Knee Cartilage Repair Research Articles

Author Reply to Editorial Comment “Autologous Minced Repair of Knee Cartilage Is Safely and Effectively Performed Using Arthroscopic Techniques“

Author Reply to Editorial Comment “Autologous Minced Repair of Knee Cartilage Is Safely and Effectively Performed Using Arthroscopic Techniques“

Trends in knee cartilage repair procedures in the United States, 2010 to 2020

IntroductionSurgical intervention of knee articular cartilage injuries may prevent degeneration in symptomatic patients. ObjectiveThis study aims to analyze trends, demographics, and yearly incidence of four different knee cartilage repair procedures in the U.S. from 2010 to 2020. MethodsThe PearlDiver database was queried for patients who underwent knee microfracture, autologous chondrocyte implantation (ACI), osteochondral autograft transfer (OAT) and osteochondral allograft transplantation (OCA) procedures from 2010 to 2020. Student t and χ-square tests were used for statistical comparisons and analysis of data trends. Regression models and Compound Annual Growth Rates (CAGR) further assessed trends of each procedure. Results220,674 patients from 2010 to 2020 were included in this study. Microfracture incurred a 62.4% decrease in occurrence (P < 0.001). Incidence of OCA trended upwards (37.7%; P = 0.065) whilst OAT procedures significantly decline (53.9%; P < 0.001). ACI procedure numbers remained relatively stable (11.2% increase; P = 0.847). ConclusionsThe incidence of microfracture significantly decreased in the United States from 2010 to 2020. There was a positive trend in the incidence of OCA cases, whilst the number of OAT cases decreased significantly. The number of ACI cases performed per year did not change significantly over the study period with the exception of an increase from 2017-2019. Microfracture procedures were performed in an older patient population than the other cartilage procedures. Males were more likely to undergo the four cartilage preservation surgeries compared to females. Similar studies should be carried out in other large health databases to confirm the external validity of these trends across the United States.

Microfractures, autologous matrix-induced chondrogenesis, osteochondral autograft transplantation and autologous chondrocyte implantation for knee chondral defects: a systematic review and network meta-analysis of randomized controlled trials.

Despite the publication of several randomized controlled trials (RCTs), it is not clear which technique for the treatment of focal chondral and osteochondral defects of the knee grants the best clinical outcome. The aim of this network meta-analysis (NMA) was to compare the efficacy and safety of microfractures (MF), autologous chondrocyte implantation (ACI), autologous matrix-induced chondrogenesis (AMIC), osteochondral autograft transplantation (OCT) at short (< 1 year), intermediate (1-5 years) and long-term (> 5 years). We carried out an NMA with Bayesian random-effect model, according to PRISMA guidelines. The search was performed in MEDLINE, EMBASE, Web of Science, CENTRAL, CINAHL, SPORTDiscus, clinicaltrials.gov, WHO ICTRP, from inception to November 2022. The eligibilities were randomized controlled trials on patients with knee chondral and osteochondral defects, undergoing microfractures, OCT, AMIC, ACI, without restrictions for prior or concomitant surgery on ligaments, menisci or limb alignment, prior surgery for fixation or ablation of osteochondritis dissecans fragments, and prior cartilage procedures as microfractures, drilling, abrasion, or debridement. Nineteen RCTs were included. No difference among treatments was shown in the pooled comparison of patient reported outcome measures (PROMs) at any timepoint. Safety data were not available for all trials due to the heterogeneity of reporting, but chondrospheres seemed to have lower failure and reoperation rates. This NMA showed no difference for PROMs with any technique. The lower failure and reoperation rates with chondrospheres must be interpreted with caution since adverse event data was heterogenous among trials. The standardization of the efficacy and safety outcome measures for future trials on knee cartilage repair and regeneration is necessary.

