Medial Joint Space Width Research Articles

Impact of Structural Severity on Outcomes in Knee Osteoarthritis: An Analysis of Data from Phase 2 and Phase 3 Lorecivivint Clinical Trials.

Developing knee osteoarthritis (OA) treatments is challenging due to assessing pain and joint structure outcomes within a highly heterogeneous disease. Lorecivivint (LOR), an intra-articular (IA) CLK/DYRK inhibitor, modulates Wnt and inflammatory pathways. This review analysis of LOR 0.07 mg trial data aims to describe the potential impact of baseline joint structure on OA pain response. Two Phase 2 and two Phase 3 trials enrolled knee OA patients with Kellgren-Lawrence (KL) Grades 2-3 and Pain Numeric Rating Scale (NRS [0-10]) ≥4 to ≤ 8 in target knee. Cumulative frequency distribution plots by KL grade summarized the percentages of patients with medial joint space width (medial JSW) < 3 mm. Osteoarthritis Research Society International Joint Space Narrowing grades and treatment responses in trials capturing Pain NRS were similarly summarized. Pain outcome changes were estimated using baseline adjusted ANCOVA. Compared with phase 2 trials, the phase 3 trials had an increased proportion of patients with baseline medial JSW < 3 mm. LOR demonstrated beneficial treatment effects vs placebo in KL 2 subgroups, which were found to have higher proportions of baseline medial JSW > 3 mm, apart from one Phase 3 trial with advanced structural knee OA. Baseline medial JSWs were heterogeneous across trials despite KL inclusion criteria. LOR demonstrated greater symptomatic improvements in patients with less structurally advanced disease, indicative of an association between OA structural damage and pain. Early treatment interventions may improve outcomes and provide insight for future OA trial inclusion criteria development. OA-02, NCT02536833; OA-04, NCT03122860; OA-10, NCT04385303; OA-11, NCT03928184.

Hip and pelvic geometry as predictors of knee osteoarthritis severity.

Malalignment is one of the most critical risk factors for knee osteoarthritis (KOA). Biomechanical factors such as knee varus or valgus, hip-knee-ankle angle, and femoral anteversion affect KOA severity. In this study, we aimed to investigate KOA severity predictive factors based on hip and pelvic radiographic geometry. In this cross-sectional study, 125 patients with idiopathic KOA were enrolled. Two investigators evaluated the knee and pelvic radiographs of 125 patients, and 16 radiological parameters were measured separately. KOA severity was categorized based on the medial tibiofemoral joint space widths (JSW). Based on JSW measurements, 16% (n = 40), 8.8% (n = 22), 16.4% (n = 41), and 56.8% (n = 147) were defined as grades 0, 1, 2, 3, respectively. There were significant differences between the JSW groups with respect to hip axis length, femoral neck-axis length, acetabular width, neck shaft angle (NSA), outer pelvic diameter, midpelvis-caput distance, acetabular-acetabular distance, and femoral head to femoral head length (P < .05). Two different functions were obtained using machine learning classification and logistic regression, and the accuracy of predicting was 74.4% by using 1 and 89.6% by using both functions. Our findings revealed that some hip and pelvic geometry measurements could affect the severity of KOA. Furthermore, logistic functions using predictive factors of hip and pelvic geometry can predict the severity of KOA with acceptable accuracy, and it could be used in clinical decisions.

Ten-year trends in values of joint space width and osteophyte area of knee joints: Comparison of the baseline and fourth ROAD study surveys

