Hypothyroidism presenting as tendinitis

Ultrasonographic evaluation of shoulder tendons in patients with Hashimoto's disease

OBJECTIVES

To investigate the thickness of the shoulder tendons and the measurement of acromiohumeral distance (AHD) in patients with Hashimoto's disease (HD).

MATERIAL AND METHODS

Twenty-eight patients with subclinical hypothyroid HD, 40 patients with euthyroid HD, and 51 healthy subjects were included. The thicknesses of biceps brachii, subscapularis, supraspinatus, infraspinatus tendons at both shoulders were evaluated with ultrasonography. Serum levels of thyroid stimulated hormone (TSH), free tri-iodothyronine, free thyroxine (FT4), anti-thyroid peroxidase (TPO) and anti-thyroglobulin (anti-TG) antibodies levels were measured.

RESULTS

Height, weight, body mass index (BMI), free T3 and free T4 levels were similar between the three groups (P = .839, P = .205, P = .374, P = .430 and P = .497, respectively). Biceps brachii, supraspinatus and infraspinatus tendon thicknesses in dominant arm and biceps brachii, subscapularis and infraspinatus tendon thicknesses in non-dominant arm were significantly increased in euthyroid HD compared to healthy controls (P = .003, P = .030, P < .001; P = .035, P = .042, P < .001, respectively). Biceps brachii tendon thickness in dominant arm and subscapularis and supraspinatus tendon thicknesses in non-dominant arms were significantly increased in subclinical hypothyroid HD compared to healthy controls (P = .025; P = .046, P = .017, respectively). However there was no such difference between euthyroid HD and subclinical hypothyroid HD groups (P < .05). There was low correlation between biceps brachii tendon thickness and free T4 level in non-dominant shoulder in patients with HD (r = .272 P = .030). For the rest of the tendons, there was no correlation between TSH, anti-TPO, anti-TG levels and tendon thicknesses in patients with HD.

CONCLUSIONS

This study suggests that thyroid autoimmunity in HD may lead to an increase in thickness of shoulder tendons.

What is the role of systemic conditions and options for manipulation of bone formation and bone resorption in rotator cuff tendon healing and repair?

Rotator cuff pathology is a significant cause of shoulder pain. Operative repair of rotator cuff is an established standard of care for these patient, however, failure of the procedure is common. Systemic conditions such as diabetes mellitus, hypocholesteremia, thyroid disease, and smoking significantly affect the outcomes of rotator cuff repair and have significant implications for the management of these patients. Diabetes mellitus has been proposed to damage tendons through non-enzymatic glycosylation of collagen with advanced glycation end product formation and impaired microcirculation. Hypocholesteremia may lead to fatty infiltration and subsequent pro-inflammatory degenerative enzymatic degeneration. Thyroid disease may disrupt tendon homeostasis through the alteration of collagen production and the accumulation of glycosaminoglycans. Lastly, smoking inhibits tendon healing through the induction of hypovascularity and hypoperfusion. Understanding of the implications these systemic conditions have on the outcomes is important in the management of rotator cuff disease.

Spontaneous rupture of the long head of the biceps tendon in a woman with hypothyroidism: a case report

Background

Tendinitis can be a presenting complaint in hypothyroidism, with symptomatic relief being obtained by appropriate management of the primary thyroid deficiency. To the best of our knowledge no other cases of spontaneous rupture of the long head of the biceps tendon during uncontrolled hypothyroidism have yet been reported.

Case presentation

This case report describes an unusual case of spontaneous rupture of the long head of the biceps tendon in a 48-year-old white woman with severe hypothyroidism. She described experiencing a sudden sharp pain and an audible pop in her right shoulder while using her personal computer. On physical examination she was positive for Yergason’s sign and a subsequent magnetic resonance imaging scan showed complete rupture of the long head of her biceps tendon. Laboratory tests revealed significantly elevated thyrotropin levels (>100 μIU/ml) and very low levels of both triiodothyronine (0.17 ng/ml) and free thyroxine (0.18 ng/dl). She was switched to a different thyroxin regimen with a progressive dosage increment. She declined surgical re-anchorage of the tendon but despite the discreet Popeye sign, her overall strength and shoulder function were satisfactory. After 2 months, she was found to be clinically euthyroid, having normal thyroid function tests (thyrotropin 2.95 μIU/mL, free thyroxine 1.07 ng/dl). At her last follow-up visit, 1 year post-injury, she reported nearly normal shoulder function in her daily activities and had a constant shoulder score of 93 points.

Conclusions

The role of thyroid hormones in the synthesis and degeneration of collagen and in the proliferation and apoptosis of human tenocytes is discussed, providing a possible mechanism whereby hypothyroidism may lead to tendon tears. This report may have a greater impact among different subspecialties as it presupposes a high degree of awareness from internists, endocrinologists and orthopedic surgeons.

Influence of Thyroid Hormones on Tendon Homeostasis

Tendinopathies have a multifactorial etiology driven by extrinsic and intrinsic factors. Recent studies have elucidated the importance of thyroid hormones in the alteration of tendons homeostasis and in the failure of tendon healing after injury. The effects of thyroid hormones are mediated by receptors (TR)-α and -β that seem to be ubiquitous. In particular, T3 and T4 play an antiapoptotic role on tenocytes, causing an increase in vital tenocytes isolated from tendons in vitro and a reduction of apoptotic ones; they are also able to influence extra cellular matrix proteins secretion in vitro from tenocytes, enhancing collagen production. From a clinical point of view, disorders of thyroid function have been investigated only for rotator cuff calcific tendinopathy and tears. In this complex scenario, further research is needed to clarify the role of thyroid hormones on the onset of tendinopathies.

Calcific tendinitis: natural history and association with endocrine disorders

A retrospective, observational cohort study of 102 consecutive patients (125 shoulders) with calcific tendinitis is presented. Of the patients, 73 (71.6%) were women and 29 (28.4%) were men. Compared with population prevalences, significant levels of endocrine disorders were found. We compared 66 patients (62 women [93.9%] and 4 men [6.1%]; mean age, 50.3 years) (81 shoulders) with associated endocrine disease with 36 patients (11 women [30.6%] and 25 men [69.4%]); mean age, 52.4 years) (44 shoulders) without endocrine disease. The endocrine cohort was significantly younger than the non-endocrine cohort when symptoms started (mean, 40.9 years and 46.9 years, respectively), had significantly longer natural histories (mean, 79.7 months compared with 47.1 months), and had a significantly higher proportion who underwent operative treatment (46.9% compared with 22.7%). Disorders of thyroid and estrogen metabolism may contribute to calcific tendinitis etiology. Classifying calcific tendinitis into type I (idiopathic) and type II (secondary or endocrine-related) aids prognosis and management.