Greater Trochanteric Pain Syndrome (GTPS) is a broad term used to describe lateral hip pain stemming from the structures attached to the greater trochanter of the femur (Pumarejo Gomez and Childress, 2023). It affects an estimated 1.8 out of 1000 patients annually in the UK and is more common in women than men (Lievense et al, 2005). It can lead to a decrease in work participation, elevated levels of pain and dysfunction impeding physical activity, and a diminished quality of life; these features align with those observed in individuals with severe hip osteoarthritis (Fearon et al, 2014). At the time of writing, there are few documented data on the economic impact of GTPS; however, given that it is comparable to hip osteoarthritis, it is plausible they are somewhat similar (Fearon et al, 2017). One study of the economic burden of hip osteoarthritis in the Netherlands reported an average annual cost of 159 sick leave calendar days and €12 482 in costs (Hardenberg et al, 2022).
Effectively managing GTPS can pose significant challenges (Reid, 2016). Typically, patients with GTPS will respond well with conservative management (Pianka et al, 2021), which can include physiotherapy, non-steroidal anti-inflammatory drugs and corticosteroid injections (CSI) (Reid, 2016; Pianka et al, 2021). As highlighted in the Chartered Society of Physiotherapy's (CSoP) guidance for advanced practice physiotherapists, injection therapy stands as one of the advanced skills used to offer patient-centred and sustainable care that is efficient, cost-effective and clinically impactful (CSoP, 2018). There is some debate regarding the specific estimation of effect of CSI; while there have been previous systematic reviews in this area (Barratt et al, 2017), they have not been followed up with meta-analysis. Because of this lack of specific certainty, Wang et al (2022) undertook a systematic review to explore the effect of CSI in the treatment of GTPS.
Aim
This commentary critically appraises the methods used within the review by Wang et al (2022) and expands upon its findings in the context of the four pillars of advanced practice: clinical practice, leadership, education and research.
Critical appraisal and key methods of Wang et al (2022)
When evaluated with the measurement tool to assess systematic reviews (AMSTAR-2) (Shea et al, 2017), Wang et al (2022) can be seen as fulfilling 12 out of the 16 required criteria (Table 1). The evaluation raised four points of concern:
| AMSTAR-2 items | Criteria/methods |
|---|---|
| Did the research questions and inclusion criteria for the review include the components of patient/population, intervention, comparison and outcomes? | Yes: Only randomised controlled trials (RCTs) that enrolled adult participants with greater trochanter pain syndrome (GTPS) were included. Corticosteroid injection had to be one of the intervention groups in these trials, while the other interventions could be any conservative treatment for GTPS. Studies that included patients who had hip surgery, infection, acute trauma or rheumatoid arthritis were excluded. Screening, data extraction and assessment of bias were carried out by two reviewers independently |
| Did the report of the review contain an explicit statement that the review methods were established before the conduct of the review and did the report justify any significant deviations from the protocol? | Yes: This systematic review was registered on PROS-PERO before commencement and no deviations from the original post were undertaken |
| Did the review authors explain their selection of the study designs for inclusion in the review? | No: There was no justification why only random controlled trials were included |
| Did the review authors use a comprehensive literature search strategy? | Yes (partially): A multi-database search was undertaken using MEDLINE, Embase and the Cochrane library from date of inception until 30th April 2021. However, there was no searching of trial registries |
| Did the review authors perform the study selection in duplicate? | Yes: Two reviewers carried out study selection independently |
| Did the review authors perform data extraction in duplicate? | Yes: Data extraction was carried out by two reviewers independently |
| Did the review authors provide a list of excluded studies and justify the exclusions? | No: A comprehensive list of excluded studies was not provided |
| Did the review authors describe the included studies in adequate details? | Yes: All key variables were given regarding studies, which were included |
| Did the review authors use a satisfactory technique for assessing the risk of bias (RoB) in the individual studies that were included in the review? | Yes: Visual inspection of funnel plot was proposed; however, a middle threshold of 10 studies were set which was not achieved |
| Did the review authors report on the sources of funding for the studies included in the review? | No: The systematic review did not indicate the funding sources of included studies |
| If meta-analysis was performed, did the review authors use appropriate methods for statistical combination of results? | Yes: This meta-analysis employed both ‘fixed’ and ‘random’ methods of synthesis. The data were analysed using RevMan 5.4.1 software. Chi-Square test (Q test) and I2 were used to evaluate the statistical heterogenicity of the pooled data. An I2 value of >50% indicated that a random–effects model was used, random <%50 heterogenicity called for the use of a fixed-effect model being adopted |
| If meta-analysis was performed, did the review authors assess the potential impact of RoB in individual studies on the results of the meta-analysis or other evidence synthesis? | Yes: The systematic review proposed to do this, but unfortunately, they had less than 10 studies |
| Did the review authors account for RoB in individual studies when interpreting/discussing the results of the review? | No: The RoB was assessed; however, it was not used in any type of subgroup or sensitivity analysis to identify its effect regards to the estimates presented |
| Did the review authors provide a satisfactory explanation for, and discussion of any heterogeneity observed in the results of the review? | Yes: Within the discussion they acknowledge that because of the potential risk of bias, there is notable uncertainty in the estimates presented |
| If they performed quantitative synthesis, did the review authors carry out an adequate investigation of publication bias (small study bias) and discuss its likely impact on the results of the review? | Yes: They were unable to carry out a funnel plot assessment, there being less than 10 studies. However, they did carry out a sensitivity analysis of the take one away of the small study, which had a notable effect of the review's findings |
| Did the review authors report any potential sources of conflict of interest, including any funding they received for conducting the review? | Yes: There is a clear indication of funding for the systematic review |
Note: AMSTAR-2 tool taken from Shea et al (2017)
Based upon this assessment, it is deemed that this systematic review provides a comprehensive overview regarding the question of interest.
