Medial Tibiofemoral Osteoarthritis Research Articles

Location of knee pain in medial knee osteoarthritis: patterns and associations with self-reported clinical symptoms

To (1) document pain location in medial tibiofemoral osteoarthritis (OA) using the patient-administered Photographic Knee Pain Map (PKPM); (2) compare pain severity, nature and likelihood of neuropathic-like symptoms, physical dysfunction and presence of symptoms at other sites across the most common pain patterns. Baseline data were analysed from 164 participants with medial tibiofemoral OA (TFJOA) participating in a randomised controlled trial (RCT). Participants completed the PKPM indicating all relevant pain zones of their most painful knee. Pain zones were collapsed into regions to determine patterns of pain. Symptoms were quantified using numeric rating scales (NRSs) of pain severity, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Intermittent and Constant Osteoarthritis Pain (ICOAP) and painDETECT questionnaires. Symptoms at other joints were categorised as present/absent. The medial joint line (n=123, 75%), patellar tendon (n=62, 38%) and posterior knee (n=61, 37%) were the most frequently reported pain zones. The most frequent patterns were diffuse (41%), isolated medial (16%), anterior-medial (12%) and medial-posterior (11%) pain. WOMAC and ICOAP scores were higher in the diffuse compared to anterior-medial patterns. Mean PainDETECT scores were higher with both diffuse and medial-posterior pain relative to anterior-medial pain. Only 16% of the cohort indicated isolated medial knee pain, whilst a diffuse pain pattern was most common. People with diffuse knee pain reported more severe pain and physical dysfunction than those with anterior-medial pain. Prevalence of possible/likely neuropathic-like symptoms tended to be more frequent in diffuse and posterior-medial patterns compared to anterior-medial pain.

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ABSTRACT Introduction: osteoarthritis of the knee is a common disease, there are a lot of poor prognosis factors in patients treated with arthroscopy alone and one of them is varus deformity and for that reason a corrective osteotomy should be performed. Objective: to analyze the advantages of simultaneous arthroscopy and osteotomy in patients suffering from medial tibiofemoral osteoarthritis of the knee associated with varus deformity. Methodology: a search in the databases Pubmed, Hinari, Scielo and Medline was done through the information locator EndNote by using the words arthroscopy of the knee, arthroscopy and osteotomy of the knee, y osteotomy of the knee, resulting in a total of 350 articles which 59 of them selected for review, 49 of them in the last five years, including three books and eight own references. Results: the relationship between intrarticular lesions and angular deformity was found, especially those located at the medial tibiofemoral compartment. The author stated that varus deformity is associated to poor prognosis, taken into account a previous investigation. Conclusions: arthroscopy and high tibial osteotomy combined offers more advantages over other interventions in the treatment of patients with knee osteoarthritis of the medial tibiofemoral compartment and varus angular deformity, such as deformity correction, proper joint function and pain relief. MED UIS. 2016;29(1):45-51. Keywords: Arthroscopy. Osteotomy. Tibial meniscus. Osteoarthritis.

Optimal gait retraining strategies in patients with knee osteoarthritis

Main topics: Rehabilitation; Experimental studies in human movement science Introduction and aim: Progression of knee osteoarthritis (OA) seems related to a high external knee adduction moment (EKAM) during gait [1,2], which can be reduced by gait retraining [3]. In healthy adults, lateral trunk lean and medializing the knee during gait reduce the EKAM effectively, although the optimal strategy seems individually dependent [3]. We aimed to determine which strategy reduces the EKAM most in patients with knee OA, and if the same strategy is most effective for all patients. Patients/materials and methods: Twenty-eight patients with radiographically diagnosed medial tibio-femoral knee OA underwent 3D gait analysis. Comfortable walking, lateral trunk lean towards the affected leg during the stance phase (Trunk Lean), and medializing the knee at initial contact (Medial Thrust) were investigated. Knee moments and kinematics of the knee and the trunk were calculated. Gait retraining strategies were assessed by comparison of EKAMpeak and impulse relative to comfortablewalking. Results: Most patients (age: 60.1±6.1 years, height: 1.71±0.10m, weight: 77.9±12.7 kg, mean KOOS-score: 46.3, KOOS subscales: pain (55.5), symptoms (52.5), daily activities (60.8), sport/recreation (26.8), knee-related QoL (36)) could finish the protocol without reporting any difficulties. One patient could not perform Medial Thrust due to knee pain. Fig. 1 shows the EKAM for all conditions. In both retraining strategies, EKAM was reduced significantly for early stance peak (MT: −0.07±0.01Nm/Bw·Ht, TL: −0.08±0.01Nm/Bw·Ht) and impulse (MT: −0.18±0.01Nms/Bw·Ht, TL: −0.03±0.01Nms/Bw·Ht). In 15 patients, Trunk Lean reduced overall EKAM peak the most (−0.09±0.04Nm/Bw·Ht). In 12 patients this was true for Medial Thrust (−0.13±0.07Nm/Bw·Ht). In the Medial Thrust group, leaning the trunk was significantly less effective than medializing the knee (p=0.005). In the Trunk Lean group, medializing the knee was significantly less effective than leaning the trunk (p=0.001). Changes in trunk angle and knee adduction angle as a result of retraining were similar between the groups (p>0.288). Discussion and conclusions: Medial Thrust and Trunk Lean effectively reduce the early stance EKAM peak and impulse during gait in patients with medial tibio-femoral knee OA. Even if the gait retraining instructions are not executed differently, the effectiveness of gait retraining strategies in reducing peak EKAM depends Fig. 1. EKAM for all conditions. Grey areas represent 95% CI for Normal Walking.

