Eur Spine J DOI 10.1007/s00586-014-3651-x

ORIGINAL ARTICLE

Sacral and pelvic osteotomies for correction of spinal deformities Arnaud Bodin • Pierre Roussouly

Received: 27 September 2014 / Revised: 1 November 2014 / Accepted: 1 November 2014 Ó Springer-Verlag Berlin Heidelberg 2014

Abstract Introduction Restoring a physiological sagittal spine balance is one of the main goals in spine surgery. Several technics have been described previously, as pedicle subtraction osteotomy. In more complicated cases involving spino-pelvic disorders, three authors proposed sacral osteotomy to restore sagittal balance of the spine. The authors describe the use of pelvic osteotomies for the correction of lumbo-sacral kyphosis, for decreasing pelvic incidence and for achieving sagittal balance correction in cases of lumbosacral sagittal deformity as an alternative of pedicle subtraction osteotomies (PSO). Materials and methods We simulate four types of pelvic osteotomies previously described for hip pathology (Salter, modified Salter, Chiari and posterior sacral osteotomy) on drawing software, and calculate during these osteotomies the variation of pelvic incidence (PI). Then, we compare the behaviour in this simulation to a cadaveric model where we perform the same four pelvic osteotomies. Via X-rays made the study, we calculate also the PI. Then, we analyse 11 patients who underwent pelvic osteotomies for sagittal unbalance, analysing operative and clinical data. Results We find a mathematical law governing the PI during anterior opening and posterior closing osteotomies (respectively Salter and sacral osteotomy):

A. Bodin Clinique Mutualiste, 4 ter rue Jean Veyrat, 38000 Grenoble, France P. Roussouly (&) CX Rouge Franc¸aise-CMCR des Massues, 92 Rue Edmond Locard, 69005 Lyon, France e-mail: [email protected]; [email protected]

PI end ¼ PI initiala  osteotomy angle: These laws are confirmed in the cadaveric model which retrieves the same behaviour. In the clinical series, Salter osteotomy is easy and efficient on sagittal rebalancing; sacral osteotomy is more powerful. Discussion The Salter osteotomy is efficient for restoring sagittal balance of the spine. The posterior sacral osteotomy is more powerful but technically demanding. The indications of such special osteotomies are fixed lumbosacral kyphosis, especially high-grade spondylolisthesis, previously operated or not. Conclusion A study of a more substantial series would be considered. Keywords Pelvic osteotomy  Sacral osteotomy  Sagittal spine balance  Spinal deformity  Pelvic incidence  Highgrade spondylolisthesis

Introduction The importance of sagittal balance parameters of the spine and pelvis and their impact on diagnosis and strategy of spinal deformities treatment has been well described in the literature. Parameters that describe balance are generally classified as pelvis parameters [pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS)], spinal parameters [lumbar lordosis (LL), thoracic kyphosis (TK)] and global parameters [C7 positioning, Sacro-spinal angle (SSA)] [1–36]. In pathology, patterns of severe sagittal unbalance are well known: loss of LL, hyperkyphosis with a global effect on a decreasing SSA and displacement of C7 Plumb Line forward of the femoral heads, associated with a major pelvis retroversion (hips extension and knee flexion). Even if a very retroverted pelvis is an effective way of balancing

123

Eur Spine J

the spine, this situation is very uncomfortable and difficult to maintain. Due to the relation PI = PT ? SS, we may consider that the bigger the PI, the bigger the PT. Another situation that may result in a very retroverted pelvis is highgrade spondylolisthesis (HGS) where the progressive slipping and rounding of L5 around a sacral doming may affect balance by increasing the lumbosacral kyphosis (LSK). Techniques of intervertebral osteotomies (Smith-Petersen, Ponte) or intravertebral osteotomies (PSO, vertebral resection) have been well described in treatment of severe kyphosis associated with spinal deformities. Their effect in lordosis restoration is very powerful and used routinely in deformities surgery [37–50]. The limits of osteotomy are reached when the degree of LL exceeds the capabilities of the technique (i.e., an acute hyperlordosis more than 90°). This is the case in very high PI ([90°) and in HGS. In those cases, the best place for an osteotomy is between the sacral plateau and the femoral heads, in order to decrease PI. Two anatomical places seem appropriate for an osteotomy: the first sacral body, just below the sacral endplate; and the iliac wings. If unilateral iliac osteotomies have been well described for hip dysplasia (Salter, Chiari) [51–60], there are only two dated descriptions of bilateral pelvic osteotomy [61, 62], and one of sacral osteotomy [63] for sagittal correction of spinal unbalance. In this study we compared the effect of different osteotomies on a cadaver, and then on a mathematical model. A short series of pelvic (double Salter) and sacral osteotomies were analysed in order to precisely determine their respective indications.

