Marked differences in local bone remodelling in response to different marrow stimulation techniques in a large animal.

Marrow stimulation, including subchondral drilling and microfracture, is the most commonly performed cartilage repair strategy, whereby the subchondral bone plate is perforated to release marrow-derived cells into a cartilage defect to initiate repair. Novel scaffolds and therapeutics are being designed to enhance and extend the positive short-term outcomes of this marrow stimulation. However, the translation of these newer treatments is hindered by bony abnormalities, including bone resorption, intralesional osteophytes, and bone cysts, that can arise after marrow stimulation. In this study, three different marrow stimulation approaches - microfracture, subchondral drilling and needle-puncture - were evaluated in a translationally relevant large-animal model, the Yucatan minipig. The objective of the study was to determine which method of marrow access (malleted awl, drilled Kirschner wire or spring-loaded needle) best preserved the underlying subchondral bone. Fluorochrome labels were injected at the time of surgery and 2 weeks post-surgery to capture bone remodelling over the first 4 weeks. Comprehensive outcome measures included cartilage indentation testing, histological grading, microcomputed tomography and fluorochrome imaging. Findings indicated that needle-puncture devices best preserved the underlying subchondral bone relative to other marrow access approaches. This may relate to the degree of bony compaction occurring with marrow access, as the Kirschner wire approach, which consolidated bone the most, induced the most significant bone damage with marrow stimulation. This study provided basic scientific evidence in support of updated marrow stimulation techniques for preclinical and clinical practice.

Outcome of Osteophytes After Only-Fixation as Treatment for Multilevel Cervical Spondylosis-A Minimum of 12 Months Follow-Up.

OBJECTIVE: This report analyzes the significance of osteophytes in the overall pathologic scheme in patients with single-level or multilevel cervical spinal degeneration. METHODS: From January 2010 to December 2018, 249 patients with cervical spondylosis were surgically treated. The alterations in ventral compression caused by disc bulges, osteophytes, and ligament buckling (disc-osteophye-ligament [DOL] complex) at single or multiple levels were evaluated after surgical treatment that involved only spinal fixation and did not involve any kind of bone or soft tissue decompression. Delayed (≥1 year after surgery) postoperative imaging was available in 165 patients and these patients formed the study group. Forty-five patients underwent facet distraction arthrodesis (group A), 106 patients underwent only-fixation involving transarticular screw insertion (group B), and 14 patients underwent hybrid fixation that involved both intra-articular spacers and transarticular fixation techniques (group C) as the surgical treatment. RESULTS: The size of the DOL complex at the segments that underwent fixation was reduced in 136 patients. The size of the DOL complex or its related dural or neural compression did not increase in any of the cases evaluated. Reduction in the size of DOL was more pronounced in patients in group A in both immediate postoperative and delayed images and in patients in group C at spinal levels at which facet distraction was performed using facet distraction spacers. CONCLUSIONS: Spinal stabilization reduces the size of osteophytes. Facet distraction spacers are more effective in reduction of the size of DOL in both immediate and delayed postoperative periods.

Hand strenght and dexterity in interphalangeal hand osteoarthritis and effects of osteophyte formations.

BACKGROUND: Hand osteoarthritis (HOA) is a complex disorder with various subtypes characterized with predominance of different features. It is challenging to estimate the severity of hand disability in HOA, since contribution of different disease components to clinical burden is yet to be clarified. The aim of the study is to investigate hand functions in nonerosive interphalangeal hand osteoarthritis (HOA) without inflammatory features, and search for effects of osteophyte formations detected by radiography and ultrasound on functionality. METHODS: Thirty one HOA patients and 20 healthy subjects with similar age, gender, body mass index were included. Hand functions were evaluated by self-reported questionnaires and objective strength and dexterity measurements. A total of 459 interphalangeal joints were evaluated and scored by radiography and ultrasound for ostephyte formations. RESULTS: Strength and dexterity measurements were similar between groups. Self-reported functionality was hampered in HOA group but not statistically significant. Osteophyte scores obtained by ultrasound and radiography were significantly higher in HOA group. Osteophyte scores obtained by ultrasound were higher than the scores obtained by radiography. Ultrasound scores showed no correlation with any of the parameters while osteophytes scores obtained by radiography partially showed a significant negative correlation with assembly part of dexterity testing. CONCLUSIONS: No significant difference observed in hand strength and dexterity in nonerosive interphalangeal HOA patients withouth signs of inflammation when compared to healthy subjects. Osteophyte formations prominent enough to be deteceted by radiography may have a negative effect on hand dexterity.

