Autologous Osteoperiosteal Transplantation for the Treatment of Large Cystic Talar Osteochondral Lesions

Recent Advances in the Clinical Treatment of Osteochondral Lesions of the Talus (2021-2023): A Narrative Review

The management of osteochondral lesions of the talus (OLT) remains a challenging clinical issue. With advances in theory and technology, treatment options for OLT have expanded significantly. This review examines recent progress in the clinical treatment of OLT, focusing on studies published from 2021 to 2023. We searched PubMed, Embase, and Cochrane databases to identify relevant clinical treatments, including both nonsurgical and surgical approaches. Surgical advancements have primarily centered on microfracture, bone transplantation, cartilage transplantation, combined cell therapy, and biomaterials. Among these, some innovative methods, such as autologous costal cartilage transplantation and biological scaffolds, have yielded promising clinical outcomes. However, high-quality clinical studies are still lacking, particularly those exploring nonsurgical treatments and physical therapy. Future research may increasingly focus on integrating biomaterials with physical therapy, which holds potential for improving patient outcomes.

Talar OsteoPeriostic Grafting From the Iliac Crest (TOPIC): Prospective 2-Year Outcomes for Large Lateral Osteochondral Lesions of the Talus

BACKGROUND

The results of the Talar OsteoPeriostic grafting from the Iliac Crest (TOPIC) procedure for lateral osteochondral lesions of the talus (OLTs) are unknown. Therefore, the present prospective study aims to assess the numeric rating scale (NRS) of pain during walking at 2-year follow-up. Secondarily, the aim is to assess other clinical, radiologic, and safety outcomes.

METHODS

This is a single-center, nonrandomized prospective cohort study in which all press-fit lateral TOPIC patients for an OLT are included. Patients with a follow-up of at least 2 years without a concomitant osteochondral lesion of the tibial plafond were included. The primary outcome is the NRS of pain during walking. Secondary clinical outcomes included the NRS during rest and during stair climbing. Additionally, the Foot and Ankle Outcome Score (FAOS), the AOFAS ankle-hindfoot score, and the mental and physical component summary of the 36-Item Short Form Health Survey were recorded. Radiologic follow-up was performed using computed tomography (CT) scans.

RESULTS

After application of the inclusion and exclusion criteria, 7 patients were included in the present study. The median age at time of surgery was 31.1 years. The NRS of pain during walking improved from a median of 5 (4-7) preoperatively to 1 (0-1) at 2 years of follow-up (P = .02). All FAOS subscales improved significantly, except the FAOS symptoms subscale. Graft consolidation was observed in 100% of the patients and cysts were present in 5 of 6 patients. No complications occurred and no patients complained of donor site morbidity. No reoperations were performed.

CONCLUSION

In the first 7 prospectively followed patients who underwent the TOPIC procedure for large osteochondral lesions of the lateral talar dome, an improvement of the NRS of pain during walking from median 5 preoperatively to 1 at 2-year follow-up was observed.

Case report: Free autologous costal cartilage transplantation for osteochondral lesions of the talus: three cases with 2-5 years follow-up

Background

Osteochondral lesions of the talus (OLT) is a common and clinically challenging condition with no consensus on the optimal treatment. The prospective case series aim to evaluate the feasibility and clinical outcomes of free autologous costal cartilage transplantation (ACCT) for OLT.

Methods

From April 2018 to October 2022, three patients who were diagnosed with OLT underwent free ACCT. Demographic characteristics, including age, gender, lesion size and location were collected at baseline. Functional and imaging outcomes were evaluated at 1 year, 2 years, and 5 years postoperatively. The primary outcomes were American Orthopedic Foot and Ankle Society (AOFAS) score and Foot and Ankle Ability Measure (FAAM) score. Secondary outcomes included Numeric Rating Scale (NRS), Tegner Activity Scale, and evaluations of images. A paired t-test was used for preoperative and postoperative comparison of the paired-design dataset.

Results

Three patients (37.33 ± 16.50 years old) were included in the study with 2-5 years follow-up. AOFAS score improved from 60 ± 11 at baseline to 96 ± 6.93 at 2 years (p < 0.01) and 94 ± 8.49 at 5 years. FAAM/ADL improved from 60.97 ± 6.58 at baseline to 98 ± 1.83 at 2 years (p < 0.01) and 97 ± 0.85 at 5 years. FAAM/Sports improved from 56.4 ± 11.95 at baseline to 88.23 ± 11.34 at 2 years (p < 0.01) and 89 ± 4.67 at 5 years. Other functional scores in patient reported outcomes also showed significant improvements. Postoperative CT and MRI showed complete defect filling and robust tissue integration after ACCT. Arthroscopic evaluations further confirmed solid integration of costal cartilage into the underlying subchondral bone with a smooth surface over the repair site.

