Revision of a failed cemented total hip prosthesis with insertion of an acetabular component without cement and a femoral component with cement. A five to eight-year follow-up study

Sixty-one consecutive so-called hybrid revision total hip arthroplasties were performed in fifty-five patients by one surgeon, from 1986 through 1988, for mechanical failure of a cemented total hip prosthesis. In all of the patients, the acetabular and femoral components were revised to a porous-coated Harris-Galante acetabular component inserted without cement and an Iowa femoral component inserted with cement. Contemporary cementing techniques were used, but structural bone graft was not. The over-all prevalence of repeat revision for aseptic loosening was 0 per cent for the acetabular components and 3 per cent (two hips) for the femoral components. In addition, 2 per cent (one) of the acetabular components and 5 per cent (three) of the femoral components demonstrated radiographic evidence of loosening. In the forty-three patients (forty-nine hips) who were alive at an average of seventy-four months (range, sixty to ninety-five months) after the revision, none of the acetabular components and 2 per cent (one) of the femoral components were revised again for aseptic loosening. An additional 2 per cent (one) of the acetabular components and 6 per cent (three) of the femoral components were radiographically loose. Ninety-eight per cent (forty-one) of the forty-two living patients (98 per cent [forty-seven] of the forty-eight hips) who had a clinical examination at least five years after the revision had increased function; 90 per cent (thirty-eight) of these patients (forty-four [92 per cent] of the hips) were satisfied with the result. The group that had a hybrid revision was compared with a group of seventy patients (seventy-four hips) who had had a revision total hip arthroplasty with use of contemporary cementing techniques for both components. These revisions had been performed by the same surgeon, before he performed the hybrid revisions, and the prevalence of repeat revision of the acetabular component was 7 per cent (five hips) and that of the femoral component was 4 per cent (three hips). In addition, 16 per cent (twelve) of the acetabular components and 3 per cent (two) of the femoral components were radiographically loose. The comparison group was not a consecutive series, as only the patients who had had radiographs made five to eight years after the revision were evaluated. In the fifty-two such patients (fifty-six hips) who were alive at five years after the revision with cement (average duration of radiographic follow-up, seventy-seven months; range, sixty to ninety-nine months), 9 per cent (five) of the acetabular components and 5 per cent (three) of the femoral components were revised again for aseptic loosening. An additional 21 per cent (twelve) of the acetabular components and 4 per cent (two) of the femoral components were radiographically loose. The results of the present study demonstrated a significant improvement (p = 0.0001) in the survival of the acetabular component of so-called hybrid revision total hip arthroplasties compared with that of revision total hip arthroplasties with cement performed by the same surgeon and followed for a comparable period.

Intraoperative custom press-fit and standard press-fit femoral components in total hip arthroplasty. A comparison of surgery, charges, and early complications

A consecutive group of 60 patients who had intraoperative custom press-fit total hip arthroplasties (67 hips; Identifit, Thackray, London, United Kingdom) was compared with a similar group of 60 patients who had standard press-fit arthroplasties (66 hips; McCutchen, Wright Medical Technologies, Arlington, Tennessee) to determine if there were differences in operative time and charges, as well as early complications and early radiographic results. The unilateral intraoperative custom group had an average anesthesia time of 3 hours, 39 minutes, an operating time of 2 hours and 26 minutes, and a blood loss of 725 mL. The averages for the standard group included an anesthesia time of 2 hours, 19 minutes, a surgical time of 1 hour, 25 minutes, and a blood loss of 480 mL. By 6 months after surgery, 49 (73%) in the custom group had subsidence of 2 mm or more, compared with 10 hips (15%) in the standard group. The custom group had 17 early postoperative complications versus 3 in the standard group. The charge for the hospital stay averaged $19,950 for the custom group and $14,322 for the standard group. At the present time, the high incidence of complications and the increased charges make the intraoperative custom hip replacement an unlikely first choice of recommendation.

