Stratification is required to ensure that only those patients likely to benefit, receive Autologous Chondrocyte Implantation (ACI); ideally by assessing a biomarker in the blood. This study aimed to assess differences in the plasma proteome of individuals who respond well or poorly to ACI. Isobaric tag for relative and absolute quantitation (ITRAQ) mass spectrometry and label-free proteomics analyses were performed in tandem as described previously by our group (Hulme et al., 2017; 2018; 2021) using plasma collected from ACI responders (n=10) compared with non-responders (n=10) at each stage of surgery (Stage I, cartilage harvest and Stage II, cell implantation). iTRAQ using pooled plasma detected 16 proteins that were differentially abundant at baseline in ACI responders compared with non-responders (n=10) (≥±2.0 fold; p<0.05). Responders demonstrated a mean Lysholm (patient reported functional score from 0–100) improvement of 33±13 and non-responders a mean worsening of −13±13 points. The most pronounced plasma proteome shift was seen in response to Stage I surgery in ACI non-responders, with 48 proteins being differentially abundant between the two surgical procedures. We have previously noted this marked shift in response to initial surgery in the SF of ACI non-responders, several of these proteins were associated with the Acute Phase Response. One of these proteins, clusterin, could be confirmed in patients’ plasma using an independent immunoassay using individual samples. Label-free proteomic data from individual samples identified only cartilage acidic protein-1 (known to associate with osteoarthritis progression) to be significantly more abundant at Stage I in the plasma of non-responders. This study indicates that proteins can be identified within the plasma that have potential use in ACI patient stratification. Further work is required to validate the findings of this discovery-phase work in larger ACI cohorts

The objectives of the study were to investigate demographic, injury and surgery/treatment-associated factors that could influence clinical outcome, following Autologous Chondrocyte Implantation (ACI) in a large, “real-world”, 20 year longitudinally collected clinical data set. Multilevel modelling was conducted using R and 363 ACI procedures were suitable for model inclusion. All longitudinal post-operative Lysholm scores collected after ACI treatment and before a second procedure (such as knee arthroplasty but excluding minor procedures such as arthroscopy) were included. Any patients requiring a bone graft at the time of ACI were excluded. Potential predictors of ACI outcome explored were age at the time of ACI, gender, smoker status, pre-operative Lysholm score, time from surgery, defect location, number of defects, patch type, previous operations, undergoing parallel procedure(s) at the time of ACI, cell count prior to implantation and cell passage number. The best fit model demonstrated that for every yearly increase in age at the time of surgery, Lysholm scores decreased by 0.2 at 1-year post-surgery. Additionally, for every point increase in pre-operative Lysholm score, post-operative Lysholm score at 1 year increased by 0.5. The number of cells implanted also impacted on Lysholm score at 1-year post-op with every point increase in log cell number resulting in a 5.3 lower score. In addition, those patients with a defect on the lateral femoral condyle (LFC), had on average Lysholm scores that were 6.3 points higher one year after surgery compared to medial femoral condyle (MFC) defects. Defect grade and location was shown to affect long term Lysholm scores, those with grade 3 and patella defects having on average higher scores compared to patients with grade 4 or trochlea defects. Some of the predictors identified agree with previous reports, particularly that increased age, poorer pre-operative function and worse defect grades predicted poorer outcomes. Other findings were more novel, such as that a lower cell number implanted and that LFC defects were predicted to have higher Lysholm scores at 1 year and that patella lesions are associated with improved long-term outcomes cf. trochlea lesions