Conclusion

Free ACCT is a feasible method for improving ankle function and quality of life for at least 2 years in patients with OLT. Promising long-term outcomes may be possible because of the good integration between the recipient talus and the implanted ACCT.

Osteoperiosteal versus osteochondral for autologous transplantation in the treatment of large cystic osteochondral lesions of the talus

BACKGROUND

Osteochondral lesions of the talus (OLTs) with a large subchondral cyst have been shown to have inferior clinical outcomes after reparative techniques. Replacement techniques such as autologous osteoperiosteal transplantation (AOPT) and autologous osteochondral transplantation (AOCT) are indicated for large lesions. The aim of the study was to compare the short-term clinical and radiographic outcomes between patients undergoing AOPT and those undergoing AOCT for large cystic OLTs.

METHODS

Patients who underwent AOPT or AOCT for medial large cystic OLTs between May 2019 and June 2023 were retrospectively evaluated. According to their characteristics, 1:1 propensity-score matching was performed, and 65 pairs of patients with ages ranging from 18 to 60 years old were recruited. Clinical outcomes were compared between both groups with the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and Visual Analogue Scale (VAS). The Ankle Activity Score (AAS), time to return to sports activity (RTA), rate of return to sports level, complications, and results of a subjective evaluation were also collected. The integrity of subchondral bone and the quality of repaired cartilage were evaluated using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score 12 months postoperatively. Second-look arthroscopy was performed 12 months postoperatively, and the cartilage repair was assessed with the criteria of the International Cartilage Repair Society (ICRS).

RESULTS

The within-group comparison showed significant improvements in pain severity and function in both groups post-treatment compared with pre-treatment. Between-group analysis, however, showed no significant statistical difference between groups in any of the variables for clinical and radiographic outcomes, except for donor-site morbidity of the AOPT group, which showed a better outcome compared to the AOCT group.

CONCLUSIONS

In the treatment of large cystic OLTs, for patients with a chondral lesion of the patellofemoral joint that is unsuitable for AOCT, AOPT may be a safe and effective choice, with lower donor-site morbidity of the normal knee joint.

Surgical treatment for medium-sized cystic osteochondral lesions of the talus: Autologous osteoperiosteal transplantation provides better clinical outcomes than bone marrow stimulation when cysts are deeper than 6 mm

PURPOSE

To compare clinical outcomes of autologous osteoperiosteal transplantation versus bone marrow stimulation (BMS) for medium-sized (100-150 mm2) cystic osteochondral lesions of the talus (OLTs) and assess the correlation between patient demographics and outcomes. It was hypothesised that autologous osteoperiosteal transplantation would provide better clinical outcomes than BMS for medium-sized cystic OLTs.

METHODS

Patients who underwent autologous osteoperiosteal transplantation or BMS for medium-sized cystic OLTs between 2014 and 2019 were retrospectively evaluated. According to their characteristics, a 1:1 propensity-score matching was performed and 33 pairs of patients were matched. The visual analogue scale, American Orthopaedic Foot and Ankle Society (AOFAS) score, Foot Ankle Outcome Score (FAOS) and Ankle Activity Score were collected preoperatively and at the last follow-up. In addition, a general linear model analysis was performed between patient demographics and clinical outcomes in two groups separately to detect potential risk factors.

RESULTS

Finally, 28 patients in the grafted group and 27 patients in the BMS group completed the follow-up and were enrolled with a mean follow-up period of 63.5 ± 13.9 months. Both groups showed significant improvement in all patient-reported outcomes (p < 0.01). At the final follow-up, no significant differences between groups were found in all postoperative scores except FAOS Pain (p = 0.02). Correlation analysis showed a moderate correlation between cyst depth and the postoperative AOFAS score in the BMS group (r = -0.48, p = 0.01). Based on the regression line, the patients in the BMS group with a cyst deeper than 6 mm showed a lower AOFAS score than the mean score (88.7 ± 9.5) of the grafted group.