Materials and methods

wearing a hemi-spica cast for 45 days, and then a brace for an additional 45 days. Clinical series: sacral osteotomy Five patients (2 women, 3 men) undergoing sacral osteotomies were included. The average age at surgery was 21 years [16–42]. The sacral osteotomies were performed by two operators in two different centers. The sacral osteotomy was performed according to a technical description by Ondra. The patient was in a prone position. By a medial approach, the posterior bone of the sacrum was skeletonized up to the iliac crests. Then a laminectomy was performed at the S1 level until the first sacral foramens. A classic pedicle subtraction osteotomy (PSO) through the S1 pedicles was done, and to separate the superior endplate of S1 from the rest of the pelvis, two vertical osteotomies were realized on the lateral wings of the sacrum, leaving the anterior sacral cortex intact. Then closure was possible using compression between pedicular lumbar screws and iliac screws. An osteotomy schematic is presented in Fig. 1. After the surgery, we recommended wearing a hemi-spica cast for 45 days, and then a lumbar brace for an additional 45 days. Data analysis Registered clinical data were: average delay of follow-up, duration of back pain, previous treatments, etiology, type of osteotomy, surgical approach, operative time, surgical blood loss, complications due to surgery, type of implants, pain before and after surgery evaluated by the pain visual scale, Oswestry disability index (ODI) pre and post operative and a satisfaction score.

Clinical series: pelvic osteotomies Eleven patients (3 men, 8 women) undergoing a pelvic osteotomy were included. All the patients were operated on by the senior author. The average age at the time of the surgery was 37.6 years (age range 18–49 years). The pelvic osteotomy was performed according to a technical description by Salter. The patient was in a prone position, the iliac crest was released on both sides between the anterio-superior and the anterio-inferior iliac spine, and a straight osteotomy was made targeting the great ischiatic notch. As such, the osteotomy was made just above the acetabulum. The osteotomy was performed in the same way controlaterally. The osteotomy separated the legs from the trunk; both osteotomies were opened simultaneously using a distractor. To maintain the anterior opening, a cage or tricortical iliac graft between the two iliac crest parts were inserted. A synthesis was added in order to improve stability and strength. After the surgery, we recommended

123

Fig. 1 The PSO S1 is made by a classic PSO through S1 and two vertical osteotomies in the sacral wings

Eur Spine J

Fig. 2 Simulation of four osteotomies: Salter; modified Salter; Chiari; PSO S1

Radiological data were extracted from long-standing pre- and post-operative x-rays with OptispineÒ software (Lyon, France): PI, SS, LL, TK, S1 offset (the horizontal distance between the hip centre of rotation and the posterosuperior point of the S1 endplate), ratio plumb line C7 on hip centre of rotation/offset S1, plumb line of external auditive ducts (PLE), plumb line of C7, pelvi-femoral angle (PFA), tilt C7 and T9, SSA; before surgery and at the last follow-up.

Using a computer (QcadÒ, IrfanviewÒGIMP 2.6.6Ò), the hip rotation centers were determined, as were the perpendiculars to the center of the sacral plate. Then the osteotomies were simulated: anterior Salter opening osteotomy in two sites on the iliac crests (classic Salter and ‘‘modified’’ Salter); Chiari osteotomy and trans sacral closure osteotomy just as a PSO S1 (PSO S1). The anterior opening osteotomies were done with an increment of 2° and the PSO S1 by an increment of 2° (see Fig. 2). PI was calculated during the various osteotomies.

Computer simulation Cadaveric model We used 15 scanners of pelvic bone made during thoracoabdominal or pelvis tomodensitometry (acquisition Somaton Siemens Sensation 16Ò). These scanners are reworked on a SyngoMMWP VE22A tool to get the views of a strict profile with transparency of the iliac wings, allowing calculation of standard pelvic parameters. Exclusion criteria were history of pelvic surgery/trauma, THP or pelvic fracture.

We used six cadaveric pelvic bones (4 women, 2 men). The pelvic bone was skeletonized taking care to maintain the L4, sacrum, hip, pelvic ring and the proximal third of the two femurs. The pelvis was separated in a mid sagittal fashion and fixed with screws on its flat cutting side on a rigid board.

123

Eur Spine J

PI evolution during Salter osteotomy 90

body 1

PI evolution during Chiari osteotomy

body 2

100

body 3

80 70

body 2

70

body 7

60

body 8

40

body 9

PI

body 6

50

30

20

body 12

20

10

body 13

2

4

6

8 10 12 14 16 18 20 22 24 26 28 30

body 6 body 7 body 8 body 9 body 10 body 11 body 12 body 13

10

body 14

0

body 5

50

body 11

0

body 4

40

body 10

30

body 3

80

body 5

60

PI

body 1

90

body 4

body 14 body 15

0

body 15

0

Angle

80

body 2

14

16

body 8 body 9

body 3 body 5 body 6

50

body 7

PI

body 7

body 2 body 4

body 6

body 8

40

body 9 body 10

30

body 10

20 10

body 11

body 11

20

body 12

10

body 12 body 13 body 14

body 13

0 0

2

4

6

8 10 12 14 16 18 20 22 24 26 28 30

Angle

Linear (body 1)

body 1

60

body 5

PI

12

70

body 4

30

10

80

body 3

40

8

PI evolution during PSO S1 body 1

50

6

90

90

60

4

Angle

PI evolution during modiied Salter osteotomy

70

2

body 14 body 15

0

body 15

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30

Linear (body 1)

Angle

Fig. 3 Behavior during the osteotomy simulations

Six comparisons of the different osteotomies were performed and we follow the evolution of PI in each osteotomy after radiology (Philips Diagnost 96Ò). – – – – – –

Body Body Body Body Body Body

1: 2: 3: 4: 5: 6:

comparison Salter/modified Salter Salter/Chiari Salter modified/Chiari Salter modified/PSO S1 Chiari/PSO S1 Salter/PSO S1

The back closure PSO S1 is made with a CD HorizonÒ device (MedtronicÒ). We follow the same process as in the computer simulation to measure PI. Statistical analyses Statistical analyses were performed using STATVIEW 5.5 (Abacus Concepts, Berkeley, CA) and the unpaired

123

nonparametric Mann–Whitney U test at a 95% confidence level. Differences were considered significant when P \ 0.05.

