Small Improvements in Postoperative Outcome with Gap Balancing Technique Compared with Measured Resection in Total Knee Arthroplasty

Effect of Posterior Cruciate Ligament Resection on Gap Balancing in Robot-assisted Total Knee Arthroplasty

OBJECTIVE

Retention or sacrifice of the posterior cruciate ligament (PCL) is one of the most controversial issues while performing total knee arthroplasty (TKA). This study aimed to evaluate the impact of PCL resection on flexion-extension gaps, femoral component rotation, and bone resection amounts during robot-assisted TKA.

METHODS

This prospective study included 40 patients with knee osteoarthritis who underwent robot-assisted posterior-stabilized (PS) TKA between September 2021 and February 2022. Of the patients, 75% were women (30/40) with a mean age and BMI of 72.6 years and 27.4 kg/m2, respectively. The guidance module and camera stand assembly were used to capture gaps before and after PCL resection. Measurements of femoral component rotation and bone resection amounts were made in cruciate-retaining (CR) TKA mode and PS-TKA mode.

RESULTS

After PCL resection, the mean change in the medial and lateral compartments of flexion gaps increased by 2.0 and 0.6 mm, respectively (p < 0.001). Compared with the CR-TKA mode group, the bone resection amounts of the medial posterior condyle and the lateral posterior condyle in the PS-TKA mode group decreased by 2.0 ± 1.1 and 1.1 ± 1.1 mm, respectively, and the external rotation of the femoral prosthesis relative to the posterior condylar axis and trans-epicondylar line was reduced by 1.0° ± 1.3° and 1.2° ± 1.6°, respectively (p < 0.001).

CONCLUSION

The release of the PCL did not affect the extension gap, but significantly increased the flexion gap. Moreover, the increases in the medial flexion gap were greater than those of the lateral flexion gap. After PCL resection, less external rotation of the femoral prosthesis and fewer bone cuts of the posterior femur were needed in PS-TKA.

The Clinical Outcomes of Measured Resection and Gap Balancing Techniques in Primary Total Knee Arthroplasty: A Meta-analysis

BACKGROUND

At present, the clinical efficacy of measured resection (MR) and gap balancing (GB) techniques in total knee arthroplasty (TKA) is still controversial. The objective of this study was to evaluate the clinical outcome indexes of the two surgical methods through a meta-analysis.

METHODS

The literature was systematically searched on PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), WANFANG, Weipu (VIP), and China Biomedical Literature (CBM) electronic databases inception until June 12, 2022. RevMan 5.3 software (the Nordic Cochrane Center, the Cochrane Collaboration, Copenhagen, Denmark) was used to analyze all data of this study. The Cochrane risk bias assessment tool is a risk bias evaluation criterion recommended by the Cochrane Handbook for systematic reviews.

RESULTS

Eleven studies involving 1268 knees in total were included. The main outcome indexes showed that the Knee Society Score (KSS) knee score (MD: -1.40; 95% CI: -2.57 to -0.22; p = 0.02) and KSS knee function score (MD: -3.11; 95% CI: -3.72 to -2.50; p < 0.001) in the GB group were higher 1 year after operation, while femoral component rotation angle (FCRA; MD: -0.75; 95% CI: -1.34 to -0.07; p = 0.03) and the osteotomy volume of the posterior medial femoral condyle (MD: -0.76; 95% CI; -1.13 to -0.38; p < 0.001) were greater in the GB group. In addition, there was no significant difference in the joint line change (MD: -0.03; 95% CI: -0.07 to 0.01; p = 0.16) between the two groups. Secondary outcome results showed that the knee joint range of motion (ROM) in 3 months, and the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score after 1 year were better in the GB group. However, the operation time of the MR group was shorter. In addition, this study revealed no significant differences in post-complications between these two groups.

CONCLUSION

Although the GB technique may not provide better radiographic results or reduce the complication rate, the recovery of joint function showed earlier improvement.

Comparison of the Imaging and Clinical Outcomes among the Measured Resection, Gap Balancing, and Hybrid Techniques in Primary Total Knee Arthroplasty

OBJECTIVE

Although many studies have compared the measured resection (MR) technique to the gap balancing (GB) technique, few studies have investigated the hybrid technique. In this study, we compared imaging and clinical outcomes of the MR, GB, and hybrid techniques in primary total knee arthroplasty (TKA).

METHODS

From January 2016 to January 2019, we conducted a retrospective study on 90 patients who underwent unilateral primary TKA; 30 received the MR technique, 30 received the GB technique, and 30 received the hybrid technique. Radiological outcomes, including joint line level, mechanical alignment of the lower limb, positions of the femoral and tibial components, and rotation of the femoral component, and clinical outcomes, including the visual analog scale score for pain, the Knee Society Score, and the range of motion, were assessed among the three groups. One-way analysis of variance and Dunnett's test were performed for normally distributed data. Kruskal-Wallis H test and Dunn-Bonferroni test were conducted for non-normally distributed data.

