Arthroscopic second generation autologous chondrocytes implantation associated with bone grafting for the treatment of knee osteochondritis dissecans: Results at 6 years

Autologous bone grafting in combination with autologous chondrocyte implantation yields favourable outcomes in the treatment of osteochondral defects of the knee: A systematic literature review

PURPOSE

This study addresses the gap in the current literature by evaluating the combined treatment of autologous bone grafting and autologous chondrocyte implantation (ABCI) for osteochondral defects of the knee. It aims to evaluate clinical outcomes against methodological quality and to summarize histological results and surgical techniques.

METHODS

A thorough search was conducted across Pubmed, Cochrane and Embase databases. Studies reporting clinical outcomes of ABCI for osteochondral defects of the knee were included. Patient-reported outcome measures (PROMs), failure rates, methodological quality and potential conflicts of interest were evaluated. Histological results and surgical techniques were summarized.

RESULTS

Eighteen studies with 344 analyzed patients met the eligibility criteria for inclusion. All studies showed a significant improvement (p < 0.05) across different PROMs (subjective International Knee Documentation Committee score, Cincinnati Knee Rating System, Visual Analogue Scale, Lysholm Score, Tegner Activity Scale, Knee injury and Osteoarthritis Outcome Score and Knee Society Score) compared to the preoperative status. Failure rates ranged from 0% to 17.6%, with a mean follow-up of 73.2 months (range: 9.0-143.6 months). Methodological quality was low to medium, including only one comparative study. Six studies reviewed reported a potential conflict of interest. The histological assessment showed effective bonding between autologous chondrocytes and bone graft. A large degree of variability was observed in the operative technique used.

CONCLUSION

The current literature suggests that ABCI yields good clinical outcomes at mid- to long-term follow-up with favourable histological results for osteochondral defects of the knee. However, future research should focus on high-quality comparative studies to better guide treatment choices. Introducing ABCI as the standard abbreviation may enhance clarity in future research.

LEVEL OF EVIDENCE

Level IV.

Do reconstructive techniques for osteochondritis dissecans of the skeletally mature knee work? A systematic review and meta-analysis

PURPOSE

Osteochondritis dissecans (OCD) is a common cause of knee pain. Management for adult-onset OCD (AOCD) usually involves surgery. Surgical treatments include palliative, reparative and reconstructive techniques. The aim of this systematic review and meta-analysis is to evaluate the efficacy of reconstructive techniques for the treatment of OCD in skeletally mature knees.

METHODS

A systematic search was carried out on four databases up to November 2023 (Medline, Embase, Cochrane Library, Web of Science). The study was registered on international prospective register of systematic reviews and performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Clinical studies on skeletally mature patients were included, which utilised reconstructive techniques such as autologous chondrocyte implantation (ACI), matrix-induced autologous chondrocyte implantation, osteochondral allograft transplantation surgery or bone marrow-derived cellular transplantation. Demographical data, patient-reported outcome measures and postoperative complications were recorded. Quantitative outcome measures that were comparable across studies were pooled for meta-analysis. A random effects model was used. Heterogeneity was assessed using the I2 statistic and Cochran's Q test. Statistical significance was set at p < 0.05. Risk of bias was assessed using the risk of bias in non-randomised studies - of interventions tool for nonrandomised studies.

RESULTS

Sixteen studies were included with 458 OCD lesions in 432 patients. The average age was 24.9, and 62.6% were male. The mean follow-up time was 61.5 months. At 36 months follow-up, International Knee Documentation Committee (IKDC) subjective, Tegner and EuroQol-visual analogue scale (EQ-VAS) scores improved from 42.4 to 78.6 (standard mean difference [SMD]: 2.47; p < 0.001), 2.27-4.99 (SMD: 2.363; p = 0.002) and 30.4-57.5 (SMD: 2.390; p < 0.001), respectively. Overall complication rate was 8.9%. Smaller OCD lesion sizes resulted in a greater improvement in IKDC subjective (SMD: 2.64 vs. 2.01; p = 0.038), EQ-VAS (SMD: 3.16 vs. 0.95; p = 0.046) and Tegner scores (SMD: 3.13 vs. 1.05; p = 0.007) and had a lower complication rate (p = 0.008). Males showed a larger improvement in IKDC subjective scores than females (SMD: 2.56 vs. 1.56; p = 0.029), while younger patients had a larger improvement in IKDC subjective scores (SMD: 2.71 vs. 2.12; p = 0.045) and fewer complications than older patients (p = 0.003). There were no significant differences between cohorts treated with ACI and those treated with non-ACI reconstructive techniques. Publication bias was not detected (n.s.).

CONCLUSION

Reconstructive techniques used to treat OCD in the skeletally mature knee resulted in significant improvements in clinical and functional outcomes, with a low overall complication rate. Since a younger age leads to a greater improvement in IKDC subjective score and a lower complication rate, surgical intervention should not be delayed, especially in AOCD lesions which are more likely to follow a progressive and unremitting clinical course.

LEVEL OF EVIDENCE

Level III.

[Treatment of osteochondritis dissecans]

Osteochondritis dissecans (OD) is a rare condition with an incidence of 30/100,000. It especially affects male patients aged 10-20 years old. During the staged progression the osteochondral fragments can detach from their base. These can damage the adjacent articular cartilage, which can lead to premature osteoarthritis. Most commonly affected are the knee, ankle and elbow joints. The exact pathogenesis of OD has so far not been clearly confirmed. Several risk factors that can lead to the development of OD are discussed. These include repeated microtrauma and vascularization disorders that can lead to ischemia of the subchondral bone and to a separation of the fragments close to the joint and therefore to the development of free joint bodies. For an adequate clarification patients should undergo a thorough radiological evaluation including X‑ray imaging followed by magnetic resonance imaging (MRI) to assess the integrity of the cartilage-bone formation with determination of the OD stage. The assessment is based on criteria of the International Cartilage Repair Society (ICRS). The instability of the cartilage-bone fragment increases with higher stages. Stages I and II with stable cartilage-bone interconnection can be treated conservatively. For stages III and IV, i.e., instability of the OD fragment or the presence of free fragments, surgical treatment should be performed. Primarily, refixation of a free joint body should be carried out depending on the size and vitality of the fragment. In cases of unsuccessful conservative treatment or fixation, a debridement, if necessary in combination with a bone marrow stimulating procedure, can be employed corresponding to the size of the defect. For larger cartilage defects, an osteochondral graft transplantation should be considered. Overall, OD lesions in stages I and II show a good healing tendency under conservative treatment. In cases of incipient unstable OD, refixation can also lead to good clinical and radiological results.

A systematic review of cartilage procedures for unstable osteochondritis dissecans

OBJECTIVES

Osteochondritis dissecans can result in significant limitations in activity, pain, and early osteoarthritis. There are various treatment modalities to address these defects. The purpose of this study was to provide a qualitative summary of the various treatment options for unstable osteochondritis dissecans in the knee.

METHODS

A literature search was performed on osteochondritis dissecans in the knee using PubMed (MEDLINE), Embase, and Cochrane electronic databases. The search was completed using a combination of the following terms: 'osteochondritis dissecans,' 'OCD,' 'osteochondral,' 'articular cartilage,' 'repair,' 'surgery,' 'treatment,' 'osteochondral allograft,' 'autologous chondrocyte implantation,' 'unstable,' 'knee,' 'clinical studies.'

RESULTS

A total of 682 studies were found, of which 24 were included in the qualitative analysis. The quality score ranged from 46 to 80, and the mean follow-up ranged from 2 to 17 years. The most common surgical procedures were internal fixation (n = 7 studies), ACI (n = 6), fragment excision (n = 3), MACI (n = 2), bone graft + ACI (n = 2), OCA (n = 2), mosaicplasty/OAT (n = 2), and scaffold (n = 2). Overall, the reported outcome measures were heterogeneous in nature. Post-operative International Knee Documentations Committee (IKDC) scores ranged from 75 to 85 and Lysholm scores ranged from 70 to 93.5. Tegner scores ranged from 4 to 5. Rates of failure, complication, and revision were highly variable across studies and surgical techniques.

CONCLUSION

There are a variety of surgical options for the treatment of unstable osteochondritis dissecans. In skeletally immature patients, internal fixation demonstrated acceptable rates of radiographic union and patient reported outcome measures. In skeletally mature patients with large lesions, MACI and OCA transplantation provided similar patient reported outcomes.

Particularities on Anatomy and Normal Postsurgical Appearances of the Knee

Detailed knowledge of anatomy helps to understand pathologic processes. This article focuses on the anatomy and functionality of the knee, with emphasis on recently studied concepts and anatomic features that have an association with the development of pathology. The most common anatomic variants posing a challenge for diagnosis and other common findings in asymptomatic patients are reviewed. Good understanding of the different surgical procedures helps in providing as much information as possible to guarantee a positive outcome, improving prognosis. We review what are the commonly expected postsurgical appearances and the most common postsurgical complications.

Surgical strategies for chondral defects of the patellofemoral joint: a systematic review

BACKGROUND

The management of chondral defects of the patellofemoral joint is debated, and definitive evidence is lacking. This study systematically updated and summarised the current literature on the surgical management of isolated chondral defects of the patellofemoral joint, discussing techniques, outcome, pitfalls, and new frontiers.

METHODS

This systematic review was conducted according to the 2020 PRISMA statement. In August 2022, PubMed, Web of Science, Google Scholar, and Embase databases were accessed with no time constrain. All the clinical studies investigating the surgical management of chondral defects of the patellofemoral joint were retrieved. Articles which reported data on patients with advanced to severe osteoarthritis were not eligible. Only studies with a minimum 24 months follow-up were considered. Studies which mixed results of patellofemoral and tibiofemoral joints were not considered.

RESULTS

Data from 10 studies (692 procedures) were retrieved. The mean follow-up was 46.9 ± 18.2 months. The mean age of the patients was 34.0 ± 6.1 years, and the mean BMI was 25.9 ± 0.8 kg/m². The mean duration of symptoms before the index surgery was 81.0 ± 24.0 months. The mean defect size was 3.8 ± 0.8 cm². All the PROMs improved from baseline to last follow-up: VAS 0-10 (P = 0.04), Tegner (P = 0.02), Lysholm (P = 0.03), and International Knee Documentation Committee (P = 0.03). The rate of hypertrophy was 5.6% (14 of 251), the rate of progression to total knee arthroplasty was 2.4% (2 of 83), the rate of revision was 16.9% (29 of 136), and the rate of failure was 13.0% (16 of 123).

CONCLUSION

Current surgical strategies may be effective to improve symptoms deriving from chondral defects of the patellofemoral joint. The limited and heterogeneous data included for analysis impact negatively the results of the present study. Further clinical studies are strongly required to define surgical indications and outcomes, and the most suitable technique.

