Lateral Tibia Research Articles

Bert model fine-tuning for text classification in knee OA radiology reports

Purpose: Traditional Natural Language Processing (NLP) techniques do a good job of understanding relationships between adjacent or nearby words. However, clinical text data such as patient notes or radiology reports require capturing interactions between distant words. BERT (Bidirectional Encoder Representations from Transformers), a new form of deep neural network recently introduced by Google, overcomes this challenge given its ability to comprehend long range word interactions. While BERT has dramatically improved outcomes in NLP tasks in the general domain such as optimizing search results, its performance in domain specific tasks such as analyzing biomedical data is still being explored. We report the findings of using a pre-trained BERT model further trained on knee radiology reports with the aim of testing its ability to identify cartilage lesions in osteoarthritis (OA) patients, the first such effort in musculoskeletal imaging. Methods: 1521 MR scans of patients with osteoarthritis and corresponding radiology reports were assessed by the clinician for all 6 cartilage compartments (Patella, Trochlea, Medial Femur, Medial Tibia, Lateral Femur and Lateral Tibia) according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) system for knee OA (Figure 1). These gradings were further simplified into binary (Normal and Abnormal) classes (WORMS target). The clinician also assessed (blinded) 89 radiology reports and provided binary targets (NLP target). Radiology reports contains Technique, Findings and Impression sections, due to reports vary in length, with median 329 and max 731 tokens for our dataset, and BERT has 512 tokens limitation, Findings section was selected as dataset for both classification tasks, Logistic Regression and BERT fine-tuning. Both models have 80/20 train test data split, trains on all 6 compartments and use the binary WORMS target. For baseline Logistic Regression model, texts were cleaned and tokenized with Spacy then applied Term Frequency Inverse Document Frequency (TF-IDF) transforming texts into numeric vectors as input and trained with class weighted logistic regression. After the training process, 5-fold cross validation was performed to evaluate performance. To fine-tune BERT text classification task, reports were preprocessed with lower cased text, added special tokens to mark beginning and end sentences, padded if reports are shorter than 512 tokens, then generated vector representations with bert-base-uncased pre-trained model into training features along with input mask, and segment id. In evaluation step, the fine-tuned BERT models were then tested on each compartment for both WORMS target and NLP target. Results: For both training and testing datasets, the ratio of normal to abnormal cases varies. Patella has the most abnormal making it more balanced while MT has the least (Figure 2A). In the more balanced compartments such as Patella and Trochlea, LFC, BERT significantly improved the classification results compares to the baseline model. However, for the imbalanced dataset, even though BERT shows higher accuracy, it overfits and predicted Normal for all. This can be solved by hyper-parameter tuning and adjusting class weight in loss function for each model. Each fine-tuned BERT model is tested with NLP Target (labels on 89 radiology reports) and compared with the earlier WORMS target (gradings from images) (Figure 2B). Accuracy significantly improves on the NLP target with more balanced dataset (Figure 3). However, the overfit problem persists on MFC, MT, LT compartments. This implies the discrepancies between MR images and the content in the radiology reports, using NLP target which provides a more accurate annotations on reports will further improve the model’s prediction abilities. Conclusions: Our results in cartilage abnormality prediction esp. in compartments with balanced data holds promise and calls for further investigating use of BERT for domain specific tasks. The ability to develop a model which can accurately decipher text sentiment from radiology reports avoiding the need of time-consuming image annotation will accelerate and augment image based deep learning approaches for anomaly detection and improve clinical workflow.View Large Image Figure ViewerDownload Hi-res image Download (PPT)View Large Image Figure ViewerDownload Hi-res image Download (PPT)

A new radiographic finding of adult symptomatic discoid lateral meniscus.