[A concept of need and construction of a hip joint prosthesis with isolation of the friction point from the tissue]

The paper presents data available in the literature and the author's own data on the causes of bone tissue resolution around endoprostheses and on the occurrence of their aseptic instability. The author's own clinical data on 546 operations and follow-ups up to 16 years are strong evidence and his experimental findings are unique in the number of animals operated on and follow-up periods. The material was examined roentgenologically, morphologically, spectroscopically and the mineral content of bone tissue microstructures were determined. With the methods applied, the author clearly shows the role of tissue metallosis in the occurrence of aseptic instability of prosthesis. The author presents two up-to-day constructions of the total-type endoprostheses with the friction point isolated from tissue. The prostheses are accessible for manufacture at the modern enterprises and require no materials in short supply.

A technique of revision of failed acetabular components leaving the femoral component in situ

Management of a failed acetabular prosthesis in the presence of a well-fixed femoral prosthesis poses a technical challenge in revision joint arthroplasty. While failures can occur at any age during the lifetime of a prosthesis, a pattern has emerged of earlier failure of the femoral component and later failure of the acetabular component. The authors describe a technique in which the stable femoral prosthesis is left in situ during acetabular revision. The advantages of this technique include excellent exposure of the acetabulum, reduction in operative time and intraoperative morbidity, as well as early postoperative mobilization.

Cost of implanting a cemented versus cementless femoral stem

Fifty stratified unselected cases of primary uncomplicated total hip arthroplasty performed at the total joint service of a university teaching hospital were examined. In 25 cases, the femoral stem was implanted with cement, and in the other 25, a cementless stem was implanted. For cemented stems, third-generation cement technique was used, including centrifugation. The average cost to the hospital for a cementless stem was $900 greater than for a cemented stem. The total cost to the hospital for accessories used to achieve modern cement technique was over $700. The operative time for implanting a cemented stem averaged 20 minutes longer, which resulted in an additional operating time charge of $270 and an additional anesthesia charge of $100. When these charges are added to the cost of cement and accessories, the actual cost to the hospital for implanting a modern cemented stem was greater than for a corresponding cementless stem.

[Femoral head necrosis treated with total hip alloplasty]

One hundred and three patients with non-traumatic osteonecrosis of the femoral head had 144 primary total hip replacements performed. Average age was 47 (22-73) years. In 85 cases a cemented prosthesis, and in 45 cases an uncemented prosthesis was used, while 14 cases had a cemented femoral stem and an uncemented cup. At follow up, 25 patients had died, 13 patients had had a revision of the prosthesis, and two patients were lost to follow-up, leaving 63 patients (92 hips) for clinical and radiological evaluation. Kaplan-Meier plots for survival of the prosthesis were constructed, showing a total risk of failure of 8% at five years, increasing to 16% at seven years. In 89% of the patients without concomitant diseases, the clinical result was excellent or good. There was no difference in the clinical or radiological result in patients with cemented and uncemented prostheses. It is concluded, that the result after total hip replacement due to non-traumatic osteonecrosis of the femoral head is comparable to that of total hip replacement due to osteoarthrosis, and that an uncemented prosthesis can be expected to yield a result comparable to a cemented prosthesis.

Prosthetic reconstruction for periacetabular malignant tumors

This article reports the reconstruction method and functional results of a newly designed tumor hip prosthesis with a constrained joint mechanism which was used after treatment for 13 primary and 5 metastatic periacetabular malignant bone tumors. The overall 5-year survival rate for patients with primary tumors (n=13) was 50%. The local recurrence rate was 30%. More than 90% of the patients whose hips were reconstructed with the constrained tumor hip prosthesis experienced pain relief and were able to walk with a cane. No patients had greater than 3 cm shortening of the involved limb. Infection was the most serious complication. This prosthesis restored iliofemoral stability after surgical resection of periacetabular malignant tumors.

