In Part 2 of this blog on intraarticular pathology, we explore the relevance of ligamentum teres tears, and effusion-synovitis.In Part 1, we discussed the relevance of labral tears, chondral pathology and bone marrow lesions with respect to hip pain and joint health. If you haven’t read Part 1 yet, you might like to go there first and then return to continue reading.
3. Ligamentum Teres Tear
The ligamentum teres (LT) contains both nociceptive and proprioceptive nerve endings, with a stable innervation pattern that persists with ageing (Haversath et al 2013). The relationship between LT pathology and nociception remains unclear with limited and variable reports of prevalence in symptomatic and asymptomatic populations. A recent systematic review and meta-analysis concluded however, that LT pathology was more common in those with hip pain (Heerey et al 2018).
Ligamentum teres tear is more likely to be present in athletes and particularly athletes whose joints are challenged by large ranges of motion (Mayes et al 2016) or the presence of morphological variations such as FAI, acetabular dysplasia or capsular laxity (Martin et al 2019). Presence of LT tear has been associated with persistent hip pain in those with labral tears, such that in one study, those with LT and labral tear were 16.5 times more likely to fail non-surgical treatment and progress to a surgical intervention that those with labral tear alone (Kaya et al 2013).
For patients presenting to clinic with joint-related pain who:
- have pain +/- a feeling of instability in sumo-style squats/deep plie, or rotational tasks
- are slower to respond to standard joint care
- are/have been athletic
- and/or have morphological variants (FAI, Acetabular Dysplasia, Capsular laxity),
be suspicious of LT pathology.
You may need to provide more specific exercise therapy to optimise joint support in positions that challenge the LT.
With regard to the potential impact of LT pathology on joint health – from a joint stability standpoint, loss of integrity of the LT will reduce joint stability particularly in deep flexion/external rotation, end range rotation and distraction. LT pathology may be associated with microinstability, particularly in those with other morphological risk factors, with potential predisposition to early joint deterioration. LT pathology is also frequently associated with signs of inflammation of the synovium that surrounds the ligament, clearly visualised at the time of arthroscopy (Figure) and there is often accompanying inflammatory change in the adjacent pulvinar fat pad. We’ll discuss the role of inflammation in degenerative joint disease in the following section.
Learn more about the ligamentum teres, pathology and implications for management in my online learning course: Anterior Hip & Groin Pain. Specific load management and therapeutic exercise strategies are covered in the practical workshop of the same name.
4. Joint Effusion-Synovitis
Effusion of the hip joint is much harder to clinically appreciate than that of other peripheral joints, due to the depth of this joint and the fact that it is encapsulated by layers of muscular structures. And yet effusion and synovitis have been associated with pain and implicated in the pathogenesis and progression of osteoarthritis (Eymard et al 2017, Hunter et al 2013, Sokolove & Lepus 2013).
The joint capsule and its synovial lining are richly innervated and a potential source of nociception (Haversath et al 2013). The synovial lining of the LT, as we have discussed, will also be a possible contributor to hip joint nociception. Less commonly considered is the possible role of highly vascularised and innervated intra-articular fat pads in hip pain and joint health. Jayasekera and colleagues (2014) described a fat pad at the anterior head-neck junction, that may become hypertrophied and inflamed secondary to repetitive femoroacetabular impingement in those with cam morphology. They hypothesised that for some patients with FAI, their pain was primarily related to this traumatised fat pad and not their labral pathology. They demonstrated that, even though the groups had no difference in cam size, if the impingement viewed arthroscopically appeared to be primarily of the fat pad rather than of the bony cam, surgical excision of the fat pad without a femoral osteoplasty returned results equal to that of cam excision.
There is also another important fat pad within the medial hip joint, the pulvinar fat pad, intimately associated with the LT and its synovium. Arthroscopists commonly note visual inflammation of this fat pad in association with synovitis of the LT. Eymard and colleagues (2017) suggest that intra-articular fat pads and their adjacent synovium should be considered unique functional units. Intra-articular fat pads of the knee and hip are composed of smaller fat cells (adipocytes) with an inflammatory phenotype characterised by a higher expression and secretion of inflammatory factors than subcutaneous fat. These intra-articular fat pads may upregulate their expression of inflammatory mediators in response to excessive mechanical loads, subsequently stimulating an inflammatory response in the synovium. The functional interaction between intra-articular adipose and synovial tissue may be a mechanism underlying OA related synovitis, with potential impacts on pain and joint health. Synovitis can drive chondral degradation and osteophyte formation and is considered to play a critical role in the pathogenesis and progression of osteoarthritis (Wang et al 2018).
