Introduction
Methods
Search terms and criteria for inclusion
Data extraction
Outcome measures
Quality assessment
Statistical analysis
Results
Authors | Year | Search | Design | Patients (n =) | Age | F/U (months) | Implant | Robotic-arm |
---|---|---|---|---|---|---|---|---|
Bhimani et al. [4] | 2020 | GS | Retrospective cohorts | 140 RATKA vs 127 mTKA | 65.4 vs 66.6 | 1.5 | Triathlon PS | Stryker Mako |
Kayani et al. [18] | 2018 | PM/ML | Prospective cohorts | 30 RATKA vs 30 mTKA | 68.5 vs 69.9 | ? | Triathlon PS | Stryker Mako |
Kayani et al. [19] | 2018 | PM/ML | Prospective cohorts | 40 RATKA vs 40 mTKA | 69.7 vs 71.4 | 1 | Triathlon PS (cemented) | Stryker Mako |
Kayani et al. [20] | 2019 | GS | Prospective cohorts | 60 RATKA vs 60 mTKA | 68.7 vs 67.6 | 1 | Triathlon PS (cemented) | Stryker Mako |
Klopas et al. [23] | 2020 | PM/ML | Prospective cohorts | 150 RATKA vs 102 mTKA | 68 vs 65 | 3 | Triathlon CR (cemented) | Stryker Mako |
King et al. [25] | 2020 | PM/ML | Retrospective cohort | 202 RATKA vs 290 mTKA | 68 vs 66 | RATKA = 15 vs mTKA = 36 | (Reported as same cemented implants only) | Stryker Mako |
Mahoney et al. [28] | 2020 | PM/ML | Prospective cohorts | 143 RATKA vs 86 mTKA | 64.6 vs 68.5 | 12 | Triathlon CR (cemented) | Stryker Mako |
Marchand et al. [30] | 2017 | PM/ML | Prospective cohorts | 28 RATKA vs 20 mTKA | 69 vs 67 | 6 | Triathlon CR (cemented) | Stryker Mako |
Marchand et al. [31] | 2019 | PM/ML | Prospective cohorts | 53 RATKA vs 53 mTKA | 65 vs 63 | 12 | Triathlon CR (cemented) | Stryker Mako |
Marchand et al. [32] | 2020 | GS | Retrospective cohorts | 20 RATKA (1 month) vs 60 RATKA (6 months) vs 60 RATKA (1 years) vs 60 mTKA | 64 vs 64 vs 65 vs 63 | ? | Triathlon CR (majority cementless, those done in first month were cemented) | Stryker Mako |
Naziri et al. [36] | 2019 | PM/ML | Retrospective cohorts | 40 RATKA vs 40 mTKA | 69.5 vs 70.9 | 3 | Triathlon CR (cemented) | Stryker Mako |
Savov et al. [44] | 2019 | GS | Prospective cohorts | 30 RATKA vs 30 mTKA | ? | ? | ? | Stryker Mako |
Smith et al. [49] | 2019 | GS | Prospective cohorts | 120 RATKA vs 103 mTKA | 68 vs 66 | 12 | Triathlon PS (majority cementless, 10 in RATKA and 14 in mTKA cemented due to osteoporosis) | Stryker Mako |
Sodhi et al. [50] | 2017 | GS | Retrospective cohorts | 40 RATKA (early) vs 40 RATKA (late) vs 40 mTKA | Not reported | Not reported | Not reported | Stryker Mako |
Sultan et al. [51] | 2019 | PM/ML | Prospective cohorts | 43 RATKA vs 39 mTKA | 67 vs 66 | 1 – 1.5 | Triathlon CR (cemented) | Stryker Mako |
Tucking et al. [52] | 2019 | GS | Prospective cohorts | 40 RATKA vs 40 mTKA | ? | ? | ? | Stryker Mako |
Learning curve (Level of evidence: good)
Operating time | ||
---|---|---|
Author | Year | Findings |
Kayani et al. [20] | 2019 | Inflexion point of proficiency after seven cases for operative times (p = 0.01) and surgical team anxiety levels (p = 0.02) |
Cumulative robotic experience did not affect accuracy of implant positioning (n.s.) limb alignment (n.s.) posterior condylar offset ratio (n.s.) posterior tibial slope (n.s.) and joint line restoration (n.s.) | ||
Utilising the Surrogate Anxiety Inventory (STAI) questionnaire, Kayani et al. demonstrated that confidence level of surgical team improved in a pattern similar to the learning curve for operative times, with an inflexion point at seven cases. After this point, there was no difference in the overall STAI scores amongst team members between RATKA and mTKA | ||
