Knee Disarticulation Treated As Above-Knee Amputation

William R. Eaton, M. D.


Two cases of knee disarticulation-one bilateral and one right only-which were fitted as above-knee stumps because of shortness, are the subjects of the following report:

Case 1-WS

This patient was born on December 17, 1947 with multiple congenital deformities - contractures of knees, absence of fibula, absence of patella, two metatarsals and three toes bilaterally, absence of third finger bilaterally, syndactylism of fourth and fifth finger on right and flexion contracture ring finger left (Fig. 1 and Fig. 2 ).

Treatment of WS started during infancy with correction of knee contractures with traction, wedge casts, etc. Syndactylism was corrected later by a plastic surgeon.

When he was one year old, the patient was fitted with ischial weight bearing braces with extended calipers and feet encased in braces. He learned to walk satisfactorily on them.

In 1955, an osteochondroma on the right femur interfered with the braces and was removed (Fig. 3 ). As growth progressed, the knees began to subluxate and the left knee was disarticulated in June 1956. In September of that year, he was fitted with an above-knee prosthesis and a pelvic band was attached to the jrace on his right leg. He walked well with two canes.

In May 1958, the right knee was disarticulated (Fig. 4 ). WS was subse-quently fitted with bilateral suction socket prostheses and walks well without canes (Fig. 5 and Fig. 6 ).

Case 2-RD

This patient was admitted to the Home for Crippled Children at age 5 with congenital malformation of the right lower leg. The rudimentary lower leg flexed firmly against the thigh with fusion of the femur and tibia and closure of the epiphysis (Fig. 7 ).

Disarticulation of the right knee was performed one month after admittance (Fig. 8 ). He was fitted with a suction socket type prosthesis but was later changed to a plug fit with a Silesian bandage. Training was slowed by a tonsil-ectomy and flexion and abduction contractures caused difficulty. Flexion was slowly corrected and the patient was discharged walking fairly well but unable to overcome the effects of the abduction contracture. The family was reluctant to consider additional surgery.

RD was followed as an out-patient. His gait was never satisfactory because of abduction caused by tight tensor fascia. The parents finally consented to surgery and, in July of 1961 (age 9 years), a subcutaneous release of tensor fascia high and low was performed.

The patient's gait improved and he walks well with an above-knee socket and Silesian bandage (Fig. 9 and Fig. 10 ). A suction socket will probably be ordered when a new prosthesis is needed.

Conclusion

In cases where the femurs are short and leg length discrepancy is not a problem, knee disarticulation and treatment as an above-knee amputation may be the treatment of choice.

William Eaton is Co-Clinic Chief Home for Crippled Children, Pittsburgh, Pennsylvania