Results Computer simulation The average PI of the population was 59.74 (39–82, D = 12.5). Via linear regression, we conclude that the PI varies following a mathematical law: PI end ¼ PI initial  a  osteotomy angle Indeed, all the bodies follow the same mathematical behavior as seen in Fig. 3. The coefficient ‘‘a’’ varies with the type of osteotomy:

Eur Spine J Table 1 Reporting of the linear coefficient a and statistical correlation Salter

Salter modified

Chiari

r2 Salter

PSO S2

r2 Salter modif

r2 chiari

r2 PSO S2

Body 1

-27.7126

-29.094

-0.0854

-47.945

0.9959

0.9962

0.4573

0.9973

Body 2

-29.9146

-30.4189

-0.1315

-45.2148

0.9935

0.9906

0.4479

0.9969

Body 3

-30.9068

-30.2145

0.1272

-50.9751

0.9932

0.9889

0.6769

0.9943

Body 4

-29.7801

-30.2147

0.1048

-47.0459

0.9972

0.9972

0.4868

0.9974

Body 5

-36.6057

-36.2515

0.015

-48.7335

0.9972

0.9967

0.0637

0.9971

Body 6

-32.0938

-31.5995

0.0648

-48.7297

0.9984

0.9995

0.5353

0.9978

Body 7

-25.4913

-28.4049

0.126

-50.1813

0.9958

0.9689

0.9072

0.9975

Body 8

-26.7828

-25.4349

0.0347

-41.0204

0.9952

0.9851

0.253

0.9968

Body 9

-28.0272

-29.4971

-0.0098

-44.5334

0.9961

0.9981

0.0498

0.9963

Body 10

-24.3965

-23.8311

-0.0196

-48.0726

0.9945

0.9985

0.0891

0.9974

Body 11 Body 12

-28.2302 -31.7875

-28.2492 -31.6749

0.0227 -0.1193

-48.5649 -46.5207

0.9963 0.9976

0.9941 0.9984

0.0184 0.5495

0.9953 0.9975

Body 13

-30.034

-29.9436

0.0499

-47.0753

0.9951

0.9866

0.5385

0.9951

Body 14

-29.5975

-27.6339

-0.0376

-44.9541

0.9921

0.9925

0.0521

0.9967

Body 15

-30.5853

-33.0051

-0.0795

-44.5016

0.9948

0.9979

0.4147

0.9971

Mean

-29.4630

-29.6978

0.00416

-46.9378

0.995526

0.9926

0.369346

0.9967

SD

2.858995

2.870008

0.081012

2.477167

0.001740

0.0080

0.269079

0.001022

D

2.151701333

2.098649778

0.068242667

1.984309333

0.001371556

0.005744

0.225330667

0.000773333

Pearson r2

0.8988856 0.907995321

Linear correlation was variable depending on the type of osteotomy: r2 = 0.9955 for Salter; r2 = 0.9926 for modified Salter; 2 r = 0.9967 for PSO S1; r2 = 0.3693 for Chiari. By a geometric construction, the height H of the anterior posterior opening or closing is related to the length L of the osteotomy (see Fig. 4) and the angle a of the osteotomy: H ¼ 2L sin a=2. The length L depends on the length of the iliac bone for the Salter and modified Salter osteotomy, and on the length of the sacral bone for PSO S1. The law of PI evolution could also be written not on the opening angle, but on the opening/closing practiced height.

H L

Then PI end ¼ PI initial  a  2 sin1 ðH=2LÞ

Table 2 Resume of the leading coefficient during cadaveric simulation

Fig. 4 Relation between height and opening angle in the pelvic incidence

Mean ‘‘a’’ Salter = 0.4964; mean ‘‘a’’ modified Salter = 0.3725; mean ‘‘a’’ Chiari = -0.0042; mean ‘‘a’’ PSO S1 = 2.1375 (see Table 1).

Body

Mean ‘‘a’’

Mean ‘‘a’’

1

A Salter = 0.4245

A modified Salter = 0.2916

2

A Salter = 0.373

A Chiari = 0.1187

3

A modified Salter 0.373

A Chiari = -0.1589

4

A modified Salter = 0.314

A PSO S1 = 0.0867

5

A PSO S1 = 1.1596

A Chiari = 0.2035

6

A Salter = 0.3334

A PSO S1 = 0.7391

123

Eur Spine J Table 3 Demographic data on patients undergoing pelvic osteotomy Follow up

9.27 (3–19) years

Length of back pain

10.2 (0.25–25) years

Previous surgeries

17 (1.6 per patient) 5 arthrodesis

PI end ¼ PI initial  a  osteotomy angle for all bodies (Table 2). Clinical series: pelvic osteotomies Epidemiological data were:

3 instrumentation ablations 1 discectomy 1 lumbar narrowed canal

– –

1 lengthening of arthrodesis 1 circumferential arthrodesis 4 hip surgeries Etiologies

5 spondyloptoses L5-S1 (1 with thoracic scoliosis, 1 with pelvis obliquity) 1 lumbo-pelvic inadequation (i.e. High incidence with low lumbar lordosis) 2 sacral fracture with vicious callus in flexion



2 lumbosacral kyphosis due to infectious diseases (1 Pott) 1 Stiffmann syndrom



Table 4 Operative data on patients undergoing pelvic osteotomy Type of osteotomy

7 bilateral Salter inominate osteotomy 1 bilateral Salter with psoas tenotomies 1 unilateral Salter inominate osteotomy 1 unilateral Salter inominate osteotomy with controlateral closure 1 unilateral Salter with 1 controlateral Chiari osteotomy

Surgical approach



Demographic data are summarized in Table 3. Operative data are listed in Table 4. Surgeries consisted of:

8 Smith-Petersen bilateral 1 Hueter bilateral 1 Watson-Jones bilateral



1 Smith-Petersen unilateral Operative time

114.5 ±35 min. (60–180 min.)

