Non-traumatic Osteoarthritis Research Articles

Regenerative Effect of Low-Intensity Pulsed Ultrasound and Platelet-Rich Plasma on the Joint Friction and Biomechanical Properties of Cartilage: A Non-traumatic Osteoarthritis Model in the Guinea Pig.

This study was aimed at investigating the effects of platelet-rich plasma (PRP) and low-intensity pulsed ultrasound (LIPUS) on the joint friction parameters and biomechanical properties of articular cartilage in a non-traumatic knee osteoarthritis (OA) model. Fifty adult male Dunkin Hartley guinea pigs were randomly divided into five groups: control, OA60, OA+US, OA+PRP and OA+US+PRP). Non-traumatic knee OA was induced with a single dose of 3 mg of mono-iodoacetate (MIA) by intra-articular injection. Intra-articular PRP was injected twice in the OA+PRP and OA+US+PRP groups. LIPUS was delivered in 10 sessions in the OA+US and OA+US+PRP groups. By use of the pendulum free oscillation test, joint friction (coefficient of friction) was measured. In addition, the instantaneous elastic modulus and aggregate modulus were measured using the stress-relaxation test. MIA injection decreased cartilage thickness, instantaneous elastic modulus and aggregate modulus, and increased joint friction. The friction coefficients in the OA+US and OA+US+PRP groups reached near-normal values, and there was no significant difference compared with the control group (p=0.232 and p=0.459, respectively). The instantaneous elastic modulus and aggregate modulus in the OA+US group increased significantly compared with the OA+PRP group (p < 0.05). It seems that both LIPUS and PRP injection effectively improved joint lubrication, but LIPUS was superior to PRP in improving the mechanical properties of the articular cartilage.

The relationship between knee loading during gait and cartilage thickness in nontraumatic and posttraumatic knee osteoarthritis.

The relationship between knee moments and markers of knee osteoarthritis progression has not been examined in different knee osteoarthritis subtypes. The objective was to examine relationships between external knee moments during gait and tibiofemoral cartilage thickness in patients with nontraumatic and posttraumatic knee osteoarthritis. For this cross-sectional study, participants with knee osteoarthritis were classified into two groups: nontraumatic (n = 22; mean age 60 years) and posttraumatic (n = 19; mean age 56 years, history of anterior cruciate ligament rupture). Gait data were collected with a three-dimensional motion capture system sampled at 100 Hz and force plates sampled at 2000 Hz. External knee moments were calculated using inverse dynamics. Cartilage thickness was determined with magnetic resonance imaging (T1-weighted, 3D sagittal gradient-echo sequence). Linear regression analyses examined relationships between cartilage thickness with knee moments, group, and their interaction. A higher knee adduction moment impulse was negatively associated with medial to lateral cartilage thickness ratio (B = -1.97). This relationship differed between participants in the nontraumatic osteoarthritis group (r = -0.56) and posttraumatic osteoarthritis group (r = -0.30). A higher late stance knee extension moment was associated with greater medial femoral condyle cartilage thickness (B = -0.86) and medial to lateral cartilage thickness (B = -0.73). These relationships also differed between participants in the nontraumatic osteoarthritis group (r = -0.61 and r = -0.51, respectively) and posttraumatic osteoarthritis group (r = 0.10 and r = 0.25, respectively). Clinical Significance: The relationship between knee moments with tibiofemoral cartilage thickness differs between patients with nontraumatic and posttraumatic knee osteoarthritis. The potential influence of mechanical knee loading on articular cartilage may also differ between these subtypes.

Should return to pivoting sport be avoided for the secondary prevention of osteoarthritis after ACL reconstruction?

Introduction: Anterior cruciate ligament (ACL) rupture is a major contributor to the development and progression of posttraumatic knee osteoarthritis, evident in young adults decades earlier than nontraumatic osteoarthritis. Returning to high-impact pivoting sport following ACL rupture and reconstruction (ACLR) represents a potential modifiable factor for post-traumatic osteoarthritis. This study aimed to evaluate if returning to pivoting sport following ACLR is associated with structural and symptomatic osteoarthritis outcomes.