Tissue engineering and future directions in regenerative medicine for knee cartilage repair: a comprehensive review

Tissue engineering and future directions in regenerative medicine for knee cartilage repair: a comprehensive review

New horizons in cartilage repair: update on treatment trends and outcomes

IntroductionArticular cartilage plays a crucial role in preserving the knee joint's structural integrity. Damage can manifest as focal chondral defects or progressive osteoarthritis. Treatment options for knee cartilage damage are multifaceted, encompassing surgical and nonsurgical interventions to repair defects, alleviate symptoms, restore function, and slow disease progression. ObjectivesGain insight and summarize the latest available evidence of knee joint preservation techniques. MethodsThe indications, outcomes, and biological characteristics of operative and nonoperative knee cartilage repair and joint preservation therapies were summarized. ResultsOsteochondral autologous transplantation and osteochondral allograft transplantation offer durable solutions with excellent long-term outcomes. Autologous chondrocyte implantation and matrix-induced autologous chondrocyte implantation are advanced, cell-based therapies effective for larger defects, especially in younger, active individuals. Non-operative therapies such as hyaluronic acid provide symptomatic relief for knee osteoarthritis. Bone marrow aspirate concentrate and platelet-rich plasma show efficacy in alleviating symptoms and improving joint function, presenting a minimally invasive approach with promising results for knee preservation and cartilage repair. ConclusionThe use of minimally invasive and nonsurgical interventions in addressing focal cartilage defects, osteoarthritis, and overall joint preservation has yielded varied results. Although recent literature has exhibited encouraging findings, the existing body of high-level evidence remains limited. The emerging evidence inspires optimism for the future, as medical practitioners shift focus to the next wave of knee cartilage repair and joint preservation methodologies. However, comprehensive research is essential to establish conclusive insights into outcomes, safety profiles, and comparative effectiveness among the diverse available treatments.

Advancing knee cartilage repair with 3D printed GelMA/SF/Haps composite hydrogels for enhanced chondrocyte regeneration

Advancing knee cartilage repair with 3D printed GelMA/SF/Haps composite hydrogels for enhanced chondrocyte regeneration

A New Zn(II) Compound: Luminescent Property and Promoting Knee Cartilage Repair by Modulating Iron Death.

The hydrothermal reactions of bis{6-{5-methyl-1H,7H-[1,2,4]triazolo[1,5-a]pyrimidin-7-one}}methane (L) and Zn(NO3)2·6H2O at 180 ℃ afforded a novel Zn(II) coordination polymer (CP), that is, {[Zn2(L)(µ2-O)2]·3H2O}n (1), which further characterized via Single crystal X-ray diffraction (SCXRD), elemental analysis (EA), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA). Besides, this CP reveals strong luminescence that may be caused by the charge transfer within the ligand. In biological study, the new compound was evaluated for its protective effect on chondrocytes. This compound significantly up-regulated GPX4 and down-regulated HO-1 mRNA levels, thereby inhibiting iron death in chondrocytes.

Proof-of-concept of a robotic-driven photogrammetric scanner for intra-operative knee cartilage repair.

This work presents a proof-of-concept of a robotic-driven intra-operative scanner designed for knee cartilage lesion repair, part of a system for direct in vivo bioprinting. The proposed system is based on a photogrammetric pipeline, which reconstructs the cartilage and lesion surfaces from sets of photographs acquired by a robotic-handled endoscope, and produces 3D grafts for further printing path planning. A validation on a synthetic phantom is presented, showing that, despite the cartilage smooth and featureless surface, the current prototype can accurately reconstruct osteochondral lesions and their surroundings with mean error values of 0.199 ± 0.096mm but with noticeable concentration on areas with poor lighting or low photographic coverage. The system can also accurately generate grafts for bioprinting, although with a slight tendency to underestimate the actual lesion sizes, producing grafts with coverage errors of -12.2 ± 3.7, -7.9 ± 4.9, and -15.2 ± 3.4% for the medio-lateral, antero-posterior, and craneo-caudal directions, respectively. Improvements in lighting and acquisition for enhancing reconstruction accuracy are planned as future work, as well as integration into a complete bioprinting pipeline and validation with ex vivo phantoms.

