Biomedical subjects

Ross M Wilkins

Publications and source records attributed to Ross M Wilkins.

10 recordsLinked to original sources

PubMed2005

Reconstruction options for pediatric bone tumors about the knee.

The surgical decisions involved with high-grade sarcoma surgery about the knee in pediatric patients are complicated. The orthopedic oncologist must have experience as well as a great deal of insight into the intricacies of each procedure and the wishes and demands of patients--not only while they are young but in into their adult life. It is difficult to predict the interests and vocation young patients will choose as their lives progress. However, if the patient qualifies as a candidate for limb preservation, the functional and cosmetic results obtained by limb preservation seem to be preferred. Amputation and rotationplasty should be reserved for patients who are not candidates for limb preservation or who are in an otherwise salvage situation. The prognosis for quality of life and limb after treatment for bone sarcomas has increased dramatically during the past decade. Survival approaching the 70% to 90% range can be expected, with >90% of those patients having limb preservation surgery. With further advancements in the biologic control of tissue healing, bioengineering, and prosthetic design and implantation, the future of these patients continues to be optimistic.

Arthroplasty, Replacement, Knee↗

PubMed2005

The value of serial arteriography in osteosarcoma: delivery of chemotherapy, determination of therapy duration, and prediction of necrosis.

PURPOSE: To investigate the value of serial arteriography to assess tumor response, predict necrosis, and individualize the duration of a combined intravenous (IV) and intraarterial (IA) neoadjuvant chemotherapy protocol in patients with biopsy-proven high-grade osteosarcoma or malignant fibrohistiocytoma of bone. MATERIALS AND METHODS: Between July 1987 and March 2003, 109 patients completed a chemotherapy protocol of neoadjuvant IV doxorubicin and IA cisplatin. Patients were eligible regardless of age, disease stage, or disease site. A minimum of three IA cycles followed by definitive surgery was required for inclusion in the final analysis. IA dose and duration were increased for tumors larger than 10 cm. Initial arteriograms were scored as indicating mild, moderate, or marked tumor neovascularity (TNV). Subsequent arteriograms were prospectively compared with the baseline image for percent change in TNV. Treatment continued until a maximum of five cycles were administered or one of three criteria were met: (i) at least 90% decrease in TNV, (ii) plateau of effect, or (iii) no response. RESULTS: Of 408 IA procedures, 42 patients underwent three cycles, 53 underwent four, and 14 required five cycles of neoadjuvant therapy. There was a 2.5% minor complication rate. Eighty-six percent of patients exhibited at least 90% decrease in TNV and 82% exhibited good histologic response (> or =90% tumor necrosis). Serial arteriography predicted a good histologic response with an accuracy of 90% and a sensitivity of 97%. CONCLUSIONS: Serial arteriography was highly sensitive and accurately predicted good responses. This individually modified, dose-intensified neoadjuvant protocol yielded an excellent histologic response rate with minimal complications. Future endeavors should involve a multiinstitutional study of this unique approach.

Adolescent↗

PubMed2004

Treatment of benign bone lesions with an injectable calcium sulfate-based bone graft substitute.

The treatment of benign bone lesions can be challenging due to the limited quantity of autogenous graft available for harvest and grafting of the defect. The use of an injectable calcium bone graft substitute, Minimally-Invasive Injectable Graft (MIIG) (Wright Medical Technology, Inc, Arlington, Tenn), material for treatment of these bone lesions is advantageous. Calcium sulfate has a long-standing history in the treatment of bone voids secondary to trauma, infection, or neoplastic processes. Minimally-Invasive Injectable Graft injectable calcium sulfate graft may be injected into surgically created osseous defects or bone defects secondary to traumatic injury. After hardening, the paste acts as a temporary intraosseous support through which internal fixation may be placed. Fifteen patients with benign space-occupying lesions were treated with curettage and grafting with an injectable, surgical-grade, calcium sulfate bone graft substitute. Bone healing was assessed postoperatively and defined as resorption of the bone graft substitute material and replacement with new bone formation. The grafted defects in 14 of the 15 patients showed complete incorporation of the graft material at an average of 8 weeks. One patient required incision and drainage for a deep infection 5 weeks postoperatively. The average follow-up was 6 months (range: 3-15 months), and Musculoskeletal Tumor Society functional outcome scores averaged 83%. This injectable, minimally invasive graft material is easy to use, provides a temporary structural support when grafting bone defects, and results in predictable rapid bone healing.