Marchand et al. [32] | 2020 | The data indicate a significant decrease in the mean RATKA operative times from 1 month to 1 year of using robotic technology (81 vs. 62 min, p < 0.00001) |
The mean surgical times continued to decrease after 6 months of RATKA. In 1 year, the surgeon was performing 88% of the RATKA between 50 and 69 min. The initial cohort and 1-year robotic-assisted mean operative times were 81 and 62 min, respectively (p < 0.00001) | ||
Mean 6-month robotic-assisted operative times were similar to manual times (p = 0.12) | ||
Naziri et al. [36] | 2019 | Proposed point of proficiency as 20 cases |
Intraoperative EBL was comparable between RATKA and traditional TKA cohorts (42.4 vs. 49 ml, p = 0.448) | ||
The RATKA cohort required slightly greater overall surgical time than the traditional TKA cohort (82.5 vs. 78.3 min, p = 0.002) | ||
There was no significant difference in surgical time when comparing the mean surgical time of the second 20 cases of RATKA to the traditional TKA group (81.1 min vs. 78.3 min, p = 0.254) | ||
Savov et al. [44] | 2019 | Inflexion point of proficiency after 11 cases for operative time |
The mean surgery time in the robotic group after finishing the learning curve was 66 min (± 4.2) and in the total manual group 67 min (± 3.5) (n.s.) | ||
Sodhi et al. [50] | 2017 | Shortening of operative time from 99 min (cases 1–40) to 84 min (cases 81–120) |
No significant differences compared with mTKA in last 40 cases, 84 min vs 81 min |
Component position accuracy (level of evidence: good)
Component accuracy | ||
---|---|---|
Kayani et al. [20] | 2019 | [Accuracy in achieving the planned implant positions compared to conventional jig based TKA] |
Mechanical alignment (degrees), mean (SD) | ||
mTKA 3.2 ± 1.2 vs RATKA 1.5 ± 0.9, p < 0.001 | ||
PCOR | ||
mTKA 0.3 ± 0.1 vs RATKA 0.2 ± 0.1, n.s | ||
Posterior slope | ||
mTKA 3.4 ± 1.1 vs RATKA 1.4 ± 0.6, p < 0.001 | ||
Joint line | ||
mTKA 2.9 ± 1.4 vs RATKA 1.0 ± 0.6, p < 0.001 | ||
Femur coronal | ||
mTKA 4.1 ± 1.1 vs RATKA 1.0 ± 0.4, p < 0.001 | ||
Femur sagittal | ||
mTKA 4.2 ± 0.8 vs RATKA 2.1 ± 0.7, p < 0.001 | ||
Tibia coronal | ||
mTKA 3.6 ± 0.8 vs RATKA 1.0 ± 0.5, p < 0.001 | ||
Tibia sagittal | ||
mTKA 3.9 ± 1.0 vs RATKA 2.0 ± 0.6, p < 0.001 | ||
Mahoney et al. [28] | 2020 | Coronal positions measured via CT (mean ± SD) |
Femoral components | ||
mTKA 0.1 (± 1.6) varus vs RATKA 0.0 (± 1.4) varus, p = 0.506 | ||
Tibial components | ||
mTKA 1.9 (± 2.4) varus vs RATKA 0.9 (± 2.0) varus, p = 0.005 | ||
Femoral component external rotation relative to the transepicondylar axis | ||
mTKA 1.1 ± 2.3 vs RATKA 0.5 ± 2.3 degrees, (p = 0.195) | ||
Tibial slopes | ||
mTKA 3.7 ± 3.0 vs 3.2 ± 1.8 degrees, (p = 0.291) | ||
Naziri et al. [36] | 2019 | Postoperative alignment was within + 3.0° of the mechanical axis for all patients in both RATKA and mTKA groups |
Savov et al. [44] | 2019 | Limb alignment and restoration of the joint line |
mTKA no difference from RATKA | ||
RATKA deviation limb alignment to the intraoperative plan, mean = 2° (± 1.1) | ||
RATKA deviation of the medial proximal tibial (mPTA) and distal lateral femoral angle (dLFA) = 1° (± 0.9) for both | ||
Sultan et al. [51] | 2019 | Postoperative PCOR, mean (SD) |