Primary total hip replacement with insertion of an acetabular component without cement and a femoral component with cement. Follow-up study at an average of six years

We performed a retrospective study of a consecutive series of patients who had had a primary total hip replacement with so-called hybrid fixation of the components (an acetabular component inserted without cement and a femoral component inserted with cement) between September 1985 and June 1989. Clinical data were available for 114 patients (125 hips), of whom 110 (121 hips) also had radiographic data. The minimum duration of follow-up was fifty-six months or until revision, and the average duration was seventy-two months. The average Harris hip score improved from 47 points preoperatively to 91 points postoperatively (for the 109 patients who did not have subsequent revision of the femoral component). Only three patients who did not have a revision had more than slight pain in the hip. Four hips (3 percent) were revised for aseptic loosening of the femoral component at an average of fifty-five months; two of these four had a fracture of the femoral component. One patient had resection arthroplasty for late infection. One patient had disassembly of an acetabular polyethylene liner, and another had dissociation of a modular femoral head; both patients had a reoperation. Radiographically, two femoral components were definitely loose, as determined by subsidence of the component in one patient and a fracture of the cement in the other. Ten hips (8 percent) had endosteal lysis of the femur. Over-all, 5 percent (six) of 121 femoral components were either revised for loosening or had definite radiographic evidence of loosening, but no acetabular component was loose. The clinical results in the 104 patients (115 hips) for whom clinical and radiographic data were available were excellent at the time of intermediate follow-up. Since few hips had progressive radiolucent lines about the acetabular of femoral component, we are optimistic that the long-term results will also be satisfactory.

Pathological fractures of the proximal femur with impending shaft fractures treated by THR and cemented intramedullary nailing: a report of nine cases

We have used total hip replacement combined with cemented intramedullary nailing to treat a selected group of nine patients with pathological fractures of the proximal femur and impending fractures of the shaft due to metastases. One patient died from cardiopulmonary failure on the third postoperative day, but the others were able to walk within the first week after operation. Complications included one recurrent dislocation of the THR and one fracture of an osteolytic lesion of the femoral shaft during nail insertion. Both were managed successfully. The hybrid osteosynthesis which we describe is an alternative to the use of tumour or long-stem prostheses; it has the advantage of preserving bone stock and muscle attachments.

Pharmacokinetic model for cefazolin distribution during total hip arthroplasty in dogs

OBJECTIVES

To compare cefazolin pharmacokinetics in serum and concentrations in tissues during total hip arthroplasty in dogs with and without hip dysplasia, and to calculate the optimal dosage of cefazolin for prophylactic use during total hip arthroplasty.

ANIMALS

10 dogs with hip dysplasia and 3 clinically normal dogs.

PROCEDURE

Blood samples and tissue specimens from the coxofemoral joint capsule, acetabulum, and femur were obtained during unilateral total hip arthroplasty. Cefazolin concentrations in serum and tissue specimen supernatant were determined, using high-performance liquid chromatography, for use in pharmacokinetic analysis. Mathematical simulation of serum cefazolin concentration was used to to predict the optimal dose.

RESULTS

Mean pharmacokinetic constants (SEM) were 0.146 (0.013) min-1 for alpha, 4.47 min for t1/2 alpha 0.015 (0.004) min-1 for beta, 46.83 min for t1/2 beta. Significant different was not detected for cefazolin distribution and elimination between dogs with and without hip dysplasia. Additional, significant difference was not observed in pharmacokinetic parameters describing distribution and elimination between the first and second doses of cefazolin. The predicted optimal dosage regimen was 8 mg/kg of body weight, i.v. every hour or mg/kg, i.v. every 2 hours.

CLINICAL RELEVANCE

For prophylactic i.v. treatment during total hip arthroplasty, use of cefazolin at a dosage of 8 mg/kg every hour or 22 mg/kg every 2 hours should maintain serum cefazolin concentrations at least 10x the minimum inhibitory concentration for 3 to 4 hours.

[Use of a custom made femoral prosthesis in the treatment of a femoral agenesis]

We describe the management of femoral agenesis in a young adult. Following previous treatment, including limb lengthening by the Ilizarov technique, the patient was left with 30 cm of shortening, a hip fused in abduction and external rotation, an ankylosed knee and an ankle which had been surgically fused. We decided to create a mono-segmental stump, based on a mobile hip, in order to accommodate a suitable prosthesis. Replacement arthroplasty of the hip was first undertaken using a femoral component with a long stem which crossed the knee into the upper tibia. This allowed correction of the rotational deformity and fusion of the knee in an appropriate position. Amputation above the ankle was then carried out under the same anaesthetic. A suction prosthesis was attached to the stump. The arthrodesis of the hip was the principle factor in deciding on this procedure rather than a Van Ness operation or further lengthening. The result at 3 years is satisfactory and the patient has good mobility.

