This is an open-access article distributed under the terms of the Creative Commons Attribution License , which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. DOI: 10.15761/GOS.1000145

BACKGROUND:The management of cartilage and osteochondral lesions in the knee remains problematic and controversial. Our group reported the 2-year and 5-year results of a randomized controlled trial comparing autologous chondrocyte implantation (ACI) and microfracture in patients with focal femoral cartilage injuries. The objective of the present study was to report the long-term results.METHODS:Eighty patients with a single symptomatic chronic cartilage defect on the femoral condyle without general osteoarthritis were included in the study at the time of the index operation (January 1999 to February 2000). We used the International Cartilage Repair Society (ICRS), Lysholm, Short Form-36 (SF-36), and Tegner forms to collect data at the time of inclusion and at follow-up evaluations. Standing weight-bearing radiographs were evaluated for evidence of osteoarthritis according to the method described by Kellgren and Lawrence. For the long-term follow-up in 2014, we used the Synaflexer frame to standardize the radiographs. The operation was considered to have failed if a reoperation was performed because of symptoms from a lack of healing of the treated defect.RESULTS:At the long-term follow-up evaluation, no significant differences between the treatment groups were detected with respect to the results on the clinical scoring systems. At the 15-year evaluation, there were 17 failures in the ACI group compared with 13 in the microfracture group. We observed that more total knee replacements were needed in the ACI group than in the microfracture group (6 compared with 3). The surviving patients in both groups, i.e., those who had not had a failure, had significant improvement in the clinical scores compared with baseline. Fifty-seven percent of the surviving patients in the ACI group and 48% of such patients in the microfracture group had radiographic evidence of early osteoarthritis (a Kellgren and Lawrence grade of ≥2); the difference was not significant.CONCLUSIONS:The survivors in both groups improved their clinical scores in the short, medium, and long-term evaluations, and no significant difference between the groups was found at the long-term follow-up. The risk of treatment failure and the frequency of radiographic osteoarthritis are problematic. Our findings raise serious concerns regarding the efficacy of these procedures in delaying osteoarthritis and preventing further surgery. Continued basic and clinical research is needed in this field.LEVEL OF EVIDENCE:Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

The aim of this manuscript is to review the current knowledge in terms of retro-trochanteric pain syndrome, make recommendations for diagnosis and differential diagnosis and offer suggestions for treatment options. The terminology in the literature is confusing and these symptoms can be referred to as ‘greater trochanteric pain syndrome’, ‘trochanteric bursitis’ and ‘trochanteritis’, among other denominations. The authors focus on a special type of sciatica, i.e. retro-trochanteric pain radiating down to the lower extremity. The impact of different radiographic assessments is discussed. The authors recommend excluding pathology in the spine and pelvic area before following their suggested treatment algorithm for sciatica-like retro-trochanteric pain. Level of evidence II.

The main goal of our study was to analyze and compare the profiles of secreted proteins from adult human articular chondrocytes in monolayers, and cartilage explants in culture, using a de novo protein labeling approach. Stable isotope labeling of proteins in culture was used to differentiate between chondrocyte-derived proteins and other preexisting matrix-derived components, or proteins coming from serum or synovial fluids. Proteins in culture supernatants were resolved by one-dimensional SDS-PAGE electrophoresis, and analyzed in tandem with LC/MS-MS (liquid chromatography/double mass spectrometry). Results from stable isotope labeling with amino acids in cell culture (SILAC) were validated by specific immunoblotting of four relevant proteins identified in the secretion media. After 8-10 days of culture, over 90% of proteins secreted during monolayer growth contained C-13(6)-Arg and C-13(6)-Lys. Nonlabeled proteins corresponded mostly to plasma-associated proteins, indicating background contamination of medium with serum remnants. The majority of the secreted proteins in 2D cultures were extracellular matrix components and matrix regulators, along with some inflammatory agents and metabolic enzymes. In explants, only 25%-30% of proteins were labeled with heavy amino acids, corresponding to matrix regulators and carrier molecules. Nonlabeled proteins corresponded primarily to structural matrix components. In qualitative terms, all labeled proteins coming from cartilage explants were also found in chondrocytes supernatants. In summary, our results show differences in the labeling pattern of proteins found in supernatants from explants and monolayers. Most proteins found in the media of explants were subproducts of matrix turnover rather than newly synthesized. To our knowledge, this study is the first one so far applying SILAC technology in the context of cartilage and chondrocytes physiology. (C) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:1040-1049, 2010