mTKA 0.53 (± 0.3) vs RATKA 0.49 (± 0.21), p = 0.024 | ||
Difference between pre- and postoperative PCOR, mean | ||
mTKA 0.03 vs RATKA 0.004, p = 0.01 | ||
Postoperative ISI outside of the normal range (0.8–0.12) | ||
mTKA 12 vs RATKA 4 | ||
Tucking et al. [52] | 2020 | Postoperative PCOR, mean (SD) |
mTKA 0.47 (± 0.05) vs RATKA 0.51 (± 0.05), p = 0.006) | ||
PCOR (difference between pre- and postoperative), mean | ||
mTKA 0.059 vs RATKA -0.017, p = 0.001 | ||
Relative deviation of PCOR, mean (SD) | ||
mTKA 12.03% (± 9.1) vs RATKA 3.9% (± 4.5) |
Knee balancing and alignment techniques (level of evidence: fair)
Author | Year | Findings |
---|---|---|
Bhimani et al. [4] | 2020 | RATKA: to achieve the desired bone cuts and target limb alignment, along with symmetrically balanced flexion and extension gaps |
Unknown which technique and which reference alignment was utilised | ||
mTKA: A gap balancing technique was utilized using a ligamentous tensioning device with the extension gap balanced followed by balancing the flexion gap after release of the posterior cruciate ligament | ||
Gap balancing techniques utilised | ||
Kayani et al. [18] | 2018 | mTKA utilised a measured resection technique aligned to the mechanical axis |
RATKA utilised dynamic referencing to achieve equal gaps throughout the range of motion, utilising gap balancing and kinematic alignment techniques | ||
Kayani et al. [19] | 2018 | RATKA: intraoperative dynamic gap balancing techniques were used with kinematic alignment assessed through the arc of motion, and enabled fine tuning of implant positioning based on laxity of the soft tissue envelope, within 2 mm of the planned bone resection |
Utilised restricted kinematic alignment techniques | ||
mTKA: measured resection and mechanical alignment as reference | ||
Mahoney et al. [28] | 2020 | Both RATKA and mTKA utilised mechanical alignment as reference for all except nine cases of two centers that were targeted within ± 3 degrees |
Marchand et al. [30] | 2017 | RATKA: the prosthesis was manipulated allowing for optimal balancing and realignment. The knee was brought into extension, and alignment was checked with the robotic-assisted device both in extension and at 90 degrees of flexion |
No mention if mechanical/kinematic alignment was utilised to check the knee in extension | ||
mTKA: measured resection techniques used with mechanical alignment as reference | ||
Smith et al. [49] | 2019 | RATKA: equal gap measurements within 1 mm between the flexion and extension gaps and the medial and lateral gaps, keeping limb alignment within 3 degrees of the mechanical axis and use the bone cuts to balance gaps instead of soft tissue releases unless the target fell out of 3 degrees window, at which point a combination of bone cuts and soft tissue releases was utilized to achieve balanced gaps within 1 mm |
Restricted kinematic alignment and gap balancing techniques | ||
mTKA: Mechanical alignment and measured resection techniques utilised | ||
Sultan et al. [51] | 2019 | RATKA: Intraoperative adjustments to the plan were performed to determine ideal component placement for a balanced knee. Ligament balancing was assessed following resections and after trialing |
mTKA was performed using a standard technique | ||
No mention of measured resection or gap balancing techniques nor how mechanical / kinematic alignment was achieved |