Human C-reactive protein aggravates osteoarthritis development in mice on a high-fat diet.

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.

What is the tolerated width of periacetabular osteophytes to avoid impingement in cementless THA?: a three-dimensional simulation study.

BACKGROUNDS: Impingement is a risk factor for instability and prosthetic failure following total hip arthroplasty (THA). If the periacetabular osteophytes are not removed at surgery, impingement could occur between the osteophytes and the femoral stem following THA. However, excessive removal of the osteophytes could lead to bleeding from the bone. The aim of our study, therefore, was to locate the site of the impingement and to determine the width of tolerable osteophytes, which does not induce impingement during activities of daily living (ADL), using a three-dimensional simulation. METHODS: On 35 hip models, virtual THA was performed. The acetabular cups were positioned at 45° abduction and 20° anteversion, and the anteversion of femoral stems was 15°. Circular osteophytes with a 30-mm rim were built around the acetabular cup. Fourteen ADL motions were simulated, and the osteophytes were removed until there was no impingement. A clock face was used to map the location and the width of tolerable osteophytes. RESULTS: The impingement mainly occurred in antero-superior and posterior portions around the acetabular cup. Only 4.2-6.2-mm osteophytes were tolerable at the antero-superior portion (12-3 o'clock) and 6.3-7.2-mm osteophytes at the posterior portion (8-10 o'clock) following a total hip arthroplasty. In antero-inferior and postero-superior portions, over-20-mm osteophytes did not induce any impingement. CONCLUSION: Osteophytes in the antero-superior and posterior portion of the acetabulum should be excised during a THA to avoid impingement of the femur-stem construct on the acetabular osteophytes during ADLs.

Controlling Abnormal Joint Movement Inhibits Response of Osteophyte Formation.

Objective Osteoarthritis (OA) is induced by accumulated mechanical stress to joints; however, little has been reported regarding the cause among detailed mechanical stress on cartilage degeneration. This study investigated the influence of the control of abnormal joint movement induced by anterior cruciate ligament (ACL) injury in the articular cartilage. Design The animals were divided into 3 experimental groups: CAJM group ( n = 22: controlling abnormal joint movement), ACL-T group ( n = 22: ACL transection or knee anterior instability increased), and INTACT group ( n = 12: no surgery). After 2 and 4 weeks, the knees were harvested for digital microscopic observation, soft X-ray analysis, histological analysis, and synovial membrane molecular evaluation. Results The 4-week OARSI scores showed that cartilage degeneration was significantly inhibited in the CAJM group as compared with the ACL-T group ( P < 0.001). At 4 weeks, the osteophyte formation had also significantly increased in the ACL-T group ( P < 0.001). These results reflected the microscopic scoring and soft X-ray analysis findings at 4 weeks. Real-time synovial membrane polymerase chain reaction analysis for evaluation of the osteophyte formation-associated factors showed that the mRNA expression of BMP-2 and VEGF in the ACL-T group had significantly increased after 2 weeks. Conclusions Typically, abnormal mechanical stress induces osteophyte formation; however, our results demonstrated that CAJM group inhibited osteophyte formation. Therefore, controlling abnormal joint movement may be a beneficial precautionary measure for OA progression in the future.

Oral administration of undenatured native chicken type II collagen (UC-II) diminished deterioration of articular cartilage in a rat model of osteoarthritis (OA).

