Comparison of the effects of ultrasound-guided steroid injection and anatomic landmark-guided injection on pain and disability in greater trochanteric pain syndrome

Abstract

Objective

Greater trochanteric pain syndrome (GTPS) is a prevalent condition that can significantly affect patient comfort and function. This study aims to compare the effectiveness of ultrasound (USG)-guided and anatomic landmark-guided corticosteroid injections in managing GTPS.

Methods

Patients diagnosed with GTPS received either USG or anatomic landmark-guided corticosteroid injections. Pain scores (Visual Analog Scale, VAS) and functional outcomes (modified Harris Hip Score, HHS) were assessed at baseline, 1 month, and 1 year post-injection. Cost-effectiveness was calculated using public and private payor pricing from June 2024.

Results

Both treatment groups exhibited significant improvements in pain and function. The USG group demonstrated greater initial improvements at the 1-month mark, particularly in VAS activity and HHS. However, these differences between the groups converged over time, with similar long-term outcomes observed in these parameters. The USG-guided injections showed more pronounced initial benefits, especially for patients with higher initial pain levels and lower functional scores. USG was found to be more cost-effective in terms of HHS, but not VAS measures.

Conclusion

While both USG and anatomic landmark-guided injections are effective for managing GTPS, USG-guided injections may provide greater initial relief in pain and function, particularly for patients with higher initial pain levels. USG does not demonstrate long-term superiority over anatomic injections. The study underscores the importance of evaluating long-term outcomes to comprehensively assess the sustained effectiveness of different treatment strategies for GTPS.

Level of Evidence

Level III, Therapeutic study.

Highlights

• Both USG-guided and anatomic palpation-guided injections in GTPS are effective treatment methods.

• The greater short-term pain relief provided by USG-guided injections can have a significant positive effect on patients’ psychological well-being and daily activities.

• Functional outcomes indicate that USG-guided injections may have better cost-effectiveness, whereas pain shows no evident advantage.

Introduction

Greater trochanteric pain syndrome (GTPS) is a common condition characterized by intermittent chronic pain and tenderness over the lateral aspect of the hip, worsened with activity and side-lying position.¹ It is often attributed to gluteal tendinopathies, tears, or trochanteric bursitis.² Diagnosis is mostly done clinically as the criteria are not specific.³

Greater trochanteric pain syndrome affects about 1.8 patients per 1000 per year, and ends up being a chronic condition in one-third of the patients.⁴ In the primary care setting, GTPS accounts for roughly 10-20% of all hip pain cases.⁵ Initial steps in the management of this condition typically involve a combination of conservative treatments, such as the promotion of weight loss, anti-inflammatory medications, and physical therapy.^4,6 Using these conservative measures to treat the syndrome may extend over a period of up to 3 months, presenting specific challenges in managing provider-patient relationships and expectations.⁴

Conservative measures may not be effective due to the heterogeneity of etiologies. In cases where conservative treatments fail to improve the symptoms, clinicians may consider glucocorticoid injections. Superior outcomes are reported in the literature when comparing local steroid injections with sham,⁷ conservative follow-up,⁸ and rehabilitation^9,10 for GTPS in short-term results. For long-term results, local steroid injections may be superior to conservative treatment.⁸ These injections target the 2 main structures related to GTPS: the subgluteus medius and the trochanteric bursa, the latter of which is shown to have a greater effect.¹¹ The complex anatomic relationships of these structures present challenges in achieving precise injections.

To overcome the challenge of precision injections into the trochanteric bursa, clinicians can utilize ultrasound (USG) guidance to visualize the region and verify precision injection by visualizing the expansion of the peri-bursa space.¹² A single cadaveric study comparing the USG-guided with anatomical landmark-guided approaches has reached no significant difference.¹³ Studies favoring the use of USG for achieving improved functional outcomes are also concerned about the increased cost associated with USG imaging and suggest reserving it for complex cases, such as morbidly obese patients, where palpating the anatomical landmarks might prove challenging.¹⁴

Given the higher costs and potential over-reliance on imaging, it is crucial to carefully assess the necessity and potential benefits of this approach. In this context, this study aimed to evaluate the impact of USG-guided injections over anatomic landmark-guided methods for trochanteric bursitis in GTPS, focusing on short-term and long-term outcomes.

