Derek F Amanatullah

Mayo Clinic - Rochester, Рочестер, Minnesota, United States

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Publications (41)56.33 Total impact

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    ABSTRACT: Background: Vertical shear fractures of the medial malleolus (44-A2 ankle fractures) occur through a supination-adduction mechanism. There are numerous methods of internal fixation for this fracture pattern. Methods: Vertical medial malleolus osteotomies were created in synthetic distal tibiae. The models were divided into four fixation groups: two parallel unicortical cancellous screws, two divergent unicortical cancellous screws, two parallel bicortical cortical screws, or an antiglide plate construct. Specimens were subjected to offset axial loading and tracked using high-resolution video. Findings: The antiglide plate construct was stiffer (P<0.05) than each of the other three constructs, and the bicortical screw construct was stiffer (P<0.05) than both unicortical screw constructs. The mean stiffness (standard deviation) was 111 (SD 35) N/mm for the parallel unicortical screw construct, 173 (SD 57) N/mm for the divergent unicortical screw construct, 279 (SD 30) N/mm for the bicortical screw construct, and 463 (SD 91) N/mm for the antiglide plate construct. The antiglide plate construct resisted displacement better (P<0.05) than each of the other three constructs. The mean force for 2mm of articular displacement was 284 (SD 51) N for the parallel unicortical screw construct, 339 (SD 46) N for the divergent unicortical screw construct, 429 (SD 112) N for the bicortical construct, and 922 (SD 297) N for the antiglide plate construct. Interpretation: An antiglide plate construct provides the stiffest initial fixation while withstanding higher load to failure for vertical medial malleolus fractures when compared to unicortical and bicortical screw fixation.
    Clinical biomechanics (Bristol, Avon) 10/2015; DOI:10.1016/j.clinbiomech.2015.10.005 · 1.97 Impact Factor
  • D F Amanatullah · H Siman · G D Pallante · D B Haber · R J Sierra · R T Trousdale ·
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    ABSTRACT: When fracture of an extensively porous-coated femoral component occurs, its removal at revision total hip arthroplasty (THA) may require a femoral osteotomy and the use of a trephine. The remaining cortical bone after using the trephine may develop thermally induced necrosis. A retrospective review identified 11 fractured, well-fixed, uncemented, extensively porous-coated femoral components requiring removal using a trephine with a minimum of two years of follow-up. The mean time to failure was 4.6 years (1.7 to 9.1, standard deviation (sd) 2.3). These were revised using a larger extensively porous coated component, fluted tapered modular component, a proximally coated modular component, or a proximal femoral replacement. The mean clinical follow-up after revision THA was 4.9 years (2 to 22, sd 3.1). The mean diameter of the femoral component increased from 12.7 mm (sd 1.9) to 16.2 mm (sd 3.4; p > 0.001). Two revision components had radiographic evidence of subsidence that remained radiographically stable at final follow-up. The most common post-operative complication was instability affecting six patients (54.5%) on at least one occasion. A total of four patients (36.4%) required further revision: three for instability and one for fracture of the revision component. There was no statistically significant difference in the mean Harris hip score before implant fracture (82.4; sd 18.3) and after trephine removal and revision THA (81.2; sd 14.8, p = 0.918). These findings suggest that removal of a fractured, well-fixed, uncemented, extensively porous-coated femoral component using a trephine does not compromise subsequent fixation at revision THA and the patient's pre-operative level of function can be restored. However, the loss of proximal bone stock before revision may be associated with a high rate of dislocation post-operatively. Cite this article: Bone Joint J 2015;97-B:1192-6. ©2015 The British Editorial Society of Bone & Joint Surgery.
