HISTORY OF SMALL ANIMAL ORTHOPAEDICS

INTRODUCTION

WAYNE H. RISER


   

From 1875 to 1920 bone fracture repair was an unexciting discipline in small animal practice. Muhler's Diseases of the Dog, translated and revised by Glass in 1887, and considered the definitive reference for small animal practice at that time, had only seven pages devoted to the skeleton, four of which concerned fracture repair.(24)

Perrin, a small animal practitioner from Nebraska, apologized for presenting a subject as dreary as fracture repair and stated that improved methods had not been introduced in over 30 years.(23) He depicted people in his part of America as being frequently indifferent about their pets, especially when it came to fractures, since dogs had little monetary or sentimental value. The exception may have been the greyhound-Airdale hybrid used on ranches to chase coyotes. Perrin considered cage rest to be the best treatment for canine fractures, since "this allowed nature to take care of the bone repair very nicely when assisted by the immobility of the part."(23) He further recommended keeping the animal quiet and applying artificial immobilization to support the limb, namely, splints and casts. His experience with splints and casts, however, led him to believe that they were usually bunglesome, unnecessary, and impractical.(26)

Other articles of that era that describe the application of splints and casts reveal that a variety of materials were used, such as plaster of paris, sodium silicate (glass water), tripolith dressing (mixture of plaster of paris and soot), fish glue, pitch, and cornstarch paste. Each of these substances, when mixed with water, made a paste that was used to saturate bandages of gauze, muslin, cheesecloth, or crinoline. The saturated bandages were then wrapped over cotton padding and supported splints that were made from a wide range of materials, including wood, tongue depressors, gutta-percha, wire gauze and screen, cardboard shirt backs, mailing tubes, flexible wooden strips from market baskets, yucca board, and corset stays. For further protection after the cast had dried, waterproof adhesive tape or electrical tape was often wound around the Cast.(6-8,18,20,23)

The first advancement in veterinary orthopaedics came in 1920 when fluoroscopy of the skeleton was introduced. Watching bone images move on the screen of the fluoroscope made orthopaedics an exciting and challenging subject. Observing the bones by fluoroscopy was so fascinating that radiographs were seldom made except for permanent records. Both fluoroscopy and radiography generated new insights into orthopaedic problems never before considered. New methods of fracture reduction were developed.

Most long-bone fractures of humans, especially those of children, were set and repaired by the local family doctor. A fluoroscopic view of the fractured bones was just what was needed to aid the family physician with fracture reduction. In response to this need, low-priced, small, light-weight and portable x-ray machines and hand-operated fluoroscopes were made available to the medical profession. Physicians who reduced fractures either purchased such equipment or shared it with a colleague.

A number of veterinarians with busy small animal practices copied the physician's procedures and used fluoroscopy extensively to reduce fractures. The increasing number of automobiles and the lack of leash laws resulted in the injury of many dogs and cats. When sodium pentobarbital, a new anesthetic that lasted for several hours, was introduced, the fluoroscope was an ideal instrument to assist in bringing about proper fracture reduction. Sometimes this reduction procedure, when difficult, required as long as an hour under the fluoroscope.

Fluoroscopy was accompanied by unanticipated hazards. Both veterinarians and physicians, after using the fluoroscope for a few years with their hands unprotected from the x-ray beam, developed permanent radiation injury of the skin of their hands: dehydration, irritation, and ulceration, with some ulcers so severe that they did not heal. Skin grafts and even amputations of fingers were occasionally necessary. In rare instances squamous cell carcinoma occurred on the hands of the most severely affected.

FIG. 1-1 This veterinarian's hands demonstrate radiation dermatitis.

In the late 1930s and 1940s, the American Animal Hospital Association notified its members of the hazards of fluoroscopy. Kodachrome slides showing burned hands of colleagues provided graphic evidence of these hazards (Fig. 1-1). The knowledge of fracture repair gained by the use of fluoroscopy had, however, resulted in great improvement in fracture treatment.

