Post-traumatic and OA-related lesions in the knee at baseline and 2 years after traumatic meniscal injury: Secondary analysis of a randomized controlled trial

OBJECTIVE

To assess the presence of early degenerative changes on Magnetic Resonance Imaging (MRI) 24 months after a traumatic meniscal tear and to compare these changes in patients treated with arthroscopic partial meniscectomy or physical therapy plus optional delayed arthroscopic partial meniscectomy.

DESIGN

We included patients aged 18-45 years with a recent onset, traumatic, MRI verified, isolated meniscal tear without radiographic osteoarthritis. Patients were randomized to arthroscopic partial meniscectomy or standardized physical therapy with optional delayed arthroscopic partial meniscectomy. MRIs at baseline and 24 months were scored using the MRI Osteoarthritis Knee Score (MOAKS). We compared baseline MRIs to healthy controls aged 18-40 years. The outcome was the progression of bone marrow lesions (BMLs), cartilage defects and osteophytes after 24 months in patients.

RESULTS

We included 99 patients and 50 controls. At baseline, grade 2 and 3 BMLs were present in 26% of the patients (n = 26), compared to 2% of the controls (n = 1) (between group difference 24% (95% CI 15% to 34%)). In patients, 35% (n = 35) had one or more cartilage defects grade 1 or higher, compared to 2% of controls (n = 1) (between group difference 33% (95% CI 23% to 44%)). At 24 months MRI was available for 40 patients randomized to arthroscopic partial meniscectomy and 41 patients randomized to physical therapy. At 24 months 30% (n = 12) of the patients randomized to arthroscopic partial meniscectomy showed BML worsening, compared to 22% (n = 9) of the patients randomized to physical therapy (between group difference 8% (95% CI -11% to 27%)). Worsening of cartilage defects was present in 40% (n = 16) of the arthroscopic partial meniscectomy group, compared to 22% (n = 9) of the physical therapy group (between group difference 18% (95% CI -2% to 38%)). Of the patients who had no cartilage defect at baseline, 33% of the arthroscopic partial meniscectomy group had a new cartilage defect at follow-up compared to 14% of the physical therapy group. Osteophyte worsening was present in 18% (n = 7) of the arthroscopic partial meniscectomy group and 15% (n = 6) of the physical therapy group (between group difference 3% (95% CI -13% to 19%)).

CONCLUSIONS

Our results might suggest more worsening of BMLs and cartilage defects with arthroscopic partial meniscectomy compared to physical therapy with optional delayed arthroscopic partial meniscectomy at 24-month follow-up in young patients with isolated traumatic meniscal tears without radiographic OA.

Association between knee magnetic resonance imaging markers and knee symptoms over 6-9 years in young adults

OBJECTIVES

To describe associations between MRI markers with knee symptoms in young adults.

METHODS

Knee symptoms were assessed using the WOMAC scale during the Childhood Determinants of Adult Health Knee Cartilage study (CDAH-knee; 2008-2010) and at the 6- to 9-year follow-up (CDAH-3; 2014-2019). Knee MRI scans obtained at baseline were assessed for morphological markers (cartilage volume, cartilage thickness, subchondral bone area) and structural abnormalities [cartilage defects and bone marrow lesions (BMLs)]. Univariable and multivariable (age, sex, BMI adjusted) zero-inflated Poisson (ZIP) regression models were used for analysis.

RESULTS

The participants' mean age in CDAH-knee and CDAH-3 were 34.95 (s.d. 2.72) and 43.27 (s.d. 3.28) years, with 49% and 48% females, respectively. Cross-sectionally, there was a weak but significant negative association between medial femorotibial compartment (MFTC) [ratio of the mean (RoM) 0.99971084 (95% CI 0.9995525, 0.99986921), P < 0.001], lateral femorotibial compartment (LFTC) [RoM 0.99982602 (95% CI 0.99969915, 0.9999529), P = 0.007] and patellar cartilage volume [RoM 0.99981722 (95% CI 0.99965326, 0.9999811), P = 0.029] with knee symptoms. Similarly, there was a negative association between patellar cartilage volume [RoM 0.99975523 (95% CI 0.99961427, 0.99989621), P = 0.014], MFTC cartilage thickness [RoM 0.72090775 (95% CI 0.59481806, 0.87372596), P = 0.001] and knee symptoms assessed after 6-9 years. The total bone area was negatively associated with knee symptoms at baseline [RoM 0.9210485 (95% CI 0.8939677, 0.9489496), P < 0.001] and 6-9 years [RoM 0.9588811 (95% CI 0.9313379, 0.9872388), P = 0.005]. The cartilage defects and BMLs were associated with greater knee symptoms at baseline and 6-9 years.

CONCLUSION

BMLs and cartilage defects were positively associated with knee symptoms, whereas cartilage volume and thickness at MFTC and total bone area were weakly and negatively associated with knee symptoms. These results suggest that the quantitative and semiquantitative MRI markers can be explored as a marker of clinical progression of OA in young adults.

Deep learning applications in osteoarthritis imaging

Deep learning (DL) is one of the most exciting new areas in medical imaging. This article will provide a review of current applications of DL in osteoarthritis (OA) imaging, including methods used for cartilage lesion detection, OA diagnosis, cartilage segmentation, and OA risk assessment. DL techniques have been shown to have similar diagnostic performance as human readers for detecting and grading cartilage lesions within the knee on MRI. A variety of DL methods have been developed for detecting and grading the severity of knee OA and various features of knee OA on X-rays using standardized classification systems with diagnostic performance similar to human readers. Multiple DL approaches have been described for fully automated segmentation of cartilage and other knee tissues and have achieved higher segmentation accuracy than currently used methods with substantial reductions in segmentation times. Various DL models analyzing baseline X-rays and MRI have been developed for OA risk assessment. These models have shown high diagnostic performance for predicting a wide variety of OA outcomes, including the incidence and progression of radiographic knee OA, the presence and progression of knee pain, and future total knee replacement. The preliminary results of DL applications in OA imaging have been encouraging. However, many DL techniques require further technical refinement to maximize diagnostic performance. Furthermore, the generalizability of DL approaches needs to be further investigated in prospective studies using large image datasets acquired at different institutions with different imaging hardware before they can be implemented in clinical practice and research studies.

Subchondral bone in knee osteoarthritis: bystander or treatment target?

The subchondral bone is an important structural component of the knee joint relevant for osteoarthritis (OA) incidence and progression once disease is established. Experimental studies have demonstrated that subchondral bone changes are not simply the result of altered biomechanics, i.e., pathologic loading. In fact, subchondral bone alterations have an impact on joint homeostasis leading to articular cartilage loss already early in the disease process. This narrative review aims to summarize the available and emerging imaging techniques used to evaluate knee OA-related subchondral bone changes and their potential role in clinical trials of disease-modifying OA drugs (DMOADs). Radiographic fractal signature analysis has been used to quantify OA-associated changes in subchondral texture and integrity. Cross-sectional modalities such as cone-beam computed tomography (CT), contrast-enhanced cone beam CT, and micro-CT can also provide high-resolution imaging of the subchondral trabecular morphometry. Magnetic resonance imaging (MRI) has been the most commonly used advanced imaging modality to evaluate OA-related subchondral bone changes such as bone marrow lesions and altered trabecular bone texture. Dual-energy X-ray absorptiometry can provide insight into OA-related changes in periarticular subchondral bone mineral density. Positron emission tomography, using physiological biomarkers of subchondral bone regeneration, has provided additional insight into OA pathogenesis. Finally, artificial intelligence algorithms have been developed to automate some of the above subchondral bone measurements. This paper will particularly focus on semiquantitative methods for assessing bone marrow lesions and their utility in identifying subjects at risk of symptomatic and structural OA progression, and evaluating treatment responses in DMOAD clinical trials.

Management of Subchondral Lesions in the Foot and Ankle

The treatment of subchondral lesions is an area with limited focus within the foot and ankle literature. The literature has shown an association between disruption of the subchondral bone plate and the formation of subchondral cysts. The primary causes of subchondral lesions are acute trauma, repetitive microtrauma, as well as idiopathic means. Evaluation of these injuries should be done carefully and often requires advanced imaging including MRI and computed tomography. Treatment does vary depending on the presentation of the subchondral lesion with or without the presence of an osteochondral lesion.

Metabolic syndrome and the progression of knee osteoarthritis on MRI

OBJECTIVE

Metabolic osteoarthritis (OA) is one of the proposed clinical phenotypes defined by the existence of metabolic syndrome (MetS). This study aimed to (1) investigate whether MetS and its components are associated with progression of knee OA magnetic resonance imaging (MRI) features, and (2) to evaluate the interaction of MetS with menopause and progression of MRI features.

METHOD

682 women from the Rotterdam Study who participated in a sub-study with knee MRI data available and 5-year follow-up were included. Tibiofemoral (TF) and patellofemoral (PF) OA features were assessed with the MRI Osteoarthritis Knee Score. MetS was quantified by the MetS severity Z-score. Generalized estimating equations were used to evaluate associations between MetS and menopausal transition and progression of MRI features.

