Prophylaxis with recombinant factor VIII can prevent joint damage and decrease the frequency of joint and other hemorrhages in young boys with severe hemophilia A. (ClinicalTrials.gov number, NCT00207597 [ClinicalTrials.gov].).

Sixty-seven closed or grade-I open fractures of the tibial shaft were examined in a prospective, randomized, double-blind evaluation of use of a new ultrasound stimulating device as an adjunct to conventional treatment with a cast. Thirty-three fractures were treated with the active device and thirty-four, with a placebo control device. At the end of the treatment, there was a statistically significant decrease in the time to clinical healing (86 ± 5.8 days in the active-treatment group compared with 114 ± 10.4 days in the control group) (p = 0.01) and also a significant decrease in the time to overall (clinical and radiographic) healing (96 ± 4.9 days in the active-treatment group compared with 154 ± 13.7 days in the control group) (p = 0.0001). The patients' compliance with the use of the device was excellent, and there were no serious complications related to its use. This study confirms earlier animal and clinical studies that demonstrated the efficacy of lowintensity ultrasound stimulation in the acceleration of the normal fracture-repair process. Ultrasound has many medical applications, including therapeutic, operative, and diagnostic procedures '. Both ultrasound therapy and operative ultrasound subject tissue to power levels that are capable of causing ACCELERATION OF TIBIAL FRACTURE-HEALING BY NON-INVASIVE. LOW-INTENSITY PULSED ULTRASOUND 27 VOL. 76.A, NO.

Summary. Participants in an international conference on prophylactic therapy for severe haemophilia developed a consensus summary of the findings and conclusions of the conference. In the consensus, participants agreed upon revised definitions for primary and secondary prophylaxis and also made recommendations concerning the need for an international system of pharmacovigilance. Considerations on starting prophylaxis, monitoring outcomes, and individualizing treatment regimens were discussed. Several research questions were identified as needing further investigation, including when to start and when to stop prophylaxis, optimal dosing and dose interval, and methods for assessment of long-term treatment effects. Such studies should include carefully defined cohorts, validated orthopaedic and quality-of-life assessment instruments, and cost-benefit analyses.

The Joint Outcome Study Investigators 7Recombinant adeno-associated virus (rAAV) is a promising gene delivery vector and has recently been used in patients with hemophilia. One limitation of AAV application is that most humans have experienced wild-type AAV serotype 2 exposure, which frequently generates neutralizing antibodies (NAbs) that may inhibit rAAV2 vector transduction. Employing alternative serotypes of rAAV vectors may circumvent this problem. We investigated the development of NAbs in early childhood by examining sera gathered prospectively from 62 children with hemophilia A, participating in a multi-institutional hemophilia clinical trial (the Joint Outcome Study). Clinical applications in hemophilia therapy have been suggested for serotypes AAV2, AAV5 and AAV8, therefore NAbs against these serotypes were serially assayed over a median follow-up of 4 years. NAbs prevalence increased during early childhood for all serotypes. NAbs against AAV2 (43.5%) were observed more frequently and at higher titers compared with both AAV5 (25.8%) and AAV8 (22.6%). NAbs against AAV5 or AAV8 were rarely observed in the absence of co-prevalent and higher titer AAV2 NAbs, suggesting that NAbs to AAV5 and AAV8 were detected following AAV2 exposure due to partial cross-reactivity of AAV2-directed NAbs. The results may guide rational design of clinical trials using alternative AAV serotypes and suggest that younger patients who are given AAV gene therapy will benefit from the lower prevalence of NAbs.

We hypothesized that magnetic resonance imaging (MRI) scans taken prior to radiosynoviorthesis may be predictive of response to the procedure in persons with haemophilia. Specifically, response would be inversely related to the severity of synovial hyperplasia. Radiosynoviorthesis was administered to 21 joints with recurrent haemorrhage (target joints). A detailed self-report of haemorrhage history, joint evaluation with scoring according to the World Federation of Haemophilia orthopaedic joint and pain scales, plain radiographs, and MRI studies of the joints were performed pre- and post-radiosynoviorthesis. To augment comparison of the MRI findings to those assessed using the Arnold-Hilgartner and Pettersson scales, a provisional MRI scale for evaluation of haemophilic arthropathy was designed. We found the MRI findings prior to the procedure were not predictive of clinical response; independent of the severity of synovial hyperplasia, most joints bled less and showed improvement by the WFH orthopaedic score. There was generally no change in the severity of synovial hyperplasia after the procedure. We conclude that MRI evaluation is not routinely indicated prior to radiosynoviorthesis.