Discoid lateral meniscus is one of the most common knee problems in clinical practice. Several radiographic findings have been reported to screen discoid lateral meniscus, but the diagnostic value of those signs varies.We introduce a new method of measurement on plain radiograph for initial screening discoid lateral meniscus and describe its efficacy and correlation to symptomatic discoid lateral meniscus.This is a retrospective case-control study.Seventy-eight arthroscopic proven symptomatic discoid lateral meniscus adult patients plus 73 patients of matched control group were retrospectively reviewed at our institution between 2012 and 2017. We studied their standardized non-weight-bearing knee radiograph anterior-posterior view and measured the following parameters: lateral joint space height, lateral tibia spine height, fibular head height, lateral tibia plateau obliquity (LTPO), and lateral condyle convex angle (LCCA).Significant statistical differences were found in the lateral joint space height, lateral tibia spine height, fibular head height, LTPO and LCCA measurements between the 2 groups (P < .05). Also, we found the phenomenon that angle parameters such as LTPO and LCCA had high sensitivities with relatively low specificities compared with height parameters.We propose that LCCA is a new measurement which is statistically larger in discoid meniscus patients. Furthermore, it can be useful for screening discoid lateral meniscus on plain radiograph with its relative high sensitivity.Level of Evidence: Level III, Case-control study.

Association between knee alignment, articular cartilage degradation, and subchondral trabecular bone remodeling in patients with knee osteoarthritis

Purpose: Knee osteoarthritis (OA) is a common disabling disease involving the entire joint tissue, its onset and progression are affected by many factors. However, the current number of studies investigating the relationship between subchondral trabecular bone (STB), knee alignment and articular cartilage degradation is limited. We aimed to investigate the variation in tibial plateau STB remodeling in knee OA patients and their association with knee alignment (hip-knee-ankle, HKA, angle) and articular cartilage degradation. Methods: Forty-three knee OA patients scheduled for total knee arthroplasty (TKA) underwent preoperative radiography to measure the HKA angle and Kellgren-Lawrence grade. Tibial plate specimens collected from TKA was used for histology, histomorphometric measurements, and immunohistochemistry to assess subchondral bone remodeling and cartilage degradation ((OARSI score). Correlations between HKA angle, OARSI score, and STB remodeling parameters were evaluated. Differences in STB remodeling parameters between varus and valgus groups based on the HKA angle were examined. Results: The HKA angle was significantly correlated with all STB remodeling parameters (p<0.01). The HKA angle was more correlated with the medial-to-lateral ratios of the remodeling parameters than with the medial or lateral tibia plateaus. The HKA angle and all STB remodeling parameters are significantly correlated with OARSI score (p<0.01). Conclusions: The variation of tibial plateau STB structural and remodeling indices is associated with the HKA angle and cartilage degradation. Knee malalignment causes the abnormal STB remodeling and microstructural sclerosis potentially affecting transmission of loading stress from the cartilage to the subchondral bone, and then resulting in accelerated OA progression in patients with knee OA. The results indicate that correction of knee malalignment could affect STB remodeling and then intervene the occurrence and development of OA. In addition, the improvement in subchondral bone with bone-metabolism agents may help mitigate OA progression.

Revision of unicompartmental knee arthroplasty using the in situ referencing technique.

Revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) with the in situ referencing technique aiming to preserve as much ligament function and epi-metaphyseal bone stock as possible. Aseptic loosening, progression of osteoarthritis, periprosthetic fracture, periprosthetic infection, arthrofibrosis, polyethylene wear, malalignment, instability, femoro-tibial impingement. Unexplained pain, localized or systemic active infection (anywhere). Referencing for the tibia and the femur cuts is performed prior to implant removal. The tibial cutting jig and the initial tibial resection level is set in away that the sawblade just fits under the tibial implant. In case too much bone needs to be removed to achieve flush implant sitting on both the medial and lateral tibia, astep cut needs to be performed to build up the medial defect with an augment. Prior to femoral component removal, rotational alignment is determined and intramedullary referencing for the distal femur osteotomy is performed. Level of constraint and additional tibial stem fixation is chosen according to the amount of bone resected and according to ligament stability. Sterile dressings and elastic compression bandaging. No limitation of active/passive range of motion. Full weight-bearing or partial weight-bearing for 2weeks postoperatively in the presence of bone or soft tissue defects. Between 2008 and 2019, 84patients underwent revision of unicompartmental knee arthroplasty. The mean follow-up was 64months (range 3-132 months). Implant survival after revision of UKA to TKA was 92% (95% CI = 82-97%) at 5years of follow-up and 86% (95% CI = 69-93%) at 10years of follow-up. The mean Oxford knee score was 20.1 (6-39, SD ± 6.5) preoperatively and 30.2 (3-48, SD ± 11.3) postoperatively. The mean visual analogue scale was 6.9 (range 1-10, SD ± 1.8) preoperatively and 3.9 (range 0-9, SD ± 2.6) postoperatively.

