Measuring leg length and offset with an imageless navigation system during total hip arthroplasty: is it really accurate?

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 risk of malpositioned components during surgery. This study will validate the intraoperative data captured using a handheld imageless THA navigation system against postoperative measurements of acetabular inclination, acetabular version, leg length and femoral offset on CT radiographs.Methods and analysisThis is a prospective observational cohort study conducted within a single-centre, single-surgeon private practice. Data will be collected for 35 consecutive patients (>18 years) undergoing elective THA surgery, from the research registry established at the surgeon’s practice. The primary outcome is the agreement between intraoperative component positioning data captured by the navigation system compared with postoperative measurements using CT. A total of ten CT scans will be reassessed for interobserver and intraobserver reliability. The influence of patient and surgical factors on the accuracy of component position will also be examined with multivariable linear regression.Ethics and disseminationEthics approval for this study was provided through a certified ethics committee (Bellberry HREC approval number 2017-07-499). The results of this study will be disseminated through peer-reviewed journals and conference presentations.Trial RegistrationAustralian and New Zealand Clinical Trials Registry (ANZCTR) Trial ID: ACTRN12620000089932.

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Accuracy of Leg Length and Offset Restoration in Femoral Pinless Navigation Compared to Navigation Using a Fixed Pin during Total Hip Arthroplasty

BioMed Research International ◽

10.1155/2018/1639840 ◽

2018 ◽

Vol 2018 ◽

pp. 1-6

Author(s):

Markus Weber ◽

Max Thieme ◽

Moritz Kaiser ◽

Florian Völlner ◽

Michael Worlicek ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Minimally Invasive ◽

Hip Arthroplasty ◽

Anterolateral Approach ◽

Leg Length ◽

Total Hip ◽

Imageless Navigation ◽

Number Of Patients ◽

Intraoperative Control ◽

Pinless Navigation

Equalization of biomechanical differences is a major goal in total hip arthroplasty (THA). In the current study we compared the accuracy of restoring leg length and offset using imageless navigation with an osseous fixed pin to a femoral pinless device in 97 minimally invasive THAs through an anterolateral approach in the lateral decubitus position. Leg length and offset differences were evaluated on magnification-corrected radiographs by a blinded observer. A postoperative mean difference of -0.9 mm (95% CI -2.8 mm to 1.1 mm, p = 0.38) between pinless navigation and navigation with a fixed pin was observed for leg length and that of -2.4 mm (95% CI -3.9 mm to -0.9 mm, p = 0.002) was observed for offset, respectively. The number of patients with a residual difference below 5 mm after THA was higher if using a fixed pin than in pinless navigation for both leg length (98.2%, 54/55 to 50.0%, 21/42, p < 0.001) and offset (100.0%, 55/55 to 71.4%, 30/42, p < 0.001). Imageless navigation is a feasible method in intraoperative control of leg length and offset in minimally invasive THA. The use of pins fixed to the bone has a higher precision than pinless devices. This trial is registered with DRKS00000739.

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Portable imageless navigation system and surgeon’s estimate for accurate evaluation of acetabular cup orientation during total hip arthroplasty in supine position

European Journal of Orthopaedic Surgery & Traumatology ◽

10.1007/s00590-020-02625-2 ◽

2020 ◽

Vol 30 (4) ◽

pp. 707-712 ◽

Cited By ~ 3

Author(s):

Ryohei Takada ◽

Tetsuya Jinno ◽

Kazumasa Miyatake ◽

Masanobu Hirao ◽

Toshitaka Yoshii ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Supine Position ◽

Navigation System ◽

Acetabular Cup ◽

Accurate Evaluation ◽

Total Hip ◽

Imageless Navigation

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Accuracy of Component Orientation and Leg Length Adjustment in Total Hip Arthroplasty Using Image-free Navigation