RESULTS

MetS severity at baseline was associated with progression of osteophytes in all compartments, bone marrow lesions (BMLs) in the PF compartment, and cartilage defects in the medial TF compartment. Waist circumference was associated with progression of osteophytes in all compartments and cartilage defects in the medial TF compartment. High-density lipoprotein (HDL)-cholesterol levels were associated with progression of osteophytes in the medial and lateral TF compartment and glucose levels with osteophytes in the PF and medial TF compartment. No interactions were found between MetS with menopausal transition and MRI features.

CONCLUSION

Women with higher MetS severity at baseline showed progression of osteophytes, BMLs, and cartilage defects, indicating more structural knee OA progression after 5 years. Further studies are required to understand whether targeting MetS components may prevent the progression of structural knee OA in women.

Conventional MRI-derived subchondral trabecular biomarkers and their association with knee cartilage volume loss as early as 1 year: a longitudinal analysis from Osteoarthritis Initiative

OBJECTIVE

To study associations between MRI-derived subchondral trabecular biomarkers obtained from conventional MRI sequences and knee cartilage loss over 12 and 24 months, using the FNIH osteoarthritis (OA) biomarkers consortium.

MATERIALS AND METHODS

Data of the 600 subjects in the FNIH OA biomarkers consortium (a nested case-control study within Osteoarthritis Initiative [OAI]) were extracted from the online database. Baseline knee MRI (intermediate-weighted (IW) sequences) were evaluated to determine conventional MRI-derived trabecular thickness (cTbTh) and bone-to-total ratio (cBV/TV). The measurements for medial and lateral volumes of cartilages using baseline, 12-, and 24-month knee MRI were extracted from the OAI database, and cartilage volume loss over 12 and 24 months of follow-up were determined using Relative Change Index. The association between conventional MRI-based subchondral trabecular biomarkers and cartilage volume loss were studied using logistic regression models, adjusted for relevant confounders including age, sex, body mass index (BMI), vitamin D use, Kellgren Lawrence grade (KLG), and tibiofemoral alignment.

RESULTS

Higher medial cTbTh and cBV/TV at baseline were associated with increased odds of medial tibial cartilage volume loss over 12 months (ORs: 1.01 [1.00-1.02] and 1.24 [1.10-1.39] per 1-SD change) and 24 months (ORs: 1.01 [1.00-1.02] and 1.22 [1.08-1.37], per 1-SD change). No significant association was observed between medial subchondral trabecular biomarkers and lateral tibial or femoral (medial or lateral) cartilage volume loss over the first and second follow-up years.

CONCLUSIONS

Conventional MRI-derived subchondral trabecular biomarkers (higher medial cTbTh and cBV/TV) may be associated with increased medial tibial cartilage volume loss as early as 1 year.

Treatment of Subchondral Bone Marrow Edema with Intralesional Viscous Bone Cement in a Young, Active Patient: A Case Report

CASE

A 23-year-old male patient presented with symptomatic, high-grade medial tibial plateau bone marrow edema unresponsive to conservative treatment. After the injection of intralesional viscous bone cement, the patient had resolution of his symptoms and returned to running.

CONCLUSION

The use of intralesional viscous bone cement has grown in popularity for the treatment of bone marrow edema in individuals older than 40 years but is uncommon in younger individuals. This case demonstrates that intralesional viscous bone cement may be considered in the treatment of high-grade bone marrow edema in young, active patients who are unresponsive to extensive conservative management.

Role of the osteochondral unit in the pathogenesis of osteoarthritis: focus on the potential use of clodronate

Osteoarthritis (OA) is a chronic disease characterized by inflammation and progressive deterioration of the joint. The etiology of OA includes genetic, phlogistic, dismetabolic and mechanical factors. Historically, cartilage was considered the target of the disease and therapy was aimed at protecting and lubricating the articular cartilage. The osteochondral unit is composed of articular cartilage, calcified cartilage, and subchondral and trabecular bone, which work synergistically to support the functional loading of the joint. Numerous studies today show that OA involves the osteochondral unit, with the participation therefore of the bone in the starting and progression of the disease, which is associated with chondropathy. Cytokines involved in the process leading to cartilage damage are also mediators of subchondral bone edema. Therefore, OA therapy must be based on the use of painkillers and bisphosphonates for both the control of osteometabolic damage and its analgesic activity. Monitoring of the disease of the osteochondral unit must be extensive, since bone marrow edema can be considered as a marker of the evolution of OA. In the present review we discuss some of the pathogenetic mechanisms associated with osteoarthritis, with particular focus on the osteochondral unit and the use of clodronate.

Knee subchondroplasty for management of subchondral bone cysts: a novel treatment method

Knee subchondroplasty (SCP) is one of the most novel minimally invasive methods for treating bone marrow lesions. The literature suggests that it is safe, with few complications and good outcomes. However, no studies have documented its usage for managing large subchondral bone cysts. This article outlines a case report and details the pearls and pitfalls of SCP in treating large subchondral bone cysts. Our patient underwent arthroscopic debridement with medial femoral condyle SCP. Mild posterior extravasation of synthetic bone substitute was observed on Postoperative Day 1, which was immediately rectified on revision arthroscopy. Gradual escalation of weight bearing and good pain relief were subsequently achieved, and the patient has remained complication-free after two years. No further extravasation were observed on repeat radiography. SCP is a feasible temporising measure that may help to delay the need for bone allograft or immediate knee arthroplasty in younger patients while retaining function and delaying loss of productivity.

Greater heterogeneity of the bone mineralisation density distribution and low bone matrix mineralisation characterise tibial subchondral bone marrow lesions in knee osteoarthritis patients

Tibial subchondral bone marrow lesions (BMLs) identified by MRI have been recognised as potential disease predictors in knee osteoarthritis (KOA), and may associate with abnormal bone matrix mineralisation and reduced bone quality. However, these tissue-level changes of BMLs have not been extensively investigated. Thus, the aim of this study was to quantify the degree of subchondral bone matrix mineralisation (both plate and trabeculae) in relation to histomorphometric parameters of bone remodelling and osteocyte lacunae (OL) characteristics in the tibial plateau (TP) of KOA patients with and without BMLs (OA-BML and OA No-BML, respectively) in comparison to nonOA cadaveric controls (CTL). Osteochondral (cartilage-bone) tissue was sampled from the BML signal region within the medial compartment for each OA-BML TP, and from a corresponding medial region for OA No-BML and CTL TPs. The tissue samples were embedded in resin, and sections stained with Von-Kossa Haematoxylin and Eosin (H&E) for quantitation of static indices of bone remodelling. Resin blocks were then further polished, and carbon-coated for quantitative backscattered electron imaging (qBEI) to determine the bone mineralisation density distribution (BMDD), as well as OL characteristics. It was found that OA-BML contained higher osteoid volume per tissue volume (OV/TV; %) and per bone volume (OV/BV; %) in both subchondral plate and trabecular bone compared to OA No-BML and CTL. The BMDD of OA-BML in both subchondral plate and trabecular bone was shifted toward a lower degree of mineralisation. Typically, an increase in both the heterogeneity of mineralisation density (Ca Width; wt%Ca) and the percentage of lower calcium (Ca Low; % B.Ar) in trabecular bone with OA-BML versus CTL was observed. Further, unmineralised OL density (#/mm²) in subchondral plate was distinctly higher in OA-BML samples compared to CTL. The KOA patients with and without BMLs had significantly decreased density of mineralised OL (#/mm²) in trabecular bone compared to CTL. Taken together, these findings indicate that tibial BMLs in advanced KOA patients are characterised by significantly hypo-mineralised subchondral bone compared with CTL. These differences associated with evidence of increased bone remodelling in OA-BML, and may influence the mechanical properties of the subchondral bone, with implications for the overlying cartilage.

Percutaneous Skeletal Fixation of Painful Subchondral Bone Marrow Edema of the Knee

Purpose

To investigate the change in patient-reported pain after percutaneous skeletal fixation (PSF) and to determine the success rate of PSF in the prevention of additional intervention for the treatment of painful subchondral bone marrow edema (SBME) of the knee over a 2-year postoperative period.

Methods

This was a retrospective, single-surgeon analysis of patients undergoing PSF for painful, atraumatic SBME of the knee confirmed on preoperative magnetic resonance imaging with a minimum 2-year follow-up. Inclusion criteria were age >18 years, pain localized to the area of edema, failure of nonsurgical intervention (4 weeks of physical therapy and non-steroidal medication use), and absence of tricompartmental Kellgren–Lawrence grade 4 osteoarthritis. All patients underwent arthroscopy, followed by isolated PSF without additional chondral procedures. Pre- and postoperative visual analog scale scores were compared. The primary outcome measure of success was defined as a lack of additional intervention. This included viscosupplementation, corticosteroid injection, or conversion to arthroplasty.

Results

A total of 74 patients with a mean age of 47.2 years and average follow-up time of 38.9 months (range 24-61 months) were evaluated. Successful treatment was noted in 61 patients (82.4%). Of the 13 patients who did not respond to PSF, 5 (6.8%) had been converted to arthroplasty, 11 received viscosupplementation, and 8 required cortisone injections. The average visual analog scale score decreased from 7.55 preoperatively to 3.16 at 2-year follow-up (P < .001). The average body mass index of successfully treated patients (28.2) was significantly less than that of the patients experiencing failure (32.2) (P = .001).