The association of subchondral and systemic bone mineral density with osteoarthritis-related joint replacements in older adults

To describe the association of subchondral and systemic bone mineral density (BMD) with knee and hip replacements (KR and HR, respectively) due to osteoarthritis. 1,095 participants (mean age 63 years, 51% female) were included. At baseline, subchondral BMD of the medial and lateral tibia in three regions of interest (ROI) for the right knee, and systemic BMD of the lumbar spine, femoral neck, total hip and whole-body, were measured using dual-energy X-ray absorptiometry. Subchondral BMD of the hip was not measured. Competing risk regression models were used to estimate sub-distribution hazard ratios (SHRs) of KR/HR per one standard deviation (SD) higher in BMD measures, with adjustment of potential confounders. Over 12.2 years, 79 (7.2%) participants underwent a KR and 56 (5.1%) an HR due to osteoarthritis. For the right side, medial subchondral BMD in ROI-3 was associated with an increased risk of KR (SHR 1.95 per SD; 95% Confidence Interval [CI], 1.57 to 2.43). In contrast, systemic BMD was not associated with the risk of KR, but higher BMD at the lumbar spine (1.42, 1.07 to 1.88) and whole-body (1.29, 1.00 to 1.66) were associated with an increased risk of HR at both sides. Subchondral BMD is positively associated with an increased risk of KR and systemic BMD with an increased risk of HR, suggesting a role of BMD in the progression of osteoarthritis.

The sensitivity of joint kinematics and kinetics to marker placement during a change of direction task

The conventional gait model (CGM) refers to several closely related biomechanical models used in the objective analysis of human motion. Their use has become popular in the analysis of change of direction tasks to inform best practice in the prevention and rehabilitation of anterior cruciate ligament injury. As externally-placed markers define segment axes origins and orientations, kinematic and kinetic outputs from the CGM are sensitive to marker placement. The aim of this investigation was to quantify the sensitivity of lower extremity kinematics and knee moments to systematic differences in marker placement across the stance phase of a change of direction task. Systematic anterior/posterior displacements were applied to the lateral thigh, femoral epicondyle and tibia markers in software. One-dimensional statistical parametric mapping was used to determine the effect of marker placement across the entire stance phase of a 90° change of direction task. Marker placement error within previously reported inter-tester variability ranges caused significant differences in knee abduction moment, hip rotation angle, knee rotation angle, ankle abduction and rotation angle across various periods of stance. Discrete measures of these variables have been associated with increased frontal plane knee loading during change of direction, considered a key mechanism of anterior cruciate ligament injury. Systematic differences in marker placement may lead to incorrect group statistical inferences in such discrete measures.

Characteristic features of the insertions of the distal tibiofibular ligaments on three-dimensional computed tomography- cadaveric study -

PurposeThe purpose of this study was to clarify the insertion sites of the anterior inferior tibiofibular ligament (AITFL) and posterior inferior tibiofibular ligament (PITFL) and related osseous landmarks on three-dimensional computed tomography images.MethodsTwenty-nine non-paired, formalin-fixed human cadaveric ankles were evaluated. The tibial and fibular insertion sites of the AITFL and PITFL were identified. The morphology and location of the insertion sites and their positional relationships with osseous structures were analyzed on three-dimensional computed tomography images.ResultsThe AITFL had a trapezoidal shape, with fibers that ran obliquely lateral from a wider insertion at the lateral distal tibia to the medial distal fibula. The PITFL had a similar shape to the AITFL; however, it ran more horizontally, with fibers running in the same direction. In the tibia, the anterior capsular ridge and the Chaput’s and Volkmann’s tubercles were useful osseous landmarks for the insertion sites. In the fibula, the centers of the insertion sites of the AITFL and PITFL were located on the edges of the distal anterior and posterior fibula, which were useful osseous landmarks. The mean distances between the center points of the tibial and fibular insertion sites of the AITFL and PITFL were 10.1 ± 2.4 mm and 11.7 ± 2.6 mm, respectively.ConclusionsThe relationships between the characteristic features of the distal tibia and fibula and the insertions of the AITFL and PITFL were consistent. The present findings improve the understanding of the anatomy of the insertions of the distal tibiofibular syndesmotic joint.

