Osteochondral Autograft: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle

Deformity Correction: Do Osteochondral Lesion of the Talus and Tibia Change After Realignment Surgery?

Malalignment of the lower limb, distal tibia, foot, and hindfoot can all contribute to altered biomechanics in the ankle joint, resulting in increased focal pressure. The development of some osteochondral lesions of the ankle joint may share a similar pathophysiology, where eccentric loading to the talus or tibia within the ankle joint can lead to cartilage injury or adaptive changes. While the association between malalignment and the development of osteochondral lesions of the ankle joint may seem intuitive, the impact of realignment procedures on these lesions and patient symptoms remains a relatively underexplored topic in the literature. A comprehensive understanding of the potential role of realignment surgery in managing osteochondral lesions of the talus and tibia is crucial for advancing our knowledge of this challenging pathologic condition.

The MOCART (magnetic resonance observation of cartilage repair tissue) 2.0 Ankle Score

OBJECTIVES

The aim of this study was to introduce the MOCART 2.0 ankle score and evaluate its utility and reproducibility for the radiological assessment of cartilage repair tissue in the ankle joint.

METHODS

The MOCART 2.0 ankle score evaluates seven individual variables, including "volume fill of (osteo)chondral defect," "Integration into adjacent cartilage and bone," "surface of the repair tissue," "signal intensity of the repair tissue," "bony defect and bony overgrowth," "presence of edema-like-marrow signal," and "presence of subchondral cysts." Overall, a MOCART 2.0 ankle score between 0 and 100 points may be reached. Two independent readers assessed the 3-T MRI examinations of 48 ankles, who had undergone cartilage repair of a talar cartilage defect using the new MOCART 2.0 ankle score. One of the readers performed two readings. Intra- and interrater reliability were assessed using intraclass correlation coefficients (ICCs) for the overall MOCART 2.0 ankle score.

RESULTS

Forty-eight ankles (mean age at surgery 30.2 ± 11.2 years) were evaluated. The overall interrater (ICC = 0.75; 95%CI 0.60-0.85), as well as the intrarater (ICC = 0.83; 95%CI 0.72-0.90) reliability of the MOCART 2.0 ankle score was good. For individual variables the interrater reliability ranged from a kappa value of 0.29 (95%CI 0.01-0.57) for "surface of the repair tissue" to 0.83 (95%CI 0.71-0.95) for "presence of subchondral cysts".

CONCLUSIONS

The newly introduced MOCART 2.0 ankle score, which encompasses the distinct anatomy of the ankle joint, demonstrates good intra- and interrater reliability.

CRITICAL RELEVANCE STATEMENT

The newly introduced MOCART 2.0 ankle score may facilitate the standardized assessment of cartilage repair in the ankle joint and allow an objective comparison of the morphological outcome between alternative treatment options and between different studies.

KEY POINTS

This study introduces the MOCART 2.0 ankle score. The MOCART 2.0 ankle score demonstrated good intra- and interrater reliability. Standardized reporting may improve communication between radiologists and other physicians.

Autologous osteoperiosteal transplantation is effective in the treatment of single cystic osteochondral lesions of the talus and the prognostic impact of age should be emphasized

PURPOSE

To investigate the clinical efficacy and prognostic factors associated with autologous osteoperiosteal transplantation for the treatment of single cystic osteochondral lesions of the talus (OLT).

METHODS

The clinical data of patients with single cystic OLT undergoing autologous osteoperiosteal transplantation at the Department of Foot and Ankle Surgery of our hospital between 2018 and 2022, including complete follow-up, were retrospectively analyzed. Imaging data from each patient were imported into Mimics software to measure the surface area, volume and depth of the lesions. Then, the talus nine-compartment partitioning method was used to partition the injury site. Preoperative and final follow-up assessments were performed using the American Orthopaedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS) for pain and 36-item Short-Form Health Survey (SF-36) to evaluate treatment efficacy and analyze prognostic factors.

RESULTS

Of the 31 patients with single cystic OLT with a complete set of follow-up data, there were 17 males and 14 females, with a mean age of 43.3 ± 13.6 years, a mean follow-up time of 30.1 ± 14.0 months and a mean illness duration of 30.4 ± 20.0 months. The postoperative final follow-up AOFAS score was 90.7 ± 5.5; this represented significant improvement when compared to the preoperative score of 57.0 ± 8.5 (P < 0.001). The final postoperative follow-up VAS score was 18.5 ± 8.3; this was significantly better than the preoperative score of 57.8 ± 8.7 (P < 0.001). The physical component summary (PCS) score and mental component summary (MCS) score on the SF-36 scale showed significant improvement at the final postoperative follow-up when compared to preoperative scores (p < 0.001). No other complications were observed during follow-up, such as wound infection or pain at the donor site. One of the patients showed less improvement, which may be related to premature weight-bearing or re-sprained ankle after surgery. There was no significant correlation between the duration of illness, gender and the location, depth, surface area and volume of the OLT and the postoperative scores. However, patient age showed a significant negative correlation with the postoperative SF-36 PCS and MCS scores.

CONCLUSION

Autologous osteoperiosteal transplantation for single cystic OLT demonstrated good clinical efficacy with a low incidence of complications. Furthermore, age represents an important factor influencing prognosis.

