1
|
Park Y, Choi D, Hwang DS, Yoon YS. Statistical Analysis of Interfacial Gap in a Cementless Stem FE Model. J Biomech Eng 2008; 131:021016. [DOI: 10.1115/1.3005176] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In cementless total hip arthroplasty, a fair amount of interfacial gap exists between the femoral stem and the bone. However, the effect of these gaps on the mechanical stability of the stem is poorly understood. In this paper, a finite element model with various interfacial gap definitions is used to quantify the effect of interfacial gaps on the primary stability of a Versys Fiber Metal Taper stem under stair climbing loads. In the first part, 500 random interfacial gap definitions were simulated. The resulting micromotion was approximately inversely proportional to the contact ratio, and the variance of the micromotion was greater with a lower contact ratio. Moreover, when the magnitude of the micromotion was compared between the gap definitions that had contact at a specific site and those that had no contact at that site, it was found that gaps located in the proximal-medial region of the stem surface had the most important effect on the micromotion. In a second trial, 17 gap definitions mimicking a gap pattern that has been observed experimentally were simulated. For a given contact ratio, the micromotion observed in the second trial was lower than the average result of those in the first, where the gaps were placed randomly. In either trial, when the contact ratio was higher than 40%, the micromotion showed no significant difference (first trial) or a gentle slope (−0.24μm∕% in the second trial) in relation to the contact ratio. Considering the reported contact ratios for properly implanted stems, variations in the amount of interfacial gap would not likely cause a drastic difference in micromotion, and this effect could be easily overshadowed by other clinical factors. In conclusion, differences in interfacial gaps are not expected to have a noticeable effect on the clinical micromotion of this cementless stem.
Collapse
Affiliation(s)
- Youngbae Park
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, KAIST 3022, Science Town, Daejeon 305-701, South Korea
| | - DonOk Choi
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, KAIST 3022, Science Town, Daejeon 305-701, South Korea
| | - Deuk Soo Hwang
- Department of Orthopedic, Medical School, Chungnam National University, Daesadong 640, Jung-Ku, Daejeon 301-721, Korea
| | - Yong-San Yoon
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, KAIST 3022, Science Town, Daejeon 305-701, South Korea
| |
Collapse
|
2
|
Park Y, Shin H, Choi D, Albert C, Yoon YS. Primary Stability of Cementless Stem in THA Improved With Reduced Interfacial Gaps. J Biomech Eng 2008; 130:021008. [DOI: 10.1115/1.2898761] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Large interfacial gaps between the stem and the bone in cementless total hip arthroplasty may prevent successful bone ingrowth at the sites, and can also be a passage for wear particles. Furthermore, interfacial gaps between the stem and the bone are believed to compromise the primary stability of the implant. Thus, a broaching method that serves to reduce gaps is expected to give clinically preferable results. A modified broach system with a canal guide is introduced to enhance the accuracy of femoral canal shaping in comparison with the conventional broach system for a Versys™ fibermetal taper stem. The primary stability of the hip systems and the ratios of the stem surface in contact with the femur were measured in a composite femur model. With the conventional method, an average of 67% of the stem surface was shown to be in contact with the bone, and an average stem micromotion/migration of 35μm∕290μm was observed under 1000cycles of stair climbing loads. With the modified method, the stem-bone contact ratio significantly increased to 82% (p<0.05), and the average micromotion/migration reduced to 29μm∕49μm, respectively (p<0.05 for migration). Our finite element models of the hip systems supported that the difference in micromotion could be attributed to the difference in interfacial contact. Interfacial gaps occurring with the conventional broach system were effectively reduced by the proposed method, resulting in improved primary stability.
