Single rod instrumentation in patients with scoliosis and co-morbidities: Indications and outcomes

Table 1 Operative and postoperative data among our patient groups

Group	Type of scoliosis	No. ofpatients	Mean age at surgery (yr)	Procedure (No. of patients)	Operatingtime (min)	Blood loss(mL)	Bloodloss (BV)	Mean follow-up (yr)	Complications
A - Complex deformity	Syndromic	21	13	PSF: 19; A/PSF: 2	164	727	27	3.0	2 rod breakages-one revision required due to non-union; 1 distal junctional kyphosis-distal fusion extension required
	Early onset idiopathic	17	11	PSF: 11; A/PSF: 6	185	519	25	2.9	None
	Congenital	13	11	PSF: 13	138	368	13	4.8	One rod breakage-no revision required
	Neuromuscular	5	14	PSF: 5	125	662	24	3.0	None
	Intraspinal anomalies	6	13	PSF: 6	145	525	22	4.5	None
B - Conversion of growing rods to definitive fusion	Early onset	21	12	PSF: 17; A/PSF: 4	159	497	20	2.8	None
C - AIS	Adolescent idiopathic	16	15.8	PSF: 16	128	406	9	2.8	None
Summary of data		99	13	PSF: 87; A/PSF: 12	153	530	20	3.2	4

PSF: Posterior spinal fusion; A/PSF: Anterior and posterior spinal fusion; BV: Blood volume; AIS: Adolescent idiopathic scoliosis.

Table 2 Type and size of deformity among our patients in groups A and B

Group	Type of scoliosis	No. of patients	Thoracic scoliosis (meanpreop/postop; degrees);(%correction)	Double thoracic scoliosis(mean preop/postop;degrees); (%correction)	Thoracic/lumbar scoliosis(mean preop/postop; degrees);(%correction)	Triple thoracic/lumbar scoliosis(mean preop/postop; degrees);(%correction)	Thoracic kyphoscoliosis(mean preop/postop;degrees); (%correction)
A – Complex deformity	Syndromic	21	78/30 (62%); 8 patients	Upper TH: 46/19 (59%) main TH: 60/24 (60%); 5 patients	TH: 55/18 (67%) L: 43/15 (65%); 4 patients	Upper TH: 32/6 (81%) main TH: 61/28 (54%) L: 52/25 (52%); 2 patients	Scoliosis: 120/48 (60%) kyphosis: 103/60 (42%); 2 patients
	Early onset idiopathic	17 (infantile: 9; juvenile: 8)	99/34 (66%); 4 patients	Upper TH: 53/25 (53%) main TH: 81/47 (42%); one patient	TH: 89/36 (60%) L: 70/27 (61%); 6 patients	Upper TH: 49/15 (69%) main TH: 84/30 (64%) L: 52/20 (62%); 5 patients	Scoliosis: 56/31 (45%) kyphosis: 122/65 (47%); one patient
	Congenital	13	58/36 (38%); 6 patients	Upper TH: 39/22 (44%) main TH: 76/40 (47%); 2 patients	TH: 75/38 (49%) L: 68/36 (47%); 3 patients	Upper TH: 41/15 (63%) main TH: 55/25 (55%) L: 44/22 (50%); one patient	Scoliosis: 70/31 (56%) kyphosis: 75/35 (53%); one patient
	Neuromuscular	5	66/19 (71%); 2 patients	-	TH: 79/31 (61%) L: 65/28 (57%); 3 patients	-	-
	Associated with intraspinal anomalies	6	82/36 (56%); 6 patients	-	-	-
B – Conversion of growing rods to definitive fusion	Syndromic	10	91/39 (57%); 6 patients	-	TH: 93/52 (44%) L: 69/37 (46%); 4 patients	-	-
	Infantile idiopathic	6	74/28 (62%); 2 patients	Upper TH: 59/34 (42%) main TH: 100/55 (45%); one patient	TH: 61/38 (38%) L: 101/52 (49%); one patient	-	Scoliosis: 63/32 (49%) kyphosis: 104/61 (41%); 2 patients
	Congenital	4	77/38 (51%); 4 patients	-	-	-	-
	Neuromuscular	1	-	-	-	-	Scoliosis: 65/25 (62%) kyphosis: 78/50 (36%); one patient

Table 3 Patients with syndromic conditions included in our study

Group A – Complex deformity (n = 21 patients)	Group B - Conversion of growing rods to definitive fusion (n = 10 patients)
Neurofibromatosis type 1 (2)	Skeletal dysplasia (2)
Osteogenesis imperfecta (1)	Oculo-auriculo-fronto-nasal syndrome (1)
Rubinstein-Taybi type 2 (1)	Chromosome abnormality (7)
Cystic Fibrosis (1)
Arthrogryposis multiplex congenital (1)
Ehlers-Danlos (1)
Angelman’s (1)
Marfan’s (1)
Prader-Willi (1)
Down’s syndrome (1)
Chromosome abnormality (4)
Undiagnosed syndromic condition (6)

Table 4 Type and size of deformity before and after surgery among our patients with adolescent idiopathic scoliosis and severe eczema (group C)