LEVEL OF EVIDENCE

Level II.

Sex-specific analysis in patients undergoing Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) for large osteochondral lesions of the talus

PURPOSE

The purpose of the present study is to assess the gender-specific differences in the presentation and outcomes following Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) between male and female patients.

METHODS

A prospective comparative analysis was performed comparing consecutive female and male patients having been treated by the press-fit TOPIC procedure. Clinical comparative assessment preoperatively and at 12 months of follow-up included determination of the Numeric Rating Scale (NRS) scores for pain during walking (primary outcome), at rest and during stair-climbing. The Foot and Ankle Outcome Score (FAOS) was also assessed. A computed tomography (CT) scan was performed for lesion size, morphology and localization determination preoperatively as well as 10-12 weeks postoperatively to assess the union of the osteotomy site and at 1 year postoperatively to assess consolidation of the graft as well as intra-graft cyst development.

RESULTS

A total of 48 patients (30 women, 18 men) were eligible for inclusion. Both men and women demonstrated significant functional improvements postoperatively concerning the clinical outcomes with no significant differences between men and women (n.s.) except for a significantly greater improvement in postoperative FAOS pain scores in women. Men presented with OLTs significantly larger in both surface area (208 mm2 for males versus 155 mm2 for females, p < 0.05) as well as lesion volume (3.0 cm3 for males versus 1.8 cm3 for females, p < 0.05). At 1-year postoperatively, all patients showed graft consolidation. Cyst formation was present in 11 females (37% of the group) and 10 males (59% of the group), respectively (n.s.).

CONCLUSION

Both males and females showed clinically relevant improvements in the clinical outcomes after undergoing the TOPIC procedure with significant differences in preoperative lesion size. The TOPIC procedure is a good treatment strategy for large OLTs in both men and women.

LEVEL OF EVIDENCE

Level III, comparative prospective clinical cohort.

Improved Results From Medium- and Long-Term Outcomes of Autogenous Osteoperiosteal Grafting for Large Cystic Lesions of the Talus

PURPOSE

To investigate the medium and long-term follow-up outcomes of large cystic medial osteochondral lesions of the talus (OLTs) treated with autologous tibial osteoperiosteal grafts from the medial tibia and to explore the risk factors influencing the treatment outcomes.

METHODS

The retrospective study included 75 patients with large cystic medial OLTs who underwent autologous osteoperiosteal cylinder graft taken from the medial tibia between January 2004 and August 2018. They were assessed preoperatively and postoperatively using a visual analog scale, the Orthopedic Foot & Ankle Society Ankle-Hindfoot Scale (AOFAS), and short-form 36-item Short Form Health Survey score. Magnetic resonance observation of cartilage repair tissue, second-look arthroscopy, and biopsy were used to evaluate the grafting areas.

RESULTS

After a follow-up period of 6.3 years, the virtual analog scale score decreased to 1.47 ± 1.32, and the AOFAS and 36-item Short Form Health Survey scores increased to 82.78 ± 11.65 and 83.26 ± 8.49, respectively, all of which showed significant improvement over preoperative scores (P < .001), and the average magnetic resonance observation of cartilage repair tissue score was 82.6 ± 8.4 (56.0-91.6). Eight patients underwent a second-look arthroscopic examination and were rated by the International Cartilage Repair Society scale; of them, 2 patients were rated grade Ⅰ, 4 were rated grade Ⅱ, and 2 were rated grade Ⅲ. Three patients underwent grafting area biopsy during the second-look arthroscopy, and the results showed that the grafting areas were rich in chondrocytes. Large OLTs (≥200 mm2) and obesity (body mass index ≥25) were responsible for the poor improvement of AOFAS score, according to multivariate Cox regression analysis.

CONCLUSIONS

Autologous osteoperiosteal grafting was an effective treatment for large cystic medial OLTs, with effective cartilage regeneration in the grafted areas in the medium and long term. However, the large OLTs and obesity may reduce the treatment outcomes.

LEVEL OF EVIDENCE

Level IV, case series.

[Advances in the Treatment of Osteochondral Lesions of the Talus]

Osteochondral lesion of the talus (OLT) is a localized cartilage and subchondral bone injury of the talus trochlea. OLT is caused by trauma and other reasons, including osteochondritis dissecans of the talus (OCD) and talus osteochondral tangential fracture. OLT can develop from being asymptomatic to subchondral bone cysts accompanied by deep ankle pain. OLT tends to occur on the medial and lateral sides of the talar vault. OLT seriously affects the patients' life and work and may even lead to disability. Herein, we reviewed advances in the treatment of OLT and the strengths and weaknesses of various treatments. Different treatment methods, including conservative treatments and surgical treatments, can be adopted according to the different subtypes or clinical symptoms of OLT. Conservative treatments mostly relieve symptoms in the short term and only slow down the disease. In recent years, it has been discovered that platelet-rich plasma injection, microfracture, periosteal bone grafting, talar cartilage transplantation, allograft bone transplantation, reverse drilling under robotic navigation, and other methods can achieve considerable benefits when each of these treatment methods is applied. Furthermore, microfracture combined with platelet-rich plasma injections, microfracture combined with cartilage transplantation, and various other treatment methods combined with anterior talofibular ligament repair have all led to good treatment outcomes.

