Ultrasound-Guided Corticosteroid versus Ozone Injection, Both Combined with Percutaneous Fasciotomy, for Plantar Fasciitis: A Randomized Controlled Trial

Abstract

Background

Plantar fasciitis is a common cause of chronic plantar heel pain, and minimally invasive interventions are frequently considered when conservative treatments fail. Although corticosteroid and ozone injections have demonstrated clinical benefits in plantar fasciitis, comparative evidence regarding these therapies when combined with percutaneous fasciotomy remains limited.

Purpose

This randomized controlled trial aimed to compare the short-term effects of ultrasound-guided corticosteroid injection combined with percutaneous fasciotomy versus ozone injection combined with percutaneous fasciotomy on pain severity, foot function, and patient satisfaction in individuals with chronic plantar fasciitis.

Patients and Methods

Forty adults with plantar fasciitis persisting for at least four months despite conservative treatment were randomly allocated to receive either ultrasound-guided methylprednisolone injection (40 mg) plus lidocaine or ozone injection plus lidocaine, with both interventions combined with percutaneous fasciotomy. All participants received standardized stretching and strengthening exercises. Pain intensity (Visual Analogue Scale [VAS]) and foot function (Foot Function Index [FFI]) were assessed at baseline, 4 weeks, and 8 weeks after treatment. Patient satisfaction was evaluated at the eighth-week follow-up.

Results

Both groups demonstrated significant reductions in VAS and FFI scores over time (P<0.001), with no significant between-group difference in VAS change (P=0.637). However, the corticosteroid combination group demonstrated greater improvement in FFI scores, with a significant between-group difference observed at week 8 (P<0.001). Patient satisfaction at week 8 differed significantly between groups (P<0.001), with a higher proportion of participants reporting excellent satisfaction in the corticosteroid group compared with the ozone group (19/20 [95%] vs 6/20 [30%]). In contrast, most participants in the ozone group reported good satisfaction (12/20 [60%]).

Conclusion

Both ultrasound-guided ozone injection combined with percutaneous fasciotomy and corticosteroid injection combined with percutaneous fasciotomy were associated with short-term improvements in pain and function in patients with chronic plantar fasciitis. The corticosteroid combination approach demonstrated greater improvement in foot function and higher patient satisfaction; however, these findings should be interpreted cautiously considering the limited sample size and short follow-up duration.

Graphical Abstract

Introduction

Plantar fasciitis (PF), also referred to as plantar fasciopathy in chronic cases, is one of the most common causes of plantar heel pain and represents a major source of functional limitation in adults. The condition is characterized by pain originating from the medial calcaneal insertion of the plantar fascia, often presenting as first-step pain after periods of rest and worsening with prolonged weight-bearing activities.¹ Although traditionally considered an inflammatory disorder, current evidence suggests that chronic PF is primarily a degenerative process involving repetitive mechanical stress, microtrauma, collagen disorganization, and impaired tissue remodeling rather than persistent inflammation alone.^1,2 The prevalence of PF is estimated to be substantial in the general population, with increased risk reported among individuals with higher body mass index, prolonged standing occupations, reduced ankle dorsiflexion, altered lower-limb biomechanics, and repetitive loading of the plantar structures.^3,4

Diagnosis of PF is mainly clinical and relies on characteristic symptoms and physical examination findings, including localized tenderness at the medial calcaneal tubercle and pain exacerbated by loading of the plantar fascia. Imaging modalities such as ultrasonography and magnetic resonance imaging may be useful in selected patients to confirm structural changes, evaluate plantar fascia thickness, and exclude alternative causes of heel pain.⁵ Initial treatment typically involves conservative strategies, including activity modification, stretching and strengthening exercises, orthotic interventions, physical therapy, and analgesic medications. Although many patients improve with non-invasive management, a considerable proportion experience persistent symptoms despite appropriate conservative treatment and may require minimally invasive interventions.^6,7

Among interventional approaches, local corticosteroid injection remains one of the most frequently used treatments for chronic PF because of its ability to provide relatively rapid symptom relief. Randomized studies and meta-analyses have demonstrated short-term improvements in pain and function following corticosteroid injection; however, its long-term effectiveness remains uncertain.^8,9 Furthermore, repeated corticosteroid administration may be associated with potential complications, including plantar fascia weakening, fat pad atrophy, and plantar fascia rupture.¹⁰ These limitations have encouraged investigation of alternative biological therapies that may provide comparable clinical benefits through different mechanisms.

