High Rate of Failure After Matrix-Assisted Autologous Chondrocyte Transplantation in Osteoarthritic Knees at 15 Years of Follow-up

Low-density cultured cartilage cells expanded in platelet lysate present distinct features to develop an innovative clinical treatment for diffuse cartilage lesions

PURPOSE

Chondrocyte-based cell therapies are effective for the treatment of chondral lesions, but remain poorly indicated for diffuse lesions in the context of early osteoarthritis (OA). The aim of this study was to develop a protocol to obtain chondroprogenitor cells suitable for the treatment of diffuse chondral lesions within early OA.

METHODS

Cartilage cells were expanded at low density in human platelet lysate (hPL). A test was performed to exclude senescence. The expression of surface cluster of differentiation 146, cluster of differentiation 166, major histocompatibility complex (MHC)-I and MHC-II and of genes of interest were evaluated, as well as the trophic potential of these cells, by the assessment of lubricin and matrix production. The immunomodulatory potential was assessed through their co-culture with macrophages.

RESULTS

Cartilage cells expanded at low density in hPL showed higher proliferation rate than standard-density cells, no replicative senescence, low immunogenicity and expression of lubricin. Moreover, they presented an increased expression of chondrogenic and antihypertrophic markers, as well as a superior matrix deposition if compared to cells cultured at standard density. Cartilage cells induced on macrophages an upregulation of CD206, although a higher increase of CD163 expression was observed in the presence of low-density cells.

CONCLUSIONS

These findings lay the grounds to explore the clinical usefulness of low-density cultured cartilage cells to treat diffuse lesions in early OA joints for both autologous and allogenic use.

LEVEL OF EVIDENCE

Not applicable.

Unicompartmental osteoarthritis: High survival rate with a combined mechanical and biological salvage approach as alternative to metal resurfacing: Results at minimum 10 years of follow-up

PURPOSE

The aim of this study was to prospectively evaluate the long-term clinical results and failure rate of patients treated with complex salvage procedures using a combined mechanical and biological approach to address unicompartmental knee osteoarthritis (OA) and postpone the need for joint replacement.

METHODS

Thirty-nine patients (40.3 ± 10.9 years old) affected by unicompartmental OA (Kellgren-Lawrence 3) in stable joints underwent a personalized surgical treatment depending on the specific requirements of the affected compartment, including high tibial osteotomy, osteochondral scaffold, meniscal scaffold and meniscal allograft transplantation. Patients were evaluated with the International Knee Documentation Committee (IKDC), Visual Analogue Scale (VAS) and Tegner scores before surgery, at 3 years and a minimum of 10 years of follow-up.

RESULTS

A significant improvement was observed over time in all scores but worsened at the final follow-up. The IKDC subjective score improved from 46.9 ± 16.2 to 79.8 ± 16.4 at 3 years (p < 0.0005) and then decreased to 64.5 ± 21.4 (p = 0.001) at 12 years. A similar trend was confirmed for VAS and Tegner scores. Only two patients subsequently underwent knee arthroplasty, and nine more patients were considered clinical failure, for a cumulative surgical and clinical failure rate of 28.2% at the final follow-up.

CONCLUSION

A personalized, joint-preserving, combined mechanical and biological approach, addressing alignment as well as meniscal and cartilage lesions, is safe and effective, providing a clinical benefit and delaying the need for arthroplasty in young patients affected by unicompartmental knee OA. At the final evaluation, the clinical improvement decreased, but more than two-thirds of the patients still benefited from this treatment at a long-term follow-up.

LEVEL OF EVIDENCE

Level IV case series.

Autologous Chondrocyte Implantation Is Not Better Than Arthroscopic Debridement for the Treatment of Symptomatic Cartilage Lesions of the Knee: Two-Year Results From a Randomized-Controlled Trial

Purpose

To compare the functional and patient-reported outcome measures after autologous chondrocyte implantation (ACI) and arthroscopic debridement (AD) in symptomatic, isolated cartilage injuries larger than 2 cm2 in patients aged 18 to 50 years.

Methods

Twenty-eight patients were included and randomized to ACI (n = 15) or AD (n = 13) and followed for 2 years. The primary outcome was the change in the Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life (QoL) subscale.

Results

The mean age at inclusion was 34.1 (standard deviation [SD] 8.5) years. There were 19 (68%) male patients. The mean size of the lesion was 4.2 (SD 1.7) cm2. There was a statistically significant and clinically meaningful improvement in patient-reported outcome measures from baseline to 2 years in both groups. The improvement from baseline to final follow-up for the primary endpoint (the KOOS QoL subscale) was larger for the AD group (39.8, SD 9.4) compared with the ACI group (23.8, SD 6.7), but this difference was not statistically significant (P = .17). However, according to a mixed linear model there were statistically significantly greater scores in the AD group for several KOOS subscales at several time points, including KOOS QoL, KOOS pain, and KOOS sport and recreation at 2 years.

