Consecutive Primary Total Hip Replacements Research Articles

Howse II cemented titanium metal-backed acetabular cups: poor 10-year results in 107 hips.

We report a retrospective clinical and radiographic review of 107 consecutive primary total hip replacements, using the cemented Howse II prosthesis. The review concentrates on the long-term performance of the acetabular cup, which was designed with a cylindrical titanium metal backing and a polyethylene liner. In all the hips in the series, this cup was used with a modular titanium straight femoral stem and a 32-mm diameter titanium head. At a mean follow-up of 9.8 (7-11) years, 28 hips had already been revised and 10 others were recognized as clinical or radiographic failures. The indication for revision in 26 of the hips was aseptic loosening and the mean time to revision was 7.2 (3.7-10.9) years This metal-backed cup has only 42% survival at 10 years, which seems to be related to certain of its design features. These include an inadequate thickness of polyethylene sterilized by gamma irradiation in air, a lack of mechanical bonding between the liner and its metal shell, and the high wear rate from the use of a 32-mm titanium femoral head.

Coding of diagnoses, comorbidities, and complications of total hip arthroplasty.

International Classification of Diseases coding of patient charts is used by hospitals to allow for billing of patients. Coding information also is used for assessing physician effectiveness. The purpose of the current study was to examine hospital coding for patients having total hip arthroplasty. One hundred consecutive primary total hip replacements were done at one medical center by two orthopaedic surgeons. Patient charts were coded by hospital coders according to the Health Care Finance Administration guidelines. Subsequently, an orthopaedist-based team did a secondary review of these charts and the two sets of codes were compared. The diagnostic codes were similar between the two groups for 87% (174 of 200 codes) of the cases. Comorbidities generally were undercoded by the hospital coders who reported 2.9 comorbidities per patient, whereas the secondary review reported 3.7 comorbidities per patient. The hospital coders found a complication rate of 1.2 per patient, whereas the secondary review revealed a rate of 0.4 per patient. Based on the results of the current study, the authors conclude that it is important to ensure three issues regarding the standard of coding and quality control: (1) the qualifications of the coders; (2) an interaction between coders and healthcare professionals to check that coding is accurate and reproducible; and (3) communication among various health professionals (including the primary surgeon) and coders to determine what actually are appropriate diagnoses, comorbidities, and complications.

Early dislocation after total hip arthroplasty

Background The average incidence of dislocation after total hip arthroplasty is approximately 3%. However, the choice of surgical approach can affect the rate of postoperative dislocation. A 5.8% dislocation rate has previously been reported when a posterolateral approach was used compaired with 2.3% when an anterolateral approach was used. The aim of this study was therefore to assess the dislocation rate after total hip replacement with the posterolateral approach.Methods: Between January 1992 and December 1998, a posterolateral approach was used for 427 consecutive primary total hip replacements. There were 291 women and 136 men. The average age of the women was 71 years (range 40–91 years) and the average age of the men was 65 years (range 34–86 years). The one-year dislocation rate was recorded.Results: A total of 24 hip replacements (6 in men and 18 in women) dislocated. The one-year dislocation rate was 6/136 = 4.4% for men and 18/291 = 6.2% for women. The overall one-year dislocation rate was therefore 24/427 = 5.6%. The average delay between the operation and the dislocation was 7 weeks (range 1 day to 1 year).

Poor results of the Freeman uncemented metal-backed acetabular component

We reviewed 120 consecutive primary total hip replacements in 109 patients in whom a Freeman uncemented metal-backed component had been used. Acetabular components were used with a Freeman neck-retaining stem in one of three configurations: cemented smooth stem, uncemented smooth stem or uncemented ridged stem. After a mean follow up of 72 months (62 to 113) there were nine cases of aseptic loosening; a survivorship at eight years of 83%. In addition, more than one-third of the remaining surviving cups showed loosening radiologically. The Freeman acetabular component demonstrated a characteristic pattern of loosening on radiographs. The high incidence of aseptic loosening can be explained by poor design and material failure.

Effect of circumferential plasma-spray porous coating on the rate of femoral osteolysis after total hip arthroplasty.

