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Biomedical subjects

Scott M Sporer

Publications and source records attributed to Scott M Sporer.

At least 19 recordsLinked to original sources
PubMed2006

A case of disassociation of a modular femoral neck trunion after total hip arthroplasty.

Modular femoral heads offer the advantages of increased intraoperative flexibility through the adjustment of leg length and offset, whereas a modular femoral neck can also allow independent adjustment of femoral anteversion. Despite the potential advantages of hip systems using increased modularity, these component designs also offer a greater number of junctions through which problems may occur. This case demonstrates the potential for dissociation of a Morse taper between a modular femoral neck and stem.

Aged↗
PubMed2006

The use of a trabecular metal acetabular component and trabecular metal augment for severe acetabular defects.

Stable acetabular fixation cannot be reliably achieved with the use of a hemispherical porous coated component alone in patients with a Paprosky type IIIa defect. The purpose of the present study was to determine the short-term results of a tantalum porous coated hemispherical acetabular component supported with a modular tantalum augment in Paprosky type IIIa defects. A total of 28 patients (28 hips) were treated for a type IIIa acetabular defect between 2001 and 2003 with the use of a trabecular metal acetabular component supported with a modular, superiorly placed trabecular metal augment. At an average of 3.1 years follow-up, 1 patient required rerevision for recurrent instability. The remaining hips remain radiographically stable. Clinically, the patients' modified Postel Merle d'Aubigne score improved from 6.8 preoperatively to 10.6 postoperatively. The use of a trabecular metal acetabular component with a superiorly placed trabecular metal augment demonstrates encouraging short-term results for Paprosky type IIIa acetabular defects.

Acetabulum↗
PubMed2006

Acetabular revision using a trabecular metal acetabular component for severe acetabular bone loss associated with a pelvic discontinuity.

Pelvic discontinuity can be encountered during acetabular revision in patients with severe bone loss. All patients who had an acetabular reconstruction for a type IIIB acetabular defect according to the classification of Paprosky et al [Paprosky WG, Perona PG, Lawrence JM. 1994. Acetabular defect classification and surgical reconstruction in revision arthroplasty. A 6-year follow-up evaluation. J Arthroplasty 9:33.] with an associated pelvic discontinuity between 2001 and 2003 were reviewed. A trabecular metal acetabular component with or that without an acetabular augment was used to obtain fixation proximal and distal to the discontinuity. Thirteen patients (13 hips) were treated for a type IIIB acetabular defect. At an average of 2.6 years of follow-up, 1 patient demonstrated possible radiographic loosening. The other 12 patients maintained radiographically stable hips. None of the patients required repeat surgical intervention. Clinically, the patients' modified Postel-Merle d'Aubigne score improved from 6.1 preoperatively to 10.3 postoperatively. The treatment of pelvic discontinuity during acetabular revision using a trabecular metal acetabular component with or that without an associated trabecular metal augment appears to provide reliable and reproducible short-term results.

Acetabulum↗
PubMed2006

Changing demographics of patients with total joint replacement.

There has been a substantial change in the population demographics of patients who potentially will require total joint replacements. We studied data regarding temporal trends in physical condition, life expectancy, education, and other population demographics of individuals most likely to receive total joint replacements. Changes in this population during the last several decades correlate with temporal changes in the prevalence of joint disease and the incidence of total hip and knee replacements. Compared with several decades ago, patients currently receiving total joint replacements are almost 20% heavier, more physically active, three times more likely to have a high school or college education, and live more than 25% longer. Patients needing total joint replacements are more likely to be female, and twice as likely to receive a total knee replacement than a total hip replacement. Treatment choices and outcome expectations are best determined with accurate knowledge of current surgical science and current patient demographics. Therefore, it is important to realize that today's population most likely to receive total joint replacements is demographically different than in the past.

Adult↗
PubMed2006

The use of structural distal femoral allografts for acetabular reconstruction. Surgical technique.