    Bone and Joint Journal 09/2015; 97-B(9):1192-6. DOI:10.1302/0301-620X.97B9.35037 · 1.96 Impact Factor
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    Derek F Amanatullah · Robert T Trousdale · Rafael J Sierra ·
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    ABSTRACT: There are approximately 1.6 million lower extremity amputees in the United States. Lower extremity amputees are subject to increased physical demands proportional to their level of amputation. Lower extremity amputees have a 6-fold higher risk of developing radiographic osteoarthritis in the ipsilateral hip and a 2-fold risk of developing radiographic osteoarthritis in contralateral hip when compared with the non-amputee population. Additionally, there is a 3-fold increased risk of developing radiographic osteoarthritis in the ipsilateral hip after an above knee amputation when compared with a below knee amputation. The authors retrospectively reviewed 35 total hip arthroplasties after lower extremity amputation. The mean clinical follow-up was 5.3±4.0 years. The mean time from lower extremity amputation to total hip arthroplasty was 12.2±12.8 years after a contralateral amputation and 5.4±6.0 years after an ipsilateral amputation (P=.050). The mean time to total hip arthroplasty was 15.6±15.4 years after an above knee amputation and 6.4±6.1 years after a below knee amputation (P=.021). There was a statistically significant improvement in the mean Harris Hip Score from 35.9±21.8 to 76.8±12.8 with total hip arthroplasty after a contralateral amputation (P<.001). There also was a statistically significant improvement in the mean Harris Hip Score from 25.4±21.7 to 78.6±17.1 with total hip arthroplasty after an ispilateral amputation (P<.001). Three (17.7%) total hip arthroplasties after a contralateral amputation and 2 (11.1%) total hip arthroplasties after an ipsilateral amputation required revision total hip arthroplasty. Patients with an ipsilateral amputation or a below knee amputation progress to total hip arthroplasty faster than those with a contralateral amputation or an above knee amputation, respectively. Lower extremity amputees experience clinically significant improvements with total hip arthroplasty after lower extremity amputation.
    Orthopedics 05/2015; 38(5):e394-400. DOI:10.3928/01477447-20150504-56 · 0.96 Impact Factor

  • Osteoarthritis and Cartilage 04/2015; 23:A38-A39. DOI:10.1016/j.joca.2015.02.090 · 4.17 Impact Factor
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    ABSTRACT: EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Identify the etiology of femoroacetabular impingement. 2. Assess femoroacetabular impingement on physical examination. 3. Recognize femoroacetabular impingement on imaging studies. 4. Discuss modern techniques to effectively treat femoroacetabular impingement, both open and arthroscopic. Femoroacetabular impingement (FAI) is a recently proposed concept describing abnormal anatomic relationships within the hip joint that may lead to articular damage. Impingement is caused by bony deformities or spatial malorientation of the femoral head-neck junction and/or the acetabulum. These abnormalities lead to pathologic contact and shearing forces at the acetabular labrum and cartilage during physiological hip motion. There is an increasing body of evidence that these forces lead to cartilage wear and eventual osteoarthritis. Treatment options for FAI are evolving rapidly. Although the gold standard remains open hip dislocation, arthroscopic techniques have shown significant promise. It is possible that early recognition and treatment of subtle deformity about the hip may reduce the rate of hip osteoarthritis in the future. [Orthopedics. 2015; 38(3):185-199.]. Copyright 2015, SLACK Incorporated.
    Orthopedics 03/2015; 38(3):185-99. DOI:10.3928/01477447-20150305-07 · 0.96 Impact Factor
  • D F Amanatullah · J L Howard · H Siman · R T Trousdale · T M Mabry · D J Berry ·
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    ABSTRACT: Revision total hip arthroplasty (THA) is challenging when there is severe loss of bone in the proximal femur. The purpose of this study was to evaluate the clinical and radiographic outcomes of revision THA in patients with severe proximal femoral bone loss treated with a fluted, tapered, modular femoral component. Between January 1998 and December 2004, 92 revision THAs were performed in 92 patients using a single fluted, tapered, modular femoral stem design. Pre-operative diagnoses included aseptic loosening, infection and peri-prosthetic fracture. Bone loss was categorised pre-operatively as Paprosky types III-IV, or Vancouver B3 in patients with a peri-prosthetic fracture. The mean clinical follow-up was 6.4 years (2 to 12). A total of 47 patients had peri-operative complications, 27 of whom required further surgery. However, most of these further operations involved retention of a well-fixed femoral stem, and 88/92 femoral components (97%) remained in situ. Of the four components requiring revision, three were revised for infection and were well fixed at the time of revision; only one (1%) was revised for aseptic loosening. The most common complications were post-operative instability (17 hips, 19%) and intra-operative femoral fracture during insertion of the stem (11 hips, 12%). Diaphyseal stress shielding was noted in 20 hips (22%). There were no fractures of the femoral component. At the final follow-up 78% of patients had minimal or no pain. Revision THA in patients with extensive proximal femoral bone loss using the Link MP fluted, tapered, modular stem led to a high rate of osseointegration of the stem at mid-term follow-up. Cite this article: Bone Joint J 2015; 97-B:312-17. ©2015 The British Editorial Society of Bone & Joint Surgery.