Abstract

Abstract. Purpose. Stratification is required to ensure that only patients likely to benefit, receive Autologous Chondrocyte Implantation (ACI). At Stage I (SI), healthy cartilage is harvested from the joint and chondrocytes culture expanded before being implanted into a chondral/osteochondral defect at Stage II (SII). In ACI non-responders, there is a marked shift in the profile and abundance of proteins detectable in the synovial fluid (SF) at SII, many being associated with an acute phase response (APR). However, clinical biomarkers are easier to measure in blood than SF, so we have now performed this investigation in plasma. Methods. Isobaric tag for relative and absolute quantitation mass-spectrometry was used to assess the proteome in plasma pooled from ACI responders (mean Lysholm improvement of 33, n=10) or non-responders (mean: −13 points, n=10), collected at SI or SII surgeries. Interactome networks were generated using STRING. Plasma proteome data were compared to matched SF data, previously analysed, to identify any proteins that changed across the fluids. Clusterin concentration was quantitated (ELISA; Biotechne). Results. The most pronounced plasma proteome shift was seen in response to SI surgery in ACI non-responders (50 proteins; ±2.0FC; p<0.05). An interactome network was generated based on these proteins. Functions associated with this network included complement and coagulation cascade (FDR= 5.99×10-. 25. ). Sixteen matched proteins were differentially abundant between SI and SII in both the SF and plasma, 75% of which were APR associated proteins. These included clusterin, which was confirmed by ELISA (p=0.001). Conclusions. Changes in APR signalling between SI and SII surgeries in non-responders to ACI can be identified in plasma and SF. The APR is the body's first systemic response to trauma and surgery. Our data indicate that ACI non-responders may have a greater innate response to initial surgery, which is detectable in both their SF and plasma

Abstract

Introduction. Autologous Chondrocyte Implantation (ACI) is an effective surgical treatment for chondral defects. ACI involves arthrotomy for cell implantation. We describe the development of an intra-articular injection of cultured MSC, progressing from in-vitro analysis, through animal model, clinical and radiological outcome at five years follow up. Materials and Methods. We prospectively investigated sixteen patients with symptomatic ICRS grade III and IV lesions. These patients underwent cartilage repair using cultured mesenchymal stem cell injections and are followed up for five years. Results. Statistically significant clinical improvement was noted by two years and was sustained for five years of the study. At five years, mean Lysholm score was 80, compared to 44 pre-operatively. Symptomatic KOOS improved to 88 from 55. Subjective IKD Calso showed improvement from 42 to 76. On morphological MRI MOCART score was 76 and qualitative MRI showed the mean T2relaxation-times were 28 and 31 for their pair tissue and native cartilage respectively. Discussion. Cultured MSC provides a good number of uncommitted stem cells to the previously prepared chondral defects of the knee by “homing on” phenomenon. Cultured cells, suspended in serum can be delivered by an intra-articular injection. Conclusion. Use of cultured MSC is less invasive, avoids complications associated with arthrotomy, compared to ACI technique. Good clinical results were found to be sustained at five years of follow-up with a regenerate that appears like surrounding native cartilage. The use of Cultured Mesenchymal Stem Cells (MSC) has represented a promising treatment to restore the articular cartilage

Symptomatic articular cartilage defects are one of the most common knee injuries, arising from acute trauma, overuse, ligamentous instability, malalignment, meniscectomy, osteochondritis dissecans. Surgical treatment options include bone marrow–stimulating techniques such as abrasion arthroplasty and microfracture, osteochondral mosaicplasty, corrective osteotomy, cartilage resurfacing techniques and tissue engineering techniques using combinations of autologous cells (chondrocytes and mesenchymal stem cells), bioscaffolds, and growth factors. Matrix induced autologous chondrocyte implantation (MACI) is considered the most surgically simple form of autologous chondrocyte implantation. Our group has involved in the development of MACI since 2000 and has led to the FDA approval of MACI as the first tissue engineering product for cartilage repair in 2016. In this article, we have documented the characterisation of autologous chondrocytes, the surgical procedure of MACI and the long term clinical assessment (15 years) of patients with treatment of MACI. We have also reported the retrospective survey in patients with MACI in Australia. Our results suggest that MACI has gained good to excellent long term clinical outcome and probably can delay total knee replacement. However, restoration of hyaline-like cartilage by MACI may be interrupted by the osteoarthritic condition of the joint in patients with progressed osteoarthritis. In addition, because articular cartilage and subchondral bone are considered a single functional unit that is essential for joint function, many cartilage repair technologies including MACI and microfractures have failed short to address the functional barrier structure of osteochondral unit. Further studies are required to develop tissue engineering osteochondral construct that is able to fulfil the function of articular cartilage-subchondral bone units.

