Mako Total Hip

Robotic-Arm Assisted Surgery

Facilitates your surgical approach of choice: direct anterior, posterolateral or anterolateral. The outcomes you can achieve have the potential to create the future of your orthopaedic service line

Over 20,000 Mako Total Hip procedures were performed through 2016.1

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

Related categories

Clinical evidence 1

Precision of acetabular cup placement in robotic integrated total hip arthoplasty11


Principal investigators

  • Henrik Malchau, MD
  • Douglas E. Padgett, MD
  • Jon Dounchis, MD
  • Richard Illgen, MD
  • Robert C. Marchand, MD

Methodology

  • 120 (110 were evaluated) robotic-arm assisted THA cases from 4 institutions’ post-op A/P pelvis and lateral X-rays were evaluated using Martell hip analysis software for cup positioning.

Results

  • Based on Mako data (3-D), 96% of robotic-arm assisted THA cases were inside the Callanan safe zone (30°- 45° inclination and 5°-25° version).
  • The 95% predictive interval was ±3.5°for inclination and ± 3.6° for version using the intra-operative recorded position of the cup by the robotic-arm.
  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
Count (n) 119 119 110

Clinical evidence 2

Comparison of robotic-assisted and conventional acetabular cup placement in THA: a matched-pair controlled study12

Principal investigators

  • Benjamin G. Domb, MD

Methodology

  • Matched groups of 50 robotic THAs and 50 manual THAs by a single surgeon using a posterior approach were analyzed radiographically for cup positioning.

Results

  • 100% of robotic-arm assisted cups were placed within the Lewinnek “Safe Zone” for anteversion and inclination compared to 80% of manual cases.
  • 92% of robotic-arm assisted cups were placed within the Callanan “Safe Zone” for anteversion and inclination compared to 62% of manual cases.

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

Clinical evidence 3

Preservation of acetabular bone stock in total hip arthroplasty using conventional vs. robotic techniques: a matched-pair controlled study13

Purpose

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.

Methods

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.

Results

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). 

Conclusions

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. 

Results: Bone Stock13

Surgical experience 1

Haptically guided robotic technology in total hip arthoplasty: a cadaveric investigation14

Methodology

  • Dr. Douglas Padgett, from Hospital for Special Surgery, who has robotic experience, performed twelve cadaveric THA procedures (six THAs using Mako Robotic-Arm Assisted Total Hip technology and six as manual THAs)

Results

  • The root mean square (RMS) error for the robotic-assisted surgery was within 3° for cup placement and within one mm for leg length equalization and offset based on comparisons of pre- and post-operative CT scans.
  • The RMS error for manual implantation compared to robotic-assistance was five times higher for cup inclination and 3.4 times higher for cup anteversion (p>0.01).

Surgical experience 2

Accuracy of cup positioning and achieving desired hip length and offset following robotic THA procedures15

Principal investigator

  • Seth Jerabek, MD

Methodology

  • Five surgeons performed 21 THAs on cadaveric hips.
  • Pre-operative CTs of each hip were used to plan the cup, stem, head diameter, neck length and liner.
  • Post-op CTs were compared with pre-operative planned and intra-operatively captured values.

Results

  • Robotic-arm assisted THA demonstrated "excellent" accuracy and precision with regard to planned cup position, hip length and offset.
  • Cup orientation vs. Intra-op plan:
    - Inclination: 2.7±2.2˚
    - Version: 2.2±1.4˚
  • Cup position vs. planned position:
    - Medial/lateral: 1.4±1.1mm
    - Anterior/posterior: 1.3±1.1mm
    - Superior/inferior: 1.4±1.2mm
  • Reduction results:
    - Hip length: 1.6±1.2mm
    - Combined offset: 1.3±0.8mm

Patient outcomes

Outcomes after primary total hip arthroplasty: manual compared with robotic-assisted techniques16-18


Principal investigators

  • Richard Illgen, MD

Methodology

  • 1st 100 consecutive manual THA cases (2000)
  • Last 100 consecutive manual THA cases (2011)
  • 1st 100 consecutive robotic-arm assisted THA cases (2012)
  • Radiographic and clinical outcomes assessment

Results

  • Robotic-arm assisted THA demonstrated significantly higher modified Harris Hip Score and UCLA activity level compared with manual THA at a minimum 1 year follow up.
  • Estimated blood loss was reduced in the rTHA patients.
  • Robotic-arm assisted THA improved both acetabular abduction and anteversion accuracy and achieved reduced early dislocation rates and improved rates of limb length discrepancy compared with manual 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