Blood loss

150 mL (50–500 mL)

Main complications

5 anterior psoas muscle pain 3 sacro iliac pain 2 conflict against ribs and iliac crest 2 patients insufficiently corrected



1 femoral neurapraxia Instrumentation

7 TelamonÒ cages (MedtronicÓ, Missouri) with Blount hooks 2 tricortical grafts with cross-shaped pins 1 tricortical graft with screws 1 tricortical graft with 1/3 duct plate and contra laterally Colorado 2Ò plate for closure (MedtronicÓ, Missouri)

Cadaveric model We found the behavior established during radiological simulations, that the PI varies according to

123

The mean follow up was 9.27 years (3–19 years). Etiologies of imbalances were five spondyloptosis L5-S1: one with a thoracic scoliosis and one with an oblique pelvis and thoracic kyphosis; one lumbosacral mismatch (high PI and low LL in young patients with hypertrophy of the posterior vertebral elements); two post traumatic sacral malunions; one lumbosacral Pott disease (L3-S1 septic fusion in kyphosis); one lumbosacral kyphosis due to septic fusion; one Stiffmann syndrome. The mean duration of symptoms was 10.2 years (0.25–25 years). There were 17 previous surgeries (mean = 1.6, 0–5): 5 arthrodesis without reduction of spondylolisthesis; 3 removal of material; 1 herniectomy; 1 surgery for spinal stenosis; 1 extension of the arthrodesis; 1 anterior and posterior combined arthrodesis; 1 stop hip; and 3 THR. The previous conservative treatments were: six corsets, one trial of IV immunoglobulin (Stiffmann syndrome).

– – –

Seven bilateral Salter surgeries; one unilateral Salter (asymmetric sacred malunion) surgery; one bilateral Salter surgery with tenotomy of the psoas (Stiffmann syndrome); one unilateral Salter surgery with contralateral closure (sacral malunion in kyphosis-rotation); one unilateral Salter ? Chiari contralaterally surgery (Pott disease: the screws of the previous THR does not allow the bilateral Salter) The surgical approach was: Smith Petersen bilaterally for eight surgeries; bilateral Hueter for one; Smith Petersen unilateral for one; bilateral Watson Jones for one The average operative time was 114.54 min (60–180) No intraoperative complication was noted Fixation was provided in seven cases with a TelamonÓ cage (MedtronicÒ) ? Blount staples, in two cases with tricortical grafts ? cross pins, in one case with a tricortical graft with direct screwing, in one case with a tricortical graft with a third tube plate for the closure side and contralateral anterior Colorado IIÓ (MedtronicÒ)

In all cases but one, patients had to wear a hemi-spica cast for three months, a lumbar orthosis for an additional three months and crutches for six months.

Eur Spine J

lumbosacral malunion; and spinopelvic inadequation. As shown in Table 6, septic malunion and Stiffmann syndrome have the worst results on PI modification.

Table 5 Radiological data on patients undergoing pelvic osteotomy Pre operative

Post operative

Modification (%)

Pelvic incidence (PI)

74.6

57.4

-23

Sacral slope (SS)

53.4

37

-30.7

Lumbar lordosis (LL)

52.5

43.4

-17.3

Thoracic kyphosis (TK)

30.5

30.4

-0.3

Offset S1 (mm)

83.3

64.4

-22.7

Ratio plumb C7/offset S1

-2.56

Plumb line EAD (PLE) (mm)

1.37 -9.2

-50.8

Plumb line C7 (mm)

97.2

50.2

-48.4

Pelvi-femoral angle (PFA)

23.7

18.5

-22

5.9 7.8

3.6 5.7

-39 -27

137.4

123.4

Sacro-spinal angle (SSA)

The mean follow up was 4.4 years (2–6 years). The patients suffered chronic low back pain and were previously treated conservatively without result. Etiologies of imbalance were, in all cases, spondyloptosis. Four had already been operated upon in another hospital, leading to a malunion in the lumbosacral kyphosis. Six surgeries were done in the four patients previously operated upon: four posterior fusion surgeries (one L5-S1, two L4-S1, one L3S1, one septic debridement, one removal of posterior device). The surgical data were:

153

-18.7

Tilt C7 Tilt T9

Clinical series: sacral osteotomy (Fig. 5)