ObjectiveConsidering the joint space width and osteophyte area (OPA) of the knee joints of Japanese adults, this study elucidated the ten-year trends in medial minimum joint space width (mJSW) and OPA using data of two independent cohorts from a population-based cohort study. MethodsThe baseline survey of the Research on Osteoarthritis/Osteoporosis Against Disability study was conducted from 2005 to 2007; 2975 participants (1041 men, 1934 women) completed all knee osteoarthritis (OA) examinations. The fourth survey was performed from 2015 to 2016; distinct 2445 participants (764 men, 1681 women) completed identical examinations. The medial mJSW and medial tibial OPA were measured bilaterally using an automated system. ResultsThe mean medial mJSW (standard deviation) was 3.22 (0.96) mm and 2.65 (0.95) mm at baseline and 3.81 (1.20) mm and 3.13 (1.15) mm in the fourth survey for men and women, respectively. The mean medial mJSW in the fourth survey was significantly greater in both men and women in all age groups than at baseline (p ​< ​0.01). The mean OPAs in men aged 40–49 and 60–69 years and women aged 40–49, 50–59, 60–69, and 70–79 years were significantly smaller in the fourth survey (p ​< ​0.05). The trend in mJSW remained the same even after adjusting for confounding factors in the multivariate analysis, but the trend in OPA was weakened. ConclusionsA significant improvement in the medial mJSW within 10 years could decrease the incidence and progression of knee OA and prevent the risk of walking disability.

Single Stance Radiography of the Knee Joint - A Novel Approach to Assess the Degree of Knee Osteoarthritis.

Conventional radiography has always been cited as the gold standard for assessing the structural changes associated with osteoarthritis (OA) of the knee. The purpose of the study was to compare the joint space width between both leg-standing and one-leg-standing radiographs in an assessment of the severity of OA of the knee. Fifty patients with medial compartment OA were deployed for the study. Patients underwent both leg standing radiographs and one-leg standing radiograph on the affected leg. Kellgren-Lawrence (KL) radiographic classification was used to assess the severity of OA using joint space width. The mean medial joint space width decreased from 3.26 mm in both legs of the standing radiograph to 1.98 mm in the one-leg standing radiograph. Patients on both leg standing radiographs appreciated an increase in grade during the single leg radiograph. Nearly 52% of patients with both leg standing radiographs have changed the KL grading to a more severe grade when undergone a single leg standing radiograph. One-leg standing radiograph was found to be a better representation of joint space width than both-leg standing radiographs.

Medial Knee Joint Space in Relation to Joint Function and Early Knee Pain in 20-45-Year Adults: A Cross Sectional Study.

Anterior knee pain is very common in the young and active age groups but there are no significant studies on the normal population. Therefore, the objective of the study was to understand the relation between medial knee joint space to the development of knee pain and functional disability with special reference to the 20-45-year age group. 250 cases with mean age of 36.36years presenting with knee pain for at least 1month were included in this prospective study (July 2021 and June 2022) and were asked to self-complete questionnaires on knee pain which included KNEST, AKPQ, VAS and IPAQ. Patients underwent X-rays of bilateral knees in AP view with weight bearing and then medial and lateral knee joint spaces were calculated. There was a higher incidence of knee pain in women compared to men. The average medial and lateral joint space widths (MJSW and LJSW) of the right knee were 4.22mm and 4.57mm, respectively. For the left knee it was 4.19mm and 4.42mm, respectively. There is a decrease in MJSW with increasing age, level of pain and BMI. Also, with an increase in physical activity, there was a higher incidence of knee pain. Overuse injuries are the main cause of knee pain in this age group. There is a significant association between medial joint space width and age, gender, level of pain, and BMI. Rising BMI patterns at a young age, leads to an increase in physical activity, which in turn leads to early knee pain and also predisposes to osteoarthritis.

Joint line obliquity after lateral closing-wedge high tibial osteotomy does not adversely affect clinical and radiological outcome: a 5-year follow-up study