Conclusions

This study indicates that AD followed by supervised physiotherapy is equal to or better than ACI followed by supervised physiotherapy in patients with isolated cartilage lesions of the knee larger than 2 cm2. The improvement in KOOS QoL score from baseline to 2 years was clinically meaningful for both groups (23.8 points for ACI and 39.8 points AD), and larger for the AD group by 16 points.

Level of Evidence

Level I, prospective randomized controlled trial.

Biological intra-articular augmentation for osteotomy in knee osteoarthritis: strategies and results : A systematic review of the literature from the ESSKA Orthobiologics Initiative

PURPOSE

To assess whether there is evidence supporting the use of augmentation strategies, either cartilage surgical procedures or injective orthobiologic options, to improve the results of osteotomies in knees with osteoarthritis (OA).

METHODS

A systematic review of the literature was performed on the PubMed, Web of Science and the Cochrane databases in January 2023 on osteotomies around the knee associated with augmentation strategies (either cartilage surgical procedures or injective orthobiologic options), reporting clinical, radiological, or second-look/histological outcomes at any follow-up. The methodological quality of the included studies was assessed with the Coleman Methodology Score (CMS).

RESULTS

Out of the 7650 records identified from the databases, 42 articles were included for a total of 3580 patients and 3609 knees treated; 33 articles focused on surgical treatments and 9 on injective treatments performed in association with knee osteotomy. Out of the 17 comparative studies with surgical augmentation, only 1 showed a significant clinical benefit of an augmentation procedure with a regenerative approach. Overall, other studies showed no differences with reparative techniques and even detrimental outcomes with microfractures. Regarding injective procedures, viscosupplementation showed no improvement, while the use of platelet-rich plasma or cell-based products derived from both bone marrow and adipose tissue showed overall positive tissue changes which translated into a clinical benefit. The mean modified CMS score was 60.0 ± 12.1.

CONCLUSION

There is no evidence to support the effectiveness of cartilage surgical treatments combined with osteotomies in terms of pain relief and functional recovery of patients affected by OA in misaligned joints. Orthobiologic injective treatments targeting the whole joint environment showed promising findings. However, overall the available literature presents a limited quality with only few heterogeneous studies investigating each treatment option. This ORBIT systematic analysis will help surgeons to choose their therapeutic strategy according to the available evidence, and to plan further and better studies to optimize biologic intra-articular osteotomy augmentation.

LEVEL OF EVIDENCE

Level IV.

Aragonite-Based Scaffold Versus Microfracture and Debridement for the Treatment of Knee Chondral and Osteochondral Lesions: Results of a Multicenter Randomized Controlled Trial

BACKGROUND

Lesions of the articular cartilage, with or without involvement of the subchondral bone, are a common cause of pain and dysfunction in the knee. Although several treatment options have been developed, the majority of previous clinical trials examined patients with isolated or focal midsized defects, which rarely represent the condition found in the general population. Rather, cartilage lesions are often associated with the presence of mild to moderate osteoarthritic changes.

PURPOSE

The present multicenter randomized controlled trial compared the clinical and radiographic outcomes of an aragonite-based osteochondral implant with a control group (arthroscopic debridement/microfractures) in patients affected by joint surface lesions of the knee, including those with concurrent mild to moderate osteoarthritis.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

A total of 251 patients were enrolled in 26 medical centers according to the following criteria: age 21 to 75 years, up to 3 cartilage defects of International Cartilage Regeneration & Joint Preservation Society grade 3a or above located on the femoral condyles and/or trochlea, total treatable area from 1 to 7 cm², bony defect depth ≤8 mm, and knee osteoarthritis grade 0 to 3 according to Kellgren-Lawrence score. Patients were randomized to the aragonite-based implant or debridement/microfracture control arm in a 2:1 ratio. Evaluation was performed at 6, 12, 18, and 24 months based on overall Knee injury and Osteoarthritis Outcome Score (KOOS) as the primary endpoint, and the KOOS subscales (Pain, Quality of Life, Activities of Daily Living), percentage of responders, and International Knee Documentation Committee (IKDC) subjective score as the secondary endpoints. Patients also underwent magnetic resonance imaging evaluation at 12 and 24 months to assess defect fill grade. Failures (ie, need for any secondary treatment) and adverse events were also recorded.

RESULTS

The implant group showed a statistically superior outcome in the primary endpoint and all secondary endpoints at each follow-up. The magnitude of improvement in the implant group was twice as large as that in the control group in terms of mean KOOS improvement at 2 years. Responder rate (defined as at least a 30-point improvement in overall KOOS) was 77.8% in the implant group as opposed to 33.6% in the control (P < .0001). Statistically superior results were seen in the IKDC score as well. At 24 months, 88.5% of the implanted group had at least 75% defect fill on magnetic resonance imaging as compared with 30.9% of controls (P < .0001). The failure rate was 7.2% for the implant group versus 21.4% for control.

