Pregnancy and childbirth after total hip arthroplasty.

We surveyed 343 young women with 420 total hip arthroplasties (THAs) regarding pregnancy and childbirth after THA. The mean age at surgery was 35 years (18 to 45). The mean length of follow-up after the initial arthroplasty was 16 years (6 to 27). Of these 343 women, 47 (13.7%) had a successful pregnancy after their primary THA. The first baby after a THA was delivered vaginally in 30 patients and by Caesarean section in 17. Of the 343 patients, 138 underwent a revision. For the entire series, the risk of revision at five years was 5%, at ten years 24%, and at 20 years 50%. After adjusting for age at surgical intervention, the risk of revision was not significantly associated with childbirth. Of the 47 patients who had a successful pregnancy, 28 (60%) noted an increase in pain in the hip during pregnancy and ten of these patients had persistent pain after their pregnancy. Seven patients complained of pain in the groin in the replaced hip after childbirth. At the time of this survey, five of these patients (70%) had had revision THA. Childbirth is not affected by the presence of a THA. Pregnancy after THA is not associated with decreased survival of the prosthesis. Pain in the hip is common during pregnancy in these patients. Pain in the groin which persists after delivery commonly leads to revision of the THA.

Primary uncemented total hip arthroplasty in patients <40 years old: 10- to 14-year results using first-generation proximally porous-coated implants.

Eighty-two consecutive primary first-generation uncemented total hip arthroplasties (72 patients) performed in patients <40 years old were reviewed with minimum follow-up of 10 years. Of 82 hips, 24 (29.3%) have been revised to date. The estimated survival free of aseptic revision or radiographic failure was 81.3% at 10 years for the acetabular components. The estimated survival free of aseptic revision or radiographic failure was 84.9% at 10 years for the femoral component. In this exclusively young patient cohort, there was a high failure rate of the acetabular component and the femoral component. The data in this report can serve as a baseline for comparison of newer implants and operative methods.

Uncemented acetabular components with bulk femoral head autograft for acetabular reconstruction in developmental dysplasia of the hip: results at five to twelve years.

BACKGROUND: Anterolateral acetabular bone deficiency is one of the technical problems associated with total hip arthroplasty in patients with developmental hip dysplasia. The purpose of this study was to evaluate the results of one method of acetabular reconstruction for hip dysplasia-placement of an uncemented socket in conjunction with a bulk femoral head autograft. METHODS: Forty-four hips in thirty-five patients (twenty-nine female and six male; average age, thirty-nine years) with developmental hip dysplasia were treated with primary total hip arthroplasty with use of an uncemented porous-coated titanium cup fixed with screws and an autogenous bulk femoral head graft. The patients were followed clinically in a prospective fashion for five to 12.3 years (mean, 7.5 years), and radiographs were analyzed retrospectively. RESULTS: Four acetabular components were revised: two, because of severe polyethylene wear and osteolysis; one, because of aseptic loosening; and one, because of fracture of the acetabular shell. The mean Harris hip score for the unrevised hips improved from 51 points preoperatively to 91 points postoperatively. No unrevised socket had definite radiographic evidence of loosening. Forty-three of the forty-four hips had no radiographic evidence of resorption of the graft or had radiographic evidence of resorption limited to the nonstressed area of the graft lateral to the edge of the cup. CONCLUSIONS: This method of reconstruction provided reliable acetabular fixation and appeared to restore acetabular bone stock in patients with developmental hip dysplasia. We use this technique for patients with moderate anterolateral acetabular bone deficiency requiring total hip arthroplasty.

Total knee arthroplasty for chronic posterior knee dislocation: report of 2 cases with technical considerations.

This article reports our experience in 2 patients with chronic knee dislocations treated with total knee arthroplasty, focusing on the technical difficulties in obtaining a well-balanced, well-aligned knee.

