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

Comparing selective and general hamstring stretching and strengthening for pain, disability, and quality of life in patients with primary knee osteoarthritis and varus deformity: A randomized clinical trial

BACKGROUND

A combination of hamstring stretching and strengthening exercises may benefit patients with knee osteoarthritis by promoting pain relief and disability improvement.

PURPOSE

The current study aimed to compare the effects of lateral hamstring strengthening and medial hamstring stretching with general hamstring stretching and general hamstring strengthening on pain, disability, and quality of life in patients with primary knee osteoarthritis and varus deformity.

METHODS

Forty patients with knee osteoarthritis were randomly assigned to two groups: a general hamstring strengthening group (14 women, 6 men) and a selective hamstring strengthening group (16 women, 4 men). In the general hamstring strengthening group, participants performed hamstring stretching and strengthening exercises broadly. In contrast, the selective hamstring strengthening group specifically targeted lateral hamstring strengthening and medial hamstring stretching. The treatment program was conducted three times a week for 4 weeks. Pain and disability levels were evaluated before and after treatment using the Knee Injury and Osteoarthritis Outcome Score (KOOS), quality of life was assessed using the Osteoarthritis Knee and Hip Quality of Life (OAKHQOL) questionnaire, and physical activity levels were determined using the Tegner activity scale.

RESULTS

Both groups demonstrated significant improvement in all outcomes except for the quality of life subscale of the KOOS questionnaire (p = .98) in the general hamstring strengthening group. However, the selective hamstring strengthening group exhibited greater improvements in symptoms (p = .02, effect size (d) = 0.92) and pain subscales (p = .01, d = 0.80) according to the KOOS questionnaire. Additionally, the pain subscale (p = .02, d = 0.79) of the OAKHQOL questionnaire exhibited greater improvements in the selective hamstring strengthening group. Tegner activity scale scores significantly improved in both groups.

CONCLUSION

Strengthening the lateral hamstring and stretching the medial hamstring muscles seem to be beneficial for reducing pain in patients with primary knee osteoarthritis and varus deformity. Attention to stabilization in frontal and horizontal planes in the knee joint might be better than simply evaluating the joint in the sagittal plane.

How Do Cartilage Lubrication Mechanisms Fail in Osteoarthritis? A Comprehensive Review

Cartilage degeneration is a characteristic of osteoarthritis (OA), which is often observed in aging populations. This degeneration is due to the breakdown of articular cartilage (AC) mechanical and tribological properties primarily attributed to lubrication failure. Understanding the reasons behind these failures and identifying potential solutions could have significant economic and societal implications, ultimately enhancing quality of life. This review provides an overview of developments in the field of AC, focusing on its mechanical and tribological properties. The emphasis is on the role of lubrication in degraded AC, offering insights into its structure and function relationship. Further, it explores the fundamental connection between AC mechano-tribological properties and the advancement of its degradation and puts forth recommendations for strategies to boost its lubrication efficiency.

Anterior and posterior hip osteoarthritis: prevalence and potential value of CT compared to radiographs

PURPOSE

To determine the added value of computed tomography (CT) to identify severe hip osteoarthritis (OA).

MATERIALS AND METHODS

A retrospective query of all cases of hip or knee arthroplasty planning CTs between January 2018 and March 2022 was performed. Age, sex, and symptoms were collected from the medical record. CTs were evaluated for the degree of osteoarthritis and classified using an adapted Kellgren-Lawrence (KL) grading system in the anterior, posterior, superior, and superomedial hip. Frontal hip or pelvis radiographs within 1 year of the CT were also graded.

RESULTS

There were 265 eligible hips in 178 subjects, age 66 ± 11 (range 31-93) years, with 85/178 (48%) males and 93/178 (52%) females, and 127/265 (48%) right and 138/265 (52%) left hips. The posterior hip joint was the most common location for grade 2/3 OA (20%), followed by superior hip joint (14%). Anterior or posterior grade 2/3 OA occurred concurrently with superior or superomedial grade 2/3 OA in 32/68 (47%) of hips. Grade 2/3 OA was detected on CT more commonly than on XR both in the superior (14 vs 8.6%, P = 0.0016) and superomedial (8.7 vs 4.8%, P = 0.016) hip joint. Of the 71 symptomatic hips, 22 (31%) hips demonstrated either anterior and/or posterior grade 2/3 OA on CT, and 9 (9/22, 41%) of these hips had superior or superomedial grade 0/1 OA.

