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Wang J, Hall TAG, Musbahi O, Jones GG, van Arkel RJ. Predicting hip-knee-ankle and femorotibial angles from knee radiographs with deep learning. Knee 2023; 42:281-288. [PMID: 37119601 DOI: 10.1016/j.knee.2023.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 01/25/2023] [Accepted: 03/09/2023] [Indexed: 05/01/2023]
Abstract
BACKGROUND Knee alignment affects the development and surgical treatment of knee osteoarthritis. Automating femorotibial angle (FTA) and hip-knee-ankle angle (HKA) measurement from radiographs could improve reliability and save time. Further, if HKA could be predicted from knee-only radiographs then radiation exposure could be reduced and the need for specialist equipment and personnel avoided. The aim of this research was to assess if deep learning methods could predict FTA and HKA angle from posteroanterior (PA) knee radiographs. METHODS Convolutional neural networks with densely connected final layers were trained to analyse PA knee radiographs from the Osteoarthritis Initiative (OAI) database. The FTA dataset with 6149 radiographs and HKA dataset with 2351 radiographs were split into training, validation, and test datasets in a 70:15:15 ratio. Separate models were developed for the prediction of FTA and HKA and their accuracy was quantified using mean squared error as loss function. Heat maps were used to identify the anatomical features within each image that most contributed to the predicted angles. RESULTS High accuracy was achieved for both FTA (mean absolute error 0.8°) and HKA (mean absolute error 1.7°). Heat maps for both models were concentrated on the knee anatomy and could prove a valuable tool for assessing prediction reliability in clinical application. CONCLUSION Deep learning techniques enable fast, reliable and accurate predictions of both FTA and HKA from plain knee radiographs and could lead to cost savings for healthcare providers and reduced radiation exposure for patients.
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Affiliation(s)
- Jinhong Wang
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Thomas A G Hall
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Omar Musbahi
- Department of Surgery and Cancer, Imperial College London, White City Campus, London W12 0BZ, United Kingdom
| | - Gareth G Jones
- Department of Surgery and Cancer, Imperial College London, White City Campus, London W12 0BZ, United Kingdom
| | - Richard J van Arkel
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom.
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2
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Shin C, Crovetti C, Huo E, Lionberger D. Unsatisfactory accuracy of recent robotic assisting system ROSA for total knee arthroplasty. J Exp Orthop 2022; 9:82. [PMID: 35984537 PMCID: PMC9391541 DOI: 10.1186/s40634-022-00522-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 08/11/2022] [Indexed: 11/30/2022] Open
Abstract
Purpose The purpose of this study was to quantify accuracy of a recently FDA-approved robotic-assisted device. Methods Thirty-seven patients underwent TKA with the Robotic Surgical Assistant (ROSA) by the same operating surgeon and team over the course of 3 months. Intra-operative mechanical axis measurements, composed of alpha (α), beta (β), gamma (γ), and delta (δ) angles, and the hip-knee-ankle angle (HKA) were calculated by the ROSA. Post-operative mechanical implant angles were taken from 36″ stitched post-op films and measured in the PACS imaging system. Accuracy was assessed by comparing the percentage of postoperative long length films within 2° and 3° of the ROSA intra-operative plan. Results The ROSA system accurately calculated the HKA, α, and β angles (95% CI), but was inaccurate in calculating both γ and δ angles. Using a window of ± 3° accuracy, the HKA, α and β angles were accurate at levels of 89, 100 and 92% respectively. In contrast, the sagittal relationships were considerably less accurate at 77 and 74% for the γ and δ angles respectively. Subsequently, the proportion of cases within 2 and 3 degrees of the intra-operative plan for resection angles was considered accurate for HKA (73% within 2°, 89% within 3°), α (92% within 2°, 100% within 3°), and β (76% within 2°, 92% within 3°) angles, but considered inaccurate for γ (51% within 2°, 77% within 3°) and δ angles (57% within 2°, 74% within 3°). Conclusions This study demonstrated that while the ROSA system seems to accurately predict coronal plane resections in TKA, it falls short in the sagittal plane. Further research in these deficiencies can provide insight into the overall efficacy of robotic assisted surgery in TKA. Level of Evidence Level III Therapeutic Study.
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Affiliation(s)
- Caleb Shin
- Department of Orthopaedic Surgery, Houston Methodist Hospital, 6445 Main St, Houston, TX, USA. .,Texas A&M College of Medicine, Bryan, TX, USA.
| | - Chelsea Crovetti
- Department of Orthopaedic Surgery, Houston Methodist Hospital, 6445 Main St, Houston, TX, USA.,Texas A&M College of Medicine, Bryan, TX, USA
| | - Enshuo Huo
- Department of Orthopaedic Surgery, Houston Methodist Hospital, 6445 Main St, Houston, TX, USA
| | - David Lionberger
- Department of Orthopaedic Surgery, Houston Methodist Hospital, 6445 Main St, Houston, TX, USA
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3
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Keuntje-Perka S, von Roth P, Worlicek M, Koch M, Alt V, Kaiser M. Pinless Navigation in Unicompartmental Knee Arthroplasty. J Clin Med 2021; 10:jcm10112422. [PMID: 34070715 PMCID: PMC8198384 DOI: 10.3390/jcm10112422] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/22/2021] [Accepted: 05/27/2021] [Indexed: 11/28/2022] Open
Abstract
Purpose: In contrast to total knee arthroplasty (TKA), unicompartmental knee arthroplasty (UKA) is a true resurfacing procedure, as none of the ligaments are replaced or released, and the pre-arthritic leg alignment is the major goal. As such, the alignment of the tibial component plays a crucial role in postoperative knee function and long-term survival. Pinless navigation has shown reliable results in total knee arthroplasty. To the best of our knowledge, the use of pinless navigation has not been investigated for UKA. Therefore, the present study investigated whether implantation of the tibial component in 3° varus, which is closer to the anatomical axis, is feasible with a pinless optical navigation system. Methods: 60 patients with the diagnosis of an unicompartmental arthritis, were eligible for UKA and treated with implantation in 3° varus alignment of the tibial component. Two groups were established. In the treatment group the tibial component was aligned using a pinless navigation technique. In the control group, a conventional extramedullary alignment guide was used. A clinical and radiographic follow up took place within 1 year of operation. Results: 57 Patients were eligible for analysis. No clinical incidents were noted in the follow up period. The desired target value, the position of the tibial component, was accurately achieved with an average of 3° medial inclination using the pinless navigation as well as using the conventional technique. Mean incision to suture time was negligible between the two techniques. The mean suture time was 43.2 min with pinless navigation and 42.7 min with the conventional technique. Conclusions: With pinless navigation in UKA, a method was presented that made it possible to achieve sled prosthesis alignment at the level of a high-volume surgeon. These results were achieved with an irrelevant increase of surgical time and without placement of pins.