Autologous matrix-induced chondrogenesis is effective for focal chondral defects of the knee

Focal chondral defects of the knee are common and their management is challenging. This study investigated the efficacy and safety of Autologous Matrix-Induced Chondrogenesis (AMIC) for focal chondral defects of the knee. A systematic review and meta-analysis was conducted (according to the 2020 PRISMA statement) to investigate the efficacy of AMIC in improving symptoms and to compare AMIC versus microfracture (MFx). In January 2022, the following databases were accessed: Pubmed, Web of Science, Google Scholar, Embase. No time constrain was used for the search. All the clinical trials investigating AMIC and/or those comparing AMIC versus MFx for focal chondral defects of the knee were accessed. Only studies published in peer reviewed journals were considered. Studies which investigated other locations of the defects rather than knee were not eligible, nor those reporting data form mixed locations. Studies which reported data on revision settings, as well as those investigating efficacy on kissing lesions or multiple locations, were not suitable. The mean difference (MD) and odd ratio (OR) effect measure were used for continuous and binary data, respectively. Data from 18 studies (548 patients) were retrieved with a mean follow-up of 39.9 ± 26.5 months. The mean defect size was 3.2 ± 1.0 cm². The visual analogue scale (VAS) decreased of − 3.9/10 (95% confidence interval (CI) − 4.0874 to -3.7126), the Tegner Activity Scale increased of + 0.8/10 (95% CI 0.6595 to 0.9405). The Lysholm Knee Scoring System increased of + 28.9/100 (95% CI 26.8716 to 29.1284), as did the International Knee Documentation Committee (IKDC) + 33.6/100 (95% CI 32.5800 to 34.6200). At last follow-up no patient showed signs of hypertrophy. 4.3% (9 of 210) of patients underwent revision procedures. The rate of failure was 3.8% (9 of 236). Compared to MFx, AMIC demonstrated lower VAS score (MD: − 1.01; 95% CI − 1.97 to 0.05), greater IKDC (MD: 11.80; 95% CI 6.65 to 16.94), and lower rate of revision (OR: 0.16; 95% CI 0.06 to 0.44). AMIC is effective for focal chondral defects of the knee. Furthermore, AMIC evidenced greater IKDC, along with a lower value of VAS and rate of revision compared to MFx.

Chondral injuries in patients with recurrent patellar dislocation: a systematic review

Background

Patellar dislocations in patients presenting with recurrent patellofemoral instability can damage the surrounding structures, limiting patient’s participation to recreational activities and quality of life. This study evaluated frequency, location, and extent of associated injuries in patients with recurrent patellar dislocation.

Methods

This systematic review was conducted according to the PRISMA checklist. PubMed, Google scholar, Embase, and Web of Science databases were accessed in July 2021. All the published clinical studies reporting frequency, location, and extent of soft tissue lesions in patients with recurrent patellar dislocations were accessed.

Results

Data from 9 articles (232 patients) were retrieved. The mean age of the included patients was 21.2 ± 5.6 years. 84.8% of patients suffering from recurrent patellar dislocations demonstrated patellar chondral defects: medial facet (34.9%), while patellar crest (34.8%) and lateral facet (17%). 27.8% of patients demonstrated trochlear chondral injuries.

Conclusion

Chondral defects of the medial facet and the crest of the patella are the most common in patients with recurrent patellofemoral instability.

Treatment of Juvenile Knee Osteochondritis Dissecans with a Cell-Free Biomimetic Osteochondral Scaffold: Clinical and MRI Results at Mid-Term Follow-up

OBJECTIVE

Osteochondral surgical procedures have been described for the treatment of unfixable osteochondritis dissecans (OCD), but only few of them have been studied for juvenile OCD (JOCD) lesions. A cell-free biomimetic osteochondral scaffold showed positive results in adult patients. The aim of this study was to evaluate the results of this scaffold for the treatment of knee JOCD at mid-term follow-up.

DESIGN

Twenty patients (14 males, 6 females) were included in this study. Mean age was 16.2 ± 1.4 years, average defect size was 3.2 ± 1.8 cm², and mean symptoms duration was 20.2 ± 17.9 months. After the implantation of the osteochondral collagen-hydroxyapatite scaffold (Maioregen, Fin-Ceramica, Faenza, Italy), patients were evaluated preoperatively and prospectively at 1, 2, and at final mean follow-up of 6 years (range 5-7 years) with International Knee Documentation Committee (IKDC) subjective and objective, Tegner, and EuroQol visual analogue scale (VAS) scores. MRI evaluation was performed with the MOCART 2.0 score.

RESULTS

All scores showed a significant improvement. IKDC subjective score went from 50.3 ± 17.4 preoperative score to 75.3 ± 14.6 at 1 year (P = 0.002), 80.8 ± 14.6 at 2 years and 85.0 ± 9.3 at 6 years. The Tegner score improved from the preoperative evaluation of 2.6 ± 1.4 to 5.5 ± 2.0 at 6 years (P < 0.0005), although without reaching the level registered before the onset of symptoms. A longer symptoms duration influenced negatively IKDC subjective and Tegner scores up to 2 years (P = 0.003 and P = 0.002, respectively) but did not affect the final outcome. Lesion size did not affect the final result. The MOCART 2.0 score showed a significant improvement between 1-year and final follow-up, but with persisting subchondral alterations.

CONCLUSIONS

This study demonstrated a clinical improvement stable over time with a high survival rate, although with persisting abnormal MRI findings, especially at subchondral bone level. This procedure can be considered a suitable option for the treatment of young patients affected by knee OCD. Level of evidence. Case series, level IV.

Cell-free osteochondral scaffolds provide a substantial clinical benefit in the treatment of osteochondral defects at a minimum follow-up of 5 years

Purpose

The treatment of osteochondral lesions is challenging and no consensus has been established about the best option for restoring both cartilage and subchondral bone. Multilayer collagen-hydroxyapatite scaffolds have shown promising clinical results, but the outcome at a follow-up longer than 5 years still has to be proved. The aim was to evaluate the clinical outcome of patients with a knee isolated osteochondral lesion treated with a biomimetic three-layered scaffold at a minimum 5 years of follow-up.

Methods

Twenty-nine patients (23 males and 6 females, mean age 31.5 ± 11.4 years) were evaluated retrospectively before surgery, at 1 and 2 years and at last follow-up (FU). Visual Analog Scale (VAS) for pain, International Knee Documentation Committee (IKDC) Subjective Score, Tegner-Lysholm Knee Scoring Scale and Tegner Activity Level Scale were collected. Mean FU was 7.8 ± 2.0 years (min 5.1 - max 11.3). The etiology of the defect was Osteochondritis Dissecans or osteonecrosis (17 vs 12 cases).

Results

At 12 months FU the IKDC score improved from 51.1 ± 21.7 to 80.1 ± 17.9 (p < 0.01), Tegner Lysholm Score from 59.9 ± 17.3 to 92.5 ± 9.0 (p < 0.01), VAS from 6.1 ± 2.1 to 1.7 ± 2.3 (p < 0.01) and Tegner Activity Level Scale from 1.6 ± 0.5 to 4.9 ± 1.7 (p < 0.01). The results remained stable at 24 months, while at last FU a statistically significant decrease in IKDC, Tegner Lysholm and Tegner Activity Scale was recorded, though not clinically relevant. Patients under 35 achieved statistically better outcomes.

Conclusions

The use of a cell-free collagen-hydroxyapatite osteochondral scaffold provides substantial clinical benefits in the treatment of knee osteochondral lesions at a minimum follow-up of 5 years, especially in patients younger than 35 years.

Level of evidence

Level IV.

Matrix-assisted chondrocyte transplantation with bone grafting for knee osteochondritis dissecans: stable results at 12 years

PURPOSE

To document clinical and radiological results of arthroscopic matrix-assisted autologous chondrocyte transplantation (MACT) combined with bone grafting for the treatment of knee osteochondritis dissecans (OCD) at long-term follow-up.

METHODS

Thirty-one knees in 29 patients (20.4 ± 5.7 years) were treated for symptomatic unfixable OCD lesions (2.6 ± 1.1 cm²) and prospectively evaluated at 2, 5, and 12 years (average, minimum 10 years). Patients were evaluated over time with IKDC subjective score, EQ-VAS, and Tegner scores. Failures were also documented. At the final follow-up, MRI evaluation was performed in 14 knees with the MOCART 2.0 score.

RESULTS

Beside 4 early failures, an overall clinical improvement was documented: the IKDC subjective score improved from 39.9 ± 16.8 to 82.1 ± 17.0 and 84.8 ± 17.2 at 2 and 5 years, respectively (p < 0.0005), and remained stable for up to 12 years (85.0 ± 20.2). EQ-VAS and Tegner scores presented similar trends, but patients did not reach their original activity level. Worse results were obtained for lesions bigger than 4 cm². At MRI evaluation, subchondral bone abnormalities were detected in over 85% of knees at long-term follow-up.

CONCLUSIONS

Arthroscopic bone grafting followed by MACT for unfixable knee OCD can offer a promising and stable clinical outcome over time in lesions smaller than 4 cm², with a low failure rate of 13%. Persistent subchondral alterations were documented at long-term MRI evaluation, suggesting the limits of this approach to regenerate the osteochondral unit in patients affected by knee OCD.

LEVEL OF EVIDENCE

IV.

Autologous Matrix-Induced Chondrogenesis (AMIC) and Microfractures for Focal Chondral Defects of the Knee: A Medium-Term Comparative Study

Introduction: The potential of autologous matrix-induced chondrogenesis (AMIC) to restore unipolar focal chondral defects of the knee is promising. However, the outcome compared to microfracturing (MFx) for certain defect sizes (2–3 cm²) is still uncertain. Therefore, the present study compared primary isolated AMIC versus MFx in a cohort of patients with borderline sized focal unipolar chondral defects of the knee at midterm follow-up. Methods: Patients with chondral defects of the knee who underwent AMIC or MFx were compared. An arthroscopic approach was used for MFx, and a minimally invasive parapatellar arthrotomy for AMIC. For those patients who underwent AMIC, a collagen membrane was used with fibrin glue. The patients answered independently: Visual Analogic Scale (VAS), Tegner Activity Scale, International Knee Documentation Committee (IKDC), and the Lysholm scores. Results: A total of 83 patients with a mean age of 30.2 and body mass index (BMI) of 26.9 kg/m² were recruited. Of them, 33.7% (28 of 83) were women, and 55.4% (46 of 83 patients) had defects in the right knee. The mean length of symptoms before surgery was 43.3 months. The mean size of the defect was 2.7 cm². The mean length of follow-up was 42.1 months. No difference was found in terms of symptoms and follow-up length, mean age and BMI, mean size of defect, sex, and side. The AMIC cohort reported greater IKCD (p > 0.0001), Lysholm (p = 0.002), VAS (p = 0.01), Tegner (p = 0.004) scores. The AMIC cohort reported lower rate of failure (p = 0.005) and revision surgery (p = 0.02). No difference was found in the rate of arthroplasty (p = 0.2). No delamination or hypertrophy were detected. Conclusion: AMIC demonstrated superiority over MFx for focal unipolar chondral defects of the knee. At approximately 40 months follow-up, the IKDC, Lysholm, and VAS scores were greater in the AMIC group. Patients treated with AMIC also demonstrated a higher level of sport activity, and lower rates of failure and revision surgeries.