CONCLUSION

Autologous osteoperiosteal transplantation and BMS are both safe and effective for medium-sized cystic OLTs. However, autologous osteoperiosteal transplantation is expected to provide better clinical outcomes than BMS when the cysts are deeper than 6 mm.

LEVEL OF EVIDENCE

Level III.

Autologous osteoperiosteal transplantation for cystic osteochondral lesions of the talus: Bone reconstruction is essential

PURPOSE

Autologous osteoperiosteal transplantation (AOPT) is one of the most feasible and effective techniques for cystic osteochondral lesions of the talus (OLT). However, few reports have been reported about the process of graft-host bone healing and bone articular surface reconstruction, which help us to further understand the actual situation of bone healing and modify surgical methods.

METHODS

The case series study retrospectively evaluated 33 osteochondral lesions in 30 patients undertaking AOPT for OLT with subchondral cysts from December 2016 to October 2021. According to CT observation, we used 4 variables to describe the bony articular repair, including the integration of the articular surface, the height of the bone filling, the status of bone union, and the appearance of bone resorption or cystic change. We also analyzed the demographic data and clinical function. Descriptive statistics were used for demographic and clinical variables. Normally distributed data were presented as mean ± SD, and non-normally distributed data were presented as median (Q1, Q3). Associations between these variables and the primary clinical outcomes were examined using t-test or one-way ANOVA test for continuous variables.

RESULTS

The patients' mean age was (41.7 ± 14.0) years old and the mean follow-up time was (29.6 ± 17.8) months. The chondral lesion size was (14.3 ± 4.1) mm. The cyst depth was (10.9 ± 3.7) mm. Significant improvements were observed in functional outcomes (according to the numeric rating scale for pain when walking and the American orthopedic foot and ankle society score) between the preoperative and latest follow-up evaluations, from 4.2 ± 2.1 to 2.2 ± 2.0 (p < 0.001), and from 66.8 ± 12.9 to 83.2 ± 10.4, respectively (p < 0.001). The overall satisfaction reached 8.3 of 10 points. All patients returned to sports and their median daily steps reached 8000 steps with 27 (81.8%) patients walking over 6000 steps daily. According to CT observation, "discontinuous bony articular surface and gap > 1 mm" was found in 27 grafts (81.8%), and "below the level of the adjacent articular surface, ≤ 1 mm" in a third of the grafts. Abnormal height of bone filling affected numeric rating scale score (p = 0.049) and American Orthopedic Foot and Ankle Society score (p = 0.027). Of note, bone resorption or cystic changes appeared in up to 13 autografts (39.4%).

CONCLUSIONS

AOPT is an effective and acceptable technique for cystic OLT. Bone reconstruction is essential for large cystic OLT. How to get better bony articular reconstruction and avoid cyst recurrence should still be paid more attention.

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.

Evaluation of the efficacy of autogenous tibial periosteal bone grafting in the treatment of osteochondral lesions of the talus and analysis of three-dimensional factors in the necrotic zone

PURPOSE

This study aims to explore the clinical value of autogenous tibial periosteal bone grafting in the treatment of osteochondral lesions of the talus (OLT) and analyze the three-dimensional factors in the necrotic zone of the talus.

METHODS

A retrospective analysis was performed on 36 patients who underwent autogenous tibial periosteal bone grafting in the Foot and Ankle Surgery Department of our hospital between September 2018 and September 2022. The American Orthopaedic Foot and Ankle Society (AOFAS), Visual Analogue Scale (VAS), and Chinese Short-Form 36 Health Survey (SF-36) were used to evaluate treatment efficacy prior to surgery and at the last follow-up. Furthermore, Mimics 21.0 software was employed to measure the three-dimensional data of the necrotic area, including surface area, volume, and depth, in order to investigate their potential impact on patient prognosis.

RESULTS

Among the 36 OLT patients who obtained complete follow-up, there were 22 males and 14 females. No complications such as surgical site infection, non-union of cartilage, post-traumatic arthritis, or donor site pain were observed. The AOFAS, VAS, and Chinese SF-36 scores of all patients at the last follow-up showed significant improvement compared to preoperative values. There was no significant correlation between the AOFAS, VAS, and Chinese SF-36 scores at the last follow-up and the depth, surface area, and volume of the necrotic zone.