Synthetic bone grafting with preserved cartilage flap via a medial malleolus osteotomy approach to treat osteochondral lesion of the talus: technical note and preliminary clinical results

PURPOSE

Although various surgical procedures are available for osteochondral lesion of the talus (OLT), there is still no consensus on its best treatment. The purposes of this study were to describe a new surgical technique to treat OLT and to analyze its preliminary clinical results.

METHODS

Eight patients were enrolled in this retrospective study between March 2019 and May 2022 in the Second Affiliated Hospital of Chongqing Medical University. All patients were treated by synthetic bone grafting with preserved cartilage flap via a medial malleolus osteotomy approach. The patients' characteristics, operative time, and estimated blood loss were evaluated. Intraoperative photos, preoperative and postoperative X-ray and MRI imaging were recorded. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and visual analog scale (VAS) score were also recorded before surgery and at each follow-up.

RESULTS

At six months after the operation, all patients showed bone ingrowth and remodeling according to X-ray and MRI. No obvious defects or ladder was found on the cartilage surface of all patients according to MRI. The AOFAS score improved from 61.63 ± 8.85 (range, 49-74) to 91.13 ± 4.49 (range, 83-97) (p < 0.001) and VAS score improved from 5.50 ± 1.60 (range, 4-8) before surgery to 1.88 ± 0.83 (range, 1-3) (p < 0.001) at latest follow-up. In all eight patients, no wound infection, skin necrosis, or delayed healing of osteotomy was found.

CONCLUSION

We proposed a simple and effective technique that restored the shape of the cartilage surface by preserving the cartilage flap and restoring the natural congruency of the subchondral bone by synthetic bone grafting. We found satisfying clinical outcomes in short-term follow-up. Our new technique might be a new surgical option for the treatment of OLT and its effectiveness should be further evaluated.

Presurgical and Postsurgical MRI Evaluation of Osteochondral Lesions of the Foot and Ankle: A Primer

The gold standard diagnostic imaging tool for ankle OCLs is magnetic resonance imaging, which allows precise evaluation of the articular cartilage and assessment of the surrounding soft tissue structures. Post-operative morphologic MRI assessment via MOCART scores provide semi-quantitative analysis of the repair tissue, but mixed evidence exists regarding its association with post-operative outcomes. Post-operative biochemical MRIs allow assessment of the collagen network of the articular cartilage via T2-mapping and T2∗ mapping, and assessment of the articular glycosaminoglycan content via delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), T1rho mapping and sodium imaging.

Etiology, Classification, Diagnostics, and Conservative Management of Osteochondral Lesions of the Talus. 2023 Recommendations of the Working Group "Clinical Tissue Regeneration" of the German Society of Orthopedics and Traumatology

METHODS

Peer-reviewed literature was analyzed regarding different topics relevant to osteochondral lesions of the talus (OLTs) treatment. This process concluded with a statement for each topic reflecting the best scientific evidence available for a particular diagnostic or therapeutic concept, including the grade of recommendation. Besides the scientific evidence, all group members rated the statements to identify possible gaps between literature and current clinical practice.

CONCLUSION

In patients with minimal symptoms, OLT progression to ankle osteoarthritis is unlikely. Risk factors for progression are the depth of the lesion on MRI, subchondral cyst formation, and the extent of bone marrow edema. Conservative management is the adaptation of activities to the performance of the ankle joint. A follow-up imaging after 12 months helps not to miss any progression. It is impossible to estimate the probability of success of conservative management from initial symptoms and imaging. Cast immobilization is an option in OLTs in children, with a success rate of approximately 50%, although complete healing, estimated from imaging, is rare. In adults, improvement by conservative management ranges between 45% and 59%. Rest and restrictions for sports activities seem to be more successful than immobilization. Intra-articular injections of hyaluronic acid and platelet-rich plasma can improve pain and functional scores for more than 6 months. If 3 months of conservative management does not improve symptoms, surgery can be recommended.

Comparison of Intermediate-Term Clinical Outcomes Between Medial and Lateral Osteochondral Lesions of the Talus Treated With Autologous Osteochondral Transplantation

BACKGROUND

The conventional operative method to treat an osteochondral lesion of the talus (OLT) is through bone marrow stimulation (BMS). Autologous osteochondral transplantation (AOT) is being used as an alternative option in cases with a large OLT, accompanying subchondral cyst, and/or failed BMS. We aimed to compare the intermediate-term clinical and radiologic results between medial and lateral OLTs after an AOT procedure.

METHODS

Among the patients who underwent AOT, 45 cases with at least 3 years' follow-up were included in this retrospective study. We had 15 cases of lateral lesions and selected 30 cases of medial lesions matched for age and gender. Lateral lesions were resurfaced without an osteotomy; medial lesion resurfacing was combined with a medial malleolar osteotomy. Clinical assessment was performed using the Foot and Ankle Outcome Score (FAOS) and Foot and Ankle Ability Measure (FAAM). Radiographic assessment included the irregularity of articular surface (subchondral plate), the progression of degenerative arthritis, and the change of the talar tilt.

