The Artelon CMC spacer compared with tendon interposition arthroplasty: A randomized, controlled, multicenter study of 109 patients with osteoarthritis followed for 1 year

Background and purpose The Artelon CMC spacer is designed for surgical treatment of osteoarthritis (OA) in the carpometacarpal joint of the thumb (CMC-I). Good results using this degradable device were previously presented in a pilot study. We now present results from a larger randomized, controlled, multicenter study

Microdialysis as a method for biochemical and physiological studies of the porcine and human disc

At present, no minimally invasive technique exists for the continuous evaluation of the biochemistry of animal and human intervertebral discs, but for research purposes microdialysis may be such a new technique. Thus, the aims of this study were to (1) evaluate if microdialysis can be used successfully in lumbar porcine disc and (2) develop a suitable procedure for the application of microdialysis in the human disc. Conventional specific pathogen-free pigs were used to evaluate cannulation ( n = 2) and then insertion of a 10 mm microdialysis membrane, including recovery of a dialysate from the nucleus pulposus ( n = 6). The procedure was performed immediately after euthanasia and aided by fluoroscopy to guide the needle and confirm catheter placement. Access to lumbar porcine disc was obtained with an 18 G 2 in. needle applied at a 35–45° angle from the sagittal plane, and took less than 8 min to perform. At a 0.5 μL/min flush rate, dialysates could be recovered and analysable amounts of glucose, lactate and pyruvate were obtained. In one human cadaver, the L4–L5 disc was accessed by a 19 G 3 in. needle inserted at a 35–40° angle. It was possible to apply 10 mm as well as 30 mm microdialysis membranes in the nucleus. In both species the position of the membranes was verified by direct fluoroscopy and with contrast fluid. The results obtained from porcine and human cadavers are promising, and encourage further in vivo studies using microdialysis technique on intervertebral discs. </jats:p

Results from a degradable TMC joint Spacer (Artelon) compared with tendon arthroplasty

PURPOSE: A new spacer for the trapeziometacarpal joint (TMC) based on a biological and tissue-preserving concept for the treatment of TMC osteoarthritis (OA) has been evaluated. The purpose was to combine a spacing effect with stabilization of the TMC joint. METHODS: Artelon (Artimplant AB, Sweden) TMC Spacer is synthesized of a degradable polyurethaneurea (Artelon), which has been shown to be biocompatible over time and currently is used in ligament augmentation procedures. Fibers of the polymer were woven into a T-shaped device in which the vertical portion separates the bone edges of the TMC joint and the horizontal portion stabilizes the joint. Fifteen patients with disabling pain and isolated TMC OA were included in the study. Ten patients received the spacer device and the remaining 5 (control group) were treated with a trapezium resection arthroplasty with abductor pollicis longus (APL) stabilization. The median ages of the 2 groups were 60 and 59 years, respectively. Pain, strength, stability, and range of motion were measured before and after surgery. Radiographic examination was performed in all patients before and after surgery. At follow-up evaluation 3 years after surgery an unbiased observer evaluated all patients. Biopsy specimens were obtained from 1 patient 6 months after surgery. RESULTS: All patients were stable clinically without signs of synovitis. In both groups all patients were pain free. The median values for both key pinch and tripod pinch increased compared with before surgery in the spacer group but not in the APL group. The biopsy examinations showed incorporation of the device in the surface of the adjacent bone and the surrounding connective tissue. No signs of foreign-body reaction were seen. CONCLUSIONS: This study showed significantly better pinch strength after Artelon TMC Spacer implantation into the TMC joint compared with APL arthroplasty

Hydroxyapatite granule/carrier composites promote new bone formation in cortical defects

BACKGROUND: A great deal of interest has been focused on finding substitutes for autogenous bone grafts. Among the most interesting materials are different calcium phosphate compositions (e.g., hydroxyapatite [HA]), due to their biocompatible properties in hard and soft tissue.PURPOSE: The bone response to porous ceramic HA granules in combination with two lipid and one polysaccharide carrier was evaluated in an experimental bone defect model in rabbits.MATERIALS AND METHODS: Circular defects (Ø 4 mm) were made in both tibias of 32 rabbits. The 64 defects were divided into four groups. Group A was augmented with a composite of HA granules and a phospholipid-diacetyl-glycerol carrier, group B with HA granules and a phospholipid carrier, group C received HA granules and a sodium hyaluronan carrier, and group D served as control. The animals were killed after 6 weeks and ground sections were evaluated using light microscopic morphometry. X-ray microfluorescence (XRF) was applied in order to evaluate the suitability of this method to examine bone-biomaterial interfaces. Calcium distribution was studied using x-ray fluorescence line scans at selected interface regions of two sections in group B.RESULTS: The HA/phospholipid composites were easier to shape and handle than the HA/hyaluronan composite. Group A had 36% newly formed bone area within the defect. Groups B and C showed significantly more newly formed bone within the defect (47% and 49%, respectively) compared to the control group (31%). The XRF analysis revealed that the amount of calcium in the newly formed bone was similar to that observed for the HA granules and slightly lower when compared to the mature, lamellar bone.CONCLUSIONS: Synchrotron radiation may be a new, suitable technique to study the interface between bone and biomaterials with regard to mineral content. The results suggest that HA granule/lipid and HA granule/hyaluronan composites have interesting properties as bone-substitute materials