Computer-assisted and robotic surgery in orthopedics: where we are in 2014

Robotic Surgery: A Comprehensive Review of the Literature and Current Trends

Robotic surgery (RS) is an evolution of minimally invasive surgery that combines medical science, robotics, and engineering. The first robots approved by the Food and Drug Administration (FDA) were the Da Vinci Surgical System and the ZEUS Robotic Surgical System, which have been improving over time. Through the decades, the equipment applied to RS had undergone a wide transformation as a response to the development of new techniques and facilities for the assembly and implementation of the own. RS has revolutionized the field of urology, enabling surgeons to perform complex procedures with greater precision and accuracy, and many other surgical specialties such as gynecology, general surgery, otolaryngology, cardiothoracic surgery, and neurosurgery. Several benefits, such as a better approach to the surgical site, a three-dimensional image that improves depth perception, and smaller scars, enhance range of motion, allowing the surgeon to conduct more complicated surgical operations, and reduced postoperative complications have made robotic-assisted surgery an increasingly popular approach. However, some points like the cost of surgical procedures, equipment-instrument, and maintenance are important aspects to consider. Machine learning will likely have a role to play in surgical training shortly through "automated performance metrics," where algorithms observe and "learn" individual surgeons' techniques, assess performance, and anticipate surgical outcomes with the potential to individualize surgical training and aid decision-making in real time.

A systematic review on the cost-effectiveness of the computer-assisted orthopedic system

Computer-assisted orthopedic system (CAOS) is rapidly gaining popularity in the field of precision medicine. However, the cost-effectiveness of CAOS has not been well clarified. We performed this review to summarize and assess the cost-effectiveness analyses (CEAs) with regard to CAOS. Publications on CEA in CAOS have been searched in PubMed and CEA Registry up to May 31, 2022. The Quality of Health Economic Studies (QHES) instrument was used to estimate the quality of studies. Relationships between qualities and potential factors were also examined. There were 15 eligible studies in the present review. Twelve studies evaluated CAOS joint arthroplasties and found that CAOS joint arthroplasties were cost-effective compared to manual methods. Three studies focused on spinal surgery, two of which analyzed the cost-effectiveness of CAOS for patients after spinal fusion, with conflicting results. One study demonstrated that CAOS was cost-effective in spinal pedicle screw insertion. The mean QHES score of CEAs included was 86.1. The potential factors had no significant relationship with the quality of studies. Based on available studies, our review reflected that CAOS was cost-effective in the field of joint arthroplasty. While in spinal surgery, the answer was unclear. Current CEAs represent high qualities, and more CEAs are required in the different disciplines of orthopedics where CAOS is employed.

Feasibility and accuracy of orthopaedic surgical robot system for intraoperative navigation to locate bone tunnel in anterior cruciate ligament reconstruction

BACKGROUND

The combination of navigational system and robotics has the potential to accurately identify and drill bone tunnels in anterior cruciate ligament (ACL) reconstruction. This study explores the feasibility and accuracy of bone tunnel positioning using the TiRobot, an orthopaedic surgical robot.

METHODS

The experiment was divided into two groups. In group A, the bone tunnels were positioned using the TiRobot surgical robot (n = 8). In group B, handheld locators were used for positioning (n = 8).

RESULTS

TiRobot can be used for positioning the ACL bone tunnel. The accuracy of positioning the femoral tunnel in group A and B was 1.00 ± 0.20 and 3.10 ± 0.59 mm, respectively (t = -9.49, P < 0.001). As for tibial tunnel, the accuracy was 1.02 ± 0.20 and 2.64 ± 0.14 mm, respectively (t = -18.54, P < 0.001).

CONCLUSIONS

The bone tunnel drilling precision using TiRobot for ACL reconstruction surgery was more accurate than traditional surgical techniques.

Current and future of anterior cruciate ligament reconstruction techniques

In recent years, anterior cruciate ligament (ACL) reconstruction has generally yielded favorable outcomes. However, ACL reconstruction has not provided satisfactory results in terms of the rate of returning to sports and prevention of osteoarthritis (OA) progression. In this paper, we outline current techniques for ACL reconstruction such as graft materials, double-bundle or single-bundle reconstruction, femoral tunnel drilling, all-inside technique, graft fixation, preservation of remnant, anterolateral ligament reconstruction, ACL repair, revision surgery, treatment for ACL injury with OA and problems, and discuss expected future trends. To enable many more orthopedic surgeons to achieve excellent ACL reconstruction outcomes with less invasive surgery, further studies aimed at improving surgical techniques are warranted. Further development of biological augmentation and robotic surgery technologies for ACL reconstruction is also required.