PurposeTo analyze the association between change in knee joint line obliquity (KJLO) and patient-reported outcome, radiological progression of osteoarthritis, and surgical survival after lateral closing-wedge high tibial osteotomy (HTO).MethodsA cohort of 180 patients treated in one single hospital with lateral closing-wedge HTO was examined. KJLO was defined by the medial proximal tibial angle (MPTA). To assess the association between KJLO and patient-reported outcome, radiological progression of osteoarthritis, and surgical survival, patient groups were defined: I, postoperative MPTA < 95.0°; II, postoperative MPTA ≥ 95.0°; A, MPTA change < 8.0°; B, MPTA change ≥ 8.0°. Propensity score matching was used for between-groups (I and II, A and B) covariates matching, including age, gender, preoperative lower limb alignment, preoperative medial joint space width (mJSW), preoperative Western Ontario and McMaster Universities osteoarthritis Index (WOMAC) score, wedge size, and postoperative follow-up time. Patient-reported outcome was assessed by the WOMAC questionnaire, radiological progression of osteoarthritis by mJSW and Kellgren–Lawrence (KL) grade progression (≥ 1) preoperatively and at follow-ups (> 2 years). Failure was defined as revision HTO or conversion to knee arthroplasty.ResultsAfter propensity score matching, groups I and II contained 58 pairs of patients and groups A and B contained 50 pairs. There were no significant differences in postoperative WOMAC score or surgical failure rate between groups I and II or between groups A and B (p > 0.05). However, the postoperative mJSW was significantly lower in group I than group II (3.2 ± 1.6 mm vs 3.9 ± 1.8 mm; p = 0.018) and in group A than group B (3.0 ± 1.7 mm vs 3.7 ± 1.5 mm; p = 0.040). KL grade progression rate was significantly higher in group I than group II (53.4% vs 29.3%; p = 0.008) and in group A than group B (56.0% vs 28.0%; p = 0.005).ConclusionIncreased KJLO (postoperative MPTA ≥ 95.0°) or MPTA change ≥ 8.0° after lateral closing-wedge HTO does not adversely affect patient-reported outcome, radiological progression of osteoarthritis, or surgical survival at an average 5-year follow-up.Level of evidenceIII, retrospective cohort study.

Association of quantitative measures of medial meniscal extrusion with structural and symptomatic knee osteoarthritis progression – Data from the OAI FNIH biomarker study

To study the association of quantitative medial meniscal position measures with radiographic and symptomatic knee osteoarthritis (OA) progression over 2-4 years. The FNIH OAI Biomarkers study comprised 600 participants in four subgroups: 194 case knees with combined structural (medial minimum joint space width (minJSW) loss ≥0.7mm) and symptomatic (persistent Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale increase ≥9 [0-100 scale]) progression; 200 knees with neither structural nor symptomatic progression; 103 knees with isolated structural and 103 with isolated symptomatic progression. Coronal double echo at steady state (DESS) MRIs were used for segmenting five central slices of the medial meniscus. Associations with progression were examined using logistic regression (adjusted for demographic and clinical data). Greater baseline medial meniscal extrusion was associated with combined structural/symptomatic progression (OR 1.59;95%CI: [1.25,2.04]). No relationship was observed for tibial plateau coverage or meniscal overlap distance. The two-year increase in meniscal extrusion (OR 1.48 [1.21, 1.83]), and reduction in tibial plateau coverage (OR 0.70 [0.58,0.86]) and overlap distance (OR 0.73 [0.60,0.89]) were associated with combined progression. Greater baseline extrusion was associated with isolated structural and less extrusion with isolated symptomatic progression. The longitudinal increase in meniscal extrusion, and reduction in tibial plateau coverage and overlap distance were associated with structural, but not with symptomatic progression. Baseline measures of medial meniscal extrusion were consistently positively associated with combined radiographic/symptomatic progression and with isolated structural, but not with isolated symptomatic progression. These measures may therefore allow one to assess the risk of structural knee OA progression and to monitor interventions restoring meniscal position and function.

Proximal fibular osteotomy as a treatment for degenerative meniscal extrusion

Meniscal extrusion treatment is a key focus area for research and clinical study of degenerative knee pathology. The contact forces between the meniscus and the bones cause external displacements of the meniscus that are resisted by the circumferential fibres. The main risk factors for the excessive deformation of the meniscus are meniscal root tears, disruption of the circumferential fibres, knee malalignment and high body mass index. Prior research has shown meniscal extrusion to be a crucial determinant of successful procedures in knee osteoarthritis treatment. The characteristics of medial knee osteoarthritis are an increase in varus malalignment and the load transferred through the medial compartment. This is associated with greatest reduction of the joint space width over the medial meniscus body and an increase in contact forces acting on the meniscus, which results in increased extrusion of the medial meniscal body. Relocating the meniscus in its anatomic position restores the correct distribution of contact force across the knee joint, and prevents destruction of the cartilage. Thus, clinical and biomechanical research focus on improving surgical techniques that allow for diminished meniscal extrusion. Proximal fibula osteotomy is a relatively new technique which involves the removal of a 10 mm piece of fibula, 4–10 cm from the fibular head. This technique has been shown to reduce the knee-lever arm, load transferred through the medial compartment and increase the medial joint space width. We hypothesise that proximal fibular osteotomy could be an effective, simple, and minimally invasive treatment for degenerative meniscal extrusion.

