There is a paucity of published Canadian literature comparing lumbar total disc arthroplasty (LDA) to fusion on patient outcomes in degenerative spondylosis. The purpose of this study is to quantify and compare the long-term patient reported outcomes following LDA and matched-fusion procedures. We conducted a matched-cohort study comparing consecutive patients enrolled by CSORN who underwent standalone primary LDA or hybrid techniques for degenerative disk disease between 2015–2019. Fusion patients were included by a primary diagnosis of degenerative disk disease, chief complaint of back pain, who received a primary fusion irrespective of technique. Fusion patients were matched by number of involved levels of surgery to LDA counterparts. Outcome scores and patient satisfaction were assessed preoperatively and 2-years postoperatively. 97 patients (39-female, 58-male) underwent LDA or hybrid construct up to 4 levels. 94 patients (52-female, 42-male) underwent a lumbar fusion were selected based on inclusion criteria. 36 LDA and 57 Fusion patients underwent a 1-level surgery. 39 LDA and 25 Fusion patients underwent 2-level surgery. 18 LDA and 7 Fusion patients underwent 3-level surgery. 4 LDA and 5 Fusion patients underwent a 4-level procedure. Slight differences in average cohort age were found (LDA-43.4yrs, Fusion-49.8yrs, p<0.01). Cohort preoperative-BMI (LDA-27.0kg/m2, Fusion-27.9kg/m2, p=0.29) and total comorbidities (LDA-2.6, Fusion-2.1, p=0.05) demonstrated no clinically significant differences. At 2 year follow-up, no differences were found in ODI improvement (LDA-20.32pts, Fusion-17.02pts, p=0.36), numerical back-pain improvement (LDA-3.5pts, Fusion-3.06pts, p=0.40), numerical leg-pain improvement (LDA-1.67pts, Fusion-1.87pts, p=0.76), and Health Scale improvement (LDA-17.12, Fusion-10.73, p=0.20) between cohorts. Similar positive findings were found in subgroups stratified by number of surgical levels. Satisfaction rate at 2 years was 86.7% and 82.4% for LDA and Fusion patients respectively. There didn't appear to be significant differences in outcomes or satisfaction through 2 years comparing patients who underwent LDA (whether used in isolation or as part of a hybrid construct) for debilitating degenerative disk disease and isolated spinal fusion for back dominant pain.
Maintenance of vertebral mechanical stability is of paramount importance to prevent pathologic fractures and resultant neurologic compromise in individuals with spinal metastases. Current non-surgical treatments for vertebral metastases (i.e. chemotherapy, bisphophonates (BP) and radiation) yield variable responses in the tumour and surrounding bone. Photodynamic therapy (PDT) is a novel, minimally-invasive technology that utilizes a drug activated by light at a specific non-thermal wavelength to locally destroy tumour cells. Previously, we observed that PDT can ablate cancer cells within bone and yield short-term (1-week) improvements in vertebral architecture and biomechanical strength, particularly when combined with BP therapy. This study aims to evaluate the effects of PDT in vertebral bone over a longer (6-week) time period, alone and combined with previous BP treatment, to determine if improvements in skeletal architecture and strength are maintained. Fourty healthy rnu/rnu rats were randomly assigned to four treatment groups: (i) untreated control, (ii) BP only, (iii) PDT only and (iv) PDT following BP. BP treatments were administered on day 0 via subcutaneous injection of zoledronic acid. PDT was administered on day 7 via an intravenous injection of BPD-MA photosensitizer. A flat-cut optical fiber was inserted percutaneously adjacent to lumbar vertebra L2. After a 15-minute drug-light interval, 75J of light energy was delivered from a 690nm laser. Six weeks later, animals were euthanized. Structural properties of excised L2 vertebral bodies were quantified through semi-automated analysis of micro-CT images. In of the specimens, mechanical properties were evaluated by loading the L2 vertebral body to failure in axial compression. The remaining L2 vertebrae were analyzed for morphology, osteoid formation and osteoclast activity using histological methods.Purpose
Method
Versican is a member of the large aggregating chondroitin sulfate proteoglycan family. Structurally, it is made up of an N-terminal G1 domain, a glycosamingoglycan attachment region, and a C-terminus containing a selectin-like (G3) domain. Versican is highly expressed in the interstitial tissues at the invasive margins of breast carcinoma and predictive of relapse and overall survival. The purpose of the study to investigate the role of of versican G3 domain in breast cancer bone metastasis. Mouse mammary tumor cell lines 66c14, 4T07 and 4T1, and human breast cancer cell lines MT-1, MDA-MB-468 and MDA-MB-231 were stably transfected with versican G3. Effects of expression of versican G3 on cell proliferation, migration, invasion, cell cycle progression, and EGFR signaling were observed. The effects of G3 on cell viability in the conditional media of serum free, apoptotic agent C2-ceramide, and chemotherapeutic agents, including Docetaxel, Doxorubicin, Epirubicin were investigated. Colony formation assay and mammosphere formation assay were performed. A syngeneic orthotopic animal model was used to do the in vivo study.Purpose
Method
Nucleus pulposus (NP) replacements represent a less invasive alternative for treatment of early stage degenerative disc disease (DDD). Hydrogel based NP replacements are of particular interest as they can be injected/implanted using minimally invasive surgical (MIS) techniques to re-establish mechanical integrity and as a scaffold for regeneration. A thiol-modified hyaluronan elastin-like polypeptide (TMHA/EP) hydrogel crosslinked using polyethylene diacrylate has shown promise as a potential NP replacement for DDD in vitro. This study aims to assess the mechanical properties of this hydrogel when injected into an induced early stage DDD porcine model and to determine the optimal injection method for delivery. It is hypothesized that minimally invasive injection of the TMHA/EP material can restore mechanical behaviour of spinal motion segments in early stage DDD. Intervertebral disc (IVD) degeneration was enzymatically induced in L2-L3 and L4-L5 lumbar levels in 10 Yorkshire boars using chondroitinase ABC (n=20 discs). An additional three animals served as healthy controls (n=6 discs). Following a four-week degradation period, the TMHA/EP solution (250microL in a 3:1 weight ratio) was injected into the degenerate NP of 16 discs by one of two MIS techniques: A direct 18G needle injection or a modified kyphoplasty technique (MKT) in which a balloon angiocatheter was inserted through an 11G trocar into the IVD and inflated to create a cavitary defect that was then filled with the hydrogel. Excised motion segments were tested in axial compression under a load of 400N and in axial rotation (AR), lateral bending (LB) and flexion/extension (FE) at 5Nm. Range of motion (ROM), neutral zone (NZ) length, NZ stiffness (NZStiff) and axial compressive stiffness (ACStiff) were quantified.Purpose
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