Can We Really “Feel” a Balanced Total Knee Arthroplasty?

Elmallah, Randa K.; Mistry, Jaydev B.; Cherian, Jeffrey J.; Chughtai, Morad; Bhave, Anil; Roche, Martin W.; Mont, Michael A.

doi:10.1016/j.arth.2016.03.054

Cited by 73 publications

(59 citation statements)

References 14 publications

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“…Manual coronal plane balance has been achieved primarily through tactile feedback and visual cues. Whether a knee is “balanced” is subjective and is affected by various factors including surgeon training, experience, and surgical volume [6] , [7] .…”

Section: Introductionmentioning

confidence: 99%

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Dynamic sensor-balanced knee arthroplasty: can the sensor “train” the surgeon?

et al. 2019

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Background Dynamic tibial tray sensors are playing an increasing role in total knee arthroplasty (TKA) coronal balancing. Sensor balance is proposed to lead to improved patient outcomes compared with sensor-unbalanced TKA, and traditional manual-balanced TKA. However, the “learning curve” of this technology is not known, and also whether sensor use can improve manual TKA balance skills once the sensor is taken away, effectively “training” the surgeon. Methods We conducted a single-surgeon prospective study on 104 consecutive TKAs. In Nonblinded Phase I (n = 49), sensor-directed releases were performed during trialing and final intercompartmental load was recorded. In Blinded Phase II (n = 55), manual-balanced TKA was performed and final sensor readings were recorded by a blinded observer after cementation. We used cumulative summation analysis and sequential probability ratio testing to analyze the surgeon learning curve in both phases. Results In Nonblinded Phase I, sensor balance proficiency was attained most easily at 10°, followed by 90°, and most difficult to attain at 45° of flexion. In Blinded Phase II, manual balance was lost most quickly at 45°, followed by 90°, and preserved for longest at 10° of flexion. The number of cases in the steady state periods (early phase periods where there is a mix of sensor balance and sensor imbalance) for both phases is similar. Conclusions A surgeon who consistently uses the dynamic sensor demonstrates a learning curve with its use, and an “attrition” curve once it is removed. Consistent sensor balance is more predictable with constant sensor use.

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Section: Introductionmentioning

confidence: 99%

“…Elmallah et al [6] established that sensor-balanced TKAs demonstrate lower medial and lateral compartmental loads and lower differences in intercompartmental loads compared to manual-balanced TKAs. What is not known is whether sensor use is able to improve manual TKA balance, or “train” the surgeon.…”

Section: Introductionmentioning

confidence: 99%

Dynamic sensor-balanced knee arthroplasty: can the sensor “train” the surgeon?

et al. 2019

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“…This results in an increase in mediolateral balance throughout the range of flexion when using the robotic-assisted tensioner compared to subjective feel by the surgeon. Similar results have been observed when using a sensor technology that measures medial and lateral force instead of gaps [2,5]. The difference in balance between the two cohorts was modest in extension and increased with flexion.…”

Section: Discussionsupporting

confidence: 80%

“…Achieving proper soft tissue balance during total knee arthroplasty (TKA) can reduce postoperative instability and stiffness as well as improve patient reported outcomes [1]. Intra-operative assessment of soft tissue balance relies on the surgeons' experience and subjective feel, and thus can result in variable and inconsistent results [2]. Recent developments in sensor and robotic technologies provide surgeons with the ability to quantitatively measure soft tissue loads and tension and gap balance intra-operatively throughout the range of motion of the knee [3,4].…”

Section: Introductionmentioning

confidence: 99%

Accuracy of Soft Tissue Balancing in Robotic-Assisted Measured-Resection TKA Using a Robotic Distraction Tool

Koenig¹,

Shalhoub²,

Chen³

et al.