Ozone therapy using oxygen-ozone (O₂-O₃) mixtures has emerged as a potential minimally invasive treatment option in musculoskeletal disorders. Proposed mechanisms include modulation of oxidative stress, regulation of inflammatory pathways, improvement of local tissue oxygenation, and stimulation of reparative responses.^11,12 In patients with chronic PF, two randomized clinical trials have directly compared ozone injection with corticosteroid injection. Babaei-Ghazani et al reported that both ultrasound-guided ozone and corticosteroid injections improved pain and functional outcomes, although corticosteroid demonstrated a faster early response while ozone showed a slower but potentially more sustained effect.¹³ Similarly, Bahrami et al found that both treatments were effective, without demonstrating clear overall superiority of either approach during follow-up.¹⁴ However, these studies evaluated injection therapies as isolated interventions and did not address the potential contribution of concomitant percutaneous plantar fascia procedures.

Percutaneous plantar fasciotomy has been investigated as a minimally invasive treatment for chronic PF. This technique aims to mechanically disrupt degenerative plantar fascia tissue and stimulate a controlled healing response. Evidence from systematic reviews suggests that plantar fasciotomy may improve pain and functional outcomes in selected patients; however, the optimal combination of fasciotomy with adjunctive injection therapies remains uncertain.^15,16 Importantly, when an injection therapy is combined with percutaneous fasciotomy, observed clinical outcomes may represent the effect of the entire treatment strategy rather than the isolated biological effect of the injected agent.

Despite increasing interest in minimally invasive treatments for chronic PF, evidence comparing ozone injection and corticosteroid injection when both are combined with percutaneous plantar fasciotomy remains limited. Previous randomized trials have primarily investigated ozone and corticosteroid injections independently, leaving uncertainty regarding their comparative effectiveness within a combined procedural approach. Therefore, this randomized controlled trial was designed to compare ultrasound-guided ozone injection and methylprednisolone injection, each combined with percutaneous plantar fasciotomy, regarding pain severity, foot function, and patient satisfaction in individuals with chronic PF. We hypothesized that there would be no significant difference between the two treatment strategies in reducing pain intensity or improving functional outcomes during the 8-week follow-up period.

Materials and Methods

Study Design

This prospective, parallel-group, randomized controlled trial was conducted at the Physical Medicine and Rehabilitation Department of Shahid Madani Hospital, affiliated with Tabriz University of Medical Sciences, between October 2024 and July 2025. The study was designed to compare two combined minimally invasive treatment strategies: ultrasound-guided corticosteroid injection combined with percutaneous plantar fasciotomy and ultrasound-guided ozone injection combined with percutaneous plantar fasciotomy for patients with chronic plantar fasciitis.

The trial protocol was approved by the Regional Ethics Committee of Tabriz University of Medical Sciences (IR.TBZMED.REC.1401.315) and prospectively registered in the Iranian Clinical Trial Registry (IRCT20220614055168N1). The study was conducted according to the principles of the Declaration of Helsinki. Written informed consent was obtained from all participants before enrollment.

Eligible participants were randomly assigned in a 1:1 ratio to receive either corticosteroid injection plus percutaneous fasciotomy or ozone injection plus percutaneous fasciotomy.

Sample Size

The primary outcome used for sample size estimation was the change in pain intensity measured by the Visual Analogue Scale (VAS). Based on previous observations,¹⁷ the expected standard deviation was estimated at 2.80 and 2.89 in the intervention groups, respectively. A minimum clinically important difference of 2 points in VAS was considered clinically meaningful. Assuming a two-sided alpha level of 0.05 and 80% statistical power, the required sample size was calculated as 20 participants per group.

