The Beginnings of Surgery for Spinal Deformities
1 The Beginnings of Surgery for Spinal Deformities
1.1 The Early Days
For more than two millennia various contraptions, casts, and braces have been used in an attempt to correct or improve spinal deformities with no success whatsoever with the exception of serial plaster casts for early-onset (infantile) idiopathic scoliosis and extension braces or casts for Scheuermann’s disease. In the fifth century BC Hippocrates described scoliosis for the first time and used a distraction apparatus in an attempt to correct the deformity. 1 In the second century AD Galen coined the terms scoliosis, kyphosis, and lordosis and treated scoliosis by chest binding and spinal jackets. 2 There was no advancement in the Dark Ages (500 to 1000 AD) except that hunch-backed patients were regarded as heretics and, like criminals, were put on the rack. 3 Ambrose Paré used external breast plates while André recommended proper tables and chairs, periods of recumbency, braces, and corsets. 4 The Le Vacher brothers introduced the Minerva cast for the treatment of tuberculosis of the spine and an extension chair with vertical traction and lateral pressure straps for scoliosis. 5 Meanwhile, Venel, in 1780, developed a day brace and traction at night. 6
Sayre, in 1877, described his technique of suspension casting. 7 He became president of the American Medical Association. Then, in 1876, Adams (of the forward bend test) much more importantly performed careful dissection of cadavers with idiopathic scoliosis thus recognizing the importance of lordosis at the curve apex. This was the most important observation about scoliosis in the entire 19th century if not the20th as well. He went to the United States with Lister to watch Sayre. 8
Meanwhile, in the 1940s, Walter Blount in Milwaukee developed the brace that bears the city’s name. 9, 10 This was specifically to support the poliomyelitis collapsing spine after surgery and to prop up the spine pressure was applied against the occiput and chin above and the pelvis below. It was never designed for any other use but it was soon used as the nonoperative treatment for idiopathic scoliosis. Then an underarm orthosis was devised by John Hall in Boston. 11 Patients were imprisoned in these braces for as many as 23 hours a day for years. This practice continued for the next 20 or 30 years and no one dared challenge this Draconian regimen. 12 Soon, however, retrospective studies 13, 14 confirmed that such braces were of no value in mitigating the progression of idiopathic scoliosis. The proponents did not like this one bit.
Then the ravages to the spine of tuberculosis, and poliomyelitis in particular, led to the introduction of surgery for spinal deformities. The first surgical attempts were in the mid to late 19th century and Delpech 15 and Guerin 16 were enthusiasts for the use of tenotomy. Guerin operated on 740 patients using tenotomy and claimed that 358 were completely cured while 287 benefitted. However, 77 did not benefit and 18 died! 16 In 1889 Volkmann carried out rib resection and this is thought to be the first known scoliosis surgery on bony structures. 17
Then, in 1895, Roentgen discovered X-rays 18 and although he won the Nobel Prize it could well be argued that reducing the three-dimensional scoliosis deformity to two dimensions on a radiograph was a major factor in preventing further development of an understanding of the pathogenesis of idiopathic scoliosis despite Adams’ original dissection and his subsequent statement that “lordosis plus rotation equals lateral flexion” 8—a statement continually ignored through the years.
Berthold Hadra first applied implants to the spine in the nature of spinous process wiring in 1891. 19 Then, in 1902, Fritz Lange implanted metal rods attached to the spinous processes with slings of silk. 20 These implants were of course for tuberculosis of the spine. Wreden in Germany was the first to apply metal implants to the spine to treat scoliosis. 21 This treatment consisted of rib resection followed by an extension bed and then the application of metal plates to the spinous processes. Although bone grafts to the skeleton had been applied in 1682 to repair a soldier’s skull 22 and in 1878 to rebuild a boy’s humeral shaft 23; the first time that this was done to the spine was by Albee in the United States 24 and De Quervain in Europe in 1911. 25 They both applied cortical struts to the spine to treat tuberculosis. Albee used a tibial strut graft in the curve concavity keying it to the spine with pieces of bone (▶ Fig. 1.1).
Fig. 1.1 Albee’s spinal operation. A bone-distracting cortical graft on the concave side acts like a distraction rod attached to the spine by horizontal bone keys.
(Reproduced with permission from Newton P, O’Brien M, Shufflebarger H, et al. Idiopathic Scoliosis: The Harms Study Group Treatment Guide. Stuttgart/New York: Thieme; 2010: 3.)