CONCLUSION

This aragonite-based scaffold was safe and effective in the treatment of chondral and osteochondral lesions in the knee, including patients with mild to moderate osteoarthritis, and provided superior outcomes as compared with the control group.

REGISTRATION

NCT03299959 (ClinicalTrials.gov identifier).

Immunomodulatory potential of secretome from cartilage cells and mesenchymal stromal cells in an arthritic context: From predictive fiction toward reality

The purpose of the present study is to predict by bioinformatics the activity of the extracellular vesicle (EV)-embedded micro RNA (miRNAs) secreted by cartilage cells (CCs), adipose tissue-derived- (ASCs), and bone marrow-derived stem cells (BMSCs) and verify their immunomodulatory potential supporting our bioinformatics findings to optimize the autologous cell-based therapeutic strategies for osteoarthritis (OA) management. Cells were isolated from surgical waste tissues of three patients who underwent total hip replacement, expanded and the EVs were collected. The expression of EV-embedded miRNA was evaluated with the QuantStudio 12 K Flex OpenArray^® platform. Mientournet and ingenuity pathway analysis (IPA) were used for validated target prediction analysis and to identify miRNAs involved in OA and inflammation. Cells shared the expression of 325 miRNAs embedded in EVs and differed for the expression of a small number of them. Mienturnet revealed no results for miRNAs selectively expressed by ASCs, whereas miRNA expressed by CCs and BMSCs were putatively involved in the modulation of cell cycle, senescence, apoptosis, Wingless and Int-1 (Wnt), transforming growth factor beta (TGFβ), vascular endothelial growth factor (VEGF), Notch, Hippo, tumor necrosis factor alpha (TNFα), interleukin 1 beta (IL-1β), insulin like growth factor 1 (IGF-1), RUNX family transcription factor 2 (RUNX2), and endochondral ossification pathways. Cartilage homeostasis, macrophages and T cells activity and inflammatory mediators were identified by IPA as targets of the miRNAs found in all the cell populations. Co-culture tests on macrophages and T cells confirmed the immuno-modulatory ability of CCs, ASCs, and BMSCs. The study findings support the rationale behind the use of cell-based therapy for the treatment of OA.

Autologous chondrocyte implantation provides good long-term clinical results in the treatment of knee osteoarthritis: a systematic review

PURPOSE

To evaluate the mid- and long-term efficacy of autologous chondrocyte implantation (ACI) and matrix-assisted chondrocyte implantation (MACI) to treat patients with knee cartilage defects in the presence of osteoarthritis (OA).

METHODS

PubMed and Cochrane databases were systematically searched for studies describing the treatment of knee OA with ACI or MACI (Kellgren-Lawrence (KL) ≥ 1, minimum follow-up 36 months). Results were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines and included Lysholm, Western Ontario McMaster University and International Knee Documentation Committee scores.

RESULTS

Of the 127 full-text articles assessed for eligibility, only five studies were selected based on inclusion/exclusion criteria (2 on ACI and 3 on MACI). In both groups, the defects were mainly located at femoral level, size 2.2-15.1 cm² in the ACI and 2.0-7.6 cm² in the MACI group. ACI was mostly used for patients affected by KL I, whereas MACI for patients with KL II-IV. The data obtained from 235 patients (161 ACI, 74 MACI) showed that ACI and MACI sustained stable clinical improvements up to 11 and 15 years, respectively, with a failure rate of about 10% up to 11 years. Scarce biological details regarding chondrocyte implantation were reported.

CONCLUSIONS

ACI and MACI procedures for the treatment of knee cartilage lesions associated to OA showed long-term success and allowed delaying arthroplasty. Additional trials reporting homogenous data and precise patient characterization are needed to conduct an effective literature meta-analysis and identify the clinical relevance of these procedures.

LEVEL OF EVIDENCE

IV.

Scaffolds for Knee Chondral and Osteochondral Defects: Indications for Different Clinical Scenarios. A Consensus Statement

OBJECTIVE

To develop patient-focused consensus guidelines on the indications for the use of scaffolds to address chondral and osteochondral femoral condyle lesions.

DESIGN

The RAND/UCLA Appropriateness Method (RAM) was used to develop patient-specific recommendations by combining the best available scientific evidence with the collective judgement of a panel of experts guided by a core panel and multidisciplinary discussers. A list of specific clinical scenarios was produced regarding adult patients with symptomatic lesions without instability, malalignment, or meniscal deficiency. Each scenario underwent discussion and a 2-round vote on a 9-point Likert-type scale (range 1-3 "inappropriate," 4-6 "uncertain," 7-9 "appropriate"). Scores were pooled to generate expert recommendations.