Reduced postoperative morbidity in computer-navigated total knee arthroplasty: A retrospective comparison of 225,123 cases

BACKGROUND

Total knee arthroplasty (TKA) is one of the most common elective surgical procedures in the United States, with more than 650,000 performed annually. Computer navigation technology has recently been introduced to assist surgeons with planning, performing, and assessing TKA bone cuts. The aim of this study is to assess postoperative complication rates after TKA performed using computer navigation assistance versus conventional methods.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried for unilateral TKA cases from 2008 to 2016. The presence of the CPT modifier for use of computer navigation was used to separate cases of computer-navigated TKA from conventional TKA. Multivariate and propensity-matched logistic regression analyses were performed to control for demographics and comorbidities.

RESULTS

There were 225,123 TKA cases included; 219,880 were conventional TKA (97.7%) and 5,243 were navigated (2.3%). Propensity matching identified 4,811 case pairs. Analysis demonstrated no significant differences in operative time, length of stay, reoperation, or readmission, and no differences in rates of post-op mortality at 30 days postoperatively. Compared to conventional cases, navigated cases were at lower risk of serious medical morbidity (18% lower, p = 0.009) within the first 30 days postoperatively.

CONCLUSION

After controlling for multiple known risk factors, navigated TKA patients demonstrated lower risk for medical morbidity, predominantly driven by lower risk for blood transfusion. Given these findings, computer-navigation is a safe surgical technique in TKA.

Can robotic technology mitigate the learning curve of total hip arthroplasty?

Aims

Traditionally, acetabular component insertion during total hip arthroplasty (THA) is visually assisted in the posterior approach and fluoroscopically assisted in the anterior approach. The present study examined the accuracy of a new surgeon during anterior (NSA) and posterior (NSP) THA using robotic arm-assisted technology compared to two experienced surgeons using traditional methods.

Methods

Prospectively collected data was reviewed for 120 patients at two institutions. Data were collected on the first 30 anterior approach and the first 30 posterior approach surgeries performed by a newly graduated arthroplasty surgeon (all using robotic arm-assisted technology) and was compared to standard THA by an experienced anterior (SSA) and posterior surgeon (SSP). Acetabular component inclination, version, and leg length were calculated postoperatively and differences calculated based on postoperative film measurement.

Results

Demographic data were similar between groups with the exception of BMI being lower in the NSA group (27.98 vs 25.2; p = 0.005). Operating time and total time in operating room (TTOR) was lower in the SSA (p < 0.001) and TTOR was higher in the NSP group (p = 0.014). Planned versus postoperative leg length discrepancy were similar among both anterior and posterior surgeries (p > 0.104). Planned versus postoperative abduction and anteversion were similar among the NSA and SSA (p > 0.425), whereas planned versus postoperative abduction and anteversion were lower in the NSP (p < 0.001). Outliers > 10 mm from planned leg length were present in one case of the SSP and NSP, with none in the anterior groups. There were no outliers > 10° in anterior or posterior for abduction in all surgeons. The SSP had six outliers > 10° in anteversion while the NSP had none (p = 0.004); the SSA had no outliers for anteversion while the NSA had one (p = 0.500).

Conclusion

Robotic arm-assisted technology allowed a newly trained surgeon to produce similarly accurate results and outcomes as experienced surgeons in anterior and posterior hip arthroplasty.

Cite this article: Bone Jt Open 2021;2(6):365–370.

Outcomes of Computer-Assisted Surgery Compared with Conventional Instrumentation in 19,221 Total Knee Arthroplasties: Results After a Mean of 4.5 Years of Follow-Up

BACKGROUND

Studies have shown improved alignment in association with the use of computer-assisted surgery (CAS) as compared with conventional instrumentation during total knee arthroplasty (TKA) but have failed to show a consistent clinical benefit. The aim of the present study was to compare the revision rates and functional outcomes following TKA performed with either CAS or conventional instrumentation. Recognizing that selection bias may arise from the preferential use of CAS in difficult or complex cases, the implant survival data and postoperative functional scores were analyzed with reference to whether the surgeon routinely performed TKA with use of CAS or conventional instrumentation.

METHODS

Revision rates and functional data in terms of the Oxford Knee Score (OKS) at 6 months, 5 years, and 10 years were obtained from the New Zealand Joint Registry (NZJR) for 19,221 TKAs performed from 2006 to 2018.These data were analyzed by comparing 2 cohorts of patients: those managed by high-volume surgeons who routinely used CAS ("routine CAS" surgeons) and those managed by high-volume surgeons who routinely used conventional instrumentation ("routine conventional" surgeons). The mean duration of follow-up was 4.5 years (range, 0 to 12 years).

