Bony abnormalities of the hip joint: a new comprehensive, reliable and radiation-free measurement method using magnetic resonance imaging

The objective of this study was to develop comprehensive and reliable radiation-free methods to quantify femoral and acetabular morphology using magnetic resonance imaging (MRI). Thirty-two hips [16 subjects, 6 with intra-articular hip disorder (IAHD); 10 controls] were included. A 1.5-T magnetic resonance system was used to obtain three-dimensional fat-suppressed gradient-echo images at the pelvis and distal femora. After acquisition, pelvic images were post-processed to correct for coronal, axial and sagittal rotation. Measurements performed included acetabular version (AV), femoral version (FV), lateral center-edge angle (LCEA), femoral neck angle (FNA) and alpha angle (AA) at 3, 2, 1 and 12 a.m. Two experienced raters, a musculoskeletal radiologist and an orthopedic physical therapist, and a novice rater, a research assistant, completed reliability testing. Raters measured all hips twice with minimum 2 weeks between sessions. Intra-class Correlation Coefficients (ICCs) were used to determine rater reliability; standard error of measurements was reported to estimate the reasonable limits of the expected error in the different raters’ scores. Inter-rater reliability was good to excellent for all raters for AV, FV, FNA and LCEA (ICCs: 0.82–0.98); good to excellent between experienced raters (ICCs: 0.78–0.86) and poor to good between novice and experienced raters (ICCs: 0.23–0.78) for AA. Intra-rater reliability was good to excellent for all raters for AV, FV and FNA (ICCs: 0.93–0.99); for one experienced and novice rater for LCEA (ICCs: 0.84–0.89); moderate to excellent for the experienced raters for AA (ICCs: 0.72-0.89). Intra-rater reliability was poor for the second experienced rater for LCEA (ICC: 0.56), due to a single measurement error and for the novice rater for AA (ICCs: 0.17–0.38). We described MRI methods to comprehensively assess femoral and acetabular morphology. Measurements such as AV, FV and FNA and the LCEA can be made reliably by both experienced and novice raters; however, the AA measurement was reliable only among experienced raters

Prospective trial of sacroiliac joint fusion using 3D-printed Triangular titanium implants

Background: Prior trials provide strong evidence supporting minimally invasive sacroiliac joint (SIJ) fusion using triangular titanium implants (TTI) for chronic SIJ dysfunction. Objective: To assess the safety and effectiveness of SIJF using a 3D-printed TTI. Methods: Fifty-one subjects with carefully diagnosed SIJ dysfunction underwent SIJF with 3D TTI. Subjects completed pain, disability and quality of life questionnaires at baseline and 3, 6 and 12 months postoperatively. Functional tests were performed in the clinic at each visit. Pelvic CT scans were independently evaluated for radiolucency, bridging bone and other endpoints. Results: Ninety percent had 12-month follow-up. Dysfunction due to pain (Oswestry Disability Index [ODI]) decreased from 52.8 at baseline to 27.9 at 12 months (p\u3c.0001 for change, p=.004 for non-inferiority primary hypothesis). SIJ pain scores improved from 78 preoperatively to 21 at 12-month follow-up (P\u3c.0001). Ninety-six percent experienced an improvement of 20 points or more in VAS SIJ pain by month 12. The percentage of subjects reporting minimal difficulty performing physical activities typically impaired by back/SIJ pain improved significantly for all activities. The proportion of subjects taking opioids for SIJ pain decreased from 57% to 22%. Three physical function tests improved markedly from baseline to 1 year. Positive radiographic findings were observed, including a 70% and 77% rate of bone bridging observed at 6 and 12 months, respectively. There was no evidence of device breakage, migration or subsidence. Conclusion: In this prospective multicenter trial, SIJF with 3D-printed TTI markedly improved pain, disability and quality of life. Results are consistent with 3 prior prospective multicenter trials of a milled implant but suggest accelerated bony fusion with the newer implant. Physical function improved, and high rates of opioid cessation were observed. Level of Evidence: Level II

Long-term prospective clinical and radiographic outcomes after minimally invasive lateral transiliac sacroiliac joint fusion using triangular titanium implants

Background: Accumulating evidence supports the long-term safety and effectiveness of minimally invasive sacroiliac joint fusion (SIJF) for sacroiliac joint dysfunction. Objective: To report 5-year clinical and radiographic follow-up in patients undergoing SIJF using triangular titanium implants (TTI). Methods: One hundred and three subjects at 12 centers treated with SIJF using TTI in two prospective clinical trials (NCT01640353 and NCT01681004) were enrolled and followed in the current study (NCT02270203) with clinic visits at 3, 4 and 5 years. CT scans performed at 5 years were compared to prior CT scans (at 1 or 2 years) by an independent radiologist. Results: Compared to baseline scores, SIJ pain scores at 5 years decreased by a mean of 54 points, disability scores (Oswestry Disability Index) decreased by 26 points, and quality of life scores (EuroQOL-5D time trade-off index) increased by 0.29 points (0-1 scale) (all p Conclusion: A 5-year follow-up showed continued excellent clinical responses in patients with SIJ pain treated with SIJF using triangular titanium implants along with a high rate (88%) of joint fusion. Level of evidence: Level II