Salvage of a recurrently dislocating total hip prosthesis with use of a constrained acetabular component. A retrospective analysis of fifty-six cases

Fifty-six constrained acetabular components were placed, between April 1988 and February 1993, in fifty-five patients who had had recurrent dislocations (average, six dislocations; range, two to twenty dislocations) of the femoral component after a previous total hip arthroplasty. All patients had additional factors contributing to the instability of the implant, including absence or disruption of the abductor mechanism, poor health, mental retardation, confusion, and Alzheimer disease. One patient was lost to follow-up. The remaining patients were followed clinically for a minimum of three years (average, sixty-four months; range, thirty-seven to ninety-seven months) or until the time of death. During the follow-up interval, only two (4 per cent) of the fifty-five patients had a subsequent dislocation. The use of this type of component should be considered for patients who have recurrent dislocation if other treatment modalities are unlikely to be effective.     

Causes of and treatment protocol for instability of total hip replacement

Dislocation of the total hip replacement is a devastating complication, physically and mentally. It was determined whether there are radiographic or operative findings predictive of repeat dislocation and whether there are causes of dislocation that require immediate reoperation. A previously published classification of dislocations was used which evaluates (1) positional (no radiographic abnormality); (2) component malposition (femur or acetabulum), which is inadequate version or position of the acetabular or femoral component; (3) soft tissue imbalance (change in the length or displacement of the hip), which is a change in the muscle functional length of the hip; and (4) component malposition and soft tissue imbalance. Categories of treatment of dislocations were established that could be correlated to the cause of the dislocation: (1) Category I is a successful closed reduction; (2) Category II is a successful reoperation; (3) Category III is a reoperation with subsequent repeat dislocations successfully treated with closed reduction; and (4) Category IV is comprised of hips that require multiple reoperations for treatment of dislocations. The results are that any dislocation of any origin may be treated successfully with closed reduction so that this should be the first choice of treatment. To avoid multiple treatments, immediate reoperation should be performed if the hip is unstable when the patient is examined under anesthesia after the closed reduction. Hips with soft tissue imbalance and weakness of the abductor musculature, with or without component malposition, are most at risk for multiple operations. These hips may be considered for mechanical stability (constraint in the acetabular replacement) at reoperation.     

Salvage of total hip instability with a constrained acetabular component

Between April 1988 and February 1993, 101 constraining acetabular components were implanted into 98 patients. One patient was lost to followup at 8 months. Otherwise, all patients were observed until death or for at least 2 years minimum followup. The average clinical followup for the living patients was 61 months (range, 24-97 months). Indications for the use of the constrained acetabular components were recurrent dislocation (an average of six dislocations, range 2-20) in 56 cases, intraoperative instability in 38 cases, and neurologic impairment in seven cases. For the entire group there were four cases of recurrent dislocation or failure of the component (4%). For the cases where this component was used for recurrent dislocation, 96% (54 of 56 cases) had no additional dislocations. Radiographically, at this short term followup, there was no evidence of an increased incidence of femoral or acetabular component loosening. The authors recommend judicious use of this component as a salvage measure for desperate cases of hip instability during or after total hip arthroplasty.     

Relation of heart rate variability and serum lipoproteins in type 1 diabetes mellitus and chronic stable angina pectoris

Extended trochanteric osteotomies have been recommended to facilitate femoral component removal, femoral cement removal, and acetabular exposure in cases of difficult revision hip arthroplasty. Complications due to the osteotomy have been rare and no nonunions have been reported when this osteotomy has been used in conjunction with extensively porous-coated implants. It has been suggested that the osteotomy should also work well with impaction grafting revisions. This is a report of two cases of nonunion of extended trochanteric osteotomies in which the impaction grafting technique was used.     

