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Dive into the research topics where Loretta B. Chou is active.

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Featured researches published by Loretta B. Chou.


Foot & Ankle International | 2009

Prospective Controlled Trial of STAR Total Ankle Replacement versus Ankle Fusion: Initial Results

Charles L. Saltzman; Roger A. Mann; Jeanette E. Ahrens; Annunziato Amendola; Robert B. Anderson; Gregory C. Berlet; James W. Brodsky; Loretta B. Chou; Thomas O. Clanton; Jonathan T. Deland; James K. DeOrio; Greg A. Horton; Thomas H. Lee; Jeffrey A. Mann; James A. Nunley; David B. Thordarson; Arthur K. Walling; Keith L. Wapner; Michael J. Coughlin

Background: Mobile-bearing ankle replacements have become popular outside of the United States over the past two decades. The goal of the present study was to perform a prospective evaluation of the safety and efficacy of a mobile-bearing prosthesis to treat end stage ankle arthritis. We report the results of three separate cohorts of patients: a group of Scandanavian Total Ankle Replacement (STAR) patients and a control group of ankle fusion patients (the Pivotal Study Groups) and another group of STAR total ankle patients (Continued Access Group) whose surgery was performed following the completion of enrollment in the Pivotal Study. Materials and Methods: The Pivotal Study design was a non-inferiority study using ankle fusion as the control. A non-randomized multi-centered design with concurrent fusion controls was used. We report the initial perioperative findings up to 24 months following surgery. For an individual patient to be considered an overall success, all of the following criteria needed to be met: a) a 40-point improvement in total Buechel-Pappas ankle score, b) no device failures, revisions, or removals, c) radiographic success, and d) no major complications. In the Pivotal Study (9/00 to 12/01), 158 ankle replacement and 66 arthrodesis procedures were performed; in the Continued Access Study (4/02 to 10/06), 448 ankle replacements were performed, of which 416 were at minimum 24 months post-surgery at time of the database closure. Results: Major complications and need for secondary surgical intervention were more common in the Pivotal Study arthroplasty group than the Pivotal Study ankle fusion group. In the Continued Access Group, secondary procedures performed on these arthroplasty patients decreased by half when compared with the Pivotal Arthroplasty Group. When the Pivotal Groups were compared, treatment efficacy was higher for the ankle replacement group due to improvement in functional scores. Pain relief was equivalent between fusion and replacement patients. The hypothesis of non-inferiority of ankle replacement was met for overall patient success. Conclusion: By 24 months, ankles treated with STAR ankle replacement (in both the Pivotal and Continued Access Groups) had better function and equivalent pain relief as ankles treated with fusion. Level of Evidence: II, Prospective Controlled Comparative Surgical Trial


Journal of Bone and Joint Surgery, American Volume | 1995

Prosthetic survival and clinical results with use of large-segment replacements in the treatment of high-grade bone sarcomas.

M M Malawer; Loretta B. Chou

We evaluated the long-term clinical results and the survival of the prostheses in eighty-two patients who had had a limb-sparing procedure by means of the implantation of a large-segment prosthesis. All patients had had a high-grade bone sarcoma of the distal, middle, or proximal part of the femur; the proximal part of the humerus; the proximal part of the tibia; or the pelvis. The duration of follow-up ranged from two to twelve years (median, three and one-half years). Function was evaluated with the revised 30-point classification system of the Musculoskeletal Tumor Society. The survival of the prostheses was analyzed with regard to several variables with use of Kaplan-Meier survival estimates. Sixty-eight patients were alive at the latest follow-up evaluation. The survival rate of the prostheses was 83 per cent at five years and 67 per cent at ten years. Twelve prostheses were revised, and eleven revisions were successful. The rate of revision was highest (six of thirteen) in the patients who had had a tumor of the proximal part of the tibia. In contrast, only three (10 per cent) of the thirty-one patients who had had a tumor of the distal part of the femur and three (10 per cent) of the twenty-nine who had had a tumor of the proximal part of the humerus had a revision. Eleven patients (13 per cent) had an infection, which necessitated an amputation in six. Five patients (6 per cent) had a local recurrence, and nine patients (11 per cent), including the six already mentioned, ultimately needed an amputation. Patients who had had a tumor of the proximal part of the humerus had the highest functional scores, while those who had had a tumor of the proximal part of the tibia had the lowest scores. Large-segment prostheses were a good reconstructive option for the treatment of high-grade bone sarcomas in our patients. The rates of long-term survival of the prostheses were acceptable and the functional results were good or excellent after this form of treatment at most of the anatomical sites at which they were used.


