Accuracy Of Component Positioning Research Articles

The accuracy of component positioning during revision total hip arthroplasty using 3D optical computer-assisted navigation.

Despite the excellent outcomes associated with primary total hip arthroplasty (THA), implant failure and revision continue to burden the healthcare system. The use of computer-assisted navigation (CAN) offers the potential for more accurate placement of hip components during surgery. While intraoperative CAN systems have been shown to improve outcomes in primary THA, their use in the context of revision total hip arthroplasty (rTHA) has not been elucidated. We sought to investigate the validity of using CAN during rTHA. A retrospective analysis was performed at an academic medical institution identifying all patients who underwent rTHA using CAN from 2016-2019. Patients were 1:1 matched with patients undergoing rTHA without CAN (control) based on demographic data. Cup anteversion, inclination, change in leg length discrepancy (ΔLLD) and change in femoral offset between pre- and post-operative plain weight-bearing radiographic images were measured and compared between both groups. A safety target zone of 15-25° for anteversion and 30-50° for inclination was used as a reference for precision analysis of cup position. Eighty-four patients were included: 42 CAN cases and 42 control cases. CAN cases displayed a lower ΔLLD (5.74 ± 7.0mm vs 9.13 ± 7.9mm, p = 0.04) and greater anteversion (23.4 ± 8.53° vs 19.76 ± 8.36°, p = 0.0468). There was no statistical difference between the proportion of CAN or control cases that fell within the target safe zone (40% vs 20.9%, p = 0.06). Femoral offset was similar in CAN and control cases (7.63 ± 5.84mm vs 7.14 ± 4.8mm, p = 0.68). Our findings suggest that the use of CAN may improve accuracy in cup placement compared to conventional methodology, but our numbers are underpowered to show a statistical difference. However, with a ΔLLD of ~ 3.4mm, CAN may be useful in facilitating the successful restoration of pre-operative leg length following rTHA. Therefore, CAN may be a helpful tool for orthopedic surgeons to assist in cup placement and LLD during complex revision cases.

Comparison of Robotic and Conventional Unicompartmental Knee Arthroplasty Outcomes in Patients with Osteoarthritis: A Retrospective Cohort Study.

Robotic-arm-assisted unicompartmental knee arthroplasty (RUKA) was developed to increase the accuracy of bone alignment and implant positioning. This retrospective study explored whether RUKA has more favorable overall outcomes than conventional unicompartmental knee arthroplasty (CUKA). A total of 158 patients with medial compartment osteoarthritis were recruited, of which 85 had undergone RUKA with the Mako system and 73 had undergone CUKA. The accuracy of component positioning and bone anatomical alignment was compared using preoperative and postoperative radiograph. Clinical outcomes were evaluated using questionnaires, which the patients completed preoperatively and then postoperatively at six months, one year, and two years. In total, 52 patients from the RUKA group and 61 from the CUKA group were eligible for analysis. The preoperative health scores and Kellgren–Lawrence scores were higher in the RUKA group. RUKA exhibited higher implant positioning accuracy, thus providing a superior femoral implant angle, properly aligned implant placement, and a low rate of overhang. RUKA also achieved higher accuracy in bone anatomical alignment (tibial axis angle and anatomical axis angle) than CUKA, but surgical time was longer, and blood loss was greater. No significant differences were observed in the clinical outcomes of the two procedures.

Validity of intraoperative imageless navigation (Naviswiss) for component positioning accuracy in primary total hip arthroplasty: protocol for a prospective observational cohort study in a single-surgeon practice

IntroductionOptimal outcomes in total hip arthroplasty (THA) are dependent on appropriate placement of femoral and acetabular components, with technological advances providing a platform for guiding component placement to reduce the...