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Affiliation(s)
- Sarah Keuntje-Perka
- Sporthopaedicum Straubing, Medical Care Center, 94135 Straubing, Germany; (S.K.-P.); (P.v.R.); (M.K.)
- Department of Trauma Surgery, Regensburg University Medical Center, 93053 Regensburg, Germany; (M.K.); (V.A.)
| | - Philipp von Roth
- Sporthopaedicum Straubing, Medical Care Center, 94135 Straubing, Germany; (S.K.-P.); (P.v.R.); (M.K.)
| | - Michael Worlicek
- Department of Trauma Surgery, Regensburg University Medical Center, 93053 Regensburg, Germany; (M.K.); (V.A.)
- Correspondence:
| | - Matthias Koch
- Department of Trauma Surgery, Regensburg University Medical Center, 93053 Regensburg, Germany; (M.K.); (V.A.)
| | - Volker Alt
- Department of Trauma Surgery, Regensburg University Medical Center, 93053 Regensburg, Germany; (M.K.); (V.A.)
| | - Moritz Kaiser
- Sporthopaedicum Straubing, Medical Care Center, 94135 Straubing, Germany; (S.K.-P.); (P.v.R.); (M.K.)
- Department of Trauma Surgery, Regensburg University Medical Center, 93053 Regensburg, Germany; (M.K.); (V.A.)
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Laddha M, Gaurav S. Assessment of Limb Alignment and Component Placement After All Burr Robotic-Assisted TKA. Indian J Orthop 2020; 55:69-75. [PMID: 34122757 PMCID: PMC8149507 DOI: 10.1007/s43465-020-00269-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 09/18/2020] [Indexed: 02/04/2023]
Abstract
BACKGROUND All burr robotic-assisted total knee arthroplasty (R-TKA) is the new way of doing TKA without conventional jigs and saw. The aim of this study is to assess the accuracy of limb alignment and component placement after R-TKA. METHODS AND MATERIALS This is the prospective study of 63 patients who underwent R-TKA between March and October 2019. Standing scanogram and AP/lateral radiograph were done on day of discharge, 5th day after surgery to calculate limb alignment and component placement angles in coronal and sagittal plane. Deformity correction Bone Ninja software had been used to calculate all this angles. RESULTS Mean difference between robotic achieved and postoperative limb alignment was 1.24°. Mean difference between planned and achieved component placement in coronal and sagittal plane for tibia was 0.33° and 0.66° and for femur was 0.62° and 0.30°, respectively. Posterior condylar offset difference was 0.03. As per planned by Navio software, R-TKA had reduced the overall outlier of coronal limb alignment from 3° to less than 1.2° and component placement malposition to less than 1° in coronal and sagittal plane. CONCLUSION R-TKA provides near perfect limb alignment and near accurate femoral/tibial component placement as planned in both coronal and sagittal plane. Posterior condylar offset was also perfectly maintained. R-TKA had reduced the overall outlier of coronal limb alignment from 3° to less than 1.2° and component placement malposition to less than 1° in coronal and sagittal plane.
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Affiliation(s)
- Mukesh Laddha
- Robotic Joint Replacement and Arthroscopy Specialist (Shoulder, Knee and Hip Surgeon), RNH Hospital, Balraj Marg, Near Dhantoli Garden, Dhantoli, Nagpur, Maharashtra 440022 India
| | - Sahu Gaurav
- Consultant Orthopaedic Surgeon, Dhamtari Christian Hospital, Dhamtari, Chhattisgarh India
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Koenen P, Ates DM, Pfeiffer TR, Bouillon B, Bäthis H. Femoral flexion position is a highly variable factor in total knee arthroplasty: an analysis of 593 conventionally aligned total knee replacements. Knee Surg Sports Traumatol Arthrosc 2020; 28:1014-1022. [PMID: 31131420 DOI: 10.1007/s00167-019-05548-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 05/17/2019] [Indexed: 12/01/2022]
Abstract
PURPOSE In contrast to coronal alignment, only few is known about sagittal alignment in total knee arthroplasty (TKA). The aim of this study was to identify the flexion position of the femoral component in a routine surgical setting of conventional TKA and to evaluate potential predictors for the degree of femoral flexion. METHODS A retrospective study was performed on 593 primary TKA using the conventional intramedullary alignment technique for distal femur. Femoral flexion was measured by the verification mode of a pinless navigation system. Correlations between femoral flexion and patient-specific data, surgery-related factors and measurements of a preoperative anterior-posterior long-leg X-ray were analysed. RESULTS The distal femoral resection showed a mean flexion of 5.5° ± 2.5° to the mechanical axis with high variation between 2.5° extension and 14° flexion. In a multivariate regression model, body height (p = 0.023), body weight (p = 0.046) and body mass index (p = 0.026) showed significant positive correlation to femoral flexion. There was no correlation to any preoperative alignment data from the anterior-posterior long-leg film. The sagittal position was also independent from surgery-related factors such as different knee systems or surgeons. CONCLUSIONS Femoral flexion is a highly variable characteristic in conventionally aligned TKA. Increasing body height, body weight and body mass index were identified as predictors for a high degree of femoral flexion. LEVEL OF EVIDENCE III.
