1. 1. What were your thoughts regarding the most likely source of Trish’s pain following the subjective examination?

1. 2. Given the insidious nature of onset combined with the pain behaviour, can you please discuss your reasoning with respect to the most likely contributing factors to this episode?

1. 3. What was your interpretation of Trish’s postural tendency to overuse her TFL, and did this suggest a particular direction for treatment?

1. 4. Did observation of standing posture, in particular, ‘hanging on one hip’ in adduction, support your hypothesis regarding the source of the symptoms?

1. 5. Can you please explain how the information from the testing of gluteal function, in particular lag of abduction, contributed to your reasoning?

Trish’s active lag of abduction was over 20 degrees on both sides but was slightly greater on the right, reflecting poor function of the trochanteric abductors on both sides. Normative data are not available in the literature; however, clinically those with normal function can usually lift the hip into an abduction range that is within 5–10 degrees of their passive range. Trish’s hip abductor strength was approximately 15% less on the right side, and both the strength test and active abduction produced a pain of 3/10 (PNRS) intensity over the greater trochanter on this side. Baseline values are reported in Table 12.3. Deficits in hip abductor muscle strength in those with symptomatic gluteal tendinopathy have been demonstrated when compared with both the asymptomatic or less symptomatic hip and a pain-free control population (Allison et al., 2016). Trish’s abductor weakness and pain reproduction during strength testing was consistent with a diagnosis of gluteal tendinopathy and provided a treatment direction for the rehabilitation process.

1. 6. What differential diagnoses were you considering at this stage? What was the supporting and refuting evidence for each?

Second, hip joint pathology should be considered. Although lateral hip and thigh pain is commonly described by those with hip osteoarthritis (OA) (Altman et al., 1991; Lesher et al., 2008), localized pain over the greater trochanter is rarely the only or primary complaint in most clinical scenarios. Groin and posterior buttock pain are the most common types of pain associated with hip OA (Lesher et al., 2008), or the patient may describe a pain which travels between the anterior and posterior hip, indicating this by grasping the hand around the lateral hip above the greater trochanter and below the ilium – referred to as the ‘C sign’ (Byrd, 2007). Hip OA is also associated with loss of range of motion, particularly end-range flexion and internal rotation (Altman et al., 1991). Acetabular labral tears may also produce hip pain in the absence of OA. The most common area of pain distribution is the anterior groin region, often extending down the anterior thigh to the knee (Burnett et al., 2006). Some patients with labral tears may experience buttock pain, and just over half complain of lateral hip pain (Burnett et al., 2006). An important clinical distinction here is that the lateral pain is not generally located over the greater trochanter but rather in the anterolateral hip region between the greater trochanter and the anterior superior iliac spine. Those with labral pathology may describe pain of an aching nature; however, many patients will also experience intermittent, sharp pain in the groin or anterolateral hip, most frequently with weight-bearing pivoting (Burnett et al., 2006; Tibor and Sekiya, 2008). Mechanical descriptions such as catching, snapping or locking are also common (Burnett et al., 2006; Tibor and Sekiya, 2008). Physical tests, such as the quadrant or scour test and FADDIR, or impingement tests (flexion 90 degrees + internal rotation) are very sensitive to the presence of intra-articular hip pathologies but have poor specificity (Reiman et al., 2013). Although the lack of specificity of such tests provides low confidence in determining the precise structural source of the pain when the test is positive, sensitive tests such as these are useful for ruling out a symptomatic pathology when the result is negative.

Trish’s description of her hip problem did not include groin or posterior buttock pain, sharp pains or mechanical sensations such as catching or locking. On physical examination, her hip range of motion was normal and equal between sides, and scour and impingement tests were negative. These findings indicated that an intra-articular hip pain source was an unlikely contributor to her current pain state.

Finally, gluteal tendinopathy remains. Lateral hip pain is reported to be most common in women aged over 40 years (Alvarez-Nemegyei and Canoso, 2004; Segal et al., 2007). Pain and tenderness over the greater trochanter are considered hallmark signs of local soft tissue pathology (Hoffmann and Pfirrmann, 2012; Labrosse et al., 2010; Segal et al., 2007). The literature describes pain that is provoked particularly by side-lying, but also standing on one leg, walking up hills or stairs and moving to standing after prolonged sitting (Fearon et al., 2013; Hoffmann and Pfirrmann, 2012). Traditionally referred to as trochanteric bursitis, it is now well established that gluteus medius and/or minimus tendinopathy is the most common pathology associated with lateral hip pain. However, there is often a co-existence of tendon and bursal changes, and even thickening of the iliotibial band (Bird et al., 2001; Blankenbaker et al., 2008; Cowan et al., 2003; Fearon et al., 2010; Hoffmann and Pfirrmann, 2012; Long et al., 2013). Physical tests do not accurately differentiate between these various pathologies but can be helpful in differentiating local soft tissue pathology from a more distant source, such as the spine or hip joint.

