Article Foot & Ankle Orthopaedics 2021, Vol. 6(3) 1-7 Clinical And Plantar Fascial Morphologic ª The Author(s) 2021 DOI: 10.1177/24730114211027323 Changes After Proximal Medial journals.sagepub.com/home/fao Gastrocnemius Release Treatment of Recalcitrant Plantar Fasciitis Alberto Ginés-Cespedosa, MD, PhD1, Ignacio Wormull Ugarte, MD2, Jesus Ares-Vidal, MD3, Alberto Solano-Lopez, MD3, Daniel Bianco Adames, MD4, and Carlo Gamba, MD5 Abstract Background: Magnetic resonance imaging (MRI) has been used as a diagnostic and prognostic instrument to evaluate the results of conservative treatment for plantar fasciitis. However, there are scarce data available relative to changes in the plantar fascia after operative treatment. The primary objective of this study is to evaluate the imaging changes in patients with recalcitrant plantar fasciitis treated operatively by means of proximal medial gastrocnemius release. Methods: Thirteen patients with recalcitrant plantar fasciitis were studied with MRI preoperatively and 1 year after operative treatment. Quantitative (plantar fascia thickness) and qualitative variables (hyperintensity in the plantar fascia, insertional calcaneus bone edema, a plantar fascia tear, and the presence of perifascial collections) were assessed by 2 musculoskeletal radiologists. Clinical results were also measured with American Orthopaedic Ankle & Society (AOFAS), visual analog scale (VAS) pain, and 36-Item Short Form Health Survey (SF-36) scales. Results: The mean plantar fascia thickness was 6.59 mm preoperatively and 6.37 mm postoperatively (P ¼ .972). No sta- tistically significant differences were found in any of the qualitative variables on comparing the pre- and postoperative periods. Patients reported clinical improvements in pain VAS, AOFAS measurement, and the physical subdomains of the SF-36 scale. Conclusion: Quantitative and qualitative variables assessed for the plantar fascia on MRI did not show any significant change after medial gastrocnemius release despite clear clinical improvement. Level of Evidence: Level II, perspective cohort study. Keywords: plantar fasciitis, MRI, proximal medial gastrocnemius release Introduction Plantar fasciitis represents the most frequent cause of talal- 1 Orthopaedics Department, Hospital del Mar, UAB–Universitat Autonoma gia in adults. It affects approximately 2 million people annu- Barcelona, Barcelona, Spain ally in the United States.25 Furthermore, it is estimated that 2 Linares Hospital, Linares, Chile 3 10% of patients will present with it at some time in their life. Department of Radiology and Radiodiagnostic, Hospital del Mar, It is a self-limiting condition that improves with conserva- Barcelona, Spain 4 Orthopaedic Department, Hospital del Mar, Universitat Autonoma tive treatment in 90% of the cases.5 The diagnosis is clinical Barcelona (UAB), Barcelona, Spain but it can be associated with imaging studies such as mag- 5 Orthopaedic Department, Hospital de la Santa Creu I Sant Pau, netic resonance imaging (MRI) and ultrasonography to rule Universitat Autonoma Barcelona, Barcelona, Spain out other pathologies.23 The thickness of the plantar fascia can be measured with those ancillary tests, with 4 mm being Corresponding Author: Alberto Ginés-Cespedosa, MD, PhD, Orthopaedic Department, Hospital considered pathologic.14 del Mar, UAB – Universitat Autonoma Barcelona, passeig maritim 25, Some 10% of patients will not improve with conservative Barcelona 08003, Spain. treatment and will enter the chronic stage of the disease, Email: AGines@parcdesalutmar.cat Creative Commons Non Commercial CC BY-NC: This article is distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 License (https://creativecommons.org/licenses/by-nc/4.0/) which permits non-commercial use, reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and Open Access pages (https://us.sagepub.com/en-us/nam/ open-access-at-sage). 