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Affiliation(s)
- Paola Koenen
- Department of Orthopaedics, Trauma Surgery and Sports Medicine, Cologne Merheim Medical Center, University of Witten/Herdecke, Ostmerheimer Str. 200, 51109, Cologne, Germany.
| | - Deha Murat Ates
- Department of Orthopaedics, Trauma Surgery and Sports Medicine, Cologne Merheim Medical Center, University of Witten/Herdecke, Ostmerheimer Str. 200, 51109, Cologne, Germany
| | - Thomas R Pfeiffer
- Department of Orthopaedics, Trauma Surgery and Sports Medicine, Cologne Merheim Medical Center, University of Witten/Herdecke, Ostmerheimer Str. 200, 51109, Cologne, Germany
| | - Bertil Bouillon
- Department of Orthopaedics, Trauma Surgery and Sports Medicine, Cologne Merheim Medical Center, University of Witten/Herdecke, Ostmerheimer Str. 200, 51109, Cologne, Germany
| | - Holger Bäthis
- Department of Orthopaedics, Trauma Surgery and Sports Medicine, Cologne Merheim Medical Center, University of Witten/Herdecke, Ostmerheimer Str. 200, 51109, Cologne, Germany
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6
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Ulivi M, Orlandini LC, Meroni V, Castoldi D, Lombardo MDM, Peretti GM. Intraoperative validation of bone cut accuracy of a pinless smart touch-screen navigation system device in total knee arthroplasty. Int J Med Robot 2019; 15:e2030. [PMID: 31379057 DOI: 10.1002/rcs.2030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Revised: 07/19/2019] [Accepted: 07/28/2019] [Indexed: 11/08/2022]
Abstract
PURPOSE Primary objective in most of the published literature on computer-assisted total knee arthroplasty (TKA) has so far been the comparison of axial alignment and components position, obtained either through navigation systems or through conventional instrumentation. We have found no studies aimed at assessing the intraoperative reliability of a navigation system in relation to bone cuts height. Aim of our study was therefore to establish bone cut accuracy of a pinless navigation system. METHODS From January 2014 to February 2016, 44 consecutive patients requiring total knee replacement (TKR) were enrolled in a prospective study. Primary end point of the study was to assess the accuracy of the DASH iPOD TOUCH Navigation System (Brainlab AG, Feldkirchen, Germany) by measuring the real thickness of both tibial and femoral osteotomies. We compared the data indicated by the navigation system with the intraoperative anatomical measurements done with the aid of a caliper. In addition, the radiographic alignment was compared with the data derived from the navigator. RESULTS The device proved to be precise. Differences between the two methods of measurement are distributed over a millimeter range. Radiological measurements showed that 95.5% of tibial components were within the range of 3° varus/valgus; same results were obtained by the navigation system; instead, 90.1% of femoral components were within the range of 3° varus/valgus based on the radiological measurement, whereas according to the navigation system, 86.4% were in this range. CONCLUSIONS The DASH iPOD TOUCH Navigation System is a precise and reliable instrument to assist in TKA navigation.
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Affiliation(s)
| | | | | | - Daniele Castoldi
- Residency Program in Orthopedics and Traumatology, University of Milan, Milan, Italy
| | | | - Giuseppe M Peretti
- IRCCS Istituto Ortopedico Galeazzi, Milan, Italy.,Department of Biomedical Sciences for Health, University of Milan, Milan, Italy
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7
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Casper M, Mitra R, Khare R, Jaramaz B, Hamlin B, McGinley B, Mayman D, Headrick J, Urish K, Gittins M, Incavo S, Neginhal V. Accuracy assessment of a novel image-free handheld robot for Total Knee Arthroplasty in a cadaveric study. Comput Assist Surg (Abingdon) 2019; 23:14-20. [PMID: 30307763 DOI: 10.1080/24699322.2018.1519038] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Surgical navigation has been shown to improve the accuracy of bone preparation and limb alignment in total knee arthroplasty (TKA). Previous work has shown the effectiveness of various types of navigation systems. Here, for the first time, we assessed the accuracy of a novel imageless semiautonomous handheld robotic sculpting system in performing bone resection and preparation in TKA using cadaveric specimens. In this study, we compared the planned and final implant placement in 18 cadaveric specimens undergoing TKA using the new tool. Eight surgeons carried out the procedures using three types of implant designs. A quantitative analysis was performed to determine the translational, angular, and rotational differences between the planned and achieved positions of the implants. The mean femoral flexion, varus/valgus, and rotational error was -2.0°, -0.1°, and -0.5°, respectively. The mean tibial posterior slope, and varus/valgus error was -0.2°, and -0.2°, respectively. We obtained higher flexion errors for the femoral implant when using cut-guides as compared to using a bur for cutting the bones. The image-free robotic sculpting tool achieved accurate implementation of the surgical plan with small errors in implant placement. Future studies will focus on determining how well the accurate implant placement translates into a clinical and functional benefit for the patient.