Tenderness over the greater trochanter has been shown to be the most accurate test for predicting gluteal tendon changes on magnetic resonance imaging (MRI; highest proportion of true results, either positive or negative), with the lowest negative likelihood ratio, indicating that if palpation is negative on clinical testing, the result significantly increases the likelihood that the MRI will be negative too. However, the specificity of palpation findings is low, and the positive likelihood ratio is less useful, meaning that although the test is useful for ruling out tendinopathy when the trochanter is non-tender, the trochanter may be tender in the absence of tendinopathy (Grimaldi et al., 2017). Palpation should then be used in combination with other tests that possess more useful positive likelihood ratios and positive predictive values. Physical tests, such as sustained single leg stance, FABER, FADER and hip adduction (passive and with resisted isometric abduction), can be used to increase the likelihood of a diagnosis of gluteal tendinopathy when positive, particularly the tests that include an active muscle contraction (single leg stance; FADER with resisted isometric internal rotation; adduction with resisted isometric abduction) (Grimaldi et al., 2017; Lequesne et al., 2008). These tests are described in more detail in Table 12.4. It is important to note, however, that many people without lateral hip pain have changes in their trochanteric tendons and bursae evident on MRI (Blankenbaker et al., 2008; Grimaldi et al., 2016). It is therefore important that radiological signs alone are not used for determining a pain source at the lateral hip. For a clinical diagnosis of symptomatic local soft tissue pathology at the lateral hip, the patient must be tender on palpation over the greater trochanter and be positive on at least one of the physical tests described in Table 12.4. A positive test is defined as one that reproduces the patient’s pain in the region of the greater trochanter.

In considering the information available for the current case study, Trish fit the population who experience lateral hip pain of local origin – female and aged over 40 years. Her description of the area, nature and aggravating factors was consistent with that outlined in the literature. Although the word ‘burning’ has not been used in the literature when describing the nature of tendinopathy or bursal pathology at the lateral hip, anecdotally, it is not an uncommon description in the absence of clinical or radiological signs of a neurogenic source. Such overlap in description can make differential diagnosis complicated, and each potential source must be closely considered. Trish tested positive for reproduction of her right lateral hip pain on the FADER and FADER tests with isometric internal rotation (8/10 pain reproduced on both tests), on the FABER test (6/10) and on sustained single leg stance, with lateral hip pain of 4/10 intensity reproduced within 5 seconds of single leg standing. Trish was tender on palpation of the right greater trochanter, particularly at the anterior aspect and proximal lateral aspect. There was also some milder tenderness over the left greater trochanter and a positive response to the left passive FADER test (5/10 pain).

Taking all subjective and objective information into consideration, Trish’s clinical diagnosis was likely right-sided gluteal tendinopathy, which may or may not have associated bursal change. Trish had some mild signs and symptoms on the left side as well, suggesting that she may have had a bilateral problem, but with the right side much more significant in terms of pain and functional limitation.

1. 7. You have performed a comprehensive physical examination. How have the results of any radiological investigations influenced your reasoning?

Trish had been referred for MRI and radiographs of the right hip (Fig. 12.3). This information was available subsequent to her initial assessment and clinical differential diagnosis. Gluteus medius and minimus tendinosis was reported on an MRI of the right hip. The gluteus minimus tendon also demonstrated some mild calcification and partial-thickness tearing of its insertional fibres, and the underlying sub-gluteus minimus bursa was oedematous. The presence of partial-thickness tearing of the deep anterior insertional fibres of the gluteus medius and moderate oedema in the sub-gluteus maximus (trochanteric) bursa was also noted by the radiologist. With respect to articular structures, changes were rated as mildly degenerative with irregular tearing of the superior acetabular labrum but with no joint effusion. The mild degenerative joint change was confirmed on radiographs, with some subtle calcification noted adjacent to the anterior aspect of the greater trochanter, consistent with the MRI findings of gluteus minimus tendon calcification. Right hip joint changes were rated by the radiologist as Grade 1 (doubtful narrowing of joint space and possible osteophytes) on the Kellgren-Lawrence Scale, where 0 is no radiographic findings, and 4 is severe joint change.