Gait risk factors for disease progression differ between non-traumatic and post-traumatic knee osteoarthritis

To examine if relationships between knee osteoarthritis (OA) progression with knee moments and muscle activation during gait vary between patients with non-traumatic and post-traumatic knee OA. This longitudinal study included participants with non-traumatic (n=17) and post-traumatic (n=18) knee OA; the latter group had a previous anterior cruciate ligament rupture. Motion capture cameras, force plates, and surface electromyography measured knee moments and lower extremity muscle activation during gait. Cartilage volume change were determined over 2 years using magnetic resonance imaging in four regions: medial and lateral plateau and condyle. Linear regression analysis examined relationships between cartilage change with gait metrics (moments, muscle activation), group, and their interaction. Measures from knee adduction and rotation moments were related to lateral condyle cartilage loss in both groups, and knee adduction moment to lateral plateau cartilage loss in the non-traumatic group only [β=-1.336, 95% confidence intervals (CI)=-2.653 to-0.019]. Generally, lower levels of stance phase muscle activation were related to greater cartilage loss. The relationship between cartilage loss in some regions with muscle activation characteristics varied between non-traumatic and post-traumatic groups including for: lateral hamstring (lateral condyle β=0.128, 95%CI=0.003 to 0.253; medial plateau β=0.199, 95%CI=0.059 to 0.339), rectus femoris (medial condyle β=-0.267, 95%CI=-0.460 to-0.073), and medial hamstrings (medial plateau; β=-0.146, 95%CI=-0.244 to-0.048). Findings indicate that gait risk factors for OA progression may vary between patients with non-traumatic and post-traumatic knee OA. These OA subtypes should be considered in studies that investigate gait metrics as risk factors for OA progression.

Should return to high-impact sport be avoided for secondary prevention of osteoarthritis after acl reconstruction? A prospective cohort study with MRI, radiographic and symptomatic outcomes

Purpose: Anterior cruciate ligament (ACL) rupture, irrespective of surgical reconstruction (ACLR), contributes to most post-traumatic knee osteoarthritis (OA) cases, evident decades earlier than non-traumatic OA. Returning to high-impact sport following ACLR represents a potential modifiable factor. Surgical success is often judged on a return to sport, and retrospective studies indicate a potential reduction in OA risk in those who return to pivoting sport. There is a need to prospectively investigate the influence of returning to high-impact sport after ACLR on the risk of longitudinal structural OA changes and knee symptoms.

Factors Affecting the Outcomes of Tibiotalocalcaneal Fusion

Category:Hindfoot; Ankle; Ankle ArthritisIntroduction/Purpose:Tibiotalocalcaneal (TTC) fusion is used to treat a variety of conditions affecting the ankle and subtalar joint, including osteoarthritis (OA), Charcot arthropathy, avascular necrosis (AVN) of the talus, failed total ankle arthroplasty, and severe deformity. The prevalence of postoperative complications remains high due to the complexity of hindfoot disease seen in these patients. The aim of this study was to analyze the relationship between preoperative conditions and postoperative complications in order to predict the outcome following primary TTC fusion.Methods:We retrospectively reviewed the medical records of 101 patients who underwent TTC fusion at the same institution between 2011 and 2019. Risk ratios (RRs) associated with age, sex, diabetes, cardiovascular disease, smoking, preoperative ankle deformity, and the use of bone graft during surgery were related to the postoperative complications. We determined from these data which pre- and perioperative factors significantly affected the outcome.Results:Patients with a preoperative diagnosis of Charcot arthropathy and non-traumatic OA had significantly higher nonunion rates of 44.4% (12 patients) and 39.1% (18 patients) (p = 0.016) and infection rates of 29.6% (eight patients) and 37% (17 patients) compared to patients with traumatic arthritis, respectively (p = 0.002). There was a significantly increased rate of nonunion in diabetic patients (RR 2.22; p = 0.010). Patients with chronic kidney disease were 2.37-times more likely to have a nonunion (p = 0.006). Patients aged over 60 years had more than a three-fold increase in the rate of postoperative infection (RR 3.60; p = 0.006). The use of bone graft appeared to be significantly protective against postoperative infection (p = 0.019).Conclusion:We were able to confirm, in the largest series of TTC ankle fusions currently in the literature, that there remains a high rate of complications following this procedure. Those with diabetes, chronic kidney disease, or aged over 60 years had an increased risk of nonunion. These findings help to confirm those of previous studies. Additionally, our study adds to the literature by showing that autologous bone graft may help in decreasing infection rates. This helps surgeons further understand which patients are at a higher risk for postoperative complications when undergoing TTC fusion.