2 Foot & Ankle Orthopaedics which is denominated recalcitrant plantar fasciitis (RPF).6 It After conservative treatment failed, patients were evalu- is only then, when nonoperative measures are exhausted, ated with preoperative MRI and ultrasonography to rule out that operative treatment should be considered.1 other masked conditions and to describe pathologic changes Currently, one of the most accepted operative treatments within and around the fascia. Subsequently, they were pro- for RPF is the release of the proximal medial gastrocnemius grammed surgical treatment with proximal release of the owing to its low rate of complications and good functional medial gastrocnemius. The surgery was performed by a results.11,23 single orthopedic surgeon. Surgical technique and clinical MRI findings like plantar fascia thickness or other quali- outcomes have been thoroughly described in a previous pub- tative variables (bone marrow edema, a high-signal intensity lished work.11 The results in terms of pain, satisfaction, area in the fascia or tear of the fascia) have been used to function, and self-reported health perception have been assess the effectiveness of plantar fasciitis treatment. MRI recorded using the visual analog scale for pain, Likert satis- findings have been assessed before and after conservative faction, and American Orthopaedic Foot & Ankle Society treatment and have been proposed as an indicator of a good hindfoot scales and the 36-Item Short Form Health Survey response in terms of pain and function.9,17,18,21 (SF-36) questionnaire, respectively. All patients were eval- Little has been published on surgical treatment and MRI uated with a new MRI at 1 year postoperatively to compare findings of RPF.31,32 To our knowledge, there is no previous the imaging changes to the preoperative MRI. study that evaluates and compares pre- and postoperative The exclusion criteria were any previous foot and ankle MRI findings after proximal medial gastrocnemius release pathology (fracture, infections, deformity, and surgery), in patients with this condition. patients with rheumatoid arthritis, the presence of neuro- The objective of this study is to evaluate, preoperatively pathic heel pain, or the need for chronic analgesics due to and 1 year postoperatively, MRI quantitative and qualitative another condition. variables in patients operated on for RPF using proximal The research was approved by the local ethics committee. medial gastrocnemius release. Our initial hypothesis was The nature of the study was explained to the patients and that there would be a decrease in the thickness of the plantar they gave their consent to participate in it. fascia and modifications in the qualitative variables after surgical treatment, especially in the hyperintensity variable Evaluation With MR Images in plantar fascia. As a secondary objective, an interobserver correlation The MRI (both preoperative and postoperative) findings were study was carried out to assess the effectiveness of an MRI evaluated by 2 musculoskeletal radiologists from the same variable findings assessment. institution preoperatively at 1 year after surgery. The quanti- tative variable considered was fascia thickness. Four qualita- tive variables were evaluated. They were a signal change in plantar fascia (hyperintensity), bone marrow edema, a plantar Materials and Methods fascia tear, and perifascial soft tissues collections. The MRI Patients and Treatment examinations were performed on a 3-tesla (T) imaging system (Achieva; Philips Medical Systems, Oakwood, GA) using a This study is a part of a randomized controlled trial of sur- phased-array knee coil. The ankle was examined in the supine gical treatment in RPF.11 Fifteen patients were included in position without support for the ankle. The 3-T MRI protocol the proximal medial gastrocnemius release group. Two comprised a sagittal T1 (response time [TR] / echo time [TE] patients did not show up for the scheduled postoperative ¼ 500 ms / 20 ms) and short-TI inversion recovery (STIR; TR/ MRI, leaving 13 patients between 30 and 68 years old TE ¼ 3543 ms / 60 ms; inversion time [TI] 230 ms) or T2 with enrolled in the study. They underwent surgery for RPF by fat-suppression (FS) sequence (2578 ms / 80 ms) and a coronal means of proximal medial gastrocnemius release in a single T1 (TR/TE ¼ 500 ms / 20 ms) or proton density (PD) fat- institution between 2012 and 2016. suppressed sequence (TR/TE ¼ 5729 ms / 30 ms). The inclusion criteria were patients older than 18 years The thickness of the plantar fascia was assessed in sagittal with a clinical diagnosis of RPF treated for at least 9 months T1-weighted images. The radiologists used a ruler within the with conservative treatment who had not responded. The software to measure the thickness