Functional alignment with robotic‑arm assisted total knee arthroplasty demonstrated better patient-reported outcomes than mechanical alignment with manual total knee arthroplasty

Revisiting terminology: The transition from 'functional alignment' to 'functional knee positioning'

Functional alignment (FA), now proposed to be termed Functional Knee Positioning (FKPos), is a modern, patient‐specific approach to total knee arthroplasty (TKA) that emphasises a three‐dimensional (3D) methodology. This approach integrates 3D bony anatomy, mediolateral laxities in extension and flexion, and anterior compartment geometry and laxity to achieve personalised implant positioning and has evolved thanks to the development of advanced surgical aids, such as robotics. The term “Functional Alignment” inadequately captures the 3D nature of the technique, which leverages robotic systems to dynamically optimise patello‐femoral (PF) and tibio‐femoral (TF) soft tissue balance while preserving the native ligamentous structure, often referred to as the knee's ‘DNA’. FKPos highlights the biomechanical decoupling of the PF and TF joints, ensuring proper PF and TF kinematics and addressing unique anatomical and alignment variations. Clinical outcomes for FKPos have demonstrated improved functional recovery, patient satisfaction and reduced complications compared to traditional alignment methods. Adopting the term FKPos more accurately represents the holistic and personalised nature of this innovative surgical approach to TKA.

Total knee arthroplasty after anterior cruciate ligament reconstruction with the use of image-based robotic technology and functional alignment

BACKGROUND

Total knee arthroplasty (TKA) in patients with prior anterior cruciate ligament reconstruction (ACLR) presents unique challenges due to altered knee kinematics, residual instability, and fixation implants that may interfere with implant positioning. Image-based robotic-assisted TKA enables the functional alignment (FA) strategy that accounts for individual bony anatomy, ligamentous laxities, and anterior compartment characteristics.

SURGICAL TECHNIQUE

This technique involves a CT-based robotic workflow where femoral and tibial components are planned based on patient-specific alignment and soft tissue balance. Intraoperative assessment with a digital tensioning device guides fine-tuning of flexion and extension gaps, ensuring balanced implant positioning while minimizing soft tissue releases. Fixation implants from prior ACLR are identified using robotic navigation, allowing for targeted adjustments such as selective removal or controlled elevation of components to avoid excessive bone loss. Patellar tracking is dynamically evaluated with a probe, facilitating real-time adjustments to optimize mediolateral tracking and anterior offset.

DISCUSSION

Given the altered biomechanics in post-ACLR knees, FA may provide a physiological alignment by accommodating native laxities and reducing the risk of residual instability. Additionally, robotic guidance allows for precise management of fixation implants, ensuring optimal implant positioning and bone preservation. While further studies are needed, robotic-assisted FA represents a promising approach for enhancing outcomes in TKA for post-ACLR patients.

Comparative study of a single design of total knee arthroplasty inserted with or without a robotic system based on control of ligament balance: Accuracy and functional outcome at 1 year

INTRODUCTION

Robotic systems are helping to improve surgical precision with the aim of improving the functional outcome of total knee arthroplasty (TKAs). The OMNIBotics system is a semi-autonomous robotic system combining a dynamic ligament tensor and a robotic cutting guide for personalized ligament balancing. To our knowledge, there is no single-operator comparative series evaluating the contribution of this system. A retrospective comparative study was therefore carried out to compare, for the same prosthesis and operator: (1) the precision of the OMNIBotics system versus conventional ancillary equipment, (2) the functional results at 1 year postoperative for each groups.

HYPOTHESIS

The OMNIBotics system would be more accurate than the mechanical ancillary for performing planned alignments by reducing the number of outliers and would allow a significant improvement in functional scores at 1 year postoperative.

MATERIAL AND METHODS

A total of 106 patients were retrospectively included between October 2017 and December 2021; 53 patients (34 women, 19 men) underwent TKA using the OMNIBotics system (OMNI group) and 53 patients (41 women, 12 men) underwent TKA using conventional mechanical ancillary (Non OMNI group). The two groups were comparable (gender, Body Mass Index (BMI), American Society of Anesthesiologist (ASA) score, deformity, preoperative Oxford score) except for age. All patients underwent a full length X-ray of the lower limbs at 3 months post-operatively to calculate the postoperative Hip Knee Ankle (HKA) angle. This was compared with the planned HKA angle, which was different for the two groups (defined by the software for the OMNI group, equal to 180 ° for the Non OMNI group). All patients responded to an Oxford score preoperatively and then to an Oxford score and Forgotten Joint Score (FJS) at 1 year postoperative.

RESULTS

The number of patients with a difference ≤1 ° between measured and planned HKA angle was significantly higher (p = 0.032) in the OMNI group (60%, n = 32) than in the non-OMNI group (40%, n = 21). The OMNI group also had significantly fewer outliers (measured HKA angle >3° of the planned HKA angle) than the non-OMNI group (94%, n = 50 versus 81%, n = 43, p = 0.038). Postoperative Oxford and Forgotten Knee scores were significantly better in the OMNI group with a mean value of 38.4 ± 6.7 [range, 24-48] and 70.7 ± 22.5 [range 9-100] for Oxford and FJS scores in the OMNI group versus 33.5 ± 10.1 [range 8-45] and 56.9 ± 22.7 [range 8-100] for the Non OMNI group (p = 0.004 and 0.002 respectively).

CONCLUSION

The OMNIBotics is a non-imaging robotic assistance system which, after analysis of the ligament balance, enables accurate reproduction of the planning carried out, improving the patient's functional result at one year compared to a conventional ancillary system.

LEVEL OF EVIDENCE

III; Retrospective comparative study.

The incidence and clinical significance of incidental findings seen on pre-operative CT planning scans for hip and knee robotic arthroplasty surgery

AIM

The incidence and clinical significance of incidental findings identified on preoperative computerised tomography (CT) planning scans for hip and knee robotic arthroplasty is disputed. This study aimed to determine this within a single hip and knee arthroplasty unit.

METHODS

A retrospective cohort study was performed for all patients that underwent CT planning scans for hip or knee arthroplasty at our institution over a 30-month period (Dec 2021-May 2024). CT scan reports were reviewed and incidental findings noted. Incidental findings were graded by independent reviewers into one of three categories: no action required, further action may be considered, urgent action required e.g. potential malignancy.

