Total hip arthroplasty with a special segmental replacement of the proximal end of the femur which varied in length from eighty to 150 millimeters was performed in twenty-one patients who had severe non-neoplastic conditions of the... more
Total hip arthroplasty with a special segmental replacement of the proximal end of the femur which varied in length from eighty to 150 millimeters was performed in twenty-one patients who had severe non-neoplastic conditions of the proximal part of the femur that necessitated salvage. Ten patients had previously failed arthroplasties associated with loss of bone structure; seven had non-union of a proximal femoral fracture or osteotomy associated with severe hip disease; there had a failed resection arthroplasty; and one had an arthrodesis and incapacitating low-back pain. Clinical and roentgenographic data during follow-up of twenty-five to ninety-two months showed that only one patient had loosening of the acetabular component. In twenty of the twenty-one patients, total hip arthroplasty with proximal femoral replacement was effective in restoring the integrity of the bone and restoring function of the hip.
Research Interests:
Numerous options are available today to reconstruct large bony defects after tumor resection, failed total joint arthroplasty, or trauma. Custom-designed segmental bone and joint implants [2] are being used widely, but the conventional... more
Numerous options are available today to reconstruct large bony defects after tumor resection, failed total joint arthroplasty, or trauma. Custom-designed segmental bone and joint implants [2] are being used widely, but the conventional prosthetic fixation method may lead to stem loosening or fracture after prolonged in vivo utilization. Since these late complications are mainly attributed to failure of the bone cement [3], biological fixation. using porous implants has been advocated. Porous coating applied to the stems to achieve biological fixation of segmental prostheses has several disadvantages which may predispose the implants to stem fracture or cause bone resorption. A new concept of prosthetic fixation through extracortical bone bridging and growth over the porous-coated segmental portion of the implant has been introduced [4–6]. Morselized corticocancellous autogenous bone grafts are applied over the porous-coated segment and adjacent to cortex to induce bone formation. The stems of these implants are solid and are cemented to achieve initial implant stability.
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Limb salvage has become a standard procedure in the management of bone tumors. Although the primary goal remains local control of the disease, limb salvage performed in centers with large experience in bone tumors has resulted in local... more
Limb salvage has become a standard procedure in the management of bone tumors. Although the primary goal remains local control of the disease, limb salvage performed in centers with large experience in bone tumors has resulted in local recurrence rates of 4%–11 % [4,5,10,11,16], which are comparable to the rates obtained after amputation [5,16].
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Since 1970, 79 patients, ranging in age from 14 to 74 years, have undergone reconstruction of the knee after en bloc resection of a primary tumor at our institute. Among these, 27 had resection arthrodesis. The functional and device... more
Since 1970, 79 patients, ranging in age from 14 to 74 years, have undergone reconstruction of the knee after en bloc resection of a primary tumor at our institute. Among these, 27 had resection arthrodesis. The functional and device evaluation results were analyzed using the rating system adopted by the Musculoskeletal Tumor Society. In this group of patients with knee arthrodesis, 74% had good or excellent results and ten had major or minor complications. Different reconstructive methods were reviewed, but no significant difference in functional results was found. Therefore, segmental bone resection and knee joint arthrodesis can provide good functional results and reconstruction longevity. However, each patient should be judged individually by considering a number of factors before a specific method of knee fusion is selected.
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Research Interests:
It has been demonstrated that osteoarthritis (OA) is activity related and may worsen when joint contact stress becomes excessive due to overloading. Hence, joint alignment and loading are considered to be the key biomechanical... more
It has been demonstrated that osteoarthritis (OA) is activity related and may worsen when joint contact stress becomes excessive due to overloading. Hence, joint alignment and loading are considered to be the key biomechanical determinants for OA. The initiation of pathologic changes in the knee has been described by the mechanism termed, "vicious cycle" in which joint axial malalignment creates excessive stresses to the localized joint cartilage/subchondral bone regions and the surrounding soft tissue which in turn produces more laxity and joint deformity and thus repeats the cyclic degradation mechanism. If this degenerative cycle can be broken with joint alignment surgery such as osteotomy, a procedure to realign the knee joint and thus redistribute joint forces applied to each compartment, performed properly and at the appropriate time, the osteoarthritic disease process can be decelerated and even reversed. The main goals of this paper are to emphasize the importance of accurate preoperative planning for osteotomy in order to properly correct joint alignment, and to justify the application of an existing computer program, OASIS (Osteotomy Analysis and Simulation Software) using plain radiographs to perform appropriate surgical planning. Normal subjects and knee osteotomy patients were studied to establish a database for the purpose of establishing the utility and efficacy of the presently proposed concept. We wish to rationalize knee osteotomy as a preferred and cost-effective treatment for patients with early symptoms of OA in the knee. This paper presents a new concept of preoperative planning for knee osteotomy based on the underlying etiology of the disease and biomechanical viewpoint with strong emphasis on surgical treatment rationales. The established principles in this paper can be applied to other joints of the body and will help implement preventive measures and other non-surgical means to manage patients with axial malalignment or early degenerative changes.