Total Ankle Arthroplasty Results Using Fixed Bearing CT-Guided Implants in Post-Traumatic Versus Non-Traumatic Arthritis

Category:Ankle; Ankle Arthritis; TraumaIntroduction/Purpose:The majority of ankle osteoarthritis are post-traumatic in etiology. Previous studies have shown that patients with post-traumatic ankle osteoarthritis are less satisfied, experience significantly more pain during normal activities and have higher revision rates. However, these studies were performed with older generation implants. The objective of this study was to compare patients hat had undergone total ankle arthroplasty secondary to either post-traumatic or non-traumatic etiologies using patient specific, third generation fixed bearing implants and compare clinical as well as radiographic outcomes.Methods:A retrospective chart review was conducted on 41 patients who had undergone total ankle arthroplasty using a third- generation fixed bearing implant with CT-based patient specific cutting guides from July 21, 2015 to December 13, 2017 performed by 2 foot and ankle surgeons. Demographic and operative data was collected. Etiology was determined based on clinical notes, operative notes, and x-rays. Clinical outcomes were obtained using the Foot and Ankle Ability Measure questionnaire. Radiographic assessment of the coronal and sagittal alignments were carried out to assess implant migration or loosening.Results:We had 26 patients in the post-traumatic group and 15 in the non-traumatic group with a mean follow-up of 32.5 months and 30.4 months respectively. There was no significant difference between both groups in terms of FAAM ADL subscore with the post-traumatic group did slightly better with 7 patients scoring ‘nearly normal’ (26.9%) and 18 patients scoring ‘normal’ (69.2%). Whereas in the non-traumatic group 5 patients score ‘nearly normal’ (33.3%) and 9 patients score ‘normal’ (60%). In terms of the self-rated subjective functioning score, mean score of 79.2% and 73.4% respectively. On radiographs, there was no subsidence or significant implant movement for both groups at mean follow-up of 28.3 months for the post-traumatic group and 26.3 months for the non-traumatic group.Conclusion:Unlike in previous studies in older implants where clinical outcomes were worse in post-traumatic ankle arthritis, our study showed that those receiving total ankle arthroplasty due to post traumatic osteoarthritis do slightly better than those with non-traumatic osteoarthritis, with more patients reporting normal levels of activity. These results may help quantify improvements in newer generation patient specific implants as well as to gain insight into how different implant designs affect post- operative outcomes based on etiology of ankle osteoarthritis.

Nociceptive mechanisms driving pain in a post-traumatic osteoarthritis mouse model

In osteoarthritis (OA), pain is the dominant clinical symptom, yet the therapeutic approaches remain inadequate. The knowledge of the nociceptive mechanisms in OA, which will allow to develop effective therapies for OA pain, is of utmost need. In this study, we investigated the nociceptive mechanisms involved in post-traumatic OA pain, using the destabilization of the medial meniscus (DMM) mouse model. Our results revealed the development of peripheral pain sensitization, reflected by augmented mechanical allodynia. Along with the development of pain behaviour, we observed an increase in the expression of calcitonin gene-related peptide (CGRP) in both the sensory nerve fibers of the periosteum and the dorsal root ganglia. Interestingly, we also observed that other nociceptive mechanisms commonly described in non-traumatic OA phenotypes, such as infiltration of the synovium by immune cells, neuropathic mechanisms and also central sensitization were not present. Overall, our results suggest that CGRP in the sensory nervous system is underlying the peripheral sensitization observed after traumatic knee injury in the DMM model, highlighting the CGRP as a putative therapeutic target to treat pain in post-traumatic OA. Moreover, our findings suggest that the nociceptive mechanisms involved in driving pain in post-traumatic OA are considerably different from those in non-traumatic OA.

Factors affecting the outcomes of tibiotalocalcaneal fusion.