    Bone and Joint Journal 03/2015; 97-B(3):312-7. DOI:10.1302/0301-620X.97B3.34684 · 1.96 Impact Factor
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    ABSTRACT: Correct recognition, description, and classification of acetabular fractures is essential for efficient patient triage and treatment. Acetabular fractures may result from high-energy trauma or low-energy trauma in the elderly. The most widely used acetabular fracture classification system among radiologists and orthopedic surgeons is the system of Judet and Letournel, which includes five elementary (or elemental) and five associated fractures. The elementary fractures are anterior wall, posterior wall, anterior column, posterior column, and transverse. The associated fractures are all combinations or partial combinations of the elementary fractures and include transverse with posterior wall, T-shaped, associated both column, anterior column or wall with posterior hemitransverse, and posterior column with posterior wall. The most unique fracture is the associated both column fracture, which completely dissociates the acetabular articular surface from the sciatic buttress. Accurate categorization of acetabular fractures is challenging because of the complex three-dimensional (3D) anatomy of the pelvis, the rarity of certain acetabular fracture variants, and confusing nomenclature. Comparing a 3D image of the fractured acetabulum with a standard diagram containing the 10 Judet and Letournel categories of acetabular fracture and using a flowchart algorithm are effective ways of arriving at the correct fracture classification. Online supplemental material is available for this article. (©)RSNA, 2015.
    Radiographics 03/2015; 35(2):555-577. DOI:10.1148/rg.352140098 · 2.60 Impact Factor
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    ABSTRACT: Optimization of patient expectations in TKA requires understanding the risk profile of each patient and tailoring preoperative counseling appropriately. There are numerous postoperative thromboprophylaxis regimens, but aspirin has gained consensus approval from the Academy of Orthopaedic Surgeons and American College of Chest Physicians and may decrease the risk of bleeding when compared to other agents. Early mobilization or mechanical compression remain useful adjuncts to chemical thromboprophylaxis. Pre-emptive multimodal pain control is effective and minimizes narcotic-related side effects. Regional blockade and periarticular injection are effective strategies for site-specific pain control and avoid opioid induced side effects. Strategies for perioperative physical therapy vary widely and there are no well-defined guidelines for postoperative rehabilitation. Rehabilitation lacks durable clinical benefits long-term for the average patient. However, targeted utilization of perioperative rehabilitation to the most debilitated patients may be beneficial.
    Current Orthopaedic Practice 01/2015; 26(3):217-223. DOI:10.1097/BCO.0000000000000230
  • D F Amanatullah · S R Rachala · R T Trousdale · R J Sierra ·
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    ABSTRACT: Dysplasia of the hip, hypotonia, osteopenia, ligamentous laxity, and mental retardation increase the complexity of performing and managing patients with Down syndrome who require total hip replacement (THR). We identified 14 patients (six males, eight females, 21 hips) with Down syndrome and degenerative disease of the hip who underwent THR, with a minimum follow-up of two years from 1969 to 2009. In seven patients, bilateral THRs were performed while the rest had unilateral THRs. The mean clinical follow-up was 5.8 years (standard deviation (sd) 4.7; 2 to 17). The mean Harris hip score was 37.9 points (sd 7.8) pre-operatively and increased to 89.2 (sd 12.3) at final follow-up (p = 1x10(-9)). No patient suffered a post-operative dislocation. In three patients, four hips had revision THR for aseptic loosening at a mean follow-up of 7.7 years (sd 6.3; 3 to 17). This rate of revision THR was higher than expected. Our patients with Down syndrome benefitted clinically from THR at mid-term follow-up. Cite this article: Bone Joint J 2014;96-B:1455-8.