Next Russell Hibbs in New York described his subperiosteal dissection of the spine right out to the facet joints and base of the transverse processes and, having excised the facet joints, then raised bone flaps in the process thus conjoining adjacent vertebrae with bone graft. 26 Then, in closing, he put the periosteum back over the fusion area and this technique is precisely the same as that used today. It should always be remembered that spinal fusion is a biological operation and that the addition of metalwork is to obtain and maintain a correction until the fusion has matured. As with skin grafting, for example, it is the recipient area that is all important and so it is with bone grafting. Skin grafts don’t “take” on bare cortical bone and nor do bone grafts. Nowadays with the insertion of a profusion of metalwork, the biological nature of the procedure tends to be relegated. All non–load-bearing cortical bone (i.e., not supporting metalwork) must be meticulously decorticated out to the tips of the transverse processes so that whatever bone graft material inserted has an optimal chance of being incorporated. Inserting metalwork and then throwing in a handful of bone graft material as an afterthought is not the way to produce a sound spinal fusion. Hibbs stated that “the dissection was in a practically dry field without injury to the muscles.” This was carried out between 1914 and 1919 on 59 patients, most of whom were polio patients who had undergone preoperative traction. Extraordinarily, there was only a 2% mortality rate.
Then in 1931 Hibbs, Risser, and Ferguson went on to report on 360 cases treated surgically over a 13-year period. 27 The aim was to prevent progression and this was achieved in almost half the cases with about a third having an increase in deformity because of too short a fusion. Risser along with Hibbs designed a turnbuckle cast which they began to use in 1920 with traction and bending preoperatively. Notwithstanding, all was not good, and in 1929 Steindler gave up spinal fusion because of a 60% pseudarthrosis rate. 28 However, in 1943, Howorth reported 600 cases with only a 14% pseudarthrosis rate. 20 In the early 1950s Risser developed his localizer cast and these were used before surgery with a window cut out of the back of the cast to perform Hibbs’ fusion operation. 29
Then, in 1941, the American Orthopaedic Association reviewed the surgical treatment of scoliosis in 425 cases. 30 There was a 28% pseudarthrosis rate and an even greater rate of complete loss of correction so that the end result was that 70% were rated fair or poor and only 30% good or excellent. Then the great polio epidemics of the mid-20th century yielded many scoliosis cases and in 1952 Cobb reported on 672 patients treated surgically with a 4% pseudarthrosis rate. 31
1.2 Posterior Instrumentation
Then came the Harrington revolution in 1962 with his two-rod distraction and compression instrumentation which still remains the basis of modern day scoliosis surgery. 32 He first performed his procedure on these polio cases without fusion, with the Milwaukee brace applied postoperatively. Then Moe, in 1966, reported on 173 patients treated by the Harrington technique versus 100 treated by Risser localizer casting and fusion and the achievement of greater correction with the Harrington instrumentation and a similar pseudarthrosis rate but a greater rate of infection. 33 However, results overall were considered to be very good. Harrington continued to improve his results and reported almost 600 cases in 1973 recommending a long fusion from above and below the end vertebrae so that the whole of the structural deformity was included. 34 Unfortunately, because the three-dimensional nature of the deformity was not appreciated, the rotational component (rib or loin hump) was not corrected (▶ Fig. 1.2).
Fig. 1.2 Harrington instrumentation. (a) Preoperative PA radiograph of a thoracic curve. (b) Appearance after use of instrumentation for distraction and compression, showing a significant improvement in the frontal plane. (c) Rib hump before surgery. (d) Rib hump 2 years after surgery, showing that the deformity in the transverse plane has remained unaltered.
(Reproduced with permission from Newton P, O’Brien M, Shufflebarger H, et al. Idiopathic Scoliosis: The Harms Study Group Treatment Guide. Stuttgart/New York: Thieme; 2010: 5.)
Then segmental instrumentation came into fashion with Resina and Alves in Portugal adding wiring to the Harrington rod. 35 This was followed by the important advance of Luque in Mexico in 1982 with his two L-rod system attached to the spine with sublaminar wires 36 (▶ Fig. 1.3). For paralytic curves that require the pelvis to be stabilized, Alan and Ferguson devised the technique known as the Galveston technique with the short L of the rod passing across the back of the pelvis. 37 However, rather like original Harrington instrumentation, this was applied to the frontal plane of the patient and so the three-dimensional nature of the deformity and in particular the apical lordosis was not addressed although it is the most important part of this three-dimensional deformity.
Fig. 1.3 Luque segmental L-rod instrumentation for a child with Friedreich’s ataxia. (a,b) PA radiograph before surgery. (c,d) PA radiograph after instrumentation.
(Reproduced with permission from Newton P, O’Brien M, Shufflebarger H, et al. Idiopathic Scoliosis: The Harms Study Group Treatment Guide. Stuttgart/New York: Thieme; 2010: 6–7.)