Because the study population was recruited from a specialized clinical setting and the follow-up duration was limited to eight weeks, the investigators anticipated a low risk of loss to follow-up. Therefore, recruitment continued until 40 participants completed the intervention allocation. All randomized participants completed follow-up and were included in the final analysis.

Study Participants

Adults with plantar heel pain referred to the Physical Medicine and Rehabilitation Department of Shahid Madani Hospital were screened for eligibility. Participants were included if they had symptoms consistent with chronic plantar fasciitis persisting for at least four months despite appropriate conservative management.

The minimum symptom duration of four months was selected to identify patients with persistent plantar fasciitis who had failed initial conservative treatment and were appropriate candidates for minimally invasive intervention.

The diagnosis of plantar fasciitis was established clinically according to established clinical practice guidelines, based on characteristic plantar medial heel pain, pain during the first steps after rest, localized tenderness at the medial calcaneal tubercle, and symptom exacerbation during weight-bearing activities.

Inclusion and Exclusion Criteria

Inclusion criteria were: age greater than 18 years; a confirmed diagnosis of plantar fasciitis based on the clinical guidelines of the International Classification of Functioning, Disability, and Health issued by the Orthopedic Section of the American Physical Therapy Association, established by an experienced physiatrist;¹⁸ symptom duration exceeding four month; pain and localized tenderness in the heel or plantar surface; morning pain in the heel or sole; and persistence of symptoms for more than four months despite standard pharmacological treatment. Enrollment was limited to patients who provided written informed consent.

Exclusion criteria included a history of systemic inflammatory diseases such as rheumatoid arthritis, prior direct trauma to the plantar bones with or without fracture, posterior heel pain associated with Achilles bursitis, and active S1 radiculopathy explaining the plantar fascia pain. Participants with structural foot deformities (eg, calcanovarus, calcanovalgus) or any contraindication to ozone injection (such as hypersensitivity to ozone, favism, pregnancy, sickle cell anemia, hyperthyroidism, severe arrhythmia, anticoagulant therapy, hemochromatosis, or treatment with iron or copper) were also excluded from the study.

Randomization and Allocation Concealment

After confirmation of eligibility and obtaining written informed consent, participants were randomly assigned in a 1:1 ratio to either the corticosteroid injection combined with percutaneous fasciotomy group or the ozone injection combined with percutaneous fasciotomy group.

The allocation sequence was generated using a computer-generated randomization procedure in SPSS software. To ensure allocation concealment, the sequentially numbered, opaque, sealed envelopes were prepared by an independent statistician who was not involved in participant recruitment, intervention administration, or outcome assessment. Each envelope contained the assigned treatment allocation and was opened by the treating physician only after participant enrollment and completion of baseline assessment. This procedure ensured that treatment allocation remained concealed until assignment and minimized the risk of selection bias.

Blinding

Due to the nature of the interventions, blinding of the treating physician and participants was not feasible. However, outcome assessment and statistical analysis were performed by independent investigators who were blinded to treatment allocation.

The outcome assessor responsible for recording VAS, FFI, and satisfaction outcomes was not involved in treatment administration and had no access to the randomization assignments. Similarly, the data analyst received coded treatment groups without information regarding the intervention allocation until completion of the statistical analyses.

Intervention Procedures

All procedures were performed by an experienced physical medicine and rehabilitation specialist under ultrasound guidance using a high-frequency linear ultrasound probe (SAMSUNG MEDISON, UK). Participants in both groups underwent the same percutaneous plantar fasciotomy procedure combined with the assigned injection therapy.

For the corticosteroid combination group, participants received an ultrasound-guided injection consisting of 1 mL methylprednisolone (40 mg) mixed with 1 mL lidocaine into the symptomatic region of the plantar fascia at its calcaneal insertion. For the ozone combination group, participants received an ultrasound-guided injection of 3 mL oxygen-ozone mixture combined with 1 mL lidocaine at the same anatomical location. The ozone concentration used in the procedure was 15 µg/mL.