Conclusions

Patients undergoing PSF for the treatment of painful SBME may expect a decrease in knee pain and low rates of additional intervention over a 2-year postoperative period.

Level of Evidence

Level IV; Therapeutic Case Series

Metabolic syndrome and subchondral bone alterations: The rise of osteoarthritis - A review

Metabolic syndrome (MS) has become one of the top major health burdens for over three decades not only due to its effects on cardiovascular health but also its implications in orthopedics. Extensive research has shown that MS is tightly linked to osteoarthritis and inflammation, a process which appears to primarily occur in the subchondral bone via the incidence of bone-marrow lesions (BMLs). Numerous studies identify obesity, dyslipidemia, insulin resistance and hypertension as the top metabolic risk factors, the so-called "deadly quartet". These factors are responsible for the disruptive physiological processes that culminate in detrimental alterations within the subchondral bone, cartilage damage and, overall, the predominant pro-inflammatory joint microenvironment. Although it has long been thought that osteoarthritis was limited to the cartilage component of the joint, other studies indicate that the disease may originate from the harmful alterations that occur primarily in the subchondral bone, especially via means of vascular pathology. Since metabolic risk factors are manageable to a certain extent, it is therefore possible to decelerate the progression of OA and mitigate its devastating effects on the subchondral bone and subsequent articular cartilage damage.

METHODS

Literature was reviewed using PubMed and Google Scholar in order to find a correlation between metabolic syndrome and osteoarthritic progression. The investigation included a combination of nomenclature such as: "metabolic syndrome", "obesity", "insulin resistance", "hypertension", "dyslipidemia", "low-grade systemic inflammation", "osteoarthritis", "subchondral bone", "cartilage" and "inflammatory biomarkers".

CONCLUSION

Based on several studies, there seems to be a significant association between The Deadly Quartet (metabolic syndrome), dysregulation of both pro- and anti-inflammatory biomarkers, and osteoarthritic progression arising from unbridled systemic inflammation.

The relation of oral bisphosphonates to bone marrow lesion volume among women with osteoarthritis

OBJECTIVE

Bone marrow lesions (BMLs) contribute to pain and progression of knee OA. Bisphosphonates may be a potential disease-modifier through amelioration of BMLs. We sought to determine the effect of oral bisphosphonates on BML volume over 12 months.

DESIGN

Women in the Osteoarthritis Initiative who newly initiated an oral bisphosphonate were propensity-score matched to non-initiators. BML volume was assessed using sagittal turbo spin echo fat-suppressed intermediate-weighted MR images at the index date and 12 months later. A validated semi-automated process was used to segment subchondral OA-related BMLs to determine total volume of BMLs based on number of voxels within the outlined area of interest. Mean change in BML volume over 12 months among bisphosphonate initiators was compared with non-initiators using multiple linear regression.

RESULTS

145 bisphosphonate initiators were identified, who were well-matched to their comparators. The difference in mean change in total BML volume between the two groups, regardless of presence of baseline BMLs, was not significant (P = 0.4, 95% CI -156.6 to +354.2). The proportion of participants with decreased, increased, or unchanged BML volumes over the 12 months were similar in both groups. Among those with baseline BMLs, bisphosphonate initiators had a greater proportion with a decrease in BML volume compared with stable or increased BML volume than non-initiators (P = 0.03).

CONCLUSIONS

In this 'real-world' setting of women starting bisphosphonates, we found no clear evidence of benefit on BML volume over a 12-month period, though a trend towards a decrease in BML volume was noted.

Size of Initial Bone Bruise Predicts Future Lateral Chondral Degeneration in ACL Injuries: A Radiographic Analysis

Background:

Bone marrow contusions are common after an acute anterior cruciate ligament (ACL) injury. It is unknown whether the severity of this initial bruise can predict the potential of developing chondral changes even after ACL reconstructive surgery (ACLR).

Purpose:

To investigate whether the initial bone bruise area could be predictive of progressive chondral defects.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A retrospective chart review was performed to capture patients with an acute ACL injury with pre- and post-ACLR magnetic resonance imaging (MRI) between January 2000 and December 2017. Lesion areas were measured on initial MRI, and chondral wear was graded on final imaging by use of the modified Outerbridge classification. An ordinal model was created to determine whether the initial area was a significant predictor for future chondral degeneration.

Results:

A total of 40 patients with a mean age of 34.5 ± 12.6 years were included for analysis. All patients underwent ACLR at a mean 139 ± 64 days from initial injury. A lateral tibial and femoral bone bruise was most commonly present in patients (77.5% and 62.5%, respectively). A medial femoral bone bruise was found in only 12.5% (5/40) of patients. The initial contusion area significantly correlated with increasing chondral wear over time in the tibia and lateral femoral condyle (P < .001). Patients with a bone bruise encompassing 100% of the lateral femoral compartment on MRI had a 74% chance of having grade 3 or 4 chondral changes at 5 years (P = .001). Absence of a bone bruise on initial MRI was the greatest predictor of no cartilage wear at 5 years in all compartments (P < .001). The presence of a concomitant lateral meniscal injury increased the risk of developing type 3 or 4 chondral wear in the lateral tibial plateau (P = .012) but did not pose increased risk of femoral wear (P = .23).

Conclusion:

A significant relationship between area of initial bone bruise at the time of injury and progressive posttraumatic chondral disease was found in the tibial and lateral femoral compartments.

Bone marrow lesions in knee osteoarthritis: regional differences in tibial subchondral bone microstructure and their association with cartilage degeneration

OBJECTIVE

The aim of this study was to investigate how bone microstructure within bone marrow lesions (BMLs) relates to the bone and cartilage across the whole human tibial plateau.

DESIGN

Thirty-two tibial plateaus from patients with osteoarthritis (OA) at total knee arthroplasty and eleven age-matched non-OA controls, were scanned ex vivo by MRI to identify BMLs and by micro CT to quantitate the subchondral (plate and trabecular) bone microstructure. For cartilage evaluation, specimens were processed histologically.

RESULTS

BMLs were detected in 75% of the OA samples (OA-BML), located predominantly in the anterior-medial (AM) region. In contrast to non-OA control and OA-no BML, in OA-BML differences in microstructure were significantly more evident between subregions. In OA-BML, the AM region contained the most prominent structural alterations. Between-group comparisons showed that the AM region of the OA-BML group had significantly higher histological degeneration (OARSI grade) (P < .0001, P < .05), thicker subchondral plate (P < .05, P < .05), trabeculae that are more anisotropic (P < .0001, P < .05), well connected (P < .05, P = n.s), and more plate-like (P < 0.05, P < 0.05), compared to controls and OA-no BML at this site. Compared to controls, OA-no BML had significantly higher OARSI grade (P < .0001), and lower trabecular number (P < .05).

CONCLUSION

In established knee OA, both the extent of cartilage damage and microstructural degeneration of the subchondral bone were dependent on the presence of a BML. In OA-no BML, bone microstructural alterations are consistent with a bone attrition phase of the disease. Thus, the use of BMLs as MRI image-based biomarkers appear to inform on the degenerative state within the osteochondral unit.

Short-Term Outcomes for the Biologic Treatment of Bone Marrow Edema of the Knee Using Bone Marrow Aspirate Concentrate and Injectable Demineralized Bone Matrix

Purpose

To evaluate short-term outcomes for the biologic treatment of bone marrow edema (BME) of the knee using bone marrow aspirate concentrate (BMAC) and injectable demineralized bone matrix (iDBM).

Methods

We performed a review of prospectively collected data from patients who underwent treatment for bone marrow lesions (BMLs) of the knee using BMAC and iDBM (IntraOsseous BioPlasty; Arthrex, Naples, FL) between May 2017 and December 2018. Inclusion criteria included patients aged 18 to 65 years with the presence of BME on T2-weighted magnetic resonance imaging in the subchondral weightbearing region of the tibia or femoral condyle, with pain corresponding to the same compartment. The International Knee Documentation Committee (IKDC), pain visual analog scale (VAS), and 12-Item Short Form Health Survey (SF-12) scores were used to evaluate clinical outcomes.

Results

We evaluated 20 patients who were treated at a single academic medical institution over a mean 14.5-month follow-up (median, 14 months; range, 6-25 months). The average patient age was 51.7 years (range 38-62 years). Compared with preoperative values, the visual analog scale decreased from 7.0 to 1.3 (P = .008). The mean International Knee Documentation Committee scores improved from 29.2 to 66.1 (P = .063). Both the Physical and Mental Component Scores of the 12-Item Short Form Health Survey also showed improvement (Physical Component Score, P = .438; Mental Component Score, P = .563). Based on postoperative magnetic resonance imaging, 75% (3 of 4) of the BMLs demonstrated complete healing. The survival rate was 93% at 1-year follow-up.

Conclusion

Biologic treatment of BME of the knee using BMAC and iDBM is an effective adjunct to arthroscopy that provides short-term pain relief for BMLs associated with degenerative conditions of the knee. This procedure is associated with clinically significant improvements in knee pain and function at a short-term follow-up.

Level of Evidence

Level IV, therapeutic case series.