Valgus Stress Radiograph Can Predict Alignment Change of Medial Mobile-Bearing Unicompartmental Knee Arthroplasty.

Finding reliable tools to predict alignment change after medial mobile-bearing unicompartmental knee arthroplasty (UKA) can help surgeons avoid under- or over-correction. This prospective study aimed to investigate whether the parameters related to medial collateral ligament tension on valgus stress radiograph can predict the alignment change of medial mobile-bearing UKA and establish a prediction model. This study prospectively included the patients undergoing medial mobile-bearing UKA for knee osteoarthritis from November 2018 and April 2021. Patients took valgus stress radiograph and MRI preoperatively and took full-length weight-bearing anterior-posterior radiograph of the lower extremity preoperatively and postoperatively. The medial joint space width (MJSW) on valgus stress radiograph, area of femoral and tibial osteophyte on MRI, medial extrusion distance (MED) of the meniscus on MRI, and the change in hip-knee-ankle angle (∆HKAA) were measured. Factors influencing ∆HKAA were analyzed by correlation analysis. Univariable and multivariable linear regression analysis was performed to establish a prediction model of ∆HKAA. One hundred and seven knees were included. On average, the preoperative HKAA was 170.84° ± 3.73°, and UKA corrected the alignment to 175.16° ± 3.21° postoperatively (p < 0.001), with ∆HKAA of 4.33° ± 1.93°. Correlation analysis showed that ∆HKAA correlated with MJSW (r = 0.628, p < 0.001), MED (r = 0.262, p < 0.001), and tibial osteophyte area (r = 0.235, p < 0.001). The prediction model for ∆HKAA was obtained by multivariable linear regression: ∆HKAA = -2.003 + 0.947 × MJSW(mm) + 1.838 × total osteophyte area(cm2 ). Valgus stress radiographic MJSW and osteophyte area are correlated to the alignment change of medial mobile-bearing UKA. The prediction model for HKAA change is: ∆HKAA = -2.003 + 0.947 × MJSW(mm) + 1.838 × total osteophyte area(cm2 ).

Automated Radiographic Measurements of Knee Osteoarthritis.

Herewith, we report the development of Orthopedic Digital Image Analysis (ODIA) software that is developed to obtain quantitative measurements of knee osteoarthritis (OA) radiographs automatically. Manual segmentation and measurement of OA parameters currently hamper large-cohort analyses, and therefore, automated and reproducible methods are a valuable addition in OA research. This study aims to test the automated ODIA measurements and compare them with available manual Knee Imaging Digital Analysis (KIDA) measurements as comparison. This study included data from the CHECK (Cohort Hip and Cohort Knee) initiative, a prospective multicentre cohort study in the Netherlands with 1,002 participants. Knee radiographs obtained at baseline of the CHECK cohort were included and mean medial/lateral joint space width (JSW), minimal JSW, joint line convergence angle (JLCA), eminence heights, and subchondral bone intensities were compared between ODIA and KIDA. Of the potential 2,004 radiographs, 1,743 were included for analyses. Poor intraclass correlation coefficients (ICCs) were reported for the JLCA (0.422) and minimal JSW (0.299). The mean medial and lateral JSW, eminence height, and subchondral bone intensities reported a moderate to good ICC (0.7 or higher). Discrepancies in JLCA and minimal JSW between the 2 methods were mostly a problem in the lateral tibia plateau. The current ODIA tool provides important measurements of OA parameters in an automated manner from standard radiographs of the knee. Given the automated and computerized methodology that has very high reproducibility, ODIA is suitable for large epidemiological cohorts with various follow-up time points to investigate structural progression, such as CHECK or the Osteoarthritis Initiative (OAI).