Nature‐Inspired Strategies for the Treatment of Osteoarthritis

AbstractArticular cartilage is devoid of nerves and blood vessels, and its nutrients must be obtained from the joint fluid; therefore, its ability to repair itself is limited. Manufactured materials such as artificial cartilage or synthetic materials are typically used in traditional approaches for knee cartilage repair. However, durability, postimplant rejection, and tissue incompatibility are the problems associated with these materials. In recent decades, tissue engineering and regenerative medicine have focused on the development of functional substitutes, particularly those based on naturally inspired biopolymers. This review focuses on sustainably produced biopolymers based on materials derived from natural sources. Furthermore, these materials have many advantages, including low antigenicity, biocompatibility, and degradability. Of course, there are also many challenges associated with natural materials, such as the lack of clinical studies and long‐term follow‐up data, unstable mechanical properties of the materials, and high demands placed on preparation and molding techniques. In this review, an overview of natural and nature‐inspired polymers that are the subject of research to date, as well as their structural designs and product performances is provided. This review provides scientific guidance for enhancing the development of naturally inspired materials for treating cartilage injuries.

The Evolution of Rehabilitation and Return to Sport Following Cartilage Surgery.

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Cartilage repair strategies in the knee according to Dutch Orthopedic Surgeons: a survey study

BackgroundThis study surveyed Dutch orthopedic surgeons on the management of cartilage defects in the knee and the adherence to the recently updated Dutch knee cartilage repair consensus statement (DCS).MethodsA web-based survey was sent to 192 Dutch knee specialists.ResultsThe response rate was 60%. Microfracture, debridement and osteochondral autografts are performed by the majority, 93%, 70% and 27% of respondents, respectively. Complex techniques are used by < 7%. Microfracture is mainly considered in defects 1–2 cm2 (by > 80%) but also in 2–3 cm2 (by > 40%). Concomitant procedures, e.g., malalignment corrections, are performed by 89%. Twenty-one percent of surgeons treat patients aged 40–60 years. Microfracture, debridement and autologous chondrocyte implantation are not considered to be highly affected by age > 40 years by any of the respondents (0–3%). Moreover, for the middle-aged there is a large spread in treatments considered. In case of loose bodies, the majority (84%) only performs refixation in the presence of attached bone.ConclusionSmall cartilage defects in ideal patients may be well treated by general orthopedic surgeons. The matter becomes complicated in older patients, or in case of larger defects or malalignment. The current study reveals some knowledge gaps for these more complex patients. Referral to tertiary centers might be indicated, as is stated by the DCS, and this centralization should enhance knee joint preservation. Since the data from present study are subjective, registration of all separate cartilage repair cases should fuel objective analysis of clinical practice and adherence to the DCS in the future.

Repair of Rabbit Knee Cartilage by Bipolar Radiofrequency with Different Energy Settings and Recovery Periods.

Arthroscopic bipolar radiofrequency energy (bRFE) is a common method for minimally invasive treatment of cartilage injuries. The benefits of bRFE are still controversial, and its safety has become the focus of attention. This study aimed to reveal the effects of energy setting and recovery period on the efficacy and safety of bRFE. The New Zealand white rabbit knee cartilage injury model was established, and bRFE was used to treat the cartilage with different energy settings, including 20 W and 40 W, and recovery periods of 0 and 1 month. By observing the immediate and late results on damaged cartilage, along with chondrocyte apoptosis, the effects of energy setting and recovery period on the efficacy and safety of bRFE were accessed. The pathological conditions, surface profile and chondrocyte viability in the bRFE treatment group produced greater late effects and were significantly better than those in the model group. Nevertheless, bRFE produced a timely injury that resulted in an increased rate of apoptosis (p < 0.05), which was alleviated in subsequent recovery (p < 0.05). bRFE can effectively trim and improve the cartilage lesion area, and reduce cracks. Although bRFE produced timely chondrocyte damage, this was alleviated on subsequent recovery. Therefore, bRFE with appropriate energy is beneficial to the recovery of cartilage damage, proper attention should be paid to the recovery period.

