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Richard A. Berger - One of the best experts on this subject based on the ideXlab platform.
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implant arthroplasty for treatment of Ulnar Head resection related instability
Hand Clinics, 2013Co-Authors: Richard A. BergerAbstract:Resection of the Ulnar Head in cases of debilitating pain owing to arthrosis of the distal radioUlnar joint can provide satisfying relief. However, there is mounting evidence that pain with heavier use, instability, and torque-generating weakness in more active individuals may result in less satisfying outcomes. Implant arthroplasty can provide a means to stabilize the radius to the ulna after Ulnar Head resection, but it requires significant attention to requisite soft tissue stabilization and alignment of the distal radius to the implant to be successful.
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Implant Arthroplasty for Treatment of Ulnar Head Resection–Related Instability
Hand clinics, 2012Co-Authors: Richard A. BergerAbstract:Resection of the Ulnar Head in cases of debilitating pain owing to arthrosis of the distal radioUlnar joint can provide satisfying relief. However, there is mounting evidence that pain with heavier use, instability, and torque-generating weakness in more active individuals may result in less satisfying outcomes. Implant arthroplasty can provide a means to stabilize the radius to the ulna after Ulnar Head resection, but it requires significant attention to requisite soft tissue stabilization and alignment of the distal radius to the implant to be successful.
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Biomechanical evaluation of the dynamic radioUlnar convergence after Ulnar Head resection, two soft tissue stabilization methods of the distal ulna and Ulnar Head prosthesis implantation
Archives of Orthopaedic and Trauma Surgery, 2011Co-Authors: Michael Sauerbier, Michael E. Hahn, Lawrence J. Berglund, Kai-nan An, Richard A. BergerAbstract:Introduction The biomechanical performance of the Darrach procedure, its stabilizing methods and the effectiveness of an Ulnar Head prosthesis was evaluated in this experiment. Purpose The purpose of this study was to: (1) analyze the dynamic effects of the resection of the distal ulna on radioUlnar convergence; and (2) evaluate the mechanical performance of two soft tissue stabilizing procedures (pronator quadratus advancement flap and ECU/FCU tenodesis) for the unstable distal Ulnar stump and the implantation of an Ulnar Head prosthesis (uHead) following a distal Ulnar resection (Darrach procedure) on radioUlnar convergence. Method With a dynamic PC-controlled forearm simulator, cadaveric forearm rotation was actively and passively performed while simultaneously loading the relevant muscles. The resultant total forearm torque and the three-dimensional kinematics of the ulna, radius and third metacarpal were simultaneously recorded in seven fresh-frozen cadaver upper extremities. Results The resection of the distal ulna created an extreme instability of the forearm with movement of the radius toward the ulna (0.92–0.38 cm compared to the intact state) in each particular loading condition. The implantation of the Ulnar Head prosthesis effectively restored the stability of the DRUJ by simulating the geometry of the Ulnar Head. There were significantly better results after the implantation of the prosthesis compared with the Darrach and the soft tissue stabilization procedures. Conclusion This study provides laboratory validity to the option of implanting an Ulnar Head endoprosthesis as an attempt to stabilize the distal forearm with instability after Darrach resection in lieu of performing soft tissue stabilization techniques.
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Biomechanical evaluation of the dynamic radioUlnar convergence after Ulnar Head resection, two soft tissue stabilization methods of the distal ulna and Ulnar Head prosthesis implantation.
Archives of Orthopaedic and Trauma Surgery, 2010Co-Authors: M. Sauerbier, Michael E. Hahn, Lawrence J. Berglund, Richard A. BergerAbstract:Introduction The biomechanical performance of the Darrach procedure, its stabilizing methods and the effectiveness of an Ulnar Head prosthesis was evaluated in this experiment.
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Indications for Ulnar Head replacement.
American journal of orthopedics (Belle Mead N.J.), 2008Co-Authors: Richard A. BergerAbstract:Implanting an endoprosthesis is a clinically proven means of reestablishing mechanical contact between the distal radius and ulna, thus providing the foundation for stability of the entire forearm. The indications for, contraindications to, and outcomes of Ulnar Head replacement are discussed, together with the underlying mechanics, pathomechanics of Ulnar Head excision, the theoretical basis for implant arthroplasty, and the designs that have been employed.