Extremity cone-beam CT for evaluation of medial tibiofemoral osteoarthritis: Initial experience in imaging of the weight-bearing and non-weight-bearing knee

PurposeTo investigate differences in joint space width (JSW) and meniscal extrusion (ME) between non-weight bearing (NWB) and weight bearing (WB) examinations of knee joints with medial compartment osteoarthritis (OA) using a cone-beam CT (CBCT) extremity imaging system. Materials and methodsIn this IRB approved prospective study, informed consent was obtained for 17 patients symptomatic for OA (11 F,6M; 31–78 years, mean 56 years) and 18 asymptomatic controls (0 F,18M; 29–48 years, mean 38.5 years) enrolled for CBCT exams in NWB and WB positions. Three independent observers measured medial tibiofemoral JSW and ME. Measurements were compared between NWB and WB images using paired Wilcoxon signed-rank sum test. ResultsOA subjects exhibited a statistically significant reduction in JSW between NWB and WB scans (average JSWNWBOA=2.1mm and JSWWBOA=1.5mm, p=0.016) and increase in ME (average MENWBOA=6.9mm and MEWBOA=8.2mm, p=0.018)). For non-OA subjects, the change in JSW and ME between NWB and WB exams was reduced (average JSWNWBnonOA=3.7mm and JSWWBnonOA=3.4mm; average MENWBnonOA=2.6mm and MEWBnonOA=2.7mm) and was not statistically significant. Inter-observer agreement was evaluated using Bland–Altman limits of agreement, with good agreement for all measurements (correlation coefficient 0.89–0.98). ConclusionThe ability to conduct NWB and WB exams in CBCT with a dose profile that is favorable in comparison to multidetector CT (MDCT) and with image quality sufficient for morphological analysis of joint space narrowing and meniscal extrusion could provide a valuable tool for OA diagnosis and treatment assessment.

Does knee malalignment predict the efficacy of realignment therapy for patients with knee osteoarthritis?

Realignment therapies, including knee braces, foot orthoses and shoes are prescribed to patients with medial knee osteoarthritis (OA) with the goal of unloading the medial tibiofemoral (TF) compartment. It is uncertain whether realignment therapies have different effects in those with knee malalignment. We studied whether the efficacy of realignment therapy for pain and function in persons with medial TF OA is predicted by the severity of the baseline knee malalignment. The baseline characteristics of 48 participants with moderate to severe medial knee OA were collected. Participants' pain and function were measured using Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scale before and after 12weeks of realignment therapy using a valgus unloader knee brace plus bilateral neutral foot orthoses and motion control shoes. Anatomical axis (AA) was measured on weight-bearing knee radiographs by a blinded reader and knee malalignment was categorized as either varus malaligned (moderate or severe) or neutral according to the AA angle. We assessed for differences in response to treatment according to alignment category. General linear statistical models were generated to determine which of the measured alignment variables and covariates predicted change in the pain outcome. Anatomical axis knee alignment was not a significant predictor of pain or function change with active treatment. Baseline WOMAC scores were the best predictor of change in WOMAC (P<0.01 and P=0.06 for pain and function, respectively). Baseline knee alignment did not predict the efficacy of 12weeks realignment therapy in participants with medial tibiofemoral OA. [Correction added on 27 August 2015, after first online publication: 'did predict' has been corrected to 'did not predict' in the conclusions of the abstract section.].