RESULTS

1452 CT arthroplasty planning scans were identified over a 30-month period. A radiologist report was not provided in 48 (3.3 %) cases, leaving 1404 (96.7 %) available for further analysis. 592 (42.2 %) incidental findings were noted, of which 244 (17.4 %) were graded further action may be considered and 16 (1.1 %) urgent action required. All patients identified as urgent action required received appropriate management.

CONCLUSION

Pre-operative CT arthroplasty planning scans have a high incidence (N = 592, 42.2 %) of incidental findings, most of which most require no further management. A significant proportion (N = 244, 17.4 %) of scans have incidental findings for which further action may be considered, whilst a small proportion (N = 16, 1.1 %) have incidental findings for which urgent action is required. Pre-operative CT planning scans should be reported by a radiologist due to the high incidence of significant incidental findings.

Restoring native posterior tibial slope within 4° leads to better clinical outcomes after cruciate-retaining robot-assisted total knee arthroplasty with functional alignment

PURPOSE

The impact of posterior tibial slope (PTS) on clinical outcomes after robot-assisted total knee arthroplasty (RTKA) with functional alignment (FA) remains unclear. This study aimed to evaluate the effect of PTS on clinical outcomes following RTKA with FA.

METHODS

A prospectively collected database was retrospectively reviewed for patients who underwent primary cruciate-retaining RTKA (CR-RTKA) with FA using the MAKO robotic system, with a minimum 1-year follow-up. Knees were categorized into two groups: the small change (SC) group (n = 47) with a small PTS change (<4°) and the large change (LC) group (n = 53) with a large PTS change (≥4°). PTS change was defined as differences between pre- and post-operative PTS values. At the 1-year follow-up, clinical outcomes including Knee Society Score (KSS), Western Ontario and McMaster University Index (WOMAC), Forgotten Joint Score-12 (FJS-12) and post-operative complications were compared between groups. A multiple linear regression analysis was conducted to identify independent factors influencing post-operative WOMAC scores.

RESULTS

The SC group demonstrated significantly better post-operative clinical outcomes than the LC group (KSS-functional score: 85.63 ± 13.00 vs. 77.08 ± 18.39, p = 0.026; WOMAC: 10.46 ± 5.36 vs. 16.98 ± 10.69, p < 0.001; FJS-12: 75.94 ± 21.96 vs. 61.37 ± 26.61, p = 0.019). In multivariate regression analysis, PTS change was identified as an independent factor correlated with the post-operative WOMAC score (β: 0.842, p = 0.001). No post-operative complications were observed in either group during the follow-up period.

CONCLUSIONS

Restoring the native PTS within 4° leads to better clinical outcomes following CR-RTKA with FA without post-operative complications for up to 1 year. Therefore, efforts to restore the native PTS are critical for achieving optimal short-term clinical outcomes after CR-RTKA with FA.

LEVEL OF EVIDENCE

Level III.

Accuracy and clinical outcomes in total knee arthroplasty using an image-free navigation system

INTRODUCTION

The purpose of this study was to investigate the accuracy of an image-free navigation system and to investigate the effect of the postoperative coronal lower limb alignment and implant alignment on clinical outcomes following mechanically aligned (MA)-total knee arthroplasty (TKA).

MATERIALS AND METHODS

In this retrospective study, 180 primary cemented posterior-stabilized TKAs were performed using an image-free navigation system. Patients were divided into groups based on their postoperative hip-knee-ankle angle (HKA; a neutral HKA group [0 ± 3°] and an outlier group [<-3° or > 3°]), lateral distal femoral angle (LDFA; a neutral LDFA group [90 ± 3°] and an outlier group [< 87° or > 93°]), and medial proximal tibial angle (MPTA; a neutral MPTA group [90 ± 3°] and an outlier group [< 87° or > 93°]). The range-of-motion, 2011 Knee Society score (2011 KSS), and Forgotten Joint Score-12 (FJS-12) were compared between the neutral and outlier groups at 1 and 2 years postoperatively.

RESULTS

The percentage of knees with a neutral HKA was 91.1% and clinical outcomes significantly improved postoperatively. No significant differences were detected between the neutral HKA (n = 164) and outlier groups (n = 16, all varus) for any clinical outcome. Considering LDFA, the outlier group was too small (n = 3, all varus) for statistical analysis. The overall 2011 KSS and symptoms at 2 years postoperatively and FJS-12 at 1 and 2 years postoperatively were significantly higher in the neutral MPTA group (n = 174) than in the outlier group (n = 6, all varus).

CONCLUSIONS

The accuracy of an image-free navigation system was satisfactory in MA-TKA and led to good clinical outcomes. No significant differences in clinical outcome were detected between postoperative patients with an HKA within 3° of the neutral position and postoperative patients with an HKA <-3°. Patients with a postoperative MPTA within 90 ± 3° achieved better clinical outcomes than those of patients with an MPTA < 87°.

The John N. Insall Award: Functional Versus Mechanical Alignment in Total Knee Arthroplasty: A Randomized Controlled Trial

BACKGROUND

Mechanical alignment (MA) in total knee arthroplasty is regarded as a gold standard; however, some patients report dissatisfaction postsurgery. Functional alignment (FA) is a potential alternative, integrating kinematic alignment (KA) principles with preresection bone balancing within defined boundaries. The use of FA aims to improve outcomes by restoring native joint lines and optimizing soft-tissue balance. However, comparative evidence is limited.

METHODS

This prospective, randomized controlled trial compared MA (n = 121) and FA (n = 123) in robotic-assisted total knee arthroplasty. For MA, components were positioned perpendicular to the limb mechanical axis, with soft-tissue releases to achieve balance. For FA, initial virtual component positioning was used to match native knee anatomy, with adjustments for soft-tissue balance before bone cuts. The primary outcome was the forgotten joint score (FJS). Outcomes were compared with a mixed-model analysis of variance.