RESULTS

The revision rate per 100 component-years was 0.437 for the "routine CAS" surgeons, compared with 0.440 for the "routine conventional" surgeons (p = 0.724). For patients <65 years of age, the revision rate per 100 component-years was equivalent for the "routine CAS" and "routine conventional" surgeons (0.585 compared with 0.508; p = 0.524). The OKS scores were similar at 6 months (38.88 compared with 38.52; p = 0.172), 5 years (42.26 compared with 41.77; p = 0.206), and 10 years (41.59 compared with 41.74; p = 0.893) when comparing the 2 cohorts. Surgeons who had performed >50 TKAs with use of CAS took 10 minutes longer on average than those who used conventional instrumentation (92 compared with 82 minutes; p = 0.012).

CONCLUSIONS

The present study demonstrated no difference in survivorship or functional outcome scores to support using CAS for TKA. Experienced surgeons using CAS had longer operative durations than comparable surgeons using conventional instrumentation.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

An umbrella review comparing computer-assisted and conventional total joint arthroplasty: quality assessment and summary of evidence

Background

Systematic reviews (SRs) of computer-assisted (CA) total knee arthroplasty (TKA) and total hip arthroplasty (THA) report conflicting evidence on its superiority over conventional surgery. Little is known about the quality of these SRs; variability in their methodological quality may be a contributing factor. We evaluated the methodological quality of all published SRs to date, summarized and examined the consistency of the evidence generated by these SRs.

Methods

We searched four databases through December 31, 2018. A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2) was applied to assess the methodological quality. Evidence from included meta-analyses on functional, radiological and patient-safety outcomes was summarized. The corrected covered area was calculated to assess the overlap between SRs in including the primary studies.

Results

Based on AMSTAR 2, confidence was critically low in 39 of the 42 included SRs and low in 3 SRs. Low rating was mainly due to failure in developing a review protocol (90.5%); providing a list of excluded studies (81%); accounting for risk of bias when discussing the results (67%); using a comprehensive search strategy (50%); and investigating publication bias (50%). Despite inconsistency between SR findings comparing functional, radiological and patient safety outcomes for CA and conventional procedures, most TKA meta-analyses favored CA TKA, whereas most THA meta-analyses showed no difference. Moderate overlap was observed among TKA SRs and high overlap among THA SRs.

Conclusions

Despite conclusions of meta-analyses favoring CA arthroplasty, decision makers adopting this technology should be aware of the low confidence in the results of the included SRs. To improve confidence in future SRs, journals should consider using a methodological assessment tool to evaluate the SRs prior to making a publication decision.

Influence of multi-angle input of intraoperative fluoroscopic images on the spatial positioning accuracy of the C-arm calibration-based algorithm of a CAOS system

Intraoperative fluoroscopic images, as one of the most important input data for computer-assisted orthopedic surgery (CAOS) systems, have a significant influence on the positioning accuracy of CAOS system. In this study, we proposed to use multi-angle intraoperative fluoroscopy images as input based on real clinical scenario, and the aim was to analyze the positioning accuracy and the error propagation rules with multi-angle input images compared with traditional two input images. In the experiment, the positioning accuracy of the C-arm calibration-based algorithm was studied, respectively, using two, three, four, five, and six intraoperative fluoroscopic images as input data. Moreover, the error propagation rules of the positioning error were analyzed by the Monte Carlo method. The experiment result showed that increasing the number of multi-angle input fluoroscopic images could reduce the positioning error of CAOS system, which has dropped from 1.01 to 0.61 mm. The Monte Carlo simulation analysis showed that for random input errors subject to normal distribution (μ = 0, σ = 1), the image positioning error dropped from 0.29 to 0.23 mm, and the staff gauge positioning error dropped from 1.36 to 1.19 mm, while the tracking device positioning error dropped from 3.41 to 2.13 mm. In addition, the results showed that image positioning error and staff gauge positioning error were all nonlinear error for the whole system, but tracker device positioning error was a strictly linear error. In conclusion, using multi-angle fluoroscopy images was helpful for clinic, which could improve the positioning accuracy of the CAOS system by nearly 30%. Graphical abstract The experiment process and Monte Carlo analysis of spatial positioning accuracy (A: Setup for the experiment; B: The process of Monte Carlo analysis; C: Results).

The Use of Navigation in Osteotomies Around the Knee

Osteotomies around the knee for treating osteoarthritis or knee instability are currently well-established procedures. Success of these realignment procedures is based on the accuracy and the reliability of correction angles in the coronal and sagittal alignment. In this context of improving precision and adapting the correction to each patient, navigation is currently being widely used. The rationale for its use is based on understanding the advantages and limitations, technical principles, and potential pitfalls. This article describes these areas and the overall clinical outcomes of this system for knee osteotomies.