Is knee function better with contemporary modular bicompartmental arthroplasty compared to total knee arthroplasty? Short-term outcomes of a prospective matched study including 68 cases

BackgroundBicompartmental knee arthroplasty (BKA) was developed to treat medial tibiofemoral and patellofemoral osteoarthritis while preserving the anterior cruciate ligament to optimise knee kinematics. Our objective here was to compare the probability of achieving forgotten knee status and the functional outcomes at least two years after BKA versus total knee arthroplasty (TKA). We hypothesised that contemporary modular BKA produced better functional outcomes than TKA after at least two years, for patients with similar pre-operative osteoarthritic lesions. Material and methodsWe conducted a two-centre prospective controlled study of 34consecutive patients who underwent BKA between January 2008 and January 2011. Each patient was matched on age, gender, body mass index, preoperative range of knee flexion, centre, and surgeon to a patient treated with TKA. An independent observer evaluated all 68 patients after six and 12months then once a year. Forgotten knee status was defined as a 100/100 value of the Forgotten Joint Score (FJS-12) and each of the five KOOS subscales. We also compared the two groups for knee range of motion, Knee Society Scores (KSSs), Timed Up-and-Go test (TUG), and UCLA Activity Score. ResultsAt a mean follow-up of 3.8±1.7 years, the probability of forgotten knee status was significantly higher in the BKA group (odds ratio, 4.64; 95% confidence interval, 1.63–13.21; P=0.007, Chi2 test). Mean post-operative extension was not significantly different between the groups, whereas mean range of knee flexion was significantly greater in the BKA group (130°±6° vs. 125°±8° after TKA; P=0.03). The BKA group had significantly higher mean values for the knee and function KSSs, TUG test, and UCLA score (P<0.04 for all four comparisons). ConclusionAfter at least two years, contemporary unlinked BKA was associated with greater comfort during everyday activities (forgotten knee) and better functional outcomes, compared to TKA. These short-term results require validation in randomised trials with longer follow-ups. Level of evidenceIII, case-control study.

Contribution of the Interleukin-6/STAT-3 Signaling Pathway to Chondrogenic Differentiation of Human Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) are multipotent cells that can differentiate into chondrocytes. Articular cartilage contains MSC-like chondroprogenitor cells, which suggests their involvement in the maintenance of cartilage homeostasis by a self-repair mechanism. Interleukin-6 (IL-6) is a cytokine with a wide range of physiologic functions, which are produced by MSCs in a steady manner and in large quantities. The purpose of this study was to investigate the involvement of IL-6 signaling in MSC differentiation into chondrocytes. Human bone marrow-derived MSCs were cultured using a pellet culture system in medium containing transforming growth factor β3. Chondrogenic differentiation was detected by cartilage matrix accumulation and chondrogenic marker gene expression. IL-6 was detected at a high concentration in culture supernatants during chondrogenic differentiation. The expression of the IL-6 receptor (IL-6R) was significantly increased, accompanied by markedly increased phosphorylation and expression of STAT-3. Addition of IL-6 and soluble IL-6R (sIL-6R) to the chondrogenic culture resulted in concentration-dependent increases in cartilage matrix accumulation and cartilage marker gene expression (type II collagen/aggrecan/type X collagen). Phosphorylation of the master transcription factor SOX9 was enhanced upon addition of IL-6 and sIL-6R. STAT-3 knockdown suppressed chondrogenic differentiation. IL-6 and the MSC markers CD166 and nestin were colocalized in macroscopically normal human cartilage taken from the lateral femoral compartment of knees with medial tibiofemoral osteoarthritis. During differentiation of human MSCs into chondrocytes, the activation of IL-6/STAT-3 signaling positively regulated chondrogenic differentiation. The presence of IL-6 around MSC-like cells in the cartilage tissue was identified, suggesting that IL-6 contributes to homeostasis and cartilage self-repair by promoting chondrogenic differentiation.

Early knee osteoarthritis is evident one year following anterior cruciate ligament reconstruction: a magnetic resonance imaging evaluation.

To determine the prevalence and factors associated with knee osteoarthritis (OA) defined by magnetic resonance imaging (MRI) and specific OA features on MRI 1 year after anterior cruciate ligament reconstruction (ACLR). Isotropic 3.0T MRI scans were obtained for 111 participants (71 men; mean ± SD age 30 ± 8 years) 1 year after ACLR as well as for 20 age-, sex-, and activity level-matched uninjured controls. The MRI OA Knee Score was used to score specific OA features. MRI-defined tibiofemoral and patellofemoral OA was evaluated based on published criteria. Logistic regression identified factors associated with MRI-defined OA and specific OA features after ACLR. Following ACLR, medial and lateral tibiofemoral OA on MRI was observed in 7 participants (6%) and 12 participants (11%), respectively, while 19 participants (17%) had patellofemoral OA on MRI. The femoral trochlea was the region most affected by bone marrow lesions (19% of participants), cartilage lesions (31% of participants), and osteophytes (37% of participants). Meniscectomy at the time of ACLR (odds ratio 6.8 [95% confidence interval 2.0-23.3]) and body mass index (BMI) >25 kg/m(2) (odds ratio 3.0 [95% confidence interval 1.3-6.9]) predicted MRI-defined tibiofemoral OA and osteophytes, respectively. Men had higher odds of patellofemoral osteophytes (odds ratio 6.3 [95% confidence interval 2.4-16.2]). No uninjured controls had tibiofemoral or patellofemoral OA on MRI, and specific OA features were uncommon. OA 1 year following ACLR was more common than previously recognized, while being absent in uninjured control knees. The patellofemoral compartment seems to be at particular risk for early OA after ACLR, especially in men. The association with meniscectomy and BMI demonstrates the construct validity of MRI criteria.