RESULTS

At the 2-year follow-up, the mean FJS was comparable (MA: 64.4 ± 30.1 versus FA: 70.1 ± 25.6, P = 0.10). The MA cases had more soft-tissue releases than FA (65 versus 16%, P < 0.001). Compared to MA patients, FA patients had higher Knee Injury and Osteoarthritis Outcome (KOOS) Symptoms (86.6 ± 12.9 versus 82.5 ± 14.0, P = 0.01) and KOOS-Quality of Life scores (76.1 ± 20.3 versus 70.7 ± 22.7, P = 0.03). More FA patients "would recommend" the procedure (94 versus 82%, P < 0.01). For patients who had preoperative Coronal Plane Alignment of the Knee Type I, FA had higher FJS (71.3 ± 24.8 versus 56.8 ± 31.6, P = 0.02) and KOOS-Quality of Life (76.4 ± 21.7 versus 64.2 ± 19.2, P = 0.02) than MA. No other differences were seen in patient-reported outcomes (Oxford Knee Score, KOOS, EuroQol-5 Dimensions, Pain Visual Analog Scale), clinical outcomes (length of stay, functional physio tests), reoperations, or implant survivorship (FA: 1 versus MA: 0 revisions).

CONCLUSIONS

While FA required fewer soft-tissue releases compared to mechanical alignment, at 2 years patient-reported and clinical outcomes were similar. The use of FA may provide improved outcomes for a specific subgroup of patients based on their preoperative alignment.

Functional alignment is a feasible alignment strategy in robotic assisted total knee arthroplasty for knee osteoarthritis with extra-articular deformity - A case series

INTRODUCTION

Extraarticular deformity (EAD) with knee arthritis is a complex condition involving tri-planar bone deformity with pathological malalignment and chronic soft tissue contracture or laxity in the knee joint. Intraarticular correction by TKA, which was previously performed with conventional manual jig by mechanical alignment technique, had its limits and difficulties especially extensive soft tissue release and risk of jeopardizing the collateral ligaments. Robotic technology allows for reproducible and precise execution of surgical plan and allows adjustment to various new personalised alignment philosophy including functional alignment (FA). FA technique involves the adjustment of components positioning that least compromise the soft tissue envelope while restoring the limb alignment and joint obliquity to create a balanced knee. The aim is to study the outcome of intra-articular correction by robotic assisted TKA using Functional Alignment (FA) technique.

METHODOLOGY

This is a single surgeon series of 8 patients with extraarticular deformity who underwent robotic assisted total knee arthroplasty (TKA) with FA technique. Soft tissue release was gradually released and followed by adjustments of implant positioning in order to achieve a balanced medio-lateral gap.

RESULTS

Postoperatively, the lower limb alignment of all patients were restored within 6° (mean 4.54°) based on functional alignment boundaries. Knee phenotype and joint line obliquity (JLO) were restored in comparison to contralateral lower limb. There were 6 varus and 2 valgus malalignment. 7 patients were implanted with posterior stabilized implants while 1 was implanted with cruciate retaining implant. Arc of knee flexion and extension improved (P = 0.002). There was a large postoperative improvement in the Knee Society Score (KSS) (P < 0.001).

DISCUSSION

Intraarticular correction by TKA for EAD with knee arthritis is technically reliable with robotic technology. It allows intraoperative adjustment following functional alignment philosophy, thereby, restoring pre-arthritic alignment, knee phenotype and joint line obliquity.

[Digital tools in primary total knee arthroplasty-Prevalence in the German-speaking region]

BACKGROUND

Digital tools are being increasingly used worldwide in primary knee arthroplasty. This study aimed to analyze the utilization density of digital tools, the preferred alignment strategies, and the obstacles and benefits of implementing these technologies in German-speaking countries.

MATERIALS AND METHODS

An online survey with 57 questions about digital tools in primary knee arthroplasty and their usage was conducted among members of the Arthroplasty Working Group (AE). The survey included questions on navigation, robotics, patient-specific instruments, individualized implants, and augmented reality.

RESULTS

The survey revealed that 18% of hospitals use navigation and 17% use robotic systems in primary total knee arthroplasty surgery. The main reasons for not implementing supportive technologies were high acquisition and ongoing costs, as well as longer surgical duration. Patient-specific instruments and individualized implants currently play a minor role. Patient-specific alignment strategies, such as kinematic (navigation: 35%; robotics: 44%) and functional alignment (navigation: 15%; robotics: 35%), are preferred in this context. With conventional instrumentation predominantly mechanical alignment was applied (79%).

DISCUSSION

The results indicate a relatively high utilization density of digital tools, which are mainly used to perform personalized alignment strategies in primary knee arthroplasty in German-speaking countries. This was particularly evident in high-volume hospitals. Economic aspects were the main reasons for not using these technologies. Future developments should aim to simplify the systems and thus achieve improved cost efficiency.

Trends and epidemiology in robotic-assisted total knee arthroplasty: Reduced complications and shorter hospital stays

INTRODUCTION

This study provides an in-depth analysis of the immediate postoperative outcomes and implications or robotic-assisted total knee arthroplasty (RA-TKA) compared with conventional TKA (C-TKA), particularly with regard to mortality, complications, hospital stay and costs, drawing from a comprehensive nationwide data set.

METHODS

The Nationwide Inpatient Sample (NIS) database, the largest all-payer inpatient healthcare database in the United States, was used to identify all patients who underwent RA-TKA or C-TKA from 2016 to 2019. A total of 527,376 cases, representing 2,638,679 patients who underwent elective TKA were identified, of which 88,415 had RA-TKA. To mitigate potential variations and selection bias in baseline characteristics between the two groups, a propensity score-matched analysis was employed to further balance and refine our data set, resulting in 176,830 patients evenly distributed between the groups. Analysis was performed according to demographics, immediate post-operative complications, and economic data, including payor class, length of stay and total charges.

RESULTS

There was a marked shift towards RA-TKA, from an initial 0.70% in 2016 to a notable 7.30% by 2019. Patients who underwent RA-TKA were slightly younger (66.2 ± SD years), compared to the C-TKA group (66.7 ± SD years). Hospital stay was 1.89 days and 2.29 days for RA-TKA and C-TKA, respectively. Charges metrics revealed slightly higher charges for RA-TKA. Less postoperative complications were found in the RA-TKA group, such as blood loss, anaemia, acute kidney injury, venous thromboembolism, pulmonary embolism, pneumonia and surgical wound complication. Even following the propensity score matching, these findings remained consistent and statistically significant.

CONCLUSIONS

RA-TKA use in the United States has grown substantially in the last few years and has been associated with significantly reduced immediate post-operative complications and length of hospital stay compared to C-TKA, offering safer surgical management for TKA patients. Further studies on the short- and long-term outcomes of RA-TKA would improve the understanding of the full potential of this technology.

LEVELS OF EVIDENCE

Level III.

