Is anterior knee pain a predisposing factor to patellofemoral osteoarthritis?

Adolescent anterior knee pain has traditionally been described as running a benign and self-limiting course. Studies more recently have questioned this supposition. This study aimed to assess how many patients who had undergone patellofemoral arthroplasty for isolated patellofemoral arthritis had previously suffered from adolescent anterior knee pain, knee instability and trauma. This group was then compared to a control group of medial unicompartmental arthroplasty patients. Both groups were surveyed by postal questionnaire, with a >75% response rate from each group. 22% of the patellofemoral arthroplasty group described adolescent or early adulthood anterior knee pain as compared to 6% in the medial unicompartmental arthroplasty group (p<0.001). Patients in the patellofemoral group had also suffered significantly more patellofemoral instability and trauma than the medial unicompartmental group (p<0.001 and p=0.02, respectively). A significant number of patients with patellofemoral arthritis have described preceding anterior knee pain in their adolescence and early adult years, raising the question as to whether anterior knee pain may be one of the contributing factors to patellofemoral osteoarthritis in later years.     

The monosodium iodoacetate model of osteoarthritis: a model of chronic nociceptive pain in rats?

Osteoarthritis (OA) is a widespread condition affecting the elderly population. One of the most prominent features but least studied symptoms is chronic pain associated with OA. The study objective was to determine pain endpoints in rats with monosodium iodoacetate (MIA) induced OA, and to investigate the efficacy of common nociceptive agents. Sprague–Dawley rats received an intraarticular injection of either 25 μl 80 mg/ml MIA or 25 μl 0.9% sterile saline into the right knee joint. Changes in von Frey thresholds and latencies to stroking with a cotton bud (punctate and dynamic allodynia, respectively) were measured pre- and for up to 10 weeks post-intraarticular injection. Changes in hind paw weight distribution were also determined. Both punctate allodynia and a weight bearing deficit were observed in MIA-treated rats for up to 10 weeks. Interestingly, dynamic allodynia was not detected at any time point tested. Morphine (0.3–3 mg/kg, s.c.) and tramadol (3–100 mg/kg, p.o.) dose-dependently inhibited punctate allodynia and partially reversed weight bearing deficit. In conclusion, the MIA model of OA is reproducible and mimics OA pain in humans. Analgesic drug studies indicate this model may be useful for investigating chronic nociceptive pain.     

Electroacupuncture for chronic pain in a model of knee arthritis北大核心

BACKGROUND: Acupuncture has been found to be effective for alleviating low back pain and acute pain due to knee arthritis, but its effect on chronic pain is under discussion. OBJECTIVE: To investigate the mechanism underlying electroacupuncture (EA) alleviating chronic pain in a New Zealand rabbit model of knee arthritis. METHODS: (1) Thirty-two New Zealand rabbits were selected, and the knee osteoarthritis model was established by injecting 4% papain into the knee articular cavity of rabbit’s bilateral hind limbs. The model rabbits were randomly divided into four groups (n=8 per group): normal saline plus EA, normal saline plus sham EA, nor-Binaltorphimine (nor-BNI) plus EA, and nor-BNI plus sham EA groups. The dosage of nor-BNI was 1 mg/kg, once daily, for consecutive 3 days. 30-minute EA was given at 2 hours after administration, once daily, until the day the rabbits were killed. Sham EA indicated no given electric current. The behaviors of the lower limbs were evaluated by Basso, Beattie, Bresnahan scores. The rabbits were respectively killed at 1, 3, 5 and 7 days after administration, the spinal cord was separated, and then fixed with formaldehyde. The expression levels of interleukin-17, interleukin-17 receptor A and NR1 in the spinal cord tissues were detected by immunofluorescence. (2) The other 24 New Zealand rabbits were randomly divided into model and control groups (n=12 per group), and the knee osteoarthritis model was established in the former group. Afterwards, the two groups were randomized into two subgroups, followed by given the intrathecal administration of normal saline, or 2 μg interleukin-17 antibody serum dissolved in 10 μL normal saline, once daily, for consecutive 3 days. The behaviors of the lower limbs were evaluated by Basso, Beattie, Bresnahan scores, and the expression levels of p-NR1 and interleukin-17 receptor were detected by western blot assy. RESULTS AND CONCLUSION: The Basso, Beattie, Bresnahan scores in the nor-BNI plus EA group were significantly increased, while the expression levels of interleukin-17, interleukin-17 receptor A and NR1 in the spinal cord tissues were significantly decreased (P < 0.05). The expression level of NRI did not differ significantly between nor-BNI plus EA and nor-BNI plus sham EA groups (P > 0.05). After administration of interleukin-17 antibody serum, the Basso, Beattie, Bresnahan scores in the model group was significantly increased, and the expression levels of interleukin-17 and NR1 in the spinal cord tissues were significantly decreased, but still significantly higher than those in the control subgroups (P < 0.05). These results suggest that chronic pain in knee arthritis is the result of an increase in the expression level of NRI induced by interleukin-17. EA can remarkably improve the pain in the model rabbits of knee arthritis by downregulating interleukin-17 in the spinal cord tissues, rather than interleukin-17 receptor. © 2017, Journal of Clinical Rehabilitative Tissue Engineering Research. All rights reserved.     

