- Orthopaedic Surgery
- Nonunions and Malunions
- Limb Lengthening and Reconstruction
- Limb Salvage
- Limb Transplantation via Immunotolerance
Clinical Professor, Orthopaedic Surgery
Unit Based Medical Director, Stanford Hospital and Clinics (2016 - 2019)
Honors & Awards
Landstuhl Distinguished Visiting Scholar, United States Department of Defense (May, 2010)
Boards, Advisory Committees, Professional Organizations
President, Osteosynthesis and Trauma Care Foundation (OTC) International (2018 - 2019)
President, Limb Lengthening and Reconstruction Society of North America (2006 - 2007)
President, Foundation for Orthopaedic Trauma (2013 - 2016)
Medical Education:UCLA David Geffen School Of Medicine Registrar (1985) CA
Residency:University of California at San Francisco School of Medicine (1990) CA
Internship:University of California at San Francisco School of Medicine (1986) CA
Board Certification: Orthopaedic Surgery, American Board of Orthopaedic Surgery (1992)
Current Research and Scholarly Interests
Dr. Lowenberg is a Past President of the Limb Lengthening and Reconstruction Society of North America. His clinical and research interests are in the treatment of nonunions and malunions with or without accompanying osteomyelitis and infection. He is well-published in the field of limb salvage and treatment of devastating limb injuries. He has ongoing research in limb transplantation via immunotolerance as well as biomechanics.
Independent Studies (5)
- Directed Reading in Orthopedic Surgery
ORTHO 299 (Aut, Win, Spr, Sum)
- Early Clinical Experience in Orthopedic Surgery
ORTHO 280 (Aut, Win, Spr, Sum)
- Graduate Research
ORTHO 399 (Aut, Win, Spr, Sum)
- Medical Scholars Research
ORTHO 370 (Aut, Win, Spr, Sum)
- Undergraduate Research
ORTHO 199 (Aut, Win, Spr, Sum)
- Directed Reading in Orthopedic Surgery
Influence of fracture obliquity and interlocking nail screw configuration on interfragmentary motion in distal metaphyseal tibia fractures.
European journal of orthopaedic surgery & traumatology : orthopedie traumatologie
The indications for the use of intramedullary (IM) nails have been extended to include extra-articular distal metaphyseal tibia fractures. We hypothesize that interfragmentary motion during physiologic compressive loading of distal tibia fractures is influenced by fracture obliquity and can be modulated by interlocking screw configuration. Sawbone specimens were osteotomized with frontal plane obliquities ranging from 0° to 60° and then fixed by IM nailing with six interlocking screw configurations. Interfragmentary motion was evaluated during loading in axial compression to 1000N. Comparisons of interfragmentary motions were made (1) between configurations for the various fracture obliquities and (2) between fracture obliquities for the various screw configurations using a mixed-effects regression model. As the degree of fracture obliquity increased, significantly more interfragmentary displacement was shown in configurations with two distal interlocking screws and one proximal screw set in dynamic mode. Fracture obliquity beyond 30° causes demonstrated instability in configurations with less than two distal locking screws and one proximal locking screw. Optimizing the available screw configurations can minimize fracture site motion and shear in distal tibial fractures with larger fracture obliquities.
View details for DOI 10.1007/s00590-019-02553-w
View details for PubMedID 31571003
- Newer perspectives in the treatment of chronic osteomyelitis: A preliminary outcome report INJURY-INTERNATIONAL JOURNAL OF THE CARE OF THE INJURED 2019; 50: S56–S61
Newer perspectives in the treatment of chronic osteomyelitis: A preliminary outcome report.
The prevalence of chronic osteomyelitis due to trauma and surgical complications does not seem to be diminishing in our society. In many African Nations, with the urbanization and shift to the larger cities that has been occurring, Trauma has been classified as the number one disease problem plaguing such societies. This brings along with it the ensuing infections. With our better understanding of how microbes gain attachment to sites in our body and morph from a planktonic state to the slow growing sessile phase of growth, combined with their formation of a highly structured biofilm colony, we have come to realize that we must resort to other forms of treatment. This means changing our philosophical approach to treatment utilized over the past nearly 70 years involving complete reliance on chemotherapeutic agents with their resultant questionable efficacy in the treatment of chronic osteomyelitis. We report on preliminary early outcome results in the treatment of 127 patients with chronic osteomyelitis treated by a single surgeon in which all patients except those with underlying immunological impairment were treated with in-hospital intravenous antibiotics only. Only 5.5% of the patient population then received intravenous antibiotics following hospital discharge, and with this treatment approach there remained a 98.4% cure rate in the treatment of this chronic infection.
