The most important finding of the present study was that bone marrow stimulation (BMS) was identified as the best treatment option.
The review summarizes 65 study groups in 52 studies that describe treatment strategies for osteochondral talar lesions. There was a great diversity in trials concerning patient characteristics, staging of the defect, duration of follow-up and outcome measures. A relatively large number of studies were dedicated to treatment by excision and curettage, excision and curettage and BMS, and OATS. The number of patients in other categories, mainly retrograde drilling, fixation and transmalleolar drilling (TMD), was too limited for a reliable interpretation of the results. Therefore, no definitive conclusions can be drawn. Recommendations concerning these techniques must be judged in this light. Retrograde drilling is usually reserved for large OCDs with intact overlying cartilage, as confirmed by arthroscopy. It is the treatment of choice when there is a large subchondral cyst with overlying healthy cartilage. However, sizes of the lesions were not described in any of the studies concerning retrograde drilling [26
]. Fixation is indicated for lesions in which a large fragment can be reattached. It is applied especially in (sub)acute cases and in adolescents and children. Transmalleolar drilling is performed when a defect is hard to reach because of its location on the talar surface. A disadvantage is that healthy tibial cartilage is damaged. The reported results do not support the use of this technique [26
]. Besides, most talar lesions can be reached by means of the standard anterior or posterior arthroscopic approach, using intermittent distraction and a 90° microfracture probe [58
The results of non-operative treatment were low compared to operative treatment. In spite of this, non-operative treatment should always be the first treatment to be considered.
Today, most publications on treatment of osteochondral lesions of the talus involve arthroscopic excision, curettage and bone marrow stimulation, ACI and OATS. They scored success percentages of 85, 76 and 87, respectively. ACI is a relatively expensive technique, and OATS gives morbidity from knee complaints in a relevant number of patients—up to 36% in literature [1
]. Therefore, we recommend arthroscopic excision, curettage and BMS to be the first treatment of choice for primary osteochondral talar lesions. It is relatively inexpensive, there is low morbidity, a quick recovery and a high success rate.
The results of this review differ slightly from the results described in the review of Verhagen et al. [61
]. Results of both reviews are listed in Table . The success percentage for BMS has changed very little. Verhagen included 21 studies and 227 patients, and this review included 18 studies and 388 patients. The success rate went from 86 to 85%. For OATS, the success rate changed from 94 to 87%. Verhagen found one study with 36 patients treated with this technique. We identified nine eligible studies comprising 243 patients. In the previous review, the ACI technique was not included. We now identified four studies, comprising 59 patients, describing the results of ACI, leading to a success percentage of 76%. Our exclusion criteria were stricter than those of the previous review. Considering the number of patients, Verhagen et al. excluded single case reports, but included series of two patients and more. To be included in our review, each study group had to involve 10 patients or more. This excluded the ‘extended case reports’ and only allowed true case series to be evaluated. Our initial goal was to only include study groups of 20 patients or more. This protocol, however, excluded too many studies, and we stretched our criteria to 10 patients. In comparison with Tol [57
], this eliminated 13 studies (and 18 treatment groups) and in comparison with Verhagen [61
] it is 30 studies.
For the quality of the review, we would have preferred to include only the highest level of evidence, which are randomized clinical trials. However, only one RCT was identified, describing the results of chondroplasty (excision and curettage), microfracturing and osteochondral transplantation [17
]. Looking at the set-up and inclusion of this study one, can debate whether this study was a truly randomized trial, as is also stated by the authors of the article. We identified no case control studies.
Assessment of quality by the adjusted NOS showed that studies scored low on study design. Studies scored moderately concerning ‘outcome’, since no study described whether blind assessment was part of the protocol, and in many studies there was a loss to follow up exceeding 5%. The NOS adjusted for case series, as used in this study, has not been validated. However, scoring low on the items described earlier leads to a higher chance of introducing bias.
The clinical relevance of the present study is the identification of the most effective treatment options for primary osteochondral lesions of the talus, which can serve as a guideline for treatment in clinical practice.