Does surgical approach affect sagittal plane alignment and pilon fracture outcomes?

PurposeSagittal plane alignment beyond articular reduction and its effect on clinical outcomes has not been emphasized. Surgical approach may influence a surgeon's ability to correct the sagittal plane alignment. The purpose of our study was to evaluate how surgical approach impacts anterior distal tibial angle (ADTA) and lateral talar station (LTS). Our hypothesis was that the anterolateral (AL) approach would improve the sagittal plane parameters due to the primary plate placement. Patients and methodsA retrospective review was performed on patients who underwent operative management for pilon fractures at 2 ACS Level 1 Academic Trauma Centers. Clinical data points including demographics, comorbidities, AO/OTA classification, surgical approach, and complications were recorded. Quality of reduction was measured using the ADTA, lateral distal tibia angle (LDTA), and lateral talar station (LTS) from radiographs. Results580 pilon fractures met inclusion criteria. When compared to the AL approach, the modified anteromedial (AM) approach had decreased rates of local wound care, and unplanned reoperations. The AM approach had increased rates of superficial infection, deep infection, non-union, and amputations. There was no difference in ADTA, LDTA, or LTS between the AM and AL approach (P = 0.49, P = 0.41, P = 0.85). There was a difference in LTS with tobacco users (P = 0.02). ConclusionsThe sagittal plane alignment does not appear to be affected by the surgical approach. Therefore, the surgical approach to pilon fractures should be based on the fracture pattern and the patient's soft tissue envelope. This study shows that the AM is a relatively safe and effective approach to complex fractures and the surgeon should consider the specific fracture pattern and patient soft tissue envelope when choosing the specific approach.

Internal tibial torsion is related to syndesmosis injury in a large osteological collection

BackgroundThe long-term consequences of tibial torsion remain unclear. This study evaluated whether syndesmotic injuries are associated with tibial torsion. MethodsA collection of over 3000 cadaveric skeletons was screened for irregular bony prominence along the lateral distal tibia, consistent with previous syndesmosis injury. Tibial torsion was measured and compared to 1034 control cadaveric tibiae. ResultsMean torsion of 236 specimens with syndesmotic injury was 6.2±8.9 degrees, while that of control specimens was 7.9±8.8 degrees (P = 0.008). Multiple regression analysis showed a non-statistically significant trend toward internal torsion and syndesmotic injury (standardized beta=−0.051, P=0.059). Syndesmosis injury was present in 48/200 specimens (24.0%) with internal torsion and 31/199 specimens (15.6%) with external torsion (P=0.035). ConclusionThis association between internal tibial torsion and syndesmotic injury suggests that internal tibial torsion might not be an entirely benign condition and merits further study.

Effects of malalignment and disease activity on osteophyte formation in knees of rheumatoid arthritis patients.

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. 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. 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 mm2, 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). 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.

Minimally invasive plate osteosynthesis of clavicular midshaft fractures under insertion guide.