View details for PubMedID 31079834
- Newer Perspectives In the Treatment of Chronic Osteomyelitis: A Preliminary Outcome Report. Injury 2019: S56-S61
Pain management in the orthopaedic trauma patient: Non-opioid solutions.
When treating pain in the orthopaedic trauma patient opioids have classically represented the mainstay of treatment. They are relatively inexpensive and modestly effective for basic pain management. However, they are fraught with considerable side effects as well as the very high risk of addiction. Their use in pain management has been implicated in the opioid epidemic. For this reason, as well as their only moderate efficacy, alternative modes of treatment have been sought for both the patient with isolated limb trauma and the patient with poly trauma. We review alternative treatment methods in pain management for those with isolated limb trauma and poly trauma. These methods include topical agents, as well as non steroidal anti-inflammatory medications, acetaminophen, gabapetoids, intravenous agents, varying degrees of local anesthetic infiltration and peripheral nerve blocks, and the newer modality of fascial plane blocks. Often, it is a combination of these analgesic modalities that gives the most optimum treatment for the trauma patient. This also, more frequently than not, must be individually tailored to the patient, as no two patients act the same in this regard. It is therefore of importance that the physician managing such patients's pain be experienced and well-versed in all these treatment modalities. We also provide a basic stepwise algorithm we have found useful in treating those with single extremity or single site trauma versus those patients with poly trauma and resultant multiple sources as pain generators. It is hoped that this breakdown of the different modalities along with a better understanding of each modality's potential benefits and indications will aid the surgeon in providing better care to patients following orthopedic trauma.
View details for PubMedID 31079833
- Effect of Electron Beam Sterilization on Three-Dimensional-Printed Polycaprolactone/Beta-Tricalcium Phosphate Scaffolds for Bone Tissue Engineering TISSUE ENGINEERING PART A 2019; 25 (3-4): 248–56
Fracture Healing Adjuncts-The World's Perspective on What Works
JOURNAL OF ORTHOPAEDIC TRAUMA
2018; 32: S43–S47
Treatment of bone defects remains a challenging clinical problem. Despite our better understanding of bone repair mechanisms and advances made in microsurgical techniques and regenerative medicine, the reintervention rates and morbidity remain high. Surgical techniques such as allograft implantation, free vascularized fibular graft, distraction osteogenesis, loaded titanium cages, and the induced membrane technique continue to evolve, but the outcome can be affected by a number of parameters including the age of the patient, comorbidities, systemic disorders, the location of the defect, and the surgeon's preference and experience. In the herein article, a brief summary of the most currently used techniques for the management of bone defects is presented.
View details for PubMedID 29461403
Proper Use of Antibiotic Agents in the Management of Musculoskeletal Infection.
Instructional course lectures
2018; 67: 543–54
Musculoskeletal infections have plagued all creatures for millions of years. The ability to manage infection via antibiotic agents has emerged only in the past 100 years. The use of antibiotic agents has not always been appropriate and judicious, which has led to widespread microbial resistance to certain antibiotic agents. Although antibiotic resistance is a considerable consequence of inappropriate antibiotic use, the systemic adverse effects of chronic antibiotic use on patients have largely been ignored. These systemic adverse effects may have been prevented if surgeons had a better understanding of the microbiology of the pathogens involved in musculoskeletal infections. Most importantly, the formation of biofilm as an infection becomes chronic makes bacteria relatively impervious to systemic antibiotic agents. Therefore, surgeons must understand the difference between and how to appropriately manage acute and chronic musculoskeletal infections. This dichotomous approach in the management of infection also must be applied in patients with periprosthetic joint infection. The appropriate use of antibiotic agents in the management of musculoskeletal infections may help mitigate the spread of antibiotic resistance and the adverse effects of inappropriate antibiotic use.