OBJECTIVE: The aim of this study was to determine the ability of undenatured native chicken type II collagen (UC-II) to prevent excessive articular cartilage deterioration in a rat model of osteoarthritis (OA). METHODS: Twenty male rats were subjected to partial medial meniscectomy tear (PMMT) surgery to induce OA. Immediately after the surgery 10 rats received vehicle and another 10 rats oral daily dose of UC-II at 0.66 mg/kg for a period of 8 weeks. In addition 10 naïve rats were used as an intact control and another 10 rats received sham surgery. Study endpoints included a weight-bearing capacity of front and hind legs, serum biomarkers of bone and cartilage metabolism, analyses of subchondral and cancellous bone at the tibial epiphysis and metaphysis, and cartilage pathology at the medial tibial plateau using histological methods. RESULTS: PMMT surgery produced moderate OA at the medial tibial plateau. Specifically, the deterioration of articular cartilage negatively impacted the weight bearing capacity of the operated limb. Immediate treatment with the UC-II preserved the weight-bearing capacity of the injured leg, preserved integrity of the cancellous bone at tibial metaphysis and limited the excessive osteophyte formation and deterioration of articular cartilage. CONCLUSION: Study results demonstrate that a clinically relevant daily dose of UC-II when applied immediately after injury can improve the mechanical function of the injured knee and prevent excessive deterioration of articular cartilage.

Regression of Anterior Disk-Osteophyte Complex Following Cervical Laminectomy and Fusion for Cervical Spondylotic Myelopathy.

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.

Hip-Spine Syndrome: Is There an Association Between Markers for Cam Deformity and Osteoarthritis of the Lumbar Spine?

PURPOSE: To examine a large osteological collection to assess the relations between the well-described means of quantifying cam deformities of the proximal femur-alpha angle (AA) and anterior femoral neck offset (AFNO)-and osteoarthritis of the lumbar spine. METHODS: AA and AFNO were measured on paired femurs of 550 well-preserved cadaveric skeletons by use of standardized cephalocaudal digital photographs. Degenerative disease of these specimens' lumbar spines was graded from 0 to 4 with a validated grading system. Proximal femurs showing obvious arthritic changes such as lipping or osteophytes were excluded. Correlations between AA and spine osteoarthritis (SOA), as well as between AFNO and SOA, were evaluated by multiple regression analysis. RESULTS: The average age for the skeletons was 47.8 ± 16.2 years. There were 456 male and 94 female specimens. The mean AA and AFNO were 52.4° ± 11.4° and 6.8 ± 1.5 mm, respectively. The average SOA score was 2.1 ± 0.9 (0 in 31 specimens, 1 in 82, 2 in 287, 3 in 106, and 4 in 44). There was a significant correlation between increasing AA and SOA (standardized ß = 0.061, P = .041). There was also a significant correlation between decreasing AFNO and SOA (standardized ß = -0.067, P = .025). There was a strong correlation between age and SOA (standardized ß = 0.582, P < .0005). CONCLUSIONS: This study provides important insight into the understanding of the hip-spine connection. Although it has no way of showing a causative or clinically significant relation, this study did show that the cam-type deformity markers of increasing AA and decreasing AFNO were significantly associated with SOA in a large osteological collection. CLINICAL RELEVANCE: Clinical and biomechanical studies to assess whether cam deformity in the younger individual may contribute to the accelerated development of SOA in later life are warranted.

Combined Anterior and Dual Posterolateral Approaches for Ankle Arthroscopy for Posterior and Anterior Ankle Impingement Syndrome.