Objective: The main goal of this study was to compare the secretion products derived from human articular chondrocytes established in either long-term monolayer cultures or in scaffold-free 3-dimensional (3-D) cultures. Methods: Stable isotope labeling of amino acids in cell culture (SILAC) was applied to investigate quantitatively the differences between proteins secreted from dedifferentiated and redifferentiated chondrocytes. Proteins in cell supernatants were resolved by 1-D gel electrophoresis and analyzed by mass spectrometry. The results from the proteomic analyses were validated by immunoblotting. Additionally, antibody arrays were used to screen culture supernatants for 79 different morphogens. Results: Quantitative SILAC showed that some relevant growth factors such as CTGF or GAS6 were elevated in monolayers, along with proteins characteristic of a dedifferentiated phenotype such as collagen type I and tenascin. In spheroids, data showed overexpression of some cartilage-specific proteins such as aggrecan, together with important matrix regulators such as chitinase-3–like protein and stromelysin-1. Antibody arrays revealed that chondrocytes in monolayer secrete higher levels of leukocyte-activating agents such as MCP-1 and GRO, whereas the spheroid configuration favors the production of cell morphogens such as MCSF and VEGF. Conclusion: Our results show that some classic dedifferentiation and redifferentiation markers are differentially expressed in 2-D or 3-D culture configurations. Other cell/matrix regulatory molecules are also found to be differentially expressed by chondrocytes in 2-D and 3-D conditions by SILAC and antibody arrays. Our data bring new information for understanding the biology of chondrocytes in general and the process of cartilage tissue reconstruction in particular.

Diffuse retro-trochanteric pain occasionally radiating to the lower extremity could be caused by the piriformis or internal obturator muscle syndromes. Thirteen patients, with retro-trochanteric pain were included in the study. All patients suffered from a diffuse, but intense and often radiating hip pain. The median duration of the symptoms was 8 (1-20) years. The patients were treated by a specific supervised stretching programme with special emphasis on the internal obturator muscle. The duration of the stretching programme was 4 weeks. At inclusion, the median pain on the visual analogue scale (VAS) was 6.0 (3-7). The VAS for pain decreased to 4.0 (0-7) (p = 0.01) at 12 weeks. Five years after treatment, the VAS for pain was still significantly lower than at inclusion, 4.0 (0-7) (p = 0.018). A significant reduction in the number of positive Freiberg's tests and in the number of patients limping was also observed, both at 3 months and at 5 years after treatment. It appears that a supervised stretching programme renders significant short and long term decrease in symptom for patients with retro-trochanteric pain.

To avoid revision surgeries in artificial joint replacements and to allow young people to have a joint replacement, using biological joint replacement created by tissue engineering is a promising alternative. Several research groups have tissue engineered bone [Warnke 2004] and cartilage [Chung 2007] separately. The tissue engineering of a joint, consisting of bone and cartilage is the next frontier. The present study focuses on the design of a novel device, named Endoreactor, that is employing the mechanosensitivity of cells to create a joint-like-structure (JLS) consisting of a bone and cartilage sandwich, similar to an amphiarthrosis, by applying a mechanical loading regime to a stem cell seeded scaffold construct during endocultivation. This way, the patients who will eventually need the new joint will serve as their own bioreactor, having the joint grow in their own body. In the JLS, the outside layers are designed to become bone, using a 6 mm thick scaffold with high stiffness. The center layer is a 4 mm thick scaffold which is compliant so as to experience more strain than the outside scaffolds to stimulate cartilage formation. Compression is realized by placing the JLSs between the long links of a kite-shaped four-bar linkage. This Endoreactor is powered by natural body motion through connection to the musculoskeletal system of the host, which in the experimental phase is a Gottingen minipig. The loading frequency and rest versus active time is dictated by the activity level of the minipig. This results in a natural loading pattern that is employed for the stimulation of cartilage formation in the JLS. A tensile force created during ambulation is converted into compressive action between the two long links of the mechanism. A mechanical stop limits the motion. This way controlled intermittent dynamic compression between 2.5% and 12.5% is realized in the cartilage layer of the JLS. All functions are integrated into a single piece compliant mechanism which is produced out of titanium using 3D rapid prototyping by selective laser melting technology. The mechanism can be fitted with cages that hold the scaffolds for bone and cartilage in place and protect them from external loads while being implanted. A safety spring was added to accommodate for large actuation excursions. A number of prototypes were produced and tested for fatigue, plastic deformation, failure load, and displacements of the long links at the JLS locations under different axial loads. These tests confirmed the proper mechanical functioning of the Endoreactor. Work with animal models making use of the device to culture an amphiarthosis-like joint is foreseen in the near future. This work was carried out at part of MYJOINT: Living Bioreactor—Growing a New Joint in a Human Back, EU FP6-2004-NEST-C-1, Proposal No. 028861.

