Use of an alumina ceramic-on-alumina ceramic bearing surface in THA in a 13 year old with JIA--a single case study.

Total hip arthroplasty (THA) has been shown to be highly effective in ameliorating pain and increasing function in adults with end stage arthritis of the hip. Early studies of cemented THA in children with advanced hip disease reported poor results, but, more recently, results of cementless THA show greatly improved outcomes. More recently, concerns related to THA in children have focused on wear of the bearing surfaces, which may result in periprosthetic bone loss and eventual loosening of the prosthetic components. This case report describes the use of an alumina ceramic-on-alumina ceramic bearing surface in THA in a 13-year-old female with bilateral end-stage arthritis of the hips. At 7 and 8 years post-THA, the patient has no pain, no limp, and is able to walk long distances without difficulty. Radiographs show no signs of implant loosening, osteolysis, or wear of the bearing surface.

Fractures and amputations in children and adolescents requiring hospitalization after farm equipment injuries.

BACKGROUND: The majority of farm-related injuries in children are caused by farm machinery. The aim of this study is to report the incidence of children requiring hospitalization for orthopaedic trauma after injury secondary to farm equipment accidents. METHODS: Data for this study were culled from the Kids' Inpatient Database for the years 2000, 2003, and 2006 using the E-code for injuries caused by agricultural machinery to identify the study group. Only those children with fractures (nonskull) and/or amputations were included for analysis. RESULTS: The 3-year study data include 292 children, 88% male, with an average age of 11.9 years. Of the 439 orthopaedic injuries, there were 115 upper extremity, 173 lower extremity, and 96 vertebral, rib, or pelvic fractures, and 55 amputations (34 upper and 21 lower extremity). There were proportionally more closed fractures of the upper extremity in children under the age of 12 years compared with the older children with no difference in rates of other fractures or amputation by age group. CONCLUSIONS: This study provides data on incidence of significant orthopaedic trauma in children in the United States as a result of farm equipment accidents. Most earlier studies have focused on fatality rates or have been limited to a single institution or single state or have been from a non-US population. This study provides pediatric orthopaedists, particularly those practicing in agricultural areas, with injury statistics related to farm equipment injuries that may lead to more and better safety education programs.

Late remodeling around a proximally HA-coated tapered titanium femoral component.

UNLABELLED: Most bone remodeling is thought to occur within the first few years after THA. Loss of bone density later may be associated with stress shielding or normal bone loss of aging. We evaluated remodeling changes over time with a proximally hydroxyapatite-coated tapered titanium stem. We evaluated plain radiographs of 143 hips for cancellous condensation, cortical hypertrophy, cortical porosis, cortical index, and canal fill at early postoperative, 5, 10, and 15 years. Average age was 51 years at THA; 69 patients (77 hips) (53%) were women; and 102 hips (71%) had primary osteoarthrosis. Based on radiographic findings at 15 years, hips were divided into three subgroups: 43 (30%) demonstrated minimal remodeling changes; 53 (37%) demonstrated cortical hypertrophy evident before 5 years; and 47 (33%) demonstrated additional late remodeling and cortical porosis, most often after 10 years. Hips with poorer bone (Dorr Types B or C) and, when including only hips with osteoarthrosis, more female hips had cortical porosis at 15 years. Late radiographic changes in patients with porosis appear more similar to that associated with an extensively rather than proximally coated stem. Whether continued bone adaptation and bone loss of aging will eventually threaten implant stability is unknown, but at 15 years, all 143 implants remained well fixed and clinically asymptomatic. LEVEL OF EVIDENCE: Level III, retrospective study. See the Guidelines for Authors for a complete description of levels of evidence.

Ceramic-on-ceramic total hip arthroplasty: update.

This prospective, randomized, multicenter study of alumina ceramic-on-alumina ceramic bearing couples includes 452 patients (475 hips). Their average age was 53 years with approximately two thirds men and 82% with osteoarthritis. At an average 8-year follow-up, clinical results were excellent and cortical erosions significantly less than in the conventional polyethylene-on-metal bearing group. Nine hips have undergone revision of one or both components for any reason. Of the 380 ceramic liners, 2 (0.5%) have fractured requiring reoperation, and 3 (0.8%) ceramic patients reported a transient squeaking sound, one of which had a head and liner change due to groin pain secondary to psoas tendinitis at 5 years. With no revisions for aseptic loosening and minimal cortical erosions, alumina-ceramic bearing couples are performing in a manner superior to the polyethylene-on-metal bearing in this young, active patient population.

Emergency department visits secondary to amusement ride injuries in children.