When imaging information is available, it is extremely important that this information is used to augment rather than replace the clinical differential diagnosis. Fifty percent of people without lateral hip pain have gluteal tendinopathy on MRI, and 88% have some form of peri-trochanteric abnormality or increase in signal around the greater trochanter (Blankenbaker et al., 2008). Acetabular labral tears are present in 69% of an asymptomatic population of average age of 37.8 years (range 15–66), and some sign of early joint degeneration is present in 73% of this population (Register et al., 2012). Similarly, in a younger active asymptomatic population with an average age of 34 years (range 27–43), labral tears on MRI were present in 80%–85% (Schmitz et al., 2012).

Trish’s imaging results helped confirm her clinical diagnosis of gluteal tendinopathy and the presence of accompanying bursal change. It also showed that she was clearly in a degenerative stage of tendinopathy, with calcification and tears evident. The mild joint change and acetabular labral tearing were in this instance considered to be irrelevant to her current pain presentation based on the differential diagnosis performed. However, a management protocol designed to improve the health of the lateral stability mechanism of the hip and pelvis and symptoms of lateral hip pain may also provide a beneficial effect for the underlying hip joint because those with hip OA also present with gluteal muscle deficits (Grimaldi et al., 2009a, 2009b).

1. 8. What were your thoughts about the optimal approach to helping Trish manage her problems?

Compressive loading has been proposed to be an important aetiological mechanism for the development of insertional tendinopathy (Almekinders et al., 2003; Cook and Purdam, 2012). The tendon enthesis naturally has a higher prevalence of larger proteoglycans than the main body of the tendon, and there is a transition to cartilage-like cells at the bony interface. These features allow better adaptation to the higher incidence of compressive loads at the tendon insertion, whereas the main tendon is more adapted to high tensile loads (Cook and Purdam, 2012). However, if the tendon is exposed to excessively high levels of compression over time, adaptation may occur within the tendon to assist with controlling compressive loads – the laying down of more large proteoglycans (such as aggrecan and versican) which draw more water into the tendon, more chondrocytes and eventually osteocytes. Thickening of the bursae is likely to reflect a similar adaptation to excessive compressive loading. Compressive loading of the gluteal tendons and associated bursae occurs between the ITB and the greater trochanter in positions of hip adduction (Birnbaum et al., 2004). Daily postures that may contribute to cumulative compression include sitting with the knees crossed or together, standing ‘hanging on one hip’ in adduction and side-lying where the lowermost greater trochanter is compressed into the bed, and the uppermost hip rests in flexion/adduction across the body. In sitting, the depth of the seat often has an impact on lateral hip pain, with lower seats such as car seats producing more aggravation. Because the ITB merges posteriorly into the gluteal fascia, which extends up into the thoracodorsal fascia, hip flexion may also increase the tension within the ITB, particularly if there is any degree of concurrent adduction. Even 10 degrees of hip adduction can produce a nine-fold increase in compressive loading at the greater trochanter (Birnbaum et al., 2004). Load management through modification of postural and dynamic loading habits is a key component of the planned intervention.

Isometric exercises have been shown to activate segmental and extra-segmental descending pain inhibitory spinal pathways (Kosek and Ekholm, 1995; Kosek and Lundberg, 2003). Furthermore, sustained low-intensity contractions (25% of maximum voluntary isometric contraction [MVIC]) have been shown to be superior in raising pain pressure thresholds as compared with high-intensity contractions (80% MVIC) in a pain-free population (Hoeger Bement et al., 2008). Isometric contractions are now recommended for their pain-relieving qualities in the management of tendinopathy (Cook and Purdam, 2013; Rudavsky and Cook, 2014), with a regime of four 70% MVIC contractions held for 45 to 60 seconds, repeated several times a day (Rudavsky and Cook, 2014), suggested for patellar tendinopathy. However, scientific evidence based on interventional studies remains lacking, leaving the gold standard for application method yet to be determined for specific pathological conditions.

The hip abductors are also directly targeted by providing loading in their primary plane of action – the coronal plane. These exercises, like the functional strengthening described previously, are all closed-chain exercises. Weight-bearing exercise has been demonstrated to elicit greater activation of gluteus medius than non-weight-bearing exercise (Bolgla and Uhl, 2005). Initially the loading is relatively light to establish the response to direct abductor loading. As tolerated, the loading is progressed toward a typical hypertrophy protocol employing low-velocity, high-load exercise. The high-load exercise is performed under supervision, using a spring-resisted sliding platform such as a Pilates reformer, to provide bilateral closed-chain loaded abduction. The added benefit of using the sliding platform is that hip adduction past neutral can be completely avoided, allowing provision of gradually greater tensile loads, without any compression imparted by the ITB across the greater trochanter.