Arthroscopic treatment of osteochondral lesions of the ankle with matrix-associated chondrocyte implantation: early clinical and magnetic resonance imaging results

The Frequency and Severity of Complications in Surgical Treatment of Osteochondral Lesions of the Talus: A Systematic Review and Meta-Analysis of 6,962 Lesions

OBJECTIVE

The primary aim was to determine and compare the complication rate of different surgical treatment options for osteochondral lesions of the talus (OLTs). The secondary aim was to analyze and compare the severity and types of complications.

DESIGN

A literature search was performed in MEDLINE (PubMed), EMBASE (Ovid), and the Cochrane Library. Methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS). Primary outcome was the complication rate per surgical treatment option. Secondary outcomes included the severity (using the Modified Clavien-Dindo-Sink Complication Classification System for Orthopedic Surgery) and types of complications. The primary outcome, the severity, and the sub-analyses were analyzed using a random effects model. A moderator test for subgroup-analysis was used to determine differences. The types of complications were presented as rates.

RESULTS

In all, 178 articles from the literature search were included for analysis, comprising 6,962 OLTs with a pooled mean age of 35.5 years and follow-up of 46.3 months. Methodological quality was fair. The overall complication rate was 5% (4%-6%; treatment group effect, P = 0.0015). Analysis resulted in rates from 3% (2%-4%) for matrix-assisted bone marrow stimulation to 15% (5%-35%) for metal implants. Nerve injury was the most observed complication.

CONCLUSIONS

In 1 out of 20 patients treated surgically for an OLT, a complication occurs. Metal implants have a significantly higher complication rate compared with other treatment modalities. No life-threatening complications were reported.

Typical Complications After Cartilage Repair of the Ankle Using Autologous Matrix-Induced Chondrogenesis (AMIC)

Background:

Autologous matrix-induced chondrogenesis (AMIC) for the treatment of osteochondral lesions of the talus (OLT) results in favorable clinical outcomes, yet high reoperation rates. The aim of this study was to report and analyze typical complications and their risk factors after AMIC for OLT.

Methods:

A total of 127 consecutive patients with 130 AMIC procedures for OLT were retrospectively assessed. All AMIC procedures were performed in an open fashion with 106 (81.5%) cases requiring a malleolar osteotomy (OT) to access the OLT. Seventy-one patients (54.6%) underwent subsequent surgery. These cases were evaluated at a mean follow-up of 3.1 years (±2.5) for complications reviewing postoperative imaging and intraoperative findings during revision surgery. Six patients (8.5%) were lost to follow-up. Regression model analysis was conducted to identify factors that were associated with AMIC-related complications.

Results:

Among the 65 (50%) patients who required revision surgery, 18 patients (28%) demonstrated AMIC-related complications with deep fissuring (83%) and thinning (17%) of the AMIC graft. Conversely, 47 patients (72%) underwent subsequent surgery due to AMIC-unrelated reasons including isolated removal of symptomatic hardware (n = 17) and surgery addressing concomitant pathologies with (n = 25) and without hardware removal (n = 5). Previous prior cartilage repair surgery was significantly associated with AMIC graft-associated complications in patients undergoing revision surgery ( P = .0023). Among age, body mass index, defect size, smoking, and bone grafting, smoking was the only factor showing statistical significance with an odds ratio of 3.7 (95% CI 1.24, 10.9; P = .019) to undergo revision surgery due to graft-related complications, when adjusted for previous cartilage repair surgery.

Conclusion:

The majority of revision surgeries after AMIC for OLT are unrelated to the performed AMIC graft but frequently address symptomatic hardware and concomitant pathologies. Both smoking and previous cartilage repair surgery seem to significantly increase the risk of undergoing revision surgery due to AMIC-related complications.

Level of evidence:

Level IV, case series.

Talar Dome Osteochondral Lesions: Pre- and Postoperative Imaging

We suggest a similar approach to evaluating osteochondral lesions of the talar dome both pre- and postoperatively. This review addresses the etiology, natural history, and treatment of talar dome osteochondral lesions with an emphasis on imaging appearances. High-resolution magnetic resonance imaging, ideally combining a small field-of-view surface coil with ankle traction, optimizes visibility of most of the clinically relevant features both pre- and postoperatively.

Prognostic factors for the management of chondral defects of the knee and ankle joint: a systematic review

Purpose

Different surgical techniques to manage cartilage defects are available, including microfracture (MFx), autologous chondrocyte implantation (ACI), osteoarticular auto- or allograft transplantation (OAT), autologous matrix-induced chondrogenesis (AMIC). This study investigated the patient-related prognostic factors on the clinical outcomes of surgically treated knee and ankle cartilage defects.

Methods

This study followed the PRISMA statement. In May 2022, the following databases were accessed: PubMed, Google Scholar, Embase, and Scopus. All the studies investigating the outcomes of surgical management for knee and/or talus chondral defects were accessed. Only studies performing mesenchymal stem cells transplantation, OAT, MFx, ACI, and AMIC were considered. A multiple linear model regression analysis through the Pearson Product–Moment Correlation Coefficient was used.

Results

Data from 184 articles (8905 procedures) were retrieved. Female sex showed a positive moderate association with visual analogue scale at last follow-up (P = 0.02). Patient age had a negative association with the American Orthopaedic Foot and Ankle Score (P = 0.04) and Lysholm Knee Scoring Scale (P = 0.03). BMI was strongly associated with graft hypertrophy (P = 0.01). Greater values of VAS at baseline negatively correlate with lower values of Tegner Activity Scale at last follow-up (P < 0.0001).

Conclusion

The clinical outcomes were mostly related to the patients’ performance status prior surgery. A greater BMI was associated with greater rate of hypertrophy. Female sex and older age evidenced fair influence, while symptom duration prior to the surgical intervention and cartilage defect size evidenced no association with the surgical outcome. Lesion size and symptom duration did not evidence any association with the surgical outcome.

Augmenting Osteochondral Autograft Transplantation and Bone Marrow Aspirate Concentrate with Particulate Cartilage Extracellular Matrix Is Associated With Improved Outcomes

BACKGROUND

Osteochondral autograft transplant (OAT) is often used to treat large osteochondral lesions of the talus and is generally associated with good outcomes. The addition of adjuncts such as cartilage extracellular matrix with bone marrow aspirate concentrate (ECM-BMAC) may further improve the OAT procedure but have not been thoroughly studied. We hypothesized that the placement of ECM-BMAC around the OAT graft would improve radiographic and patient-reported outcomes following OAT.

METHODS

Patients who received OAT, with ECM-BMAC or BMAC alone, were screened and their charts were reviewed. For patients who did receive ECM-BMAC, the mixture was spread around the edges of the OAT plug and into any surrounding areas of cartilage damage. Survey and radiographic data were collected. Average follow-up in both groups was over 2 years. Magnetic resonance imaging scans were scored using the Magnetic Resonance Observation of Cartilage Tissue (MOCART) system. Outcomes were compared statistically between groups.

RESULTS

Patients treated with ECM-BMAC (n = 34) demonstrated significantly greater improvement of scores in the FAOS categories Symptoms (17 vs -3; P = .02) and Sports Activities (40 vs 7; P = .02), and the MOCART category Subchondral Lamina (P = .008) compared to those treated with BMAC alone (n = 30). They also experienced significantly lower rates of postoperative cysts (53% vs 18%, P = .04) and edema (94% vs 59%, P = .02).

CONCLUSION

The addition of ECM-BMAC to OAT was associated with improved imaging and clinical outcomes compared to OAT with BMAC alone.

Nonoperative and Operative Soft-Tissue and Cartilage Regeneration and Orthopaedic Biologics of the Foot and Ankle: An Orthoregeneration Network Foundation Review

Orthoregeneration is defined as a solution for orthopaedic conditions that harnesses the benefits of biology to improve healing, reduce pain, improve function, and optimally, provide an environment for tissue regeneration. Options include drugs, surgical intervention, scaffolds, biologics as a product of cells, and physical and electromagnetic stimuli. The goal of regenerative medicine is to enhance the healing of tissue after musculoskeletal injuries as both isolated treatment and adjunct to surgical management, using novel therapies to improve recovery and outcomes. Various orthopaedic biologics (orthobiologics) have been investigated for the treatment of pathology involving the foot and ankle (including acute traumatic injuries and fractures, tumor, infection, osteochondral lesions, arthritis, and tendinopathy) and procedures, including osteotomy or fusion. Promising and established treatment modalities include 1) bone-based therapies (such as cancellous or cortical autograft from the iliac crest, proximal tibia, and/or calcaneus, fresh-frozen or freeze-dried cortical or cancellous allograft, including demineralized bone matrix putty or powder combined with growth factors, and synthetic bone graft substitutes, such as calcium sulfate, calcium phosphate, tricalcium phosphate, bioactive glasses (often in combination with bone marrow aspirate), and polymers; proteins such as bone morphogenic proteins; and platelet-derived growth factors; 2) cartilage-based therapies such as debridement, bone marrow stimulation (such as microfracture or drilling), scaffold-based techniques (such as autologous chondrocyte implantation [ACI] and matrix-induced ACI, autologous matrix-induced chondrogenesis, matrix-associated stem cell transplantation, particulated juvenile cartilage allograft transplantation, and minced local cartilage cells mixed with fibrin and platelet rich plasma [PRP]); and 3) blood, cell-based, and injectable therapies such as PRP, platelet-poor plasma biomatrix loaded with mesenchymal stromal cells, concentrated bone marrow aspirate, hyaluronic acid, and stem or stromal cell therapy, including mesenchymal stem cell allografts, and adipose tissue-derived stem cells, and micronized adipose tissue injections. LEVEL OF EVIDENCE: Level V, expert opinion.