CONCLUSION

CT may be warranted when the patient has pain suggestive of osteoarthritis not detected on radiographs.

In-Office Needle Arthroscopy With Cartilage Allograft Extracellular Matrix Application for Cartilage Lesions of the Knee

Chondral and osteochondral lesions of the knee are a common cause of pain, mechanical symptoms, and swelling for patients. The benefits of in-office needle arthroscopy (IONA) include the ability to diagnose and treat chondral or osteochondral lesions in the office, quicker patient recovery, reduced cost, and improved patient satisfaction. The purpose of this technical note is to describe the technique for performing in-office needle arthroscopy for chondral or osteochondral contained lesions of the knee, with special consideration of the technique for obtaining adequate local anesthesia, proper indications, adequate visualization, and the advantages of performing these procedures in the office rather than the operating room.

Risk factors for the long-term incidence and progression of knee osteoarthritis in older adults: role of nonsurgical injury

Background

For one of the most chronic medical conditions, osteoarthritis, uncertainties remain on the impact of injury chronology, the role of repeat injury on the incidence/progression of this disease and the need for knee arthroplasty.

Objectives

To explore, in an older adult population, how nonsurgical knee injuries relate to osteoarthritis incidence/progression and the weight of independent risk factors for arthroplasty.

Design

A cohort study design evaluates the long-term impact of injuries on knee osteoarthritis outcomes.

Methods

Knees with no prior injury (n = 6358) and with at least one injury (n = 819) ⩽20 years before study inclusion were from the Osteoarthritis Initiative cohort. Sociodemographic, clinical and structural [X-ray, magnetic resonance imaging (MRI)] data at study inclusion and changes within 96 months were analysed. Statistics included a mixed model for repeated measurements, generalized estimating equations and multivariable Cox regression with covariates.

Results

At inclusion, knees with prior injury demonstrated greater incidence and severity of osteoarthritis (p ⩽ 0.001). At 96 months, there was a greater increase in symptoms [Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain, p = 0.002], joint space width (JSW, p = 0.039) loss, medial cartilage volume loss (CVL, p ⩽ 0.001) and bone marrow lesion size (BML, p ⩽ 0.049). Knees with/without injury at inclusion but with new ones over time had a pronounced increase in symptoms (all WOMAC scores, p ⩽ 0.001), JSW loss, lateral (without) and medial CVL, lateral (without) and medial meniscal extrusion and medial BML (without; all p ⩽ 0.030). Levels of lateral and medial meniscal extrusion (without) and symptoms (with/without; all WOMAC scores, p ⩽ 0.001) were all accentuated with a repeated new injury. Risk factors associated with the highest knee arthroplasty occurrence are new meniscal extrusion and new injury (p ⩽ 0.001).

Conclusion

This study highlights the importance of nonsurgical knee injury in older adults as an independent risk factor for knee osteoarthritis and arthroplasty. These data will be beneficial in clinical practice as they will help identify individuals at greater risk of significant disease progression and worst disease outcomes for a customized therapeutic approach.

Application of 3D Modeling Software to Preoperative MRI for Prediction of Surface Area of Tissue Applied During Osteochondral Allograft Reconstruction of the Knee

Background

Preoperative magnetic resonance imaging (MRI) is used to estimate the quantity of tissue provided for fresh osteochondral allograft (FOCA) in the knee. Use of 3-dimensional (3D) MRI modeling software for this purpose may improve defect assessment, providing a more accurate estimate of osteochondral allograft tissue required and eliminating the possibility of acquiring an inadequate quantity of tissue for transplant surgery.

Purpose

To evaluate the capacity of damage assessment (DA) 3D MRI modeling software to preoperatively estimate the osteochondral allograft surface area used in surgery.

Study Design

Cohort study (diagnosis); Level of evidence, 2.

