Long-term comparison of the Charnley, Muller, and trapezoidal-28 total hip prostheses: A survival analysis

Seven hundred ninety-one total hip arthroplasties (242 Charnley prostheses, 146 Muller prostheses, and 403 Trapezoidal-28) performed between 1969 and 1980 by one surgeon were evaluated using survival analysis to predict success and/or failure over time. Only 6.4% of the population was excluded because of failure to return for follow-up evaluation. All other patients were included in the analysis. It is expected that at 10 years after operation, 91% of the Charnley, 88% of the T-28, and 80% of the Muller prostheses will survive (P less than .05). The acetabular cup of the Muller prosthesis showed significant premature loosening, compared with the Charnley and T-28 prostheses (P less than .0001 and P less than .05, respectively). The Muller femoral stem was inferior only to the Charnley (P less than .025). The T-28 femoral stem showed no difference in success compared with the other two prostheses, despite 10 T-28 femoral stem fractures. Multivariate survivorship regression analysis revealed significant factors that may have predisposed the above failures. Women (P less than .0005) and older patients (P less than .0005) had significantly higher success rates. Significant intrinsic factors included radiolucency about the entire acetabular bone-cement interface (P less than .0005), fracture in the acetabular cement (P less than .005), and radiolucency about the entire femoral bone-cement interface (P less than .0005).     

The premature failure of the Charnley Elite-Plus stem: a confirmation of RSA predictions

We performed a clinical and radiological study to determine the rate of failure of the Charnley Elite-Plus femoral component. Our aim was to confirm or refute the predictions of a previous roentgen stereophotogrammetric analysis study in which 20% of the Charnley Elite-Plus stems had shown rapid posterior head migration. It was predicted that this device would have a high early rate of failure.We examined 118 patients at a mean of nine years after hip replacement, including the 19 patients from the original roentgen stereophotogrammetric study. The number of revision procedures was recorded and clinical and radiological examinations were performed.The rate of survival of the femoral stems at ten years was 83% when revision alone was considered to be a failure. It decreased to 59% when a radiologically loose stem was also considered to be a failure. All the patients previously shown in the roentgen stereophotogrammetric study to have high posterior head migration went on to failure. There was a highly significant difference (p = 0.002) in posterior head migration measured at two years after operation between failed and non-failed femoral stems, but there was no significant difference in subsidence between these two groups.Our study has shown that the Charnley Elite-Plus femoral component has an unacceptably high rate of failure. It confirms that early evaluation of new components is important and that roentgen stereophotogrammetric is a good tool for this. Our findings have also shown that rapid posterior head migration is predictive of premature loosening and a better predictor than subsidence.     

Polyethylene wear in total hip arthroplasty in patient-matched groups: A comparison of stainless steel,cobalt chrome,and titanium-bearing surfaces

Osteolysis and component loosening secondary to polyethylene (PE) debris are of paramount concern to today's joint replacement surgeon. This retrospective clinical study measures linear wear in 568 implanted total hip prostheses in which three different metals were used as bearing surfaces (307 stainless steel T-28 [Zimmer, Warsaw, IN], 162 cobalt chrome Tr-28 [Zimmer], and 99 nonion implanted titanium Miami Orthopedic Surgical Consultants [Biomet, Warsaw, IN] prostheses) implanted by a single surgeon over an 8-year period. The acetabular component in all cases was nonmetal-backed compression-molded PE, and all components were cemented. Linear wear was measured using the radiographic technique described by Livermore et al. (The effect of femoral head size on wear of the polyethylene acetabular component. J Bone Joint Surg 72A: 518, 1990) in which change in acetabular component thickness is determined from serial radiographs. A separate evaluation of this technique confirmed accuracy to within 0.18 mm. Radiographs were also evaluated for femoral and acetabular radiolucencies, femoral subsidence, and osteolysis. Patients were matched for sex, age, weight, and length of follow-up period to eliminate these retrospective variables for comparison of wear. The patient-matched groups consisted of 77 patients from each group (43 women, 34 men) with the following demographics: age, 66 years; weight, 158.9 lbs.; follow-up period, 7.9 years. Results revealed linear wear rates of 0.06 stainless steel, 0.05 cobalt chrome, and 0.08 titanium in the patientmatched groups. These differences were not significant based on analysis of variance (P>.05). Radiolucencies, osteolysis, and component subsidence did not correlate with rates of PE wear. This study is the first to evaluate PE wear with different bearing surfaces in a clinical series. Cobalt chrome produces the lowest amount of PE debris when used as a bearing surface. However, this was not significantly less than nonion implanted titanium.     

