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Objective: People who sustain joint injuries such as anterior cruciate ligament (ACL) rupture often develop post-traumatic osteoarthritis (PTOA). In human patients, ACL injuries are often treated with ACL reconstruction. However, it is still unclear how effective joint restabilization is for reducing the progression of PTOA. The goal of this study was to determine how surgical restabilization of a mouse knee joint following non-invasive ACL injury affects PTOA progression., Design: In this study, 187 mice were subjected to non-invasive ACL injury or no injury. After injury, mice underwent restabilization surgery, sham surgery, or no surgery. Mice were then euthanized on day 14 or day 49 after injury/surgery. Functional analyses were performed at multiple time points to assess voluntary movement, gait, and pain. Knees were analyzed ex vivo with micro-computed tomography, RT-PCR, and whole-joint histology to assess articular cartilage degeneration, synovitis, and osteophyte formation., Results: Both ACL injury and surgery resulted in loss of epiphyseal trabecular bone (-27-32%) and reduced voluntary movement at early time points. Joint restabilization successfully lowered OA score (-78% relative to injured at day 14, p < 0.0001), and synovitis scores (-37% relative to injured at day 14, p = 0.042), and diminished the formation of chondrophytes/osteophytes (-97% relative to injured at day 14, p < 0.001, -78% at day 49, p < 0.001)., Conclusions: This study confirmed that surgical knee restabilization was effective at reducing articular cartilage degeneration and diminishing chondrophyte/osteophyte formation after ACL injury in mice, suggesting that these processes are largely driven by joint instability in this mouse model. However, restabilization was not able to mitigate the early inflammatory response and the loss of epiphyseal trabecular bone, indicating that these processes are independent of joint instability., Competing Interests: Declaration of Competing Interest No author in this paper has competing interests to disclose., (Copyright © 2024 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Angiogenesis and vascular endothelial growth factor (VEGF) are involved in osteoarthritis (OA). We previously reported the inhibitory effect of bevacizumab in a rabbit model of OA. In the current study, we investigated the effects of lenvatinib, an angiogenesis inhibitor targeting the VEGF and fibroblast growth factor receptors, on synovitis, osteophyte formation, and cartilage degeneration in a rabbit OA model. Posttraumatic OA was induced by anterior cruciate ligament transection (ACLT) on one knee of each rabbit. Rabbits were placed into four groups according to the following lenvatinib doses: untreated control ( n = 12), L0.3: 0.3 mg/kg/day ( n = 15), L1.0: 1.0 mg/kg/day ( n = 14), and L3.0: 3.0 mg/kg/day ( n = 13) groups. We evaluated limb pain using the weight distribution ratio measured with an incapacitance tester, macroscopic osteophyte formation, and femoral condyle synovium and cartilage histology. For cartilage evaluation, the following distal sites of the femur were evaluated separately: femoral-tibial (FT), femoral-patellar (FP), and femoral corner (between FP and FT). The weight distribution ratio at 12 weeks after surgery was higher in the L0.3 and L1.0 groups than in the control group. Osteophyte formation and synovitis scores were significantly lower in the L0.3, L1.0, and L3.0 groups than in the control group. The Osteoarthritis Research Society International scores of the FT, corner, and FP sites in the L0.3 group were lower than in the control group. The cartilage thickness ratio at the FT and corner sites was significantly lower in the L0.3 group than in the control group. Krenn's grading system of cartilage synovitis showed that all lenvatinib-administered groups had significantly lower scores than the control group. MMP3 expression level in cartilage tissue was significantly lower in the L3.0 group compared with the other three groups. ADAMTS5 expression was lower in the L3.0 group compared with the control and L0.3 groups. Oral administration of lenvatinib inhibited synovitis, osteophyte formation, and cartilage degeneration and reduced pain in a rabbit ACLT model. Lenvatinib is an oral VEGF inhibitor that is easier to administer than other VEGF inhibitors and may have potential as a treatment of posttraumatic OA.

Objective: Females have reduced osteoarthritis (OA) in surgical models. The objective of the current study was to evaluate a sex-linked gut microbiome in the pathogenesis of OA., Methods: We induced OA via destabilization of the medial meniscus surgery in adult male and female C57BL6/J mice with and without opposite-sex microbiome transplantation. Eight weeks later, animals were euthanized, and OA severity, synovitis, and osteophyte scores were determined. Serum lipopolysaccharide was measured chromogenically, and serum cytokines were quantified via multiplex immunoassay. Cecal microbiome profiles were generated using 16S deep sequencing., Results: Males had worse OA histology (3.5x, P = 6 × 10 -7 ), synovitis (2.4x, P = 5 × 10 -4 ), and osteophyte scores (3.7x, P = 3 × 10 -4 ) than females. Male-into-female transplantation worsened all outcomes (histology 1.8x, P = 0.02; synovitis 2.0x, P = 3 × 10 -5 ; osteophyte 2.1x, P = 0.01) compared to females, whereas female-into-male transplantation improved all outcomes except for synovitis (histology 0.53x, P = 2 × 10 -4 ; osteophyte 0.28x, P = 5 × 10 -4 ) compared to males. In the gut microbiome analysis, 44 clades were different in at least one group comparison; 5 clades were correlated with the Osteoarthritis Research Society International score (Lactobacillus R = -0.40, Aldercreutzia R = -0.40, rc4&#95;4 R = -0.55, Sutterella R = -0.37, and Clostridiales R = 0.36). In the cytokine analysis, 10 analytes were different in at least one group comparison; 3 were different in two groups (female and female-into-male transplants vs male comparisons, all reduced in female and female-into-male transplants), including interleukin-12 (0.66x, P = 0.02; 0.66x, P = 0.02, respectively), eotaxin (0.74x, P = 5 × 10 -6 ; 0.57x, P = 0.03), and tumor necrosis factor ⍺ (0.49x, P = 0.03; 0.52x, P = 0.009)., Conclusion: Sex-linked differences in the mouse gut microbiome are associated with OA outcomes, are reversible by opposite-sex microbiome transplantation, and are associated with serum cytokine changes., (© 2023 American College of Rheumatology.)

Objective: To estimate the risk of magnetic resonance imaging (MRI)-based structural changes in knee osteoarthritis (OA) among individuals with meniscal tear and knee OA, using MRIs obtained at baseline and 18 and 60 months after randomization in a randomized controlled trial of arthroscopic partial meniscectomy (APM) versus physical therapy (PT)., Methods: We used data from the Meniscal Tear in Osteoarthritis Research (METEOR) trial. MRIs were read using the MRI OA Knee Score (MOAKS). We used linear mixed-effects models to examine the association between treatment group and continuous MOAKS summary scores, and Poisson regression to assess categorical changes in knee joint structure. Analyses assessed changes in OA between baseline and month 18 and between months 18 and 60. We performed both intention-to-treat and as-treated analyses., Results: The analytic sample included 302 participants. For both treatment groups, more OA changes were seen during the early interval than during the later interval. ITT analysis revealed that, between baseline and month 18, APM was significantly associated with an increased risk of having a worsening cartilage surface area score, involving both any worsening across all knee joint subregions (risk ratio [RR] 1.35 [95% confidence interval (95% CI) 1.14, 1.61]) and the number of subregions damaged (RR 1.44 [95% CI 1.13, 1.85]) having a worsening effusion-synovitis score (RR 2.62 [95% CI 1.32, 5.21]), and having ≥1 additional subregion with osteophytes (RR 1.24 [95% CI 1.02, 1.50]). Significant associations were detected between months 18 and 60 only for having any subregion with a worsening osteophyte score (RR 1.28 [95% CI 1.04, 1.58])., Conclusion: These findings suggest that the association between APM and MRI-based structural changes in knee OA is most apparent during the initial 18 months after surgery. The reason for attenuation of this association over longer follow-up merits further investigation., (© 2022 American College of Rheumatology.)

