European Journal of Cardiovascular Medicine

Lateral epicondylitis (LE), commonly referred to as “tennis elbow,” is a degenerative overuse tendinopathy primarily involving the extensor carpi radialis brevis origin. It is characterized by pain and progressive impairment of grip strength, forearm rotation, and the execution of routine tasks such as lifting, grasping, and twisting motions. The resulting functional disability often interferes with occupational duties and quality of life, particularly in individuals engaged in repetitive upper limb activities.^1-3

Traditional treatments for LE, including NSAIDs, physiotherapy, and corticosteroid injections, offer varying degrees of symptom control. Among these, corticosteroid injections have historically been preferred for their rapid analgesic effect. However, emerging evidence suggests that their benefit is often short-lived and may not translate into long-term functional restoration.^4-6 As the understanding of LE pathophysiology shifts from inflammation to degeneration, attention has turned toward regenerative treatment modalities—notably, prolotherapy with hypertonic dextrose.

Dextrose prolotherapy is a minimally invasive intervention that promotes localized healing through osmotic irritation and stimulation of a mild inflammatory response. This triggers tissue repair mechanisms involving fibroblast proliferation and collagen synthesis, potentially reversing tendinosis at the structural level.^7-9 Clinical studies have shown promising results in pain reduction, but the impact of dextrose on functional disability—arguably the most clinically relevant outcome—remains underexplored.

The Patient-Rated Tennis Elbow Evaluation (PRTEE) questionnaire provides a validated and sensitive tool to assess functional limitations in LE. Its Functional Disability Subscale specifically quantifies the impact of symptoms on daily activities, making it an ideal metric for assessing treatment efficacy from the patient’s perspective.¹⁰

This study aims to compare the effect of hypertonic dextrose versus corticosteroid injections on functional disability in patients with lateral epicondylitis, using the PRTEE Functional Subscale across multiple follow-up intervals. We hypothesize that while both interventions would yield functional improvements, dextrose prolotherapy would result in superior and more sustained recovery of upper limb function.

Study Design and Ethical Approval

This study was designed as a prospective, randomized, controlled, single-center clinical trial aimed at comparing the impact of hypertonic dextrose versus corticosteroid injections on functional disability in patients with lateral epicondylitis (LE). Ethical approval was obtained from the Institutional Ethics Committee prior to the initiation of the study, and all participants provided written informed consent in accordance with the Declaration of Helsinki and Good Clinical Practice guidelines.

Participants

A total of 60 adult patients (aged 18–60 years) with clinically diagnosed unilateral lateral epicondylitis were recruited from the outpatient orthopaedics and physical medicine departments. Diagnosis was based on classical clinical features, including localized tenderness over the lateral epicondyle and pain exacerbated by resisted wrist extension or gripping tasks.

Inclusion criteria:

• Symptom duration ≥ 6 weeks
• PRTEE functional disability score ≥ 20/50
• No prior injection or physical therapy in the last 3 months

Exclusion criteria:

• Bilateral symptoms or prior elbow surgery
• Rheumatoid arthritis or other inflammatory joint diseases
• Diabetes mellitus or immunosuppression
• Recent NSAID use, physiotherapy, or concurrent participation in other interventions

Randomization and Blinding

Participants were randomized using a computer-generated sequence into two equal groups (n = 30 per group):

• Group A (Dextrose): Received a single injection of 25% hypertonic dextrose
• Group B (Steroid): Received a single injection of methylprednisolone acetate (40 mg/mL)

Allocation concealment was ensured using sequentially numbered, sealed opaque envelopes, opened only at the time of injection. Although the nature of the interventions did not permit patient blinding, outcome assessments were conducted by an independent, blinded evaluator.

Intervention Technique

All injections were performed under strict aseptic conditions by the same experienced physician to maintain procedural consistency. Patients were positioned comfortably with the elbow flexed and forearm pronated. Using a 25G needle, a 2 mL injection was administered into the point of maximal tenderness near the lateral epicondyle, using the peppering technique to ensure dispersion within the affected tendon area.

• Group A: 25% dextrose in sterile normal saline
• Group B: Methylprednisolone acetate (40 mg/mL), no additional anesthetic or adjuvant used

Patients were advised to rest the arm for 24–48 hours post-injection and then resume normal activities as tolerated. No concomitant analgesics, NSAIDs, or physical therapy were permitted during the follow-up period.

Outcome Measure: PRTEE Functional Disability Subscale

Functional impairment was assessed using the Functional Disability Subscale of the Patient-Rated Tennis Elbow Evaluation (PRTEE)—a validated, condition-specific instrument that measures self-reported difficulty in performing daily activities requiring forearm function [36]. This subscale includes 10 functional tasks, each rated on a 0–10 Likert scale (0 = no difficulty, 10 = unable to perform), with a maximum score of 50. Higher scores denote greater functional limitation.