Tibiotalocalcaneal (TTC) fusion is used to treat a variety of conditions affecting the ankle and subtalar joint, including osteoarthritis (OA), Charcot arthropathy, avascular necrosis (AVN) of the talus, failed total ankle arthroplasty, and severe deformity. The prevalence of postoperative complications remains high due to the complexity of hindfoot disease seen in these patients. The aim of this study was to analyze the relationship between preoperative conditions and postoperative complications in order to predict the outcome following primary TTC fusion. We retrospectively reviewed the medical records of 101 patients who underwent TTC fusion at the same institution between 2011 and 2019. Risk ratios (RRs) associated with age, sex, diabetes, cardiovascular disease, smoking, preoperative ankle deformity, and the use of bone graft during surgery were related to the postoperative complications. We determined from these data which pre- and perioperative factors significantly affected the outcome. Out of the 101 patients included in the study, 29 (28.7%) had nonunion, five (4.9%) required below-knee amputation (BKA), 40 (39.6%) returned to the operating theatre, 16 (15.8%) had hardware failure, and 22 (21.8%) had a postoperative infection. Patients with a preoperative diagnosis of Charcot arthropathy and non-traumatic OA had significantly higher nonunion rates of 44.4% (12 patients) and 39.1% (18 patients) (p = 0.016) and infection rates of 29.6% (eight patients) and 37% (17 patients) compared to patients with traumatic arthritis, respectively (p = 0.002). There was a significantly increased rate of nonunion in diabetic patients (RR 2.22; p = 0.010). Patients with chronic kidney disease were 2.37-times more likely to have a nonunion (p = 0.006). Patients aged over 60 years had more than a three-fold increase in the rate of postoperative infection (RR 3.60; p = 0.006). The use of bone graft appeared to be significantly protective against postoperative infection (p = 0.019). We were able to confirm, in the largest series of TTC ankle fusions currently in the literature, that there remains a high rate of complications following this procedure. We found that patients with a Charcot or non-traumatic arthropathy had an increased risk of nonunion and postoperative infection compared to individuals with traumatic arthritis. Those with diabetes, chronic kidney disease, or aged over 60 years had an increased risk of nonunion. These findings help to confirm those of previous studies. Additionally, our study adds to the literature by showing that autologous bone graft may help in decreasing infection rates. These data can be useful to surgeons and patients when considering, discussing and planning TTC fusion. It helps surgeons further understand which patients are at a higher risk for postoperative complications when undergoing TTC fusion. Cite this article: Bone Joint J. 2020;102-B(3):345-351.

Non-traumatic primary and secondary osteoarthritis of the distal radioulnar joint.

A retrospective radiographic study was conducted to determine the prevalence and severity of non-traumatic primary and secondary osteoarthritis of the distal radioulnar joint in a group of 718 patients. Non-traumatic primary and secondary osteoarthritis was found in 77 patients (11%) with a mean age of 63 years. In 34 cases it was bilateral. Mild signs of osteoarthritis were present in 53, moderate in 17 and severe in seven patients. The prevalence of primary osteoarthritis was 8.2% and 2.5% had secondary non-traumatic osteoarthritis. The prevalence and severity of the osteoarthritis were similar in women and men. Ulnar wrist pain was associated with osteoarthritis of the distal radioulnar joint in 13% of patients with mild, 35% with moderate and 43% with severe radiological degeneration. Level of evidence: IV.

The relationship between muscle activation during gait and cartilage volume loss in patients with non-traumatic and post-traumatic knee osteoarthritis