AMIC Procedure for Treatment of Osteochondral Lesions of Talus-A Systematic Review of the Current Literature

Osteochondral lesions of talus are a common injury where surgery is indicated in case of failed non-operative treatment or displaced lesions. Many studies have been conducted on the effectiveness of the AMIC procedure. The goal of our study is to create an overview of the current literature. A systematic search adhering to the PRISMA guidelines was conducted in PubMed (MEDLINE) and EMBASE on May 27, 2020. All included studies were evaluated according to the modified Coleman Methodology Score and information on study type, patient numbers, age, follow-up period, grade, location and size of the lesion, study in- and exclusion criteria, associated surgery, surgical technique, scaffold- and fixation technique, postoperative restrictions, reoperation rates, study outcome score, rehabilitation program, and surgical complications was extracted. Ninety-six studies were identified with 18 studies being included in our analysis. The overall quality of the literature was fair with no studies being graded as excellent. Data on preoperative evaluation and surgical technique, complication and reoperation rates, postoperative management and study outcome was extracted in order to create an overview of the current literature. The literature supports the use of the AMIC procedure as an effective treatment for osteochondral lesions of talus. Great heterogeneity exists and comparative studies are missing. While the number of studies on the topic is increasing further are needed and especially with optimized design.

Fibrin glue does not assist migration and proliferation of chondrocytes in collagenic membranes: an in vitro study

Background

Some authors secured the membrane during matrix-induced autologous chondrocyte implantation (mACI) with fibrin glue or did not use a formal fixation. The real impact of fibrin glue addition on chondrocytes migration and proliferation has not yet been clarified. This study evaluated the impact of fibrin glue on a chondrocyte loaded collagenic membrane.

Methods

A resorbable collagen I/III porcine derived membrane commonly employed in AMIC was used for all experiments. Chondrocytes from three difference donors were used. At 1-, 2-, 3-, 4-, 6-, and at 8-week the membranes were embedded in Mounting Medium with Dapi (ABCAM, Cambridge, UK). The Dapi contained in the mounting medium ties the DNA of the cell nucleus and emits a blue fluorescence. In this way, the spreading of the cells in the membrane can be easily monitored. The outcomes of interest were to evaluate (1) cell migration and (2) cell proliferation within the porous membrane layer. DAPI/nuclei signals were analysed with fluorescence microscope under a magnification of 100-fold.

Results

The no-fibrin group demonstrated greater migration of the cells within the membrane. Although migration resulted higher in the no-fibrin group at every follow-up, this difference was significant only at week 1 (P < 0.001), 2 (P = 0.004), and 3 (P = 0.03). No difference was found at week 3, 6, and 8. The no-fibrin group demonstrated greater proliferation of the chondrocytes within the membrane. These differences were significant at week 4 (P < 0.0001), 6 (P < 0.0001), 8 (P < 0.0001).

Conclusion

The use of fibrin glue over a resorbable membrane leads to lower in vitro proliferation and migration of chondrocytes.

Correlation of Postoperative Imaging With MRI and Clinical Outcome After Cartilage Repair of the Ankle: A Systematic Review and Meta-analysis

Background:

Magnetic resonance imaging (MRI) is commonly used for evaluation of ankle cartilage repair, yet its association with clinical outcome is controversial. This study analyzes the correlation between MRI and clinical outcome after cartilage repair of the talus including bone marrow stimulation, cell-based techniques, as well as restoration with allo- or autografting.

Methods:

A systematic search was performed in MEDLINE, Embase, and Cochrane Collaboration. Articles were screened for correlation of MRI and clinical outcome. Guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) were used. Chi-square test and regression analysis were performed to identify variables that determine correlation between clinical and radiologic outcome.

Results:

Of 2687 articles, a total of 43 studies (total 1212 cases) were included with a mean Coleman score of 57 (range, 33-70). Overall, 93% were case series, and 5% were retrospective and 2% prospective cohort studies. Associations between clinical outcome and ≥1 imaging variable were found in 21 studies (49%). Of 24 studies (56%) using the composite magnetic resonance observation of cartilage repair tissue (MOCART) score, 7 (29%) reported a correlation of the composite score with clinical outcome. Defect fill was associated with clinical outcome in 5 studies (12%), and 5 studies (50%) reported a correlation of T2 mapping and clinical outcome. Advanced age, shorter follow-up, and larger study size were associated with established correlation between clinical and radiographic outcome (P = .021, P = .028, and P = .033).

Conclusion:

Interpreting MRI in prediction of clinical outcome in ankle cartilage repair remains challenging; however, it seems to hold some value in reflecting clinical outcome in patients with advanced age and/or at a shorter follow-up. Yet, further research is warranted to optimize postoperative MRI protocols and assessments allowing for a more comprehensive repair tissue evaluation, which eventually reflect clinical outcome in patients after cartilage repair of the ankle.

Level of Evidence: Level III, systematic review and meta-analysis.

Outcomes Following Repeat Ankle Arthroscopy and Microfracture for Osteochondral Lesions of the Talus

BACKGROUND

The management of symptomatic osteochondral lesions of the talus (OLTs) previously treated with arthroscopy is controversial. Minimal data exist on the role for repeat arthroscopy. Here, we describe our experience with repeat arthroscopy and microfracture for symptomatic OLTs.

METHODS

Our database was queried over an 8-year period to identify patients undergoing repeat arthroscopy and microfracture as treatment for symptomatic OLTs. Phone surveys were conducted to assess residual pain, patient satisfaction, and need for subsequent surgery. We compared patient outcomes based on the size of their OLT (small lesions ≤150 mm2, large >150 mm2) and the presence or absence of subchondral cysts.

RESULTS

We identified 14 patients who underwent repeat arthroscopy and microfracture for symptomatic OLTs. Patients reported reasonable satisfaction (7.6 ± 3.5 out of 10) but moderate residual pain (4.7 ± 3.4 out of 10) at midterm follow-up (5.1 ± 2.9 years). In total, 21% (3/14) of patients had undergone subsequent surgery. Patients with small (n = 5) and large OLTs (n = 9) had similar postoperative pain scores (4.2 ± 4.1 vs 4.9 ± 3.2) and postoperative satisfaction levels (6.4 ± 4.9 vs 8.3 ± 2.5).

CONCLUSION

At midterm follow-up, repeat arthroscopy for symptomatic OLTs demonstrated reasonable satisfaction but moderate residual pain. Lesion size or presence of subchondral cysts did not affect outcome, but our sample size was likely too small to detect statistically significant differences. These data show that repeat ankle arthroscopy can be performed safely with modest outcomes, and we hope that this report aids in managing patient expectations.Level of Evidence: Level IV Case Series.

The Role of Magnetic Resonance Imaging in Autologous Matrix-Induced Chondrogenesis for Osteochondral Lesions of the Talus: Analyzing MOCART 1 and 2.0

OBJECTIVE

To determine the role of magnetic resonance imaging (MRI) MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) 1 and 2.0 scores in the assessment of postoperative outcome after autologous matrix-induced chondrogenesis (AMIC) for the treatment of osteochondral lesions of the talus (OLTs). It was hypothesized that preoperative patient factors or OLT morphology are associated with postoperative MOCART scores; yet postoperative clinical outcome is not.

STUDY DESIGN

Cohort study; Level of evidence, 4. This study evaluated isolated AMIC that were implanted on the talus of 35 patients for the treatment of symptomatic OLT. Tegner and AOFAS (American Orthopaedic Foot and Ankle Society) scores were obtained at an average follow-up of 4.5 ± 1.8 years and postoperative MRI scored according to the MOCART 1 and 2.0.

RESULTS

OLT size showed significant correlation with postoperative MRI scores (MOCART 1: P = 0.006; MOCART 2.0: P = 0.004). Bone grafting was significantly associated with a MOCART 1 subscale (signal intensity of repair tissue; P = 0.038). Age and defect size showed significant correlations with MOCART 2.0 subscales (P < 0.05). Patients with shorter follow-up had a significantly higher MOCART 1 score and a trend toward better MOCART 2.0 scores than patients with longer follow-up (64.7 vs. 52.9 months, P = 0.02; 69.4 vs. 60.6 months, P = 0.058). No MOCART score was associated with postoperative patient-reported outcomes (n.s.).

CONCLUSION

Osteochondral lesion size is associated with postoperative MOCART scores in patients treated with AMIC for OLTs, with decreasing MOCART scores over time. Yet clinical outcome does not correlate with any MOCART score. Thus, MOCART assessment seems to have no significant role in the postoperative treatment of asymptomatic patients that underwent AMIC for OLTs.

Demographics in Patients Receiving Matrix-Assisted Chondrocyte Implantation (MACI) in the Ankle

Objective. To compare demographics and cartilage lesion characteristics of patients enrolled in clinical trials investigating autologous chondrocyte implantation (ACI) in the ankle joint with those actually scheduled for matrix-assisted chondrocyte implantation (MACI) using database records. Design. Anonymized data from patients scheduled for MACI treatment in the ankle in Australia/Asia and Europe were obtained from the Genzyme/Sanofi database. Average age, defect size, and male-female ratio were analyzed and compared by country. A literature search was performed on PubMed and Google Scholar and clinical cohort studies and prospective comparative trials using ACI and related treatments in the ankle joint were identified. Weighted average age, weighted defect size, and male-female ratio were analyzed and compared with database data. Results. The 167 patients included from the databases from Europe and Australia had a mean age of 33.4 years (range 14-64 years) and a mean defect size of 2.27 cm² (range 0.25-16 cm²). Male-female ratio was 4:3. Patients from European countries were significantly younger and had significantly larger defects compared with patients from Australia. From the literature search a total of 472 patients were included from 28 studies. The mean age was 32.2 years (range 15-62 years). Male-female ratio was 3:2. Weighted mean size was 1.94cm² (range 0.3-16). There were no significant differences between previous studies and databases. Conclusion. No differences in sizes and age were found between patients enrolled in clinical trials and patients scheduled for MACI outside clinical trials. The sizes of treated defects followed the general recommendations. There were, however, significant differences between countries.

