Sacral Agenesis-Three Treatment Variations

Elizabeth Hamilton, P.T. Sheila Hubbard, P.T. Dietrich Bochmann, C.P.O. (C) Wallace Motloch, C.O.(C)

The recognized method of treatment for lumbosacral agenesis is bilateral amputations at the hips and fitting with a Canadian-type prosthesis extended proximally to bear weight under the rib cage.

Three cases are presented. Two received amputations at the knee and attempts at spinal fusion. In both cases, the spinal fusion failed, resulting in pseudarthrosis. The amount of hip function differed in each case and different methods of fitting were tried. The third and least severe case was not amputated and ambulates with specially constructed orthoses. Should any of these methods of management prove to be unsatisfactory, the recognized procedure of amputation at the hips and fitting with a hemicorporectomy-type prosthesis can still be followed.

Case Histories

Case No. 1-C.R., born August 2, 1962, exhibited lumbosacral agenesis from L2 to the coccyx. Associated abnormalities present were neurogenic bowel and bladder, and pyloric stenosis.

At admission on August 1, 1968, the defect was characterized by severe kyphosis of the spine, an undeveloped pelvis, and gross deformities of the lower extremities with the legs in flexion contracture and the feet in equinovarus (Fig. 1 ). Abduction and adduction muscle power of both hips was rated as "trace." Flexion was present in the left hip only. Sensation was available in both extremities. At five years of age C.R. was able to crawl on his legs and scoot in all directions on his bottom. Rolling and independent seating were also achieved.


On December 13, 1967, bilateral knee disarticulations were performed. On February 6, 1968, an attempt was made at spinal fusion using tibial grafts. On August 7, 1968, the necks and heads of both femurs were excised.

Pre-prosthetic Management

Prior to fitting, each leg was bandaged separately and a third bandage was used in an attempt to bring the legs closer together, thus gradually increasing the range of motion in adduction. The mat program included upper-extremity strengthening and weight-bearing on the stumps for short periods of time. By the end of October C.R. was able to walk with a swing-to gait in the parallel bars.


On November 5, 1968, the patient was fitted with temporary prostheses incorporating quadrilateral sockets made of plaster of Paris, with partial end-bearing. To correct hip abduction, these sockets were joined distally by one connecting metal plate with rubber soling. This plate acted as a platform for walking trials. Below-knee (PTB) alignment jigs and SACH feet were installed at a later date (Fig. 2 ).

To stabilize the spine, hip joints with hip locks were added. These extended upward to approximately two inches below the axilla where a two-in.-wide webbing chest strap was attached. On testing the patient in these prostheses, it was found that the hip flexion present was not as great as previously thought and could not be increased through treatment. A large amount of flexion actually took place at the pseudarthrosis of the spine. Thus, sitting was unsatisfactory although ambulation with a swing-to gait on forearm crutches was progressing well.

For this reason, the prosthetic prescription was changed and a one-piece socket was provided to bear some weight in the thoracic area and some on the distal ends of the stump (Fig. 3 ). This socket was then fitted with legs as a hip-disarticulation prosthesis. Because of the small pelvis and short femurs, the overall length from the shoulders to the distal ends of the stumps was only slightly greater than the overall length of a normal person from the shoulder to the ischium (Fig. 4 ). Thus, it was possible to place the prosthetic hip joints just anterior and proximal to the distal ends of the femurs.

The plaster body cast was made in three stages. The first, made while the patient was supported under the axillae, extended from the sternal notch downward to the level of the ilium. The patient was suspended in this body cast while the thigh sockets were molded to provide some end bearing. Plaster-of-Paris bandages were applied between the thigh sockets and the body cast to connect the parts and make a rigid cast.

This patient also required the aid of a urinal appliance. To provide a carrying space for the urinal bag, a compartment was created between the thigh sockets by cutting away the medial walls of the sockets and bridging them anteriorly and posteriorly.

In the actual socket a three-in.-wide opening was cut into the bucket in the area of the groin. It extended proximally to the navel and to the same height posteriorly. Before lamination, 1/4-in.-thick Plastazote* was laid onto the positive cast around the rib-cage region to act as padding. Suspension was provided by a 1-in.-wide webbing strap placed over each shoulder and attached to the socket anteriorly and posteriorly.


Training commenced with a wood base attached to the socket in lieu of legs. Canadian hip joints were then added and the leg length increased periodically to raise the child to near normal height. Strong elastic straps were added to maintain full hip and knee extension during swing phase.


On April 22, 1969, C.R. was able to complete all wheelchair transfers independently and was proficient in both four-point and swing-to gait patterns but required assistance with swing-through gait (Fig. 5 ).

Physiotherapy continues at home to encourage and maintain independence in gait on rough ground as well as in managing stairs, etc.

Case No. 2-Debbie Van Huizen was born November 11, 1964, with lumbosacral agenesis below L2. Associated abnormalities were a repaired cleft palate, Klippel-Feil deformity of the neck, an umbilical hernia, and a neurogenic bowel and bladder. The spine exhibited marked kyphosis with the apex at the D12 and L1 level.

At admission on Feb. 4, 1969, both hips were contracted in flexion and external rotation with an active flexion range of about 30 deg. and a force of three plus (Fair plus). An abduction force of two minus (Poor minus) was also noted. The right hip was dislocated.

The knees were without movement and held in flexion by extensive webbing. The feet were fixed at about 90 deg. Sensation was present in both limbs.


On February 12, bilateral knee disarticulations were carried out and on March 11, an attempt was made at spinal fusion using tibial grafts. On May 6, subtrochanteric osteotomies were done bilaterally and supported in a full-length body cast which included the stumps.