Management of Patellar Chondral Defects with Autologous Matrix Induced Chondrogenesis (AMIC) Compared to Microfractures: A Four Years Follow-Up Clinical Trial

Introduction: Evidence on the management of chondral defects of the patella arises from studies in which the patellofemoral joint was treated together with the femorotibial joint and primary and revision settings. Furthermore, the superiority of Autologous Matrix Induced Chondrogenesis (AMIC) over microfractures (MFx) for patellar chondral defects is uncertain. Therefore, the present study compared primary isolated AMIC versus MFx for focal unipolar chondral defects of the patellar facet joints at midterm follow-up. Methods: Patients undergoing AMIC or isolated MFx surgery for borderline-sized focal unipolar chondral defects of the patellar facet joints were followed at our institution. All surgeries were performed in the same fashion by experienced surgeons. A parapatellar arthrotomy was adopted in all surgeries. The outcomes of interest were: Visual Analogic Scale (VAS), Tegner Activity Scale, International Knee Documentation Committee (IKDC), and the Lysholm scores. The Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) was assessed by a blinded radiologist, who had not been involved in the clinical management of the patients. Results: 38 patients were enrolled in the present study: 27 underwent AMIC, and 11 MFx. The mean follow-up was 45.1 months. The mean age of the patients at baseline was 34.5 years. The mean size of the defect was 2.6 cm². The MFx cohort experienced a shorter length of the hospitalization (P = 0.008). There was no difference in terms of follow-up and previous symptoms duration, mean age, sex, side, defect size, and BMI. At last follow-up, the AMIC cohort reported greater IKDC (P = 0.01), Lysholm (P = 0.009), and Tegner (P = 0.02), along with a low rate of failure (P = 0.02). VAS was lower in the AMIC group (P = 0.002). No difference was found in the MOCART score (P = 0.09), rates of revision (P = 0.06), and arthroplasty (P = 0.2). Conclusion: The AMIC procedure achieves greater IKDC and Lysholm score, and a significant reduction of the VAS score in the management of patellar chondral defects. The Tegner scale demonstrated greater activity after AMIC procedure. Finally, the AMIC group evidenced a lower rate of failure. Similarity was found on MOCART score, rates of revision, and arthroplasty between the two procedures.

AMIC for Focal Osteochondral Defect of the Talar Shoulder

BACKGROUND

The management of a focal osteochondral lesion of the talus (OLT) is challenging. Evidence concerning the role of the autologous matrix-induced chondrogenesis (AMIC) procedure in patients with focal OLT is promising. The purpose of the present study was to investigate clinical outcomes and radiographic findings of the AMIC technique for focal unipolar OLT.

MATERIAL AND METHODS

The present study was performed according to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guidelines. Twenty-four patients who underwent AMIC for focal OLT were prospectively recruited at our institution. All the surgeries were performed by two experienced surgeons through malleolar osteotomy and autologous cancellous bone grafting. The outcomes of interest were the American orthopedic foot and ankle score (AOFAS), the foot-function index (FFI), and the magnetic resonance observation of cartilage repair tissue (MOCART). Surgical duration, hospitalization length, and complications were also collected.

RESULTS

24 patients were included in the present study. The mean follow-up was 25.17 ± 13.1 months. The mean age of the patients at surgery was 46.75 ± 15.2 years, the mean BMI 26.92 ± 5.7 kg/m², and 50% (12 of 24) of patients were female. The right ankle was involved in 62.5% (15 of 24) of patients. The mean defect size was 6.95 ± 2.9 mm². The mean surgical duration was 112 ± 20 min while the mean hospitalization 5.58 ± 1.7 days. At last follow-up, the AOFAS increased by 27.8 points (p < 0.0001), while the FFI reduced by 25.3 points (p < 0.0001) and the MOCART score increased by 28.33 points (p < 0.0001). No complications were observed.

CONCLUSION

The AMIC procedure for focal osteochondral defects of the talar shoulder is feasible and reliable at midterm follow-up.

Osteochondral autograft transplantation versus autologous bone-cartilage paste grafting for the treatment of knee osteochondritis dissecans

PURPOSE

To compare the results of two groups of patients affected by osteochondritis dissecans (OCD) of the knee and treated with either osteochondral autologous transplantation (OAT) or bone-cartilage paste grafting (PG).

METHODS

A total of 27 patients affected by OCD lesions of the femoral condyles were included: 15 treated with OAT, 12 with PG, with comparable baseline characteristics (mean age 22.4 ± 7.2 vs. 24.2 ± 8.5 p = n.s., mean defect size 2.2 ± 1 cm² vs 2.6 ± 1 cm² p = n.s.). Patients were evaluated pre-operatively and at 24 and 84 months post-operatively with the International Knee Documentation Committee (IKDC) subjective and objective scores. Sport activity level was evaluated with the Tegner activity score. Adverse events and failures were also recorded.

RESULTS

The IKDC subjective score improved significantly in both groups. At 24 months, a significant improvement from 53.4 ± 9.1 to 80.8 ± 12.9 (p = 0.005) was obtained in the OAT group and from 44.6 ± 11.0 to 71.4 ± 25.3 in the PG group (p = 0.008). A further statistically significant increase was observed at 84 months in both groups. No significant differences were found between OAT and PG at both follow-ups. One OAT patient required post-operative knee mobilization under narcosis and two complained of donor site symptoms. More failures were documented in the PG vs OAT group (25% vs 0%; p = 0.043).

CONCLUSION

Both PG and OAT provided overall satisfactory results up to 84 months follow-up. However, while PG presents the advantages of a less invasive approach with lower adverse events, the higher failure rate of PG should be considered when choosing between these two surgical treatment options for restoration of the articular surface in patients affected by knee OCD.

[Technique of all arthroscopic autologous chondrocyte implantation (ACI) for the treatment of cartilage defects in the knee]

OBJECTIVE

All arthroscopic treatment of deep cartilage defects in the knee for reconstruction of the articular surface.

INDICATIONS

Focal cartilage defects of the knee (ICRS ≥ grade 3) from a size of 2.5 cm² and more.

CONTRAINDICATIONS

Osteoarthritis (Kellgren-Lawrence > grade 2), osseus defect situation, cartilage lesion of the opposing articular surfaces (ICRS > grade 2), instability, malalignment (>3-4°), inflammatory joint diseases.

SURGICAL TECHNIQUE

First procedure (cell harvesting): Treatment of additional pathologies, preparation of the cartilage defect, harvesting of osteochondral cylinders for cell culture. Second procedure (cell implantation): Dry arthroscopy, cleaning and drying of the already prepared defect, implantation of the in situ crosslinking cartilage cell suspension.

POSTOPERATIVE MANAGEMENT

First procedure (cell harvesting): Early functional treatment with weight bearing as tolerated. Second procedure (cell implantation): No drains, extension brace for 4 days, then free range of motion, partial weight bearing for 4 weeks in patellofemoral implantation and for 8 weeks in tibiofemoral implantation, continuous passive motion beginning in postoperative week 2, cycling from postoperative week 9.

RESULTS

In the literature, results for ACI in the knee are reported to be good, especially for larger cartilage defects. Arthroscopic techniques should lead to a decrease of complications and perioperative morbidity. No technique-specific complications occurred in our cohort. From 2012-2015, 98 patients were treated using the above mentioned technique, whereby 62 patients were retrospectively evaluated after 31.0 ± 14.8 (12.5-61.4) months. In 15 patients (28%) additional procedures were performed (7 anterior cruciate ligament reconstructions, 3 correction osteotomies and 5 medial patellofemoral ligament reconstructions). Average cartilage defect size was 4.7 ± 2.8 cm², in 18 patients (29%) more than one cartilage defect was treated. The subjective IKDC and total KOOS scores resulted in 66 ± 10 and 73 ± 19 points.

Long-term Results of Matrix-assisted Autologous Chondrocyte Transplantation Combined With Autologous Bone Grafting for the Treatment of Juvenile Osteochondritis Dissecans

BACKGROUND

Osteochondritis dissecans is a pathology affecting young patients that involves the entire osteochondral unit. In the case of unfixable fragments, regenerative cartilage treatments are a viable solution, but little is known about the use of these procedures for the treatment of juvenile osteochondritis dissecans (JOCD). The aim of this study was to evaluate the long-term results offered by matrix-assisted autologous chondrocyte transplantation combined with autologous bone grafting for the treatment of JOCD.

METHODS

Nineteen patients have been enrolled. The mean age at the time of treatment was 16.8±1.5 years, with a mean body mass index of 22.9±2.7. The average size of the defects was 2.8±1.2 cm. All patients were evaluated prospectively before surgery and at 12, 24, 60, and at a final follow-up of 120 months with International Knee Documentation Committee scores, EuroQol-Visual Analogue Scale, and the Tegner Score.

RESULTS

A statistically significant improvement in all clinical scores was observed from baseline evaluation to 120 months of final follow-up. In particular, the International Knee Documentation Committee subjective score improved from the preoperative evaluation of 38.7±17.3 to 74.0±21.8 at 12 months (P<0.0005), with scores remaining stable for up to 120 months (83.8±20.7), with all follow-ups showing a statistically significant improvement compared with the basal value (P<0.0005). Three patients failed at 12 months, for a failure rate of 16% at 10 years of follow-up. Lesions >3.5 cm obtained worse subjective results. In addition, lesion size and female sex were significantly associated with failures.

CONCLUSIONS

The matrix-assisted autologous chondrocyte transplantation technique with autologous bone grafting is a valid treatment option for JOCD in case of unfixable fragments. The clinical improvement obtained is significant and stable, with good results maintained for up to 10 years of follow-up and an overall low failure rate. Lesion size and sex could influence the clinical outcome and should be considered in the treatment choice.

LEVEL OF EVIDENCE

Level IV-case series.

Arthroscopic autologous chondrocyte implantation in the knee with an in situ crosslinking matrix: minimum 4-year clinical results of 15 cases and 1 histological evaluation

PURPOSE

To clinically evaluate an arthroscopic autologous chondrocyte implantation (ACI) technique with an in situ crosslinking matrix for the treatment of full thickness cartilage defects of the knee and to present histological results of a graft cartilage biopsy obtained after 1.5 years.

