We read with interest the article entitled “Is Reconstruction Preserving the First Ray or First Two Rays Better than Full Transmetatarsal Amputation in Diabetic Foot?”1 The authors concluded that preservation of the first ray or first two rays with free flap reconstruction functionally benefited the patients. Although the study was well conducted, some points were not well addressed.
First, the sample size in this study was small, with only 59 patients. However, for Cox proportional hazard regression model analysis, positive outcome events equivalent to at least 15 to 20 times the number of covariates were required.2 So, we suggest the authors conduct a research study on a larger sample size.
Second, all patients had a minimum of 12 months of follow-up (range, 12 to 121 months). The follow-up period varied widely; the mean follow-up period was 26 months in the transmetatarsal amputation group and 32 months in the ray group. It may be more useful to think of patients who have achieved wound closure as being in remission rather than being healed, since recurrence is common. The follow-up period was too short and many outcomes were outside the follow-up period. It would have been better if the authors had assessed the prognosis at 5 years, which has been regarded as long-term follow-up.3
Third, retrospective data accumulation was not controlled by researchers, and the integrity and authenticity of the records directly affected the reliability of the results, which may lead to a low level of evidence and great bias. The outcomes are better determined using a blind method, which is used to prevent research outcomes from being influenced by the placebo effect or observer bias. Since this study aimed to compare the effects of two different amputation methods in the diabetic foot, a randomized controlled trial might have been a better choice.
Fourth, we thought that risk factors shown in Table 1 were not comprehensive. Common indicators, such as amputation history and ischemia, were associated with reconstructive outcomes.4 We suggest that the authors should have added more risk factors to their study.
Fifth, this study included three outcomes: reconstructive outcomes, additional procedures after initial healing, and functional analysis. The first two outcomes were not significantly different, while the third one suggested that preservation of the first ray or first two rays with free flap reconstruction may functionally benefit the patients. However, the authors also pointed out that progressive deformity of the preserved first and second toes will inevitably occur, requiring patients to undergo further surgery. Therefore, we think preserving the first ray or first two rays in the diabetic foot might not be effective enough. Locally applied antibiotics combined with reconstruction preserving the first ray or first two rays may reduce the probability for further amputation.5
In conclusion, we think more evidence is needed for the effectiveness of reconstruction preserving the first ray or first two rays in diabetic foot amputation.
This work was supported by Innovation Training Program Project of Nantong University (project no. 2018169).
The authors have no financial interest to declare in relation to the content of this communication.
Xue-Lei FuHong-Lin Chen, M.D.School of NursingNantong UniversityNantong, Jiangsu, People’s Republic of China
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