Mesenchymal progenitor cells from bone marrow hold great potential as a cell source for cartilage repair. Aspiration from the iliac crest is the most widely used method to harvest bone marrow cells for cartilage repair. The objective of our study was to establish a new method to isolate mesenchymal progenitor cells by direct aspiration of bone marrow from the subchondral spongious bone underneath cartilage defects during microfracture treatment and to confirm the chondrogenic potential of the resulting cell cultures.

Twelve patients with clinical signs of retro-trochanteric pain syndrome were randomized to either operative treatment or a control group. Six patients were operated on with sectioning of the tendon to the internal obturator near its insertion to the trochanter major. There was no significant pain decrease in either group at 6 months. However, at 8 years, the decrease in pain was significant in the surgical group (P < 0.03) but not in the control group. Three patients in the surgical group who needed pain medication with opioids preoperatively managed without such drugs at 8 years. Two patients in the surgical group were working half time at the 8 year follow-up. Before the start of the study the patients had been out of work for 3 and 10 years, respectively. At inclusion 4/12 patients had minor degenerative changes at the L3-L5 level as seen on computerized tomography or magnetic resonance imaging. At 8 years, the corresponding change was found in 7/9 patients (P = 0.025). In conclusion, at 8 years after surgical release of the internal obturator muscle, the patients had a significant decrease in pain compared with the finding at inclusion. The corresponding was not found in the control group.

Gluteal compartment syndrome may, in its severe form, have serious consequences. It may result in severe rhabdomyolysis, and if left untreated it can result in acute renal collapse, multiorgan failure and even death. The present report concerns a patient who developed a gluteal compartment syndrome after lumbar surgery. The syndrome was complicated by acute renal failure with high concentrations of serum creatinine kinase, myoglobin, and potassium, requiring acute haemodialysis before surgical release. The operation revealed increased intracompartmental pressure with weak or absent reaction of muscles to electric stimulation. To prevent the development of gluteal compartment syndrome during operative procedures, it is important to avoid harmful pressure to the gluteal regions on the operating table. It is also important to optimise muscle circulation by adequate hydration therapy and avoidance of nephrotoxic stimuli. If gluteal compartment syndrome develops, immediate diagnosis and surgical decompression are mandatory .

BACKGROUND:Recalcitrant lateral epicondylitis (elbow tendinosis) is a common cause of elbow pain. There are many forms of treatment, none being superior.HYPOTHESIS:The main hypothesis tested in this study is that radiofrequency microtenotomy offers better results than the extensor tendon release and repair operation for elbow tendinosis, especially earlier recovery.STUDY DESIGN:Randomized controlled trial; Level of evidence, 1.METHODS:Twenty-four patients were randomized into 2 treatment groups, extensor tendon release and repair, and microtenotomy. Dynamic infrared thermography (DIRT) was employed as an objective method to verify the diagnosis as well as to document the outcome 3 months after the surgical procedure.RESULTS:Visual analog scale pain scores in the microtenotomy but not in the release group decreased significantly after 3 weeks. There was no statistically significant difference in pain scores between the 2 groups at 3, 6, and 12 weeks, and at 10 to 18 months. At 12 weeks, grip strength had improved significantly in the microtenotomy but not in the release group. The functional score was significantly increased in both groups. The DIRT group showed significant differences in epicondyle skin temperature between diseased and normal elbows both pre- and postoperatively. Abnormal DIRT images correlated well with elevated pain scores.CONCLUSIONS:Radiofrequency microtenotomy provides a promising alternative to the release operation for elbow tendinosis. Dynamic infrared thermography provides a reliable, noninvasive, objective method for the diagnosis of elbow tendinosis, as well as for evaluation of the outcome following treatment.