METHODS

Fifteen cases of arthroscopic autologous chondrocyte implantation in the knee performed between November 2011 and October 2012 were included in the study. Medical charts and operational reports were screened and the patients were contacted after 0.8 ± 0.3 years (0.4-1.3) and 4.3 ± 0.3 years (4.0-4.8) to asses subjective IKDC and re-operation. The Tegner activity scale was collected at the second follow-up time point. Subjective IKDC response rates were assessed at both follow-up time points.

RESULTS

The first and second follow-up was completed by all 15 patients (100%). The subjective IKDC scores showed a significant improvement (pre-operative 44.5 ± 15.9, first follow-up 71.1 ± 15.9, p < 0.001, second follow-up 72.6 ± 17.3, p < 0.001). The overall response rate was 66.7% (n = 10) at follow-up one and two. There were no significant differences in pre-injury (4, range 1-9) and follow-up two (4, range 2-7) Tegner activity scales (p = n.s.). Two patients required re-operation in the index knee, not related to the ACI procedure. No complication related to the ACI or the implantation technique occurred. The histological results showed excellent cartilage regeneration.

CONCLUSION

Arthroscopic ACI using an in situ crosslinking matrix is a safe and reliable treatment option for full-thickness cartilage defects of the knee.

Low rate of return to pre-injury sport level in athletes after cartilage surgery: a 10-year follow-up study

PURPOSE

Although articular surface is frequently damaged in athletes, results in terms of return to sport and level of activity after cartilage surgery remain rather unpredictable and poorly documented. The aim of this study is to evaluate the clinical outcome in terms of rate and level of return to sport in a group of competitive athletes who underwent matrix-assisted autologous chondrocyte transplantation (MACT), as well as the impact on their athletic career.

METHODS

Thirty-one male patients (mean age 22.6 ± 6.3 years) p racticing sport at competitive level, affected by focal chondral/osteochondral lesions of the distal femur, were enrolled and treated with arthroscopic hyaluronan-based MACT. Patients were evaluated prospectively at 1-year intervals with the IKDC subjective, Tegner, and EuroQol VAS scores during their pre-operative visit and subsequent follow-ups for up to 10 years. Return to sport in terms of level, time and maintenance of the activity level was documented, together with surgical or clinical failures.

RESULTS

A marked improvement in all scores was found: IKDC increased from 40.3 ± 13.4 to 81.7 ± 14.4 (p < 0.0005) at 12 months; a further improvement was observed at 2 years (89.5 ± 11.3; p = 0.008), then results were stable for up to 10 years (87.3 ± 13.6). The analysis of return to sport documented that 64.5% of patients were able to return at a competitive level, and 58.1% performed at the same pre-injury level, with activity rates decreasing over time. The rate of patients returning to competitive level was 84% in those without previous surgery (vs. 33% who had undergone previous surgery), 87% for those with traumatic lesions (vs. 33% and 50% for degenerative and OCD lesions, respectively), and 92.3% in younger patients (age < 20 years). Among these factors, multivariate analysis demonstrated that previous surgery was the single most influencing factor for returning to the same sport level (p = 0.010).

CONCLUSIONS

These long-term results showed that chondrocyte-based regenerative approach has some limitations in terms of sport-related outcomes. The level of high functional knee restoration needed for such high-demanding activity level can be challenging to achieve, especially in patients with a more compromised joint homeostasis. Return to sport rate varies significantly according to specific patient and lesion characteristics and best results are obtained in young patients with traumatic lesions without previous surgery, which should be considered when treating athletes affected by cartilage lesions.

LEVEL OF EVIDENCE

IV.

Enhanced chondrogenesis from human embryonic stem cells

Human embryonic stem cells (hESCs) have great potential for the repair of damaged articular cartilage. We developed a serum-free 14-day protocol for hESC differentiation into chondrocyte progenitors, which surprisingly lacked strong cartilage matrix production in in vitro tests. In order to direct these progenitors to a more mature phenotype, we investigated substituting different members of the TGFβ family in the protocol. Initially, we supplemented, or substituted GDF5 (day 11-14), with combinations of BMP7 and TGFβ-1, or -3, but these modifications yielded no improvement in matrix gene expression. However, replacing BMP4 with BMP2 (days 3-10 of the protocol) resulted in a more rapid increase in SOX9 gene expression and increased expression of chondrogenic genes SOX5, ACAN and COL2A1. The replacement of BMP4 with BMP2 also enhanced the formation of chondrogenic cell aggregates, with greater deposition of type II collagen. This change was not accompanied by hypertrophic chondrocyte marker COL10A1 expression. The results demonstrate that BMP2 has greater specificity for the generation of chondrogenic cells from hESCs than BMP4 and this was consistent in two hESC lines (HUES1 and MAN7). hESC-chondrogenic cells derived with either BMP2 or BMP4 were tested in vivo by implanting them in fibrin into osteochondral defects in the femur of RNU rats. Repaired cartilage tissue, positive for Safranin O and type II collagen was detected at 6 and 12 weeks with both cell sources, but the BMP2 cells scored higher for tissue quality (Pineda score). Therefore, BMP2 is more effective at driving chondrogenic differentiation from human pluripotent stem cells than BMP4 and the effect on the resulting chondroprogenitors is sustained in an in vivo setting.

Treatment of unstable knee osteochondritis dissecans in the young adult: results and limitations of surgical strategies-The advantages of allografts to address an osteochondral challenge

Joint surface incongruence resulting from osteochondritis dissecans (OCD) alters the articular physiologic congruence, increasing the contact stress on adjacent joint surfaces and accelerating wear and the cascade of joint degeneration. Accordingly, the restoration of articular surface integrity is of major importance, especially in young adults where, in lesions left untreated or following simple fragment excision, early osteoarthritis can be anticipated. Therefore, the treatment algorithm in unstable knee OCD of the young adult foresees surgical options to restore the articular surface. Several procedures have been proposed, including refixation of the detached fragment bone marrow stimulation, osteochondral autograft implantation, fresh osteochondral allograft transplantation, and cell-based or cell-free regenerative techniques. The aim of this review was to summarize the evidence for these surgical strategies, reporting their results and limitations. The overall evidence documents positive results for each of the assorted surgical procedures applied to treat unstable OCD, thus indicating support for their selected use to treat osteochondral defects paying particular attention to their specific indications for the lesion characteristics. The fixation of a good quality fragment should be pursued as a first option, while unfixable small lesions may benefit from autografts. For large lesions, available cell-based or cell-free osteochondral scaffold are a feasible solution but with limitation in terms of regenerated tissue quality. In this light, fresh allografts may offer articular surface restoration with viable physiologic osteochondral tissue providing a predictably successful outcome, and therefore they may currently represent the most suitable option to treat unstable irreparable OCD lesion in young adults. LEVEL OF EVIDENCE: V.

Treatment of large deep osteochondritis lesions of the knee by autologous matrix-induced chondrogenesis (AMIC): Preliminary results in 13 patients

BACKGROUND

Osteochondral defects due to advanced osteochondritis of the knee eventually cause osteoarthritis. Autologous matrix-induced chondrogenesis (AMIC) may hold potential for overcoming the treatment challenges raised by defects larger than 2cm². The primary objective of this study was to assess medium-term functional outcomes of AMIC. The secondary objective was to confirm the absence of adverse events.

HYPOTHESIS

AMIC significantly improves knee function in patients with osteochondritis responsible for osteochondral defects grade III or IV in the International Cartilage Repair Society (ICRS) classification.

MATERIAL AND METHODS

A total of 13 consecutive patients managed using AMIC between September 2011 and November 2016 were included in a prospective, single-centre, single-surgeon study. There were 8 males and 5 females with a mean age of 29 years (range, 15-51 years). Among them, 9 had had previous surgery. The ICRS grade was IV in 12 patients and III in 1 patient. The defects had a mean surface area of 3.7cm² (range, 2.2-6.9cm²) and mean depth of 0.5mm (range, 0.4-0.8). In each patient, knee function was assessed by an independent examiner based on validated instruments (Knee injury and Osteoarthritis Outcome Score [KOOS], subjective International Knee Documentation Committee [IKDC] score, and visual analogue scale [VAS] pain score).

RESULTS

After a median follow-up of 24 months (range, 12-42 months; minimum, 1 year), 11 patients had significant improvements, with mean increases in the IKDC score and KOOS of 27 and 28 points, respectively. The scores remained stable after the first year. Of the 2 patients with poorer outcomes, 1 had a history of multiple surgical procedures and the other was a 51-year-old female with a defect surface area of 6.9cm². No post-operative complications were recorded.

CONCLUSION

AMIC is a reliable single-stage method that is both reproducible and widely available. AMIC significantly improves knee function scores in patients with large osteochondral defects due to advanced osteochondritis of the knee.

LEVEL OF EVIDENCE

IV, prospective cohort study.

Treatment of osteochondral defects with a combination of bone grafting and AMIC technique

INTRODUCTION

Osteochondral defects of the knee may cause functional impairment of young and sportively active patients. Different surgical treatment options have been proposed using either one or two step procedures. The aim of the current study was to evaluate mid-term outcomes of combined bone grafting with autologous matrix-associated chondrogenesis (AMIC) for the treatment of large osteochondral defects.

MATERIALS AND METHODS

15 Patients with osteochondrosis dissecans of the medial femoral condyle grade III or IV according to ICRS classification were treated with a single step surgical procedure combining bone grafting and the AMIC procedure. Mean defect size was 4.98 cm² (± 3.02) and patients were examined at 6, 12 weeks, 6 and 12 month and at mean final follow-up of 49 months (36-61). Patients were evaluated using VAS, IKDC, KOOS, Lysholm, Tegner activity scores and psychological and physical health assessed using the SF 12. MRI evaluation was performed at final follow-up using the MOCART score.

RESULTS

Pain had significantly decreased at final follow-up (7.2 ± 1.4 vs. 2.4 ± 2.6) compared to preoperative baseline. All functional scores had improved significantly throughout the follow-up period (IKDC from 36.6 ± 20.6 vs. 72.2 ± 18.7; KOOS 50.0 ± 18.9 vs. 81.7 ± 13.9; LYSHOLM 39.3 ± 19.5 vs. 79.8 ± 15.1). SF12 evaluation showed a significant increase in physical component summary (PCS) (31.2 ± 11.1 preoperative vs. 46.3 ± 9.9 at final follow-up), while mental component summary (MCS) remained stable (51.8 ± 8.9 vs. 57.3 ± 3.3). MOCART score revealed a mean overall score of 77 ± 15 at final follow-up. Integration to the adjacent cartilage was complete in 79%, incomplete in 21%. Defect filling was complete in 64%, incomplete in 36%.

CONCLUSION

Significant improvement of knee function and restoration of homogenous cartilage morphology could be achieved with simultaneous AMIC procedure and bone grafting in 2/3 of all patients with large osteochondral lesions at 4 years postoperatively.

