This article has been retracted at the request of the Author.
The authors have plagiarized part of a paper that had appeared in BONE & JOINT RESEARCH (BJR), vol. 6 (2017) 399–404 (doi: 10.1302/2046-3758.67.BJR.2016-0255.R1). The name of the first author, Wei Zhang, was used without his permission, without authorisation before publication and without contribution to the paper. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.