Association of Medial Meniscal Volume With Decreased Joint Space Width After Medial Opening-Wedge High Tibial Osteotomy.

Medial opening-wedge high tibial osteotomy (MOWHTO) reduces contact stress by altering the weightbearing axis from the medial to the lateral compartment, relieves knee pain, and slows the progression of osteoarthritis. To evaluate whether the volume of the medial meniscus affects outcomes after MOWHTO. It was hypothesized that reduced medial meniscal volume would be associated with worse midterm clinical and radiographic outcomes. Cohort study; Level of evidence, 3. Included were 59 patients who underwent MOWHTO and had ≥4 years of follow-up data. The mean follow-up period was 66.5 ± 15.1 months (range, 48-110 months). The cohort was classified into 3 groups according to the status of the medial meniscus on arthroscopic examination before osteotomy: no meniscal tear, degenerative tear leading to partial meniscectomy, and degenerative tear leading to subtotal meniscectomy. The Hospital for Special Surgery score and Knee Society objective and functional scores were compared among the groups at 2 time points (preoperative and latest follow-up), and the medial joint space width (JSW) was compared among the groups at 3 time points (preoperative, 1 year postoperative, and latest follow-up). Overall, 9 patients had no meniscal tear, 20 patients underwent partial meniscectomy, and 30 patients underwent subtotal meniscectomy. The clinical scores improved significantly from preoperatively to the latest follow-up (P ≤ .001 for all), with no significant difference among the groups. Post hoc analysis indicated that at the latest follow-up, JSW was significantly lower in the subtotal meniscectomy group compared with the no-tear group on both 45° of flexion posterior-anterior (2.5 ± 1.3 vs 3.9 ± 1.8 mm; P = .004) and anterior-posterior (3.4 ± 1.1 vs 4.5 ± 0.9 mm; P = .011) radiographs. Subtotal meniscectomy of the medial meniscus performed during arthroscopic examination with MOWHTO was associated with decreased JSW at midterm follow-up. Efforts should be made to preserve the medial meniscus as much as possible during MOWHTO.

Radiological and clinical outcomes of concurrent hamstring stretching with quadriceps strengthening in patients with knee osteoarthritis: A randomized clinical trial

BACKGROUND: Hamstring shortening altered joint reaction forces during activities of daily living (ADL), causing knee pain. Moreover, weak quadriceps may negatively distribute the compressive and shear forces at the knee joint. PURPOSE: The study examined the effect of adding hamstring stretching to quadriceps strengthening exercises on joint space narrowing (JSN), medial joint space width (mJSW), and physical abilities in patients with knee osteoarthritis (KOA). METHODS: A total of 42 osteoarthritis patients, aged from 50 to 65 years, were randomized and assigned into 2 groups: the study and the control groups. Quadriceps strengthening exercises were given to both groups, while static hamstring stretching was applied to only the study group. Patients of both groups were screened with a weight-bearing x-ray beam to investigate the JSN, mJSW, and functional abilities measured in the WOMAC scale. The Outcomes were evaluated at the baseline and immediately after 6 weeks of treatment. RESULTS: The mJSW improved in the study group (p&lt; 0.001) compared to the control group (p= 0.07). The OARSI JSN was enhanced significantly in both groups, but in favor of the study group (p&lt; 0.001) over the control group (p= 0.046). Both MVIC and total score of WOMAC were significantly improved in both groups (p&lt; 0.001). CONCLUSION: Adding static hamstring stretching to quadriceps strengthening exercises provided a substantial effect on mJSW, JSN, and functional abilities in KOA patients.