Following localization of the medial calcaneal insertion of the plantar fascia using ultrasound, the probe was positioned longitudinally to visualize the plantar fascia and surrounding structures, followed by transverse imaging to guide the intervention. Ultrasound-guided percutaneous plantar fasciotomy was performed by first identifying the plantar fascia at its calcaneal insertion using a longitudinal ultrasound view. The probe was then rotated 90° to obtain a transverse view, allowing direct visualization of the plantar fascia and needle trajectory during the procedure. A 23-gauge needle was repeatedly advanced and withdrawn through the abnormal plantar fascia tissue under continuous ultrasound guidance to create controlled microtrauma. This technique was intended to stimulate a localized healing response and promote tissue remodeling in chronic plantar fasciitis. Similar ultrasound-guided needle-based plantar fascia release techniques have been described as minimally invasive approaches for chronic plantar fasciitis.¹⁹

After the procedure, all participants received the same standardized post-intervention management, including meloxicam 15 mg daily for up to three days, ice massage for 10 minutes every two hours during the first 2-3 days, and elevation of the affected limb to reduce swelling.

Post-Procedure Rehabilitation Program

All participants received the same standardized home-based rehabilitation program following the intervention to minimize differences in postoperative care between groups. The rehabilitation protocol consisted of plantar fascia-specific stretching, calf muscle stretching, and strengthening exercises targeting the intrinsic foot muscles and plantar flexor muscles.

Participants were instructed to perform plantar fascia and calf stretching exercises daily. Plantar fascia stretching was performed by manually extending the toes and maintaining the stretch position for approximately 10 seconds, repeated 10 times per session. Calf stretching exercises were performed with the knee extended and flexed to target both the gastrocnemius and soleus muscles, with each stretch maintained for approximately 30 seconds and repeated several times during each session.

Strengthening exercises included progressive activation of the intrinsic foot muscles and plantar flexor strengthening through controlled heel-raise exercises. Participants were advised to gradually increase exercise intensity according to symptom tolerance while avoiding activities that aggravated heel pain.

The exercise program was explained by the treating physician after the procedure, and patients received instructions regarding correct exercise techniques and continuation throughout the 8-week follow-up period. Compliance with the rehabilitation program was assessed during follow-up visits through patient self-report.

Outcome Assessment

The primary outcomes were pain intensity and foot function, assessed using the Visual Analogue Scale (VAS) and Foot Function Index (FFI), respectively. Outcomes were evaluated at baseline and at 4 and 8 weeks after the intervention.

Pain intensity was assessed using a 10-cm VAS, where 0 represented no pain and 10 represented the worst imaginable pain. Participants were instructed to indicate their average heel pain intensity during daily activities. Eligibility required a baseline pain score of at least 2 cm.

Foot function was assessed using the Foot Function Index (FFI), a validated questionnaire consisting of 17 items evaluating pain and disability related to foot function. Lower FFI scores indicate better functional status.

Foot function was evaluated using the FFI, a validated 17-item questionnaire comprising five items on pain and 12 items on disability. In the validation study by Moein et al²⁰ the FFI demonstrated high internal consistency (Cronbach’s alpha 0.73-0.94) and an intraclass correlation coefficient (ICC) of 0.79-0.82. Reliability assessed by the test-retest method yielded ICC values between 0.79-0.82.

The secondary outcome was patient satisfaction, evaluated at the eighth-week follow-up using a four-point Likert scale categorized as excellent, good, moderate, or poor.

Safety outcomes were assessed throughout the 8-week follow-up period. Participants were questioned during follow-up visits regarding procedure-related adverse events, including increased pain, injection-site complications, infection, allergic reactions, neurovascular symptoms, or any other unexpected clinical events. Any adverse events reported by participants were recorded and evaluated by the treating physician.

Statistical Analysis

Statistical analyses were performed using SPSS software version 17.0 (SPSS Inc., Chicago, IL, USA). Continuous variables were assessed for normality using the Shapiro-Wilk test, together with evaluation of distribution characteristics including skewness, kurtosis, and graphical methods.

Normally distributed continuous variables were presented as mean ± standard deviation, while categorical variables were summarized as frequency and percentage. Baseline characteristics between the two groups were compared using independent samples t-tests for continuous variables and chi-square tests for categorical variables.