Introduction

The management of early OA in young patients with joint preservation techniques utilizing cartilage repair remains challenging and a suitable treatment remains unclear. The management of bipolar chondral lesions in the patello-femoral (PF) and in the tibio-femoral (TF) compartment with cartilage repair is especially troublesome. The purpose of this study was to evaluate the clinical outcomes and survivorship after ACI for the treatment of bipolar chondral lesions in the PF and TF compartment.

Optimal treatment for symptomatic talus Osteochondral Lesions (OCLs) where primary surgical techniques have failed has not been established. Recent advances have focussed on biological repair such as Autologous Chondrocyte Implantation (ACI) however funding for this treatment is limited. Stem cell therapy in the ankle has not been assessed. The purpose of this pilot study was to evaluate the safety and efficacy of stem cell therapy in the treatment of ankle OCLs. The study was approved by the new procedures committee. Between January 2015 and December 2016, 26 patients, mean age of 36 years (range 16–58 years) with persisting disabling symptoms underwent Complete Cartilage Regeneration (CCR) using stem cells for failed primary treatment for ankle OCLs. Treatment involved iliac crest bone marrow aspiration, centrifugation to obtain bone marrow concentrate (BMC), and then injection of the BMC combined with hyaluronic acid into the OCL. Any necessary additional procedures, e.g. bone grafting or lateral ligament reconstruction were also undertaken. In 18 patients the lesion was on the medial talar dome, in 5 the lateral talar dome, 2 multiple, 1 tibial plafond. The Manchester-Oxford Foot Questionnaire (MOXFQ) was utilised to assess outcome. Average pre-operative MOXFQ scores were Walking dimension −78, Pain dimension − 65, and Social dimension − 64.2. Average 3 month post-operative MOXFQ scores were Walking − 54.8, Pain − 35.4, Social − 38.9. Average 6 month post-operative MOXFQ scores were Walking − 34.4, Pain − 35.4, Social − 28. Two patients from the beginning of the series had AOFAS scores only which improved from an average of 55 pre-operatively to 76 post-operatively. No early complications were noted. We conclude that CCR treatment is a safe treatment for talus OCLs in patients who have failed primary treatment. The procedure avoids two-stage surgery of ACI in some patients without large cysts. The early clinical outcome is favourable with no complications noted. Longer term follow-up is required

The current study aims to ascertain the outcome of ACI with simultaneous transplantation of an autologous bone plug for the restoration of osteoarticular defects in the femoral condyle of the knee (‘Osplug’ technique).

Seventeen patients (mean age of 27±7 years), twelve with Osteochondritis dissecans (OD) and five with an osteochondral defect (OCD) was treated with unicortical autologous bone graft combined with ACI (‘Osplug’ technique). Functional outcome was assessed with Lysholm scores obtained for 5 years post-operatively. The repair site was evaluated with the Oswestry Arthroscopy Score (OAS), MOCART MRI score and ICRS II histology score.

The mean defect size was 4.5±2.6 SD cm² and mean depth was 11.3±5 SD mm. A significant improvement of Lysholm score from 45 (IQR 24, range 16–79) to 77 (IQR 28, range 41–100) at 1 year (p-value 0.001) and 70 (IQR 35, range 33–91) at 5 years (p-value 0.009). The mean OAS of the repair site was 6.2 (range 0–9) at a mean of 1.3 years. The mean MOCART score was 61 ± 22SD (range 20–85) at 2.6 ± 1.8SD years. Histology demonstrated generally good integration of the repair cartilage with the underlying bone. Poor lateral integration of the bone graft on MRI and low OAS were significantly associated with a poor outcome and failure.

The Osplug technique shows significant improvement of functional outcome for up to 5 years. This is the first report describing the association of bone graft integration with functional outcome after such a procedure.