Treatment of Knee Osteochondritis Dissecans With a Cell-Free Biomimetic Osteochondral Scaffold: Clinical and Imaging Findings at Midterm Follow-up

BACKGROUND

Osteochondritis dissecans (OCD) is a developmental condition of subchondral bone that may result in secondary separation and instability of the overlying articular cartilage, which in turn may lead to degeneration of the overall joint and early osteoarthritis. Biphasic scaffolds have been developed to address defects of the entire osteochondral unit by reproducing the different biological and functional requirements and guiding the growth of both bone and cartilage.

PURPOSE

To evaluate midterm clinical and imaging results after cell-free osteochondral scaffold implantation for the treatment of knee OCD.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty-seven patients (8 women, 19 men; mean age, 25.5 ± 7.7 years) were treated for knee OCD, with International Cartilage Repair Society (ICRS) grade 3 to 4 lesions with a mean size of 3.4 ± 2.2 cm² (range, 1.5-12 cm²), and prospectively evaluated for up to 5 years using the ICRS classification system and the Tegner score. Eighteen patients underwent magnetic resonance imaging (MRI) at 24 and 60 months of follow-up, and the graft was evaluated using the magnetic resonance observation of cartilage repair tissue (MOCART) score for the cartilage layer, while a specific score was used for subchondral bone.

RESULTS

All patients significantly improved their clinical scores at each follow-up until their final evaluation. The mean International Knee Documentation Committee (IKDC) subjective score improved from 48.4 ± 17.8 to 82.2 ± 12.2 at 2 years ( P < .0005), and it then remained stable for up to 5 years postoperatively (90.1 ± 12.0). The mean Tegner score increased from 2.4 ± 1.7 preoperatively to 4.4 ± 1.6 at 2 years ( P = .001), with a further increase up to 5.0 ± 1.7 at 5 years of follow-up ( P < .0005 vs preoperatively), reaching almost the preinjury level (5.7 ± 2.2). The MOCART score showed stable results between 24 and 60 months, whereas the subchondral bone status significantly improved over time. No correlation was found between MRI findings and clinical outcomes.

CONCLUSION

This 1-step cell-free scaffold implantation procedure showed good and stable results for up to 60 months of follow-up for the treatment of knee OCD. MRI showed abnormalities, in particular at the subchondral bone level, but there was an overall improvement of features over time. No correlation was found between imaging and clinical findings.

Clinical and imaging outcome of osteochondral lesions of the talus treated using autologous matrix-induced chondrogenesis technique with a biomimetic scaffold

BACKGROUND

The purpose of our study was to assess the clinical and imaging outcome of autologous matrix-induced chondrogenesis (AMIC) technique consisting of microfractures followed by the filling of osteochondral lesions of the talus (OLTs) with a cell-free biphasic collagen-hydroxyapatite osteochondral scaffold (MaioRegen).

METHODS

Sixteen patients (eight males, age: 42.6 ± 18.4, range 14-74) with OLT repaired using AMIC technique, with implantation of MaioRegen, were clinically evaluated through the American Orthopedic Foot and Ankle Society Score (AOFAS) and a 10-point Visual Analogue Scale (VAS) pain score after a mean follow-up of 30 ± 16.9 months. The MRI examinations were performed 12 and 24 months after surgery. A paired t-test was applied to compare pre- and post-operative clinical findings (VAS and AOFAS) and Magnetic resonance observation of cartilage repair tissue (MOCART) score changes in the follow-up. To assess the correlation between variation of AOFAS and MOCART scores, the Pearson's correlation coefficient was calculated.

RESULTS

No complications after surgery were encountered. From pre-operative to post-operative values, there was a significant (P < 0.001) reduction of mean VAS pain score (6.3 ± 0.9,range: 4-8 and 2.9 ± 1.8,range: 0-6, respectively) and increase of AOFAS score (60.2 ± 7.8,range: 50-74 and 77.4 ± 16.2,range: 50-100, respectively). Among 16 patients, six (37%) were not satisfied at the end of follow-up, six (37%) were moderately satisfied and four (25%) were highly satisfied. The treatment was considered failed in five out of 16 patients (31%). Among them, four (25%) required re-interventions with implantation of ankle prostheses, whereas one patient was treated with a further AMIC technique combined with autologous bone graft and platelet-rich plasma. The mean MOCART score was 41.9 ± 14.6 (25-70) 12 months after surgery and 51.9 ± 11.6 (30-70) after 24 months, with a statistically significant increase (P = 0.012). However, no correlation was seen between AOFAS and MOCART changes (r = 0.215, p = 0.609).

CONCLUSION

The high rates of treatment failure encountered in our study using MaioRegen need to be confirmed by larger studies and should induce the scientific community questioning the reliability of this biomimetic scaffold for the treatment of OLTs.

Age Is Not a Contraindication for Cartilage Surgery: A Critical Analysis of Standardized Outcomes at Long-term Follow-up

BACKGROUND

Age is commonly accepted as a negative prognostic factor in cartilage surgery, and cutoff values of 30 to 40 years have been previously suggested as treatment indication. However, the lower outcome scores documented in older patients do not take in consideration the decreasing requirements of an aging joint.

PURPOSE

To analyze the real effect of age in terms of recovery with respect to the functional level expected for different age categories of patients treated for cartilage lesions.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients with International Cartilage Repair Society (ICRS) grade 3-4 defects, involving femoral condyles or trochlea without osteoarthritis, were treated with arthroscopic matrix-assisted autologous chondrocyte transplantation; 157 patients were evaluated with IKDC subjective and Tegner scores before surgery and then after 2 and 10 years. Results were first evaluated by dividing patients into 2 age groups according to the generally approved cutoff value of 40 years. The analysis was then repeated after the scores of each patient were standardized according to the score achievable per the normative data in healthy patients for the corresponding sex and age category.

RESULTS

A significant improvement in all scores was observed. IKDC subjective score improved from 38.9 ± 14.5 to 74.7 ± 21.8 at 10 years. When a cutoff value of 40 years was used, older patients reached a significantly worse IKDC subjective value at 10 years (65.8 ± 24.3 vs 77.2 ± 20.4, P = .007). However, different findings were obtained after the scores were standardized. Although optimal results were still found in younger patients (<30 years), patients older than 40 years also appeared to benefit from the treatment, and no significant differences were noted compared with the younger population.

CONCLUSION

The benefit of cartilage treatments in patients with increasing age but without any sign of osteoarthritis was higher than previously reported in literature. In fact, when the decreasing functional level expected by an aging population was considered, standardized results showed an overall benefit after cartilage treatment in patients older than 40 years that was not significantly different from the outcome achieved in younger patients. Thus, age is not a strict contraindication as previously suggested, and future studies should consider standardization of data to prove the real age limit of cartilage treatments.

Outcomes following impaction bone grafting for treatment of unstable osteochondritis dissecans

BACKGROUND

Many methods have been proposed to treat unstable osteochondritis dissecans (OCD). Our purpose is to report outcomes in a cohort of patients undergoing impaction bone grafting for treatment of knee OCD.

METHODS

Patients undergoing impaction bone grafting for knee OCD between 1998 and 2011 were contacted and stratified into (a) those who have undergone subsequent surgery on the affected knee and (b) those who have not had revision surgery performed on the affected knee since the impaction bone grafting procedure. For those not undergoing another procedure, physical examination, radiographs, MRI, and functional outcomes (SF12, Tegner, Activity Rating Scale, and IKDC) were obtained.

RESULTS

Of nine patients (10 knees) undergoing the procedure, seven (eight knees) were available for follow-up. Three had revision surgery. One had debridement due to surface overgrowth and had no symptoms 43months following debridement, while two had osteochondral allograft and autograft procedures at three and 10years after initial surgery, respectively. Four patients did not require a revision surgical procedure at average follow-up of 55.4months (range, 21-116months). All had complete MRI fill of the cartilaginous defect with less than 50% of surface irregularity and redeveloped the tidemark and a heterogeneous cartilaginous surface. Follow-up Tegner, ARS, and SF12-PCS averaged 6.8, 67.5, and 56.6, respectively. All four had good/excellent IKDC results.

CONCLUSION

Impaction bone grafting can reliably restore osteocartilaginous defect produced by OCD and is a readily available and less-expensive option in treating OCD lesions. Further investigation is necessary to determine the long-term durability of the results. Level IV - Case series.

Cartilage failures. Systematic literature review, critical survey analysis, and definition

PURPOSE

While midterm results of matrix-assisted autologous chondrocyte transplantation (MACT) are now available, less attention has been paid to the evaluation of failures of this surgical approach. Aim of this study was to analyse how "failures" are generally defined in cartilage surgery, in order to understand how the survival rate may change according to different definitions of failure.

METHODS

A systematic review on MACT in the knee was conducted to report failure rates as well as different failure definitions in the available literature. Afterwards, we analysed the survival curve at 8.5-year follow-up of a survey of 193 patients treated with MACT. Using different definitions to identify failures, we compared how the survival rate changed according to the different definitions of failure.

RESULTS

The systematic review on 93 papers showed that the average failure rate reported on 3,289 patients was 5.2 % at a mean 34 months of follow-up. However, 41 studies (44.1 %) did not even consider this aspect, and failures were variously defined, thus generating confusing data that make a meta-analysis or a study comparison meaningless. The failure analysis of the MACT survey showed that the survival curve changed significantly depending on the definition applied; in fact, the failure rate ranged from 3.6 to 33.7 %. According to a critical literature and survey analysis, we proposed a combined surgical- and improvement-based definition which led to a failure rate of 25.9 % at midterm/long-term follow-up.

CONCLUSION

Nowadays, failure definitions of cartilage treatments differ in scientific articles, thus generating confusion and heterogeneous data even when applied to the same cohort of patients. While the literature analysis shows a low number of failures, this study demonstrated that if properly addressed with a comprehensive definition, the real failure rate of cartilage surgical procedures in the knee is higher than previously reported. Recognizing failures would give a better understanding and a more realistic prognosis to patients and physicians seeking treatment for cartilage lesions.

LEVEL OF EVIDENCE

IV.

Surgical treatment of early knee osteoarthritis with a cell-free osteochondral scaffold: results at 24 months of follow-up

PURPOSE

"Early Osteoarthritis (EOA)" has been defined combining clinical, imaging and surgical parameters, with the aim to identify patients in early degenerative phases, who might benefit from the use of available regenerative procedures. Aim of this first clinical trial is to prospectively evaluate the results obtained in a group of patients meeting the inclusion criteria of "EOA" as proposed by the ESSKA Cartilage Committee, and surgically treated with the implantation of a multi-phasic osteochondral scaffold.