Purpose: Gait measures have been shown to relate to disease progression in patients with knee osteoarthritis (OA). For instance, higher co-contraction of medial knee muscles during gait was related to medial tibial cartilage loss over 12 months in patients with knee OA; higher co-contraction of the lateral knee muscles was protective against cartilage loss. Differences in muscle activation during gait have been found between patients with non-traumatic (i.e. no previous traumatic injury) and post-traumatic (i.e. history of previous trauma) knee OA. Patients with non-traumatic OA had higher quadriceps activation and prolonged lateral hamstring activation compared to patients with post-traumatic knee OA. Considering these differences, the relationship between disease progression and muscle activation might also vary between these knee OA subtypes. Therefore, the objective was to explore relationships between muscle activation during gait and cartilage volume loss over 2 years in patients with non-traumatic and post-traumatic knee OA. Methods: Participants with non-traumatic (n=14) and post-traumatic (n=10) knee OA were recruited. This latter group had a history of anterior cruciate ligament rupture confirmed on magnetic resonance imaging (MRI). Muscle activation of vastus lateralis, vastus medialis, lateral hamstrings, and medial hamstrings were recorded with surface electromyography (EMG) as participants completed five gait trials at self-selected speeds. Ensemble averages were created from the five trials and gait EMG were normalized to maximum voluntary isometric contractions. Principal component analysis determined important characteristics (principal components) from EMG waveforms and individual participant waveforms were scored against these principal components (PC-scores). Cartilage volume was measured with a 3.0T MRI with a knee coil, and scans were completed on two occasions separated by 2 years. The sequence was a T1-weighted, 3D sagittal gradient echo sequence with fat suppression. The change in cartilage volume over 2 years was determined with an automatic procedure in the medial and lateral knee compartments (Medical Imaging, ArthroLab Inc., Montreal, Quebec, Canada). Pearson correlations between PC-scores from gait EMG and cartilage volume change were calculated separately for non-traumatic and post-traumatic OA groups. Results: Both higher lateral hamstring activation (PC1; r=0.59, p=0.03) and higher vastus lateralis activation during terminal stance/early swing (PC2; r=0.57, p=0.03) were significantly related to less medial compartment cartilage volume loss in the non-traumatic OA group. Also, earlier onset of vastus lateralis activation (PC3) was related to greater medial compartment cartilage volume loss in the non-traumatic OA group (r=-0.65, p=0.01). There were no significant correlations between muscle EMG and cartilage volume loss in the post-traumatic OA group and no significant correlations in the lateral compartment for both groups (Table 1). Conclusions: Higher activation of the lateral hamstrings and vastus lateralis during gait were protective against medial compartment cartilage loss in participants with non-traumatic knee OA. These muscle activation patterns might represent an attempt to unload the medial compartment, although there is inconsistency in the literature if this truly occurs. Earlier onset of vastus lateralis led to increased medial compartment cartilage loss in the non-traumatic OA group. This muscle might not be at peak activation when maximum joint loads typically occur and thus is not adequately controlling joint loading. There were no significant findings in the post-traumatic OA group. Thus, the role of muscle function in OA progression likely varies between patients with non-traumatic and post-traumatic knee OA. Long term studies with larger study samples are required to further examine the relationship between muscle function and disease progression in these OA subtypes.Tabled 1Table 1 Correlations (r) between EMG PC-scores and cartilage volume loss.MusclePrincipal ComponentNon-traumatic OAPost-traumatic OALateral CompartmentMedial CompartmentLateral CompartmentMedial CompartmentVastus Lateralis1-0.110.450.030.2320.250.570.320.143-0.01-0.650.35-0.34Vastus Medialis1-0.030.440.020.2220.170.400.440.193-0.21-0.340.40-0.05Lateral Hamstrings10.210.59-0.41-0.0320.030.390.280.4230.03-0.29-0.570.18Medial Hamstrings10.100.37-0.22-0.322-0.050.420.30-0.3130.110.15-0.450.06 Open table in a new tab

A comparison of muscle activation and knee mechanics during gait between patients with non-traumatic and post-traumatic knee osteoarthritis

The objective was to compare muscle activation and knee mechanics during gait between participants with non-traumatic knee osteoarthritis (OA), post-traumatic knee OA, and healthy adults. Participants with non-traumatic knee OA (n=22), post-traumatic knee OA (n=19), and healthy adults (n=22) completed gait trials for this observational, cross-sectional study. Post-traumatic OA group had a history of traumatic anterior cruciate ligament (ACL) rupture. Surface electromyography (EMG) measured activation of seven lower extremity muscles. Motion capture cameras and force plates measured motion and force data. Principal component analysis (PCA) determined waveform characteristics (principal components) from EMG, knee angle, and knee external moment waveforms. Analysis of variance (ANOVA) examined group differences in principal component scores (PC-scores). Regression analyses examined if a variable that coded for OA group could predict PC-scores after accounting for disease severity, alignment, and lateral OA. There was lower gastrocnemius EMG amplitudes (P<0.01; ANOVA) in the post-traumatic OA group compared to healthy group. Non-traumatic OA group had higher vastus lateralis, vastus medialis, and rectus femoris EMG compared to post-traumatic OA group (P=0.01 to 0.04) in regression analyses. Also, non-traumatic OA group had higher and prolonged lateral hamstring EMG compared to healthy (P=0.03; ANOVA) and post-traumatic OA (P=0.04; regression) groups respectively. The non-traumatic OA group had lower knee extension (P<0.05) and medial rotation (P<0.05) moments than post-traumatic and healthy groups. Muscle activation and knee mechanics differed between participants with non-traumatic and post-traumatic knee OA and healthy adults. These OA subtypes had differences in disease characteristics that may impact disease progression.