of the fascia and measure- diagnosis was clinical and consisted of mechanical heel ments were performed 1 cm from the insertion site of the pain, especially in the first steps of the day or after a pro- fascia into the calcaneus on an axis perpendicular to it. This longed period of rest and acute pain on palpation on the is the area where the greatest thickness of the plantar fascia medial side of the proximal insertion of the plantar fascia. has been found.10 An example is shown in Figure 1. Conservative treatment included anti-inflammatory drugs, The qualitative variables were assessed in STIR sagittal physical therapy consisting of calf muscle and fascia elonga- and T2-weighted FS sagittal sequences as shown in Figure 2. tion exercises (checked for good compliance), the use of The assessment criteria were (1) hyperintensity: increasing inserts (mainly padded inserts in the heel), and infiltrative signal change within the plantar fascia (comparing it to the therapy (1 mL of local anesthetic with triamcinolone).7 hypointensity of the normal plantar fascia); (2) bone edema: Ginés-Cespedosa et al 3 Figure 1. (A) Pre- and (B) postoperative sagittal T1-weighted MRI: no changes are observed in the thickness of the plantar fascia. Figure 2. (A) Preoperative sagittal STIR MRI image shows hyperintensity in the plantar fascia (single arrow) as well as perifascial collections. (B) No changes (double arrow) are observed after surgery. MRI, magnetic resonance imaging; STIR, short-TI (inversion time) inversion recovery. rising signal in calcaneus bone marrow in the area of plantar the most accurate and representative to evaluate each vari- fascia attachment; (3) plantar fascia tear marked hyperinten- able in each patient. This second measurement (consensus) sity (fluid signal) with partial or complete disruption of the was used to make the statistical pre- and postoperative com- fascia; (4) presence of perifascial collections (fluid signal in parison of all the variables studied. soft tissues surrounding plantar fascia). Both radiologists carried out a blinded reading of the MRI variables. They did not know whether the images were pre- Statistical Analysis or postoperative. Moreover, all the MRI images for each A descriptive statistical analysis of data was performed. The participant were scored randomly, mixing pre- and post- interobserver correlation study was done using a correlation operative images. coefficient index for quantitative variables, and a Kappa For the interobserver correlation study, 2 different assess- index was used to assess the qualitative variables. ments were done. The first was done without a consensus for A Wilcoxon signed-rank test was used to compare pre- any specific image of the sequence seen. Each radiologist and postoperative fascia thickness. The McNemar test was assessed all the images in the same sequence to score the used for repeated comparisons of qualitative variables. Data variable. were analyzed using IBM-SPSS 26.0 (IBM Corp, Armonk, In the second one, a consensus between both radiologists NY). A P value <.05 was considered to indicate statistical was reached to determine which image of the sequence was significance. 4 Foot & Ankle Orthopaedics Table 1. Interobserver Correlation (No Consensus). Quantitative findings Observer 1 Observer 2 CCI P Fascia thickness, mm, mean (SD) Preoperative 6.00 (1.9) 6.40 (2.1) 0.33 .124 Postoperative 5.91 (1.8) 6.24 (2.0) –0.13 .671 Qualitative findingsa Observer 1 Observer 2 Kappa P Hyperintensity Preoperative 9 6 –.34 .164 Postoperative 11 6 –.02 .906 Bone edema Preoperative 10 6 .40 .067 Postoperative 11 4 –.09 .522 Tear Preoperative 4 3 –.35 .188 Postoperative 1 1 –.08 .764 Collection Preoperative 12 2 .03 .657 Postoperative 12 2 –.16 .015 Abbreviations: CCI, correlation coefficient index; postop, postoperatively; preop, preoperatively. a Qualitative findings are expressed in number of feet. Table 2. Interobserver Correlation (Consensus). from the images evaluated in consensus by the 2 radiologists were used. The average thickness of the plantar fascia before Quantitative findings Observer 1 Observer 2 CCI P surgery was 6.58 mm for observer 1 and 6.6 mm for observer Fascia 2. One year after surgery, the average was 6.41 mm for thickness, mm observer 1 and 6.34 mm for observer 2. No statistically Preoperative 6.58 6.60 .993 <.001 