The Open Orthopaedics Journal ◽

10.2174/1874325001711011432 ◽

2017 ◽

Vol 11 (1) ◽

pp. 1432-1439 ◽

Cited By ~ 5

Author(s):

Yu Takeda ◽

Shigeo Fukunishi ◽

Shoji Nishio ◽

Yuki Fujihara ◽

Shinichi Yoshiya

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Navigation System ◽

Intraoperative Navigation ◽

Consecutive Series ◽

Leg Length ◽

Basic Study ◽

Total Hip ◽

Prosthetic Alignment ◽

Component Orientation

Purpose: The purpose of this study was to examine the accuracy of implant orientation and leg length in total hip arthroplasty (THA) with an image-free navigation system based on a comparison of the intraoperative navigation and postoperative CT evaluations. Material and Methods: A consecutive series of 111 patients (118 hips) who underwent THA using the current version of the image-free navigation system constituted the basic study population. Subsequently, a total of 101 patients (108 hips) meeting the inclusion and exclusion criteria were selected as study subjects for the analysis. THA was performed using an image-free navigation system that was capable of adjusting both the prosthetic position and leg length. Postoperative CT examination was performed for all study subjects, and the prosthetic position and leg length were measured on CT images using the image analysis software. Subsequently, the intraoperative navigation results and the corresponding values obtained from the postoperative CT measurements were compared to test the accuracy of the navigation system. Results: The average discrepancies between the intra- and postoperative assessments were 6.8°, 3.7°, and 5.7° for cup anteversion, cup inclination, and stem anteversion, respectively. The corresponding value in leg length averaged 4.1 mm. Conclusion: Average discrepancies between the intra- and postoperative measurements were less than 10° in all prosthetic alignment parameters and less than 5 mm in leg length. Intraoperative assessments with the use of the image-free navigation in THA could afford satisfactory result.

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Imageless Navigation Improves Intraoperative Monitoring of Leg Length Changes during Total Hip Arthroplasty for Legg-Calve-Perthes Disease: Two Case Reports

Case Reports in Orthopedics ◽

10.1155/2018/4362367 ◽

2018 ◽

Vol 2018 ◽

pp. 1-4

Author(s):

Ritesh R. Shah ◽

Varsha Gobin ◽

Jeffrey M. Muir

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Case Reports ◽

Assistive Technologies ◽

Perthes Disease ◽

Computer Assisted ◽

Leg Length ◽

Total Hip ◽

Imageless Navigation ◽

Length Changes

Legg-Calve-Perthes disease is a rare condition characterized by avascular necrosis and malformation of the femoral head. For many patients, total hip arthroplasty (THA) is the only viable treatment option; however, there are challenges associated with THA in this population, primarily the equalization of leg lengths. Here, we present two cases of Legg-Calve-Perthes disease treated via total hip arthroplasty with the assistance of an imageless, computer-assisted navigation device. In each case, the device provided intraoperative data on leg length in real time, allowing for improved accuracy of component placement. Postoperative leg lengths were confirmed to be equalized in each case using radiographs. These cases are, to our knowledge, the first such cases using imageless navigation during THA and demonstrate the benefits of such assistive technologies in challenging cases such as Legg-Calve-Perthes disease.

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Accuracy of imageless navigation for functional cup positioning and restoration of leg length in total hip arthroplasty: a matched comparative analysis

Current Orthopaedic Practice ◽

10.1097/bco.0000000000000952 ◽

2020 ◽

Vol 32 (1) ◽

pp. 48-52

Author(s):

Morteza Meftah ◽

Vinay Hosuru Siddappa ◽

Jeffrey M. Muir

Keyword(s):

Comparative Analysis ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Leg Length ◽

Total Hip ◽

Imageless Navigation ◽

Cup Positioning

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Value of 3D Preoperative Planning for Primary Total Hip Arthroplasty Based on Biplanar Weightbearing Radiographs

BioMed Research International ◽

10.1155/2019/1932191 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 6

Author(s):