RESULTS

No significant difference in the mechanical alignment (p = 0.151) and the positions of the tibial and femoral components (p = 0.230 for α angle, p = 0.517 for β angle, p = 0.686 for femoral flexion angle, and p = 0.918 for tibial slope angle) was found among the three groups. No significant difference in the elevation of the joint line between the MR and the hybrid groups was found (2.1 ± 0.3 mm vs 2.1 ± 0.1 mm, p = 0.627), but the GB group (2.8 ± 0.2 mm) differed significantly from the other two groups (p < 0.001). Although rotation of the femoral component in the GB group was larger than that of the MR and hybrid groups, the difference was not significant (1.8° ± 0.2° vs 1.7° ± 0.3° vs. 1.7° ± 0.2°, p = 0.101). The clinical outcomes were not significantly different (p > 0.05), although the results in the hybrid group were slightly higher.

CONCLUSION

The hybrid technique helped to restore the mechanical alignment of the lower limb and realize optimal positions of the femoral and tibial components without significant differences relative to the MR and GB techniques. The hybrid technique was more helpful for maintaining the original height of the joint line, which was similar to the MR technique. Additionally, although the improvement in the clinical outcomes in the hybrid group was slightly higher, it was not significantly different among the three groups.

Measurement for gap balancing technique in patients undergoing total knee arthroplasty: a large retrospective observational study

Background

Many traditional methods are available to prevent unbalance of extension and flexion gap during total knee arthroplasty (TKA), but there are no reports on the use of measurement and positioning method before tibial osteotomy with self-made tools. We designed a self-made tool measuring the location before tibial osteotomy and determined the clinical effect.

Methods

The retrospective study included patients who received TKA at our hospital, between January 1, 2012 and December 31, 2015. A new method, named as the measurement and localization before osteotomy with self-made tools, was developed to measure the osteotomy position of the posterior femoral condyle during TKA. They were divided into two groups, one that received the new method (Group I), and the other that received the traditional method as a control (Group I I). HSS score, Oxford score, VAS score and knee joint activity were evaluated in two groups.

Results

One hundred and eighty-seven of 210 eligible patients were included. The function of knee joint in all patients was improved and the pain was obviously relieved. Significant differences were found in the HSS score, Oxford score, VAS score, knee joint activity between two groups at 5-year follow-up (p < 0.05).

Conclusions

The biomet knee prosthesis was selected for all intraoperative implants. All operations were completed by the same senior surgeon. The use of self-made tools may contribute to improve the balance between flexion and extension gaps as well as the balance between internal and external gaps during TKA, and overcome knee flexion instability.

Intra- and postoperative assessment of femoral component rotation in total knee arthroplasty: an EKA knee expert group clinical review

PURPOSE

Malrotation of the femoral component after primary total knee arthroplasty (TKA) is one of the most important problems leading to painful TKA requiring revision surgery.

METHODS

A comprehensive systematic review of the literature was performed to present current evidence on how to optimally place the femoral component in TKA. Several landmarks and techniques for intraoperative determination of femoral component placement and examination of their reliability were analyzed.

RESULTS

2806 articles were identified and 21 met the inclusion criteria. As there is no unquestioned gold standard, numerous approaches are possible which come along with specific advantages and disadvantages. In addition, imaging modalities and measurements regarding postoperative femoral component rotation were also investigated. Femoral component rotation measurements on three-dimensional (3D) reconstructed computerised tomography (CT) images displayed intraclass correlation coefficients (ICC) above 0.85, significantly better than those performed in radiographics or two-dimensional (2D) CT images. Thus, 3D CT images to accurately evaluate the femoral prosthetic component rotation are recommended, especially in unsatisfied patients after TKA.

CONCLUSION

The EKA Femoral Rotation Focus Group has not identified a single best reference method to determine femoral component rotation, but surgeons mostly prefer the measured resection technique using at least two landmarks for cross-checking the rotation.

LEVEL OF EVIDENCE

III.

Clinical and Radiographic Outcome of Gap Balancing Versus Measured Resection Techniques in Total Knee Arthroplasty

Background

There is no consensus regarding superiority between gap balancing (GB) and measured resection (MR) techniques to implant total knee arthroplasties. In a multicenter setup, we compared both techniques using the same prosthesis.

Methods

We included 262 balanSys posterior-stabilized total knee arthroplasties from 4 centers: 3 using the MR (n = 162) and one using the GB technique (n = 100), without navigation.

Results

There was no significant difference in the Knee Society Score or visual analog scale pain at 2- and 7-year follow-up. The visual analog scale for satisfaction was significantly better in the MR group at 2 but not at 7 years. We found a significantly higher average valgus in the GB group, but the overall alignment was within 2° of neutral on the full-leg radiographs. There were no significant differences concerning radiolucency and survival.

Conclusions

We found no significant differences in the functional outcome, pain, alignment, or survival, but a tendency toward better function using MR and better survival with GB.