Yang-guk Chung - One of the best experts on this subject based on the ideXlab platform.
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during forearm rotation the three dimensional ulnolunate distance is affected more by translation of the Ulnar Head than change in Ulnar variance
Journal of Hand Surgery (European Volume), 2019Co-Authors: Seung-han Shin, Yong-suk Lee, Keunyoung Choi, Daisoon Kwak, Yang-guk ChungAbstract:Ulnolunate abutment has been thought to be aggravated by pronation because of an increase in Ulnar variance. We hypothesized that the ulnolunate distance might be greater in pronation because the Ulnar Head is dorsally translated. Twenty-one three-dimensional reconstructions of computed tomographic scans of wrists taken in supination and pronation were investigated. The ulnolunate distance was measured in each position, and the change in ulnolunate distance from supination to pronation was calculated. The changes in Ulnar variance from supination to pronation and the amount of translation of the Ulnar Head were measured directly by superimposing three-dimensional reconstructions. The mean ulnolunate distance in pronation was significantly greater than in supination. There was no significant correlation between the changes in ulnolunate distance and in the Ulnar variance. The change in ulnolunate distance had a significant positive linear relationship with the amount of translation of the Ulnar Head. The change in ulnolunate distance during forearm rotation is determined by the amount of translation of the Ulnar Head rather than by change in Ulnar variance. Level of evidence: IV.
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Where Is the Ulnar Styloid Process? Identification of the Absolute Location of the Ulnar Styloid Process Based on CT and Verification of Neutral Forearm Rotation on Lateral Radiographs of the Wrist
Clinics in Orthopedic Surgery, 2018Co-Authors: Seung-han Shin, Yong-suk Lee, Jin-woo Kang, Dong-young Noh, Joon-yong Jung, Yang-guk ChungAbstract:Background The location of the Ulnar styloid process can be confusing because the radius and the hand rotate around the ulna. The purpose of this study was to identify the absolute location of the Ulnar styloid process, which is independent of forearm pronation or supination, to use it as a reference for neutral forearm rotation on lateral radiographs of the wrist. Methods Computed tomography (CT) images of 23 forearms taken with elbow flexion of 70° to 90° were analyzed. The axial CT images were reconstructed to be perpendicular to the distal Ulnar shaft. The absolute location of the Ulnar styloid process in this study was defined as the position of the Ulnar styloid process on the axial plane of the Ulnar Head relative to the long axis of the humeral shaft with the elbow set in the position for standard lateral radiographs of the wrist. To identify in which direction the Ulnar styloid is located on the axial plane of the Ulnar Head, the angle between "the line of humeral long axis projected on the axial plane of the ulna" and "the line passing the center of the Ulnar Head and the center of the Ulnar styloid" was measured (Ulnar styloid direction angle). To identify how volarly or dorsally the Ulnar styloid should appear on the true lateral view of the wrist, the ratio of "the volar-dorsal diameter of the Ulnar Head" and "the distance between the volar-most aspect of the Ulnar Head and the center of the Ulnar styloid" was calculated (Ulnar styloid location ratio). Results The mean Ulnar styloid direction angle was 12° dorsally. The mean Ulnar styloid location ratio was 1:0.55. Conclusions The Ulnar styloid is located at nearly the Ulnar-most (the opposite side of the humerus with the elbow flexed) and slightly dorsal aspects of the Ulnar Head on the axial plane. It should appear almost midway (55% dorsally) from the Ulnar Head on the standard lateral view of the wrist in neutral forearm rotation. These location references could help clinicians determine whether the forearm is in neutral or rotated position on an axial CT/magnetic resonance imaging scan or a lateral radiograph of the wrist.