Medial compartment defects progress at a more rapid rate than lateral cartilage defects in older adults with minimal to moderate knee osteoarthritis (OA): data from the OA initiative

PURPOSE

To determine: (1) rates and risk factors for progression of lateral and medial full-thickness cartilage defect size in older adults without severe knee osteoarthritis (OA), and (2) whether risk factors for defect progression differ for knees with Kellgren-Lawrence OA grade 3 (moderate) OA versus grades 0-2 (none to mild) OA.

METHODS

Three-hundred and eighty adults enrolled in the Osteoarthritis Initiative were included (43% male, mean age 63.0 SD 9.2 years). Ethical approval was obtained at all study sites prior to enrollment. All participants had full-thickness tibial or weight-bearing femoral condylar cartilage defects on baseline knee MRIs. Baseline OA grade was KL grade 3 in 71.3% and grades 0-2 in 21.7% of participants. Repeat MRIs were obtained at a minimum 2-year follow-up. Independent risk of progression in defect size due to demographic factors, knee alignment, OA grade, knee injury and surgery history, and baseline knee symptoms was determined by multivariate Cox proportional hazards and linear regression modeling.

RESULTS

The average increase in defect size over 2 years for lateral defects was 0.18 cm² (SD 0.60) and for medial defects was 0.49 cm² (SD 1.09). Independent predictors of medical defect size progression were bipolar defects (beta 0.47 SE 0.08; p < 0.001), knee varus (per degree, beta 0.08 SE 0.03; p = 0.02) and increased weight (per kg, beta = 0.01 SE 0.004; p = 0.01). Independent predictors for lateral defect progression were larger baseline defect size (per 1.0 cm², beta 0.14 SE 0.03; p < 0.001) and tibial sided defects (beta 0.12 SE 0.04) and degrees valgus (per degree, beta 0.04 SE 0.01; p = 0.001).

CONCLUSIONS

Medial compartment full-thickness defects progress at a more rapid rate than lateral defects in older adults with minimal to moderate OA. Medial defect progression was greatest for bipolar defects in heavier adults with varus knees. Lateral defect progression was greatest for large tibial-sided defects in adults with valgus knees.

LEVEL OF EVIDENCE

II.

Changing MRI after subchondroplasty with partial meniscectomy for knee osteoarthritis

A 54-year old woman with primary osteoarthritis and a tibial bone marrow lesion underwent subchondroplasty with injectable calcium phosphate. Post-operatively, the patient's symptoms worsened, and she lost the ability to bear weight. Follow-up MRI revealed previously absent, diffuse STIR hyperintensity in the tibia extending far beyond the surgical site. Twelve months post-operatively, symptoms spontaneously resolved. As the prevalence of subchondroplasty grows it will be important to recognize potential complications. To the authors' best knowledge this is the first report of significantly worsening pain and difficulty bearing weight corresponding with diffuse hyperintense T2 signal in the tibia after a calcium phosphate subchondroplasty.

Subchondroplasty for the treatment of post-traumatic bone marrow lesions of the medial femoral condyle in a pre-clinical canine model

This study characterizes long-term outcomes associated with subchondroplasty (SCP) treatment for impact-induced subchondral bone marrow lesions (BML) using a validated pre-clinical canine model. With IACUC approval, purpose-bred research hounds (n = 16) underwent arthroscopic impact injury (40N) to both medial femoral condyles. At 3 months, functional assessments, arthroscopy, and MRI were performed and knees (n = 32) were randomly assigned to SCP (3 ml fluoroscopically guided percutaneous injection of AccuFill BSM into BML bone defects) or sham injection (Control). Dogs were assessed at 3, 6, 12, and 24 months after treatment using functional assessments, radiographic evaluation, arthroscopy, and MRI. Dogs were humanely euthanatized at 3, 6, 12, or 24 months after treatment for gross, microCT, and histologic assessments. All knees had focal articular cartilage defects with associated subchondral BMLs, as well as clinical dysfunction, 3 months after injury. At the 3 and 6 months, SCP knees showed more functional impairment than Control knees, however, these differences were not statistically significant. At 1- and 2-year post-treatment, function in SCP knees was better than in Control knees with range of motion being significantly (p < 0.05) better for SCP. Radiographic, arthroscopic, MRI, gross, microCT, and histologic findings matched the functional assessments well with Control being associated with better results at the two early time points and SCP being associated with better results at 1 and 2 years. Clinical significance: SCP treatment using calcium phosphate bone void filler was associated with an initial increase in pain and dysfunction followed by symptomatic benefits for up to 2 years after treatment for post-traumatic femoral condyle BMLs in a preclinical canine model. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2709-2717, 2018.

Safety and Effectiveness of Talus Subchondroplasty and Bone Marrow Aspirate Concentrate for the Treatment of Osteochondral Defects of the Talus

Eleven patients with symptomatic talus osteochondral defects who underwent subchondroplasty with bone marrow aspirate concentrate injection were retrospectively reviewed. Foot and Ankle Outcome Score and visual analog scale pain score were recorded preoperatively and at the 1-year postoperative visit. The mean osteochondral defect size was 1.3×1.4 cm. The weight-bearing visual analog scale pain score improved from a mean of 7.8 to 1.8, and the Foot and Ankle Outcome Score improved from a mean of 67.1 to 89.6. At 1-year follow-up, 10 patients reported they would have the procedure again. Subchondroplasty and bone marrow aspirate concentrate injection offered good pain relief for talus osteochondral defects. The procedure allows immediate weight bearing postoperatively and does not compromise future treatments. [Orthopedics. 2018; 41(5):e734-e737.].

How Do MRI-Detected Subchondral Bone Marrow Lesions (BMLs) on Two Different MRI Sequences Correlate with Clinically Important Outcomes?

The aim of this study is to describe the association of bone marrow lesions (BMLs) present on two different MRI sequences with clinical outcomes, cartilage defect progression, cartilage volume loss over 2.7 years, and total knee replacement (TKR) over 13.3 years. 394 participants (50-80 years) were assessed at baseline and 2.7 years. BML presence at baseline was scored on T1-weighted fat-suppressed 3D gradient-recalled acquisition (T1) and T2-weighted fat-suppressed 2D fast spin-echo (T2) sequences. Knee pain, function, and stiffness were assessed using WOMAC. Cartilage volume and defects were assessed using validated methods. Incident TKR was determined by data linkage. BMLs were mostly present on both MRI sequences (86%). BMLs present on T2, T1, and both sequences were associated with greater knee pain and functional limitation (odds ratio = 1.49 to 1.70; all p < 0.05). Longitudinally, BMLs present on T2, T1, and both sequences were associated with worsening knee pain (β = 1.12 to 1.37, respectively; p < 0.05) and worsening stiffness (β = 0.45 to 0.52, respectively; all p < 0.05) but not worsening functional limitation or total WOMAC. BMLs present on T2, T1, and both sequences predicted site-specific cartilage defect progression (relative risk = 1.22 to 4.63; all p < 0.05) except at the medial tibial and inferior patellar sites. Lateral tibial and superior patellar BMLs present on T2, T1, and both sequences predicted site-specific cartilage volume loss (β = - 174.77 to - 140.67; p < 0.05). BMLs present on T2, T1, and both sequences were strongly associated with incident TKR. BMLs can be assessed on either T2- or T1-weighted sequences with no clinical predictive advantage of either sequence.

A protocol for a multicentre, randomised, double-blind, placebo-controlled trial to compare the effect of annual infusions of zoledronic acid to placebo on knee structural change and knee pain over 24 months in knee osteoarthritis patients - ZAP2

BACKGROUND

Bisphosphonates are a class of drugs that slow bone loss and are a promising candidate to treat knee osteoarthritis (OA) patients. In a pilot study, we demonstrated that zoledronic acid reduced knee pain and size of subchondral bone marrow lesions (BMLs) over 6 months in knee OA patients with significant knee pain and BMLs. A longer, larger study is required to assess whether decreases in BML size will translate to reductions in cartilage loss over time. We are currently conducting a multicentre, randomised, double-blind, placebo-controlled trial over 24 months that aims to compare the effect of annual infusions of zoledronic acid to placebo on knee structural change (assessed using magnetic resonance imaging (MRI)) and knee pain in knee OA patients.

METHODS

Two hundred sixty-four patients with clinical knee OA, significant knee pain and subchondral BMLs present on MRI will be recruited in Hobart, Melbourne, Sydney and Adelaide. They will be randomly allocated to the two arms of the study, receiving an annual identical intravenous infusion of either 100 mL of fluid containing zoledronic acid (5 mg/100 mL) or placebo (0.9% NaCl 100 mL), at baseline and 1 year later. MRI of the study knee will be performed at screening, month 6 and 24. Knee structure, symptoms and function will be assessed using validated methods. The primary outcome is absolute change in tibiofemoral cartilage volume (mm3) over 24 months. Secondary outcomes include improvement in knee pain over 3, 6, 12, 18, and 24 months and reductions in BML size over 6 and 24 months. The primary analyses will be intention-to-treat analyses of primary and secondary outcomes. Per protocol analyses will be performed as the secondary analyses.

DISCUSSION

This study will provide high-quality evidence to assess whether zoledronic acid has a novel disease modifying effect in OA by slowing cartilage loss and reducing pain. If zoledronic acid proves effective, it suggests great potential for cost savings through a delay or reduced need for joint replacement surgery, and potential for great improvements in quality of life for OA suffers.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry: ACTRN12613000039785 , registered on 14 January 2013.