Views on a new surgical assistance method for implanting the glenoid component during total shoulder arthroplasty. Part 2: From three-dimensional reconstruction to augmented reality: Feasibility study

INTRODUCTION

The main goal of this study was to propose a new method of surgical assistance for the implantation of a total shoulder prosthesis, with the use of augmented reality (AR). The advantage of this approach is that it supplements information, on the one hand pre-existing or disappeared due to a pathological process, such as the premorbid glenoid, and on the other hand already existing but not accessible to the surgeon during the procedure, such as the so-called "hidden" face of the scapula.

MATERIAL AND METHODS

Several information preparation steps were needed. The first consisted in the three-dimensional (3D) rendering of the pathological glenoid, from a point cloud corresponding to the premorbid glenoid based on previously developed regression equations. A library of "healthy" generic glenoids was then created by hierarchical bottom-up analysis. From this database, a so-called adequate normal generic glenoid was fused and matched to the pathological glenoid reconstructed using a morphing technique. An experimental AR application was constructed. Smart glasses were used to display the prepared 3D information.

RESULTS

A pathological 3D glenoid was reconstructed and used for the AR application. A complete display of the scene, reconstructed glenoid and full scapula was obtained. However, an offset from reality was observed. The main limitations were technical, related to the connected tool itself and the operating software.

DISCUSSION/CONCLUSION

This was a feasibility study of the different steps required to apply AR, from information preparation to its visualization. A new parameter crossing experiment is needed to optimize each step of this process.

LEVEL OF EVIDENCE

IV, Basic science study.

Making the transition from traditional to robotic-arm assisted TKA: What to expect? A single-surgeon comparative-analysis of the first-40 consecutive cases

Objective/methods

We compared short-term outcomes following 40 traditional, cemented total knee arthroplasty (TKA) to the first 40 cemented robotic-arm assisted TKA (raTKA) and analyzed the learning curve for raTKA.

Results

LOS was longer for traditional TKA compared to raTKA (1.92 vs. 1.27days, p < 0.0001). There was no difference in surgical time between the second 20 raTKA and all traditional TKA cases (81.1 vs. 78.3 mins, p = 0.254). raTKA patients had improved 90-day ROM (+3.8° vs. -8.7°, p < 0.05) but comparable complications rates, Knee Society Scores, and patient-reported outcomes at all timepoints.

Conclusion

Despite comparable outcomes, the learning curve for raTKA appeared to progress rapidly.

Influence of the quality of intraoperative fluoroscopic images on the spatial positioning accuracy of a CAOS system

BACKGROUND

Spatial positioning accuracy is a key issue in a computer-assisted orthopaedic surgery (CAOS) system. Since intraoperative fluoroscopic images are one of the most important input data to the CAOS system, the quality of these images should have a significant influence on the accuracy of the CAOS system. But the regularities and mechanism of the influence of the quality of intraoperative images on the accuracy of a CAOS system have yet to be studied.

METHODS

Two typical spatial positioning methods - a C-arm calibration-based method and a bi-planar positioning method - are used to study the influence of different image quality parameters, such as resolution, distortion, contrast and signal-to-noise ratio, on positioning accuracy. The error propagation rules of image error in different spatial positioning methods are analyzed by the Monte Carlo method.

RESULTS

Correlation analysis showed that resolution and distortion had a significant influence on spatial positioning accuracy. In addition the C-arm calibration-based method was more sensitive to image distortion, while the bi-planar positioning method was more susceptible to image resolution. The image contrast and signal-to-noise ratio have no significant influence on the spatial positioning accuracy. The result of Monte Carlo analysis proved that generally the bi-planar positioning method was more sensitive to image quality than the C-arm calibration-based method.

CONCLUSIONS

The quality of intraoperative fluoroscopic images is a key issue in the spatial positioning accuracy of a CAOS system. Although the 2 typical positioning methods have very similar mathematical principles, they showed different sensitivities to different image quality parameters. The result of this research may help to create a realistic standard for intraoperative fluoroscopic images for CAOS systems.