Progress on knee cartilage repair by knee joint distraction

Knee joint distraction is a new technology for the treatment of knee osteoarthritis in recent years. It could reduce knee pain and improve knee function, which is inseparable from the role of cartilage repair. The mechanism and influencing factors of knee joint distraction in repairing cartilage are the focus of current research. In this paper, the author reviewed literature and found that knee joint distraction could reduce knee joint load and provide a appropriate mechanical environment for cartilage repair, and it is resulting hydrostatic pressure fluctuation in the knee joint not only helps cartilage to absorb nutrients, but also promotes cartilage formation genes and inhibits cartilage matrix degrading enzyme gene expression. In addition, knee joint distraction creates conditions for synovial mesenchymal stem cells to be collected to cartilage injury, and improves ability of synovial mesenchymal stem cells to proliferate and differentiate into a chondrogenic lineage. Knee joint distraction could reduce inflammatory reaction and cartilage injury of knee joint by reducing content of inflammatory factors and inhibiting expression of inflammatory genes. At present, it is known that the factors affect repair of cartilage by knee joint distraction include, increasing weight-bearing activity and height and time of distraction is helpful for cartilage repair, male patients and patients with higher severity of knee osteoarthritis have better cartilage repair effect after knee joint distraction.The better efficacy of cartilage repair on the first year after knee joint distraction predicts a higher long-term survival rate of knee joint distraction with knee preservation. However, the research on the above hot spots is only at the initial stage and further exploration is still needed, in order to better guide clinical application of knee joint distraction.

Injectable Scaffold with Microfracture using the Autologous Matrix-Induced Chondrogenesis (AMIC) Technique: A Prospective Cohort Study.

Autologous matrix-induced chondrogenesis (AMIC) is a one-step surgical cartilage repair procedure involving the insertion of a scaffold into the chondral defect after microfracture. BST-CarGel [Smith and Nephew, Watford, England] is an injectable chitosan-based scaffold which can more easily fill defects with irregular shapes and be used to treat vertical or roof chondral lesions. The study aims to evaluate the clinical outcomes of knee cartilage repair with microfracture surgery and BST-CarGel using the AMIC technique for a minimum of two years. A prospective study of patients undergoing cartilage repair with microfracture surgery and BST-CarGel at our institution from 2016 to 2019 was performed. Clinical outcomes were determined using the Lysholm Knee Scoring System and Knee Injury and Osteoarthritis Outcome Score (KOOS). These questionnaires were administered before the surgery and at a minimum of two years after surgery. A total of 21 patients were identified and recruited into the study. 31 cartilage defects were seen and treated in 21 knees. These included horizontal lesions (e.g., trochlear, lateral tibial plateau), vertical lesions (e.g., medial femoral condyle, lateral femoral condyle) and inverted lesions (e.g., patella). No complications or reoperations were seen in our study population. For the average duration of follow-up of 42.5±8.55 months, there was an average improvement in Lysholm score of 25.8±18.6 and an average improvement in KOOS score of 22.5±15.0. BST-CarGel with microfracture surgery using the AMIC technique is a safe and effective treatment for cartilage defects in the short to medium term.

A Systematic Review of Focal Cartilage Defect Treatments in Middle-Aged Versus Younger Patients.

