Excessive acetabular coverage is the most common cause of pincer-type
femoroacetabular impingement. To date, an association between acetabular
over-coverage and genetic variations has not been studied. In this
study we investigated the association between single nucleotide
polymorphisms (SNPs) of paralogous Homeobox (HOX)9 genes and acetabular
coverage in Japanese individuals to identify a possible genetic
variation associated with acetabular over-coverage. We investigated 19 total SNPs in the four HOX9 paralogs, then
focused in detail on seven of those located in the 3’ untranslated
region of Objectives
Methods
There is no diagnostic, non-invasive method for the early detection of loosening after total hip arthroplasty. In a pilot study, we have analysed two serum markers of bone remodelling, procollagen I C-terminal extension peptide (PICP) and cross-linked N-terminal telopeptide (NTx), as well as the diagnostic performance of NTx for the assessment of osteolysis. We recruited 21 patients with loosening (group I), 18 with a well-fixed prosthesis (group II) and 17 at the time of primary arthroplasty for osteoarthritis (OA) (group III). Internal normal reference ranges were obtained from 30 healthy subjects (group IV). The serum PICP level was found to be significantly lower in patients with OA and those with loosening, when compared with those with stable implants, while the NTx level was significantly increased only in the group with loosening, suggesting that collagen degradation depended on the altered bone turnover induced by the implant. This hypothesis was reinforced by the finding that the values in the pre-surgery patients and stable subjects were comparable with the reference range of younger healthy subjects. A high specificity and positive predictive value for NTx provided good diagnostic evidence of agreement between the test and the clinical and radiological evaluations. The NTx level could be used to indicate stability of the implant. However, further prospective, larger studies are necessary.