View details for PubMedID 31411438
- Proper Understanding and Usage of Antibiotics in Musculoskeletal Infections Instr Course Lect. American Academy of Orthopaedic Surgeons 2018; 67: 543-554
Cement Arthrodesis of the Knee with a Custom Long Recon Nail After Failed Total Knee Arthroplasty: Surgical Technique and Results.
The Open Orthopaedics Journal
2018; December (1): 554-566
View details for DOI 10.2174/1874325001812010554
Unstable Proximal Femur Fractures Treated With Proximal Femoral Locking Plates: A Retrospective, Multicenter Study of 111 Cases.
Journal of orthopaedic trauma
2016; 30 (9): 489-495
A few small case series have found that proximal femur fractures treated with a proximal femur locking plate (PFLP) have experienced more failures than expected. The purpose of this study was to review the clinical results of patients with acute, unstable proximal femur fractures treated with proximal femoral locking plates in a large, multicenter patient cohort.This is a retrospective clinical study.The study included patients from 12 regional trauma centers and tertiary referral hospitals.One hundred eleven consecutive patients with unstable proximal femur fractures stabilized with a PFLP and having required clinical and radiographic follow-up at a minimum of 12 months after injury.Surgical repair of an unstable proximal femur fracture with a PFLP.Treatment failures (failure of fixation, nonunion, and malunion) and need for revision surgery.Forty-six patients (41.4%) experienced a major treatment failure, including failed fixation with or without nonunion (39), surgical malalignment or malunion (18), deep infection (8), or a combination of these. Thirty-eight (34%) patients underwent secondary surgeries, including 30 for failed fixation, nonunion, or both. Treatment failure was found to occur at a significantly higher rate in patients with major comorbidities, in femurs repaired in varus malalignment, and using specific plate designs.Proximal femoral locking plates are associated with a high complication rate, frequently requiring revision or secondary surgeries in the treatment of unstable proximal femur fractures. Given the high complication rate with PFLPs, careful attention to reduction, use of a PFLP implant, and consideration should be given to alternative implants or fixation techniques when appropriate.Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
View details for DOI 10.1097/BOT.0000000000000602
View details for PubMedID 27144821
- A Technotheoretical Approach to the Management of Osteomyelitis TECHNIQUES IN ORTHOPAEDICS 2015; 30 (4): 209–14
- In Memorium: George Cierny, MD - Modern Father of Osteomyelitis Surgery TECHNIQUES IN ORTHOPAEDICS 2015; 30 (4): 207–8
- Complex Limb Reconstruction With Simultaneous Muscle Transfer and Circular External Fixation TECHNIQUES IN ORTHOPAEDICS 2015; 30 (3): 156–60
A Clinical Perspective on Musculoskeletal Infection Treatment Strategies and Challenges
JOURNAL OF THE AMERICAN ACADEMY OF ORTHOPAEDIC SURGEONS
2015; 23: S44-S54
Orthopaedic implants improve the quality of life of patients, but the risk of postoperative surgical site infection poses formidable challenges for clinicians. Future directions need to focus on prevention and treatment of infections associated with common arthroplasty procedures, such as the hip, knee, and shoulder, and nonarthroplasty procedures, including trauma, foot and ankle, and spine. Novel prevention methods, such as nanotechnology and the introduction of antibiotic-coated implants, may aid in the prevention and early treatment of periprosthetic joint infections with goals of improved eradication rates and maintaining patient mobility and satisfaction.
View details for DOI 10.5435/JAAOS-D-14-00379
View details for Web of Science ID 000354129700008
View details for PubMedID 25808969
Advances in the understanding and treatment of musculoskeletal infections.
Instructional course lectures
2015; 64: 37-49
Musculoskeletal infections are a challenging treatment problem for orthopaedic surgeons. Despite advances in aseptic techniques and improved chemotherapeutic options, there has not been a substantial decrease in the incidence of musculoskeletal infections for the past quarter century. Understanding how microbes gain a foothold in tissue and bone and establish a chronic infectious state is imperative to the successful treatment of bone and soft-tissue infections. The methodic establishment of microbes in a sessile state in a mature biofilm represents the basis for instituting a chronic microbial defense system and sustainability in a host. To properly eradicate such infections requires a stepwise treatment algorithm of meticulous and thorough débridement, dead-space management, and soft-tissue and bone reconstruction. A comprehensive understanding of the reconstruction ladder combined with a detailed treatment plan from the initial staging of an infection through final reconstruction can cure an infection and achieve good functional results for patients.