T. S. Axelrod - One of the best experts on this subject based on the ideXlab platform.
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Madelung's Deformity: radial opening wedge osteotomy and modified Darrach procedure using the Ulnar Head as trapezoidal bone graft
Journal of Hand Surgery (European Volume), 2010Co-Authors: R. Kampa, A. Al-beer, T. S. AxelrodAbstract:Surgery may be indicated in treating Madelung’s deformity and numerous techniques have been described. This study reports the early clinical and radiological results of a radial biplanar opening wedge osteotomy and modified Darrach procedure, using the excised Ulnar Head as a trapezoidal bone graft. Between 2000 and 2008, five adult wrists with symptomatic Madelung’s deformity underwent surgery. All patients were female, with an average age at surgery of 34 years. Assessment included range of movement, grip strength, DASH scores and radiological imaging. All patients improved both subjectively and objectively with regards to pain, functional range of movement, and appearance at mean follow-up of 55 months (range 14—113). All osteotomies united. One patient required removal of hardware for restricted rotation. This technique provided satisfactory results that are comparable to other studies, and avoids the use of iliac crest bone graft.
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Madelung’s deformity: radial opening wedge osteotomy and modified Darrach procedure using the Ulnar Head as trapezoidal bone graft
The Journal of hand surgery European volume, 2010Co-Authors: R. Kampa, A. Al-beer, T. S. AxelrodAbstract:Surgery may be indicated in treating Madelung's deformity and numerous techniques have been described. This study reports the early clinical and radiological results of a radial biplanar opening wedge osteotomy and modified Darrach procedure, using the excised Ulnar Head as a trapezoidal bone graft. Between 2000 and 2008, five adult wrists with symptomatic Madelung's deformity underwent surgery. All patients were female, with an average age at surgery of 34 years. Assessment included range of movement, grip strength, DASH scores and radiological imaging. All patients improved both subjectively and objectively with regards to pain, functional range of movement, and appearance at mean follow-up of 55 months (range 14-113). All osteotomies united. One patient required removal of hardware for restricted rotation. This technique provided satisfactory results that are comparable to other studies, and avoids the use of iliac crest bone graft.
Alex Radin - One of the best experts on this subject based on the ideXlab platform.
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Modular Ulnar Head decoupling force: case report.
The Journal of hand surgery, 2009Co-Authors: Sanjiv H. Naidu, Alex RadinAbstract:Cobalt-chrome modular distal Ulnar Head replacement arthroplasty is a surgical option to restore stability to the distal radioUlnar joint rendered unstable by hemi-resection arthroplasty or a total resection arthroplasty. However, the revision of dislocated modular cobalt-chrome Ulnar Head implants may pose an important intraoperative challenge. The Morse-taper disassembly force of modular Ulnar Head implants is not available in the current published literature. We present a case in which tremendous difficulty was encountered while revising a dislocated modular cobalt-chrome distal Ulnar Head implant. The mean Morse-taper disassembly force of the retrieved modular cobalt-chrome implant was 2958 N ± 1272. At nearly 4.5 times the average body weight, the modular Ulnar Head Morse-taper disassembly strength presented a formidable force to overcome intraoperatively.
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Isoelastic distal Ulnar Head prosthesis: an in vitro joint simulator study.
Journal of Hand Surgery (European Volume), 2009Co-Authors: Sanjiv H. Naidu, Alex RadinAbstract:PURPOSE: A prosthetic Ulnar Head that matches the mechanical properties of the sigmoid notch of the radius may produce a superior clinical outcome. In this study, we investigated the feasibility of an ultrahigh-molecular-weight polyethylene (UHMWPE) Ulnar Head prosthesis as a bearing material and compared the tribology (wear properties) with that of a cobalt chrome (CoCr) distal Ulnar replacement. METHODS: We compared the friction properties, termed lubricity of the UHMWPE Ulnar Head prosthesis and polished CoCr Ulnar Head in an in vitro joint simulator with physiologic saline maintained at body temperature. Wear of the UHMWPE Ulnar Head and polished CoCr Ulnar Head against a synthetic bone counterface for 1 million cycles was simulated in the in vitro joint simulator. Finally, we studied the fatigue of the UHMWPE prosthesis for 3.1 million cycles of cyclic loading. Both the fatigued and nonfatigued surface were studied with thermal analysis to characterize the UHMWPE prosthesis. RESULTS: The dynamic coefficient of friction for the UHMWPE prosthesis was 0.087 +/- 0.016 and was not significantly different from the polished CoCr coefficient. The synthetic counterface bone wear was 45 times less for the UHMWPE Ulnar Head prosthesis compared with the polished CoCr Head. Both the thermal properties and the viscoelastic moduli for the fatigued UHMWPE remained unchanged compared with unloaded specimens. CONCLUSIONS: Ultrahigh-molecular-weight polyethylene is a low-friction material with stable fatigue properties. In addition, in light of its low modulus of elasticity, the UHMWPE Ulnar Head prosthesis demonstrated low synthetic bone counterface wear compared with the polished cobalt chrome alloy prosthesis. In vitro joint simulation showed that there is a potential role for the UHMWPE Ulnar Head prosthesis in distal radioUlnar joint prosthetic arthroplasty.