The less invasive stabilization systems for the distal femur and proximal lateral tibia have been developed to simplify the surgical technique of minimally invasive plate osteosynthesis (MIPO). MIPO, however, has simply been introduced into clavicular midshaft fixation without the aid of insertion guide though the procedure for midshaft clavicular fractures was found to produce satisfactory clinical and radiologic outcomes without serious complications. The purpose of this study was to determine the outcome of MIPO of clavicular midshaft fractures using an insertion guide. A total of 15 patients with clavicular midshaft fractures treated by MIPO using insertion guide between September 2016 and September 2018 were included. We assessed bony union, shoulder function by the Constant score, and complications at a mean follow-up of 15.4 months (ranged from 12 to 24 months). The mean surgical time 55.9±9.4 min (ranged from 50 to 70 min) and the fluoroscopic time was 146.5±29.0 s (ranged from 110 to 190 s). In all patients, the bony union was achieved at 8.8±1.0 weeks (ranged from 8 to 10 weeks) with no delayed unions or nonunions. The average Constant score was 99.1±1.2 (ranged from 96 to 100) at follow-up. Postoperative complications including infections, screw pull-out, hardware prominence, and neurovascular injury were not observed, however, one patient complained of mild plate discomfort. MIPO using insertion guide is believed to be an acceptable and effective choice in the operative treatment of clavicular midshaft fractures.

The entry point of intramedullary tibia cutting guide should vary according to the individual tibia morphology in TKA.

In total knee arthroplasty (TKA) using the intramedullary tibial cutting guide (IMTCG), the positioning of the IMTCG is important for accurate tibial bone resection. The aim of this study was to evaluate the ideal entry point of IMTCG and affecting radiologic factors. From May 2017 to February 2018, 91 consecutive TKAs for osteoarthritis were included. From preoperative full-length radiographs, we measured the medial proximal tibia angle (MPTA), lateral distal tibia angle (LDTA), tibial bowing angle (TBA), medial to lateral width of the tibial plateau, tibial length, and ideal coronal entry point. In preoperative short knee lateral radiographs, we measured the anterior to posterior length of the tibial plateau, tibial posterior slope angle (TPSA), metaphysio-diaphyseal angle (MDA), and ideal sagittal entry point. The ideal coronal and sagittal entry points were defined as the points crossing the tibial plateau and tibial anatomical axis on the coronal and sagittal radiographs, respectively. The ideal entry point was 51.4 ± 4.3% (SD) from the medial margin and 27.0 ± 5.8% (SD) from the anterior margin of the tibial plateau. However, the range varied from 39.8 to 60.5% on the coronal plane and from 9.6 to 37.7% on the sagittal plane, respectively. As the MPTA (rho = -0.490) and TBA (rho = -0.433) were increased, the coronal entry point moved medially. As TPSA (rho = -0.761) and MDA (rho = -0.495) were increased, the sagittal entry point moved anteriorly. The ideal entry point of IMTCG should vary according to the individual tibial morphology.

Association of age, sex and BMI with the rate of change in tibial cartilage volume: a 10.7-year longitudinal cohort study

BackgroundTo describe the association of age, sex and body mass index with the rate of change of tibial knee cartilage volume over 10.7 years in a community-based sample of older adults.MethodsFour hundred and eighty-one participants (49% female, mean age 60.8 years [range 51.1–79.7], 49% had knee pain and 58% radiographic osteoarthritis) were included. Tibial cartilage volume of the right knee was assessed on T1-weighted fat-suppressed 1.5 T MRI at baseline and 10.7 years. Data analyses were performed using linear regression models.ResultsThe average rate of loss of cartilage volume was 1.2%/year (range 0.2–3.9%) with all participants losing cartilage volume over the study period. There was a significant association between age and loss of tibial cartilage volume in the medial (0.023%/year, 95% confidence interval [CI] 0.010 to 0.036%, p < 0.001), lateral (0.013%/year, 95% CI 0.003 to 0.023%, p = 0.012) and total tibia (0.018%/year, 95% CI 0.009 to 0.026%, p < 0.001). Higher body mass index at baseline and increases in body mass index over time were associated with a greater tibial cartilage loss at the medial (body mass index at baseline 0.040%/year, 95% CI 0.022 to 0.058%, p < 0.001; increases in body mass index 0.055%/year, 95% CI 0.018 to 0.093%, p = 0.004) but not lateral compartment. No evidence of non-linear relationships was observed. Compared to males, females lost more lateral tibial cartilage with increasing age (0.023%/year, 95% CI 0.003 to 0.043%, p = 0.024 for interaction).ConclusionsTibial cartilage volume declines at a faster rate with increasing age and body mass index in both males and females, particularly in the medial compartment. In contrast to the low rate of change in radiographs, our findings suggest that cartilage loss at the tibia is universal in this age group.