RESULTS

Scaffold (chondral vs. osteochondral), patient characteristics (age and sport activity level), and lesion characteristics (etiology, size, and the presence of osteoarthritis [OA]) were considered to define 144 scenarios. The use of scaffold-based procedures was considered appropriate in all cases of chondral or osteochondral lesions when joints are not affected by OA, while OA joints presented more controversial results. The analysis of the evaluated factors showed a different weight in influencing treatment appropriateness: the presence of OA influenced 58.3% of the indications, while etiology, size, and age were discriminating factors in 54.2%, 29.2%, and 16.7% of recommendations, respectively.

CONCLUSIONS

The consensus identified indications still requiring investigation, but also the convergence of the experts in several scenarios defined appropriate or inappropriate, which could support decision making in the daily clinical practice, guiding the use of scaffold-based procedures for the treatment of chondral and osteochondral knee defects.

Engineered nasal cartilage for the repair of osteoarthritic knee cartilage defects

[Figure: see text].

Cell-Free Biomimetic Osteochondral Scaffold for the Treatment of Knee Lesions: Clinical and Imaging Results at 10-Year Follow-up

BACKGROUND

Cell-free devices have been introduced to restore osteochondral defects, avoiding the limitations of cell-based procedures. Among these, an osteochondral scaffold made of type I collagen and hydroxyapatite has been investigated with promising results up to medium-term follow-up. However, the clinical and imaging results over time still need to be documented.

PURPOSE

To evaluate the clinical outcome and tissue maturation at long-term follow-up after the implantation of the osteochondral scaffold.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 24 patients (7 women, 17 men; age, 36 ± 9.5 years) underwent surgical implantation of the osteochondral scaffold and were prospectively evaluated before surgery, at 2-, 5-, and 10-year follow-up. The mean defect size was 2.9 ± 1.4 cm². Patients were evaluated using the International Knee Documentation Committee (IKDC) subjective and objective scores, and the activity level was documented with the Tegner score. Magnetic resonance imaging (MRI) evaluation involved the use of the magnetic resonance observation of cartilage repair tissue score combined with 5 more variables focused on the bone layer.

RESULTS

A statistically significant improvement of all clinical scores was documented from the baseline to the final evaluation. The IKDC subjective score improved from the preoperative level to 2 years (41 ± 13.2 and 77.1 ± 14.6, respectively) (P < .0005), with stable results up to 10 years (77.4 ± 19.4). The IKDC objective score changed from 52% of normal and nearly normal knees before the treatment to 84% at 10 years (P < .0005). Tegner sports activity at the final evaluation (3.8 ± 1.7) was higher compared with the preoperative level (1.6 ± 1.1; P < .05), but it remained significantly lower compared with the preinjury level (5.5 ± 2.6; P < .05). Treatment failed in 1 patient. Persisting graft alterations were observed on MRI scans, although without correlating with the clinical outcome.

CONCLUSION

The regenerative potential of this scaffold is limited, as demonstrated by the signal alterations persisting over time on MRI scans. On the other hand, the clinical improvement was significant and stable over time both in terms of subjective and objective outcomes, including activity level, with overall good results.

Bone marrow aspirate concentrate and scaffold for osteochondral lesions of the talus in ankle osteoarthritis: satisfactory clinical outcome at 10 years

PURPOSE

To evaluate at long-term follow-up patients undergoing a one-step procedure of debridement and BMAC seeded in situ onto a scaffold for the treatment of osteochondral lesions of the talus (OLT) in ankles affected by osteoarthritis (OA), documenting the duration of the clinical benefit and its efficacy in postponing end-stage procedures.

METHODS

This series included 56 consecutive patients. Patients were evaluated preoperatively and up to a mean of 10 years of follow-up with the AOFAS score and the AOS scale, including pain and disability subscales. Furthermore, patients were asked to rate the satisfaction and failures were documented as well.

RESULTS

The AOFAS score improved from 52.3 ± 14.3 to 73.5 ± 23.1 at 10 years (p  < 0.0005); the AOS pain and disability subscales decreased from 70.9 ± 14.1 to 37.2 ± 32.7 and from 69.0 ± 14.8 to 34.2 ± 29.3, respectively (both p < 0.0005). The overall rate of satisfaction was 61.8 ± 41.2 and 68.6% of patients would undergo again the surgical procedure. A total of 17 failures was documented, for a failure rate of 33.3%. Older patients and those with more complex cases requiring previous or combined surgeries had lower outcomes, as well as those affected by grade 3 OA, who experienced a high failure rate of 71.4%.

CONCLUSIONS

This one-step technique for the treatment of OLT in OA ankles showed to be safe and to provide a satisfactory outcome, even if patients with end stage OA presented a high revision rate at 10 years. Moreover, this procedure was effective over time, with overall good results maintained up to a long-term follow-up. However, older age, more complex cases requiring previous or combined surgeries, and advanced OA led to an overall worst outcome and a significantly higher failure rate.