Long term outcome analysis of fixed bearing total knee arthroplasty

Introduction: Survivorship of TKA is directly related to appropriate alignment and balance. Surgeons should evaluate the biomechanics of knee alignment and determine the proper position of the implant. Malalignment of total knee prostheses has been implicated in few difficulties, including tibiofemoral instability, patellofemoral instability, patellar fracture, stiffness, accelerated polyethylene wear, and implant loosening. The aim of this study is to analyse the long term follow up of functional and radiological results of twenty cases of fixed bearing Total Knee Arthroplasty prospectively done in our institute during the period April 2008 to September 2009. Materials & Methods: This is a prospective study done in our department form 2008- 2009 which included total knee arthroplasty done for bicompartmental osteoarthritis without gross deformity. 20 cases were included in the study. The age range was 32 to 65 years. There were 5 male patients and 15 female patients. The accuracy of component position was assessed by mechanical axis restoration, coronal tibio femoral angle, sagittal femoral angle, posterior tibial slope by X-ray and the transepicondylar line-posterior condyle component angle by CT. We used Depuy PFC fixed bearing knee in 17 patients, Stryker knee in 2 patients and Indus knee in 1 patient. Knee society score was used to measure the functional outcome of the surgery. Results: The average postoperative flexion in the rheumatoid group was 105.4 degrees and in the osteoarthritis group was 115.8 degrees. There was no incidence of periprosthetic fractures. No patients had neurological deficit or dislocations. One case had valgus instability postoperatively. In our study all our patients showed an improvement in knee score with mean preop score of 50.4 (range: 46-57) improved to 75.6 (range: 65-88). 2 patients had excellent score (80-100).16 patients had good score (70-79) and 2 patients had fair results (60-69). No patients had maltracking of patella clinically.one patient with anterior knee pain and two patients with limited flexion post operatively were evaluated with axial view of knee. There were no evidence of patellar tilt or subluxation. No patients had loosening and osteolysis noted around the femoral and tibial components. No implant needed to be revised during the period of study. There was no incidence of superficial or deep infection. Of the 20 patients 18 cases returned to their premorbid condition. Two patients who were rheumatoid has persistent pain. The average follow up was 9.2 years (range 8.4 to 10.7 years). Conclusion: In patients with ideal placement of the components i.e. with mechanical axis and the rotational alignment accurate better knee flexion and knee score was obtained provided other factors are normal. We conclude that the correct positioning of the components both axially and rotationally improves the functional outcome of fixed bearing knee in low demand patients with an excellent long term clinical outcome.

Computer Navigation Assisted Total Hip Arthroplasty: Use and Outcomes Compared with Conventional Technique

AbstractComputer-assisted surgery (CAS) for total hip arthroplasty (THA) was developed to improve the accuracy of component positioning. There is insufficient evidence on CAS THA in terms of early postoperative outcomes and complications. The aim of this study is to determine the time-related trends in computer navigation use and to compare outcomes to conventional technique. The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database containing primary THAs from 2008 to 2015 was retrospectively analyzed. Demographics, operative time, postoperative transfusions, hospital length of stay (LOS), wound complications, early reoperation, and readmissions were compared between CAS THA and traditional THA using univariate and multivariable regression analyses. The percent use of navigation in THA within the NSQIP database shows an increasing trend. There were more smokers and patients with higher American Society of Anesthesiologists ratings (p < 0.011) in the traditional THA group. According to multivariable regression, CAS THA was associated with lower postoperative transfusion rate and shorter LOS, but longer operative time (p < 0.001 for all) than traditional THA. Similarly, superficial infections were also lower in that group after controlling confounders (p = 0.028). There were no differences in overall infections, wound dehiscence, return to the operating room, or readmissions. CAS THA appears to be increasingly used over time within this database and is associated with lower transfusion rates, superficial infections, and shorter LOS. However, it may not afford any major advantages in operative time, overall infection rate, early return to the operating room, or early readmissions. These findings should be interpreted in light of potential long-term benefits that may be associated with CAS THA.

Accuracy assessment of measuring component position after total ankle arthroplasty using a conventional method

BackgroundThis study was to assess the accuracy of measuring the tibial and talar components position and to investigate the outlier rate of each component and predisposing factors related to component malalignment after total ankle arthroplasty (TAA) using a conventional method.MethodsOne hundred fifty consecutive primary total ankle arthroplasty were performed using the three-component HINTEGRA prosthesis for ankle end-stage osteoarthritis. Radiographic analysis for the accuracy of component position in coronal and sagittal plane was conducted at postoperative 6 months. Additionally, the accuracy of component position was evaluated according to presence of preoperative deformity or joint incongruency.ResultsThe mean postoperative coronal angles of the tibial and talar components (α and γ) were 91.9° and 91.3°. The mean postoperative sagittal angles of the tibial and talar components (β and δ angle) were 84.6° and 91.7°. In the coronal plane, 16 (10.7%) tibial components and 15 (10.0%) talar components showed outliers greater than 5°. In sagittal plane, 15 (10.0%) tibial components and 29 (19.3%) talar components showed outliers greater than 5°. There was no meaningful increase of the outlier rate regarding presence of preoperative deformity or joint incongruency.ConclusionsIn conventional method of TAA, the outlier rate of the tibial and talar components was about 10 to 20%, especially, the outlier rate of talar component in sagittal plane was up to 20%. Therefore, careful attention should be paid to implant the talar component in conventional TAA.

A randomized controlled trial to compare component placement in navigated total knee arthroplasty using original and streamlined registration processes.