BACKGROUND: We introduce a novel method of combining the standard anteromedial and anterolateral approaches and dual posterolateral approaches in the arthroscopic treatment of posterior and anterior ankle impingement syndrome and compare the postoperative outcomes with conventional anteromedial/anterolateral and posteromedial/posterolateral approaches. METHODS: From January 2013 to January 2015, we treated 28 patients with posterior and anterior ankle impingement syndrome by arthroscopy. The patients were divided into the conventional group (n = 13) and the modified group (n = 15) according to the surgical approaches used in the operation. Preoperative and postoperative American Orthopaedic Foot & Ankle Society (AOFAS) score, visual analog scale (VAS) score, range of ankle motion, and operation time were recorded. The average follow-up was 16 months (range 6-24 months). RESULTS: Posterior and anterior ankle impingement syndrome was confirmed arthroscopically in all patients. After the operation, the range of ankle motion in all patients was restored. There was no significant difference in postoperative AOFAS score, VAS score, dorsiflexion, and plantarflexion between the conventional group and the modified group. Moreover, the operation time was significantly reduced in the modified group compared with the conventional group. There was no recurrence of osteophyte and no complications such as infection, neurovascular injury, or delayed healing of surgical incision in the modified group. CONCLUSIONS: Dual posterolateral approaches combined with standard anteromedial and anterolateral approaches was a novel method for arthroscopic treatment of posterior and anterior ankle impingement syndrome. It proved to be safe and effective, and significantly reduced the operation time. Reposition, repeated prep and drape, and limb distraction were avoided. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Ultrasound of knee osteoarthritis: interobserver agreement and correlation with Western Ontario and McMaster Universities Osteoarthritis.

The aim of this work was to assess the reproducibility of ultrasound findings of knee osteoarthritis and to correlate ultrasound findings with Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Prospective study was conducted upon 80 patients (56 F, 24 M; mean age 57 years) with primary osteoarthritis of knee joint. All patients underwent clinical assessment with calculation of WOMAC and high-resolution ultrasound of the knee joint. The ultrasound images were analyzed for cartilage thinning, osteophytes, synovial effusion, synovial proliferation, popliteal cyst, and meniscal protrusion. Image analysis was performed by two readers and linear regression analysis was used to determine association of ultrasound findings with WOMAC. There was excellent inter-observer agreement of both readers for cartilage thinning (k = 0.99, P = 0.001), osteophytes (k = 0.94, P = 0.001), synovial effusion (k = 0.98, P = 0.001), synovial thickening (k = 0.96, P = 0.001), popliteal cyst (k = 1.00, P = 0.001), and meniscal protrusion (k = 0.86, P = 0.001). There was significant association of WOMAC with cartilage changes (t = 3.406, 3.302, P = 0.001), osteophytes (t = 3.841, 3.006, P = 0.001), and synovial effusion (t = 4.140 and 2.787, P = 0.05) of both readers. We concluded that ultrasound is a reproducible method for assessment of knee osteoarthritis and well correlated with WOMAC.

The CSAW Study (Can Shoulder Arthroscopy Work?) - a placebo-controlled surgical intervention trial assessing the clinical and cost effectiveness of arthroscopic subacromial decompression for shoulder pain: study protocol for a randomised controlled trial.

BACKGROUND: Arthroscopic subacromial decompression (ASAD) is a commonly performed surgical intervention for shoulder pain. The rationale is that removal of a bony acromial spur relieves symptoms by decompressing rotator cuff tendons passing through the subacromial space. However, the efficacy of this procedure is uncertain. The objective of this trial was to compare the efficacy and cost-effectiveness of ASAD in patients with subacromial pain using appropriate control groups, including placebo intervention. METHODS/DESIGN: The trial is a three-group, parallel design, pragmatic, randomised controlled study. The intervention content for each group (ASAD, active monitoring with specialist reassessment (AMSR) and investigational shoulder arthroscopy only (AO)) enables assessment of (1) the efficacy of the surgery against no surgery; (2) the need for a specific component of the surgery-namely, removal of the bony spur; and (3) quantification of the placebo effect. Concealed allocation was performed using a 1:1:1 randomisation ratio and using age, sex, baseline Oxford Shoulder Score (OSS) and centre as minimisation criteria. The primary outcome measure is the OSS at 6 months post randomisation. A total of 300 patients recruited over 24 months from a minimum of 14 UK shoulder units over 24 months were required to detect a difference of 4.5 points on the OSS (standard deviation, 9) with 90% power and to allow for 15% loss to follow-up. Secondary outcomes include cost-effectiveness, pain, complications and patient satisfaction. A substantial qualitative research component is included. The primary analysis will be conducted on the modified intention-to-treat analysis. Sensitivity analysis will be used to assess the robustness of the results with regard to the underlying assumptions about missing data using multiple imputation. DISCUSSION: This trial uses an innovative design to account for the known placebo effects of surgery, but it also will delineate the mechanism for any benefit from surgery. The investigational AO group is considered a placebo intervention (not sham surgery), as it includes all components of subacromial decompression except the critical surgical element. Some discussion is also dedicated to the challenges of conducting placebo surgery trials. TRIAL REGISTRATIONS: UK Clinical Research Network UKCRN12104. Registered 22 May 2012. International Standard Randomised Controlled Trial ISRCTN33864128 . Registered 22 June 2012. ClinicalTrials.gov NCT01623011 . Registered 15 June 2012.