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Patients who present with failed total hip arthroplasty and significant proximal femoral bone loss pose a challenging reconstructive problem. When the integrity of the host proximal femur can be salvaged with cortical strut grafts,... more
Patients who present with failed total hip arthroplasty and significant proximal femoral bone loss pose a challenging reconstructive problem. When the integrity of the host proximal femur can be salvaged with cortical strut grafts, conventional long-stem femoral components can be used. If there is massive proximal femoral bone loss, hip salvage can be accomplished with a proximal femoral replacement prosthesis or an allograft-prosthesis composite. Although our early results with a proximal femoral replacement prosthesis were good, long-term results reveal a high rate of dislocation and acetabular component loosening, with an overall survivorship of 73% at 11 years. We have, therefore, limited the use of a proximal femoral replacement prosthesis to the elderly and inactive patient. We are encouraged by the preliminary results of total hip arthroplasty with a second-generation, modular, porous-coated, proximal femoral replacement prosthesis. Longer follow-up is required to determine whether these design modifications improve the results of this type of reconstructive procedure in revision total hip arthroplasty.
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Research Interests:
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The majority of the damaging forces to the soft tissue, bone, and articular joint structures of modern hockey players during the energetic activities involved in the game are attributable to impact action during high-speed motion. In... more
The majority of the damaging forces to the soft tissue, bone, and articular joint structures of modern hockey players during the energetic activities involved in the game are attributable to impact action during high-speed motion. In addition, non-contact musculoligamentous injuries are common because of the complex forces that are involved. The injury potential of this sport is assessed indirectly from the force and motion involved. The experimental method of measuring the kinematic motion and the impact forces inherent to the sport are presented. Although hockey is a fast and furious game with high injury potential, fortunately the number of serious injuries is not as great as one might expect.
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BackgroundLocally recurrent rectal cancer involving the upper sacrum is generally considered a contra‐indication to curative surgery. The aim of this study was to determine if a survival benefit was seen in patients undergoing high... more
BackgroundLocally recurrent rectal cancer involving the upper sacrum is generally considered a contra‐indication to curative surgery. The aim of this study was to determine if a survival benefit was seen in patients undergoing high sacrectomy.MethodsAll patients with locally recurrent rectal cancer involving the sacrum above the 3rd sacral body between 1999 and 2007 were retrospectively reviewed. Kaplan–Meier survival analysis was performed.ResultsNine patients were identified with a median age of 63 years. The proximal extent of sacral resection was through S2 (n = 6), S1 (n = 2), and L5‐S1 (n = 1). All patients had R0 negative‐margin resection. Median operative time was 13.7 hr, and median operative blood transfusion was 3.7 L. Thirty‐day mortality was nil. Postoperative complications requiring surgical intervention occurred in three patients. Local re‐recurrence in the pelvis occurred in one patient. The overall median survival was 31 months (range, 2–39 months). Three patients still alive are free of disease after 40, 76, and 101 months, respectively. Ultimately, all deaths were due to metastatic disease.ConclusionsHigh sacrectomy that achieves clear margins in patients with recurrent rectal cancer is safe and feasible. A majority will die of metastatic disease, but long‐term survival may be possible in some patients. J. Surg. Oncol. 2011; 103:105–109. © 2010 Wiley‐Liss, Inc.
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Advances in adjuvant chemotherapy and improvements in techniques of oncologic reconstruction have stimulated renewed interest in limb saving operation for malignant bone tumors. Between 1970 and 1981, 160 patients underwent local... more
Advances in adjuvant chemotherapy and improvements in techniques of oncologic reconstruction have stimulated renewed interest in limb saving operation for malignant bone tumors. Between 1970 and 1981, 160 patients underwent local resection for malignant osseous lesions at the Mayo Clinic. This included 102 patients with chondrosarcoma, 44 with osteosarcoma, and 14 with fibrosarcoma. Ninety-three of the lesions were stage I and 67 were stage II. The overall local recurrence rate was 11.8%. The reconstructive procedures were effective in providing adequate functional restoration. Limb sparing operation is a valid viable option in carefully selected patients with malignant bone tumors. A continued search for effective adjuvant treatment programs is necessary.
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Total replacement of the knee and of a long segment of the femur or tibia provided functional recovery of the knee joint in thirteen patients in whom the length of the bone replaced ranged from seventy-five to 150 millimeters. Nine... more
Total replacement of the knee and of a long segment of the femur or tibia provided functional recovery of the knee joint in thirteen patients in whom the length of the bone replaced ranged from seventy-five to 150 millimeters. Nine patients had benign bone tumors, three had malignant lesions, and one patient had salvage of a failed total knee arthroplasty, associated with loss of bone structure. After follow-up of two years or more, all patients had a stable extremity, excellent relief of pain, and a useful range of motion, although one patient required revision for loosening.
