FEMORAL BONE LENGTHENING*

ROGER ANDERSON, M.D., F.A.C.S.

Orthopedic Surgeon, King County Hospital

SEATTLE, WASHINGTON

T HE many advantages of femoral bone lengthening over either femoral short­ening or tibial lengthening justify

presenting a method based on Putti's principles, so revised as to be practicable.

The anatomico-physiological relation­ships of the thigh account for the better results obtained by femoral versus tibial lengthening, as the musculature with its rich vascularity so completely envelopes the femur, that the superior blood supply induces earlier callus formation with less chance of delayed union, or refracture. Due to the equal placement of the muscles and fibrous tissue around the femur, in contra­distinction to that of the superficially placed tibia, the tendency to angulation in femoral lengthening is less pronounced. Moreover, the relatively less tough, te­nacious fascia in the thigh allows corre­spondingly less resistance to the stretching process. The fact that two fragments only are involved in femoral lengthening de­creases the difficulties in maintaining apposition. And last but not least in this day of freedom in dress, an operative scar or any persisting bony angulation would be less noticeable on the thigh.

With femoral lengthening there is no need of postponing a reconstruction opera­tion on the foot, contraindicated in tibial lengthening. In fact, these operations on the foot may be done prior to, or after the femoral opera:tion, or even at the same time and both the thigh and the foot may be safely immobilized in the same cast.

Poliomyelitis, the causative factor of most cases of shortening, as a rule leaves the legs with relatively more paralysis below the knee than above it. And since

the orthopedic dictum still holds that no segment of an extremity should be length­ened unless sufficient musculature remain to move such elongated portion, a length­ened femur obviously provides better prospects of functioning than an operated tibia.

It is thus apparent that the method of femoral lengthening as advocated by Putti would have been in popular usage today were it not for the difficulties encountered in attempting control of the fragments. However, command of the situation is obtained by employing a certain type of apparatus, the new device reconstructed by the attachment of accessories to the Automatic Leg Splint (Fig. 2). A special horseshoe for either pin or wire is attached to its universal bracket through the medium of an extension coupling, and is applicable for either thigh. Its construction permits rotation and manipulations to be carried out on the normal anatomical axis, all movements at the upper end being obtained with the head of the femur as a center; while at the knee the splint is designed so that the center of the shaft is the axis.

The operating principle is based upon skeletal transfixion of each fragment in such a manner that control of both upper and lower femoral fragments is a safe, mechanical achievement.

The practicality oj transfixing the upper end oj the Jemur has been rightfully ques­tioned because of fear of penetrating vital structures. However, a review of topograph­ical anatomy demonstrates the feasibility of piercing the upper femur in the region of the trochanters, provided approach is made as deliniated in Figure I. The subcutaneous

.. Demonstrated at the meeting of The American Academy of Orthopedic Surgeons, New York City, January 14, 1935·

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480 American Journal of Surgery Anderson-Femoral Lengthening

position of the greater trochanter fur­nishes a safe route for transfixion III an anteroposterior direction. Oblique trans-

FIG. I. A. Normal lateral angulation of the upper femur is used advantageously in the placement of the superior pin in order to avoid vulnerable structures. B. Cross section of right femur just distal to tro­chanters. Note diagonal insertion of the superior pin and its distant relation to vital vessels and nerves. c. Cross section of right femur about I inch above condyles. Note the relationship between the distal pin on the one side and the suprapatellar bursa on the other. The distal wire or pin is inserted obliquely to the transverse axis of the knee joint, for the purpose of better immobilization, while the superior trans­fixion is usually inserted at the optional site through the intertrochanteric level as shown in A.

fixion, however, not only passes still further from the sciatic nerve, but has the advantage of facilitating after care.

In the majority of cases, the pin or wire is a matter of personal choice for both superior and distal transfixions; on the other hand, a %2 inch stainless steel pin is preferable in cases of well developed musculature. To tighten the wire and maintain tautness a light stainless steel Tautnor has been devised for ready attach­ment to the splint. When detached, the Tautnor is easily carried in the cast during the ambulatory stage. .