Ankle motion influences the external knee adduction moment and may predict who will respond to lateral wedge insoles?: an ancillary analysis from the SILK trial

SummaryObjectiveLateral wedge insoles are a potential simple treatment for medial knee osteoarthritis (OA) patients by reducing the external knee adduction moment (EKAM). However in some patients, an increase in their EKAM is seen. Understanding the role of the ankle joint complex in the response to lateral wedge insoles is critical in understanding and potentially identifying why some patients respond differently to lateral wedge insoles.MethodParticipants with medial tibiofemoral OA underwent gait analysis whilst walking in a control shoe and a lateral wedge insole. We evaluated if dynamic ankle joint complex coronal plane biomechanical measures could explain and identify those participants that increased (biomechanical non-responder) or decreased (biomechanical responder) EKAM under lateral wedge conditions compared to the control shoe.ResultsOf the 70 participants studied (43 male), 33% increased their EKAM and 67% decreased their EKAM. Overall, lateral wedge insoles shifted the centre of foot pressure laterally, increased eversion of the ankle/subtalar joint complex (STJ) and the eversion moment compared to the control condition. Ankle angle at peak EKAM and peak eversion ankle/STJ complex angle in the control condition predicted if individuals were likely to decrease EKAM under lateral wedge conditions.ConclusionsCoronal plane ankle/STJ complex biomechanical measures play a key role in reducing EKAM when wearing lateral wedge insoles. These findings may assist in the identification of those individuals that could benefit more from wearing lateral wedge insoles.

Cartilage health in high tibial osteotomy using dGEMRIC: Relationships with joint kinematics

PurposeThe aims of this study are to determine how opening-wedge high tibial osteotomy (HTO) affects cartilage health in the tibiofemoral (TF) joint and patella, and to explore relationships between TF and patellofemoral (PF) joint kinematics and cartilage health in HTO. Methods14 knees (13 subjects) with medial TF osteoarthritis (OA) were examined before HTO and 6 and 12months after HTO using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) to evaluate cartilage health at the TF joint and patella. They were also examined using a validated 3D MR knee kinematics measurement to obtain 11 rotations and translations at both TF and PF joints. ResultsNo statistically significant differences in overall TF or patellar dGEMRIC score were found at 6 or 12months after HTO. However three subjects had large decreases (mean 105ms) in TF dGEMRIC at 6months that recovered at 12months. Kinematics for these subjects were compared to subjects who did not have decreases in TF dGEMRIC at 6months (n=5). Differences were observed between groups with HTO in anterior and proximal tibial translation (mean differences 3.05mm and 1.35mm), and patellar flexion (mean difference 3.65°). These changes were consistent between 6 and 12months, despite recovery of TF dGEMRIC values. ConclusionsWe did not find significant differences in TF or patellar dGEMRIC before and after HTO with all subjects, however there were differences in kinematics between subjects who had a decrease in TF dGEMRIC at 6months and those who did not. This suggests a link between joint kinematics and cartilage health in HTO. Clinical relevanceThe effect of opening-wedge high tibial osteotomy on cartilage GAG concentration may be linked to specific changes in knee kinematics following surgery

High Tibial Valgus Osteotomy and Concomitant Anterior Cruciate Ligament Reconstruction. Which is the most appropriate surgical technique?