BACKGROUND: Amusement rides are located not only in large amusement parks but also at local fairs and carnivals, in shopping malls, and at schools, and are even rented for private use. Millions of children in the United States participate in amusement rides annually. The amusement park industry has a vested interest in the safety of its equipment, and indeed, reports of severe injury or death are rare compared to the huge number of rides per year. Nonetheless, injuries severe enough to require an emergency department (ED) visit occur, and this study aims to quantify and describe those injuries in children. METHODS: The code for amusement rides was used to cull data for children age 18 years and younger from the National Electronic Injury Surveillance System database, part of the US Consumer Product Safety Commission. This database includes a probability sample of hospital EDs in the United States from which national estimates can be calculated. Incidences of musculoskeletal injuries (fractures, dislocations, and sprains/strains) by age group as well as demographic variables were examined. RESULTS: Extrapolated numbers indicate that approximately 9200 children are treated annually in a hospital-based ED secondary to an amusement ride injury. Average age is 8.5 years, with both sexes evenly represented. The vast majority of children (95%) are treated and released. Ninety percent of fractures and 81% of dislocations occurred in aged younger children (2-12 years), whereas sprains/strains were the most frequent musculoskeletal injury in adolescents. Fractures of the upper extremity are more prevalent than of the lower extremity, and the majority of fractures occur distal to the elbow or knee. CONCLUSIONS: Catastrophic injury and death are rare secondary to amusement ride injuries, although those reports often make headline news. Less severe injuries are also uncommon; however, such injuries do occur, and there are little data describing the incidence or patterns of these injuries in children. This study, despite many limitations of the available data, provides the pediatric orthopaedic surgeon with information, which may, in turn, assist in continued advocacy efforts for safety within the amusement ride industry. LEVEL OF EVIDENCE: Level IV.

Long-term outcome of surface replacement with comparison to an age- and time-matched primary total hip arthroplasty cohort.

Surface replacement (SR) was introduced as a bone-conserving alternative to total hip arthroplasty (THA) 3 decades ago, then was abandoned due to polyethylene wear, stress shielding, and loosening. Improved bearing surfaces have renewed interest in SR. This study examined long-term SR outcome compared to an age- and time-matched THA cohort. Average age was 47 years at index procedure with 16 years follow-up (range, 5-28). Revision rates were 86% and 40% in SR and THA groups, respectively. However, at 20 years, with an end point of either intact SR or primary THA in the SR group, survivorship was 64% +/- 6% versus 39% +/- 7% unrevised in THA cohort. Contemporary and rapidly changing technology may result in longer-term SR success and improved THA longevity in young patients.

Trochanteric excision following persistent nonunion of the greater trochanter.

Trochanteric nonunion associated with total hip arthroplasty (THA) may result from 1 of 3 situations: 1) isolated fracture of the greater trochanter; 2) complication of trochanteric osteotomy; or 3) fracture secondary to cystic formation or osteolysis from wear debris post-THA. Isolated fracture of the greater trochanter can occur during primary or revision THA or as a result of trauma in the post-THA patient. It is estimated that approximately 5% of intraoperative femoral fractures involve just the greater trochanter. Perhaps the most common case is subsequent to trochanteric osteotomy. Although trochanteric osteotomy is more often used in revision THA, it may be used in primary THA where there is severe femoral deformity, developmental dysplasia of the hip, or in cases where previous intraosseous hardware is removed. Finally, trochanteric nonunion may be seen in subsequent to late fracture through an osteolytic lesion of the greater trochanter. Regardless of the etiology, nonunion of the greater trochanter can result in significant pain, Trendelenberg gait, and functional limitations, and additional surgery to reattach the trochanter may be required. Reattachment may be accomplished using various techniques, including abductor slide, trochanteric claw plate, Dalls-Miles cable grip system, and various wiring techniques. The nonunion rate following trochanteric osteotomy ranges up to 6%, and persistent nonunion following reattachment ranges up to 39%.

Primary osteoarthritis of the elbow: lack of radiographic evidence for morphologic predisposition, results of operative debridement at intermediate follow-up, and basis for a new radiographic classification system.

This study evaluated whether or not a morphologic predisposition exists to the development of primary osteoarthritis and establishes a classification tool to predict outcome in surgical treatment of elbow osteoarthritis. Detailed radiographic morphologic analysis of the ulnotrochlear and radio-capitellar joints in 90 normal and 24 osteoarthritic elbows showed few differences. Based upon commonly demonstrated radiographic features of degenerative changes, joint space narrowing, and marginal osteophytes, a classification system for rating the severity of primary osteoarthritis of the elbow was developed and applied retrospectively classified the preoperative radiographs of 18 patients (21 elbows) who had undergone elbow debridement and capsular release through a lateral collateral ligament preserving approach. Clinical and radiographic outcomes were assessed at an average 65 months postoperative. Total elbow motion and Mayo elbow performance scores were best in those who had been classified as class I preoperatively and worst in those in class III. This newly developed radiographic classification system is a useful tool in predicting surgical outcome following debridement of primary elbow osteoarthritis.

