A Randomized Trial of Autologous Chondrocyte Implantation Versus Alternative Forms of Surgical Cartilage Management in Patients With a Failed Primary Treatment for Chondral or Osteochondral Defects in the Knee

Outcomes of Revision Cartilage Restoration Surgery for Failed Primary Treatment of Chondral or Osteochondral Defects of the Knee: A Systematic Review

BACKGROUND

Failure of primary cartilage restoration procedures of the knee that proceed to necessitating revision cartilage procedures represent a challenging clinical scenario with variable outcomes reported in previous literature.

PURPOSE

To perform a systematic review and meta-analysis of clinical outcomes and adverse events after revision cartilage restoration procedures of the knee for failed primary cartilage procedures.

STUDY DESIGN

Systematic review and meta-analysis; Level of evidence, 4.

METHODS

The PubMed, OVID/MEDLINE, and Cochrane databases were queried in August 2023 for trials reporting on the outcomes of revision cartilage restoration procedures of the knee. Information pertaining to rates of failure, reoperations, graft-related complications, and patient-reported outcome measures were extracted. A meta-analysis using inverse-variance proportion models using Freeman-Tukey double-arcsine transformations and DerSimonian-Laird random-effects estimators was constructed to quantitatively describe the cumulative incidence of adverse events.

RESULTS

Sixteen studies (1361 patients; mean age, 35.7 ± 9.3 years) were included. The most frequently performed revision cartilage procedure was autologous chondrocyte implantation (ACI; n = 755 [55.5%]). The overall rate of failure was 25.1% (95% CI, 14.4%-37.3%) at a mean 6.5 years (range, 2-26 years). The majority of studies (n = 9) reported a failure rate exceeding 20%. A significant reduction in failure was observed in favor of the revision osteochondral allograft cohort (19.0% [75/395] vs 35.7% [273/764]; relative risk, 0.63; P < .0001) compared with the revision ACI cohort. The pooled all-cause reoperation event rate was 40.8%, which ranged between 18.2% and 71.4% (13 studies). Of these studies, 12 reported reoperation rates exceeding 20%, and 7 reported rates exceeding 40%. The pooled graft-related complication event rate was 27.2%, which ranged between 5.4% and 56.6% (11 studies). Notably, all analyses demonstrated considerable or moderate heterogeneity, potentially influencing the observed variability in pooled effect estimates.

CONCLUSION

One of every 4 patients may experience a secondary failure after undergoing a revision cartilage procedure. Revision using an osteochondral allograft may confer a meaningful reduction in the risk of failure relative to revision using ACI. High rates of graft-related complications and reoperations are also frequently observed in this population, highlighting the challenge of treating patients with failed primary treatment of chondral or osteochondral defects of the knee.

A Randomized Controlled Trial Comparing "Early" Versus "Late" Periosteal Patch Attachment to Knee Chondral Defects in Autologous Chondrocyte Implantation

OBJECTIVE

Traditional autologous chondrocyte implantation (ACI) involves arthroscopically harvesting a cartilage biopsy (stage 1), followed by arthrotomy 3 to 4 weeks later to apply a periosteal patch and implant culture-expanded chondrocytes underneath (stage 2). This study aimed to determine if patch application during stage 1 rather than stage 2 improved clinical outcome.

DESIGN

A randomized controlled trial was conducted from 1998 to 2001. Patients were randomized to receive either traditional ACI (control/late) or ACI with "early" patch during stage 1 (intervention/early). Clinical outcome (Lysholm score) was assessed pre-operatively and annually post-operatively.

RESULTS

Seventy-seven patients were recruited, with 40 patients randomized to the early and 37 to the late patch group. The overall mean pre-operative Lysholm score was 51.8 (range 11-89) and significantly improved by 11.1 points (95% confidence interval [CI] = 4.8 to 17.4) at mean 12.7 years (range 1.5-23.7) follow-up. Latest mean Lysholm scores for the early and late groups were 68.4 (95% CI = 19 to 100) versus 56.7 (95% CI = 18 to 98). Adjusted for covariate imbalances, no evidence was found for a difference between the groups (mean difference = 8.5, 95% CI = -5.2 to 22.2, P = 0.22). Twenty-year survival until any re-operation or arthroplasty was 59.6%/82.1% for the early and 56.8%/69.5% for the late group, with no evidence for a difference.

CONCLUSION

ACI is an effective durable treatment for cartilage defects, with high levels of patient satisfaction and low failure rates. No evidence was found that applying the periosteal patch at the time of chondrocyte harvest improved long-term Lysholm scores or survival until any re-operation or arthroplasty.