BACKGROUND:Liver sinusoidal endothelial cells (LSECs) are specialized scavenger cells, with crucial roles in maintaining hepatic and systemic homeostasis. Under normal physiological conditions, the oxygen tension encountered in the hepatic sinusoids is in general considerably lower than the oxygen tension in the air; therefore, cultivation of freshly isolated LSECs under more physiologic conditions with regard to oxygen would expect to improve cell survival, structure and function. In this study LSECs were isolated from rats and cultured under either 5% (normoxic) or 20% (hyperoxic) oxygen tensions, and several morpho-functional features were compared.RESULTS:Cultivation of LSECs under normoxia, as opposed to hyperoxia improved the survival of LSECs and scavenger receptor-mediated endocytic activity, reduced the production of the pro-inflammatory mediator, interleukin-6 and increased the production of the anti-inflammatory cytokine, interleukin-10. On the other hand, fenestration, a characteristic feature of LSECs disappeared gradually at the same rate regardless of the oxygen tension. Expression of the cell-adhesion molecule, ICAM-1 at the cell surface was slightly more elevated in cells maintained at hyperoxia. Under normoxia, endogenous generation of hydrogen peroxide was drastically reduced whereas the production of nitric oxide was unaltered. Culture decline in high oxygen-treated cultures was abrogated by administration of catalase, indicating that the toxic effects observed in high oxygen environments is largely caused by endogenous production of hydrogen peroxide.CONCLUSION:Viability, structure and many of the essential functional characteristics of isolated LSECs are clearly better preserved when the cultures are maintained under more physiologic oxygen levels. Endogenous production of hydrogen peroxide is to a large extent responsible for the toxic effects observed in high oxygen environments.

The main purpose of this work has been to establish a new culturing technique to improve the chondrogenic commitment of isolated adult human chondrocytes, with the aim of being used during cell-based therapies or tissue engineering strategies. By using a rather novel technique to generate scaffold-free three-dimensional (3D) structures from in vitro expanded chondrocytes, we have explored the effects of different culture environments on cartilage formation. Three-dimensional chondrospheroids were developed by applying the hanging-drop technique. Cartilage tissue formation was attempted after combining critical factors such as serum-containing or serum-free media and atmospheric (20%) or low (2.5%) oxygen tensions. The quality of the formed microtissues was analyzed by histology, immunohistochemistry, electron microscopy, and real-time PCR, and directly compared with native adult cartilage. Our results revealed highly organized, 3D tissue-like structures developed by the hanging-drop method. All culture conditions allowed formation of 3D spheroids; however, cartilage generated under low oxygen tension had a bigger size, enhanced matrix deposition, and higher quality of cartilage formation. Real-time PCR demonstrated enhanced expression of cartilage-specific genes such us collagen type II and aggrecan in 3D cultures when compared to monolayers. Cartilage-specific matrix proteins and genes expressed in hanging-drop-developed spheroids were comparable to the expression obtained by applying the pellet culture system. In summary, our results indicate that a combination of 3D cultures of chondrocytes in hanging drops and a low oxygen environment represent an easy and convenient way to generate cartilage-like microstructures. We also show that a new specially tailored serum-free medium is suitable for in vitro cartilage tissue formation. This new methodology opens up the possibility of using autogenously produced solid 3D structures with redifferentiated chondrocytes as an attractive alternative to the currently used autologous chondrocyte transplantation for cartilage repair.

We investigated the effect of beta-endorphin on the activities of mitogen-activated protein kinases in cultured human articular chondrocytes in order to elucidate its effect on cartilage. Monolayer cultures of chondrocytes obtained from patients undergoing total knee arthroplasty were treated with 60, 600, or 6000 ng/ml beta-endorphin, or 100 ng/ml naltrexone combined with 600 ng/ml beta-endorphin. The regulation of three major mitogen-activated protein kinases phosphorylation, ERKp44/p42, p38, and JNK, was determined by Western blotting. We also examined the influence of specific mitogen-activated protein kinase inhibitors on IL-1 beta protein levels during beta-endorphin stimulation. The results demonstrate that beta-endorphin, dependent on concentration and duration of stimulation, significantly affected the activation of the three mitogen-activated protein kinases in cultured human articular chondrocytes. Naltrexone in some cases significantly regulated the mitogen-activated protein kinases in different ways when added to beta-endorphin 600 ng/ml. Furthermore, specific mitogen-activated protein kinase inhibitors hindered the increase of IL-1 beta during beta-endorphin incubation. The effect of beta-endorphin seen in this study is considered critical for the production of several mediators of cartilage damage in an arthritic joint.