Research Interests:
The increased interest in limb saving resection for malignant bone tumors emphasizes the need for continued research and development to improve techniques of oncological reconstruction. The bioengineer plays an important role on the limb... more
The increased interest in limb saving resection for malignant bone tumors emphasizes the need for continued research and development to improve techniques of oncological reconstruction. The bioengineer plays an important role on the limb salvage team. At the present time, custom joint implants are opening up new horizons in rehabilitation of patients following resection of bone tumors. In the future, modular prosthetic systems such as the system described will eliminate the need for individual, customized manufacture of prostheses and will make these oncological reconstructive techniques more available.
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Research Interests:
Research Interests:
Research Interests: Surgery, Medicine, Fibula, Limb Salvage, Resection, and 2 morePathological and Springer Ebooks(Pathological and Springer Ebooks)
(Pathological and Springer Ebooks)
Research Interests:
Between 1986 and 1999, 94 patients (96 hips) including 31 male and 63 female (mean age 59.5 years), with massive bone loss had a revision hip arthroplasty using an allograft-prosthesis composite (APC). A previous history of infection was... more
Between 1986 and 1999, 94 patients (96 hips) including 31 male and 63 female (mean age 59.5 years), with massive bone loss had a revision hip arthroplasty using an allograft-prosthesis composite (APC). A previous history of infection was present in 21 of these cases. At an average follow-up of 11 years (range, 8 to 20 years), 72 patients were alive, 21 patients died, and 1 patient was lost to follow-up. Major complications occurred in 33 cases: femoral stem loosening (12); dislocation (15); periprosthetic fracture (10); and infection (7). Further revision surgery was performed in 21 of the 96 cases including revision of the acetabular component (3), femoral APC (16) or both (2). The 10 year survival of the APCs was 68.8% (95% CI 58.6%–79%, 26 cases remaining at risk). There was no statistically significant difference in survival time between gender, age, indication for APC (including infection), surgical approach and APC technique. Statistically significant factors negatively impact...
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Adamantinomas are rare bone tumors, commonly affecting the tibia. Due to the rare nature of disease, previous studies are small or from multiple centers. The purpose of this study is to investigate outcomes of patients with adamantinoma... more
Adamantinomas are rare bone tumors, commonly affecting the tibia. Due to the rare nature of disease, previous studies are small or from multiple centers. The purpose of this study is to investigate outcomes of patients with adamantinoma treated in a single institution. Forty-six histological confirmed adamantinomas of the extremities were reviewed at our institution between 1939 and 2012. Follow-up data included clinical and radiographical information focusing on complications, local recurrence, metastasis, and overall survival after the treatment. The mean follow-up was 16 years (range 2-42 years). The most common location was the tibia (n = 31). Patients commonly presented with pain and swelling. The mean age was 24 years (7-79 years). Thirty-seven patients were treated with limb salvage. The 39% of patients required a reoperation. The 10-year disease specific- and recurrence free survival was 92% and 72%, with three patients having a recurrence over 15 years postoperative. Older ...
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The extent of extracortical bone-bridging and ingrowth into porous-coated prostheses for the stabilization of segmental defects was studied in a canine model. Initial fixation of the implant was achieved using bone cement. Autogenous bone... more
The extent of extracortical bone-bridging and ingrowth into porous-coated prostheses for the stabilization of segmental defects was studied in a canine model. Initial fixation of the implant was achieved using bone cement. Autogenous bone grafts were applied over the porous-coated segmental portion of the prosthesis to stimulate the ingrowth and formation of bone. At twelve weeks, bone-bridging and ingrowth occurred uniformly in both the titanium fibermesh and the cobalt-chromium-molybdenum beaded prostheses. Maximum formation of osseous tissue over the implants occurred at two to four weeks. More bone formed in the posterior aspect of the prosthesis. At twelve weeks, 26 per cent of the porous space of the titanium fibermesh prosthesis and 47 per cent of the porous space of the cobalt-chromium-molybdenum beaded prosthesis were filled with bone. The torsional strength and stiffness of the prosthetic midsection that contained a conical coupling joint were increased significantly due to bone-bridging and ingrowth. The cortical bone that was apposed to the segmental prosthesis showed an increase in porosity. The use of bone cement did not appear to impede new-bone formation extracortically. The initial stability of the implant and the application of sufficient autogenous bone grafts are two important factors that contribute to the ultimate stable fixation of an implant by extracortical bone formation.