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Affiliation(s)
| | | | - Rahul Khare
- a Smith & Nephew Inc. , Pittsburgh , PA , USA
| | | | - Brian Hamlin
- b Department of Orthopaedic Surgery , The Bone and Joint Center, Magee Womens Hospital of the University of Pittsburgh Medical Center , Pittsburgh , PA , USA
| | - Brian McGinley
- c John T. Mather Memorial hospital , Port Jefferson , NY , USA
| | - David Mayman
- d Orthopaedic Surgery , Hospital for Special Surgery , New York , NY , USA
| | - Jeff Headrick
- e Orthopedic Surgeon , The Center for Orthopedic Surgery , Lubbock , TX , USA
| | - Kenneth Urish
- f Arthritis and Arthroplasty Design Group , The Bone and Joint Center, Magee Womens Hospital of the University of Pittsburgh Medical Center , Pittsburgh , PA , USA.,g Department of Orthopaedic Surgery, Department of Bioengineering, and Clinical and Translational Science Institute , University of Pittsburgh , Pittsburgh , PA , USA.,h Department of Biomedical Engineering , Carnegie Mellon University, University of Pittsburgh , Pittsburgh , PA , USA
| | | | - Stephen Incavo
- j Adult Reconstructive Surgery , Houston Methodist Hospital Center for Orthopaedic Surgery , Houston , TX , USA.,k Houston Methodist Hospital , Houston , TX , USA
| | - Vivek Neginhal
- l Orthopedic Surgeon, Scott Orthopedic Center , Huntington , WV , USA
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8
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The Impact of Pinless Navigation in Conventionally Aligned Total Knee Arthroplasty. Adv Orthop 2018; 2018:5042536. [PMID: 29593913 PMCID: PMC5822932 DOI: 10.1155/2018/5042536] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/20/2017] [Accepted: 01/04/2018] [Indexed: 11/18/2022] Open
Abstract
Background Restoration of the mechanical axis is a main objective in total knee replacement (TKR). Aim of this study was to analyse the verification tool of a pinless navigation system in conventional TKR (cTKR). Methods In a prospective study, 147 TKR were performed by conventional technique. Using the “pinless verification” mode of a smartphone based navigation system, the cutting block position and final resection plane for distal femur and proximal tibial resection were measured. If necessary, the block position or resection level were optimized, corrections were protocolled. Postoperatively, standardized radiographs were performed. Results In 65.3%, intraoperative measurements changed the surgical procedure (corrections: 20.4% femoral, 25.9% tibial, 19% both). The additional time for surgery compared to cTKR averaged 6 minutes (79 ± 15 versus 73 ± 17 minutes). Using navigation data, the final femoral and tibial axes were in 93% within a range of ±2°. A mean difference of 1.4° and 1.6° could be shown between the final measurement of the navigation system and the postoperative mLDFA and mMPTA. Conclusion Intraoperative pinless navigation has impact on the surgical procedure in the majority of cTKR. It represents a less time-consuming tool to improve implant position while maintaining the routine of conventional technique.
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9
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Maderbacher G, Keshmiri A, Schaumburger J, Zeman F, Birkenbach AM, Craiovan B, Grifka J, Baier C. What is the optimal valgus pre-set for intramedullary femoral alignment rods in total knee arthroplasty? Knee Surg Sports Traumatol Arthrosc 2017; 25:3480-3487. [PMID: 27154280 DOI: 10.1007/s00167-016-4141-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 04/14/2016] [Indexed: 11/27/2022]
Abstract
PURPOSE In total knee arthroplasty (TKA), intramedullary guides are often used for aligning the distal femoral cutting block. Because of the highly varying angles between the mechanical axis and the anatomical femoral axis (AMA), different valgus pre-sets have been recommended. The present study investigated the optimal valgus pre-set (measuring the AMA in long-leg radiographs or at 5°, 6°, 7° or 8° valgus) to align the cutting block perpendicularly to the mechanical axis. METHODS The AMA was preoperatively measured in weight-bearing long-leg radiographs. After alignment of the cutting block by means of an intramedullary rod, deviation of the block from the mechanical femoral axis was measured with a pinless navigation device. The true AMA (tAMA) was calculated by adding the valgus pre-set of the alignment rod to the deviation measured with the navigation device. Mean deviations between the tAMA and (a) the AMA measured by the surgeon, (b) the AMA calculated with the computer software, (c) 5°, (d) 6°, (e) 7° and (f) 8° valgus pre-sets were measured for each patient. The lowest mean differences were determined. RESULTS The 40 knees measured showed a mean tAMA of 7.2° valgus (1.7 SD) (range 4°-11.5°). The following mean differences and 95 % limits of agreement were calculated: 2.2 (-1.2, 5.5) to the tAMA for the 5° valgus pre-set, 1.2 (-2.2, 4.5) for 6°, 0.2 (-3.2, 3.5) for 7° and -0.8 (-4.2, 2.5) for 8°. AMA measurements by the surgeon and with the digital medical planning software yielded mean differences of 0.6 (-3.1, 4.3) and 0.4 (-4.1, 4.8), respectively. CONCLUSION In the present setting, the best mean distal femoral cutting block alignment perpendicular to the mechanical femoral axis could be achieved with a valgus pre-set of 7° and not by measuring the AMA. Nevertheless, we recommend conducting weight-bearing radiographs of the entire leg prior to TKA for easy detection of any anatomical varieties, old fractures, long stems of total hip arthroplasties or cement. However, surgeons must be aware that exact coronal component alignment can only be achieved by navigational devices. LEVEL OF EVIDENCE Diagnostic study, Level II.
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Affiliation(s)
- G Maderbacher
- Department of Orthopedic Surgery, University Medical Center Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany.
