presenting haemoglobin concentration of 8.2 g/100 ml in the study group, presented with 131 musculo-skeletal pathologies in 118 anatomic sites. Osteomyelitis 31 (31%) and septic arthritis 19 (19%) were most commonly observed in children less than 10 years. Skin ulcers and avascular necrosis (AVN) occurred predominantly in the older age groups, with frequencies of 13 (13.0%) and 26 (26.0%) respectively. 20 (71.5%) of diagnosed cases of AVN presented with radiological grade 4 disease. The lower limbs were involved in 84 (71.1%) of sites affected. Lesions involving the spine were rare 11 (0.9%). Multiple presentations occurred in 89 (28.0%) of patients; 62 (69.7%) of which were children below 10 years. CONCLUSIONS: Musculo-skeletal complications are common features of sickle cell anaemia seen in 31.4%. Infectious aetiologies predominate with long bones and joints of lower limbs more commonly affected by osteomyelitis and septic arthritis. Healthcare providers managing SCA should be aware of the potential morbidity and mortality of these conditions to ensure early diagnosis and adequate management.