Subchondral Bone and the Osteochondral Unit: Basic Science and Clinical Implications in Sports Medicine

Context:

Articular cartilage injuries and early osteoarthritis are among the most common conditions seen by sports medicine physicians. Nonetheless, treatment options for articular degeneration are limited once the osteoarthritic cascade has started. Intense research is focused on the use of biologics, cartilage regeneration, and transplantation to help maintain and improve cartilage health. An underappreciated component of joint health is the subchondral bone.

Evidence Acquisition:

A comprehensive, nonsystematic review of the published literature was completed via a PubMed/MEDLINE search of the keywords “subchondral” AND “bone” from database inception through December 1, 2016.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Methods:

Articles collected via the database search were assessed for the association of bone marrow lesions and osteoarthritis, cartilage regeneration, and ligamentous and meniscal injury; the clinical disorder known as painful bone marrow edema syndrome; and the subchondral bone as a target for medical and surgical intervention.

Results:

A complex interplay exists between the articular cartilage of the knee and its underlying subchondral bone. The role of subchondral bone in the knee is intimately related to the outcomes from cartilage restoration procedures, ligamentous injury, meniscal pathology, and osteoarthritis. However, subchondral bone is often neglected when it should be viewed as a critical element of the osteochondral unit and a key player in joint health.

Conclusion:

Continued explorations into the intricacies of subchondral bone marrow abnormalities and implications for the advent of procedures such as subchondroplasty will inform further research efforts on how interventions aimed at the subchondral bone may provide durable options for knee joint preservation.

Bone matrix microdamage and vascular changes characterize bone marrow lesions in the subchondral bone of knee osteoarthritis

INTRODUCTION

Bone marrow lesions (BMLs) in the subchondral bone in osteoarthritis (OA) are suggested to be multifactorial, although the pathogenic mechanisms are unknown. Bone metabolism and cardiovascular risk factors associate with BML in epidemiologic studies. However, there are no studies at the tissue level investigating the relationship between these processes and BML. The aim of this study was to investigate the relationship between BMLs in the tibial plateau (TP) of knee OA and bone matrix microdamage, osteocyte density and vascular changes.

METHODS

TP were obtained from 73 patients at total knee replacement surgery and BMLs were identified ex vivo in TP tissue using MRI. Comparator 'No BML' tissue was from matched anatomical sites to the BMLs. Quantitative assessment was made of subchondral bone microdamage, bone resorption indices, osteocyte cellularity, and vascular features.

RESULTS

Several key parameters were different between BML and No BML tissue. These included increased microcrack burden (p = .01, p = .0001), which associated positively with bone resorption and negatively with cartilage volume, and greater osteocyte numerical density (p = .02, p = .01), in the subchondral bone plate and subchondral trabeculae, respectively. The marrow tissue within BML zones contained increased arteriolar density (p = .04, p = .0006), and altered vascular characteristics, in particular increased wall thickness (p = .007) and wall:lumen ratio (wall thickness over internal lumen area) (p = .001), compared with No BML bone.

CONCLUSIONS

Increased bone matrix microdamage and altered vasculature in the subchondral bone of BMLs is consistent with overloading and vascular contributions to the formation of these lesions. Given the important role of BMLs in knee OA, these contributing factors offer potential targets for the treatment and prevention of knee OA.

Improved clinical outcome measures of knee pain and function with concurrent resolution of subchondral Bone Marrow Edema Lesion and joint effusion in an osteoarthritic patient following Pentosan Polysulphate Sodium treatment: a case report

Background

At present, there are no registered products for the treatment of subchondral Bone Marrow Edema Lesion (BML) and associated knee pain. Patients who do not respond to current anti-inflammatory therapies are left with limited treatment options, and may resort to operative management with Total Knee Arthroplasty (TKA). We report the use of Pentosan Polysulphate Sodium (PPS) for the treatment of BMLs of the knee.

Case presentation

We report the case of a 70-year-old female with knee osteoarthritis presenting with a high level of knee pain, scoring 8 on the Numerical Rating Scale (NRS), and functional limitation demonstrating a poor Lysholm Knee Score of 37. MRI scans of the knee revealed subchondral BML in the medial femoral condyle and medial tibial plateau. The patient was administered a course of Pentosan Polysulphate Sodium (PPS) intramuscularly twice weekly, for 3 weeks. MRI scans 2 weeks post-treatment showed complete resolution of the bone marrow edema at the medial femoral condyle and medial tibial plateau with concomitant recovery from pain (NRS pain score of 0), and a 43% improvement of the Lysholm Knee Score. In addition, marked reduction in joint effusion was also demonstrated in the MRI scan post PPS therapy.

Conclusion

The MRI interpretations demonstrate improved clinical outcome measures ensuing therapeutic intervention with PPS, and warranting further investigation into the efficacy of PPS in the treatment of BML associated pain and dysfunction in the osteoarthritic population via randomized controlled trial, or equivalent rigorous methodological technique.

Novel Surgical Technique for Bone Marrow Lesion — Case Report

Introduction: Bone marrow lesions (BMLs) are commonly described as magnetic resonance imaging (MRI) findings associated with stress injuries or trauma. The presence of BMLs closely correlates with pain and rapid joint deterioration. Case presentation: A 51-year-old healthy man presented to our clinic with severe knee pain due to BMLs. After 3 months of conservative treatment, arthroscopy and subchondroplasty (SCP) of the medial femoral condyle was performed. The IKDC (International Knee Documentation Committee) score improved from 39.9 to 66.7 at 6 months, and to 87.4 at 1 year after surgery. The KOOS (Knee Injury and Osteoarthritis Outcome) score improved from 38.5 to 77.7 at 6 months, and to 92.6 at 1 year after surgery. The Tegner Lysholm score improved from 23 to 80 at 6 months, and to 95 at 1 year after surgery. Conclusion: SCP may provide a viable approach to reduce pain associated with BML, with minimal risk of significant complications.

Bone-cartilage crosstalk: a conversation for understanding osteoarthritis

Although cartilage degradation is the characteristic feature of osteoarthritis (OA), it is now recognized that the whole joint is involved in the progression of OA. In particular, the interaction (crosstalk) between cartilage and subchondral bone is thought to be a central feature of this process. The interface between articular cartilage and bone of articulating long bones is a unique zone, which comprises articular cartilage, below which is the calcified cartilage sitting on and intercalated into the subchondral bone plate. Below the subchondral plate is the trabecular bone at the end of the respective long bones. In OA, there are well-described progressive destructive changes in the articular cartilage, which parallel characteristic changes in the underlying bone. This review examines the evidence that biochemical and biomechanical signaling between these tissue compartments is important in OA disease progression and asks whether such signaling might provide possibilities for therapeutic intervention to halt or slow disease development.

Correlates of Hip Cartilage Defects: A Cross-sectional Study in Older Adults

OBJECTIVE

Knee cartilage defects are a key feature of osteoarthritis (OA) but correlates of hip defects remain unexplored. The aims of this cross-sectional study were to describe the correlates of hip cartilage defects.

METHODS

The study included 194 subjects from the Tasmanian Older Adult Cohort who had right hip short-tau inversion recovery magnetic resonance imaging (MRI). Hip cartilage defects were assessed and categorized as grade 0 = no defects, grade 1 = focal blistering or irregularities on cartilage or partial thickness defect, and grade 2 = full thickness defect. Hip pain was determined by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Hip structural changes were measured on MRI, and hip radiographic OA (ROA) was assessed. Leg strength and physical activity were assessed using dynamometer and pedometers, respectively. Data were analyzed using log binomial and linear regression.

RESULTS

Of 194 subjects, 24% (n = 48) had no defects, 34% (n = 66) had grade 1, and 41% (n = 80) had grade 2. In multivariable analyses, any hip defects were associated with greater hip pain [prevalence ratio (PR) 1.20, 95% CI 1.02-1.35] and lower mean leg strength (men; mean ratio 0.83, 95% CI 0.67-0.98). Grade 1 defects were associated with hip bone marrow lesions (BML; PR 1.42, 95% CI 1.03-1.96) and high cartilage signal (men; PR 1.84, 95% CI 1.27-2.70), but not with hip pain or other structural findings. Grade 2 defects were associated with greater hip pain (PR 1.40, 95% CI 1.09-1.80), hip BML (PR 1.45, 95% CI 1.15-1.85), hip effusion cross-sectional area (PR 1.14, 95% CI 1.01-1.30), hip ROA (men; PR 1.60, 95% CI 1.13-2.25), and steps/day (PR 0.97, 95% CI 0.96-0.99).

CONCLUSION

Grade 2 defects in both sexes and grade 1 defects (mostly in men) are associated with clinical, demographic, and structural factors relevant for OA. Damage to the hip cartilage could be one of the major causes of rapid disease progression and pathophysiology of hip defects. The topic needs further study.

Bone marrow lesions detected by specific combination of MRI sequences are associated with severity of osteochondral degeneration

BACKGROUND

Bone marrow lesions (BMLs) are useful diagnostic and prognostic markers in knee osteoarthritis (OA), but what they represent at the tissue level remains unclear. The aim of this study was to provide comprehensive tissue characterization of BMLs detected using two specific MRI sequences.