The purpose of this study was to clarify the histological effect of reducing the loading to knee on cartilage degeneration, osteophyte formation, and synovitis in early-stage osteoarthritis (OA) using a post-traumatic rat model. Ten male rats were randomly allocated into two experimental groups: OA induction by surgical destabilization of medial meniscus (DMM, OA group) and hindlimb suspension after OA induction by DMM (OAHS group). The articular cartilage, osteophyte formation, and synovial membrane in the medial tibiofemoral joint were analyzed histologically and histomorphometrically at 2 and 4 weeks after surgery. The histological scores and changes in articular cartilage and osteophyte formation were significantly milder and slower in the OAHS group than in the OA group. At 2 and 4 weeks, there were no significant differences in cartilage thickness and matrix staining intensity between both the groups, but chondrocytes density was significantly lower in the OA group. Synovitis was milder in OAHS group than in OA group at 2 weeks. Reducing knee joint loading inhibited histological OA changes in articular cartilage, osteophyte formation, and synovial inflammation. This result supports the latest clinical guidelines for OA treatment. Further studies using biochemical and mechanical analyses are necessary to elucidate the mechanism underlying delayed OA progression caused by joint-load reduction., Competing Interests: The authors have declared that no competing interests exist.

Objectives: Responsive biomarkers are needed to assess the progression of OA and their lack has hampered previous clinical trials. Statistical shape modelling (SSM) from radiographic images identifies those at greatest risk of fast-progression or joint replacement, but its sensitivity to change has not previously been measured. This study evaluates the responsiveness of SSM in knee OA in a 12-month observational study., Methods: A total of 109 people were recruited who had undergone knee radiographs in the previous 12 months, and were grouped based on severity of radiographic OA (Kellgren-Lawrence grading). An SSM was built from three dual-energy X-ray absorptiometry scans at 6-month intervals. Change-over-time and OA were assessed using generalized estimating equations, standardized response means (SRM) and reliable change indices., Results: Mode 1 showed typical features of radiographic OA and had a strong link with Kellgren-Lawrence grading but did not change significantly during the study. Mode 3 showed asymmetrical changes consistent with medial cartilage loss, osteophytes and joint malalignment, and was responsive to change, with a 12-month SRM of 0.63. The greatest change was observed in the moderate radiographic OA group (SRM 0.92) compared with the controls (SRM 0.21), and the reliable change index identified 14% of this group whose progression was clinically significant., Conclusion: Shape changes linked the progression of osteophytosis with increasing malalignment within the joint. Modelling of the whole joint enabled quantification of change beyond the point where bone-to-bone contact has been made. The knee SSM is, therefore, a responsive biomarker for radiographic change in knees over 12 months., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: Osteophytes are common anatomical signs of advanced osteoarthritis. It remains unclear whether they develop from physio-molecular, and/or mechanical stimuli. This study examined the effects of mechanical impact on the knee joint periosteum leading to osteophyte formation., Design: Eighteen mature rats received one single impact load of 53 N (30 MPa) to the periosteum of the experimental medial femoral condyles. Contralateral knees were used as controls. Animals were sacrificed at 24 h, 3, 6 and 9 weeks post-impact. Distal femurs were harvested and prepared for histology. Hematoxylin and Eosin, and Masson's trichrome stained slides were examined by light microscopy. Nuclear density was quantified to assess the tissue reaction., Results: 24 h: The synovium membrane, fibrous and cambium periosteum were damaged. Blood infiltration pooled in the impacted medial collateral ligament (MCL) region. Week 3: A cartilaginous tissue spur, chondrophyte, was found in every rat at the impacted site of the MCL. Chondrophytes were composed of fibrocartilage and cartilage matrix, with signs of cartilage mineralization and remodelling activity. Week 6: Chondrophytes presented signs of more advanced mineralisation, recognized as osteophytes. Week 9: Osteophytes appeared to be more mineralized with almost no cartilage tissue., Conclusions: Osteophytes can be induced with a single mechanical impact applied to the periosteum in rat knees. These data indicate that a moderate trauma to the periosteal layer of the joint may play a role in osteophyte development., (Copyright © 2020 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Osteophytes - bony outgrowths on joint structures - are found in healthy individuals but are specifically present in late osteoarthritis (OA). Osteophyte development and function is not well understood, yet biomechanical stimuli are thought to be critical. Bone adapts to mechanical forces via the cellular network of osteocytes. The involvement of osteocytes in osteophyte formation and maturation has not been unravelled. Forty-three osteophytes from tibias of 23 OA patients (65 ± 9 years) were analysed. The trabecular bone structure of osteophytes presented with fewer trabeculae of lower bone mineral density compared to subchondral bone. We identified 40% early stage and 60% late stage osteophytes that significantly differed in their trabecular bone characteristics. Osteophyte bone revealed a higher number of osteocytes and a lower number of empty osteocyte lacunae per bone area than the subchondral bone. We found that OA osteophytes consist of younger bone material comprised of woven and lamellar bone with the capacity to develop into a late stage osteophyte potentially via the involvement of the osteocyte network. Our analysis of OA osteophytes implies a transition from woven to lamellar bone as in physiological bone growth within a pathological joint. Therefore, osteophyte development and growth present a valuable research subject when aiming to investigate the osteogenic signalling cascade.

Background: Surface replacement arthroplasty (SRA) through a volar approach for the proximal interphalangeal (PIP) joint can preserve the integrity of the extensor tendon, which allows early range of motion (ROM) exercise postoperatively. However, a few reports have shown that the PIP ROM tends to decline with longer follow-up. The goal of this study is to assess the results of at least 5 years of follow-up of SRA through a volar approach and also to investigate the cause of deterioration of ROM with time after SRA through this approach. Methods: Eleven fingers with degenerative osteoarthritis that underwent SRA through the volar approach were examined. ROM of the PIP joint preoperation, 1 year after the surgery, and at final follow-up was measured and statistically analyzed. Also, the relationship between PIP ROM and the osteophyte developed postoperatively was examined. Results: The average follow-up period was 7.3 years. The average PIP ROM of the PIP joints was 52.3° preoperatively, 54.1° at 1 year postoperatively, and 31.1° at the final follow-up. PIP ROM at the final follow-up was significantly decreased compared with that preoperatively or at 1 year postoperatively. Also, the development of an osteophyte was negatively correlated with the ROM of the PIP joint at the final follow-up. Conclusions: PIP ROM after SRA through a volar approach has the tendency to deteriorate with a longer follow-up. Development of an osteophyte is considered to be a main risk factor of deterioration in the cases of SRA through a volar approach.

Purpose: Rheumatoid arthritis (RA) patients with secondary osteoarthritis (OA) in a knee joint following a total knee arthroplasty (TKA) procedure have been increasing. Here, we investigated osteophyte formation in knee joints of RA patients and associated factors., Methods: We retrospectively examined findings of 35 knees in 30 RA patients (26 females, 4 males; mean age: 63.0 years; median disease duration: 15 years) who underwent TKA, including preoperative anteroposterior view radiographs of the knee joint. Using the ImageJ software package, osteophyte size in the medial femur (MF), medial tibia (MT), lateral femur (LF), and lateral tibia (LT) regions was also determined., Results: The mean femorotibial angle was 179°, while Larsen grade was 2 in 1, 3 in 12, 4 in 18, and 5 in 2 patients. Osteophyte sizes in the MF, MT, LF, and LT regions were 37.2, 17.0, 27.2, and 4.57 mm 2 , respectively, and significantly greater in the medial compartment (MC; MF+MT) than the lateral compartment (LC; LF+LT) ( p < 0.001). In varus cases, osteophyte size in the MC was significantly larger than normal and valgus cases ( p = 0.0016). Furthermore, osteophyte size in the MC was negatively correlated with the inflammatory markers C-reactive protein ( r = -0.492, p = 0.0027) and erythrocyte sedimentation rate ( r = -0.529, p = 0.0016), whereas that in the LC was negatively correlated with disease activity ( r = -0.589, p = 0.0023)., Conclusion: Our results suggest that alignment and disease activity influence osteophyte formation in RA patients, with secondary OA a more prominent symptom in RA patients with controlled inflammation.