Foot & Ankle International | 2002

Autologous osteochondral grafting for talar cartilage defects.

Raad Al-Shaikh; Loretta B. Chou; Jeffrey A. Mann; Sharon M. Dreeben; David Prieskorn

The purpose of this study was to evaluate the clinical results of Osteochondral Autograft Transfer System (OATS) for the treatment of symptomatic osteochondral defects of the talus using standardized outcome analysis. Nineteen patients with symptomatic osteochondral defect (OCD) of the talus were treated with autologous osteochondral grafting. There were six men and 13 women. The average age was 32 years (range, 18 to 48 years). The average duration of symptoms prior to surgery was 4.2 years (range, three months to 12 years). All patients had failed nonoperative treatment, and 13 (68%) patients had failed prior excision, curettage and/or drilling of the lesion. The average size of the lesion prior to autografting was 12 mm × 10 mm (range, 10 × 5 mm to 20 × 20 mm). Donor plugs were harvested from the trochlear border of the ipsilateral femoral condyle. Ankle exposure was obtained with a medial malleolar osteotomy in 13 patients, arthrotomy in five patients and lateral malleolar osteotomy in one patient. Clinical evaluations were performed for both the recipient ankle and donor knee using the AOFAS Ankle/Hindfoot Scale and Lysholm knee scale, respectively. The average follow-up time was 16 months (range, 12 to 30 months). The average postoperative AOFAS ankle score was 88 (range, 60 to 100). Most patients had occasional mild pain, but excellent function, range of motion, stability and alignment. The average postoperative ankle score for the 13 patients who failed prior surgery was 91 (range, 84 to 100). The average postoperative Lysholm knee score was 97 (range, 87 to 100). Only two patients had mild knee pain. Postoperative radiographs were available for 13 patients. There was no evidence of graft subsidence and all grafts healed. All malleolar osteotomies united. Seventeen (89%) patients said that they would undergo the procedure again. The results of osteochondral autograft transplant for OCD lesions of the talus demonstrate excellent postoperative ankle scores including improvement of pain and function with minimal knee donor site morbidity. Also, our results indicate that this is an effective salvage procedure following failed previous procedures and for patients with longstanding symptoms.


Journal of The American Academy of Orthopaedic Surgeons | 2008

Osteoarthritis of the Ankle: The Role of Arthroplasty

Loretta B. Chou; Michael T. Coughlin; Sigvard Hansen; Andrew Haskell; Gregg Lundeen; Charles L. Saltzman; Roger A. Mann

Abstract Total ankle arthroplasty was developed to reduce pain and retain motion of the ankle joint in patients with osteoarthritis. The ankle joint has unique, complex anatomic and biomechanical characteristics that must be considered in a successful total ankle arthroplasty prosthesis. Initial designs from the 1960s to the 1970s had many failures. Current designs use two or three components, and recent reports on total ankle arthroplasty show consistent good to excellent intermediate clinical results, with up to 90% decreased pain and high patient satisfaction. The follow‐up time of these studies is limited, however, and long‐term studies with 10‐ to 15‐ year follow‐ups are needed. Also, a wide variety of complications has been reported, including osteomyelitis and osteolysis. To limit the number of complications and improve clinical outcome of total ankle arthroplasty, careful patient selection and surgeon experience are important.


