The disappearance of femoral head and neck resulting from extensive bone defect caused by secondary syphilis: a case report and literature review.

BACKGROUND: Treponema Pallidum (TP), the pathogen of syphilis, commonly infects bones in cases of congenital and tertiary syphilis, but it is rare in the primary and secondary stages. With its mild symptoms and rare clinical findings, it might be easy to dismiss the diagnosis of early syphilis. Usually, effective results can be achieved after the conventional strategy of antibiotic treatments, mainly penicillin. To our knowledge, our case is so far the most serious reported case of destructive bone lesion in secondary syphilis, and our treatment for the case is the first strategy using total hip arthroplasty in secondary syphilis. CASE PRESENTATION: We present the case of a 71-year-old man with local repeated pain and dysfunction in the right hip. Radiologic examinations showed the disappearance of the ipsilateral femoral head and neck. After excluding the aetiologies of cancer metastasis and tuberculosis, we confirmed the diagnosis of syphilitic arthritis. The patient received the medical treatment of antibiotics and the surgical treatment of total hip arthroplasty. At the follow-up of 1, 3, and 5.5 years after the operation, the patient presented with a pain-free and functional hip prosthesis without local signs of infection and loosening. CONCLUSIONS: This report highlights the difficulties of early diagnosis of secondary syphilis with bone involvement. Bone defect of the femur with secondary syphilis, especially at the proximal femur, was an extremely rare complication in the previous reports. Our case was the first case of a patient who experienced the disappearance of femoral head and neck caused by secondary syphilis. Follow-up after the operation proved the successful treatment of the extensive bone defect of femur by total hip arthroplasty.

3D MRI Quantification of Femoral Head Deformity in Legg-Calvé-Perthes Disease.

The purpose of this study was to quantify femoral head deformity in patients with Legg-Calvé-Perthes disease (LCPD) using a novel three dimensional (3D) magnetic resonance imaging (MRI) reconstruction and volume based analysis. Bilateral femoral heads of 17 patients (mean age 9.9 ± 2.0 years; 12 boys, 5 girls) with LCPD were scanned 1-2 times (n = 33 LCPD heads, 20 normal heads) using a 1.5T MRI scanner. Fourteen patients had unilateral and three had bilateral LCPD with five hips in the Waldenström initial stage, 9 in the fragmentation stage, 14 in the reossification stage, and 5 in the healed stage. 3D digital reconstructions of femoral heads were created using MIMICS software. Deformity was quantified using a 3D volume ratio method based on reference hemisphere volume as well as two surface geometry methods. Intra-observer analysis showed that 97% of the LCPD femoral heads were within 10% of the original value and test shapes had 99.6% accuracy. For normal femoral heads, the volume ratios of all except one were between 95 and 98% (n = 20) of a perfect hemisphere volume. For femoral heads affected with LCPD, the volume ratios ranged from 43% to 96% of a perfect hemisphere (n = 33). The volume ratio method and the two surface geometry comparison methods had high correlation (r = 0.89 and 0.96). In summary, the 3D MRI volume ratio method allowed accurate quantification and demonstrated small changes (<10%) of the femoral head deformity in LCPD. This method may serve as a useful tool to evaluate the effects of treatment on femoral head shape. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2051-2058, 2017.