Osteochondral Lesions of the Tibial Plafond: A Systematic Review

Background:

There is a paucity of data regarding osteochondral lesions of the tibial plafond (OLTPs), in part because they are far less common than osteochondral lesions of the talus.

Purpose:

To evaluate the topographical characteristics of OLTPs and outcomes after surgical intervention, while analyzing the level of evidence (LOE) and quality of evidence (QOE) of the included studies.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review of the MEDLINE, EMBASE, and Cochrane Library databases was performed in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies reporting clinical data for OLTPs were included. The LOE and QOE of the included studies were evaluated using a 5-level grading system and the modified Coleman Methodology Score, respectively.

Results:

Included were 20 studies with 426 OLTPs; 4 studies were LOE 2 and 16 studies were LOE 4. Overall, 86.7% of OLTPs were associated with a traumatic history and/or previous ankle sprain. OLTPs were most commonly located in the centromedial region of the tibial plafond (30.4%), with the fewest number of OLTPs found in the anteromedial region of the tibial plafond (3.9%). In 17 of the studies, a total of 46.9% of OLTPs were associated with coexisting osteochondral lesions of the talus. The most frequently used surgical technique to treat OLTPs was microfracture, which resulted in good clinical outcomes at midterm follow-up.

Conclusion:

The results of this systematic review indicated that OLTPs are frequently preceded by ankle trauma and are often associated with coexisting osteochondral lesions of the talus. Clinical outcomes after arthroscopic intervention appear to produce good results in the midterm, but the low LOE, poor QOE, marked heterogeneity, and underreporting of the data confound any recommendation based on this systematic review.

Reliability of the MOCART score: a systematic review

BACKGROUND

The present systematic review analysed the available literature to assess reliability of the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score in the evaluation of knee and ankle osteochondral lesions.

METHODS

All the studies using the MOCART score for knee and/or talus chondral defects were accessed in March 2021. A multivariate analysis was performed to assess associations between the MOCART score at last follow-up and data of patients at baseline, clinical scores and complications. A multiple linear model regression analysis was used.

RESULTS

The MOCART score evidenced no association with patient age (P = 0.6), sex (P = 0.1), body mass index (P = 0.06), defect size (P = 0.9), prior length of symptoms (P = 0.9) or visual analogue scale (P = 0.07). For chondral defects of the knee, no statistically significant association was found between the MOCART score and the International Knee Documentation Committee (P = 0.9) and with the Lysholm Knee Scoring Scales (P = 0.2), Tegner Activity Scale (P = 0.2), visual analogue scale P = 0.07), rate of failure (P = 0.2) and revision (P = 0.9). For chondral defect of the talus, no statistically significant associations were found between the MOCART score and the American Orthopedic Foot and Ankle Score (P = 0.3), Tegner Activity Scale (P = 0.4), visual analogue scale (P = 0.1), rate of failure (P = 0.1) and revision (P = 0.7).

CONCLUSION

The MOCART score demonstrated no association with patient characteristics and with the surgical outcome in patients who underwent surgical management for knee and talus chondral defects.

LEVEL OF EVIDENCE

Level IV.

Surgical Treatment of Osteochondral Lesions of the Tibial Plafond: A Systematic Review and Meta-Analysis

BACKGROUND

The literature on osteochondral lesions of the tibial plafond (OLTPs) is sparse. The aim of this study was therefore to provide an overview of clinical and radiological outcomes following treatment of OLTPs.

METHODS

We performed a systematic search of the MEDLINE, Embase, and Cochrane library databases. The review was performed in accordance with the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines and included all original articles on treatment outcomes for OLTPs. The methodological quality of the articles was assessed using the Methodological Index for Non-Randomized Studies (MINORS). Baseline patient and lesion characteristics were pooled and weighted according to the number of lesions per study. The primary outcome was any clinical or patient-reported outcome measure pooled by treatment method when separable data were available. Secondary outcomes were complications, reoperation rates, radiological outcomes, and sport outcomes.

RESULTS

The search yielded 2,079 articles, of which 10 studies (1 prospective case series, 1 retrospective comparative study, and 8 retrospective case series) with a total of 175 patients were included. The overall methodological quality of the studies was low. All patients were treated surgically; 96% of the lesions were primary cases (i.e., first-time surgery) and 58% were solitary tibial lesions (i.e., no opposing talar lesion). Arthroscopic bone marrow stimulation was the most frequently used treatment strategy (51%), followed by cartilage transplantation (17%), chondrogenesis-inducing techniques (11%), osteochondral transplantation (3%), retrograde drilling (3%), and mixed (i.e., inseparable) treatments (15%). The clinical outcomes of the different surgical therapies were considered to be moderate to good. The pooled postoperative AOFAS (American Orthopaedic Foot & Ankle Society) score for bone marrow stimulation and osteochondral transplantation was 54.8 (95% confidence interval [CI], 49.5 to 85.0) (n = 14) and 85.3 (95% CI, 56 to 100) (n = 3), respectively. Overall, complications and reoperations were rarely reported. The pooled complication and reoperation rates could only be calculated for bone marrow stimulation and were 5% and 7%, respectively.

CONCLUSIONS

Surgical interventions for OLTPs appear to yield moderate to good clinical outcomes. Bone marrow stimulation resulted in a moderate AOFAS score. Complications and reintervention rates were found to be low. The current evidence in the literature is limited because of the underreporting of clinical, radiological, and sport data and the heterogenous outcome scores reported.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Comparison of Functional and Radiographic Outcomes of Talar Osteochondral Lesions Repaired With Micronized Allogenic Cartilage Extracellular Matrix and Bone Marrow Aspirate Concentrate vs Microfracture

BACKGROUND

Microfracture (MF) has been used historically to treat osteochondral lesions of the talus (OLTs), with favorable outcomes reported in approximately 80% to 85% of cases. However, MF repairs have been shown to degrade over time at long-term follow-up, suggesting that further study into optimal OLT treatment is warranted. The use of adjuvant extracellular matrix with bone marrow aspirate concentrate (ECM-BMAC) has not been extensively evaluated in the literature. We present a comparison of patient-reported and radiographic outcomes following ECM-BMAC repair vs traditional MF.

METHODS

Patients who underwent MF (n = 67) or ECM-BMAC (n = 62) treatment for an OLT were identified and their charts were retrospectively reviewed. Postoperative magnetic resonance imaging (MRI) was evaluated and patient-reported outcome scores, either Foot and Ankle Outcome Scores (FAOS) or Patient-Reported Measurement Information System (PROMIS) scores, were collected. MRIs were scored by a radiologist, fellowship trained in musculoskeletal radiology, using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) system. Radiographic and clinical outcomes were compared between groups.

RESULTS

On average, patients treated with ECM-BMAC demonstrated a higher total MOCART score compared to the MF group (73 ± SD 11.5 vs 54.0 ± 24.1; P = .0015). ECM-BMAC patients also had significantly better scores for the Infill, Integration, and Signal MOCART subcategories. Last, patients treated with ECM-BMAC had a lower rate of revision compared to those treated with MF (4.8% vs 20.9%; P = .007). FAOS scores were compared between groups, with no significant differences observed.

CONCLUSION

When comparing outcomes between patients treated for an OLT with ECM-BMAC vs traditional MF, we observed superior MRI results for ECM-BMAC patients. The rate of revision surgery was higher for MF patients, although patient-reported outcomes were similar between groups. The use of ECM-BMAC as an adjuvant therapy in the treatment of OLTs may result in improved reparative tissue when compared to MF.

LEVEL OF EVIDENCE

Level III, comparative series.

High-Density Autologous Chondrocyte Implantation as Treatment for Ankle Osteochondral Defects

PURPOSE

Two-year follow-up to assess efficacy and safety of high-density autologous chondrocyte implantation (HD-ACI) in patients with cartilage lesions in the ankle.

DESIGN

Twenty-four consecutive patients with International Cartilage repair Society (ICRS) grade 3-4 cartilage lesions of the ankle were included. Five million chondrocytes per cm² of lesion were implanted using a type I/III collagen membrane as a carrier and treatment effectiveness was assessed by evaluating pain with the visual analogue scale (VAS) and American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score at baseline, 12-month, and 24-month follow-up, together with dorsal and plantar flexion. Magnetic resonance observation for cartilage repair tissue (MOCART) score was used to evaluate cartilage healing. Histological study was possible in 5 cases.

RESULTS

Patients' median age was 31 years (range 18-55 years). Median VAS score was 8 (range 5-10) at baseline, 1.5 (range 0-8) at 12-month follow-up, and 2 (rang e0-5) at 24-month follow-up (P < 0.001). Median AOFAS score was 39.5 (range 29-48) at baseline, 90 (range 38-100) at 12-month follow-up, and 90 (range 40-100) at 24-month follow-up (P < 0.001). Complete dorsal flexion significantly increased at 12 months (16/24, 66.7%) and 24 months (17/24, 70.8%) with regard to baseline (13/24, 54.2%) (P = 0.002). MOCART at 12- and 24-month follow-ups were 73.71 ± 15.99 and 72.33 ± 16.21. Histological study confirmed that neosynthetized tissue was cartilage with hyaline extracellular matrix and numerous viable chondrocytes.

CONCLUSION

HD-ACI is a safe and effective technique to treat osteochondral lesions in the talus, providing good clinical and histological results at short- and mid-term follow-ups.

Matrix-induced autologous chondrocyte implantation versus autologous matrix-induced chondrogenesis for chondral defects of the talus: a systematic review

INTRODUCTION

Chondral defects of the talus are common and their treatment is challenging.

SOURCE OF DATA

Recent published literatures.

AREAS OF AGREEMENT

Membrane-induced Autologous Chondrocyte Implantation (mACI) and Autologous Matrix-Induced Chondrogenesis (AMIC) have been proposed as management for chondral defects of the talus.

