The Orthopilot Navigation System for Primary Bicontact Total Hip Replacement

Kiefer, Hartmut; Othman, A.

doi:10.1055/s-2007-965650

Cited by 5 publications

(5 citation statements)

References 10 publications

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“…Accuracy within 5mm occurs in 89% of cases (Table 2 ), and this means that surgeons utilizing navigation can be reassured that the results are a close approximation of actual changes. This finding improves upon the observations of Kiefer and Othman, where a different navigation system was studied and found to be accurate within 5mm 83-85% of the time [ 23 ]. The correlation between methods was not as strong in this study (R=0.71) compared to the findings of Renkawitz et al (R=0.92) [ 24 ] and Renkawitz et al (R>0.80) [ 25 ].…”

Section: Discussionsupporting

confidence: 87%

“…It was decided to examine the mean absolute difference to look at the average size of the navigation measurement discrepancy irrespective of direction from radiographic measurements. As a result, the mean difference of 2.6mm found in this study is slightly higher than differences described in the literature, which range from 0.2 to 1.3mm [6,[22][23][24][25]. Furthermore, it was greater than the experimental mean difference of 0.5mm using the same navigation system in a cadaveric study and 0.5mm in vivo [6,24,25].…”

Section: Discussioncontrasting

confidence: 77%

“…Intra-operative measurements of leg length and offset made by navigation systems in both experimental and patient studies show varying reliability [6,[22][23][24][25]. A comparative study assessed the same navigation software in cadavers [6,24].…”

Section: Introductionmentioning

confidence: 99%

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Accuracy of Leg Length and Offset Measurements During Total Hip Arthroplasty Using an Imageless Navigation System

Lambers¹,

Marley²,

Jennings³

et al. 2023

Cureus

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Introduction Leg length and offset are important considerations in total hip arthroplasty (THA). Navigation systems are capable of providing intra-operative measurements of leg length and offset, and high accuracy has been shown in experimental studies. This study assesses the accuracy of an imageless navigation system with a pinless femoral array (Hip 5.1, BrainLAB, Feldkirchen, Germany) in measuring leg length and offset changes in vivo. Methods A prospective, consecutive series of 37 patients undergoing navigated THA were included in the study. Intra-operative measurements of leg length and offset were recorded using the navigation system. For each patient, pre- and post-operative digital radiographs were scaled and analyzed to provide radiographic measurements for comparison. Results Measurements of leg length change made by the navigation system showed a strong correlation with the size of change measured radiographically (R = 0.71; p<0.0001). The mean difference between the radiographic and navigational measurement was 2.6mm ± 3.0mm (0.0-16.0mm) (mean, SD, range). The navigation system was accurate to within 1mm of the radiographic measurement in 49% of cases, within 2mm in 66% of cases, and within 5mm in 89% of cases. Measurements of offset change by the navigation system also showed a correlation with radiographic measurements, albeit less pronounced (R = 0.35; p=0.035). The mean difference between navigational and radiographic measurements was 5.5mm ± 4.7mm (0.0-16.0mm) (mean, SD, range). The navigation system was accurate within 1mm of the radiographic measurement in 22% of cases, within 2mm in 35% of cases, and within 5mm in 57% of cases. Conclusions This research demonstrates in vivo that an imageless, non-invasive navigation system is a reliable tool for intra-operative leg length (accurate within 2mm) and to a lesser extent offset measurement (accurate within 5mm) when compared to standard practice of plain film radiographs.

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Section: Discussionsupporting

confidence: 87%

Section: Discussioncontrasting

confidence: 77%

See 1 more Smart Citation

Accuracy of Leg Length and Offset Measurements During Total Hip Arthroplasty Using an Imageless Navigation System

Lambers¹,

Marley²,

Jennings³

et al. 2023

Cureus

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“…Most of them use partially or fully the data collected during surgery by the computer [23,24]. This study leads us to conclude that it is possible to guide cup orientation using a kinematicsbased (i.e.…”

Section: Discussionmentioning

confidence: 83%

Imageless computer assistance to orientate the cup of total hip arthroplasties: a new system based on joint kinematics