BACKGROUND: Acetabular fixation during revision total hip arthroplasty in patients who have a nonsupportive superior dome and proximal migration of the acetabular component (a Paprosky Type-IIIa defect) cannot be achieved reliably with use of a hemispherical porouscoated component alone. The purposes of the present study were to determine the long-term results associated with the use of a porous-coated hemispherical acetabular component, supported with a distal femoral structural allograft, for revision at the site of a Type-IIIa defect and to determine if graft resorption leads to late failure. METHODS: Thirty-one patients who had an acetabular reconstruction with use of a distal femoral allograft for the treatment of a Type-IIIa defect between January 1985 and December 1990 were followed annually with clinical and radiographic evaluations. At the time of the latest follow-up, eight patients had died and one patient had been lost to follow-up. One of the patients who died had had a clinical failure at 4.5 years postoperatively and was included in the analysis. Therefore, twenty-three patients, who had had an average age of sixty-one years at the time of the index procedure, were evaluated at an average of 10.3 years postoperatively. RESULTS: Five acetabular components were re-revised because of aseptic loosening at an average of 5.3 years after the index procedure. Radiographically, all but one of the remaining components were stable and showed evidence of bone ingrowth. The average Merle D'Aubigné and Postel hip score improved from 5 points preoperatively to 10 points at the time of the latest follow-up. Allograft bone resorption, although difficult to quantitate, was observed around six of the seventeen stable components and around two of the five components that failed clinically. CONCLUSIONS: Acetabular revision with use of a porous-coated acetabular component along with a structural distal femoral allograft for the treatment of a Type-IIIa defect demonstrated a high rate of clinical and radiographic success after an average of ten years of follow-up.

Acetabulum↗
PubMed2006

The geographic incidence and treatment variation of common fractures of elderly patients.

Fractures of the hip, wrist, proximal humerus, and ankle frequently are observed among the elderly patient population in the United States. The Medicare patient population has shown dramatic geographic variation in the rates of these common fractures, with an increased incidence observed throughout the Southeast. Treatment (surgical versus nonsurgical) is also highly variable and dependent on the geographic location but not necessarily on the type of injury. Whereas regional variation in medical treatment may be attributed to variations in practice patterns, the etiology behind the dramatic variations in fractures is less well-defined and is likely multifactorial, related to environmental, occupational, genetic, or nutritional factors.

Aged↗
PubMed2006

Managing bone loss in acetabular revision.

The management of bone loss encountered during acetabular revision remains challenging. In order to obtain a successful surgical result, preoperative planning is required to estimate the severity and location of bone defects. Most acetabular revisions can be treated with the use of a cementless hemispherical component. However, a successful surgical reconstruction requires component stability. Depending on the degree of bone loss, the surgical reconstruction may require the use of cancellous or structural bone graft, acetabular augmentation, an acetabular cage, a custom implant, or an acetabular transplant.

Acetabulum↗
PubMed2005

The treatment of pelvic discontinuity during acetabular revision.

Pelvic discontinuity is frequently encountered during acetabular revision in patients with severe acetabular bone loss. Prompt recognition of the discontinuity and appropriate intraoperative management are essential for a successful clinical outcome. The treatment of the discontinuity is dependent upon the remaining host bone, the potential for healing of the discontinuity, and the potential for biologic ingrowth of acetabular components. If healing potential of the discontinuity exists, the discontinuity should be treated in compression with a posterior column plate and structural allograft or with the use of trabecular metal acting as an internal plate. If healing potential for the discontinuity does not exist, the discontinuity can be bridged and treated in distraction with either an acetabular transplant supported with a cage or with the use of a custom Triflange implant. However, the poor clinical results observed with either of these treatment modalities for a type IIIB defect with an associated pelvic discontinuity have prompted the senior author to explore the use of a trabecular metal acetabular component with 1 or 2 augments in the majority of his current type IIIB cases. The long-term clinical results of this treatment remain unknown.

Acetabulum↗
PubMed2005

Biologic fixation and bone ingrowth.

Total hip arthroplasty has provided thousands of patients with pain relief and has improved their quality of life. Advances in orthopaedic surgical techniques and implant biomaterials now allow predictable surgical results in most patients. Despite the overwhelming success of this surgical procedure, the debate continues surrounding the optimal choice of implants. Femoral and acetabular implants with varying geometries and fixation methods are currently available. Acrylic bone cement has been used extensively in the past for acetabular and femoral fixation. This mode of component fixation currently remains the technique used most frequently throughout Europe and has shown excellent long-term results. Problems inherent with acrylic bone cement, however, have encouraged other surgeons to use alternative surfaces to allow biologic fixation.

Arthroplasty, Replacement, Hip↗
PubMed2005

Decision analysis in orthopaedics.

Orthopaedic surgeons are faced with an ever-growing amount of clinical information from which they are required to make treatment decisions. Many of these decisions can be approached with relative certainty. However, there are many situations where the optimal decision is less clear. These treatment decisions will have competing risks, benefits, or costs. Decision analysis is one method to critically evaluate alternative treatment options with multiple potential outcomes. This method of decision making can be extremely valuable because of the growing number of treatment alternatives, and to the ever-increasing complexity of medical scenarios.

Decision Support Techniques↗
PubMed2005

The treatment of acetabular bone defects with an associated pelvic discontinuity.