Collapse
Affiliation(s)
- Youngbae Park
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea
| | - HoChul Shin
- Intelligent Robot Research Division, Electronics and Telecommunications Research Institute, Daejeon, 305-700, Republic of Korea
| | - DonOk Choi
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea
| | - Carolyne Albert
- Department of Materials Engineering, and Department of Orthopaedics, University of British Columbia, 2329 West Mall, Vancouver, BC, V6T 1Z4, Canada
| | - Yong-San Yoon
- Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701, Republic of Korea
| |
Collapse
|
3
|
Schulz AP, Seide K, Queitsch C, von Haugwitz A, Meiners J, Kienast B, Tarabolsi M, Kammal M, Jürgens C. Results of total hip replacement using the Robodoc surgical assistant system: clinical outcome and evaluation of complications for 97 procedures. Int J Med Robot 2007; 3:301-6. [DOI: 10.1002/rcs.161] [Citation(s) in RCA: 122] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
4
|
Kettenbach J, Kronreif G, Figl M, Fürst M, Birkfellner W, Hanel R, Ptacek W, Bergmann H. Robot-Assisted Biopsy Using Computed Tomography-Guidance. Invest Radiol 2005; 40:219-28. [PMID: 15770140 DOI: 10.1097/01.rli.0000155285.05672.cf] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE We sought to develop a robotic system for computed tomography (CT)-guided biopsy to validate the feasibility, accuracy, and efficacy of the system using phantom tests. MATERIALS AND METHODS Ten peas (mean diameter 9.9+/-0.4 mm) embedded within a gel phantom were selected for biopsy. Once the best access was defined on CT images, the position of the phantom was recorded by an optical tracking system. Positional data about the phantom and the corresponding CT image was transferred to the robot planning system (Linux-based industrial PC equipped with video capture card). Once the appropriate position, angulation, and pitch were calculated, the robotic arm moved automatically with 7 degrees-of-freedom to the planned insertion path, aiming the needle-trajectory at the center of the target. Then, the biopsy was performed manually using a coaxial technique. The length of all harvested specimens was measured and short cut pieces of a guidewire were pushed into the target to evaluate the deviation of the actual needle track from the target. RESULTS In all targets, biopsy specimens (mean length 5.6+/-1.4 mm) were harvested with only 1 needle pass required. The mean deviation of the needle tip from the center of the target in the x and z axes was 1.2+/-0.9 mm and 0.6+/-0.4 mm, respectively. CONCLUSIONS Robotic-assisted biopsies in vitro, using CT guidance, were feasible and provided high accuracy.
Collapse
Affiliation(s)
- Joachim Kettenbach
- Department of Radiology, Medical University Vienna, General Hospital, Vienna, Vienna, Austria.
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Kretschmer T, Antoniadis G, Börm W, Richter HP. [Iatrogenic nerve injuries. Part 1: Frequency distribution, new aspects, and timing of microsurgical treatment]. Chirurg 2005; 75:1104-12. [PMID: 15580330 DOI: 10.1007/s00104-004-0879-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE The aim of this study was to analyze the number and types of iatrogenic nerve injuries operated on during a 13-year period at a relatively busy nerve center. METHOD Retrospective analysis was done of 191 cases surgically treated because of iatrogenic nerve injuries. RESULTS Most iatrogenic nerve injuries occurred after surgical procedures. As a rule, symptoms and signs appeared immediately after the procedure. Single nerves most often involved were the spinal accessory nerve at the neck ( n=27), most frequently after lymph node biopsy, and the median nerve in the carpal tunnel ( n=25), usually after carpal tunnel release and most frequently after endoscopic technique. Following in frequency are the common peroneal nerve ( n=16), superficial sensory radial nerve ( n=13), genitofemoral ( n=12), and superficial peroneal and tibial nerves ( n=9 each). Clinical improvement after neurosurgical intervention appeared in 70% of cases. Frequently iatrogenic nerve lesions are referred with significant delay, that is, not during a time interval deemed appropriate for surgical intervention. CONCLUSION Iatrogenic nerve lesions must be recognized in a timely manner and should be operated upon as early as other traumatic nerve injuries to ensure best chances for successful recovery.