Dislocation following total hip endoprosthesis. Association with surgical approach and other factors

During a period of eight years (1984 to 1992) we found 45 dislocations in 1734 patients treated by total hip arthroplasty. We compared this retrospectively evaluated group with a randomized control group of 61 patients. As a cause for an increasing number of dislocations in 1989 we found: age over 70 years, high CCD-stem-angle (142 degrees), dorsal approach, abduction of the acetabular component under certain circumstances (left side). Revision operations always are a high risk procedure. Acetabular anteversion, anaesthesia, way of component fixation did not induce an increased rate of dislocation. We now left the dorsal approach and use only stems with an CCD-angle of 135 degrees or less by now. Careful positioning of the acetabular components and a better patient-instruction helped to decrease the number of dislocations. Because of these measures we reduced the THA-dislocations rate from 5.6 to 0.17 per cent (first operations) and from 12.1 to 6.5 per cent (revision operations).     

Charnley total hip arthroplasty in patients less than fifty years old. A twenty to twenty-five-year follow-up note

We evaluated the results twenty to twenty-five years after ninety-three consecutive, nonselected Charnley total hip arthroplasties performed with cement by the senior one of us in sixty-nine patients who were less than fifty years old at the time of the procedure. Seventy of the seventy-two hips in the living patients were followed radiographically for at least twenty years. Twenty-seven hips (29 per cent) had a revision or a resection of the prosthesis during the follow-up period. The revision or the resection was performed because of aseptic loosening in twenty-one hips (23 per cent), infection in four (4 per cent), dislocation in one (1 per cent), and fracture of the femur in one. Eighteen acetabular components (19 per cent) and five femoral components (5 per cent) were revised because of aseptic loosening, and an additional fourteen acetabular components (15 per cent) and seven femoral components (8 per cent) demonstrated definite or probable radiographic loosening. The present study demonstrates the long-term durability of total hip arthroplasty performed with cement in an active population of patients. The fixation of the femoral component was found to perform better than that of the acetabular component at twenty to twenty-five years after the procedure.     

Effect of nitric oxide, prostacyclin, and thromboxane on the vasospastic action of hydrogen peroxide on human umbilical artery

During the years 1991-1994, the Norwegian Arthroplasty Register recorded 1,324 primary hip arthroplasties implanted with the Boneloc cement. We have compared the survival until revision due to aseptic loosening for charnley (n 955) and Exeter (n 172) prostheses. The Boneloc cemented hips were also compared with high viscosity cemented hips implanted during the same period. In the Boneloc cemented group, the estimated probability of survival at 4.5 years of a Charnley femoral component was 74% and for an Exeter femoral component 97% (p < 0.0001). Using a Cox regression model with adjustment for age, gender, type of cement, systemic antibiotic and stratified for diagnosis, an 8 times higher risk of revision was found in Boneloc cemented Charnley femoral components than in Exeter femoral components (p < 0.0001). For the acetabular components, the difference between the Charnley and Exeter components with Boneloc cement was not statistically significant. In both the Charnley and the Exeter prostheses, the high viscosity cemented components had significantly better survival than the Boneloc cemented components. The Cox regression model showed that a Boneloc cemented Charnley femoral component had a 14 times higher risk of revision than a high viscosity cemented component (p < 0.0001), and for Exeter femoral components a 7 times higher revision risk was found in the Boneloc cemented components (p = 0.003). Our results confirm the previously reported inferior results of Charnley prostheses implanted with Boneloc cement and inferior results of Boneloc cemented Exeter prostheses as well, but less pronounced than for Charnley prostheses.     