Foot & Ankle International | 2006

Current Concepts Review: Lisfranc Injuries

Elizabeth A. Desmond; Loretta B. Chou

The tarsometatarsal joint is named after Jacques Lisfranc de Saint-Martin (1790–1847),12 a French Napoleonic-era field surgeon who studied under Dupuytren in Paris. He described an amputation level through the tarsometatarsal joint, and it is for this reason that the joint is commonly referred to by his name. However, according to Cassebaum,8 Lisfranc did not describe the injuries or mechanism of injury at this joint.8 Injuries at the Lisfranc joint are relatively rare with a reported incidence of 1 per 55,000 yearly and make up only 0.2% of all fractures.2,11 Males are between two and four times more likely to sustain a fracture through the Lisfranc joint than females. Fractures involving the Lisfranc joint can occur at any age, although they are more common in the third decade of life. One of the largest published series of Lisfranc injuries was reported by Myerson et al.,27 who reviewed 76 fractures and dislocations. In their case series (Level of Evidence IV) most (58%) Lisfranc injuries occurred in polytraumatized patients (58%). Two-thirds of the injuries were caused by motor vehicle accidents. Crush injuries and falls from a height accounted for most of the remaining fractures. It has been estimated that up to 20% of Lisfranc injuries are misdiagnosed or missed altogether on initial evaluation.14,27 A delayed diagnosis or misdiagnosis of a major Lisfranc injury can compound associated vascular compromise. Perhaps more commonly, the seriousness of a Lisfranc injury is not initially appreciated and patients are given an overly optimistic assessment of their recovery time and prognosis.


Foot & Ankle International | 2004

Functional Evaluation of the Scandinavian Total Ankle Replacement

Chris O. Dyrby; Loretta B. Chou; Thomas P. Andriacchi; Roger A. Mann

The purpose of this study was to evaluate the function of the ankle joint during walking before and after Scandinavian Total Ankle Replacement (STAR). Nine patients (six males and three females) with an average age of 65 years, scheduled for unilateral total ankle replacement for osteoarthritis and rheumatoid arthritis, were evaluated both preoperatively and postoperatively in a gait analysis laboratory. Arthroplasty patients showed reduced range of motion at the ankle compared to normal controls. Postoperative arthroplasty subjects had significantly improved external ankle dorsiflexion moment, the moment that affects the plantarflexor muscles, when compared to their preoperative status. The moment in arthroplasty patients was increased, indicating improved function of the ankle joint.


Foot & Ankle International | 2001

Intramedullary Screw Fixation of Proximal Fifth Metatarsal Fractures: A Biomechanical Study

Steven N. Shah; Guenther O. Knoblich; Derek P. Lindsey; Jennifer L. Kreshak; Scott A. Yerby; Loretta B. Chou

Intramedullary screw fixation is a popular technique for treatment of proximal fifth metatarsal fractures. The purpose of this study was to compare the fixation rigidity of a 5.5 mm partially threaded cannulated titanium screw, with presumed superior endosteal purchase, to a similar 4.5 mm screw. Acute fifth metatarsal fractures were simulated in cadavers, stabilized with intramedullary screws, and loaded to failure in three-point bending. The initial failure loads for the metatarsals fixed with 4.5 mm and 5.5 mm screws were not significantly different (332.4 N vs. 335.2 N, respectively), nor were the ultimate failure loads (849.8 N vs. 702.2 N, respectively). Based upon our results, maximizing screw diameter does not appear to be critical for fixation rigidity and may increase the risk of intraoperative or postoperative fracture.


Foot & Ankle International | 1998

Biplanar Chevron Osteotomy

Loretta B. Chou; Roger A. Mann; Mark M. Casillas

We retrospectively reviewed the results of using a biplanar chevron osteotomy performed on patients who presented with hallux valgus deformities with an increased distal metatarsal articular angle (DMAA). The study included 17 feet (14 patients) of 12 women and 2 men. The average follow-up was 33 months. The average American Orthopaedic Foot and Ankle Society Hallux Metatarsophalangeal-lnterphalangeal Clinical Rating Score was 91. Ten of the 14 patients (13 of 17 feet) stated that they would choose to undergo the procedure again. The hallux valgus angle was improved from an average of 22° to 18°, the intermetatarsal angle from 11° to 9°, and the DMAA from 16° to 9°. We have demonstrated this procedure to be useful in the treatment of symptomatic bunion deformities with an increased DMAA.


