Biomedical subjects

William N Capello

Publications and source records attributed to William N Capello.

At least 19 recordsLinked to original sources

PubMed2006

Impaction grafting for femoral component revision using a non-polished bead-blasted chrome cobalt stem-average 8 1/2-year follow-up.

Impaction grafting for femoral component revision in patients with significant bone loss has been reported using a tapered polished femoral component that is meant to subside. This study reports our results of femoral component revision using impaction grafting with a bead-blasted chrome cobalt stem designed not to subside. Forty-eight femoral component revisions using impaction grafting were retrospectively reviewed with a minimum 6 1/2-year follow-up. There were 2 failures due to aseptic loosening of the femoral component (4%). There were 22 total complications, and the overall failure rate was 21%. Impaction grafting for femoral component revision using a bead-blasted chrome cobalt stem in patients with a large femoral canal diameter has shown good results with respect to aseptic loosening with minimal subsidence.

Adult↗

PubMed2006

Multichannel CT Imaging of Orthopedic Hardware and Implants.

The introduction of multichannel CT scanners provides both radiologists and surgeons with a new tool to image patients with orthopedic hardware. The key parameters that have made it possible to image the implants and the surrounding bone with multichannel CT are the higher available technical factors (kVp and mAs) coupled with the ability to acquire thin slices over a large scan region. These properties make it possible to produce high-quality multiplanar reformations that facilitate visualization of the orthopedic device and the surrounding bone. An important consideration for multichannel CT imaging of hardware is the reduction of cone beam artifacts caused by the geometry of multichannel CT scanners. This artifact is reduced by using a narrower x-ray beam collimation and a low pitch setting. This article discusses CT scan parameters and image postprocessing used at our institution and illustrates common clinical problems encountered when imaging implanted orthopedic devices. These include fracture healing, loosening of joint prostheses, evaluation of particle disease, and the use of CT for preoperative planning in revision arthroplasty.

Equipment Failure↗

PubMed2006

The basis for a second-generation highly cross-linked UHMWPE.

Highly cross-linked ultra-high molecular weight polyethylene (UHMWPE) decreases wear at the hip by more than 50% compared with conventional UHMWPE. However, melted highly cross-linked polyethylene may be susceptible to fatigue cracking, and annealed highly cross-linked polyethylene may be susceptible to in vivo oxidation. The second-generation highly cross-linked UHMWPE (X3 HXPE) uses a sequential irradiation and annealing process. It preserves mechanical strength properties and has the highest survivorship in functional fatigue testing. The free radical content is low, and its performance under accelerated aging is the same as virgin UHMWPE. Hip simulator studies with 32-mm acetabular components demonstrated 97% wear reduction compared with conventional UHMWPE, and 62% compared with a clinically successful first-generation annealed highly cross-linked polyethylene. The crystallinity, density, and tensile strength of the X3 HXPE material was unchanged by oxidative challenge. X3 HXPE material articulating on cobalt-chromium alloy yields a volumetric wear rate very similar to that of metal-on-metal articulations, but eliminates the concerns of metal ion release. Wear particles generated from the X3 HXPE were the same size as those produced from conventional UHMWPE. Preliminary results suggest X3 HXPE can be used for cups larger than 36 mm.

Equipment Failure Analysis↗

PubMed2006

Hydroxyapatite-coated femoral components: 15-year minimum followup.

Hydroxyapatite-coated femoral components were introduced to enhance fixation, but concerns were raised about whether the coating would be maintained over time. We therefore determined the long-term clinical and radiographic results of a proximally hydroxyapatite-coated femoral component and compared the mechanical failure rate to other fixation methods at similar lengths of followup. The study group, culled from a large, multicenter prospective study population, consisted of 146 patients (166 hips) with followup of 15 to 18 years. Average age at time of the index procedure was 51 years, and the most common diagnoses were osteoarthritis (71%) and osteonecrosis (11%). Average Harris hip scores were 42.7 preoperatively and 91.5 at most recent followup. Radiographically, one stem showed stable fibrous fixation, and all other unrevised stems were bony stable. Of 13 stem revisions in the study population, only one stem has been revised for aseptic loosening. Forty-nine percent of hips have an osteolytic lesion in proximal areas of Gruen Zones 1, 7, 8, or 14 only. Both the femoral aseptic revision and mechanical failure rates are 0.6% at 15-year minimum followup. The data demonstrate excellent long-term survivorship of this hydroxyapatite-coated femoral component used in a relatively young patient group.

