Discussion
chronic plantar fasciitis, contracture, Chronic plantar fasciitis, pain
MINOR, SECONDARY, COMPLICATIONS
The study demonstrates improved long-term function and reduced level of pain by PMGR surgery and stretching compared with stretching alone for patients with chronic plantar fasciitis in combination with an isolated gastrocnemius contracture. The effect of surgery is not reduced after 6 years. A long-term difference in ankle dorsiflexion could not be found between the groups, and no clinically relevant differences in performance of the Achilles complex could be demonstrated.Molund et alThe main strength of this study is that it is a randomized controlled trial, and that the follow-up time is long. The follow-up rate of 82.5 percent is good considering that 6 years has passed since primary inclusion. Another strength is that patients are evaluated by several clinical outcomes.The main limitation of the study is its small study population. More robust results would have been achieved in a larger study. Seven patients were lost to follow-up, and most missing patients were found in the group primarily allocated to surgical intervention. By doing a linear mixed model analysis on our results, the loss to follow-up is handled. When designing the study, a power analysis was made that required 16 patients in each group. The PP and PPEC analysis can therefore be considered underpowered.Another limitation of the study is the quality of the primary outcome: the AOFAS ankle-hindfoot score. This tool is widely used and gives clinicians the opportunity to compare results of many studies. However, the AOFAS ankle-hindfoot score has been criticized for its lack of responsiveness, poor inter- and intrarater reliability, ceiling effects, and for its nature of being a clinician-reported outcome, where the opinion of the examining clinician heavily affects the result.The statistical analysis of our data was complicated by 7 missing patients and 7 patients crossing over from nonoperative to operative treatment after the 1-year follow-up. By running the linear mixed effects model allocating patients to ITT, PP, and PPEC we could add sensitivity to our result and compensate for missing data. For the main outcome AOFAS score and for VAS for pain, all analysis pointed in the same direction and showed significant differences between the groups. For the primary effect estimate, which was the marginal mean difference from the mixed model with PPEC allocation between AOFAS score at 6 years, the difference surpassed what was set as minimally clinical important difference (MCID) of 10 points. However, no studies have estimated the MCID for the AOFAS score in this patient group. MCID values from studies on other foot pathologies had to be considered.For the secondary outcome, MOxFQ, there were differences in favor of surgery by all methods of analysis, for both the total and the subdomains. However, only the ITT and PPEC analysis could demonstrate significant differences. The MOxFQ results support the main conclusion, but because no baseline data exist for the MOxFQ, this result should only be interpreted in an exploratory or descriptive manner. In this regard, it can be noted that in the walking/standing and in 2 of the pain subdomain analyses (ITT and PPEC), the MOxFQ reached the threshold of the MCID values of 16 and 12.When descriptively comparing 6-year results to baseline, a greater increase in the AOFAS ankle-hindfoot score and greater decrease in VAS is seen in the operative group (From baseline to 6 years, no clinically relevant changes in ankle dorsiflexion could be seen in patients receiving surgery (6 degrees [−3, 15] vs 7.6 degrees [6.1, 9.0]). The increase in ankle dorsiflexion seen between baseline and 1 year (6 vs 10.5 degrees)The Achilles complex test battery evaluated different modalities in Achilles complex performance. At 6 years, our data showed minor differences between the groups that cannot be considered clinically relevant. Our data are too small to make any certain conclusions on this matter. However, and most importantly, the results indicate that no obvious negative effect on Achilles complex performance can be seen in patients treated with PMGR. Hypothetically, cutting the tight outer layer of the medial gastrocnemius muscle may reduce the function of the muscle, but no such effect can be demonstrated.This study finds no functional reduction and a low rate of complications,Chronic plantar fasciitis may be mimicked by other foot pathologies.