The Conservative Treatment of the Bony Overgrowth Problem in the Juvenile Amputee
LAWRENCE W. FRIEDMANN, MD*AND LIESL FRIEDMANN, OTR**East Meadow, New York
Children with acquired amputation experience bony overgrowth fairly frequently. Overgrowth is accompanied by "spike" formation of the end of the bone which has a thinned cortex, absent medullary canal and loss of bony substance. The bone grows while the soft tissue seems either to grow at a slower pace or to shrink. Eventually the bone end becomes covered with a bursa, and the skin adheres to the underlying bone. Finally, the skin is pierced, with infection of the bone and the soft tissues (Fig. 1 ).
The incidence of overgrowth is 12.4 percent according to Aitken, affecting in decreasing order of incidence the humerus, fibula, tibia and femur1. Overgrowth is rare in the radius and ulna. The problem is unusual in the child with congenital limb deficiency, except in the humerus and does not occur in the disarticulated patient. It is encountered mainly in children who undergo diaphyseal section for any reason. Many congenital amputees with overgrowth have been seen by Marquardt and us. Aitken postulates that the congenital cases are due to true intrauterine amputation, noting "This amputation has been the necessary preexisting trauma to a growing bone that is necessary to produce overgrowth."1 This assumption is as yet unproved.
Spicule formation occurs in adults but is of a different nature and has another clinical course. A number of theories have been proposed as to why this phenomenon occurs. Aitken has proven that the bone grows from the distal bony end1. Periosteal stripping and endosteal curetting are generally insufficient to prevent the problem in surgical amputations. Another theory is that the proximal epiphysis grows excessively. Epiphysiodesis does not cure the problem. Whether contraction of the soft tissues causes the problem is as yet undetermined.
Many treatment methods have been used to solve the problem. The most common is the repeated resection of the bone as it protrudes through the skin. While this measure is temporarily effective it leads to progressive shortening of the amputation limb, decreasing the bony lever for control of the prosthesis. In some instances shortening is not detrimental to function. Attempts have been made to apply plastic materials over the end of the bone to prevent overgrowth, especially silicone plugs4 and caps2. Bone blocks and tibiofibular synostosis have been used to provide an end-bearing limb and at the same time to prevent bony overgrowth.
Marquardt uses cartilaginous end plugs derived from epiphysial patient cartilage or, rarely, bank cartilage for construction of an end pad on the bone. The spicule of the bone is split into a fork after the infected area has been removed. The epiphysis is impaled upon the split spike. The crotch of the split is filled with cancellous bone, and the edges of the epiphysis are held to the bone by attachment of the muscles to its margins. Weightbearing, applied many times a day on the epiphysis, stimulates bone growth. The limb becomes longer than it was prior to the surgery rather than shorter, as in bone-resection procedures. The limb is stronger, weight-bearing is tolerated and bony overgrowth does not recur3.
In the late 1960s Marquardt mentioned that he had used skin traction quite successfully. We assumed he had used this method on many patients. We subsequently used a modified form of the traction procedure he outlined. During the 1981 annual meeting of the Association of Children's Prosthetic-Orthotic Clinics, when Marquardt reported on his latest results with cartilaginous implantation, it became clear that he had used traction only once and then developed his surgical treatment. Many years' success with traction indicates it is an alternative to surgery for the treatment of bony overgrowth.
Success requires a cooperative child and parent. Great intelligence is not needed but consistency of treatment is. People who are impatient for results are not candidates for this type of treatment. Surgical management as performed by Marquardt also demands parent and patient cooperation. The child's activity level is irrelevant because the method can be used with an extremely lively patient. Good appreciation for hygiene is needed, because the skin may be irritated if the socket is unclean. The adhesive irritates some patients.
Traction is especially beneficial for children with short amputation limbs in whom further shortening would preclude efficient prosthetic use. Treatment can be successful at any amputation level when started early, done properly and performed consistently.
Treatment should commence when the distal skin starts to become stretched over the bone end, preferably before the skin becomes adherent to the underlying bursa, reddened and certainly before the skin is perforated. It can be used after perforation in the absence of osteomyelitis. Where osteomyelitis supervenes, the infected portion must be removed surgically.