Adolescent↗

PubMed2003

Reoperation after limb preservation surgery for sarcomas of the knee in children.

Limb preservation surgery compares favorably with amputation in oncologic and functional outcomes. However, an increased incidence of complications and reoperations is associated with limb preservation. This study compared the outcome of a group of young patients who required at least one reoperation after limb preservation surgery because of a complication or need for prosthetic lengthening with the outcome of a similar group who did not require additional surgery. The functional scores before and after reoperation are compared to determine the impact on reported function and patient satisfaction. Forty-four consecutive patients younger than 19 years were treated for a malignancy of the distal femur or proximal tibia. Six of these patients required an amputation because of extensive disease or inadequate response to chemotherapy. The Musculoskeletal Tumor Society functional evaluation scores of 26 patients who required at least one reoperation (Group A) were compared with the scores of 10 patients who have not required additional surgery (Group B). Average before and after reoperation functional scores were compared to discern a decline in function with time. The minimum followup was 2 years. Patients in Group A required 54 reoperations. No difference in mean functional scores between Group A and Group B was detected. Likewise, after isolating Group A scores, no significant difference was detected between the average functional scores before (67%) and after (68%) reoperation or lengthening. Despite relatively small numbers, the current study suggests that adequate function is maintained despite reoperation or revision in young patients with malignancies of the knee who have limb preservation surgery.

Adolescent↗

PubMed2003

Treatment of metastatic disease of the tibia.

Metastatic lesions to bone outnumber primary bone malignancies. Osseous metastases to the tibia tend to be less common than osseous metastases to other long bones. This study examined the treatment options for a population of patients with metastatic disease to the tibia, with surgical intervention being the cornerstone of treatment for the osseous lesion. A multicenter study had 592 patients with metastatic disease to the bone, with 26 lesions occurring in the tibia (4.4%) during a 13-year period. No patient had concurrent metastases distal to the elbow. After confirmation of metastatic disease, treatment consisted of surgical intervention in all patients, including plate osteosynthesis, intramedullary rodding and cementation, endoprosthetic replacement, and in most patients, postoperative radiation therapy. In 96% of patients, the reconstruction outlasted their life expectancy. All patients were satisfied with their reconstruction. Four complications were encountered in the postoperative period, all requiring additional surgery. Aggressive treatment of osseous metastasis is justified in patients with metastatic disease despite a limited life expectancy. Intervention by an orthopaedic oncologist may result in fewer reconstructive failures. Surgical intervention contributes to an improved quality of life and limb function, ease of nursing care, and may help in maintaining patient independence.

Adult↗

PubMed2003

Early multicenter experience with a noninvasive expandable prosthesis.

A noninvasive expandable prosthesis for skeletally immature children after limb salvage surgery has been developed. Between 1998 and 2001, 18 Phenix prostheses were implanted in 15 pediatric patients who had been diagnosed and treated for osteosarcoma about the knee. Of the 15 original prostheses, 10 were implanted at the time of primary tumor resection and five were revisions from an endoprosthetic modular knee system. Sixty expansions of the 18 prostheses were done, with all but two done as outpatient procedures. An average 8.5 mm was obtained per lengthening (range, 1-30 mm). The average followup was 21.5 months (range, 12-33 months) and the latest Musculoskeletal Tumor Society functional scores averaged 90%. Eight revisions were required for stem fracture or loosening. There was one amputation because of a postoperative arterial thrombosis. The principle of the Phenix prosthesis involves storage of energy in a spring compressed by a locking system. Lengthening is achieved via exposure to an electromagnetic field that allows controlled release of the spring. This is a unique expandable custom prosthesis that offers many benefits in maintaining limb length equality in growing patients. Although the early experience is promising, additional data are required regarding the long-term structural integrity of the prosthesis. We are optimistic that this technology will prove beneficial, not only for patients with malignant bone tumors but in applications requiring serial limb length equalizations or for spinal deformities.

Activities of Daily Living↗

PubMed2003

Superior survival in treatment of primary nonmetastatic pediatric osteosarcoma of the extremity.