WITHDRAWN: Limited value of MRI in the preoperative assessment of lateral-compartment cartilage in potential candidates for medial unicompartmental knee arthroplasty

Abstract Background Intact lateral-compartment cartilage is a requirement for the long-term success of medial unicompartmental knee arthroplasty (UKA). The value of MRI to rule out lateral-compartment cartilage lesions (OARSI ≥ grade 2) in potential candidates for medial UKA was prospectively evaluated. Methods One-hundred consecutive knees undergoing total knee arthroplasty for varus osteoarthritis (OA) were included. Knees with lateral-compartment OA (Kellgren-Lawrence > grade 2) were excluded, leaving 84 knees for final assessment. On MRI, lateral-compartment cartilage was assessed using a validated score. In corresponding locations, cartilage was histologically assessed using the OARSI system. Results The prevalence of histologically intact (OARSI grade 0/1) cartilage was: distal lateral femur: 71/84 (85%); lateral tibia plateau: 22/84 (26%). The sensitivity of MRI to rule out advanced cartilage lesions (OARSI ≥ grade 2) was 77% (17/22) for the lateral tibia plateau. The precision of MRI to correctly identify intact cartilage (OARSI grade 0/1) on the lateral tibia plateau was 38% (17/45). For the distal lateral femur, MRI was able to rule out OARSI ≥ grade 2 cartilage lesions in 85% (60/71) with high precision (60/62 (97%)). Conclusion MRI does not have a high accuracy of ruling out patients with more advanced (ORASI ≥ grade 2) cartilage damage on the lateral tibia plateau. MRI can reliably rule out advanced histologic cartilage lesions on the distal lateral femur, however, advanced cartilage lesions are rare in varus OA of the knee. The current study does not support the routine use of MRI to rule out lateral-compartment cartilage damage.

Coronal malalignment of lower legs depending on the locations of the exostoses in patients with multiple hereditary exostoses

BackgroundsThough malalignment of lower legs is a common pathologic phenomenon in multiple hereditary exostoses (MHE), relationship between locations of exostoses and malalignment of lower legs remains unclear. This study examined radiographs of MHE patients in an attempt to evaluate the tendency of coronal malalignment of lower legs with different location of exostoses on lower legs consisting of two parallel long bones.MethodsBetween 2000 and 2017, we retrospectively reviewed the anteroposterior films of the teleo-roentgenographics of 63 patients with MHE. The patients were classified into four different groups depending on the locations of the exostosis, which occurred on both proximal and distal tibiofibular joints (A), proximal tibiofibular joint (B), distal tibiofibular joint (C), and not for the tibiofibular joint area (D). To evaluate the influence of the location of exostoses on coronal malalignment of lower legs, medial proximal tibia angle (MPTA), lateral distal tibia angle (LDTA), and fibular shortening were analyzed for each group.ResultsSignificant difference was observed in multiple comparative analyses for each of the four groups. On MPTA radiologic analysis, group A showed greatest value with significant difference compared with groups C and D (vs. (B): p = 0.215; vs. distal joints (C): p = 0.004; vs. (D): p = 0.001). Group B showed significant difference only with group D (vs. distal joints (C): p = 0.388; vs. (D): p = 0.002), but for group C and D showed no significant difference. For LDTA, only group A showed significant difference compared to other groups (p < 0.001). With regard to tibiofibular ratio for evaluation of fibular shortening, group A showed the lowest ratio (vs. (B): p = 0.004; vs. (C): p = 0.655; vs. (D): p < 0.001). Group C also presented the significant lower ratio than group D (p = 0.002).ConclusionsFor evaluation of the coronal malalignment of lower legs in MHE patients, not only ankle around the distal tibiofibular joint but also proximal tibiofibular joint should be examined, in that, lower limb deformity occurred by two parallel long bone which has self-contained joint.Level of evidenceLevel III, retrospective comparative study.

