Matrix-Associated and Autologous Chondrocyte Transplantation in the Ankle: Clinical and MRI Follow-up after 2 to 11 Years

Operative Treatment of Nonprimary Osteochondral Lesions of the Talus: A Systematic Review

Background

Nonprimary osteochondral lesions of the talus (OLT) pose a significant challenge in orthopaedics, with no definitive consensus on optimal surgical treatment.

Purpose

To consolidate the most recent evidence on operative treatments for nonprimary OLT by assessing patient-reported outcomes (PROs), postoperative complications, and clinical failures.

Study Design

Systematic review; Level of evidence, 4.

Methods

This review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 and PRISMA in Exercise, Rehabilitation, Sport medicine and Sports science guidelines. Searches were conducted in PubMed, Embase, and Cochrane Library databases through June 2023. Eligible studies evaluated operative outcomes in skeletally mature patients with nonprimary OLT after failed previous surgeries. Primary outcomes included clinical and functional PROs. Secondary outcomes included postoperative complications and clinical failures. Quantitative analyses involved weighted means, mean differences, minimal clinically important differences, success rates (95% binomial proportion confidence interval), and a pre-to-postoperative meta-analysis.

Results

Out of 3992 identified records, 50 studies involving 806 ankles from 794 patients were included. All operative treatments significantly improved PROs (P < .05), except osteochondral allograft transplantation (OCA) for American Orthopaedic Foot and Ankle Society and pain (visual analog scale/numeric rating scale [VAS/NRS]) scores and HemiCAP for pain (VAS/NRS) scores. Autologous chondrocyte implantation (ACI) and osteochondral autologous transplantation (OAT) demonstrated the greatest PRO success rates, exceeding 80%. Postoperative complications occurred in 4% of cases, most frequently with HemiCAP. Clinical failures affected 22% of cases, particularly with autologous matrix-induced chondrogenesis, OAT, OCA, and HemiCAP.

Conclusion

Our systematic review demonstrated that ACI and OAT are promising treatments for nonprimary OLT, with ACI showing fewer clinical failures than OAT. Conversely, OCA and HemiCAP exhibited lower effectiveness and higher clinical failure rates, suggesting a need for reassessment.

[Treatment of osteochondritis dissecans]

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

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.

Summary Report of the Arthritis Foundation and the American Orthopaedic Foot & Ankle Society's Symposium on Targets for Osteoarthritis Research: Part 2: Treatment Options

This second of a 2-part series of articles recounts the key points presented in a collaborative symposium sponsored jointly by the Arthritis Foundation and the American Orthopaedic Foot & Ankle Society with the intent to survey current treatment options for osteoarthritis (OA) of the foot and ankle. A meeting was held virtually on December 10, 2021. A group of experts were invited to present brief synopses of the current state of knowledge and research in this area. Topics were chosen by meeting organizers, who then identified and invited the expert speakers. Part 2 overviews the current treatment options, including orthotics, non-joint destructive procedures, as well as arthroscopies and arthroplasties in ankles and feet. Opportunities for future research are also discussed, such as developments in surgical options for ankle and the first metatarsophalangeal joint. The OA scientific community, including funding agencies, academia, industry, and regulatory agencies, must recognize the importance to patients of addressing the foot and ankle with improved basic, translational, and clinical research.

LEVEL OF EVIDENCE

Level V, review article/expert opinion.

Evidence for operative treatment of talar osteochondral lesions: a systematic review

Purpose

Operative treatment of talar osteochondral lesions is challenging with various treatment options. The aims were (i) to compare patient populations between the different treatment options in terms of demographic data and lesion size and (ii) to correlate the outcome with demographic parameters and preoperative scores.

Methods

A systemic review was conducted according to the PRISMA guidelines. The electronic databases Pubmed (MEDLINE) and Embase were screened for reports with the following inclusion criteria: minimum 2-year follow-up after operative treatment of a talar osteochondral lesion in at least ten adult patients and published between 2000 and 2020.

Results

Forty-five papers were included. Small lesions were treated using BMS, while large lesions with ACI. There was no difference in age between the treatment groups. There was a correlation between preoperative American Orthopaedic Foot and Ankle Society (AOFAS) score and change in AOFAS score (R = −0.849, P < 0.001) as well as AOFAS score at follow-up (R = 0.421, P = 0.008). Preoperative size of the cartilage lesion correlates with preoperative AOFAS scores (R= −0.634, P = 0.001) and with change in AOFAS score (R = 0.656, P < 0.001) but not with AOFAS score at follow-up. Due to the heterogeneity of the studies, a comparison of the outcome between the different operative techniques was not possible.