For outcomes measured repeatedly over time (VAS and FFI), repeated-measures analysis of variance (RM-ANOVA) was used to evaluate the effects of time, treatment group, and the time × treatment group interaction. When significant effects were observed, pairwise comparisons were performed to identify differences between groups at specific follow-up time points.

Between-group comparisons of post-intervention outcomes were additionally interpreted considering baseline values. The assumptions of repeated-measures analysis, including sphericity, were assessed before analysis. When assumptions were violated, appropriate corrections were applied.

Categorical satisfaction outcomes were compared between groups using the chi-square test or Fisher’s exact test when appropriate. Adverse events were summarized descriptively.

All statistical tests were two-sided, and P values <0.05 were considered statistically significant.

Results

A total of 40 patients with plantar heel pain were assessed for eligibility between October 2024 and July 2025. All eligible participants were randomized in a 1:1 ratio to the ozone injection combined with percutaneous plantar fasciotomy group (n=20) or the corticosteroid injection combined with percutaneous plantar fasciotomy group (n=20). All randomized participants completed the 8-week follow-up and were included in the final analysis according to the intention-to-treat principle (Figure 1).

Figure 1.

CONSORT 2025 flow-diagram for the randomized clinical trial of the efficacy of ozone and corticosteroid therapy for plantar fasciitis.

Baseline Characteristics

The baseline demographic characteristics of participants are summarized in Table 1. The ozone and corticosteroid combination groups were comparable regarding age, sex distribution, education level, employment status, marital status, and anthropometric characteristics. The mean age was 45.65 ± 6.08 years in the ozone group and 50.65 ± 8.70 years in the corticosteroid group (P=0.101). No statistically significant differences were observed between groups in baseline characteristics, indicating successful randomization and comparability between treatment groups.

Table 1.

Baseline Demographic Characteristics of Participants^a

Variable	Category	Ozone Group (n = 20)	Corticosteroid Group (n = 20)	p-valueb
Age (years)		45.65 ± 6.08	50.65 ± 8.70	0.101
Sex	Male	5 (25%)	2 (10%)	0.206
	Female	15 (75%)	18 (90%)
Education level	Illiterate	1 (5%)	0 (0%)	0.512
	Below diploma	7 (35%)	9 (45%)
	Diploma	9 (45%)	10 (50%)
	University	3 (15%)	1 (5%)
Occupation	Unemployed	11 (55%)	13 (65%)	0.749
	Employee	7 (35%)	6 (30%)
	Retired	2 (10%)	1 (5%)
Marital status	Single	2 (10%)	2 (10%)	0.890
	Married	16 (80%)	15 (75%)
	Divorced/Other	2 (10%)	3 (15%)

Notes: ^aNumeric scales are expressed as mean ± SD or median (IQR), and categorical measures are reported as No. (%). ^bP Value less than 0.05 was considered significant.

Primary Outcomes

Pain Intensity (VAS)

At baseline, mean VAS scores were comparable between groups (ozone group: 8.30 ± 1.45; corticosteroid group: 8.60 ± 1.09; P=0.466).

Repeated-measures ANOVA demonstrated a significant effect of time on VAS scores (P<0.001; F=59.017), indicating significant pain reduction during the 8-week follow-up period in both groups. However, the main effect of treatment group was not statistically significant (P=0.637), and no significant time × group interaction was observed (P=0.183).

Post hoc comparisons showed no significant between-group differences at week 4 (P=0.382) or week 8 (P=0.482). These findings indicate that both combined treatment approaches were associated with improvement in pain intensity, without evidence of superiority of either approach for pain reduction (Table 2 and Figure 2).

Table 2.