| | - A Keshmiri
- Department of Orthopedic Surgery, University Medical Center Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany
| | - J Schaumburger
- Department of Orthopedic Surgery, University Medical Center Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany
| | - F Zeman
- Center of Clinical Studies, University Medical Center Regensburg, Franz-Josef-Strauß-Allee 11, 93053, Regensburg, Germany
| | - A M Birkenbach
- Department of Orthopedic Surgery, University Medical Center Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany
| | - B Craiovan
- Department of Orthopedic Surgery, University Medical Center Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany
| | - J Grifka
- Department of Orthopedic Surgery, University Medical Center Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany
| | - C Baier
- Department of Orthopedic Surgery, University Medical Center Regensburg, Kaiser-Karl-V Allee 3, 93077, Bad Abbach, Germany
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10
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Weinberg DS, Williamson DFK, Gebhart JJ, Knapik DM, Voos JE. Differences in Medial and Lateral Posterior Tibial Slope: An Osteological Review of 1090 Tibiae Comparing Age, Sex, and Race. Am J Sports Med 2017; 45:106-113. [PMID: 27587744 DOI: 10.1177/0363546516662449] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Injuries to the anterior cruciate ligament (ACL) are common, and a number of knee morphological variables have been identified as risk factors for an ACL injury, including the posterior tibial slope (TS). However, limited data exist regarding innate population differences in the TS. PURPOSE To (1) establish normative values for the medial and lateral posterior TS; (2) determine what differences exist between ages, sexes, and races; and (3) determine how internal or external tibial rotation (as occurs during sagittal knee motion) influences the stereotactic perception of the TS. STUDY DESIGN Cross-sectional study; Level of evidence, 3. METHODS A total of 545 cadaveric specimens (1090 tibiae) were obtained from the Hamann-Todd osteological collection. Specimens were leveled in the coronal, sagittal, and axial planes using a digital laser. Virtual representations of each bone were created with a 3-dimensional digitizer apparatus. The TS of the medial and lateral tibial plateaus were measured using techniques adapted from previous radiographic protocols. Medial and lateral TS were then again measured on 200 tibiae that were internally and externally rotated by 10° (axially). RESULTS The mean (±SD) medial TS was 6.9° ± 3.7° posterior, which was greater than the mean lateral TS of 4.7° ± 3.6° posterior ( P < .001). Neither the medial nor lateral TS changed with age. Women had a greater mean TS compared with men on both the medial (7.5° ± 3.8° vs 6.8° ± 3.7°, respectively; P = .03) and lateral (5.2° ± 3.5° vs 4.6° ± 3.5°, respectively; P = .04) sides. Black specimens had a greater mean medial TS (8.7° ± 3.6° vs 5.8° ± 3.3°, respectively; P < .001) and lateral TS (5.9° ± 3.3° vs 3.8° ± 3.5°, respectively; P < .001) compared with white specimens. Axial rotation was shown to increase the perception of the medial and lateral TS ( P < .001). CONCLUSION The medial TS was shown to be greater than the lateral TS. Important sex- and race-based differences exist in the TS. This study also highlights the role of axial rotation in measuring the TS.
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Affiliation(s)
- Douglas S Weinberg
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, Ohio, USA
| | - Drew F K Williamson
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, Ohio, USA
| | - Jeremy J Gebhart
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, Ohio, USA
| | - Derrick M Knapik
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, Ohio, USA
| | - James E Voos
- Department of Orthopaedic Surgery, Case Western Reserve University, Cleveland, Ohio, USA
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11
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Jiang L, Chen JY, Chong HC, Chia SL, Lo NN, Yeo SJ. Clinical outcomes of computer-assisted total knee arthroplasty using pinless navigation. J Orthop Surg (Hong Kong) 2017; 25:2309499016684319. [PMID: 28117632 DOI: 10.1177/2309499016684319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This study aims to evaluate the 2-year post-operative clinical outcomes of patients undergoing total knee arthroplasty (TKA) with computer-assisted surgery (CAS) using the pinless BrainLAB® VectorVision® Knee 2.5 Navigation System versus standard CAS. A retrospective case-control study of 200 patients who underwent TKA with CAS from 2008 to 2012 was conducted. Patients in the pinless arm underwent a shorter duration of surgery compared to the standard CAS arm with 72 ± 13 min and 83 ± 11 min, respectively ( p < 0.001), with improvement in Oxford Knee Score from 34 ± 8 to 18 ± 5 and 34 ± 9 to 18 ± 5, respectively, without statistically significant differences in clinical outcomes at 2 years.
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Affiliation(s)
- Lei Jiang
- Department of Orthopaedic Surgery, Singapore General Hospital, Singapore, Singapore
| | - Jerry Yongqiang Chen
- Department of Orthopaedic Surgery, Singapore General Hospital, Singapore, Singapore
| | - Hwei-Chi Chong
- Department of Orthopaedic Surgery, Singapore General Hospital, Singapore, Singapore
| | - Shi-Lu Chia
- Department of Orthopaedic Surgery, Singapore General Hospital, Singapore, Singapore
| | - Ngai-Nung Lo
- Department of Orthopaedic Surgery, Singapore General Hospital, Singapore, Singapore
| | - Seng Jin Yeo
- Department of Orthopaedic Surgery, Singapore General Hospital, Singapore, Singapore
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Surgical accuracy in high tibial osteotomy: coronal equivalence of computer navigation and gap measurement. Knee Surg Sports Traumatol Arthrosc 2016; 24:3410-3417. [PMID: 26801783 DOI: 10.1007/s00167-016-3983-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2015] [Accepted: 01/05/2016] [Indexed: 01/30/2023]
Abstract
PURPOSE Medial opening wedge high tibial osteotomy (MOW HTO) is now a successful operation with a range of indications, requiring an individualised approach to the choice of intended correction. This manuscript introduces the concept of surgical accuracy as the absolute deviation of the achieved correction from the intended correction, where small values represent greater accuracy. Surgical accuracy is compared in a randomised controlled trial (RCT) between gap measurement and computer navigation groups. METHODS This was a prospective RCT conducted over 3 years of 120 consecutive patients with varus malalignment and medial compartment osteoarthritis, who underwent MOW HTO. All procedures were planned with digital software. Patients were randomly assigned into gap measurement or computer navigation groups. Coronal plane alignment was judged using the mechanical tibiofemoral angle (mTFA), before and after surgery. Absolute (positive) values were calculated for surgical accuracy in each individual case. RESULTS There was no significant difference in the mean intended correction between groups. The achieved mTFA revealed a small under-correction in both groups. This was attributed to a failure to account for saw blade thickness (gap measurement) and over-compensation for weight bearing (computer navigation). Surgical accuracy was 1.7° ± 1.2° (gap measurement) compared to 2.1° ± 1.4° (computer navigation) without statistical significance. The difference in tibial slope increases of 2.7° ± 3.9° (gap measurement) and 2.1° ± 3.9° (computer navigation) had statistical significance (P < 0.001) but magnitude (0.6°) without clinical relevance. CONCLUSION Surgical accuracy as described here is a new way to judge achieved alignment following knee osteotomy for individual cases. This work is clinically relevant because coronal surgical accuracy was not superior in either group. Therefore, the increased expense and surgical time associated with navigated MOW HTO is not supported, because meticulously conducted gap measurement yields equivalent surgical accuracy. LEVEL OF EVIDENCE I.