Conclusion

Patient groups with bigger lesions and inferior preoperative scores did improve the most after surgery.

Level of evidence

IV.

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.

Quantitative MRI T2 Mapping Is Able to Assess Tissue Quality After Reparative and Regenerative Treatments of Osteochondral Lesions of the Talus

BACKGROUND

Quantitative MRI has potential for tissue characterization after reparative and regenerative surgical treatment of osteochondral lesions of the talus (OCLTs). However available data is inconclusive and quantitative sequences can be difficult to implement in real-time clinical application.

PURPOSE

To assess the potential of T2 mapping in discriminating articular tissue characteristics after reparative and regenerative surgery of OCLTs in real-world clinical settings.

STUDY TYPE

Observational and prospective cohort study.

POPULATION

15 OCLT patients who had received either reparative treatment with arthroscopic microfracture surgery (MFS) for a grade I lesion or regenerative treatment with bone marrow derived cell transplantation (BMDCT) for a grade II lesion.

FIELD STRENGTH/SEQUENCE

1.5 T, proton density weighted TSE, T2-weighted true fast imaging with steady-state-free precession and multi-echo T2 mapping sequences.

ASSESSMENT

Patients were evaluated at a minimum postoperative follow-up of 24 months. T2 maps of the ankle were generated and the distribution of T2 values was analyzed in manually identified volumes of interest (VOIs) for both treated lesions (TX) and healthy cartilage (CTRL). The amount of fibrocartilage, hyaline-like and remodeling tissue in TX VOIs was obtained, based on T2 thresholds from CTRL VOIs.

STATISTICAL TESTS

Fisher's exact test for categorical data, nonparametric Mann-Whitney U test for continuous data. The statistical significance level was P < 0.05.

RESULTS

From CTRL VOI analysis, T2 < 25 msec, 25 msec ≤ T2 ≤ 45 msec, and T2 > 45 msec were considered as representative for fibrocartilage, hyaline-like and remodeling tissue, respectively. Tissue composition of the two treatment groups was different, with significantly more fibrocartilage (+28%) and less hyaline-like tissue (-15%) in MFS than in BMDCT treated lesions. No difference in healthy tissue composition was found between the two groups (P = 0.75).

DATA CONCLUSIONS

T2 mapping of surgically treated OCLTs can provide quantitative information about the type and amount of newly formed tissue at the lesion site, thereby facilitating surgical follow-up in a real-word clinical setting.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 3.

Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) for large medial talar osteochondral defects : Operative technique

OBJECTIVE

Provision of a natural scaffold, good quality cells, and growth factors in order to facilitate the replacement of the complete osteochondral unit with matching talar curvature for large medial primary and secondary osteochondral defects of the talus.

INDICATIONS

Symptomatic primary and secondary medial osteochondral defects of the talus not responding to conservative treatment; anterior-posterior or medial-lateral diameter >10 mm on computed tomography (CT); closed distal tibial physis in young patients.

CONTRAINDICATIONS

Tibiotalar osteoarthritis grade III; multiple osteochondral defects on the medial, central, and lateral talar dome; malignancy; active infectious ankle joint pathology.

SURGICAL TECHNIQUE

A medial distal tibial osteotomy is performed, after which the osteochondral defect is excised in toto from the talar dome. The recipient site is microdrilled in order to disrupt subchondral bone vessels. Then, the autograft is harvested from the ipsilateral iliac crest with an oscillating saw, after which the graft is adjusted to an exact fitting shape to match the extracted osteochondral defect and the talar morphology as well as curvature. The graft is implanted with a press-fit technique after which the osteotomy is reduced with two 3.5 mm lag screws and the incision layers are closed. In cases of a large osteotomy, an additional third tubular buttress plate is added, or a third screw at the apex of the osteotomy.

POSTOPERATIVE MANAGEMENT

Non-weight bearing cast for 6 weeks, followed by another 6 weeks with a walking boot. After 12 weeks, a CT scan is performed to assess consolidation of the osteotomy and the inserted autograft. The patient is referred to a physiotherapist.

RESULTS

Ten cases underwent the TOPIC procedure, and at 1 year follow-up all clinical scores improved. Radiological outcomes showed consolidation of all osteotomies and all inserted grafts showed consolidation. Complications included one spina iliaca anterior avulsion and one hypaesthesia of the saphenous nerve; in two patients the fixation screws of the medial malleolar osteotomy were removed.

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.