Screening for or diagnosing medial meniscal root injury using peripheral medial joint space width ratio in plain radiographs

To evaluate the sensitivity and specificity for screening and diagnosis of medial meniscal root injury using the distance ratio of medial joint space width between affected and unaffected knees in patients with potential medial meniscal root injury (MMRI) using plain radiographs, the study enrolled 49 patients with suspected MMRI who were then evaluated for MMRI using plain radiographs of both knees in the anteroposterior view and magnetic resonance imaging (MRI) findings. The ratios of peripheral medial joint space width between the affected and unaffected sides were calculated. The cut point value, sensitivity and specificity were calculated according to a receiver operating characteristic (ROC) curve. In the study, 18 and 31 patients were diagnosed with and without MMRI, respectively. The mean peripheral medial joint space width ratios comparing the affected side to the unaffected side in the standing position of the anteroposterior view of both knees in the MMRI and non-MMRI groups were 0.83 ± 0.11 and 1.04 ± 0.16, respectively, which was a significant difference (p-value < 0.001). The cut point value of the peripheral medial joint space width ratio between the affected and unaffected sides for suspected MMRI was 0.985, with sensitivity and specificity of 0.83 and 0.81, respectively, and for diagnosis was 0.78, with sensitivity and specificity of 0.39 and 1.00, respectively. The area under the ROC curve was 0.881. Patients with a possible MMRI had peripheral medial joint space width ratios less than patients with non-MMRI. This test can be used for reliably screening for or diagnosing medial meniscal root injury in primary or secondary care settings.

Biomechanical effect of fibular osteotomy on the knee joint in high tibial osteotomy: A cadaveric study.

Closed-wedge high tibial osteotomy (CWHTO) with a fibular osteotomy (FO) causes medial joint space widening in the knee. However, the effect of FO on the joint space width remains unclear. This study aimed to examine the effect of FO on the knee in HTO. A compression load test was performed on two amputated human limbs under four conditions: (1) normal (without any osteotomy), (2) open-wedge HTO (OWHTO), (3) OWHTO with FO, and (4) CWHTO. The contact area of the femoral and tibial cartilages and the medial and lateral joint space widths in each condition were evaluated using a motion capture system with computed tomography (CT) and magnetic resonance imaging (MRI) data. The contact area increased on the lateral side after OWHTO, which increased more on the lateral side with a concomitant decrease on the medial side in both subjects when FO was added to OWHTO. An increase in the medial joint space width and a decrease on the lateral side were seen in both OWHTO with FO and CWHTO. The contact area and joint space widths are affected by the FO, and the effect is more pronounced than the way of HTO (OWHTO or CWHTO).

Analysis of the determinant factor of the medial joint space width after medial opening wedge high tibial osteotomy.

The decrease in the medial joint space width (MJSW) in patients with osteoarthritis (OA) is proportional to the degree of arthritis. The purpose of this study was to evaluate the affecting factors of the MJSW by serial radiologic assessment after medial open wedge high tibial osteotomy (MOW-HTO). Between March 2014 and March 2019, 162 MOW-HTO knees that underwent serial radiologic assessment and follow-up MRI were enrolled. Changes in the MJSW were analyzed by dividing into three groups: group I, low quartile (< 25%); II, middle quartile (25-75%); and III, high quartile (> 75%), according to the magnitude of the MJSW. The correlation between the MJSW and weight-bearing line ratio (WBLR), hip knee ankle angle (HKA), joint line convergence angle (JLCA), medial proximal tibial angle (MPTA), mechanical lateral distal femoral angle (m-LDFA), joint line orientation angle (JLOA), and MRI cartilage status was analyzed. Multiple linear regression analysis was used to analyze factors affecting the amount of change in the MJSW. The clinical outcome was also correlated with the MJSW. The amount of change in the JLCA, which has the largest beta value (weight-bearing standing anteroposterior (AP) view and 45° flexion posteroanterior view (Rosenberg view) β = - 0.699 and β = -5.221, both p < 0.001, respectively), had the greatest contribution to the change in the MJSW. The WBLR was also related (standing AP and Rosenberg β = 0.177 and β = 0.264, p = 0.015 and p = 0.004, respectively). There was no statistical difference between the amount of change in the MJSW and the change in cartilage. The clinical outcomes did not differ between the groups. The JLCA was the most important contributing factor for the MJSW, followed by WBLR. This contribution was more pronounced in Rosenberg view than standing AP view. Changes in cartilage status were not related to the MJSW and JLCA. The clinical outcome was not related to the MJSW, either. Level of evidence Cohort study; level III.