If the parents and/or child prove uncooperative, surgical resection is the only alternative.
Prior to skin perforation, lifting massage should be performed a-minimum of four times daily to prevent adherence and ischemia of the distal skin. Cocoa butter or lanolin should be applied preventively to soften the skin once daily at the bedtime massage session. Neither substance should ever be used on open lesions.
Pushing the limb into the socket causes the distal soft tissues to "mushroom", because they are held in the proximal portion of the socket by friction while the bone pushes distally through the soft tissues. Pulling the soft tissues in ahead of the bone and keeping tension on the tissues avoid the problem. Although the bone pistons within its soft tissue envelope, the envelope is not perforated; bone at its maximal distal excursion merely reaches the prestressed soft-tissue covering.
The skin is cleaned, and an adhesive, such as Hollister medical skin adhesive (Dow Corning), is applied. Washed cotton stockinette or nylon stocking of appropriate diameter is placed on the limb over the adhesive and pressed onto the skin firmly. The cloth should terminate at the proximal joint, if possible, or at least cover 5 cm of limb length, and should extend several centimeters beyond the end of the limb. After the stockinette and adhesive dry, in approximately 10 minutes, the loose end of the fabric is split into medial and lateral "tails." The tails are cut to the skin margin where the stockinette is adherent to the skin.
The prosthetic socket requires an insert with a distal hole. To don the prosthesis, the child places the tails of the stockinette in the insert, then out of the hole. Limb tissues are pulled into the insert, then the insert is placed partially in the socket (Fig. 2 ). Two holes are to have been drilled in the socket near the distal end. The holes should be opposite each other, generally on the medial and lateral sides. A rod is placed through the holes. Once the amputation limb is situated in the insert and the insert is partially lodged in the socket, each fabric tail can be crossed under the rod and pulled through the opposite hole (Fig. 3 ). The patient pulls the soft tissues into the socket with the stockinette, holding the limb back slightly while pulling on the tails until the limb is completely within the socket. The ends of the stockinette are tied under moderate tension around the outside of the socket with a square knot. When the limb is moved in and out of the socket by gravity, or use, the soft tissues are held distally. It is only the bone that can move within its soft-tissue envelope. This prevents retraction of the skin relative to the bone. If a rod is impractical because of the length of the limb, the tails of the stockinette can be drawn through the socket holes and tied to each other outside the socket. The smooth hole edge replaces the rod as the pulley.
At night, the tails of the stockinette are attached to a cord which goes through a pulley at the foot or side of the patient's bed. Pulley location depends upon the position of maximum patient comfort. The rope is attached to a 0.5 to 2.0 kg weight (Fig. 4 ). The amount of weight used depends upon the resistance of the pulley and patient tolerance. Gradual weight increase is advised. As the child turns during the night, the limb will move but constant traction will be applied to the skin, elongating the tissues and orienting the growth of the fibroblasts in the long axis of the bone. Continued traction helps to prevent retraction of the soft tissues which contributes to the overgrowth problem. Difficulty in sleep is rarely a problem past the first week of use. For that week only, a sedative may be taken at bedtime.
Traction is applied 23 hours a day with one hour off for bathing and cleansing. The stockinette need not be removed daily; it may be left on for a week. It is removed by many substances, the most appropriate being the solvent for the Hollister medical skin adhesive. If that is irritating, other solvents may be tried, such as Uni-Solve liquid or Neutrogena soap.
The apparatus is small enough to be taken with the patient when the family goes on trips. The treatment must be performed daily without fail. Traction should be continued until bony growth stops.
One alternative is to use a sock with a closed end. To the end of the sock is attached webbing with Velcro (Fig. 5 ). The webbing has the Velcro loop proximal and the Velcro hook distal, so that when folded on itself the strip forms a loop. The loop will be used to hold a rope for night traction. During prosthesis wear the webbing goes under the rod, then through a single hole in the socket, and is pulled proximally. The distal Velcro hook on the webbing is held by pressure-sensitive Velcro loop glued to the outer wall of the socket or is looped on itself through a D-ring. If there is insufficient room distal to the limb for the rod, then the webbing may be pulled directly through the socket hole. This, however, pulls unequally on the sides of the limb. Another variation involves a closed sock and a length of string. The midpoint of the string is tied to the end of the sock and the ends of the string are tied outside the socket.