Assessments were conducted at four time points:

• Baseline (pre-injection)
• 1 Week
• 6 Weeks
• 3 Months post-intervention

Statistical Analysis

Data were entered and analyzed using SPSS version [e.g., 26.0]. Descriptive statistics were used to summarize demographic and baseline characteristics. Functional scores were expressed as mean ± standard deviation (SD). Intragroup differences over time were analyzed using paired t-tests, while independent t-tests were used for intergroup comparisons at each follow-up interval.

A p-value < 0.05 was considered statistically significant. The sample size was calculated a priori to detect a minimum clinically significant difference of 4 points on the PRTEE disability subscale with 80% power and a 5% alpha error.

Table 1. Baseline Demographic and Clinical Characteristics of Study Participants

Table 1 illustrates the baseline demographic and clinical profile of participants enrolled in the study. Both treatment groups were statistically comparable across all measured parameters, ensuring the internal validity of subsequent functional outcome comparisons.

The mean age of participants was 42.66 ± 11.15 years in the dextrose group (Group A) and 43.36 ± 12.88 years in the steroid group (Group B), with no significant age difference (p = 0.823). Gender distribution was balanced between groups (17M/13F in Group A vs. 15M/15F in Group B, p = 0.605), and right-arm dominance was prevalent in both groups, reflecting typical patterns seen in lateral epicondylitis.

The average duration of symptoms was similar (11.43 weeks in Group A vs. 11.86 weeks in Group B, p = 0.673), indicating comparable chronicity of the condition across the cohorts. Importantly, the baseline PRTEE Functional Disability scores—the primary outcome measure—were also statistically indistinguishable between groups (37.26 ± 4.78 in Group A vs. 38.03 ± 4.55 in Group B, p = 0.472), confirming that both arms started with equivalent functional impairment.

This uniformity at baseline reinforces the robustness of the randomization process and ensures that any post-treatment differences in functional recovery can be attributed to the therapeutic effect of the interventions rather than pre-existing disparities.

Table 2. Intergroup Comparison of PRTEE Functional Disability Scores Between Group A and Group B at Different Time Intervals

Table 2 presents the intergroup comparison of functional disability scores (as measured by the PRTEE Functional Subscale) between the dextrose (Group A) and corticosteroid (Group B) groups at various follow-up intervals.

At baseline, the functional disability scores were statistically comparable between the two groups (Group A: 34.26 ± 4.40 vs. Group B: 34.70 ± 3.29; p = 0.667), confirming effective randomization and group matching.

However, significant differences in favor of the dextrose group emerged as early as 1 week post-injection, with Group A showing a lower mean disability score (27.53 vs. 30.00; p = 0.009). The trend became more pronounced at 6 weeks, where the dextrose group continued to exhibit better functional recovery (19.90 ± 3.64 vs. 23.33 ± 3.51; p = 0.000). By the 3-month follow-up, the difference widened further (11.93 ± 3.32 vs. 16.16 ± 3.63; p = 0.000), indicating sustained and superior functional improvement in the dextrose group.

The progressively widening gap in scores over time supports the regenerative mechanism of hypertonic dextrose, in contrast to the short-lived suppressive effects of corticosteroids. These results suggest that dextrose prolotherapy not only facilitates pain relief but significantly enhances daily function and task performance, which is crucial for long-term rehabilitation in patients with lateral epicondylitis.

Table 3. Intragroup Comparison of PRTEE Functional Disability Scores in Group A (Dextrose) at Different Time Intervals

Table 3 demonstrates the longitudinal improvement in functional ability within the dextrose-treated cohort (Group A) using the PRTEE Functional Disability Subscale. The analysis shows a statistically significant and progressive reduction in disability across all follow-up intervals compared to baseline.

At 1 week, Group A exhibited a significant decrease in functional limitation (mean reduction: 8.66 points; p < 0.001), indicating an early onset of therapeutic benefit. By 6 weeks, this improvement deepened to a mean difference of 16.56 points, reflecting continued healing and restoration of forearm function (p < 0.001). The most pronounced improvement was seen at the 3-month mark, where the mean functional score dropped from 33.80 to 15.76, yielding an overall mean reduction of 18.03 points (p < 0.001).

These findings suggest that hypertonic dextrose prolotherapy not only initiates early symptom relief but also supports durable functional recovery over time. The consistency and magnitude of the improvements reinforce its potential regenerative effect on tendinopathic tissue, particularly relevant to restoring upper limb functionality in daily life and occupational tasks.