UNLABELLED: Pelvic discontinuity is encountered frequently during acetabular revision in patients with severe acetabular bone loss. Prompt recognition of the discontinuity and appropriate intraoperative treatment are essential for a successful clinical outcome. The treatment of the discontinuity is dependent on the remaining host bone, the potential for healing of the discontinuity, and the potential for biologic ingrowth of acetabular components. If healing potential of the discontinuity exists, the discontinuity should be treated in compression with a posterior column plate and structural allograft or with the use of trabecular metal acting as an internal plate. If healing potential for the discontinuity does not exist, the discontinuity should be bridged and treated in distraction with an acetabular transplant supported with a cage, a trabecular metal component with trabecular metal augmentation, or with the use of a custom triflange implant. LEVEL OF EVIDENCE: Therapeutic study, Level III-1 (case-control study). See the Guidelines for Authors for a complete description of levels of evidence.

Acetabulum↗
PubMed2005

Ankle fractures in the elderly: what you get depends on where you live and who you see.

OBJECTIVES: This study was performed to determine 1) the rate of ankle fractures in the elderly in the United States stratified by hospital referral region, and 2) whether the percentage of ankle fractures treated surgically is affected by factors, such as fracture location, hospital referral region, concentration of orthopaedists, presence of a teaching hospital in that region, patient age, race, gender, or the number and type of specific medical comorbidities. DESIGN: A 20% sample of Medicare Part B claims from the years 1998 to 2000 was analyzed. PATIENTS/INTERVENTION: The CPT codes for operative and nonoperative treatment of isolated medial malleolar, isolated lateral malleolar, bimalleolar, and trimalleolar fractures were identified. These codes were used to determine the overall rate of ankle fractures and individual fracture types. MAIN OUTCOME MEASUREMENT: : The rate of ankle fractures was evaluated by hospital referral region, patient age (groups of 5 years, aged 65 years or older), gender, and race. The percentage of surgical treatment was determined for each fracture type as the number of surgically treated fractures over the total number of ankle fractures within each subtype and analyzed by fracture type, hospital referral region, and concentration of orthopaedists in that region, presence of a teaching hospital within the hospital service area, patient age, gender, race, and number and type of specific medical comorbidities. Regression was performed by using the above variables. RESULTS: We identified 33,704 ankle fractures: 7.6% were isolated medial malleolar, 50.8% were isolated lateral malleolar, 27.4% were bimalleolar, and 14.2% were trimalleolar fractures. The overall United States average was 4.2 ankle fractures per 1000 Medicare enrollees. The rate of ankle fractures varied by a factor of 8, from 1 per 1000 Medicare enrollees in San Francisco, CA, to 8.3 in Hickory, NC. The rate of ankle fractures was highest in white women at 5.8 and lowest in nonwhite men at 1.5 per 1000 Medicare enrollees. The overall rate of ankle fractures that underwent surgical stabilization was 33%, ranging from 14% in Binghampton, NY, to 72% in Napa, CA. The rate of surgical intervention was 22% for isolated medial malleolar fractures, 11% for isolated lateral malleolar fractures, 58% for bimalleolar fractures, and 74% for trimalleolar fractures. In regression analysis, the factors associated with nonoperative care after ankle fracture were: older age, female gender, increasing number of comorbidities as measured by the Charlson index, presence of diabetes or peripheral vascular disease, and living in a hospital service area that had a designated teaching hospital. Beneficiaries living in areas in which a hospital was a member of the Council of Teaching Hospitals were less likely to receive surgical treatment of their ankle fracture. Increasingly older age was strongly associated with decreased likelihood of having surgical intervention, with each 5 year age grouping progressively less likely to have surgical treatment. The concentration of orthopaedists in the region was not associated with the likelihood of having surgical treatment. CONCLUSIONS: The term ankle fracture involves a wide spectrum of injuries. We found a large variation through the United States in both the rate of ankle fractures and the percentage of those that undergo surgical intervention.

Age Distribution↗
PubMed2005

The use of structural distal femoral allografts for acetabular reconstruction. Average ten-year follow-up.

BACKGROUND: Acetabular fixation during revision total hip arthroplasty in patients who have a nonsupportive superior dome and proximal migration of the acetabular component (a Paprosky Type-IIIa defect) cannot be achieved reliably with use of a hemispherical porous-coated component alone. The purposes of the present study were to determine the long-term results associated with the use of a porous-coated hemispherical acetabular component, supported with a distal femoral structural allograft, for revision at the site of a Type-IIIa defect and to determine if graft resorption leads to late failure. METHODS: Thirty-one patients who had an acetabular reconstruction with use of a distal femoral allograft for the treatment of a Type-IIIa defect between January 1985 and December 1990 were followed annually with clinical and radiographic evaluations. At the time of the latest follow-up, eight patients had died and one patient had been lost to follow-up. One of the patients who died had had a clinical failure at 4.5 years postoperatively and was included in the analysis. Therefore, twenty-three patients, who had had an average age of sixty-one years at the time of the index procedure, were evaluated at an average of 10.3 years postoperatively. RESULTS: Five acetabular components were re-revised because of aseptic loosening at an average of 5.3 years after the index procedure. Radiographically, all but one of the remaining components were stable and showed evidence of bone ingrowth. The average Merle D'Aubigné and Postel hip score improved from 5 points preoperatively to 10 points at the time of the latest follow-up. Allograft bone resorption, although difficult to quantitate, was observed around six of the seventeen stable components and around two of the five components that failed clinically. CONCLUSIONS: Acetabular revision with use of a porous-coated acetabular component along with a structural distal femoral allograft for the treatment of a Type-IIIa defect demonstrated a high rate of clinical and radiographic success after an average of ten years of follow-up.