Results of Wang et al (2022)
A total of 80 records were identified, of which, eight RCTs were identified and subsequently included in a meta-analysis. Of these, the main areas of concern of risk of bias were regarding the lack of blinding of participants (n=5), small sample bias (n=4), blinding of outcome assessor (n=3) and lack of allocation concealment (n=3).
When including all RCTs that assessed the effects of CSI—compared to ‘wait and see’, ‘usual care’ or ‘sham intervention’—there was no evidence of effect for short-term pain relief (1 to ≤ 6 weeks). However, one analysis of a single RCT, which was deemed to be a potential outlier and had a small sample size, demonstrated a clinically and statistically significant large reduction in short-term pain (SMD −0.78, 95%CI: −1.04 to −0.53); I2=0%). For the medium term [6 to ≤ 12 weeks], there was also a clinically and statistically significant moderate reduction of pain when compared to ‘wait and see’ and ‘usual care’ for both analyses performed (SMD −0.47, 95%CI: −0.72 to −0.22, I2=0%). Irrespective of which tools were used in each study, the effect levels did notably change. For pain relief at 6 months, there was no evidence of effect. However, at 12 months, there was a borderline statistically significant but non-clinically significant reduction in pain (SMD −0.27, 95%CI: −0.52 to −0.02, I2=0%). Similarly, there was a borderline statistically significant improvement in functionality at 12 months (SMD − 0.26, 95%CI: −0.51 to −0.02, I2=0%).
When comparing CSI to exercise, there was no evidence of effect for short-(1 to ≤ 6 weeks) and long-term [3-month and 6-month] pain relief. There was also no evidence of effect in improvement in functionality when comparing CSI to platelet-rich plasma in the short- and medium-term. However, one RCT demonstrated a statistically significant reduction in improvement in long-term functionality (MD −38.25, 95%CI: −44.56 to −31.94).
One RCT found no evidence of difference between CSI versus dry needling in the short term. Another found a statistically significant reduction in short-(1 to ≤ 6 weeks) (MD −3.4, 95%CI: −4.34 to −2.46), moderate-(4 months) (MD 1.3, 95%CI: 0.44 to 2.16) and long-term pain relief (15 months) (MD 2.9, 95%CI: 1.87 to 3.93).
Commentary
Clinical practice
The findings from Wang et al (2022) are broadly in keeping with other published literature and consensus opinion on GTPS management, which recognises the value of CSI in providing short and medium-term pain relief, and the enduring impact of CSI on pain (Reid, 2016; Barratt et al, 2017).
However, because of the limited availability of evidence, these estimates carry a degree of uncertainty. While there was substantial heterogeneity observed concerning the short-term impact on pain; the limited number of studies included in Wang et al (2022) prevented a thorough exploration of it. Nevertheless, upon examination of the three studies encompassed in the CSI versus ‘wait and see’ and ‘usual care’ meta-analysis (short and medium term), they exhibited similar protocols and dosages. These included the administration of either 1 ml Betamethasone (5.7 mg/ml) or 1 ml Triamcinolone Acetonide (40 mg/ml), in combination with 1% or 2% Lidocaine, or 2ml Bupivacaine, or 1 ml Marcaine. These doses are similar to what is commonly recommended for treating GTPS using CSI (Le and Sha, 2023).
However, Wang et al (2022) focused on pain and function, and did not assess adverse events of CSI. While Coombes et al (2010) proposed that serious adverse events for CSI are relatively rare, this was based upon a relatively small evidence base that mainly focused on a single injection. When evaluating potential adverse events and risks, it is important for advanced practitioners to consider various factors, including the use of oral steroids, the frequency of injections, the specific types of steroids administered and the timing of any significant surgical procedures (Stout et al, 2019). Also, when addressing potential risks, it is important for advanced practitioners (APs) to engage in discussions with patients about potential outcomes such as pain, bleeding, infection, allergic reactions and injury (Le and Sha, 2023). In light of this uncertainty, diminishing effects observed over time and possible adverse events, it is imperative to conduct consistent, regular and standardised monitoring of pain (Dydyk and Grandhe, 2023). This practice is essential in the monitoring of the appropriate trajectory of pain and effective management.