Computer-Assisted Hip Arthroscopic Surgery for Femoroacetabular Impingement

Precise osteochondroplasty is key for success in hip arthroscopic surgery, especially for femoroacetabular impingement (FAI) caused by cam or pincer morphology. In this Technical Note, we present computer-assisted hip arthroscopic surgery for FAI, including preoperative planning by virtual osteochondroplasty and intraoperative computer navigation assistance. The important concept of this technique is that navigation assistance for osteochondroplasty is based on planning made by computer simulation analysis. The navigation assistance allows us to perform neither too much nor too little osteochondroplasty. Specifically, computer simulation was used to identify the impingement point. Virtual osteochondroplasty was then performed to determine the maneuvers that would improve range of motion. Thereafter, the planning data were transported to a computed tomography-based computer navigation system that directly provided intraoperative assistance. Thus, computer-assisted technology including preoperative simulation, virtual osteochondroplasty planning, and intraoperative navigation assistance may promote precise hip arthroscopic surgery for FAI.

Robotic-assisted total knee arthroplasty may lead to improvement in quality-of-life measures: a 2-year follow-up of a prospective randomized trial

PURPOSE

Despite reduction in radiological outliers in previous randomized trials comparing robotic-assisted versus conventional total knee arthroplasty (TKA), no differences in short-term functional outcomes were observed. The aim of this study was to determine whether there was improvement in functional outcomes and quality-of-life (QoL) measures between robotic-assisted and conventional TKA.

METHODS

All 60 knees (31 robotic-assisted; 29 conventional) from a previous randomized trial were available for analysis. Differences in range of motion, Knee Society (KSS) knee and function scores, Oxford Knee scores (OKS), SF-36 subscale and summative (physical PCS/mental component scores MCS) were analysed. In addition, patient satisfaction, fulfilment of expectations and the proportion attaining a minimum clinically important difference (MCID) in KSS, OKS and SF-36 were studied.

RESULTS

Both robotic-assisted and conventional TKA displayed significant improvements in majority of the functional outcome scores at 2 years. Despite having a higher rate of complications, the robotic-assisted group displayed a trend towards higher scores in SF-36 QoL measures, with significant differences in SF-36 vitality (p = 0.03), role emotional (p = 0.02) and a larger proportion of patients achieving SF-36 vitality MCID (48.4 vs 13.8 %, p = 0.009). No significant differences in KSS, OKS or satisfaction/expectation rates were noted.

CONCLUSION

Subtle improvements in patient QoL measures were observed in robotic-assisted TKA when compared to conventional TKA. This finding suggests that QoL measures may be more sensitive and clinically important than surgeon-driven objective scores in detecting subtle functional improvements in robotic-assisted TKA patients.

LEVEL OF EVIDENCE

II.

[Clinical application of computer-assisted cannulated screw internal fixation system based on error correction method for femoral neck fractures]

Objective

To investigate the clinical efficacy of computer-assisted cannulated screw internal fixation system based on error correction method for femoral neck fractures.

Methods

A retrospective analysis was made on the clinical data of 20 femoral neck fracture patients treated by computer-assisted cannulated screw internal fixation system based on error correction method between January 2014 and October 2015 (trial group), and 36 femoral neck fracture patients undergoing traditional manual surgery with closed reduction by cannulated screw fixation in the same period (the control group). There was no significant difference in gender, age, injury cause, side of fracture, types of fracture, and time from injury to operation between 2 groups ( P>0.05). The operation time, intraoperative blood loss, intraoperative frequency of fluoroscopy and guide pin insertion, fracture healing time, fracture healing rate, and Harris hip score were compared between 2 groups.

Results

All incisions healed by first intention after operation, and no complication of blood vessel and nerve injury occurred. The operation time of trial group was significantly longer than that of control group ( t=2.290, P=0.026), however, the intraoperative blood loss, intraoperative frequency of fluoroscopy and guide pin insertion of trial group were significantly less than those of control group ( t=-10.650, P=0.000; t=18.320, P=0.000; t=-16.625, P=0.000). All patients were followed up 12-18 months (mean, 14.7 months). X-ray films showed that fracture healing was obtained in 2 groups, showing no significant difference in fracture healing time between 2 groups ( t=0.208, P=0.836). No complication of ischemic necrosis of femoral head occurred during follow-up period. At last follow-up, the Harris hip score was 87.05±3.12 in trial group and was 86.78±2.83 in control group, showing no significant difference ( t=0.333, P=0.741).

Conclusion

Computer-assisted cannulated screw internal fixation surgery based on error correction method for femoral neck fractures is better than traditional manual surgery in decreasing intraoperative radiation and surgical trauma during operation.

What do we get from navigation in primary THA?

Navigation in primary total hip arthroplasty has a history of over 20 years. During this process, imageless computer navigation can be particularly helpful in optimally restoring the hip’s biomechanics. This involves the accurate placement of the acetabular component with the determination of the anteversion and abduction, whereby the navigated femur-first technique also allows for a calculation of the combined anteversion. Additional critical parameters such as the reconstruction of the rotation centre, as well as the femoral and acetabular offset, can also be optimally adjusted. Last but not least, an intra-operative evaluation and equalisation of the leg length is possible.