Ceramic endoprosthesis in total hip arthroplasty

Aluminia-on-aluminia hip prosthesis with titanium alloy stem was used in 255 cases, for 143 patients with cemented acetabular cup and 112 with an uncemented screw cup. The average age of the patients was 62 years. Of the patients, 35 were treated bilaterally. The indication for surgery was osteoarthritis in 186 cases, fractures and nonunions of the hip joint in 34 cases, and congenital dislocations of the hip joint in 16 cases. Previous surgery of the hip joint was recorded for 43 cases. All procedures were primary arthroplasties. Only personal clinical examinations together with radiographic studies were accepted as clinical data. Three patients failed to show up for routine follow-up evaluation and these were excluded from the series. Revision operation was classified as failure. The indications for revision were aseptic loosening, late infection, and fracture of the acrylic cement resulting in loosening of the acetabular or femoral component. The acetabular component was cemented in 143 patients and the mean follow-up period for these patients was 6.7 years (range, 1-12 years). In this series, a revision operation was undertaken for 16 patients (11%). In 12 cases, broken acrylic cement resulted in acetabular aseptic loosening. In the series of 112 patients with uncemented titanium screw cup, the mean follow-up period was 3.6 years (range, 1-7 years) and a revision operation was undertaken in seven cases (7%). In two, the indication was late infection; in one, technical failure; and in two, progression of Pigmented villonodular synovitis. Acetabular aseptic loosening resulted in revision in only two cases. With cementless acetabular component bone transplantation is indicated.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dislocation in total hip arthroplasties

In a series of 1,443 total hip arthroplasties performed between 1970 and 1975, dislocation was the most frequent complication and its incidence was found to be increasing. Dislocatin was frequently associated with component malposition that the surgeon was not aware of at the time of surgery and was relatively frequent among less experienced surgeons. It was especially frequent if the patient had had previous hip surgery and was related to the difficulty of the surgery rather than the primary hip disease. Increasing incidence was associated with change in operative technique and less stringent patient selection. Dislocation was 2 1/2 times more frequent if trochanteric osteotomy was not performed. The tip of the greater trochanter was moved significantly closer to the center of the prosthetic head in the patients who dislocated. Traction for up to three weeks did not lower the incidence of subsequent dislocation compared with mobilization of the patients as soon as tolerated after dislocation. Surgery was effective in preventing further dislocations in patients with recurrent dislocation and component malposition. The use of an articulated prosthesis is not recommended.     

Effects of candesartan cilexetil in patients with systemic hypertension. Candesartan Cilexetil Study Investigators

In the case described, infrarenal aortic thrombosis occurred after acetabular component revision in an 86-year-old man with recurrent dislocation of a total hip arthroplasty. Early diagnosis and prompt emergency vascular bypass operation were successful in restoring flow to the extremity, although the dislocation recurred. The literature is reviewed, and judicious steps for the avoidance of this serious complication are discussed.     

Automated seeded lesion segmentation on digital mammograms

The clinical results of eighty-four total hip arthroplasties performed through a transtrochanteric approach in sixty-seven patients who had a high dislocation of the hip (the femoral head completely out of the acetabulum), from 1976 to 1994, were reviewed. The acetabular component was placed in the true acetabulum and the femur was shortened at the level of the femoral neck, along with release of the psoas tendon and the small external rotators, in order to facilitate reduction of the components and to avoid neurovascular complications. Eleven hip prostheses (13 per cent) failed at a mean of 6.4 years (range, two months to sixteen years) postoperatively; the failure was due to aseptic loosening of both components in four hips, aseptic loosening of the stem only in three, late infection in three, and malpositioning of the acetabular component that caused recurrent dislocations in one. The other seventy-three hips were functioning well at the latest follow-up examination, two to twenty years (mean, 7.1 years) postoperatively. The overall cumulative rate of success was 92.4 per cent (95 per cent confidence interval, 89.5 to 95.3 per cent) at five years and 88.0 per cent (95 per cent confidence interval, 82.2 to 93.8 per cent) at ten years. We believe that this operative technique of total hip arthroplasty is effective for the treatment of the difficult condition of high dislocation of the hip.     