Radiographic performance of two different total hip cemented arthroplasties. A survivorship analysis

Detailed serial radiographic analysis of the femoral and acetabular components of 367 Charnley (cobalt-chrome alloy) and 383 STH (titanium alloy) primary cemented total hip prostheses was conducted. The follow-up of the Charnley prosthesis ranged from 1 to 16 years (mean follow-up, 9 years), and for the STH from 1 to 11 years (mean follow-up, 80 months). Both single period and survivorship analyses were done to evaluate the radiographic performance. The analysis revealed that the curved STH prostheses' overall radiographic performance was less satisfactory than the Charnley prostheses. However, the STH with a straight stem had significantly better radiographic performance compared with the Charnley prostheses in all parameters except in the incidence of bone-cement radiolucent lines.     

Radiographic analysis of a low-modulus titanium-alloy femoral total hip component. Two to six-year follow-up

We performed a detailed serial radiographic analysis of the femoral component of 323 cemented low-modulus titanium-alloy total hip prostheses. There was a low incidence of femoral component loosening as manifested by radiolucent zones at the stem-cement interface or cement fractures. There was also a low incidence of resorption of the calcar and cortical hypertrophy. Comparison of our data with those of others indicated that the incidence of loosening, calcar resorption, and cortical hypertrophy was usually lower than with similarly designed conventional high-modulus Charnley stems. These findings appear to support computer-modeling studies that have predicted a more even distribution of stresses along the entire length of the stem of the titanium-alloy prosthesis. Of the two configurations of femoral components used, the straight stems demonstrated a significantly lower incidence of radiographic evidence of loosening, calcar resorption, and cortical hypertrophy than the curved stems did. These findings have provided sufficient biomechanical rationale for the evolutionary development of the second-generation femoral components, which incorporate many features of the straight stem.     

Knee arthroplasty using a cementless PCA prosthesis with a porous-coated central tibial stem. Clinical and radiographic review at five years

In 44 consecutive patients, 60 porous-coated anatomic total knee (PCA) prostheses with a porous-coated central tibial stem were implanted without using cement. The clinical results and bony remodelling have been assessed after five years' follow-up. The average Hospital for Special Surgery knee score was 33.1 before operation and 95.7 at the latest follow-up, while the average range of movement improved from 63 degrees to 123 degrees. No subsidence or migration of the components was seen. A radiodense line appeared around the components at six months to one year after the operation and became more dense with time. There was no evidence of bone resorption related to stress-shielding in the tibial plateau.     

Revision of the femoral prosthesis with impaction allografting and a Charnley stem. A 2- to 12-year follow-up

Impacted morcellised bone allograft and a Charnley stem was used to revise 59 loose femoral components in 57 consecutive patients. Femoral bone loss was rated as Endo-Klinik grade 2 in nine patients, grade 3 in 41, and grade 4 in nine. The immediate postoperative radiographs and those taken at the most recent follow-up were compared for radiolucencies, subsidence and incorporation of the graft. One patient was lost to follow-up and two were not available for radiological analysis. The mean clinical follow-up in 58 procedures was 56.7 months (24 to 144) and the mean radiological review of 56 reconstructions was 54.4 months (24 to 144). An intraoperative femoral fracture occurred in one patient (1.7%) and was successfully treated by strut grafting and cerclage wiring. Extrusion of cement through perforations or incomplete hoop fractures was detected in the postoperative radiographs of ten procedures (17%); none of these patients sustained a complete fracture. Three patients had dislocations (5%) and two (3.5%) developed painful subsidence of the stem which required a further revision. The latest follow-up radiographs in 56 reconstructions showed a well fixed stem and radiological healing of the graft in 52 (93%), and definite loosening in four (7%). Of these four, two were revised again and two were asymptomatic after a follow-up of 120 months each. The mean subsidence in the 52 successful revisions was 0.38 mm (0 to 4). Impaction allografting with a Charnley stem restored bone stock and provided adequate fixation of the stem in 93% of the hips. There was a low rate of rerevision (3.5%) and a low incidence of intraoperative and postoperative complications.     