Nonetheless, the disadvantages of this surgical technique in terms of the high costs in the acquisition and preservation of the necessary devices, as well as the longer operation time, must be taken into account. However, economic aspects are not the only thing preventing widespread use of the navigation technique. Determining the plane of reference (APP) for the optimal orientation of the implants is based on palpation of the bony landmarks – and this is influenced by the thickness of the soft tissue layer. Furthermore, the experience of the surgeon constitutes a variable that influences the accuracy of navigation.

In summary, hip navigation certainly offers an interesting technique for the optimisation of total hip arthroplasty with reconstruction of proper biomechanics. At the same time, there is currently a lack of high-quality randomised controlled long-term trials that evaluate the clinical advantage for the patients, together with cost utility and survival rates.

Cite this article: Renner L, Janz V, Perka C, Wassilew GI. What do we get from navigation in primary THA? EFORT Open Rev 2016;1:205-210. 10.1302/2058-5241.1.000034.

A computer-assisted navigation technique to perform bone tumor resection without dedicated software

PURPOSE

In oncological orthopedics, navigation systems are limited to use in specialized centers, because specific, expensive, software is necessary. To resolve this problem, we present a technique using general spine navigation software to resect tumors located in different segments.

MATERIALS AND METHODS

This technique requires a primary surgery during which screws are inserted in the segment where the bone tumor is; next, a CT scan of the entire segment is used as a guide in a second surgery where a resection is performed under navigation control. We applied this technique in four selected cases. To evaluate the procedure, we considered resolution obtained, quality of the margin and its control.

RESULTS

In all cases, 1 mm resolution was obtained; navigation allowed perfect control of the osteotomies, reaching the minimum wide margin when desired. No complications were reported and all patients were free of disease at follow-up (average 25.5 months).

CONCLUSIONS

This technique allows any bone segment to be recognized by the navigation system thanks to the introduction of screws as landmarks. The minimum number of screws required is four, but the higher the number of screws, the greater the accuracy and resolution. In our experience, five landmarks, placed distant from one another, is a good compromise. Possible disadvantages include the necessity to perform two surgeries and the need of a major surgical exposure; nevertheless, in our opinion, the advantages of better margin control justify the application of this technique in centers where an intraoperative CT scanner, synchronized with a navigation system or a dedicated software for bone tumor removal were not available.

Computer-Assisted Navigation in High Tibial Osteotomy

Computer-assisted navigation is used to improve the accuracy and precision of correction angles during high tibial osteotomy. Most studies have reported that this technique reduces the outliers of coronal alignment and unintended changes in the tibial posterior slope angle. However, more sophisticated studies are necessary to determine whether the technique will improve the clinical results and long-term survival rates. Knowledge of the navigation technology, surgical techniques and potential pitfalls, the clinical results of previous studies, and understanding of the advantages and limitations of the computer-assisted navigation are crucial to successful application of this new technique in high tibial osteotomy. Herein, we review the evidence concerning this technique from previous studies.

Current use of navigation system in ACL surgery: a historical review

PURPOSE

The present review aims to analyse the available literature regarding the use of navigation systems in ACL reconstructive surgery underling the evolution during the years.

METHODS

A research of indexed scientific papers was performed on PubMed and Cochrane Library database. The research was performed in December 2015 with no publication year restriction. Only English-written papers and related to the terms ACL, NAVIGATION, CAOS and CAS were considered. Two reviewers independently selected only those manuscripts that presented at least the application of navigation system for ACL reconstructive surgery.

RESULTS

One hundred and forty-six of 394 articles were finally selected. In this analysis, it was possible to review the main uses of navigation system in ACL surgery including tunnel positioning for primary and revision surgery and kinematic assessment of knee laxity before and after different surgical procedures. In the early years, until 2006, navigation system was mainly used to improve tunnel positioning, but since the last decade, this tool has been principally used for kinematics evaluation. Increased accuracy of tunnel placement was observed using navigation surgery, especially, regarding femoral, 42 of 146 articles used navigation to guide tunnel positioning. During the following years, 82 of 146 articles have used navigation system to evaluate intraoperative knee kinematic. In particular, the importance of controlling rotatory laxity to achieve better surgical outcomes has been underlined.