-10.1

– We noted one transfusion and two uses of intraoperative cell saver. A total of 23 complications were reported: 5 patients suffering from groin pain; 5 from pain at the sacro-iliac joint; 2 at the operative site; 2 increases of scoliosis previously operated upon; 3 hip disorders leading to total hip replacement (THR); 2 ribs-and-iliac crest impingements; 2 patients insufficiently corrected (they still have a positive plumb line); 1 femoral neurapraxia; 1 delay in wound closure. Hip mobility was reported for four patients: there was an improvement in two cases and stagnation in two cases. The mean PVS pre op was 7 and 6, and post op it was 4 and 5; the mean ODI pre op was 76 % and post op it was 34 %; mean satisfaction was 84 %. Radiological data of our series are listed in Table 5. We compared the PI measured on x-rays and the theoretical PI with the mathematical law: there is no statistical difference (p = 0.003, r = 0.782). The population was split into five categories: the spondylolisthesis; the septic malunion; Stiffmann syndrome; Table 6 Radiological parameters for the five indications of pelvic osteotomy

– –

In all cases, a PSO S1 was done. A combination of L3iliac fusion was realized in two cases, L2-iliac in two cases and L1-iliac in one. The mean operative duration time was 260 min (180–360). Blood loss was 2,000 mL on average (700–3,500 mL). No intra-operative complications were noted.

Complications after surgery included two transient neurologic deficits both in the L5 nerve root. At one year follow up, the two patients had recovered all neurologic function. We also noted a persistent sagittal imbalance in one case, leading to a prolongation of the arthrodesis in the thoracic spine combined with a L1 PSO. Clinical and radiological data are listed in Table 7. Discussion Technical description Correction of sagittal unbalance is now regularly treated by spinal osteotomies. The advantages and/or complications of PSO techniques or the Smith-Petersen technique are well described in the literature. The best indications are

Spondylo

Inadequation

Septic

Malunion

PI pre´

96.32

76.9

55.2

49.6

PI post

73.44

50.6

49.1

32.4

Modification of PI (%) LL pre´

-23.75

-34.20

-11

-34.70

78.85

65.6

-8.8

48.3

LL post

62.48

42.3

-11.2

38.1

Plumb line EAD pre´

-5.9

5.9

-12.1

Plumb line EAD post SSA pre´

-10.01

5.9

152.7

144.8

SSA post

131.6

114.1

94.3

Stiffmann 52.6 50.6 -4 65.6 68.9

-37

-71.5256

-7.4

-15.7

-11.4441

101.2

138.1

139.6

127.8

141.3

123

Eur Spine J Fig. 5 Results on sagittal balance of the sacral osteotomy. Note the iliac fixation with two screws per side

severe kyphosis associated with loss of LL. Restoration of balance is obtained by posterior spinal subtraction osteotomy to increase LL. In some cases, kyphosis is very distal, at the lumbosacral level, with a compensative lumbar hyperlordosis. In those cases, increasing LL by a classical technic of subtraction osteotomy may be technically very demanding and rationally inadequate. This is the situation of failed surgery in spondyloptosis, or very high PI. As the cause of the sagittal trouble is very distal, the rational of reduction has to be located below the sacral plateau in order to decrease PI. Technically, this may be achieved by a posterior sacral subtraction or an anterior pelvis addition. In our pre-operative study, we demonstrated via CT-scan simulation and cadaveric osteotomies that there was a direct correlation between the quantity of osteotomies and the reduction of PI. Double Salter and sacral subtraction osteotomies were the most efficient with an advantage for the last

123

one. In reality, in most of our clinical cases, sacral osteotomy was done to decrease a fixed lumbosacral kyphosis. Unilateral anterior pelvis addition in acetabulum dysplasia was well described by Salter. In a unilateral osteotomy, the lower part of the unipelvis below the osteotomy is turning around the pubis, tilting the distal part to cover the femoral head. When the osteotomy is bilateral, both inferior pelvis parts are turning together, opening the pelvis forward. The immediate effect is modifying the geometrical relation between the sacral end and femoral heads. The effect of an anterior open double Salter osteotomy is a decreasing PI angle. In our study, we demonstrated that the other techniques of well-known pelvic osteotomies, like Chiari, were less efficient at reducing PI. This may be explained by the main geometrical effect of the Chiari osteotomy that translates posteriorly the inferior part of the pelvis and rotates less.

Eur Spine J Table 7 Clinical and radiological data during sacral PSO Case 1

Case 2

Case 3

Case 4

Case 5

PVS pre

70

80

80

90

70

PVS post

10

20

30

50

20

ODI pre

68

74

42

82

40

ODI post

10

30

28

40

20

Satisfaction (%)

90

70

70

45

90

PI pre

109

88

94

105

90

PI post LL pre

79 37

55 64

54 71

70 36

90 67

LL post

62

46

58

59

69

101

204

268

192

106

81

67

60

107

92

PL C7/offset S1 pre (%) PL C7/offset S1 post (%) SSA pre

121

132

135

112

133

SSA post

125

118

118

137

139

Technically, a double Salter osteotomy is not very demanding. It is mandatory to maintain a posterior bone bridge at the level of the sciatic notch in order to have a good hinge to stabilize the bone opening. Otherwise, the opening osteotomy is no longer possible. We had no specific implants for this technique. To maintain the open wedge, we stopped using TLIF cages in order to save bone graft. Stabilization was obtained using wires or screws with or without plates. We never had fusion or loss of correction troubles. Post-operative management was difficult, probably because of an inadaptable and unsafe synthesis. We preferred to use a hemi-spica brace for two months to preserve the osteotomy, with an important limitation for walking. Femoral pain was almost constant during the first months, limiting rehabilitation. Regarding balance positioning and preoperative pain improvement, spondyloptosis malunions and lumbosacral inadequation provided the best result via PI reduction. L5S1 hyper kyphosis due to a Pott disease was not appropriate. The pelvic osteotomy decreased the rib-ilium distance with a painful conflict. The mechanical effect of a sacral osteotomy is more important in reducing PI. The proximity of the sacral endplate directly above the osteotomy probably explains this improved efficiency. First described by Ondra, the only technical difficulty is cutting laterally the sacral wings to liberate the sacral endplate. Iliac screw fixation was necessary to stabilize the instrumentation. In our series, there were only two true sacral osteotomies that maintained the sacral endplate. In three cases, a technique of dome resection was used with a close effect of decreasing PI. In one case of true sacral osteotomy, we have had a late L5 root deficit at day two in a spondyloptosis malunion. It