Femoral component loosening after total hip arthroplasty.

To determine the long-term durability of total hip arthroplasty and to identify factors responsible for femoral component loosening, 106 total hip arthroplasties were reviewed in patients with a minimum postoperative period of 3 years. Seventy-four had Charnley-Müller prostheses and 32 had Charnley prostheses. Femoral component loosening occurred in 16 of 106 hips. Not all loose components were symptomatic. The femoral component at risk was the femoral Charnley-Müller type that had been inserted in varus position in a functioning active heavy patient who previously had had a femoral head prosthesis.     

The Charnley versus the Spectron hip prosthesis: radiographic evaluation of a randomized, prospective study of 2 different hip implants.

A total of 410 hips were randomized to treatment with either a Charnley (206 hips) or a Spectron (204 hips) total hip arthroplasty. The patients were operated on by a standardized procedure using a contemporary cementing technique and were followed after 1, 3, 5 to 6, and 10 years. The postoperative radiographs showed a significantly increased rate of malalignment and consequently low grade of cement mantle quality of the Charnley stem compared to the Spectron. No differences concerning cement mantle quality or positioning were found between the Charnley ogee cup and the metal-backed Spectron. Evaluation of the follow-up radiographs revealed 10 loose Charnley stems and 1 loose Spectron stem and 4 loose Charnley ogee cups and 23 loose Spectron metal-backed cups. The differences of revision rate for the femoral and acetabular components of the 2 prostheses were significant (P = .03, Charnley femoral component more frequent; P = .03, Spectron acetabular component more frequent). The radiographic evaluation strengthened this disparity. Poor wear characteristics of the metal-backed Spectron cup are perhaps the main reason for the highly significant difference in mechanical failure rate between the 2 cups. We therefore propose that metal-backing of cemented cups should be avoided, at least when combined with larger femoral heads. The difficulty in positioning the Charnley stem with an adequate cement mantle, especially in the absence of trochanteric osteotomy, might explain the inferior Charnley stem longevity in this study.     

Charnley total hip arthroplasty with use of improved cementing techniques: a minimum twenty-year follow-up study.

BACKGROUND: In total hip arthroplasty, techniques for cementing the femoral component have changed over time. The purpose of the present study was to determine whether a cementing technique that includes use of a distal cement plug and retrograde filling of the femoral canal affects the fixation of the femoral component at a minimum of twenty years after the operation. METHODS: Between 1976 and 1978, the senior one of us (R.C.J.) performed 357 total hip arthroplasties with use of a Charnley flatback polished femoral stem and a contemporary cementing technique (insertion of a distal cement plug and retrograde filling of the femoral canal with cement) in 320 patients. The results after a minimum follow-up of twenty years were compared with those after 330 total hip arthroplasties performed, between 1970 and 1972, with the same femoral stem by the same surgeon with use of a hand-packing technique of cementing in 262 patients. The clinical and radiographic evaluation as well as the duration of follow-up were identical in the two groups. RESULTS: In the group managed with the contemporary cementing technique, six (1.8%) of the 336 hips that had not been lost to follow-up or revised because of infection or dislocation were revised because of aseptic loosening of the femoral component. Of the ninety-one hips in the eighty-two patients who were alive at a minimum of twenty years, five (5%) had a revision because of aseptic loosening of the femoral component. Only one hip was revised during the fifteen-to-twenty-year follow-up interval. (The revision was performed because of a fracture of the femoral component.) The rate of failure when radiographic signs of loosening were included was 4.8% (sixteen of 336 femoral components that had not been revised because of infection or dislocation) for the group managed with the contemporary cementing technique compared with 6.3% (twenty of 319 hips) in the group managed with the hand-packing technique; the difference was not significant (p = 0.40). Adequate filling of the femoral canal with cement was found to be associated with improved survival of the femoral component (p = 0.03). CONCLUSIONS: While no significant difference between the two cementing techniques could be identified, the ability to deliver adequate cement around the femoral component was more predictable with the contemporary cementing technique. In addition, the prevalence of loosening of the femoral component was low with use of either technique, a tribute to the Charnley flatback polished femoral component design.     