An examination of anatomic variants and incidental peroneal tendon pathologic features: a comprehensive MRI review of asymptomatic lateral ankles.

Intraoperatively, foot and ankle surgeons will encounter peroneal pathologic features in patients with asymptomatic lateral ankles. The purpose of the present study was to review the ankle magnetic resonance imaging (MRI) scans of patients without a history of ankle trauma or lateral ankle pain to determine which anatomic variants correlate with peroneal tendon pathologic features and noted pathophysiology. A total of 500 MRI scans were screened, 108 (41.90 ± 20.42) of which met the inclusion criteria. The peroneus brevis tendon was intact in 104 MRI scans (96.30%), and the peroneus longus tendon was intact in 108 (100.00%). The results of the present study have confirmed statistically significant correlations between the presence of an os perineum and tendinopathy of the peroneus longus [rs(106) = 0.27], undulating peroneal grooves and the severity of peroneal brevis tears [rs(106) = 0.32], a boomerang-shaped peroneus brevis tendon and increasing tendinopathy of the peroneal tendons [brevis (rs(106) = 0.37; longus rs(106) = 0.33], and low-lying muscle bellies and chronic injuries of the superior peroneal retinaculum (rϕ = 0.19). However, the present study did not find evidence to support the presumed correlations between peroneal tendon pathologic findings and hypertrophied peroneal tubercles, low-lying muscle bellies, or the peroneus quartus muscle. Adding to the published data, the present study found a statistically significant correlation between undulating peroneal grooves and an increasing prevalence of osteophytes within the peroneal groove [rs(106) = 0.32]. MRI findings of anatomic variants or peroneal pathologic features might be useful for injury prevention; however, we advise caution from using the findings alone to advocate surgical intervention. To definitively assess causation, prospective, long-term cohort studies are warranted.

Inflammatory bone spur formation in psoriatic arthritis is different from bone spur formation in hand osteoarthritis.

OBJECTIVE: To investigate the different patterns of bone spur formation in psoriatic arthritis (PsA) and hand osteoarthritis (OA), using high-resolution peripheral quantitative computed tomography (QCT). METHODS: The study group comprised 70 subjects (25 patients with PsA, 25 patients with hand OA, and 20 healthy controls). The 2 patient groups were similar with regard to age and sex distribution and clinical involvement of the metacarpophalangeal (MCP) joints. All patients underwent high-resolution peripheral QCT scanning of the second, third, and fourth MCP joints of the dominantly affected hand. Demographic and disease-specific data were recorded, and the number, size, and distribution of bone spurs were assessed and compared between patients with PsA and patients with hand OA. RESULTS: The overall number and size of bone spurs were similar in patients with PsA and patients with hand OA. However, localization of lesions within individual joints was substantially different between patients with PsA and those with hand OA. In PsA, bone spurs dominated the radial sides of the joints (for the metacarpal head of the second joint, P < 0.001 versus hand OA; for the base of the second phalangeal joint, P < 0.001 versus hand OA), whereas the palmar and dorsal quadrants were the predilection sites in hand OA. Detailed anatomic analysis showed that bone spurs in the entheseal regions were prominent in patients with PsA but rare in patients with hand OA, and that bone spurs in patients with hand OA typically emerged at the cartilage-bone interphase and the joint margins. CONCLUSION: Our findings show that the overall number and size of bone spurs are similar in patients with PsA and patients with hand OA. Nonetheless, the anatomic sites of bone proliferation are different between these 2 groups of patients.

Total dorsal capsulectomy for the treatment of mucous cysts.