Adolescent↗

PubMed2005

Five-year experience with Crossfire highly cross-linked polyethylene.

UNLABELLED: Our purpose was to compare the clinical wear performance of highly cross-linked (Crossfire) polyethylene with conventional (N2Vac) polyethylene total hip bearings. We implanted 56 hips (47 patients) with Crossfire acetabular bearing liners and compared their wear performance with 53 conventional polyethylene inserts. Wear and clinical data were collected retrospectively at a minimum 4-year and average 5-year followup. The linear femoral head penetration rate measured from plain radiographs was 0.055 mm/year +/- 0.022 mm/year for the Crossfire polyethylene and 0.138 mm/year +/- 0.073 mm/year for the control, a reduction of 60% for the Crossfire components. Calculated annual wear was 0.036 mm/year for the Crossfire components and 0.131 mm/year for the controls, a reduction of 72%. Radiographic review at most recent followup showed a reduction in erosive osteolytic lesions of the proximal femur for the Crossfire components compared with controls, also suggesting a reduction in debris release for the Crossfire components. Complications leading to revision were not seen in the Crossfire or control groups. These clinical findings suggest that this particular highly cross-linked polyethylene can provide wear reduction and an alternate bearing surface for active patient populations. LEVEL OF EVIDENCE: Therapeutic study, Level III (retrospective comparative study). See the Guidelines for Authors for a complete description of levels of evidence.

Aged↗

PubMed2005

Arc-deposited hydroxyapatite-coated cups: results at four to seven years.

UNLABELLED: A second-generation arc-deposited hydroxyapatite-coated acetabular component was developed after detailed analysis of a failed first-generation grit-blasted hydroxyapatite-coated cup. In our prospective multicenter study we aimed to compare clinical results and survivorship of the newly designed cup to the previous cup and to a similarly designed porous-coated cup during the same time period. The effect of bearing surface-alumina-on-alumina to polyethylene-on-metal-was analyzed. Consecutive patients were assigned randomly to one of three groups: arc-deposited hydroxyapatite-coated cup with alumina-on-alumina bearing surface; porous-coated cup with alumina-on-alumina bearing surface; or porous-coated cup with polyethylene-on-metal bearing surface. A fourth comparison group with a grit-blasted hydroxyapatite-coated cup and polyethylene-on-metal bearing surface was culled from a previous study. Acetabular mechanical failure rate is 0.0%, 0.0%, 1.9%, and 11.2% for the arc-deposited hydroxyapatite-coated, porous-coated with alumina bearing surface, porous-coated with polyethylene-on-metal bearing, and grit-blasted hydroxyapatite-coated cup, respectively, at 4- to 7-years' followup. There are no cases of acetabular osteolysis or femoral neck scalloping and no radiolucent lines in any zone with the arc-deposited hydroxyapatite-coated cup. The cups with the alumina-on-alumina bearing surface had less scalloping of the femoral neck than those with a polyethylene-on-metal bearing surface. Early results with this second-generation arc-deposited hydroxyapatite-coated cup are promising. LEVEL OF EVIDENCE: Therapeutic study, Level I (high-quality randomized trial with statistically significant difference or no statistically significant difference but narrow confidence intervals). See the Guidelines for Authors for a complete description of levels of evidence.

Adult↗

PubMed2005

A titanium-encased alumina ceramic bearing for total hip arthroplasty: 3- to 5-year results.