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To achieve limb salvage and provide the patient with a functional extremity, vascularized free fibula transfer has become the workhorse for segmental bony reconstruction. Because of various host factors, there has been a high complication... more
To achieve limb salvage and provide the patient with a functional extremity, vascularized free fibula transfer has become the workhorse for segmental bony reconstruction. Because of various host factors, there has been a high complication rate following oncologic reconstruction. The authors reviewed the experience of their institution with the use of free fibula reconstruction following an oncologic resection in the extremities. The authors reviewed 56 cases of free fibula transfer performed for limb salvage following oncologic resection from 1994 through 2013. The cohort consisted of 30 male patients and 26 female patients; with a mean age of 19 years and a mean follow-up of 7 years. Sixty-three percent of the tumors were located in the lower extremity. The overall 2-, 5-, 10-, and 15-year survival rates were 98, 86, 73, and 73 percent, respectively. With regard to disease-specific survival, the overall 2-, 5-, 10, and 15-year survival rates were 82, 75, 67, and 50 percent, respect...
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During the past decade, advances in preoperative imaging, adjuvant and neoadjuvant chemotherapy, artificial implant design, and surgical techniques have greatly stimulated the enthusiasm for limb salvage for carefully selected patients... more
During the past decade, advances in preoperative imaging, adjuvant and neoadjuvant chemotherapy, artificial implant design, and surgical techniques have greatly stimulated the enthusiasm for limb salvage for carefully selected patients with malignancy [1–6]. The early results of the use of custom-made prostheses were encouraging, in spite of certain residual problems [5–8]. The purpose of this study was to critically review the results after reoperation for failed initial prosthetic replacement or for other nonimplant-related complications after tumor resectionand to identify the main problems for future improvement of surgical technique, implant design, and postoperative patient management.
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Although the management of bone tumors continues to be one of the most challenging tasks in oncology, significant advances have been made. In recent years, interest has increased in en bloc resection (Wilson and Lance, 1965), not only for... more
Although the management of bone tumors continues to be one of the most challenging tasks in oncology, significant advances have been made. In recent years, interest has increased in en bloc resection (Wilson and Lance, 1965), not only for aggressive benign and low-grade tumors but also for limbsalvage procedures involving high-grade lesions (Jaffe et al, 1978; Marcove and Rosen, 1980). Recent improvements in clinical staging, particularly by the use of computed tomography, have enhanced our ability to assess the local extent of involvement of the tumor accurately and to decide which lesions are amenable to limb-saving resection.
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Multiple myeloma is a malignancy of monoclonal plasma cells (plasma cells are of B-lymphocyte lineage of the hematopoietic system). It is the second most prevalent blood malignancy after... more
Multiple myeloma is a malignancy of monoclonal plasma cells (plasma cells are of B-lymphocyte lineage of the hematopoietic system). It is the second most prevalent blood malignancy after non-Hodgkin's lymphoma. It accounts for approximately 1 % of all malignancies and 2 % of all cancer deaths. Bony involvement is very common; the incidence of pelvic and periacetabular involvement in MM is reported to be around 6 %. Lytic lesions comprise a hallmark of multiple myeloma, which may be complicated with pathologic fractures in a substantial percentage of patients. Pelvic and periacetabular bony involvement of multiple myeloma is associated with some unique characteristics regarding the biomechanics of this specific anatomical region, the morbidity, the overall survival, and prognosis, which all reflect to impairment of quality of life. In this paper, we review the special features of multiple myeloma lesions around the pelvis and acetabulum and present an algorithm of management with the use of current surgical techniques.
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Curative treatment of malignancies in the sacrum and lower lumbar spine frequently requires en bloc spinopelvic resection. There is no standard classification of these procedures. We present outcomes and a classification scheme with... more
Curative treatment of malignancies in the sacrum and lower lumbar spine frequently requires en bloc spinopelvic resection. There is no standard classification of these procedures. We present outcomes and a classification scheme with oncologic and reconstructive guidelines for spinopelvic tumors based on an analysis of 30 cases of en bloc resection and reconstruction performed with curative intent. Mean follow-up of surviving patients was 38 months. Tumors included osteosarcoma (n=9), chondrosarcoma (n=6), chordoma (n=5), other sarcomas (n=5), neurogenic tumors (n=4), and local extension of carcinoma (n=1). Resections could be divided into 4 types. Type 1 resections (n=12) included a total sacrectomy with lower lumbar spine and bilateral medial iliac resections. Type 2 resections (n=6) included hemisacrectomy, partial lumbar spine excision, and medial iliac resection. Type 3 resections (n=9) encompassed external hemipelvectomy with hemisacrectomy and partial lumbar spine excision. Type 4 resections (n=3) encompassed external hemipelvectomy, total sacrectomy, and lumbar spine excision. For each resection type, we have developed staged surgical approaches to allow resection with wide margins and reconstruction of spinopelvic continuity. Tumor free margins were achieved in all cases. Perioperative mortality was 3/30. Seven additional patients have died of disease, two died of other causes, two are alive with disease, and 16 have no evidence of disease. 13/18 surviving patients are independent in their activities of daily living. In our practice en bloc excision and reconstruction of spinopelvic neoplasms may be classified into four types. For each type, we have devised surgical treatment guidelines to allow for wide resection and reconstruction of spinopelvic continuity. Long term survival and independent function can be achieved in this challenging patient population. This represents the first standardised classification of oncologic spinopelvic resections and reconstructions.
