[Disarticulation of the knee joint]

The authors report their experience with exarticulation in the knee joint, describe the relevant surgical procedure, assess the outcomes of different modifications of the surgical treatment and emphasize the advantages of the stump following exarticulation in the knee joint.

The sample included 19 patients, 13 women and 6 men, operated on in the period from 1987 to 2001. One of the women had bilateral surgery. Their average age at the time of surgery was 48 years, the range was 5 to 82 years. In most of the patients, exarticulation in the knee joint was indicated because of a malignant tumor in the crux region that could not be treated by any radical but, at the same time, limb-saving procedure. Other indications included an infected allograft of the tibia, chronic osteomyelitis of the tibia complicated by spinocellular carcinoma in a fistula, a stump after high amputation in the tibia that could not be fitted with a prosthesis, chronic lymphedema and diabetic microangiopathy.

Exarticulation is an amputation of the peripheral part of a limb in a joint, i.e., without cutting bone. The authors used a modified Rogers' procedure. Under the use of a tourniquet, a ventral incision, 10 cm long, was run from the articular fissure level distally and a dorsal incision, 5 cm long, was cut distal to the articular fissure. This produced a longer ventral and a shorter dorsal flap. The subsequent procedure included the discission of the ligamentum patellae at the tibial attachments, the articular capsule, m. sartorius, m. gracilis, m. semitendinosus, m. semimembranosus and biceps femoris, all cut at their distal attachments, as well as the tractus iliotibialis. The collateral and cruciate ligaments were incised at their femoral attachments. After dissection of the neuro-vascular bundle, the vessels were incised and double ligated. The n. tibialis and n. peronaeus were infiltrated with mesocaine and cut through. Then the m. popliteus, ligamentum popliteum arcuatum and the two heads of the m. gastrocnemius were incised and the crux separated. After removal of the pneumatic tourniquet, bleeding was arrested. The condyles, patella and synovialis were left intact. The ligamentum patellae was sutured to the tendons of the m. semimemranosus, m. semitendinosus and biceps femoris. The m. satorius and m. tractus iliotibialis were sutured to the extensor apparatus. The layer after layer was sutured with individual stitches and two Redon's drains were inserted below the fascia.

Five patients were referred back to the initial hospital. Of six patients who died, five developed complications due to dissemination of the underlying malignant disease and one died of causes unrelated to the major disease. Eight patients were followed up at regular intervals. Of these, seven were satisfied with their stump and only one patient complained of pressure sores and therefore changed prosthetic care. Patients' complaints that would lead to repeat operations or amputation in the femur were not recorded.

The surgical technique described is fast, gentle in terms of tissue damage and relatively easy to perform. All patients in the group showed good healing. The authors point out that the stump achieved by exarticulation has good weight-bearing qualities because of a large surface controlled by strong musculature that can maintain muscular balance and control the rotation of a prosthesis. The results of this study are in agreement with the data published in the English, German and Russian literature. In the Czech literature, this issue has not been reported yet.

The advantages of exarticulation in the knee joint are as follows: quick, gentle and uncomplicated surgical procedure with low blood losses; good potential for per primam healing; high quality of the stump surface to be fitted with a prosthesis; current availability of good quality prostheses that are easier to fit than those applied after high amputation in the crux with a stump less than 11 cm or after low amputation in the femur.