A new gap balancing technique with functional alignment in total knee arthroplasty using the MAKO robotic arm system: a preliminary study

BACKGROUND

Gap tension is an important factor influencing the clinical outcomes of total knee arthroplasty (TKA). Traditional mechanical alignment (MA) places importance on neutral alignment and often requires additional soft tissue releases, which may be related to patient dissatisfaction. Conversely, the functional alignment requires less soft tissue release to achieve gap balance. Conventional gap tension instruments present several shortcomings in practice. The aim of this study is to introduce a new gap balancing technique with FA using the modified spacer-based gap tool and the MAKO robotic arm system.

METHODS

A total of 22 consecutive patients underwent primary TKA using the MAKO robotic arm system. The gap tension was assessed and adjusted with the modified spacer-based gap tool during the operation. Patient satisfaction was evaluated post-operatively with a 5-point Likert scale. Clinical outcomes including lower limb alignment, Knee Society Score (KSS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC) were recorded before surgery, 3 months and 1 year after surgery.

RESULTS

The range of motion (ROM) was significantly increased (p < 0.001) and no patients presented flexion contracture after the surgery. KSS and WOMAC score were significantly improved at 3 months and 1 year follow-up (p < 0.001 for all). During the surgery, the adjusted tibial cut showed more varus than planned and the adjusted femoral cut presented more external rotation than planned (p < 0.05 for both). The final hip-knee-ankle angle (HKA) was also more varus than planned (p < 0.05).

CONCLUSIONS

This kind of spacer-based gap balancing technique accompanied with the MAKO robotic arm system could promise controlled lower limb alignment and improved functional outcomes after TKA.

The effect of different alignment strategies on trochlear orientation after total knee arthroplasty

PURPOSE

When planning and delivering total knee arthroplasty (TKA), there are multiple coronal alignment strategies such as functional alignment (FA), kinematic alignment (KA), mechanical and adjusted mechanical alignment (MA, aMA). Recent three-dimensional and robotic-assisted surgery (RAS) studies have demonstrated that KA potentially better restores the trochlear anatomy than MA. The purpose of this study was to compare the restoration of the native trochlear orientation in patients undergoing RAS TKA using four different alignment strategies. It was hypothesised that FA would result in the lowest number of outliers.

METHODS

This is a prospective study of 200 patients undergoing RAS-TKA with a single implant. All patients were analysed for MA and KA prebalancing, and 157 patients received aMA and 43 patients FA with intraoperative balancing. Preoperative transverse computed tomography scans were used to determine the posterior condylar axis (PCA), lateral trochlear inclination (LTI) angle, sulcus angle (SA) and anterior trochlear line (ATL) angle. Implant measurements were obtained using a photographic analysis. Intraoperative software data combined with implant data and preoperative measurements were used to calculate the differences. Outliers were defined as ≥3° of alteration. Trochlea dysplasia was defined as LTI < 12°.

RESULTS

Native transepicondylar PCA had a median of 2°, LTI 18°, SA 137°, ATL 4°. LTI outliers were observed in 47%-60% of cases, with KA < FA < aMA < MA. For ATL, the range of outliers was 40.5%-85%, KA < FA < aMA < MA. SA produced 81% of outliers. Of all median angle values, only LTI when using KA was not significantly altered compared to the native knee.

CONCLUSION

There is a significant alteration of trochlear orientation after TKA, regardless of the alignment strategy used. KA produced the lowest, but a substantial, number of outliers. The uniform design of implants causes the surgeon to compromise on balance in flexion versus trochlear position. The clinical relevance of this compromise requires further clinical investigations.

LEVEL OF EVIDENCE

Level II, prospective cohort study.

Robotic assisted Total Knee Arthroplasty (TKA) is not associated with increased patient satisfaction: a systematic review and meta-analysis

PURPOSE

Total knee arthroplasty (TKA) is a common orthopedic surgery, yet postoperative dissatisfaction persists in around 20% of cases. Robotic total knee arthroplasty (rTKA) promises enhanced precision, but its impact on patient satisfaction compared to conventional TKA remains controversial (cTKA). This systematic review aims to evaluate patient satisfaction post-rTKA and compare outcomes with cTKA.

METHODS

Papers from the following databases were identified and reviewed: PubMed, Scopus, Web of Science, and the Cochrane Online Library, using keywords like "Knee replacement," "Total knee arthroplasty," "Robotic," and "Patient satisfaction." Extracted data included patient satisfaction measures, Knee Society Score, Oxford Knee Score, Forgotten Joint Score, SF-36, HSS, and KOOS. Statistical analysis, including odds ratio and 95% CI was performed using R software. Heterogeneity was assessed using Cochrane's Q test.

RESULTS

The systematic review included 17 articles, involving 1148 patients (571 in the rTKA group and 577 in the cTKA group) assessing patient satisfaction following rTKA. An analysis of proportions reveals rTKA satisfaction rate was 95%, while for cTKA, it was 91%. A meta-analysis comparing rTKA and cTKA found no statistically significant difference in patient satisfaction. Additionally, various patient-reported outcome measures (PROMs) were examined, showing mixed results across different studies and follow-up periods.

CONCLUSIONS

The results of this study found no difference in patient satisfaction outcomes in the short to mid-term for rTKA compared to conventional methods. This study does not assert superiority for the robotic approach, highlighting the need for careful consideration of various factors influencing outcomes in knee arthroplasty.

CPAK classification cannot be used to determine segmental coronal extra-articular knee deformity

PURPOSE

While the coronal plane alignment of the knee (CPAK) classification serves as a useful guide in personalising total knee arthroplasty (TKA), the extent of its correlation with segmental coronal extra-articular knee deformities remains uncertain. This study aims to investigate the potential correlation between CPAK matrix groups and segmental coronal extra-articular deformities in prearthritic knees, shedding light on the relationship between these two factors that seems to be both essential to perform personalised TKA.

MATERIALS AND METHODS

A radiological assessment of 1240 nonarthritic knees was performed by evaluating lower limb measurements following the protocol established by Paley et al. Subsequently, all knees were classified into their respective CPAK matrix groups. In our quest to discern any correlation between the CPAK matrix groups and the presence of segmental coronal extra-articular knee deformities, nine potential coronal extra-articular deformity phenotype (CEDP) groupswere identified based on medial proximal tibial angle (MPTA) and mechanical lateral distal femoral angle (mLDFA). Neutral values for MPTA and mLDFA were set at 90.0° ± 3.0° and then at 87.0° ± 2.0°. Each CPAK matrix group underwent detailed coronal morphology analysis and then, segmental coronal extra-articular deformities were assessed by comparing them with the CEDP groups.