Radiographs made it apparent that leather, wood, and metal commonly applied with or without starch, adhesive, and plaster of paris were not as effective as they were once thought to be.(3,6-9,21,22)

Overriding of fractured bones, especially of the femur and the humerus, was a major unsolved problem in fracture reduction. Muscle spasms were ever-present, causing fractured bone ends to overlap, and correction was extremely difficult. In humans, tongs and traction applied to the distal fragment of the bone brought encouraging results. In 1931 Dibbell reported the use of small tongs applied to the distal fragment of the dog's femur, with traction applied by means of a cast.(6) This sometimes corrected the overriding, but osteomyelitis often developed at the point at which the points of the tongs were inserted into the bone.(6,7)

In 1933 Schroeder,(35) having been inspired at Massachusetts General Hospital, wrote

"Having made use of x-rays before and after reduction especially in fractures of the humerus and femur, we have become convinced that reduction and fixation without incorporating some form of traction is ineffective in most cases. Gross displacement of the fractured bone is always to be expected in complete fractures. The overriding is due to unapposed muscular contraction and spasm. Without continuous traction to offset the unapposed muscular action in these fractures, reduction cannot be maintained." (35,36)

Thomas in 1875 and Jones in 1913 introduced to human orthopaedics a splint to correct overriding.(19,40) It was made by bending a metal rod in such a fashion as to apply traction to both the proximal and distal ends of the fracture. To a considerable extent this overcame the muscle spasm and corrected the overriding. In 1933 Schroeder (Fig.%20I-2)adapted the concept of this splint to canine practice and applied traction to the proximal end of the fracture by padded wire rings applied to the body and adhesive tape attached to the skin after the hair has been removed.(35,33) Gauze wraps were also used, and in difficult cases tongs or Kirschner pins were applied to the distal end of the fractured bone. The Schroeder splint was made with a metal rod, bending a ring at the proximal end through which the limb was placed. The padded ring rested against the body, the latter serving as countertraction while the joint and the foot below were attached under tension to the other end of the splint. The limb was also fastened to the side bars of the splint to further align the bone fragments. This arrangement permitted movement of the splint at the joint next to the body while the limb was secured inside the splint. The animal could remain ambulatory.(35,36)

This splint, the Schroeder-Thomas splint, could be fashioned from various materials. For cats and toy dogs, coat hangers and steel brace wire from fences were used.For larger dogs, light, pliable, and inexpensive rods of aluminum alloy were used.(35,36)

FIG. 1-2 Erwin F. Schroeder, DVM. 188:3 December 26, 1952
In spite of improved traction and splinting techniques, the fluoroscope and radiographs revealed that some complicated fractures still resisted complete reduction and healed in a malaligned fashion. More sophisticated and adaptable methods were sought to achieve satisfactory results. Surgical intervention at the site of the injury was a feasible approach, but the complications of sepsis and osteomyelitis proved too great for most surgeons. Attempts to minimize sepsis brought the second major achievement in fracture repair.

Rigid aseptic or sterile technique in which all instruments, solutions, drapes, and towels were subjected to sterilization by live steam pressure and in which the operators were covered by sterile gowns and rubber gloves with hair and mouth covered by clean caps and masks had been used for some time in human medicine.(10,41) Schlotthauer and Man of the Mayo Clinic,(32) Riser of Des Moines,(21) Farquehanson of Colorado State,(10) Gadd of Baltimore(11) and Stader of Philadelphia (38,39) were among the first to adopt sterile techniques in veterinary surgical procedures. It was found that if aseptic technique could be maintained, a closed fracture could be invaded for approximately 20 minutes and still heal by first intention without infection or drainage. The chances of a complicated infection increased rapidly after 25 minutes. However, results obtained using aseptic technique were sufficiently encouraging to prove that pin insertion, even multiple pin insertion in which the pins were allowed to extend beyond the skin, was a procedure that usually elicited a favorable response.