significant differences were found in plantar fascia thickness Postoperative 6.41 6.34 .995 <.001 (P ¼ .97), as seen in Table 3. Regarding qualitative vari- ables, no statistically significant differences for any of the Qualitative Observer 1 Observer 2 Kappa P findings a variables were found after 1 year of the surgical treatment. Those data are summarized in Table 4. Hyperintensity Preoperative 9 9 1 .001 Postoperative 11 11 1 <.001 Clinical Outcomes Bone edema Although it is not the aim of this study, it is important to Preoperative 5 5 1 .001 highlight that the majority of the patients that took part in a Postoperative 5 5 1 <.001 Tear previously published study11 showed improved clinical Preoperative 3 3 1 <.001 results at 1 year of surgery in terms of pain, quality of life, Postoperative 1 1 1 <.001 and function with a satisfaction rate above 85%. The results Collection are summarized in Tables 5 and 6. Preoperative 11 9 .05 .021 Postoperative 11 6 .27 .155 Abbreviation: CCI, correlation coefficient index. Discussion a Qualitative findings are expressed in numbers of feet. The main finding of the study was that there was no imaging variation in all variables studied between the preoperative Results and postoperative periods. With regard to plantar fascia thickness, a minimum non- The interobserver correlation of the variables analyzed when significant difference was found after the release of the prox- there was no consensus on the specific image observed imal medial gastrocnemius (Figure 1). This is in contrast to turned out to be nonsignificant, which are specified in what is described in numerous studies in the literature about Table 1. The interobserver correlation improved when there the relationship between treatment response and plantar fas- was a consensus, being higher and significant for the major- cia thickness changes in plantar fasciitis. It is well known ity of the variables. They are summarized in Table 2. For the that patients who have plantar fasciitis suffer an increase in pre- to postoperative comparison analysis, the data obtained plantar fascia thickness.2,4,10,20 A decrease in plantar fascia Ginés-Cespedosa et al 5 Table 3. Preoperative vs Postoperative Comparison of Plantar Fascia Thicknessa Plantar Fascia Thickness, mm Preoperative, Mean (SD) Postoperative, Mean (SD) Mean Difference P Observer 1 6.58 (2.2) 6.41 (1.7) .17 .972 Observer 2 6.60 (2.1) 6.34 (1.7) .26 .972 Average 6.59 (2.1) 6.37 (1.7) .22 .972 a Data were obtained from radiologic consensus. Table 4. Preoperative vs Postoperative Comparison of Qualitative Table 6. SF-36 at 1-Year Follow-up. Variables.a SF-36 Preoperative 12 mo P Qualitative Variable Preoperative Postoperative P Physical functioning 35.2 + 9.2 43.8 + 12.7 <.001 Hyperintensity Physical role functioning 40.5 + 10.3 45.6 + 8.1 . 01 Observer 1 9 11 .371 Bodily pain 31.8 + 7.6 41.3 + 12.9 .01 Observer 2 9 11 .522 General health perceptions 45.2 + 7.6 48.6 + 9 .21 Bone edema Vitality 46.4 + 8.4 51.3 + 12 .14 Observer 1 5 5 .276 Social role functioning 41.2 +9.3 44.6 + 10.2 .3 Observer 2 5 5 .207 Emotional role functioning 39.6 +13.2 47.4 + 11.6 .14 Tear Mental health 37.8 + 13.8 46.9 + 13.1 .16 Observer 1 3 1 .569 Observer 2 3 1 .569 Abbreviation: SF-36, 36-Item Short Form Health Survey. Collections Observer 1 11 11 .140 and fibrosis that brings on degeneration of the fascia (fascio- Observer 2 9 6 .308 sis) rather than chronic inflammation.10,16,22 These kinds of a Data were obtained from the radiologic consensus. Values are expressed changes can be considered irreversible. In these cases, the in numbers of feet. plantar fascia thickness measured by MRI is not supposed to be modified by the treatment.19 These chronic histological degenerative changes are thought to be the main explanation Table 5. Clinical Results at 1-Year Follow-up. for the MRI findings in plantar fascia thickness reported in this article. The mean time from the onset of the symptoms to AOFAS VAS (0-100) surgery was 29 months. During the symptomatic period, they Preoperatively 65.25 + 10.4 68.1 + 18.8 received conservative treatment. Therefore, the minimum 1 mo 87.1 + 8.1 36.3 + 21.3 follow-up period was at least 9 months for all patients, during 3 mo 87.44 + 9.3 44.9 + 31.7 which there was comprehensive monitoring and checking for 6 mo 89.9 + 9.3 25.4 + 19.1 compliance prior