Commercial Insurance Coverage Criteria for Autologous Chondrocyte Implantation Poorly Reflect Current Research

OBJECTIVE

The aim of this study is to both quantify and qualify the way insurance companies justify their coverage policies for autologous chondrocyte implantation (ACI) and determine whether these policies align with recent research on the subject.

DESIGN

The top 11 national commercial health insurance payers for ACI were identified. Coverage policy documents were recovered for 8 payers. These documents were examined, and the type of reference and the level of evidence (LOE) were recorded for each applicable reference. Specific coverage criteria for each individual payer were then extracted and assessed for similarities among commercial payers. Finally, all references cited by each payer were examined to determine whether they mentioned the specific payer criteria.

RESULTS

This study found that the majority of cited references were primary journal articles (86, 58.1%) and that only 30 (20.2%) references were level I or level II evidence. This study also found significant homogeneity among payer coverage criteria. Cited sources inconsistently mentioned specific payer coverage criteria. In addition, payer criteria tended to be poorly supported by current evidence on ACI.

CONCLUSIONS

This study demonstrates that commercial insurance payers' coverage policies for ACI poorly cite references, cite a majority of references with low LOE, and cite references which infrequently mention their specific coverage criteria. In addition, payer coverage policies have a high degree of homogeneity and many of their specific criteria are poorly supported by current research on ACI.

A randomized controlled trial demonstrating sustained benefit of autologous matrix-induced chondrogenesis (AMIC®) over microfracture: 10-year follow-up

PURPOSE

Autologous matrix-induced chondrogenesis (AMIC®) and microfracture are established treatments for focal chondral defects in the knee, but there are little clinical data concerning these procedures over the long term. This study evaluates the outcomes of AMIC® compared to microfracture over 10-year follow-up.

METHODS

Forty-seven patients were randomized and treated either with MFx (n = 13), sutured AMIC® (n = 17) or glued AMIC® (n = 17) in a prospective, randomized, controlled multicentre trial. The Modified Cincinnati Knee Score, a visual analogue scale for pain and MOCART score were used to assess outcomes over 10 years post-operatively.

RESULTS

All treatment arms improved in the first 2 years, but a progressive and significant deterioration in scores was observed in the MFx group, while both AMIC® groups remained stable. MOCART scores were comparable between groups.

CONCLUSION

The AMIC® procedure results in improved patient outcomes in comparison with microfracture up to 10 years following surgery for the repair of focal chondral defects in the knee.

CLINICALTRIALS

gov Identifier: NCT02993510.

Glycosphingolipids in Osteoarthritis and Cartilage-Regeneration Therapy: Mechanisms and Therapeutic Prospects Based on a Narrative Review of the Literature

Glycosphingolipids (GSLs), a subtype of glycolipids containing sphingosine, are critical components of vertebrate plasma membranes, playing a pivotal role in cellular signaling and interactions. In human articular cartilage in osteoarthritis (OA), GSL expression is known notably to decrease. This review focuses on the roles of gangliosides, a specific type of GSL, in cartilage degeneration and regeneration, emphasizing their regulatory function in signal transduction. The expression of gangliosides, whether endogenous or augmented exogenously, is regulated at the enzymatic level, targeting specific glycosyltransferases. This regulation has significant implications for the composition of cell-surface gangliosides and their impact on signal transduction in chondrocytes and progenitor cells. Different levels of ganglioside expression can influence signaling pathways in various ways, potentially affecting cell properties, including malignancy. Moreover, gene manipulations against gangliosides have been shown to regulate cartilage metabolisms and chondrocyte differentiation in vivo and in vitro. This review highlights the potential of targeting gangliosides in the development of therapeutic strategies for osteoarthritis and cartilage injury and addresses promising directions for future research and treatment.

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.

Three Milliliters of Peripheral Blood Is Sufficient for Preparing Liquid Platelet-Rich Fibrin (PRF): An In Vitro Study

Platelet-rich fibrin (PRF) has assumed an important role in supporting tissue regeneration in different fields. To date, the standard protocol for liquid PRF requires at least 10 mL of peripheral blood. The present study aimed to analyze the composition, growth factor release, and effects on the cell proliferation of PRF samples produced using 3 mL vs. 10 mL of peripheral blood in vitro. Peripheral venous blood from six healthy donors was used to prepare liquid PRF using either 3 mL or 10 mL tubes. Three different centrifugation protocols were used according to the low-speed centrifugation concept. The cellular distribution was evaluated using immunohistology and automated cell count. ELISA was used to determine the release of different growth factors (EGF, TGF-β1, and PDGF) and interleukin 8 at different time points. Primary human osteoblasts (pOBs) were cultivated for 7 days using PRF-conditioned media acquired from either 3 mL or 10 mL of peripheral blood. The results showed that 3 mL of peripheral blood is sufficient to produce a liquid PRF concentrate similar to that acquired when using 10 mL blood. The concentrations of platelets and leukocytes were comparable regardless of the initial blood volume (3 mL vs. 10 mL). Similarly, the release of growth factors (EGF, TGF-β1, and PDGF) and interleukin 8 was often comparable in both groups over 7 days. The cultivation of pOBs using PRF-conditioned media showed a similar proliferation rate regardless of the initial blood volume. This proliferation rate was also similar to that of pOBs treated with 20% FBS-conditioned media. These findings validated the use of 3 mL of peripheral blood to generate liquid PRF matrices according to the low-speed centrifugation concept, which may open new application fields for research purposes such as in vivo experiments and clinical applications such as pediatric surgery.