Large Osteochondral Lesions of the Talus Treated With Autologous Bone Graft and Periosteum Transfer

Background:

The treatment of large osteochondral lesions of the talus (OLTs) is challenging due to the poor intrinsic reparative capability of the damaged articular cartilage. Autologous transfer of bone and periosteum has been used successfully in the treatment of large defects in animals, and therefore it was believed that this technique might show similar results in humans. The purpose of this study was to assess the outcome of an innovative technique for autologous transplantation of cancellous tibial graft with periosteal transfer in large OLTs.

Methods:

Forty-one patients (22 females, 19 males), with a mean age of 34.9 years (range, 18-72 years), with a large OLT (>200 mm²) were treated with autologous bone graft and periosteum transfer. OLTs averaging 310 mm² were identified on a preoperative computed tomography scan. The procedure consisted of malleolar osteotomy, curettage of sclerotic bone, autologous bone graft from the proximal tibia, and transfixion of periosteum over the graft. Outcome measures, including the pain visual analog scale (VAS), ankle range of motion (ROM), American Orthopaedic Foot & Ankle Society (AOFAS) score, and Foot & Ankle Disability Index (FADI), were compared between preoperative and 1 and 2 years following surgery.

Results:

There were significant improvements in VAS pain score from 7.7 before surgery to 1.1 at 1 year after surgery and 0.4 at 2 years or more after surgery. The AOFAS and FADI scores were also significantly improved from 40.3 and 53.3 preoperatively to 95 and 93.2 postoperatively at 1 year and 95 and 93.2 at 2 or more years postoperatively, respectively. Postoperative complications included 2 patients who required removal of medial malleolar osteotomy tension bands due to symptomatic hardware. There were no nonunions or malunions of the osteotomies and no donor site complications.

Conclusion:

Autologous bone graft and periosteum transfer was an effective treatment for large OLTs leading to significant decreases in pain and improvement in functional scores at more than 2 years after surgery.

Level of Evidence:

Level IV, retrospective case series.

Autologous Chondrocyte Implantation for Talar Osteochondral Lesions: Comparison Between 5-Year Follow-Up Magnetic Resonance Imaging Findings and 7-Year Follow-Up Clinical Results

Autologous chondrocyte implantation (ACI) is an established surgical procedure that has provided satisfactory results. The aim of the present study was to correlate the clinical outcomes of a series of 20 patients treated by ACI at a 7-year follow-up examination with the magnetic resonance imaging (MRI) T2-mapping 5-year follow-up findings. We evaluated 20 patients using the American Orthopaedic Foot and Ankle Society (AOFAS) score preoperatively and the established follow-up protocol until 87.2 ± 14.5 months. MRI T2-mapping sequences were acquired at the 5-year follow-up examination. At the MRI examination (60 ± 12 months), the mean AOFAS score improved from 58.7 ± 15.7 to 83.9 ± 18.4. At the final follow-up examination at 87.2 ± 14.5 months, the AOFAS score was 90.9 ± 12.7 (p = .0005). Those patients who experienced an improvement between 5 and 7 years after surgery had a significant greater percentage of T2-map value of 35 to 45 ms (hyaline cartilage) compared with those patients who did not improve (p = .038). MRI T2 mapping was shown to be a valuable tool capable of predicting reproducible clinical outcomes after ACI even 7 years after surgery. The quality of the regenerated tissue and the degree of defect filling became statistically significant to the clinical results at the final follow-up examination.

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.

Revision and Salvage Management: 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 was to report on the consensus statements on "Revision and Salvage Management" 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 on 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 8 statements on revision and salvage management reached consensus during the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. One achieved unanimous support and 7 reached strong consensus (greater than 75% agreement). All statements reached at least 85% agreement.

CONCLUSIONS

This international consensus derived from leaders in the field will assist clinicians with revision and salvage management in the cartilage repair of the ankle.

No superior treatment for primary osteochondral defects of the talus

PURPOSE

The purpose of this systematic literature review is to detect the most effective treatment option for primary talar osteochondral defects in adults.

METHODS

A literature search was performed to identify studies published from January 1996 to February 2017 using PubMed (MEDLINE), EMBASE, CDSR, DARE, and CENTRAL. Two authors separately and independently screened the search results and conducted the quality assessment using the Newcastle-Ottawa Scale. Subsequently, success rates per separate study were calculated. Studies methodologically eligible for a simplified pooling method were combined.