Background. Microfracture (MF) and Autologous Chondrocyte Implantation (ACI) are used to repair symptomatic condylar cartilage defects (grade II-IV Outerbridge). Superiority of ACI to MF is still debated. The aim of the study was to conduct a systematic literature review, compare superiority of ACI versus MF in a meta-analysis and investigate the correlation between patient age and outcome of both treatments. Methods. Extended literature search was conducted (papers from January 2001 to present), looking at patient characteristics, pre- and post-operative scores and cartilage repair assessment evaluation. Methodological quality was verified through modified Coleman score and assessment bias. A fixed-effect meta-analysis was conducted, comparing post-operative standardised mean differences between ACI and MF. Pearson correlation coefficient between post-operative score and age was calculated against ACI and MF. Results. of 490 studies systematically analysed, 8 met the inclusion criteria, accounting for 255 patients treated with ACI and 259 with MF. Overall mean postoperative scores were 81.38±8.31 for ACI and 74.9±7.0 for MF, with no significant difference (p=0.13). The average modified Coleman score of the studies was 82.6, with low bias among them. The meta-analysis displayed an overall effect estimate of 0.3 favouring ACI treatment versus MF (95%CI=0.12–0.48, P=0.001). Significant heterogeneity was although observed (I2>70%). Pearson correlation coefficient calculated between mean post-operative score and mean age, surprisingly failed to indicate clear correlation for ACI (r=0.11) and MF (r=0.18) respectively. Conclusions. Minor statistically significant superiority of ACI intervention versus MF in knee cartilage repair was found, together with high levels of heterogeneity, halting the possibility to make full recommendation of ACI versus MF. Level of Evidence. Ia (systematic review and meta-analysis)

A prospective case control study analysed clinical and radiographic results in patients operated on with the periosteum autologous chondrocyte implantation (ACI) due to cartilage lesions on the femoral condyles over 10 years ago.

31 out of the 45 patients (3 failures, 9 non-responders, 2 others) were available for a continuous clinical (Lyshom/Tegner, IKDC, KOOS) and radiographic (Kellgren-Lawrence) follow-up at 0, 2, 5, and 10 years after the ACI procedure. The patients were sub-grouped into focal cartilage lesions (FL) – 10, osteochondritis dissecans (OCD) – 12, and cartilage lesions with simultaneous ACL reconstruction (ACL) – 9 subgroups.

Lysholm, Tegner, and IKCD subjective scores revealed stable results over the period from 2 to 10 years with a significant improvement toward the pre-operative levels, but the patients had not reached their pre-injury Tegner levels. KOOS profile at 10 years was: Pain 78.6, Symptoms 78.1, Activities of daily living 82.5, Sports 56.9, and Quality of life 55.1. A 10-year IKDC knee examination classified operated knees as: 14 normal, 10 nearly normal, 5 abnormal and 2 severely abnormal. Kellgren-Lawrence scores of 2 and above were found in 10 patients (FL 5, OCD 0, and ACL 5). Seven patients in the group required an arthroscopic re-intervention (3 ACI related, 4 ACI unrelated).

ACI provided safe and stable performance of operated knees over ten years. High incidence of knee osteoarthritis in FL and ACL subgroups, and low incidence in OCD patients indicate that best long performance is expected in localised low-impact cartilage lesions of young patients.

Osteochondral lesions (OCLs) occur in up to 70% of sprains and fractures involving the ankle. Atraumatic aetiologies have also been described. Techniques such as microfracture, and replacement strategies such as autologous osteochondral transplantation, or autologous chondrocyte implantation are the major forms of surgical treatment. Current literature suggests that microfracture is indicated for lesions up to 15 mm in diameter, with replacement strategies indicated for larger or cystic lesions. Short- and medium-term results have been reported, where concerns over potential deterioration of fibrocartilage leads to a need for long-term evaluation.

Biological augmentation may also be used in the treatment of OCLs, as they potentially enhance the biological environment for a natural healing response. Further research is required to establish the critical size of defect, beyond which replacement strategies should be used, as well as the most appropriate use of biological augmentation. This paper reviews the current evidence for surgical management and use of biological adjuncts for treatment of osteochondral lesions of the talus.

Cite this article: Bone Joint J 2014;96-B:164–71.

This study investigated confocal laser scanning microscopy (CLSM) as a novel method of imaging of chondrocytes on a collagen membrane used for articular cartilage repair. Cell viability and the effects of surgery on the cells were assessed.