    Bone and Joint Journal 11/2014; 96-B(11):1455-8. DOI:10.1302/0301-620X.96B11.34089 · 1.96 Impact Factor
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    ABSTRACT: Introduction Some patients opt to undergo conversion to a THA for continued pain or progression of hip arthritis after periacetabular osteotomy. Whether patients are at greater risk for postoperative complications, revision THA, poor clinical outcomes, or compromised radiographic results after periacetabular osteotomy is debatable. Questions/purposes When compared with a matched cohort of patients who underwent THAs for developmental dysplasia of the hip (DDH) without previous periacetabular osteotomy, we asked whether a THA after a periacetabular osteotomy has (1) a higher complication rate, (2) a higher likelihood of resulting in revision THA, (3) comparable improvements in Harris hip score, and (4) comparable radiographic results. Patients and Methods A multicenter retrospective review of 562 patients undergoing 645 periacetabular osteotomies was performed. Twenty-three hips in 22 patients underwent a THA after periacetabular osteotomy. The patients were matched for age, sex, and BMI with 23 hips in 23 patients with DDH undergoing THA without a history of periacetabular osteotomy. Minimum followup for both groups of patients was 2 years (mean, 10 ± 4 years and 6 ± 4 years, respectively). Comparisons were made to answer the study questions based on a retrospective review from prospectively maintained registries of clinical and radiographic information at two participating centers. Results With the numbers available, there was no difference in complication or revision rates between the two groups (p = 0.489 and 1.000, respectively); however, a post hoc power analysis showed our study was underpowered to detect a difference in the rate of postoperative complications or revision THA. There was marked improvement in Harris hip score with THA after periacetabular osteotomy (p
    Clinical Orthopaedics and Related Research 10/2014; 473(2). DOI:10.1007/s11999-014-4026-7 · 2.77 Impact Factor
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    ABSTRACT: The utility of heterotopic ossification (HO) classification systems is debatable. The range of motion and Harris hip score (HHS) were calculated in 104 patients with known HO after total hip arthroplasty and 208 matched controls without HO. The patients with HO were radiographically divided into high and low grade HO groups. There was no statistically significant association of HHS with high or low grade HO. High grade HO had a statistically significant 6° loss of terminal hip flexion, 4° loss of abduction, and 6° loss of internal rotation at the hip. The small changes terminal hip range of motion and lack of an association with HHS may be the result of false radiographic continuity resulting in an overestimation of the disability in high grade HO.
    The Journal of Arthroplasty 10/2014; 30(3). DOI:10.1016/j.arth.2014.09.019 · 2.67 Impact Factor
  • Derek F. Amanatullah · Robert T. Trousdale · Rafael J. Sierra ·
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    ABSTRACT: Below knee amputation protects the ipsilateral knee from osteoarthritis and overloads the contralateral knee predisposing it to symptomatic osteoarthritis. We retrospectively reviewed 13 primary TKA patients with a prior lower extremity amputation. Twelve TKAs were performed on the contralateral side of the amputated limb while only one TKA was performed on the ipsilateral side. The average clinical follow-up was 6.8 ± 4.8 years. Knee Society scores improved from 30.4 ± 11.8 to 88.5 ± 4.2 after TKA with a prior contralateral amputation. Three (23.1%) patients with TKA after contralateral amputation had aseptic loosening of the tibial component. Patients experience clinically significant improvement with TKA after lower extremity amputation. Augmentation of tibial fixation with a stem may be advisable during TKA after contralateral amputation.