RESULTS

The study revealed a mean hip-knee-ankle angle (HKA) of 178.6° ± 4.4°, mLDFA of 86.9° ± 2.5°, MPTA of 85.4° ± 2.4°, arithmetic HKA of -1.4° ± 3.2° and joint line obliquity of 172.5° ± 3.7°. The varus CPAK groups (I/IV/VII) included 435 patients, the neutral groups (II/V/VIII) comprised 630 patients and the valgus groups (III/VI/IX) had 175 patients. Notably, CPAK matrix groups were not distinctly associated with specific coronal extra-articular deformity phenotype (CEDP) groups. Particularly among the most common CPAK matrix groups (I/II/III/IV/V), there was a significant variation in segmental coronal extra-articular deformity patterns. Moreover, when neutral MPTA/mLDFA values were set at 87.0° ± 2.0°, the CPAK matrix groups exhibited even greater variability in coronal extra-articular deformities.

CONCLUSION

The CPAK matrix groups do not exhibit a direct correlation with a specific extra-articular deformity pattern (CEDP), thus rendering them unsuitable for determining segmental coronal extra-articular knee deformities.

LEVEL OF EVIDENCE

Level III, retrospective diagnostic study.

Methods of alignment in total knee arthroplasty, systematic review

Introduction

Although total knee arthroplasty (TKA) is a very frequent surgery, one in five patients is not completely satisfied. Mechanical alignment (MA) is the most popular technique for implanting TKA. However, to improve clinical outcomes, new techniques that aim to rebuild the native alignment of the knee have been developed.

Objective

The aim of this study is to perform a systematic review of the available clinical trials and observational studies comparing clinical and radiological outcomes of different methods of alignment (kinematic, anatomic, functional) to MA.

Methods

A systematic review is performed comparing results of patient reported outcome measures (PROMs) questionnaires (WOMAC, OKS, KSS, KOOS, FJS), radiological angles (HKA, mLDFA, MPTA, JLOA, femoral rotation and tibial slope) and range of motion (ROM).

Results

Kinematic and functional alignment show a slight tendency to obtain better PROMs compared to mechanical alignment. Complication rates were not significantly different between groups. Nevertheless, these results are not consistent in every study. Anatomic alignment showed no significant differences compared to mechanical alignment.

Conclusion

Kinematic alignment is an equal or slightly better alternative than mechanical alignment for patients included in this study. However, the difference between methods does not seem to be enough to explain the high percentage of dissatisfied patients. Studies implementing lax inclusion and exclusion criteria would be needed to resemble conditions of patients assisted in daily surgical practice. It would be interesting to study patient's knee phenotypes, to notice if any method of alignment is significantly better for any constitutional deviation.

Impact of change in coronal plane alignment of knee (CPAK) classification on outcomes of robotic-assisted TKA

BACKGROUND

Mechanical alignment with total knee arthroplasty (TKA) has been widely used since the implantation of the first prosthetic knee. Multiple studies have reported 80% patient satisfaction with TKA. However, the reported patients' dissatisfaction is believed to be caused by having to convert different knee alignments to neutral alignments. It is postulated that a change in the CPAK classification of knees leads to patient dissatisfaction. Thus, we hypothesized that a change in CPAK classification with robot-assisted TKA with mechanical alignment does not significantly lead to patient dissatisfaction.

METHODS

We retrospectively analyzed 134 patients who underwent robot-assisted mechanical alignment total knee arthroplasty (MA-TKA) using cementless implants and classified them into CPAK system pre- and post-operatively. One year after TKA surgery, we recorded binary responses to patients' satisfaction with the outcome of surgery and analyzed if a change in CPAK classification is associated with the outcome of surgery.

RESULTS

We found that 125 out of 134 patients (93.28%) were happy with the outcome of surgery. CPAK classification was changed in 116 patients (86.57%) and maintained in 18 patients (13.43%). Our results also showed that 111 (95.7%) out of 116 patients who had a change in CPAK and 14 (77.8%) out of 18 patients who maintained their CPAK post-surgery were happy with the outcome of surgery (OR = 6.3, CI 1.741-25.17, P value = 0.019).

CONCLUSION

We concluded that changing the patient's native joint line and CPAK classification does not significantly change the outcome of surgery in terms of satisfaction. The dissatisfaction rate of 20% as published by previous researchers may be confounded by other reasons and not just due to changes in alignment and joint line.

Functional alignment maximises advantages of robotic arm-assisted total knee arthroplasty with better patient-reported outcomes compared to mechanical alignment

PURPOSE

Robotic arm-assisted total knee arthroplasty (RTKA) enables adjustment of implant position to achieve the surgeon's preferred alignment. However, the alignment concept that most effectively enhances patient satisfaction remains unclear. This study compares the clinical outcomes of patients who underwent functionally aligned RTKA (FA-RTKA), mechanically aligned conventional TKA (MA-CTKA) and mechanically aligned RTKA (MA-RTKA).

METHODS

A prospectively collected database was retrospectively reviewed for patients who underwent primary TKA for knee osteoarthritis. One hundred and forty-seven knees were performed with MA-CTKA, followed by 72 consecutive knees performed with MA-RTKA, and subsequently, 70 consecutive knees performed with FA-RTKA were enrolled. After 1:1 propensity score matching of patient demographics, 70 knees were finally included in each group. The extent of additional soft tissue release during surgery was identified, and the Coronal Plane Alignment of the Knee classification was utilised to categorise the alignment. At the 1-year follow-up, patient-reported outcomes, including the pain Visual Analogue Scale, Knee Society Score, Western Ontario and McMaster Universities Arthritis Index and Forgotten Joint Score-12, were also compared among the groups.

RESULTS

The FA-RTKA group showed significantly less additional soft tissue release than the MA-CTKA and MA-RTKA groups (15.7%, 38.6% and 35.7%, respectively; p = 0.006). Statistically significant differences in functional scores were observed in the postoperative 1-year clinical outcomes in favour of the FA-RTKA group, which had a significantly larger percentage of knees that maintained constitutional alignment and joint line obliquity than those of the other groups.

