Trial Outcomes & Findings for Robotic Arm Assisted Total Knee Arthroplasty (NCT NCT02058069)

Results Overview

Surgeon assessment of standardized TKA complications (Healey et al. CORR 2012) both intra-operatively and at short term follow up. The nine complications relating to soft tissue damage for primary TKA that were assessed as part of this study were as follows: Blood loss, Vascular injury, MCL injury, Periprosthetic fracture, Extensor mechanism disruption, Patellofemoral dislocation, Tibiofemoral dislocation, Neurological impairment, Instability.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

100 participants

Primary outcome timeframe

Subject will be assessed for these complications intra-operatively. The assessment occurs after the surgeon has completed the surgical procedure, but while the subject is still in the operating room with the surgeon.

Results posted on

2017-04-18

Participant Flow

Participant milestones

Participant milestones
Measure	Robotic Assisted Total Knee Arthroplasty Participants who underwent primary total knee arthroplasty using the Mako robotic arm system. "Participants" throughout this posting is equivalent to the number of knees.
Overall Study STARTED	100
Overall Study COMPLETED	89
Overall Study NOT COMPLETED	11

Reasons for withdrawal

Reasons for withdrawal
Measure	Robotic Assisted Total Knee Arthroplasty Participants who underwent primary total knee arthroplasty using the Mako robotic arm system. "Participants" throughout this posting is equivalent to the number of knees.
Overall Study Exclusion due to implant size	5
Overall Study Withdrawal by Subject	6

Baseline Characteristics

Robotic Arm Assisted Total Knee Arthroplasty

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure	Robotic Assisted Total Knee Arthroplasty n=89 Participants Participants who underwent primary total knee arthroplasty using the Mako robotic arm system.
Age, Continuous	65.78 years STANDARD_DEVIATION 8.49 • n=5 Participants
Sex: Female, Male Female	49 Participants n=5 Participants
Sex: Female, Male Male	40 Participants n=5 Participants

PRIMARY outcome

Timeframe: Subject will be assessed for these complications intra-operatively. The assessment occurs after the surgeon has completed the surgical procedure, but while the subject is still in the operating room with the surgeon.

Population: participants = knees.

Surgeon assessment of standardized TKA complications (Healey et al. CORR 2012) both intra-operatively and at short term follow up. The nine complications relating to soft tissue damage for primary TKA that were assessed as part of this study were as follows: Blood loss, Vascular injury, MCL injury, Periprosthetic fracture, Extensor mechanism disruption, Patellofemoral dislocation, Tibiofemoral dislocation, Neurological impairment, Instability.

Outcome measures

Outcome measures
Measure	Robotic Assisted Total Knee Arthroplasty n=89 Participants Participants who underwent primary total knee arthroplasty using the Mako robotic arm system.
Intra-Operative Complications	0 intra-operative complications

PRIMARY outcome

Timeframe: Subjects will be assessed for incidence of intra-operative complications at the conclusion of their hospital stay, or an average of 3 days post-operatively.

Population: participants = knees.

Surgeon assessment of standardized TKA complications (Healey et al. CORR 2012) both intra-operatively and at short term follow up. The nine complications relating to soft tissue damage for primary TKA that were assessed as part of this study were as follows: Blood loss, Vascular injury, MCL injury, Periprosthetic fracture, Extensor mechanism disruption, Patellofemoral dislocation, Tibiofemoral dislocation, Neurological impairment, Instability.

Outcome measures

Outcome measures
Measure	Robotic Assisted Total Knee Arthroplasty n=89 Participants Participants who underwent primary total knee arthroplasty using the Mako robotic arm system.
Intra-Operative Complications	0 intra-operative complications

PRIMARY outcome

Timeframe: 3 Month Post Op

Population: participants = knees.

Surgeon assessment of standardized TKA complications (Healey et al. CORR 2012) both intra-operatively and at short term follow up. The nine complications relating to soft tissue damage for primary TKA that were assessed as part of this study were as follows: Blood loss, Vascular injury, MCL injury, Periprosthetic fracture, Extensor mechanism disruption, Patellofemoral dislocation, Tibiofemoral dislocation, Neurological impairment, Instability.