A modified direct lateral approach for primary and revision total hip arthroplasty. A prospective analysis of 453 cases

A prospective analysis of 453 consecutive primary and revision total hip arthroplasties (THAs) were reviewed. The modified direct lateral approach was used in 306 of 319 (96%) primary THAs and 115 of 134 (86%) revision cases for a total of 421 of 453 (93%) procedures. There were three dislocations in the revision group of patients. All three patients had at least two previous arthroplasties prior to their index surgery and at the time of surgery were noted to have very poor tissue quality, making the repair difficult. There were no postoperative dislocations in the primary THA group, with an overall dislocation rate of 0.7%. The incidence of postoperative limp in the primary THA group was 18%. The overall incidence, including revision surgery, was 27%. The presence of a persistent limp after initial rehabilitation was dependent on the number of previous surgeries, leg-length discrepancy greater than 2.7 cm, revision THA requiring a proximal femoral allograft, and preexisting deformities. Limp was therefore believed not to be related to the use of the modified direct lateral approach.

Cementless hemispheric acetabular components. A 4- to 8-year follow-up report

A retrospective radiographic analysis was performed on 71 cementless acetabular components followed from 4 to 8 years after surgery. A Harris-Galante (Zimmer, Warsaw, IN) cup was used in 46 cases and an Optifix (Smith & Nephew Richards, Memphis, TN) cup was used in 25 cases. There were 66 primary and 5 revision cases. Nonprogressive radiolucencies were common in both types of cups (64% of Optifix, 70% of Harris-Galante). Radiolucencies were almost exclusively less than or equal to 1 mm in width and were most common in zones 1 and 3. Ten cups had continuous but nonprogressive radiolucencies, none greater than 1 mm in all three zones. No radiolucent lines wider than 2 mm were seen in any case. Four cups had progressive radiolucency that stabilized. Radiolucency around fixation screws was seen in one case, and demonstrated stable ingrowth at revision surgery. No cases of osteolysis, screw breakage, migration, or loss of fixation surface occurred. A single case of a broken locking mechanism of a Harris-Galante cup 2 years after liner exchange is reported.

Uncemented total hip arthroplasty using the CLS stem: a titanium alloy implant with a corundum blast finish. Results at a mean 6 years in a prospective study

An uncemented titanium alloy stem with a corundum blast finish and an uncemented titanium fibermetal mesh socket were implanted in a series of 57 hips. These prostheses were selected for use in the youngest, most active, and/or heaviest candidates for total hip arthroplasty. Fifty hips were available for study at a minimum 60 months. At a mean 6 years, 92% of the hips were rated good or excellent. The mean Harris hip score was 92. One patient experienced mild thigh pain. The corundum blast finish was associated with reliable implant stability. Survival analysis predicted a 96% rate of implant survival at 92 months. Loss of bone density was rated mild, minimal, or none in 88% of the hips. Three hips developed severe bone loss due to systemic disease. Polyethylene wear was measurable in 86% of the hips. Twenty hips developed focal proximal femoral bone erosions. One hip had endosteal cavitation distal to zone 7. The presence of proximal femoral erosions or endosteal cavitation correlated positively with the presence of measurable polyethylene wear. The limited and proximal distribution of femoral bone erosion despite evidence of extensive polyethylene wear suggested that bone apposition to the corundum blast finish resulted in a barrier to migration of wear debris.

Uncemented press-fit total hip arthroplasty using the Identifit custom-molding technique. A prospective minimum 2-year follow-up study

Fifty-three primary uncemented custom-molded Identifit (Depuy, Warsaw, IN) hip arthroplasties were evaluated prospectively at a mean follow-up period of 30 months. The custom technique provided the capability to reproduce the unique femoral offset, version, and height in each hip and to achieve high percentages of femoral canal fill. Surgical time for unilateral cases was a mean 153 minutes. Clinical results, however, were disappointing. Nine hips (17%) required stem revision for persistent thigh pain and limping. Of the remaining 44 hips, the mean Harris hip score was 83, and 20% experienced moderate to severe thigh pain and 50% had a limp. Radiographically, 65% of the stems had subsided and 27% had migrated into valgus. Survivorship analysis predicted an 80% stem survival rate at 43 months. A precise fit and fill of the femoral canal is not in itself sufficient for femoral implant stability in total hip arthroplasty surgery.