AREAS OF CONTROVERSY

It is debated whether AMIC provides greater outcomes compared to mACI for chondral regeneration. Several clinical studies showed controversial results, and the best treatment has not yet been clarified.

GROWING POINTS

To investigate whether AMIC provide superior outcomes than mACI at midterm follow-up.

AREAS TIMELY FOR DEVELOPING RESEARCH

AMIC exhibits similar clinical results to mACI. However, AMIC involves one single surgical procedure, no articular cartilage harvest and hence no morbidity from it, no need for chondrocyte expansion in a separate laboratory setting. For these reasons, AMIC may be preferred to mACI.

Autologous Matrix-Induced Chondrogenesis With Lateral Ligament Stabilization for Osteochondral Lesions of the Talus in Patients With Ankle Instability

Background:

Autologous matrix-induced chondrogenesis (AMIC) has been shown to result in favorable clinical outcomes in patients with osteochondral lesions of the talus (OLTs). Though, the influence of ankle instability on cartilage repair of the ankle has yet to be determined.

Purpose/Hypothesis:

To compare the clinical and radiographic outcomes in patients with and without concomitant lateral ligament stabilization (LLS) undergoing AMIC for the treatment of OLT. It was hypothesized that the outcomes would be comparable between these patient groups.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Twenty-six patients (13 with and 13 without concomitant ankle instability) who underwent AMIC with a mean follow-up of 4.2 ± 1.5 years were enrolled in this study. Patients were matched 1:1 according to age, body mass index (BMI), lesion size, and follow-up. Postoperative magnetic resonance imaging and Tegner, American Orthopaedic Foot & Ankle Society (AOFAS), and Cumberland Ankle Instability Tool (CAIT) scores were obtained at a minimum follow-up of 2 years. A musculoskeletal radiologist scored all grafts according to the MOCART (magnetic resonance observation of cartilage repair tissue) 1 and MOCART 2.0 scores.

Results:

The patients’ mean age was 33.4 ± 12.7 years, with a mean BMI of 26.2 ± 3.7. Patients with concomitant LLS showed worse clinical outcome measured by the AOFAS (85.1 ± 14.4 vs 96.3 ± 5.8; P = .034) and Tegner (3.8 ± 1.1 vs 4.4 ± 2.3; P = .012) scores. Postoperative CAIT and AOFAS scores were significantly correlated in patients with concomitant LLS (r = 0.766; P = .002). A CAIT score >24 (no functional ankle instability) resulted in AOFAS scores comparable with scores in patients with isolated AMIC (90.1 ± 11.6 vs 95.3 ± 6.6; P = .442). No difference was seen between groups regarding MOCART 1 and 2.0 scores (P = .714 and P = .371, respectively).

Conclusion:

Concurrently performed AMIC and LLS in patients with OLT and ankle instability resulted in clinical outcomes comparable with isolated AMIC if postoperative ankle stability was achieved. However, residual ankle instability was associated with worse postoperative outcomes, highlighting the need for adequate stabilization of ankle instability in patients with OLT.

Outcomes of arthroscopic bone graft transplantation for Hepple stage V osteochondral lesions of the talus

Background

Based on MRI imaging findings, osteochondral lesions of the talus (OLT) can be classified into five stages, in which stage V represents OLT with subchondral cyst formation. The aim of this study was to evaluate the outcomes of patients undergoing arthroscopic transplantation of calcaneus bone graft for Hepple stage V OLT.

Methods

This retrospective study included 24 patients with Hepple stage V OLT (15 men and 9 women), with an average age of 39.8±12.9 years old. The mean follow-up period was 18.9±11.8 months. At this follow-up, all patients were clinically evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) score, the Karlsson Ankle Function Score (KAFS), the Tegner score, and the visual analogue scale (VAS). Furthermore, 14 patients underwent MRI imaging examinations, and the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) 2.0 score was assessed.

Results

The AOFAS score, KAFS, Tegner activity score, and VAS pain score (preoperative: 62.2, 60.4, 2.1, and 6.2, respectively; postoperative: 92.8, 88.5, 4.2, and 1.6, respectively) improved significantly (P=0.0001). The MRI-based MOCART score of the articular cartilage repair tissue after surgery was 68±14.8.

Conclusions

Arthroscopic transplantation of calcaneus bone graft for Hepple stage V OLT could obtain satisfying clinical and radiological outcomes in the short-term.

Osteochondral Lesions of the Distal Tibial Plafond: A Systematic Review of Lesion Locations and Treatment Outcomes

BACKGROUND

Osteochondral lesions of the tibial plafond (OLTPs) remain less common than osteochondral lesions of the talus (OLTs), but recognition of the condition has increased.

PURPOSE

To systematically evaluate the literature on lesion locations and treatment outcomes of OLTPs, whether in isolation or in combination with OLTs.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

A search was performed using the PubMed, Embase, and CINAHL databases for studies on lesion locations or with imaging or treatment outcomes of OLTPs. Case reports and reports based on expert opinion were excluded. Lesion locations as well as outcome measure results were aggregated. The Methodological Index for Non-randomized Studies score was used to assess methodological quality when applicable.

RESULTS

Included in this review were 10 articles, all published in 2000 or later. Most studies were evidence level 4, and the mean Methodological Index for Non-randomized Studies score was 8.6 (range, 8-10). Overall, 174 confirmed OLTP cases were identified, and the mean patient age was 38.8 years. Of the 157 lesions with confirmed locations, the most common was central-medial (32/157; 20.4%). Of 6 studies on treatment outcomes, all but 1 evaluated bone marrow stimulation techniques. Microfracture of small lesions (<150 mm2) was the most common treatment utilized. Imaging and functional outcomes appeared favorable after treatment. The data did not support differences in outcomes between isolated OLTPs and OLTPs with coexisting OLTs.

CONCLUSION

Osteochondral lesions of the distal tibia most commonly occurred at the central-medial tibial plafond. Microfracture of small lesions was the most common treatment utilized, and clinical and magnetic resonance imaging results were favorable, although data were heterogeneous. Areas for future research include the following: the effect of patient factors and additional pathologies on outcomes; larger or deeper lesion treatment; more direct comparisons of outcomes between kissing or coexisting lesions and isolated lesions; and head-to-head comparison of treatments, such as microfracture, bone marrow-derived cell transplantation, and osteochondral autografts/allografts.

An Evidence-Based Systematic Review of Human Knee Post-Traumatic Osteoarthritis (PTOA): Timeline of Clinical Presentation and Disease Markers, Comparison of Knee Joint PTOA Models and Early Disease Implications

Understanding the causality of the post-traumatic osteoarthritis (PTOA) disease process of the knee joint is important for diagnosing early disease and developing new and effective preventions or treatments. The aim of this review was to provide detailed clinical data on inflammatory and other biomarkers obtained from patients after acute knee trauma in order to (i) present a timeline of events that occur in the acute, subacute, and chronic post-traumatic phases and in PTOA, and (ii) to identify key factors present in the synovial fluid, serum/plasma and urine, leading to PTOA of the knee in 23-50% of individuals who had acute knee trauma. In this context, we additionally discuss methods of simulating knee trauma and inflammation in in vivo, ex vivo articular cartilage explant and in vitro chondrocyte models, and answer whether these models are representative of the clinical inflammatory stages following knee trauma. Moreover, we compare the pro-inflammatory cytokine concentrations used in such models and demonstrate that, compared to concentrations in the synovial fluid after knee trauma, they are exceedingly high. We then used the Bradford Hill Framework to present evidence that TNF-α and IL-6 cytokines are causal factors, while IL-1β and IL-17 are credible factors in inducing knee PTOA disease progresssion. Lastly, we discuss beneficial infrastructure for future studies to dissect the role of local vs. systemic inflammation in PTOA progression with an emphasis on early disease.

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.

Current treatment concepts for osteochondral lesions of the talus

Osteochondral lesions of the talus (OLT) are a well-known cause of ankle joint pain and can sometimes lead to instability. These lesions are not only confined to articular hyaline cartilage, they can also affect the subchondral bone at the weight-bearing aspect of the talar dome. Nonoperative treatment is the preferred option for small lesions, however surgical intervention is recommended for large lesions or those for which conservative treatment has failed. Microfracture, abrasion arthroplasty and multiple drilling are all classified as bone marrow stimulation procedures; they are used to try to recruit precursor cells for cartilage regeneration and are especially suitable for small OLT lesions. For large lesions, osteochondral autografting and allografting are better options to reconstruct the articular defect, as they have better contours and mechanical strength. When there is limited subchondral bone involvement in large lesions, cell-based therapies such as autogenous chondrocyte implantation, potentially combined with a biomaterial matrix, are a promising option and acceptable functional outcomes have been reported. To provide evidence-based recommendations for clinicians, this article evaluates the currently available treatment strategies for OLT and their evolution over the past few decades.

Comparison of Chitosan-Based Liquid Scaffold and Hyaluronic Acid-Based Soft Scaffold for Treatment of Talus Osteochondral Lesions

BACKGROUND

The aim of this study was to evaluate the clinical and radiologic results of 2 different scaffolds with hyaluronan or chitosan-based structure used in the treatment of talus osteochondral lesions.

METHODS

Eighty-one patients who underwent chondral lesion repair with hyaluronan (n = 42) or chitosan-based (n = 39) scaffold were included. American Orthopaedic Foot & Ankle Society (AOFAS) and visual analog scale (VAS) scores were evaluated within and between groups preoperatively and at the 3rd, 12th, and 24th month postoperatively. In all patients, magnetic resonance imaging was performed between the 12 and 18th month postoperatively and compared with magnetic resonance observation of cartilage repair tissue (MOCART) scoring.

RESULTS

Within-group evaluations revealed significant improvements in AOFAS and VAS scores at postoperative 3 and 12 months. The postoperative 24th-month results of AOFAS scores in any group did not differ significantly from the 12th-month results. There was no significant difference between the groups in comparison of AOFAS, VAS, and MOCART scores at any time period.