View details for PubMedID 25745893
Malignant Transformation in Chronic Osteomyelitis: Recognition and Principles of Management
JOURNAL OF THE AMERICAN ACADEMY OF ORTHOPAEDIC SURGEONS
2014; 22 (9): 586-594
Malignant transformation as a result of chronic osteomyelitis represents a relatively rare and late complication with a declining incidence in the modern world. For most patients, the interval between the occurrence of the original bacterial infection and the transformation to malignant degeneration is several years. The diagnosis of malignant transformation in a chronic discharging sinus requires a high index of clinical suspicion. Wound biopsies should be obtained early, especially with the onset of new clinical signs such as increased pain, a foul smell, and changes in wound drainage. Squamous cell carcinoma is the most common presenting malignancy. Definitive treatment is amputation proximal to the tumor or wide local excision, combined with adjuvant chemotherapy and radiation therapy in selected patients. Early diagnosis may sometimes allow for treatment consisting of en bloc excision and limb salvage techniques. However, the most effective treatment is prevention with definitive treatment of the osteomyelitis, including adequate débridement, wide excision of the affected area, and early reconstruction.
View details for DOI 10.5435/JAAOS-22-09-586
View details for Web of Science ID 000341068800006
Temporal trends in the incidence, treatment and outcomes of hip fracture after first kidney transplantation in the United States.
American journal of transplantation
2014; 14 (4): 943-951
It is currently unknown whether any secular trends exist in the incidence and outcomes of hip fracture in kidney transplant recipients (KTR). We identified first-time KTR (1997-2010) who had >1 year of Medicare coverage and no recorded history of hip fracture. New hip fractures were identified from corresponding diagnosis and surgical procedure codes. Outcomes studied included time to hip fracture, type of surgery received and 30-day mortality. Of 69 740 KTR transplanted in 1997-2010, 597 experienced a hip fracture event during 155 341 person-years of follow-up for an incidence rate of 3.8 per 1000 person-years. While unadjusted hip fracture incidence did not change, strong confounding by case mix was present. Using year of transplantation as a continuous variable, the hazard ratio (HR) for hip fracture in 2010 compared with 1997, adjusted for demographic, dialysis, comorbid and most transplant-related factors, was 0.56 (95% confidence interval [CI]: 0.41-0.77). Adjusting for baseline immunosuppression modestly attenuated the HR (0.68; 95% CI: 0.47-0.99). The 30-day mortality was 2.2 (95% CI: 1.3-3.7) per 100 events. In summary, hip fractures remain an important complication after kidney transplantation. Since 1997, case-mix adjusted posttransplant hip fracture rates have declined substantially. Changes in immunosuppressive therapy appear to be partly responsible for these favorable findings.
View details for DOI 10.1111/ajt.12652
View details for PubMedID 24712332
Principles of Tibial Fracture Management with Circular External Fixation
ORTHOPEDIC CLINICS OF NORTH AMERICA
2014; 45 (2): 191-?
There is a growing mass of literature to suggest that circular external fixation for high-energy tibial fractures has advantages over traditional internal fixation, with potential improved rates of union, decreased incidence of posttraumatic osteomyelitis, and decreased soft tissue problems. To further advance our understanding of the role of circular external fixation in the management of these tibial fractures, randomized controlled trials should be implemented. In addition to complication rates and radiographic outcomes, validated functional outcome tools and cost analysis of this method should be compared with open reduction with internal fixation.
View details for DOI 10.1016/j.ocl.2013.11.003
View details for PubMedID 24684913
Long-term results and costs of muscle flap coverage with Ilizarov bone transport in lower limb salvage.