Revisión del componente femoral en la artroplastia total de cadera / Revision of the femoral component of total hip arthroplasty

La revisión con éxito del componente femoral en la artroplastia total de cadera requiere indentificar el mecanismo de fracaso de la reconstrucción previa, indicar acertadamente la técnica quirúrgica idónea para cada paciente, ejecutar cuidadosamente los diferentes pasos del procedimiento y proteger adecuadamente la reconstrucción en el postoperatorio. La reconstrucción con vástagos de fijación distal es idónea en pacientes con hueso cortical de adecuada calidad y grosor. Si el canal medular está ensanchado significativamente y las corticales son delgadas, resulta de elección la técnica de aloinjerto compactado. El uso de vástagos cementados se reserva fundamentalmente para pacientes con edad avanzada y baja demanda funcional y reimplantes tras infecciones. Defectos segmentarios masivos pueden requerir la utilización de compuestos aloinjerto-prótesis. Los componentes modulares de fijación metafisodiafisaria pueden ser útiles en presencia de deformidades significativas. La revisión con vástagos de fijación exclusivamente metafisaria proporciona malos resultados y debe ser evitada. Actualmente se puede conseguir una tasa elevada de resultados satisfactorios en la cirugía de revisión del componente femoral siempre que se realice una adecuada selección y ejecución de la reconstrucción femoral (AU)

Possible guidelines for autologous red blood cell donations before total hip arthroplasty based on the surgical blood order equation.

OBJECTIVES: To determine, in patients undergoing total hip arthroplasty (THA), clinical predictive criteria for preoperative autologous blood donation and to propose guidelines to increase the efficiency and reduce the cost of preoperative autologous blood donation. PATIENTS AND METHODS: In this retrospective analysis of 165 adult patients undergoing primary THA, a stepwise regression analysis was used to determine which clinical variables predict erythropoiesis in patients donating autologous blood before THA. The surgical blood order equation (SBOE), which includes values for hemoglobin lost at surgery, preoperative hemoglobin level, and minimal acceptable hemoglobin level, was used to estimate the number of units of red blood cells (RBCs) needed for each patient at surgery and thus identify which patients should have made preoperative autologous blood donations. RESULTS: The statistically significant indicators for RBC production were predonation hemoglobin concentration (P<.001) and male sex (P=.003). Combining the regression equation for erythropoiesis with the SBOE allowed development of guidelines for the use of preoperative autologous RBC donation and erythropoietic therapy. For primary THA surgery, a patient with a predonation hemoglobin level higher than 14.7 g/dL does not need preoperative autologous donation. Preoperative autologous RBC donation would be effective for men with hemoglobin concentrations of 14.7 g/dL or less and for women with predonation hemoglobin levels of 13.2 to 14.7 g/dL. In women whose hemoglobin level is less than 13.2 g/dL, erythropoietic therapy should accompany autologous donation. CONCLUSION: Incorporation of patient factors with the SBOE system may result in increased efficiency and decreased cost of autologous blood ordering practices before THA.

Pelvic discontinuity in revision total hip arthroplasty.

BACKGROUND: Pelvic discontinuity is a distinct form of bone loss, occurring in association with total hip arthroplasty, in which the superior aspect of the pelvis is separated from the inferior aspect because of bone loss or a fracture through the acetabulum. The purpose of this study was to describe the population of patients who are at risk for this condition, to identify the characteristic radiographic features associated with it, and to report the results of revision total hip arthroplasty for the treatment of pelvic discontinuity. METHODS: The cases of all twenty-seven patients (thirty-one hips) who were identified as having a pelvic discontinuity at the time of a reoperation for a failed hip arthroplasty at one institution were reviewed retrospectively, and demographic information was collected. The preoperative radiographs and the operative notes were reviewed, and the postoperative results and complications were recorded. RESULTS: Pelvic discontinuity was identified in association with thirty-one (0.9 percent) of 3505 acetabular revisions. The mean age of the patients was sixty-one years (range, thirty-eight to eighty years). Twenty-eight hips were in women, and three were in men. Women (p < 0.001) and patients who had rheumatoid arthritis (p = 0.003) had a significantly increased risk of pelvic discontinuity. The radiographic findings included a visible fracture line through the anterior and posterior columns, medial translation of the inferior aspect of the hemipelvis relative to the superior aspect (seen as a break in Kohler's line), and rotation of the inferior aspect of the hemipelvis relative to the superior aspect (seen as asymmetry of the obturator rings) on a true anteroposterior radiograph. Two patients died within two years after the revision, and two had a resection arthroplasty for the treatment of the pelvic discontinuity; thus, twenty-seven hips were reconstructed and were eligible for follow-up at least two years after the operation. A number of different methods were used for reconstruction, but the results were best in patients who did not have severe segmental acetabular bone loss (type IVa [a satisfactory result in three of three hips]) and poorer in those who had severe segmental or combined segmental and cavitary bone loss (type IVb [a satisfactory result in ten of nineteen hips]) and in those who previously had been treated with irradiation to the pelvis (type IVc [a satisfactory result in three of five hips]). Nine of the twenty-seven hips needed another operation: four, because of aseptic loosening of the acetabular component; four, because of recurrent dislocation; and one, because of deep infection. Excluding three hips that were revised early because of infection or dislocation, a mechanically stable construct (that is, a stable socket and a possibly or definitely healed discontinuity) was obtained in seventeen of twenty-four hips. CONCLUSIONS: Pelvic discontinuity is uncommon, and treatment is associated with a high rate of complications. For hips with type-IVa bone loss and selected hips with type-IVb defects, in which a socket inserted without cement can be satisfactorily supported by native bone, we prefer to use a posterior column plate to stabilize the pelvis and a porous-coated socket inserted without cement. For most hips with type-IVb and type-IVc bone loss, we prefer to use particulate bone graft or a single structural bone graft protected with an antiprotrusion cage.

