This poster is published under an
open license. Please read the
disclaimer for further details.
Type:
Educational Exhibit
Keywords:
Prostheses, Surgery, Outcomes analysis, CT, Pelvis, Musculoskeletal joint, Bones
Authors:
E. S. Lomtatidze1, M. D. Abakirov1, A. A. Dedyurin1, O. M. Urvantseva1, A. Albluwi2, A. R. Sarukhanyan1, Y. Borisov1; 1Moskow/RU, 2Moscow /RU
DOI:
10.1594/ecr2014/C-1004
Findings and procedure details
240 THA for femoral neck fracture performed from 2010 to 2013 at a single institution divided in 2 groups: in 140 patients,
alignment made using mechanical guide with goal 45° inclination and 15° anteversion and in 100 patients acetabular component was placed parallel to the TAL (Table1).
Table 1.
Characteristics of the groups
Factor
|
TAL-group
|
MG-group
|
Number of THA
|
100
|
140
|
Sex
|
Female
|
Female
|
Mean age (yr)
|
72 (from 63 to 88)
|
75 (from 61 to 96)
|
Cementless THA
|
46 (46%)
|
59 (42%)
|
Cemented THA
|
54 (54%)
|
81 (58%)
|
Head size (mm)
|
28
|
28
|
Approach
|
Anterolateral
|
Anterolateral
|
Limb length differences absence
|
94 (94%)
|
131 (94%)
|
Limb length differences less than1.5 cm
|
6 (6%)
|
9 (6%)
|
CT-scan used for control of the acetabular component position in all patients.
CT scans were obtained three to seven days after THR with a 64-channel multi-detector CT system.
From the CT scan sections,
the acetabular anteversion angle (AAA) was measured according to the usual routine protocol,
with the patient in a supine position on the axial section,
similar to the protocol described by Stem et al [10].
According to the CT-scan,
the middle anteversion in MG-group was 13° (from -15° to 38°,
11 cases (7.8%) of retroversion); middle inclination was 44° (from 37° to 59°).
In TAL-group the middle anteversion was 20° (from -3° to 41°,
2 cases (2%) retroversion); middle inclination was 42° (from 27° to 50°).
Inside the "safe zone" (converted from radiographic into anatomic Murray’s definition [11,
12]) located 111 (79%) cups in the MG-group,
and 93 (93%) cups in the TAL-group.
There were 8 (5.7%) posterior dislocations in the MG-group (6 of them outside the "safe zone") (Fig 5,
7),
and 2 (2%) in the TAL-group (Table 2).
Table 2.
Results.
Measurements of acetabular component position in TAL and MG groups.
Factor
|
TAL-group
|
MG-group
|
Mean acetabular version angle (degrees)
|
20° (from -3° to 41°)
|
13° (from-15° to 38°)
|
Mean acetabular inclination angle (degrees)
|
42°(from 27° to 50°).
|
44°(from 37° to 59°).
|
Acetabular retroversion rate
|
2 (2%)
|
11 (7.8%)
|
Acetabular components inside the “Safe zone”
|
93 (93%)
|
111 (79%)
|
Dislocation rate
|
2 (2%)
|
8 (5.7%)
|
Rate of acetabular components outside the “Safe zone” in cause of dislocation
|
0 (0%)
|
6 из 8 (75%)
|