Osteolysis of the femur has been a serious problem associated with some designs of total hip-replacement implants; it frequently leads to failure of the femoral component. We evaluated the effect of a circumferential plasma-spray porous coating on the rate of osteolysis in a study that included two groups of hips, each of which received an implant with the same design except for the extent of the porous coating. Our goal was to determine the possible role of circumferential porous coating in protecting the bone-implant interface from osteolysis. A series of consecutive primary total hip replacements performed with insertion of the Mallory-Head implant without cement was divided into two study groups. The first 126 hips (Group 1) were treated with a femoral stem that had a noncircumferential plasma-spray porous titanium coating. The next ninety hips (Group 2) were treated with a circumferentially coated stem of the same design. The average duration of radiographic follow-up was 7.8 years in Group 1 and 7.5 years in Group 2. The average rate of polyethylene wear was similar for the two groups (0.187 millimeter per year in Group 1 and 0.189 millimeter per year in Group 2). The prevalence of osteolysis in Group 1 (40 percent; fifty of 126 hips) was significantly higher than that in Group 2 (10 percent; nine of ninety hips) (p < 0.001). Osteolysis remote from the joint space (distal to zones 1 and 7) was found in 11 percent (fourteen) of the hips in Group 1 but in none of those in Group 2 (p = 0.0004). The average total area of osteolysis in Group 1 (5.0 square centimeters) was significantly larger than that in Group 2 (2.9 square centimeters) (p < 0.05). A circumferential plasma-spray titanium porous coating on the femoral component of a total hip-replacement prosthesis inserted without cement appears to provide an effective barrier preventing wear debris from gaining access to the endosteal surface of the femur and the greater trochanter. This finding supports the hypothesis of the so-called effective joint space, which predicts that wear debris from the joint bearing can migrate, driven by intracapsular pressures, to all areas to which joint fluid has access and thus can result in osteolysis. The reduction of the prevalence of osteolysis and the elimination of osteolysis from the zones remote from the joint space by the use of a circumferential plasma-spray porous coating indicates that the femur was effectively sealed off from the joint space. We believe that the durability and longevity of the femoral component should be enhanced by the use of such a coating.

Survival analysis of the Harris-Galante I acetabular cup.

We reviewed 264 consecutive primary total hip replacements in 244 patients in which the Harris-Galante I porous-coated acetabular component had been used. The mean follow-up was 95 months (69 to 132). In 221 arthroplasties a 32 mm ceramic head had been used, and in the other 43 one of cobalt-chrome alloy. There were 124 women and 120 men with a mean age at operation of 56.8 years (21 to 83). Survival analysis of the acetabular components was performed using the following definitions of failure: 1) infection; 2) removal because of aseptic loosening; 3) removal for any cause; and 4) a worst-case analysis including removal of the cup or infection or loss to follow-up. Two well-fixed cups had been removed because of deep infection and three, similarly sound cups had been exchanged at the time of femoral revision. None of the acetabular components had required revision for aseptic loosening. After 11 years survival was 97.7% using the worst-case criterion. Radiological analysis of 187 acetabular components at a mean of 82 months (41 to 132) revealed no case of aseptic loosening. Pelvic osteolysis was seen in only one patient, but was not progressive and showed signs of regression. The results using these acetabular components are encouraging but the need for regular follow-up remains since complications such as significant wear of the liner, massive osteolysis of the pelvis, aseptic loosening and late infection may increase in the second decade.