Objective: Joint injury involving destabilisation of the joint and damage to the articular cartilage (e.g., sports-related injury) can result in accelerated post-traumatic osteoarthritis (PTOA). Destabilised medial meniscotibial ligament (DMM) surgery is one of the most commonly used murine models and whilst it recapitulates Osteoarthritis (OA) pathology, it does not necessarily result in multi-tissue injury, as occurs in PTOA. We hypothesised that simultaneous cartilage damage and joint destabilisation would accelerate the onset of OA pathology., Methods: OA was induced in C57BL/6 mice via (a) DMM, (b) microblade scratches of articular cartilage (CS) or (c) combined DMM and cartilage scratch (DCS). Mice were culled 7, 14 and 28 days post-surgery. Microcomputed tomography (μCT) and histology were used to monitor bone changes and inflammation. Dynamic weight bearing, an indirect measure of pain, was assessed on day 14., Results: Osteophytogenesis analysis via μCT revealed that osteophytes were present in all groups at days 7 and 14 post-surgery. However, in DCS, osteophytes were visually larger and more numerous when compared with DMM and cartilage scratch (CS). Histological assessment of cartilage at day 14 and 28, revealed significantly greater damage in DCS compared with DMM and CS. Furthermore, a significant increase in synovitis was observed in DCS. Finally, at day 14 osteophyte numbers correlated with changes in dynamic weight bearing., Conclusion: Joint destabilisation when combined with simultaneous cartilage injury accelerates joint deterioration, as seen in PTOA. Thus, DCS provides a novel and robust model for investigating multiple pathological hallmarks, including osteophytogenesis, cartilage damage, synovitis and OA-related pain., (Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: To investigate the longitudinal association between objectively measured ambulatory activity (AA) and knee MRI-detected osteophytes (OPs), and to test whether this relationship was modified by common risk factors for OA including sex, obesity, disease severity and knee injury history., Methods: 408 community-dwelling adults aged 51-81 years were assessed at baseline and 2.7 years. T1-weighted fat-suppressed MRI was used to evaluate knee OPs at both time points. AA was assessed at baseline by pedometers and categorized as: less active (≤7499 steps per day), moderately active (7500-9999 steps per day) and highly active (≥10,000 steps per day)., Results: Statistically significant interactions were detected between knee OA risk factors and AA on increases in MRI-detected OPs (all P < 0.05). In stratified analyses, being moderately active, compared to being less active, was protective against an increase in MRI-detected OPs (score change of ≥1) in females (relative risk (RR) = 0.42, 95%CI, 0.25-0.70, P < 0.01), those who were obese (RR = 0.50, 95%CI, 0.30-0.83, P < 0.01), those with radiographic OA (ROA) (RR = 0.68, 95%CI, 0.47-0.97, P = 0.02) and those with a history of knee injury (RR = 0.27, 95%CI, 0.08-0.88, P = 0.02) in almost every knee compartment, after adjustment for confounders. No statistically significant associations were found in males, non-obese, non-ROA or non-injury groups., Conclusions: Being moderately active is protective against an increase in MRI-detected OPs in females, those with ROA, those who are obese and those with a history of knee injury. These findings suggest that being moderately active is beneficial for individuals who are at higher risk of knee OA., (Copyright © 2019 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Purpose: We aimed to determine the factors that influence the symptoms of naviculo-cuneiform (NC) coalition using radiography and computed tomography (CT)., Methods: We retrospectively reviewed the radiographic and CT findings of 37 NC coalition cases. The existence of a large pit (depth >3 mm), irregular articular surface, joint space narrowing, dorsal bony spur, subchondral sclerosis, multiple subchondral bony cysts, and intra-articular loose body were evaluated on radiographs or CT. The size of the largest subchondral bony cyst was also measured using CT. All cases were divided into two subgroups according to the symptoms. Fisher's exact test was used to distinguish the factors influencing the symptoms., Results: Twenty-three and fourteen feet were enrolled into the symptomatic and asymptomatic groups, respectively. The rates of the large pit on either radiograph (47.83 vs. 21.43%) or CT (65.22 vs. 28.57%) were significantly different between both groups ( p = 0.001). The mean size of the largest subchondral bony cyst on CT was also significantly greater in the symptomatic group (4.25 vs. 1.53 mm, p = 0.005)., Conclusion: A large deep pit and huge subchondral bony cyst on the radiograph or CT can be related to symptoms for the patient with NC coalition. A CT is highly recommended for a more accurate evaluation in patients with NC coalition.

Objective: C-reactive protein (CRP) levels can be elevated in osteoarthritis (OA) patients. In addition to indicating systemic inflammation, it is suggested that CRP itself can play a role in OA development. Obesity and metabolic syndrome are important risk factors for OA and also induce elevated CRP levels. Here we evaluated in a human CRP (hCRP)-transgenic mouse model whether CRP itself contributes to the development of 'metabolic' OA., Design: Metabolic OA was induced by feeding 12-week-old hCRP-transgenic males (hCRP-tg, n = 30) and wild-type littermates (n = 15) a 45 kcal% high-fat diet (HFD) for 38 weeks. Cartilage degradation, osteophytes and synovitis were graded on Safranin O-stained histological knee joint sections. Inflammatory status was assessed by plasma lipid profiling, flow cytometric analyses of blood immune cell populations and immunohistochemical staining of synovial macrophage subsets., Results: Male hCRP-tg mice showed aggravated OA severity and increased osteophytosis compared with their wild-type littermates. Both classical and non-classical monocytes showed increased expression of CCR2 and CD86 in hCRP-tg males. HFD-induced effects were evident for nearly all lipids measured and indicated a similar low-grade systemic inflammation for both genotypes. Synovitis scores and synovial macrophage subsets were similar in the two groups., Conclusions: Human CRP expression in a background of HFD-induced metabolic dysfunction resulted in the aggravation of OA through increased cartilage degeneration and osteophytosis. Increased recruitment of classical and non-classical monocytes might be a mechanism of action through which CRP is involved in aggravating this process. These findings suggest interventions selectively directed against CRP activity could ameliorate metabolic OA development., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Anterior ankle impingement (AAI) results from repetitive microtrauma leading to pain and decreased dorsiflexion due to spur formation and synovial hypertrophy. Information about the prevalence of anterior spur formation in a large population, and the individual contributions of the talus and tibia to osseous impingement, is limited. A total of 670 ankle specimens from 344 individuals (n = 111 females, n = 233 males) aged 20 to 40 years at the time of death were examined. Matching tibia and talus were opposed and any spurring causing impingement was recorded. Spur locations were measured and ratios calculated to allow for inter-specimen comparison between: (1) medial-to-lateral and anterior-to-posterior spur location versus dimensions of talar neck width, and (2) medial-to-lateral spur location to dimensions of distal anterior tibial width. Differences in spur prevalence in relation to sex, race, height and age were identified by univariant and multivariable statistical analyses. Bony impingement was observed in 21% (n = 72) of specimens, with bilateral involvement in 8% (n = 27). For ankles with AAI, spurs were seen on the talus only in 61%, on the tibia only in 14%, and on both the tibia and talus in 26%. Spurs were significantly more prevalent in males (P = 0.001) and with increasing specimen age (P = 0.002). There were no significant differences related to specimen height or race. Spurs were predominately located on the anterolateral talus (78%) and the anterolateral portion of the distal tibial margin (80%). AAI was present in 21% of young osseous specimens and was significantly more prevalent in males and with increasing specimen age. Clin. Anat. 31:1144-1150, 2018. © 2018 Wiley Periodicals, Inc., (© 2018 Wiley Periodicals, Inc.)