Cell images were acquired under four conditions: 1, Pre-operative 2, After handling 3, Heavily grasped with forceps 4, Cut around the edge. Live and dead cell stains were used. Images were obtained for cell counting and morphology. Mean cell density was 1.12–1.68 ± 0.22 × 10⁶ cells/cm² in specimens without significant trauma (n=25 images), this decreased to 0.253 × 10⁶ cells/cm² in the specimens that had been grasped with forceps (p <0.001) (5 images). Cell viability on delivery grade membrane was 86.8±2.1%. The viability dropped to 76.3 ± 1.6% after handling and 35.1 ± 1.7% after crushing with forceps. Where the membrane was cut with scissors, there was a band of cell death where the viability dropped to 17.3 ± 2.0% compared to 73.4 ± 1.9% in the adjacent area (p <0.001). Higher magnification revealed cells did not have the rounded appearance of chondrocytes.

CLSM can quantify and image the fine morphology of cells on a MACI membrane. Careful handling of the membrane is essential to minimise chondrocyte death during surgery.

Although cartilage repair has been around since the time of open Pridie drilling, clinical outcomes for newer techniques such as arthroscopic debridement, microfracture (MFX), osteochondral autograft transfers (OATS), osteochondral allograft transplantation and Autologous Chondrocyte Implantation (ACI) are still finding their place in treating injured knees. Early mechanical symptoms are best managed by a gentle arthroscopic debridement of loose articular flaps. This allows the surgeon to assess the defect size, location in the tibio-femoral or patellofemoral joint, status of the cartilage overall and patients response to the intervention. If the symptom improvement is not satisfactory to the patient, after assessing background factors that will influence the results of a cartilage repair procedure, (alignment of the patellofemoral joint or axial alignment, ligament stability and status of the meniscus), the surgeon can choose the best procedure for that individual based on the expected outcomes of the various cartilage repair techniques while addressing the background factors. As all the techniques have failures and informed discussion with the patient prior to performing the procedure is critical in avoiding disappointment for the patient and the surgeon. The repair technique used should incorporate considerations of the defect size, location, and the patient age, activity level, expectations and ability to comply with the longer rehabilitation needed for biological procedures as compared to prosthetic implants

Introduction and Aim

The management of grade 4 articular cartilage defects of the knee is a great challenge and surgical techniques are evolving. This single surgeon series evaluated the results of articular cartilage implantation using matrix assisted autologous cartilage implantation (B Braun, Tetec, Reutlingen Germany) in 28 patients who had failed previous micro-fracture or chondroplasty.

Introduction. Meniscus deficiency leads to the development of early arthritis. Total knee replacement may be the only available treatment option in certain situations. However it is generally best avoided in young patients. We hypothesized that a combination of the two procedures, Allograft Meniscal Transplantation (AMT) and Autologous Chondrocyte Implantation (ACI) would be a solution to treat bone-on-bone arthritis in meniscal deficient knees and postpone the need for a total knee replacement (TKR). Materials/Methods. 12 consecutive patients who underwent both ACI and AMT between 1998 and 2005 were followed up prospectively. The patients were assessed by a self-assessed Lysholm score prior to the procedure and yearly thereafter. All operations were performed by the senior author (JBR). ACI procedure was performed according to the standard technique. Frozen meniscal allograft with bone plugs at either ends secured by sutures in the bone tunnels. Post operatively all patients underwent a strict Oscell Rehabilitation protocol. A repeat procedure or progression to a TKR was taken as a failure. Results. Out of the twelve patients only eleven were included as one had died at three months after surgery. Three patients had delayed TKR, and two were heading towards TKR at 8 years. The median pre-operative lysholm score in the remaining six patients rose from 45 to 64 at last follow up. Conclusions. In our small pilot study there was a 19 point increase in the lysholm score. The combination of ACI & AMT could give a good result defer the need for TKR