Comparison of the Variables in the Two Groups at Different Intervals^a

Variables and Time Points	Ozone Group	Corticosteroid Group	Total	Test Resultb	Pairwise Comparisons	P Valueb
Visual Analogue Scale in the morning
At baseline	8.30 ± 1.45	8.60 ± 1.09	8.45 ± 1.28	F(time) = 59.017, P < 0.001	At baseline	0.466
Week 4	4.15 ± 0.87	3.90 ± 0.91	4.02 ± 0.89		Week 4	0.382
Week 8	2.45 ± 0.82	2.70 ± 1.34	2.57 ± 1.10		Week 8	0.482
Total	4.96 ± 0.67	5.06 ± 0.65
Test result	F(group) = 0.225, P = 0.637			F(group×time) = 1.838, P = 0.183
Foot Function Index
At baseline	92.50 ± 23.02	91.05 ± 19.39	91.77 ± 21.02	F(time) = 24.484, P < 0.001	At baseline	0.831
Week 4	74.90 ± 23.48	60.95 ± 18.24	67.92 ± 21.92		Week 4	0.043
Week 8	52.50 ± 33.23	13.90 ± 7.10	33.20 ± 30.73		Week 8	<0.001
Total	73.40 ± 25.76	55.30 ± 14.34	–
Test result	F(group) = 7.452, P = 0.010			F(group×time) = 7.640, P = 0.009

Notes: ^aAll values are expressed as Mean ± SD. ^bP Value less than 0.05 was considered significant.

Figure 2.

Trend of changes in visual analogue scale throughout the study.

Foot Function (FFI)

Baseline FFI scores were similar between groups (ozone group: 92.50 ± 23.02; corticosteroid group: 91.05 ± 19.39; P=0.831).

Repeated-measures ANOVA demonstrated a significant effect of time (P<0.001; F=24.484), indicating progressive improvement in foot function in both groups. A significant treatment group effect (P=0.010; F=7.452) and time × group interaction (P=0.009; F=7.640) were observed, demonstrating different patterns of functional improvement between groups.

Post hoc comparisons showed no significant difference at baseline but demonstrated greater improvement in the corticosteroid combination group at week 4 (P=0.043) and week 8 (P<0.001) (Table 2 and Figure 3).

Figure 3.

Trend of changes in foot function index throughout the study.

Secondary Outcome

Patient satisfaction at the eighth-week follow-up differed significantly between groups (P<0.001). Excellent satisfaction was reported by 19/20 participants (95%) in the corticosteroid combination group compared with 6/20 participants (30%) in the ozone combination group. Conversely, good satisfaction was more frequent in the ozone group (12/20, 60%) than in the corticosteroid group (1/20, 5%). Moderate satisfaction was reported by two participants in the ozone group (10%), while no participant in either group reported poor satisfaction (Figure 4).

Figure 4.

Comparing patient satisfaction with interventions.

Adverse Events

No major adverse events occurred during the 8-week follow-up period. No procedure-related adverse events were reported during the 8-week follow-up period. No cases of infection, allergic reaction, neurovascular injury, or other procedure-related complications were observed.

Discussion

In this randomized controlled trial, we compared two combined minimally invasive treatment approaches for chronic plantar fasciitis: ultrasound-guided corticosteroid injection combined with percutaneous plantar fasciotomy and ultrasound-guided ozone injection combined with percutaneous plantar fasciotomy. Both groups demonstrated significant reductions in pain intensity and improvements in foot function during the 8-week follow-up period. Although pain reduction was comparable between groups, the corticosteroid combination group demonstrated greater improvement in FFI scores and higher patient satisfaction at the final follow-up.

Because percutaneous plantar fasciotomy was performed in both groups, the observed improvements should be interpreted as the effects of the complete treatment strategies rather than the isolated effects of corticosteroid or ozone injection alone. The current study therefore provides comparative evidence regarding two combined approaches rather than determining the independent efficacy of either injection modality.