RESULTS

The mean FAOS and FAAM scores significantly improved after surgery in both groups. Up to 1 year postoperatively, there was significant difference in FAAM scores between the both groups (mean 75.3 points in medial group and 87.2 points in lateral group, P < .001). Delayed union or malunion of the malleolar osteotomy was found in 4 cases (13%) in the medial group. In addition, the progression of joint degeneration was observed in 3 cases (10%) in the medial group. There were no significant differences in the irregularity of articular surface and the change of talar tilt between both groups.

CONCLUSION

A comparison between medial and lateral OLTs treated with AOT demonstrated comparable intermediate-term clinical outcomes. However, patients with medial OLT required a longer period to restore ability for daily and sport activities. In addition, we found more complications and higher rate of progression in the radiologic arthritis grade after medial malleolar osteotomy.

LEVEL OF EVIDENCE

Level IV, retrospective comparative study.

Osteochondral Lesions of the Ankle and Foot

Osteochondral lesions (OCLs) in the ankle are more common than OCLs of the foot, but both share a similar imaging appearance. Knowledge of the various imaging modalities, as well as available surgical techniques, is important for radiologists. We discuss radiographs, ultrasonography, computed tomography, single-photon emission computed tomography/computed tomography, and magnetic resonance imaging to evaluate OCLs. In addition, various surgical techniques used to treat OCLs-debridement, retrograde drilling, microfracture, micronized cartilage-augmented microfracture, autografts, and allografts-are described with an emphasis on postoperative appearance following these techniques.

Short-term Results of Hemiarthroplasty of the Ankle Joint for Talar-Sided Cartilage Loss

Background

Ankle hemiarthroplasty is a 1-piece implant system replacing the talar side of the tibiotalar joint. Hemiarthroplasty offers limited bone resection and may provide easier revision options than joint-ablating procedures.

Methods

Prospective, multicenter, noncomparative, nonrandomized clinical study with short term follow-up on patients undergoing hemiarthroplasty of the ankle. Radiologic and functional outcomes (Foot and Ankle Outcome Score FAOS, Foot and Ankle Ability Measure [FAAM], Short Form-36 Health Survey [SF-36], Short Musculoskeletal Functional Assessment [SMFA], and visual analog scale [VAS] pain scores) were obtained at 3 and 12 months and the last follow-up (mean 31.9 months).

Results

Ten patients met the inclusion criteria. Three were converted to total ankle replacement at 14, 16, and 18 months. Pain VAS scores improved on average from 6.8 to 4.8 (P = .044) of the remaining 7 at a mean of 31.9 months' follow-up. For these 7 in the Survival Group, we found that SF-36 physical health component improved from 25.03 to 42.25 (P = .030), SMFA dysfunction and bother indexes improved from 46.36 to 32.28 (P = .001), and from 55.21 to 30.14 (P = .002) in the Survival Group, and FAAM sports improved from 12.5 to 34.5 (P = .023).

Conclusion

Patients undergoing hemiarthroplasty of the ankle joint for talar-sided lesions had a 30% failure rate by 18 months. Those who did not have an early failure exhibited modest pain reduction, functional improvements, and better quality of life in short-term follow-up. This procedure offers a possible alternative for isolated talar ankle cartilage cases.

Level of Evidence

Level IV, prospective 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.

Paediatric ankle cartilage lesions: 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 "Pediatric Ankle Cartilage Lesions" developed at the 2019 International Consensus Meeting on Cartilage Repair of the Ankle.

METHODS

Forty-three international experts in cartilage repair of the ankle representing 20 countries convened to participate in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within four 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 characterised as follows: consensus: 51-74%; strong consensus: 75-99%; unanimous: 100%.

RESULTS

A total of 12 statements on paediatric ankle cartilage lesions reached consensus during the 2019 International Consensus Meeting on Cartilage Repair of the Ankle. Five achieved unanimous support, and seven reached strong consensus (>75% agreement). All statements reached at least 84% agreement.

CONCLUSIONS

This international consensus derived from leaders in the field will assist clinicians with the management of paediatric ankle cartilage lesions.

Clinical and MRI Donor-Site Outcomes After Autograft Harvesting From the Medial Trochlea for Talar Osteochondral Lesions: Minimum 5-Year Clinical Follow-up

Background:

Autologous osteochondral transplantation (AOT) is a treatment option for large or cystic osteochondral lesions of the talus (OLTs), with promising clinical results. However, donor-site morbidity (DSM) has always been a concern with this procedure.

Purpose:

To investigate the clinical and radiological outcomes of autograft harvesting from the medial trochlea for OLTs.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 46 consecutive patients were included after AOT procedures for OLTs, with donor autografts (single or double plugs) harvested from the medial trochlea of the ipsilateral knee. Lysholm scores were collected postoperatively at 12-month intervals to assess clinical outcomes. Postoperative magnetic resonance imaging (MRI) was used to assess the donor site using the MOCART (magnetic resonance observation of cartilage repair tissue) score. DSM was evaluated at 12-month intervals. Statistical analysis was performed to compare patients treated with single-plug and double-plug AOT procedures and establish whether there was any correlation between MOCART and Lysholm scores.