Material and methods

Ethics board approval for the retrospective use of institutional databases for this study was obtained from Koç University Ethics Committee with Approval No. 2024.046.IRB2.020 on 22/02//2024. For this retrospective analysis, the ethics board determined that no informed consent was necessary.

Participants and data collection

Electronic medical records from Orthopedics and Traumatology and Physical Medicine and Rehabilitation clinics of a tertiary center were filtered for outpatient visits tagged with ICD-10 code M70.60 (Trochanteric Bursitis) between January 1st, 2019, and January 15th, 2024. Per departmental practices in our institution, physicians in the Orthopedics and Traumatology clinic perform these injections using anatomic landmarks, whereas physicians in Physical Medicine and Rehabilitation utilize USG guidance. Inclusion criteria were age ≥ 18 years and duration of pain ≥ 3 months. Exclusion criteria were the presence of hip deformities, known tears of the gluteus medius, gluteus minimus, piriformis, superior and inferior gemellus muscle tendons, diagnosis of lumbosacral spine nerve root impingement, previous lumbar spinal surgery, recent trauma, hemorrhagic diathesis, use of warfarin or other anticoagulants, the presence of infection, previous corticosteroid injection into the hip in the preceding 6 months, previously diagnosed neurologic, cognitive, psychiatric, or rheumatologic diseases, cancer, systemic infection, or inflammation. The resulting search query was used to manually sort through patients who were treated conservatively and identify which patients received USG or anatomic injections. Harris Hip Scores (HHS), Visual Analog Scale (VAS) activity scores, VAS rest scores, and VAS night scores were obtained from clinical charts across 3 time points: baseline, 1 month, and 1 year.

Procedures

All USG-guided procedures were performed by a physiatrist (MT with 10 years of experience). All anatomic landmark-guided procedures were performed by an orthopedic surgeon (LAwith 11 years of experience). The trochanteric bursa injection procedure was standardized for both USG and anatomic landmark groups, using the posterior approach. Patients were positioned in the lateral recumbent posture, with the asymptomatic hip down and the symptomatic hip up, flexed to 40°, and the knee flexed to 75°. For the USG-guided technique, an Esaote MyLab Class C US device (Genova, Italy) with a curvilinear array US transducer (5-8 MHz) was utilized to visualize the injection site on the trochanteric bursa. The injection site was marked with ink. Antisepsis was performed using povidone-iodine. A 22-gauge, 1.5-inch or 2-inch needle, attached to a 5-mL syringe filled with 4 mL of 1% lidocaine (Jetmonal) and 1 mL of 5+2 mg/mL betamethasone dipropionate and betamethasone sodium phosphate (Diprospan), was injected until resistance was felt at the lateral inferior greater trochanter. The needle was then withdrawn with firm pressure, and a sterile bandage was applied to the puncture site.

For the palpation-guided anatomic landmark technique, the trochanteric bursa was identified by deep palpation over the posterolateral aspect of the greater trochanter of the femur. Similar to the USG group, antisepsis was performed using povidone-iodine. Using a 22-gauge, 1.5-inch or 2-inch needle, attached to a 5-mL syringe filled with 4 mL of 1% lidocaine (Jetmonal) and 1 mL of 5+2 mg/mL betamethasone dipropionate and betamethasone sodium phosphate (Diprospan), the injection continued until resistance was felt at the syringe. The needle was then withdrawn with firm pressure, and a sterile bandage was applied to the puncture site.

Statistical analysis

Descriptive statistics were used to analyze the demographic information of the study population. Baseline comparisons between groups were conducted using independent t-tests for continuous variables and chi-square tests for categorical variables.