seems that the PSO S1 had a traction effect on the L5 root on the pre-sacral route. Surgically, we had no solution to solve this problem because of an L5 inaccessibility. As we routinely do after HGS reduction, we recommend a delay in lower limb extension after surgery and a standing position when sciatic pain occurs. A hemi-spica brace was recommended for the first two months. Indications and limits Even if we have demonstrated the mechanical efficacy of pelvic or sacral osteotomies, are there still indications for pelvic osteotomies? Failure in surgical treatment of HGS is not rare, with severe alteration of sagittal balance. The main cause is an insufficient reduction of the lumbosacral kyphosis. Generally, wild laminectomies have been done, precluding an L5 PSO due to fragility of the nerve roots. In those cases, a trans sacral PSO takes advantages of a free canal for a lower and efficient vertebral resection. Development of iliac fixation techniques allows dealing with the difficult problem of distal implant stability. Proximally, instrumentation needs to be extended at least to L4 to sufficiently stabilize the sacral osteotomy. Conservation of distal lumbar mobility may occasionally be an option. This is the case when the lumbar spine is unable to provide the degree of lordosis required by a pelvis with a very high PI (lumbo-pelvic inadequation). A painful hyper-lordosis could be treated by a pelvic osteotomy, like the double Salter technique. Decreasing PI induces a decreasing of SS with less need of LL. This option would enable maintaining lumbar mobility before degeneration occurs. Comparison to lumbar arthrodesis is required in order to assert that a pelvic osteotomy may be preferable to a lumbar fusion. Could we think about an anterior subtraction osteotomy to increase PI? We know that extreme values of PI are problematic. Until now, pelvic osteotomies have been proposed to reduce an excessive PI. Too low of a PI may strongly affect spinal sagittal balance. Generally, the lumbar spine associated with a low PI has poor extension capability and an increasing lordosis. This is the reason why we think that increasing PI via pelvic osteotomy cannot be a good option in low PI inbalance.

Conclusion We are able, via mathematical modeling supported by a cadaver study, to state that pelvic osteotomies are effective at varying PI, and that earlier openings (Salter type) or after closures (PSO S1) respond to respective laws:

123

Eur Spine J

PI end ¼ PI initial  29:6=L  opening height PI end ¼ PI initial  46:94=L  opening height

12.

PSO S1 appears more capable of varying the PI than the anterior opening. The Chiari osteotomy is technically not reliable because it is not schedulable and very powerful in our study. The clinical study confirms the theoretical mathematical behavior. The technique is simple and has few major morbidities, but the follow-up is demanding. It can be considered in cases of fixed spondyloptosis, lumbo-pelvic inadequation and lumbosacral malunion in kyphosis. Compared with OTP, this technique causes fewer neurological complications and is accompanied by more moderate bleeding, but seems less capable of correcting sagittal imbalance, except in cases where the imbalance is pelvic or lumbosacral in origin. A study of a more substantial series should be considered.

13.

14.

15.

16.

17.

18.

19. Conflict of interest

None. 20.

References 21. 1. Barrey C, Jund J, Noseda O, Roussouly P (2007) Sagittal balance of the pelvis-spine complex and lumbar degenerative diseases. A comparative study about 85 cases. Eur spine J 16:1459–1467 2. Berthonnaud E, Dimnet J, Roussouly P, Labelle H (2005) Analysis of the sagittal balance of the spine and pelvis using shape and orientation parameters. J Spinal Disord Tech 18:40–47 3. Birnbaum K, Pastor A, Prescher A, Heller KD (2000) Complications of Chiari and Salter osteotomies. Surg Radiol Anat 22:225–233 4. Blondel B, Jouve JL, Panuel M, Adalian P, Solari C, Tropiano P, Bollini G (2008) Etude de la fiabilite´ des mesures de l’incidence pelvienne dans l’analyse de l’e´quilibre sagittal du bassin. Rev Chir Orthop 94:321–326 5. Boulay C, Tardieu C, Hecquet J, Benaim C, Mouilleseaux B, Marty C, Prat-Pradal D, Legaye J, Duval-Beaupe`re G, Pelissier J (2006) Sagittal alignment of spine and pelvis regulated by pelvic incidence. Eur Spine J 15:415–422 6. Duval-Beaupe`re G, Legaye J (2004) Composante sagittale de la statique rachidienne. Rev Rhum 71:105–119 7. Gangnet N, Dumas R, Pomero V, Mitulescu A, Skalli W, Vital JM (2006) 3D spinal and pelvic alignment in an asymptomatic population. Spine 31:E507–E512 8. Gangnet N, Pomero V, Dumas R, Skalli W, Vital JM (2003) Variability of the spine and pelvis location with respect to the gravity line. Surg Radiol Anat 25:424–433 9. Guigui P, Levassor N, Rillardon L, Wodecki P, Cardinne L (2003) Valeurs physiologiques des parame`tres pelviens et rachidiens de l’e´quilibre sagittal du rachis. Rev chir Orthop 89:496–506 10. Hovorka I, Rousseau P, Amoretti N, Challali M, Julia M, Carles M, Daideri G, Bronsard N, Boileau P (2008) Extension reserve of the hip in relation with spine in Spine Concepts 2007 Sauramps medical. Rev Chir Orthop Reparatrice Appar Mot 94(8):771–776 11. Hovorka I, Rousseau P, Bronsard N, Challali M, Julia M, Carles M, Amoretti N, Boileau P (2008) Mesure de la reserve