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Verification of in vivo accuracy of Trumatch™ patient-specific instrumentation in total knee replacement using pin-less computer navigation. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY AND TRAUMATOLOGY 2016; 27:125-132. [PMID: 27604905 DOI: 10.1007/s00590-016-1849-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 08/26/2016] [Indexed: 10/21/2022]
Abstract
PURPOSE Accurate component alignment in total knee replacement (TKR) is one of the important factors in determining long-term survivorship. This has been achieved by conventional jigs, computer-assisted technology (CAS) and more recently patient-specific instrumentation (PSI). The purpose of the current study was to investigate the in vivo accuracy of Trumatch™ PSI using validated pin-less computer navigation system. METHOD Twenty consecutive selected patients that fulfilled our inclusion/exclusion criteria underwent TKR using PSI. Coronal alignment, posterior slope, resection thickness and femoral sagittal alignment were recorded using pin-less navigation. The position of the actual cutting block was appropriately adjusted prior to proceeding to definitive resections. RESULTS The coronal alignment using PSI without the assistance of navigation would have resulted in 14 (70 %) within ±3°, 11 (55 %) within ±2° and 6 (30 %) outside acceptable alignment. Thirty-five percentage of proposed femur sagittal alignment and 55 % of posterior tibial slope were achieved within ±3°. Components size was accurately predicted in 95 % of femurs and 90 % of tibia. CONCLUSION The purported advantages in restoring alignments using Trumatch™ PSI alone over standard equipment are debatable. However, it predicts sizing well, and femoral coronal alignment is reasonable. Combining Trumatch™ PSI with CAS will allow in vivo verification and necessary corrections. LEVEL OF EVIDENCE IV.
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14
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Appropriate sagittal femoral component alignment cannot be ensured by intramedullary alignment rods. Knee Surg Sports Traumatol Arthrosc 2016; 24:2453-60. [PMID: 25682166 DOI: 10.1007/s00167-015-3541-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 02/09/2015] [Indexed: 10/24/2022]
Abstract
PURPOSE The intraoperative sagittal cutting block alignment when intramedullary alignment rods are used was investigated. Its absolute orthogonal orientation in relation to the mechanical femoral axis should be analysed. It was hypothesized that (1) alignment rods do not ensure a desired deviation within a range between 0° and 3° flexion as it has been shown to be favourable for clinical and functional outcome. Further, the degree of flexion cannot be (2) foreseen by the surgeon or (3) estimated by clinical or radiological parameters. METHODS Forty knees allocated to total knee arthroplasty were included. The distal femoral cutting block was aligned using an intramedullary rod. By means of a navigation device, the sagittal alignment of the cutting block in degrees of flexion was measured. RESULTS The mean measured flexion of the cutting block was 4.4° (3.6 SD). Twenty-five per cent (10/40) of the values were within a corridor between 0° and 3° of flexion. The mean difference between expected and measured flexion was -1.5° (-7.6 to 4.7 95 % limits of agreement). The dorsoventral diameter of the distal femur showed a significant influence on measured flexion (R (2) = 0.112, p = 0.035). CONCLUSION Intramedullary alignment rods used in the present study do not ensure a distal cutting block alignment between 0° and 3° of flexion in relation to the femoral mechanical axis. The extent of flexion could not be foreseen either by the surgeon. The dorsoventral diameter of the distal femur correlated with measured flexion. However, only limited data is available on influence of femoral component flexion on implant failure or clinical and functional outcome. LEVEL OF EVIDENCE Diagnostic study, Level II.
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Liow MHL, Goh GSH, Pang HN, Tay DKJ, Lo NN, Yeo SJ. Computer-assisted stereotaxic navigation improves the accuracy of mechanical alignment and component positioning in total knee arthroplasty. Arch Orthop Trauma Surg 2016; 136:1173-80. [PMID: 27349233 DOI: 10.1007/s00402-016-2483-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Indexed: 12/14/2022]
Abstract
INTRODUCTION This study reports on a novel computer-assisted stereotaxic navigation (CASN) system that attempts to combine the accuracy of computer navigation with familiarity of conventional methods. We hypothesize that CASN would improve mechanical alignment and component positioning when compared to conventional instrumentation. MATERIALS AND METHODS 145 patients (192 knees) retrospectively matched for age, BMI, gender and pre-operative scores, underwent total knee arthroplasty (TKA) using CASN (n = 92) or conventional instrumentation (n = 100). Pre- and post-operative radiological alignment [Acceptable ranges: mechanical axis (MA) 0° ± 3°, coronal femoral-component angle (CFA) and coronal tibia-component angle (CTA) 90° ± 3°] and clinical outcomes (Knee Society Scores, Oxford Knee Score and Short Form-36) at 6 months were examined. RESULTS The CASN group had significantly improved mean MA (1.9° ± 1.4°, versus 2.8° ± 2.0° in the conventional group, p = 0.001), CFA (1.6° ± 1.3°, versus 2.1° ± 1.5° in the conventional group, p = 0.035) and CTA (1.6° ± 1.2°, versus 2.1° ± 1.5° in the conventional group, p = 0.024). 91.3 % of knees in the CASN group were within 3° of a neutral mechanical axis, versus 74 % in the conventional group (p < 0.001). The duration of surgery was significantly longer in the CASN group (84 ± 22 vs 73 ± 15 min, p = 0.001) and cost an additional USD 850 per operation. There were no significant differences in clinical outcomes or satisfaction rates at 6 months post-operatively (p > 0.05). CONCLUSIONS CASN improved TKA mechanical alignment and component positioning, however, resulted in longer and costlier surgery with no benefits in short-term functional outcomes, despite providing familiarity to surgeons accustomed to conventional instrumentation. LEVEL OF EVIDENCE III.