METHODS

Tibial plateaus were obtained from 60 patients (29 females, 31 males), undergoing knee arthroplasty for OA. To identify BMLs, MRI was performed ex vivo using T1 and PDFS-weighted sequences. Multi-modal tissue level analyses of the osteochondral unit (OCU) were performed, including cartilage volume measurement, OARSI grading, micro-CT analysis of bone microstructure, routine histopathological assessment and quantitation of bone turnover indices.

RESULTS

BMLs were detected in 74 % of tibial plateaus, the remainder comprising a No BML group. Of all BMLs, 59 % were designated BML 1 (detected only by PDFS) and 41 % were designated BML 2 (detected by both PDFS + T1). The presence of a BML was related to degeneration of the OCU, particularly within BML 2. When compared to No BML, BML 2 showed reduced cartilage volume (p = 0.008), higher OARSI scores (p = 0.004), thicker subchondral plate (p = 0.002), increased trabecular bone volume and plate-like structure (p = 0.0004), increased osteoid volume (p = 0.002) and thickness (p = 0.003), more bone marrow oedema (p = 0.03), fibrosis (p = 0.002), necrosis (p = 0.01) and fibrovascular cysts (p = 0.04). For most measures, BML 1 was intermediate between No BML and BML 2.

CONCLUSIONS

BMLs detected by specific MRI sequences identify different degrees of degeneration in the OCU. This suggests that MRI characteristics of BMLs may enable identification of different BML phenotypes and help target novel approaches to treatment and prevention of OA.

Correlates of knee bone marrow lesions in younger adults

Background

Subchondral bone marrow lesions (BMLs) play a key role in the pathogenesis of osteoarthritis (OA) and are associated with pain and structural progression in knee OA. However, little is known about clinical significance and determinants of BMLs of the knee joint in younger adults. We aimed to describe the prevalence and environmental (physical activity), structural (cartilage defects, meniscal lesions) and clinical (pain, stiffness, physical dysfunction) correlates of BMLs in younger adults and to determine whether cholesterol levels measured 5 years prior were associated with current BMLs in young adults.

Methods

Subjects broadly representative of the Australian young adult population (n = 328, aged 31–41 years, female 48.7 %) underwent T1- and proton density-weighted fat-suppressed magnetic resonance imaging (MRI) in their dominant knee. BMLs, cartilage defects, meniscal lesions and cartilage volume were measured. Knee pain was assessed by Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and physical activity was measured by the International Physical Activity Questionnaire (IPAQ). Cholesterol levels including high-density lipoprotein (HDL) were assessed 5 years prior to MRI.

Results

The overall prevalence of BML was 17 % (grade 1: 10.7 %, grade 2: 4.3 %, grade 3: 1.8 %). BML was positively associated with increasing age and previous knee injury but not body mass index. Moderate physical activity (prevalence ratio (PR):0.93, 95 % CI: 0.87, 0.99) and HDL cholesterol (PR:0.36, 95 % CI: 0.15, 0.87) were negatively associated with BML, while vigorous activity (PR:1.02, 95 % CI: 1.01, 1.03) was positively associated with medial tibiofemoral BMLs. BMLs were associated with more severe total WOMAC knee pain (>5 vs ≤5, PR:1.05, 95 % CI: 1.02, 1.09) and WOMAC dysfunction (PR:1.75, 95 % CI: 1.07, 2.89), total knee cartilage defects (PR:2.65, 95 % CI: 1.47, 4.80) and total meniscal lesion score (PR:1.92, 95 % CI: 1.13, 3.28).

Conclusions

BMLs in young adults are associated with knee symptoms and knee structural lesions. Moderate physical activity and HDL cholesterol are beneficially associated with BMLs; in contrast, vigorous physical activity is weakly but positively associated with medial tibiofemoral BMLs.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-016-0938-9) contains supplementary material, which is available to authorized users.

High Kellgren-Lawrence Grade and Bone Marrow Lesions Predict Worsening Rates of Radiographic Joint Space Narrowing; The SEKOIA Study

OBJECTIVE

Determinants of radiographic progression in osteoarthritis (OA) are poorly understood. We investigated which features on baseline magnetic resonance imaging (MRI) acted as predictors of change in joint space width (JSW).

METHODS

A total of 559 men and women over the age of 50 years with clinical knee OA [Kellgren-Lawrence (KL) grade 2-3] were recruited to the placebo arm of the SEKOIA study (98 centers; 18 countries). Minimal tibiofemoral joint space and KL grade on plain radiograph of the knee were assessed at baseline and at yearly followup up to 3 years. In a subset, serial knee MRI examinations were performed. Individuals with a bone marrow lesion (BML) ≥ grade 2 at the tibiofemoral joint at baseline were classified as BML-positive. Relationships between change in JSW and risk factors were assessed using linear regression.

RESULTS

The mean age of study participants was 62.8 (SD 7.5) years and 73% were female; 38.6% had BML. Mean baseline JSW was 3.65 mm. This reduced by 0.18 (0.30) mm/year in men and 0.13 (0.23) mm/year in women. Those with BML had a significantly higher rate of annualized change in JSW; this relationship remained robust after adjustment for age, sex, and baseline KL grade [β = -0.10 (95% CI -0.18, -0.02) mm/yr]. Age, sex, baseline KL grade, and other MRI findings did not influence the rate of change in JSW.

CONCLUSION

The rate of change in JSW was similar in men and women. BML on knee MRI predicted the rate of radiographic change in JSW. This relationship was independent of age, sex, and baseline KL grade.

Baseline radiographic osteoarthritis and semi-quantitatively assessed meniscal damage and extrusion and cartilage damage on MRI is related to quantitatively defined cartilage thickness loss in knee osteoarthritis: the Multicenter Osteoarthritis Study

OBJECTIVES

To provide a comprehensive simultaneous relation of various semiquantitative knee OA MRI features as well as the presence of baseline radiographic osteoarthritis (OA) to quantitative longitudinal cartilage loss.

METHODS

We studied Multicenter OA Study (MOST) participants from a longitudinal observational study that included quantitative MRI measurement of cartilage thickness. These subjects also had Whole Organ MRI Score (WORMS) scoring of cartilage damage, bone marrow lesions (BMLs), meniscal pathology, and synovitis, as well as baseline radiographic evaluation for Kellgren and Lawrence (KL) grading. Knee compartments were classified as progressors when exceeding thresholds of measurement variability in normal knees. All potential risk factors of cartilage loss were dichotomized into "present" (score ≥2 for cartilage, ≥1 for others) or "absent". Differences in baseline scores of ipsi-compartmental risk factors were compared between progressor and non-progressor knees by multivariable logistic regression, adjusting for age, sex, body mass index, alignment axis (degrees) and baseline KL grade. Odds ratios (OR) and 95% CIs were calculated for medial femorotibial compartment (MFTC) and lateral femorotibial compartment (LFTC) cartilage loss. Cartilage loss across both compartments was studied using Generalized Estimating Equations.

RESULTS

196 knees of 196 participants were included (age 59.8 ± 6.3 years [mean ± SD], BMI 29.5 ± 4.6, 62% women). For combined analyses of MFTC and LFTC, baseline factors related to cartilage loss were radiographic OA (KL grade ≥2: aOR 4.8 [2.4-9.5], cartilage damage (aOR 2.3 [1.2-4.4])), meniscal damage (aOR 3.9 [2.1-7.4]) and extrusion (aOR 2.9 [1.6-5.3]), all in the ipsilateral compartment, but not BMLs or synovitis.

CONCLUSION

Baseline radiographic OA and semiquantitatively (SQ) assessed MRI-detected cartilage damage, meniscal damage and extrusion, but not BMLs or synovitis is related to quantitatively measured ipsi-compartmental cartilage thinning over 30 months.

Bone marrow lesions can be subtyped into groups with different clinical outcomes using two magnetic resonance imaging (MRI) sequences

Introduction

Bone marrow lesions (BMLs) are features detected on MRI that are important in the pathogenesis of knee osteoarthritis. Since BMLs reflect heterogeneous pathologies this prospective cohort study examined whether BMLs detected using different MRI sequences are associated with distinct structural and clinical endpoints.

Methods

A total of 297 community-based adults without knee pain were examined to identify BMLs visualised using three-dimensional T1-weighted gradient-echo fat-suppressed (T1-weighted sequences) fat-suppressed and fat-saturated FSE T2-weighted MRI sequences (T2-weighted sequences) at baseline. Cartilage volume was measured at baseline and follow-up, while incident knee pain was assessed at follow-up, an average of 2.3 years later.

Results

At baseline, 46 BMLs were visualised in 39 participants. Of the 45 BMLs visualised on T2-weighted sequences, 34 (74 %) were also seen on T1-weighted sequences. One BML was seen on only T1-weighted sequences. Knees with BMLs visualised on both T1- and T2-weighted sequences had significantly higher medial tibial cartilage volume loss (45 mm³/annum, standard error of the mean (SEM) 14) than those with BMLs identified on only T2-weighted sequences (−13 mm³/annum SEM 19), after adjustment for age, gender and body mass index (p = 0.01). Incident knee pain was more likely in individuals with BMLs in the medial compartment visualised on both T1- and T2-weighted (eight participants, 53 %) compared to those with BMLs on only T2-weighted sequences (0 %) or no BMLs (76 participants, 31 %, p = 0.02).