Introduction:The aim of this study is to evaluate advantages of close vs. open HTO of a group of patients who underwent a one-stage combined operation for chronic ACL rupture and early medial compartment arthritis.Material and Methods:We retrospective evaluated two series of patients operated on for anterior cruciate ligament (ACL) reconstruction combined with high tibial valgus osteotomy (HTO) for chronic anterior knee instability associated with medial tibio femoral osteoarthritis. Close HTO using rigid plate fixation and ACL reconstruction with bone patellar tendon bone graft was performed in Group A (7 patients). An open HTO using Puddu plate and ACL reconstruction with hamstring tendon graft was performed in Group B (9 patients). The mean age in Group A was 41 years old with an average varus of 8 degrees. Mean age in Group B was 42 years old and with 4 degrees of varus. Lysholm Score, HSS and Radiographs were performed.Results:Group A obtained a mean Lysholm score of 94, mean HSS of 91. Group B showed a mean Lysholm score of 83, mean HSS of 87. The mean follow-up was 5 years in both groups. In all cases osteotomies consolidated.Discussion:Technically we found that open HTO with hamstrings had several advantages such as lower risk of peroneal nerve injury, use of one incision, no problems as regards graft length, possibility of fixing the graft in the proximal tibia, maintenance of tibial slope and preservation of bone stock. The Open HTO need of osseous graft, may produce patella baja and the risk of nonunion is higher. This technique is indicated for relaxed medial collateral ligament. As regards the Close HTO there may be possibilities of a peroneal nerve injury, it may decrease the tibial slope, patellar ascent, loss of bone, the need to disrupt either the fibula or proximal tibio-fibular joint and may generate instability in the posterolateral corner and the screws could compromise the tunnels path. The advantages are provision of bone to bone contact with excellent union rates and the potential for full early weight-bearing.Conclusion:In spite of these issues, both procedures relieved pain and restored knee stability and the choice will depend on each particular case.

Extrusion of the medial meniscus in knee osteoarthritis assessed with a rotating clino-orthostatic permanent-magnet MRI scanner

The objectives of this study were to assess the influence of weight-bearing on tibiofemoral osteoarthritis, including medial meniscal extrusion, by using a low-field (0.25 T) rotating clino-orthostatic permanent-magnet magnetic resonance (MR) scanner, and to analyse correlations of medial meniscal extrusion with the patient's Kellgren-Lawrence score, body mass index, and all the osteoarthritis features of the WORMS scoring system. Twenty-six patients (69.2% women and 30.8% men; mean age 67 ± 9.7 years) with medial tibiofemoral knee osteoarthritis were prospectively enrolled and MR sequences were acquired in both clino- and orthostatic position. MR images were assessed by two independent radiologists, according to the WORMS scale. Medial meniscal extrusion was measured and its clino-orthostatic difference (∆MME) was calculated. Intra- and inter-observer agreement of the WORMS Global Score readings was high by Cohen's K test (>0.81). No significant clino-orthostatic changes in the scoring parameters of the medial tibiofemoral joint were shown by Wilcoxon's test. Medial meniscal extrusion measured on orthostatic images was significantly higher than that measured in clinostatic position (p < 0.0001). At univariate analysis, the Kellgren-Lawrence score, WORMS Global Score, cartilage loss, meniscal damage, and osteophytes were significantly correlated to ∆MME (p < 0.005). Using a multiple regression model, tibiofemoral cartilage loss was found to correlate independently with ∆MME (p = 0.0499). Medial meniscal extrusion, evaluated with an open-configuration, rotating MR scanner, increased from the clinostatic to the orthostatic position. ∆MME, a new meniscal parameter, correlated with several important features of medial tibiofemoral osteoarthritis.

What predicts the first peak of the knee adduction moment?

The first peak of the knee adduction moment curve during walking has been shown to be a good clinical surrogate measure of medial tibiofemoral joint loading and osteoarthritis. Defining the relative contributions of the variables that dictate the knee adduction moment, such as center of mass, center of pressure, vertical ground reaction force, and knee adduction angle (i.e. lower limb alignment), has not been formally investigated within the same cohort of individuals. Therefore, the goal of this study was to determine which of these variables is the biggest determinant of the first peak of knee adduction moment curve. Instrumented gait analysis was collected for 30 individuals. Variables significantly correlated with the peak knee adduction moment were input into a stepwise multi-variable linear regression model. The knee adduction angle predicted 58% of the variance in the first peak knee adduction moment and the vertical ground reaction force magnitude predicted the second most variance (20%). The most effective way to modify the peak knee adduction moment may be to change the knee adduction angle (e.g. off loader brace), followed by changing the vertical magnitude of the ground reaction force (e.g. cane use). Defining the major determinants of the knee adduction moment may help guide clinicians in choosing conservative interventions to reduce it in conditions such as medial tibiofemoral osteoarthritis.