Unicompartmental bipolar osteochondral and meniscal allograft transplantation is effective for treatment of medial compartment gonarthrosis in a canine model

Osteochondral allograft (OCA) transplantation can restore large articular defects in the knee. Bipolar OCA transplantations for partial and whole joint resurfacing often have less favorable results than single-surface transplants. This study was designed to use a large animal model to test the hypothesis that unicompartmental bipolar osteochondral and meniscal allograft transplantation (BioJoint) would be as or more effective for treatment of medial compartment osteoarthritis (OA) compared to standard-of-care nonoperative treatment. OA was induced in one knee of each research hound (n = 8) using a meniscal release model and pretreatment assessments were performed. After 3 months, dogs were randomly assigned to either the control group (n = 4, no surgical intervention, daily nonsteroidal antiinflammatory drugs [NSAIDs]) or the BioJoint group (n = 4). Clinical, radiographic, and arthroscopic assessments were performed longitudinally and histopathology was evaluated at the 6-month endpoint. At study endpoint, functional, pain, and total pressure index measures, as well as radiographic and arthroscopic grading of graft appearance and joint health, demonstrated superior outcomes for BioJoints compared to NSAID controls. Furthermore, histologic assessments showed that osteochondral and meniscal transplants maintain integrity and integrated into host tissues. Clinical significance: The results support the safety and efficacy of unicompartmental bipolar osteochondral and meniscal allograft transplantation in a preclinical model with highly functional outcomes without early OA progression.

[Cartilage repair procedures for early osteoarthritis]

BACKGROUND

Commonly used cartilage repair procedures have been established for focal cartilage lesions; however, degenerative lesions with accompanying changes of other intraarticular structures are much more common in clinical practice. This stage, in which classic radiological signs of osteoarthritis are absent, is called early osteoarthritis and is characterized by impaired joint homeostasis with biomechanical and biochemical changes that can have a negative effect on regenerative cartilage therapy procedures.

INDICATION

Cartilage repair procedures are indicated for symptomatic focal early osteoarthritis, defined as cartilage degeneration ICRS grades I or II around a focal cartilage defect ICRS grades III or IV. In more advanced osteoarthritis with significant narrowing of the joint space, cartilage repair procedures are generally contraindicated.

THERAPY

The most studied cartilage repair procedure for early osteoarthritis is autologous chondrocyte implantation, which has shown acceptable results in case series, although higher failure rates are to be expected compared to focal, traumatic cartilage lesions. The use of bone marrow-stimulating techniques seems to be limited in early osteoarthritis and should only be used in cases of lesion < 2 cm² and very little surrounding cartilage degeneration. Concomitant surgical procedures, especially unloading osteotomies, are very important.

Aragonite-Based Scaffold for the Treatment of Joint Surface Lesions in Mild to Moderate Osteoarthritic Knees: Results of a 2-Year Multicenter Prospective Study

BACKGROUND

Osteoarthritis (OA) is considered a contraindication to most cartilage repair techniques. Several regenerative approaches have been attempted with the aim of delaying or preventing joint replacement, with controversial results. Currently, there is a paucity of data on the use of single-step techniques, such as cell-free biomimetic scaffolds, for the treatment of joint surface lesions (JSLs) in OA knees.

PURPOSE

To present the 2-year follow-up clinical and radiological outcomes after implantation of a novel, cell-free aragonite-based scaffold for the treatment of JSLs in patients with mild to moderate knee OA in a multicenter prospective study.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 86 patients, 60 male and 26 female, with a mean age of 37.4 ± 10.0 years, mild to moderate knee OA, and a mean defect size of 3.0 ± 1.7 cm², were recruited at 8 medical centers according to the following criteria: radiographic mild to moderate knee OA (Kellgren-Lawrence grade 2 or 3); up to 3 treatable chondral/osteochondral defects (International Cartilage Repair Society grades 3 and 4) on the femoral condyles or trochlea; a total defect size ≤7 cm²; and no concurrent knee instability, severe axial malalignment, or systemic arthropathy. All patients were evaluated at baseline and at 6, 12, 18, and 24 months after implantation using the Knee injury and Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) subjective score. Additionally, magnetic resonance imaging (MRI) was performed to assess the amount of cartilage defect filling at the repaired site.

RESULTS

Significant improvement on all KOOS subscales was recorded from baseline (Pain: 49.6 ± 13.1; Activities of Daily Living [ADL]: 56.1 ± 18.4; Sport: 22.8 ± 18.8; Quality of Life [QoL]: 23.5 ± 16.5; Symptoms: 55.4 ± 19.9) to the 24 months' follow-up (Pain: 79.5 ± 21.1 [P < .001]; ADL: 84.1 ± 21.4 [P < .001]; Sport: 60.8 ± 31.9 [P < .001]; QoL: 54.9 ± 30.4 [P < .001]; Symptoms: 77.7 ± 21.2 [P < .001]). The IKDC subjective score showed a similar trend and improved from 37.8 ± 14.7 at baseline to 65.8 ± 23.5 at 24 months (P < .001). MRI showed a significant increase in defect filling over time: up to 78.7% ± 25.3% of surface coverage after 24 months. Treatment failure requiring revision surgery occurred in 8 patients (9.3%).