Introduction: The surgical technique used in unicompartmental knee arthroplasty (UKA) is crucial for achieving good short and long term clinical outcomes. The medial mobile bearing UKA has shown excellent clinical outcomes and survivorship. But release of the medial collateral ligament during entering joint is cause of mobile bearing dislocation in short term outcomes and lateral compartment osteoarthritis may occur in the mid to long term outcomes. Removing all osteophytes at the time of UKA is sometime impossible due to their large size and extend to the inferior part of medial tibial plateau and removing them completely my result in release of the MCL. But no data exist on clinical outcomes in such patients., Methods: We conducted a prospective study from 2010 to 2015 of patients undergoing mobile bearing UKA and classified them in to two groups: those with (Gp1) and without (Gp2) residual osteophytes. Osteophyte size was measured using Hernborg's technique. The primary outcomes were pain score, functional score, and knee scores and the presence of reported medial knee pain., Results: 176 patients who underwent 199 mobile bearing UKAs were recruited: Gp1 = 42 patients (46 knees) and Gp2 = 134 patients (153 knees). Residual osteophyte sizes ranged from 2.13-9.42 mm (mean 4.12). The mean Gp1 Gp2 pain score (49.04, 48.92, p = 0.84), functional score (83.75, 84.04, p = 0.83) and knee score (89.86, 98.7, p = 0.0.78) scores were almost identical and no one complained of medial joint pain. Followed up ranged from 2 - 7 years (mean 4.23). No patients were lost to follow up., Conclusion: The patients with residual osteophytes of length less than 9 mm had good and similar clinical outcomes as patients without residual osteophytes following mobile bearing UKA., Level of Evidence: Level II-2, evidence obtained from well-designed cohort studies or case-control studies, preferably from more than one center or research group., Competing Interests: The authors have declared that no competing interests exist.

Osteophytes are a typical radiographic finding during osteoarthritis (OA), but the mechanisms leading to their formation are not well known. Comparatively, fracture calluses have been studied extensively; therefore, drawing comparisons between osteophytes and fracture calluses may lead to a deeper understanding of osteophyte formation. In this study, we compared the time courses of osteophyte and fracture callus formation, and investigated mechanisms contributing to development of these structure. Additionally, we investigated the effect of mechanical unloading on the formation of both fracture calluses and osteophytes. Mice underwent either transverse femoral fracture or non-invasive anterior cruciate ligament rupture. Fracture callus and osteophyte size and ossification were evaluated after 3, 5, 7, 14, 21, or 28 days. Additional mice were subjected to hindlimb unloading after injury for 3, 7, or 14 days. Protease activity and gene expression profiles after injury were evaluated after 3 or 7 days of normal ambulation or hindlimb unloading using in vivo fluorescence reflectance imaging (FRI) and quantitative PCR. We found that fracture callus and osteophyte growth achieved similar developmental milestones, but fracture calluses formed and ossified at earlier time points. Hindlimb unloading ultimately led to a threefold decrease in chondro/osteophyte area, and a twofold decrease in fracture callus area. Unloading was also associated with decreased inflammation and protease activity in injured limbs detected with FRI, particularly following ACL rupture. qPCR analysis revealed disparate cellular responses in fractured femurs and injured joints, suggesting that fracture calluses and osteophytes may form via different inflammatory, anabolic, and catabolic pathways. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:699-710, 2018., (© 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Interactions among risk factors for osteoarthritis (OA) are not well understood. We investigated the combined impact of two prevalent risk factors: mechanical loading and genetically abnormal cartilage tissue properties. We used cyclic tibial compression to simulate mechanical loading in the cho/+ (Col11a1 haploinsufficient) mouse, which has abnormal collagen fibrils in cartilage due to a point mutation in the Col11a1 gene. We hypothesized that the mutant collagen would not alter phenotypic bone properties and that cho/+ mice, which develop early onset OA, would develop enhanced load-induced cartilage damage compared to their littermates. To test our hypotheses, we applied cyclic compression to the left tibiae of 6-month-old cho/+ male mice and wild-type (WT) littermates for 1, 2, and 6 weeks at moderate (4.5 N) and high (9.0 N) peak load magnitudes. We then characterized load-induced cartilage and bone changes by histology, microcomputed tomography, and immunohistochemistry. Prior to loading, cho/+ mice had less dense, thinner cortical bone compared to WT littermates. In addition, in loaded and non-loaded limbs, cho/+ mice had thicker cartilage. With high loads, cho/+ mice experienced less load-induced cartilage damage at all time points and displayed decreased matrix metalloproteinase (MMP)-13 levels compared to WT littermates. The thinner, less dense cortical bone and thicker cartilage were unexpected and may have contributed to the reduced severity of load-induced cartilage damage in cho/+ mice. Furthermore, the spontaneous proteoglycan loss resulting from the mutant collagen XI was not additive to cartilage damage from mechanical loading, suggesting that these risk factors act through independent pathways. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:711-720, 2018., (© 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Objective: Positive associations between radiographic osteoarthritis (OA) and areal bone mineral density (BMD) have been demonstrated and appear strongest when bony features of OA are considered. To date, these associations have not been assessed using HRpQCT., Design: A total of 318 participants (170 men and 148 women), aged 72.1-81.4 years from a non-selected cohort, underwent HRpQCT of the distal radius and tibia along with hip radiography. Differences in bone microarchitecture were assessed between those with and without osteophytes, sclerosis or joint space narrowing (JSN) in either hip., Results: Men with osteophytes alone had significantly higher radial trabecular volumetric BMD (Tb.vBMD) and radial and tibial trabecular thickness (Tb.Th). Men with both sclerosis and osteophytes had significantly higher cortical volumetric BMD (Ct.vBMD) and cortical thickness (Ct.Th) at the distal tibia than those with osteophytes alone (P < 0.05). These relationships were maintained after adjustment for age and Body Mass Index (BMI), and were not replicated in women. Bone microarchitecture did not differ significantly in those with JSN from those without it in men or women., Conclusions: Our findings suggest higher Tb.vBMD and Tb.Th in men with osteophytosis but higher tibial Ct.vBMD and Ct.Th in men with hip joint sclerosis. These results do however require replication in other cohorts., (Copyright © 2017 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Objective: To investigate whether short-term, systemic depletion of macrophages can mitigate osteoarthritis (OA) following injury in the setting of obesity., Methods: CSF-1R-GFP+ macrophage Fas-induced apoptosis (MaFIA)-transgenic mice that allow conditional depletion of macrophages were placed on a high-fat diet and underwent surgery to induce knee OA. A small molecule (AP20187) was administrated to deplete macrophages in MaFIA mice. The effects of macrophage depletion on acute joint inflammation, OA severity, and arthritic bone changes were evaluated using histology and micro-computed tomography. Immunohistochemical analysis was performed to identify various immune cells. The levels of serum and synovial fluid cytokines were also measured., Results: Macrophage-depleted mice had significantly fewer M1 and M2 macrophages in the surgically operated joints relative to controls and exhibited decreased osteophyte formation immediately following depletion. Surprisingly, macrophage depletion did not attenuate the severity of OA in obese mice; instead, it induced systemic inflammation and led to a massive infiltration of CD3+ T cells and particularly neutrophils, but not B cells, into the injured joints. Macrophage-depleted mice also demonstrated a markedly increased number of proinflammatory cytokines including granulocyte colony-stimulating factor, interleukin-1β (IL-1β), IL-6, IL-8, and tumor necrosis factor in both serum and joint synovial fluid, although the mice showed a trend toward decreased levels of insulin and leptin in serum after macrophage depletion., Conclusion: Our findings indicate that macrophages are vital for modulating homeostasis of immune cells in the setting of obesity and suggest that more targeted approaches of depleting specific macrophage subtypes may be necessary to mitigate inflammation and OA in the setting of obesity., (© 2017, American College of Rheumatology.)