CONCLUSION

Both scaffolds were found to be effective in cartilage healing but had no clinical or radiologic superiority to each other. This is the first study to compare the use of different cell-free scaffold types in osteochondral defects of the talus.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Mechanotransduction and Stiffness-Sensing: Mechanisms and Opportunities to Control Multiple Molecular Aspects of Cell Phenotype as a Design Cornerstone of Cell-Instructive Biomaterials for Articular Cartilage Repair

Since material stiffness controls many cell functions, we reviewed the currently available knowledge on stiffness sensing and elucidated what is known in the context of clinical and experimental articular cartilage (AC) repair. Remarkably, no stiffness information on the various biomaterials for clinical AC repair was accessible. Using mRNA expression profiles and morphology as surrogate markers of stiffness-related effects, we deduced that the various clinically available biomaterials control chondrocyte (CH) phenotype well, but not to equal extents, and only in non-degenerative settings. Ample evidence demonstrates that multiple molecular aspects of CH and mesenchymal stromal cell (MSC) phenotype are susceptible to material stiffness, because proliferation, migration, lineage determination, shape, cytoskeletal properties, expression profiles, cell surface receptor composition, integrin subunit expression, and nuclear shape and composition of CHs and/or MSCs are stiffness-regulated. Moreover, material stiffness modulates MSC immuno-modulatory and angiogenic properties, transforming growth factor beta 1 (TGF-β1)-induced lineage determination, and CH re-differentiation/de-differentiation, collagen type II fragment production, and TGF-β1- and interleukin 1 beta (IL-1β)-induced changes in cell stiffness and traction force. We then integrated the available molecular signaling data into a stiffness-regulated CH phenotype model. Overall, we recommend using material stiffness for controlling cell phenotype, as this would be a promising design cornerstone for novel future-oriented, cell-instructive biomaterials for clinical high-quality AC repair tissue.

Return to Sports After Surgical Treatment of Osteochondral Defects of the Talus: A Systematic Review of 2347 Cases

BACKGROUND

Osteochondral defects (OCDs) of the talus are found subsequent to ankle sprains and ankle fractures. With many surgical treatment strategies available, there is no clear evidence on return-to-sport (RTS) times and rates.

PURPOSE

To summarize RTS times and rates for talar OCDs treated by different surgical techniques.

STUDY DESIGN

Systematic review; Level of evidence, 4.

METHODS

The literature from January 1996 to November 2018 was screened, and identified studies were divided into 7 different surgical treatment groups. The RTS rate, with and without associated levels of activity, and the mean time to RTS were calculated per study. When methodologically possible, a simplified pooling method was used to combine studies within 1 treatment group. Study bias was assessed using the MINORS (Methodological Index for Non-Randomized Studies) scoring system.

RESULTS

A total of 61 studies including 2347 talar OCDs were included. The methodological quality of the studies was poor. There were 10 retrospective case series (RCSs) that investigated bone marrow stimulation in 339 patients, with a pooled mean rate of RTS at any level of 88% (95% CI, 84%-91%); 2 RCSs investigating internal fixation in 47 patients found a pooled RTS rate of 97% (95% CI, 85%-99%), 5 RCSs in which autograft transplantation was performed in 194 patients found a pooled RTS rate of 90% (95% CI, 86%-94%), and 3 prospective case series on autologous chondrocyte implantation in 39 patients found a pooled RTS rate of 87% (95% CI, 73%-94%). The rate of return to preinjury level of sports was 79% (95% CI, 70%-85%) for 120 patients after bone marrow stimulation, 72% (95% CI, 60%-83%) for 67 patients after autograft transplantation, and 69% (95% CI, 54%-81%) for 39 patients after autologous chondrocyte implantation. The mean time to RTS ranged from 13 to 26 weeks, although no pooling was possible for this outcome measure.

CONCLUSION

Different surgical treatment options for talar OCDs allow for adequate RTS times and rates. RTS rates decreased when considering patients' return to preinjury levels versus return at any level.

Autologous Matrix-Induced Chondrogenesis for Osteochondral Lesions of the Talus: A Clinical and Radiological 2- to 8-Year Follow-up Study

BACKGROUND

Autologous matrix-induced chondrogenesis (AMIC) has become an interesting treatment option for osteochondral lesions of the talus (OLTs) with promising clinical short- to midterm results.

PURPOSE

To investigate the clinical and radiological outcome of the AMIC procedure for OLTs, extending the follow-up to 8 years.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Thirty-three patients (mean age, 35.1 years; body mass index, 26.8) with osteochondral lesions of the medial talar dome were retrospectively evaluated after open AMIC repair at a mean follow-up of 4.7 years (range, 2.3-8.0 years). Patients requiring additional surgical procedures were excluded. All OLTs (mean size, 0.9 cm²; range, 0.4-2.3 cm²) were approached through a medial malleolar osteotomy, and 28 patients received subchondral autologous bone grafting. Data analysis included the visual analog scale for pain, the American Orthopaedic Foot and Ankle Society score for ankle function, the Tegner score for sports activity, and the MOCART (magnetic resonance observation of cartilage repair tissue) scoring system for repair cartilage and subchondral bone evaluation.

RESULTS

Mean ± SD visual analog scale score improved significantly from 6.4 ± 1.9 preoperatively to 1.4 ± 2.0 at latest follow-up ( P < .001). The mean American Orthopaedic Foot and Ankle Society score was 93.0 ± 7.5 (range, 75-100). The Tegner score improved significantly from 3.5 ± 1.8 preoperatively to 5.2 ± 1.7 at latest follow-up ( P < .001), and 79% returned to their previous sports levels. The MOCART score averaged 60.6 ± 21.2 (range, 0-100). Complete filling of the defect was seen in 88% of cases, but 52% showed hypertrophy of the cartilage layer. All but 1 patient showed persistent subchondral bone edema. The patient's age and body mass index, the size of the osteochondral lesion, and the MOCART score did not show significant correlation with the clinical outcome. There were no cases of revision surgery for failed AMIC. Fifty-eight percent underwent reoperation, mainly for symptomatic hardware after malleolar osteotomy.

CONCLUSION

AMIC for osteochondral talar lesions led to significant pain reduction, recovery of ankle function, and successful return to sport. The MOCART score did not correlate with the good clinical results; the interpretation of postoperative imaging remains therefore challenging.

Osteochondral Allograft Transplantation for Osteochondral Lesions of the Talus: Midterm Follow-up

BACKGROUND:

Fresh osteochondral allograft (OCA) transplantation represents a biologic restoration technique as an alternative treatment option for larger osteochondral lesions of the talus (OLT). The purpose of this study was to evaluate midterm outcomes after OCA transplantation for the treatment of OLT.

METHODS:

Nineteen patients (20 ankles) received partial unipolar OCA transplant for symptomatic OLT between January 1998 and October 2014. The mean age was 34.7 years, and 53% were male. The average graft size was 3.8 cm². All patients had a minimum follow-up of 2 years. Outcomes included the American Academy of Orthopaedic Surgeons Foot and Ankle Module (AAOS-FAM), the Olerud-Molander Ankle Score (OMAS), and pain and satisfaction questionnaires. Failure of OCA was defined as conversion to arthrodesis or revision OCA transplantation.

RESULTS:

Five of 20 ankles (25%) required further surgery, of which 3 (5%) were considered OCA failures (2 arthrodesis and 1 OCA revision). The mean time to failure was 3.5 (range, 0.9 to 6.7) years. Survivorship was 88.7% at 5 years and 81.3% at 10 years. The median follow-up of the 17 patients with grafts in situ was 9.7 years. The mean OMAS improved significantly from 40 points preoperatively to 71 points postoperatively ( P < .05; range, 5 to 55). The mean postoperative AAOS-FAM core score was 81.5 ± 15 (range, 40.5 to 96.6). Fifteen of 17 patients responded to follow-up questions regarding their ankle; 14 patients reported less pain and better function, and 13 patients were satisfied with the results of the procedure.

CONCLUSION:

Our study of midterm results after OCA transplantations showed that this procedure was a reasonable treatment option for large OLT.

LEVEL OF EVIDENCE:

Level IV, case series.

Arthroscopic Treatment of Osteochondral Lesions of the Talus Using Juvenile Articular Cartilage Allograft and Autologous Bone Marrow Aspirate Concentration

Juvenile allogenic chondrocyte implantation (JACI; DeNovo NT Natural Tissue Graft^®; Zimmer, Warsaw, IN) with autologous bone marrow aspirate concentrate (BMAC) is a relatively new all-arthroscopic procedure for treating critical-size osteochondral lesions (OCLs) of the talus. Few studies have investigated the clinical and radiographic outcomes of this procedure. We collected the clinical and radiographic outcomes of patients who had undergone JACI-BMAC for talar OCLs to assess treatment efficacy and cartilage repair tissue quality using magnetic resonance imaging (MRI). Forty-six patients with critical-size OCLs (≥6 mm widest diameter) received JACI-BMAC from 2012 to 2014. We performed a retrospective medical record review and assessed the functional outcomes pre- and postoperatively using the Foot and Ankle Outcome Score (FAOS) and Short-Form 12-item general health questionnaire. MRI was performed preoperatively and at 12 and 24 months postoperatively. Cartilage morphology was evaluated on postoperative MRI scans using the magnetic resonance observation of cartilage tissue (MOCART) score. The pre- to postoperative changes and relationships between outcomes and lesion size, bone grafting, lesion location, instability, hypertrophy, and MOCART scores were analyzed. Overall, the mean questionnaire scores improved significantly, with almost every FAOS subscale showing significant improvement postoperatively. Concurrent instability resulted in more changes that were statistically significant. The use of bone grafting and the presence of hypertrophy did not result in statistically significant changes in the outcomes. Factors associated with outcomes were lesion size and hypertrophy. Increasing lesion size was associated with decreased FAOS quality of life subscale and hypertrophy correlating with changes in the pain subscale. Of the 46 patients, 22 had undergone postoperative MRI scans that were scored. The average MOCART score was 46.8. Most patients demonstrated a persistent bone marrow edema pattern and hypertrophy of the reparative cartilage. Juvenile articular cartilage implantation of the DeNovo NT allograft and BMAC resulted in improved functional outcome scores; however, the reparative tissue still exhibited fibrocartilage composition radiographically. Further studies are needed to investigate the long-term outcomes and determine the superiority of the arthroscopic DeNovo procedure compared with microfracture and other cartilage resurfacing procedures.

