The Hinge Prosthesis For The Treatment Of Malignant Bone Tumor Of Knee

Osteocarcinoma found on limbs is a kind of malignant tumor that imposes great threats on patients'lives. It could not only maim the limbs of the patients involved in the disease but may metastasize via blood to vital organs and endanger patients'lives. Since 1980s, thanks to the development of the medicine for chemotherapy and the surgery of limb-construction, limb-salvage operation has been widely recognized and accepted as a standard operation on the basis of continual clinical experiments. With no cancerometastasis and good control of infected parts, limb-preservation surgery can retain kinesthetic functions of patients'limbs and prolong their life expectancy to a maximum degree.With the innovation of therapy for malignant tumor and the progress made in material technology, more alternatives are available for the reconstruction of limb functions after tumor resection. Replacement of artificial knee-joint as one of these possibilities has gained rapid development. Hinge prosthetic knee was the first artificial knee-joint applied in the treatment of malignant tumor on limbs for the preservation of the patients'limbs due to its excellent stability. However, prosthetic knees used in early periods belonged to highly restrictive types and were liable to come loose. In recent years, improvements were made on the original prosthetic knees and rotating hinge prosthetic knees (includingtypes especially made for tumor patients) were invented. With greater flexibility and negative effects caused by rotation minimized, rotating hinge prosthetic knees have won greater popularity in clinical treatment. Patient-tailored prosthetic knee-joints for tumor which patients can adapt to various cases of osteocarcinoma resection with different parts of knees amputated and create favorable conditions for the preservation of functions of the diseased limbs. With malignant tumor removed and artificial knee-joint replaced, not only is the chance of survival enhanced, but the possibility of relapse and metastasis is reduced as well. What's more, this can make patients take up functional exercises as early as possible postoperation. However, we should not neglect some complications like relapse of tumor, metastasis, local infection and loosening of artificial knee-joints that will be inevitably ensue operations. How to play the merits of prosthetic knees in reconstructing kinesthetic functions of limbs and constrain the occurrence of complication to the minimum extent is the answer that clinical doctors are in quest for long time. By analyzing 12 cases form Jan 2001 to Jan 2006 in which hinge prosthetic knees were applied to the treatment of malignant tumors on knees, a general comprehension of earlier period therapeutic effects and complication of the operation is derived and to what conditions is the operation applicable has been discussed in the study.Theoretically, this paper aims to contribute something to the regulation of the treatment of malignant tumors of knees in limb-preservation surgery. Practically, relevant clinical experiences of applying hinge prosthetic knees are presented in this paper.Object: To follow the earlier period outcomes of limb-preservation treatment in which hinge prosthetic knees are used to cure malignant knee tumors, so as to approach the surgical operation indications, operational methods and ensuing complications.Method: By reviewing 12 cases that occurred from Jan 2001 to Jan 2006 in which hinge prosthetic knees are applied to cure malignant knee tumors. All patients were followded up postoperation. Time spent on each patient varies from 12 months to 49 months.Results: The MSTS scores range from 19 to 27, with an average of 23. At 2-week postopetation,the average ROM of knees was 72°(60°-105°). Within 4 years postopetation, pulmonary metastasis of osteocarcinoma occurred on four patients, with three of them dead and one surviving now. The mortality reaches 25%.One patient suffered from relapse at local part of the affected-limb. Later, the limb was amputated. The rate of limb-salvage is 83.3%. One patient had infections on soft tissue of tibia. At 6-month and 1-year postopetation,reexaminations show that no loosening of the prosthetic knees are reported of all the 12 cases.Conclusions: 1, The replacement of hinge prosthetic knee is an important therapy to preserve limbs and reconstruct functions after tumors of knee are removed. It can help patients resume functions of legs. With lower rate of metastasis and recurrent, the outcome in earlier period is desirable. The mid-term and long-term outcomes are still to be discovered in the following observations.2, Chemotherapy is the only way to enhance survival rate. Limb-sparing operation must be supplemented with efficient chemotherapy.3, Operation is still adopted as the major alternative to cure osteocarcinoma. Operations can completely remove tumor tissues, which is crucial to reducing the chances of relapse. Therefore, operators'technique and experiences should meet higher requirement.4, Surgical indications must be followed strictly. Though limb-salvage operation is much more acceptable than amputation, it has been found that more complications follow the operations. Therefore, orthopaedic surgeons should be prudent before they plan to perform limb-salvage operations.5, Earlier period functional exercise of limb after operation is the final seal to the success of operations. Rational use of CPM is conducive to recoverfunctions of knee-joint. 3 months and 6 months after operations, patients still should be guided to do exercises after they had left hospitals.