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Object Sacrectomy positioning must balance surgical exposure, localization, associated operative procedures, and patient safety. Poor positioning may increase hemorrhage, risk of blindness, and skin breakdown. Methods The authors... more
Object Sacrectomy positioning must balance surgical exposure, localization, associated operative procedures, and patient safety. Poor positioning may increase hemorrhage, risk of blindness, and skin breakdown. Methods The authors prospectively identified positioning-related morbidity in 17 patients undergoing 19 prone sacral procedures from September 2008 to August 2009 following institution of a standardized positioning protocol. Key elements include skull traction/head suspension, an open radiolucent frame, and wide draping for associated closure and reconstructive procedures. Results Tumors included 5 chordomas, 4 high-grade sarcomas, 1 chondrosarcoma, 2 presacral extradural myxopapillary ependymomas, and 5 others. Mean patient age was 49.9 years (range 17–74 years); mean body mass index was 27.6 kg/m2 (range 19.3–43.9 kg/m2). Mean preoperative Braden skin integrity score was 21.1 (range 17–23). Average operative time was 501 minutes (range 158–1136 minutes). Prone surgery was a ...
Research Interests:
Research Interests:
Research Interests: Surgery, Medicine, Chordoma, Sacrum, Perioperative, and 2 morelumbar and Chondrosarcoma(lumbar and Chondrosarcoma)
(lumbar and Chondrosarcoma)
Multicentric osteosarcoma (M-OGS) is characterized by multicentricity of osseous osteosarcomas, either synchronous or metachronous, without visceral involvement. The study’s purpose was to clinicopathologically and radiographically... more
Multicentric osteosarcoma (M-OGS) is characterized by multicentricity of osseous osteosarcomas, either synchronous or metachronous, without visceral involvement. The study’s purpose was to clinicopathologically and radiographically analyze 56 cases of M-OGS (22 synchronous and 34 metachronous). The distal femur was the most common site. Histologically, all tumors were high grade. Of 22 patients with synchronous M-OGS, 16 had 3 or more simultaneous tumors; the axial skeleton was involved in 14 (64%) of 22 cases. In metachronous M-OGS, the second malignancy occurred after a median of 22 months. Treatment was surgery, chemotherapy, radiotherapy, or a combination of these. Patients with metachronous osteosarcoma had a median survival longer than did patients with synchronous tumors. Overall, 8 long-term survivors were treated by aggressive surgery with wide margins (plus chemotherapy and/or radiotherapy). M-OGS combines multiple skeletal locations of high-grade conventional osteosarcoma...
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Research Interests:
Aim: The purpose of our study is to present the survival results, clinical outcome and complications from the use of APC in cases with a history of periprosthetic infection. Materials and Methods: Between 1986 and 1999, twenty-two... more
Aim: The purpose of our study is to present the survival results, clinical outcome and complications from the use of APC in cases with a history of periprosthetic infection. Materials and Methods: Between 1986 and 1999, twenty-two patients (twenty-two hips) 11 male and 11 female (mean age 57.5 years – range 38 to 77 years) with massive bone loss (Paprosky IIIA 2 cases, IIIB 4 cases, and IV 16 cases) were included to our study. They all had a history of periprosthetic infection after an average of 3.3 (range 1 to 5) revision hip arthroplasties and were submitted to a two stage revision arthroplasty using an allograft-prosthesis composite. Results: At an average follow-up of eleven years (range, eight to twenty years), 14 patients were alive, 7 patients died, and 1 patient was lost to follow-up. The ten year survival of the allograft-prosthesis composites was 74.9 per cent (95 per cent confidence interval 55.1 to 94.7 per cent, 4 cases remaining at risk). Seven cases presented with APC failure needing re-revision, 2 due to re-infection (4 and 23 months from revision by the same microorganism species as for the initial infection (Staph aureus to both cases), 3 due to allograft non union (at 21, 43, 79 months) and 2 cases due to graft resorption (164, 175 months post revision). Delayed healing and wound drainage occurred to 2 more cases. Conclusion: Reconstruction of massive proximal femoral bone loss with an allograft-implant composite is a demanding procedure. Biologic means of reconstruction is a major advantage preserving bone stock for future surgery. However, high complication rate should be considered.