In 1940 a third breakthrough occurred that added confidence to successful fracture repair: the introduction of antibiotics to minimize infections. Penicillin and a number of sulfa derivatives were the first agents used. Initially these were quite crude and complicated to use. Veterinarians, armed with radiography, sterile technique, and antibiotics, made rapid progress in fracture repair and reconstruction.

One of the best-known contributors to fracture reconstruction was Stader,(33,39) a one-time Wisconsin and Illinois bovine sterility specialist turned small animal practitioner (Fig. 1-3). Fracture repair was fascinating to Stader because of the mechanics involved. His father, a trained machinist, had developed and patented instruments for sterility treatment.(39)

Stader was enthralled by the work of Gadvilli, a Swiss surgeon who introduced the Steinmann pin to America.(39) This pin was inserted transversely through the fractured end of the bone and surrounding soft tissues. Pins above and below the fracture could be used to bring the fractured bone ends together and hold them in apposition. The ends of the pins were then incorporated in a cast until the bone healed. Although this technique had been used with success in humans, when applied to animals, especially the dog, the results were unsatisfactory because it was impossible to keep the cast free of moisture, contamination from urine and feces, and damage from chewing.

These unsatisfactory experiences led Stader to draw on his mechanical imagination and youthful training to invent a new splint using the feature of the inserted pins. He employed four short Steinmann pins pointed on one end. Two pins were inserted through a tailored block as a guide in a V-shaped direction to add strength and to prevent them from being pulled out. A set of pins and block was placed in the proximal and distal fracture fragments in a similar manner. Each pin was inserted on the lateral side of the limb through the skin, soft tissue, lateral bone cortex, and medullary cavity, with the points of the pins emerging slightly through the medial cortex. The ends of the pins that protruded through the proximal and distal blocks on the side of the limb were maneuvered into position and secured. The metal parts of the splint were rigid and stable. The apparatus was easy to clean and offered immediate patient mobility.

This unique splint attracted worldwide attention from physicians, universities, hospitals, and the armed forces. The nation was just entering World War II, and the Navy gave special attention to this new dimension of fracture repair, since with it shipboard personnel with fractures could be immediately mobile and unrestricted by heavy casts.(38,39)

Human orthopaedics, upon recognition as a specialty in medicine, quickly devised improvements and modifications stimulated by the Stader splint. Veterinarians, especially those in the immediate vicinity of medical training centers, rapidly added innovations to improve the techniques used. Anderson, an orthopaedic surgeon, simplified the Stader splint,(l) and veterinarians Ehmer and Olson (8) introduced methods and instruments that greatly aided fracture reduction and stabilization. These included the Gordon extender and the hand pin inserter.

Once it became safe to invade bone through limb soft tissues, other internal reduction methods were considered. The medullary canal of a long bone was attractive for holding materials that would keep the fractured bone ends together and in alignment. Metallic materials such as piano wire, bicycle spokes, silver wire, stainless steel rods, and tantalum were tried. Processed animal tissues such as bovine bone slabs, gut, and tendon were also tried(3,7-9,25,28)

The use of metallic and animal materials, encouraging as it was, brought new problems, primarily those associated with tissue rejections, metal oxidation, and metal fatigue. Occasionally as many as three or four types of metal were used in the same reduction. As intramedullary pinning came into wider use, the disadvantage of the protrusion of the pin ends from bones remained. Even though the ends were covered by skin, seromas and fistulas (4) often remained. This disadvantage stimulated the development of a self-retaining intramedullary extension splint. This new splint, the Jonas splint, consisted of three separate pieces of nonmagnetic surgical stainless steel, a hollow sleeve, a spring that extended into the sleeve, and a pin.(17,18)

The splint was available in various diameters and lengths. One end was open, making possible the insertion of a spring and pin. The length and tension of the spring varied, depending upon the type of fracture. It was simple to insert and hold the fracture ends in excellent alignment. Because of satisfactory bone alignment and ease of use, the splint gained immediate acceptance. However, shortly after the fracture was satisfactorily healed, tissue reaction became apparent.