Y. Knafo ◽

F. Houfani ◽

B. Zaharia ◽

F. Egrise ◽

I. Clerc-Urmès ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Preoperative Planning ◽

Femoral Stem ◽

Leg Length ◽

Femoral Offset ◽

Postoperative Result ◽

Total Hip ◽

Planning Software ◽

Navigated Surgery

Two-dimensional (2D) planning on standard radiographs for total hip arthroplasty may not be sufficiently accurate to predict implant sizing or restore leg length and femoral offset, whereas 3D planning avoids magnification and projection errors. Furthermore, weightbearing measures are not available with computed tomography (CT) and leg length and offset are rarely checked postoperatively using any imaging modality. Navigation can usually achieve a surgical plan precisely, but the choice of that plan remains key, which is best guided by preoperative planning. The study objectives were therefore to (1) evaluate the accuracy of stem/cup size prediction using dedicated 3D planning software based on biplanar radiographic imaging under weightbearing and (2) compare the preplanned leg length and femoral offset with the postoperative result. This single-centre, single-surgeon prospective study consisted of a cohort of 33 patients operated on over 24 months. The routine clinical workflow consisted of preoperative biplanar weightbearing imaging, 3D surgical planning, navigated surgery to execute the plan, and postoperative biplanar imaging to verify the radiological outcomes in 3D weightbearing. 3D planning was performed with the dedicated hipEOS® planning software to determine stem and cup size and position, plus 3D anatomical and functional parameters, in particular variations in leg length and femoral offset. Component size planning accuracy was 94% (31/33) within one size for the femoral stem and 100% (33/33) within one size for the acetabular cup. There were no significant differences between planned versus implanted femoral stem size or planned versus measured changes in leg length or offset. Cup size did differ significantly, tending towards implanting one size larger when there was a difference. Biplanar radiographs plus hipEOS planning software showed good reliability for predicting implant size, leg length, and femoral offset and postoperatively provided a check on the navigated surgery. Compared to previous studies, the predictive results were better than 2D planning on conventional radiography and equal to 3D planning on CT images, with lower radiation dose, and in the weightbearing position.

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Staged reconstruction of unilateral neglected hip dislocation through total hip arthroplasty and subsequent intramedullary femoral lengthening

International Orthopaedics ◽

10.1007/s00264-021-05099-x ◽

2021 ◽

Author(s):

Bjoern Vogt ◽

Christoph Theil ◽

Georg Gosheger ◽

Adrien Frommer ◽

Burkhard Moellenbeck ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Plate Fixation ◽

Hip Dislocation ◽

Leg Length ◽

Total Hip ◽

Femoral Lengthening ◽

Shortening Osteotomy ◽

Successful Approach ◽

Staged Reconstruction

Abstract Background and purpose Total hip arthroplasty (THA) is a successful approach to treat unilateral symptomatic neglected hip dislocation (NHD). However, the extensive leg length discrepancy (LLD) can hereby only be partially corrected. In case of residual LLD of more than 2 cm, subsequent femoral lengthening can be considered. Patients/material/methods Retrospective analysis of clinical data and radiographs of five patients (age 38.1 (28–51) years) with unilateral NHD who underwent THA with (n = 3) or without (n = 2) subtrochanteric shortening osteotomy (SSO) and secondary intramedullary femoral lengthening through a retrograde magnetically-driven lengthening nail (follow-up 18.4 (15–27) months). Results LLD was 51.0 (45–60) mm before and 37.0 (30–45) mm after THA. Delayed bone union at one SSO site healed after revision with autologous bone grafting and plate fixation. Subsequent lengthening led to leg length equalisation in all patients. Complete consolidation was documented in all lengthened segments. Conclusion Staged reconstruction via THA and secondary femoral lengthening can successfully be used to reconstruct the hip joint and equalise LLD. The specific anatomical conditions have to be taken into consideration when planning treatment, and patients ought to be closely monitored.

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