Table 4. Intragroup Comparison of PRTEE Functional Disability Scores in Group B (Steroid) at Different Time Intervals

Table 4 outlines the within-group progression of functional recovery in patients who received corticosteroid injections (Group B), assessed using the PRTEE Functional Disability Subscale.

A statistically significant reduction in disability was observed at 1 week, with the mean score decreasing from 35.06 to 30.26 (mean difference: 4.80; p < 0.001), indicating a rapid onset of functional improvement post-steroid injection. The improvement was more marked at 6 weeks (mean difference: 11.50; p < 0.001), suggesting ongoing therapeutic benefit.

By 3 months, Group B showed a total mean reduction of 18.73 points, with functional scores declining to 16.33 ± 3.72—a result that reflects substantial recovery over time (p < 0.001).

While these findings confirm the effectiveness of corticosteroids in improving upper limb function, the trajectory appears less robust and slightly delayed when compared to the dextrose group (Group A). The initial rapid response may be attributed to anti-inflammatory action, but sustained improvements likely plateau relative to regenerative therapies.

The present study investigated and compared the impact of hypertonic dextrose and corticosteroid injections on functional disability in patients with lateral epicondylitis (LE), as quantified using the PRTEE Functional Disability Subscale. Both treatment modalities demonstrated statistically significant improvements over time; however, patients receiving dextrose therapy showed greater and more sustained enhancement in functional ability, particularly at 6 weeks and 3 months follow-up.

At baseline, the two groups were statistically comparable in terms of age, sex distribution, dominance, symptom duration, and functional disability scores, confirming effective randomization and eliminating confounding baseline variability. The functional trajectory, however, diverged markedly after the first week of intervention.

Our findings align with previous evidence highlighting the short-term analgesic benefit of corticosteroids due to their anti-inflammatory properties. In Group B, functional improvement was apparent as early as one week post-injection (mean difference: 4.80; p < 0.001), corroborating studies, who reported early pain relief and improved grip strength following corticosteroid administration.^4,5 However, by 6 weeks and 3 months, the rate of functional gain began to plateau, with diminishing comparative advantage over regenerative modalities.⁶

In contrast, dextrose prolotherapy resulted in significantly greater functional recovery throughout the follow-up period. Group A exhibited a larger reduction in PRTEE disability scores at 1 week (mean diff: 8.66; p < 0.001), and this improvement continued to widen at 6 weeks and 3 months (mean diff: 18.03; p < 0.001). These results are consistent with the regenerative theory underlying prolotherapy, which posits that hyperosmolar dextrose induces localized inflammation, fibroblast proliferation, and extracellular matrix remodeling, thereby addressing the degenerative pathology of tendinosis rather than merely suppressing inflammation.^7-9

Previous clinical trials, support our findings, demonstrating superior long-term outcomes in function and pain with dextrose compared to corticosteroids in musculoskeletal conditions.^11,12 Moreover, the continuous trajectory of improvement seen in the dextrose group underscores its biological healing effect, not merely symptomatic relief, making it a compelling therapeutic option for chronic overuse tendinopathies like LE.

One of the key strengths of this study is the use of the PRTEE Functional Disability Subscale, a condition-specific and validated instrument, which allowed for a nuanced understanding of how each treatment impacted real-world tasks such as gripping, lifting, and carrying. Functional outcomes are more clinically meaningful than pain scores alone, especially for working populations or individuals with high upper-limb demand.

Despite the compelling results, this study is not without limitations. The follow-up duration was limited to three months, and while the trends favor dextrose in terms of durability, longer-term follow-up would be required to determine the persistence of functional gains. Additionally, blinding of participants was not feasible due to the nature of the injectates, potentially introducing expectation bias. Future multicenter, double-blind trials with larger sample sizes and extended follow-up periods are warranted to confirm these results and assess recurrence rates.

This prospective comparative study demonstrated that both hypertonic dextrose and corticosteroid injections significantly improve functional disability in patients with lateral epicondylitis. However, the trajectory and magnitude of improvement were markedly superior in the dextrose group, with earlier onset, greater magnitude, and sustained functional gains up to 3 months post-injection.

While corticosteroids provided short-term functional benefit, their effects plateaued over time, consistent with their anti-inflammatory mechanism. In contrast, dextrose prolotherapy elicited progressive improvements suggestive of tissue healing and structural regeneration, which translated into enhanced grip function, reduced disability in daily tasks, and better quality of life.

Given its regenerative potential and sustained outcomes, hypertonic dextrose prolotherapy should be considered a preferred intervention for patients with persistent or chronic lateral epicondylitis, especially when long-term functional restoration is the clinical objective.

Future studies with longer follow-up and imaging correlation are recommended to further validate its efficacy and explore its role as a first-line treatment option.

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