Changes in HHS, VAS activity scores, VAS rest scores, and VAS night scores were analyzed across 3 time points: baseline, 1 month, and 1 year. Mean scores for each measure were calculated for both treatment groups at each time point. Normality was assessed using Shapiro–Wilk’s test. Repeated measures analysis of variance (ANOVA) was conducted to evaluate the effects of treatment types and time points. Paired t-tests were used to compare scores between groups at each time point. Post-hoc pairwise comparisons were conducted using Tukey’s honestly significant difference (HSD) to compare the treatment groups (USG vs. anatomic) at each time point for the clinical scores.

Statistical analyses were conducted using Python 3 (Python Software Foundation, Wilmington, Delaware, USA) with Pandas and SciPy Statistics Libraries.^15,16 Visualizations were created using the MatPlotLib library. ¹⁷A P-value < .05 was considered statistically significant.

Cost-effectiveness analysis

Cost-effectiveness analysis was done using hospital pricing for both public and private insurance payors from the month of June 2024 in Turkish Liras (TL) (Table 1). Ultrasonographic and anatomic study groups were each modeled with both insurance alternatives. Average improvements in HHS at 1 month were calculated for each study group and divided by the costs of each insurance type.

Table 1.

Summary of costs in Turkish Lira for public and private insurance from June 2024. On the day of price collection, June 3rd, 2024, the Central Bank of the Republic of Türkiye reported an exchange rate of 1 United States Dollar = 32.15 Turkish Lira.

Cost component	Public insurance	Private insurance
USG injection cost	2680	8200
Anatomic injection cost	1150	1900
Visit cost	2400	3800
USG government contribution	131	–
Anatomic government contribution	55	–
USG total cost	5211	12 000
Anatomic total cost	3605	5700

Results

This study compared the outcomes of USG-guided and anatomic landmark-guided hip injections in 2 groups of patients over a 1-year period. The primary outcome measures were VAS scores at 1 month for pain during activity, at rest, and at night, as well as functional outcomes assessed by the HHS. A total of 185 hips received injections, with 92 performed using USG guidance and 93 using anatomic palpation. Table 2 depicts a summary of demographic findings within the study. No significant difference was observed in terms of age, gender distribution, and the number of bilaterally injected patients. The USG group had a significantly higher mean BMI as opposed to the anatomic group (28.57 vs. 26.51, P = .0045). Shapiro–Wilk’s tests returned no values greater than P = .05 for all study parameters.

Table 2.

Group size (n = number), mean, standard deviation (SD) for weight (kilograms), body mass index (BMI).

Total (n = 158)	USG (n = 79)	Anatomic (n = 79)
Bilateral patients, n (%)	13 (16.5%)	14 (17.7%)
Female patients, n (%)	68 (86.1%)	69 (87.3%)
Age, median(Q2-Q3)	60.0 yēars (49.0-68.0)	58.0 years (40.0-66.0)
Body mass index (BMI), mean (SD)	28.55 kg/m2 (4.87)	26.50 kg/m2 (4.15)
Height, mean (SD)	162.33 cm (7.40)	163.09 cm (8.13)
Weight, mean (SD)	75.48 kg (14.05)	70.92 kg (13.05)

BMI, body mass index; cm, centimeters; kg, kilograms; m², square meters; SD, standard deviation, USG,

Overall findings of study outcomes and their progression across time points are displayed in Figure 1. At baseline, the USG group reported significantly higher mean VAS activity compared to the anatomic group (7.19 vs. 5.46, P < .0001). This difference persisted at 1 month post-intervention (2.78 vs. 2.13, P = .0033), albeit with substantial improvements in both groups. By the 1-year follow-up, the difference in VAS activity scores was no longer statistically significant (3.96 vs. 3.46, P = .1228), indicating similar long-term outcomes for pain during activity.

Figure 1.