The tissue reaction mimicked osteomyelitis, with swelling, lameness, and fever. The disadvantages of this splint became apparent when it was realized that there was no satisfactory way of removing it without extensive removal of large amounts of bone cortex. The popularity of what seemed an ideal splint was short-lived. Two physicians named Rush (31) developed hooked rods made of spring steel. These were designed to be introduced at the epiphysis and pass across the fracture line and into the medullary cavity of both fracture fragments. The spring effect of two such rods held the fracture ends in excellent apposition. The technique was introduced in the veterinary literature in 1952 by Carney. (5) This method of fixation is still used today.

In 1950, Jenny (Fig. 1-4), after studying in Europe, first described the use of the Kuntschner nail in canine fractures. While the indications were limited, it represented the principles of very stable internal fixation. (15,l6)

Bone plates were introduced by Lane in 1907(30) and by Sherman in 1912(37) These plates contained four or eight screw holes and were designed for attachment to the lateral side of the fractured portions of bone. In the mid 1960s bone plating became one of the most successful methods of internal fixation with the introduction of the Arbeitsgemeinschaft fur Osteosynthesefragen (AO) system of implants from Switzerland. Brinker, Hohn, Jenny, and Stoyak were the first American veterinary orthopaedists to work extensively with this equipment.

During the first half of the century the canine orthopaedic literature dealt almost entirely with fracture repair. Relatively unnoticed at first were reports of Schnelle (1935-1937; Fig. 1-5), who discovered from pelvic radiographs that more than half of large and giant breed dogs had hip joints that were deformed by osteoarthritis. The osteoarthritic lesion involved both the acetabula and femoral heads. Schnelle reported that despite these lesions, many of the affected dogs were unrestricted in their gait, and the bony changes had not been suspected before the radiographs were taken.(33,34)

Schnelle reported these findings to the American Kennel Club (1935)(33) and to the veterinary profession (1937).(34) Because most affected dogs moved satisfactorily under pet and kennel conditions, his reports were not taken seriously. However, when World War II occurred, Schnelle entered the Army and was assigned the task of securing German shepherd dogs for sentry duty training. It was soon discovered that those with the affected hips broke down rapidly and could not be used for rigid training. This finding alarmed German shepherd fanciers, especially when they realized that this disease was hip dysplasia. First reports suggested that the dogs of Germany of this breed did not have this defect, and that hip dysplasia had gotten into the bloodline of the US German shepherd after the breed was imported following World War I. Because of the war, this story could not be verified, but fanciers believed with great fear that hip dysplasia would rapidly cripple the entire breed. A number of conscientious fanciers became so concerned with saving the breed that in many kennels the affected dogs were destroyed (33,34)

FIG. 1-3 Otto Stader, VMD. April 4, 1984-September 10, 1962

FIG. 1-4 Jacques Jenny, Dr. med. vet. October 19, 1917-November 20, 1971

FIG. 1-5 Gerry B. Schnelle, VMD. July 20, 1904 May 4, 1976

At the same time that hip dysplasia was established as a disease entity in America, Moltzen-Neilson from Denmark reported hip problems in toy and small dogs. Usually only one hip was affected, and the chief signs were acute lameness and atrophy of the thigh muscles of the affected leg.(23) This condition is now referred to as ischemic necrosis of the femoral head.(23)

By the mid 1940s, many other skeletal diseases of the dog were being recognized and characterized. Among these were medial patella subluxation and malalignment of the stifle in the toy proportionate dwarf, intervertebral disk disease in the chondrodystrophic breeds,(12-14) osteochondrosis dissecans of the shoulder in large and giant breed dogs,2 ununited anconeal process,(4) cranial bowing of the radius in the giant breed dog,(29) lateral deviation of the front foot,(3,10) and retained cartilage of the ulnar metaphysis in the rapidly growing giant dog.(29)

Veterinary orthopaedics, which began as fracture repair and enlarged into orthopaedic diseases of animals, now includes contributions in genetics, electron microscopy, histochemistry, biomechanics, computer sciences, and other specialized disciplines. The future should continue to expand the horizons of veterinary orthopaedics. Our humble beginnings can be traced to three major steps made by the medical community: radiography, sterile technique, and antibiotics.