OPERATIVE TECHNIQUE

Transfixions (Fig. I). Subsequent to surgical preparation, the distal femoral transfixion is inserted through the condyles at the superior border in an oblique direc-

tion to the transverse axis of the knee. After localizing pulsations of the femoral artery, the superior transfixion is put

FIG. 2. The late "model for femoral lengthening made by attaching the special horseshoe (a) and its extension (d) to the Anatomic Femur splint. The Universal Bracket (j) swivels directly under the center of the hip joint (locked at Hi") whereby abduction and adduction corrections are made. Rotation on the normal anatomical axis is obtained through the handle (c) and the teeth of the rotating horseshoe (a), while flexion and extension are controlled by the pivot bolt (b).

through at the intertrochanteric or sub­trochanteric level, from a point on the anterior thigh slightly lateral to the center, penetrating the femur in an oblique direc­tion posteriorly and laterally. Sterile dress­ings are held with sheet wadding bandage, and the ends of wire or pins are protected by corks or metal covers.

The Operation Proper. The femoral shaft is approached through a posterior lateral incision along the lateral inter­muscular septum. A long oblique osteotomy, performed with a chisel, is simplified by previously inserting a line of drill holes. To assist in maintaining la~er bony contact, such an obliquity should exist so that the distal end of the upper fragment is poste­rior with the superior end of the lower frag­ment anterior. The periosteum, lateral septum and fascia lata are likewise incised obliquely, followed by regulation skin closure.

Osteotomy Reduction. While an assistant pulls on the leg, a box about 12 inches high

NEwSERIES VOl. XXXI, NO·3 Anderson-Femoral Lengthening American Journ a l of Surger.v 48 I

is placed under the head and shoulders and the sacral rest adjusted to the size of patient, so that the thigh is positioned in

radiographic check, the upper half of the cast is applied from midthorax to mid­thigh, firmly incorporating the superior

FIG. 3. A. FIG. 3. B.

FIG. 3. A. Lateral view six weeks postoperative. B. Eight weeks postoperative, with over 2 7~ inches of lengthening. Note large amount of callus. Arrows on the anterior thigh designate the markers on the tongue depressor ruler.

the splint in readiness for fastening the pins or wire Tautnors into their respective horseshoes (Fig. 2. a, j.). The Well-Thigh Support, if available, dispenses with the problem of holding the uninjured leg, and slides into the slot provided under the base plate of the splint. Moreover, the reliability of the Calf Support exceeds that of a sandbag in holding the leg of the operated extremity. At this stage when the transfixions are connected, it is advisable to wrap a single plaster bandage around the upper transfixion to prevent the thigh from sliding posteriorly. The spica cast which is applied in two sections remains separated until the lengthening process is completed. With the knee in slight flexion the lower half of the cast is now applied from midthigh to midcalf or toes, inclusive of the distal transfixion. Sufficient active traction is then immediately engendered to gain about % inch. After the fragments have been mechanically apposed with

transfixion. The patient should be returned to a bed

in which the regular mattress has been replaced by a fracture board, while two small mattresses of a combined 12 inch thickness are placed crosswise on the fracture board so as to cushion only the upper portion of the body down to the buttocks. The Sacral Rest should be re­moved and replaced by two crib mattresses, 12 inches high, laid obliquely under the well leg and buttocks to accommodate nursing care. The apparatus itself is placed directly upon the fracture board, the leg portion of the cast remaining upon the Calf Support or sand bag.

