Abstract
Introduction:
The development of new prostheses due to large resections has offered important opportunities to orthopedic surgeons mainly in oncology. A medline research can easily underline how poor is the international experience about this cases in nonunion: 75 results for megaprosthesis just 7 works in nonunion.
It is proposed the experience of our department, which deals specifically with the treatment of nonunion, in cases of repeated failures to treatment.
One of the most significant problems in the treatment of relapsing nonunion is the consequent worsening of joint function.
Critical bone defects, sepsis, joint fractures and unclear relapsing nonunions are the most common cases for a megaprosthesis treatment.
In these cases, even if it obtains the healing of nonunion the functional result would be presumptively poor. This radiological or clinical situation drove us, in such cases, to drastic solutions following the principles of cancer cases.
We implanted megaprosthesis with either techniques: 1 stage or 2 stages depending on the clinical findings. In nonunion the main decision making was the septic or aseptic status.
Materials and Methods:
we treated 32 patients with megaprosthesis replacing the nearest joint to the nonunion segment or both the proximal e distal one as follows: proximal femur, distal femur, proximal tibia, and total femur.
The mean follow-up of patients is 12 months (2 yrs max, min 3 months). Clinical and serial radiographic evaluations with standard methods (RX in 45 days, 3-6-12-24 months) was performed; as well as monitoring of blood parameters for 2 months.
Results:
Despite the average follow-up is not high, we do not aspect main differences to oncologic survival of the device, so our expectations and main interest to our experience is faced to the functional status of these patients and clinical evaluation in septic cases. In all cases, however, we get encouraging clinical results with such prosthesis. Complications: no neurologic defect was observed. The main surgical difficulty was the chronic reducing of the range of motion of the extending mechanism of the knee, usually not involved in such a way in oncologic cases.
In these cases we were forced to reinforce mainly the patellar tendon with tendon substitutes.
Discussion:
mega-prosthesis in post-traumatic cases can be considered, in extreme cases, as an available solution to the orthopedic surgeon. In oncological surgery the opportunity to get back to a good function although not a “restitution ad integrum” is a success, if it is possible to eradicate the tumor. Unfortunately, the high mortality associated with this disease does not allow us to have long-term follow-up due to the big amount of cases lost at the follow up. This situation creates a lack of certainty about the survival of this type of prosthesis and the medium-and long-term complications that may occur. Nevertheless, the patients treated by us should be considered oncological patients, not because of the disease but for the limited therapeutic options available.
Conclusions:
We have to consider not mega-prosthesis more like a pipe dream, but rather, as a viable opportunity.
