Transforming growth factor-b (TGF-b) has been demonstrated as a potential therapeutic target in osteoarthritis. However, beneficial effects of TGF-b supplement and inhibition have both been reported, suggesting characterization of the spatiotemporal distribution of TGF-b during the whole time course of osteoarthritis is important. To investigate the activity of TGF-b in osteoarthritis progression, we collected knee joints from Dunkin-Hartley (DH) guinea pigs at 3, 6, 9, and 12-month old (n ¼ 8), which develop spontaneous osteoarthritis in a manner extraordinarily similar to humans. Via histology and micro-computed tomography (CT) analysis, we found that the joints exhibited gradual cartilage degeneration, subchondral plate sclerosis, and elevated bone remodeling during aging. The degenerating cartilage showed a progressive switch of the expression of phosphorylated Smad2/3 to Smad1/5/8, suggesting dual roles of TGF-b/Smad signaling during chondrocyte terminal differentiation in osteoarthritis progression. In subchondral bone, we found that the locations and age-related changes of osterix þ osteoprogenitors were in parallel with active TGF-b, which implied the excessive osteogenesis may link to the activity of TGF-b. Our study, therefore, suggests an association of cartilage degeneration and excessive bone remodeling with altered TGF-b signaling in osteoarthritis progression of DH guinea pigs. ß

The present study revealed that wearing high-heeled shoes can lead to increased LL and an uneconomic body position. This finding may help explain why some women complain that wearing high-heeled shoes causes them to experience low back pain.

Background To date, there is a paucity of reports clarifying the change of spinopelvic parameters in patients with adult spinal deformity (ASD) who underwent long segment spinal fusion using iliac screw (IS) and S2-alar-iliac screw (S2AI) fixation. Methods A retrospective review of consecutive patients who underwent deformity correction surgery for ASD between 2013 and 2017 was performed. Patients were divided into two groups based on whether IS or S2AI fixation was performed. All radiographic parameters were measured preoperatively, immediately postoperatively, and the last follow-up. Demographics, intraoperative and clinical data were analyzed between the two groups. Additionally, the cohort was subdivided according to the postoperative change in pelvic incidence (PI): subgroup (C) was defined as change in PI ≥5° and subgroup (NC) with change < 5°. In subgroup analyses, the 2 different types of postoperative change of PI were directly compared. Results A total of 142 patients met inclusion criteria: 111 who received IS and 31 received S2AI fixation. The IS group (65.6 ± 26°, 39.8 ± 13.8°) showed a significantly higher change in lumbar lordosis (LL) and upper lumbar lordosis (ULL) than the S2AI group (54.4 ± 17.9°, 30.3 ± 9.9°) (p < 0.05). In subgroup (C), PI significantly increased from 53° preoperatively to 59° postoperatively at least 50% of IS cohort, with a mean change of 5.8° (p < 0.05). The clinical outcomes at the last follow-up were significantly better in IS group than in S2AI group in terms of VAS scores for back and leg. The occurrence of sacroiliac joint pain and pelvic screw fracture were significantly greater in S2AI group than in IS group (25.8% vs 9%, p < 0.05) and (16.1% vs 3.6%, p < 0.05). Conclusions Compared with the S2AI technique, the IS technique usable larger cantilever force demonstrated more correction of lumbar lordosis, and possible increase in pelvic incidence. Further study is warranted to clarify the clinical impaction of these results.