Collapse
Affiliation(s)
- T Kretschmer
- Neurochirurgische Klinik der Universität Ulm am BKH Günzburg, Günzburg.
| | | | | | | |
Collapse
|
6
|
Kettenbach J, Kronreif G, Figl M, Fürst M, Birkfellner W, Hanel R, Bergmann H. Robot-assisted biopsy using ultrasound guidance: initial results from in vitro tests. Eur Radiol 2004; 15:765-71. [PMID: 15449006 DOI: 10.1007/s00330-004-2487-x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2004] [Revised: 06/28/2004] [Accepted: 08/06/2004] [Indexed: 11/28/2022]
Abstract
The purpose of this study was to develop a robotic system for ultrasound (US)-guided biopsy and to validate the feasibility, accuracy and efficacy using phantom tests. Twenty peas (mean diameter 9.3+/-0.1 mm) embedded within a gel-phantom were selected for biopsy. Once the best access was defined, the position of the US transducer was recorded by an optical tracking system. Positional data of the transducer and the corresponding US image were transferred to the roboter planning system (LINUX-based industrial PC equipped with video capture card). Once the appropriate position, angulation and pitch were calculated, the robotic arm moved automatically with seven degrees-of-freedom to the planned insertion path, aiming the needle-positioning unit at the center of the target. Then, the biopsy was performed manually using a coaxial technique. The length of all harvested specimens was measured, and the deviation of the actual needle tract from the center of the target was evaluated sonographically. In all targets, the biopsy specimen (mean length 5+/-1.2 mm) was harvested with only one needle pass required The mean deviation of the needle tip from the center of the target was 1.1+/-0.8 mm. Robotic assisted biopsies in-vitro using US-guidance were feasible and provided high accuracy.
Collapse
Affiliation(s)
- Joachim Kettenbach
- Division of Angiography and Interventional Radiology, Department of Radiology, Medical University Vienna, General Hospital, Währinger Guertel 18-20, 1090 Vienna, Austria.
| | | | | | | | | | | | | |
Collapse
|
7
|
Bann S, Khan M, Hernandez J, Munz Y, Moorthy K, Datta V, Rockall T, Darzi A. Robotics in surgery. J Am Coll Surg 2003; 196:784-95. [PMID: 12742213 DOI: 10.1016/s1072-7515(02)01750-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Simon Bann
- Department of Surgical Oncology and Technology, Faculty of Medicine, Imperial College of Science, Technology and Medicine, St Mary's Hospital, London, UK
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Musahl V, Plakseychuk A, Fu FH. Current opinion on computer-aided surgical navigation and robotics: role in the treatment of sports-related injuries. Sports Med 2003; 32:809-18. [PMID: 12392442 DOI: 10.2165/00007256-200232130-00001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Computer-assisted surgery (CAS) may allow surgeons to be more precise and minimally invasive, in addition to being an excellent research tool. Medical imaging, such as magnetic resonance and computed tomography is not only an important diagnostic tool, but also a necessary planning tool. In orthopaedic sports medicine, precision is needed when placing tunnels for soft tissue fixation of replacement grafts. Two types of CAS systems -- passive and active -- have been developed. Passive systems, or surgical navigation systems, provide the surgeon with additional information prior to and during the surgical procedure (in real time). Active systems have the ability of performing certain surgical steps autonomously. Both active and passive CAS systems are currently a subject of basic science and clinical investigations and will be discussed and commented on in this article. In summary, passive navigation systems can provide additional information to the surgeon and can therefore lead to more precise tunnel placement. Active robotic technology seems to be accurate and feasible with promising initial results from Europe. However, active and passive CAS can only be as precise as the surgeon who plans the procedure. Therefore, future studies have to focus on integrating, arthroscopy, 3-D image-enhanced computer navigation, and virtual kinematics, as well as to increase precision in surgical techniques.
Collapse
Affiliation(s)
- Volker Musahl
- Department of Orthopedic Surgery, University of Pittsburgh Physicians, Pittsburgh, Pennsylvania 15213, USA
| | | | | |
Collapse
|
9
|
|
10
|
Meijer DW. Robots in surgery: what's in the name? J Laparoendosc Adv Surg Tech A 2002; 12:115-6. [PMID: 12019570 DOI: 10.1089/10926420252939637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Dirk W Meijer
- Department of Experimental Surgery, University of Amsterdam, The Netherlands.
| |
Collapse
|