Subtrochanteric femoral shortening osteotomy in total hip arthroplasty for high-riding developmental dislocation of the hip

A surgical technique, which uses a transverse osteotomy, for subtrochanteric femoral shortening and derotation in total hip arthroplasty for high-riding developmental dislocation of the hip is described. Anteversion is set by rotating the osteotomy fragments, and torsional stability is augmented with allograft struts and cables when indicated. Eight patients with 9 total hip arthroplasties were followed for an average of 43 months (range, 24-84 months). Good to excellent results were obtained in 87% of patients (7 of 8). Eight of 9 osteotomies (89%) demonstrated radiographic evidence of healing at an average of 5 months. One patient had an asymptomatic nonunion of the osteotomy site but still had a good overall clinical result. Another patient suffered fatigue failure of a distally ingrown porous device, which necessitated revision total hip arthroplasty 18 months after surgery. Subtrochanteric osteotomy in total hip arthroplasty for developmental dislocation of the hip allows for acetabular exposure and diaphyseal shortening while facilitating femoral derotation. Furthermore, proximal femoral bone stock is maintained and some of the potential complications of greater trochanteric osteotomy may be avoided.     

Total hip arthroplasty with porous-coated prostheses fixed without cement in patients who are sixty-five years of age or older

We reviewed the results of 212 total hip arthroplasties performed without cement in 203 unselected, consecutive patients who were sixty-five years of age or older. The outcome was known for 196 hips, thirty-seven of which had been followed until the death of the patient and 159 of which had been followed for a minimum of five years. A reoperation was done in 4 percent (seven) of the 196 hips. These reoperations included one revision because of loosening of the stem and five revisions of the cup. Three of the acetabular revisions were done because of fracture due to polyethylene wear; one, because of recurrent dislocation; and one, because of polyethylene wear and a fracture due to lysis. In the seventh reoperation, a cup and stem were exchanged because of infection. The probability that a hip prosthesis would survive twelve years without a reoperation was 0.92 (95 percent confidence interval, 0.85 to 0.99). We evaluated the clinical results for 152 patients who had not had a reoperation and had been followed for at least five years (mean, 8.5 years; range, five to fourteen years). Of these patients, thirteen (9 percent) had pain that limited activity: five (3 percent) had pain in the thigh (four patients) or groin (one patient), and eight (5 percent) had trochanteric pain and tenderness. One hundred and forty-four (95 percent) of the patients noted an improvement in overall function, and 149 (98 percent) reported satisfaction with the outcome. One hundred and thirty-five hips that were not revised were followed radiographically for at least five years (mean, 8.2 years; range, five to fourteen years). In this group, osteolysis was observed in three hips (2 percent); loosening of the cup, in three (2 percent); and loosening of the stem, in one (1 percent). Stress-shielding was seen on the two-year postoperative radiographs of forty-five (26 percent) of the 174 hips that were followed for at least that duration. The prevalence of osteolysis, loosening of a component, and reoperations was no greater in this subgroup than in the overall group. These results indicate that total hip arthroplasty without cement can be successful in older patients. This study also provides a reference for comparison with the results of total hip arthroplasty performed with cement and those of so-called hybrid total hip arthroplasty (an acetabular component fixed without cement and a femoral component fixed with cement) in patients who are sixty-five years of age or older.     

Porous-coated total hip replacement

Fifteen years of clinical experience with porous-coated prostheses demonstrated the durability of this type of fixation. This experience was documented by clinical follow-up study of the 393 cases treated by the senior author before 1985. Only six of these femoral components have been revised: three for loosening, two for stem breakage, and one for infection. Thus, the revision rate for the porous-coated stems was 1.5%. Porous-coated acetabular components were used in 227 of the arthroplasties. Five of these porous-coated cups have been revised: four for malposition leading to dislocation and one for late loosening secondary to osteolysis. Thus, the revision rate for these porous-coated acetabular components was 2.2%. Twenty bipolar and 146 cemented acetabular components were used in the remaining 166 cases treated before 1985. Eleven (7.5%) of the cemented acetabular components were revised. Revisions of the porous-coated components were rare in the first ten postoperative years. The clinical data were supplemented with analysis of postmortem specimens from 15 patients. Mechanical testing of the femoral specimens showed the relative micromotion at the porous surface to be exceptionally small (less than 40 microns). Seven of these postmortem retrievals involved cases with unilateral arthroplasties. In these cases, the contralateral normal femur also was removed, and a prosthesis identical to that in the in vivo implanted side was inserted to simulate the immediate postoperative condition. Dual-energy X-ray absorptiometry (DEXA) of the seven paired femora demonstrated that bone remodeling can be expected to produce a 5%-52% loss of periprosthetic bone mineral content, with the greatest loss occurring in the more osteoporotic patients.(ABSTRACT TRUNCATED AT 250 WORDS)     