UNLABELLED: We examined whether encasing the alumina ceramic total hip arthroplasty insert in a thin titanium sleeve would reduce significantly or eliminate insert chipping on impaction of the insert into the shell. We also compared results, including observations of osteolysis, of the Trident study group with those of the predecessor alumina bearing couple design to determine clinical improvement and radiographic stability. Beginning in October 1996, 328 alumina ceramic bearings were implanted by six surgeons in 316 patients as a part of a prospective, randomized United States Investigational Device Exemption three-arm study comparing an alumina ceramic bearing with a control bearing of cobalt-chromium on polyethylene. In September 1999, a fourth arm of the study (Trident) was added. The Trident insert was recessed within a thin titanium sleeve. At three to five years followup, osteolysis was found in 0% of the patients with the Trident insert and in 0.5% of the patients with an alumina bearing couple. At a mean followup of 4.2 years (range, 3-5 years) no ceramic chips, fractures, or ceramic bearing failures have occurred. Encasing the alumina ceramic insert in a titanium sleeve seems to have resolved the issue of insert chipping on impaction and supports the continued use of Trident bearings in relatively young patients. LEVEL OF EVIDENCE: Therapeutic study, Level II-1 (prospective comparative study-patients treated one way compared with a group of patients treated in another way at the same institution). See the Guidelines for Authors for a complete description of levels of evidence.

Aluminum Oxide↗

PubMed2005

Alternative bearing surfaces: alumina ceramic bearings for total hip arthroplasty.

Osteolysis resulting from polyethylene wear debris is one of the most common causes of implant failure in young, active individuals who undergo total hip arthroplasty. Reducing wear may help extend the life of the implant in these patients. Contemporary alumina ceramic/alumina ceramic bearing articulations are harder, scratch resistant, and more hydrophilic than other bearing couples, resulting in reduced wear and reduction of particle load to the surrounding tissue. Therefore, bearings made of alumina ceramic may be a preferable bearing choice for younger, more active patients. To investigate this hypothesis, 495 patients (514 hips), average age 53 years, were enrolled in a prospective, randomized, multicenter study comparing an alumina-on-alumina ceramic bearing to a cobalt-chromium-on-polyethylene bearing control. At an average of 4 years after implantation, no difference in clinical outcome was observed between groups. There were no fractures of the ceramic head or liner, nor were there any revisions caused by the ceramic liner. Another investigational group was added to the study 1 year after enrollment in the original study was closed. The same inclusion/exclusion criteria were used. A total of 194 consecutive patients (209 hips) received an alumina liner that included a thin metal backing designed to allow bearing replacement and ease surgical assembly. At an averagefollow-up of 30 months, no liner or head chips or fractures were observed in this group.

Aluminum Oxide↗

PubMed2005

Does smoking affect implant survivorship in total hip arthroplasty? A preliminary retrospective case series.

This retrospective study aimed to explore the effects of smoking on hip implant survivorship. The study included 147 patients (165 hips) from 1985 to 1991 who underwent total hip arthroplasty (THA) with a particular uncemented cup, and either a cemented or uncemented femoral component of the same design. Thirty-one patients (34 hips, 21 percent of study group) smoked at the time of surgery. Of 13 components (seven cups, five cemented and one cementless stem) revised for aseptic loosening, eight (8/68, 11.8 percent) were revised in six smokers, and five (5/262, 1.9 percent) were revised in four nonsmokers (p = 0.0012). Multivariate covariate analysis revealed a 4.5 times greater risk of implant loosening in smokers (p = 0.0662). Based on this preliminary study, further larger studies should be performed to determine the extent that smoking may contribute to THA survivorship.

Adult↗

PubMed2004

Use of a constrained tripolar acetabular liner to treat intraoperative instability and postoperative dislocation after total hip arthroplasty: a review of our experience.

Constrained acetabular components have been used to treat certain cases of intraoperative instability and postoperative dislocation after total hip arthroplasty. We report our experience with a tripolar constrained component used in these situations since 1988. The outcomes of the cases where this component was used were analyzed for component failure, component loosening, and osteolysis. At average 10-year followup, for cases treated for intraoperative instability (2 cases) or postoperative dislocation (4 cases), the component failure rate was 6% (6 of 101 hips in 5 patients). For cases where the constrained liner was cemented into a fixed cementless acetabular shell, the failure rate was 7% (2 of 31 hips in 2 patients) at 3.9-year average followup. Use of a constrained liner was not associated with an increased osteolysis or aseptic loosening rate. This tripolar constrained acetabular liner provided total hip arthroplasty construct stability in most cases in which it was used for intraoperative instability or postoperative dislocation.

Adult↗

PubMed2004

Salvage of a recurrently dislocating total hip prosthesis with use of a constrained acetabular component. A concise follow-up of a previous report.

