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Lawrence M. White

Bio: Lawrence M. White is an academic researcher from University of Toronto. The author has contributed to research in topics: Magnetic resonance imaging & Soft tissue sarcoma. The author has an hindex of 47, co-authored 168 publications receiving 7804 citations. Previous affiliations of Lawrence M. White include Women's College Hospital & Thomas Jefferson University Hospital.


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Journal ArticleDOI
TL;DR: Patellar dislocators who present with a history of patellofemoral instability are more likely to be female, are older, and have greater risk of subsequent patellar instability episodes than first-time patellary dislocation patients.
Abstract: BackgroundThe goals of this study were to (1) define the epidemiology of acute patellar dislocation, (2) determine the risk of subsequent patellar instability episodes (subluxation and/or redislocation) during the study period, and (3) identify risk factors for subsequent instability episodes.Study DesignProspective cohort study.MethodsThe authors prospectively followed 189 patients for a period of 2 to 5 years. Historical data, injury mechanisms, and physical and radiographic measurements were recorded to identify potential risk factors for poor outcomes.ResultsRisk was highest among females 10 to 17 years old. Patients presenting with a prior history of instability were more likely to be female (P < .05) and were older than first-time dislocation patients (P < .05). Fewer first-time dislocators (17%) had episodes of instability during follow-up than patients with a previous history of instability (49%) (P < .01). After adjusting for demographics, patients with a prior history had 7 times higher odds of ...

895 citations

Journal ArticleDOI
TL;DR: Injury to the medial retinaculum, MPFL, and VMO may be identified at MR imaging after acute LPD, and concave impaction deformity of the inferomedial patella is a specific sign of prior LPD.
Abstract: PURPOSE: To assess magnetic resonance (MR) imaging findings after acute lateral patellar dislocation (LPD) with emphasis on the medial patella restraints and to describe a medial patellar impaction deformity. MATERIALS AND METHODS: Knee MR images obtained within 8 weeks after LPD were evaluated for medial retinacular and medial patellofemoral ligament (MPFL) disruption, vastus medialis obliquus (VMO) edema and/or elevation, and other derangements. One hundred patients with no evidence of prior LPD were evaluated as controls. The Student t test was used for statistical comparisons. RESULTS: Eighty-two examinations were performed in 81 patients with LPD (mean age, 20 years; age range, 9–57 years). Seventy-six percent (62 of 82 examinations) showed medial retinacular disruption at its patellar insertion; 30% (25 of 82), at its midsubstance. The MPFL femoral origin was identified in 87% (71 of 82); of these, 49% (35 of 71) showed injury. Forty-eight percent (39 of 82) showed more than one site of injury to th...

350 citations

Journal ArticleDOI
TL;DR: The results of the present study suggest that the risk of local recurrence after curettage with a high-speed burr and reconstruction with autogenous graft with or without allograft bone is similar to that observed after use of cement and other adjuvant treatment.
Abstract: Background: The use of curettage, phenol, and cement is accepted by most experts as the best treatment for giant-cell tumor of bone. The present study was performed to evaluate whether equivalent results could be obtained with curettage with use of a high-speed burr and reconstruction of the resulting defect with autogenous bone graft with or without allograft bone. Methods: The prospectively collected records of patients who had a giant-cell tumor of a long bone were reviewed to determine the rate of local recurrence after treatment with curettage with use of a high-speed burr and reconstruction with autogenous bone graft with or without allograft bone. All of the patients were followed clinically and radiographically, and a biopsy was performed if there were any suspicious changes. Results: Fifty-nine patients met the criteria for inclusion in the study. According to the grading system of Campanacci et al., two patients (3 percent) had a grade-I tumor, twenty-nine (49 percent) had a grade-II tumor, and twenty-eight (47 percent) had a grade-III tumor. Seventeen patients (29 percent) had a pathological fracture at the time of presentation. The mean duration of follow-up was eighty months (range, twenty-eight to 132 months). Seven patients (12 percent) had a local recurrence. Six of these seven were disease-free at the latest follow-up examination after at least one additional treatment with curettage or soft-tissue resection (one patient). One patient had resection and reconstruction with a prosthesis after a massive local recurrence and pulmonary metastases. Conclusions: Despite the high rates of recurrence reported in the literature after treatment of giant-cell tumor with curettage and bone-grafting, the results of the present study suggest that the risk of local recurrence after curettage with a high-speed burr and reconstruction with autogenous graft with or without allograft bone is similar to that observed after use of cement and other adjuvant treatment. It is likely that the adequacy of the removal of the tumor rather than the use of adjuvant modalities is what determines the risk of recurrence.