Analysis of muscle activation patterns during transitions into and out of high knee flexion postures

Increased risk of medial tibiofemoral osteoarthritis (OA) is linked to occupations that require frequent transitions into and out of postures which require high knee flexion (>90°). Muscle forces are major contributors to joint loading, and an association between compressive forces due to muscle activations and the degeneration of joint cartilage has been suggested. The purpose of this study was to evaluate muscle activation patterns of muscles crossing the knee during transitions into and out of full-flexion kneeling and squatting, sitting in a low chair, and gait. Both net and co-activation were greater when transitioning out of high flexion postures, with maximum activation occurring at knee angles greater than 100°. Compared to gait, co-activation levels during high flexion transitions were up to approximately 3 times greater. Co-activation was significantly greater in the lateral muscle group compared to the medial group during transitions into and out of high flexion postures. These results suggest that compression due to activation of the medial musculature of the knee may not be the link between high knee flexion postures and increased medial knee OA observed in occupational settings. Further research on a larger subject group and workers with varying degrees of knee OA is necessary.

Knee muscle strength after recent partial meniscectomy does not relate to 2-year change in knee adduction moment.

Knee muscle weakness and a greater external knee adduction moment are suggested risk factors for medial tibiofemoral knee osteoarthritis. Knee muscle weakness and a greater knee adduction moment may be related to each other, are potentially modifiable, and have been observed after arthroscopic partial meniscectomy. The aim of this exploratory study was to determine if knee muscle weakness 3 months after arthroscopic partial meniscectomy (baseline) is associated with an increase in external knee adduction parameters during the subsequent 2 years. Eighty-two participants undergoing medial arthroscopic partial meniscectomy were assessed at baseline, and 66 participants who were reassessed 2 years later were included in our study. Isokinetic muscle strength and external adduction moment parameters (peak and impulse) during normal and fast walking were measured at baseline and followup. Multiple linear regression models were used to examine the association between baseline muscle strength and 2-year change in adduction moment parameters. A post hoc power calculation showed we had 80% power to detect a correlation of 0.31 between baseline muscle strength and change in the external knee adduction, with an alpha error of 0.05 and two-sided significance. Maximal isokinetic muscle strength 3 months after arthroscopic partial meniscectomy was not associated with change in adduction moment parameters (p value range from 0.12 to 0.96). No evidence was found to suggest that improving maximal knee muscle strength after a recent arthroscopic partial meniscectomy would reduce change in knee adduction moment observed during the subsequent 2 years. As muscle function is modifiable, future investigation of other aspects of muscle function that may relate to change in knee adduction moment is warranted.

Association of hip and pelvic geometry with tibiofemoral osteoarthritis: Multicenter Osteoarthritis Study (MOST)

Lateral tibiofemoral osteoarthritis (OA) is overall less common than medial tibiofemoral OA, but it is more prevalent in women. This may be explained by sex differences in hip and pelvic geometry. The aim of this study is to explore sex differences in hip and pelvic geometry and determine if such parameters are associated with the presence of compartment-specific knee OA. This case-control study reports on 1,328 hips/knees from 664 participants and is an ancillary to the Multicenter Osteoarthritis Study (MOST). Of the 1,328 knees, 219 had lateral OA, 260 medial OA, and 849 no OA. Hip and pelvic measurements were taken from full-limb radiographs on the ipsilateral side of the knee of interest. After adjusting for covariates, means were compared between sexes and also between knees with medial and lateral OA vs no OA using separate regression models. Women were shown to have a reduced femoral offset (FO) (mean 40.9mm vs 45.9mm; P=0.001) and more valgus neck-shaft angle (mean 128.4° vs 125.9°; P<0.001) compared to men. Compared to those with no OA, knees with lateral OA were associated with a reduced FO (P=0.012), increased height of hip centre (HHC) (P=0.003), more valgus neck-shaft angle (P=0.042), and increased abductor angle (P=0.031). Knees with medial OA were associated with a more varus neck-shaft angle (P=0.043) and a decreased abductor angle (P=0.003). These data suggest anatomical variations at the hip and pelvis are associated with compartment-specific knee OA and may help to explain sex differences in patterns of knee OA.

Resultados clínicos de la osteotomía tibial valguizante de cuña abierta y cerrada para el manejo de deformidad en genu varo y gonartrosis mecánica femorotibial medial

BackgroundThere is a huge controversy regarding proximal tibial osteotomies outcomes when treating genu varum deformities and medial tibiofemoral compartment arthrosis. The aim of this study was to determine the clinical outcomes of the open and closed wedge tibial valgus osteotomy in patients with genu varus deformity and mechanical medial tibiofemoral osteoarthritis, according to Lysholm and Tegner scales. Material and methodsA descriptive, case series study was conducted on 24 patients with varus deformity of the knee and unicompartmental mechanical arthrosis of the medial tibiofemoral compartment of the knee from January 2006 to January 2011. A medial open wedge tibial osteotomy was performed in patients with medial collateral ligament laxity, while a closed wedge osteotomy was performed in those patients with strained medial collateral ligament, as observed by the valgus stress maneuvers performed during the preoperative evaluation. ResultsExcellent results were obtained in 91.7% of subjects, and 8.3% were good according to the Lysholm scale, with a mean score on the Tegner scale of 4.4%. DiscussionThe tibial valgus osteotomy offers good and excellent clinical outcomes in patients with mechanical medial tibiofemoral osteoarthritis and varus knee deformity.