TL 18206 - Foot and ankle insufficiency fractures among postmenopausal sedentary women

Introduction: Insufficiency fractures occur in bones with decreased elastic strength. In contrast to fatigue or stress fractures, which affect normal bones and have been extensively studied in the literature, foot and ankle insufficiency fractures have been poorly researched to date. The objective of this study was to identify behavioral, biomechanical and metabolic factors associated with the development of foot and ankle insufficiency fractures. Methods: In total, 53 sedentary postmenopausal female patients who had foot and ankle insufficiency fractures and who were treated at the São Paulo State Civil Servant Hospital (Hospital do Servidor Público do Estado de São Paulo) were included in the treatment group, and 53 individuals were included in the control group. Data were collected on fracture site, body mass index (BMI), corticoid use, femoral and lumbar T-score measured by bone densitometry, and serum 25-hydroxyvitamin D level. The calcaneal angle, the angle between the first metatarsal and the talus and the metatarsus adductus angle were measured in radiographs. Results: The fractures affected the metatarsal bones in 47 patients. Other fracture sites included the lateral malleolus, lateral cuneiform bone, cuboid bone, tibia and calcaneus. All metatarsal bones were affected, most frequently the 5th. The most common fracture was a 5th metatarsal base fracture in zone II. There was no significant difference in mean BMI, serum 25-hydroxyvitamin D levels, alcohol consumption or smoking between the groups. The development of fractures was significantly associated with corticoid use (p&lt;0.0001), low femur (p=0.028) and lumbar spine (p=0.002) bone mineral density and metatarsus adductus angle (p=0.02). When analyzed separately, 4th and 5th metatarsal fractures were associated with smaller angles between the talus and the first metatarsal (p=0.01). Conclusion: Foot and ankle insufficiency fractures among sedentary postmenopausal women are associated with corticoid use, low bone mineral density and biomechanical characteristics, such as pes cavus and metatarsus adductus. The presence of such fractures may be the first sign of bone fragility and should be used as criteria for initiating adequate treatment to prevent other fractures.

A New Reference to Evaluate Syndesmosis in Sagittal Plane Radiographs of the Ankle: The Lateral Posterior Ankle Ratio.

Confirmation of anatomical reduction of ankle syndesmosis is mandatory because improper reduction leads to poor functional results. Coronal plane evaluation of syndesmosis is well described in the literature, but there is little information about sagittal plane evaluation. We sought to evaluate the relationship of fibula and tibia in the sagittal plane and create a new reference that can be applied easily and reliably. Lateral ankle radiographs of 337 individuals with no history of ankle fracture were evaluated. A line was drawn between the anterior and posterior cortices of the distal lateral tibia, and the length of this line was measured (line 1). The distance between the anterior and posterior cortices of the fibula on this line was measured, and the center of this second distance was identified and marked. The posterior half of the fibular width was divided by line 1 and was named the lateral posterior ankle ratio (LPAR). Statistical analysis was performed by side and sex. Mean patient age was 38.6 years; mean LPAR was 0.48. There was a significant difference between men and women by age (P < .001) and LPAR (P = .01). There was no significant difference between right and left ankles by age (P = .63) and LPAR (P = .64). The LPAR was less than 0.40 in 6.8% of the radiographs, 0.40 to 0.50 in 57.9%, and greater than 0.50 to 0.60 in 32.9%. The LPAR should approximate 50% in normal lateral ankle images and, by extrapolation, after syndesmotic reduction.

Chondrocalcinosis is associated with increased knee joint degeneration over 4 years: data from the Osteoarthritis Initiative