Scaffold-Based Therapies: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle

BACKGROUND

The evidence supporting best practice guidelines in the field of cartilage repair of the ankle are based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article is to report the consensus statements on "Scaffold-Based Therapies" developed at the 2017 International Consensus Meeting on Cartilage Repair of the Ankle.

METHODS

Seventy-five international experts in cartilage repair of the ankle representing 25 countries and 1 territory were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 11 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed upon in unanimous fashion within the working groups. A final vote was then held, and the strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimous, 100%.

RESULTS

A total of 9 statements on scaffold-based therapies reached consensus during the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. One achieved unanimous support, 8 reached strong consensus (greater than 75% agreement), and 1 was removed because of redundancy in the information provided. All statements reached at least 80% agreement.

CONCLUSIONS

This international consensus derived from leaders in the field will assist clinicians with applying scaffold-based therapies as a treatment strategy for osteochondral lesions of the talus.

LEVEL OF EVIDENCE

Level V, expert opinion.

Human osteochondritis dissecans fragment-derived chondrocyte characteristics ex vivo, after monolayer expansion-induced de-differentiation, and after re-differentiation in alginate bead culture

BACKGROUND

Autologous chondrocyte implantation (ACI) is a therapy for articular cartilage and osteochondral lesions that relies on notch- or trochlea-derived primary chondrocytes. An alternative cell source for ACI could be osteochondritis dissecans (OCD) fragment-derived chondrocytes. Assessing the potential of these cells, we investigated their characteristics ex vivo and after monolayer expansion, as monolayer expansion is an integral step of ACI. However, as monolayer expansion can induce de-differentiation, we asked whether monolayer-induced de-differentiation can be reverted through successive alginate bead culture.

METHODS

Chondrocytes were isolated from the OCD fragments of 15 patient knees with ICRS grades 3-4 lesions for ex vivo analyses, primary alginate bead culture, monolayer expansion, and alginate bead culture following monolayer expansion for attempting re-differentiation. We determined yield, viability, and the mRNA expression of aggrecan and type I, II, and X collagen.

RESULTS

OCD fragment-derived chondrocyte isolation yielded high numbers of viable cells with a low type I:II collagen expression ratio (< 1) and a relatively high aggrecan and type II and X collagen mRNA expression, indicating chondrogenic and hypertrophic characteristics. As expected, monolayer expansion induced de-differentiation. Alginate bead culture of monolayer-expanded cells significantly improved the expression profile of all genes investigated, being most successful in decreasing the hypertrophy marker type X collagen to 1.5% of its ex vivo value. However, the chondrogenic phenotype was not fully restored, as the collagen type I:II expression ratio decreased significantly but remained > 1.

CONCLUSION

OCD fragment derived human chondrocytes may hold not yet utilized clinical potential for cartilage repair.

Long-term Follow-up of Revision Osteochondral Allograft Transplantation of the Ankle

BACKGROUND

Osteochondral allograft (OCA) transplantation is a useful alternative for treatment of posttraumatic ankle arthritis in young patients but has a relatively high failure rate and further procedures are often required. The purpose of this study was to evaluate outcomes of patients who underwent revision OCA transplantation of the ankle after failed primary OCA transplantation.

METHODS

Twenty patients underwent revision OCA transplantation of the ankle between 1988 and 2015. Mean age was 44 years, 55% (11 of 20) were female. The mean time from primary to revision OCA was 3.0 ± 1.7 years. All patients had a minimum follow-up of 2 years. Outcomes included the American Academy of Orthopaedic Surgeons Foot and Ankle Module (AAOS-FAM) and questionnaires evaluating pain and satisfaction. Failure of the revision OCA was defined as a conversion to arthroplasty, arthrodesis, or amputation.

RESULTS

Ten of 20 ankles required further surgery, of which 30% (6 of 20) were considered OCA revision failures (4 arthrodeses, 1 arthroplasty, and 1 amputation). The mean time to failure was 6.7 (range, 0.6-13.1) years. Survivorship of the revision OCA was 84% at 5 years and 65% at 10 years. The 14 patients with grafts remaining in situ had an average follow-up of 10.3 years; mean AAOS-FAM Core Score was 70.5 (range, 42.3-99). Of the patients who answered the follow-up questions, 4 of 7 reported moderate to severe pain, and 5 of 12 were satisfied with the results of the procedure.

CONCLUSION

Although the results of revision ankle OCA transplantation are not inferior to primary OCA transplantation, the high rates of persistent pain, further surgery, and graft failure suggest that the indications for OCA as a revision procedure should be carefully evaluated, with proper patient selection. Considering the treatment alternatives, revising a failed OCA transplantation can be a useful treatment option, especially for young and active patients who wish to avoid arthrodesis or arthroplasty.

LEVEL OF EVIDENCE

Level IV, case series.

Primary Versus Secondary Osteochondral Autograft Transplantation for the Treatment of Large Osteochondral Lesions of the Talus

BACKGROUND

Recent studies have reported promising clinical results after osteochondral autograft transplantation (OAT) for the treatment of large osteochondral lesions of the talus (OLT). However, no study has yet compared clinical outcomes between primary and secondary OAT for large OLT.

PURPOSE

To compare clinical outcomes among patients with large OLT who receive primary OAT versus those who receive secondary OAT after failure of marrow stimulation and to identify factors associated with clinical failure.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

From 2005 to 2014, 46 patients with large OLT (≥150 mm²) underwent OAT: 18 underwent OAT as initial surgical management (primary OAT group), and 28 patients underwent secondary OAT after failure of previous arthroscopic marrow stimulation (secondary OAT group). In both groups, OAT procedures included arthroscopic inspection and debridement of concomitant soft tissue injuries. Clinical outcomes were assessed using pain visual analog scale (VAS), the Roles and Maudsley score, Foot and Ankle Outcome Scores (FAOS), and revisional surgery rates. Factors associated with clinical failures were evaluated using bivariate and logistic regression analyses. Survival outcomes were compared using Kaplan-Meier analysis.

RESULTS

Mean follow-up time was 6 years (range, 2-10.8 years). Mean lesion size was 194.9 mm² (range, 151.7-296.3 mm²). There were no significant differences between groups in patient demographics and preoperative findings. Postoperative pain VAS, Roles and Maudsley score, FAOS, and revisional surgery rates were not significantly different at last follow-up. Prior marrow stimulation was not significantly associated with clinical failure on bivariate analysis. Lesion size greater than 225 mm² on preoperative magnetic resonance imaging was significantly associated with clinical failure. Survival probabilities from Kaplan-Meier plots were not significantly different between the primary and secondary OAT groups ( P = .947).

CONCLUSION

Clinical outcomes of patients with large OLT treated with secondary OAT after failed marrow stimulation were found to be comparable with those who were treated with primary OAT. These results may be helpful to orthopaedic surgeons deciding appropriate surgical options for patients with large OLT.

Surgical management of large talar osteochondral defects using autologous chondrocyte implantation

BACKGROUND

Talar osteochondral lesions (OLT) occur frequently in ankle sprains and fractures. We hypothesize that matrix-induced autologous chondrocyte implantation (MACI) will have a low reoperation rate and high patient satisfaction rate in treating OLT less than 2.5cm².

METHODS

A systematic review was registered with PROSPERO and performed with PRISMA guidelines using three publicly available free databases. Clinical outcome investigations reporting OLT outcomes with levels of evidence I-IV were eligible for inclusion. All study, subject, and surgical technique demographics were analyzed and compared. Statistics were calculated using Student's t-tests, one-way ANOVA, chi-squared, and two-proportion Z-tests.

RESULTS

Nineteen articles met our inclusion criteria, which resulted in a total of 343 patients. Six studies pertained to arthroscopic MACI, 8 to open MACI, and 5 studies to open periosteal ACI (PACI). All studies were Level IV evidence. Due to study quality, imprecise and sparse data, and potential for reporting bias, the quality of evidence is low. In comparison of open and arthroscopic MACI, we found both advantages favoring open MACI. However, open MACI had higher complication rates.

CONCLUSIONS

No procedure demonstrates superiority or inferiority between the combination of open or arthroscopic MACI and PACI in the management of OLT less than 2.5cm². Ultimately, well-designed randomized trials are needed to address the limitation of the available literature and further our understanding of the optimal treatment options.

Seven-Year Follow-up of Matrix-Induced Autologous Implantation in Talus Articular Defects

BACKGROUND

Osteochondral lesions of the talus (OLT) are difficult to treat because of the poor intrinsic healing capability of articular cartilage. Matrix-induced autologous chondrocyte implantation (MACI) has been shown to be a reliable method for treating cartilage lesions that fail to respond to traditional microfracture and debridement. The purpose of this study was to assess 7-year clinical follow-up data of this technique and demonstrate midterm success of this implant.

METHODS

A prospective investigation of MACI was performed on 10 patients with OLTs who had failed previous arthroscopic treatment. In all, 5 male and 5 female patients were included in the study. Of the 10 patients, 9 were available for 7-year follow-up. Functional and clinical evaluations were done at 7 years postoperatively using the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot evaluation and the Short Form Health Survey (SF-36) and compared with preoperative values.

