Improved accuracy of implant placement with an imageless handheld robotic system compared to conventional instrumentation in patients undergoing total knee arthroplasty: a prospective randomized controlled trial using CT-based assessment of radiological outcomes

PURPOSE

Image-free handheld robotic-assisted total knee arthroplasty (RATKA) has shown to achieve desired limb alignment compared to conventional jig-based instrumented total knee arthroplasty (CTKA). The aim of this prospective randomized controlled trial (RCT) was to evaluate the accuracy of a semi-autonomous imageless handheld RATKA compared to CTKA in order to achieve the perioperative planned target alignment of the knee postoperatively.

METHODS

Fifty-two patients with knee osteoarthritis were randomized in 1:1 ratio to undergo unilateral CTKA or an imageless handheld RATKA. A full-length lower limb CT-scan was obtained pre- and 6-week postoperative. The primary outcomes were radiologic measurements of achieved target hip-knee-ankle axis (HKA-axis) and implant component position including varus and external rotation and flexion of the femur component, and posterior tibial slope. The proportion of outliers in above radiographic outcomes, defined as > 3° deviation in postoperative CT measurements as compared to perioperative planned target, were also noted. Knee phenotypes were compared with use of the Coronal Plane Alignment of the Knee (CPAK) classification.

RESULTS

Baseline conditions were comparable between both groups. The overall proportion and percentage of outliers (n = 38, 24.4% vs n = 9, 5.8%) was statistically significant (p < 0.001) in favor of RATKA. The achieved varus-valgus of the femoral component (varus 1.3° ± 1.7° vs valgus - 0.1° ± 1.9°, p < 0.05) with statistically significant less outliers (0% vs 88.5%, p < 0.01), the achieved HKA-axis (varus 0.4° ± 2.1° vs valgus - 1.2° ± 2.1°, p < 0.05) and the posterior tibial slope (1.4° ± 1.1° vs 3.2° ± 1.8°, p < 0.05) were more accurate with RATKA. The most common postoperative CPAK categories were type II (50% CTKA vs 61.5% RATKA), type I (3.8% CTKA vs 23.1% RATKA) and type V (26.9% CTKA vs 15.4% RATKA). CPAK classification III was only found in CTKA (19.2%). Type VI, VII, VIII, and IX were rare in both populations.

CONCLUSIONS

The present trial demonstrates that an imageless handheld RATKA system can be used to accurately perioperatively plan the desired individual component implant positions with less alignment outliers whilst aiming for a constitutional alignment.

LEVEL OF EVIDENCE

I.

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.

NAVIO RATKA shows similar rates of hemoglobin-drop, adverse events, readmission and early revision vs conventional TKA: a single centre retrospective cohort study

PURPOSE

Despite widespread adoption of NAVIO robotic-assisted total knee arthroplasty (NAVIO RATKA) in clinical practice, clinical outcome in terms of adverse events and complications remains unclear. The purpose of this study was to compare adverse events, length of stay, surgical time, hemoglobin drop, early readmission rate and revision rate between conventional TKA (CTKA) and NAVIO RATKA.

METHODS

This single-centre retrospective cohort analysis compared 230 NAVIO RATKA patients to 489 CTKA patients with a minimal follow-up of 12 months. Baseline demographic and comorbidity parameters were collected, as well as length of stay, revision rate and reason for revision, early readmission rate (< 6w) and reason for readmission, post-operative hemoglobin levels, adverse events, surgical time and operating room time. Data were compared using Mann-Whitney U test for continuous data without normal distribution and ordinal data, categorical variables were compared using the Chi-square or Fisher exact test.

RESULTS

There were no clinically relevant baseline demographic or comorbidity differences between groups. CTKA had shorter length of stay than NAVIO RATKA (5.0 days vs 5.4 days, p = 0.010) but trended towards a higher reoperation rate (4.1% vs 1.7%, p = .144, n.s). No differences were found in hemoglobin drop, readmission rate or overall incidence of adverse events, but CTKA showed more hematoma formation (1.6% vs 0%, p = .044) and higher incidence of periprosthetic joint infection (PJI) (1% vs 0%, p = n.s.), whilst NAVIO RATKA showed more periprosthetic fractures and persistent wound drainage (0.4% vs 2.2%, p = .038 and 0.6% vs 4.3%, p = .001, respectively). Surgical time remained significantly longer in NAVIO RATKA during all 230 cases (87 min vs 67.6 min) and showed a continuous downward trend.