Survival analysis of the Harris-Galante I acetabular cup

We reviewed 264 consecutive primary total hip replacements in 244 patients in which the Harris-Galante I porous-coated acetabular component had been used. The mean follow-up was 95 months (69 to 132). In 221 arthroplasties a 32 mm ceramic head had been used, and in the other 43 one of cobalt-chrome alloy. There were 124 women and 120 men with a mean age at operation of 56.8 years (21 to 83). Survival analysis of the acetabular components was performed using the following definitions of failure: 1) infection; 2) removal because of aseptic loosening; 3) removal for any cause; and 4) a worst-case analysis including removal of the cup or infection or loss to follow-up. Two well-fixed cups had been removed because of deep infection and three, similarly sound cups had been exchanged at the time of femoral revision. None of the acetabular components had required revision for aseptic loosening. After 11 years survival was 97.7% using the worst-case criterion. Radiological analysis of 187 acetabular components at a mean of 82 months (41 to 132) revealed no case of aseptic loosening. Pelvic osteolysis was seen in only one patient, but was not progressive and showed signs of regression. The results using these acetabular components are encouraging but the need for regular follow-up remains since complications such as significant wear of the liner, massive osteolysis of the pelvis, aseptic loosening and late infection may increase in the second decade.

Total hip replacements using the ceramic Mittelmeier prosthesis.

One hundred twelve consecutive primary total hip replacements were performed for osteoarthritis or osteonecrosis by a single surgeon using the Mittelmeier ceramic prosthesis without cement between January 1983 and July 1984. Ninety-three of these hips were followed prospectively to a minimum of 60 months and a median of 108 months. Five (5.4%) hips have been revised for loosening. Of the remaining hips, 77 (87.5%) were rated clinically satisfactory. Cumulative survival probability using revision as endpoint was estimated to be 92.7% at 5 years and 87.9% at 10 years. However, overall mechanical failure rates were 21.5% for the cup and 22.6% for the stem. There was no case of either femoral or acetabular osteolysis observed.

Incidence of heterotopic ossification after total hip replacement

The incidence and severity of heterotopic ossification after sixty-five consecutive primary uncemented total hip replacements were compared with those after seventy consecutive primary hybrid total hip replacements (consisting of an uncemented acetabular component and a cemented femoral component). All patients had had the arthroplasty because of osteoarthrosis. The sex distribution, prevalence of bilateral disease of the hip, and frequency of previous operations were similar in both groups. All of the operations were performed by one surgeon who used the same operative approach. Preoperative, immediate postoperative, and six-month follow-up radiographs were reviewed for all patients. For 90 per cent of the hips, radiographs that were made after a minimum follow-up of one year were also reviewed. In the group of patients who had an uncemented femoral component, there was a statistically significant increase in the frequency of heterotopic bone and in its severity. Either none or only class-I ectopic bone developed in 74 per cent of the hips in the hybrid group, compared with 40 per cent of the hips in the uncemented group (p less than 0.005). In contrast, class-III or IV heterotopic ossification was evident in 13 per cent of the hips in the uncemented group (p less than 0.005). None of the patients in the hybrid group needed reoperation for excision of ectopic bone, but four (6 per cent) of the patients in the uncemented group needed such a reoperation because of severe limitation of motion.(ABSTRACT TRUNCATED AT 250 WORDS)

Total hip replacement after medial-displacement osteotomy of the proximal part of the femur.

Intertrochanteric osteotomy has been recommended as an alternative to total hip replacement for the treatment of osteoarthrosis of the hip in younger patients because of the higher risk of mechanical loosening after total hip replacement in this age-group. The results of 112 consecutive cemented total hip replacements that were performed after a medial-displacement intertrochanteric osteotomy had failed (the conversion group) were compared with the results of 262 consecutive primary total hip replacements with cement (the control group). The mean length of follow-up was fifty-six months for the first group and fifty-four months for the second. The mean time between the osteotomy and the total hip replacement was six years. Two hundred and four Müller prostheses and 170 Lubinus hip prostheses were used. Pain was satisfactorily relieved in 89 per cent of the group that had a conversion and in 91 per cent of the control group. There were only minor differences in the range of motion of the hip and in walking performance between the two groups. The femoral component was more frequently in a varus position in the control group (p less than 0.05). The radiographic findings, including migration of the stem and radiolucency around the stem, were not inferior in the group that had a conversion. The rate of intraoperative fracture was significantly greater in the group that had a conversion, and it was correlated with the amount of displacement of the osteotomy. There were four failures (1.5 per cent) in the control group and one (0.9 per cent) in the group that had a conversion.(ABSTRACT TRUNCATED AT 250 WORDS)