CONCLUSION

The use of an aragonite-based osteochondral scaffold in patients with JSLs and mild to moderate knee OA provided significant clinical improvement at the 24-month follow-up, as reported by the patients. These findings were associated with good cartilage defect filling, as observed on MRI.

[Guidelines for the treatment of unicompartmental cartilage defects of the knee-Cartilage repair, osteotomy, mini-implant or arthroplasty?]

The treatment of unicompartmental cartilage defects offers a large variety of therapeutic options. With help of an algorithm, decision-making for the most suitable treatment approach is supported. Correction of malalignment is key for successful treatment. Defect size, influencing factors such as "age" and prior treatments play an important role in choosing the most appropriate operative treatment option.

Third-Generation Autologous Chondrocyte Implantation at the Knee Joint Using the Igor Scaffold: A Case Series With 2-Year Follow-up

Background:

For large, locally restricted cartilage defects in young patients, third-generation matrix-supported autologous chondrocyte implantation (ACI) with a variety of scaffolds has shown good mid- to long-term results.

Purpose/Hypothesis:

This study aimed to monitor the clinical and radiological outcomes of patients who received ACI at the knee joint using the Igor scaffold (IGOR–Institute for Tissue and Organ Reconstruction) at 2-year follow-up. Our hypothesis was that there would be improvements in postoperative subjective scores and cartilage repair tissue quality.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 21 patients (12 male and 9 female) were available for 2-year follow-up after third-generation ACI using the Igor scaffold. All were clinically assessed using the Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner Activity Scale, Brittberg score, International Knee Documentation Committee (IKDC) Subjective Knee Form, Noyes Sports Activity Rating Scale, and visual analog scale for pain. For morphological evaluation, the magnetic resonance observation of cartilage repair tissue (MOCART) and MOCART 2.0 scores were calculated using 3-T magnetic resonance imaging performed at 3, 6, 12, and 24 months postoperatively. Results were compared between baseline and 24 months postoperatively.

Results:

After 2 years, the clinical and radiological scores showed good to excellent results in the majority of patients. On the IKDC, 10 patients were graded as excellent, 4 as good, 5 as fair, and 2 as severe; on the KOOS, 7 patients were graded as excellent, 8 as good, 4 as fair, and 2 as severe. From baseline to latest follow-up, visual analog scale pain scores decreased from 5.6 ± 3.2 (mean ± SD) to 1.5 ± 2; KOOS results increased from 51 ± 20.7 to 75.2 ± 15.4; and the Tegner score improved from 2.2 ± 1.8 to 4.3 ± 1.3. The MOCART and MOCART 2.0 scores were comparable at 2-year follow-up, with mean values of 74 ± 10 and 78 ± 13, respectively. Satisfactory filling and integration were found in 90.5%. Overall, 16 of 21 patients (76.1%) were satisfied with the surgery and would undergo the procedure again.

Conclusion:

Third-generation ACI using the Igor scaffold showed improvements in clinical and radiological results that were comparable with other scaffolds for patients with large traumatic or degenerative cartilage defects. Patients reported a decrease in pain and an increase in activity, with the majority reporting good results.

Editorial Commentary: Stem Cell Treatment in Knee Osteoarthritis: What for? Pain Management or Cartilage Regeneration?

The efficacy of mesenchymal stem cells regarding clinical outcomes and cartilage regeneration in knee osteoarthritis remains unclear; however, their theoretical role in multilineage cellular differentiation and immunomodulation of the arthritic cascade has been investigated. Several studies have reported that the use of stem cell therapy for knee osteoarthritis helps in pain improvement, but its effect on cartilage regeneration has not yet been explored. Moreover, numerous studies have reported high heterogeneity in the cell sources, as well as methods of culture expansion or cell concentration, and differences in delivery methods, assessment tools, and concomitant surgical procedures, which could affect the clinical outcomes or evaluation of cartilage regeneration potency. Furthermore, future studies are warranted to examine these factors in detail to interpret the results of mesenchymal stem cell treatment for knee osteoarthritis.

Excellent histological results in terms of articular cartilage regeneration after spheroid-based autologous chondrocyte implantation (ACI)

PURPOSE

Traumatic lesions of articular cartilage represent a crucial risk factor for osteoarthritis. Even if several strategies exist to treat such damages, the optimal solution has not yet been found. A new strategy represents the scaffold-free spheroid-based autologous chondrocyte transplantation. In this method, spheroids of chondrocytes are synthesized after chondrocyte isolation and expansion, followed by the implantation in a second intervention.

