Acetabular cup positioning1, 2, leg length discrepancy3 and global offset4 are important parameters associated with outcomes following total hip arthroplasty (THA). Deviation from an accepted range of values for each of these parameters can lead to significant complications including nerve injury, low back pain, abnormal gait, increased dislocation rate, and bearing surface wear. The primary purpose of this study was to assess whether the use of the MAKO™ robotic hip system is reliable in predicting post-operative radiographic measurements of cup inclination, cup anteversion, leg length change, and global offset change in THA. All robotic-assisted THAs performed using the MAKO™ system between June 2011 and Dec 2012 were reviewed. A single surgeon performed all cases through a mini-posterior approach. The intra-operative measurements of cup inclination and anteversion angles, leg length change, and global offset change recorded by the MAKO™ system were compared to the post-operative radiographic measurements.Background:
Materials and Methods:
Improper acetabular component orientation has been shown to negatively affect the outcome of total hip arthroplasty through increasing dislocation rates, component impingement, bearing surface wear, and the rate of revision surgeries. The “Safe Zone” was defined by Lewinnek et al. in 1978 as 5 to 25 degrees of cup version and 30 to 50 degrees of cup inclination. Later, the inclination “Safe Zone” values were modified to 30 to 45 degrees. The primary purpose of this study was to assess whether the use of Mako robotic hip system improves cup positioning when compared to traditional THR.Introduction
Objectives