Relationship between alignment and cartilage thickness in patients with non-traumatic and post-traumatic knee osteoarthritis

To compare cartilage thickness between patients with non-traumatic and post-traumatic knee osteoarthritis (OA) and healthy controls and to determine if disease severity and alignment impact these differences. Participants with non-traumatic (n=22) and post-traumatic (n=19) knee OA, and healthy controls (n=22) were recruited for this cross-sectional study. Participants underwent 3T magnetic resonance imaging (T1-weighted, 3D sagittal gradient echo sequence) and cartilage thickness was determined in four regions: medial and lateral condyle, and medial and lateral plateau. Lower extremity alignment (mechanical axis angle) and disease severity (Kellgren-Lawrence scores) were measured from full length radiographs. Statistical analysis included one-way analysis of variance (ANOVA) and modified Bonferroni test adjusting for multiple pairwise comparisons. Linear regression analyses examined the relationship between cartilage thickness and knee OA group after controlling for disease severity, meniscal status, and alignment. In participants with predominantly medial compartment knee OA, compared to healthy controls, those with non-traumatic knee OA had diminished cartilage thickness in the medial plateau (p=0.035) and those with post-traumatic knee OA had greater cartilage thickness in the lateral condyle (p=0.044). In the lateral condyle, data revealed that alignment accounted for the variance in cartilage thickness (p=0.035), in which a stronger relationship was found in the non-traumatic (r=-0.61) than the post-traumatic (r=-0.12) OA group. Emerging data demonstrated that participants with non-traumatic knee OA have a stronger relationship between alignment and cartilage thickness than those with post-traumatic knee OA. This indicates that factors involved in knee OA initiation and progression may differ between these OA subtypes.

TLR4 Promotes and DAP12 Limits Obesity-Induced Osteoarthritis in Aged Female Mice.

ABSTRACTAging and female sex are the strongest risk factors for nontraumatic osteoarthritis (OA); whereas obesity is a modifiable risk factor accelerating OA. Prior studies indicate that the innate immune receptor toll‐like receptor 4 (TLR4) mediates obesity‐induced metabolic inflammation and cartilage catabolism via recognition of damage‐associated molecular patterns and is increased with aging in OA joints. TLR4 responses are limited by innate immunoreceptor adapter protein DNAX‐activating protein of 12kDA (DAP12). We undertook this study to test the hypothesis that TLR4 promotes, whereas DAP12 limits, obesity‐accelerated OA in aged female mice. We fed 13‐ to 15‐month‐old female WT, TLR4 KO, and DAP12 KO mice a high‐fat diet (HFD) or a control diet for 12 weeks, and changes in body composition, glucose tolerance, serum cytokines, and insulin levels were compared. Knee OA was evaluated by histopathology and μCT. Infrapatellar fat pads (IFPs) were analyzed by histomorphometry and F4/80+ crown‐like structures were quantified. IFPs and synovium gene expression were analyzed using a targeted insulin resistance and inflammation array. All HFD‐treated mice became obese, but only WT and TLR4 KO mice developed glucose intolerance. HFD induced cartilage catabolism in WT and DAP12 KO female mice, but not in TLR4 KO mice. Gene‐expression analysis of IFPs and synovium showed significant differences in insulin signaling, adipokines, and inflammation between genotypes and diets. Unlike young mice, systemic inflammation was not induced by HFD in the older female mice independent of genotype. Our findings support the conclusion that TLR4 promotes and DAP12 limits HFD‐induced cartilage catabolism in middle‐aged female mice. © 2018 The Authors JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

EXPERIMENTAL OSTEOARTHRITIS MODELING: FROM SEARCHING OF “GOLD STANDARD” TO PHENOTYPIC PRINCIPLE

The authors present a review of literature on experimental osteoarthritis (OA) within searching for its universal model. Classification, advantages, disadvantages, methodological inaccuracies of various authorial approaches from the point of view of conformity to human disease were identified based on analysis of the array of literature. Among techniques for OA modeling traumatic techniques were in most common use; among them "local" surgical manipulations, local devascularization, intraarticular injections of chemical-and-mechanical inducers and adjuvants which were followed up by gross changes in joint structures and, probably, severe pain. The influence of age and some genetic characteristics of cartilage structure were studied during experiments on laboratory animals with modified genetic apparatus. The methods of indirect "systemic" influence on joint structures are the most advanced in simulation of non-traumatic OA; however the etiological adequacy of proposed models is debatable. The concept of searching for the "gold standard" of the experimental model of OA formed earlier requires reconsideration because the modern identification of different OA subtypes leads to the development of new approaches on its reproducing in animals with ultimate imitation of a particular phenotype.

Cemented total hip arthroplasty following acetabular fracture.