Outcome measures

Outcome measures
Measure	Robotic Assisted Total Knee Arthroplasty n=89 Participants Participants who underwent primary total knee arthroplasty using the Mako robotic arm system.
Intra-Operative Complications	0 intra-operative complications

SECONDARY outcome

Timeframe: pre-op plan, 3 Month Post Op

Population: Of the 89 patients who received a robotic assisted total knee arthroplasty as part of the IDE, 2 patients were excluded from analysis for the Secondary Endpoint only due to issues related to the accurate measurement of limb alignment from the radiographs available (not for reasons involving the surgical procedure or clinical outcomes).

Radiographic limb alignment of the operative knee according to the technique defined by Barrack et al. was assessed at the 3 month post-operative follow-up by two independent reviewers. The measured post-operative limb alignment was to be compared to the planned pre-operative limb alignment as extracted from the system log file.

Outcome measures

Outcome measures
Measure	Robotic Assisted Total Knee Arthroplasty n=87 Participants Participants who underwent primary total knee arthroplasty using the Mako robotic arm system.
Change in the Radiographic Assessment of Limb Alignment From Pre-Operative to 3 Months Post-Operative	1.54 degrees Standard Deviation 1.01

SECONDARY outcome

Timeframe: Pre-op Plan, 3 Month Post Op

Population: Participants = knees

The difference between the actual 3 month limb alignment was compared to the pre-op planned alignment. Any measurement difference \<4.38 was considered a success; \>4.38 degrees was considered a failure.

Outcome measures

Outcome measures
Measure	Robotic Assisted Total Knee Arthroplasty n=87 Participants Participants who underwent primary total knee arthroplasty using the Mako robotic arm system.
Participants With Limb Alignment Difference <4.38 Degrees	87 Participants

OTHER_PRE_SPECIFIED outcome

Timeframe: Pre-Op, 3 Month Post Op [change assessed between the two time periods]

Population: participants = knees.

The WOMAC collects information specific to osteoarthritis outcomes. The patient-response questionnaire uses a visual analog scale for pain, measuring factors of general pain, stiffness, and function. Each question is scored from 0 to 4 for each set of factors, with 0 indicating no pain, stiffness, or limit in function, and 4 indicating extreme pain, stiffness, or limit in function. Total WOMAC scores range from 0 to 96 with lower values representing better outcomes. The posted mean, noted as a negative number, represents the mean DECREASE in total WOMAC score from pre-operative to 3 month post-operative patient assessment.

Outcome measures

Outcome measures
Measure	Robotic Assisted Total Knee Arthroplasty n=89 Participants Participants who underwent primary total knee arthroplasty using the Mako robotic arm system.
Patient Satisfaction - Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC)	-33.1 units on a scale Standard Deviation 20.04

Adverse Events

Robotic Assisted Total Knee Arthroplasty

Serious events: 9 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure	Robotic Assisted Total Knee Arthroplasty n=100 participants at risk Participants who underwent primary total knee arthroplasty using the Mako robotic arm system. Note regarding serious AEs: Adhesions and arthrofibrosis are surgical complications that can result from knee surgery and present as stiffness and restriction of ROM. Reasons for stiffness and restriction of ROM after TKA are multifactorial and may be influenced by factors such as the patient's overall health, motivation, and compliance to their rehabilitation regimen. The Principal Investigator and study Investigators stated these adverse events are not related to the use of the Investigational Device.
Musculoskeletal and connective tissue disorders Arthrofibrosis	4.0% 4/100 • Subject enrollment to end of study. Participants = knees
Musculoskeletal and connective tissue disorders Adhesions	4.0% 4/100 • Subject enrollment to end of study. Participants = knees
Vascular disorders Pulmonary Embolism	1.0% 1/100 • Subject enrollment to end of study. Participants = knees

Other adverse events

Adverse event data not reported

Additional Information

Michael Conditt

MAKO Surgical Corp.

Phone: 7132408675

Email: [email protected]

Results disclosure agreements

Principal investigator is a sponsor employee
Publication restrictions are in place

Restriction type: GT60