AFTER CARE

Regulatory daily lengthening of about H 6 inch is obtained by screwing the trac­tion nut one or more complete turns, de­pending upon the degree of muscular resistance. Frequent roentgenograms check

482 American Journal of Surgery Anderson-Femoral Lengthening MARCH,I936

the alinement, which can be easily con­troIled by mechanical adjustment. Radio­graphic measurements of this extension

FIG. 4. An earlier model of apparatus, whereas the latest type of splint rests directly on the fracture board.

process can be gauged with a simple tongue depressor ruler, which is fashioned by wrapping the depressor with adhesive plaster, gummed side out. Little pieces of wire about ,H 6 inch in length are then stuck in the adhesive, spaced exactly .%: inch apart so that when the ruler is placed opposite the femur, the exact amount of lengthening can be quickly and accurately seen on the films. For example, for a lateral x-ray the ruler is placed on the anterior side of the thigh directly over the femur, and as both femur and ruler are equaIly distant from the film, (the usual distortion of the projected shadows of the femur and the ruler being equal), the exact amount of lengthening will be recorded on the same film.

On obtaining the desired length, the sections of the cast are adjoined, and the splint then removed, the protruding ends of the pins, or Tautnors being covered with corks and plaster.

Patients can be safely allowed on crutches at an early date, for there is no danger of loss in lengthening or of bowing with transfixions so firmly incorporated in plaster, a secure fixation which results in earlier union.

Tendency to stiffness at the knee may be averted by removing the cast from the knee down after the sixth or eighth week,

whereupon active and passive motions are gradually instituted. Such action at this date should cause little disturbance of

FIG. 5. J. R., right femur lengthened 2% inches with resultant correction of most of the scoliosis, while a triple arthrodesis corrected the deformity in this right foot.

alinement, provided the distal transfixion has been made obliquely as delineated in the foregoing. Another expedient, which permits movement of the knee joint from the first day without disturbing apposition, is to insert at time of operation a second wire or pin through the distal fragment at a level about 2 inches superior to the original distal transfixion. But if one plans on utilizing the extra pin, it were better to put the lower transfixion through the condyles closer to the knee. To immobilize the osteotomy fracture securely, the extra transfixion is also incorporated in the lower segment of the cast, the upper end of this section being fastened to the sides of the distal horseshoe with lateral struts of rein­forced plaster bandage.A better procedure is to attach to the distal horseshoe a device, referred to as the Side Arm Exten­sions. This second distal transfixion when fastened into this device can be accurately raised or lowered through mechanical means.

NEW SERIES VOL. XXXI, NO.3 Anderson--Femoral Lengthening American Journal of Surgery 483

Later contingencies occasionally demand mechanical manipulation of the upper fragment, which adjustment can be readily made when the upper section of cast is circularly divided at the groin. To prevent the patient from sitting up, a duraluminum right angle bar, called the Body Bar, should be slipped in and clamped to the slot on the under side of the base plate, and fastened to the side of the body cast by a single plaster bandage. Such an attachment does not interfere with any later mechanical adjustments on the upper fragment. Hence, the cast may be left in three separate sec­tions until the desired length is attained.

At times it is advisable to apply the original cast in three parts: (I) from groin to midthigh including the superior trans­fixion; (2) from midthorax to groin attaching this body bar; and (3) from midthigh to midcalf or toes incorporating the distal pin. By employing the body bar the three segments are maintained free from each other until completion of lengthening.

This procedure can also be utilized In

young adults past the age amenable to

gland growth therapy for correction of embarrassing shortness in stature.

These principles of lengthening are equally applicable for treating fresh frac­tures of the femoral shaft, such patients becoming immediately crutch ambulatory. Moreover, if one does not desire to make a complete transfixion of the upper thigh, the requisite counterextension is obtainable by the Anatomic Femur technique, in which case the means of superior trans­fixion is a specialized set of dual half pins, inserted from the latter aspect into the greater trochanter and adjacent shaft. (Details of this method are to appear elsewhere. *)

SUMMARY

Femoral lengthening with its many advantages can now be achieved with relative ease by a revised mechanical technique.

* ANDERSON, ROGER. An ambulatory method of treating fractures of the shaft of the femur. To be published in Surg., Gynec. &' Obst.