Association of physical activity with loss of knee joint space width over two years: a compositional data analysis in the Osteoarthritis Initiative

There is continued debate as to how engaging in physical activity (PA), including moderate-to-vigorous PA (MVPA), light PA (LPA), and sedentary time (SED), affects one's risk for knee osteoarthritis (OA). Traditional regression methods do not account for the codependence of these categories of PA, whereby when one category increases, the others must decrease. Thus, we used compositional data analysis (CoDA) to examine time spent in each category of PA, or PA composition, and its association with loss of knee joint space width (JSW), a common indicator of knee OA progression. We performed a secondary analysis of data from a subset of participants in the Osteoarthritis Initiative. These participants had minute-by-minute activity data collected over 7 days at baseline; we then categorized each minute as MVPA, LPA, or SED. Our exposure, PA composition, represented min/day spent in each category. Our outcome, medial JSW loss, was the difference in medial tibiofemoral JSW from baseline to 2years later. We employed CoDA, using an isometric log-ratio transformation, to examine the association of PA composition with medial JSW loss over 2years, adjusting for potential confounders. We included 969 participants (age: 64.5 years, 56% female, body mass index [BMI]: 28.8kg/m2). Mean PA composition was: MVPA 9.1min/day, LPA 278min/day, SED 690min/day. Per adjusted regression models, higher MVPA was not associated with greater medial JSW loss (β=-0.0005, P=0.97), nor was LPA (β=0.06, P=0.27) or SED (β=-0.06, P=0.21). Using CoDA, PA composition was not associated with medial JSW loss over 2years.

Exploring the differences between radiographic joint space width and MRI cartilage thickness changes using data from the IMI-APPROACH cohort.

Longitudinal weight-bearing radiographic joint space width (JSW) and non-weight-bearing MRI-based cartilage thickness changes often show weak correlations. The current objective was to investigate these correlations, and to explore the influence of different factors that could contribute to longitudinal differences between the two methods. The current study included 178 participants with medial osteoarthritis (OA) out of the 297 knee OA participants enrolled in the IMI-APPROACH cohort. Changes over 2years in medial JSW (ΔJSWmed), minimum JSW (ΔJSWmin), and medial femorotibial cartilage thickness (ΔMFTC) were assessed using linear regression, using measurements from radiographs and MRI acquired at baseline, 6months, and 1 and 2years. Pearson R correlations were calculated. The influence of cartilage quality (T2 mapping), meniscal extrusion (MOAKS scoring), potential pain-induced unloading (difference in knee-specific pain scores), and increased loading (BMI) on the correlations was analyzed by dividing participants in groups based on each factor separately, and comparing correlations (slope and strength) between groups using linear regression models. Correlations between ΔMFTC and ΔJSWmed and ΔJSWmin were statistically significant (p < 0.004) but weak (R < 0.35). Correlations were significantly different between groups based on cartilage quality and on meniscal extrusion: only patients with the lowest T2 values and with meniscal extrusion showed significant moderate correlations. Pain-induced unloading or BMI-induced loading did not influence correlations. While the amount of loading does not seem to make a difference, weight-bearing radiographic JSW changes are a better reflection of non-weight-bearing MRI cartilage thickness changes in knees with higher quality cartilage and with meniscal extrusion.