307 citations

Journal ArticleDOI
TL;DR: The proportion with an increase in tear size was significantly larger for shoulders with fatty infiltration than for those without it, and magnetic resonance imaging can be used to monitor rotator cuff changes and guide patient management.
Abstract: Background: Rotator cuff tears are very common, but little is known about the outcome of nonoperative treatment of symptomatic tears in terms of progression and the need for surgical intervention. Methods: Fifty-nine shoulders in fifty-four patients (thirty-three women and a mean age of 58.8 years) with rotator cuff tears on initial magnetic resonance imaging who had been managed nonoperatively were studied retrospectively. All had magnetic resonance imaging scans acquired six months or more after the initial study. The progression of the rotator cuff tears was associated with age, anatomical and associated parameters, follow-up time, and structural and other magnetic resonance imaging findings. Results: Baseline magnetic resonance imaging scans demonstrated thirty-three full-thickness tears, twenty-six partial-thickness tears, and four combined full-thickness and partial-thickness tears. Fifty-eight of the fifty-nine tears involved the supraspinatus tendon, and ten involved multiple tendons. Progression in tear size occurred more often among the patients who were followed more than eighteen months (thirteen [48%] of twenty-seven shoulders) compared with those who were followed for less than eighteen months (six [19%] of thirty-two shoulders). Five tears (one partial-thickness tear) decreased in size. More than half (52%; seventeen) of the thirty-three full-thickness tears increased in size compared with 8% (two) of the twenty-six partial-thickness tears (p = 0.0005). Only 17% (six) of the thirty-five tears in patients who were sixty years old or less deteriorated compared with 54% (thirteen) of the twenty-four tears in patients who were more than sixty years old (p = 0.007). No shoulder in a patient with a partial-thickness tear demonstrated supraspinatus atrophy, whereas 24% of those with a full-thickness tear demonstrated atrophy (p = 0.007). The proportion with an increase in tear size was significantly larger for shoulders with fatty infiltration than for those without it (p = 0.0089). Conclusions: Factors that are associated with progression of a rotator cuff tear are an age of more than sixty years, a full-thickness tear, and fatty infiltration of the rotator cuff muscle(s). In the long-term follow-up of nonoperatively treated rotator cuff tears, magnetic resonance imaging can be used to monitor rotator cuff changes and guide patient management. Level of Evidence: Prognostic Level IV. See Instructions to Authors for a complete description of levels of evidence.

238 citations

Journal ArticleDOI
TL;DR: By using simple modifications to standard MR imaging sequences, diagnostic-quality MR imaging of THA complications can be performed, particularly around the femoral prosthetic stem.
Abstract: PURPOSE: To investigate the use of standard magnetic resonance (MR) imaging sequences with simple parameter modifications for the detection and characterization of total hip arthroplasty (THA) complications. MATERIALS AND METHODS: An initial phantom study was performed with cobalt-chrome and titanium prostheses to establish the imaging parameters for a subsequent clinical study. In the clinical study, coronal and transverse MR imaging of 14 THA prostheses was performed before and after intravenous contrast material administration in 12 patients who were being considered for revision arthroplasty. The images were reviewed for evidence of juxtaarticular or periprosthetic abnormalities, patterns of contrast enhancement, and quality of periprosthetic tissue depiction. RESULTS: Phantom study results showed improved periprosthetic tissue depiction with use of thin sections, increased frequency-encoding gradient strength, and fast spin-echo sequences. The clinical study results demonstrated periprosthetic abnorm...

221 citations


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Book ChapterDOI
01 Jan 2010

5,842 citations

01 Jan 2016
TL;DR: This application applied longitudinal data analysis modeling change and event occurrence will help people to enjoy a good book with a cup of coffee in the afternoon instead of facing with some infectious virus inside their computer.
Abstract: Thank you very much for downloading applied longitudinal data analysis modeling change and event occurrence. As you may know, people have look hundreds times for their favorite novels like this applied longitudinal data analysis modeling change and event occurrence, but end up in malicious downloads. Rather than enjoying a good book with a cup of coffee in the afternoon, instead they are facing with some infectious virus inside their computer.

2,102 citations

01 Jan 2014
TL;DR: Lymphedema is a common complication after treatment for breast cancer and factors associated with increased risk of lymphedEMA include extent of axillary surgery, axillary radiation, infection, and patient obesity.

1,988 citations

Journal ArticleDOI
TL;DR: This manuscript focuses on the NCCN Guidelines Panel recommendations for the workup, primary treatment, risk reduction strategies, and surveillance specific to DCIS.
Abstract: Ductal carcinoma in situ (DCIS) of the breast represents a heterogeneous group of neoplastic lesions in the breast ducts. The goal for management of DCIS is to prevent the development of invasive breast cancer. This manuscript focuses on the NCCN Guidelines Panel recommendations for the workup, primary treatment, risk reduction strategies, and surveillance specific to DCIS.

1,545 citations