Tumor induced osteomalacia: A single center experience on 17 patients.

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome due to a phosphaturic tumor, which overproduces Fibroblast Growth Factor 23 (FGF-23), causing hyperphosphaturia, hypophosphatemia, low 1,25(OH)2D and osteomalacia. Tumor localization is critical, diagnostic delay ranges from 2.5 to 28 years and to date surgical removal is considered effective treatment. We retrospectively evaluated patients with definite diagnosis of TIO referred to a tertiary Rheumatology Center between September 2000 and May 2020, investigating clinical management and disease outcome. We included 17 patients: 10 (58.8%) were females, mean age at diagnosis was 55.3 ± 13.9 years (mean ± standard deviation), with a diagnostic delay from symptoms onset to tumor detection of 6.6 ± 6.25 years. Biochemical data were: serum phosphorus 1.3 ± 0.4 mg/dL (Reference Range: 2.5-4.6), serum 1,25(OH)2D 31.8 ± 22.9 ng/mL (RR: 25-86), intact FGF-23, 358.9 ± 677 pg/mL (RR: 25-45); 24 h-Urine Phosphorus was increased in only 2 patients, while tubular reabsorption of phosphate (TRP) was decreased in all patients confirming a renal phosphate wasting. In 2013 68Ga- DOTA-based PET/CT was introduced in routinely practice and diagnostic delay was consistently reduced (from 8.6 ± 7.9 to 4.3 ± 2.4 years). Thirteen patients underwent surgery, one patient underwent radiofrequency ablation; 3 patients, not eligible for surgery, were treated only with supplements of phosphorus and calcitriol. One was started on Burosumab after several unsuccessful surgical attempts. After surgery or ablation, 8 patients had complete remission, 3 TIO persistence, and 3 had overtime relapse. Relapses were observed only in patients who previously underwent closed biopsy. To our knowledge, this is the widest European cohort of TIO patients in the last two decades. We confirm a usual diagnostic delay and recommend a stepwise diagnostic approach. Tumor biopsy is not recommended due to the potential cell spilling. Surgery is generally considered a definitive treatment, even though other approaches have been successful in curing TIO. Active surveillance on possible recurrence is always needed. Burosumab appears a promising therapy.

Surgical site infections in oncologic orthopaedic prosthetics surgery.

BACKGROUND: Literature reports an incidence of surgical site infections (SSIs) in oncological patients undergoing prosthetic replacement between 8% and 35% after first implantation and 43% after revision. The purpose of this retrospective study, conducted at the oncologic orthopaedic unit of G. Pini Orthopaedic Hospital in Milan, was to evaluate: - number of SSIs in oncological megaprosthetic reconstruction between 2008 and 2011, - possible risk factors associated with the onset of SSIs, - antibiotic prophylaxis applied. DESIGN AND METHODS: We reviewed medical records of patients who underwent megaprosthetic reconstruction and collected data on whole treatment and follow up after discharge, focusing on possible risk factors implied in the onset of SSIs such as patient characteristics, site of surgery, duration of surgery, number of persons in the operating room, size of resection, antibiotic prophylaxis. We recorded every SSI which met the criteria set by the Hospital in Europe Link for Infection Control through Surveillance (HELICS) protocol. RESULTS: One-hundred and eleven surgeries were evaluated. Administration of prophylaxis was generally recorded and continued postoperatively for an average of 18.89 days, often depending on the length of the post-surgical stay. Mean duration of surgery was 254 minutes with an average of 7 persons attending the operating room. We recorded 6 SSIs.

[Percutaneous radio-frequency ablation of osteoid osteoma: technique and preliminary results]. / Termocoagulazione percutanea degli osteomi osteoidi mediante radiofrequenza: tecnica e risultati preliminari.

PURPOSE: To report our personal experience with the percutaneous technique for in situ destruction of osteoid osteoma using radio-frequency ablation. MATERIAL AND METHODS: From January 2000 to January 2001 we performed 16 radio-frequency ablations in 15 patients. All candidates for treatment had previously undergone clinical and radiologic examinations to confirm features typical of osteoid osteoma. After administration of spinal anesthetic, procedures were performed with CT-guidance, using a Kirschner wire introduced into the localized lesion, and a guiding cannula. A hole was first cut into the bone with a cutter, then a few biopsy specimens were obtained with a Jamshidi needle. Finally, we introduced a small radio-frequency electrode into the bone, through the biopsy track. Sufficient current was used to heat the electrode tip to 85-90 degrees C with consequent thermal necrosis of the tissue. The healing was continued for 6 minutes. RESULTS: All patients well tolerated the percutaneous procedure and only 1 underwent a second, successful radio-frequency ablation. In all cases, pain relief was noted to occur very rapidly and all patients could bear full weight on the treated extremity within 24 hours after the procedure. No late complications attributable to the ablation were noted, except for a small eschar next to the puncture site. DISCUSSION AND CONCLUSIONS: The results of the present study suggest that percutaneous ablation is preferred to operative excision because it generally requires shorter hospital stay and is not associated with complications. Furthermore, in our experience, pain relief was noted to occur very rapidly in 100% of cases. In agreement with the literature data, our results show that CT-guided percutaneous radio-frequency ablation can actually replace operative excision in the treatment of osteoid osteoma as it achieves the same clinical outcomes with significantly lower costs.