Primary total hip reconstruction with a titanium fiber-coated prosthesis inserted without cement

A prospective study was done of the intermediate-term clinical and radiographic results of 121 total hip arthroplasties in which a Harris-Galante porous titanium-fiber-coated prosthesis was inserted without cement in 110 patients. The average age at the time of the operation was forty-nine years (range, twenty to seventy years). The average duration of follow-up was sixty-seven months (range, fifty-five to seventy-nine months). The average preoperative Harris hip score was 55 points, and the average postoperative score was 93 points. One acetabular component was revised due to recurrent dislocation. Eleven femoral implants were unstable, and of these, four were revised. Cortical erosion was present around the distal part of the femoral stem in nine patients (8 per cent) who had stable implants, and one of these femoral implants was revised because the erosion was extensive. Survivorship analysis at five years revealed a 97 per cent chance of survival (95 per cent confidence limit, 0.937 to 1.0) of the Harris-Galante femoral-stem implant inserted without cement.     

Implant stability in revision total hip arthroplasty: allograft bone packing following extended proximal femoral osteotomy

One method of revising the femoral component in revision total hip arthroplasty in the presence of compromised femoral bone stock is to pack the upper femur with particulate allograft and then to cement the femoral component into the allograft bed. This technique is being used clinically with encouraging results. Additionally, surgical exposure of the femoral canal during revision total hip arthroplasty can be greatly improved with an extended trochanteric osteotomy, which is subsequently repaired with wires or cables. To assess the feasibility of performing the allograft bone packing technique following an extended trochanteric osteotomy, the stability of this construct in a cadaver model was measured, using micromotion sensing instruments and loads applied on a materials testing machine. The stability of the cemented allograft impaction construct following extended trochanteric osteotomy was comparable to the stability of the control construct, which consisted of a similar impacted allograft construct without osteotomy. The stability of the osteotomized side was comparable to that of the control side. It is concluded that the initial in vitro stability of the allograft impaction technique following extended proximal femoral osteotomy is adequate to justify experimental in vivo use.     

Radiotherapy for elderly patients

Fifty-seven revision total hip arthroplasties in fifty-six patients were performed with a Harris-Galante porous-coated acetabular component by one surgeon, and the patients were followed prospectively for a mean of seven years (range, five to twelve years). A trochanteric osteotomy was performed in forty hips, and a posterior approach with an extended anterior capsulectomy was used in the other seventeen. The acetabular defect was classified as segmental in seven hips, cavitary in twenty-three, and combined in twenty-one; six hips had no notable defect. A bulk allograft was used in eleven hips, and morseled cancellous-bone allograft or autogenous graft was used in thirty-four hips; twelve hips did not have bone-grafting. Both the femoral and the acetabular component were revised in forty-five hips, and only the acetabular component was revised in twelve. Thirty-nine hips (68 per cent) had a good or excellent clinical result according to the Harris hip score. The acetabular component was well fixed in the fourteen hips that had a fair result and the four hips that had a poor result. The acetabular component was considered to have migrated if there was a change in the angle of the cup of 5 degrees or more or a change in the horizontal or vertical position of the cup of more than three millimeters. Despite varying degrees of bone loss, no acetabular component had radiographic evidence of loosening at the latest follow-up examination. No component was revised and no revisions were scheduled. One hip was debrided for a late metastatic infection, but the component was well fixed and was not revised. There were no complications related to the use of screws for fixation. These mid-term results confirm the early success of acetabular revisions performed with fixation of a titanium fiber-metal-coated hemispherical component with multiple screws and no cement.     