Results:

The mean follow-up period was 98.3 months (range, 67-144 months). The Lysholm scores for all patients were 92.5 ± 6.1 and 99.9 ± 0.2 at the 12-month and final follow-ups, respectively. MRI of the donor sites was taken at an average of 93.8 ± 20.5 (range, 61-141) months postoperatively, and the mean MOCART score was 76.2 ± 4.9. The overall incidence of DSM in this study was 4.3% at 12 months, postoperatively, which decreased to 0% at the 24-month follow-up. There was no significant difference in either the Lysholm score (P = .16) or the MOCART score (P = .83) between the single-plug and double-plug groups at the final follow-up. There were no significant correlations between MOCART and Lysholm scores and patient age, number of grafts, or body mass index.

Conclusion:

According to the study findings, the DSM of donor autografts harvested from the medial trochlea was low, and the number (single or double) of grafts did not affect the functional outcome.

Functional Outcomes of Autologous Matrix-Related Chondrogenesis to Treat Large Osteochondral Lesions of the Talus

BACKGROUND

Osteochondral lesions of the talus (OLT) treatment is widely debated when the lesion size exceeds 150 mm². The aim of this study was to assess functional outcome and satisfaction rates of the autologous matrix-related chondrogenesis (AMIC) technique and compare the outcomes for OLTs larger than 150 mm² that were classified as primary, primary with local tumor-related OLT, or revision cases.

METHODS

A total of 77 patients who were operated by AMIC were included. The average age of the population was 39.6 years. The mean body mass index (BMI) was 27.2. Smoker rate was 28.5% of the population. Forty-two patients were primary cases, 14 patients had primary with local tumor-related OLT, and 18 patients were revision cases. Overall and subgroup functional outcomes were evaluated by visual analog scale (VAS) and Foot and Ankle Disability Index (FADI) scores. Satisfaction rates were queried, and failures were recorded.

RESULTS

After a median follow-up of 32 months, the score improvement for primary, primary with local tumor-related, and revision group were for VAS, 5.4 ± 0.4, 5.6 ± 0.7, and 3.6 ± 0.8, and for FADI, 46.5 ± 3.8, 45.3 ±6.5, and 26.6 ± 6.7, respectively (P < .001). Intergroup comparison showed greater improvement for the primary OLT group when compared to the revision group (P < .001). The failure rates for the primary, primary with local tumor-related, and revision group were 4.8%, 11.8%, and 38.9%, respectively.

CONCLUSION

AMIC procedure provides good functional outcome and satisfactory rates in patients with primary and primary with local tumor-related OLT larger than 150 mm², but in revision cases, the AMIC success rate was not encouraging as all had advanced OLT operative interventions.

LEVEL OF EVIDENCE

Level III, therapeutic retrospective study.

Magnetic Hydrogel for Cartilage Tissue Regeneration as well as a Review on Advantages and Disadvantages of Different Cartilage Repair Strategies

There is a clear clinical need for efficient cartilage healing strategies for treating cartilage defects which burdens millions of patients physically and financially. Different strategies including microfracture technique, osteochondral transfer, and scaffold-based treatments have been suggested for curing cartilage injuries. Although some improvements have been achieved in several facets, current treatments are still less than satisfactory. Recently, different hydrogel-based biomaterials have been suggested as a therapeutic candidate for cartilage tissue regeneration due to their biocompatibility, high water content, and tunability. Specifically, magnetic hydrogels are becoming more attractive due to their smart response to magnetic fields remotely. We seek to outline the context-specific regenerative potential of magnetic hydrogels for cartilage tissue repair. In this review, first, we explained conventional techniques for cartilage repair and then compared them with new scaffold-based approaches. We illustrated various hydrogels used for cartilage regeneration by highlighting the magnetic hydrogels. Also, we gathered in vitro and in vivo studies of how magnetic hydrogels promote chondrogenesis as well as studied the biological mechanism which is responsible for cartilage repair due to the application of magnetic hydrogel.

Outcomes of Autologous Osteochondral Transplantation With and Without Extracellular Matrix Cartilage Allograft Augmentation for Osteochondral Lesions of the Talus

BACKGROUND

Autologous osteochondral transplantation (AOT) using a cylindrical graft in the treatment of osteochondral lesions of the talus (OLTs) is typically indicated for patients with larger lesions. However, with lesions that are irregular in shape, the AOT graft may not completely replace the lesion. For these lesions, we utilize extracellular matrix cartilage allograft (EMCA) augmentation in AOT to act as a physiologic grout at the host-graft interface.

PURPOSE

To determine if the combination of EMCA with concentrated bone marrow aspirate (CBMA) would improve integration of the host-graft interface and subsequently reduce postoperative cyst formation after AOT. It was also hypothesized that EMCA in conjunction with CBMA would demonstrate improved MOCART (magnetic resonance observation of cartilage repair tissue) scores and functional outcome scores at a minimum 2 years after surgery.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A retrospective analysis was performed comparing patients treated with AOT/CBMA alone and AOT with CBMA/EMCA. Clinical outcomes were evaluated with the Foot and Ankle Outcome Score. Magnetic resonance imaging appearance was evaluated with the use of the MOCART (magnetic resonance observation of cartilage repair tissue) score. Cyst formation was also evaluated on postoperative magnetic resonance imaging.