Patientnumber	Gender	Risser grade	Scoliosis type(No. ofpatients)[9]	Procedure(posterior spinalfusion/levels)	Upper thoracic scoliosis(pre-op/post-op;degrees); (% correction)	Main thoracic scoliosis(pre-op/post-op;degrees); (% correction)	Lumbar scoliosis (pre-op/post-op; degrees);(%correction)	Kyphosis (pre-op/post-op);(degrees)	Lordosis (pre-op/post-op);(degrees)	Coronal balance(pre-op/post-op);(cm)	Sagittal balance (pre-op/post-op); (cm)
1	F	5	2A	PSF T2-T10	52/23 (56%)	49/22 (55%)	-	19/52	49/52	0/0	-3.5/0
2	F	5	1B	PSF T3-T11	-	48/15 (69%)	35/17 (51%- spontaneous correction)	27/52	47/53	0.3/0	-2.8/0
3	M	2	2A	PSF T2-L1	32/11 (66%)	47/11 (77%)	-	35/44	40/42	0.8/0	-0.8/0
4	F	4	1A	PSF T2/T9	-	45/0 (100%)	-	45/55	55/58	2.3/0	-0.3/0
5	M	5	2A	PSF T2-T11	32/12 (62.5%)	52/16 (69%)	30/6 (80%-spontaneous correction)	23/44	59/45	0.8/0	-3.1/0
6	F	5	3C	PSF T2-L4	-	55/12 (78%)	48/10 (79%)	25/50	40/50	1.2/0	-2.8/0
7	F	5	2B	PSF T3-T12	35/12 (66%)	55/21 (62%)	36/11 (69%-spontaneous correction)	28/48	50/50	1/0	-3.0/0
8	M	4	1A	PSF T2-T12	-	60/15 (75%)	39/10 (74%-spontaneous correction)	16/38	43/42	0/0	1.5/0
9	F	3	2A	PSF T3-T12	29/9 (69%)	48/14 (71%)	30/2 (93%-spontaneous correction)	17/38	33/38	0.6/0	-1.2/0
10	F	3	1A	PSF T2-T11	-	52/20 (61.5%)	36/15 (58%-spontaneous correction)	24/46	61/51	0/0	-2.5/0
11	M	5	1B	PSF T2-T11	-	55/16 (71%)	30/15 (50%-spontaneous correction)	20/48	47/50	3.5/0	4.1/0
12	F	4	2A	PSF T3-T12	32/11 (66%)	59/17 (71%)	32/13 (59%-spontaneous correction)	46/48	57/46	0.8/0.2	-3.5/-1
13	M	4	1A	PSF T2-T11	-	52/15 (71%)	30/15 (50%-spontaneous correction)	20/47	48/46	3/0	3.5/0
14	F	5	2B	PSF T2-T11	42/15 (64.3%)	60/25 (58.3%)	40/14 (65%-spontaneous correction)	31/48	46/47	1.2/0.5	-2.3/0
15	F	4	2A	PSF T3-T12	39/14 (64%)	69/23 (67%)	37/14 (62%-spontaneous correction)	31/47	45/50	0.5/0	-0.5/0
16	F	3	2A	PSF T3-L2	22/8 (64%)	59/20 (66%)	28/9 (68%-spontaneous correction)	56/54	54/53	2.5/0.3	2.2/0
Summary of data	11 F; 5 M	Mean: 4.1	Scoliosis type 1 (1); 2 (2); 3 (6); 4 (7)	15 TH fusions; one TH/L fusion	Mean values: 35/12.7 (64%)	Mean values: 54/16 (70.4%)	Mean values: 35/11.6 (67%)	Mean values: 29/47.4 (63.4%)	Mean values: 48/48 no change	Mean values: 1.16/0.06 (95%)	Mean values: 2.35/0.06 (97.4%)

F: Female; M: Male; PSF: Posterior spinal fusion; TH: Thoracic; L: Lumbar.

Table 5 Cost analysis and comparison between the single and double rod constructs in the treatment of adolescent idiopathic scoliosis based on the Universal Spinal System instrumentation

No. of levels included	Type of construct	Instrumentation	Comparative cost
10 (thoracic fusion)	Double rod construct with bilateral segmental pedicle screws (implant density: 2)	20 pedicle screws 20 sleeves and nuts 2 rods	100%
	Double rod construct using the authors’ preferred technique (implant density: 1.38)[10]	14 pedicle screws 14 sleeves and nuts 2 rods	29% reduction compared to bilateral segmental pedicle screw construct
	Single rod hybrid construct	3 pedicle screws 3 pedicle screw hooks 1 transverse process hook 7 sleeves and nuts 1 rod	65% reduction compared to bilateral segmental pedicle screw construct; 51% reduction compared to authors’ preferred technique
15 (Thoracic and Lumbar fusion)	Double rod construct with bilateral segmental pedicle screws (implant density: 2)	30 pedicle screws 30 sleeves and nuts 2 rods	100%
	Double rod construct using authors preferred technique (implant density: 1.38)[10]	21 pedicle screws 21 sleeves and nuts 2 rods	29% reduction compared with bilateral segmental pedicle screw construct
	Single rod construct	6 pedicle screws 5 pedicle screw hooks 1 transverse process hook 12 sleeves and nuts 1 rod	64% reduction compared to bilateral segmental pedicle screw construct; 49% reduction compared to authors’ preferred technique