Uncemented revision total hip arthroplasty: a 4-to-6-year review

A review of 52 cementless revision total hip arthroplasties in 51 patients with a 4- to 6-year clinical and radiographic followup was conducted. Mallory Head titanium alloy prostheses using proximally porous-coated femoral stems were used in all cases. There were 2 revisions of the femoral component only and 1 was an acetabular revision. At an average followup of 4.6 years, 5 (10%) unstable femoral stems had been rerevised and another 7 (14%) stems were unstable radiographically, but rerevision had been refused or postponed. Three (6%) sockets were considered unstable but no acetabular revisions have been done. Eleven of the 12 stem failures were in femora with moderate or severe prerevision femoral bone loss. The Harris Hip Score averaged 76 points for the entire group, and scores were much worse in patients with preexisting femoral bone deficiency. Twenty (40%) femoral fractures occurred during stem insertion. This short-term study shows inadequate fixation of proximally porous-coated femoral stems in revisions with femoral bone loss; adequate stability is achieved if bone loss is limited. Porous-coated acetabular fixation using fins and screws where necessary is adequate in the majority of cases.

Total hip arthroplasty

Total hip arthroplasty continues to be an extremely successful procedure, with ever-widening indications and regular improvement in technique, materials, and design. In the past year several studies were published evaluating the results of both cemented and cementless total hip arthroplasty at mid- to long-term follow-up. In addition, careful analysis of basic laboratory studies including finite-element analyses have added to our understanding of materials and design. Specific findings in the past year included poor results with cemented hips in younger patients at long-term follow-up of greater than 16 years. A lower incidence of loosening has been found for cobalt chrome-cemented components compared with titanium-cemented components. No difference was found in the results of metal-backed versus non-metal backed cemented acetabular components, and an increasing incidence of loosening was shown for cemented acetabular components with time. The newer cementless hip arthroplasties showed evidence of learning curve, particularly with regard to innovative design such as acetabular screw rings, whereas porous-coated hemispherical cups appeared to do well. Thigh pain continues to be a problem with cementless designs, and the controversy of titanium versus cobalt chrome for cementless femoral stem designs continues at full tilt.

Total hip replacement in dysplastic hips using femoral head shelf autografts

A consecutive series of 30 dysplastic hips were treated with total hip arthroplasty using femoral head autograft shelf reconstruction and were reviewed. Cemented cups were used in 13 hips and uncemented cups were used in 17 hips. The average followup was 8.1 years (range, 5.2-13.3 years). In the cemented group, the average preoperative Harris Hip Score was 44.8 points (range, 22-82 points), and in the uncemented group, it was 45 points (range, 23-61 points). At the final review, the average clinical score was 71.5 points (range, 46-98 points) in the cemented group, and in the uncemented group it was 87.5 points (range, 63-100 points). Of the 30 cases, only 3 had unsuccessful results, giving a success rate of 90%. In terms of the autograft, all united to host bone. Resorption, when seen in either cemented or uncemented cups, was minor and restricted to the lateral nonweightbearing part of the graft. The present study supports using shelf autografts to reconstruct dysplastic hips at the time of total hip arthroplasty. In this series, cemented and uncemented cups performed equally well.

Cementless total hip arthroplasty with autologous bone grafting for hip dysplasia

The fate of autologous femoral head bone grafts in acetabular roof reconstruction for severely dysplastic hips was investigated in 25 patients (25 cementless total hip arthroplasties). Twenty patients were women and 5 were men, whose average age was 55 years old; their average followup was 58 months. The average Harris Hip Rating improved from a preoperative value of 49 points to a postoperative value of 85 points. Radiographic measurements did not indicate any vertical or horizontal socket migration >2 mm. The grafted bone was incorporated by an average time of 7 months, and the acetabular sclerosis had disappeared in 23 hips by 9.4 months. One year after operation, the grafted bone was reduced in size significantly. Radionuclide uptake at the site of the bone graft remained high for as long as 18 months after the operation, then normalized. The autologous acetabular bone grafts were incorporated completely and remodeled 18 months after surgery.