Conclusions

BMLs present on both T1- and T2-weighted MRI sequences were associated with increased medial tibial cartilage loss and incident knee pain compared with those BMLs seen only on T2-weighted sequences. This suggests that combining different MRI sequences may provide more informative targets in the prevention and treatment of knee osteoarthritis.

Association of patellar bone marrow lesions with knee pain, patellar cartilage defect and patellar cartilage volume loss in older adults: a cohort study

AIM

To examine the cross-sectional and longitudinal associations of patellar bone marrow lesion (BMLs) with knee pain, cartilage defects and cartilage volume in older adults.

METHODS

A total of 904 randomly selected subjects (mean 62.4 years, 49.9% female) were studied. Fat suppressed T1-weighted spoiled gradient recall and T2-weighted fast spin echo magnetic resonance imaging (MRI) sequences were used to assess cartilage volume, cartilage defects and/or BMLs at baseline (n = 904) and 2.6 (range: 1.4-4.8) years' follow-up (n = 414). Knee pain was assessed by self-administered Western Ontario McMaster Osteoarthritis Index (WOMAC) questionnaire at baseline (n = 904) and follow-up (n = 790).

RESULTS

The prevalence of any patellar BMLs was 19% and was higher in those with tibiofemoral BMLs. In multivariable analyses, patellar BMLs were positively associated with any knee pain at baseline and an increase in knee pain when going up/down stairs (odds ratio (OR): 1.67, 95% confidence interval (CI): 1.08, 2.59) but not with other knee pain subscales. Patella BMLs were also associated with patellar cartilage defects both at baseline and change over time (OR: 1.76, 95% CI: 1.00, 3.70) but not tibiofemoral defects. Patellar BMLs were negatively associated with baseline and change in patella cartilage volume (β: -2.10%, 95% CI: -3.39%, -0.80%). These associations remained significant after further adjustment for tibiofemoral BMLs.

CONCLUSIONS

Patellar BMLs were consistently associated with increased knee pain especially going up/down stairs, increased patellar cartilage defects, and decreased patellar cartilage volume cross-sectionally and longitudinally, suggesting a predominantly compartment specific role for patellar BMLs.

Subchondral Calcium Phosphate is Ineffective for Bone Marrow Edema Lesions in Adults With Advanced Osteoarthritis

BACKGROUND

Injury to subchondral bone is associated with knee pain and osteoarthritis (OA). A percutaneous calcium phosphate injection is a novel approach in which subchondral bone marrow edema lesions are percutaneously injected with calcium phosphate. In theory, calcium phosphate provides structural support while it is gradually replaced by bone. However, little clinical evidence supports the efficacy of percutaneous calcium phosphate injections.

QUESTIONS/PURPOSES

We asked: (1) Does percutaneous calcium phosphate injection improve validated patient-reported outcome measures? (2) What proportion of patients experience failure of treatment (defined as a low score on the Tegner Lysholm Knee Scoring Scale)? (3) Is there a relationship between outcome and age, sex, BMI, and preoperative grade of OA?

METHODS

Between September 2012 and January 2014, we treated 33 patients with percutaneous calcium phosphate injections. Twenty-five satisfied our study inclusion criteria; of those, three patients were lost to followup and 22 (88%; 13 men, nine women) with a median age of 53.5 years (range, 38-70 years) were available for retrospective chart review and telephone evaluation at a minimum of 6 months (median, 12 months; range, 6-24 months). Our general indications for this procedure were the presence of subchondral bone marrow edema lesions observed on MR images involving weightbearing regions of the knee associated with localized pain on weightbearing and palpation and failure to respond to conservative therapy (> 3 months). Patients with pain secondary to extensive nondegenerative meniscal tears with a flipped displaced component at the level of bone marrow edema lesions, or with mechanical axis deviation greater than 8° were excluded. All patients had Grades III or IV chondral lesions (modified Outerbridge grading system for chondromalacia) overlying MRI-identified subchondral bone marrow edema lesions. Percutaneous calcium phosphate injection was performed on the medial tibial condyle (15 patients), the medial femoral condyle (five patients), and the lateral femoral condyle (two patients). Concomitant partial meniscectomy was performed in 18 patients. Preoperative and postoperative scores from the Knee Injury and Arthritis Outcome Score (KOOS) and the Tegner Lysholm Knee Scoring Scale were analyzed.

RESULTS

For patients available for followup, the outcome scores improved after treatment. The KOOS improved from a mean of 39.5 ± 21.8 to 71.3 ± 23 (95% CI, 18.6-45.2; p < 0.001) and the Tegner and Lysholm score from 48 ± 15.1 to 77.5 ± 20.6 (95% CI, 18.8-40.2; p < 0.001). However, seven of the 22 patients had poor clinical outcomes as assessed by the Tegner Lysholm Knee Scoring Scale, whereas three had fair results, five had good results, and seven had excellent results. The postoperative Tegner Lysholm score was inversely related to the preoperative Kellgren-Lawrence OA grade (R(2) = 0.292; F (1.20) = 9.645; p = 0.006). We found no relationship between outcome scores and age, sex, or BMI.

CONCLUSIONS

In a study that would have been expected to present a best-case analysis (short-term followup, loss to followup of patients with potentially unsatisfactory results, and use of invasive cotreatments including arthroscopic débridements), we found that percutaneous calcium phosphate injection in patients with symptomatic bone marrow edema lesions of the knee and advanced OA yielded poor results in a concerning proportion of our patients. Based on these results, we advise against the use of percutaneous calcium phosphate injections for patients with advanced osteoarthritic changes.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Effect of accelerated weightbearing after matrix-associated autologous chondrocyte implantation on the femoral condyle: a prospective, randomized controlled study presenting MRI-based and clinical outcomes after 5 years

BACKGROUND

Long-term effects of different weightbearing (WB) modalities after matrix-associated autologous chondrocyte implantation (MACI) on changes in knee articular cartilage and clinical outcomes are needed to establish more evidence-based recommendations for postoperative rehabilitation.

HYPOTHESIS

There will be no differences between accelerated WB compared with delayed WB regarding knee articular cartilage or patient self-reported knee function or activity level 5 years after MACI. Furthermore, significant correlations between magnetic resonance imaging (MRI)-based outcomes and patient-reported outcome measures 5 years postoperatively will exist.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

After MACI, 31 patients (23 male, 8 female) were randomly assigned to the accelerated WB group (AWB group) or to the delayed WB group (DWB group). With the exception of time and increase to full WB, both groups underwent the same rehabilitation program. The AWB group was allowed full WB after 6 weeks and the DWB group after 10 weeks. Assessments were performed 3 months, 2 years, and 5 years postoperatively, but this long-term follow-up study only included changes from 2 to 5 years postoperatively. The magnetic resonance observation of cartilage repair tissue (MOCART) score (primary outcome), the MRI-based variables of bone edema and effusion, the Knee Injury and Osteoarthritis Outcome Score (KOOS), and the Tegner scale were included. In addition, the association between MRI-based outcomes and the KOOS at 5 years postoperatively was investigated.

RESULTS

There was a significant decrease in the MOCART score and a significant increase in bone edema 2 and 5 years postoperatively but no significant group differences. The only significant correlation between the MRI-based variables and the KOOS was found for bone edema and the KOOS subscale of pain (r=-0.435, P<.05) at 5-year follow-up.

CONCLUSION

There were no significant differences in the MRI-based or clinical outcomes between the AWB group and DWB group 5 years after MACI. While the clinical outcomes remained stable, a decline of the MRI-based findings was observed between 2 and 5 years postoperatively. Furthermore, a significant association between bone edema and pain was found. No occurrence of unintended effects was observed.

Association between urinary C-telopeptide fragments of type II collagen and knee structure in middle-aged women without clinical knee disease

OBJECTIVE

There is evidence for an association between levels of urinary C-telopeptide fragments of type II collagen (uCTX-II) and risk of knee osteoarthritis (OA). The aim of this cohort study was to examine the association between uCTX-II levels and knee cartilage and bone changes in middle-aged women without clinical knee disease.

DESIGN

140 women, aged 40-67 years, with no significant knee pain, knee injury or any forms of arthritis, underwent knee magnetic resonance imaging (MRI) at baseline and 2 years later. Cartilage volume, cartilage defects, tibial plateau bone area and bone marrow lesions (BMLs) were measured using validated methods. Baseline uCTX-II was measured using enzyme-linked immunosorbent assay (ELISA).

RESULTS

For every one unit (natural logarithm transformed) increase in baseline uCTX-II level, there was an increase in the prevalence of medial tibiofemoral cartilage defects (Odds ratio (OR) 4.36, 95% confidence interval (CI) 1.58-12.04), medial (80.2 mm(2), 95% CI 9.3-151.1) and lateral (86.0 mm(2), 95% CI 33.3-138.7) tibial plateau bone area, and the prevalence of lateral tibiofemoral BMLs (OR 10.62, 95% CI 1.82-61.85). Baseline uCTX-II levels were not significantly associated with baseline tibial cartilage volume or changes in knee cartilage volume or defects or bone area over 2 years, although there was a trend for the deterioration of medial tibiofemoral BMLs (P = 0.06).

