procedure is not entirely failure-free and new designs are continually developing. 2 , 3 In the late 20th century, a new design has been introduced: the modular neck (MN) femoral stem. It is intended to give the surgeon the possibility to improve
Giuseppe Solarino, Giovanni Vicenti, Massimiliano Carrozzo, Guglielmo Ottaviani, Biagio Moretti, and Luigi Zagra
Michael M. Morlock, Robert Hube, Georgi Wassilew, Felix Prange, Gerd Huber, and Carsten Perka
axis and poorly under bending loading (as in high offset stems, long heads, large heads, and especially for modular necks and revision stems). Fig. 1 Definition of the head-stem taper connection. The male stem taper geometry is defined by the
Mattia Loppini and Guido Grappiolo
and the mean rate of stress shielding was 26.9% (5.2% to 66%) in 556 hips. 16 , 22 , 26 , 28 , 31 Metaphyseal total hip arthroplasty (METHA) The METHA (Aesculap) is an uncemented neck-retaining monoblock or modular stem ( Fig. 2 ). It is
Catalin Cirstoiu, Bogdan Cretu, Sergiu Iordache, Mihnea Popa, Bogdan Serban, and Adrian Cursaru
secondary to resection and measurements for the final prosthesis. (C) Postoperative image of the resection reconstruction with a modular tapered, fluted stem. Figure 3 (A) Preoperative anterior-posterior image of the pelvis of a 68-year
Luigi Zagra
. Modularity became a major issue in the last few years. Metal-backed liners and stem-head modularity are considered a standard for implant and nowadays no one will go back to monoblock implants out of all-poly cemented cups. Exchangeable necks have been
Ashoklal Ramavath, Jonathan N. Lamb, Jeya Palan, Hemant G. Pandit, and Sameer Jain
to bypass the fracture site by a minimum of 2.5 cortical diameters. These are increasingly available as tapered isthmic fitting stems with modular body, neck and head options to allow greater flexibility when balancing leg lengths and stability. These
Khaled M. Sarraf, Ravi Popat, Kathryn L. Kneale, Rajarshi Bhattacharya, Manoj Ramachandran, Pramod Achan, and Sammy A. Hanna
trochanter fracture ( n = 1, 0.4%), modular neck fracture ( n = 1, 0.4%) and unexplained pain ( n = 1, 0.4%). Revision rate There were 32 failures in total necessitating revision surgery in the 268 cases (11.9%). Seven hip resurfacings failed
Alexis Nogier, Idriss Tourabaly, Sonia Ramos-Pascual, Jacobus H. Müller, Mo Saffarini, and Cyril Courtin
versatility, as most designs are available in a range of sizes, neck lengths and offsets. Custom femoral stems were introduced for selected THA patients, notably those with major anatomical deformities, 2 , 3 for which off-the-shelf implants would not be
M M Morlock, E Gomez-Barrena, D C Wirtz, A Hart, and J P Kretzer
Fracture of the neck piece of a bi-modular hip stem. All the above-mentioned products failed despite intensive laboratory testing and the approval of regulatory competent authorities either in the US or in Europe. Failures despite fulfilling all
Marko Nabergoj, Patrick J. Denard, Philippe Collin, Rihard Trebše, and Alexandre Lädermann
components, modular stem or polyethylene disassociations, or glenoid screw problems. 19 Meanwhile, they defined a ‘problem’ as an intraoperative or postoperative event that was not likely to affect the patient’s final outcome. They considered these to