to including them in the investigation. It 12 mo 89 + 9.9 15.1 + 18.3 means that all of them were diagnosed with RPF. Moreover, Abbreviations: AOFAS, American Orthopaedic Foot & Ankle Society; VAS, this finding is consistent with the results observed by Gamba visual analog scale. et al10 where no correlations were found between plantar fascia thickness and the clinical status of patients with RPF thickness measured by means of MRI after conservative treat- in terms of pain, function, and perceived quality of life. ment has been reported in acute cases3 as well as in cases with Relative to the qualitative variables, no significant differ- a chronic symptoms onset.12,30 This decrease has been corre- ences in these measurements (hyperintensity of the plantar lated with a good treatment response in those cases. This is fascia, insertional bone edema, fascia tear, and perifascial probably due to the fact that all of these studies enrolled collections) were seen at 1 year of surgery (Figure 2). Once patients who did not have a longstanding evolution time from more, these findings are also contrary to what is reported in the onset of the symptoms. It is thought that inflammatory previous studies of conservative treatment in acute cases or changes are present in plantar fascia at the moment of treat- even chronic evolution from the onset of plantar fasciitis ment, early in the clinical course while still modifiable. symptoms.3,19 Those authors reported changes in the quali- Therefore, they can be resolved with the effect of the conser- tative variables after conservative treatment. The majority of vative treatment applied, and this fact is reflected in a reduc- them used shock wave therapy. It is especially the case for tion of plantar fascia thickness. On the other hand, patients hyperintensity of the fascia and bone edema. These MRI who have chronic symptoms of plantar fasciitis and do not findings have been associated with acute inflammation, and respond to conservative treatment finally develop RPF. the hyperintensity and edema tend to be reduced or mini- Herein, the reparative process produces neovascularization mized. In contrast, Ulusoy et al30 found no important 6 Foot & Ankle Orthopaedics differences in those 2 variables on comparing them before a consensus among radiologists. A strict protocol drastically conservative treatment and 1 month after it.30 The main changed the reproducibility of the variable assessments. This reason those results are consistent with ours may lie in the has been previously demonstrated to happen with ultrasono- fact that they included patients with more than 6 months graphic evaluations of the plantar fascia. When a strictly of symptoms. Moreover, they were already unresponsive at agreed protocol is introduced to obtain the measurement of 6 weeks of the first-step conservative treatment. It is not variables, reproducibility improves.4,27 The results from this enough time to visualize changes in the MRI because of the study bring to light the subjectiveness around these variables short follow-up. The sample in our study includes patients and the great importance of reaching a consensus among who had symptoms for some years and were unresponsive observers. after more than 9 months of distinct conservative treatments. This study had some limitations. First, it is a small sample. Therefore, it seems that RPF shows unmodifiable MRI This corresponds to a sample of patients from a line of inves- qualitative findings after treatment. The greater the evolu- tigation used to research other aspects of the PF. Addition- tion from the onset of symptoms, the more unmodifiable the ally, the few previous studies of this topic had a similar MRI qualitative variables. sample size. Second, these variables have a measurement The most widely accepted surgical treatment for PF has error for which a correlation study between 2 musculoskele- long been the partial plantar fasciotomy.26,29 However, foot tal specialized observers tried to minimize. These observa- and ankle surgeons moved to “gastrocnemius recession” tech- tions improved their correlations when a consensus had been niques because of some characteristic biomechanical compli- established (in terms of the specific image of the sequence cations,12,13 the unsatisfactory results with some patient that should be examined). However, it