Revision of medial Oxford unicompartmental knee replacement to a total knee replacement: Similar to a primary?

Unicompartmental knee replacement (UKR) is an option for the treatment of isolated medial compartment osteoarthritis. A commonly perceived potential advantage is that revision of a UKR is straightforward. The purpose of this study was to determine the early outcomes and the level of complexity of revisions of Oxford UKRs performed at our hospital. A retrospective review of a prospective database of all phase III Oxford UKRs was undertaken. This identified 89 Oxford UKRs which were revised at our institution between 2002 and 2008. The median time from the primary procedure to revision was 19 months (interquartile range 2-73 months). Nine were revised to another UKR. Eighty were revised to a total knee replacement (TKR). Fifty-three were revised with primary TKR components. Twenty-seven were revised using stems and/or augments. The median overall tibial component thickness (including augments) was 15 mm. Forty-five knees had an overall tibial component thickness greater than 15 mm. A primary Oxford UKR bearing thickness of greater than 6mm was associated with an increased likelihood of requiring revision components. On the basis of this review, tibial bone defects were commonly encountered when revising UKRs. Reconstruction with either an augment and a stem, or thick polyethylene component was often required. We recommend that the potential complexity of revision for UKR failure should be borne in mind when considering a primary Oxford UKR.     

Ectopic discharge in Aβ afferents as a source of neuropathic pain

Ectopic discharge in axotomized dorsal root ganglion neurons is a key driver of neuropathic pain. However, the bulk of this activity is generated and carried centrally in large diameter myelinated Aβ afferents, a cell type that normally signals touch and vibration sense. Evidence is considered suggesting that following axotomy, Aβ afferents undergo a change in their electrical characteristics and also in the neurotransmitter complement that they express. This dual phenotypic switching renders them capable of (1) directly driving postsynaptic pain signaling pathways in the spinal cord, and (2) triggering and maintaining central sensitization.     

Primates: another source of grafts?

The catarrhini primates of the genus Papio, and particularly Papio anubis, may be a source of transplants whose compatibility with the human receptor doesn't induce acute rejection. The risk of zoonosis transmission is not higher than with pig transplants.     

The 'anvil' osteophyte-a primary cause of fixed flexion of the knee?

Three cases are reported in which clinical presentation was with arthritic symptoms and inability to straighten the knee. An unusually prominent anterior tibial osteophyte, whose shape is remarkably suggestive of a blacksmith's anvil, appeared to be a contributory factor through its apparent impingement with the femoral trochlea at the limit of extension. The osteophyte was radically removed arthroscopically in each case as an isolated gesture, and the patients were followed up with particular emphasis on fixed flexion deformity. At clinical review, after a mean follow-up period of 5.3 years, it was concluded that there had not been a convincing or sustained improvement in knee function, although the fixed flexion deformities had not increased significantly. Our conclusion is that the 'anvil' osteophyte may simply be a part of a more diffuse degenerative process and that it was probably not, in itself, the primary cause of fixed flexion deformity in these cases.     

Unexplained pain following total knee arthroplasty: Is rotational malalignment the problem?

Background

Malrotation of tibial and femoral components is a potential source of pain following total knee arthroplasty (TKA). This study aimed to 1) compare component rotation in TKA patients with unexplained pain versus a control group with well-functioning TKAs and 2) investigate the relationship between TKA component rotation and pain.

The thrombocytopenia of WAS: a familial form of ITP?

In the first report of the concurrent immunodeficiency, thrombocytopenia, and eczema that we now call the Wiskott-Aldrich Syndrome (WAS), Alfred Wiskott asked whether it could be a familial form of Werlhof's disease (now called ITP). This review summarizes what is known about platelet production, consumption, and function in clinical and murine WAS. Both platelet production and consumption are affected by WASP deficiency. Likely molecular mechanisms have been identified for the former process, but remain problematic for the latter. Recent data in a murine model suggest that WASP deficiency could increase both the incidence of antiplatelet antibodies and susceptibility to their enhancement of platelet consumption. Wiskott's original speculation about the relationship between WAS and ITP may need to be reconsidered.     

Reflection contrast microscopy (RCM): a forgotten technique?

Reflection contrast microscopy (RCM), which utilizes the optical phenomena caused by oblique epi-illumination in combination with a specific optical apparatus, provides an approach for exploring biological phenomena in greater detail. The lack of stray reflection makes it superior to other microscopes. It bridges light and electron microscopic capabilities by allowing the analysis of ultrathin sections beyond the usual light microscopic magnification. By using consecutive image analysis, quantitation can be achieved. The wide range of applications of RCM can be combined with most microscopical techniques, so extending the spectrum of information that can be gathered. Twenty-five years after the development of RCM, there is still scope for its application in modern cell biology.     

Partners of mutation-carriers for Huntington's disease: forgotten persons?