Harris hip scores (HHS), Visual analog scale (VAS) scores for rest, activity, and night across the follow-up periods.

The repeated measures ANOVA showed significant effects of time, group (USG and Anatomic), and the interaction between time and group across all measures. Both groups demonstrated significant improvements over time in VASAct, VASRest, VASNight, and HHS (P < .001). There were significant differences between the USG and Anatomic groups for all measures, with the USG group showing more favorable outcomes (P < .001). Significant interaction effects indicated that changes over time differed between groups, with the USG group experiencing greater improvements overall (Table 3).

Table 3.

Repeated measures ANOVA results for VAS and HHS and their interactions across the effects of time, group (USG vs. Anatomic).

Measure	Source of variation	Sum of squares	df	F-value	P
VASAct	Time	1449.52	2	231.78	< .001
VASAct	Group	179.86	1	57.52	< .001
VASAct	Time × Group	47.78	2	7.64	< .001
VASAct	Residual	1716.65	549	–	–
VASRest	Time	584.41	2	96.19	< .001
VASRest	Group	217.98	1	71.76	< .001
VASRest	Time × Group	93.84	2	15.45	< .001
VASRest	Residual	1667.68	549	–	–
VASNight	Time	181.34	2	20.96	< .001
VASNight	Group	807.21	1	186.63	< .001
VASNight	Time × Group	369.7	2	42.74	< .001
VASNight	Residual	2374.48	549	–	–
HHS	Time	91 501.11	2	255.76	< .001
HHS	Group	7857.09	1	43.92	< .001
HHS	Time × Group	2448.06	2	6.84	< .001
HHS	Residual	98 206.74	549	–	–

Statistically significant differences were observed across all measures for time, group, and the time *group interaction (P < .001 for all comparisons). Residual variance is also shown for each measure.

The USG group initially reported significantly higher mean pain at rest (5.27 vs. 2.99, P < .0001). While both groups showed improvement over time, the USG group maintained higher VAS rest pain scores at 1 month (2.56 vs. 1.77, P = .0011) and 1 year (2.73 vs. 2.03, P = .0416) post-intervention. However, the magnitude of this difference decreased over time. The night pain scores followed a similar pattern to rest pain. The USG group started with significantly higher mean scores (5.38 vs. 1.15, P < .0001) and, despite showing more substantial improvement, maintained higher night pain scores at both 1-month (3.24 vs. 1.27, P < .0001) and 1-year (3.42 vs. 1.58, P < .0001) follow-ups. The difference in night pain scores between groups remained significant throughout the study period.

At baseline, the anatomic group demonstrated significantly better mean HHS scores compared to the USG group (55.16 vs. 43.70, P < .0001). However, the USG group showed more marked improvement, with the difference becoming non-significant at 1 month (81.77 vs. 78.33, P = .0017) and at 1 year (73.20 vs. 72.25, P = .2082). To assess between-group differences in improvement levels among USG and anatomic groups, Tukey's HSD post-hoc pairwise comparisons were performed. Results revealed that both groups experienced significant improvements across all measures, with the most substantial changes occurring in the first month. The USG group consistently showed better outcomes across all measures. Specifically:

For VAS activity, both groups showed significant improvements at each time point (P < .001), with the largest improvement from baseline to 1 month. The USG group maintained lower scores throughout the study.

VAS rest scores improved significantly from baseline to 1 month and 1 year (P < .05), but showed no significant change between 1 month and 1 year. The USG group consistently had lower scores.

VAS night scores improved significantly at all time points (P < .05), with the largest improvement in the first month, followed by a slight increase in pain from 1 month to 1 year. The USG group showed substantially better outcomes for night pain.

Harris hip score improved significantly at each time point (P < .05), with the largest improvement in the first month and continued improvement up to 1 year. The USG group demonstrated better functional outcomes overall.