PURPOSE: To describe the technique of total dorsal capsulectomy alone for mucous cysts of the distal interphalangeal (DIP) joint and evaluate its outcomes and complications. METHODS: Nineteen patients (18 women and 1 man) with 19 mucous cysts were treated by a total dorsal capsulectomy without cyst excision or osteophyte removal. The average age at surgery was 63 years. The thumb was involved in 4 patients, index finger in 1, middle finger in 7, ring finger in 4, and little finger in 3. Twelve patients had nail deformities associated with the mucous cyst. The average period of postoperative follow-up was 26 months. The dorsal half of the DIP joint capsule was resected with a punch and curette. The cyst and osteophytes were left intact. RESULTS: The average preoperative range of motion for the DIP joint was from 10° of extension to 45° of flexion. Radiographs showed osteophytes at the DIP joint in all affected digits. After surgery, all cysts disappeared at an average of 3 weeks. There was no recurrence at the time of final follow-up. All nail deformities had resolved at an average of 5 months after surgery. The average motion for the DIP joint at the time of final follow-up was from 8° of extension to 56° of flexion. There were no acquired nail deformities or other complications. CONCLUSIONS: A total dorsal capsulectomy alone was a simple treatment for mucous cysts and did not lead to any recurrence. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

The fate of osteophytes in the superolateral region of the acetabulum after total hip arthroplasty.

Acetabular osteophytes are common during total hip arthroplasty (THA). However, the fate and role of superolateral osteophytes of the acetabulum after THA remain unclear. The present study reviewed a series of radiographic changes in the osteophytes on the superolateral region of the acetabulum in 35 hips. The mean follow-up period was 42.2months. The results revealed that the osteophytes that were not in contact with the superolateral edge of acetabular cup were gradually absorbed after THA. In contrast, the osteophytes that were in contact with the superolateral edge of the acetabular cup underwent remodeling, formed regular trabecula, were stress bearing, and eventually integrated with the acetabular cup and the original acetabular bone, and should play a role in stabilizing the acetabular cup.

Differences in structural and pain phenotypes in the sodium monoiodoacetate and meniscal transection models of osteoarthritis.

OBJECTIVES: To characterize differences in joint pathology and pain behavior between two rat models of osteoarthritis (OA) in order to inform selection of animal models for interventional studies. METHOD: Knee OA was induced in Sprague Dawley rats by either meniscal transection (MNX) or intra-articular injection of monosodium iodoacetate (MIA). Controls were subjected to sham surgery or saline-injection. In a separate experiment, a single intra-articular injection of triamcinolone acetonide was administered 14 days after MNX or MIA arthritis induction. Pain behavior and joint pathology were quantified. RESULTS: Both models displayed synovial inflammation, chondropathy and osteophytosis. Chondropathy scores increased with time similarly in the two models. Inflammation and osteophyte scores were greater in MNX model compared to the MIA model. At day 49, the MNX model exhibited a greater number of channels crossing the osteochondral junction compared to all other groups. The MNX model exhibited greater weight bearing asymmetry compared to the MIA model, whereas the MIA model displayed more consistent hindpaw allodynia. Triamcinolone attenuated weight bearing asymmetry and distal allodynia to control levels in the MNX model, but distal allodynia was unaltered in the MIA model. CONCLUSIONS: The comparison of the two models of OA in rats, using identical assessment tools has demonstrated that although both models display features of OA, there are differences between the models which may represent different aspects of human OA. Thus, model selection should be based on the pathological aspects of OA under investigation.

Pain, motor and gait assessment of murine osteoarthritis in a cruciate ligament transection model.