CONLUSIONS

Several applications have been described and despite the contribution of navigation systems, its potential uses and theoretical advantages, there are still controversies about its clinical benefit. The present papers summarize the most relevant studies that have used navigation system in ACL reconstruction. In particular, the analysis identified four main applications of the navigation systems during ACL reconstructive surgery have been identified: (1) technical assistance for tunnel placement; (2) improvement in knowledge of the kinematic behaviour of ACL and other structures; (3) comparison of effectiveness of different surgical techniques in controlling laxities; (4) navigation system performance to improve the outcomes of ACL reconstruction and cost-effectiveness.

LEVEL OF EVIDENCE

IV.

Inter-observer variability and its correlation to experience in measurement of lower limb mechanical axis on long leg radiographs

INTRODUCTION

Restoration of mechanical axis (MA) is one of the most important aims of treatment of knee arthritis. The measurement of MA is often done on hip knee ankle (HKA) radiographs (LLR), but its measurement is often difficult and variable. We studied to check if inter-observer variability in the measurement of MA is dependent on the experience of the observer.

MATERIALS AND METHODS

48 patients (70 knees) underwent measurement of MA on HKA radiographs. The measurement was done by five observers of different experience. All the results were tested for inter-observer variability.

RESULTS

The overall intra-class correlation was 0.70. The two full time consultants had good agreeability among them (p < 0.456). All the surgeons who had less than five years of experience among them also had good agreeability amongst them (all p values >0.005). All the other groups (except senior consultant and senior registrar) had statistically significant difference amongst them (all p values <0.005).

CONCLUSION

There is an inter-observer variability in the measurement of MA on the HKA radiographs. The agreeability between the observers increases as the experience of the personnel increases. Although long leg radiographs can be used for assessment for HKA, this variability should be kept in mind while using this as a tool for planning management of the arthritic knee.

A Smart Tool for Intraoperative Leg Length Targeting in Total Hip Arthroplasty: A Retrospective Cohort Study

BACKGROUND

Leg length discrepancies following total hip arthroplasty (THA) may necessitate subsequent interventions, from heel lifts to revision surgery. Current intraoperative methods of determining leg length are either inaccurate or expensive and invasive.

OBJECTIVE

The objective of the current study was to investigate the ability of a novel, intraoperative smart tool (Intellijoint HIP^®, Intellijoint Surgical^®, Inc., Waterloo, ON) to provide accurate, real-time leg length measurements during THA.

METHODS

We retrospectively reviewed the medical records of 25 patients who underwent THA utilizing the Intellijoint HIP smart tool between February and August 2014. Intraoperative leg length data was compared with radiographic leg length calculations. Two observers blinded to the Intellijoint HIP findings independently assessed all post-procedure radiographs.

RESULTS

The mean difference between smart tool and radiographic measurements was 1.3 mm [CI: -0.1, 2.7]. 88% (22/25) of intraoperative measurements were within 5 mm of radiographic measurements; 100% (25/25) were within 10 mm. A Bland-Altman analysis showed excellent agreement, with 96% (24/25) of measurements within the statistical limit for acceptable agreement, and 84% (21/25) within the clinically acceptable range (± 5 mm). Removal of the first 13 procedures (surgeon training) decreased the mean difference between methods to 0.6 mm [-0.6, 1.9]. All post-training procedures were associated with a difference of <5 mm. There were no reported adverse events related to the use of the smart tool.

CONCLUSION

The Intellijoint HIP smart tool is a safe and accurate tool for providing intraoperative measurements of leg length in real-time.

Thirty-Day Complications of Conventional and Computer-Assisted Total Knee and Total Hip Arthroplasty: Analysis of 103,855 Patients in the American College of Surgeons National Surgical Quality Improvement Program Database

BACKGROUND

Computer-assisted surgery (CAS) has gained popularity in orthopedics for both total knee arthroplasty (TKA) and total hip arthroplasty (THA) in the past decades.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients who underwent a primary, unilateral THA and TKA from 2011 to 2013. Multivariate analysis was conducted to compare the postoperative complications in patients whose surgery involved the use of CAS with those by conventional techniques.

RESULTS

We identified 103,855 patients who had THA and TKA in the database between 2011 and 2013. There were higher overall adverse events (odds ratio [OR], 1.40; CI, 1.22-1.59), minor events (OR, 1.38; CI, 1.21-1.58), and requirements for blood transfusion (OR, 1.44; CI, 1.25-1.67) in the conventional group when compared with CAS for TKA. However, rate of reoperation was higher in the CAS group for TKA (OR, 1.60; CI, 1.15-2.25). The results also showed higher overall adverse events (OR, 2.61; CI, 2.09-3.26), minor events (OR, 2.82; CI, 2.24-3.42), and requirements for blood transfusion (OR, 3.41; CI, 2.62-4.44) in the conventional group when compared to CAS for THA. Nevertheless, superficial wound infections (OR, 0.46; CI, 0.26-0.81) were shown to be higher in the CAS group undergoing THA.

