Halo gravity traction for pediatric scoliosis and kyphoscoliosis: A review of current evidence and best practices

Table 1 Change in pulmonary function test (forced vital capacity and forced expiratory volume in 1 second) before and after halo gravity traction, and at final follow-up

Ref.	Year	Sample size	Mean follow-up	Pre-traction FVC/FEV1	Post traction FVC/FEV1	FVC/FEV1 at final follow-up
Grabala et al[38]	2024	20	3.8 years	54.5%/60.8%	66.7%/70.1%	74.9%/75.9%
LaMont et al[19]	2019	107	2 years	38%/37.7%	43.9%/42.1%	43.5%/43.2%
Koller et al[6]	2012	45	33 months	FVC%-49.5%	FVC%-49.5%	FVC%-45%
Wang et al[28]	2024	33	NA	43.5%/41.9%	47.3%/45.2%	NR
Iyer et al[9]	2019	30	16 months	75.43%/64.35%	68.11%/ 60.83%	NR
Garabekyan et al[16]	2014	21	2.4 years	FVC-1.31 L, FEV1-1.01 L	FVC-1.61 L, FEV1-1.3 L	NR
Bogunovic et al[11]	2013	33	NA	45.4%/43.7%	53.1%/52.7%	NR

FVC: Forced vital capacity; FEV1: Forced expiratory volume in 1 second; NA: Not available; NR: Not report.

Table 2 Change in body mass index before and after halo gravity traction, mean ± SD

Ref.	Year	Sample size	Mean follow-up	Mean age at surgery (years)	BMI before traction (kg/m2)	BMI at surgery (kg/m2)	Duration of halo in days	Maximum weight applied (SD)
Wang et al[28]	2024	33	NA	17.79	17.2 ± 3.9	17.7 ± 3.7	129 ± 63	45.2% (± 13.2%) of body weight
Iyer et al[9]	2019	30	16 months	9.0	15.1 ± 1.9	16.1 ± 2.0	79 ± 43	50% of body weight

BMI: Body mass index; NA: Not available.

Table 3 Coronal and sagittal Cobb angle corrections, after application of halo gravity traction and after definitive fusion

Ref.	Year	Sample size	Mean follow-up	Mean age at surgery (years)	Mean traction time	Maximum weight applied (% body weight)	Coronal Cobb correction				Sagittal Cobb correction
							Pre-traction coronal Cobb (degrees)	Post traction coronal Cobb (% correction)	Coronal Cobb after surgery (% correction)	Cobb at final follow-up	Pre-traction sagittal Cobb	Post traction sagittal Cobb (% correction)	Sagittal Cobb at final surgery (% correction)	Sagittal Cobb at final follow-up
Grabala et al[38]	2024	20	3.8 years	16.5	36 days	50	124	76.4 (38.4)	45 (63.7)	44.09	96.5	68.5 (29)	45.8 (52.5)	44
Hwang et al[26]	2020	59	NA	15.2	3.1 weeks	44	96.98	63.38 (34.4)	32.58 (65.9)	39.4	26.5	NA	22.2 (16)	23.5
LaMont et al[19]	2019	107	2 years	11.3	82.1 days	49.50	92.6	65.8 (29)	47 (50)	48.4	74	56.8 (23.2)	47.7 (35.5)	50.9
Garabekyan et al[16]	2014	21	2.4 years	13	77 days	50	Major curve-101; compensatory minor curve-63	Major curve-69 (31.6); compensatory minor curve-41 (34.9)	Major curve-58 (43); compensatory minor curve-39 (38)	Major curve-62; compensatory minor curve-44	67	50 (25.4)	47 (29.8)	50
Koller et al[6]	2012	45	33 months	24	30 days	33	106	94 (11.3)	76 (28.3)	84	90.7	76 (16.2)	70 (22.8)	76
Sink et al[5]	2001	21	NA	7.4	13 weeks	25 to 50	83	55 (33.7)	51 (38.5)	61	97	72 (25.8)	NA	82

NA: Not available.