Outcome of total hip arthroplasties with cement: Results after implantation of the Harris Design 2 prosthesis, 1983–1985

Most reports of excellent long-term results of cemented total hip arthroplasty originate from studies of Charnley prostheses. A radiographic and clinical study was performed on 126 patients who underwent a cemented total hip arthroplasty from 1983 to 1985 with the Harris Design 2 prosthesis (Howmedica, Rutherford, NJ). The femoral component was cobalt—chromium and it had a broad, rounded medial border and a collar. The head diameter was 26 mm. A cemented all-polyethylene socket was used in all cases. At the last follow-up examination, 71% of the patients were completely free of pain and no patient had severe pain or pain at rest. Kaplan—Meier survival analysis estimated the revision rate at 10 years after operation to be 5 ± 2% (mean ± SEM) (including planned revisions). The rate of complete acetabular demarcation was 20% at 10 years, and femoral demarcation involving more than 50% of the bone—implant surface or endosteal cavitation was noted in only three cases. These results are as good as the best reported after total hip arthroplasty with the Charnley prosthesis.     

Total hip arthroplasty in patients less than 40 years old with avascular necrosis of the femoral head. A 5 to 19-year follow-up study

We evaluated 34 total hip arthroplasties (THA) for avascular necrosis of the femoral head in 26 patients who were younger than 40 years at the time of the index operation. The average age at the time of THA was 283 (17-38) years. The mean follow-up was 10.9 (5-19) years. We used 6 cemented and 28 cementless acetabular components and a cemented polished tapered stem in all hips. The mean Charnley modified Merle d' Aubigné Postel score was 8.9 points preoperatively and 16.6 points at final follow-up. Two cemented metal-backed cups were revised because of aseptic loosening at 10 years, one cemented polyethylene cup failed at 12 years and 2 more all polyethylene cups had pending failure. The metal-backed cemented cups and the all polyethylene cups had a longer follow-up than the uncemented cups. Therefore and because of the proven unfavourable long-term outcome of the cemented metal-backed Exeter cup we are not able to draw any firm conclusions regarding the preferred choice between cemented and uncemented cups in this particular group of patients. On the femoral site none of the stems had to be revised. Our results show that a cemented polished tapered femoral component has an excellent survival in primary total hip replacement in young patients with avascular necrosis of the femoral head.     

Staged bilateral total hip arthroplasty using rough and smooth surface femoral stems with similar design: 10-year survivorship of 48 cases

Background?Various studies have reported good long-term results using femoral stems with either smooth or rough surfaces. In this retrospective cross-sectional survivorship study, we reviewed the 10-year results of 51 bilateral staged cemented total hip arthroplasties using the Harvard or the Charnley femoral stems—which have almost similar geometry but a different surface finish.

Methods?51 patients were reviewed at median interval of 10 (Harvard group) and 11 years (Charnley group) after the primary operation. We evaluated cement mantle thickness, alignment of the components, presence of radiolucent lines, and aseptic loosening. Kaplan-Meier analysis was performed to calculate the survival rate using various endpoints.

Results?8 hips in the Harvard group were revised for aseptic loosening of thefemoral component at a median interval of 6.3 years after the primary procedure. 3 hips in the Charnley group were revised for aseptic loosening of the femoral and acetabular components between 10 and 11 years after the primary procedure. The 10-year survival rate for the femoral component using revision surgery for aseptic loosening as an endpoint was 80% (95% CI: 31–42) and 95% (95% CI: 44–47) in the Harvard and the Charnley group, respectively. Cox regression analysis did not reveal any statistically significant effect of various radiographical parameters on the survival rate (p < 0.05).

