Real-world differences in dosing and clinical utilization of OnabotulinumtoxinA and AbobotulinumtoxinA in the treatment of upper limb spasticity

According to prescribing information, potency units are not interchangeable between botulinum toxin A products. This exploratory study compared real-world dosing and utilization of onabotulinumtoxinA and abobotulinumtoxinA in adults with upper limb spasticity. In this retrospective study, 101 clinicians provided chart data via online surveys for 215 US post-stroke patients treated for upper limb spasticity with ≥3 onabotulinumtoxinA or abobotulinumtoxinA doses (phase 1: 9/18/2020-12/10/2020; phase 2: 9/30/2021-12/7/2021). Most participating clinicians were physicians (70.3%) specializing in neurology (71.3%) or physiatry (20.8%). In the onabotulinumtoxinA (n = 107) and abobotulinumtoxinA (n = 108) groups, ∼75% of patients had moderate-to-severe spasticity. A range of onabotulinumtoxinA:abobotulinumtoxinA dose ratios (1:2.2 [95%CI: 1.8-2.6] to 1:4.1 [95%CI: 3.0-6.0]) was observed across muscles. For the most recent dose, mean number of muscles injected was greater for onabotulinumtoxinA (4.3) versus abobotulinumtoxinA (3.1; P = 0.0003). For onabotulinumtoxinA versus abobotulinumtoxinA, the proportion of injections was 81.3% versus 63.9% (P = 0.0067) in forearm muscles and 23.4% versus 3.7% (P = 0.0001) in hand muscles. Mean injection intervals were similar (onabotulinumtoxinA: 102.0 days; abobotulinumtoxinA: 99.1 days). Differences in real-world dosing and utilization of onabotulinumtoxinA and abobotulinumtoxinA for upper limb spasticity were observed. There was no standard dose-conversion ratio, consistent with each product's prescribing information.

Temporary Botulinum Immobilization of Residuum Muscles for Facilitation of the Initial Ingrowth of Skin to the Porous Skin and Bone Integrated Pylon in the Technology of Direct Skeletal Attachment: Large Animal Model

Enhancing the technology of bone-anchored limb prosthetics, we present a modified porcine model for developing an infection-free integration between the skin and a percutaneous bone implant. The deeply porous Skin and Bone Integrated Pylon (SBIP) presented an infection-free skin-implant interface both after implantation into the dorsum and after implantation into the residuum after below-knee amputation. However, deep ingrowth of skin into the porous cladding of the SBIP was achieved better in the dorsal procedure, while implantation to the residuum sometimes developed a stoma, probably due to the high mobility of the skin and soft tissues in the pig's thigh. Uncontrolled high skin mobility during the first week after implantation constituted a limitation for the porcine animal model, which we tried to address in the current study. As our previous studies showed that casting of the leg residuum did not sufficiently limit the skin's movement around the implant, we tested a modified protocol of the implantation, which included injection of botulinum toxin into the thigh muscles. During the course of the study, we identified proper botulinum toxin componentry, dosage, and the period after injections to achieve a maximal effect of immobilization of the muscles affecting skin movements. To verify the immobilization, we used kinetic data on the asymmetry of loading during gait with the Strideway System, Tekscan, Inc., Boston, MA, USA. We found that injections in the four muscles of the distal thigh of the left hind leg with MYOBLOC® (rimabotulinumtoxinB; 5,000 units/muscle) were sufficient to provide noticeable immobilization by the fourth week after the procedure. This conclusion was made based on the analysis of the dynamics of asymmetry in vertical ground reactions on the injected (left hind) and uninvolved (right hind) legs during gait over an instrumented walkway.