On the way to total integration of prosthetic pylon with residuum

Abstract

Two decades after introducing threaded titanium dental implants, Dr. Per-Ingvar Brånemark used a similar technique in the 1980s to pioneer the direct skeletal attachment (DSA) of limb prostheses. He and his colleagues used convincing clinical experience to overcome the skepticism of their peers, affording a new dimension of prosthetic rehabilitation to almost 100 individuals with amputation. As a result, more research has been initiated worldwide to move DSA to a level of greater safety, longevity, and reliability. This review highlights the trends and milestones in current DSA development. It also identifies ideas from previous studies in various fields that may be useful in future DSA development.

Figure 1

(a) Titanium abutment penetrating residuum skin, (b) surrounding skin, and (c) layer of pus between skin and abutment. Source: Reprinted from Pitkin M, Raykhtsaum G, Galibin OV, Protasov MV, Chihovskaya J V, Belyaeva I G. Skin and bone integrated prosthetic pylon: A pilot animal study. J Rehabil Res Dev. 2006;43(4):573–80. [PMID: 17123195] DOI:10.1682/JRRD.2005.05.0160

Figure 2

Implant fixture for tooth prosthesis by Brånemark. Source: Adapted from Brånemark P. Implant fixture for tooth prosthesis. United States patent US 4988299. 1991 Jan 29.

Figure 3

(a) Schematic of histological section of skin with smooth surface implant. Epidermis migrates and proliferates inward along implant causing marsupialization. (b) Epidermal migration through porosity or permigration. Source: Adapted by permission from Von Recum AF. Applications and failure modes of percutaneous devices: A review. J Biomed Mater Res. 1984;18(4):323–36. [PMID: 6234317] DOI:10.1002/jbm.820180403

Figure 4

Minimal force needed for detachment of skin cells A, B, and C from pylon. F₁ = “cell-to-wall” detachment (prior art), F₂ = “cell-to-wall-to-inner cell” detachment in skin and bone integrated pylon design. Source: Adapted from Pitkin M, Raykhtsaum G, Pilling J, Galibin OV, Protasov MV, Chihovskaya JV, Belyaeva IG, Blinova MI, Yudintseva NM, Potokin IL, Pinaev GP, Moxson V, Duz V. Porous composite prosthetic pylon for integration with skin and bone. J Rehabil Res Dev. 2007;44(5):723–38. [PMID: 17943684] DOI:10.1682/JRRD.2006.12.0160

Figure 5

Modeling of moment of resistance to bending of pylon (1) implanted to medullary canal (2) via (a) osseointegration and (b) arthroplasty. L₁ = lever arm with respect to point B₁ of bending force F applied to point O₁, L₂ = lever arm with respect to point B₂ of force F applied to point O₂, l₁ = lever arm of reaction force f₁ with respect to point B₁, l₂ = lever arm of reaction force f₂ with respect to point B₂. Source: Reprinted from Pitkin M. One lesson from arthroplasty to osseointe-gration in search for better fixation of in-bone implanted prosthesis. J Rehabil Res Dev. 2008;45(4):vii–xiv. [PMID: 18712634]

Figure 6

Linkow’s bone adapting tissue packing post system. Source: Adapted from Linkow LI, inventor; Oratronics, Inc, assignee. Bone adapting tissue packing post system. United States patent US 3849888. 1974 Nov 26.

Figure 7

Poly-Orth International pylon with three pairs of fins (1).