Study Design: A retrospective case-control study., Objective: To investigate whether posterior cervical laminectomy and fusion modifies the natural course of anterior disk-osteophyte complex in patients with multilevel cervical spondylotic myelopathy., Summary of Background Data: Dorsal migration of the spinal cord is the main purported mechanism of spinal cord decompression following cervical laminectomy and fusion but other potential mechanisms have received scant attention in the literature. This study was conducted to investigate whether cervical laminectomy and fusion affects the size of anterior disk-osteophyte complex., Methods: The medical records and radiographic imaging of 44 patients who underwent cervical laminectomy and fusion for cervical spondylotic myelopathy between 2006 and 2013 were analyzed. The size of the anterior disk-osteophyte complex was measured preoperatively and postoperatively on MR images taken at an interval of >3 months apart. A control group consisted of 20 nonoperatively treated advanced cervical spondylosis patients. Patients in the control met the same inclusion and exclusion criteria and also had sequential magnetic resonance imaging (MRI) taken at an interval of >3 months apart., Results: The nonoperative and operative groups were statistically similar in the pertinent patient demographics and characteristics including sex, age, time to second MRI, size of anterior disk-osteophyte complex on baseline MRI, mean number of levels affected, and percentage of patients with T2 signal change. As expected the mJOA scores were significantly lower in the operative versus nonoperative cohort (13.6 vs. 16.5, P<0.01). A significant decrease in the size of anterior disk osteophyte was observed in the operative group postoperatively (P<0.01). In comparison, there was no statistically significant change in the size of the anterior disk-osteophyte complex in the control group (P>0.05). The magnitude of the change in disk size between the 2 groups was statistically significant (P<0.01)., Conclusions: The findings of this study suggest that regression of anterior disk-osteophyte complex occurs following cervical laminectomy and fusion, and likely provides another mechanism of spinal cord decompression.

Osteophytes are a typical radiographic finding during osteoarthritis (OA). Osteophytes are thought to form in response to joint instability; however, the time course of osteophyte formation and joint stabilization following joint injury is not well understood. In this study, we investigated the time course of osteophyte formation and joint function following non-invasive knee injury in mice. We hypothesized that initial joint instability following knee injury would initiate osteophyte formation, which would in turn restabilize the joint and reduce range of motion (ROM). Mice were subjected to non-invasive anterior cruciate ligament (ACL) rupture. Anterior-posterior (AP) joint laxity, ROM, and chondro/osteophyte formation were measured immediately after injury, and 2, 4, 6, and 8 weeks post-injury. Chondrophyte areas at each time point were measured with histology, while mineralized osteophyte volume was determined using micro-computed tomography. Immediately after ACL rupture, AP joint laxity was increased twofold, while ROM was increased 11.7%. Chondrophytes appeared by 2 weeks post-injury, corresponding with a decrease in AP joint laxity and ROM. By 8 weeks post-injury, considerable osteophyte formation was observed around the joint, AP joint laxity returned to control levels, and joint ROM decreased to 61% of control values. These data support a role for chondro/osteophytes in joint restabilization after injury, and provide crucial insight into the time course and pathology of joint degeneration during OA development in the mouse. Statement of Clinical Significance: Results from this study increase understanding of conditions leading to osteophyte formation.© 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:466-473, 2017., (© 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Background: Acute lateral ankle ligamentous sprains (ALALS) are common injuries. This injury does not always have a favourable long-term outcome. Studies reporting the prognosis of ALALS after functional treatment are scarce., Objective: To determine the prognosis of functionally treated ALALS, in terms of recurrent ALALS and residual symptoms., Study Design: Retrospective cohort study., Setting: Patients were recruited from 20 family practices, nine physical therapy practices, the emergency departments of a regional hospital and a university hospital., Patients: Adult patients with an ALALS caused by an inversion trauma were invited to participate in this study 2.5-5 years after their initial injury., Independent Variables: Functional treatment of the initial ALALS., Main Outcome Measures: Acute lateral ankle ligamentous sprain recurrences and residual symptoms., Results: A total of 44 patients were included, with an average follow-up period after the initial ankle sprain of 204 weeks (range 150-274 weeks). Eight patients (18.1%) had reinjured their ankle. Explicit pain around the ankle joint at physical examination was experienced by 45.5%. Clinical symptoms of anterior ankle impingement were present in 25% (all athletes), with radiologically confirmed tibiotalar osteophyte bone formation in 82% of them., Conclusions: A large proportion of patients with ALALS experience recurrences and persistent symptoms after their initial ankle injury. The high percentage of patients with anterior ankle impingement syndromes illustrates the need for early assessment of this impairment in patients with persistent complaints., (© The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Introduction: Tibiofemoral syndesmosis injuries are common but have not been extensively researched. The primary objective of this study was to evaluate the outcomes after temporary screw fixation with ligament repair of these injuries. The secondary objective was to look for factors that could impact these outcomes. We hypothesised that this double fixation (screw+suture) would lead to good outcomes with minimal secondary opening of the syndesmosis upon screw removal., Material and Methods: This was a retrospective study of 285 patients with a tibiofemoral syndesmosis injury (01/2004-12/2011) who were treated by temporary tricortical or quadricortical screw fixation and ligament repair. The operated leg was unloaded for 6-8 weeks postoperative with the patient wearing a walking cast. The screw was removed in all patients before weight bearing was allowed. At follow-up, the range of motion, return to sports, pain, and functional scores (AOFAS and OMAS) were determined, and a radiological assessment was performed., Results: One hundred twenty-six patients were reviewed after a mean follow-up of 5.9±5.7years (2.9-10.5). Mean plantarflexion was 95% of the contralateral side and mean dorsiflexion was 93%. Return to sports occurred after a mean of 10weeks; 83% of patients returned to their pre-injury level of participation. Pain on VAS was 0.8/10 on average. The mean AOFAS and OMAS scores were both above 90 points. At the review, 4% of screws had broken. Diastasis was found in 5.6% of cases, osteoarthritis in 6.3% and an osteophyte in 11.1% of cases, but with no clinical repercussions. No risk factors were identified., Discussion and Conclusion: Treatment by temporary screw fixation and ligament repair leads to good objective results, confirming our hypothesis. However, there is little published data and no consensus on the fixation method or the need to remove the screw., Level of Evidence: IV, retrospective, non-comparative., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

An osteophyte is a fibrocartilage-capped bony outgrowth that is one of the features of osteoarthritis. This study reviewed the types, risk factors, pathophysiology, clinical presentations, and medical and surgical treatment of osteophytes. Extraspinal osteophytes are classified as marginal, central, periosteal, or capsular, whereas vertebral osteophytes are classified as traction or claw. Risk factors for development of osteophytes include age, body mass index, physical activity, and other genetic and environmental factors. Transforming growth factor β plays a role in the pathophysiology of osteophyte formation. Osteophytes can cause pain, limit range of motion, affect quality of life, and cause multiple symptoms at the spine. Medical treatment involves the use of bisphosphonates and other non-steroidal anti-inflammatory agents. Surgical treatment in the form of cheilectomy for impingement syndromes during joint replacement is recommended.

We previously showed that repetitive cyclic loading of the mouse knee joint causes changes that recapitulate the features of osteoarthritis (OA) in humans. By applying a single loading session, we characterized the temporal progression of the structural and compositional changes in subchondral bone and articular cartilage. We applied loading during a single 5-minute session to the left tibia of adult (26-week-old) C57Bl/6 male mice at a peak load of 9.0N for 1,200 cycles. Knee joints were collected at times 0, 1, and 2 weeks after loading. The changes in articular cartilage and subchondral bone were analyzed by histology, immunohistochemistry (caspase-3 and cathepsin K), and microcomputed tomography. At time 0, no change was evident in chondrocyte viability or cartilage or subchondral bone integrity. However, cartilage pathology demonstrated by localized thinning and proteoglycan loss occurred at 1 and 2 weeks after the single session of loading. Transient cancellous bone loss was evident at 1 week, associated with increased osteoclast number. Bone loss was reversed to control levels at 2 weeks. We observed formation of fibrous and cartilaginous tissues at the joint margins at 1 and 2 weeks. Our findings demonstrate that a single session of noninvasive loading leads to the development of OA-like morphological and cellular alterations in articular cartilage and subchondral bone. The loss in subchondral trabecular bone mass and thickness returns to control levels at 2 weeks, whereas the cartilage thinning and proteoglycan loss persist. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1941-1949, 2016., (© 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.)