Purpose:Opiates have been of interest in research for their potential and infection.Both opiates and opioid-binding sites have been localized on cartilage in animal models, and the presence of opiates on human cartilage and chondrocytes. Methods and Materials:In the present study a search for opioid receptors and opiate production was done on cartilage and monolayer cultures of chondrocytes obtained from patients and IL-1 beta produced by cultured chondrocytes.Various methods such as PCR, immunohistochemistry, immunocytochemistry and qualitative Western-blot were used.To quantify beta-endorphin's effect on CREB and MAPK phosphorylation and TNF-alpha and IL-1 beta levels, we used semi-quantitative Western-blot and ELISA determination.Results: We found that human chondrocytes do have mu-opioid opioid stimulation of chondrocytes may regulate CREB, MAPK, IL-1 beta and TNF-alpha depending on the concentration of opiates and duration of incubation.Furthermore, the opioid effect on IL-1 beta opiates in cartilage or chondrocytes.Conclusions: opiates of both endogenous and exogenous origin via mu-

OBJECTIVE:Information that a painkiller has been administrated induces an expectancy of reduced pain, and the expectancy has been shown to reduce pain. This is termed placebo analgesia. We hypothesized that an expectancy of reduced pain reduces stress. METHODS:The present study (N=84) investigated this hypothesis. To further study the effects of stress and emotions on pain, we provided information about the pain stimulus to half the subjects. Pain was induced by the submaximum tourniquet technique. RESULTS:Expectations and pain information both decreased pain to the same degree, but independently, and only in males. Lower pain was not related to subjective stress, cortisol, or circulating beta-endorphin. All experimenters were women, and the finding of placebo analgesia only in males fits well with findings that males report less pain to female experimenters. CONCLUSION:Placebo analgesia is not related to stress and is influenced by the social context in which pain is recorded.

In the present study, we have investigated the presence of pro-opiomelanocortin C-terminal fragment derived-peptides in human articular cartilage and cultured chondrocytes. beta-Lipotropin and beta-endorphin were monitored in different cell cultures and biopsies using different techniques. Biopsies were taken from patients undergoing total knee arthroplasty due to osteoarthritis. Both fresh tissue sections and chondrocytes cultured in monolayer were used in the study. Immunohistochemistry, immunocytochemistry, reverse transcriptase-polymerase chain reaction and qualitative Western blots were carried out. The results of the reverse transcriptase-polymerase chain reaction showed transcription of a truncated-form of mRNA for pro-opiomelanocortin in native cartilage and cultured chondrocytes. There was no detection of endogenous production of beta-lipotropin or beta-endorphin in human articular chondrocytes, either in situ or in vitro. Whether pro-opiomelanocortin-derived peptides of non-cartilaginous origin are present in articular cartilage itself still remains unclear.

In order to investigate if beta-endorphins anti-inflammatory effect in cartilage-damaging states is mediated via tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta), we examined its influence on these two cytokines in vitro. Human articular chondrocytes were obtained from patients undergoing total knee arthroplasty and stimulated with beta-endorphin (60-6000 ng/ml). Protein levels of TNF-alpha and IL-1 beta were measured by ELISA in supernatants from articular chondrocyte cultures. beta-Endorphin significantly increased the levels of IL-1 beta for all concentrations used after 15 min incubation, and when stimulated with 600 and 6000 ng/ml after 24 h incubation. The opioid-induced increase in IL-1 beta was blocked by naltrexone in the group tested. TNF-alpha expression was also significantly stimulated by 60 and 600 ng/ml beta-endorphin after 15 min, an effect blocked by naltrexone in the group tested. These findings indicate that the mechanism of beta-endorphins anti-inflammatory influence in cartilage-damaging states is not apparently mediated via these two cytokines modulation.