CONCLUSIONS

This study further validates the usage of NAVIO RATKA as a safe method to perform TKA, with comparable short term outcomes to CTKA in terms of early revisions and adverse events. Surgeons should be mindful of the differing adverse event profile in NAVIO RATKA and adjust their patient selection accordingly to ensure optimal outcomes. In addition, surgeons using NAVIO RATKA should expect a linear learning curve and a surgical time exceeding that of CTKA.

LEVEL OF EVIDENCE

Level III (therapeutic retrospective cohort study).

Achieving functional alignment in total knee arthroplasty: early experience using a second-generation imageless semi-autonomous handheld robotic sculpting system

PURPOSE

In order to minimize errors during achieving the targeted alignment of the total knee arthroplasty (TKA) components, robotic-assisted surgery has been introduced with the aim to help surgeons to improve implant survival, clinical outcomes, and patient satisfaction. The primary goal of this paper is to highlight surgical tips and tricks on how to achieve functional alignment (FA) through intra-operative boney mapping, numeric gap, and alignment data, using the next generation of imageless robotic surgical systems.

METHOD

This retrospective case-series contains planned and achieved data on the FA and joint gap data obtained from 526 patients captured and assessed with use of a semi-autonomous imageless handheld robotic sculpting systems. All patients were operated upon by two experienced TKA surgeons.

RESULTS

The mean difference between planned and achieved alignment was 1.46° (≥ 7° varus group), 1.02° (< 7° varus group), 1.16° (< 7° valgus group), and 1.43° (≥ 7° valgus group). The mean observed planned and achieved extension and flexion gaps were below 1.47 mm for medial extension gaps, 1.12 mm for the lateral extension gaps, 1.4 mm for the medial flexion gaps, and 1.16 mm for the lateral flexion gaps.

CONCLUSION

Analysis of these first cases highlights the capability of the next generation of imageless robotic-assisted total knee replacement using a semi-autonomous handheld robotic sculpting to maintain accuracy of the desired alignment. The system allows the surgeon to choose freely their own alignment philosophy while maintaining efficiency.

Improved joint line and posterior offset restoration in primary total knee replacement using a robotic-assisted surgical technique: An international multi-centre retrospective analysis of matched cohorts

Background

Accurate restoration of joint line height and posterior offset in primary Total Knee Arthroplasty (TKA) have been shown to be important factors in post-operative range of movement and function. The aim of this study was to assess the accuracy of joint line and posterior offset restoration in a group of patients that underwent robotic-assisted TKA (raTKA). A matched cohort of patients that underwent a TKA using a conventional jig-based technique was assessed for comparison. The null hypothesis was that there would be no difference between groups.

Methods

This study was a retrospective analysis of a cohort of 120 patients with end-stage knee osteoarthritis that received a TKA using the Navio Surgical System (n = 60), or Conventional manual TKA (n = 60). Procedures were performed between 1 January 2019 and 1 October 2019 at six different centres. Joint line height and posterior offset was measured pre-operatively and post-operatively on calibrated weight bearing plain radiographs of the knee. Two observers performed measurements using validated measuring tools. A BMI and age-matched cohort of patients that underwent TKA using a conventional technique in the same six centres were assessed for comparison. Mean values, standard deviations and confidence intervals are presented for change and absolute change in joint line height and posterior offset. Student’s t-test was used to compare the changes between techniques.

Results

Patients that underwent robotic-assisted TKA had joint line height and posterior offset restored more accurately than patients undergoing TKA using a conventional technique. Average change from pre-operative measurement in joint line height using raTKA was -0.38mm [95% CI: -0.79 to 0.03] vs 0.91 [0.14 to 1.68] with the conventional technique. Average absolute change in joint line height using raTKA was 1.96mm [1.74 to 2.18] vs 4.00mm [3.68 to 4.32] with the conventional technique. Average change in posterior offset using raTKA was 0.08mm [-0.40 to 0.56] vs 1.64mm [2.47 to 0.81] with the conventional technique. Average absolute change in posterior offset with raTKA was 2.19mm [1.92 to 2.46] vs 4.24mm [3.79 to 4.69] with the conventional technique. There was a significant difference when comparing absolute change in joint line height and posterior offset between groups (p<0.01).