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Affiliation(s)
- Ming Han Lincoln Liow
- Department of Orthopaedic Surgery, Singapore General Hospital, 20 College Road, Academia, Level 4, Singapore, 169865, Singapore. .,Department of Orthopaedic Surgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, 02114, Massachusetts, USA.
| | - Graham Seow-Hng Goh
- Department of Orthopaedic Surgery, Singapore General Hospital, 20 College Road, Academia, Level 4, Singapore, 169865, Singapore
| | - Hee-Nee Pang
- Department of Orthopaedic Surgery, Singapore General Hospital, 20 College Road, Academia, Level 4, Singapore, 169865, Singapore
| | - Darren Keng Jin Tay
- Department of Orthopaedic Surgery, Singapore General Hospital, 20 College Road, Academia, Level 4, Singapore, 169865, Singapore
| | - Ngai Nung Lo
- Department of Orthopaedic Surgery, Singapore General Hospital, 20 College Road, Academia, Level 4, Singapore, 169865, Singapore
| | - Seng Jin Yeo
- Department of Orthopaedic Surgery, Singapore General Hospital, 20 College Road, Academia, Level 4, Singapore, 169865, Singapore
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16
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Chen JY, Chin PL, Li Z, Yew AKS, Tay DKJ, Chia SL, Lo NN, Yeo SJ. Radiological outcomes of pinless navigation in total knee arthroplasty: a randomized controlled trial. Knee Surg Sports Traumatol Arthrosc 2015; 23:3556-62. [PMID: 25119055 DOI: 10.1007/s00167-014-3226-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Accepted: 07/31/2014] [Indexed: 11/25/2022]
Abstract
PURPOSE This study aimed to investigate the accuracy of pinless navigation (BrainLAB(®) VectorVision(®) Knee 2.5 Navigation System) as an intra-operative alignment guide in total knee arthroplasty (TKA). The authors hypothesized that pinless navigation would reduce the proportion of outliers in conventional TKA, without a significant increase in the duration of surgery. METHODS Between 2011 and 2012, 100 patients scheduled for a unilateral primary TKA were randomized into two groups: pinless navigation and conventional surgery. All TKAs were performed with the surgical aim of achieving neutral coronal alignment with a 180° mechanical axis. The primary outcomes of this study were post-operative radiographic assessment of lower limb alignment using hip-knee-ankle angle (HKA) and components placement using coronal femoral-component angle (CFA) and coronal tibia-component angle (CTA). RESULTS There was a smaller proportion of outliers for HKA, CFA and CTA at 10, 2 and 2 % respectively, in the pinless navigation group, compared to 32, 16 and 16 %, respectively, in the conventional group (p = 0.013, p = 0.032 and p = 0.032, respectively). The mean CFA was also more accurate at 90° in the pinless navigation group compared to 91° in the conventional group (p = 0.002). There was no difference in the duration of surgery between the two groups (n.s.). CONCLUSIONS Pinless navigation improves lower limb alignment and components placement without a significant increase in the duration of surgery. The authors recommend the use of pinless navigation to verify the coronal alignments of conventional cutting blocks in TKA before the bone cuts are made. LEVEL OF EVIDENCE I.
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Affiliation(s)
- Jerry Yongqiang Chen
- Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore.
| | - Pak Lin Chin
- Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore
| | - Zongxian Li
- Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore
| | - Andy Khye Soon Yew
- Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore
| | - Darren Keng Jin Tay
- Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore
| | - Shi-Lu Chia
- Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore
| | - Ngai Nung Lo
- Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore
| | - Seng Jin Yeo
- Department of Orthopaedic Surgery, Singapore General Hospital, Outram Road, Academia Building Level 4, Singapore, 119228, Singapore
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Abstract
Successful outcomes after orthopedic surgical procedures are believed to be highly dependent on reproducible anatomic accuracy. Immediate intraoperative feedback helps surgeons to achieve this accuracy as has been demonstrated with the use of fluoroscopy. Non-image-based computer navigation has been used in joint arthroplasty, anterior cruciate ligament reconstruction, high tibial osteotomy, and cartilage procedures along with applications in hip and shoulder arthroscopy. Most short-term studies have demonstrated superior accuracy when compared with conventional techniques; however, very few studies have shown better clinical outcomes. Robotic-assisted surgery has been most popular in total and unicompartmental arthroplasty, which again has greater accuracy but similar clinical outcomes when compared with conventional techniques. Economic analyses indicate that these high-cost technologies may only be cost-effective in high-volume centers. Other studies have shown that computer navigation improves the accuracy of lower volume surgeons to a greater degree than higher volume surgeons allowing the former to have results similar to the latter.