METHODS

23 patients were prospectively evaluated at 12 and 24 months of follow-up. Etiology of the chondral or osteochondral defect was rated as microtraumatic or degenerative in 18 cases, and traumatic in 5 cases. Patients included were complaining of clinical symptoms like knee pain and affected by chondral and osteochondral lesions located at the femoral condyles or trochlea and MRI findings demonstrating articular cartilage degeneration and/or meniscal degeneration and/or subchondral bone marrow lesions.

RESULTS

All patients increased significantly in any clinical score adopted. The IKDC subjective score increased from 42.8 ± 13.8 at basal evaluation to 74.3 ± 17.4 at 12 months' (p < 0.0005), being stable (74.9 ± 20.4) up to the final follow-up of 24 months. Tegner score showed a statistically significant improvement in sports activity from 3.3 ± 2.7 pre-operative to 4.6 ± 2.2 at 12 months (p < 0.005), with a slight improvement to the final evaluation (4.7 ± 2.1; n.s.). However, the activity level was significantly lower than the pre-injury one (6.1 ± 2.6; p = 0.004). A significant difference was shown between patients younger versus older than 40 years, with younger patients had better clinical improvement (76.0 ± 18.6 vs 45.1 ± 38.8 respectively, p = 0.037).

CONCLUSIONS

The implantation of a multi-phasic osteochondral scaffold represents a good option after failure of conservative management for Early OA patients, where younger age represent an important factor for a better outcome. Longer follow-up is needed to evaluate the benefit over time.

LEVEL OF EVIDENCE

IV, case series.

Scaffold-based cartilage treatments: with or without cells? A systematic review of preclinical and clinical evidence

PURPOSE

Regenerative scaffold-based procedures are emerging as a potential therapeutic option for the treatment of chondral and osteochondral lesions. In general, we can summarize most of the recent developments to reach clinical application into 2 major trends: the use of different cell sources or the application of biomaterials as a cell-free approach. The aim of this systematic review was to analyze both preclinical and clinical studies on these new trends to understand how the available evidence supports the use of cell sources or justifies the cell-free approach for the scaffold-based treatment of cartilage lesions.

METHODS

The research was performed using the PubMed database by looking at studies published in the English language referring to chondral or osteochondral defect repair with scaffold-based procedures until the end of 2013. The following strings were used: ("cartilage"[MeSH] AND "tissue scaffolds"[MeSH]).

RESULTS

The search showed an increasing number of published articles each year for both scaffold-based approaches, identifying a total of 305 articles. Among clinical trials, 116 used cell-based scaffold treatments and 11 used scaffolds alone. In the preclinical setting, a scaffold/cell combination was the most used treatment approach (133 v 45 articles), with mesenchymal stem cells (MSCs) being the favorite cell type. Bone marrow was the most used cell source, but other sources are gaining interest. Among articles comparing scaffolds with or without cells, the majority reported superior results for cells (71 of 89 articles). In the clinical setting, most of the articles analyzed chondrocyte-based scaffolds, with only 7 studies using MSCs; all cells were from bone marrow. Despite the lower number of articles, cell-free scaffolds are gaining popularity, with a recent increase in published studies showing promising results.

CONCLUSIONS

This systematic review underlined the difficulties in understanding the real need for cells to increase the scaffold-based cartilage healing potential because of the heterogeneity of products used as well as the design of the published studies. Scaffold and cell combinations were the most investigated option in the preclinical setting, showing generally superior results, but in the clinical setting, both strategies remain used. In particular, although chondrocytes are the most commonly used cell type, research showed increasing interest in the potential of MSCs for cartilage regeneration. However, the difficulties in managing cell cultures, together with the development of a new generation of materials able to exploit the intrinsic tissue regeneration ability, justifies the clinical use of cell-free scaffolds, with increasing literature and promising preliminary results.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I to IV studies.

Cartilage repair using human embryonic stem cell-derived chondroprogenitors

In initial work, we developed a 14-day culture protocol under potential GMP, chemically defined conditions to generate chondroprogenitors from human embryonic stem cells (hESCs). The present study was undertaken to investigate the cartilage repair capacity of these cells. The chondrogenic protocol was optimized and validated with gene expression profiling. The protocol was also applied successfully to two lines of induced pluripotent stem cells (iPSCs). Chondrogenic cells derived from hESCs were encapsulated in fibrin gel and implanted in osteochondral defects in the patella groove of nude rats, and cartilage repair was evaluated by histomorphology and immunocytochemistry. Genes associated with chondrogenesis were upregulated during the protocol, and pluripotency-related genes were downregulated. Aggregation of chondrogenic cells was accompanied by high expression of SOX9 and strong staining with Safranin O. Culture with PluriSln1 was lethal for hESCs but was tolerated by hESC chondrogenic cells, and no OCT4-positive cells were detected in hESC chondrogenic cells. iPSCs were also shown to generate chondroprogenitors in this protocol. Repaired tissue in the defect area implanted with hESC-derived chondrogenic cells was stained for collagen II with little collagen I, but negligible collagen II was observed in the fibrin-only controls. Viable human cells were detected in the repair tissue at 12 weeks. The results show that chondrogenic cells derived from hESCs, using a chemically defined culture system, when implanted in focal defects were able to promote cartilage repair. This is a first step in evaluating these cells for clinical application for the treatment of cartilage lesions.

Clinical results of multilayered biomaterials for osteochondral regeneration

Several techniques have been used during the years to treat chondral and osteochondral lesions. Among them, the emerging trend in the field of osteochondral regeneration is to treat the entire osteochondral unit by implanting cell-free scaffolds, which provide a three-dimensional support for the cell growth and may act themselves as stimuli for an "in situ" tissue regeneration. Various multi-layered products have been proposed that mimic both the subchondral bone and the cartilaginous layer. Among these, three have currently been reported in the literature. One has been widely investigated: it is a nanocomposite three-layered collagen-hydroxyapatite scaffold, which is showing promising results clinically and by MRI even at mid-term follow-up. The second is a PLGA-calcium-sulfate bilayer scaffold: however, the literature findings are still controversial and only short-term outcomes of limited case-series have been published. The most recent one is a solid aragonite-based scaffold, which seems to give promising clinical and MRI outcomes, even if the literature is still lacking more in-depth evaluations.Even though the Literature related to this topic is quickly increasing in number, the clinical evidence it is still limited to some case series, and high-level studies are needed to better demonstrate their real effectiveness.

Treatment of osteochondritis dissecans of the knee with a biomimetic scaffold. A prospective multicenter study

PURPOSE

the aim of the present study was to evaluate the clinical outcome of the treatment of osteochondritis dissecans (OCD) of the knee with a type-I collagen-hydroxyapatite nanostructural biomimetic osteochondral scaffold.

METHODS

twenty-three patients affected by symptomatic knee OCD of the femoral condyles, grade 3 or 4 of the International Cartilage Repair Society (ICRS) scale, underwent biomimetic scaffold implantation. The site of the defect was the medial femoral condyle in 14 patients, whereas in 9 patients the lateral femoral condyle was involved. The average size of the defects was 3.5±1.43 cm(2). All patients were clinically evaluated using the ICRS subjective score, the IKDC objective score, the EQ-VAS and the Tegner Activity Score. Minimum follow-up was two years. MRI was performed at 12 and 24 months after surgery and then every 12 months thereafter.

RESULTS

the ICRS subjective score improved from the baseline value of 50.93±20.6 to 76.44±18.03 at the 12 months (p<0.0005) and 82.23± 17.36 at the two-year follow-up (p<0.0005). The IKDC objective score confirmed the results. The EQ-VAS showed a significant improvement from 3.15±1.09 to 8.15±1.04 (p<0.0005) at two years of follow-up. The Tegner Activity Score improvement was statistically significant (p<0.0005).

CONCLUSIONS

biomimetic scaffold implantation was a good procedure for treating grade 3 and 4 OCD, in which other classic techniques are burdened by different limitations. This open one-step surgery gave promising stable results at short-term follow-up.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Treatment of Large Knee Osteochondral Lesions With a Biomimetic Scaffold: Results of a Multicenter Study of 49 Patients at 2-Year Follow-up

BACKGROUND

Osteochondral knee lesions represent a challenging condition encountered by orthopaedic surgeons. A variety of methods have been developed to repair articular cartilage defects. However, these techniques are limited by donor site morbidity or by the requirement for a staged procedure.

PURPOSE

To assess the effectiveness of a biomimetic osteochondral scaffold for the treatment of large osteochondral knee lesions.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

From 2009 to 2011, a total of 49 patients affected by isolated large osteochondral knee lesions (mean [± SD] size, 4.35 ± 1.26 cm2) were treated with the biomimetic scaffold. Patients were evaluated using the International Knee Documentation Committee (IKDC), Tegner, and visual analog scale (VAS) pain scores, as well as magnetic resonance imaging (MRI) up to 3-year follow-up. The MOCART (magnetic resonance observation of cartilage repair tissue) score was performed to analyze different variables. Biopsies were carried out in 5 patients. Four of the 5 second-look arthroscopies and biopsies were performed on patients with failed results because of ethical issues.

RESULTS

The mean IKDC subjective score increased significantly from 45.45 ± 19.29 preoperatively to 70.86 ± 18.08 at 1-year follow-up and to 75.42 ± 19.31 at 2-year follow-up (P < .001). The IKDC objective score changed from 50% normal and nearly normal knees before treatment to 89.79% at the 2-year follow-up. There was a statistically significant improvement (P < .005) in VAS score from the preoperative level (6.69 ± 1.88) to the 2-year follow-up (1.96 ± 2.47). Tegner scores increased (P < .001) from the preoperative value (2.20 ± 0.67) to the 2-year follow-up (4.9 ± 1.73) without achieving preinjury level. A correlation was found between the IKDC subjective score and age (P < .001, r = -0.497, ρ = -0.502). Patients affected by osteochondritis dissecans (OCD) achieved a statistically significantly better outcome (P < .05). A subgroup of 19 competitive athletes showed a statistically significantly improvement (P < .001) in the subjective IKDC (86.5 ± 13.2) compared with the nonathletic subpopulation (69.03 ± 19.41) at the 2-year follow-up. The MRI findings of 30 patients were available at 2-year follow-up: 70% showed complete filling of the lesion, 63.3% had an intact articular surface, and 86% had mild or no effusion. In all cases, in dual T2-weighted fast spin echo sequence, the repair tissue showed a hyperintensive signal with respect to the surrounding subchondral bone; however, no edema was observed.

CONCLUSION

The study findings indicate that the biomimetic scaffold that was investigated is an off-the-shelf, cell-free, and cost-effective implant that can regenerate either cartilage or subchondral bone. The scaffold allows a 1-step surgical procedure that can be used for osteochondral lesions, OCD, and in some cases osteonecrosis.

Is the clinical outcome after cartilage treatment affected by subchondral bone edema?