CONCLUSION

In middle-aged women without clinical knee disease, higher uCTX-II levels were associated with early detrimental structural changes at the knee (cartilage defects, tibial bone expansion and BMLs) at baseline but not over 2 years. Further work will be needed to determine its sensitivity to change and whether it predicts disease progression over longer time periods.

Questionnaire to identify knee symptoms: development of a tool to identify early experiences consistent with knee osteoarthritis

BACKGROUND

Current diagnostic procedures for knee osteoarthritis (OA) identify individuals late in the disease process. A questionnaire may be a useful and inexpensive method to screen for early symptoms of knee OA.

OBJECTIVE

The purpose of this study was to develop a brief, self-administered questionnaire for clinical and research settings to identify emerging knee problems in people who could benefit from conservative interventions.

DESIGN

This prospective study utilized a mixed-methods approach.

METHODS AND RESULTS

Questionnaire items were generated from interview data from individuals with emerging chronic knee problems. These items were reviewed by 16 rheumatology experts, resulting in a 35-item draft questionnaire. To reduce the number of items, questionnaires were mailed to 228 adults, aged 40 to 65 years, with evidence of ongoing knee problems. One hundred thirteen completed questionnaires were returned (63.1% response rate), with 105 usable questionnaires. Using principal components analysis, the number of items was reduced to a final 13-item version, the Questionnaire to Identify Knee Symptoms (QuIKS). The QuIKS has 4 subscales: medications, monitoring, interpreting, and modifying. The QuIKS demonstrated strong internal consistency.

LIMITATIONS

A sampling bias among respondents who provided data for item reduction likely means that the QuIKS reflects those who self-report knee problems to a health care provider, which may not be generalizable to the population.

CONCLUSIONS

The QuIKS is a short, self-administered questionnaire used to promote activity by identifying the experiences associated with early symptoms consistent with knee OA, such as monitoring intermittent symptoms, interpreting the meaning of these symptoms, modifying behaviors, and including the use of medications. If future work validates the QuIKS, its use in developing samples could expand our understanding of early disease and improve interventions.

Association between bone marrow lesions detected by magnetic resonance imaging and knee pain in community residents in Korea

OBJECTIVE

To describe the frequency of bone marrow lesions (BMLs) detected by magnetic resonance imaging (MRI), and to examine the association of BMLs with knee pain severity in community residents in Korea.

METHODS

Participants were randomly chosen from the population-based Hallym Aging Study, irrespective of whether they had knee osteoarthritis (OA) or pain. Demographic and knee pain data were obtained by questionnaire. Radiographic evaluations consisted of weight-bearing knee anteroposterior radiographs and 1.5-T MRI scans. MRI was performed in the dominant knees of subjects without knee pain and in the more symptomatic knees of subjects with knee pain. BMLs were graded according to the whole-organ MRI score.

RESULTS

The mean age of the 358 study subjects was 71.8 years, and 34.5% of subjects had radiographically detected knee OA. The prevalences of BMLs and large BMLs in the tibiofemoral compartments were 80.3% and 40.4%, respectively. After adjusting for age, sex, and body mass index, total and medial compartment BML scores were significantly associated with the presence of knee pain, and the association was stronger as the summary score for BML increased. In proportional regression analysis, knee pain severity increased with BML severity in any compartment and in the medial compartment.

CONCLUSION

BMLs detected by MRI were highly prevalent in this elderly Asian population. BMLs were significantly linked to knee pain, and BML severity correlated with knee pain severity. BMLs may be important surrogate targets for monitoring pain and structure modification in OA therapeutics.

What is the predictive value of MRI for the occurrence of knee replacement surgery in knee osteoarthritis?

Knee osteoarthritis is associated with structural changes in the joint. Despite its many drawbacks, radiography is the current standard for evaluating joint structure in trials of potential disease-modifying osteoarthritis drugs. MRI is a non-invasive alternative that provides comprehensive imaging of the whole joint. Frequently used MRI measurements in knee osteoarthritis are cartilage volume and thickness; others include synovitis, synovial fluid effusions, bone marrow lesions (BML) and meniscal damage. Joint replacement is considered a clinically relevant outcome in knee osteoarthritis; however, its utility in clinical trials is limited. An alternative is virtual knee replacement on the basis of symptoms and structural damage. MRI may prove to be a good alternative to radiography in definitions of knee replacement. One of the MRI parameters that predicts knee replacement is medial compartment cartilage volume/thickness, which correlates with radiographic joint space width, is sensitive to change, and predicts outcomes in a continuous manner. Other MRI parameters include BML and meniscal lesions. MRI appears to be a viable alternative to radiography for the evaluation of structural changes in knee osteoarthritis and prediction of joint replacement.

Computational investigation of in situ chondrocyte deformation and actin cytoskeleton remodelling under physiological loading

Previous experimental studies have determined local strain fields for both healthy and degenerate cartilage tissue during mechanical loading. However, the biomechanical response of chondrocytes in situ, in particular the response of the actin cytoskeleton to physiological loading conditions, is poorly understood. In the current study a three-dimensional (3-D) representative volume element (RVE) for cartilage tissue is created, comprising a chondrocyte surrounded by a pericellular matrix and embedded in an extracellular matrix. A 3-D active modelling framework incorporating actin cytoskeleton remodelling and contractility is implemented to predict the biomechanical behaviour of chondrocytes. Physiological and abnormal strain fields, based on the experimental study of Wong and Sah (J. Orthop. Res. 2010; 28: 1554-1561), are applied to the RVE. Simulations demonstrate that the presence of a focal defect significantly affects cellular deformation, increases the stress experienced by the nucleus, and alters the distribution of the actin cytoskeleton. It is demonstrated that during dynamic loading cyclic tension reduction in the cytoplasm causes continuous dissociation of the actin cytoskeleton. In contrast, during static loading significant changes in cytoplasm tension are not predicted and hence the rate of dissociation of the actin cytoskeleton is reduced. It is demonstrated that chondrocyte behaviour is affected by the stiffness of the pericellular matrix, and also by the anisotropy of the extracellular matrix. The findings of the current study are of particular importance in understanding the biomechanics underlying experimental observations such as actin cytoskeleton dissociation during the dynamic loading of chondrocytes.

Effect of long-term vigorous physical activity on healthy adult knee cartilage

INTRODUCTION

Whether participation in long-term vigorous physical activity affects knee cartilage is unclear and may depend on the state of knee health. We examined the association between vigorous physical activity during a decade and the subsequent changes in knee cartilage among healthy adults. We then examined whether this effect differed in those with and without bone marrow lesions (BMLs), as an indicator of preclinical joint damage.

METHODS

A total of 297 healthy adults age 50-79 yr were recruited. Physical activity was assessed via questionnaire at baseline (1990-1994) and at follow-up (2003-2004), and a score for persistence of vigorous physical activity score was determined. Each subject underwent knee magnetic resonance imaging in 2003-2004 and in 2006-2007. Cartilage volume, defects, and BMLs were measured using validated methods.

RESULTS

Persistent participation in vigorous physical activity was associated with worsening of medial knee cartilage defects (odds ratio (OR) = 1.5, 95% confidence interval (CI) = 1.0-2.3). In the subgroup with BMLs, but not in those without BML, persistent vigorous physical activity was associated with a significant worsening of medial knee cartilage defects (OR = 3.4, 95% CI = 1.0-16.5) and a trend toward an increased rate of loss of medial knee cartilage volume (21.6 mm·yr, 95% CI = -0.4 to 43.6).

CONCLUSIONS

In knees with BMLs, persistent participation in vigorous physical activity was associated with adverse cartilage changes in the medial compartment. This suggests that the long-term effects of vigorous physical activity may depend on the preexisting health of the joint.

Clinical significance of bone changes in osteoarthritis

Osteoarthritis (OA), the most common form of arthritis, is now understood to involve all joint tissues, with active anabolic and catabolic processes. Knee OA in particular is considered to be a largely mechanically-driven disease. As bone adapts to loads by remodeling to meet its mechanical demands, bone alterations likely play an important role in OA development. Subchondral bone changes in bone turnover, mineralization, and volume result in altered apparent and material density of bone that may adversely affect the joint's biomechanical environment. Subchondral bone alterations such as bone marrow lesions (BMLs) and subchondral bone attrition (SBA) both tend to occur more frequently in the more loaded knee compartments, and are associated with cartilage loss in the same region. Recently, MRI-based 3D bone shape has been shown to track concurrently with and predict OA onset.The contributions of structural abnormalities to the clinical manifestations of knee OA are becoming better understood as well. While a structure-symptom discordance in knee OA is thought to exist, such observations do not take into account all potential factors that can contribute to between-person differences in the pain experience. Using novel methodology, pain fluctuation has been associated with changes in BMLs, synovitis and effusion. SBA has also been associated with knee pain, but the relationship of osteophytes to pain has been conflicting.Understanding the pathophysiologic sequences and consequences of OA pathology will guide rational therapeutic targeting. Importantly, rational treatment targets require understanding what structures contribute to pain as pain is the reason patients seek medical care.