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Azoury et al. Plast Aesthet Res 2020;7:4 I http://dx.doi.org/10.20517/2347-9264.2019.44 Page 9 of 20

A B

Figure 5. Pre (A) and post (B) osseointegration demonstrating the improved range of motion and absence of need for suspension straps

experience from several hundred procedures, Branemark has worked to standardize the implant system,
surgical technique, and rehabilitation protocol with a program entitled Osseointegrated Prostheses for
the Rehabilitation of Amputees (OPRA, Integrum AB). Standardized OPRA protocols are now available
[61]
for femur, humerus, forearm, and thumb amputees . The growing interest in OI is demonstrated by the
numerous different osseointegrated implants currently in development or clinical use in multiple centers
throughout the world. The Compress Transcutaneous Implant (CTI; Zimmer Biomet), Integral Leg
Prosthesis (IPL; OrthoDynamics GmbH), and Osseointegrated Prosthetic Limb (OPL; OrthoDynamics)
[62]
have all been used in persons with transfemoral and transhumeral amputations .

Safety
Concerns related to infection at the skin penetration site remain the single greatest barrier to widespread
adoption of the technique. While circumventing the soft tissue issues produced by weight bearing or
controlling a prosthetic through a soft tissue intermediary, percutaneous placement of a permanent
implant creates a host of new challenges. The soft tissues of a residual limb are significantly thicker and
more mobile than those found in the mouth or head and neck, where OI has previously been employed
successfully. The relative motion between the abutment (percutaneous component) and the surrounding
soft tissues concentrates stress at the skin-implant interface, leading to inflammation, tissue breakdown,
[63]
fluid generation (e.g., drainage), and potential infection . Additionally, extremity soft tissues are less
well vascularized than the intraoral and facial tissues where OI has previously been successful. The rates of
superficial soft tissue infection following extremity OI have been reported to be as high as 30%-66% [64-67] .
However, most superficial infections are successfully treated with oral antibiotic therapy, with a 10-year
[68]
cumulative risk of deep infection leading to implant extraction reported as less than 10% .
Technical details
While surgical technique varies between implant systems and OI centers, growing experience has identified
a universal need to limit the thickness and redundancy of the surrounding soft tissue, in order to minimize
motion at the skin penetration site. In the two-stage OPRA procedure, the soft tissues are thinned to the
thickness of a full-thickness skin graft, which is affixed to the cortical bone surrounding the percutaneous
abutment. In single-stage OPL, IPL, and CTI procedures, the vascularity of the surrounding tissues are
preserved to a much greater extent, but the adjacent soft tissue flap is thinned at least to the level of scarpa’s
fascia. These soft tissue management strategies were born out of clinical experience that saw revision
surgery for soft tissue redundancy or hypergranulation exceed the need to return to the operating room