Fixation of femoral allograft/prosthesis composites after 25%, 50% and 75% resection

The relative linear and angular displacements of proximal femoral reconstructions were compared within six different replacement techniques during ex vivo axial compression, mediolateral bending, and axial torsion in dogs. Each femur was osteotomized at 25%, 50%, or 75% of its length and the proximal portion subsequently replaced using one of six techniques. The reconstruction techniques included various combinations of proximal and distal fixation methods (graft fixation/distal fixation): (1) an allograft/prosthesis composite (APC) press-fit proximally and cemented distally (press-fit/cement); (2) APC cemented proximally and distally (cement/cement); (3) APC cemented proximally and the host bone/graft interface double plated (cement/plates); (4) APC cemented proximally and secured distally with bicortical screws (cement/screws); (5) APC secured proximally and distally with bicortical screws (screws/screws); (6) Segmental proximal femoral replacement cemented into the distal femur without an allograft (no graft/cement). For axial compression and mediolateral bending, the combined resection lengths revealed no differences in linear and angular displacements, respectively, between reconstruction methods. During axial torsion, the cement/cement technique allowed larger angular displacements than all but the press-fit/cement technique which had larger displacements than the cement/screws, screws/screws, and no graft/cement groups (p < 0.0001). Overall, the measured implant stability was solid and consistent as evidenced by small amounts of relative displacement and small error values.

The frequency of venous thrombosis in cemented and non-cemented hip arthroplasty

We randomised 250 patients undergoing unilateral, elective hip arthroplasty for osteoarthritis to receive either a cemented or a non-cemented Mallory Head prosthesis. Aspirin was used as prophylaxis against thromboembolism during the first half of the study and adjusted-dose warfarin during the second half. Postoperatively, all patients were asked to have bilateral venography and 80% agreed. All were evaluated clinically for pulmonary embolism. There was no difference in the frequency of deep-venous thrombosis between the two groups (50% cemented nu 47% non-cemented, p = 0.73; 95% CI of the difference -13.6% to 19.3%). Three of the 64 patients (5%) in whom venography had demonstrated isolated distal thrombi developed pulmonary emboli.

Remodelling and pain after uncemented total hip replacement

We studied 70 patients after uncemented hip replacement with the Lord prosthesis which has a relatively long, completely macrotextured stem. The mean follow up was for 9.5 years. We compared radiographs at one year after operation, at 5 years and at the last follow up. Twenty-five patients (36%) had deep or circumferential pain in the thigh. Of the 44 who were most active at 5 years those with thigh pain had less proximal cortical loss than those without (p < 0.05), most cortical bone formation distally and most often had incomplete radiolucent lines at the mid-stem level, perhaps indicating more elastic displacement of the bone relative to the prosthesis. The presence of radiolucent lines correlated with the increase in cortical width at 5 years (p < 0.01). Cortical remodelling continued after 5 years at all levels except at the tip (p < 0.01). The relative elastic displacement at the interface could cause pain and may contribute to the pattern of bone remodelling in the femur after uncemented hip replacement.

One stage revision arthroplasty of the hip for deep gram negative infection

We describe the use of one stage revision arthroplasty of the hip for deep gram negative infections. We have followed up 15 patients for an average of 8 years following operation. Two procedures failed, one at two years due to aseptic loosening and another because of persistent infection. We attribute the low reinfection rate (1/15) to meticulous surgical technique, preoperative parenteral antibiotics and antibiotic loaded cement. Both failures occurred in the two operations performed without antibiotic loaded cement. We do not recommend the use of plain cement for exchange hip arthroplasty in the presence of gram negative infection.

Hydroxyapatite-coated hip prostheses: difficulties with revision in 4 cases

The introduction of hydroxyapatite ceramic (HAC) coating on hip implants in 1985 (Furlong and Osborn 1991) was hailed as a major advancement for fixation of uncemented protheses. A problem that is now becoming evident is the extraction of these securely fixed prostheses for purposes of revision. We report on 4 patients who have had HAC-coated protheses implanted (2 as revision procedures and 2 at primary hip replacement) who had either continuing pain or a proven infection, so that it became necessary to carry out a revision hip arthroplasty. The prostheses were well-fixed and difficult to remove. A transfemoral, longitudinal osteotomy was used in 3 cases.