    The Journal of Arthroplasty 10/2014; 29(8). DOI:10.1016/j.arth.2014.03.041 · 2.67 Impact Factor
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    ABSTRACT: Total femoral arthroplasty (TFA) is an option to amputation in the setting of excessive bones loss during revision total hip and knee arthroplasty. Twenty non-oncologic TFAs with a minimum of 2years follow-up were retrospectively reviewed. The average clinical follow-up was 73±49months. The incidence of new infection was 25% (5/20), while the overall infection rate was 35% (7/20). The incidence of primary hip instability was 10% (2/20), while the overall instability rate was 25% (5/20). Six patients (30%) required revision. The average pre-operative HHS was 30.2±13.1. The average post-operative HHS was 65.3±16.9. TFA is a viable alternative to amputation in non-oncologic patients with massive femoral bone deficiency. However, TFA performed poorly in the setting of infection and instability.
    The Journal of Arthroplasty 05/2014; 29(10). DOI:10.1016/j.arth.2014.05.012 · 2.67 Impact Factor
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    Derek F Amanatullah · Joel C Williams · David P Fyhrie · Robert M Tamurian ·
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    ABSTRACT: The optimal management of pathologic long bone lesions remains a challenge in orthopedic surgery. The goal of the current study was to investigate the effect of defect depth on the torsional properties of the distal femur. A laterally placed distal metaphyseal cylindrical defect was milled in the cortex of the distal femur in 20 composite models. The proximal extent of the defects was constant. By decreasing the radius of the cylinder that intersected this predefined cord, 4 different radii defining 4 different depths of resection of the distal femur were created for testing: 17%, 33%, 50%, and 67% cortical defects, when normalized to the width of the femur at the level of resection. Each femur was mounted into a hydraulic axial/torsion materials testing machine and each specimen underwent torsional stiffness testing and torsional failure in external rotation. The specimens with less than a 33% cortical loss consistently demonstrated a superiorly oriented spiral fracture pattern, while the specimens with greater than a 50% cortical loss consistently demonstrated an inferiorly oriented transverse fracture pattern. The cortical defects were all statistically (P<.05) less stiff in torsion as the defect grew larger. There was a strong linear correlation between the mean torsional stiffness and cortical defect size (r(2)=0.977). This observation is supported by finite element analysis. The amount of femur remaining is crucial to stability. This biomechanical analysis predicts a critical loss of torsional integrity when a cortical defect approaches 50% of the width of the femur. [Orthopedics. 2014; 37(3):158-162].
    Orthopedics 03/2014; 37(3):158-62. DOI:10.3928/01477447-20140225-51 · 0.96 Impact Factor
  • Derek F Amanatullah · Tyler R Clark · Matthew J Lopez · Dariusz Borys · Robert M Tamurian ·
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    ABSTRACT: EDUCATIONAL OBJECTIVES As a result of reading this article, physicians should be able to: 1. Identify at-risk populations for giant cell tumor of bone. 2. Recognize the biology that drives giant cell tumor of bone. 3. Describe modern surgical and adjuvant techniques to effectively treat giant cell tumor of bone. 4. Recognize the complications associated with radiation therapy, poor resection, and adjuvant treatments. Giant cell tumor of bone (GCT) is a benign, locally aggressive bone tumor. Giant cell tumor of bone primarily affects the young adult patient population. The natural history of GCT is progressive bone destruction leading to joint deformity and disability. Surgery is the primary mode of treatment, but GCT has a tendency to recur locally despite a range of adjuvant surgical options. Pulmonary metastasis has been described. However, systemic spread of GCT rarely becomes progressive, leading to death. This review presents the clinicopathologic features of GCT and a historical perspective that highlights the current rationale and contro-versies regarding the treatment of GCT. [Orthopedics. 2014;37(2):112-120.].