Osteochondral Regeneration in the Knee Joint with Autologous Peripheral Blood Stem Cells plus Hyaluronic Acid after Arthroscopic Subchondral Drilling: Report of Five Cases

BACKGROUND

Treatment of osteochondral defects (OCDs) of the knee joint remains challenging. The purpose of this study was to evaluate the clinical and radiological results of osteochondral regeneration following intra-articular injections of autologous peripheral blood stem cells (PBSC) plus hyaluronic acid (HA) after arthroscopic subchondral drilling into OCDs of the knee joint.

CASE PRESENTATION

Five patients with OCDs of the knee joint are presented. The etiology includes osteochondritis dissecans, traumatic knee injuries, previously failed cartilage repair procedures involving microfractures and OATS (osteochondral allograft transfer systems). PBSC were harvested 1 week after surgery. Patients received intra-articular injections at week 1, 2, 3, 4, and 5 after surgery. Then at 6 months after surgery, intra-articular injections were administered at a weekly interval for 3 consecutive weeks. These 3 weekly injections were repeated at 12, 18 and 24 months after surgery. Each patient received a total of 17 injections. Subjective International Knee Documentation Committee (IKDC) scores and MRI scans were obtained preoperatively and postoperatively at serial visits. At follow-ups of >5 years, the mean preoperative and postoperative IKDC scores were 47.2 and 80.7 respectively (p = 0.005). IKDC scores for all patients exceeded the minimal clinically important difference values of 8.3, indicating clinical significance. Serial MRI scans charted the repair and regeneration of the OCDs with evidence of bone growth filling-in the base of the defects, followed by reformation of the subchondral bone plate and regeneration of the overlying articular cartilage.

CONCLUSION

These case studies showed that this treatment is able to repair and regenerate both the osseous and articular cartilage components of knee OCDs.

Recent advances in 3D bioprinted cartilage-mimicking constructs for applications in tissue engineering

Human cartilage tissue can be categorized into three types: hyaline cartilage, elastic cartilage and fibrocartilage. Each type of cartilage tissue possesses unique properties and functions, which presents a significant challenge for the regeneration and repair of damaged tissue. Bionics is a discipline in which humans study and imitate nature. A bionic strategy based on comprehensive knowledge of the anatomy and histology of human cartilage is expected to contribute to fundamental study of core elements of tissue repair. Moreover, as a novel tissue-engineered technology, 3D bioprinting has the distinctive advantage of the rapid and precise construction of targeted models. Thus, by selecting suitable materials, cells and cytokines, and by leveraging advanced printing technology and bionic concepts, it becomes possible to simultaneously realize multiple beneficial properties and achieve improved tissue repair. This article provides an overview of key elements involved in the combination of 3D bioprinting and bionic strategies, with a particular focus on recent advances in mimicking different types of cartilage tissue.

Microfracture- and Xeno-Matrix-Induced Chondrogenesis for Treatment of Focal Traumatic Cartilage Defects of the Knee: Age-Based Mid-Term Results

The aim of this study was to investigate clinical and instrumental outcomes of the autologous matrix-induced chondrogenesis (AMIC) technique for the treatment of isolated traumatic condyle and femoropatellar cartilage lesions. A total of 25 patients (12 males, 13 females, mean age 47.3 years) treated between 2018 and 2021 were retrospectively reviewed and subdivided into two groups based on age (Group A, age < 45 years; Group B, age > 45 years). A clinical evaluation was performed using the International Knee Documentation Committee (IKDC), Lysholm score and Visual Analogue Score (VAS). Cartilage regeneration was evaluated via magnetic resonance (1.5 Tesla) and classified according to a Magnetic resonance Observation of CArtilage Repair Tissue (MOCART) scoring system. At a minimum follow-up of 2 years, Group A patients obtained greater instrumental results in comparison to group B: in fact, the MOCART score was statistically significantly correlated with IKDC (r = 0.223) (p < 0.001) exclusively in group A. Nevertheless, a significant improvement in clinical functionality was shown in Group B (p < 0.001), demonstrating that this technique is safe, reproducible and capable of offering satisfactory clinical results regardless of age.