Foot & Ankle International | 2004

Informed Consent for Ankle Fracture Surgery: Patient Comprehension of Verbal and Videotaped Information

Michael Rossi; Robert McClellan; Loretta B. Chou; Kristin Davis

Background: The purpose of our study was to evaluate the effectiveness of using a videotape to give patients information about the risks, benefits, alternatives, and treatment of a common orthopaedic procedure before they sign consent forms. Methods: During a 9-month period, 48 patients with isolated closed ankle fractures requiring surgical intervention were randomized into two groups that received either videotaped or conventional verbal information regarding consent for surgery. The study group watched a videotape containing information about the risks, benefits, and treatment alternatives, while the control group obtained this information verbally. To determine comprehension and retention, all patients completed a multiple-choice questionnaire immediately after receiving the information, and 37 patients (77%) were available to complete a questionnaire at an average of 10 weeks later. Results: The videotape group outperformed the verbal consent group by 40.1% on the initial questionnaire (p = .0002) and by 27.2% on the followup questionnaire (p = 0.0139). Patients with educational levels of less than or equal to the 12th grade performed 67.8% better on the initial questionnaire after watching the video than after receiving the information verbally. (p = .0001). Conclusion: Patients who received information about their surgery on a videotape before giving their consent demonstrated a significant increase in comprehension compared to patients who received this information verbally. The benefit was even greater for patients with lower education levels.


Foot & Ankle International | 2006

Surgical Treatment of Severe Hallux Valgus: The State of Practice among Academic Foot and Ankle Surgeons

Stephen Pinney; Kyle Song; Loretta B. Chou

Background: The purpose of this study was to evaluate the operative procedures used for treatment of severe hallux valgus by academic foot and ankle surgeons practicing in the United States. Methods: A patient with severe hallux valgus deformity was developed as a hypothetical case: a 50-year-old woman with a severe deformity (intermetatarsal angle = 20 degrees; hallux valgus angle = 42 degrees). The patient was symptomatic with pain, did not improve with conservative measures, and wanted the deformity corrected. This case was sent to academic foot and ankle surgeons in a survey to determine their preferred operative treatment for this case. The overall response rate was 84% (128 of 153). To be included in the study group each surgeon had to have 1) foot and ankle patients comprising 50% or more of his clinical practice and 2) direct responsibility for teaching orthopaedic residents. One hundred and five respondents met the inclusion criteria and formed the study group; however, three surveys with invalid responses were deleted. Results: Fifty-two percent (54 of 102) of the respondents chose a metatarsal osteotomy, 26% (26 of 102) a first metatarsophalangeal (MTP) joint arthrodesis, and 24% (24 of 102) a Lapidus procedure. Two respondents chose both an arthrodesis and a metatarsal osteotomy. Among the 54 respondents who chose metatarsal osteotomies, 24 used a Ludloff, 16 a proximal crescentic, eight a proximal chevron, two a scarf, two a distal chevron, and two other. In addition, secondary procedures to enhance the correction included a Weil osteotomy in 46% (47 of 102) and an Akin osteotomy in 30% (31 of 102). Conclusions: There was a wide variation in the type of procedure used to correct this severe hallux valgus deformity; approximately 50% of the respondents chose a metatarsal osteotomy, 25% chose a first MTP joint arthrodesis, and 25% a Lapidus procedure.

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Martin M. Malawer

George Washington University

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Derek P. Lindsey

VA Palo Alto Healthcare System

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Alex H. S. Harris

VA Palo Alto Healthcare System

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Roger A. Mann

Shriners Hospitals for Children

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Andrew Haskell

Palo Alto Medical Foundation

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