PURPOSE

Subchondral bone edema is a common finding after cartilage treatment, but its interpretation is still debated. The aim of this study is to analyse the presence of edema after matrix-assisted autologous chondrocyte transplantation (MACT) for knee cartilage lesions at different follow-up times and its correlation with the clinical outcome.

METHODS

Two hundred and forty-eight magnetic resonance imagings (MRIs) of patients treated with a hyaluronic acid-based MACT for lesions of the knee articular surface were considered. The MRIs belonged to 116 patients (mean age at surgery 28.6 ± 10.3 years, average defect size 2.4 ± 1.0 cm(2)), 57 affected by degenerative cartilage lesions, 27 traumatic and 32 were osteochondritis dissecans (OCD). MRI follow-up was performed from 6 to 108 months after treatment. Other than its presence or absence, the subchondral bone edema was evaluated using a 3-level grading considering extension and hyperintensity, and with the WORMS score edema classification. The IKDC subjective score was collected at the time of every MRI.

RESULTS

An analysis of the entire MRI group showed that edema is not constantly present through the follow-up, but presents a particular and well-defined trend. Edema was present within the first 2 years and was then markedly reduced or disappeared at 2 and 3 years (p = 0.044). Afterwards the level of edema increased again (p < 0.0005) and remained steadily present at medium/long-term follow-up. Patellar lesions presented significantly lower edema (p = 0.012), whereas OCD lesions presented more edema at all follow-up (p = 0.002) and a different trend, with an increasing level of edema over time. No correlation was found between edema and clinical outcome.

CONCLUSIONS

Edema after MACT is present during the first phases of cartilage maturation up to 2 years of follow-up, and then tends to disappear. However, after a few years, it tends to reappear. Less edema was found in the patella, whereas more edema was found in the OCD, where subchondral bone is primarily involved. Interestingly, the presence of edema was not correlated with a poorer clinical outcome. Whether this might be a prognostic factor at longer follow-up remains to be determined, but our results give some indication on what to expect on both MRI edema and clinical outcome after MACT.

LEVEL OF EVIDENCE

Case series, Level IV.

Use of innovative biomimetic scaffold in the treatment for large osteochondral lesions of the knee

PURPOSE

Large osteochondral defects involve two different tissues characterized by different intrinsic healing capacity. Different techniques have been proposed to treat these lesions with results still under discussion. The aim of the study is to evaluate the clinical outcome of 19 patients treated with a type I collagen-hydroxyapatite nanostructural biomimetic osteochondral scaffold at minimum follow-up of 2 years.

METHODS

Twenty lesions, 19 patients were treated with this scaffold implantation. The lesions size went from 4 to 8 cm(2) (mean size 5.2 ± 1.6 cm(2)). All patients were clinically evaluated using the International Repair Cartilage Society score, the Tegner Score and EQ-VAS. MRI was performed at 12 and 24 months after surgery and then every 12 months and evaluated with magnetic resonance observation of cartilage repair tissue scoring scale.

RESULTS

The IKDC subjective score improved from a mean score of 35.7 ± 6.3 at the baseline evaluation to 67.7 ± 13.4 at 12-month follow-up (p < 0.0005). A further improvement was documented from 12 to 24 months (mean score of 72.9 ± 12.4 at 24 months) (p < 0.0005). The IKDC objective score confirmed the results. The Tegner activity score improvement was statistically significant (p < 0.0005). The EQ-VAS showed a significant improvement from 3.15 ± 1.09 to 7.35 ± 1.14 (p < 0.0005) at 2-year follow-up. The lesion' site seems to influence the results showing a better outcome in the patients affected in the medial femoral condyle.

CONCLUSIONS

The use of the MaioRegen scaffold is a good procedure for the treatment for large osteochondral defects where other classic techniques are difficult to apply. It is an open one-step surgery with promising stable results at medium follow-up.

LEVEL OF EVIDENCE

IV.

Follow-up of a new arthroscopic technique for implantation of matrix-encapsulated autologous chondrocytes in the knee

PURPOSE

The purpose of this study was to evaluate the clinical and sequential imaging follow-up results at a mean of 36 months after an arthroscopic technique for implantation of matrix-encapsulated autologous chondrocytes for the treatment of articular cartilage lesions on the femoral condyles.

METHODS

Ten patients underwent arthroscopic implantation of autologous chondrocytes seeded onto a bioabsorbable scaffold. The patients were evaluated clinically using a visual analog scale (VAS) for pain and International Knee Documentation Committee (IKDC), Lysholm, and Tegner scores. Magnetic resonance imaging (MRI) T2-mapping and magnetic resonance observation of cartilage repair tissue (MOCART) evaluations were also performed. Second-look arthroscopic evaluation using the International Cartilage Repair Society (ICRS) grading classification was performed at 12 months.

RESULTS

Compared with their preoperative values, at 36 months mean values ± standard deviation for the VAS scale for pain were 6.0 ± 1.5 to 0.3 ± 0.4. Improvement in clinical scores between preoperative values and 36-month follow-up values in subjective IKDC scores was 46.9 ± 18.5 to 77.2 ± 12.8; in Lysholm scores, it was 51.8 ± 25.1 to 87.9 ± 6.5, and in the Tegner activity scale it was 2.9 ± 1.7 to 5.9 ± 1.9. Mean T2 mapping and MOCART scores improved over time to 38.1 ± 4.4 ms and 72.5 ± 10, respectively. Mean ICRS score by second-look arthroscopy at 1 year was 10.4 ± 0.1.

CONCLUSIONS

All clinical scores improved over time compared with the preoperative values. Clinical results are comparable with MRI T2 mapping and ICRS evaluations, suggesting that this arthroscopic technique for cell-based cartilage repair is efficacious and reproducible at a mean of 36 months of follow-up.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Treatment of Full-Thickness Chondral Defects With Hyalograft C in the Knee: Long-term Results

BACKGROUND

Matrix-associated autologous chondrocyte transplantation (MACT) has become an established articular cartilage repair technique. It provides good short-term and midterm results; however, long-term results are lacking.

PURPOSE

To prospectively assess the clinical outcome after MACT in the knee to report long-term results.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Fifty-three subjects (females/males, 22/31; mean age, 32 ± 12 years) were treated between 2000 and 2006 with a hyaluronan-based MACT product and were followed prospectively. The mean body mass index (BMI) was 24.5 ± 3.8 kg/m(2) and the mean defect size was 4.4 ± 1.9 cm(2). Fifty patients had single defects and 3 had multiple defects (41 medial femoral condyle, 6 lateral femoral condyle, 2 patella, 1 tibia). Two patients had 2 defects (medial femoral condyle [MFC]/lateral femoral condyle and tibial/MFC), and in 1 case, multiple defects on the MFC were treated. The patients were stratified into 23 "simple," 22 "complex," and 8 "salvage" cases. Instability or malalignment was treated before or at the time of graft implantation. For 6 patients with small defects (<2 cm(2)), microfracturing was used as first-line treatment before MACT. Clinical assessment was performed once a year with the subjective and objective International Knee Documentation Committee (IKDC) scores, Lysholm score, and a modified Cincinnati Knee Rating System.

RESULTS

The mean follow-up time was 9.07 ± 2.9 years (range, 5-12 years). Treatment failure occurred in 12 of 53 cases (22.6%) an average of 2.99 ± 1.40 years after surgery. There was 1 failure (4.3%) among the simple cases, 4 failures (18.2%) in complex cases, and 7 failures (87.5%) in salvage cases. Statistically significant increases were observed in all scores at all time points compared with presurgery levels (P < .05). The subjective IKDC score improved from median 40.4 preoperatively to 74.7 at 10-year follow-up (n = 13 patients; P < .05).

CONCLUSION

MACT is an excellent surgical therapy for full-thickness cartilage defects of the knee, with good long-term results for simple defects. However, it should not be used in salvage cases.

Clinical profiling in cartilage regeneration: prognostic factors for midterm results of matrix-assisted autologous chondrocyte transplantation

BACKGROUND

Matrix-assisted autologous chondrocyte transplantation (MACT) was developed to overcome the limitations of first-generation autologous chondrocyte implantation. Although short-term/midterm results are now available for a small series of patients, the literature still lacks studies on large cohorts of patients evaluated at midterm/long-term follow-up.

PURPOSE

Not all patients can have the same benefit from this procedure. The aim of this study is to analyze a large cohort of patients treated with hyaluronan-based MACT to perform clinical profiling and to highlight the patient- and lesion-specific aspects that play a key role in determining the prognosis.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 142 patients were treated for lesions involving the femoral condyles and trochleae; 133 knees were followed up yearly for 7 years. The average size of the defects was 2.3 ± 1.0 cm2. The origin was traumatic in 44 cases and degenerative in 57 cases, and 32 knees were affected by osteochondritis dissecans (OCD). The clinical outcome was analyzed using the International Knee Documentation Committee (IKDC), EuroQol visual analog scale, and Tegner scores. The influence of the following factors was analyzed: sex, age, body mass index, site, lesion origin, lesion size, previous or combined surgery, and symptom duration.

RESULTS

A marked improvement in all scores was found: the IKDC subjective score increased from the basal level of 39.6 ± 14.4 to 71.9 ± 19.8 (P < .0005) at 12 months; a further improvement was observed at 24 months (77.0 ± 20.5; P < .0005). The results were stable over time up to the 7-year evaluation (77.4 ± 22.1). The failure rate was 10.7%. Better results were seen in the trochleae, and among femoral condyles, the following factors were found to influence the clinical outcome positively: traumatic and OCD origin, male sex, short symptom duration (for traumatic lesions), small lesion size (for OCD), young age, and no previous surgery.

CONCLUSION

Treatment with MACT provides good and stable clinical results. Injury origin, sex, symptom duration, lesion size, lesion site, age, and previous surgery might determine the final outcome and can be used as a sort of clinical profiling to guide the surgeon in the choice of this procedure and in giving realistic expectations to patients requiring cartilage treatment.

Osteochondral scaffold reconstruction for complex knee lesions: a comparative evaluation

BACKGROUND

The primary aim of the present study is to evaluate the results obtained in challenging knee lesions with the implant of an osteochondral scaffold and concomitant treatment of all comorbidities. The secondary aim is to compare the results obtained with those found when a chondral scaffold was applied.

MATERIALS AND METHODS

Patients affected by complex lesions of the knee articular surface were included. "Complex cases" were defined according to the following criteria: previous clinical history of intra-articular fracture, lesion located at the tibial plateau, concurrent knee axial realignment procedure, concurrent meniscal scaffold or allograft implantation, and multiple articular surface lesions treated. Thirty-three patients were treated with the implantation of an osteochondral scaffold. The results of a homogeneous group of 23 patients previously treated and prospectively evaluated after implantation of a chondral scaffold were analyzed and compared.