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Modular Ulnar Head decoupling strength: a biomechanical study.
The Journal of hand surgery, 2009Co-Authors: Sanjiv H. Naidu, Alex RadinAbstract:Purpose Knowing the assembly and disassembly forces of modular Ulnar Head implants will be invaluable to the surgeon faced with the challenge of either revising or extracting the implant. Our goal in this study was to evaluate the decoupling strength of the modular Ulnar Head implant as a function of assembly impaction force for the 3 most commonly used combinations of modular Ulnar Head implants. Methods Assembly forces and axial decoupling strength for 3 combinations of modular Ulnar Head implants were measured on an Instron 4206 instrument. Correlations between Morse taper decoupling strength and assembly forces were investigated. Results The cobalt chrome Head–cobalt chrome stem Morse taper couple showed the most predictable correlation with impaction assembly force, followed by cobalt chrome Head-titanium stem couple and ceramic Head–titanium couple, respectively. Conclusions Peak assembly impaction blow at the time of implantation determines the ultimate decoupling strength of the modular Ulnar Head Morse taper for all 3 material combinations studied. Prosthesis-specific regression curves will permit the surgeon to estimate decoupling force as a function of impact force.
Timothy J. Herbert - One of the best experts on this subject based on the ideXlab platform.
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salvage of failed resection arthroplasties of the distal radioUlnar joint using an Ulnar Head prosthesis long term results
Journal of Hand Surgery (European Volume), 2009Co-Authors: Jorg Van Schoonhoven, Diego L Fernandez, Marion Muhldorferfodor, Timothy J. HerbertAbstract:Purpose The aim of this prospective multicenter study was to evaluate the long-term outcome of the Herbert Ulnar Head prosthesis for painful instability of the distal radioUlnar joint (DRUJ) following resection of the Ulnar Head. Methods Twenty-three patients were treated with a Herbert Ulnar Head prosthesis in 3 international hand centers. One patient was excluded from the study because a septic prosthesis had to be removed after 3 months. Sixteen of the remaining 22 patients could be assessed at 2 follow-up times, 28 months (range, 10–43 mo) and 11 years and 2 months (range, 97–158 mo) after surgery, for DRUJ stability, forearm rotation, grip strength, pain level (0–10), and satisfaction (0–10). Standardized radiographs of the wrist were evaluated for displacement of the Ulnar Head and loosening or bony reactions at the sigmoid notch or the ulna shaft. Results All patients demonstrated a clinically stable DRUJ at the latest examination, and no patient required further surgery at the DRUJ since the short-term evaluation in 1999. Average pain measured 3.7 before surgery, 1.7 at the short-term follow-up, and 1.7 at the long-term follow-up; patients' satisfaction, 2.2, 8.2, and 8.9; pronation, 73°, 86°, and 83°; supination, 52°, 77°, and 81°; and grip strength, 42%, 72%, and 81% of the unaffected side. All clinical parameters improved significantly from before surgery to the short-term follow-up, with no further statistically significant change between the short-term and long-term follow-up. Radiographs demonstrated no signs of stem loosening or incongruity of the DRUJ. Conclusions The previously reported short-term results with the Herbert prosthesis did not deteriorate in the long term. Reconstruction of the DRUJ with this prosthesis in painful radioUlnar impingement following Ulnar Head resection is a reliable and reproducible procedure with lasting results. Type of study/level of evidence Therapeutic IV.