Biomechanics of total hip arthroplasty.

The biomechanics of the hip joint provide an understanding of the development, evolution, and treatment of many disabling conditions of this joint. The available methods of biomechanical analysis include in vitro studies, in vivo studies, and theoretical mathematic analyses. The information obtained from these analyses have enabled the design of therapeutic programs to alleviate the symptoms of, and possibly delay the progression of, hip disease. The design of surgical procedures has been based on alterations of the biomechanics of the hip. These procedures have proven useful for treating pathologies such as osteoarthritis, hip dysplasia, and hip fractures. The study of biomechanics and biomaterials are integral to the current success of total hip arthroplasty in achieving pain relief and functional restoration.

Early experience and results with the periacetabular osteotomy. The Mayo Clinic experience.

The purpose of the present study was to review the early results of periacetabular osteotomy in the initial group of patients undergoing this procedure at the authors' institution. The first 21 hips in 19 patients with greater than 2 years followup, which represents the learning curve with this operation, were reviewed retrospectively. There were 14 females and five males with an average age of 21 years (range, 17-43 years). Intertrochanteric osteotomy was performed simultaneously on four patients with coxa valga and inadequate correction with periacetabular osteotomy alone. At an average of 38 months of followup (range, 24-52 months), the Mayo hip scores improved from an average of 46 points (range, 34-58 points) to an average of 68 points (range, 42-80 points). Hip range of motion declined slightly in all three arcs of motion. The lateral center edge angle of Wiberg improved from an average of 2 degrees to an average of 24 degrees. The loading zone angle (Tönnis) improved from an average of 24 degrees to an average of 11 degrees. The anterior center edge angle of Lequesne improved from an average of -6 degrees to an average of 38 degrees. Complications included two peroneal palsies, both of which resolved completely; three ischial fractures that healed uneventfully; three asymptomatic pubic nonunions; and asymptomatic heterotopic ossification in five patients. One patient underwent subsequent total hip arthroplasty for progressive arthritis and pain. Another patient required intertrochanteric osteotomy at a later date. The early results in this initial group of patients treated with periacetabular osteotomy show reliable radiographic correction of deformity and improved function with an acceptable complication rate. Patients should be counseled carefully about possible loss of motion postoperatively. Additional study is necessary to assess the long term results of this procedure.

Total hip arthroplasty in patients with cerebral palsy.

The records of 16 patients (16 hips) with cerebral palsy who underwent total hip arthroplasty were reviewed. There were no dislocations, and other complications were rare. Pain relief was good to excellent in 87%. Function, as assessed by ambulatory status, was improved in 79%. Reasonable longevity of the implants can be expected even in patients <50 years. Total hip arthroplasty is a valuable option for the cerebral palsy patient with incapacitating hip pain.

Total hip arthroplasty for osteonecrosis: matched-pair analysis of 188 hips with long-term follow-up.