RESULTS

IKDC subjective score improved significantly from pre-operative (40.4±14.1) to 12months' follow-up (69.6±17.0; p<0.0005) with a further improvement at the final evaluation at 24months (75.5±15.0; p=0.038). The same positive trend was confirmed by the VAS and Tegner scores. At final follow-up the group treated with the osteochondral scaffold presented a better subjective IKDC score with respect to the group treated with the chondral scaffold (p=0.034).

CONCLUSIONS

A regenerative procedure to address the entire osteochondral unit, together with the treatment of all comorbidities, might offer good results also in complex cases otherwise doomed to non-biological resurfacing.

LEVEL OF EVIDENCE III

Comparative study.

Treatment of knee osteochondritis dissecans with a cell-free biomimetic osteochondral scaffold: clinical and imaging evaluation at 2-year follow-up

BACKGROUND

Osteochondritis dissecans (OCD) is an acquired lesion of the subchondral bone that may result in separation and instability of the overlying articular cartilage. Unstable lesions must be treated surgically to reestablish the joint surface as anatomically as possible. Hypothesis/

PURPOSE

The aim of this study was to evaluate the potential of a biomimetic osteochondral scaffold to treat OCD by analyzing the results obtained at 2-year follow-up. The hypothesis was that this scaffold, which was developed to treat the entire osteochondral unit, might restore the articular surface and improve symptoms and function in patients affected by knee OCD.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Twenty-seven consecutive patients (19 men, 8 women; age [mean ± SD], 25.5 ± 7.7 years) who were affected by symptomatic knee OCD of the femoral condyles (average defect size 3.4 ± 2.2 cm(2)), grade 3 or 4 on the International Cartilage Repair Society (ICRS) scale, were enrolled and treated with the implantation of a 3-layer collagen-hydroxyapatite scaffold. Patients were prospectively evaluated by subjective and objective International Knee Documentation Committee (IKDC) and Tegner scores preoperatively and at 1- and 2-year follow-up. An MRI was also performed at the 2 follow-up times.

RESULTS

A statistically significant improvement in all clinical scores was obtained at 1 year, and a further improvement was found the following year. At the 2-year follow-up, the IKDC subjective score had increased from 48.4 ± 17.8 preoperatively to 82.3 ± 12.2, the IKDC objective evaluation from 40% to 85% of normal knees, and the Tegner score from 2.4 ± 1.7 to 4.5 ± 1.6. The MRI evaluations showed good defect filling and implant integration but also inhomogeneous regenerated tissue and subchondral bone changes in most patients at both follow-up times. No correlation between the MOCART (magnetic resonance observation of cartilage repair tissue) score and clinical outcome was found.

CONCLUSION

This biomimetic osteochondral scaffold seems to be a valid treatment option for knee OCD, showing a good clinical outcome at 2-year follow-up. Moreover, the improvement was not correlated with lesion size, so large lesions can benefit from this implant. Less favorable findings were obtained with MRI evaluation.

Does patient sex influence cartilage surgery outcome? Analysis of results at 5-year follow-up in a large cohort of patients treated with Matrix-assisted autologous chondrocyte transplantation

BACKGROUND

Sexual dimorphism in humans has already been documented at different levels, and preliminary findings also suggest the importance of patient sex on clinical outcome in the treatment of cartilage lesions.

PURPOSE

To document and analyze the influence of sex on clinical outcome in a large cohort of patients treated with a cartilage regenerative procedure for knee chondral lesions and prospectively followed at midterm follow-up.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 250 knees were treated with matrix-assisted autologous chondrocyte transplantation (MACT) and prospectively evaluated with International Knee Documentation Committee (IKDC), EuroQol visual analog scale (EQ-VAS), and Tegner scores at 1-, 2-, and minimum 5-year follow-ups to compare results obtained in men and women. The lesions were focal International Cartilage Repair Society grade III-IV chondral knee defects involving femoral condyles, trochleae, and patellae. Two homogeneous groups of 56 male patients and 56 female patients were then selected by a blinded statistician for a matched-pair analysis.

RESULTS

A statistically significant improvement in all the scores in both men and women was observed in the general population. The IKDC subjective score showed better results for men at all follow-up times: at 5 years, the mean IKDC subjective score was 79.5 ± 18.6 versus 64.3 ± 20.2 for men and women, respectively (P < .0005), and the same trend was confirmed with the EQ-VAS and Tegner scores. The matched-pair analysis confirmed the difference of final results achieved (74.1 ± 19.8 vs 63.7 ± 20.2, respectively; P = .006). However, men and women started with different preoperative levels, and the analysis of the improvement obtained was not significantly different. Finally, when scores were standardized for each patient, according to the mean score typical for the corresponding age and sex category in a healthy population, a sex-related difference was not confirmed at any of the follow-ups. Etiological factors, lesion site, and preinjury activity level differed in women and men of the general population and were the confounding factors responsible for the different outcome not confirmed by the analysis of homogeneous cohorts of patients.

CONCLUSION

Women have a different knee chondral lesion pattern and more often have unfavorable conditions related to the cause of injury, site, and activity level, and they also have lower raw, not standardized, scores. However, a matched-pair analysis with data standardized for the specific patient categories showed that, on equal terms, women have the same possibilities for successful outcome as men after surgical treatment for knee cartilage regeneration.

Matrix assisted autologous chondrocyte transplantation for cartilage treatment: A systematic review

OBJECTIVES

Matrix-assisted autologous chondrocyte transplantation (MACT) has been developed and applied in the clinical practice in the last decade to overcome most of the disadvantages of the first generation procedures. The purpose of this systematic review is to document and analyse the available literature on the results of MACT in the treatment of chondral and osteochondral lesions of the knee.

METHODS

ALL STUDIES PUBLISHED IN ENGLISH ADDRESSING MACT PROCEDURES WERE IDENTIFIED, INCLUDING THOSE THAT FULFILLED THE FOLLOWING CRITERIA: 1) level I-IV evidence, 2) measures of functional or clinical outcome, 3) outcome related to cartilage lesions of the knee cartilage.

RESULTS

The literature analysis showed a progressively increasing number of articles per year. A total of 51 articles were selected: three randomised studies, ten comparative studies, 33 case series and five case reports. Several scaffolds have been developed and studied, with good results reported at short to medium follow-up.

CONCLUSIONS

MACT procedures are a therapeutic option for the treatment of chondral lesions that can offer a positive outcome over time for specific patient categories, but high-level studies are lacking. Systematic long-term evaluation of these techniques and randomised controlled trials are necessary to confirm the potential of this treatment approach, especially when comparing against less ambitious traditional treatments.

Repair of osteochondral defects in joints--how to achieve success

Osteochondral defects in the knee are difficult to repair because intrinsic healing of cartilage is poor and gradual progression to "early-onset" osteoarthritis leads to severe pain and disability. Of all methods tested to achieve regeneration of hyaline cartilage and long-lasting repair, autologous chondrocyte transplantation (ACI-C and MACI) has been the most successful with 80% of good results and graft survival in this unit in a very large series over 10 years. The repair mechanism is unclear but our work shows that the criteria for success are: young patient age, no previous operative procedures on the defect, no obesity, no smoking, defect on femoral condyles or trochlea and no pre-existing degenerative joint changes. Future research is aimed at non-transplantation, single-stage procedures aided by use of new scaffolds and growth factors and the extension of such techniques into arthritic joints.

Treatment of cartilage lesions: what works and why?

Cartilage injuries have a high incidence and a high impact on society. In an attempt to fulfill patients' expectations and successfully treat this pathology, various techniques have been developed over the years. Treatments proposed for cartilage lesions are described with their rationale and indications, ranging from conservative measures to surgical approaches, reparative or regenerative. Among the numerous and heterogeneous procedures proposed over time to treat cartilage defects none has clearly proven to lead to a hyaline articular surface nor to offer better clinical results. Regenerative procedures have been introduced as ambitious techniques that aim to overcome the limitations of the more traditional reparative approaches and restore the articular surface with a hyaline-like tissue; improvement in tissue engineering with new scaffolds as well as new regenerative options involving growth factors or MSCs are currently being investigated as promising solutions to further improve the treatment of cartilage lesions. However, the current literature findings are not conclusive. Randomized controlled trials are necessary to evaluate new regenerative approaches, to show clearly advantages and disadvantages with respect to the more traditional procedures, besides their potential, limits, and indications to improve the treatment of patients affected by chondral and osteochondral lesions. Since clear and commonly accepted treatment algorithms are not available in the literature, the massively increasing number of controversial results may be confusing for the orthopaedic surgeon who has to choose the proper management of patients with cartilage lesions. Thus, the results obtained through the study of the authors' 20 years' experience in cartilage treatment were analyzed to give some indications on the potential and limits of different treatment approaches available in clinical practice.

Matrix-assisted autologous chondrocyte transplantation for cartilage regeneration in osteoarthritic knees: results and failures at midterm follow-up

BACKGROUND

Young patients with osteoarthritic knees are a challenging population because of a combination of high functional demands and limited indication for joint replacement.

PURPOSE

To analyze the potential of the cartilage regenerative approach by documenting the results and failures of matrix-assisted autologous chondrocyte transplantation (MACT) at midterm follow-up.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Forty-four patients affected by cartilage lesions in osteoarthritic knees underwent MACT as a salvage procedure. The mean age at surgery was 42 years (range, 20-58 years), and the average defect size was 4 cm(2) (range, 1.5-9 cm(2)). Patients were prospectively evaluated with the subjective International Knee Documentation Committee (IKDC), EuroQol visual analog scale (EQ-VAS), and Tegner scores preoperatively; at 1, 2, and 5 years; and at a final assessment at 9 years' mean follow-up. Adverse events and failures were also reported.

RESULTS

A statistically significant improvement was observed in all scores from the initial evaluation to the final follow-up. The mean ± standard deviation IKDC subjective score improved from 38.0 ± 15.8 to 67.0 ± 18.3 at 2 years (P < .0005), with a subsequent decrease to 57.8 ± 20.6 at the final follow-up (P = .012). The same trend was confirmed by the EQ-VAS score. The activity level revealed by the Tegner score improved at all follow-ups but without achieving the preinjury level. The analysis of the influencing factors showed the importance of the meniscus condition, revealing a significantly inferior outcome in knees with previous or combined partial meniscectomy procedures. During the study period, 12 patients had failed results, producing a cumulative failure rate of 27.3%. At the last evaluation, half of the patients considered their condition not better than before the treatment, and 39% would not repeat the treatment considering the results obtained.

CONCLUSION

Despite a statistically significant improvement, the clinical outcome was poor. A higher improvement could be obtained in patients who had not undergone previous or combined meniscectomies, but this was limited over time. The failure rate was also high, regardless of the degree of osteoarthritis. Tissue-engineered cartilage implantation is questionable for this indication, and the limits of this scaffold-based procedure have to be considered if it is used as a salvage procedure for young patients affected by knee osteoarthritis.