METHODS

Fine Jamshidi-needle biopsies from five patients (one from each patient, Ø 2 mm) treated with a spheroid-based autologous chondrocyte implantation (ACI) after traumatic lesions of the articular cartilage of the knee were analysed histologically and immunohistologically for collagen II, collagen X and aggrecan expression. The indication for a second look arthroscopy was given by arthrofibrosis or meniscus-lesions, respectively. The time between ACI and second-look arthroscopy ranged between 6 and 16 months.

RESULTS

In all patients, the histological examinations revealed an avascular cartilage tissue with a homogenic extracellular matrix. The subchondral bone neither showed bleeding, necrosis nor hypertrophy. A homogenous alcian blue staining indicated high amounts of mucopolysaccharides and glycosaminoglycans. Collagen II staining was highly positive, whereas collagen X staining was negative in every patient, ruling out hypertrophic chondrocyte differentiation. In addition, intense aggrecan staining indicated a strong expression of this extracellular matrix component.

CONCLUSION

The present case series represents the first histological and immunohistological analyses of spheroid-based ACI in humans. Spheroid-based ACI revealed excellent histological results regarding the regeneration of hyaline articular cartilage. These results indicate that spheroid based ACI is a promising strategy for treating traumatic lesions of the articular cartilage of the knee.

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.

Long-term Results of Arthroscopic Matrix-Assisted Autologous Chondrocyte Transplantation: A Prospective Follow-up at 15 Years

BACKGROUND

Matrix-assisted autologous chondrocyte transplantation (MACT) procedures have been developed to overcome some of the limits of first-generation autologous chondrocyte implantation. However, while good autologous chondrocyte implantation results have been documented over time, data are scarce on the long-term MACT results.

PURPOSE

To evaluate long-term clinical results of a large cohort of patients treated with hyaluronic acid-based MACT for articular cartilage defects of the knee.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A long-term evaluation of 113 patients was performed (91 men, 22 women; mean ± SD age, 29.0 ± 10.6 years) for 115 knees affected by chondral and osteochondral lesions of the femoral condyles and trochlea. Of these, 61 knees had undergone previous surgery, while other procedures were combined during the same operation in 48 knees. These patients were prospectively evaluated before surgery and at 2, 5, and 10 years after surgery, as well as at a final mean follow-up of 15 years (range, 12-18 years), with various clinical scores: International Knee Documentation Committee (IKDC), EuroQol visual analog scale (EQ-VAS), and Tegner. Both surgical and clinical failures were documented.

RESULTS

The IKDC subjective score increased from the basal level of 39.9 ± 14.6 (mean ± SD) to 77.3 ± 20.5 (P < .0005) at 2 years; results remained stable up to the 15-year follow-up (76.9 ± 20.5). EQ-VAS and Tegner scores showed a statistically significant improvement up to 10 years, with a further significant improvement at the final follow-up. A failure rate of 15.0% was documented, which increased to 21.7% when clinical failures were also considered. A worse outcome was found for older age (P < .0005), female sex (P = .002), degenerative lesions (P < .0005), longer duration of symptoms (P = .005), and previous surgery (P < .0005).

CONCLUSION

Arthroscopic MACT offered good and long-lasting results that were stable over time and resulted in a limited number of failures and reinterventions for up to 15 years of follow-up. Several factors were identified as having a prognostic value: a worse outcome could be expected in older patients, female patients, those affected by lesions with a degenerative cause, those having a longer duration of symptoms, and patients who underwent previous surgery.

Physioxia Expanded Bone Marrow Derived Mesenchymal Stem Cells Have Improved Cartilage Repair in an Early Osteoarthritic Focal Defect Model

Focal early osteoarthritis (OA) or degenerative lesions account for 60% of treated cartilage defects each year. The current cell-based regenerative treatments have an increased failure rate for treating degenerative lesions compared to traumatic defects. Mesenchymal stem cells (MSCs) are an alternative cell source for treating early OA defects, due to their greater chondrogenic potential, compared to early OA chondrocytes. Low oxygen tension or physioxia has been shown to enhance MSC chondrogenic matrix content and could improve functional outcomes of regenerative therapies. The present investigation sought to develop a focal early OA animal model to evaluate cartilage regeneration and hypothesized that physioxic MSCs improve in vivo cartilage repair in both, post-trauma and focal early OA defects. Using a rabbit model, a focal defect was created, that developed signs of focal early OA after six weeks. MSCs cultured under physioxia had significantly enhanced in vitro MSC chondrogenic GAG content under hyperoxia with or without the presence of interleukin-1β (IL-1β). In both post-traumatic and focal early OA defect models, physioxic MSC treatment demonstrated a significant improvement in cartilage repair score, compared to hyperoxic MSCs and respective control defects. Future investigations will seek to understand whether these results are replicated in large animal models and the underlying mechanisms involved in in vivo cartilage regeneration.