RESULTS

SF-36 data at 7 years showed significant improvements in Physical Functioning (P < .01), Lack of Bodily Pain (P < .1), and Social Functioning (P < .001) compared with preoperative data. The mean AOFAS hindfoot scores of the 9 patients at 7 years was 78.3 ± 18.1 (P = .05) compared with their preoperative mean of 61.8 ± 14.3.

CONCLUSIONS

MACI provides a stable midterm chondral replacement strategy for osteochondral lesions that fail initial microfracture.

LEVELS OF EVIDENCE

Level IV: Prospective case series.

Comparison of Juvenile Allogenous Articular Cartilage and Bone Marrow Aspirate Concentrate Versus Microfracture With and Without Bone Marrow Aspirate Concentrate in Arthroscopic Treatment of Talar Osteochondral Lesions

BACKGROUND

The purpose of this study was to compare the functional and radiographic outcomes of patients who received juvenile allogenic chondrocyte implantation with autologous bone marrow aspirate (JACI-BMAC) for treatment of talar osteochondral lesions with those of patients who underwent microfracture (MF).

METHODS

A total of 30 patients who underwent MF and 20 who received DeNovo NT for JACI-BMAC treatment between 2006 and 2014 were included. Additionally, 17 MF patients received supplemental BMAC treatment. Retrospective chart review was performed and functional outcomes were assessed pre- and postoperatively using the Foot and Ankle Outcome Score and Visual Analog pain scale. Postoperative magnetic resonance images were reviewed and evaluated using a modified Magnetic Resonance Observation of Cartilage Tissue (MOCART) score. Average follow-up for functional outcomes was 30.9 months (range, 12-79 months). Radiographically, average follow-up was 28.1 months (range, 12-97 months).

RESULTS

Both the MF and JACI-BMAC showed significant pre- to postoperative improvements in all Foot and Ankle Outcome Score subscales. Visual Analog Scale scores also showed improvement in both groups, but only reached a level of statistical significance ( P < .05) in the MF group. There were no significant differences in patient reported outcomes between groups. Average osteochondral lesion diameter was significantly larger in JACI-BMAC patients compared to MF patients, but size difference had no significant impact on outcomes. Both groups produced reparative tissue that exhibited a fibrocartilage composition. The JACI-BMAC group had more patients with hypertrophy exhibited on magnetic resonance imaging (MRI) than the MF group ( P = .009).

CONCLUSION

JACI-BMAC and MF resulted in improved functional outcomes. However, while the majority of patients improved, functional outcomes and quality of repair tissue were still not normal. Based on our results, lesions repaired with DeNovo NT allograft still appeared fibrocartilaginous on MRI and did not result in significant functional gains as compared to MF.

LEVEL OF EVIDENCE

Level III, comparative series.

All-arthroscopic AMIC® (AT-AMIC®) technique with autologous bone graft for talar osteochondral defects: clinical and radiological results

PURPOSE

Autologous Matrix-Induced Chondrogenesis (AMIC^®) is known to provide satisfactory clinical results for the treatment of knee, hip, and ankle cartilage lesions. The purpose of this study was to evaluate clinical and radiological outcomes of patients treated with a new all-arthroscopic AMIC^® (AT-AMIC^®) technique with autologous bone graft for talar osteochondral defects at a follow-up of 24 months.

METHODS

Twenty patients underwent the AT-AMIC^® procedure and autologous bone graft for type III and IV talar osteochondral lesions. Patients were evaluated pre-operatively and at 6, 12, and 24 months post-operatively using the American Orthopedic Foot and Ankle Society (AOFAS) score, the visual analog scale, and the SF-12 (Short Form-12). Radiological assessment included computed tomography (CT), magnetic resonance imaging (MRI), and magnetic resonance observation of cartilage repair tissue (MOCART).

RESULTS

All scores significantly improved (p < 0.05) with respect to pre-operative values after 6 months. Further improvements were detected at 24 months (AOFAS, from 57.1 ± 14.9 before surgery to 86.6 ± 10.9 after 24 months; VAS, from 8.1 ± 1.4 to 2.5 ± 2.2; SF-12, from 29.9 ± 4.1 to 48.5 ± 6.9 and from 43.8 ± 2.9 to 53.1 ± 3.9, respectively, for Physical and Mental component score). Lesion area significantly reduced from 111.1 ± 43.2 mm² pre-operatively to 76.9 ± 38.1 mm² (p < 0.05) at final follow-up as assessed by CT, and from 154.1 ± 93.6 to 94.3 ± 61.3 mm² (p < 0.05) as assessed by MRI. The mean MOCART score was 42.8 ± 23.5 points and 50.9 ± 24.9 points, respectively, at 12 and 24 months after surgery (p < 0.05).

CONCLUSIONS

AT-AMIC^® with autologous bone grafting has proven to be a safe and effective minimal invasive technique, able to rapidly and significantly improve pain, function, and radiological healing of osteochondral talar lesions, with progressive further improvements up to 24 months. Orthopedic surgeons specialized in foot and ankle surgery should adopt the AT-AMIC^® technique for the treatment of osteochondral talar lesions, which proved to be effective and minimally invasive, avoiding malleolar osteotomy with a low risk of complications.

LEVEL OF EVIDENCE

IV.

Clinical and MRI Outcomes After Surgical Treatment of Osteochondral Lesions of the Talus in Skeletally Immature Children

BACKGROUND

The literature on the osteochondral lesion of the talus (OLT) in skeletally immature children is scarce and little is known about the clinical outcomes and the radiologic appearance of these lesions after surgical treatment. The aim of this study was to assess mid-term clinical and magnetic resonance imaging (MRI) outcomes after arthroscopic microfracture (AM) of OLT in skeletally immature children.

METHODS

Thirteen patients with OLT treated by AM before skeletal maturity were included in the study. The Berndt and Harty outcome question, the Single Assessment Numeric Evaluation question, and the Martin questionnaire were used to obtain patients' subjective satisfaction with their operated ankle. Functional outcomes preoperatively and postoperatively were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score. MRI scans were performed postoperatively using a magnetic resonance observation of cartilage repair tissue (MOCART) scoring system for 11 ankles.

RESULTS

The median age was 15 years (range, 13 to 16 y) and the median follow-up period was 5.6 years (range, 3.8 to 13.6 y). According to the Berndt and Harty outcome question, good clinical results were reported in 10 (76.9%) and fair in 3 (23.1%) patients. The postoperative AOFAS score was significantly improved when compared with the preoperative AOFAS score, with a mean increase of 35 points (P<0.001). The overall MOCART score was 65 (range, 10 to 75). MRI variables of the MOCART scoring system showed no association with clinical outcomes.

CONCLUSIONS

AM seems to be an effective surgical method for the treatment of OLT in skeletally immature children.

LEVEL OF EVIDENCE

Level IV-therapeutic studies, case series.

Serial Changes in the Joint Space Width and Joint Line Convergence Angle After Closed-Wedge High Tibial Osteotomy

BACKGROUND

There have been little data concerning serial changes in the joint space width (JSW) and joint line convergence angle over the course of follow-up periods after closed-wedge high tibial osteotomy (CWHTO).

PURPOSE

To evaluate serial changes in the JSW and joint line convergence angle after CWHTO.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 100 computer-assisted CWHTOs with a minimum follow-up period of 3 years (mean, 4.4 years) were analyzed. Clinically, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was evaluated. Radiographically, the mechanical axis was measured preoperatively and postoperatively. The minimal JSW was measured as the shortest distance between the femur and the tibia. The convergence angle was measured as the angle between the tangent to the subchondral plates of the femoral condyle and the tibial plateau. Serial changes in these measurements were analyzed preoperatively; at 3 months, 6 months, 1 year, and 2 years postoperatively; and at the final follow-up. The intraclass correlation coefficients for all measurements were greater than 0.8.

RESULTS

The mean WOMAC score improved from 41.4 preoperatively to 14.9 at the final follow-up. The preoperative and postoperative mean mechanical axis was 8.1° varus and 1.6° valgus, respectively. The mean minimal JSW was 2.5, 2.9, 2.9, 3.1, 3.2, and 3.1 mm preoperatively and at 3 months, 6 months, 1 year, 2 years, and the final follow-up, respectively ( P < .001). The mean convergence angle was 4.4°, 3.9°, 4.0°, 4.1°, 4.2°, and 4.3°, respectively, during the same time periods ( P = .068).

CONCLUSION

Cartilage healing, as indicated by the JSW, and clinical improvement were maintained over the minimum 3-year follow-up after CWHTO. Cartilage pressure, as indicated by the convergence angle, remained unchanged after CWHTO.

Single-Step Arthroscopic Repair With Cell-Free Polymer-Based Scaffold in Osteochondral Lesions of the Talus: Clinical and Radiological Results

PURPOSE

To report the clinical and radiological results of patients with talar osteochondral lesions who were treated by microfracture and cell-free scaffold implantation in a single-step arthroscopic surgery.

METHODS

Forty patients, treated with a single-step arthroscopic surgery, were evaluated in this single-center-based retrospective study. Patients with degenerative arthritis (n = 1), history of ankle fracture (n = 1), kissing lesions (n = 1), lower extremity deformity (n = 1), and lesions <1.5 cm² (n = 4) were excluded. Oversized (>10 mm depth) bone cysts were additionally treated with bone graft. Patients were evaluated clinically, using the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot score. Radiological assessment was performed with magnetic resonance imaging, using the magnetic resonance observation of cartilage repair tissue (MOCART) score.

RESULTS

Thirty-two patients with a mean age of 38 ± 12 years were evaluated. The mean defect size was 2.5 ± 0.8 cm² and the mean defect volume was 2.4 ± 1.9 cm³. The mean preoperative AOFAS score was 52.8 ± 13.9 and increased to 87.1 ± 11.1 postoperatively at the mean follow-up of 33.8 ± 14.0 months (P = .0001). A total of 84.4% of patients had good to excellent clinical scores. Clinical scores had no significant relation with age, lesion size, depth, or body mass index. The mean MOCART score was 64.2 ± 12.0. There was no significant correlation between the total MOCART and AOFAS scores (P = .123). A significant relation was found between the defect filling (the subgroup of the MOCART score) and the clinical outcomes (P = .0001, rho = 0.731).

