Sergio Gutierrez

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The purpose of this study was to determine the effects of prosthetic design and surgical technique of reverse shoulder implants on total abduction range of motion and impingement on the inferior scapular neck. Custom implants in three glenosphere diameters (30, 36, and 42 mm), with 3 different centers of rotation offsets (0, +5, and +10 mm), were placed(More)
We evaluated the effectiveness of a novel bicompartmental knee arthroplasty prosthesis for the treatment of degenerative disease affecting the medial and patellofemoral compartments. The study included 36 knees in 32 patients with a mean follow-up of 21 months. The mean Knee Society functional survey and Western Ontario McMaster Osteoarthritic Index Survey(More)
We present jPET, a whitebox test-case generator (TCG) which can be used during software development of Java applications within the Eclipse environment. jPET builds on top of PET, a TCG which automatically obtains test-cases from the bytecode associated to a Java program. jPET performs reverse engineering of the test-cases obtained at the bytecode level by(More)
Reverse shoulder arthroplasty is being used more frequently to treat irreparable rotator cuff tears in the presence of glenohumeral arthritis and instability. To date, however, design features and functions of reverse shoulder arthroplasty, which may be associated with subluxation and dislocation of these implants, have been poorly understood. We asked: (1)(More)
BACKGROUND Evaluations of functional outcomes of reverse shoulder arthroplasty have revealed variable improvements in the range of motion and high rates of scapular notching. The purpose of this study was to systematically examine the impact of surgical factors (location of the glenosphere on the glenoid and tilt angle of the glenosphere on the glenoid) and(More)
There has been renewed interest in reverse shoulder arthroplasty for the treatment of glenohumeral arthritis with concomitant rotator cuff deficiency. Failure of the prosthesis at the glenoid attachment site remains a concern. The purpose of this study was to examine glenoid component stability with regard to the angle of implantation. This investigation(More)
BACKGROUND CONTEXT The lateral transpsoas approach to interbody fusion is gaining popularity because of its minimally invasive nature and resultant indirect neurologic decompression. The acute biomechanical stability of the lateral approach to interbody fusion is dependent on the type of supplemental internal fixation used. The two-hole lateral plate (LP)(More)
HYPOTHESIS/BACKGROUND Reverse shoulder arthroplasty is being used with greater frequency for patients with severe rotator cuff deficiency. There are several commercially available reverse shoulder devices, each with different glenosphere options. The purpose of this study was to determine: (1) forces at the baseplate-bone interface in glenospheres with(More)
OBJECTIVE The purpose of this study was to determine if proximity of cannulated lag screws to the articular surface of the patella combined with the tension band technique affects resistance to fracture gap opening, and if an alternative locking nut and bolt device without a tension band behaves in a biomechanically similar fashion. METHODS Thirty-three(More)
BACKGROUND Modifications in reverse shoulder arthroplasty (RSA) have been made with the intent of maximizing motion, although there is little objective evidence outlining their benefit. This study investigated the RSA component combinations that impart the greatest effect on impingement-free glenohumeral motion. METHODS A previously validated virtual(More)