VOL. 2, No. 9, SEPTEMBER 2013 200  HIP The effect of surgical approach on the histology of the femoral head following resurfacing of the hip ANALYSIS OF RETRIEVAL SPECIMENS H. W. Amarasekera, P. C. Campbell, N. Parsons, J. Achten, J. Masters, D. R. Griffin, M. L. Costa From University of Warwick and University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, United Kingdom  H. W. Amarasekera, MS, FRCS(Ed), Orthopaedic PhD Fellow  J. Achten, MSc, PhD, Senior Research Fellow  D. R. Griffin, MA(Cantab), MPhil(Cantab), FRCS(Tr & Orth), Professor of Trauma and Orthopaedic Surgery Warwick Medical School, Warwick University, Coventry CV4 7AL, UK.  P. C. Campbell, PhD, Adj. Professor Orthopaedic Hospital, 2400 S. Flower Street, Los Angeles, California 90007, USA.  N. Parsons, PhD, Statistician Warwick Medical School, Statistics and Epidemiology, Warwick University, Coventry CV4 7AL, UK.  J. Masters, BSc, MBBS, Academic Foundation Doctor University Hospitals Coventry and Warwickshire NHS Trust, Clifford Bridge Road, Coventry CV2 2DX, UK.  M. L. Costa, PhD, FRCS(Tr & Orth), Professor of Trauma and Orthopaedic Surgery Warwick Clinical Trials Unit, Gibbet Hill Road, Coventry CV4 7AL, UK. Correspondence should be sent to H. W. Amarasekera; e-mail: hiran.amarasekera@warwick.ac.uk 10.1302/2046-3758.29.2000179 $2.00 Bone Joint Res 2013;2:200–5. Received 25 March 2013; Accepted after revision 2 September 2013 Objectives We aimed to determine the effect of surgical approach on the histology of the femoral head following resurfacing of the hip. Methods We performed a histological assessment of the bone under the femoral component taken from retrieval specimens of patients having revision surgery following resurfacing of the hip. We compared the number of empty lacunae in specimens from patients who had originally had a posterior surgical approach with the number in patients having alternative surgical approaches. Results We found a statistically significant increase in the percentage of empty lacunae in retrieval specimens from patients who had the posterior approach compared with other surgical approaches (p < 0.001). Conclusions This indicates that the vascular compromise that occurs during the posterior surgical approach does have long-term effects on the bone of the femoral head, even if it does not cause overt avascular necrosis. Cite this article: Bone Joint Res 2013;2:200–5. Article focus  We studied the long-term effects of surgi- cal approach on vascularity of femoral head using retrieval specimens from failed hip resurfacings  We used a nuclei-counting method to compare the vascularity of femoral heads between posterior and anterior type approaches, such as the trochanteric flip and anterolateral approaches  The research question we aimed to answer by this study is: “Does the poste- rior surgical approach have any long- term effects on vascularity of the femoral head compared with other anterior-type approaches?” Key messages  There is a statistically significant increase in the percentage of empty lacunae in retrieval specimens from patients who had the posterior approach compared with other surgical approaches  The posterior surgical approach does have long-term effects on the bone of the femoral head, even if it does not cause overt avascular necrosis Strengths and limitations  The main strength of this study was the systematic analysis of 47 histology slides from 12 retrieval specimens  Limitations include the relatively small number of specimens and the potential effect of thermal necrosis in cemented specimens Introduction Modern hip resurfacing arthroplasty has been a popular option for treating young active patients with arthritis of the hip for the last decade. 1 Its potential advantages over Freely available online Keywords: Retrieval, Hip resurfacing, Femoral head vascularity, Histology, Nuclei counts, Avascular necrosis