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18
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Affiliation(s)
- Heiko Graichen
- Department for Arthroplasty, Orthopaedic Hospital Lindenlohe, 92421 Schwandorf, Germany
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Maderbacher G, Schaumburger J, Keshmiri A, Barthel M, Springorum HR, Craiovan B, Grifka J, Baier C. Pinless navigation in total knee arthroplasty: navigation reduced by the maximum? INTERNATIONAL ORTHOPAEDICS 2014; 39:455-60. [PMID: 25242460 DOI: 10.1007/s00264-014-2529-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 09/03/2014] [Indexed: 10/24/2022]
Abstract
PURPOSE Restoring a neutral mechanical axis in total knee arthroplasty (TKA) (within ±3° of varus/valgus) is associated with superior functional outcome and reduced early implant failure. Using conventional alignment jigs results in malalignment in >20 % of cases. In this study, we investigated the reduction of outliers within the threshold of ±3° of leg alignment using a "pinless" navigation system in comparison with conventional alignment jigs investigated. METHODS In this randomised prospective study, 80 patients were randomly assigned/allocated to the pinless or conventional control group. After surgery, the two groups were compared regarding outliers > ±3° by means of hip-knee-ankle angle (HKA), mechanical medial proximal tibia angle (mMPTA), mechanical lateral distal femoral angle (mLDFA) and duration of surgery. Student's unpaired t test was used for quantitative variables, Fisher's exact test compared groups (pinless vs. control) and a two-sided p value of ≤0.05 was considered statistically significant. RESULTS In the pinless group, outliers regarding HKA and mLDFA > ±3° was significantly reduced (p = 0.025 and p = 0.002 respectively). In the pinless group, the surgery duration was significantly longer (75.6 vs. 64.5 minutes, p < 0.001). CONCLUSION Pinless navigation is effective in reducing outliers > ±3° regarding HKA without risking pin-related complications, such as fractures, infections or breaking screws. However, not all tools for conventional navigation in TKA, such as real-time measurements of the tibiofemoral axis and gap balancing, are available.
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Affiliation(s)
- Günther Maderbacher
- Department of Orthopaedic Surgery, University of Regensburg, Regensburg, Germany,
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Renkawitz T, Winkler S, Weber M, von Kunow F, Grifka J, Baier C. [Update on navigation in total knee arthroplasty. Where are we today and what lies in the future?]. DER ORTHOPADE 2014; 43:448-54. [PMID: 24718607 DOI: 10.1007/s00132-013-2193-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The implantation of an artificial knee is one of the most common operative interventions in German hospitals. Navigation procedures have developed into an integral component of such interventions in the operating theatres of many clinics. METHODS For orthopedic surgeons who want to implement an as exact as possible reconstruction of the mechanical leg axis and require intraoperative control of the three dimensional positioning of components and/or the capsular ligament situation, navigation is a well-proven intraoperative tool. The immediate intraoperative control possibility of bone resection and capsular ligament soft tissue balancing means that navigation is a valuable instrument for the biomechanical fundamental understanding in training operations for further education of orthopedic surgeons in training. DEVELOPMENTS The greater precision obtained by the implementation of the procedure has not yet been conclusively reflected in an improved postoperative knee function or an increased durability of prostheses. New developments in navigated knee prostheses are pinless navigation and navigation kinematics. In pinless navigation the conventional reference marker system fixed in the femur and shin bones is replaced by a non-invasive reference system. With the aid of navigation kinematics it is possible to image the tibiofemoral and patellofemoral movement dynamics, intraoperatively. PERSPECTIVE The aim of the next generation navigation systems for computer-assisted knee prosthetics is implant positioning aligned to the individual anatomy of patients with high and stable range of movement for optimum patellar guidance and kinematics of the artificial joint.
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Affiliation(s)
- T Renkawitz
- Orthopädische Klinik für die Universität Regensburg, Asklepios Klinikum Bad Abbach, Kaiser-Karl-V.-Allee 3, 93077, Bad Abbach, Deutschland,
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Baier C, Fitz W, Craiovan B, Keshmiri A, Winkler S, Springorum R, Grifka J, Beckmann J. Improved kinematics of total knee replacement following partially navigated modified gap-balancing technique. INTERNATIONAL ORTHOPAEDICS 2014; 38:243-9. [PMID: 24126498 PMCID: PMC3923938 DOI: 10.1007/s00264-013-2140-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 09/20/2013] [Indexed: 02/04/2023]
Abstract
PURPOSE Navigation-based total knee arthroplasty (TKA) has proven its value for restoration of the limb axis. However, patient-orientated results after TKA show a wide variation from the correct implantation technique. Nonphysiological kinematics without posterior femoral rollback and tibial internal rotation in flexion could be one reason for this. We postulated that a modified gap-balancing technique with navigation of the tibia alone, in comparison to a conventional navigated technique, would: (1) obtain lateral femoral rollback, (2) alter condylar liftoff without midflexion instability, (3) significantly differ in femoral and tibial cuts, (4) not be inferior in leg-axis restoration and (5) be comparable in clinical short-term scores. METHODS In this prospective study, we compared in vivo navigation-based kinematics pre- and postoperatively of 40 consecutive TKA comprising 21 conventional navigation-based TKA and 19 TKA with the modified gap-balancing technique and a reduced navigation workflow. All cuts were double checked and compared with cuts proposed by the navigation system. Clinical results were assessed preoperatively and six months postoperatively. RESULTS The modified gap-balancing technique resulted in significantly increased lateral femoral rollback (mean 16.3 mm) and lateral condylar liftoff (mean 1.3 mm) compared to the conventional group. The modified technique comprised an average of 2.1 mm less distal femoral resection and an average of 4° less external rotation and 3.5° more flexion of the femoral component compared with the control group. Average tibial resection height was 1.1 mm greater and average tibial slope was 0.5° elevated compared to the control group. A neutral leg axis was achieved in all cases. Results showed no significant differences in clinical scores between groups. CONCLUSION A partial navigation solely of the tibial cut can securely restore the leg axis. Modification of the surgical technique can possibly reproduce more physiological knee kinematics with higher lateral femoral rollback in flexion without midflexion instability. This might help reduce postoperative problems with the new implant and thus reduce the amount of unsatisfactory results. Despite equal short-term results, mid- to long-term results are needed to prove whether or not this correlates with better clinical results and at least equal implant longevity.
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Affiliation(s)
- Clemens Baier
- Orthopaedic Surgery, University of Regensburg, Regensburg, Germany,
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