Changes in body mass index following primary elective total hip arthroplasty. Correlation with outcome at 2 years.

Weight has been shown to increase following total hip arthroplasty (THA). It is also reported that the preoperative weight does not correlate to the outcome of the surgery. Body mass index (BMI) is regarded as a better tool for analysis. However, only a few studies have analysed BMI, BMI change or its correlation to the outcome. We present a retrospective study of 78 consecutive patients undergoing elective primary cemented THA for osteoarthritis (OA) with a minimum 2-year follow-up from a single centre. Only 26% had an acceptable BMI at the time of surgery and at follow-up, there was a mean absolute weight increase of 2.5% and BMI increase of 2.1%. Fifty seven percent correctly predicted their weight change. BMI values were independent of the level of satisfaction or mobility using Western Ontario McMaster Universities OA Index (WOMAC) score and SF12 score. We conclude that the majority of patients undergoing primary THA will increase their BMI given sufficient follow-up irrespective of the outcome. Pre-operative BMI or BMI change post operatively is not a predictor of complications or mid term outcome of THA.

Paediatric post-traumatic cortical defects of the distal radius.

Paediatric post-traumatic cortical defects, although rare, are predominately seen affecting the distal radius following a greenstick or torus fracture. We review the literature and present a further two cases supported by CT and MRI. Images from an acute greenstick fracture are also presented to help understand the pathogenesis. Defects are typically solitary on plain radiographs and are usually noticed late, proximal to the site of compression. They are non-expansile in an otherwise healthy child. CT and MRI may reveal smaller multiple subperiosteal defects. Typical defects require no further management other than reassurance and advice that they may occasionally cause discomfort but resolve with time.