To evaluate the outcomes of cemented total hip arthroplasty (THA) following a fracture of the acetabulum, with evaluation of risk factors and comparison with a patient group with no history of fracture. Between 1992 and 2016, 49 patients (33 male) with mean age of 57 years (25 to 87) underwent cemented THA at a mean of 6.5 years (0.1 to 25) following acetabular fracture. A total of 38 had undergone surgical fixation and 11 had been treated non-operatively; 13 patients died at a mean of 10.2 years after THA (0.6 to 19). Patients were assessed pre-operatively, at one year and at final follow-up (mean 9.1 years, 0.5 to 23) using the Oxford Hip Score (OHS). Implant survivorship was assessed. An age and gender-matched cohort of THAs performed for non-traumatic osteoarthritis (OA) or avascular necrosis (AVN) (n = 98) were used to compare complications and patient-reported outcome measures (PROMs). The mean time from fracture to THA was significantly shorter for patients with AVN (2.2 years) or protrusio (2.2 years) than those with post-traumatic OA (9.4 years) or infection (8.0 years) (p = 0.03). Nine contained and four uncontained defects were managed with autograft (n = 11), bulk allograft (n = 1), or trabecular metal augment (n = 1). Initial fracture management (open reduction and internal fixation or non-operative), timing of THA (>/< one year), and age (>/< 55 years) had no significant effect on OHS or ten-year survival. Six THAs were revised at mean of 12 years (5 to 23) with ten-year all-cause survival of 92% (95% confidence interval 80.8 to 100). THA complication rates (all complications, heterotopic ossification, leg length discrepancy > 10 mm) were significantly higher following acetabular fracture compared with atraumatic OA/AVN and OHSs were inferior: one-year OHS (35.7 versus 40.2, p = 0.026); and final follow-up OHS (33.6 versus 40.9, p = 0.008). Cemented THA is a reasonable option for the sequelae of acetabular fracture. Higher complication rates and poorer PROMs, compared with patients undergoing THA for atraumatic causes, reflects the complex nature of these cases. Cite this article: Bone Joint J 2017;99-B:1399-1408.

Extensor Tendon Rupture in Non-Traumatic Osteoarthritis of Distal Radioulnar Joint: Vaughan-Jackson Syndrome – A Rare Case Report from Indian Subcontinent

Osteoarthritis of distal radioulnar joint with rupture of extensor tendon of hand is a rare problem seen in elderly. It was first reported by Vaughen and Jackson in 1948 and the syndrome is named after them. The rupture results from attrition of dorsally dislocated ulnar head during pronation and supination movements. This dislocation of ulnar head is due to dehiscence of dorsal capsule of the distal radioulnar joint. “Scallop sign”1 is a radiological sign which are seen in this condition and signifies impending rupture of extensor tendon. Tendon transfer with excision of ulnar head is a viable option. We present a case of attritional rupture of extensor tendon of 4th and 5th fingers in a patient with non-traumatic osteoarthritis of distal radioulnar joint (DRUJ) in an elderly female. To the best of our knowledge no case of attritional rupture of extensor tendon of hand with osteoarthritis of distal radioulnar joint has been reported from Indian subcontinent.

Comparison of Gait Characteristics Between Patients With Nontraumatic and Posttraumatic Medial Knee Osteoarthritis

To compare knee kinematics and kinetics during walking in patients with posttraumatic versus nontraumatic medial compartment knee osteoarthritis (OA). Participants with medial compartment knee OA were classified as nontraumatic (n = 122) or posttraumatic (n = 93) based on evidence of previous anterior cruciate ligament tear, confirmed arthroscopically. Kellgren/Lawrence severity scores and mechanical axis angle (MAA) were determined from radiographs. Knee flexion and adduction angles and external moments were calculated from gait analysis using a 3-dimensional optical motion capture system and force plate. Peak values were identified and principal component (PC) analysis determined waveform characteristics (PC scores). Linear regression models examined whether the OA group (posttraumatic or nontraumatic) predicted peak values and PC scores after controlling for age, gait speed, and severity. Models were repeated with and without controlling for MAA. The knee OA group was a significant predictor of peak knee adduction angles (P = 0.04) and moments (P = 0.05). Similarly, it was a significant predictor for some knee adduction angle (P = 0.02 to 0.64) and moment (P = 0.02 to 0.25) PC scores. The nontraumatic OA group had higher adduction angles and moments. There were no significant relationships between OA group and knee flexion angles and moments. After controlling for MAA, only one significant relationship remained between knee adduction moment shape characteristics and OA group. Frontal plane knee kinematics and kinetics during walking differ between patients with posttraumatic versus nontraumatic medial compartment knee OA, with posttraumatic OA showing relatively decreased adduction.