Leadership and management
Current National Institute for Health and Care Excellence (NICE) guidelines advocate CSI as a second-line treatment to be considered for APs if initial conservative treatments (reassurance, avoidance of provocative movements, ice, analgesia and lifestyle advice) do not provide adequate pain relief (NICE, 2021). It is proposed that whenever feasible, CSI should be complemented by physiotherapy (NICE, 2021). As highlighted in a previous systematic review on the management of GTPS, CSI may provide a pain relief window that may contribute to positive treatment outcomes (Reid, 2016). Understanding the most effective moment to offer injection therapy for GTPS to maximise patient outcomes is paramount for APs (McEvoy et al, 2013). This would suggest that from a patient pathway perspective, CSI may be needed at the start of a physiotherapy regimen. As an AP, it is crucial to consider the debate regarding pre- or post-CSI when reflecting on managing this condition for each patient. The physiotherapy regimen would typically involve exercises that emphasise hip abduction, aimed at strengthening and stretching the gluteus medius and minimus muscles, or exercises for quadriceps strengthening, and iliotibial band stretching (Speers and Bhogal, 2017; NICE, 2021). It has been suggested that exercise regimens should be personalised to meet the specific needs of the individual, with an initial emphasis on enhancing gluteal strength and control (Speers and Bhogal, 2017). As hip control improves, the focus can then shift to strengthening the hip abductor muscles (Speers and Bhogal, 2017).
Despite these recommendations, there remains a significant degree of uncertainty regarding the most effective exercises for treating GTPS (Reid, 2016). Further research in this field is needed to identify key moderating factors for this type of intervention (Reid, 2016). Regrettably, Wang et al (2022) did not investigate the effectiveness of combining both CSI and exercise as a treatment approach. Nonetheless, when a direct comparison was made, no significant differences were observed in terms of pain improvement between CSI and exercise, both in the short- and long-term. It is worth noting that these estimates had considerably wider confidence intervals, indicating a higher degree of uncertainty (Wang et al, 2022). Therefore, without additional studies, these results remain inconclusive. In a similar vein, when compared to platelet-rich plasma treatment, there was no evidence of a difference in the short-term and mid-term effects of pain reduction (Wang et al, 2022). Similar to the exercise comparison, these findings remain uncertain, primarily because of limited numbers of studies resulting in broad confidence intervals seen in these estimates. Given this uncertainty in comparing the two interventions, the decision-making process will heavily rely on patient preference and clinical experience (Szajewska, 2018).
Education
Education was not a component of the conservative treatments compared or explored in Wang et al's (2022) study. Contemporary evidence suggests that the optimal treatment for tendinopathies requires a programme that targets the underlying pathology of tendinopathy, and uses education for load management and exercise (Cook and Purdam, 2012). Education helps to re-educate the possible maladaptive beliefs and cognitions that influence pain and disability (Fenton et al, 2015; Brodal, 2017). Other studies suggest that education is primarily implemented through in-person, face-to-face discussions (Jayaseelan et al, 2019; Sancho et al, 2019; Hasani et al, 2021). This approach fosters a dialogue centred on posing questions and providing answers to uncover implicit assumptions, thereby cultivating critical thinking skills (Wijma et al, 2016). This thorough evaluation is essential for pinpointing the patient's requirements and customising the educational material and presentation format accordingly (Wijma et al, 2016).
The inclusion of educational sessions at the beginning of treatment (eg through long sessions) may be used to promptly establish satisfactory adherence and a knowledge foundation that motivates physical activity and exercise (Jayaseelan et al, 2019; Sancho et al, 2019; Hasani et al, 2021). Incorporating an additional active educational learning strategy, where patients acquire knowledge through materials like videos and brochures, empowers therapists to customise interventions on an individual basis; this allows for a more focused exploration of aspects that patients find uncertain during subsequent face-to-face sessions (Escriche-Escuder et al, 2023). Regardless of the approach chosen, the focal point of education should centre on addressing the individual's specific functional challenges. This involves diminishing the persistence of pain by minimising provocation, especially during sustained or repetitive positions (Mellor et al, 2022). Additionally, enhancing pain self-efficacy can be achieved by improving comprehension of pathophysiology, understanding the effects of appropriate loading, alleviating fear and offering clear, specific instructions (Mellor et al, 2022). To adopt these educational strategies, it is important for APs to reflect upon their current pedagogical knowledge of these principles (Glaze, 2001; Health Education England (HEE), 2017). It is important to seek out further pedagogical training in the domains where learning needs and development are identified (HEE, 2017).
Research
As an AP, it is essential to use robust methods when engaging in research to assess clinical practice (HEE, 2017). Wang et al (2022) highlight key methodological lessons that should be incorporated into future research in this area:
Conclusions
Wang et al (2022) offer a comprehensive examination of the evidence on whether CSI is effective in reducing pain symptoms in adults with GTPS. Their findings indicate that CSI may significantly reduce pain in the short term for adults with GTPS. Acute pain reduction is a clinical benefit, which aligns with secondary recommendations from NICE (2021) that suggest CSI should be considered with additional physiotherapy. When comparing CSI to exercise, no evidence of difference was found in either the short or long term. As with the use of CSI, the type of, duration and frequency of exercise for GTPS appears to be uncertain. Future research should focus on robust, double-blind RCTs, which focus on active (combination therapy, duration, frequency and dose) and non-active comparisons.