BackgroundThis randomized controlled trial validated a redesigned version of navigated total knee arthroplasty software with a streamlined registration (Smart) against the previous version (Classic). The objectives were to determine if Smart software had the same accuracy of component positioning and whether registration and operative time were reduced.MethodsA total of 220 patients were recruited and had a navigated total knee arthroplasty performed. With the exception of the software, all patients had the same perioperative care. At 6-week follow-up with an independent arthroplasty service, all patients had a computerized tomography scan. This was assessed by an independent radiologist to measure the mechanical alignment of the components.ResultsThe mean postoperative mechanical femorotibial angles were equivalent between groups (mean difference −0.2°, 95% confidence interval −0.7° to 0.3°, P = .407). Component positions were similar in both groups. Mean registration time was significantly shorter for the Smart group (2 minutes 30 seconds ± 54 seconds) than the Classic group (3 minutes 23 seconds ± 39 seconds), P < .001. The mean operative time was 72 ± 12 minutes in both groups (P = .855). At 6-week follow-up, both groups had similar clinical outcomes with 96.5% of patients being satisfied or very satisfied.ConclusionsThe study verified that a reduced registration time did not alter the accuracy of component placement. However, despite a shorter registration time, the overall surgical time was not reduced.

Direct anterior total hip arthroplasty: Comparative outcomes and contemporary results.

Direct anterior total hip arthroplasty has become increasingly more popular among arthroplasty surgeons, in large part due to the use of an intramuscular interval and desire to reduce soft tissue damage. Several studies have now been published comparing the anterior intramuscular to other commonly used approaches, and many studies have published complication rates on large series of patients. Review of comparative studies indicates direct anterior hips tend towards shorter hospital stays and high rates of patients discharged to home. Although some studies show evidence of early benefit in functional outcomes, there is no strong evidence that the anterior approach provides any long term functional improvements compared to other approaches. Additionally, evidence to support reduced damage to soft tissue may not translate to certain clinical significance. Rates of intra-operative femur fracture, operative time and blood loss rates are notably higher for those developing familiarity with this approach. However, when surgeons have performed a modest number of procedures, the complication rates tend to markedly decrease in most studies to levels comparable to other approaches. Accuracy of component positioning also favors the anterior approach in some studies. This review summarizes the available literature comparing the direct anterior to other approaches for total hip arthroplasty and provides a comprehensive summary of common complications.

Accuracy of Component Positioning in 1980 Total Hip Arthroplasties: A Comparative Analysis by Surgical Technique and Mode of Guidance

The purpose of this multi-surgeon study was to assess and compare the accuracy of acetabular component placement, leg length discrepancy (LLD), and global offset difference (GOD) between six different surgical techniques and modes of guidance in total hip arthroplasty (THA). A total of 1980 THAs met inclusion criteria. Robotic- and navigation-guided techniques were more consistent than other techniques in placing the acetabular cup into Lewinnek's safe zone (P<0.005 and P<0.05, respectively). Robotic-guided surgery was more consistent than other techniques in placing the acetabular component within Callanan's safe zone (P<0.005). No statistically significant differences were found between groups in the frequency of patients with excessive LLD. Clinically significant differences between groups were not found in the frequency of patients with excessive GOD. Level of Evidence: IV

Oxford unicompartmental knee arthroplasty: medial pain and functional outcome in the medium term.

BackgroundIn our experience results of the Oxford unicompartmental knee replacement have not been as good as had been expected. A common post operative complaint is of persistent medial knee discomfort, it is not clear why this phenomenon occurs and we have attempted to address this in our study.Methods48 patients were retrospectively identified at a mean of 4.5 years (range = 3 to 6 years) following consecutive Oxford medial Unicompartmental Knee arthroplasties for varus anteromedial osteoarthritis. The mean age at implantation was 67 years (range 57-86). Of these 48 patients, 4 had died, 4 had undergone revision of their unicompartmental knee replacements and 2 had been lost to follow up leaving 38 patients with 40 replaced knees available for analysis using the 'new Oxford Knee Score' questionnaire. During assessment patients were asked specifically whether or not they still experienced medial knee discomfort or pain.ResultsThe mean 'Oxford score' was only 32.7 (range = 16 to 48) and 22 of the 40 knees were uncomfortable or painful medially.The accuracy of component positioning was recorded, using standard post operative xrays, by summing the angulation or displacement of each component in two planes from the ideal position (according to the 'Oxford knee system radiographic criteria'). No correlation was demonstrated between the radiographic scores and the 'Oxford scores', or with the presence or absence of medial knee discomfort or pain.ConclusionIn our hands the functional outcome following Oxford Unicompartmental knee replacement was variable, with a high incidence of medial knee discomfort which did not correlate with the postoperative radiographic scores, pre-op arthritis and positioning of the prosthesis.