CONCLUSION

The use of autogenous tibial periosteal bone grafting can safely and effectively treat Hepple V OLT. Additionally, there is no significant correlation between the three-dimensional factors of the necrotic area and the prognosis of the patients.

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.

Comparison of Arthroscopic Microfracture for Osteochondral Lesions of the Talus With and Without Small and Shallow Subchondral Cysts

BACKGROUND

Whether arthroscopic microfracture is effective in treating cystic osteochondral lesions of the talus (OLTs) remains controversial. In this study, outcome parameters in patients with small and shallow subchondral cysts are compared to patients without cysts with the hypothesis that equivalent outcomes may be found after primary microfracture treatment.

METHODS

From 2018 to 2021, all 50 OLTs treated with arthroscopic microfracture in the authors' hospital were retrospectively reviewed for eligibility. Single unilateral symptomatic lesions were included and divided into the cyst and noncyst groups, whereas kissing lesions and arthritic lesions were excluded. Numeric rating scale (NRS) scores, American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scores, Tegner activity level scores, Foot and Ankle Ability Measure (FAAM) scores, and magnetic resonance (MR) imaging results were used to describe outcomes.

RESULTS

A total of 35 patients were included, 16 in the cyst group and 19 in the noncyst group. The patient characteristics were similar between the 2 groups (P > .05). In the cyst group the average cysts depth was 5.0 ± 1.3 mm. After a mean follow-up duration of 36.2 ± 10.2 months, no significant differences were found between the 2 groups in NRS, AOFAS, FAAM, or Tegner score improvement (P > .05). Three patients (19%) in the cyst group had no NRS score improvement.

CONCLUSION

OLTs with small and shallow subchondral cysts can be treated with arthroscopic microfracture and achieve similar outcomes as noncystic lesions. A few cystic lesions may not respond to microfracture treatment.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Analysis of preoperative and postoperative depression and anxiety in patients with osteochondral lesions of the talus

Purpose

This study aims to investigate the psychological status of patients with Hepple V osteochondral lesions of the talus (OLT) and evaluate the effect of autologous osteoperiosteal transplantation (AOPT) on their psychological well-being.

Methods

Fifty patients with Hepple V OLT who underwent AOPT at the Comprehensive Foot and Ankle Surgery Ward of Xi'an Honghui Hospital from November 2021 to May 2023 were included in this study. The patients were divided into two groups based on the presence or absence of preoperative symptoms of anxiety/depression. Group A comprised patients with preoperative symptoms, while Group B included patients without such symptoms. Preoperative and final follow-up assessments included the Hospital Anxiety and Depression Scale for evaluating anxiety and depression, the visual analogue scale for pain assessment, and the American Orthopaedic Foot and Ankle Society scores for assessing ankle and hindfoot function.

Results

Among the 50 Hepple V OLT patients who obtained complete follow-up, twenty-four had preoperative symptoms of anxiety/depression, with an incidence rate of up to 48%. Patients in Groups A and B showed significant improvement in all evaluation indexes after AOPT compared to the preoperative period, but the overall prognosis of Group A was poorer than that of Group B.

Conclusion

AOPT can effectively improve patients' pain, functional activities, and psychological status, and there is a significant correlation between patients' preoperative psychological status and prognosis.

Autologous Costal Chondral/Osteochondral Transplantation and Costa-Derived Chondrocyte Implantation for Articular Cartilage Repair: Basic Science and Clinical Applications

There has been increasing application of autologous costal chondral/osteochondral transplantation (ACCT/ACOT) and costa-derived chondrocyte implantation (ACCI) for articular cartilage repair over the past three decades. This review presents the major evidence on the properties of costal cartilage and bone and their qualifications as grafts for articular cartilage repair, the major clinical applications, and the risks and strategies for costal chondral/osteochondral graft(s) harvest. First, costal cartilage has many specific properties that help restore the articular surface. Costa, which can provide abundant cartilage and cylindrical corticocancellous bone, preserves permanent chondrocyte and is the largest source of hyaline cartilage. Second, in the past three decades, autologous costal cartilage-derived grafts, including cartilage, osteochondral graft(s), and chondrocyte, have expanded their indications in trauma and orthopaedic therapy from small to large joints, from the upper to lower limbs, and from non-weight-bearing to weight-bearing joints. Third, the rate of donor-site complications of ACCT or ACOT is low, acceptable, and controllable, and some skills and accumulated experience can help reduce the risks of ACCT and ACOT. Costal cartilage-derived autografting is a promising technique and could be an ideal option for articular chondral lesions with or without subchondral cysts. More high-quality clinical studies are urgently needed to help us further understand the clinical value of such technologies.

