Introduction Intraobserver and interobserver reliabilities of the several different methods to measure lumbar lordosis have been reported. However, it has not been studied sofar in patients with ankylosing spondylitis (AS). Materials and methods We evaluated the inter and intraobserver reliabilities of six specific measures of global lumbar lordosis in patients with AS. Ninety-one consecutive patients with AS who met the most recently modified New York criteria were enrolled and underwent anteroposterior and lateral radiographs of whole spine. The radiographs were divided into non-ankylosis (no bony bridge in the lumbar spine), incomplete ankylosis (lumbar spines were partially connected by bony bridge) and complete ankylosis groups to evaluate the reliability of the Cobb L1-S1, Cobb L1-L5, centroid, posterior tangent L1-S1, posterior tangent L1-L5, and TRALL methods. Results The radiographs were composed of 39 nonankylosis, 27 incomplete ankylosis and 25 complete ankylosis. Intra-and inter-class correlation coefficients (ICCs) of all six methods were generally high. The ICCs were all C0.77 (excellent) for the six radiographic methods in the combined group. However, a comparison of the ICCs, 95 % confidence intervals and mean absolute difference (MAD) between groups with varying degrees of ankylosis showed that the reliability of the lordosis measurements decreased in proportion to the severity of ankylosis. The Cobb L1-S1, Cobb L1-L5 and posterior tangent L1-S1 method demonstrated higher ICCs for both inter and intraobserver comparisons and the other methods showed lower ICCs in all groups. The intraobserver MAD was similar in the Cobb L1-S1 and Cobb L1-L5 (2.7°-4.3°), but the other methods showed higher intraobserver MAD. Interobserver MAD of Cobb L1-L5 only showed low in all group. Conclusion These results are the first to provide a reliability analysis of different global lumbar lordosis measurement methods in AS. The findings in this study demonstrated that the Cobb L1-L5 method is reliable for measuring the global lumbar lordosis in AS.

PurposeWe compared and analyzed the short term results of high flexion total knee arthroplasty (TKA) with mobile-bearing and fixed bearing designs.Materials and MethodsWe studied 32 patients that had undergone TKA with LPS-Flex Mobile and 34 patients with LPS-Flex Fixed using an electromagnetic navigation system between January 2010 and June 2010, and were followed up for at least 1 year.ResultsKnee Society Functional Score (KSFS) and Knee Society Knee Score (KSKS) of the mobile-bearing group were 94.5 and 93.8 points, respectively, and were 48.2 and 45.3 points preoperatively, whereas those of the fixed-bearing group were 95.1 and 94.2 points, respectively, and were 49.5 and 46.9 points preoperatively. Postoperative mechanical axis deviation and implant position of the femoral and tibial component both on the coronal and sigittal planes showed no significant differences between the two groups. Range of motion (ROM) and maximal flexion angle (MFA) of the knee joint also showed no significant differences between the two groups. The possibility of crossed-legged sitting and kneeling position also showed no significant differences between the two groups.ConclusionsClinical and radiologic parameters, ROM and MFA of knee joints showed no significant differences in both the groups, but long term follow-up results may be necessary, including survival rate.

Patellectomized patients may have less satisfactory clinical outcomes following total knee arthroplasty (TKA) due to a decreased extensor mechanism efficiency and potential instability. Furthermore, the existing literature does not provide concrete guidance on the expected results of TKA or the type of implant that should be used in patellectomized patients. We present a case of a patient with an ankylosing knee who had undergone patellectomy due to gunshot injury 45 years ago and was treated with primary TKA using a posterior stabilized prosthesis at our institution. TKA using this prosthesis in the ankylosed knee with a previous history of patellectomy yielded good results in terms of postoperative clinical scores, range of motion and joint stability.

These results suggest that the ERα gene polymorphism using XbaI restriction enzyme influences the perception of back pain in patients with DS.