A Prospective Randomized Trial of Mini-incision Posterior and Two-incision Total Hip Arthroplasty

The two-incision approach to THA has been controversial, with some authors reporting its use is associated with a rapid recovery whereas others report no differences in outcomes and a higher risk of perioperative complications secondary to increased surgical complexity. We therefore compared early postoperative variables including pain, length of stay, functional recovery, complications, and complexity of the mini-posterior and two-incision approaches to THA. We prospectively enrolled 72 patients scheduled for THA and randomized them into two groups: mini-incision posterior approach and the two-incision approach. Preoperative teaching, anesthetic protocols, implants used, and rehabilitation pathways were identical for both groups. All variables were assessed at a maximum of 1 year postoperatively. All key outcomes were similar in the two groups: mean visual analog scale (VAS) scores for pain during the first 3 postoperative days and the first 6 weeks, total narcotic requirements in the hospital and during the first 6 weeks, mean length of stay (51 hours versus 48 hours), and mean Harris hip scores and SF-12 scores. Achievement of functional milestones was similar between the two groups. There was one reoperation in each group. Mean operative time was longer for patients in the two-incision group (98 minutes versus 77 minutes), however the accuracy of component positioning was similar. We found no differences in perioperative outcomes between these two approaches for THA. Variables other than the surgical approach including perioperative protocols, patient expectations, and the patient's general health may have a greater effect on outcomes such as pain during the early postoperative period, functional recovery, and length of hospital stay. The use of small incisions for THA was safe as was a shortened hospital stay in selected patients.

Preliminary radiological evaluation of the Vector Vision CT-free knee module for implantation of the LCS knee prosthesis

We have assessed the bone cuts achieved at surgery as compared to the planned cuts produced during computer assisted surgery (CAS) using a CT-free navigation system. In addition, two groups of matched patients were compared to assess the post-operative mechanical alignment achieved. Fourteen patients received a LCS total knee replacement (TKR) using the Vector Vision module and 14 received a TKR using a conventional method of extramedullary alignment jigs. The deviation in each plane (valgus–varus, flexion–extension and proximal–distal) was calculated. For the tibia the mean deviation in coronal plane was 0.21° of varus (SD = 1.37) and in the sagittal plane was 1.29° of flexion (SD = 3.73) and 0.24 mm of resection distal to the anticipated cut (SD = 2.14). For the femur the mean deviation in the coronal plane was 0.88° (SD = 2.2) of valgus and in the sagittal plane the mean deviation was 0.3° (SD = 2.91) of extension. In the transverse plane there was a mean deviation of 0.07° (SD = 1.57) of external rotation. There was a mean deviation of 2.33 mm of proximal resection (SD = 2.9) and 1.05 mm of anterior shift (SD = 2.81). On comparing the two groups, no statistically significant differences were found for the angles between the femoral component and the femoral mechanical axis, the tibial component and the tibial mechanical axis, the femoral and tibial mechanical axis and the femoral and tibial anatomical axis. This study has presented preliminary data regarding the efficacy of a particular navigation system with regards to improving upon the accuracy of component position with the long-term aspiration of improving upon TKR longevity. A further randomised controlled trial with greater numbers of cases and controls would improve upon our knowledge as to the efficacy of the Vector Vision system and a power analysis based upon the findings of this pilot study has suggested that at least thirty subjects be included in each group.

THA Performed using Conventional and Navigated Tissue-preserving Techniques

Less invasive methods of performing total hip arthroplasty have been considered controversial after increased complication rates and component malpositioning were reported. A new method of performing total hip arthroplasty through an incision in the superior capsule, posterior to the abductors and anterior to the posterior capsule, was developed with the aim of producing a technique that maintained the joint stability of the transgluteal exposure and the rapid abductor recovery of the posterior exposure. We assessed the recovery and complications of this technique performed with surgical navigation. The study group was compared with similar subjects who had conventional total hip arthroplasty, without surgical navigation, using the transgluteal exposure. There were 185 consecutive total hip arthroplasties in the study group and 189 nonconsecutive historical total hip arthroplasties in the control group. The two groups were controlled for complexity and had no differences in body mass index, gender, diagnosis, operative side, bilateral operations, and previous surgeries. Patients were evaluated for clinical recovery and perioperative complications at 9 and 24 weeks. The study group recovered faster at both followup examinations. The study group had fewer perioperative and postoperative complications compared with the control group. Accuracy of component positioning was not compromised compared to the control group. Less invasive surgery with the philosophy of maximally preserving the abductors, posterior capsule, and short rotators may result in a safer operation with faster recovery than traditional techniques.