OBJECTIVE: The major complaint of Osteoarthritis (OA) patients is pain. However, due to the nature of clinical studies and the limitation of animal studies, few studies have linked function impairment and behavioral changes in OA animal models to cartilage loss and histopathology. Our objective was to study surrogate markers of functional impairment in relation to cartilage loss and pathological changes in a post-traumatic mouse model of OA. METHOD: We performed a battery of functional analyses in a mouse model of OA generated by cruciate ligament transection (CLT). The changes in functional analyses were linked to histological changes graded by OARSI standards, histological grading of synovitis, and volumetric changes of the articular cartilage and osteophytes quantified by phase contrast micro-computed tomography (µCT). RESULTS: OA generated by CLT led to decreased time on rotarod, delayed response on hotplate analysis, and altered gait starting from 4 weeks after surgery. Activity in open field analysis did not change at 4, 8, or 12 weeks after CLT. The magnitude of behavioral changes was directly correlated with higher OARSI histological scores of OA, synovitis in the knee joints, cartilage volume loss, and osteophyte formation. CONCLUSION: Our findings link functional analyses to histological grading, synovitis, comprehensive three-dimensional assessment of cartilage volume and osteophyte formation. This serves as a reference for a mouse model in predicting outcomes of OA treatment.

Osteoarthritis develops in the operated joint of an ovine model following ACL reconstruction with immediate anatomic reattachment of the native ACL.

We tested the hypothesis that immediate reattachment of the native anterior cruciate ligament (ACL) can prevent kinematic changes and the development of osteoarthritis (OA). Five sheep underwent anatomic unilateral ACL reconstruction (ACL-R). Animals from a previous study served as sham (n = 7) or non-operated (n = 17) controls. At 4 points of walking gait, 6 degrees of freedom stifle joint kinematics of ACL-R animals were compared with sham controls at 4 and 20 weeks post-surgery. Gross cartilage, bone, and meniscal changes were graded at euthanasia; paired and differential scores were compared. Inter-animal differences were noted in all groups. Of 48 points of gait comparison between ACL-R and sham operated groups, 42 points showed no difference (p > 0.05). Of the six significant differences (p < 0.05), internal rotation in ACL-R animals accounted for three. At 20 weeks, differential scores showed that sham operated joints were morphologically indistinguishable from non-operated controls (p ≥ 0.129) while ACL-R joints had significantly higher combined cartilage and osteophyte scores than those controls (p ≤ 0.003). This method of ACL reconstruction in sheep did not restore normal walking gait kinematics completely and allowed some OA to develop in operated joints. OA may result from relatively subtle mechanical abnormalities, apparently more so in some individuals than others.

Baseline radiographic damage, elevated acute-phase reactant levels, and cigarette smoking status predict spinal radiographic progression in early axial spondylarthritis.

OBJECTIVE: To assess prospectively the rates and to explore predictors of spinal radiographic progression over 2 years in a cohort of patients with early axial spondylarthritis (SpA). METHODS: Two hundred ten patients with axial SpA from the German Spondyloarthritis Inception Cohort were selected for this analysis based on the availability of radiographs at baseline and after 2 years of followup. Spinal radiographs were scored by 2 trained readers in a blinded, randomly selected order according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). Spinal radiographic progression was defined as worsening of the mean mSASSS by ≥2 units over 2 years. RESULTS: Among the patients with axial SpA, 14.3% showed spinal radiographic progression after 2 years (20% of those with AS and 7.4% of those with nonradiographic axial SpA). The following parameters were independently associated with spinal radiographic progression: presence of syndesmophytes at baseline (odds ratio [OR] 6.29, P < 0.001), elevated levels of markers of systemic inflammation (for the erythrocyte sedimentation rate, OR 4.04, P = 0.001; for C-reactive protein level time-averaged over 2 years, OR 3.81, P = 0.001), and cigarette smoking (OR 2.75, P = 0.012). These associations were confirmed by multivariate logistic regression analysis. No clear association with spinal radiographic progression was observed for HLA-B27 status, sex, age, disease duration, Bath Ankylosing Spondylitis Disease Activity Index, Bath Ankylosing Spondylitis Functional Index, presence of peripheral arthritis, enthesitis, psoriasis, treatment with nonsteroidal antiinflammatory drugs, or treatment with disease-modifying antirheumatic drugs at baseline. CONCLUSION: The presence of radiographic damage at baseline (syndesmophytes), elevated levels of acute-phase reactants, and cigarette smoking were all independently associated with spinal radiographic progression in patients with early axial SpA.