RESULTS

Fifty-two studies with 1236 primary talar osteochondral defects were included of which forty-one studies were retrospective and eleven prospective. Two randomised controlled trials (RCTs) were identified. Heterogeneity concerning methodological nature was observed, and there was variety in reported success rates. A simplified pooling method performed for eleven retrospective case series including 317 ankles in the bone marrow stimulation group yielded a success rate of 82% [CI 78-86%]. For seven retrospective case series investigating an osteochondral autograft transfer system or an osteoperiosteal cylinder graft insertion with in total 78 included ankles the pooled success rate was calculated to be 77% [CI 66-85%].

CONCLUSIONS

For primary talar osteochondral defects, none of the treatment options showed any superiority over others.

LEVEL OF EVIDENCE

IV.

No superior surgical treatment for secondary osteochondral defects of the talus

PURPOSE

The purpose of this systematic review was to identify the most effective surgical treatment for talar osteochondral defects after failed primary surgery.

METHODS

A literature search was conducted to find studies published from January 1996 till July 2016 using PubMed (MEDLINE), EMBASE, CDSR, DARE and CENTRAL. Two authors screened the search results separately and conducted quality assessment independently using the Newcastle-Ottawa scale. Weighted success rates were calculated. Studies eligible for pooling were combined.

RESULTS

Twenty-one studies with a total of 299 patients with 301 talar OCDs that failed primary surgery were investigated. Eight studies were retrospective case series, twelve were prospective case series and there was one randomized controlled trial. Calculated success percentages varied widely and ranged from 17 to 100%. Because of the low level of evidence and the scarce number of patients, no methodologically proper meta-analysis could be performed. A simplified pooling method resulted in a calculated mean success rate of 90% [CI 82-95%] for the osteochondral autograft transfer procedure, 65% [CI 46-81%] for mosaicplasty and 55% [CI 40-70%] for the osteochondral allograft transfer procedure. There was no significant difference between classic autologous chondrocyte implantation (success rate of 59% [CI 39-77%]) and matrix-associated chondrocyte implantation (success rate of 73% [CI 56-85%]).

CONCLUSIONS

Multiple surgical treatments are used for talar OCDs after primary surgical failure. More invasive methods are administered in comparison with primary treatment. No methodologically proper meta-analysis could be performed because of the low level of evidence and the limited number of patients. It is therefore inappropriate to draw firm conclusions from the collected results. Besides an expected difference in outcome between the autograft transfer procedure and the more extensive procedures of mosaicplasty and the use of an allograft, neither a clear nor a significant difference between treatment options could be demonstrated. The need for sufficiently powered prospective investigations in a randomized comparative clinical setting remains high. This present systematic review can be used in order to inform patients about expected outcome of the different treatment methods used after failed primary surgery.

LEVEL OF EVIDENCE

IV.

Comparison of T2 Relaxation Values in Subtalar Cartilage between Patients with Lateral Instability of the Ankle Joint and Healthy Volunteers

PURPOSE

To evaluate the difference between T2 relaxation values of the subtalar cartilage in lateral ankle instability patients and healthy volunteers.

MATERIALS AND METHODS

This institutional review board-approved study included 27 preoperative magnetic resonance imaging (MRI) examinations of 26 patients who underwent Broström operations. Data of previously enrolled healthy volunteers (12 volunteers, 13 MRIs) were used as controls. Two radiologists independently measured T2 values in eight posterior subtalar joint cartilage compartments: central calcaneus anterior (CCA) and posterior (CCP), central talus anterior (CTA) and posterior (CTP), lateral calcaneus anterior (LCA) and posterior (LCP), and lateral talus anterior (LTA) and posterior (LTP). Patient and control values were compared using linear regression analysis. Inter- and intraobserver agreement was calculated.

RESULTS

Mean T2 values were significantly higher in the patient group in all measurements of subtalar joint cartilage compartments (p < 0.05) except that in LTP (p = 0.085) measured by reviewer 1. Both inter- and intraobserver agreements were excellent.

CONCLUSIONS

The T2 relaxation values of the subtalar cartilage were significantly higher in lateral ankle instability patients compared with those of controls.

KEY POINTS

• Subtalar cartilage T2 values are increased in patients with lateral ankle instability. • This trend was demonstrated regardless of the presence of talar dome cartilage lesions. • Inter-and intraobserver agreements were excellent (intraclass coefficient range, 0.765-0.951) in subtalar cartilage T2 mapping.

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.

Scaffolds based therapy for osteochondral lesions of the talus: A systematic review

AIM

To clarify the effectiveness of scaffold-based therapy for osteochondral lesions of the talus (OLT).