Background:Focal cartilage defects are often debilitating, possess limited potential for regeneration, are associated with increased risk of osteoarthritis, and are predictive for total knee arthroplasty. Cartilage repair studies typically focus on the outcome in younger patients, but a high proportion of treated patients are 40 to 60 years of age (ie, middle-aged). The reality of current clinical practice is that the ideal patient for cartilage repair is not the typical patient. Specific attention to cartilage repair outcomes in middle-aged patients is warranted.Purpose:To systematically review available literature on knee cartilage repair in middle-aged patients and include studies comparing results across different age groups.Study Design:Systematic review; Level of evidence, 4.Methods:A systematic search was performed in EMBASE, MEDLINE, and the Cochrane Library database. Articles were screened for relevance and appraised for quality.Results:A total of 21 articles (mean Coleman Methodology Score, 64 points) were included. Two out of 3 bone marrow stimulation (BMS) studies, including 1 using the microfracture technique, revealed inferior clinical outcomes in middle-aged patients in comparison with younger patients. Nine cell-based studies were included showing inconsistent comparisons of results across age groups for autologous chondrocyte implantation (ACI). Bone marrow aspirate concentrate showed age-independent results at up to 8 years of follow-up. A negative effect of middle age was reported in 1 study for both ACI and BMS. Four out of 5 studies on bone-based resurfacing therapies (allografting and focal knee resurfacing implants [FKRIs]) showed age-independent results up to 5 years. One study in only middle-aged patients reported better clinical outcomes for FKRIs when compared with biological repairs.Conclusion:Included studies were heterogeneous and had low methodological quality. BMS in middle-aged patients seems to only result in short-term improvements. More research is warranted to elucidate the ameliorating effects of cell-based therapies on the aging joint homeostasis. Bone-based therapies seem to be relatively insensitive to aging and may potentially result in effective joint preservation. Age subanalyses in cohort studies, randomized clinical trials, and international registries should generate more evidence for the large but underrepresented (in terms of cartilage repair) middle-aged population in the literature.

Magnetization‐Switchable Implant System to Target Delivery of Stem Cell‐Loaded Bioactive Polymeric Microcarriers

Various magnetic microcarrier systems capable of transporting cells to target lesions are developed for therapeutic agent-based tissue regeneration. However, the need for bioactive molecules and cells, the potential toxicity of the microcarrier, and the large volume and limited workspace of the magnetic targeting device remain challenging issues associated with microcarrier systems. Here, a multifunctional magnetic implant system is presented for targeted delivery, secure fixation, and induced differentiation of stem cells. This magnetic implant system consists of a biomaterial-based microcarrier containing bioactive molecules, a portable magnet array device, and a biocompatible paramagnetic implant. Among biomedical applications, the magnetic implant system is developed for knee cartilage repair. The various functions of these components are verified through in vitro, phantom, and ex vivo tests. As a result, a single microcarrier can load ≈1.52 ng of transforming growth factor β (TGF-β1) and 3.3 × 103 of stem cells and stimulate chondrogenic differentiation without extra bioactive molecule administration. Additionally, the implant system demonstrates high targeting efficiency (over 90%) of the microcarriers in a knee phantom and ex vivo pig knee joint. The results show that this implant system, which overcomes the limitations of the existing magnetic targeting system, represents an important advancement in the field.

T2-mapping MRI evaluation of patellofemoral cartilage in patients submitted to intra-articular platelet-rich plasma (PRP) injections

