Search

Objective To compare structural findings between US, micro-CT (µCT) and histology in people with OA of the hands. Methods We analysed DIP and PIP joints of 31 fingers from 15 dissecting-room cadavers with OA of the hands. The occurrence of bone erosions and osteophytes were recorded by US, µCT and histology at 16 regions for each joint and compared for each method. Results In total, US (n  = 558, 56.2% of 992 examined regions) and µCT (n  = 493, 49.7%) detected a higher frequency of osteophytes at PIP and DIP joints than histology (n  = 161, 23.4% of 689 histological examined regions; P  = 0.01). We found a comparable number of erosions with each method [US, n  = 52 (5.2%); µCT, n  = 43 (4.3%); histology, n  = 35 (5.2%)]. Both imaging techniques correlated moderately with each other regarding the detection of osteophytes (r  = 0.54, P  = 0.002) and erosions (r  = 0.43, P  = 0.017). Neither US nor µCT correlated with histology regarding erosions or osteophytes. With histology as the reference, US had a sensitivity of 80% and a specificity of 32% to detect osteophytes, whereas µCT had a sensitivity of 73% and a specificity of 27%. For erosions, sensitivities (US 10% and µCT 6%, respectively) were much lower. Microscopically, erosions contained fibrous myxoid tissue extending from subcortical cavities through the breach of cortical bone. Conclusions The ability of US to identify osteophytes was comparable to that of µCT, yielding a good sensitivity when histology was used as the gold standard. The sensitivity of US and µCT to detecting erosions was low compared with histology. [ABSTRACT FROM AUTHOR]

Osteosynthesis of metacarpal and phalangeal fractures with headless compression screws leads to a defect in the articular surface and possibly damage to the extensor tendons. This study aimed to quantify the articular surface defect and extensor tendon injuries after implant placement in cadaveric hands. Defect size was assessed with computed tomography. Extensor tendon injuries were assessed by direct visualization and measurement after dissection. In the middle phalanx, the defect size in relation to the joint surface was significantly smaller after anterograde screw placement when compared with retrograde placement. Also, a mini-open approach was found to cause significantly less tendon injury than a percutaneous approach, but there was no difference in tendon damage between retrograde and antegrade screw insertion into the middle phalanx. [ABSTRACT FROM AUTHOR]

ABSTRACT Osteoarthritis (OA) of the hand is a common disease resulting in pain and impaired function. The pathogenesis of hand OA (HOA) is elusive and models to study it have not been described. Chondrocyte culture has been essential to understand cartilage degeneration, which is a hallmark of OA. We investigated the feasibility of human chondrocyte culture derived from proximal interphalangeal (PIP) finger joints. Hyaline cartilage of the PIP and knee joints was obtained from human cadavers. Chondrocytes harvested up to 236 h after death of the donors were viable and expressed chondrocyte-specific genes. Gene expression comparing chondrocytes from PIP and knee joints using Affymetrix GeneChip arrays resulted in a unique PIP-specific gene expression pattern. Genes involved in developmental processes including the WNT pathway were differentially expressed between the joints. These findings suggest that our knowledge on chondrocyte biology derived mainly from knee and hip joints may not apply to chondrocytes of the PIP joints and some of the distinctive features of HOA may be caused by the specific properties of PIP chondrocytes. Chondrocyte culture of PIP cartilage is a novel tool to study cartilage degeneration in HOA. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1569-1575, 2016. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Supraclavicular brachial plexus block-variant relation of brachial plexus to subclavian artery in the first rib," by Manickam et al in a 2009 issue of "Regional Anesthesia and Pain Medicine."

Background: The use of fresh-frozen (FF) specimens represents the gold standard for biomechanical investigations. Since FF specimens are often difficult to obtain, chemical-fixed specimens (formalin (FA), Thiel (TH)) are also used., Objective: Since fixation methods can alter the mechanical properties of bone tissue, the purpose of this study was to examine their influence on the fracture force of lumbar vertebral bodies (VB)., Methods: First the VB were subdivided into three focus groups: FF, TH, and FA. After removing the soft tissue and the processus transverses of all VB, the endplates were planned with a thin layer of epoxy resin, in order to apply a constant strain to the surface and sub-surface. The VB were subjected to axial compression tests in order to determine fracture force. Lastly a standardized compression fracture was generated., Results: The mean values of the fracture force of the focus groups were 4529.5 N (FF), 3211.3N (TH) and 2947.9N (FA). Consequently a significant difference between the FF and the other two groups could be demonstrated (p< 0.05)., Conclusion: The preliminary tests showed that the fraction force of fresh-frozen VB were significantly higher than TH/FA-fixed VB. Therefore, these fixation methods could potentially have an influence on the biomechanical properties of VB. This leads to the assumption that if load-to-failure tests are performed, it is probably recommended to use fresh-frozen specimens.

Osteosynthesis of metacarpal and phalangeal fractures with headless compression screws leads to a defect in the articular surface and possibly damage to the extensor tendons. This study aimed to quantify the articular surface defect and extensor tendon injuries after implant placement in cadaveric hands. Defect size was assessed with computed tomography. Extensor tendon injuries were assessed by direct visualization and measurement after dissection. In the middle phalanx, the defect size in relation to the joint surface was significantly smaller after anterograde screw placement when compared with retrograde placement. Also, a mini-open approach was found to cause significantly less tendon injury than a percutaneous approach, but there was no difference in tendon damage between retrograde and antegrade screw insertion into the middle phalanx.