CONCLUSIONS

Functionally aligned TKA showed superior 1-year postoperative patient-reported outcomes compared with those of conventional and robotic arm-assisted mechanically aligned TKA. Therefore, the advantage of RTKA is maximised when the implant positioning is based on functional alignment. The application of RTKA with mechanical alignment has been proven ineffective in improving the clinical outcomes of patients.

LEVEL OF EVIDENCE

Level III.

Functional alignment in robotic-assisted total knee arthroplasty: a systematic review

PURPOSE

The present study systematically reviewed current evidence on functional alignment (FA) in robotic total knee arthroplasty (TKA), discussing advantages and limitations, possible pitfalls, and prospects.

METHODS

This study was conducted according to the 2020 PRISMA statement. In August 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar, and Embase with no additional filters or time constraints. All the clinical studies investigating functional alignment in robotic TKA were accessed. Only studies published in peer-reviewed journals were considered. The risk of bias was evaluated following the guidelines in the Cochrane Handbook for Systematic Reviews of Interventions. Non-randomized controlled trials (non-RCTs) were evaluated using the Risk of Bias in Nonrandomised Studies of Interventions (NRSI) (ROBINS-I) tool.

RESULTS

Data from 1198 patients (seven studies) were retrieved. The mean length of the follow-up was 17.1 ± 6.4 months. The mean age was 67.2 ± 5.4 years, and the mean BMI was 30.9 ± 2.7 kg/m2.

CONCLUSION

FA might improve resection accuracy, implant alignment, and gap balancing in TKA, and additional high-quality clinical trials are necessary to properly establish the superiority of FA to other alignment techniques in TKA. Long-term clinical trials are needed to investigate the impact of FA on implant survivorship.

LEVEL OF EVIDENCE

Level IV, systematic review and meta-analysis.

High three-dimensional accuracy of component placement and lower limb alignment using a robotic arm-assisted system and gap-balancing instrument in total knee arthroplasty

PURPOSE

It was hypothesized that robotic arm-assisted total knee arthroplasty (RA-TKA) using additionally a gap-balancing instrumentation will show high accuracy in executing the planning in femoral and tibial component placement throughout the range of knee motion (ROM) during TKA surgery.

METHODS

Prospectively collected data were analysed for patients undergoing RA-TKA. A cruciate retaining cemented design was implanted using the MAKO® robotic system. Lower limb alignment at 0°, 30°, 45°, 60° and 90° of flexion was recorded at the beginning of surgery and finally after implantation of the components. A ligament tensioner was inserted after tibial precut to measure the extension and flexion gap, and final component placement was planned based on 3D CT images. Femoral and tibial component placement was measured in all three planes.

RESULTS

A total of 104 patients were included (mean age 69.4 ± 9 years; 44 male, 60 female). The difference in component placement after planning and final implantation showed less valgus of 0.7° ± 1.4° (p < 0.001), less external rotation of 0.6° ± 1.9° (p = 0.001) and less flexion of 0.9° ± 1.8° (p < 0.001) for the femoral component. The tibial component was placed in more varus of 0.2° ± 0.9° (p = 0.056) and more posterior slope of 0.5° ± 0.9° (p < 0.001). The lower limb alignment in extension was 4.4° ± 5.2° of varus of the native knee and changed to 1.2° ± 1.9° of varus after TKA (p < 0.01).

CONCLUSION

Robotic-assisted TKA helps to achieve the target of alignment and component placement very close to the planning. It allows optimal component placement of off-the-shelf implants respecting patient's specific anatomy.

LEVEL OF EVIDENCE

Level II.

Short-term functional outcomes of robotic-assisted TKA are better with functional alignment compared to adjusted mechanical alignment

INTRODUCTION

Ligament balancing is essential to the functional outcome of total knee arthroplasty (TKA). The optimal method of alignment remains a controversial issue. The primary objective was to compare the clinical outcomes of TKA between functional and adjusted mechanical alignment techniques. The secondary objectives were to compare bone resection, robotic alignment, and radiological assessment.

MATERIALS AND METHODS

This was a retrospective case-control series comparing TKA performed with functional alignment (FA) and adjusted mechanical alignment (aMA). Sixty-four FA subjects were matched with 64 aMA controls. These two groups were matched for age, gender, body mass index (BMI), surgeon, and type of frontal deformity. Both surgical procedures were performed using the MAKO® haptic robotic system. Functional scores (Forgotten Joint Score (FJS), Knee Society Score (KSS), and Oxford Knee Score (OKS)) were measured at the final postoperative follow-up. A radiographic evaluation was performed at the same time.

RESULTS

Mean FJS were respectively 63.4 ± 25.1 [0-100] and 51.2 ± 31.8 [0-100] in FA versus aMA group (p = 0.034). Mean OKS were respectively 40.8 ± 6.3 [21-48] and 34.9 ± 11.8 [3-48] in FA versus aMA group (p = 0.027). Mean KSS were respectively 184.9 ± 17.0 [126-200] and 175.6 ± 23.1 [102-200] in FA versus aMA group (p = 0.02). The main residual symptom was "none" for 73.0% versus 57.8%, "instability" for 6.4% versus 21.9%, "Pain" for 19.1% versus 12.5%, and "effusion" for 1.6% and 7.8% respectively for FA and aMA group (p = 0.016). There were 4 complications in the FA group versus 5 in the aMA group (p > 0.999). Mean postoperative hip-knee-ankle (HKA) robotic assessment were respectively 177.3° ± 2.0 [172-180] and 178.2° ± 2.0 [173-180] for FA and aMA group (p = 0.018). The median difference between HKA robotic and HKA radiological was -3.0° (IQR = 3.0; p < 0.001).

CONCLUSION

With greater residual deformity and without release, functional alignment showed a statistically significantly better short-term clinical outcome than adjusted mechanical alignment. This difference may not be clinically significant.