Table 4 Results of other methods of spinal deformity correction by temporary internal distraction devices

Ref.	Sample size	Preoperative deformity	Deformity after temporary internal distraction (stage 1)	Deformity after final fusion (stage 2)	Complication	Blood loss	FEV1%	FVC%	Loss of correction at final follow up
Cheng et al[38]	18	Cobb angle: 129.8°; K angle: 94.7°	Cobb angle: 70.5°; K angle: 46.2°	Cobb angle: 51.8°; K angle: 32.9°	Intraoperative loss of SSEP signals in 1 case; pleural effusion in 2 cases; subcutaneous hydrops in 1 case; no permanent neurodeficit, infection, implant failure	211 mL in stage 1; 1597 mL in stage 2	58.6 to 67.6 (stage 1)	61.2 to 70.3 (stage 1)	3.3° of coronal correction and 2.6° of sagittal correction lost at final follow up
Hu et al[37]	11	Cobb angle: 149°; K angle: 79°	Cobb: 79°; K angle: 59°	Cobb angle: 55°; K angle: 35°	Paralytic ileus in 1 which resolved conservatively; no neurodeficit; no implant failure	210 mL in stage 1; 1512 mL in stage 2	61.4 to 71.3 (stage 1); 71.3 to 76.3 (stage 2)	59.3 to 68.7 (stage 1); 68.7 to 71.2 (stage2)	No significant deterioration in spinal alignment or PFT
Buchowski et al[35]	10	Cobb angle: 104°	Cobb angle: 49°	Cobb angle: 20°	Spontaneous pneumothorax in one case; one death unrelated to surgery; no neurodeficit, infection or implant failure	NR	NR	NR	NR

SSEP: Somatosensory evoked potentials; K: Kyphosis; NR: Not report; FEV1: Forced expiratory volume in 1 second; FVC: Forced vital capacity; PFT: Pulmonary function test.

Table 5 Comparisons between halo gravity traction and alternative preoperative strategies

Ref.		Sample size	Preoperative deformity	Deformity after temporary internal distraction (stage 1)	Deformity after final fusion (stage 2)	Complication	Blood loss (mL)	FEV1%	FVC%	Loss of Correction at final follow up
Grabala et al[38]	HGT	20	Cobb angle: 124°; K angle: 96.5°	NA	Cobb angle: 45°; K angle: 45.8°	Neuromonitoring alerts in 15% cases; pin tract infection: 35%; deep infections: 5%; pneumonia: 10%; neck/back pain: 55%	588	60.8 to 70.1 after HGT; 74.4 after fusion; 74.9 at final follow-up	54.5 to 66.7 after HGT; 73.4 after fusion; 75.9 at final follow up	NR
	TID	42	Cobb angle: 122°; K angle: 92°	NA	Cobb angle: 37.4°; K angle: 36.2°	Neuromonitoring alerts in 12% cases; deep infections: 2%; pneumonia: 5%; neck/back pain: 7%	282 + 458 in each stage	58 to 66 after TID; 71.2 after fusion; 78 at final follow up	49 to 55.2 after TID; 67 after fusion; 76 at final follow up	NR
Oliveira et al[39]	HGT	12	Cobb angle: 104.6°; K angle: 43.5°	Cobb after HGT: 85.6°	Cobb angle: 49.5°; K angle: 30.3°	Intraoperative neurodeficit: 3 cases; pneumothorax: 6 cases; implant failure: 1 case; infection: 1 case	1642.22 ± 1058.79	NA	NA	NR
	TID	7	Cobb angle: 100°; K angle: 40.7°	Cobb after TID: 94.7°	Cobb angle: 39.5°; K angle: 30.5°	Intraoperative neurodeficit: 4 cases; pneumothorax: 3 cases; implant failure: 2 cases; infection: 1 case	1400.00 ± 718.33	NR	NR	NR
Caubet and Emans[40]	HGT	13	Cobb angle: 92°; K angle: 99.5°	NA	Cobb angle: 40% improved	3 patients with neurodeficit; implant loosening in 7 patients	NA	NA	NA	Loss of kyphosis correction: 29%; loss of scoliosis correction: 20%
	SR	14	Cobb angle: 73.3°; K angle: 67.6°	NA	Cobb angle: 63% improve	2 patients with neurodeficit; implant loosening in 9 patients	NA	NA	NA	Loss of kyphosis correction: 26%; loss of scoliosis correction: 9%
	Control group	71		NA	Cobb angle: 41% improved	3 patients with neurodeficit; implant loosening in 20 patients	NA	NA	NA	Loss of kyphosis correction: 15%; loss of scoliosis correction: 5%

HGT: Halo gravity traction; TID: Temporary internal distraction; SR: Surgical release; K: Kyphosis; NA: Not available; NR: Not report; FEV1: Forced expiratory volume in 1 second; FVC: Forced vital capacity.