Statistical modeling: Assessing the anatomic variability of knee joint space width

Population-based knee joint space width (JSW) assessments are promising for the prevention and early diagnosis of osteoarthritis. This study aimed to establish the statistical shape and alignment model (SSAM) of knee joints for assessing anatomic variation in knee JSW in the healthy Chinese male population. CT scans of asymptomatic knee joints of healthy male participants (n = 107) were collected for manual segmentation to create mesh samples. The as-scanned positional error was reduced by a standard processing flow of deformable mesh registration. Principal component analysis (PCA) was performed to create a tibiofemoral SSAM that was trained on all mesh samples. The anatomic variability of the JSW in the healthy Chinese male population was then assessed using the SSAM with regression analysis and 3D analysis by color-coded mapping. Almost all PCA modes had a linear influence on the anatomic variation of the medial and lateral JSW. The JSW variability within the SSAM was mainly explained by mode 1 (45.1 % of variation), demonstrating that this mode had the greatest influence on JSW variation. 3D assessment of the JSW showed that the minimum medial JSW varied from 2.76 to 3.23 mm, and its site shifted a short distance on the medial tibial plateau. The root-mean-square fitting and generalization errors of the SSAM were below 1 mm. This study will benefit the design and optimization of prosthetic devices, and may be applicable to the prevention and early diagnosis of osteoarthritis.

Changes in Bone Marrow Lesions Following Root Repair Surgery Using Modified Mason-Allen Stitches in Medial Meniscus Posterior Root Tears.

Root repair can prevent osteoarthritis (OA) by restoring hoop tension in medial meniscus posterior root tears (MMPRTs). This study aims to investigate bone marrow edema (BME) lesions known to be associated with OA following MMPRTs. Methods: Thirty patients with transtibial pull-out repair were recruited. Subchondral BME lesions were evaluated using magnetic resonance imaging (MRI) at 1-year follow-ups. Participants were categorized into three groups: no change of BME lesions (group one), improved BME lesions (group two) and worsened BME lesions (group three). Clinical scores and radiological outcomes, specifically Kellgren-Lawrence grade, medial joint space width and cartilage grade and meniscal extrusion were evaluated and compared between groups. Results: After surgery, twenty-three patients with no BME, three patients with BME lesions on the medial femoral condyle, one patient with BME lesions on the medial tibia plateau and three patients with BME lesions on both were investigated. A total of 20 patients in group one (66.7%) showed no change in BME lesions. In group two, seven patients (23.3%) presented with improved BME lesions. Only three patients (10%) showed worsened BME lesions (group three). Moreover, Lysholm scores and the rate of progression of cartilage grades were significantly worse in group three patients. Meniscal extrusion was significantly reduced in group two, whereas extrusion was significantly progressed in group three. Conclusion: Patients with worsened BME lesions showed less favorable outcomes than other patients. A decrease in meniscal extrusion can have a positive effect on BME lesions after root repair.

It's not arthritis! Resolution of the illusion of joint space narrowing with acetabuloplasty and labral reconstruction for the calcified labrum.

Labral calcification may be part of the natural history of untreated femoroacetabular impingement syndrome (FAIS) in certain patients, making it a potential target for intervention with the goal of preserving the hip joint. The purpose of this study was to investigate if calcified labra create the appearance of lateral joint space narrowing and report minimum 2-year patient-reported outcome measures (PROMs) after treating patients with arthroscopic acetabuloplasty and labral reconstruction. Prospectively collected data on patients who underwent primary hip arthroscopy for FAIS and labral tearing from February 2015 to April 2021 were reviewed. Patients treated with primary labral reconstruction for an intraoperatively confirmed diagnosis of labral calcification were included. A sub-analysis was performed for patients with a minimum of 2-year follow-up. Preoperative and postoperative PROMs for the modified Harris hip score, nonarthritic hip score, the International Hip Outcome Tool-12 and visual analog scale for pain were recorded. Forty-six hips (46 patients) were included, with 19 hips in the sub-analysis. There was a significant increase in apparent lateral joint space width (JSW) measured on supine anteroposterior (AP) pelvis radiographs with no significant changes in medial and central JSW and significant decreases in the lateral and anterior center-edge angles and alpha angle. Patients experienced significant increases in PROMs and high rates of achieving psychometric thresholds. Patients presenting with FAIS and calcified labra may have apparent lateral joint space narrowing on pre-operative supine AP pelvis radiographs. These patients have low rates of full-thickness femoral head and acetabular cartilage pathology, this apparent narrowing can be corrected and excellent outcomes and survivorship can be achieved, with primary labral reconstruction.