Proximal Femoral Focal Deficiency: A Case Report of a Necropsy

Charles H. Epps, Jr., M.D., F.A.C.S.


Proximal femoral focal deficiency is a congenital anomaly that has attracted considerable attention in recent years, both from the point of view of classification and of treatment. (1-5) A recent opportunity to inspect the necropsy specimen obtained from a mature adult patient with this interesting anomaly prompted the present report. It is believed that this is the first report on a pathological specimen of this type obtained from an adult, although Amstutz and Wilson (3) have illustrated a specimen obtained from a nine-month-old male at the time of operation.

Case History

M.H., a 60-year-old female, was seen in consultation because of a history of back pain and a desire for prosthetic rehabilitation. She had used crutches for ambulation and was completely independent in all activities. She exhibited a gait which utilized a single axillary crutch.

Examination revealed a markedly foreshortened left lower extremity. The development of the lower leg segment and the foot was normal, although they were slightly smaller than the contralateral side, and extended only to the level of the un-involved knee. The entire left extremity was externally rotated, and the proximal segment was flexed and abducted. The hip joint was fairly stable, although all ranges of motion were reduced. The left knee flexed well beyond a right angle.

Roentgenographic examination revealed marked hypoplasia of the femur and acetabulum, with anomalous development of the neck-shaft area producing an angle of less than 90°. The tibia and the fibula were also hypoplastic. The cortices were thinner and the trabeculations less dense than normal (Fig. 1 and 2 ).

The patient's history revealed that she had experienced life-long anxiety over the deformity. Because she had been under psychiatric care for many years, clearance was sought from her psychiatrist prior to making firm plans for the operation. Disarticulation of the foot and knee fusion were under consideration.

Before plans could be finalized, the patient was admitted to the hospital with a low-grade fever and a swelling of the supraclavicular area of one month's duration. An open biopsy established the diagnosis of reticulum cell sarcoma. She received chemotherapy (Cytoxan) on two occasions and was discharged to outpatient care.

Readmission was necessary after 18 days because of anemia. Chemotherapy was continued, but the patient's condition progressively deteriorated. At this time she showed enlarged

lymph nodes in both axillae and a palpable mass in the supraumbilical area. She died 11 days after the second admission.

The postmortem examination revealed malignant lymphoma, reticulum cell type, involving the inguinal, periaortic, peripancreatic, gastro-hepatic, mediastinal peribronchial, cervical, and axillary lymph nodes; the spleen; the stomach; the left adrenal; the ovaries; the lungs; the liver; the kidneys; the pia-arachnoid; and the brain.

Both femora were removed. The left femur was 25 cm long; the femoral head was small and had an irregular surface. The condyles were flattened and partially deformed. The greater trochanter was a separate bone attached to the shaft by cartilage. The distal femoral condyles were externally rotated a full 90° with respect to the plane of the femoral neck and head (Fig. 3 and Fig. 4 ).

Comment

The normal architecture of the upper end of the femur has been described in considerable detail and analyzed mathematically.(6,7) The normal trabecular pattern provides strength against shearing and bending forces with a minimum of material. Proximal femoral focal deficiency is a condition involving varying degrees of developmental failure of the upper end of this bone. The present case illustrates an interesting variation in the femur. Roentgenograms of the necropsy specimen, when compared to the contralateral normal femur, showed absence of the usual medial compressive and the lateral tensile pattern of trabeculations (Fig. 5 , Fig. 6 and 7 ). The trabecular pattern did appear to be thicker on the inferior surface of the neck. Failure of this extremity to bear weight normally was probably a major factor in the development of an abnormal trabecular pattern. However, a more basic defect in the developmental potential of the proximal femur is apparently present in these cases.

Acknowledgments

The author wishes co acknowledge with appreciation the cooperation of Dr. H.W. Edwards, Department of Pathology, Washington Hospital Center, Washington, D.C, in making the autopsy material available.

Charles H. Epps, Jr., M.D., F.A.C.S. is associated with the Juvenile Amputee Clinic Department of Public Health D.C. General Hospital Washington, D.C.

References:
1. King, Richard E.: Concepts of Proximal Femoral Focal Deficiencies, ICIB , I:1-7 (Nov.) 1961.
2. Yelton, Chestley L.: Femoral Deficiencies, ICIB, II:1-5 (Sept.) 1963.
3. Amstutz, H.C., and Wilson, P.D.: Dysgenesis of the Proximal Femur (Coxa Vara), and the Surgical Management, JBJS, 44A:1-24 (Jan.) 1962.
>4. King, Richard E.: Proximal Femoral Focal Deficiencies, ICIB, III:1-5 (July) 1964.
5. Hall, John E.: Rotation of Congenitally Hypoplastic Lower Limbs to Use the Ankle Joint as a Knee, ICIB, VI:3-9 (Nov.) 1966.
6. Gray, Henry: Anatomy of the Human Body, Charles Mayo Goss (ed), Philadelphia: Lea and Febiger, 25th ed, 1948.
7. Tobin, William J.: The Internal Architecture of the Femur and Its Clinical Significance, JBJS, 37A:57-72 (Jan.) 1955.