Purpose. Traumatic articular cartilage (AC) defects are common in young adults and frequently progresses to osteoarthritis. Matrix-Induced Autologous Chondrocyte Implantation (MACI) is a recent advancement in cartilage resurfacing techniques and is a variant of ACI, which is considered by some surgeons to be the gold standard in AC regeneration. MACI involves embedding cultured chondrocytes into a scaffold that is then surgically implanted into an AC defect. Unfortunately, chondrocytes cultured in a normoxic environment (conventional technique) tend to de-differentiate resulting in decreased collagen II and increased collagen I producing in a fibrocartilagous repair tissue that is biomechanically inferior to AC and incapable of withstanding physiologic loads over prolonged periods. The optimum conditions for maintenance of chondrocyte phenotype remain elusive. Normal oxygen tension within AC is <7%. We hypothesized that hypoxic conditions would induce gene expression and matrix production that more closely characterizes normal articular chondrocytes than that achieved under normoxic conditions when chondrocytes are cultured in a collagen scaffold. Method. Chondrocytes were isolated from Outerbridge grade 0 and 1 AC from four patients undergoing total knee arthroplasty and embedded within 216 bovine collagen I scaffolds. Scaffolds were incubated in hypoxic (3% O2) or normoxic (21% O2) conditions for 1hr, 21hr and 14 days. Gene expression was determined using Q-rt-PCR for col I/II/X, COMP, SOX9, aggrecan and B actin. Matrix production was determined using glycosaminoglycan (GAG) content relative to cell count determined by DNA quantification. Cell viability and location within the matrix was determined by Live/Dead assay and confocal microscopy. Statistical analysis was performed using a two-tailed T-test. Results. Chondrocytes cultured under hypoxic conditions showed an upregulation of all matrix related genes compared to normoxic conditions noted most markedly in col II, COMP and SOX9 expression. There were similar numbers of chondrocytes between hypoxic and normoxic groups (P=0.68) but the chondrocytes in the hypoxic group produced more GAG per cell (P= 0.052). Viable cells were seen throughout the matrix in both groups. Conclusion. Important matrix related genes (col II, COMP, SOX9) were most significantly upregulated in hypoxic conditions compared to normoxic conditions. This was supported by an increase in GAG production per cell in hypoxic conditions. The results indicate that hypoxia induces an upregulation in the production of extracellular matrix components typical of AC with only modest increases in col I (possibly related to the col I based scaffold used in this experiment). These results indicate that hypoxic conditions are important for the maintenance of chondrocyte phenotype even when the cells are cultured in a 3D environment. In conclusion, hypoxic culture conditions should be used to help maintain chondrocyte phenotype even when culturing these cells in a 3D scaffold

Chondral injuries of the knee are extremely common and present a unique therapeutic challenge due to the poor intrinsic healing of articular cartilage. These injuries can lead to significant functional impairment. There are several treatment modalities for articular osteochondral defects, one of which is autologous chondrocyte implantation. Our study evaluates the mid to long term functional outcomes in a cohort of 828 patients who have undergone an autologous chondrocyte implantation procedure (either ACI or MACI), identifying retrospectively factors that may influence their outcome.

The influence of factors including age, sex, presence of osteoarthritis and size and site of lesion have been assessed individually and with multivariate analysis. All patients were assessed using the Bentley Functional Score, Visual Analogue Score and the Cincinnati Functional Score. Assessment were performed pre-operatively and of their status in 2010. The majority of patients had several interim scores performed at varying intervals.

The longest follow-up was 12 years (range 24 to 153 months) with a mean age of 34 years at time of procedure. The mean defect size was 486 mm2 (range 64 to 2075 mm2). The distribution of lesions was 51% Medial Femoral Condyle, 12.5% Lateral Femoral Condyle, 18% Patella (single facet), 5% Patella (Multifacet) and 6% Trochlea. 4% had cartilage transplant to multiple sites. 30% failed following this procedure at a mean time of 72 months. 52% patients stated a marked improvement in their functional outcomes within the first two years. 49% stated an excellent result following their procedure.

High failure rate was noted in those with previous cartilage regenerative procedures, transplants occurring on the patella, particularly if involving multifacets. Multiple site cartilage transplantation was also associated with a high failure rate.

Autologous chondrocyte implantation is an effective method of decreasing pain and increasing function, however patient selection plays clear role in the success of such procedure.

Introduction

Autologous chondrocyte implantation (ACI) is contra-indicated in a joint rendered unstable by a ruptured anterior cruciate ligament (ACL). We present our experience of ACI repair with ACL reconstruction