RESULTS

A total of 26 patients were included in the AOT + CBMA/EMCA group (10 male, 16 female), and 34 patients were included in the AOT/CBMA group (17 male, 17 female). The mean Foot and Ankle Outcome Score significantly improved in both groups (P < .001) across all subscales (symptoms, pain, activities of daily living, sports activities, and quality of life), but there was no significant difference between groups at final follow-up. There was no significant difference in mean MOCART scores between the groups (P = .118). In the AOT/CBMA group, 3 patients (8.8%) complained of knee pain, and 1 (2.9%) required additional surgery (hardware removal). In the AOT + CBMA/EMCA group, 2 patients (7.7%) complained of knee pain, and 6 patients (23%) required additional surgery (3 hardware removals and 3 arthroscopic debridements of scar tissue in the ankle).

CONCLUSION

We found that while EMCA with CBMA has benefit in regeneration and repair of OLT treated with bone marrow stimulation, there appears to be little benefit of EMCA over CBMA alone as a physiologic grout at the graft-host interface in OLT treated with AOT.

Long-term outcome for repair of osteochondral lesions of the talus by osteochondral autograft: A series of 56 Mosaicplasties®

INTRODUCTION

The present study analyzed results in 56 osteochondral Mosaicplasty® autografts for osteochondral lesion of the talus (OLT) at more than 5 years' follow-up.

HYPOTHESIS

Mosaicplasty® shows long-term efficacy and low morbidity in the treatment of OLT.

PATIENTS AND METHODS

A multicenter retrospective study included patients treated by Mosaicplasty® with more than 5 years' follow-up. Preoperative data were collected from medical files, and all patients were reassessed. AOFAS scores and FAOS were calculated at last follow-up. Imaging comprised standard radiographs and MRI or CT arthrography of the ankle.

RESULTS

Fifty-six patients were included, with a mean age of 34 years (range, 18-60 years). Seventeen involved work accidents. Mean follow-up was 8.5 years (range, 5-20 years). Mean AOFAS score at follow-up was 80.6±19.4 and mean FAOS 77.8±21.5. Work accident, preoperative osteoarthritis and untreated laxity correlated significantly with poorer results. At last follow-up, 22 patients (39%) showed signs of osteoarthritis. There was no morbidity implicating the malleolar osteotomy. There were 11 cases (20%) of persistent patellar syndrome at the donor site.

DISCUSSION

The present results were comparable to those reported elsewhere, showing that functional results of Mosaicplasty® autograft for OLT do not deteriorate over the long term. Work accidents correlated significantly with poorer functional outcome. Any associated instability must always be treated. Malleolar osteotomy provides good exposure without additional morbidity.

LEVEL OF EVIDENCE

IV; retrospective study.

Surgical Treatment for Osteochondral Lesions of the Talus

Osteochondral lesions of the talus (OLT) are often associated with ankle pain and dysfunction. They can occur after ankle trauma, such as sprains or fractures, but they usually present as a continued ankle pain after the initial injury has resolved. Chronic ankle ligament instability and subsequent microtrauma may lead to insidious development of an OLT. Medial-sided lesions are more common (67%) than lateral-sided lesions. For acute lesions that are nondisplaced, nonoperative management is initially performed, with a 4-6 week period of immobilization and protected weight bearing. Symptomatic improvement results in more than 50% of patients by 3 months. Acute osteochondral talus fractures, which have a bone fragment thickness greater than 3 mm with displacement will benefit from early surgical intervention. These injuries should undergo primary repair via internal fixation with bioabsorbable compression screws 3.0 mm or smaller using at least 2 points of fixation. Acute lesions that are too small for fixation can be treated with morselization and reimplantation of the cartilage fragments. If OLTs are persistently symptomatic following an appropriate course of nonoperative treatment, various reparative and restorative surgical options may be considered on the basis of diameter, surface area, depth, and location of the lesion. A small subset of symptomatic osteochondral lesions of the talus involve subchondral pathology with intact overlying articular cartilage; in these cases, retrograde drilling into the cystic lesion can be employed to induce underlying bony healing. Cancellous bone graft augmentation may be used for subchondral cysts with volume greater than 100 mm³ or with those with a depth of more than 10 mm. Debridement, curettage, and bone marrow stimulation is a reparative technique that may be considered in lesions demonstrating a diameter less than 10 mm, with surface area less than 100 mm², and a depth less than 5 mm. This technique is commonly performed arthroscopically using curettes and an arthroscopic shaver to remove surrounding unstable cartilage. A microfracture awl of 1 mm or less is used to puncture the subchondral bone with 3-4 mm of spacing between to induce punctate bleeding. Initial (<5 year) results are good to excellent in 80% of cases, with some deterioration of improvement over time. Factors contributing to poor results include surface area greater than 1.5 cm², overall osteochondral lesion depth over 7.8 mm, smoking history, age over 40, and uncontained lesions. Lesions greater than 1.29 cm², cystic lesions, and lesions that have failed prior treatment are potential candidates for osteochondral autograft transplantation. The autograft is typically harvested from the lateral femoral condyle of the ipsilateral knee with an optimal plug depth and diameter of 12-15 mm. Transplantation often involves open technique and may even require malleolar osteotomy for perpendicular access to the defect, as well as visualization of a flush, congruent graft fit. Good to excellent outcomes have been reported in up 87.4% of cases with the most common complication being donor site morbidity in up to 15% of cases. Failure rates increased significantly in lesions larger than 225 mm². Scaffold-based therapies, such as matrix-associated chondrocyte implantation, can be employed in primary or revision settings in lesions larger than 1 cm², including uncontained shoulder lesions with or without cysts. Lesions with greater than 4 mm of bone loss following debridement may require bone grafting to augment with the scaffold. This technique requires an initial procedure for chondrocyte harvest and a secondary procedure for transplantation of the scaffold. Outcomes have been good to excellent in up to 93% of cases; however, this technique requires a two-stage procedure and can be cost-prohibitive. Particulated juvenile cartilage is a restorative technique that employs cartilage allograft from juvenile donors. The cartilage is placed into the defect and secured with fibrin glue in a single-stage procedure. Studies have shown favorable outcomes in 92% of cases, with lesions between 10 and 15 mm in diameter, but increased failure rates and poorer outcomes in lesions larger than 15 mm. This may be an alternative option for contained lesions between 10 and 15 mm in diameter. Osteochondral allograft plugs are an option for larger contained lesions (>1.5 cm in diameter) and in patients with knee osteoarthritis (OA) and concern for donor site morbidity. Furthermore, bulk osteochondral allograft from a size-matched talus can also be used for even larger, unstable/uncontained shoulder lesions. An anterior approach is often employed and fixation is achieved via placement of countersunk headless compression screws. Failure of the aforementioned options associated with persistent pain or progressive OA would then lend consideration to ankle arthroplasty versus ankle arthrodesis.