This study evaluated the ability of T2 mapping magnetic resonance imaging at 3 T, in addition to morphological sequences, to assess efficacy of platelet-rich plasma (PRP) injections, characterizing qualitatively and quantitatively the grade of knee cartilage repair in patients with patellofemoral chondropathy. We retrospectively studied 34 patients (22 men, 12 women, mean age 41.8 years, including 22 men) with patellofemoral knee chondropathy, who underwent intra-articular PRP injections and completed a clinical and instrumental follow-up. As control group, we evaluated 34 patients who underwent non-operative therapy. All patients were submitted to clinical (using VAS and WOMAC index) and imaging studies with 3 T magnetic resonance with cartilage analysis with T2 mapping sequences for cartilage analysis before and after treatment. In the study group, mean pre-treatment T2 relaxation time values were 44.2 ± 2.5 ms, considering all articular cartilage compartments, with significant reduction at the follow-up (p < 0.001). At the index compartment, mean pre-treatment T2 relaxation times values were 47.8 ± 3.6 ms, with statistically significant reduction at the follow-up (p < 0.001). Evaluation of focal cartilage lesions reported pre-treatment mean T2 value of 70.1 ± 13.0 ms and post-treatment mean value of 59.9 ± 4.6 ms (p < 0.001). From a clinical point of view, the pre-treatment WOMAC and VAS scores were 18.3 ± 4.5 and 7 (IQR:6–7.2), respectively; the post-treatment values were 7.3 ± 3.2 and 2 (IQR: 1.7–3.0), respectively (p < 0.001). In the control group, despite clinical improvement, we didn’t find significant T2 values change during the follow-up period. In conclusion, T2 mapping is a valuable indicator for chondropathy and treatment-related changes over time.

Combination of chondrocytes and chondrons improves extracellular matrix production to promote the repairs of defective knee cartilage in rabbits.

BackgroundChondrons are composed of chondrocytes and the surrounding pericellular matrix (PCM) and function to enhance chondrocyte-mediated cartilage tissue engineering. This study aimed at investigating the potential effect of combined chondrocytes with chondrons on the production of proteoglycan and collagen-II (Col-2) and the repair of defective knee cartilage in rabbits.MethodsChondrocytes and chondrons were isolated from the knee cartilage of rabbits, and cultured alone or co-cultured for varying periods in vitro. Their morphology was characterized by histology. The levels of aggrecan (AGG), Col-2 and glycosaminoglycan (GAG) expression were quantified by qRT-PCR, Alcian blue-based precipitation and ELISA. The effect of combined chondrocytes with chondrons in alginate spheres on the repair of defective knee cartilage was examined in rabbits.ResultsThe isolated chondrocytes and chondrons displayed unique morphology and began to proliferate on day 3 and 6 post culture, respectively, accompanied by completely degenerated PCM on day 6 post culture. Evidently, chondrocytes had stronger proliferation capacity than chondrons. Longitudinal analyses indicated that culture of chondrons, but not chondrocytes, increased AGG mRNA transcripts and GAG levels with time and Col-2 mRNA transcripts only on day 3 post culture. Compared with chondrocytes or chondrons alone, co-culture of chondrocytes and chondrons significantly up-regulated AGG and Col-2 expression and GAG production, particularly at a ratio of 1:1. Implantation with chondrocytes and chondrons at 1:1 significantly promoted the repair of defective knee cartilage in rabbits, accompanied by reduced the Wakiteni scores with time.ConclusionCombined chondrons with chondrocytes promoted the production of extracellular matrix and the repair of defective knee cartilage in rabbits.The translational potential of this articleThis study explores that the combination of chondrons and chondrocytes may be new therapeutic strategy for cartilage tissue engineering and repair of defective cartilage.

Mesenchymal Stem Cell Implantation in Knee Osteoarthritis: Midterm Outcomes and Survival Analysis in 467 Patients.