Hip and knee arthroplasties and their significance in personal injury practice

Complications of hip and knee arthroplasty are frequently a source of litigation. The circumstances surrounding the complication - and whether it results from substandard care - need to be opined upon by a surgeon with considerable experience in that field. The subject was reported by McWilliams et al1 from a review of the records of the NHS Litigation Authority (NHSLA) in the UK. However, hip and knee arthroplasty is also a source of interest in some personal injury claims, particularly after tibial plateau and acetabular fractures. Legal advisers are usually interested in four things: *What is the likelihood of arthroplasty in the future? *When is it likely to be required? *What is the likely outcome, i.e. is the outcome similar in nature to arthroplasty for non-traumatic osteoarthritis? What is the likelihood of a revision being required in the patient/claimant’s lifetime? *If the patient/claimant is still in employment, how much time will they lose from work and how likely are they to get back to work? All orthopaedic surgeons are aware that the decision to recommend joint arthroplasty for a painful symptomatic hip/knee joint is very much a quality of life decision. This applies in both the post-traumatic and non-traumatic situation. A proper risk/benefit analysis needs to be conducted with the patient. The likelihood of post-traumatic arthritis developing after hip or knee injury depends upon the precise nature of the original injury and the adequacy of the initial surgery, if the fracture was treated operatively. Following analysis of the case, the expert should be in a position to make an educated estimate as to whether and when arthroplasty will be required in the future on the basis …

The Critical Shoulder Angle is Predictive of Rotator Cuff Tears and Shoulder Osteoarthritis and is Better Assessed with Radiographs over MRI

Objectives:The critical shoulder angle (CSA) (Moor et al., Annual Meeting AAOS 2013) is measured as the angle between glenoid and lateral border of the acromion and has been associated with glenohumeral osteoarthritis (OA) as well as rotator cuff tears (RTC). The purpose of this study was to determine the reproducibility of the CSA for the detection of patients with RTC or OA by x-ray and to determine whether the CSA can also be measured with magnetic resonance imaging (MRI).Methods:In this IRB approved study, a pre-hoc power analysis was performed to determine sample size. The CSA was measured by x-ray and MRI in 3 age-matched groups of 10 patients each, consisting of a non-traumatic full-thickness RCT group, a non-traumatic and non-inflammatory OA group, and a non-RCT/non-OA-pathology group. All patients underwent routine x-rays with a standardized technique and had standard shoulder MRI’s in a 3.0T magnet. All pathologies were determined from pre-op imaging studies and were confirmed at surgery. Subjects were retrieved from a prospectively collected data registry. Three independent observers, one radiologist and 2 orthopedic surgeons, performed the measurements. CSA angles were measured using Stryker OfficePACS Power 4.1 Express Edition (Kalamozoo, MI).Results:The inter-observer correlation coefficients of the measurements done by x ray and MRI were 0.95 and 0.83, respectively. There were differences in the mean CSA’s among the three groups, measured by x-ray (ANOVA between RCT, OA, non-RCT/non-OA: p <0.001). MRI showed greater variability in the CSA measurements among observers and across pathologies. Radiographs were more predictive of pathology than MRI. For example, patients with CSAs greater than 35° had a 79.3% chance to be part of the RCT group when measured by x-ray, whereas the chance was only 69.0% using MRI. Those with angles less than 30° by x-ray had an 82.6% probability to be part of the OA group, whereas the probability dropped to 47.3% when the measurement was done by MRI. When the study groups were compared, no significant differences were seen in the mean CSAs by x-ray and MRI in the RCT and non-RCT/non-OA pathology group, 37.3±2.6° versus 36.4±1.9° (p = 0.24) and 32.7±2.5° versus 31.8±2.7 (p = 0.20), respectively. Whereas a significant difference was observed the OA group by x-ray 28.7±2.2° versus 31.3±4.4 by MRI (p = 0.01), although the trend remained for a lower CSA in OA.Conclusion:The CSA measured by x-ray showed excellent inter-observer agreement and less variability than measurements done by MRI, especially in patients with OA. The CSA was also highly diagnostic for predicting RCT’s and OA of the shoulder. This study furthermore confirms the work of Moor and Gerber and suggests that there may be biomechanical and anthropomorphic components that underlie these shoulder disorders. CSA may also have effects on clinical outcome after surgical treatment. Furthermore, novel surgical procedures might be able to affect the CSA to hasten or prevent progression of RCT’s or OA.