METHODS

A systematic search of MEDLINE and EMBASE databases was performed during August 2016 and updated in January 2017. Included studies were evaluated with regard to the level of evidence (LOE) and quality of evidence (QOE) using the Modified Coleman Methodology Score. Variable reporting outcome data, clinical outcomes, and the percentage of patients who returned to sport at previous level were also evaluated.

RESULTS

Twenty-eight studies for a total of 897 ankles were included; 96% were either LOE III or IV. Studies were designated as either of poor or fair quality. There were 30 treatment groups reporting six different scaffold repair techniques: 13 matrix-induced autologous chondrocyte transplantation (MACT), nine bone marrow derived cell transplantation (BMDCT), four autologous matrix-induced chondrogeneis (AMIC), and four studies of other techniques. The categories of general demographics (93%) and patient-reported outcome data (85%) were well reported. Study design (73%), imaging data (73%), clinical variables (49%), and patient history (30%) were also included. The weighted mean American Orthopaedic Foot and Ankle Society (AOFAS) score at final follow-up was: 86.7 in MACT, 88.2 in BMDCT, and 82.3 in AMIC. Eight studies reported that a weighted mean of 68.3% of patients returned to a previous level of sport activity.

CONCLUSION

Scaffold-based therapy for OLT may produce favorable clinical outcomes, but low LOE, poor QOE, and variability of the data have confounded the effectiveness of this treatment.

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.

New Technology in Imaging Cartilage of the Ankle

The incidence of osteochondral lesions, as well as osteoarthritis of the ankle joint following osteochondritis dissecans and trauma, has been reappraised in recent years. Consequently, an increasing number of surgical interventions using different cartilage repair techniques is performed in the ankle joint, which has resulted in a growing demand for repetitive and objective assessment of cartilage tissue and its repair. While morphological imaging does enable monitoring of macroscopic changes with increasing precision, it fails to provide information about the ultrastructural composition of cartilage. The significance of molecular changes in cartilage matrix composition, however, is increasingly recognized, as it is assumed that macroscopic cartilage degeneration is preceded by a loss in glycosaminoglycans and a disorganization of the collagen network. Recent advances in biochemical magnetic resonance imaging (MRI) have yielded sequences sensitive to these changes, thus providing invaluable insight into both early cartilage degeneration and maturation of repair tissue, on a molecular level. The aim of this review was to provide a comprehensive overview of these techniques, including water and collagen-sensitive T2/T2* mapping, as well as glycosaminoglycan-sensitive sequences such as delayed gadolinium-enhanced MRI of cartilage dGEMRIC, and sodium imaging, and describe their applications for the ankle joint.

Cartilage repair of the ankle: first results of T2 mapping at 7.0 T after microfracture and matrix associated autologous cartilage transplantation

BACKGROUND

Both microfracture (MFX) and matrix associated autologous cartilage transplantation (MACT) are currently used to treat cartilage defects of the talus. T2 mapping of the ankle at 7 T has the potential to assess the collagen fibril network organization of the native hyaline cartilage and of the repair tissue (RT). This study provides first results regarding the properties of cartilage RT after MFX (mean follow-up: 113.8 months) and MACT (65.4 months).

METHODS

A multi-echo spin-echo sequence was used at 7 T to assess T2 maps in 10 volunteer cases, and in 10 cases after MFX and MACT each. Proton weighted morphological images and clinical data were used to ensure comparable baseline criteria.

RESULTS

A significant zonal variation of T2 was found in the volunteers. T2 of the superficial and the deep layer was 39.3 ± 5.9 ms and 21.1 ± 3.1 ms (zonal T2 index calculated by superficial T2/deep T2: 1.87 ± 0.2, P < 0.001). In MFX, T2 of the reference cartilage was 37.4 ± 5.0 ms and 25.3 ± 3.5 ms (1.51 ± 0.3, P < 0.001). In the RT, T2 was 43.4 ± 10.5 ms and 36.3 ± 7.7 ms (1.20 ± 0.2, P = 0.009). In MACT, T2 of the reference cartilage was 39.0 ± 9.1 ms and 27.1 ± 6.6 ms (1.45 ± 0.2, P < 0.001). In the RT, T2 was 44.6 ± 10.4 ms and 38.6 ± 7.3 ms (1.15 ± 0.1, P = 0.003). The zonal RT T2 variation differed significantly from the reference cartilage in both techniques (MFX: P = 0.004, MACT: P = 0.001).

CONCLUSION

T2 mapping at 7 T allows for the quantitative assessment of the collagen network organization of the talus. MACT and MFX yielded RT with comparable T2 properties.