Functional outcomes (level of evidence: good)
Author | Year | Findings |
---|---|---|
Kayani et al. [19] | 2018 | Shorter time to straight leg raise |
mTKA 31.0 (IQR 24.0–44.0) vs RATKA 20.0 (IQR 18.0–21.0), p < 0.001 | ||
Improved maximum knee flexion at discharge | ||
mTKA 93.3 (90.0–110.0) vs RATKA 104.1 (90.0–120.0), p < 0.001 | ||
Mean pain score – Day 3, mean (range) | ||
mTKA 4.5 (2.0–7.0) vs RATKA 2.6 (1.0–5.0) | ||
Khlopas et al. [23] | 2020 | KSS scores (Improvements in functional activity walking and standing), 4 to 6 weeks postoperatively, mean |
mTKA 1.2 vs RATKA 1.4 (p = 0.019) | ||
KSS (functional activity score), 3 months, mean (estimated SD) | ||
mTKA 67.2 (± 21) vs RATKA 65.5 (± 20.3), p = 0.613 | ||
KSS Pain scores improvements, 3 months, mean | ||
Walking | ||
mTKA 4.1 vs RATKA 4.3, p = 0.06 | ||
Total symptoms | ||
mTKA 10.3 vs RATKA 10.5, p = 0.781 | ||
KSS Patient Satisfaction Scores Mean (estimated SD) | ||
4–6 weeks: | ||
mTKA 25.9 (± 8) vs RATKA 25.2 (± 10), p = 0.268 | ||
3 months: | ||
mTKA 29.1 (± 8.5) vs RATKA 29.4 (± 10), p = 0.268 | ||
Mahoney et al. [28] | 2020 | [For all PROMs, longitudinal trends mTKA and RATKA similar at 1 year except VR12 physical scores] |
KSS Adjusted mean (95% C.I.) | ||
symptoms | ||
mTKA 20.3 [18.4, 22.2] vs RATKA 20.8 [18.9, 22.7] p = 0.531 | ||
Satisfaction | ||
mTKA 35.2 [32.0, 38.4] vs RATKA 35.9 [32.6, 39.2] p = 0.532 | ||
Expectations | ||
mTKA 10.6 [9.2, 12.0] vs RATKA 11.2 [9.7, 12.7] p = 0.192 | ||
Function | ||
mTKA 81.1 [75.5, 86.8] vs RATKA 84.6 [78.8, 90.4] p = 0.159 | ||
Veterans RAND 12-item health scale Adjusted mean (95% C.I.) | ||
physical component | ||
mTKA 50.5 [47.5, 53.5] vs RATKA 52.9 [49.9, 55.9] p = 0.034 | ||
Mental component | ||
mTKA 56.0 [53.7, 58.3] vs RATKA 54.6 [52.2, 57.0] p = 0.213 | ||
Marchand et al. [30] | 2017 | WOMAC (physical function), 6-month postoperative, mean (SD) |
mTKA 9 (± 5) vs RATKA (4 ± 5), p = 0.055 | ||
WOMAC (pain), 6-month postoperative, mean (SD) | ||
mTKA 5 (± 3) vs RATKA 3 (± 3) p < 0.05 | ||
Converted WOMAC scores | ||
mTKA 32(20) vs RATKA 52(20) | ||
mTKA 10(6) vs RATKA 14(6) | ||
Total: mTKA 42 vs RATKA 76 | ||
Marchand et al. [31] | 2019 | WOMAC (Physical Function), mean (SD) |
mTKA 6 (± 5) points vs RATKA 4 (± 4) points, p < 0.05 | ||
WOMAC (Pain scores), mean (SD) | ||
mTKA 3 (± 4) points, vs RATKA 2 (± 3) points, p = 0.06 | ||
Converted WOMAC scores | ||
PF: mTKA 44 (20) vs RATKA 52(16) | ||
PS: mTKA 14(8) vs RATKA 16(6) | ||
Total: mTKA 58 vs RATKA 78 | ||
Naziri et al. [36] | 2019 | Range of motion improvement at 90 days |
mTKA -8.7 deg vs RATKA + 3.8 deg, p < 0.05 | ||
KSS at 30, 60, 90 days, mean | ||
mTKA 90.9 vs RATKA 86.0, p = 0.082 | ||
mTKA 91.7 vs RATKA 91.9 p = 0.938 | ||
mTKA 89.5 vs RATKA 88.2 p = 0.730 | ||
LEAS at 30, 60, 90 days | ||
mTKA 11.50 vs RATKA 11.63, p = 0.736 | ||
mTKA 11.65 vs RATKA 12.06, p = 0.271 | ||
mTKA 11.94 vs RATKA 12.18, p = 0.519 | ||
[No report on the spread of data hence not included in the meta-analysis] | ||
Smith et al. [49] | 2019 | Range of motion |
mTKA 1 to 116 degrees vs RATKA 0 to 119 degrees (p = 0.88 and p = 0.02 for extension and flexion) | ||
KSS function score (6-week and 1-year average score) | ||
mTKA 58 and 73 vs RATKA 63 and 80, p = 0.02 and p = 0.005) | ||
1-year KSS knee score | ||
