Characterizing the Progression of Varying Types of Calcific Tendinitis around Hip

PURPOSE: To assess the progression of clinical symptoms and disease course of calcific tendinitis in the hip region according to types of calcification. MATERIALS AND METHODS: Among patients with the hip pain, 28 patients (21 males and 7 females; mean age 51 years, range 32-74 years) showing calcified lesions in simple radiography without other possible sources of pain were analyzed retrospectively. Twelve patients displayed a symptom duration of less than three weeks (acute; average=1±0.9 week) and 16 displayed greater than three weeks (chronic; average=21.0±19.5 weeks). Lesions were classified as nodular (11, 39.3%), nodular-fragmented (13, 46.4%), or amorphous (4, 14.3%). Initial symptoms, progression of clinical features, radiological findings and prognosis were investigated and analyzed according to calcification type. RESULTS: In 15 patients (53.6%), lesions were located superior to the great trochanter. On average, the acute group was younger (44.58 vs. 55.44 years, P=0.006), suffered more (mean pain Numeric Rating Scale [NRS], 6.3 vs. 3.8; P<0.001), and recovered more (difference between initial and follow-up NRS, 5.1 vs. 2.63; <<0.001) than the chronic group. The mean length of initial lesions was longer in the acute group than the chronic group (15.8 vs. 9.1 mm, P=0.008). When compared to patients with distinctive margins (15, 53.6%), those with nondistinctive margins showed better improvement (difference between initial and follow-up NRS, 4.7 vs. 2.8; P=0.01) and more significant decrease in lesion size (difference between initial and follow-up length, 10.8 vs. 2.6 mm; P=0.003). CONCLUSION: Calcific tendinitis occurring in the hip area displayed a variety of characteristics. Although complaining of more severe pain in the initial phase, patients with acute pain or calcific lesions with nondistinctive margins showed better symptom improvement when compared to their counterparts.