123

22. 23.

24. 25.

26.

27.

28.

29.

30. 31. 32.

33.

d’extension de la hanche en relation avec le rachis. Rev Chir Orthop 94:771–776 Itoi E (1991) Roentgenographic analysis of posture in spinal ostoporotics. Spine 6:750–756 Jackson RP, Hales C (2000) Congruent spinopelvic alignment on standing lateral radiographs of adult volunteers. Spine 25:2808–2815 Jackson RP (1998) Compensatory spinopelvic balance over the hip axis and better reliability in measuring lordosis to the pelvic radius on standing lateral radiographs of adult volunteers and patients. Spine 23:1750–1767 Kobayashi T, Atsuta Y, Matsuno T, Takeda N (2009) A longitudinal study of congruent sagittal spinal alignement in an adult cohort. Spine 29:671–676 Kuntz C, Levin LS, Ondra SL, Shaffrey CI, Morgan CJ (2007) Neutral upright sagittal spinal alignment from the occiput to the pelvis in asymptomatic adults. J Neurosurg Spine 6:104–112 Lafage V, Schwab F, Skalli W, Hawkinson N, Gagey PM, Ondra S, Farcy JP (2008) Standing balance and sagittal plane spinal deformity. Spine 33:1572–1578 Lafage V, Schwab F, Patel A, Hawkinson N, Farcy JP (2008) T1 tilt may outperform the plum-line in clinical correlation in meeting of international society for the study of lumbar spine meeting abstracts:115 Lafage V, Schwab F, Rubio F, Farcy JP (2008) Impact of sagittal plane spinal deformity on the spino-pelvic relationship and gravity line in adults. J Bone Joint Surg Br 2008(90):supp III 433 Lazennec JY, Charlot N, Gorin M, Roger B, Arafati N, Bissery A, Saillant G (2004) Hip-spine relationship. Surg Radiol Anat 26:136–144 Lee CS, Lee CK, Kim YT, Hong YM, Yoo JH (2001) Dynamic sagittal imbalance of the spine in degenerative flat back. Spine 26:2029–2035 Legaye J, Duval-Beaupe`re G, Hecquet J, Marty C (1998) Pelvic incidence. Eur Spine J 7:99–103 Levassor N, Rillardon L, Deburge A, Guigui P (2003) Les parame`tres pelviens et rachidiens de l’e´quilibre sagittal du rachis. Rev Chir Orthop;89:21 supple´ment Mangione P, Se´ne´gas J (1997) L’e´quilibre rachidien dans le plan sagittal. Rev Chir Orthop 83:22–32 Morvan G, Wybier M, Mathieu P, Vuillemin V, Guerini H (2008) Cliche´s simples du rachis: statique et relations entre rachis et bassin. J Radiol 89:654–666 Roussouly P, Transfeldt E, Schwender J, Berthonnaud E, Dimnet J (2002) Sagittal morphology and equilibrium of pelvis and spine in normals. Spine J 2:47S–128S Roussouly P, Gollogly S, Noseda O, Berthonnaud E, Dimnet J (2006) The vertical projection of the sum of the ground reactive forces of a standing patient is not the same as the C7 plumb-line. Spine 31:E320–E325 Roussouly P, Berthonnaud E, Dimnet J (2003) Analyse ge´ome´trique et me´canique de la lordose lombaire dans une population de 160 adultes asymptomatiques. Rev Chir Orthop 89:632–639 Roussouly P, Gollogly S, Berthonnaud E, Dimnet J (2005) Classification of the normal variation of the sagittal alignment of the human lumbar spine and pelvis in the standing position. Spine 30:346–353 Schwab F, Lafage V, Boyce R, Skalli W, Farcy JP (2006) Gravity line analysis in adult volunteers. Spine 31:E959–E967 Tassin JL (2004) Equilibre sagittal du rachis Confe´rence d’enseignement de la SOFCOT Vialle R, Levassor N, Rillardon L, Templier A, Skalli W, Guigui P (2005) Radiographic analysis of the sagittal alignment and balance of the spine in asymptomatic subjects JBJS 87A(2):260–267 Vital JM, Obeid I (2008) Statique rachidienne dans le plan sagittal Me´moire pour la socie´te´ d’imagerie musculo squelettique