The demographic characteristics of participants were comparable to previous randomized studies evaluating injection therapies for plantar fasciitis. Similar to previous reports, the majority of participants in our cohort were women, supporting the previously described higher prevalence of plantar fasciitis among female populations. For example, Babaei-Ghazani et al, in a similar comparative study of ozone and corticosteroid injections, reported that 83.9% of participants were female, with a mean age of 57.9 ± 9.2 years.¹³ Similarly, Bahrami et al observed a predominantly female cohort (65.9%) with a mean age of 47.9 years in their study comparing the same interventions.¹⁴

Both treatment groups experienced significant reductions in VAS scores at weeks 4 and 8, without significant differences between groups. These findings suggest that both combined interventions may provide short-term pain relief in patients with chronic plantar fasciitis. Previous randomized trials comparing ozone and corticosteroid injections alone have reported similar improvements in pain outcomes, although differences have been observed depending on follow-up duration, corticosteroid type, and outcome measurement methods. The absence of a significant between-group difference in pain reduction in the present study may partly reflect the shared contribution of percutaneous plantar fasciotomy and standardized rehabilitation provided to both groups.

Our finding aligns with the results of Bahrami et al, who also reported significant pain reduction in both ozone and corticosteroid groups without a between-group difference.¹⁴ In contrast, Babaei-Ghazani et al and Raeissadat et al found that, at three months of follow-up, corticosteroid therapy resulted in a significantly greater decrease in VAS scores compared with ozone therapy.^13,21 The discrepancy between these results and the present findings may be attributable to differences in follow-up duration and sample size. Furthermore, Elsawy et al, in a comparative study of ozone therapy, platelet-rich plasma (PRP), and corticosteroid injection, reported that both ozone and corticosteroid groups achieved greater VAS reductions than the PRP group, a pattern consistent with the pain reduction observed in our study at follow-up.²²

In contrast to pain outcomes, foot function demonstrated a significant difference between groups, with greater improvement observed in the corticosteroid combination group. Similar findings were reported by Bahrami et al¹⁴ who observed better functional outcomes following methylprednisolone compared with ozone injection in plantar fasciitis. The functional advantage observed in our study may reflect differences in the early biological effects of corticosteroid and ozone therapies; however, because both groups underwent percutaneous fasciotomy, the observed functional differences represent the combined effect of the complete treatment protocols.

Bahrami et al assessed post-intervention outcomes using VAS, pressure-pain threshold (PPT), and the Foot and Ankle Ability Measure (FAAM) and reported that functional performance at follow-up was significantly better in the methylprednisolone group compared with the ozone therapy group, consistent with the present study’s FFI findings.¹⁴ Similarly, a meta-analysis by Li et al, which reviewed four randomized controlled trials, concluded that corticosteroid injections significantly reduced pain compared with placebo in plantar fasciitis; however, this benefit was short-lived, persisting for only one month, with no significant differences in pain intensity or plantar fascia thickness observed at two- and three-month follow-ups.⁸

The short-term improvements observed in both groups suggest potential clinical utility in patients requiring symptom reduction after failure of conservative management; however, functional recovery beyond the measured outcomes requires further investigation. In selected cases, ozone therapy may serve as a viable alternative, offering pain relief without the associated risk of corticosteroid-related complications.¹³

Evidence on the efficacy of ozone injection for chronic inflammatory conditions, including plantar fasciitis, remains limited, with most available studies focusing on each treatment modality individually rather than in direct comparison.^13,14 McMillan et al evaluated the effect of a 1 mL corticosteroid injection (dexamethasone 4 mg/mL) versus a 1 mL normal saline placebo in patients with plantar fasciitis, using the Foot Health Status Questionnaire to assess pain severity at weeks 4, 8, and 12. Consistent with the present findings, their study confirmed the short-term (4-week) efficacy of corticosteroids in reducing pain; however, no statistically significant difference between groups was observed at the 12-week follow-up.⁹ Notably, differences in pain assessment tools, corticosteroid type, and follow-up duration between that trial and the current study should be considered when comparing results.