Methods

Included were 36 patients who had undergone FOCA surgery to the distal femur. Based on the preoperative MRI scans, the DA software estimated the total surface area of the lesion as well as the surface areas of each subarea of injury: full-thickness cartilage injury (International Cartilage Repair Society [ICRS] grade 4), partial-thickness cartilage injury (ICRS grade 2-3), bone marrow edema, bone loss, and bone cyst. The probability of overestimation of graft tissue areas by the DA software was calculated using a Bayes-moderated proportion, and the relationship between the prediction discrepancy (ie, over- or underestimation) and the magnitude of the DA estimate was assessed using nonparametric local-linear regression.

Results

The DA total surface area measurement overestimated the actual area of FOCA tissue transplanted 81.6% (95% CI, 67.2%-91.4%) of the time, corresponding to a median overestimation of 3.14 cm², or 1.78 times the area of FOCA transplanted. The DA software overestimated the area of FOCA transplanted 100% of the time for defect areas measuring >4.52 cm². For defects <4.21 cm², the maximum-magnitude underestimation of tissue area was 1.45 cm² (on a fold scale, 0.63 times the transplanted area); a plausible heuristic is that multiplying small DA-measured areas of injury by a factor of ∼1.5 would yield an overestimation of the tissue area transplanted most of the time.

Conclusion

The DA 3D modeling software overestimated osteochondral defect size >80% of the time in 36 distal femoral FOCA cases. A policy of consistent but limited overestimation of osteochondral defect size may provide a more reliable basis for predicting the minimum safe amount of allograft tissue to acquire for transplantation.

Decision-making factors and their thresholds for total knee arthroplasty in lateral tibiofemoral osteoarthritis patients: a retrospective cohort study

BACKGROUND

There has been no study examining lateral tibiofemoral (TF) osteoarthritis (OA) and objective decision-making factors affecting when patients decide to have total knee arthroplasty (TKA). The purpose of this study was to assess which factors and their thresholds cause patients with lateral TF OA to decide on TKA.

METHODS

We conducted a retrospective cohort study and identified patients who had initially been diagnosed with isolated lateral TF OA from October 2004 to February 2021. We finally included 56 patients; patients who had chosen conservative treatment followed by in-depth interviews for the deliberation stage (n = 32), and the other patients who decided to undergo TKA for the decision-making stage (n = 24). Demographic, clinical, and radiographic characteristics were considered candidate predictive factors. Radiographic variables included the Ahlbäck grade, hip-knee-ankle (HKA) angle, joint line convergence angle (JLCA), and TF subluxation. Univariate and multivariate logistic regression analyses were performed.

RESULTS

Clinically, the pain visual analog scale (VAS) score was significantly higher and the knee flexion angle was lower at the decision-making stage. Radiographic measurements showed that the Ahlbäck grade, HKA angle, JLCA, and TF subluxation measured at the center, in addition to the tibiotalar angle, differed statistically between the two stages. According to univariate analyses, two clinical characteristics and six radiographic variables on the ipsilateral side of the leg, and one radiographic variable on the contralateral side of the leg were included as factors influencing the patients' decision to undergo TKA. After making adjustments based on multivariate analysis, the ipsilateral knee pain VAS (OR = 1.61; 95% CI = 1.14-2.28, p = 0.007) and medial TF subluxation measured at the center (OR = 1.14, 95% CI = 1.01-1.32, p = 0.072) were found to be significant factors for choosing TKA. The area under the curve (AUC) for pain VAS was 0.757 and the cutoff value was 4.5. The AUC for TF subluxation measured at the center was 0.697 and the cutoff value was -4.10% of medial TF subluxation.

CONCLUSION

Higher ipsilateral knee pain VAS and more severe medial TF subluxation measured at the center were independent factors affecting patient decisions to undergo TKA with lateral TF OA. Understanding the determining factors that may affect patient decision-making when considering TKA may be an essential aspect of evaluating the prognosis of patients with lateral TF OA.

LEVEL OF EVIDENCE

III.

Biological Augments for Acetabular Chondral Defects in Hip Arthroscopy-A Scoping Review of the Current Clinical Evidence

PURPOSE OF REVIEW

A wide array of joint-preserving surgical techniques exists in the management of acetabular chondral defects (ACDs). The purpose of this review is to summarize the clinical outcomes of the recent biologics used to treat ACDs during hip arthroscopy.