Second-Look Arthroscopy Shows Inferior Cartilage after Bone Marrow Stimulation Compared with Other Operative Techniques for Osteochondral Lesions of the Talus: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare cartilage quality after different surgical interventions for osteochondral lesions of the talus (OLT), evaluated by second-look arthroscopy. Secondary aims were to report concomitant diagnoses, and to correlate cartilage quality with clinical and radiological outcomes. This review hypothesizes that the cartilage repair after bone marrow stimulation (BMS) is inferior to the other available treatment options.

METHODS

PROSPERO ID: CRD42022311489. Studies were retrieved through PubMed, EMBASE (Ovid), and Cochrane Library. Studies were included if they reported cartilage quality after second-look investigation after surgical treatment of OLT. The primary outcome measure was the cartilage quality success and failure rates (%) per surgical intervention group. Correlations between the cartilage quality and clinical or radiological outcomes were calculated.

RESULTS

Twenty-nine studies were included, comprising 586 ankles that had undergone second-look arthroscopy on average 16 months after initial surgery. The success rate for BMS was 57% (95% confidence interval [CI] = 48%-65%), for fixation (FIX) 86% (95% CI = 70%-94%), for osteo(chondral) transplantation (OCT) 91% (95% CI = 80%-96%), for cartilage implementation techniques (CITs) 80% (95% CI = 69%-88%), and for retrograde drilling 100% (95% CI = 66%-100%). The success rate of BMS was significantly lower than FIX, OCT, and CIT (P < 0.01). There were no significant differences between other treatment groups. A moderate positive significant correlation between the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score and the International Cartilage Repair Society score (ICRS) was found (ρ = 0.51, P < 0.001).

CONCLUSIONS

Successful restoration of cartilage quality was found in the majority of surgically treated OLTs. However, BMS yields inferior cartilage quality compared with FIX, OCT, and CIT. Study Design. Systematic review and meta-analysis. Level of evidence. Level IV, systematic review and meta-analysis.

Autologous Costal Osteochondral Transplantation for Cystic Osteochondral Lesions of the Talus: Feasible and Effective

OBJECTIVE

Osteochondral lesions of the talus (OLT) is a common and clinically challenging disease. The optimal management is still under debate. The purpose of this prospective study was to investigate the feasibility and clinical outcomes of autologous costal osteochondral transplantation (ACOT) for the treatment of cystic OLT.

METHODS

From November 2021 to April 2023, five patients underwent autologous costal osteochondral transplantation (ACOT) for cystic OLT. The demographic data was described, including age, gender, lesion size and location. We prospectively evaluated their functional and imaging outcomes of the five patients for 12 months postoperatively, including numeric rating score (NRS) for pain when walking, Tegner score, American Orthopedic Foot & Ankle Society (AOFAS) score and Foot and Ankle Ability Measure (FAAM) score, and imaging results. A paired t-test was used for preoperative and postoperative comparison of the paired-design dataset.

RESULTS

The average age was 36.6 ± 11.1 years. The average diameter of chondral lesions was 14.95 ± 2.71 mm, the average diameter of subchondral cysts was 10.66 ± 1.84 mm, and their average depth was 10.40 ± 1.86 mm. At 12 months postoperatively, the clinical function indexes improved significantly, including NRS (from 5.2 ± 2.3 to 0), Tegner score (from 3.2 ± 0.4 to 5.8 ± 0.4), AOFAS score (from 72.8 ± 10.0 to 98.2 ± 4.0), and FAAM score (FAAM/ADL from 61.2 ± 24.7 to 99.3 ± 1.6; FAAM/Sports from 32.5 ± 13.73 to 96.3 ± 8.4). Their magnetic resonance observation of cartilage repair tissue (MOCART) scores reached 78.0 ± 7.6 points. ICRS scores of three patients were nearly normal (10 or 11 points). The biopsy of the surviving grafts showed plenty of hyaline cartilage matrix and scattered chondrocytes histologically. No major severe complications were reported during the 12 months follow-up.

CONCLUSION

ACOT could significantly relieve the symptoms of patients with OLT and improve their clinical function at short-term follow-up. ACOT might be a feasible and useful method for repairing OLT with subchondral cysts.