This study focuses on psychological distress and coping strategies in partners of tested persons 5 years after predictive testing for Huntington's disease. A total of 16 carrier-couples and 17 noncarrier-couples participated in the study. Self-report questionnaires were used, assessing depression level, anxiety, intrusive and avoidance thoughts and coping strategies. Partners of carriers have as much distress as carriers, and for some distress variables even more (P<0.05-0.001). They clearly experience more psychological distress than noncarriers' partners, as expected (P<0.05-0.001). Regarding coping strategies, carriers' partners adopt more passive strategies (passive-regressive and avoiding reactions; P<0.05) and less active strategies (social support seeking and problem solving; P<0.05-0.001), compared to carriers. For both carriers and partners, the adoption of more passive strategies for coping was associated with more distress and the use of more active strategies with less distress (for carriers: P<0.05-0.001; for carriers' partners: P<0.05). The presence of children before predictive testing was an additional result-specific distress factor in carriers and their partners. In conclusion, carriers' partners have at least as much psychological distress as carriers, but partners have the tendency to draw back. The results suggest that the grief of carriers' partners may be 'disenfranchised', or not socially recognised, as if they have no right to mourn. We moreover interpreted the results referring to concepts such as anticipatory grief, psychological defences, dissonance processes and imbalanced partner relationship. Finally, we formulated some implications for genetic counselling.     

The epidemiologic study of dementia: a life-long quest?

Based on many experimental and observational studies we now understand that neurodegenerative brain changes begin by middle age. Characteristics of the risk factors for these brain changes may also change with age. A review is conducted of studies that report on the association of mid-life risk factors to late cognitive impairment and dementia. Issues related to the interpretation of the data are discussed. The studies suggest that mid-life cardiovascular risk factors, and in particular elevated levels of blood pressure, increase the risk for late-life cognitive impairment and dementia. Our understanding the contribution of cardiovascular risk factors to late age brain disease has been helped tremendously by prospective studies with long follow-up. To better understand which risk factors lead to disease initiation, progression and prognosis, a life course approach to the epidemiologic study of dementia is needed.     

Recurrent patellar dislocations with patellar cartilage defects: A pain in the knee?

BackgroundRecurrent patellar dislocation in combination with cartilage injures are difficult injuries to treat with confounding pathways of treatment. The aim of this study was to compare the clinical and functional outcomes of patients operated for patellofemoral instability with and without cartilage defects.MethodsEighty-two patients (mean age 28.8 years) with recurrent patellar dislocations, who underwent soft-tissue or bony procedures, were divided into two matched groups (age, sex, follow up and type of procedure) of 41 each, based on the presence or absence of cartilage defects in patella. Chondroplasty, microfracture, osteochondral fixation or autologous matrix-induced chondrogenesis (AMIC)-type procedures were performed depending on the nature of cartilage injury. Lysholm, Kujala, Tegner and Subjective Knee scores of both groups were compared and analysed. Complications and return to surgery were noted.ResultsWith a mean follow up of 8 years, there was a significant improvement observed in all the mean postoperative patient-reported outcome measures of both groups, as compared with the preoperative scores (P < 0.05). Comparing the two groups, postoperative Lysholm, Kujala and Subjective knee scores were significantly higher in patients operated without cartilage defects (P < 0.05). Three patients operated for patellofemoral instability with cartilage defects underwent patellofemoral replacement subsequently. The odds ratio for developing complications was 2.53 for patients operated with cartilage defects.ConclusionAlthough there is a significant improvement in the long-term outcome scores of patients operated for recurrent patellar dislocation with cartilage defects, the results are significantly inferior compared with those without cartilage defects, along with a higher risk of developing complications and returning to surgery.     

The many lives of IL-9: a question of survival?

Although the cytokine interleukin 9 (IL-9) was discovered decades ago, it remains one of the most enigmatic cytokines identified so far, in particular because its functional activities remain far from clear. Breakthroughs made through the use of IL-9 reporter mice have allowed the identification of cell types that produce IL-9 in vivo and, contrary to expectations based on previous results obtained in vitro, it is not T cells but instead a previously unknown type of innate lymphoid cell, called the 'ILC2 cell', that is the main cell type that expresses IL-9 in vivo. In this perspective, we put forward a hypothesis about the potential biological functions of IL-9 in the immune system and beyond.     

The biographical component of schizophrenia: a two-faced definition of relationship?

The schizophrenic's disturbed relationship with reality is generally ascribed to a mental illness of endogenous origin. Following the author's paper on a fixation disorder (1) provable in these patients, she expounds that their disturbed relationship with reality does not primarily concern their consciousness of objective reality but of their own self. As a result of contradictory definitions of relationship within his group (2,3) the schizophrenic is unable to integrate the awareness of his potentialities with the awareness of his social role. He cannot protect himself against a joker role imposed on him since his fixation disorder acts like a one-way valve impeding him from taking an active part in the definition of relationship. A hypothesis is presented as to how the schizophrenic's described fixation disorder may cause this one-way functioning of the definition of relationship.