Interpretation?Our results demonstrate that in the group of patients studied, the femoral stem component with the matt surface finish had less satisfactory 10-year survival than the femoral stem of similar design which had a smooth surface finish.

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Long-term results of total hip arthroplasty for femoral neck fracture nonunion

BACKGROUND: Hip arthroplasty for the treatment of nonunion at the site of a femoral neck fracture has provided good short-term results. The purpose of the present study was to evaluate the long-term results and complications of total hip arthroplasty for the treatment of femoral neck nonunion. METHODS: The records of ninety-nine patients who had been managed with total hip arthroplasty with use of a cemented Charnley acetabular component and a cemented Charnley monoblock femoral component for the treatment of a femoral neck nonunion were retrospectively reviewed. The average age at the time of the arthroplasty was sixty-eight years. Eighty-four patients (85%) were followed until death, revision, or component removal or for at least two years (mean, 12.2 years) postoperatively. RESULTS: Twelve patients were treated with revision (eleven) or resection arthroplasty (one), eleven were lost to follow-up, and four died less than two years postoperatively. Of the remaining seventy-two unrevised hips that were followed for at least two years, sixty-nine (96%) had no or mild hip pain at the time of the last follow-up. The rate of component survival free of revision or removal for any reason was 93% at ten years and 76% at twenty years. The risk factors that were significantly associated with revision for aseptic loosening included an age of less than sixty-five years at the time of the arthroplasty (p = 0.045), a body-mass index of >/=30 (p < 0.01), and male gender (p = 0.02). The second most common complication after loosening was dislocation, which occurred in nine patients (9%). CONCLUSIONS: Total hip arthroplasty is an effective method for the treatment of nonunion of the femoral neck and provides satisfactory long-term results. However, the rate of implant survival is poorer than that reported in most other studies of Charnley total hip arthroplasty in the general population.     

The uncemented bipolar hemiarthroplasty for displaced femoral neck fractures. 6-year follow-up of 171 cases

We report a study of 168 consecutive patients (171 prostheses) with a displaced femoral neck fracture and a physiologic age older than 75 years who were treated with an uncemented bipolar Monk hard-top hemiarthroplasty. Four prostheses dislocated postoperatively, but none after discharge. Two prostheses were later extracted. Five patients sustained an ipsilateral femoral fracture. Totally, 7 patients (4 percent) were reoperated on. One year after the operation, 22 percent of the patients were dead. An increased mortality rate was recorded during the first 6 months after surgery. At follow-up 6 (3-9) years after the operation, 4 of the 62 patients alive had weight-bearing pain. Three had subsidence of the prosthesis, but none had protrusion of the acetabulum. Ninety-five percent of the patients were free from complications requiring a reoperation or outpatient evaluation.     

Long-term survival of the T-28 versus the TR-28 cemented total hip arthroplasties

Between 1974 and 1980, 550 total hip arthroplasties (THAs) (479 patients) were performed using T-28 and TR-28 cemented prostheses (TR-28 is shot-blast chrome and T-28 is polished stainless steel). There were 379 cemented THAs in 321 patients in the T-28 group and 171 cemented THAs in 158 patients in the TR-28 group. Average follow-up of the patients still alive at the end of the study was 20.96 years in the T-28 group and 17.54 years in the TR-28 group. When considering failure as revision of the hip for aseptic acetabular loosening, there were 36 (9.5%) failures in the T-28 group and 12 (7%) failures in the TR-28 group. This difference was statistically significant (P = .0132). When considering failure as radiographic acetabular loosening with or without radiographic femoral loosening, there were 52 failed acetabula (13.7%) in the T-28 group and 18 failed acetabula (10.5%) in the TR-28 group. These differences were not statistically significant. When considering failure as revision for aseptic femoral loosening with or without acetabular component loosening, there were 42 failures (11.1%) in the T-28 group and 22 failures (12.8%) in the TR-28 group. This difference was not statistically significant. When considering failure as radiographic femoral loosening with or without acetabular component loosening, there were 42 failures (11.1%) in the T-28 group and 27 failures (15.8%) in the TR-28 group. This difference was statistically significant for log-rank test (P = .0318) and Wilcoxon's test (P = .0083). Surface finish may be an important contributor to the survival of cemented femoral stems.     