Total hip arthroplasty with Boneloc: loosening in 102/157 cases after 0.5-3 years

We report the outcome of 177 consecutive primary Charnley total hip arthroplasties inserted with Boneloc cement between November 1991 and November 1993. There were 107 women and 70 men. The mean age at the time of the operation was 71 years. 11 patients (13 hips) died during the follow-up period and 3 patients were too weak to attend a follow-up examination. Of the 161 remaining hips, 4 had been revised because of deep infection. The mean follow-up time for the remaining 157 hips was 2 (0.5-3) years. 24 hips had been revised and 6 are waiting for revision because of stem loosening. Of the remaining 127 hips, 72 showed radiographic signs of stem loosening and 2 hips were probably loose. Osteolysis was seen around the femoral component in 56 hips.

Femoral shortening in total arthroplasty for completely dislocated hips: 3-7 year results in 25 cases

During the years 1988-1991, we performed 25 total hip replacements for completely dislocated hips in 15 women and 4 men with a median age of 54 (17-67) years. In all cases, femoral shortening at the subtrochanteric level was performed to obtain reduction of the hip. The patients have been followed for 3-7 years. 1 patient experienced sciatic nerve palsy, 1 a delayed union and 1 a malunion at the osteotomy site. There were no signs of mechanical failure. All patients were satisfied. According to the Charnley hip score, function was excellent in 15 cases, good in 9 and fair in 1. The median Harris hip score improved from 43 at the time of operation to 93 at follow-up. 7 hips had a positive and 18 a negative Trendelenburg test. Before operation, all patients had a Trendelenburg limp. Our intermediate results indicate that femoral shortening at the subtrochanteric level is a suitable adjunct to total arthroplasty for a completely dislocated hip.

Hypotensive epidural anesthesia for total hip arthroplasty: a review

Hypotensive epidural anesthesia provides arterial hypotension to maintain a mean arterial pressure of 50 mmHg and it can be used to reduce blood loss during total hip replacement. The technique combines an extensive epidural blockade with an intravenous infusion of low-dose epinephrine. This results in arterial hypotension, but with preservation of central venous pressure, heart rate, stroke volume, cardiac output, and an augmentation of blood flow to the lower extremity. The technique does not appear to adversely affect cardiac, renal, or cerebral function and is used safely in patients with hypertension, ischemic heart disease, and in the elderly. Intraoperative blood losses during primary total hip replacement are between 100 and 300 mL. Perioperative transfusions have declined with the introduction of the technique. Radiological evidence of improved fixation of cemented acetabular components has been observed. Rates of deep-vein thrombosis are low: 2-3% proximal deep-vein thrombosis with an overall rate of 10%. In-hospital mortality is 0.1%; lower than previously published rates. In conclusion, hypotensive epidural anesthesia is safe and provides a number of advantages over conventional anesthetic techniques for total hip replacement.

[Reduced blood utilization in hip arthroplasty. Introduction of a blood preservation program]

In spring 1992 a blood conservation programme was established at Nordland Central Hospital with emphasis on indications for blood transfusion and intraoperative blood salvage (cell-saver). Medical records from all patients who underwent hip arthroplasty during the period 1 June 1991 to 28 February 1994 were examined. Mean transfusion of homologous SAGMAN-blood (bank blood) was substantially reduced during the period: for total prosthesis (n = 192) from 2.6 to 1.1 units per operation (p < 0.0001) and for hemiprosthesis (n = 66) from 3.1 to 0.9 units per operation (p = 0.0202). The percentage of patients in each of these two groups who did not receive blood transfusion at all increased from 18 to 61 in the first group (p < 0.0001) and from 24 to 65 (p = 0.0202) in the second. The substantial reduction of bank blood transfusion in this material conforms with current international transfusion guidelines. A particular benefit, considering the risk of transfusing contagious blood, is the marked increase in the number of patients who did not receive any blood product at all.