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Ulnar Head replacement.
Techniques in hand & upper extremity surgery, 2007Co-Authors: Timothy J. Herbert, Joerg Van SchoonhovenAbstract:Recent years have seen an increasing awareness of the anatomical and biomechanical significance of the distal radioUlnar joint (DRUJ). With this has come a more critical approach to surgical management of DRUJ disorders and a realization that all forms of "excision arthroplasty" can only restore forearm rotation at the expense of forearm stability. This, in turn, has led to renewed interest in prosthetic replacement of the Ulnar Head, a procedure that had previously fallen into disrepute because of material failures with early implants, in particular, the Swanson silicone Ulnar Head replacement. In response to these early failures, a new prosthesis was developed in the early 1990s, using materials designed to withstand the loads across the DRUJ associated with normal functional use of the upper limb. Released onto the market in 1995 (Herbert Ulnar Head prosthesis), clinical experience during the last 10 years has shown that this prosthesis is able to restore forearm function after Ulnar Head excision and that the materials (ceramic Head and noncemented titanium stem), even with normal use of the limb, are showing no signs of failure in the medium to long term. As experience with the use of an Ulnar Head prosthesis grows, so does its acceptance as a viable and attractive alternative to more traditional operations, such as the Darrach and Sauve-Kapandji procedures. This article discusses the current indications and contraindications for Ulnar Head replacement and details the surgical procedure, rehabilitation, and likely outcomes.
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Ulnar Head prosthesis
Der Orthopade, 2003Co-Authors: J. V. Schoonhoven, Timothy J. Herbert, Diego L Fernandez, Karl-josef Prommersberger, Hermann KrimmerAbstract:The Ulnar Head prosthesis has been the subject of a prospective multicenter-study since 1995. Until 2000, it has been used in 57 patients by the study group. In 35 patients, the indication was painful instability of the distal end of the ulna following previous resection arthroplasties, and in 22 patients it was painful arthritis of the distal radioUlnar joint (DRUJ). The mean follow-up was 38 months. Pronation increased from a preoperative mean of 63 degrees to a postoperative value of 78 degrees, while supination increased from 43 degrees to 76 degrees. Grip strength improved from a preoperative mean of 51% to a postoperative mean of 77% of the opposite limb. Pain, measured on the verbal pain scale (1-4), was reduced remarkably from a preoperative mean level of 3.6 to a postoperative mean of 1.7. Patient' satisfaction was evaluated using the visual analog scale (0-10) and improved from a preoperative mean of 2.1 to a postoperative mean of 7.9. With one exception of loosening, we consistently found bony integration of the shaft of the prosthesis. Stability of the DRUJ was achieved in all but three patients. This method has given reliable and excellent results as a salvage procedure for failed resection arthroplasties of the DRUJ with painful instability of the distal end of the ulna. We consider the method an alternative treatment option for the arthritically destroyed DRUJ. Sufficient soft tissue to stabilise the prosthesis is needed to successfully reconstruct the DRUJ.
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salvage of failed resection arthroplasties of the distal radioUlnar joint using a new Ulnar Head prosthesis
Journal of Hand Surgery (European Volume), 2000Co-Authors: Jorg Van Schoonhoven, William H. Bowers, Diego L Fernandez, Timothy J. HerbertAbstract:Abstract Twenty-three patients with painful instability following total or partial resection of the Ulnar Head were treated using a new Ulnar Head prosthesis combined with a simple soft tissue repair. Stability and marked symptomatic improvement were achieved in all patients. With a mean follow-up period of 27 months, this improvement has been maintained in all but 1 patient, whose prosthesis had to be removed because of a low-grade infection. These results suggest that the use of a prosthesis is a satisfactory way to restore stability and relieve secondary symptoms that may be associated with partial or total excision of the Ulnar Head. (J Hand Surg 2000;25A:438–446. Copyright © 2000 by the American Society for Surgery of the Hand.)
