BACKGROUND CONTEXTHyperextension orthoses (HOs) for nonoperative treatment of osteoporotic vertebral fractures (OVFs) are widely prescribed. However, the compliance, how much an HO is worn after it has been prescribed, is widely unknown. PURPOSEThis study was performed to assess the wearing time of HOs for OVFs in a prospective blinded, sensor-controlled manner. STUDY DESIGN / SETTINGA prospective, single blinded observational study was performed. PATIENT SAMPLEThis study prospectively included 18 patients who were treated nonoperatively with an HO for OVFs. OUTCOME MEASURESThe true wearing time was measured using a hidden temperature-based sensor. The patients were invited to return for regular follow-up every 2 weeks for 6 weeks, at which time clinical evaluation (including a visual analog scale for pain and the Oswestry disability questionnaire) and radiographs of the spine were performed. METHODSFull compliance was defined as a wearing time of 15 hours per day. Correlation between compliance and demographic differences, patient reported outcomes and radiographic changes of the vertebral structures were calculated. RESULTSThe mean HO wearing time was 5.5±3.3 hours (37%±22% compliance). Female patients used the HO significantly longer per day than did male patients (6.5±3.2 vs 2.9±2.0 hours, p=.039). Age and body mass index had no influence on wearing behavior. CONCLUSIONSOverall, compliance with wearing HOs is poor and shows great variability with significant gender-dependency but not associated with BMI, age, or pain-level. Further studies are required to confirm our results that the wearing time does not have an influence on kyphotic progression of the osteoporotic fractured segment, nor on clinical outcome at short term. LEVEL OF EVIDENCEI