Conclusion

Robotic-assisted primary TKA restores the joint line height and posterior offset more accurately than conventional jig-based techniques.

Improved joint awareness two years after total knee arthroplasty with a handheld image-free robotic system

Literature into the short-term follow-up of total knee arthroplasty (TKA) using a handheld image- free robotic system are scarce. The purpose of this study was to compare the clinical outcomes and patient-reported outcome measures (PROMs) between patients operated for TKA with an image- free robotic system (robot group) or conventionally TKA (conventional group) 2 years postoperatively. A total of 147 patients were evaluated after TKA, respectively 73 in the robot and 74 in conventional group. Outcome measures included adverse events (AEs), hospital readmission rate, patient satisfaction and the following PROMs: Pain Visual Analogue Score (VAS), Oxford Knee Score (OKS), Forgotten Joint Score Knee (FJS-12) and the EuroQOL-5D (EQ-5D). There were no statistically significant differences in the number of AEs; 8 (10.8%) in the conventional group versus 7 (9.7%) in the robot group. The FJS (p ≤ 0.05) and OKS (p ≤ 0.05) differed statistically in favour of the robot group. The EQ-5D and EQ-5D VAS did not statistically differed between the groups (p=0.231 and p=0.373 respectively). The VAS pain improved statically significant in both groups when comparing the pre- and postoperative values (5.8 points). Patients operated with a handheld image-free robotic system have the ability to forget their artificial knee joint in everyday life as measured with the FJS-12 at short-term follow-up.

Injuries in male versus female soccer players: epidemiology of a nationwide study

The aim of this study is to analyse soccer injuries on a national scale over one decade and to compare injury rates by gender. Detailed injury data obtained from the Royal Belgian Football Association from seasons 1999-2000 and 2009-2010 were recorded and gender differences in incidences of injuries, type of injury, affected body part and timing of injury were compared. A significant decrease in injuries from 7.56 to 5.96 injuries per 100 players was seen (p<0.0001). Overall male players sustained more cont usions, fractures, joint dislocations and musculotendinous injuries than female players. Proportionally, females sustained more severe injuries than men (p<0.0001). Significantly more injuries where sustained during competition in both males and females. The number of injuries in male and female soccer players has decreased over the past decade. A higher injury rate was seen in men but proportionally, females sustained more severe injuries.

The effectiveness of preventive programs in decreasing the risk of soccer injuries in Belgium: national trends over a decade

BACKGROUND

Although characterized by a relatively high injury rate, soccer is the world's most popular sport. In Belgium, the national Royal Belgian Football Association involves about 420,000 licensed players, whose injury reports are collected in a nationwide registry. Over a period of 10 years, the association has introduced the Fédération Internationale de Football Association preventive programs and has initiated a stringent postponement policy of competition in case of nonoptimal weather conditions.

HYPOTHESIS

The authors questioned whether these preventive programs effectively decreased the incidence of soccer-related injuries.

STUDY DESIGN

Descriptive epidemiology study.

METHODS

The authors compared the incidence, location, timing, and severity of all registered soccer injuries in Belgium during 2 complete seasons separated by a decade (1999-2000 vs 2009-2010).

RESULTS

A total of 56,364 injuries were reported, with an average of 6.8 injuries per 100 players per season. There was a 21.1% reduction in injury rate in the second season (rate ratio = 0.789; 95% confidence interval, 0.776-0.802), predominantly caused by a significant reduction in injuries during the winter period. In both seasons, an injury peak was noted during the first 3 months of the season. Recreational players had a higher risk for injury than national-level players (7.2 vs 4.4 injuries per 100 players per season; rate ratio = 1.64; 95% confidence interval, 1.59-1.69). The relative proportion of severe injuries was higher for female players and male youth players in general.

CONCLUSION

The introduction of injury preventive programs has led to a significant reduction of soccer-related injuries, especially during the winter period. However, there is still room for improvement, and preventive programs can become more effective when specific parameters are targeted, such as adequate conditioning of players in the preseason.