An x-ray taken on July 21 revealed a fracture through the tibial grafts with resultant pseudarthrosis (Fig. 6 and 7 ).

Pre-prosthetic Management

Prior to removal of the body cast, a wooden platform was attached at its distal end to allow standing.

After cast removal each stump was bandaged separately. Additional bandaging was applied over a disposable diaper and rubber pants to hold the stumps together and maintain the hips in a neutral position.

A San-splint* torso splint was constructed to allow standing at a table and a swing-through gait in the parallel bars.

Hydrotherapy was used as an aid to hip mobilization and upper-extremity strengthening was encouraged by having the child crawl on the floor and use a scooter.


Because the child could flex her hips actively to 30 deg. and passive flexion to 45 deg. was available, the prostheses were designed to utilize this function.

Separate end-bearing thigh sockets were made and attached with hip joints to a thoracic shell.

The body cast was made in three stages, as with Craig Robberstad, resulting in a one-piece plaster positive which included the thorax and stumps. The hip joints were mounted before the laminations were separated and removed from the cast, to ensure proper alignment.

A mechanism to connect the two limbs was made by modifying two hip joints and connecting them with Bowden cables. By means of this mechanism, flexion in one stump would produce extension in the other and vice versa (Fig. 8 , Fig. 9 , and Fig. 10 ). Through a hole drilled in a standard-locking hip joint, an additional metal bar was attached by a pivot. This third bar was attached to the thoracic shell and the distal bar of the original joint was attached to the thigh section, thus providing a free joint between the thigh and thorax. The proximal bar of the original joint was allowed to extend upward to within one inch of the upper brim of the thoracic shell. The top end of this bar was joined to the like bar on the opposite side with Bowden cables anteriorly and posteriorly. A 1/16-in. steel cable was used with triple swivels at each end. Rulon-lined cable housings were attached to the thoracic shell. These housings were short enough to allow about three inches of cable excursion. When the hip joints were unlocked, the limbs could be flexed for sitting.

Wooden block feet with rubber soles were added to the sockets as temporary feet.


Training with these limbs was begun on October 24, 1969, and within 10 days the patient had progressed to a four-point gait using special forearm crutches. Training also included practice in falling, and in transfers from floor to standing and standing to sitting positions. The patient was discharged at this point because of homesickness.

Next time the patient is admitted to the Centre the legs will be lengthened in several stages to bring the child up to normal height. Knees and SACH feet will be added. Training in the washroom, and on stairs, rough ground, ramps, curbs, etc., will also be carried out.

Case No. 3-J.M. (female) was born March 12, 1965, with agenesis of the lower sacrum. Associated abnormalities included chronic constipation due to stenosis of the pelvic outlet, perineal webbing, and a systolic pericardial heart murmur.

At admission the pelvis and lower extremities were abnormally small but exhibited sensation in all areas and some muscle power was present in both hip flexors and quadriceps. Flexion contractures of about 60 deg. were present in both knees and hips and the feet were fixed in equinovarus.

Since she was 18 months of age, J.M. has walked on her hands, dragging her legs, and has attempted to stand using furniture for support.


On June 6, 1968, bilateral supracondylar osteotomies were performed followed by bilateral excision of the tali.

By February 20, 1969, the hip-flexion contractures had been reduced to 35 deg. on the right and 45 deg. on the left; and the knee contractures to 45 deg. on the right and 25 deg. on the left. At this time both hips were assessed as "good" in flexion, "fair" in adduction, and "a trace" in abduction and rotation. In addition, both knees demonstrated "fair" strength in flexion and "good" in extension. The patient walked forward on her hands and feet and attempted to stand (Fig. 11 ).


In February 1969, a body jacket was fitted to stabilize the lumbar area (Fig. 12 and Fig. 13 ). The jacket was formed directly on the patient from 1/8-in. Sansplint in two halves (front and back). The two sections were welded together on the left side and fitted with Velcro straps 2-in. wide on the right side for closure. The jacket added about two inches of height in sitting. However, despite liberal flaring over the thighs, the device interfered with crawling on all fours.

Temporary devices were fitted in September 1969 to evaluate walking possibilities. These devices were twin plaster shells covering each side from the thorax almost to the knees. Plywood extensions simulating legs extended below the level of the feet (Fig. 14 ). With this equipment the patient could stand comfortably and gave indications that she might be able to walk in parallel bars.

On October 9, the next stage of treatment was begun. Orthoses consisting of a thoracic weight-bearing shell and a diaper-like sling were fitted. Free hip joints were added with metal extensions which attached to foot plates. The child's own feet rested on these plates with suitable blocking beneath. For control her legs were strapped just above the ankles to the bars of the orthosis. The soles of the foot plates were angled about 10 deg. so that only the medial edge contacted the floor in standing. This facilitated the side-to-side rocking which is essential for ambulation.


With little training, J.M. achieved a reciprocating gait with a parallel walker and later with H-frame crutches (Fig. 15 ).

With encouragement from the physical therapist, she was able to do everything with the brace that she could without it. Standing unaided was no problem (Fig. 16 ).

On her next admission J.M. will be refitted with a new brace which will incorporate the same principles but be more attractive in appearance. It is also anticipated that the orthoses can be lengthened to bring her up to normal height.

*Plastazote is a foamed polyethylene available from Smith & Nephew Ltd., Lachine, Que.

*San-splint is the trade name for a thermoplastic material which is formable at 140 deg. F. It was developed by the Polymer Corporation of Sarnia, Ontario, and is also supplied by Smith & Nephew Ltd.

Elizabeth Hamilton, P.T., Sheila Hubbard, P.T., Dietrich Bochmann, C.P.O. (C), and Wallace Motloch, C.O.(C) are associated with the Ontario Crippled Children's Centre Toronto, Canada