Effects of a 10-week toe-out gait modification intervention in people with medial knee osteoarthritis: a pilot, feasibility study

To examine the feasibility of a 10-week gait modification program in people with medial tibiofemoral knee osteoarthritis (OA), and to assess changes in clinical and biomechanical outcomes. Fifteen people with medial knee OA completed 10 weeks of gait modification focusing on increasing toe-out angle during stance 10° compared to their self-selected angle measured at baseline. In addition to adherence and performance difficulty outcomes, knee joint symptoms (Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale and total score, numerical rating scale (NRS) of pain), and knee joint loading during gait (late stance peak knee adduction moment (KAM)) were assessed. Participants were able to perform the toe-out gait modification program with minimal to moderate difficulty, and exhibited significant increases in self-selected toe-out angle during walking (P < 0.001). Joint discomfort was reported by five participants (33%) in the hip or knee joints, though none lasted longer than 2 weeks. Participants reported statistically significant reductions in WOMAC pain (P = 0.02), NRS pain (P < 0.001), WOMAC total score (P = 0.02), and late stance KAM (P = 0.04). These preliminary findings suggest that toe-out gait modification is feasible in people with medial compartment knee OA. Preliminary changes in clinical and biomechanical outcomes provide the impetus for conducting larger scale studies of gait modification in people with knee OA to confirm these findings.

Association of Knee Confidence With Pain, Knee Instability, Muscle Strength, and Dynamic Varus–Valgus Joint Motion in Knee Osteoarthritis

To investigate associations between self-reported knee confidence and pain, self-reported knee instability, muscle strength, and dynamic varus-valgus joint motion during walking. We performed a cross-sectional analysis of baseline data from 100 participants with symptomatic and radiographic medial tibiofemoral compartment osteoarthritis (OA) and varus malalignment recruited for a randomized controlled trial. The extent of knee confidence, assessed using a 5-point Likert scale item from the Knee Injury and Osteoarthritis Outcome Score, was set as the dependent variable in univariable and multivariable ordinal regression, with pain during walking, self-reported knee instability, quadriceps strength, and dynamic varus-valgus joint motion during walking as independent variables. One percent of the participants were not troubled with lack of knee confidence, 17% were mildly troubled, 50% were moderately troubled, 26% were severely troubled, and 6% were extremely troubled. Significant associations were found between worse knee confidence and higher pain intensity, worse self-reported knee instability, lower quadriceps strength, and greater dynamic varus-valgus joint motion. The multivariable model consisting of the same variables significantly accounted for 24% of the variance in knee confidence (P < 0.001). Worse knee confidence is associated with higher pain, worse self-reported knee instability, lower quadriceps muscle strength, and greater dynamic varus-valgus joint motion during walking. Since previous research has shown that worse knee confidence is predictive of functional decline in knee OA, addressing lack of knee confidence by treating these modifiable impairments could represent a new therapeutic target.

External hip adduction moment and progression of medial tibiofemoral cartilage damage and bone marrow lesions in persons with knee osteoarthritis