Orthopaedic injuries in children with nonaccidental trauma: demographics and incidence from the 2000 kids' inpatient database.

The purpose of this study was to examine the demographic and injury characteristics of children hospitalized with nonaccidental trauma as a causative factor using a large national database. Of the nearly 2.5 million cases in the database, 1794 (0.1%) were identified through diagnostic coding of abuse. Both sexes were equally represented, and two thirds had Medicaid as their primary payer. About one half of the children were younger than 1 year, but all ages were represented. The most common orthopaedic injuries were fractures of the femur or humerus, and most of those fractures occurred in children younger than 2 years. The most common nonorthopaedic injuries were contusions and brain injuries, with or without skull fracture, and 62 (3.5%) of the abused children died; almost all deaths were associated with brain trauma. Nearly one half of the abused hospitalized children between the ages of 3 and 20 years had a concomitant psychiatric or neurological condition. These data provide the orthopaedic surgeon with additional information to assist in identification of potential cases of nonaccidental trauma. In addition to presence of long bone fractures in infants and toddlers, older children with concomitant psychiatric or neurological conditions presenting with nonaccidental injuries should be assessed for possible abuse.

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.

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.

Epidemiology and mechanisms of femur fractures in children.

The most common pediatric orthopaedic injury requiring hospitalization is a femur fracture. This study aimed to identify the epidemiology and mechanisms of injury so that these injuries might be reduced through specifically targeted safety measures. Data for this study were culled from the 2000 Kids' Inpatient Database representing over 2.5 million pediatric hospital discharges. Of the nearly 10,000 femur fractures, 1076 (11%) occurred in children younger than 2 years; 2119 (21%) in children aged 2 to 5 years; 3237 (33%) in children aged 6 to 12 years; and 3528 (35%) in adolescents aged 13 to 18 years. The most (71%) occurred in male patients. Falls and motor vehicle collisions accounted for two thirds of those injuries, with the incidence of falls greater in the younger children and motor vehicle collisions more prevalent in older children. Fifteen percent of femoral fractures in children younger than 2 years were because of child abuse. Length of hospital stay, number of diagnoses and procedures, and hospital charges were greatest in the adolescent age group, likely because of high-energy trauma with resultant polytrauma. Hospital charges were more than 222 million dollars with the average charge over 2.5 times that in adolescents compared with infants/toddlers. Pediatric orthopaedists must continue to press for increased safety for our children, particularly adolescent motor vehicle safety. Abuse should be considered when a child younger than 2 years presents with a femoral fracture.

Orthopaedic implants in children: survey results regarding routine removal by the pediatric and nonpediatric specialists.

The role of orthopaedic implant removal in children is controversial. Some children later require adult reconstruction; implant removal may be difficult or may adversely affect the outcome. The purpose of this study is to compare the opinions of the pediatric and nonpediatric specialists regarding routine implant removal in children. Participants were asked to complete a Web-based questionnaire containing demographics, general opinions, and a series of specific case scenarios related to implant removal/retention. The study group consisted of 273 pediatric, and 99 nonpediatric specialists, with an average of 17-year experience. Regarding asymptomatic, stainless steel implants in children, 41% indicated removal most or all of the time, 36% reported sometimes, and the remaining 22% reported almost never or never. Implant location was the only important factor in the decision to remove or retain the implant. A greater percentage of pediatric specialists endorsed implant retention in the hip or pelvis in older children compared with nonpediatric specialists. More experienced surgeons, regardless of specialty area, recommended implant removal. Pediatric specialists may wish to reconsider their preference to retain large hip implants in older children because their nonpediatric colleagues, who presumably are faced with the removal from these children when they reach adulthood, recommend implant removal once they have served their purpose. The number of such cases and the role of early removal in improving the long-term outcome need further study.

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.

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.

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.

Septic arthritis of the ankle due to Salmonella enteritidis: a case report.

Salmonella septic arthritis in healthy individuals is a rare phenomenon in the United States. This case report chronicles the clinical course of a 41-year-old male farmworker who presented with a 3-week history of fever, chills, night sweats with pain, and swelling and redness of his left ankle. He had an open fracture of the ankle 2 years earlier that healed and was asymptomatic despite prior radiographic evidence of avascular necrosis of the talar dome. One month before presentation, he had an ipsilateral periungual abscess of the great toe that he opened and drained himself. Joint cultures were positive for Salmonella enteritidis that was successfully treated with a 6-week course of i.v. ceftriaxone.

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.

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.