What this means for healthcare practitioners is that we must be mindful of the possible presence of effusion and synovitis in those with hip joint related pain, the implications for nociception and joint health, and the potentially vital role of load management in the long term care of your patient’s hip.
In the last 2 blogs, a number of possible sources of nociception for those with intra-articular hip pain have been highlighted. All of these structures play an important role in maintaining joint homeostasis and health, although sources of nociception and mechanical and inflammatory drivers of pain and pathology will vary between individuals. Optimal outcomes may be best achieved by considering an individual’s joint status and morphological, functional and inflammatory drivers, within a biopsychosocial framework.
Atukorala, I, Kwoh, CK., Guermazi, A., et al. (2016). Synovitis in knee osteoarthritis: A precursor of disease? Annals of Rheumatic Diseases, 75, pp.390e5.
Botser, I., Martin, D., Stout, C. and Domb, B. (2011). Tears of the Ligamentum Teres. The American Journal of Sports Medicine, 39(1_suppl), pp.117-125.
Eymard, F., Pigenet, A., Citadelle, D., et al. (2017). Knee and hip intra-articular adipose tissues (IAATs) compared with autologous subcutaneous adipose tissue: a specific phenotype for a central player in osteoarthritis. Annals of the Rheumatic Diseases, 76(6), pp.1142-1148.
Haversath, M., Hanke, J., Landgraeber, S., et al. (2013). The distribution of nociceptive innervation in the painful hip. The Bone & Joint Journal, 95-B(6), pp.770-776.
Heerey, J., Kemp, J., Mosler, A., et al. (2018). What is the prevalence of imaging-defined intra-articular hip pathologies in people with and without pain? A systematic review and meta-analysis. British Journal of Sports Medicine, 52(9), pp.581-593.
Hunter, D., Guermazi, A., Roemer, F., Zhang, Y. and Neogi, T. (2013). Structural correlates of pain in joints with osteoarthritis. Osteoarthritis and Cartilage, 21(9), pp.1170-1178.
Jayasekera, N., Aprato, A. and Villar, R. (2014). Fat Pad Entrapment at the Hip: A New Diagnosis. PLoS ONE, 9(2), p.e83503.
Kaya, M., Kano, M., Sugi, A., et al. (2013). Factors contributing to the failure of conservative treatment for acetabular labrum tears. European Orthopaedics and Traumatology, 5(3), pp.261-265.
Martin, R., McDonough, C., Enseki, K., et al. (2019). Clinical relevance of the ligamentum teres: a literature review. International Journal of Sports Physical Therapy, 14(3), pp.459-467.
Mayes, S., Ferris, A., Smith, P., et al. (2016). Atraumatic tears of the ligamentum teres are more frequent in professional ballet dancers than a sporting population. Skeletal Radiology, 45(7), pp.959-967.
Mayes, S., Ferris, A., Smith, P. and Cook, J. (2018). Hip Joint effusion-synovitis is associated with hip pain and sports/recreation function in female professional ballet dancers. Clinical Journal of Sport Medicine, [23 Mar 2018].
Roemer FW, Hunter DJ, Winterstein A, et al. (2011). Hip Osteoarthritis MRI Scoring System (HOAMS): reliability and associations with radiographic and clinical findings. Osteoarthritis Cartilage, 19, pp.946–962.
Sokolove, J. and Lepus, C. (2013). Role of inflammation in the pathogenesis of osteoarthritis: latest findings and interpretations. Therapeutic Advances in Musculoskeletal Disease, 5(2), pp.77-94.
Wang, X., Hunter, D., Jin, X. and Ding, C. (2018). The importance of synovial inflammation in osteoarthritis: current evidence from imaging assessments and clinical trials. Osteoarthritis and Cartilage, 26(2), pp.165-174.