Acetabulum↗
PubMed2005

Extensor mechanism allograft reconstruction after total knee arthroplasty.

BACKGROUND: Disruption of the extensor mechanism is an uncommon but catastrophic complication of total knee arthroplasty. We evaluated two techniques of reconstructing a disrupted extensor mechanism with the use of an extensor mechanism allograft in revision total knee arthroplasty. METHODS: Twenty consecutive reconstructions with the use of an extensor mechanism allograft consisting of the tibial tubercle, patellar tendon, patella, and quadriceps tendon were performed. The first seven reconstructions (Group I) were done with the allograft minimally tensioned. The thirteen subsequent procedures (Group II) were performed with the allograft tightly tensioned in full extension. All surviving allografts were evaluated clinically and radiographically after a minimum duration of follow-up of twenty-four months. RESULTS: All of the reconstructions in Group I were clinical failures, with an average postoperative extensor lag of 59 degrees (range, 40 degrees to 80 degrees ) and an average postoperative Hospital for Special Surgery knee score of 52 points. All thirteen reconstructions in Group II were clinical successes, with an average postoperative extensor lag of 4.3 degrees (range, 0 degrees to 15 degrees ) (p < 0.0001) and an average Hospital for Special Surgery score of 88 points. Postoperative flexion did not differ significantly between Group I (average, 108 degrees ) and Group II (average, 104 degrees ) (p = 0.549). CONCLUSIONS: The results of reconstruction with an extensor mechanism allograft after total knee arthroplasty depend on the initial tensioning of the allograft. Loosely tensioned allografts result in a persistent extension lag and clinical failure. Allografts that are tightly tensioned in full extension can restore active knee extension and result in clinical success. On the basis of the number of knees that we studied, there was no significant loss of flexion. Use of an extensor mechanism graft for the treatment of a failure of the extensor mechanism will be successful only if the graft is initially tensioned tightly in full extension.

Arthroplasty, Replacement, Knee↗
PubMed2005

Case report: Salmonella infection following total hip arthroplasty.

A case of a total hip arthroplasty infection with Staphylococcus aureus, co-infected with Salmonella choleraesuis was treated with two-stage exchange and administration of vancomycin and ciprofloxacin. No signs of re-infection have appeared fourteen months after surgery. Cases of salmonella infection of hip prostheses are quite rare, with only a handful of reports in the literature.

Aged↗
PubMed2005

Extensively coated cementless femoral components in revision total hip arthoplasty: an update.

The vast majority of femoral revisions that an orthopaedic surgeon encounters can be treated successfully with an extensively porous coated stem. Long-term results have demonstrated that this type of implant can provide reliable initial fixation with a high propensity for long-term fixation. Depending on the degree of femoral bone loss (Paprosky Type IIIA or Type IIIB bone), a longer cementless stem may be required to obtain initial axial and rotational stability. If severe bone loss is present (Paprosky Type IV bone), large canal diameters are encountered (>19 mm), or if torsion remodeling of the proximal femur has occurred, alternative methods of fixation may be required.

Arthroplasty, Replacement, Hip↗
PubMed2004

Primary total hip arthroplasty using a modular proximally coated prosthesis in patients older than 70: two to eight year results.

Patients older than 70 years who underwent primary total hip arthroplasty using a modular proximally porous-coated femoral stem with an ingrowth hemispherical acetabular component were evaluated. This included 135 hips in 122 patients, with an average 5-year follow-up period. This study included 96 patients (107 hips) still living; 26 patients (28 hips) patients had died, and 8 patients were lost to follow up. In this study, 93% of patients had little or no pain, and 95% were extremely or very satisfied with the operation. Mean Harris Hip score was 83, with a Short Form-36 (SF-36) physical component and mental component summary score of 41 and 51, respectively. Osteolysis surrounding the femur was seen in 8 hips (7%) and around the acetabulum in 6 hips (5%). No components were loose or required revision.

Aged↗