BACKGROUND: A protocol to treat osteosarcoma of the extremity was developed at two local institutions. METHODS: The study involved a dose-intensified neoadjuvant protocol of intravenous doxorubicin and intra-arterial cisplatin administered repetitively until maximum angiographic response was noted. Definitive surgery was delayed until > or =90% reduction in tumor neovascularity was documented. Prospective assessment of serial arteriograms was highly accurate (94%) in predicting histological response and assisted in surgical planning. After resection, if patients were determined to be good responders (> or =90% tumor necrosis), they underwent a 4-month postoperative course with the same agents. Poor responders (<90% necrosis) were treated with alternative agents for 12 months from diagnosis. Forty-seven assessable patients with primary, high-grade, nonmetastatic osteosarcoma of the extremity were included in this analysis. The median age was 15 years (range, 7-21 years). RESULTS: Patients underwent an average of four preoperative intra-arterial courses. Forty-three patients underwent limb-preservation procedures, and 41 had >90% tumor necrosis. With an average follow-up of 92 months (range, 20-178 months), 39 patients were continuously disease free, 3 died of disease, 1 died of other causes, and 4 have no evidence of disease 11 to 51 months after relapse (all pulmonary metastases). There were no local recurrences. Kaplan-Meier analysis demonstrated a 10-year overall survival of 92% and an event-free survival of 84%. CONCLUSIONS: This study demonstrates excellent survival with a dose-intensified neoadjuvant protocol. Future endeavors should involve a multi-institutional randomized study comparing this approach with another multiagent intravenous neoadjuvant protocol.

Adolescent↗

PubMed2003

Percutaneous treatment of long bone nonunions: the use of autologous bone marrow and allograft bone matrix.

Sixty-six patients with 69 "stiff" nonunions (no gross motion) of long bones were entered into a prospective study. The only therapeutic intervention was the percutaneous administration of a mixture of autologous bone marrow and allograft demineralized bone matrix on an outpatient basis. Sixty-one of the percutaneous treatments (88%) resulted in union at an average of 8.1 months (range: 2 months to 3 years). This method of treating nonunions is as successful as standard iliac crest autologous bone grafting and offers the distinct advantages of decreased morbidity, reduced costs, and shorter hospital stay.

Adolescent↗

PubMed2003

The effect of allomatrix injectable putty on the outcome of long bone applications.

Long bone defects due to nonunion or surgical excision of benign bone tumors result in areas that require rapid regeneration of local bone. This clinical and radiographic article details the results of a commercially prepared allograft demineralized bone matrix in patients with long bone voids or gaps. Of the 76 patients included for study, 41 (54%) patients were undergoing surgical intervention for removal of benign tumors or space-occupying lesions and 35 (46%) patients had long bone nonunions. AlloMatrix Injectable Putty (Wright Medical Technology, Inc, Arlington, Tenn) was used alone in 74 (97%) patients and in combination with bone marrow aspirate in two (3%) patients with tibial nonunion. Adjunctive strut allografts were used in three patients with humeral nonunion. The average time to follow-up for the combined population was 7 months (nonunion group 6 months; benign tumor group 7 months). At the most recent follow-up, radiographic evidence of the average percent of bone healing was 85.1% for the nonunion patient group and 93% for the benign tumor patient group. From this study, AlloMatrix Injectable Putty used as a bone void filler in long bone nonunions and benign tumors shows results equal to those historically reported for autograft and other materials.

Adolescent↗

PubMed2002

Revision of the failed distal femoral replacement to allograft prosthetic composite.

Orthopaedic oncologists often prefer a modular prosthetic cemented prosthesis for reconstruction after tumor excision in the distal femur. However, these frequently young patients face the prospect of either mechanical failure or loosening during their lifetime. Between 1993 and 2000, 41 patients (18 males, 23 females) with a malignancy of the distal femur had distal femoral replacement. Eight revisions and one amputation were required. Of these, four patients had revision to an allograft-prosthetic composite because of prosthetic fracture or loosening. These patients comprise the study population. Revisions were required at an average of 4 years after distal femoral replacement and the average age of the patients at revision was 17 years. The average time to achieve healing at the allograft-host junction was approximately 3 months and patients were fully weightbearing by that time. Followup from revision surgery to the last visit averaged 59 months, with average Musculoskeletal Tumor Society and Hospital for Special Surgery scores of 62% and 72%, respectively. There have been no mechanical problems, fractures, or osteolysis to signify loosening in the allograft or host bone. It is anticipated that this type of revision will survive longer than a conventional cemented revision and obviate the need for multiple reoperations in young patients who have difficulty with the biologic features of a cemented prosthesis construct.

Adolescent↗