Abstract
The presence of an unremovable cemented tibial nail presents a unique challenge for limb salvage reconstructions utilizing a rotating hinge knee. All manufacturers’ designs except Link America incorporate a vertically-oriented rotational channel in the proximal tibia to provide the housing for a rotational axis stem. Such channel placement may be impossible in patients with pre-existing tibial hardware that obliterates the proximal tibial intramedullary canal. The Link America design utilizes a superiorly-projecting rotational stem that articulates with a housing located on the rotational yoke component; however it requires an intramedullary tibial stem for component stabilization. Thus all currently available rotating hinge knees require placement of a stem or a stem equivalent into the tibial intramedullary canal.
We describe a limb salvage case employing a Link America rotating hinge knee with a tibial component incorporating a custom hollow stem in a patient with an unremovable centralized, straight, cemented tibial nail. This reconstruction was required following an intra-articular fracture of a successfully incorporated massive proximal tibial osteoarticular allograft. The allograft had been implanted seven years previously following resection of a proximal tibia osteosarcoma.
This custom device allowed a relatively simple limb salvage reconstruction with good results and only a two day hospital stay.
This custom hollow-stemmed device allowed limb salvage in a situation that otherwise would have required either an amputation or resection of a healed tibial allograft that had successfully incorporated, replacing approximately 50% of the length of the tibia shaft. While rarely required, such an implant can allow a relatively simple and straight-forward functional salvage of an extremity in those patients whose only other choices for limb salvage include much more extensive bone resections and complex reconstructions. The potential for subsequent articular level failure should be considered whenever utilizing an osteoarticular allograft. A cemented, retrograde inserted, intramedullary nail can provide reliable internal fixation of such an allograft. If such fixation is selected, a straight intramedullary nail (as in this case) should be utilized, so that the intramedullary device is centered in the proximal tibia. This will allow for future revision to a total knee with a hollow stemmed tibial component should the need arise.
Correspondence should be addressed to Diane Przepiorski at ISTA, PO Box 6564, Auburn, CA 95604, USA. Phone: +1 916-454-9884; Fax: +1 916-454-9882; E-mail: ista@pacbell.net