We previously reported the results at a mean of five years following the use of a tripolar constrained acetabular component to treat recurrently dislocating total hip prostheses. In this study, we report the results after longer follow-up, with emphasis on the prevalence of implant loosening, osteolysis, and later recurrent instability. Fifty-five patients treated with a total of fifty-six constrained acetabular components because of recurrent dislocations of a total hip prosthesis (average, six dislocations; range, two to twenty dislocations) were followed for an average of 10.2 years (range, 7.0 to 13.2 years) or until death. Four (7%) of the fifty-six hips had a subsequent dislocation or failure of the device. Three femoral components (5%) and two acetabular components (4%) were revised because of aseptic loosening. One hip was revised because of osteolysis. We concluded that this constrained acetabular component provides durable protection against additional dislocations without substantial deleterious effects on component fixation. We use this device to treat recurrent dislocation when other modalities are unlikely to be effective.

Acetabulum↗

PubMed2003

Clinical outcome and incidence of pregnancy after bipolar and total hip arthroplasty in young women.

Female patients under 45 years of age (average, 32.5; range, 14-44) at the time of primary bipolar or total hip arthroplasty (THA) were surveyed an average 10.5 years (range, 1.7 to 20.3 years) after the index procedure. Most patients were satisfied with the pain relief and functional abilities. Of the 109 respondents (137 hips), 37 (34%) had undergone 50 additional hip procedures. Thirteen women (12%) had 19 children at an average of 3 years after hip arthroplasty. Seven women had 1 child each; 6 had 2 children; and 1 had dizygotic twins. Eleven infants were delivered vaginally and 8 by cesarean section (5 planned, 3 unplanned). Two pregnancies were considered high risk unrelated to the hip arthroplasty. Pregnancy-related complications for these patients did not differ from those in the general population.

Adolescent↗

PubMed2003

Use of constrained acetabular components for hip instability: an average 10-year follow-up study.

The short-term efficacy of using constrained acetabular components for hip instability in the total hip arthroplasty construct has been documented. However, long-term concerns including late dislocation, loosening of components, and osteolysis have not been addressed. The authors evaluated, at an average 10.3-year follow-up, 101 tripolar constrained components (Stryker Howmedica Osteonics) used in the total hip arthroplasty construct. At final follow-up, 6 hips had dislocated or had failure of the constrained component, 5 of which were revised. In addition, 4 hips were revised for aseptic loosening of the acetabular component, 4 hips were revised for aseptic femoral loosening, and 1 hip was revised for acetabular osteolysis. Considering the complexity of the cases, this component has provided durable fixation and hip stability at this intermediate-term follow-up.

Acetabulum↗

PubMed2003

A 10-year minimum follow-up of hydroxyapatite-coated threaded cups: clinical, radiographic and survivorship analyses with comparison to the literature.

We evaluated the clinical, radiographic, and survivorship outcomes in a series of 418 threaded hydroxyapatite-coated acetabular cups (Arc2f; Osteonics, Allendale, NJ) implanted in a consecutive series of 384 patients undergoing primary total hip arthroplasty. In all cases, the cup was screwed into the prepared acetabulum. Bone screws were used to provide secondary fixation. At a minimum 10-year follow-up, 304 cups were available for analysis. The cumulative survivorship (mechanical failure as endpoint) at that time was 99.43% +/- 0.0104. Two hundred seventy-six hips were available for full clinical and radiographic review at or after the tenth anniversary. No unstable implants were noted; all implant fixation interfaces were classified as "stable bone ingrown," and the cup migration rate was zero. Based on the survivorship achieved with this implant, our results compare favorably with survivorship reported for the best cemented and cementless acetabular implant designs.

Acetabulum↗

PubMed2003

Primary hybrid total hip arthroplasty with a roughened femoral stem: integrity of the stem-cement interface.