The incidence of knee and anterior cruciate ligament injuries over one decade in the Belgian Soccer League

In an epidemiological study we assessed the evolution in the incidence and possible risk factors of knee injuries, especially anterior cruciate ligament (ACL) injuries, in Belgian soccer over one decade. Two soccer seasons (1999-2000 and 2009-2010) were compared and 56,364 injury reports registered by the KBVB-URBSFA were retrieved. Knee injuries totaled 9.971 cases, 5.495 in the first season (1999-2000) and 4.476 in the second (2009-2010): a significant decrease in incidence from 1.5 per 100 players in 2000 to 1.2 knee injuries in 2010. Six percent of all knee injuries were ACL injuries. The reported incidence of ACL tears slightly increased from 0.081 to 0.084 per 100 players. Female gender, competition and age over 18 years were prognosticators for ACL injuries. Enhanced prevention programs for ACL injuries, especially in those sports groups are warranted.

Predictive factors for functional outcome and failure in angular stable osteosynthesis of the proximal humerus

INTRODUCTION

Angular stable osteosynthesis has become the gold standard in the operative treatment of proximal humeral fractures. The aim of this article is to determine the indications for osteosynthesis versus primary arthroplasty based on clinical and radiological parameters.

METHODS

A total of 368 surgically treated proximal humeral fractures were reviewed. Preoperative X-rays were used to evaluate the displacement and vascularity of the humeral head (according to the Hertel criteria) and the AO (Arbeitsgemeinschaft für Osteosynthesefragen) fracture type. Postoperative X-rays were analysed to assess the quality of the reduction, the reconstruction of the medial hinge and the displacement of the tuberosities. Follow-up X-rays were used to evaluate healing progress, the occurrence of avascular necrosis, loss of reduction and implant related failures. The American Shoulder and Elbow Surgeons score (ASES score) was used to evaluate the functional outcome. Correlations between a set of variables, type of treatment and eventual outcome were verified in both univariate and multivariate settings, with the significance rate set at p<0.05.

RESULTS

In total, 307 shoulders were evaluated. Mean follow-up was 4.3 years and showed a 15.3% failure rate, a 23.8% re-operation rate and a mean ASES score of 75.3. Better results were noted in patients who were younger at the time of surgery. More displaced fractures, AO type C fractures, varus fracture configuration and reduced head vascularity all led to a worse outcome. Anatomical reduction correlated with better results. Articular fractures had better results when treated with a plate.

CONCLUSION

Surgical treatment of proximal humeral fractures remains difficult, with a failure rate of 15.3% and a re-operation rate of 23.8% at 4.3 years. A significantly displaced varus articular fracture in the older patient results in the worst outcome.

Femoral component loosening in high-flexion total knee replacement

High-flexion total knee replacement (TKR) designs have been introduced to improve flexion after TKR. Although the early results of such designs were promising, recent literature has raised concerns about the incidence of early loosening of the femoral component. We compared the minimum force required to cause femoral component loosening for six high-flexion and six conventional TKR designs in a laboratory experiment.

Each TKR design was implanted in a femoral bone model and placed in a loading frame in 135° of flexion. Loosening of the femoral component was induced by moving the tibial component at a constant rate of displacement while maintaining the same angle of flexion. A stereophotogrammetric system registered the relative movement between the femoral component and the underlying bone until loosening occurred.

Compared with high-flexion designs, conventional TKR designs required a significantly higher force before loosening occurred (p < 0.001). High-flexion designs with closed box geometry required significantly higher loosening forces than high-flexion designs with open box geometry (p = 0.0478). The presence of pegs further contributed to the fixation strength of components.

We conclude that high-flexion designs have a greater risk for femoral component loosening than conventional TKR designs. We believe this is attributable to the absence of femoral load sharing between the prosthetic component and the condylar bone during flexion.

Liver tuberculosis mistaken for malignancy. The role of needle biopsy

Despite advances in imaging techniques rare or atypical liver lesions still pose a diagnostic challenge. In many centres percutaneous fine needle aspiration cytology or biopsy is routinely performed in order to obtain a definitive diagnosis. However because of the risk of tumour seeding along the needle tract this attitude may jeopardize the patient's chances for cure in case of malignancy. The role of percutaneous liver biopsy is reappraised in the light of an observation in which major hepatectomy was performed for suspected neoplasia only to discover at pathology that the lesion was a benign tuberculosis pseudotumour.