mTKA 82 vs RATKA 85, p = 0.046 | ||
Overall patient reported satisfaction reported with a Likert scoring system | ||
mTKA 82% vs RATKA 94% (p = 0.036) | ||
KSS Patient satisfaction scores mean | ||
mTKA 6.6 vs RATKA 7.1, (p = 0.027) | ||
[No report on the spread of data hence not included in the meta-analysis] |
Complications (level of evidence: good)
Author | Year | Findings |
---|---|---|
Bhimani et al. [4] | 2020 | Pain scores (mean) – 2 weeks |
At rest | ||
mTKA 3.5 vs RATKA 2.6, p = 0.001 | ||
With activity | ||
mTKA 7.0 vs RATKA 6.3, p = 0.03 | ||
Pain scores (mean) – 6 weeks | ||
At rest | ||
mTKA 1.6 vs RATKA 1.0, p = 0.03 | ||
With activity | ||
mTKA 4.7 vs RATKA 3.8, p = 0.02 | ||
Time to discharge (days) | ||
mTKA 2.3 vs RATKA 1.9, p < 0.001 | ||
MUA | ||
mTKA 0 vs RATKA 0 | ||
Superficial and deep infections | ||
mTKA 1 and RATKA 2 (prosthetic joint infections) | ||
Wound dehiscence | ||
mTKA 0 vs RATKA 0 | ||
Kayani et al. [19] | 2018 | MUA |
mTKA 0 vs RATKA 0 | ||
Superficial and deep infections | ||
mTKA 0 vs RATKA 0 | ||
Wound dehiscence | ||
mTKA, 1 (distal part of the midline incision) vs RATKA group 1 (incision for the proximal tibial registration pins), all recovered with regular dressings and prophylactic oral antibiotics | ||
Time to discharge (hrs), median (IQR) | ||
mTKA 105.0 (IQR 98.0–126.0) vs RATKA 77.0 (IQR 74.0–81.0), p < 0.001 | ||
Post-operative pain score – day 3, mean (range) | ||
mTKA 4.5 (2.0–7.0) vs RATKA 2.6 (1.0–5.0), p < 0.001 | ||
Kayani et al. [20] | 2019 | MUA |
mTKA 0 vs RATKA 0 | ||
Superficial and deep infections | ||
mTKA 0 vs RATKA 0 | ||
Wound dehiscence | ||
mTKA, 1 (distal part of the midline incision) vs RATKA group 1 (incision for the proximal tibial registration pins), all recovered with regular dressings and prophylactic oral antibiotics | ||
King et al. [25] | 2020 | Pain scores, mean |
mTKA 5.1 vs RATKA 5.5, p = 0.288 | ||
Time to discharge, days | ||
mTKA 2.6 vs RATKA 2.3, p < 0.001 | ||
Early readmissions | ||
mTKA 4 vs RATKA 3, p = 0.9 | ||
Most common reason for readmission across both groups was related to bleeding events (3/7) | ||
Return to ED | ||
mTKA 21 vs RATKA 10, p = 0.30 | ||
Most common reason was leg swelling, this accounted for only 1/10 (10%) of RATKA while it accounted for 7/21 (33%) of mTKA (p = 0.17) | ||
MUA | ||
mTKA 6 vs RATKA 0 | ||
Superficial and deep infections | ||
mTKA 1 vs RATKA 0 | ||
Wound dehiscence | ||
mTKA 0 vs RATKA 0 | ||
Naziri et al. [36] | 2019 | Time to discharge (days), median (IQR not reported) |
mTKA 1.92 vs RATKA 1.27, p < 0.001 | ||
30 days | ||
Minor Complications—None reported | ||
Major Complication Rate | ||
mTKA 2.5% vs RATKA 0.0%, p = 0.320 | ||
[mTKA with Arthrofibrosis requiring Manipulation under Anesthesia (MUA) (n = 1)] | ||
MUA | ||
mTKA 1 vs RATKA 0 | ||
Superficial and deep infections | ||
mTKA 0 vs RATKA 0 | ||
Wound dehiscence | ||
mTKA 0 vs RATKA 0 | ||
No complications for 60 and 90 day follow ups | ||
Smith et al. [49] | 2019 | Time to discharge (days) |
mTKA 3 vs RATKA 2 | ||
MUA | ||
mTKA 9 vs RATKA 9 | ||
[If patients did not reach active range of motion to 105 degrees of flexion at 6 weeks then manipulation was recommended.] | ||
Superficial and deep infections | ||
mTKA 0 vs RATKA 0 | ||
Wound dehiscence | ||
mTKA 0 vs RATKA 0 | ||
Non-fatal pulmonary embolism | ||
mTKA 0 vs RATKA 2 |