CONCLUSION

The use of CAS in THA and TKA reduced the number of minor adverse events in the first 30 days postoperatively. However, CAS was associated with an increased number of reoperations and superficial infections. The clinical benefits and disadvantages of CAS should be considered when determining the potential benefit-cost ratio of this technology.

Identifying the procedural gap and improved methods for maintaining accuracy during total hip arthroplasty

Osteoarthritis is a ubiquitous condition, affecting 26 million Americans each year, with up to 17% of adults over age 75 suffering from one variation of arthritis. The hip is one of the most commonly affected joints and while there are conservative options for treatment, as symptoms progress, many patients eventually turn to surgery to manage their pain and dysfunction. Early surgical options such as osteotomy or arthroscopy are reserved for younger, more active patients with less severe disease and symptoms. Total hip arthroplasty offers a viable solution for patients with severe degenerative changes; however, post-surgical discrepancies in leg length, offset and component malposition are common and cause significant complications. Such discrepancies are associated with consequences such as low back pain, neurological deficits, instability and overall patient dissatisfaction. Current methods for managing leg length and offset during hip arthroplasty are either inaccurate and susceptible to error or are cumbersome, expensive and lengthen surgical time. There is currently no viable option that provides accurate, real-time data to surgeons regarding leg length, offset and cup position in a cost-effective manner. As such, we hypothesize that a procedural gap exists in hip arthroplasty, a gap into which fall a large majority of arthroplasty patients who are at increased risk of complications following surgery. These complications and associated treatments place significant stress on the healthcare system. The costs associated with addressing leg length and offset discrepancies can be minor, requiring only heel lifts and short-term rehabilitation, but can also be substantial, with revision hip arthroplasty costs of up to $54,000 per procedure. The need for a cost-effective, simple to use and unobtrusive technology to address this procedural gap in hip arthroplasty and improve patient outcomes is of increasing importance. Given the aging of the population, the projected increases in the volume of procedures over the coming decades and the economic pressures associated with downward pricing pressure and bundled payments, the need to address this gap is underscored.

The current status and future prospects of computer-assisted hip surgery

The advances in computer assistance technology have allowed detailed three-dimensional preoperative planning and simulation of preoperative plans. The use of a navigation system as an intraoperative assistance tool allows more accurate execution of the preoperative plan, compared to manual operation without assistance of the navigation system. In total hip arthroplasty using CT-based navigation, three-dimensional preoperative planning with computer software allows the surgeon to determine the optimal angle of implant placement at which implant impingement is unlikely to occur in the range of hip joint motion necessary for daily activities of living, and to determine the amount of three-dimensional correction for leg length and offset. With the use of computer navigation for intraoperative assistance, the preoperative plan can be precisely executed. In hip osteotomy using CT-based navigation, the navigation allows three-dimensional preoperative planning, intraoperative confirmation of osteotomy sites, safe performance of osteotomy even under poor visual conditions, and a reduction in exposure doses from intraoperative fluoroscopy. Positions of the tips of chisels can be displayed on the computer monitor during surgery in real time, and staff other than the operator can also be aware of the progress of surgery. Thus, computer navigation also has an educational value. On the other hand, its limitations include the need for placement of trackers, increased radiation exposure from preoperative CT scans, and prolonged operative time. Moreover, because the position of a bone fragment cannot be traced after osteotomy, methods to find its precise position after its movement need to be developed. Despite the need to develop methods for the postoperative evaluation of accuracy for osteotomy, further application and development of these systems are expected in the future.

Tibial baseplate positioning in robotic-assisted and conventional unicompartmental knee arthroplasty

This study compared tibial baseplate alignment (TBA) between robotic-arm-assisted (RAA) and conventional (CONV) unicompartmental knee arthroplasties (UKAs). We hypothesized that RAA would increase the percentage of implants within a predetermined safe zone (SZ). We identified 177 CONV and 87 RAA UKAs through our center's patient registry. Two individuals reviewed postoperative knee radiographs and determined TBA. Coronal baseplate positioning was more accurate (i.e., within the SZ) for RAA (2.6° ± 1.5° vs. 3.9° ± 2.4°, p < 0. 0001). Conversely, sagittal alignment was more accurate for CONV (4.9° ± 2.8° vs. 2.4° ± 1.6°, p < 0.0001). RAA was more precise in both planes (p < 0.0001). There was no difference in the percentage of implants within the SZ between the two groups (p = 1.0).