Effectiveness and safety of polydioxanone thread-embedding acupuncture (TEA) and electroacupuncture (EA) treatment for knee osteoarthritis (KOA) patients with postoperative pain: An assessor-blinded, randomized, controlled pilot trial

BACKGROUND

Degenerative knee osteoarthritis (KOA) shows an increase in morbidity with improvement in the living conditions and extended lifespans. Treatment for degenerative KOA has been gaining attention since it significantly affects the life of the elderly population and is also associated with increased expenses for medical services and high socioeconomic costs. Treatments for degenerative KOA include nondrug therapy, drug therapy, and surgical treatment. For cases that show little response to conservative treatment but have not involved severe deformation of the knee, procedures such as arthroscopic surgery, autologous chondrocyte implantation, or autologous osteochondral transplantation can be performed. However, effective treatment is required for patients experiencing sustained knee pain after surgery. Although studies confirming the therapeutic effects of acupuncture or thread-embedding acupuncture (TEA) treatment for degenerative KOA have been reported, clinical studies on a combination of TEA and electroacupuncture (EA) in patients complaining of knee pain after arthroscopic surgery, autologous chondrocyte implantation, or autologous osteochondral transplantation have not yet been reported. Therefore, this study aimed to evaluate the effectiveness and safety of this combination treatment in patients with persistent knee pain after arthroscopic surgery, autologous chondrocyte implantation, or autologous osteochondral transplantation.

METHODS/DESIGN

This study has been designed as a 2-group, parallel, single-center, randomized, controlled, assessor-blinded trial. Thirty-six patients with degenerative KOA who complained of pain even after arthroscopic surgery, autologous chondrocyte implantation, or autologous osteochondral transplantation will be randomized to either the (TEA + EA + Usual care) group or the (Usual care only) group in a 1:1 ratio. The patients in the (TEA + EA + Usual care) group will receive TEA treatment once a week for 4 weeks for a total of 4 sessions and EA twice a week for a total of 8 sessions while continuing usual care. The (Usual care only) group will only receive usual care for 4 weeks. To assess the efficacy of the TEA and EA combination treatment, the visual analogue scale, the Korean version of the Western Ontario and McMaster Universities Osteoarthritis Index, the EuroQol 5-Dimension 5-Level, and the doses of the rescue drug taken will be evaluated at baseline (1W) and weeks 2 (2W), 4 (4W), 6 (6W), and 8 (8W). The primary efficacy endpoint is the mean change in visual analogue scale at week 4 (4W) compared to baseline. Adverse events will be assessed at every visit.

DISCUSSION

This study will provide useful data for evaluating the clinical efficacy and safety of TEA and electroacupuncture combination treatment for improving pain and quality of life after surgery for degenerative KOA.

TRIAL REGISTRATION

Clinical Research Information Service of Republic of Korea (CRIS- KCT0004804), March 6, 2020.

Biological Regeneration of Articular Cartilage in an Early Stage of Compartmentalized Osteoarthritis: 12-Month Results

BACKGROUND

Biological regeneration in an early stage of osteoarthritis (OA) is an important clinical challenge. An early-stage compartmentalized OA model was used to evaluate different biological regeneration techniques.

HYPOTHESIS

Biological regeneration in an early stage of compartmentalized OA is possible.

STUDY DESIGN

Controlled laboratory study.

METHODS

A 7-mm cartilage defect was surgically created in 24 sheep. After 3 months, by which time early OA had set in, the sheep were randomized into 4 different treatment groups and operated for the second time. One group (CONTROL) served as a long-term follow-up group for the further development of OA. The other 3 groups (regeneration groups) each underwent a different regeneration procedure after abrasion of the subchondral bone (defect size: 20 × 10 mm with a depth of 2.5 mm): spongialization alone (SPONGIO), spongialization followed by implantation of an unseeded hyaluronan matrix (MATRIX), or spongialization followed by implantation of a hyaluronan matrix seeded with autologous chondrocytes (MACT). Then, 12 months after the second operative procedure, the animals were euthanized and the defects subjected to macroscopic and histological grading. Historical 4-month data were compared with the 12-month results.

RESULTS

After 12 months of follow-up, advanced cartilage degeneration was observed in the CONTROL group. On the other hand, all regeneration groups improved significantly compared with the 4-month results using the Mankin score. Cartilage quality in the MACT group was significantly better than in the MATRIX group, as determined by the Mankin and the O'Driscoll scores.

CONCLUSION

There are no existing clinical options for preventing early OA from progressing to a severe disease. This study provides important information on how a surgical intervention can forestall the development of OA.

CLINICAL RELEVANCE

OA of the knee is very common. Total joint replacement is not an acceptable option for active patients. Biological regeneration in OA is successful for focal cartilage defects; however, a long-term follow-up for biological regeneration in OA is missing. It is essential to have long-term results for a regenerative procedure involving cartilage, which is a tissue with a very slow turnover.