Hallux rigidus is a degenerative condition leading to arthritis of the first metatarsophalangeal joint. Cheilectomy is a surgical procedure that is used in the treatment of hallux rigidus. It removes dorsal and dorsomedial or dorsolateral osteophytes, primarily relieving the impingement at the first metatarsophalangeal joint, which causes patients pain. The minimally invasive technique has proven to be an excellent technique to remove bony spurs to relieve symptoms with minimal surgical complications and fast recovery time., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Study Design: A retrospective study., Objective: To evaluate radiographic changes of patients with osteophytes at the anterior border of the caudal vertebral body who were treated with anterior cervical discectomy and fusion using dynamic rotational plates., Summary of Background Data: Dynamic cervical plates are widely used in surgeries of the anterior cervical spine. One concern in using dynamic plates is that the subjacent anterior osteophytes might act as a bony block and prevent dynamization of the plate. To our knowledge, there are no studies that have investigated the validity of this concern., Materials and Methods: Twenty-eight patients were selected for the study out of patients who had undergone 1-level anterior cervical discectomy and fusion using a dynamic rotational plate. They were divided into 2 groups on the basis of the presence of osteophytes located at the anterior border of the subjacent vertebrae. Thirteen patients had osteophytes and 15 control patients did not. The mean follow-up period was 10.8±8.4 months (range, 6-36 mo). Lateral radiographs were taken preoperatively, immediately postoperatively, and at the final follow-ups to assess changes in the following radiographic parameters: Cobb angle of the adjacent segments and fused segment, horizontal distance between C2 and C7 plumb lines, height of the bone graft, vertebral heights of the operated segment, and migration distance of the plate., Results: No statistical significance was found in the Cobb angles of the adjacent segments and fused segment, distance between the C2-C7 plumb lines, height of the graft, height of vertebral bodies of the operated segment, and migration distance of the plate through the preoperative, postoperative, and final follow-ups between the 2 groups., Conclusion: Osteophytes did not appear to affect the dynamization of plates in any of the measured radiographic parameters.

Objective: To investigate differences in MRI features between two etiologically distinct subtypes of knee osteoarthritis (OA): one group with metabolic syndrome and one lean group with frequent physical activity., Methods: We included two groups of 50 subjects of the Osteoarthritis Initiative (OAI) incidence subcohort, with KL ≥ 2 in at least one knee at 48 months follow-up. Inclusion criteria for the metabolic syndrome group were a body mass index (BMI) ≥ 30 kg/m(2) and two out of three of the following criteria: hypertension (RR > 130/85 mm Hg or hypertension medication), insulin resistance (high blood sugar or diabetic medication) or dyslipidemia (lipid lowering medication). Inclusion criteria for the active lean group were a BMI < 25 kg/m(2) and a Physical Activity Scale for the Elderly (PASE) score ≥ 2. MRI scans were scored using MR Imaging Osteoarthritis Knee Score (MOAKS). Differences in MOAKS items between groups were tested using generalized linear models adjusted for sex and age., Results: Scores for cartilage damage were significantly higher in the patella, trochlea and lateral femur in the metabolic syndrome group. Osteophyte scores were higher for all compartments in the metabolic syndrome group, though only significant for the patella, trochlea and medial tibia. Hoffa synovitis was significantly more prevalent in the active lean group while prepatellar bursa signal was more prevalent in the metabolic syndrome group., Conclusion: Metabolic OA and OA related to physical activity showed differences in MRI features, depending on knee compartment. These results show that different etiological processes in knee OA can lead to differences in structural degradation., (Copyright © 2015 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

This case report presents a 37-year-old man with clinical signs of myelopathy almost 9 years after implantation of a Bryan disc prosthesis (Medtronic Sofamor Danek, Memphis, TN, USA) for C5/C6 soft disc herniation. As demonstrated on MRI and CT scan, spinal cord compression was caused by bony spurs due to heterotopic ossification posterior to the still moving prosthesis. The device, as well as the ectopic bone deposits, had to be removed because of myelopathy and its imminent aggravation. Conversion to anterior spondylodesis was performed., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Objective: To investigate the role of the heparan sulfate (HS) proteoglycan perlecan (HSPG-2) in regulating fibroblast growth factor (FGF) activity, bone and joint growth, and the onset and progression of posttraumatic osteoarthritis (OA) in a mouse gene-knockout model., Methods: Maturational changes were evaluated histologically in the knees of 3-, 6-, and 12-week-old wild-type (WT) mice and Hspg2(Δ3-/Δ3-) mice (Hspg2 lacking domain 1 HS, generated by ablation of exon 3 of perlecan). Cartilage damage, subchondral bone sclerosis, osteophytosis, and synovial inflammation were scored at 4 and 8 weeks after surgical induction of OA in WT and Hspg2(Δ3-/Δ3-) mice. Changes in cartilage expression of FGF-2, FGF-18, HSPG-2, FGF receptor 1 (FGFR-1), and FGFR-3 were examined immunohistochemically. Femoral head cartilage from both mouse genotypes was cultured in the presence or absence of interleukin-1α (IL-1α), FGF-2, and FGF-18, and the content and release of glycosaminoglycan (GAG) and expression of messenger RNA (mRNA) for key matrix molecules, enzymes, and inhibitors were quantified., Results: No effect of perlecan HS ablation on growth plate or joint development was detected. After induction of OA, Hspg2(Δ3-/Δ3-) mice had significantly reduced cartilage erosion, osteophytosis, and synovitis. OA-induced loss of chondrocyte expression of FGF-2, FGF-18, and HSPG-2 occurred in both genotypes. Expression of FGFR-1 after OA induction was maintained in WT mice, while FGFR-3 loss after OA induction was significantly reduced in Hspg2(Δ3-/Δ3-) mice. There were no genotypic differences in GAG content or release between unstimulated control cartilage and IL-1α-stimulated cartilage. However, IL-1α-induced cartilage expression of Mmp3 mRNA was significantly reduced in Hspg2(Δ3-/Δ3-) mice. Cartilage GAG release in either the presence or absence of IL-1α was unaltered by FGF-2 in both genotypes. In cartilage cultures with FGF-18, IL-1α-stimulated GAG loss was significantly reduced only in Hspg2(Δ3-/Δ3-) mice, and this was associated with maintained expression of Fgfr3 mRNA and reduced expression of Mmp2/Mmp3 mRNA., Conclusion: Perlecan HS has significant roles in directing the development of posttraumatic OA, potentially via the alteration of FGF/HS/FGFR signaling. These data suggest that the chondroprotection conferred by perlecan HS ablation could be attributed, at least in part, to the preservation of FGFR-3 and increased FGF signaling., (© 2016, American College of Rheumatology.)

Objective: Muscle activities during the sit-to-stand motion (STS) are characterized by coordinated movements between hip extensors and knee extensors. However, previous reports regarding the STS and lower extremity muscle activities have focused on some quantitative assessment, but little qualitative research. This study aimed to examine the muscle activities of the lower extremity both quantitatively and qualitatively., Methods: Study participants included 13 patients with knee osteoarthritis (knee OA) and 11 age-matched asymptomatic controls. The task was STS from a chair with a height-adjustable seat. EMG activities were acquired using surface electromyogram. The root mean square signals normalized as a percentage of maximum voluntary isometric contraction values (RMS%MVC) and the mean power frequency (MPF) were calculated., Results: During STS, knee OA patients had increased RMS%MVC of the vastus medialis and raised MPF of the rectus femoris before buttocks-off., Conclusion: These findings suggest that STS of knee OA patients not only increased relative muscle activity of the vastus medialis, but also enlisted the rectus femoris in knee extension to improve muscle contraction force by activating more type II fibers to accomplish buttocks-off.