A matched comparison was made between total hip arthroplasties done for osteonecrosis and those done for osteoarthritis. Patients were matched for age, sex, surgical approach, prosthesis, and surgeon. All received cemented Charnley replacements and had minimal follow-up of 10 years. There were 118 women and 70 men with a mean age of 58 years. Thirty-five patients were younger than 50. The mean follow-up was 17.8 years (range, 10 to 25.4 years). Revision rates for osteonecrosis and osteoarthritis were 18% and 19% (not significant). The mechanical failure rate (revision for loosening plus radiographic loosening) was greater, but not significantly so, in the osteonecrosis group. In patients younger than 50 years, the revision rate in osteonecrosis (50%) was significantly higher than that in any other group. Similarly, the mechanical failure rate in osteonecrosis was significantly greater in the patients younger than 50. Radiographic femoral loosening was greater in osteonecrosis at all follow-up intervals, and dislocations occurred more frequently in the osteonecrosis group than in the osteoarthritis group. Results of arthroplasty in both groups were comparable in patients over 50 years of age, although patients with osteonecrosis had an increased rate of dislocation. Patients with osteonecrosis who are younger than 50 years have a significantly higher rate of mechanical failure than those with osteoarthritis who are younger than 50 years. Cemented total hip arthroplasty should be recommended in this group with caution if at all.

A prospective randomized trial of the surgical blood order equation for ordering red cells for total hip arthroplasty patients.

BACKGROUND: The majority of crossmatched blood is for surgical patients, and most of it is never transfused. An alternative system for ordering red cell (RBC) units, called the surgical blood order equation (SBOE), which incorporates specific patient variables for surgical patients, has been developed. STUDY DESIGN AND METHODS: A prospective double-blind randomized trial compared the SBOE with the maximal surgical blood order schedule (MSBOS) system for ordering allogeneic RBC units in 60 patients undergoing total hip arthroplasty. Autologous RBCs were available for none of the patients. RESULTS: There were no differences in patient demographic, surgical, or laboratory variables at any time. The median number (range) of allogeneic RBC units ordered was 2 (2-3) for the MSBOS and 0 (0-3) for the SBOE (p<0.0001). The SBOE ordered the correct number of RBC units for 58 percent of patients, while the MSBOS did so for 7 percent (p<0.0001). The SBOE had a lower crossmatch-to-transfusion ratio than the MSBOS (0.83 vs. 4.12). Costs were also lower with the SBOE. CONCLUSION: Incorporation of patient factors in the use of the SBOE system resulted in increased efficiency of blood-ordering practices for total hip arthroplasty.

Histologic and biochemical differences between osteolytic and nonosteolytic membranes around femoral components of an uncemented total hip arthroplasty.

The unique design characteristics of an uncemented femoral component were used to study differences in the periprosthetic membranes in the presence and absence of osteolysis. A component (Omniflex, Osteonics, Allendale, NJ) that has a large midportion of the stem that does not contact bone was studied. A membrane forms, even in the absence of bone resorption, in Gruen zones 3 and 5 of this component. Analysis of this membrane showed noninflammatory fibrous tissue, no or minimal particulate debris, and few macrophages. In contrast, analysis of membranes from osteolytic regions around the same prosthesis demonstrated typical inflammatory characteristics. Collagenase, gelatinase, and stromelysin expression was high in osteolytic membranes but was low in tissues from noninflammatory regions without osteolysis. The data suggest a sequence of events in periprosthetic membrane formation. A noninflammatory membrane initially forms between the bone and the prosthesis. This membrane is transformed into an inflammatory membrane by the influx of particulate debris. Matrix metalloproteinases are selectively expressed in regions of osteolysis, implicating these enzymes in periprosthetic bone loss and suggesting a possible level for pharmaceutical intervention to prevent or treat osteolysis. Formation of the noninflammatory membrane around the distal part of the prosthesis of this or similar designs in the absence of bone resorption implies that these tissue samples could serve as useful negative control tissues to identify factors present in osteolytic periprosthetic membranes.

Reconstruction rings and bone graft in total hip revision surgery.

This article deals with the design and indications of use of reconstruction rings and cages plus bone graft for acetabular revision. Details of the technique and the available results are presented and the advantages and disadvantages of current designs are discussed.