et al. 2008

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Purpose of the study: Most imageless navigation systems for computer-assisted (CAS) total hip arthroplasty (THA) aim at orientating the cup with regard to the anterior pelvic plane (APP). However, these systems have some limitations: 1) the adequate position is not well defined to prevent impingement and dislocation; 2) dynamic variation of the APP according to activities (sitting, climbing stairs, etc.) are not integrated in determining the adequate orientation; 3) intraoperative assessment of the APP is not reliable with conventional tools, requiring ultrasound or two-stage identification. To address these issues, we developed an imageless CAS system without using APP, based on a kinematic approach of the hip joint. This system does not use the APP as the reference plane to orient the cup. The system helps the surgeon to orient the cup in relation to the cone describing the hip joint range of motion. The purpose of this study was to detail the technique and to analyze preliminary results.Materials and methods: Twenty-four primary cementless THAs were implanted using CAS Pleos with optoelectronic tracking system (18 women, 6 men; mean age, 67 AE 7.8 years, age range, 54-83 years) because of primary osteoarthritis. Two optoelectronic sensors are fixed percutaneously on the pelvis and the distal femur. The acetabulum is prepared first, followed by the femur using reamers and broaches of increasing size. The last broach placed in the femur was equipped with a large head adapted to the newly prepared acetabulum. The range of hip motion is recorded to determine the maximal range of motion cone. The acetabular cup is thus positioned so that the prosthesis range of motion totally covers the maximal range of motion of the hip joint.Results: The Postel-Merle-d'Aubigné score improved from 8.1 AE 3.2 (range, 3-13) preoperatively to 17.1 AE 0.8 (range, 16-18) at last follow-up. There were no complaints of patients about the sensor insertion and no cases of hematoma or fracture. Operative time was 35-40 min longer for the first four cases and was progressively reduced by 15-20 min for the last four cases. Mean leg length discrepancy was 5.6 AE 7.5 mm (range, 0-25 mm) before implantation and 0.6 AE 3 mm (range, -5 to 10 mm) at last follow-up, eighteen were equal. Mean frontal cup inclination was 47 AE 7 (range, 38-60 ). After CT-scan measurement, mean anteversion of the femoral implant was 16.8 AE 9.2 (0-31 ). The mean cup anteversion was 25.2 AE 9.2 (range, 8-40 ) for ''anatomical anteversion''. Only 10 of the 24 cups were orientated inside the Lewinnek safe zone (there was only one dislocation that was traumatic with a cup orientated in the safe zone).Conclusion: This method can be used in routine procedures without lengthening operative time significantly. It safely controls leg length and helps position the cup. This study demonstrates that there is no ideal position for the cup that can be used for all patients. Because of the wide range of inclination and anteversion figures, 58% of the cups were outside the safe zone r...

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“…Ohashi (&), M. Matsuura, Y. Okamoto, Y. Okajima Department of Orthopaedic Surgery, Saiseikai Nakatsu Hospital, 2-10-39 Shibata, Kita-ku, Osaka 530-0012, Japan e-mail: LU7H-OOHS@asahi-net.or.jp mechanically guided implantation and navigated implantation [5,7,11,22,29,30] and established when the cup was positioned within a presumed safe zone or when the deviations from the desired cup position occurred. Accuracy has been determined by comparing the intraoperative measurement by the navigation system to the postoperative measurement on plain radiograph or CT scan, assuming the radiograph or CT scan are gold standards [2, 6,14,18,33]. The difference of the angles between what is known on the gold standard and what is discerned by the navigation system indicates the accuracy.…”

Section: Introductionmentioning

confidence: 99%

Intra- and Intersurgeon Variability in Image-free Navigation System for THA

Ohashi

Matsuura

Okamoto

et al. 2009

Clinical Orthopaedics &Amp; Related Research

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In image-free navigation systems, cup orientation is determined in the pelvic coordinate by registration of bony landmarks. While the value of navigation relates primarily to the reliability and accuracy of cup placement, the reliability of registration plays a role in cup placement. We therefore examined intra- and intersurgeon variability in registration and the distance between registration points in each bony landmark. Thirty-seven THAs were performed in the lateral position and 15 THAs in the supine position. The cup was fixed using a navigation system. The registration was repeated two more times by operator and assistant, and the intra- and intersurgeon variability of cup abduction angle and anteversion was analyzed by ICC (intraclass correlation coefficients). In 25 hips, the distance between intrasurgeon registration points and between intersurgeon registration points in each landmark were calculated. The ICC in the lateral position ranged between 0.59 and 0.81, and between 0.85 and 0.95 in the supine position. The ICCs of cup abduction angle for the intra- and intersurgeon variability were 0.92 and 0.95 for the supine position and 0.65 and 0.59 for the lateral position. Those of anteversion were 0.93, 0.85, and 0.81, 0.72, respectively. The variability in locating the ASIS in the lateral position was greater than that in the supine position. The variability of registration points depended on bony landmarks and patient position but the range of variability we found would not likely result in a large variability in cup placement.

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The Orthopilot Navigation System for Primary Bicontact Total Hip Replacement

Cited by 5 publications

References 10 publications

Accuracy of Leg Length and Offset Measurements During Total Hip Arthroplasty Using an Imageless Navigation System

Accuracy of Leg Length and Offset Measurements During Total Hip Arthroplasty Using an Imageless Navigation System

Imageless computer assistance to orientate the cup of total hip arthroplasties: a new system based on joint kinematics

Intra- and Intersurgeon Variability in Image-free Navigation System for THA

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