Enables you to more accurately plan and place components,2 potentially reducing variability within the THA procedure and allowing for enhanced functional and clinical outcomes.2-9
Has demonstrated greater accuracy in achieving planned leg length compared with manual total hip replacements2 in a cadaveric model.10
|Pre-op plan average ± std. dev.||Intra-op plan robotic-arm measurement average ± std. dev.||Radiographic Measurement average ± std. dev.|
|Inclination||40.0º ± 1.2º||39.9º ± 2.0º||40.4º ±4.1º|
|Version||18.7º ± 3.1º||18.6º ± 3.9º||21.5º ± 6.1º|
RTHA cups positions in relation to Lewinnek's and Callanan's safe zones12
CTHA cups positions in relation to Lewinnek's and Callanan's safe zones12
To compare the acetabular component size relative to the patient’s native femoral head size between conventional THA (CTHA) approach and robotic-arm assisted THA (RTHA) to infer which of these technologies preserved more acetabular bone.
Patients were included if they had primary osteoarthritis (OA) and underwent total hip replacement between June 2008 and March 2014. Patients were excluded if they had missing or rotated postoperative antero-posterior radiographs. RTHA patients were matched to a control group of CTHA patients, in terms of preoperative native femoral head size, age, gender, body mass index (BMI) and approach. Acetabular cup size relative to femoral head size was used as a surrogate for amount of bone resected. We compared the groups according to 2 measures describing acetabular cup diameter (c) in relation to femoral cup diameter (f): (i) c-f, the difference between cup diameter and femoral head diameter and (ii) (c-f)/f, the same difference as a fraction of femoral head diameter.
57 matched pairs were included in each group. There were no significant differences between groups for demographic measures, femoral head diameter, or acetabular cup diameter (p>0.05). However, measures (i) and (ii) did differ significantly between the groups, with lower values in the RTHA group (p<0.02).
Using acetabular cup size relative to femoral head size as an approximate surrogate measure of acetabular bone resection may suggest greater preservation of bone stock using RTHA compared to CTHA. Further studies are needed to validate the relationship between acetabular cup size and bone loss in THA.
|First manual 100||Last manual 100||First robotic-arm 100|
|31% in target zone||45% in target zone||76% in target zone|
|5% dislocation (4/5 anterior)||3% dislocation (2/3 anterior)||0% dislocation|
|3% fractured liners||0% fractured liners||0% fractured liners|