Gap balancing versus measured resection for primary total knee arthroplasty: a meta-analysis study

INTRODUCTION

To achieve the most desirable post-operative results, operation techniques and procedures for total knee arthroplasty (TKA) are highly standardized. However, debates persist whether patients having undergone a gap balancing technique (GB) perform better than those having undergone measured resection (MR) technique. Therefore, a meta-analysis study was conducted to investigate advantages of GB compared to the MR. The focus of the present study was on clinical and functional scores, radiological measurements and further complications.

MATERIALS AND METHODS

The present meta-analysis was conducted according to the PRISMA checklist. In November 2019, literature search was performed. All clinical studies comparing measured resection technique versus gap balancing technique for primary total knee arthroplasty were considered for inclusion. Only articles reporting quantitative data under the outcomes of interest were eligible for inclusion. The methodological quality assessment and statistical analyses were performed through the Review Manager Software version 5.3 (The Cochrane Collaboration, Copenhagen).

RESULTS

Data from 25 clinical trials (2971 procedures) were collected. Patient baseline demonstrated a good comparability. No difference among the two cohorts was found in terms of SF-12 Mental and Physical, ROM, KSS, KSS Function, OKS, WOMAC. No difference was found in the alignment of mechanical axis and femoral rotation. During the knee motion, no difference was found between the medial and lateral gaps among the two techniques. The GB showed a significant elevated joint line (P < 0.0001), along with a longer duration of the operating time (P = 0.001). No differences were found in terms of revision surgery, aseptic loosening or prosthetic infections.

CONCLUSION

GB and MR achieve similar outcomes for TKA. In the GB group, a proximalisation of the joint line and extended operating time was detected. Regarding the additional outcomes of interest, the present analysis showed comparability between both groups, MR and GB.

Cumulative Incidence of Revision for a Balanced Knee System at a Mean 8-Year Follow-Up: A Retrospective Review of 500 Consecutive Total Knee Arthroplasties

Purpose

The primary purpose of this study was to evaluate mid-term survival of a Balanced Knee System in the first 500 total knee arthroplasty (TKA) cases using a fully cemented, posterior stabilized TKA at a high-volume private practice.

Patients and Methods

In this IRB approved retrospective cohort study, data were extracted from a surgical registry at a high-volume orthopaedic practice for the first 500 total knee arthroplasty (TKA) cases performed using the Balanced Knee® System (BKS, Ortho Development®, Draper, Utah, USA). Procedures were performed between June 2000 and September 2003 by one of two orthopaedic surgeons. Follow-up was performed at 6 weeks, 6 months, 1 year, 5 years, and 10 years. 48 patients (9.6%) were considered lost to follow-up. A competing risk analysis was performed to evaluate the cumulative incidence of revision while accounting for the competing risk of death. In the model, failure was defined as revision of any BKS component. Those who failed prior to two years remained in the analysis.

Results

The mean age of the population was 69 years (range: 40–94) and 73% were female. The cumulative incidence of revision of any component was approximately 1% at a mean 8-year follow-up (range: 0.11–14.1 years) when accounting for the competing risk of death. When considering all those lost to follow-up as failures, the cumulative incidence of failure at 8 years was approximately 10%.

Conclusion

Based on the results of the current study, a posterior stabilized primary TKA, implanted using a flexion and extension gap balancing technique, had excellent survivorship and outcomes at a mean 8-year follow-up.

Clinical Outcomes of Gap Balancing vs Measured Resection in Total Knee Arthroplasty: A Systematic Review and Meta-Analysis Involving 2259 Subjects

BACKGROUND

The argument on the clinical effects between gap balancing (GB) and measured resection (MR) in total knee arthroplasty remains to be resolved. A systematic review and meta-analysis was performed to investigate which technique in total knee arthroplasty has better clinical effect.

METHODS

A total of 20 studies involving 2259 cases were included in the meta-analysis. The primary outcome measure was Knee Society Score (KSS), whereas the secondary outcomes included other function assessment systems (eg, range of motion, Western Ontario and McMaster University Osteoarthritis Index), radiological outcomes (eg, femoral component rotation, total outliers), revision rate, complications (eg, infection, loosening, instability), and surgical time.

RESULTS

The GB technique was associated with statistically significant increases in the primary outcomes of KSS-function in 1 year. However, a mean difference of 2.12 points was below the minimal clinically important difference of 6 points. No differences were found in the analyses of KSS-knee and KSS-function in any other follow-up periods. Secondary outcome assessments showed significant decreased surgical time (mean difference, 16.18; P < .00001) for MR. Although statistically significant difference in favor of GB was identified in total outliers (risk ratio, 1.72, P = .0004), the 2 techniques were comparable in range of motion, Western Ontario and McMaster University Osteoarthritis Index, femoral component rotation, complications, and revision rate.

CONCLUSION

We conclude that both techniques can result in equivalent results when done properly, and each surgeon must understand the strengths and weaknesses of each technique.