Functional alignment is associated with increased incidence of pre-balance, reduced soft-tissue release, and post-operative pain compared to mechanical alignment in patients undergoing simultaneous bilateral robotic-assisted TKA

This study aimed to compare two alignment strategies in the same patient undergoing simultaneous bilateral robotic-assisted TKA (SB-RATKA): mechanical alignment (MA), the gold-standard, and functional alignment (FA), a balance-driven, personalized alignment strategy. The outcome measures included quantitative assessment of soft-tissue release, incidence of knee balance, and post-operative pain. This was a prospective, self-controlled, randomized-controlled trial involving 72 patients who underwent SB-RATKA using the MAKO® robotic system with comparable grades of deformity and pain in both knees. 65 patients were finally included with one alignment strategy done per knee, with the patients blinded to the strategy used. The study recorded the additional soft-tissue releases required, incidence of pre-balance, and daily post-operative VAS pain scores. The mean age of the study population was 57.95 years, with a female preponderance (N = 53, 81.6%). MA group had significantly more medial compartment tightness in both flexion (MA-15.6 ± 1.8; FA-17 ± 1.3) and extension (MA-14.9 ± 1.9; FA-17 ± 1.1) (p < 0.0001) compared to the FA group after dynamic balancing. 66% of knees in the FA group (N = 43) achieved pre-balance compared to 32.3% in the MA group (N = 21) (p < 0.0001). VAS scores showed a significant reduction in pain in the FA group up to 72 h post-surgery (p < 0.0001). The requirement for posteromedial release (PM), posterior capsular (PC) release, tibial reduction osteotomy (TRO), and superficial MCL pie crusting (sMCL) were significantly lower in FA (PM-22, PC-13, TRO-8, sMCL-2) compared to MA (PM-44, PC-29, TRO-18, sMCL-8). Functional alignment strategy consistently resulted in a higher incidence of knee balance with a significant reduction in soft-tissue releases and immediate post-operative pain when compared to MA in the same patient undergoing SB-RATKA. Therapeutic Level 1.

Robotic-arm assisted total knee arthroplasty is associated with comparable functional outcomes but improved forgotten joint scores compared with conventional manual total knee arthroplasty at five-year follow-up

PURPOSE

This study reports the five-year functional outcomes from a prospective cohort study comparing robotic-arm assisted total knee arthroplasty (RO TKA) versus conventional manual total knee arthroplasty (CO TKA).

METHODS

This prospective single-surgeon study included 120 patients with symptomatic end-stage knee arthritis undergoing primary TKA. This included 60 consecutive patients undergoing CO TKA followed by 60 consecutive patients undergoing RO TKA using a semi-automated robotic device. Study patients were reviewed at one, two, and five years after surgery and the following outcomes recorded: The University of California at Los Angeles activity-level (UCLA), Knee Society Score (KSS), Oxford Knee Score (OKS) Forgotten Joint Score (FJS), and any complications.

RESULTS

There were no statistical differences between RO TKA and CO TKA in the median UCLA score (p = N.S), median KSS (p = N.S), and median OKS (p = N.S) at five-year follow-up. RO-TKA was associated with statistically significant improvements in the FJS at one (p = 0.001), two (p = 0.003), and five (p = 0.025) years of follow-up compared with CO TKA. There was no statistical difference in the incidence of knee stiffness requiring manipulation under anesthesia between the two treatment groups (p = N.S).

CONCLUSION

Patients in both treatment groups had excellent functional outcomes with comparable patient reported outcomes at five-year follow-up. RO TKA was associated with statistically significant improvements in the FJS compared with CO TKA, but these differences did not reach the minimal clinically important difference at any follow-up interval. There was no overall difference in complications between the two treatment groups at five-year follow-up.

LEVEL OF EVIDENCE

II (Prospective cohort study).

Tracing the evolution of robotic-assisted total knee arthroplasty: a bibliometric analysis of the top 100 highly cited articles

Robotic-assisted surgical systems hold promise in enhancing total knee arthroplasty (TKA) outcomes and patients' quality of life. This study aims to comprehensively analyze the literature on robot-assisted total knee arthroplasty (r-TKA), providing insights into its current development, clinical application, and research trends. A systematic search was conducted in the Web of Science Core Collection (WOSCC) to identify relevant articles. Data were collected from the top 100 highly cited articles. Article evidence levels were assessed following established guidelines. Statistical analyses and visualizations were performed to reveal publication trends, citations, research hotspots, and collaborative networks. The analysis covered 100 highly cited articles meeting the research criteria, with a focus on the last five years. The United States emerged as a major contributor, with most publications and citations in the Journal of Knee Surgery and Knee Surgery Sports Traumatology Arthroscopy. Research priorities revolved around clinical outcomes, accuracy, and alignment of r-TKA. Notably, higher evidence levels correlated with more citations, indicating greater attention. Interest in and research on r-TKA is steadily increasing, with a few countries at the forefront of these endeavors. While numerous studies have already reported short- to medium-term follow-up results, it is crucial to conduct longer-term investigations to gain a more comprehensive understanding of the clinical benefits that r-TKA offers compared to conventional techniques. Through ongoing research and a greater embrace of robotic technology, we can continue to improve the quality of life for patients undergoing knee arthroplasty.

Definitions and consequences of current alignment techniques and phenotypes in total knee arthroplasty (TKA) - there is no winner yet

Dissatisfaction following total knee arthroplasty (TKA) has been extensively documented and it was attributed to numerous factors. In recent years, significant focus has been directed towards implant alignment and stability as potential causes and solutions to this issue. Surgeons are now exploring a more personalized approach to TKA, recognizing the importance of thoroughly understanding each individual patient's anatomy and functional morphology. A more comprehensive preoperative analysis of alignment and knee morphology is essential to address the unresolved questions in knee arthroplasty effectively. The crucial task of determining the most appropriate alignment strategy for each patient arises, given the substantial variability in bone resection resulting from the interplay of phenotype and the alignment strategy chosen. This review aims to comprehensively present the definitions of different alignment techniques in all planes and discuss the consequences dependent on knee phenotypes.Level of evidence V.

Image-free handheld robotic-assisted technology improved the accuracy of implant positioning compared to conventional instrumentation in patients undergoing simultaneous bilateral total knee arthroplasty, without additional benefits in improvement of clinical outcomes

PURPOSE

The purpose of this study was to compare the clinical and radiological outcomes in patients who underwent simultaneous bilateral total knee arthroplasty (SB-TKA) using either robotic-assisted TKA (RA-TKA) or conventional TKA (C-TKA).

METHODS

Included were the patients who underwent SB-TKA between January 2018 and January 2020 and had a minimum follow-up of 2 years. Of 151 patients included, 117 patients were operated using an image-free handheld robotic sculpting system (RA-TKA group) and 34 patients operated using conventional instrumentation (C-TKA group). The key outcomes noted were multiple patient-reported outcomes (PROs), adverse events, and radiological outcomes. Two investigators independently measured the radiological outcomes on pre- and post-operative radiographs in coronal plane (medial proximal tibial angle [MPTA] and anatomic lateral distal femoral angle [aLDFA]) and sagittal plane (posterior tibial slope [PTS] and posterior condylar offset [PCO]). The chi-square test was used to examine categorical variables. Student's t test was used to analyze the continuous variables.