Intra-group improvements across time points showed statistical significance (P < .001) for most study outcomes in both treatment groups. However, for the USG group, there was no statistically significant change in VAS rest scores between 1 month and 1 year. The cost-effectiveness analysis of trochanteric injections, comparing 1-month and 1-year outcomes, revealed significant differences in HHS between USG-guided and anatomic-guided treatments, as well as between public and private insurance options (Table 4). USG injections demonstrated superior effectiveness and improved over time, with average HHS improvements increasing from 24.62 at 1 month to 30.34 at 1 year for both insurance types. In contrast, anatomic-guided injections showed a slight decline, from 13.05 to 11.49. USG with public insurance proved most cost-effective, improving from 211.66 per TL/HHS point at 1 month to 171.75 at 1 year, while anatomic-guided with private insurance was least cost-effective, declining from 436.78 to 496.08. Public insurance consistently outperformed private insurance, with cost savings ranging from 56.6% to 36.8% for USG and anatomic-guided injections respectively. Cost-effectiveness for VAS measures showed no clear trend and varied across time points and parameters.

Table 4.

Cost-effectiveness (CE) ratios across differing time points, insurance types, and study groups.

Measure	Treatment	Time	Average improvement	Public insurance CE	Private insurance CE
HHS	USG	1 month	24.62	211.66	487.41
HHS	USG	1 year	30.34	171.75	395.52
HHS	Anatomic	1 month	13.05	276.25	436.78
HHS	Anatomic	1 year	11.49	313.75	496.08
VASAct	USG	1 month	3.79	1374.93	3166.23
VASAct	USG	1 year	3.95	1319.24	3037.97
VASAct	Anatomic	1 month	2.82	1278.37	2021.28
VASAct	Anatomic	1 year	2.37	1520.25	2405.06
VASRest	USG	1 month	3.44	1514.83	3488.37
VASRest	USG	1 year	3.62	1439.5	3314.92
VASRest	Anatomic	1 month	2.38	1514.29	2394.96
VASRest	Anatomic	1 year	2.05	1758.54	2780.49
VASNight	USG	1 month	3.72	1400.81	3225.81
VASNight	USG	1 year	3.87	1346.51	3100.77
VASNight	Anatomic	1 month	2.54	1419.29	2244.09
VASNight	Anatomic	1 year	2.18	1653.67	2614.68

CE, cost-effectiveness; HSS, Harris hip score; VAS, visual analog scale; USG, ultrasonographic.

Discussion

This study aimed to evaluate the effectiveness of USG-guided compared to anatomic landmark-guided gluteus medius injections in patients with GTPS, focusing on short-term and long-term outcomes. Our findings show that USG-guided injections may provide greater initial relief in pain and function, particularly for patients with higher initial pain levels.

Corticosteroid injections are a widely used and effective treatment for trochanteric bursitis, often yielding positive outcomes.⁸ A previous study reported the efficacy of corticosteroid injections for trochanteric bursitis, demonstrating success rates of 77% at 1 week and 69% at 6 weeks post-injection.¹⁸ Similarly, our results demonstrated significant improvements in pain and function for both USG-guided and anatomic landmark-guided intervention groups over a 1-year period. At baseline, the USG group had worse pain scores and lower functional scores; despite this, patients in the USG group showed greater improvements at the 1-month follow-up, particularly in pain at rest (VAS rest) and night pain (VAS night), as well as in the HHS. By the 1-year follow-up, the differences between the 2 groups in pain during activity and functional scores had largely converged, indicating similar long-term outcomes for these measures.

Before the treatment, the patients who received USG-guided injections exhibited consistently worse pain scores across all VAS subscales and lower functional HHS scores compared to those who received anatomic landmark-guided injections. Despite this, both groups showed significant improvements over the study period. VAS activity scores gradually approached levels comparable to the anatomic group by the 1-year follow-up. However, they continued to experience higher levels of pain during rest and at night throughout the study. This suggests that while USG-guided injections may lead to greater initial improvements, the long-term benefits converge between the 2 techniques. Recognizing both immediate and sustained outcomes is crucial in optimizing treatment strategies for GTPS. A previous study reported that GTPS could greatly impact a patient’s comfort during both activity and rest.¹⁸ VAS activity improvements were observed in both groups, with the USG group showing larger improvements. For VAS rest and VAS night, the USG group demonstrated larger improvements compared to the anatomic group. The anatomic group showed minimal improvement or slight worsening in VAS night scores. Harris hip score improvements were observed in both groups, with the USG group consistently showing larger improvements. However, small sample sizes in some categories limit the generalizability of this finding.