Research Interests:
The technique of extracortical bone-bridging and ingrowth fixation with a porous coating over the shoulder region of the implant and augmentation by autogenous bone-grafting was introduced to improve the longevity of implant fixation. The... more
The technique of extracortical bone-bridging and ingrowth fixation with a porous coating over the shoulder region of the implant and augmentation by autogenous bone-grafting was introduced to improve the longevity of implant fixation. The potential advantages of this technique are that new-bone formation across the bone-prosthesis junction may share stress and may prevent osteolysis by sealing off this critical region against the infiltration of wear particles. The objectives of this study were to examine the prevalence of stem-loosening with use of the extracortical bone-bridging and ingrowth technique, the amount of bone formation over the porous-coated region of this prosthesis, and the characteristics of bone formation over the porous-coated region and adjacent bone. Forty-three patients who had prosthetic reconstruction with the extracortical bone-bridging and ingrowth technique from 1976 to 1990 were included in this retrospective study. The mean length of follow-up was 9.7 years (range, two to twenty-one years). All but one patient were managed with autogenous bone graft; five, with allograft and autograft; and one, with allograft only. Extracortical bone formation was measured over a 2-cm length of the porous-coated region of the prosthesis in four zones (the medial and lateral aspects on anteroposterior radiographs and the anterior and posterior aspects on lateral radiographs) and was reported as the percentage of the total length (8 cm) covered by extracortical bone with a thickness of >1 mm. The Spearman rank coefficient was used to assess the correlation between pairs of continuous variables. The final average percentage of the porous-coated region that was covered by extracortical bone formation was 76% +/- 34% for all patients and anatomical sites of reconstruction. Use of bone cement was associated with less bone formation (p = 0.04), and this value remained lower at the final measurement (p = 0.06). One stem had aseptic loosening, but no sign of osteolysis was found. The radiographic appearance of the bone formation had stabilized at two years of follow-up. All patients with allograft augmentation had greater bone formation. The amount of extracortical bone formation did not differ in relation to the type of porous coating, anatomical sites, pathological disorder, sex or age of the patient, or length of reconstruction. As shown by the low prevalence of stem-loosening (two of fifty-six stems or one of forty-three patients), the use of the extracortical bone-bridging and ingrowth fixation technique is associated with improved stem fixation in segmental bone-replacement prostheses applied for limb salvage. In the demanding biomechanical environment and with the risk of stress and particle-related bone resorption, the extracortical bone-bridging and ingrowth fixation is an attractive method to provide long-lasting implant fixation.
Research Interests:
The concept of extracortical bone bridging and ingrowth as a means of achieving long-term biological fixation of porous-coated modular segmental bone/joint prostheses has been validated using experimental bench tests, theoretical... more
The concept of extracortical bone bridging and ingrowth as a means of achieving long-term biological fixation of porous-coated modular segmental bone/joint prostheses has been validated using experimental bench tests, theoretical modeling, and animal experiments. Aside from being available at the time of surgery, other potential advantages of such an implant system include: (a) allowing optimal dimensional match to the bone defect; (b) minimizing stem fracture, loosening, or bone resorption; (c) enhancing initial implant stability; and (d) facilitating easier implant removal. Additional studies and continuous clinical follow-up are necessary to ensure long-term success of the present porous-coated modular segmental bone/joint prosthetic devices.
Research Interests:
The goals of treatment for patients with metastatic disease are control of pain and maintenance of function. Prosthetic arthroplasty is a useful technique for selected indications. Specific indications include (1) reconstruction of large... more
The goals of treatment for patients with metastatic disease are control of pain and maintenance of function. Prosthetic arthroplasty is a useful technique for selected indications. Specific indications include (1) reconstruction of large destructive areas that are not amenable to internal fixation, (2) salvage of failed internal fixation devices, and (3) salvage of lesions in which there are no radiotherapy options to prevent disease progression. Custom modular devices allow resection of varying segments of the skeleton. Immediate rigid fixation is achieved with cemented intramedullary stems. Patients are allowed to bear full weight as tolerated immediately postoperatively. A custom modular diaphyseal segmental replacement system allows resection of large diaphyseal lesions and immediate fixation. The complication rate is low after arthroplasty.
Research Interests:
Limb ablation for tumors of the shoulder is a devastating procedure. Recent advances in preoperative investigative measures, adjuvant chemotherapy, and reconstructive techniques have resulted in an increased interest in limb-sparing... more
Limb ablation for tumors of the shoulder is a devastating procedure. Recent advances in preoperative investigative measures, adjuvant chemotherapy, and reconstructive techniques have resulted in an increased interest in limb-sparing resection. For limb-sparing procedures to present a viable alternative in these cases, recurrence rates must be comparable to those obtained with ablative surgery. In addition, the resection must result in an improvement over the status obtainable with prosthetic devices. Twenty-four patients underwent limb-salvage procedures of various forms for primary bone tumors of the shoulder girdle. At follow-up (average: 33 months), 19 patients were alive without disease, one was alive with disease, and four were dead. One patient had local recurrence. All surviving patients enjoyed nearly normal function of the distal extremity. Improvements in techniques of soft tissue reconstruction in an effort to gain function and stability after wide resection of these tumo...