Autologous minced cartilage repair for chondral and osteochondral lesions of the knee joint demonstrates good postoperative outcomes and low reoperation rates at minimum five-year follow-up

PURPOSE

Minced cartilage is a one-step, autologous procedure with promising short-term results. The aim of the present study was to evaluate mid-term results in a patient cohort with chondral and osteochondral lesions in the knee joint treated with minced cartilage.

METHODS

From 2015 through 2016, a total of 34 consecutive patients were treated with a single-step, autologous minced cartilage for knee chondral and osteochondral lesions. Numeric analogue scale (NAS) for pain and knee function were obtained prior to surgery and at 12, 24 and 60 months postoperatively. Secondary outcomes, including Lysholm score, Tegner activity score, and the International Knee Documentation Committee (IKDC) score, were recorded at final follow-up. MRI examinations of patients with unplanned radiological follow-up were analysed using the MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score.

RESULTS

A total of 28 patients (44.1% females, age at surgery: 29.5 ± 11.5 years) were available at a mean follow-up of 65.5 ± 4.1 months. Mean defect size was 3.5 ± 1.8 cm2. NAS for pain decreased from a median of 7 (range: 2-10) preoperatively to 2 (0-8) postoperatively. NAS knee function improved from a median of 7 (range: 2-10) to 3 (0-7) after five years, respectively. Satisfactory Lysholm (76.5 ± 12.5), IKDC (71.6 ± 14.8) and Tegner activity (4, range 3-9) scores were reported at final follow-up. Of all patients, 21(75%) and 19 (67.9%) reached or exceeded the PASS for the IKDC- and Lysholm score at final follow-up, respectively. The average overall MOCART 2.0 scores for all postoperatively performed MRIs (n = 23) was 62.3 ± 17.4. Four (14.2%) postoperative complications were directly linked to minced cartilage, one (3.5%) of which required revision surgery.

CONCLUSION

One-step, autologous minced cartilage repair of chondral and osteochondral lesions of the knee without the necessity for subchondral bone treatment demonstrated good patient-reported outcomes, low complication rates, and graft longevity at mid-term follow-up. Minced cartilage represents a viable treatment option to more traditional cartilage repair techniques even in mid-term.

LEVEL OF EVIDENCE

Level III.

Costal chondrocyte-derived pellet-type scaffold-free autologous chondrocyte implantation provided acceptable mid-term outcomes in osteochondral defects with up to 10-mm depth

PURPOSE

To evaluate clinical, radiographic, and magnetic resonance (MR) results of costal chondrocyte-derived pellet-type scaffold-free autologous chondrocyte implantation (CCP-ACI) in osteochondral defects (ODs) up to 10-mm depth during 5 years of follow-up.

METHODS

Ten patients with CCP-ACI performed in ODs with depth up to 10 mm were retrospectively analyzed. The minimum follow-up period was 5 years. The median age was 36.5 (range 20-55) years. The median size and the depth of the OD lesion were 4.25 cm2 (range 2-6) and 7.0 mm (6-9), respectively. Clinically, the International Knee Documentation Committee, Lysholm, and visual analog scale pain scores were evaluated. Radiographically, the hip‒knee‒ankle (HKA) angle and the Kellgren‒Lawrence (K‒L) grade were assessed. On MR imaging, the magnetic resonance observation of cartilage repair tissue (MOCART) 2.0 score and the defect depth were evaluated.

RESULTS

All average clinical scores improved significantly by 1, 2, and 5 years postoperatively. The average HKA angle and the proportion of K‒L grade did not change significantly within 5 years. The median total MOCART scores were 50 (range 45-65), 50 (35-90), 57.5 (40-90), and 65 (50-85) at 6 months, 1 year, 2 years, and 5 years postoperatively, respectively (p = 0.001), with significant improvement at 2 years compared to that at 6 months postoperatively. The signal intensity of the repair tissue and subchondral change significantly improved from 10 (range 10-10) to 12.5 (10-15) (p = 0.036), and from 10 (10-10) to 17.5 (0-20) (p = 0.017), respectively. Significant improvements were seen at 5 years postoperatively for the former and at 2 years postoperatively for the latter. The average depths on MR imaging were 6.7, 6.7, 6.8, 6.6, and 6.6 mm preoperatively and at 6 months, 1 year, 2 years, and 5 years postoperatively with no significant changes (n.s).

CONCLUSION

CCP-ACI provided acceptable mid-term outcomes in ODs up to 10-mm in depth without bone grafting despite of no scaffold. The procedure can be one of minimally invasive treatment options for ODs without scaffold-related problems.

LEVEL OF EVIDENCE

IV.