Outcomes from Osteochondral Autograft Transplant or Mosaicplasty in 26 Patients with Type V Osteochondral Lesions of the Talus

Background

Mosaicplasty osteochondral transplantation (MOT) has been proved a feasible choice for the treatment of talus osteochondral injury. It can reduce ankle pain and allow performance of daily living activities and elementary sports. However, there are very little data on the restoration of normal life with large lesions. Our investigation focused on assessing outcomes in patients with large lesions.

Material/Methods

The MOT operation was used, and the donor site was located at the lateral condyle of the femur. Clinical evaluation included the Berndt and Harty outcome question, Visual Analog Scale (VAS) pain score (during rest, walking and running), American Orthopedic Foot and ankle Association (AOFAS) score, International Knee Documentation Committee (IKDC) subjective knee evaluation form, and the Short Form 36 (SF-36). Twenty-four months after surgery, the graft binding was assessed by MRI using the magnetic resonance observation of cartilage repair tissue (MOCART) score.

Results

We assessed 26 patients, including 14 males and 12 females. The average follow-up time was 33.9±5.2 months. The average lesion size was 173.1±23.5 mm². The average VAS score during rest improved from 4.62±0.85 preoperatively to 1.08±0.27 postoperatively (P<0.05), the score during walking improved from 5.19±0.63 preoperatively to 1.15±0.37 postoperatively (P<0.05), and the score during running improved from 6.08±0.74 preoperatively to 1.39±0.57 postoperatively (P<0.05). The average postoperative AOFAS ankle score improved to 91.5±2.6 (range, 88 to 96), compared with preoperative 75.0±2.8 (range, 70 to 79) (P<0.05). Two patients developed pain in the donor site of the knee joint, and both of them had 2 or more osteochondral plugs harvested. The postoperative SF-36 score increased to 92.2±2.4 (P<0.05). In the last follow-up, 18 patients answered the Berndt and Harty outcome question, all with “good” as the result.

Conclusions

MOT is a feasible choice for patients with larger lesions. It can improve the VAS/AOFAS/IKDC/SF-36 scores, and has high patient satisfaction. Graft incorporation helps improve patient quality of life. Our results indicate that a larger osteochondral plug area increases the risk of developing knee donor site pain.

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.

Graphene Oxide-Doped Gellan Gum-PEGDA Bilayered Hydrogel Mimicking the Mechanical and Lubrication Properties of Articular Cartilage

Articular cartilage (AC) is a specialized connective tissue able to provide a low-friction gliding surface supporting shock-absorption, reducing stresses, and guaranteeing wear-resistance thanks to its structure and mechanical and lubrication properties. Being an avascular tissue, AC has a limited ability to heal defects. Nowadays, conventional strategies show several limitations, which results in ineffective restoration of chondral defects. Several tissue engineering approaches have been proposed to restore the AC's native properties without reproducing its mechanical and lubrication properties yet. This work reports the fabrication of a bilayered structure made of gellan gum (GG) and poly (ethylene glycol) diacrylate (PEGDA), able to mimic the mechanical and lubrication features of both AC superficial and deep zones. Through appropriate combinations of GG and PEGDA, cartilage Young's modulus is effectively mimicked for both zones. Graphene oxide is used as a dopant agent for the superficial hydrogel layer, demonstrating a lower friction than the nondoped counterpart. The bilayered hydrogel's antiwear properties are confirmed by using a knee simulator, following ISO 14243. Finally, in vitro tests with human chondrocytes confirm the absence of cytotoxicity effects. The results shown in this paper open the way to a multilayered synthetic injectable or surgically implantable filler for restoring AC defects.

