To the Editor: Hypothyroidism is a common autoimmune disease, but few pediatric endocrinologists are attuned to the symptom of claudication. The slipped capital femoral epiphysis (SCFE) is always ignored and misdiagnosed. We report two cases having hypothyroidism with SCFE.

Case 1: A 15-y-old boy, with a five-year history of growth retardation and constant limping, experienced intermittent left lower limb pain for 1 y. He was short, obese, and pale. Orthopedic examination showed that his left leg was 1 cm shorter. His left hip was also slightly limited in flexion and the right hip had a full, painless range of motion. The outcomes of laboratory examination and imaging are summarized in Table 1. Anteroposterior radiography of the left hip revealed SCFE (Fig. 1). After receiving sodium levothyroxine daily for a week, bilateral in situ fixation of caput femoris was done. Following 6 mo of hormonal therapy, the patient gained 3 cm in height and lost 1 kg of body weight.

Table 1 Baseline clinical and laboratory patient data
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Fig. 1
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Anteroposterior view of the pelvis: left slipped capital femoral epiphysis

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Case 2: A 12-y-old boy, clearly overweight, with slow growth in recent 5 y, suffered worsening of agnogenic claudication 1 mo ago. Musculoskeletal examination showed that both lower limbs were equal in length, but the right quadriceps femoris was atrophied. Coccygeal abduction and flexion were limited as well. Physical examination findings are recorded in Table 1. The treatment given was same as in Case 1. Radiographs of the hips pre- and postoperatively are shown as Fig. 2. Five months after the surgery, the patient was able to walk without a limp, and had gained 3 cm in height.

Fig. 2
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a Preoperative pelvic radiograph showing right slipped capital femoral epiphysis b Postoperative pelvic radiograph (same patient) after bilateral percutaneous in situ fixation

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In hypothyroid children degeneration of chondrocytes is accelerated and calcification of cartilage matrix is enhanced, whereas, ossification of cartilaginous matrix is suppressed [1, 2]. Most studies indicate that SCFE resulting from thyroid hormone deficiency is rooted in loss of stability at the growth plate [1–3]. In the past, the relative researches of hypothyroidism and SCFE have not been paid sufficient attentions by the pediatric endocrinologists. In routine practice of endocrinology, leg pain in hypothyroid patients should not be ignored. A comprehensive clinical examination is vital to a diagnosis of SCFE.