EPiC Series in Health Sciences

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Achieving proper soft tissue balance during total knee arthroplasty (TKA) can reduce post- operative instability and stiffness as well as improve patient reported outcomes. The objective of this study was to compare final intra-operative coronal balance throughout the knee range of motion in navigated robotic-assisted TKA when performed with quantifiable feedback from a robotic ligament tensioning tool versus with standard trials and navigation measurements alone.The study included a prospective cohort of 52 patients undergoing robotic-assisted TKA using a measured resection technique. The cohort was divided into two sequential groups: a non-sensor-assisted group (n=25) and a subsequent sensor-assisted group (n=27). Once bony cuts and soft tissue balancing was performed in the non-sensor cohort, the final tibiofemoral gaps were measured throughout the knee range of motion using a robotic-assisted tensioner with the surgeon blinded to the measurements. For the sensor cohort, the surgeon preformed soft-tissue releases or re-cuts in order to balance the knee using the gap measurement data from the robotic tensioner. The robotic-assisted tensioner was then used to measure the final medial and lateral gap measurements.The average mediolateral gap difference throughout the range of flexion was 1.9 ± 0.7 mm with maximum difference of 7.8 mm for the non-sensor cohort. The sensor cohort had an average mediolateral difference of 1.5 ± 0.6 mm and a maximum difference of 3.8 mm. The difference between the two groups was statistically significant from 60 to 90 degrees of flexion. 38-41% of knees were balanced to within 1 mm mediolaterally in the non-sensor group compared to 48-70% for the sensor group when measured at various flexion angles. 65-76% of knees were balanced to within 2 mm for the non-sensor group compared to 78-86% for the sensor-assisted group. The number of knees requiring subsequent soft tissue releases was similar in each group. Soft tissue balancing with the aid of a robotic tensioning tool resulted in significantly more accurate soft tissue balance than when using navigation measurements and standard trials alone in this single surgeon study.

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“…A further enhancement in balancing technique was an instrumented tibial trial in which lateral and medial contact forces were monitored over a full flexion range, with balanced knees showing some evidence of higher satisfaction levels [10] , [11] . Also, balancing using such a device was more accurate than by relying on surgeon feel [12] .…”

Section: Introductionmentioning

confidence: 99%

Relationship between surgical balancing and outcome measures in total knees

Chu¹,

Meere²,

Oh³

et al. 2019

Arthroplasty Today

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Background The purpose of the study was to investigate the accuracy of balancing which could be achieved at total knee surgery and its relation to functional outcomes. Methods During surgery, the forces on the medial and lateral plateaus were measured at 10-15 degrees flexion in 101 patients, using an instrumented tibial trial, with equal forces being targeted. Of the initial 101 cases, 71 cases completed all follow-up visits to 1 year. At each follow-up visit, the function was measured using the Knee Society Scoring System, and varus and valgus laxity angles were measured. Results The mean medial/(medial + lateral) compartmental force ratio was 0.52, with a standard deviation of 0.09. The total contact force was 217 Newtons, with a standard deviation of 72 Newtons. No correlations were found between the functional scores and the compartmental force ratio or total contact force. However, the mean varus and valgus laxity angles, 2.8 and 2.3 degrees, respectively, were very close to the angles of normal intact knees. Conclusions The likely reason for the lack of correlation of function was that the large majority of the balancing ratios were within the range 0.4-0.6 but with a wide spread of functional scores typical of total knee study groups. However, the normal varus and valgus angles achieved at follow-up indicated that equal balancing in early flexion was a reasonable surgical target. Using instrumented tibial trials enabled accurate and consistent balancing values to be achieved, as well as normal varus and valgus laxity angles, which may be important in obtaining optimal outcomes.

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Can We Really “Feel” a Balanced Total Knee Arthroplasty?

Cited by 73 publications

References 14 publications

Dynamic sensor-balanced knee arthroplasty: can the sensor “train” the surgeon?

Dynamic sensor-balanced knee arthroplasty: can the sensor “train” the surgeon?

Accuracy of Soft Tissue Balancing in Robotic-Assisted Measured-Resection TKA Using a Robotic Distraction Tool

Relationship between surgical balancing and outcome measures in total knees

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