Osteochondral Lesions of the Talus: An Individualized Treatment Paradigm from the Amsterdam Perspective

Osteochondral lesions of the talus (OLTs) are characterized by damage to the articular cartilage of the talus and its underlying subchondral bone. Up to 75% of OLTs are caused by trauma, such as an ankle sprain or fracture. Physical examination and imaging are crucial for diagnosis and characterization of an OLT. No superior treatment for OLTs exists. It is paramount that an evidence-based personalized treatment approach is applied to patients with OLTs because lesion and patient characteristics guide treatment. This current concepts review covers clinical and preclinical evidence on OLT etiology, presentation, diagnosis, and treatment, all based on the Amsterdam perspective.

Current management strategies for osteochondral lesions of the talus

The management of symptomatic osteochondral lesions of the talus (OLTs) can be challenging. The number of ways of treating these lesions has increased considerably during the last decade, with published studies often providing conflicting, low-level evidence. This paper aims to present an up-to-date concise overview of the best evidence for the surgical treatment of OLTs. Management options are reviewed based on the size of the lesion and include bone marrow stimulation, bone grafting options, drilling techniques, biological preparations, and resurfacing. Although many of these techniques have shown promising results, there remains little high level evidence, and further large scale prospective studies and systematic reviews will be required to identify the optimal form of treatment for these lesions. Cite this article: Bone Joint J 2021;103-B(2):207-212.

Wear Behavior Characterization of Hydrogels Constructs for Cartilage Tissue Replacement

This paper aims to characterize the wear behavior of hydrogel constructs designed for human articular cartilage replacement. To this purpose, poly (ethylene glycol) diacrylate (PEGDA) 10% w/v and gellan gum (GG) 1.5% w/v were used to reproduce the superior (SUP) cartilage layer and PEGDA 15% w/v and GG 1.5% w/v were used to reproduce the deep (DEEP) cartilage layer, with or without graphene oxide (GO). These materials (SUP and DEEP) were analyzed alone and in combination to mimic the zonal architecture of human articular cartilage. The developed constructs were tested using a four-station displacement control knee joint simulator under bovine calf serum. Roughness and micro-computer tomography (µ-CT) measurements evidenced that the hydrogels with 10% w/v of PEGDA showed a worse behavior both in terms of roughness increase and loss of uniformly distributed density than 15% w/v of PEGDA. The simultaneous presence of GO and 15% w/v PEGDA contributed to keeping the hydrogel construct's characteristics. The Raman spectra of the control samples showed the presence of unreacted C=C bonds in all the hydrogels. The degree of crosslinking increased along the series SUP < DEEP + SUP < DEEP without GO. The Raman spectra of the tested hydrogels showed the loss of diacrylate groups in all the samples, due to the washout of unreacted PEGDA in bovine calf serum aqueous environment. The loss decreased along the series SUP > DEEP + SUP > DEEP, further confirming that the degree of photo-crosslinking of the starting materials plays a key role in determining their wear behavior. μ-CT and Raman spectroscopy proved to be suitable techniques to characterize the structure and composition of hydrogels.

Autologous Osteochondral Transplantation for Large Osteochondral Lesions of the Talus Is a Viable Option in an Athletic Population

BACKGROUND

Autologous osteochondral transplantation (AOT) has been shown to be a viable treatment option for large osteochondral lesions of the talus. However, there are limited data regarding the management of large lesions in an athletic population, notably with regard to return to sport. Our investigation focused on assessing both qualitative and quantitative outcomes in the high-demand athlete with large (>150 mm²) lesions.

HYPOTHESIS

AOT is a viable option in athletes with large osteochondral lesions and can allow them to return to sport at their preinjury level.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

The study population was limited to professional and amateur athletes (Tegner score, >6) with a talar osteochondral lesion size of 150 mm² or greater. The surgical intervention was AOT with a donor site from the lateral femoral condyle. Clinical outcomes at a minimum of 24 months included return to sport, visual analog scale (VAS) for pain score, and Foot and Ankle Outcome Score (FAOS). In addition, graft incorporation was evaluated by magnetic resonance imaging (MRI) using MOCART (magnetic resonance observation of cartilage repair tissue) scores at 12 months after surgery.

RESULTS

A total of 38 athletes, including 11 professional athletes, were assessed. The mean follow-up was 45 months. The mean lesion size was 249 mm². Thirty-three patients returned to sport at their previous level, 4 returned at a lower level compared with preinjury, and 1 did not return to sport (mean return to play, 8.2 months). The VAS improved from 4.53 preoperatively to 0.63 postoperatively (P = .002). FAOSs improved significantly in all domains (P < .001). Two patients developed knee donor site pain, and both had 3 osteochondral plugs harvested. Univariant analysis demonstrated no association between preoperative patient or lesion characteristics and ability to return to sport. However, there was a strong correlation between MOCART scores and ability to return to sport. The area under receiver operating characteristic of the MOCART score and return to play was 0.891 (P = .005), with a MOCART score of 52.50 representing a sensitivity of 0.85 and specificity of 0.80 in determining ability to return to one's previous level of activity.

CONCLUSION

Our study suggests that AOT is a viable option in the management of large osteochondral talar defects in an athletic population, with favorable return to sport level, patient satisfaction, and FAOS/VAS scores. The ability to return to sport is predicated upon good graft incorporation, and further research is required to optimize this technique. Our data also suggest that patients should be aware of the increased risk of developing knee donor site pain when 3 osteochondral plugs are harvested.

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.