Research Interests: Orthopedic Surgery, Surgery, Plastic Surgery, Adolescent, Medicine, and 10 moreHumans, Osteosarcoma, Male, Clavicle, Clinical Sciences, Humerus, Adult, Scapula, Shoulder joint, and Chondrosarcoma(Humans, Osteosarcoma, Male, Clavicle, Clinical Sciences, Humerus, Adult, Scapula, Shoulder joint, and Chondrosarcoma)
(Humans, Osteosarcoma, Male, Clavicle, Clinical Sciences, Humerus, Adult, Scapula, Shoulder joint, and Chondrosarcoma)
We analyzed 84 hips in 82 patients with proximal femur prosthetic replacement as a reconstructive procedure after tumor resection. Forty-nine patients had primary disease while 37 patients had metastases. The mean follow-up time was 30.4... more
We analyzed 84 hips in 82 patients with proximal femur prosthetic replacement as a reconstructive procedure after tumor resection. Forty-nine patients had primary disease while 37 patients had metastases. The mean follow-up time was 30.4 months in all patients; the median survival was 79 months for primary cases and 9 months for metastatic cases. The most common surgical indication was tumor size and position in primary cases and pathological fractures in metastatic cases. Nine cases had primary tumor recurrence. Overall functional scores were good and excellent in 54.7%, while only one patient required revision for femoral loosening. There were radiographic lucencies around 10 of 22 acetabular components at 5 years. Implant-related osteopenia was seen in 31 of 72 assessable femurs. There is a definite role for bipolar implants in both primary and metastatic disease.
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The intermediate functional results were assessed for fifty-seven patients who had had a limb-salvage procedure for treatment of a tumor of the shoulder girdle region at our institution from 1980 through 1990. Fifty-three patients had a... more
The intermediate functional results were assessed for fifty-seven patients who had had a limb-salvage procedure for treatment of a tumor of the shoulder girdle region at our institution from 1980 through 1990. Fifty-three patients had a malignant bone tumor (a sarcoma) and four had an extensive giant-cell tumor. The resections were classified according to the system of the Musculoskeletal Tumor Society. A variety of reconstructive procedures were performed after resection of the tumor, with the choice of procedure depending on the type of resection and the needs of the patient. The functional results were described and graded quantitatively according to the functional rating system of the Musculoskeletal Tumor Society. The average duration of follow-up was 5.3 years (median, 4.6 years) for the forty-seven patients who were still alive at the time of the latest follow-up examination. Eight patients died of disease and two others died of unrelated malignant tumors an average of 1.8 years postoperatively. The resection of the tumor was classified as wide in forty of the fifty-three patients who had a sarcoma and as marginal in thirteen; four patients had local recurrence (two, after a wide resection, and two, after a marginal resection). One of the four patients who had a giant-cell tumor had local recurrence. The functional results were related to the type of resection and the method of skeletal reconstruction. After resection of the entire scapula and the proximal aspect of the humerus, reconstruction with a spacer frequently resulted in asymptomatic superior subluxation of the implant and poor function of the shoulder. After extra-articular resection of the glenoid cavity and the proximal aspect of the humerus with loss of the abductor mechanism, osseous arthrodesis resulted in good function that was superior to that found after reconstruction with a spacer or a proximal humeral replacement prosthesis. Our preferred method to achieve fusion was insertion of an intercalary allograft and a vascularized fibular graft. However, the allograft fractured in three of four patients in whom primary fusion had been obtained with this technique. An osteoarticular allograft inserted after intra-articular resection of the proximal aspect of the humerus and preservation of the abductor mechanism provided good function that was superior to that found after reconstruction with a proximal humeral replacement prosthesis, which produced symptomatic instability that led to a secondary arthrodesis in some patients. However, subchondral fracture and collapse of the osteoarticular allograft occurred in four of eight patients by the time of the latest follow-up examination. The results of all methods of reconstruction were satisfactory with regard to pain, emotional acceptance, and manual dexterity. We believe that the use of a method of reconstruction that is appropriate with regard to the needs of the patient and preoperative counseling regarding the expected functional level and restrictions of activity are critical for a high level of postoperative satisfaction.
