Introduction

Patients with both joint hypermobility and musculoskeletal complaints can be classified as having hypermobility spectrum disorder (HSD). It is reported that at least four out of five patients with HSD present with chronic pain and shoulder instability. They experience symptoms of subluxation, dislocation, and pain or they report a sensation of the shoulder giving way. The more subtle symptoms of giving way and subluxations are sometimes difficult to diagnose compared to a dislocation that gets evaluated by radiography and obviously needs a reduction. The more subtle forms of shoulder instability are evaluated through several clinical tests. According to the authors, shoulder instability can then be classified as either anterior, multidirectional, localized shoulder hypermobility or generalized joint hypermobility. It is thought that a higher number of diagnoses and positive tests may lead to higher complexity. A patient with instability or laxity in all directions is expected to have greater impairments compared with having instability or laxity in one direction. But is higher complexity related to higher impairment? This study tried to seek this out in a patient population with hypermobility spectrum disorder.

Methods

This study was a secondary analysis of cross-sectional data obtained from an RCT by Liaghat et al in 2022, which we recently reviewed. Patients were recruited from several medical and physiotherapy clinics in primary care in Denmark and were examined by one of four blinded physiotherapists. Participants were eligible for inclusion when they were between the ages of 18 and 65 and met the following inclusion criteria:

• Generalized HSD (G-HSD), defined using a Beighton score cut off ≥ 5/9 for females up to the age of 50 years, and ≥ 4/9 for those > 50 years and all males without age-specific cut-points, or Historical HSD (H-HSD) if the Beighton score was 1 point below the age and sex-specific cut-off and the 5PQ was positive (≥ 2/5 positive answers). The Beighton Score

And

• One or more of the following self-reported (yes/no) symptomatic musculoskeletal manifestations present:
  • Pain in at least one shoulder for at least three months.
  • Recurrent joint dislocations or joint instability without a reported history of trauma, defined as (a) a minimum of three atraumatic dislocations in the same shoulder, (b) a minimum of two atraumatic dislocations in two different joints (a minimum of one in the shoulder) occurring at different times, and/or (c) medical confirmation of joint instability in at least two joints (a minimum of one in the shoulder).

After inclusion, a physical assessment was conducted where these subjects were evaluated by filling out the Western Ontario Shoulder Index (WOSI), rating their pain on the Numeric Pain Rating Scale (NPRS), and 10 clinical shoulder tests:

1. Anterior apprehension
2. Anterior relocation
3. Surprise test
4. Sulcus sign
5. Load and Shift test in anterior direction
6. Load and Shift test in posterior direction
7. Gagey test
8. Rotes Querol external rotation test:
9. Shoulder flexion hypermobility test
10. Shoulder rotation hypermobility test

The supplementary file 3, accessible here explains the tests mentioned above and the corresponding criteria to be rated as either positive or negative.

Participants were divided into the following three pre-defined possible clinical shoulder diagnoses using the ten clinical shoulder tests.

1. Anterior Instability, if the participant had a positive Anterior Apprehension Test and at least one positive test of the Anterior Relocation Test and/or the Surprise Test.
2. Multidirectional Instability, if the participant had a positive Sulcus Sign and at least one positive Load and Shift Test in either posterior and/ or anterior direction.
3. Localized Shoulder Hypermobility, if the participant had at least one positive clinical test for hypermobility of the shoulder, including Gagey, Rotes-Querol External Rotation Test, Shoulder Flexion Hypermobility Test, and Shoulder Rotation Hypermobility Test.

Results

In total, 100 participants with a mean age of 37 years were enrolled of which 54 fulfilled the criteria for anterior shoulder instability, 78 for multidirectional shoulder instability, 90 for localized shoulder hypermobility and 4 participants were negative for all of the 10 shoulder tests. This resulted in 18 participants with none or 1 diagnosis, 38 with 2 diagnoses, and 44 with 3 diagnoses.

So, is higher complexity related to higher impairment? It appears not. Compared with having none or only 1 clinical shoulder diagnosis, there was no difference in functional level between having neither two (difference in WOSI: 68.8 95% CI -139.8, 277.4) nor three (difference in WOSI: 20.7 95% CI -183.3, 224.6) clinical shoulder diagnoses.

The number of positive tests was not related to their function and quality of life (based on the WOSI questionnaire), nor to their pain levels (NPRS).

Questions and thoughts

So, is higher complexity related to higher impairment? This study found that it is not related. So when a patient with complex shoulder pathology comes to see you, you don’t have to expect many more physical impairments or disabilities than you would expect in a patient with less complex pathology.

This study examined anterior, multidirectional shoulder instability, localized shoulder hypermobility, or generalized joint hypermobility but did not mention posterior shoulder instability. It is a rare condition than anterior shoulder instability but exists. Furthermore, the authors acknowledge that there is a lack of consensus about multidirectional shoulder instability and that it is rarely described. Yet they include it as one of the possible diagnoses, and the criteria that this condition has to fulfill may be questioned due to the lack of consensus reported.

Every participant underwent the 10 clinical shoulder tests as described previously. The criteria to rate a test as positive are described in the supplementary file, which is accessible through the link mentioned above. However, if a participant was unable to perform the test as intended due to pain or other symptoms, the test was rated as negative. I find this a bit odd because you would expect a negative test only in the absence of the intended findings. This may have caused a greater number of negative tests and may pose a problem in the interpretation of these results. When a patient for example has a high level of apprehension on the apprehension test and is not allowed to conduct the test as described, it would mean that in this case the test would be rated as negative, which is obviously not the case!

Talk nerdy to me

Higher complexity related to higher impairment is not the case, at least in shoulder patients with HSD. Even though this data was obtained from another RCT study, a statistical analysis plan for this cross-sectional analysis was pre-registered. This increases transparency and exactness but also avoids positive finding bias. Another positive point is that the study foresaw a standardization of the examination procedures. By examining the subjects by one of four trained physiotherapists. This ensured that even though participants were recruited from different centers and seen by different physios, we can assume that the obtained results had high inter-clinician reliability.
A relevant side note can be placed at the following. The sample consisted of more women than men (79% female) and therefore these results shouldn’t be extrapolated to men.

Take home messages

Higher complexity related to higher impairment does not seem likely in hypermobility disorders of the shoulder. There was no difference in function and quality of life, nor in pain levels between individuals who had a more complex clinical picture (multiple shoulder diagnoses) compared to less complex patients. There was no relationship between having multiple positive clinical shoulder tests and functional ability, quality of life, and pain.

Reference

Kjærbæk F, Juul-Kristensen B, Skou ST, Søndergaard J, Boyle E, Søgaard K, Liaghat B. The association between number of shoulder diagnoses and positive clinical tests with self-reported function and pain: A cross-sectional study of patients with hypermobile joints and shoulder complaints. Musculoskelet Sci Pract. 2022 Jul 30;62:102624. doi: 10.1016/j.msksp.2022.102624. Epub ahead of print. PMID: 35944447.