Karimzadeh et al compared autologous peripheral blood injection with corticosteroid therapy and reported findings consistent with the present study.²³ Both groups demonstrated significant improvements in mean pain intensity (VAS) and functional status (PPT) at one- and three-month follow-ups, with no statistically significant differences between groups. Similarly, Mahindra et al comparedPRP with corticosteroids and placebo in patients with plantar fasciitis and found that PRP was comparable, and in some cases superior, to corticosteroids in improving pain and function. In line with the current results, their study showed a significant reduction in VAS scores in both corticosteroid and PRP groups at three-week and three-month follow-ups.²⁴

As previously noted, few studies have investigated ozone therapy specifically for plantar fasciitis, whereas its application has been more extensively studied in other musculoskeletal conditions. Raeissadat et al²⁵ demonstrated the effectiveness of ozone injection in reducing pain and local/systemic inflammation in osteoarthritis. Similarly, Borrelli et al reported that ozone therapy yielded meaningful improvements in chronic oxidative stress among patients with spinal disc herniation and knee arthritis.²⁶ Additional studies have documented beneficial effects of ozone injections in carpal tunnel syndrome and recurrent headaches, supporting its broader therapeutic potential.^27,28

Patient satisfaction was significantly higher in the corticosteroid combination group, with a greater proportion of participants reporting excellent satisfaction compared with the ozone combination group. This finding was consistent with the superior improvement in FFI observed in the corticosteroid group. Nevertheless, satisfaction is a multidimensional patient-reported outcome influenced by symptom improvement, functional recovery, and individual expectations, and should not be interpreted as a direct measure of treatment safety or tolerability.

The findings of this trial contribute to the limited evidence regarding combined injection and percutaneous fasciotomy strategies for chronic plantar fasciitis. Previous studies have primarily evaluated ozone or corticosteroid injections as isolated interventions, whereas the current trial evaluated their application within a minimally invasive procedural framework. The results suggest that both approaches may be effective short-term options after failure of conservative therapy, while corticosteroid combined with percutaneous fasciotomy may provide greater functional improvement during early follow-up.

Strengths and Limitations

This study has several strengths, including its randomized controlled design, ultrasound-guided administration of both interventions, standardized rehabilitation protocol, and blinded outcome assessment and data analysis. Furthermore, the study directly compared two clinically relevant combined treatment strategies in patients with chronic plantar fasciitis who had failed conservative management, addressing a gap in previous studies that primarily evaluated injection therapies separately. Nevertheless, several limitations should be considered. First, the relatively small sample size may have limited statistical power and reduced the generalizability of the findings. Second, because both groups received percutaneous plantar fasciotomy, lidocaine injection, and the same rehabilitation program, the independent contribution of corticosteroid or ozone injection cannot be determined. Third, the absence of a placebo or fasciotomy-only control group prevents evaluation of the isolated effects of each treatment component. Finally, the short 8-week follow-up period limits conclusions regarding long-term efficacy, recurrence, and potential delayed adverse effects.

Conclusion

Both ultrasound-guided ozone injection combined with percutaneous plantar fasciotomy and ultrasound-guided corticosteroid injection combined with percutaneous plantar fasciotomy were associated with significant short-term improvements in pain intensity and foot function among patients with chronic plantar fasciitis refractory to conservative treatment. Although the corticosteroid combination group demonstrated greater improvement in foot function and higher patient satisfaction at 8 weeks, these findings should be interpreted cautiously given the relatively small sample size and short follow-up period. Larger randomized controlled trials with longer follow-up are required to determine the comparative effectiveness, durability of response, and long-term safety of these combined treatment approaches.

Funding Statement

This study was financially supported by Physical Medicine and Rehabilitation Research Center, Tabriz University of Medical Sciences (Grant No. 67838). The funding body had no role in the design of the study, data collection, data analysis, interpretation of results, or manuscript preparation.

Data Sharing Statement

The data that support the findings of this study are available on reasonable request from the corresponding author, S.P. The data are not publicly available due to privacy and confidentiality restrictions related to the research participants.

Ethical Considerations

The trial protocol was approved by the Regional Ethics Committee of Tabriz University of Medical Sciences (IR.TBZMED.REC.1401.315) and prospectively registered in the Iranian Clinical Trial Registry (IRCT20220614055168N1; Link: https://en.irct.ir/trial/64942). The study was conducted in accordance with the principles of the Declaration of Helsinki. All participants received verbal and written information about the study objectives, procedures, potential benefits, and possible risks. Written informed consent was obtained prior to enrollment. No personally identifiable data were collected, confidentiality was ensured throughout, and participants incurred no costs.

Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no competing interests.