To determine if presence of calcium-containing crystals (CaC) is associated with increased knee joint degeneration over 4years and assess if total number of CaCs deposited is a useful measure of disease burden. Seventy subjects with CaCs in right knees at baseline were selected from the Osteoarthritis Initiative and matched to 70 subjects without evidence of CaCs. T1-weighted gradient-echo sequences were used to confirm presence of CaCs and count the numbers of distinct circumscribed CaCs. Morphological abnormalities were assessed at baseline and 4-year follow-up using the modified semi-quantitative Whole-Organ Magnetic Resonance Imaging Score (WORMS). Linear regression models were used to analyze the associations between presence of CaCs at baseline and changes in WORMS and to analyze the associations between numbers of circumscribed CaCs at baseline and changes in WORMS. Presence of CaCs was associated with increased cartilage degeneration in the patella (coefficient: 0.33; 95% confidence interval (CI): 0.04-0.63), the medial femur (coefficient: 0.51; 95% CI: 0.18-0.83), the lateral tibia (coefficient: 0.36; 95% CI: 0.01-0.71) as well as the medial and lateral meniscus (coefficient: 0.38; 95% CI: 0.00-0.75 and coefficient: 0.72; 95% CI: 0.12-1.32). Knees with higher numbers of CaCs had increased cartilage degeneration in the patella and medial femur (coefficient: 0.09; 95% CI: 0.05-0.14; P<0.001 and coefficient: 0.08; 95% CI: 0.02-0.14; P=0.005). CaCs were associated with increased cartilage and meniscus degeneration over a period of 4years. Assessing the number of CaC depositions may be useful to evaluate risk of onset and worsening of degenerative disease.

The influence of femoral and tibial bony anatomy on valgus OA of the knee.

Approximately 10% of all patients that require a total knee arthroplasty present with valgus osteoarthritis (OA) of the knee. Valgus OA goes along with posterolateral bone loss and lateral soft tissue tightness. The role of malalignment on the development of OA is not fully understood. The current study investigates whether the femoral offset (FO), femoral mechanical-anatomical (FMA) angle, anatomical lateral distal femur angle (aLDFA), mechanical lateral distal femur angle (mLDFA), medial proximal femur angle (MPFA), medial proximal tibia angle (MPTA) or lateral distal tibia angle (LDTA) differ in patients with valgus OA of the knee. FO, FMA angle, aLDFA, mLDFA, MPFA, MPTA and LDTA were assessed and compared between 100 consecutive knees with minimal valgus OA (50 male, 50 female) and 100 consecutive knees with minimal varus OA (50 male, 50 female). FO was significantly higher in males with valgus OA (p = 0.002) and females with varus OA (p = 0.01). The observed values for the FMA angle were significantly higher in males with valgus OA (p = 0.002) and females with varus OA (p = 0.041). The aLDFA and mLDFA were significantly smaller in all patients with valgus OA (p < 0.001). No differences between the varus and valgus groups were detected regarding MPFA (males: p = 0.052; females: p = 0.719). Tibial measurements showed significantly higher values for the MPTA (p < 0.001) in both valgus groups and no difference for LDTA (men: p = 0.139; women: p = 0.196). Bony alterations in the femoral anatomy seem to be more important than in the tibial anatomy. While in male patients with valgus OA, the main anatomic variation is the hypoplasia of the lateral femoral condyle, in females both decreased femoral offset of the hip as well as hypoplasia of the lateral condyle are present. III.

Biochemical changes in knee articular cartilage of novice half-marathon runners.

ObjectiveTo evaluate changes in knee articular cartilage of novice half-marathon runners using magnetic resonance imaging T2 relaxation time mapping.MethodsHealthy subjects were recruited from local running clubs who met the following inclusion criteria: (i) age 18–45 years; (ii) body mass index less than 30 kg/m2; (iii) had participated in one half-marathon or less (none within the previous 6 months); (iv) run less than 20 km/week; (v) no previous knee injury or surgery; (vi) no knee pain. T2 signals were measured pre- and post-race to evaluate the biochemical changes in articular cartilage after the subjects run a half-marathon.ResultsA significant increase in the mean ± SD T2 relaxation time was seen in the outer region of the medial tibial plateau (50.1 ± 2.4 versus 54.7 ± 2.6) and there was a significant decrease in T2 relaxation time in the lateral femoral condyle central region (50.2 ± 4.5 versus 45.4 ± 2.9). There were no significant changes in the patella, medial femoral condyle and lateral tibia articular surfaces.ConclusionAn increase in T2 relaxation time occurs in the medial tibial plateau of novice half-marathon runners. This limited region of increased T2 values, when compared with complete medial compartment involvement seen in studies of marathon runners, may represent an association between distance run and changes seen in articular cartilage T2 values.