Isolated revision acetabuloplasty using a porous-coated cementless acetabular component without removal of a well-fixed femoral component. A 3- to 9-year follow-up study

The results of isolated acetabular revision performed in 31 patients (32 hips) were monitored for between 3 and 9 years. All femoral components were well fixed and not removed or revised at the time of index surgery. There were 4 hips with little or no acetabular bony defect, 2 hips with pure segmental defects (type I), 10 hips with cavitary defects (type II), 15 with combined segmental cavitary defects (type III), and I with pelvic discontinuity (type IV). All revision acetabular implants were cementless, using a porous-coated hemispheric cup with or without bone-graft. There were four grade I reconstructions, 16 grade II reconstructions, and 12 grade III reconstructions. At final follow-up evaluation 94% of the cups were judged to be stable. Two hips required a second revision acetabuloplasty because of loss of fixation of the cup. The 2 repeat revisions were also done without removal of the femoral component. One acetabular component had evidence of rotational migration, which stabilized and remained nonprogressive. There were no cases of femoral component radiographic or clinical failure. The mean pre and postoperative hip scores were 44 and 83, respectively. The pre- and postoperative pain scores were 12 and 42, respectively. The findings of this study suggest that isolated acetabular revision, using a cementless porous-coated hemispheric cup, can be successfully performed without removing or revising a well-fixed femoral stem and not compromise the final outcome.     

Relationship of femoral head and acetabular size to the prevalence of dislocation

Two clinical studies, one prospective randomized and one retrospective, were performed to evaluate the relationship of femoral head size and acetabular component outer diameter to the prevalence of dislocation of the modular total hip replacement. Between October 1995 and April 1996, 31 primary total hip arthroplasties in 30 patients were randomized to a femoral head diameter of 22 mm or 28 mm, for two groups of acetabular components of outer diameters of 56 mm or larger and 54 mm or smaller. Head size (22 mm) and acetabular component outer diameter (> or = 56 mm) were found to increase the risk of dislocation. From December 1984 to January 1994, 308 primary total hip arthroplasties were performed through a posterior approach by one surgeon using a modular 28 mm femoral head and one type of uncemented acetabular component. The rate of dislocation for acetabular components with an outer diameter of 62 mm or larger was increased significantly (five of 36 hips, 14%) compared with those with an outer diameter of 60 mm or smaller (11 of 272 hips, 4%).     

Impaired bile flow and disordered hepatic calcium homeostasis are early features of halothane-induced liver injury in guinea pigs

Although an acetabular component with an elevated rim is thought to improve the postoperative stability of a total hip prosthesis, the actual clinical value has not yet been demonstrated. To address this question, we reviewed the results of 5167 total hip arthroplasties that had been performed at our institution from April 1, 1985, through December 31, 1991. The prostheses included 2469 acetabular components with an elevated-rim liner (10 degrees of elevation) and 2698 with a standard liner. The cumulative probability of dislocation was estimated as a function of time since the operation with use of the Kaplan-Meier survivorship method. Forty-eight of the 2469 hips that had the elevated-rim acetabular liner dislocated within two years, compared with 101 of the 2698 hips that had the standard acetabular liner. The two-year probability of dislocation was 2.19 per cent for the hips with the elevated-rim liner and 3.85 per cent for those with the standard liner (p = 0.001). A similar trend was seen at five years; however, because of a smaller sample the difference was not significant. Increased stability at two years was also demonstrated for the hips with the elevated-rim liner when the hips were analyzed according to the operative approach, the mode of fixation, the sex of the patient, and the type of total hip arthroplasty (primary or revision). Although these data demonstrate improved stability after total hip arthroplasty when an elevated liner is used, particularly in hips that are at greater risk for dislocation of the prosthesis, the long-term effect of this elevated liner on wear and loosening remains unknown but is of considerable concern. The elevated liner deserves additional study to clarify its effect on wear and loosening.