RESULTS

Patients in both groups were similar in baseline characteristics (gender, body mass index, incidence of comorbidities, and length of hospital stay) except that RA-TKA group patients younger (66.7 ± 8.9 vs 70.4 ± 10.5, P = 0.037) than C-TKA group. The operative time was longer in RA-TKA group as compared to C-TKA (189.3 ± 37.1 vs 175.0 ± 28.2, P = 0.040). The final PROs at each were similar between the two groups (P > 0.05). The values of PROs at final follow-up in RA-TKA compared to C-TKA were VAS pain (0.4 ± 0.9 vs 0.4 ± 0.5), KOOS-JR (89.3 ± 5.8 vs 87.1 ± 5.3), and physical (55.9 ± 2.8 vs 55.4 ± 3.2), mental (61.1 ± 4.4 vs 60.2 ± 4.7) component of VR-12 scores, and KSS satisfaction (37.5 ± 1.1 vs 37.1 ± 2.2) (all P > 0.50 or non-significant [n.s.]). While one patient in RA-TKA required revision of femoral component for peri-prosthetic fracture, none of the patient in conventional group were revised (0.85% vs 0%, P = n.s.). The proportion of patients with outliers in RA-TKA group was lower for aLDFA (2.6% vs 22.1%, P < 0.01) and PTS (0% vs 35%, P < 0.01).

CONCLUSION

This comparative study in patients undergoing SB-TKA found reduction of outliers in femoral and tibial implant positioning with RA-TKA as compared to C-TKA. There were no differences in both groups for pain, function, and satisfaction at a minimum of 2 years of follow-up.

LEVEL OF EVIDENCE

III Therapeutic Study.

High degree of alignment precision associated with total knee arthroplasty performed using a surgical robot or handheld navigation

PURPOSE

The purpose of this study was to compare the precision of bony resections during total knee arthroplasty (TKA) performed using different computer-assisted technologies.

METHODS

Patients who underwent a primary TKA using an imageless accelerometer-based handheld navigation system (KneeAlign2®, OrthAlign Inc.) or computed tomography-based large-console surgical robot (Mako®, Stryker Corp.) from 2017 to 2020 were retrospectively reviewed. Templated alignment targets and demographic data were collected. Coronal plane alignment of the femoral and tibial components and tibial slope were measured on postoperative radiographs. Patients with excessive flexion or rotation preventing accurate measurement were excluded.

RESULTS

A total of 240 patients who underwent TKA using either a handheld (n = 120) or robotic (n = 120) system were included. There were no statistically significant differences in age, sex, and BMI between groups. A small but statistically significant difference in the precision of the distal femoral resection was observed between the handheld and robotic cohorts (1.5° vs. 1.1° difference between templated and measured alignments, p = 0.024), though this is likely clinically insignificant. There were no significant differences in the precision of the tibial resection between the handheld and robotic groups (coronal plane 0.9° vs. 1.0°, n.s.; sagittal plane 1.2° vs. 1.1°, n.s.). There were no significant differences in the rate of overall precision between cohorts (n.s.).

CONCLUSIONS

A high degree of component alignment precision was observed for both imageless handheld navigation and CT-based robotic cohorts. Surgeons considering options for computer-assisted TKA should take other important factors, including surgical principles, templating software, ligament balancing, intraoperative adjustability, equipment logistics, and cost, into account.

LEVEL OF EVIDENCE

III.

Navigated functional alignment total knee arthroplasty achieves reliable, reproducible and accurate results with high patient satisfaction

PURPOSE

The decision on which technique to perform a total knee arthroplasty (TKA) has become more complicated over the last decade. Perceived limitations of mechanical alignment (MA) and kinematic alignment (KA) have led to the development of the functional alignment (FA) philosophy. This study aims to report the 2-year results of an initial patient cohort in terms of revision rate, PROMs and complications for Computer Aided Surgery (CAS) Navigated FA TKA.

METHODS

This paper reports a single surgeon's outcomes of 165 consecutive CAS FA TKAs. The final follow-up was 24 months. Pre-operative and post-operative patient-reported outcome measures, WOMAC and KSS, and intra-operative CAS data, including alignment, kinematic curves, and gaps, are reported. Stress kinematic curves were analysed for correlation with CAS final alignment and CAS final alignment with radiographic long-leg alignment. Pre- and post-operative CPAK and knee phenotypes were recorded. Three different types of prostheses from two manufacturers were used, and outcomes were compared. Soft tissue releases, revision and complication data are also reported.

RESULTS

Mean pre-operative WOMAC was 48.8 and 1.2 at the time of the final follow-up. KSS was 48.8 and 93.7, respectively. Pre- and post-operative range of motion was 118.6° and 120.1°, respectively. Pre-operative and final kinematic curve prediction had an accuracy of 91.8%. CAS data pre-operative stress alignment and final alignment strongly correlate in extension and flexion, r = 0.926 and 0.856, p < 0.001. No statistical outcome difference was detected between the types of prostheses. 14.5% of patients required soft tissue release, with the lateral release (50%) and posterior capsule (29%) being the most common.

CONCLUSION

CAS FA TKA in this cohort proved to be a predictable, reliable, and reproducible technique with acceptable short-term revision rates and high PROMs. FA can account for extremes in individual patient bony morphology and achieve desired gap and kinematic targets with soft tissue releases required in only 14.5% of patients.

LEVEL OF EVIDENCE

IV (retrospective case series review).

Homogeneity in Surgical Series: Image Reporting to Improve Evidence

Good clinical practice guidelines are based on randomized controlled trials or clinical series; however, technical performance bias among surgical trials is under-assessed. The heterogeneity of technical performance within different treatment groups diminishes the level of evidence. Surgeon variability with different levels of experience-technical performance levels even after certification-influences surgical outcomes, especially in complex procedures. Technical performance quality correlates with the outcomes and costs and should be measured by image or video-photographic documentation of the surgeon's view field during the procedures. Such consecutive, completely documented, unedited observational data-in the form of intra-operative images and a complete set of eventual radiological images-improve the surgical series' homogeneity. Thereby, they might reflect reality and contribute towards making necessary changes for evidence-based surgery.