First clinical experience with posterior lumbar interbody fusion using a thermal-sprayed silver-containing hydroxyapatite-coated cage.

BACKGROUND: To investigate the possibility of silver (Ag)-induced adverse events and the degree of bone fusion in posterior lumbar interbody fusion surgery using an Ag-containing hydroxyapatite (HA) lumbar interbody cage. METHODS: An Ag-HA cage consisting of highly osteoconductive HA interfused with Ag was developed, and we applied it clinically at three university-affiliated hospitals from April 2020 to December 2020. During the 12-month postoperative observation period, Ag-related adverse events, neuropathy, and postoperative complications were investigated as indicators of safety, while clinical improvement and the fusion status were investigated as indicators of efficacy. Clinical improvement was defined as improvement beyond the minimum clinically important difference (MCID) in the numerical rating scale (NRS; 1.6) for low back and lower limb pain and the Oswestry Disability Index (ODI; 12.8). RESULTS: We performed lumbar interbody fusion using an Ag-HA cage for 48 patients (female, n = 25; mean age, 67.5 years). The mean preoperative NRS was 6.4 (standard deviation, 1.9), while the mean preoperative ODI was 44 [12]. No adverse effects (i.e., argyria) were identified during the 12-month observation period. Surgical site infection occurred in one case, although the implant was preserved via immediate debridement. In total, 39 (81%) participants showed clinical improvement beyond MCID for both NRS and ODI. Bone fusion was achieved at 45 levels (88%) at 6 months and 48 levels (91%) at 12 months postoperatively. CONCLUSIONS: The results of this study suggest that Ag-HA cages can be safely used in spinal fusion procedures and have the potential to prevent postoperative infections, prevent deterioration of the quality of life, and result in favorable outcomes. Larger-scale and longer-term follow-up studies will be required to corroborate these conclusions. Trial registration UMIN 000039964 (date: April 01, 2020).

A simple method to determine the pelvic inclination angle based on anteroposterior radiographs.

BACKGROUND: The aim of this study was to propose a simple method to determine the pelvic inclination angle using anteroposterior radiographs of the hip. METHODS: The 283 subjects were randomly selected from patients who had undergone hip surgery at our institution from July 2002 to June 2004. Anteroposterior (AP) and lateral radiographs of the pelvis were obtained in the standing position. To assess the pelvic inclination angle from AP radiographs, a formula was determined by a trigonometric function. A significant correlation between the angle calculated by the formula and the measured angle (theta(0)) on lateral radiographs was confirmed. The calculated angle (theta(1)) was obtained from two measured values: the pelvic foramen height (H) on AP radiographs and the pelvic foramen distance (D) on lateral radiographs. The formula used was as follows: sin theta = H/D. The calculated angle (theta(2)) was obtained from one measured value--the pelvic foramen height on AP radiographs--because the pelvic foramen distance on lateral radiographs substituted for the average of the pelvic foramen distance investigated in 236 patients. The formula was sin theta = H/average. RESULTS: The correlation between the calculated angle (theta(1)) and the measured angle (theta(0)) was significant, and the correlation between calculated angle theta(1) and calculated angle theta(2) was also significant. CONCLUSIONS: The pelvic inclination angle can be estimated by measuring the height of the pelvic foramen according to our formula. Our formula was shown to have adequate reliability and reproducibility.

Pyogenic vertebral osteomyelitis caused by Prevotella intermedia.

We describe a case of vertebral osteomyelitis caused by Prevotella intermedia, which is an extremely unusual cause of vertebral osteomyelitis. The organism was isolated from vertebral biopsies and the patient was treated successfully with intravenous ampicillin-sulbactam and clindamycin. Diagnosis and management of this condition are described, and the importance of anaerobic bacteria in the pathogenesis of vertebral osteomyelitis is discussed.