Several limitations should be considered when interpreting the results of this study. Firstly, the experience of the physicians differed; USG-guided injections were performed by physiatrists, while anatomic landmark-guided injections were performed by orthopedists, potentially introducing bias due to differences in clinician expertise and technique. This variation could have influenced the outcomes independently of the injection method. As displayed in Table 2, the USG group had a more heterogeneous baseline distribution, with physiatrists treating patients who were experiencing more pain as opposed to those treated by orthopedic surgeons. This selection bias may have affected the results, and future studies should aim to standardize clinician experience and patient selection criteria. Furthermore, VAS scoring is subjective and can be influenced by individual perceptions and biases. The retrospective design and reliance on electronic medical records provide limited control over confounding variables. We were unable to perform physical examinations at the second follow-up, which could have provided additional objective measures of outcomes. Lastly, the single-institution study population may limit the generalizability of the findings to more diverse populations, and future research with multicenter studies and larger sample sizes could help validate these findings.

The findings of this study suggest that while both treatment approaches are effective, the treatment alternative utilizing USG guidance may be particularly beneficial for patients with higher initial pain levels and lower reported functional scores. However, the long-term outcomes between the 2 techniques appear to converge, indicating that the initial advantages of USG guidance may not be sustained over time. This highlights the critical importance of assessing and monitoring both immediate and long-term outcomes to comprehensively evaluate the sustained effectiveness of treatment strategies for GTPS.

The analysis also highlights the importance of considering different pain contexts (activity, rest, night) separately in the case of USG utilization, as they show different patterns of improvement and group differences over time.

Our findings demonstrated higher cost-effectiveness in terms of HHS using USG than anatomic-guided injections regardless of insurance type or time point, with the advantage becoming more pronounced at 1 year. When measuring VAS, our results agree with previous studies regarding cost-effectiveness,¹⁴ as there is no clear beneficial trend. However, it is important to note differing calculation methods and outcome parameters between the 2 studies. The mentioned study reported costs of USD 207 ± 95 and 297 ± 99 for anatomic and USG respectively per year, with a cost difference of 43%.¹⁴ In our study, no yearly costs were estimated, and the cost differences were 44.55% for public and 110.53% for private insurance.

Both groups demonstrated significant improvements in pain and function from baseline to 1 month, with these improvements largely sustained at 1 year. Initial differences between groups converged over time, particularly for VAS activity and HHS scores, indicating similar long-term outcomes in these parameters. However, the persistence of significant differences in VAS rest and VAS night at 1 year suggests enduring variations in pain experiences between the groups during periods of inactivity. The USG group consistently showed greater improvement at the 1-month mark compared to the anatomic injection group, highlighting its superior short-term efficacy. By the 1-year mark, both groups had converged to similar levels of improvement, indicating that the initial advantage of the USG group was not sustained in the long term.

This study reaffirms that both USG-guided and anatomic landmark-guided injections are effective for managing GTPS in the long term. However, the greater short-term pain relief provided by USG-guided injections can have a significant positive effect on patients’ psychological well-being and daily activities. Recognizing the importance of both immediate and sustained outcomes is crucial in optimizing treatment strategies for GTPS. Further investigation into potential confounding factors, including clinician experience and patient characteristics, could provide additional insights into the effectiveness of these treatments.

Funding Statement

The authors declared that this study has received no financial support.

Data availability statement

The data that support the findings of this study are available on request from the corresponding author.