Research Interests: Biomedical Engineering, Adolescent, Medicine, Humans, Child, and 15 moreFemale, Osteosarcoma, Male, Sarcoma, Clinical Sciences, Aged, Middle Aged, Humerus, Adult, Pediatric Orthopaedics, Giant Cell Tumor of Bone, Scapula, Bone Transplantation, Chondrosarcoma, and Paediatrics and reproductive medicine
Soft tissue attachment to a metallic prosthesis is required for the improvement of the functional outcome of endoprosthetic reconstructions. Direct tendon attachment to the metallic surface can be achieved through fibrous ingrowth, but... more
Soft tissue attachment to a metallic prosthesis is required for the improvement of the functional outcome of endoprosthetic reconstructions. Direct tendon attachment to the metallic surface can be achieved through fibrous ingrowth, but such an attachment has a mechanical strength less than one fifth of that of a normal tendon insertion. Regeneration of a transitional structure between the tendon and the metallic surface similar to the normal morphology of a direct tendon insertion may improve the mechanical strength of the new tendon insertion. The objective of the study was to investigate the effect of placement of an interpositional autogenous cancellous bone plate augmented with bone marrow on the mechanical strength of the soft tissue attachment to the metallic surface. The insertion of the supraspinatus tendon was reattached to a porous titanium prosthesis in a canine shoulder model. An autogenous cancellous bone plate supplemented with bone marrow was positioned between the metallic surface and the tendon. Assessment of load-bearing, as a measure of functional recovery, and radiological analysis were performed at 3, 6, 9, 12, and 15 weeks. The animals were euthanized 16 weeks after surgery, and the specimens were subjected to tensile mechanical testing (six animals) and microradiographic-histologic evaluation (three animals). Functional analysis showed a 90.3% recovery of preoperative weight-bearing by 16 weeks (p < 0.05). The mineralized area around the prostheses increased by 63% over time (p < 0.05). Tensile stiffness and strength of the reconstruction were 43.6% and 42.8% of the intact tendon insertion values, respectively. These results were higher than in previous experiments using the direct tendon attachment (p < 0.01, p < 0.05, respectively) or the interpositional bone plate without marrow supplementation (p < 0.05, p < 0.05, respectively). Morphologically, the tendon reattachment site contained the basic tissue transition zones in normal tendon insertion to bone. Inductive bone grafting, supplemented with bone marrow, in the biologic augmentation of tendon anchoring onto a porous metallic prosthesis was an effective technique to increase the mechanical strength of the tendon attachment to the metallic prosthesis.
Research Interests: Functional Analysis, Materials Science, Biomedical Engineering, Orthopaedic, Medicine, and 15 moreDogs, Bone graft, Cancellous bone, Animals, Bone marrow, Clinical Sciences, Mechanical Testing, Functional Recovery, Implant, prosthesis Design, Bone Plates, Bone Transplantation, Mechanical strength, Metallic Surface, and functional outcome
Research Interests:
Research Interests:
Research Interests: Quality of life, Survival Analysis, Treatment Outcome, Humans, Female, and 14 moreMale, Follow-up studies, Dissection, Clinical Sciences, Intensive Care Unit, Aged, Middle Aged, Kaplan-Meier, Adult, Postoperative Complication, Blood Loss, Electron beam irradiation, Rectal Cancer, and Wound infection
A comparative analysis was made of subchondral replacement with polymethylmethacrylate and autogeneic bone grafts in defects in the medial femoral condyles of dogs. The defect produced a 50% reduction in subchondral stiffness. An in vitro... more
A comparative analysis was made of subchondral replacement with polymethylmethacrylate and autogeneic bone grafts in defects in the medial femoral condyles of dogs. The defect produced a 50% reduction in subchondral stiffness. An in vitro preparation helped establish that subchondral stiffness returned to normal after reconstruction with polymethylmethacrylate. The in vivo model demonstrated a reduction in subchondral stiffness in both groups at three weeks, but the bone grafted side returned to normal and the methylmethacrylate side recovered to 79% of the control at 12 weeks. There were no deleterious effects on the articular cartilage in either group when analyzed histologically and biochemically. A marked increase in new bone formation and subchondral porosity was found in the polymethylmethacrylate groups. This study supports the clinical use of subchondral polymethylmethacrylate after the exteriorization and curettage of benign bone tumors such as giant cell tumors.
Research Interests:
Research Interests:
Research Interests:
After nodal metastasis from malignant melanoma, approximately 80% of patients die from disseminated disease. To clarify the role of radiation therapy (XRT) following node dissection. 56 patients with biopsy-proven nodal metastasis... more
After nodal metastasis from malignant melanoma, approximately 80% of patients die from disseminated disease. To clarify the role of radiation therapy (XRT) following node dissection. 56 patients with biopsy-proven nodal metastasis participated in a randomized, prospective clinical trial which compares radiation therapy to the regional lymph node area following lymphadenectomy (27 patients) with lymphadenectomy alone (29 patients). Interesting differences in the survival curves (p = 0.09) and in the disease-free interval curves (p = 0.08) for the two treatment groups proved to be attributable to imbalances in the age and nodal distributions in the treatment groups. Covariate analysis identified age and sex as the factors having the most significant (p less than 0.04) effect on survival and identified the number of positive nodes as the covariate having the most significant (p less than 0.02) effect on disease-free interval. Treatment did not have a significant effect upon survival or disease-free interval.