Eur Spine J 34. Vital JM, Gille O, Gangnet N (2004) Equilibre sagittal et applications cliniques. Rev Rhum 71:120–128 35. Jackson RP, Kanemura T, Kawakami N, Hales C (2000) Lumbopelvic lordosis and pelvic balance on repeated standing lateral radiographs of adult volunteers and untreated patients with constant low back pain. Spine 25:575–586 36. Molinari RW (2005) Sagittal plane decompensation. Curr Opin Orthop 16:148–151 37. Bridwell KH (2006) Decision making regarding Smith Petersen vs. pedicle subtraction osteotomy vs. vertebral column resection for spin al deformity. Spine 31:S171–S178 38. Bridwell KH, Lenke LG, Lewis SJ (2001) Treatment of spinal stenosis and fixed sagittal imbalance. Clin Orthop Rel Res 384:35–44 39. Chang KW, Cheng CW, Chen HC, Chang KI, Chen TS (2008) Closing opening wedge osteotomy for the treatment of sagittal imbalance. Spine 33:1470–1477 40. Chen IH, Chien JT, Yu TC (2001) Transpedicular wedge osteotomy for correction of thoracolumbar kyphosis in ankylosing spondylitis. Spine 26:E354–E360 41. Gill JB, Lewin A, Burd T, Longley M (2008) Corrective osteotomies in spine surgery. JBJS Am 90:2509–2520 42. Mummaneni PV, Dhall SS, Ondra SL, Mummaneni VP, Berven S (2008) Pedicle subtraction osteotomy. Neurosurg 63S:171–176 43. Ondra SL, Marzouk S, Koski T, Silva F, Salehi S (2006) Mathematical calculation of pedicule subtraction osteotomy size to allow precision correction of fixed sagittal deformity. Spine 31:E973–E979 44. Rose PS, Bridwell KH, Lenke LG, Cronen GA, Mulconrey DS, Buchowski JB, Kim YJ (2009) Role of pelvic incidence, thoracic kyphosis and patient factors on sagittal plane correction following pedicule subtraction osteotomy. Spine 34:785–791 45. Roussouly P (2006) Correction des de´se´quilibres sagittaux et frontaux du rachis par oste´otomie rachidienne ou du bassin Confe´rence d’enseignement de la SOFCOT confe´rences d’enseignement, vol 91, pp 24–42 46. Sansur CA, Fu KMG, Oskouian RJ, Jagannathan J, Kuntz C, Shaffrey CJ (2008) Surgical management of global spinal deformity in ankylosing spondylitis. Neurosurg Focus 24:E8 47. Van Royen BJ, De Gast A, Smit TH (2000) Deformity planning for sagittal plane corrective osteotomies of the spine in ankylosing spondylitis. Eur Spine J 9:492–498

48. Wang MY, Berven SH (2007) Lumbar pedicule subtraction osteotomy. Neurosurg 60:140–146 49. Yang BP, Yang CW, Ondra SL (2007) A novel mathematical model of the sagittal spine. Spine 32:466–470 50. Yang BP, Ondra SL (2006) A method for calculating the exact angle required during pedicule subtraction osteotomy for fixed sagittal deformity. Neurosurg 59S:458–463 51. Carlioz H (2000) Les oste´otomies du bassin chez l’enfant et l’adolescent. Acta Orthop Belgica 66:321–328 52. Carlioz H, Madi F (2004) Les oste´otomies pelviennes in Confe´rences d’enseignement de la SOFCOT confe´rences d’enseignement, vol 87, pp 10–23 53. Macnicol MF, Al Rawashdeh H, Auld J (2000) Technical aspects of the Salter innominate osteotomy. Cur Orthop 14:209–214 54. Macnicol MF (2007) The Salter innominate osteotomy. Cur Orthop 21:85–93 55. Patil S, Sherlock DA (2007) The Chiari medial displacement osteotomy. Cur Orthop 21:109–114 56. Pfeifer R, Hurschler C, Ostermeier S, Windhagen H, Pressel T (2008) In vitro investigation of biomechanical changes of the hip after Slater pelvic osteotomy. Clin Biomec 23:299–304 57. Rab GT (1978) Biomechanical aspects of Salter osteotomy. Clin Orthop Rel Res 132:82–87 58. Sales de Gauzy J (1997) Indications des oste´otomies pelviennes chez l’enfant Confe´rences d’enseignement de la SOFCOT 62:71–90 59. Salter RB (1961) The classic innominate osteotomy in the treatment of congenital dislocation and subluxation of the hip. JBJS Brit 43B:518–531 60. Vaz G, Bejui-Hugues T (2003) Oste´otomie pelvienne dans le traitement de la dysplasie ace´tabulaire in Journe´es Lyonnaises de Chirurgie de la Hanche. Livre du congre`s, 73–82 61. Ge´rard Y, Segal P, Jacob M (1971) L’oste´otomie pelvienne pre´fe´re´e a` l’oste´otomie rachidienne pour le traitement des grandes cyphoses de la spondylarthrite ankylosante. Rev Rhum 38:221–229 62. Wilson PD, Levine DB (1969) Compensatory pelvic osteotomy for ankylosing spondylitis. JBJS Am 51:142–148 63. Hsieh PC, Ondra S, Wienecke RJ, O’Shaughnessy BA, Koski TR (2007) A novel approach to sagittal balance restoration following iatrogenic sacral fracture and resulting sacral kyphotic deformity. J Neurosurg Spine 6:368–372

123

Sacral and pelvic osteotomies for correction of spinal deformities.

Restoring a physiological sagittal spine balance is one of the main goals in spine surgery. Several technics have been described previously, as pedicl...
2MB Sizes 0 Downloads 11 Views