Purpose: Gait biomechanics at the hip may affect medial joint loading at the knee in persons with knee osteoarthritis (OA). A greater external hip adduction moment (reflecting torque generation by the hip abductor muscles) during the stance phase of gait may limit excessive hip drop or trunk lean. This, in turn, may prevent excessive medial knee joint loading and eventual progression of knee OA. Little is known about the relationship between the external hip adduction moment and progression of medial tibiofemoral OA as assessed by MRI. We hypothesized that a greater magnitude of the baseline external hip adduction moment is associated with reduced risk of baseline-to-2-year progression of medial tibiofemoral cartilage damage and bone marrow lesions in persons with knee OA. Methods: Participants with knee OA, defined by osteophyte presence in at least one knee, underwent quantitative gait analysis at baseline using an 8-camera Digital Real-Time Eagle motion analysis system and force plate. Inverse dynamics were used to calculate the external hip adduction moment, normalized to %bodyweight*height. Both knees underwent 3.0T MRI at baseline and two year follow-up using double oblique coronal and axial FLASHwe, coronal T1-weighted spin-echo (SE), and sagittal, axial and coronal fat-suppressed turbo spin echo sequences. We assessed cartilage damage and bone marrow lesions using WORMS scoring, blinding readers to hypotheses and all other data. We used logistic regression statistical models with generalized estimating equations (GEE) to account for correlation between the 2 limbs of each person, to assess the association between external hip adduction moment at baseline and baseline-to-2-year cartilage damage progression and bone marrow lesion progression, defined as any worsening of score in the medial compartment as a whole and within each joint surface. Analyses were adjusted for gait speed, age, gender, and disease severity (using K/L radiographic grade). Results are reported as odds ratios (ORs) and 95% confidence intervals (CIs). Results: 204 persons [mean age 64.2 years (±9.9, SD), mean BMI 28.5 kg/m2 (±5.7), 76.5% women] contributing 391 knees comprised the study sample. The mean external hip adduction moment was 4.43 (±0.9, SD) %body weight*height. As shown in Table 1, a greater external hip adduction moment was significantly associated with a reduced likelihood of cartilage damage progression in the medial tibiofemoral compartment and also at the medial femoral surface. After adjustment for the indicated covariables, these associations were no longer statistically significant at the 5% level. Table 2 shows the means (±SD) of the external hip adduction moment at baseline for knees with and without cartilage damage and bone marrow lesion progression in specific subregions. In analyses of specific regions, a greater external hip adduction moment was significantly associated with a reduced likelihood of cartilage damage progression at the posterior femoral subregion [OR per 1 unit of external hip adduction moment (95% CI): 0.51 (0.31, 0.86)] and bone marrow lesion progression at the central femoral subregion [OR per 1 unit (95% CI): 0.56 (0.35, 0.89)]. Conclusions: In persons with knee osteoarthritis, a greater external hip adduction moment was associated with a reduced likelihood of 2-year medial tibiofemoral cartilage damage progression and bone marrow lesion progression, but these findings were no longer statistically significant in adjusted analyses. The consistently protective direction of the findings at compartment, joint surface, and subregional levels warrants further evaluation at longer follow-up.Table 1Unadjusted and adjusted ORs (95% CIs) for medial tibiofemoral OA progression at 2 yearsMedial Tibiofemoral CompartmentMedial Femoral SurfaceMedial Tibial SurfaceCartilage damage progressionBone marrow lesion progressionCartilage damage progressionBone marrow lesion progressionCartilage damage progressionBone marrow lesion progressionNumber of knees (%) with progression61/391 (16%)87/391 (22%)48/391 (12%)53/391 (14%)29/391 (7%)48/391 (12%)Baseline predictorExternal Hip Adduction Moment (%BW*HT)Unadjusted0.70 (0.51, 0.97)0.75 (0.55, 1.01)0.68 (0.50, 0.93)0.72 (0.48, 1.08)0.88 (0.59, 1.32)0.96 (0.67, 1.37)Adjusted*0.82 (0.58, 1.15)0.85 (0.61, 1.17)0.79 (0.56, 1.12)0.80 (0.53, 1.21)1.07 (0.70, 1.64)1.20 (0.83, 1.75)Results are per 1 unit (%BW*HT) of external hip adduction moment (n = 391 knees from 204 persons)*adjusted for gait speed, age, gender, and K/L grade Open table in a new tab Table 2Means (SD) for the external hip adduction moment in medial tibial and femoral subregionsExternal Hip Adduction Moment (%BW*HT), mean (SD)Cartilage damage progression at 2-year follow-upPosterior femurCentral femurPosterior tibiaCentral tibiaAnterior tibiaNumber of knees (%) with progression20/391 (5%)33/391 (8%)7/391 (2%)25/391 (6%)8/391 (2%)Knees without progression, mean (SD)4.45 (0.88)4.44 (0.90)4.43 (0.89)4.43 (0.89)4.43 (0.89)Knees with progression, mean (SD)3.97 (0.85)4.36 (0.67)3.98 (0.57)4.32 (0.79)4.61 (0.87)Bone marrow lesion progression at 2-year follow-upNumber of knees (%) with progression19/391 (5%)38/391 (10%)12/391 (3%)33/391 (8%)21/391 (5%)Knees without progression, mean (SD)4.43 (0.87)4.47 (0.87)4.43 (0.89)4.44 (0.89)4.43 (0.88)Knees with progression, mean (SD)4.38 (1.19)4.05 (0.92)4.38 (0.84)4.34 (0.79)4.52 (0.96) Open table in a new tab Results are per 1 unit (%BW*HT) of external hip adduction moment (n = 391 knees from 204 persons) *adjusted for gait speed, age, gender, and K/L grade