Outcome of total hip arthroplasty in small-proportioned patients

In a prospective, consecutive series, 41 total hip arthroplasties were performed in 27 small-proportioned patients with small femoral dimensions. The 17 female and 10 male patients averaged 23.6 years (range, 14-47 years), and the mean height and weight were 157 cm (range, 132-183 cm) and 53.5 kg (range, 36-84 kg). The most common preoperative diagnosis was juvenile rheumatoid arthritis in 18 patients (28 hips). Most patients were severely disabled in their daily activity, and 68% of the patients were classified as Charnley functional class C. The femoral implants consisted primarily of the proximally porous-coated miniature Anatomic Medullary Locking femoral component (AML/CDH, Depuy, Warsaw, IN) in 33 hips in 22 patients (average stem diameter, 9.5 mm; range, 8-12.0 mm). A porous ingrowth acetabular cup fixed with screws was used in all procedures. At an average follow-up of 51 months, Harris Hip Scores improved significantly from 34 points (range, 0-65 points) preoperatively to 85 points (range, 33-100 points) after arthroplasty. There were no intraoperative complications. There was 1 revision because of femoral implant loosening. Three cementless femoral components showed evidence of nonprogressive subsidence. One patient had significant bilateral acetabular component polyethylene wear and underwent revision. All other femoral and acetabular components were radiographically stable. The relief of pain and improvement of function were dramatic. The miniature AML/CDH femoral component, combined with an uncemented acetabular cup, provides a promising, off-the-shelf alternative in small-proportioned patients.     

Total hip arthroplasty with satin finish, tapered stems

Subsidence of femoral hip prostheses with a rough surface has been associated with osteolysis and loosening. However, recent evidence has suggested that smooth-finish tapered stems may not incur these problems. An experimental monobloc satin finish, tapered femoral component was designed to subside within the cement. There were 49 femoral components implanted, and patients averaged a 1.8-mm subsidence at the prosthesis-cement interface with a follow-up of 6.76 years. There were no failures attributable to aseptic loosening at the cement-bone interface. This study supports the use of a satin finish, tapered femoral component in cemented total hip arthroplasty.     

Staged bilateral total hip arthroplasty using rough and smooth surface femoral stems with similar design: 10-year survivorship of 48 cases

BACKGROUND: Various studies have reported good long-term results using femoral stems with either smooth or rough surfaces. In this retrospective cross-sectional survivorship study, we reviewed the 10-year results of 51 bilateral staged cemented total hip arthroplasties using the Harvard or the Charnley femoral stems-which have almost similar geometry but a different surface finish. METHODS: 51 patients were reviewed at median interval of 10 (Harvard group) and 11 years (Charnley group) after the primary operation. We evaluated cement mantle thickness, alignment of the components, presence of radiolucent lines, and aseptic loosening. Kaplan-Meier analysis was performed to calculate the survival rate using various endpoints. RESULTS: 8 hips in the Harvard group were revised for aseptic loosening of the femoral component at a median interval of 6.3 years after the primary procedure. 3 hips in the Charnley group were revised for aseptic loosening of the femoral and acetabular components between 10 and 11 years after the primary procedure. The 10-year survival rate for the femoral component using revision surgery for aseptic loosening as an endpoint was 80% (95% CI: 31-42) and 95% (95% CI: 44-47) in the Harvard and the Charnley group, respectively. Cox regression analysis did not reveal any statistically significant effect of various radiographical parameters on the survival rate (p < 0.05). INTERPRETATION: Our results demonstrate that in the group of patients studied, the femoral stem component with the matt surface finish had less satisfactory 10-year survival than the femoral stem of similar design which had a smooth surface finish.