Background:A cell-based tissue engineering approach that uses mesenchymal stem cells (MSCs) has addressed the issue of articular cartilage repair in knees with osteoarthritis (OA).Purpose:To evaluate the midterm outcomes, analyze the survival rates, and identify the factors affecting the survival rate of MSC implantation to treat knee OA.Study Design:Case series; Level of evidence, 4.Methods:We retrospectively evaluated 467 patients (483 knees) who underwent MSC implantation on a fibrin glue scaffold for knee OA with a minimum 5-year follow-up. Clinical outcomes were determined based on the International Knee Documentation Committee (IKDC) and Tegner activity scale results measured preoperatively and during follow-up. Standard radiographs were evaluated using Kellgren-Lawrence grading. Statistical analyses were performed to determine the survival rate and the effect of different factors on the clinical outcomes.Results:The mean IKDC scores (baseline, 39.2 ± 7.2; 1 year, 66.6 ± 9.6; 3 years, 67.2 ± 9.9; 5 years, 66.1 ± 9.7; 9 years, 62.8 ± 8.5) and Tegner scores (baseline, 2.3 ± 1.0; 1 year, 3.4 ± 0.9; 3 years, 3.5 ± 0.9; 5 years, 3.4 ± 0.9; 9 years, 3.2 ± 0.9) were significantly improved until 3 years postoperatively and gradually decreased from 3- to 9-year follow-up (P < .05 for all, except for Tegner score at 5 years vs 1 year [P = .237]). Gradual deterioration of radiological outcomes according to the Kellgren-Lawrence grade was found during follow-up. Survival rates based on either a decrease in IKDC or an advancement of radiographic OA with Kellgren-Lawrence scores were 99.8%, 94.5%, and 74.5% at 5, 7, and 9 years, respectively. Based on multivariate analyses, older age and the presence of bipolar kissing lesion were associated with significantly worse outcomes (P = .002 and .013, respectively), and a larger number of MSCs was associated with significantly better outcomes (P < .001) after MSC implantation.Conclusion:MSC implantation provided encouraging outcomes with acceptable duration of symptom relief at midterm follow-up in patients with early knee OA. Patient age, presence of bipolar kissing lesion, and number of MSCs were independent factors associated with failure of MSC implantation.

The Clinically Important Difference and Patient Acceptable Symptomatic State for Commonly Used Patient-Reported Outcomes After Knee Cartilage Repair

Background: In patients undergoing cartilage restoration of the knee, limited information is available regarding clinically important difference (CID) and Patient Acceptable Symptomatic State (PASS) estimates for commonly used patient-reported outcome measures (PROMs). Purpose: The objective of this study was to determine the CID and PASS in the population with knee cartilage restoration for the Knee injury and Osteoarthritis Outcome Score (KOOS), the International Knee Documentation Committee Subjective Knee Form (IKDC) score, and the Lysholm score. Study Design: Cohort study (Diagnosis); Level of evidence, 2. Methods: Between 2012 and 2017, patients who underwent a cartilage restoration procedure were prospectively enrolled. Patients completed the KOOS, IKDC, and Lysholm, all of which were scored from 0 to 100, and completed relevant anchor questions at baseline and 1 year postoperatively. Receiver operating characteristic curve analyses were conducted to determine CID and PASS cutoff points. Multivariable regression analyses were performed to determine the effect of age, sex, and baseline score on likelihood of achieving CID and PASS. Results: Of the 113 patients enrolled, 53 (47%) were male, and the mean age was 36 years. The CID values for the PROMs were 10.7 for KOOS Symptoms, 8.3 for KOOS Pain, 8.8 for KOOS Activities of Daily Living (ADL), 30.0 for KOOS Sports and Recreation, 18.8 for KOOS Quality of Life (QOL), 9.2 for IKDC, and 13.0 for Lysholm. The PASS values were 71.5 for KOOS Symptoms, 72.2 for KOOS Pain, 86.8 for KOOS ADL, 43.8 for KOOS Sports and Recreation, 50.0 for KOOS QOL, 62.1 for IKDC, and 70.0 for Lysholm. Patients with higher baseline scores were more likely to achieve PASS for the IKDC (odds ratio, 2.28; P = .03). Baseline score did not have an effect on the likelihood of achieving CID. Younger age was an independent predictor of achieving PASS and CID across all outcomes (P < .05), but sex did not have such an effect. Conclusion: This study determined CID and PASS values for the KOOS, IKDC, and Lysholm scores among patients treated with knee cartilage restoration. Younger age was a positive prognostic variable, and higher baseline scores implied achieving PASS for the IKDC. The information in this study can be used in designing randomized controlled trials, counseling individual patients as to anticipated outcomes, and conducting responder analyses when evaluating new cartilage technology from a regulatory perspective.