Objective: Alarmins S100A8 and S100A9 are major products of activated macrophages regulating cartilage damage and synovial activation during murine and human osteoarthritis (OA). In the current study, we investigated whether S100A8 and S100A9 are involved in osteophyte formation during experimental OA and whether S100A8/A9 predicts osteophyte progression in early human OA., Methods: OA was elicited in S100A9-/- mice in two experimental models that differ in degree of synovial activation. Osteophyte size, S100A8, S100A9 and VDIPEN neoepitope was measured histologically. Chondrogenesis was induced in murine mesenchymal stem cells in the presence of S100A8. Levels of S100A8/A9 were determined in plasma of early symptomatic OA participants of the Cohort Hip and Cohort Knee (CHECK) cohort study and osteophytes measured after 2 and 5 years., Results: Osteophyte size was drastically reduced in S100A9-/- mice in ligaments and at medial femur and tibia on days 21 and 42 of collagenase-induced OA, in which synovial activation is high. In contrast, osteophyte size was not reduced in S100A9-/- mice during destabilised medial meniscus OA, in which synovial activation is scant. S100A8 increased expression and activation of matrix metalloproteinases during micromass chondrogenesis, thereby possibly increasing cartilage matrix remodelling allowing for larger osteophytes. Interestingly, early symptomatic OA participants of the CHECK study with osteophyte progression after 2 and 5 years had elevated S100A8/A9 plasma levels at baseline, while C-reactive protein, erythrocyte sedimentation rate and cartilage oligomeric matrix protein were not elevated at baseline., Conclusions: S100A8/A9 aggravate osteophyte formation in experimental OA with high synovial activation and may be used to predict osteophyte progression in early symptomatic human OA., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

Background: In treating pediatric lateral condyle fractures (LCFs) of the humerus, closed reduction and percutaneous pinning (CRPP) is an attractive alternative to open reduction and internal fixation (ORIF) because of the potential decrease in tissue injury, shorter surgical times, and faster functional recovery. However, there is limited information available regarding its outcome., Methods: The data on 191 pediatric LCFs [163 fractures (85%) treated with ORIF (group 1) and 28 fractures (15%) treated with CRPP (group 2)], who were followed for over 12 weeks, was included in the present analysis. We compared several aspects related to the outcome of CRPP (as compared with ORIF), including issues related to surgical time, recovery of range of motion, lateral spur formation, complications, and overall outcome., Results: The surgical time was significantly shorter for patients in group 2 (mean: 25.4 min; range: 18 to 50 min), as compared with group 1 (mean: 52.6 min; range: 24 to 121 min). A nearly anatomic reduction (<2 mm of residual displacement) was obtained in all fractures. No intraoperative or immediate postoperative complications were observed. The recovery of range of motion was similar in both groups: during the latest follow-up appointment, elbows in group 1 and 2 had achieved a mean relative arc of motion of 99.2% and 99.7%, respectively (P=0.3). Lateral spur formation was seen in 75% of fractures in group 1 and in 68% of fractures in group 2 (P=0.2). The overall rate of complications was 6.3% and 3.6% for fractures is groups 1 and 2, respectively (P=0.5). A satisfactory outcome was observed in 88.3% of fractures in group 1 and in 89.3% of fractures in group 2 (P=0.6) (Table 1)., Conclusions: CRPP is a viable alternative for the treatment of pediatric LCFs with limited initial displacement (between 2 and 4 mm). In addition to the obvious cosmetic advantage of avoiding an unsightly scar, it is associated with decreased surgical times and does not significantly increase the incidence of complications.

The development of osteophytes, ectopic bone, or malleolar impingement following total ankle replacement represents common complications that will frequently lead to secondary procedures to relieve painful impingement. Many studies have been conducted to discover the cause of these postoperative impingement syndromes; however, there is a paucity of literature with regard to the prevention, diagnosis, and management of these conditions. The authors discuss the potential causes of formation of osteophytes and ectopic bone formation, as well as malleolar impingement syndromes following primary total ankle replacement with focus placed on diagnosis and management of these complications., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: There is very little information for today's clinician on olecranon spurs. In addition, there is some ambiguity in the literature, with the terms "olecranon spur" and "olecranon osteophyte" sometimes being used interchangeably. This review presents the current knowledge about olecranon spur anatomy, pathophysiology, clinical presentation, diagnosis, treatment options and their outcomes, as well as clarification of the terms "spur" and "osteophyte"., Methods: The PubMed and Google Scholar databases were searched using the terms "olecranon spur," "olecranon traction spur," and "olecranon osteophyte." The resulting articles were used to find other manuscripts pertaining to the subject., Results: Very few articles were found as a result of these search criteria and were limited to a few case reports and a study investigating the postoperative outcomes of spur removal. Confusion of the terms "olecranon spur" and "olecranon osteophyte" was noted in 6 of the manuscripts., Conclusions: The mechanism of olecranon spur formation has not been confirmed but seems to be similar to that of spurs at other entheses. In addition, the current literature represents a small number of patients and selects only those who required surgical intervention. Three methods of spur resection have been published, and all have good outcomes with small patient numbers and limited follow-up., (Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)

Advances in implant technology have made total ankle arthroplasty an increasingly popular alternative to arthrodesis for the management of ankle arthritis. However, a frequent complication of the procedure is nerve impingement related to either to heterotrophic bone growth or the prosthesis itself. Successful resolution of this complication presents a challenge to clinicians. We present a case of lateral impingement following total ankle arthroplasty that was successfully treated using a partial transmalleolar approach to effect a partial osteotomy of the lateral malleolus and create a fragment attached to the anterior talofibular and calcaneofibular ligaments. This approach provides a good operative field in the lateral gutter with minimal soft tissue impairment. It also facilitates curettage, and resolution of tissue impingement. The osteotomy site healed fully by 3 months postoperative, and the pain around the lateral malleolus resolved. Furthermore, the patient's score on the Japanese Society for Surgery of the Foot Ankle/Hindfoot Scale improved from 33 preoperatively to 82 at 6 months postoperative., (Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

A 46-year-old woman sustained a rupture of the extensor pollicis longus tendon more than 30 years after wrist injury. She was successfully treated with palmaris longus tendon graft and excision of the osseous spur. Attrition of the extensor pollicis longus tendon by a newly formed osseous spur was the major mechanism.

