Limb length discrepancy after total knee arthroplasty: A systematic review and meta-analysis

Table 4 Factors affecting limb length variation/limb length discrepancy in total knee arthroplasty

Ref.	Type of deformity
	Varus					Valgus
	No of knees	Preop varus (o)	Postop varus (o)	Change in angle	Average lengthening	No of knees	Preop varus (o)	Postop varus (o)		Change in angle	Average lengthening
Lang et al[12], 2012	66	8.7 ± 4.6	2.1± 2.5	-6.6	5.2 ± 5.8 (S)	36	-8.9 ± 5.9	-1.1 ± 3.3		-7.8	8.4 ± 8.2 (S)
Tipton et al[14], 2015	87	9.34 ± 4.66	4.86 ± 3.03	-4.99 (4.77)	3.77 ± 11.1 (S)	45	-6.67 ± 5.79	-0.468 ± 3.57		-6.08 ± 5.72	5.56 ± 11.3 (S)
	Severity of deformity
	-10 to 10 degree		< -10 (valgus)		> 10 (varus)
	No of knees	Limb length change	No of knees	Limb length change	No of knees	Limb length change
Lang et al[12], 2012	65	4.7 ± 6.4 (S)	12	12 ± 8.6 (S)	25	7.9 ± 5.2 (S)
Tipton et al[14], 2015	93	1.64 ± 10.3 (NS)	9	15.1 ± 10 (NS)	35	8.51 ± 10.7 (NS)
	Unilateral or bilateral TKA
	Unilateral TKA		Bilateral TKA
	No of knees	LLD	No of knees	LLD
Vaidya et al[11], 2010	30	15.3 ± 2.88	30	5 ± 2.01 (S)
Lang et al[12], 2012	54	3.0 (95%CI: 0.5-5.4, NS)	47	0.9 (95%CI: −0.9-2.7, NS)
Chang et al[13], 2013	171	6 ± 4	295	5 ± 4 (S)
	Severity of OA in contralateral nonoperative limb/ipsilateral limb in preoperative period
	KL 1, 2			LLD (mm)		No of knees in KL 3, 4			LLD (mm)
Lang et al[12], 2012	Contralateral knee OA status (n = 26)			2 ± 5		Contralateral limb status (n = 28)			3.9 ± 11.5 (NS)
Tipton et al[14], 2015	Ipsilateral preop knee OA status			-2.00 ± 8.87 (only limb lengthening)		Ipsilateral preop knee OA status			0.594 ± 1.11 (NS)

S: Significant P < 0.05, NS: Non-significant P > 0.05; OA: Osteoarthritis; LLD: Limb length discrepancy; TKA: Total knee arthroplasty.