Journal of orthopaedic trauma
2013; 27 (10): 576-581
OBJECTIVES:: To determine long-term outcomes and costs of Ilizarov bone transport and flap coverage for lower limb salvage. DESIGN:: Case series with retrospective review of outcomes with at least six year follow-up. SETTING:: Academic, tertiary care medical center. PATIENTS:: Thirty-four consecutive patients with traumatic lower extremity wounds and tibial defects who were recommended amputation but instead underwent complex limb salvage from 1993 to 2005. INTERVENTION:: Flap reconstruction and Ilizarov bone transport. MAIN OUTCOME MEASUREMENTS:: Outcomes assessed were flap complications, infection, union, malunion, need for chronic narcotics, ambulation status, employment status, and need for re-operations. A cost analysis was performed comparing this treatment modality to amputation. RESULTS:: Thirty-four patients (mean age, 40 years) were included with 14 acute Gustilo IIIB/C defects and 20 chronic tibial defects (nonunion with osteomyelitis). Thirty five muscle flaps were performed with one flap loss (2.9%). The mean tibial bone defect was 8.7 cm, mean duration of bone transport was 10.8 months, and mean follow-up was 11 years. Primary nonunion rate at the docking site was 8.8% and malunion rate was 5.9%. All patients achieved final union with no cases of recurrent osteomyelitis. No patients underwent future amputations, 29% required re-operations, 97% were ambulating without assistance, 85% were working full time, and only 5.9% required chronic narcotics. Mean lifetime cost per patient per year after limb salvage was significantly less than the published cost for amputation. CONCLUSIONS:: The long-term results and costs of bone transport and flap coverage strongly support complex limb salvage in this patient population. LEVEL OF EVIDENCE:: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
View details for DOI 10.1097/BOT.0b013e31828afde4
View details for PubMedID 23412507
Temporal Trends in the Incidence, Treatment, and Outcomes of Hip Fracture in Older Patients Initiating Dialysis in the United States
CLINICAL JOURNAL OF THE AMERICAN SOCIETY OF NEPHROLOGY
2013; 8 (8): 1336-1342
BACKGROUND AND OBJECTIVES: Patients with ESRD experience a fivefold higher incidence of hip fracture than the age- and sex-matched general population. Despite multiple changes in the treatment of CKD mineral bone disorder, little is known about long-term trends in hip fracture incidence, treatment patterns, and outcomes in patients on dialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Fourteen annual cohorts (1996-2009) of older patients (≥67 years) initiating dialysis in the United States were studied. Eligible patients had Medicare fee-for-service coverage for ≥2 years before dialysis initiation and were followed for ≤3 years for a first hip fracture. Type of treatment (internal fixation or partial or total hip replacement) was ascertained along with 30-day mortality. Cox and modified Poisson regressions were used to describe trends in study outcomes. RESULTS: This study followed 409,040 patients over 607,059 person-years, during which time 17,887 hip fracture events were recorded (29.3 events/1000 person-years). Compared with patients incident for ESRD in 1996, adjusted hip fracture rates increased until the 2004 cohort (+41%) and declined thereafter. Surgical treatment included internal fixation in 56%, partial hip replacement in 29%, and total hip replacement in 2%, which remained essentially unchanged over time; 30-day mortality after hip fracture declined from 20% (1996) to 16% (2009). CONCLUSIONS: Hip fracture incidence rates remain higher today than in patients reaching ESRD in 1996, despite multiple purported improvements in the management of CKD mineral bone disorder. Although recent declines in incidence and steady declines in associated short-term mortality are encouraging, hip fractures remain among the most common and consequential noncardiovascular complications of ESRD.
View details for DOI 10.2215/CJN.10901012
View details for PubMedID 23660182
Assessment of Compromised Fracture Healing
JOURNAL OF THE AMERICAN ACADEMY OF ORTHOPAEDIC SURGEONS
2012; 20 (5): 273-282
No standard criteria exist for diagnosing fracture nonunion, and studies suggest that assessment of fracture healing varies among orthopaedic surgeons. This variability can be problematic in both clinical and orthopaedic trauma research settings. An understanding of risk factors for nonunion and of diagnostic tests used to assess fracture healing can facilitate a systematic approach to evaluation and management. Risk factors for nonunion include medical comorbidities, age, and the characteristics of the injury. The method of fracture management also influences healing. Comprehensive evaluation includes an assessment of the patient's symptoms, signs, and immune and endocrine status as well as the biologic capacity of the fracture, presence of infection, and quality of reduction and fixation. Diagnostic tests include plain radiography, CT, ultrasonography, fluoroscopy, bone scan, MRI, and several laboratory tests, including assays for bone turnover markers in the peripheral circulation. A systematic approach to evaluating fracture union can help surgeons determine the timing and nature of interventions.
View details for DOI 10.5435/JAAOS-20-05-273
View details for PubMedID 22553099