 

References

1. Anderson R: Fractures of the radius and ulna: New anatomical method of treatment. J Bone Joint Surg 16:379, 1934
2. Brass W: Osteochondritis in the dog. Tierarztliche Umschau 2:200, 1956
3. Brinker WO: The use of intramedullary pins in small animal fractures. North Am Vet 29:292, 1948
4. Carlson WD, Severin GH: Elbow dysplasia in the dog. J Am Vet Med Assoc 138, No. 6:295, 1961
5. Carney JP: Rush intramedullary fixation of long bones as applied to veterinary surgery. Vet Med 47:43, 1952
6. Dibbell EB: Lower third femoral fracture in dogs. North Am Vet 12:37, 1931
7. Dibbell EB: Dislocation of the hip in dogs and cats. North Am Vet 15:37, 1934
8. Ehmer EB: Special cast for the treatment of pelvis and femoral fractures and coxofemoral luxations. North Am Vet, December 1934, p 31
9. Erick EJ, Witter RS, Mosier JE: Treatment of fracture by intramedullary pinning. North Am Vet 29:95,1948
10. Farquehanson J: Fundamental of surgical technique. North Am Vet 26:591, 1945
11. Gadd JD: Sterile surgical demonstration. Proc Am Anim Hosp Assoc 15: 71, 1946
12. Hansen HJ: A pathologic-anatomical interpretation of disc degeneration in dogs. Acta Orthop Scand 20:280, 1951
13. Hansen HJ: A pathologic-anatomical study on disc degeneration in dogs. Acta Orthop Scand (suppl) 11:1952
14. Hoerlein BF: Intervertebral disc protrusions in the dog: I. Incidence and pathological lesions; Il. Symptomatology and clinical diagnosis; III. Radiological diagnosis. Am J Vet Res 14:260, 1953
15. Jenny J, Kanter U, Knoll H: Die Behandlung von Femurfrakturen des Hundes durch Marknagelung. Schweiz Arch Tierheilkd 85:547, 1946
16. Jenny J: Kuentscher's medullary nailing in femur fractures of the dog. J Am Vet Med Assoc 17:381, 1950
17. Jonas S: A new method of intramedullary pin fixation. J Am Vet Med Assoc 115: 9, 1949
18. Jonas S, Jonas AM: Self retaining medullary extension splint. J Am Vet Med Assoc 122:361, 1953
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20. Kunstcher G: Zentralbl Chir 67: 1145, 1940
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33. Schnelle GB: Some new diseases in the dog. Am Kennel Gaz 52:25, 1935
34. Schnelle GB: Congenital subluxation of the coxofemoral joint in a dog. University of PA Bull 65: 15, 1937
35. Schroeder EF: The traction principles in treating fractures and dislocations in the dog and cat. North Am Vet 14:32, 1933
36. Schroeder EF: Multiple bone fractures in a bull terrier. North Am Vet 15:34, 1934
37. Sherman WO'N: Vanadium steel bone plates and screws. Surg Gynecol Obstet 14:629, 1912
38. Stader O: Treating fractures of long bones with the reduction splint. North Am Vet 20:62, 1934
39. Stader O: Stader splint approved in human surgery. J Am Vet Med Assoc 104:48, 1943
40. Thomas HO: Disease of the Hip, Knee and Ankle Joints. Liverpool, T Dobb and Co, 1875
41. Warbasse JP: Asepsis and antisepsis. In Warbasse JP: Surgical Treatment, pp 27-32. Philadelphia, WB Saunders, 1918