is our opinion that series 14 and their better understanding of biomecha- these items (especially the qualitative variables) are subjec- nics.6,8,13,15,23,28 In particular, the proximal medial gastrocne- tive variables. As a result, they are quite difficult to assess. mius release procedure has gained favor in recent years and Presumably, an intraobserver correlation may increase the come to be one of the most common surgical option for most accuracy of this measurement. Finally, no correlations with surgeons. This technique manages to decrease the excess ten- clinical and functional results are mentioned. It was not sile stress on the Achilles-calcaneal-plantar complex enough considered worthwhile as no pre-post changes were observed to prevent the potential biomechanical complications of the in the MRI findings. Additionally, the vast majority of partial fasciotomy. Moreover, good clinical and functional patients had a significant improvement in terms of pain, results have been supported by new findings.11,23,24 function, and quality of life. Notably, some 86% were satis- Regarding surgical treatment and MRI findings, studies fied with the result of the surgery.11 by Yu et al31,32 have described the pre- vs post-MRI changes in partial plantar fasciotomy. Those authors studied asymp- Conclusion tomatic individuals who had had a partial fasciotomy after 24 months (range 11-46). They found a minimum reduction As best we can tell from this limited series using the meth- of the fascia at the site of enthesis (only a 14% reduction), odologies we had to assess outcomes, plantar fascia but the fascial thickness at the fasciotomy site nearly morphology did not significantly change after medial gas- doubled. On the other hand, an absence of edema in the trocnemius release in patients with RPF, despite the clear fascia and perifascial tissues as well as an absence of bone symptomatic improvement. Further study is clearly war- marrow edema were the main key postoperative observa- ranted to better elucidate the cause of clinical improvement tions. It contrasted with our observation after surgical treat- after surgical release of the medial head of the gastrocne- ment relative to the qualitative variables. Some drawbacks in mius to treat RPF. the methodology of this article may explain these results. Ethical Approval First, only 5 patients had preoperative MRI images to facil- itate comparing the pre- and postoperative periods. Second, The research was approved by the local ethics committee. The nature of the study was explained to the patients and they gave the postsurgical changes made by means of this local surgery their consent to participate in it. of the plantar fascia may be an impediment to an accurate assessment of the subjective qualitative variables. Other- Declaration of Conflicting Interests wise, medial gastrocnemius release produces a biomechani- The author(s) declared no potential conflicts of interest with respect cal effect at a distance. It makes it possible for the observers to the research, authorship, and/or publication of this article. to do a better local MRI assessment. This at-a-distance bio- ICMJE forms for all authors are available online. mechanical effect probably explains why these qualitative variables had not changed at 1 year of surgical treatment. As Funding far as we know, the present study is the first to evaluate MRI The author(s) received no financial support for the research, changes after proximal medial gastrocnemius release in authorship, and/or publication of this article. patients with RPF. It is important to highlight that these results are based on ORCID iD measurements obtained after a rigorous process of coming to Carlo Gamba, MD, https://orcid.org/0000-0001-5150-1487 Ginés-Cespedosa et al 7 References 17. Liang H, Wang T, Chen W. Thinner plantar fascia predicts 1. Abbassian A, Kohls-gatzoulis J, Solan MC. Proximal medial decreased pain after extracorporeal shock wave therapy. Clin gastrocnemius release in the treatment of recalcitrant plantar Orthop Relat Res. 2007;460:219-225. fasciitis. Foot Ankle Int. 2012;33(1):14-19. 18. Mahowald S, Legge BS, Grady JF. The correlation between 2. Berkowitz F.Plantar fasciitis: MR imaging. Radiology. 1991; plantar fascia thickness and symptoms of plantar fasciitis. 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