In properly selected cases the results are gratifying. We have used traction on seven amputees. One boy wore a traction device for six and one-half years after three surgical revisions. He is now 17 1/2 years old and has needed no revision since traction was instituted. The patient is very active. The problem only recurred when he went camping for two weeks, when he did not apply traction. Upon returning home the bone was almost piercing the skin. An active program of traction and lifting massage was reinstituted, avoiding the need for surgery. Traction was discontinued when bony growth stopped with no adverse effects for two years.
A 13-year-old girl had surgical spur removal and two operations for tibial penetration of the skin. The patient has cutis marmorata, a seizure disorder, and borderline hypertension. Traction was instituted and used consistently. The child was very sensitive about the prosthesis and her below-knee limb. It was difficult to discuss it with her or to examine it because of her extreme fear. Even her mother had difficulty touching the limb because of the girl's complaints of tenderness. Despite this, traction worked extraordinarily well for two years. During the patient's hospitalization for glaucoma surgery, skin traction was not performed and the Marquardt procedure was done the following year. Overgrowth has not recurred, although the terminal skin is not normal and pain persisted for two years. Eventually the child tolerated limited end weight-bearing. Even in this marginally successful case, traction delayed surgical revision for two years, thus preserving bony length.
In single-bone limb segments, the soft tissues are moved with much greater facility than in two-bone limb segments. Fewer tough septae tether the skin and subcutaneous tissue to the underlying bone. In below-knee limbs, the interosseous membrane and related structures hold the soft tissues more firmly to the bone. Skin traction is therefore more difficult.
The traction technique is similar to that used in open amputation, except that less weight is needed. It is the uninterrupted nature of the skin traction more than the amount of weight that is important. Maintenance of the traction night and day is crucial to success.
Marquardt states that contrary to the generally held opinion, bony overgrowth has been observed in transverse diaphyseal congenital deficiencies. Overgrowth is particularly troublesome when it occurs in a weight-bearing segment, such as the tibia. Where both legs are involved, the problem is accentuated.
Traction treatment for bony overgrowth is an effective measure and should be used in properly selected cases where surgery is not acceptable.
All articles submitted for publication in the ICIB are subjected to peer review. The following are comments from the review of Robert D. Keagy, MD, Co-Clinic Chief, Rehabilitation Institute of Chicago:
"Skin traction is a frequently useful technique in the management of amputees. It can be used to secure full-thickness closure in transverse amputations and to produce full-thickness redundancy to permit excision of scar at bone ends. This paper extends the spectrum of usefulness. This is particularly pertinent in an era when the torso is too frequently attacked for full-thickness myocutaneous transfer when this slower but less mutilating procedure is available."
*Chairman, Department of Physical Medicine and Rehabiliation, Nassau County Medical Center, 2201 Hempstead Turnpike, East Meadow, NY 11554
**Amputation Specialist, Occupational Therapy Department, Rusk Institute of Rehabilitation Medicine, New York University Medical Center, 400 East 34th Street, New York, NY 10016
- Aitken, G. T.: Osseous Overgrowth in Amputations in Children, Limb Development and Deformity. In Problems of Evaluation and Rehabilitation, edited by Chester A. Swinyard. Springfield, Illinois: Charles C Thomas, 1968.
- Lusskin, R., W. A. Thompson and A. Pena: Bone Contouring under Silicone Polymer Implants. Clin Orthop 83:300-316, 1972.
- Marquardt, E.: Plastische Operationen Bei Drohender Knochenburchspiesung Am Kindlichen Oberarmstumps. Z Orthop 114:711-714, 1976.
- Swanson, A. B.: Silicone Rubber Implants to Control the Overgrowth Phenomena in the Juvenile Amputee. Inter-Clin Inform Bull 11:(9)58, 1972.