RECENT FINDINGS

Increasing evidence is available for different biological solutions used in the hip. Studies have shown promising outcomes with minimal complications when using biologics as augmentation to microfracture (MF), including different scaffolds or stem cells, or to enhance autologous chondrocyte implantation (ACI). However, data so far is scarce, and more trials and longer follow-ups are needed to better delineate the appropriate indications and benefits for each technique. Presently, the level of evidence is low, but in general, biologics appear safe and trend toward beneficial compared to standard surgical techniques. Augmented MF is recommended for small to medium ACDs, and matrix-assisted ACI or three-dimensional ACI is recommended for medium to large defects.

Identification of the most important features of knee osteoarthritis structural progressors using machine learning methods

Objectives:

The aim was to identify the most important features of structural knee osteoarthritis (OA) progressors and classification using machine learning methods.

Methods:

Participants, features and outcomes were from the Osteoarthritis Initiative. Features were from baseline (1107), including articular knee tissues (135) assessed by quantitative magnetic resonance imaging (MRI). OA progressors were ascertained by four outcomes: cartilage volume loss in medial plateau at 48 and 96 months (Prop_CV_48M, 96M), Kellgren–Lawrence (KL) grade ⩾ 2 and medial joint space narrowing (JSN) ⩾ 1 at 48 months. Six feature selection models were used to identify the common features in each outcome. Six classification methods were applied to measure the accuracy of the selected features in classifying the subjects into progressors and non-progressors. Classification of the best features was done using an automatic machine learning interface and the area under the curve (AUC). To prioritize the top five features, sparse partial least square (sPLS) method was used.

Results:

For the classification of the best common features in each outcome, Multi-Layer Perceptron (MLP) achieved the highest AUC in Prop_CV_96M, KL and JSN (0.80, 0.88, 0.95), and Gradient Boosting Machine for Prop_CV_48M (0.70). sPLS showed the baseline top five features to predict knee OA progressors are the joint space width, mean cartilage thickness of the medial tibial plateau and sub-regions and JSN.

Conclusion:

In this comprehensive study using a large number of features (n = 1107) and MRI outcomes in addition to radiological outcomes, we identified the best features and classification methods for knee OA structural progressors. Data revealed baseline X-ray and MRI-based features could predict early OA knee progressors and that MLP is the best classification method.

Cartilage survival of the knee strongly depends on malalignment: a survival analysis from the Osteoarthritis Initiative (OAI)

PURPOSE

Progression of osteoarthritis over time is poorly understood. The aim of the current study was to establish a timeline of "cartilage survival rate" per subregion of the knee in relation to mechanical alignment of the lower extremity. The study hypothesized that there are differences in progression of osteoarthritis between varus, valgus and physiologic lower extremity alignment.

METHODS

Based on hip-knee-ankle standing radiographs at baseline, 234 knees had physiologic (180° ± 3°, mean 179.7°), 158 knees had varus (< 177°; mean 174.5°) and 66 knees valgus (> 183°; mean 185.2°) alignment (consecutive knees of the OAI "Index Knee" group, n = 458; mean age 61.7; 264 females). The Osteoarthritis Initiative (OAI; a multi-center, longitudinal, prospective observational study of knee osteoarthritis [30] using MRIs) defines progressive OA as a mean decrease of cartilage thickness of 136 µm/year and a mean decrease of cartilage volume by 5% over 1 year (DESS sequences, MRI). A Kaplan-Meier curve was generated for osteoarthritis progression based on OAI criteria.

RESULTS

Osteoarthritis progression based on volume decrease of 5% in varus knees occurred after 30.8 months (medial femoral condyle), after 37 months (medial tibia), after 42.9 months (lateral femoral condyle) and 43.4 months (lateral tibia), respectively. In a valgus alignment progression was detectable after 31.5 months (lateral tibia), after 36.2 months (lateral femoral condyle), after 40.4 months (medial femoral condyle) and 43.8 months (medial tibia), respectively. The physiological alignment shows a progression after 37.8 months (medial femoral condyle), after 41.6 months (lateral tibia), after 41.7 months (medial tibia) and after 43 months (lateral femoral condyle), respectively.

CONCLUSION

Based on data from the OAI, the rate and location (subregion) of osteoarthritis progression of the knee is strongly associated with lower extremity mechanical alignment.

LEVEL OF EVIDENCE

Level I (prognostic study).