One hundred and two consecutive cemented femoral stems were evaluated in 92 patients at an average 9-year follow-up and a minimum 5-year follow-up (range, 5-14 years). The stem used was cobalt chromium with a collar, normalization steps, and a roughened surface (Ra 40); the stem was inserted using contemporary cementing techniques. This series demonstrated a femoral component aseptic loosening rate of 2.0% and a femoral component survivorship of 97.2 +/- 2.0% at 10 years. One of 2 failed stems was revised at 95 months for failure at the cement-bone interface. The second failed stem showed failure at the cement-bone interface with incomplete debonding radiographically at 65 months. The remaining femoral components did not demonstrate any evidence of debonding at the stem-cement interface. These results compare favorably with other series of cemented femoral stems, as well as with those with a polished surface.

Aged↗

PubMed2003

Elective primary total hip arthroplasty in octogenarians.

BACKGROUND: Total hip arthroplasty (THA) has resulted in decreased pain and increased function in people with end-stage hip arthritis for several decades. In elderly people, THA has been used most often following femoral neck fracture. However, with life spans increasing and people remaining healthy and active well into their eighties, arthroplasty surgeons are now performing primary THA as an elective procedure in octogenarians. The aim of this study was to demonstrate the efficacy of elective total hip arthroplasty in patients aged 80 years or older with end-stage hip arthritis. METHODS: Forty patients (46 THAs), aged 80 or older at the time of surgery, were identified for this study. Clinical assessment included amount of hip pain, limp, and use of assistive devices for ambulation at most recent follow-up. Radiographic assessment included implant stability, heterotopic bone formation, and osteolysis. Medical and hip-related complications, reoperations, and revisions were recorded from medical records. RESULTS: Eleven patients (27.5%) suffered a medical complication and six patients (15%) had a hip-related complication, all of which were treated and were not life threatening. Clinically, 80% were pain free and 70% walked without assistance at an average 4-year follow-up. Radiographically, all implants were stable without osteolysis. No components had been revised; however, four patients had undergone a reoperation, three for recurrent dislocation. CONCLUSIONS: Elective total hip arthroplasty is a safe and effective treatment for end-stage osteoarthritis of the hip in the elderly patient. However, the procedure is not without risk. Complications, often related to preexisting comorbidities, do occur, but mortality rates are low.

Aged↗

PubMed2003

Ten-year results with hydroxyapatite-coated total hip femoral components in patients less than fifty years old. A concise follow-up of a previous report.

We report the results of total hip arthroplasty with use of a proximally hydroxyapatite-coated femoral component after a minimum follow-up of ten years in a group of patients who were less than fifty years old at the time of the primary procedure. In the five years since the original publication of our study, two additional stems have undergone revision. Thus, a total of six stems have been revised. A small amount of erosive scalloping of the proximal part of the femur was seen in nearly one-half of the hips; however, all unrevised stems were radiographically stable and no hip had intramedullary osteolysis. The revision rate because of aseptic loosening of the stem was 0.9%, which compares favorably with that for other stems and other fixation methods in young patients at this point in time. This stem is currently being paired with a highly cross-linked polyethylene liner because of cup failures and the need for reoperation secondary to excessive polyethylene wear and proximal femoral osteolysis.

Adolescent↗

PubMed2002

Hydroxyapatite coated stems in younger and older patients with hip arthritis.

A primary aim of research in total hip arthroplasty is to extend longevity through improved fixation and decreased wear and osteolysis. Age range of patients receiving hip implants is ever increasing as technology improves and average life span increases. The current report focuses on minimum 10-year results of a proximally hydroxyapatite-coated stem in patients with degenerative joint disease, comparing those 45 years and older (n = 229 hips) with younger patients (n = 41 hips). Clinically, the average Harris hip score is 91 points and 88 points in the older and younger groups, respectively. Mechanical failure rates for the stem are 0.4% and 2.4%, with one stem revision for aseptic loosening and no radiographically loose stems in each age group. Proximal femoral osteolysis is seen more often in younger patients (48% versus 38%), and younger patients (six hip arthroplasties) had reoperation for wear or osteolysis. Therefore, this stem has performed well at a 10-year minimum followup. However, polyethylene wear and osteolysis have led the authors to begin a United States Food and Drug Administration study of an alumina ceramic-on-alumina ceramic bearing surface in conjunction with the same stem. At 2 years minimum followup, there have been no complications related to the ceramic bearing surfaces, no cortical erosions, and no stem revisions for aseptic loosening.

Age Factors↗