CONCLUSIONS

The arthroscopic scaffold implantation technique is a single-step, safe, and effective method for the treatment of talar osteochondral lesions with satisfactory clinical and radiological outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Tissue engineering-relevant characteristics of ex vivo and monolayer-expanded chondrocytes from the notch versus trochlea of human knee joints

PURPOSE

The aim was to analyse the biological characteristics of chondrocytes from the two biopsy sites notch vs. trochlea of human knee joints. The question was whether tissue engineering-relevant characteristics such as viability and mRNA expression profile would be comparable ex vivo and after monolayer expansion, as these are parts of routine autologous chondrocyte implantation (ACI).

METHODS

Biopsies from the intercondylar notch and the lateral aspect of the trochlea from 20 patients with ICRS grades 3 and 4 cartilage defects were harvested during arthroscopy. Collagen types 1, 2, and 10 mRNA were quantified by polymerase chain reaction.

RESULTS

Compared with notch chondrocytes, ex vivo trochlea chondrocytes had comparable cell numbers, vitality and aggrecan, collagen types 1, -2 and -10 mRNA expression. After monolayer expansion both notch and trochlea chondrocyte characteristics were comparably altered, regardless of their biopsy origin, and no significant differences in viability and mRNA expression were noted.

CONCLUSIONS

Collectively, these findings suggest that tissue engineering-relevant characteristics of notch and trochlea chondrocytes are comparable ex vivo and after monolayer expansion. Thus, trochlea chondrocytes promise clinical potential and chondrocytes for ACI could potentially be generated from both notch and trochlea biopsy sites.

Evaluation of reproducibility of the MOCART score in patients with osteochondral lesions of the talus repaired using the autologous matrix-induced chondrogenesis technique

PURPOSE

To evaluate the applicability and reproducibility of magnetic resonance observation of cartilage repair tissue (MOCART) score for morphological evaluation of osteochondral lesions of the talus (OLT) repaired using autologous matrix-induced chondrogenesis (AMIC) technique.

METHODS

Two radiologists (R1-R2) and two orthopaedists (O1-O2) independently reviewed 26 ankle MRIs performed on 13 patients (6 females; age: 38.9 ± 15.9, 14-63) with OLT repaired using AMIC. The MRIs were performed at 6 and 12 months from surgery. For inter/intra-observer agreement evaluation for each variable of the MOCART, we used Cohen's kappa coefficient. Progression of MOCART between 6- and 12-month evaluation was assessed using the Wilcoxon test. The Spearman's correlation coefficient was used to evaluate the correlation between baseline lesion size and MOCART.

RESULTS

The inter-observer agreement between R1 and R2 ranged from poor (adhesions, k = 0.124) to almost perfect (subchondral bone, k = 0.866), between O1 and O2 from absent (effusion, k = -0.190) to poor (surface, k = 0.172), and between R1 and O1 from absent (cartilage interface, k = -0.324) to fair (signal intensity, k = 0.372). The intra-observer agreement of R1 ranged from poor (signal intensity, k = 0.031) to substantial (subchondral lamina, k = 0.677), while that of O1 from absent (subchondral bone, k = -0.061) to substantial (surface, k = 0.663). There was a significant increase of MOCART between 6- and 12-month evaluation of R1 (Z = -2.672; P = 0.008), R2 (Z = -2.721; P = 0.007) and O1 (Z = -3.034; P = 0.002). Conversely, the increase of MOCART of O2 was not significant (Z = -1.665; P = 0.096). Inverse correlation between lesion size at baseline and MOCART was significant at 12-month evaluation (-0.726; P = 0.005).

CONCLUSION

MRI has an important role in the follow-up of surgical repaired OLT, but MOCART score does not seem to be sufficiently reproducible to be applied for this purpose.

Induced Redifferentiation of Human Chondrocytes from Articular Cartilage Lesion in Alginate Bead Culture After Monolayer Dedifferentiation: An Alternative Cell Source for Cell-Based Therapies?

Human chondrocytes isolated from articular cartilage (AC) lesions as an alternative cell source to the standard nonweight-bearing notch biopsy site may hold clinical potential for cell-based therapies. The aim was to characterize human AC lesion site chondrocytes, compare them to notch chondrocytes, and evaluate their redifferentiation potential after monolayer expansion and subsequent three-dimensional (3D) alginate bead culture. Lesion chondrocytes from knee joints of 20 patients with International Cartilage Repair Society (ICRS) grade 3 and 4 cartilage defects were analyzed ex vivo or cultured in primary alginate bead culture, monolayer expansion, or redifferentiated in alginate culture following monolayer expansion. The mRNA expression of the types I, II, and X collagen, and the proteoglycan aggrecan was compared between the four groups. In addition, notch chondrocytes of nine patients were compared to lesion chondrocytes ex vivo. AC lesion chondrocytes displayed ex vivo a nondegenerative phenotype, characterized by a relatively high mRNA expression of aggrecan and type II and X collagen, but a low type I collagen expression and a low ratio of type I to II collagen mRNA expression. Compared to notch chondrocytes, the mRNA expression of aggrecan and type II collagen was comparable and the ratio of type I to II collagen mRNA expression was below 1 in both groups, indicating a functional chondrocyte phenotype. Dedifferentiation led to a significantly altered degenerative mRNA expression profile. Induced redifferentiation in alginate beads after monolayer expansion significantly improved the mRNA expression of aggrecan, the type I and II collagen, and the type I to II collagen ratio, compared to monolayer expansion only. These data suggested that redifferentiating lesion chondrocytes after monolayer expansion in alginate beads resulted in a pool of cells with greater chondrogenic potential, compared to expanded dedifferentiated chondrocytes. Collectively, these data suggest that ex vivo and redifferentiated lesion chondrocytes may hold nonutilized clinical potential for the tissue engineering of AC.

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.

Osteochondral lesions of the talus in the athlete: up to date review

PURPOSE OF REVIEW

Osteochondral lesions of the talus (OLT) are common injuries in athletes. The purpose of this study is to comprehensively review the clinical results and return to sport capacity in athletes following treatment for OLT.

RECENT FINDINGS

Reparative procedures, such as bone marrow stimulation, and replacement procedures, such as autologous osteochondral transplantation, provide good clinical outcomes in short- and mid-term follow-up in the athlete. Recently, biological augmentation and scaffold-based therapies have been shown to improve clinical and radiological outcomes in OLT in both the general population and athletes. Most studies are of a low level of evidence. Studies analyzing the return to sport capability in athletes are further lacking. High-level evidence and well-designed clinical trials are required to establish the most effective treatment protocol.

Current management of talar osteochondral lesions

Osteochondral lesions of the talus (OLT) occur in up to 70% of acute ankle sprains and fractures. OLT have become increasingly recognized with the advancements in cartilage-sensitive diagnostic imaging modalities. Although OLT may be treated nonoperatively, a number of surgical techniques have been described for patients whom surgery is indicated. Traditionally, treatment of symptomatic OLT have included either reparative procedures, such as bone marrow stimulation (BMS), or replacement procedures, such as autologous osteochondral transplantation (AOT). Reparative procedures are generally indicated for OLT < 150 mm² in area. Replacement strategies are used for large lesions or after failed primary repair procedures. Although short- and medium-term results have been reported, long-term studies on OLT treatment strategies are lacking. Biological augmentation including platelet-rich plasma and concentrated bone marrow aspirate is becoming increasingly popular for the treatment of OLT to enhance the biological environment during healing. In this review, we describe the most up-to-date clinical evidence of surgical outcomes, as well as both the mechanical and biological concerns associated with BMS and AOT. In addition, we will review the recent evidence for biological adjunct therapies that aim to improve outcomes and longevity of both BMS and AOT procedures.

[Arthroscopic treatment of chondral lesions of the ankle joint. Evidence-based therapy]

Ankle sprains are the most relevant injuries of the lower extremities and can lead to damage to ligaments and osteochondral lesions. Up to 50 % of patients with a sprained ankle later develop a lesion of the cartilage in the ankle joint or an osteochondral lesion of the talus. This can lead to osteoarthritis of the injured ankle joint. Spontaneous healing is possible in all age groups in cases of a bone bruise in the subchondral bone but in isolated chondral injuries is only useful in pediatric patients. In many cases chondral and osteochondral injuries lead to increasing demarcation of the affected area and can result in progressive degeneration of the joint if not recognized in time. There also exist a certain number of osteochondral changes of the articular surface of the talus without any history of relevant trauma, which are collectively grouped under the term osteochondrosis dissecans. Perfusion disorders are discussed as one of many possible causes of these alterations. Nowadays, chondral and osteochondral defects can be treated earlier due to detection using very sensitive magnetic resonance imaging (MRI) and computed tomography (CT) techniques. The use of conservative treatment only has a chance of healing in pediatric patients. Conservative measures for adults should only be considered as adjuvant treatment to surgery.Based on a comprehensive analysis of the current literature, this article gives an overview and critical analysis of the current concepts for treatment of chondral and osteochondral injuries and lesions of the talus. With arthroscopic therapy curettage and microfracture of talar lesions are the predominant approaches or retrograde drilling of the defect is another option when the chondral coating is retained. Implantation of autologous chondral cells or homologous juvenile cartilage tissue is also possible with arthroscopic techniques. Osteochondral fractures (flake fracture) are usually performed as a mini-open procedure supported by arthroscopy. The use of the osteochondral autograft transfer system (OATS), implantation of membranes with or without autologous bone marrow transfer and possibly with growth factors or implantation of stem cells are carried out in combination with arthroscopic mini-open procedures. The results from the literature are discussed and compared with own results after arthroscopic treatment of chondral lesions of the talus.