    Orthopedics 02/2014; 37(2):112-20. DOI:10.3928/01477447-20140124-08 · 0.96 Impact Factor

  • Current Orthopaedic Practice 01/2014; 25(3):297-301. DOI:10.1097/BCO.0000000000000103
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    ABSTRACT: Osteonecrosis of the hip accounts for about 10% of all total hip arthroplasty cases and presents a significant challenge for those patients with and without femoral head collapse. Subtrochanteric femur fractures have been reported with numerous types of proximal femoral implants. Care must be taken to avoid penetrating the lateral cortex of the proximal femur inferior to the distal border of the lesser trochanter. Core decompression requires a 3 mm to 20 mm defect in the lateral femoral cortex. Subtrochanteric femur fractures are a well-known complication of core decompression as well. We present a case of a subtrochanteric fracture following the removal of a porous tantalum implant.
    12/2013; 2013:946745. DOI:10.1155/2013/946745
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    Jeffrey A Arthur · Derek F Amanatullah · Gannon D Kennedy · Paul E Di Cesare ·
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    ABSTRACT: Several risk factors for dislocation after total hip arthroplasty (THA) have been identified including operative-, patient-, and implant-related factors. The following case report describes the dislocation of a revision THA without disruption of the constrained liner or containment ring. The possible mechanisms leading to this type of failure include lever-out impingement and poor abductor function, or tension secondary to prior surgery. Dislocation without disruption of containment ring has not been described for the Pinnacle Acetabular Cup with the Enhanced Stability Constrained Liner (DePuy Orthopaedics, Warsaw, Indiana).
    American journal of orthopedics (Belle Mead, N.J.) 12/2013; 42(12):566-8.
  • Andrea S Bauer · Avreeta K Singh · Derek Amanatullah · Joel Lerman · Michelle A James ·
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    ABSTRACT: Congenital pseudarthrosis of the radius or ulna is a rare entity. It is associated with neurofibromatosis, but occurs much less commonly than congenital pseudarthrosis of the tibia. Pseudarthrosis of the forearm can lead to pain, deformity, and limited forearm rotation. Nonsurgical management leads to poor results, as do surgical treatments such as open reduction internal fixation and conventional bone grafting. The transfer of a free vascularized fibula to the forearm pseudarthrosis has been more successful, and it is our preferred method of treatment for children with this condition. Because the transfer is often performed in young children, there is the potential for valgus deformity at the ankle after the fibula is removed. We describe here our technique for the transfer, including the technique for distal tibiofibular fusion (Langenskiöld procedure) after removal of the fibular graft. In addition, we present the results of 5 patients who have undergone this combination of procedures for pseudarthrosis of the forearm at our institution.
    Techniques in hand & upper extremity surgery 09/2013; 17(3):144-50. DOI:10.1097/BTH.0b013e318295238b
  • Derek F Amanatullah · Paul E Di Cesare · Patrick A Meere · Gavin C Pereira ·
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    ABSTRACT: Incorrect registration during computer assisted total knee arthroplasty (CA-TKA) leads to malposition of implants. Our aim was to evaluate the tolerable error in anatomic landmark registration. We incorrectly registered the femoral epicondyles, femoral and tibial centers, as well as the malleoli and documented the change in angulation or rotation. We found that the distal femoral epicondyles were the most difficult anatomic landmarks to register. The other bony landmarks were more forgiving. Identification of the distal femoral epicondyles has a high inter-observer and intra-observer variability. Our observation that there is less than 2mm of safe zone in the anterior or posterior direction during registration of the medial and lateral epicondyles may explain the inability of CA-TKA to improve upon the outcomes of conventional TKA.
    The Journal of arthroplasty 04/2013; 28(6). DOI:10.1016/j.arth.2012.12.013 · 2.67 Impact Factor

Publication Stats

86 Citations
56.33 Total Impact Points


  • 2014-2015
    • Mayo Clinic - Rochester
      Рочестер, Minnesota, United States
    • Stanford University
      • Department of Orthopaedic Surgery
      Palo Alto, California, United States
  • 2010-2015
    • University of California, Davis
      • Department of Orthopaedic Surgery
      Davis, California, United States
  • 2012-2013
    • California State University, Sacramento
      Sacramento, California, United States