Is standing postural control more impaired in young patients with hip-disarticulation than transfemoral amputation? A pilot study

A hip disarticulation is an amputation of the entire lower limb. It is a rare but very disabling condition in young people who have high expectations regarding rehabilitation outcomes . Since the 1950s, hip-disarticulation (HD) amputation has mainly involved use of the “Canadian prosthesis” composed of a socket containing the pelvis from the stump to the contralateral iliac crest, hip and knee joints enabling flexion and extension movements only and a rigid prosthetic foot. The purpose of this prosthesis is to support body weight during standing and walking, thus allowing daily activities . Hip-disarticulation and the prosthesis characteristics significantly affect gait, particularly frontal plane kinetics . The single axis of the artificial hip may have a negative impact on postural control of patients with HD amputation, which has never been compared to postural control in patients with transtibial or transfemoral (TF) amputation. Here, we compared postural control in patients with HD and TF amputation and healthy subjects to examine behavioral adaptations associated with the loss of physiological hip. We hypothesized that mediolateral balance would be more impaired with HD than TF amputation, especially in active postural tasks, because of the loss of hip muscles .

We included 3 subjects with HD amputation (HD1, HD2, HD3) and 8 with TF amputation as well as 17 age-matched healthy controls. Patients gave their informed consent according to the principles of the Declaration of Helsinki. For HD amputees, sockets were made of laminated polyethylene and included the whole pelvis, with a moveable part fixed above the iliac crest on the non-amputated side. TF amputees wore a full-contact ischial-containment socket. All patients performed a two-minute walk test . Details are given in the Table 1 .

Table 1

Characteristics of patients with hip-1 disarticulated amputation (HD1, HD2, 2 and HD3), transfemoral (TF) amputees, and controls.

Participants	HD1	HD2	HD3	TF amputees	Controls
Gender	Male	Male	Female	6 m/2 f	11 m/6 f
Height (cm)	173	173	166	177 ± 6	174 ± 9
Weight (kg)	57	70	53	77 ± 17	70 ± 14
Age (year)	33	41	37	37 ± 9	36 ± 7
Cause of amputation	Trauma	Trauma	Tumour	Trauma: 5 Tumour: 2 Infection: 1	–
Side of amputation	Right	Right	Right	3 right/5 left	–
Duration of prosthesis wearing (years)	1.8	4.5	24	8.2 ± 3.8	–
Rate of prosthesis use	Seldom	Daily	Daily	Daily	–
Two-minute walk test (distance in m)	117	118	162	203 ± 34	–
Satisfied with the prosthesis (%)	47	73	79	81 ± 9	–
Prosthetic hip	7E7	7E7	7E7	–	–
Prosthetic knee	3R15	C-Leg	C-Leg	C-Leg	–
Prosthetic foot	1D10	Variflex	1C30	1C40: 4 Triton: 3 FlexWalk: 1	–
Employment	No	Yes	Yes	6 yes/2 no	–