Purpose: The aim of the study was to evaluate the efficacy of temporalis muscle-fascia graft, fresh and cryopreserved human amniotic membrane as an interpositional material in preventing temporomandibular joint ankylosis in a rabbit model., Materials and Methods: In this experimental study, 21 New Zealand white rabbits were used. The condyle and the joint disc were removed to induce ankylosis in left TMJs. Reconstruction was immediately performed with temporalis muscle-fascia graft (tMFG) in group I (n = 7), fresh human amniotic membrane (fHAM) in group II (n = 7) and cryopreserved human amniotic membrane (cHAM) in group III (n = 7). All rabbits were sacrificed at 3 months after the operation. The comparison was made among three groups by means of vertical mouth opening and weight measurements, radiologic and histologic findings obtained before and after surgery., Results: In all rabbits, there was no statistically significant difference in the jaw movements and weight among groups at commencement and 3 months after surgery. The condylar surfaces were more irregular in HAM groups. There were mild osteophyte formations, sclerosis, fibrosis and calcification around the condyle in all groups however the joint gap was more preserved in group I. All interpositional materials were also seen to be partially present in the joint gap at 3 months. Ankylosis was not seen in the joint gap in any group., Conclusion: With the results of this study it was concluded that interpositional arthroplasty with HAM and tMFG have an almost similar effect in preventing TMJ ankylosis after discectomy in the rabbit model., (Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: The aim of this study was to evaluate the natural progression of bridging osteophyte formation in diffuse idiopathic skeletal hyperostosis (DISH) on CT by a newly proposed scoring system., Methods: CT examinations of the thoracic/lumbar spine of DISH patients (Resnick criteria) obtained at two or more time points within a minimum of 3 years were evaluated. Twenty-six patients (mean age at first CT 57 years, 21 males) fulfilled the entry criteria. A semi-quantitative scoring system for osteophyte progression was evaluated for intra- and interreader reliability on 68 vertebral units (VUs) in five patients. CT sagittal reformates of all 26 study patients were scored by two readers in consensus., Results: Scoring intra- and interobserver intraclass correlation coefficient values were high (0.971 and 0.893, respectively). The average time points per patient was 3.6 in 398 VUs analysed for 93 time points. The average time between the first and last scans was 5.6 years (range 3-10). The scores of six patients were unchanged. The scores of 20 patients increased by 3 units in 48 VUs over 5.6 (s.d. 3.1) years. The time for a DISH score to increase by 1 scoring unit was 1.6 (s.d. 0.4) years. Two bridging patterns were observed: osteophyte fusion associated with a calcified anterior longitudinal ligament (ALL, 66%) and osteophyte fusion without apparent ALL calcification (33%). Both patterns were observed concomitantly in 15 patients., Conclusion: The new scoring system may enable earlier diagnosis and help predict disease progression into its final confluent osteophyte form. The two described patterns may indicate an underlying inflammatory rather than a degenerative pathogenesis., (© The Author 2013. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Subchondral drilling is an established marrow stimulation technique., Hypothesis: Osteochondral repair is improved when the subchondral bone is perforated with small drill holes, reflecting the physiological subchondral trabecular distance., Study Design: Controlled laboratory study., Methods: A rectangular full-thickness chondral defect was created in the trochlea of adult sheep (n = 13) and treated with 6 subchondral drillings of either 1.0 mm (reflective of the trabecular distance) or 1.8 mm in diameter. Osteochondral repair was assessed after 6 months in vivo by macroscopic, histological, and immunohistochemical analyses and by micro-computed tomography., Results: The application of 1.0-mm subchondral drill holes led to significantly improved histological matrix staining, cellular morphological characteristics, subchondral bone reconstitution, and average total histological score as well as significantly higher immunoreactivity to type II collagen and reduced immunoreactivity to type I collagen in the repair tissue compared with 1.8-mm drill holes. Analysis of osteoarthritic changes in the cartilage adjacent to the defects revealed no significant differences between treatment groups. Restoration of the microstructure of the subchondral bone plate below the chondral defects was significantly improved after 1.0-mm compared to 1.8-mm drilling, as shown by higher bone volume and reduced thickening of the subchondral bone plate. Likewise, the microarchitecture of the drilled subarticular spongiosa was better restored after 1.0-mm drilling, indicated by significantly higher bone volume and more and thinner trabeculae. Moreover, the bone mineral density of the subchondral bone in 1.0-mm drill holes was similar to the adjacent subchondral bone, whereas it was significantly reduced in 1.8-mm drill holes. No significant correlations existed between cartilage and subchondral bone repair., Conclusion: Small subchondral drill holes that reflect the physiological trabecular distance improve osteochondral repair in a translational model more effectively than larger drill holes., Clinical Relevance: These results have important implications for the use of subchondral drilling for marrow stimulation, as they support the use of small-diameter bone-cutting devices., (© 2014 The Author(s).)

Objective: To describe cross-sectional associations between mass effect or signal intensity alteration of the suprapatellar fat pad (SPFP) with knee symptoms and structure in older adults., Methods: A cross-sectional sample of 904 randomly selected subjects (mean 62.4 years, 49.9% female) was studied. T1- or T2-weighted fat suppressed magnetic resonance imaging (MRI) was used to assess mass effect or signal intensity alteration of SPFP, cartilage volume, cartilage defects, and bone marrow lesions (BMLs). Knee pain was assessed by self-administered Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaire. The Osteoarthritis Research Society International (OARSI) atlas was used to assess knee osteophyte, joint space narrowing (JSN) and radiographic osteoarthritis (ROA). Univariable and multivariable linear or logistic regression analyses were used to examine the associations., Results: After adjustment for confounders including age, sex, body mass index (BMI), disease status, tibial bone area and/or ROA, the presence of SPFP mass effect was significantly associated with any knee pain (OR: 2.39; 95% confidence interval (CI): 1.54, 3.70) and ROA (OR: 2.10; 95% CI: 1.33, 3.31) but not with cartilage volume, cartilage defects or BMLs. The presence of SPFP signal intensity alteration was significantly associated with any knee pain (OR: 1.90; 95% CI: 1.43, 2.53), ROA (OR: 1.83; 95% CI: 1.37, 2.45), any BMLs (OR: 1.55; 95% CI: 1.17, 2.06) but not with cartilage volume and cartilage defects. Significant associations with knee pain and BMLs were more evident in subjects with ROA. Presence of SPFP mass effect and/or signal intensity alteration combined was associated with any tibial cartilage defects (OR: 1.45; 95% CI: 1.04, 2.04)., Conclusions: SPFP mass effect and/or signal intensity alterations are deleteriously associated with knee pain, radiographic OA and BMLs in this cross-sectional study, suggesting that SPFP abnormalities may contribute to pain and structural abnormalities in the knee., (Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)

Background: Radiographic measures of osteoarthritis (OA) are based upon two dimensional projection images. Active appearance modelling (AAM) of knee magnetic resonance imaging (MRI) enables accurate, 3D quantification of joint structures in large cohorts. This cross-sectional study explored the relationship between clinical characteristics, radiographic measures of OA and 3D bone area (tAB)., Methods: Clinical data and baseline paired radiographic and MRI data, from the medial compartment of one knee of 2588 participants were obtained from the NIH Osteoarthritis Initiative (OAI). The medial femur (MF) and tibia (MT) tAB were calculated using AAM. 'OA-attributable' tAB (OA-tAB) was calculated using data from regression models of tAB of knees without OA. Associations between OA-tAB and radiographic measures of OA were investigated using linear regression., Results: In univariable analyses, height, weight, and age in female knees without OA explained 43.1%, 32.1% and 0.1% of the MF tAB variance individually and 54.4% when included simultaneously in a multivariable model. Joint space width (JSW), osteophytes and sclerosis explained just 5.3%, 14.9% and 10.1% of the variance of MF OA-tAB individually and 17.4% when combined. Kellgren Lawrence (KL) grade explained approximately 20% of MF OA-tAB individually. Similar results were seen for MT OA-tAB., Conclusion: Height explained the majority of variance in tAB, confirming an allometric relationship between body and joint size. Radiographic measures of OA, derived from a single radiographic projection, accounted for only a small amount of variation in 3D knee OA-tAB. The additional structural information provided by 3D bone area may explain the lack of a substantive relationship with these radiographic OA measures., (Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Objective: We sought to develop a comprehensive scoring system for evaluation of pre-clinical models of osteoarthritis (OA) progression, and use this to evaluate two different classes of drugs for management of OA., Methods: Post-traumatic OA (PTOA) was surgically induced in skeletally mature rats. Rats were randomly divided in three groups receiving either glucosamine (high dose of 192 mg/kg) or celecoxib (clinical dose) or no treatment. Disease progression was monitored utilizing micro-magnetic resonance imaging (MRI), micro-computed tomography (CT) and histology. Pertinent features such as osteophytes, subchondral sclerosis, joint effusion, bone marrow lesion (BML), cysts, loose bodies and cartilage abnormalities were included in designing a sensitive multi-modality based scoring system, termed the rat arthritis knee scoring system (RAKSS)., Results: Overall, an inter-observer correlation coefficient (ICC) of greater than 0.750 was achieved for each scored feature. None of the treatments prevented cartilage loss, synovitis, joint effusion, or sclerosis. However, celecoxib significantly reduced osteophyte development compared to placebo. Although signs of inflammation such as synovitis and joint effusion were readily identified at 4 weeks post-operation, we did not detect any BML., Conclusion: We report the development of a sensitive and reliable multi-modality scoring system, the RAKSS, for evaluation of OA severity in pre-clinical animal models. Using this scoring system, we found that celecoxib prevented enlargement of osteophytes in this animal model of PTOA, and thus it may be useful in preventing OA progression. However, it did not show any chondroprotective effect using the recommended dose. In contrast, high dose glucosamine had no measurable effects., (Copyright © 2014 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.)