Bipolar hip arthroplasty in ankylosing spondylitis

Nineteen severely affected hips in 12 young patients with ankylosing spondylitis were treated with bipolar hip arthroplasty followed by a comprehensive postoperative rehabilitation programme. Additional operative procedures of adductor tenotomy, knee flexion release, supracondylar femoral osteotomy for genu valgum and tendo Achillis lengthening for equinus contracture were required in 13 limbs. After a mean follow-up of 45.8 months, results were good in all cases with respect to relief from pain, and there was significant improvement in posture and function. All the patients resumed employment. The average gain in sum total range of hip movements was 194 deg, and the mean preoperative Harris hip score of 27.8 improved to 82.6 after bipolar arthroplasty. Ectopic ossification did not develop in any case. Bipolar hip arthroplasty appears to be ideally suited for young patients with ankylosing spondylitis.

Incidence of deep sepsis in uncemented total hip arthroplasty using clean air facility as a function of antibiotic prophylaxis

Eight hundred and twenty two uncemented primary total hip arthroplasties (THAs) were performed between September 1980 and December 1992. The population that underwent uncemented THA can be divided into two groups based on the perioperative antibiotic prophylaxis: group 1 contains 439 primary THAs from September 1980 to September 1987 without antibiotic prophylaxis; group 2 contains 383 primary THAs who received short-term cefamandole prophylaxis from October 1987 to December 1992. Laminar air-flow and whole-body exhaust suits were used during the whole period of this study. Both groups consisted of relatively young patients with a mean age of 53.8 years in group 1, and 54.3 years in group 2. Using Kaplan-Meier survivorship analysis, the estimated survival rate of sepsis-free hips in group 1 was 97.9% at one year, 97.6% at two years, and 97.4% at three and up to eleven years. In group 2 with antibiotic prophylaxis no deep infection occurred; the rate of sepsis-free hips at five years is 100%. Under clean air conditions, antibiotic prophylaxis significantly decreased the incidence of deep sepsis (p log-rank 0.004).

Periprosthetic bone density in uncemented femoral hip implants with proximal hydroxylapatite coating

The short term results of a prospective dual energy x-ray absorptiometry (DEXA) study of periprosthetic bone remodeling around titanium femoral stems proximally coated with hydroxyapatite are presented. Thirty patients underwent DEXA scanning on the 15th and 45th postoperative days, 12th, 18th postoperative month. DEXA showed global femoral periprosthetic remodeling during the first 18 postoperative months. However, no significant variation in bone mineral density occurred around the lateral metaphyseal regions, where cancellous bone is greatest.

[Acetabular implant in Charnley's total arthroplasty. Review of 309 cases with a minimum of 15 years follow-up]

PURPOSE OF THE STUDY

The aim of this study was to appreciate the long term result of 309 acetabular components of total hip arthroplasty.

MATERIALS AND METHODS

All were performed using Charnley's prosthesis and cement, by one surgeon, between January 1972 and December 1975. Clinical function was graded according to Postel-Merle-d' Aubigné's scoring system (PMA score). We measured wear of polythylene using a personal method, on anteroposterior radiographs of the pelvis. Radiolucent line were appreciated by Delee and Charnley's criteria, migration by Massin's criteria. Survivorship curves were calculated with radiolucent lines, as migration, on 15 years. We compared the effect of different parameters on wear and loosening of the sockets.

RESULTS

At 15 years follow-up, we found 51.5 per cent hips with the highest PMA score (18). Revision for socket loosening was 3.88 per cent, the same for dislocations. Concerning 25 per cent of the sockets, wear of polyethylene was evaluated less than 0.065 mm a year, concerning 50 per cent of them, it was evaluated less than 0.11 mm a year, at last concerning 75 per cent of them, it was evaluated less than 0.16 mm a year. No significant correlation was established between the tilt of the acetabular component and the wear of polyethylene. We observed no radiolucent lines for 60 per cent of the implants, nor migration for 83 per cent of them. Statistical analysis proved the influence of the wear on radiolucent lines and migration.

DISCUSSION AND CONCLUSION

The analysis confirms a moderate wear of polyethylene during 15 years. We introduce an original method for its measurement and its formulation. This method allows a truly description of wear in long term results. This analysis confirms also that several parameters intercede on loosening; these are different if one considers radiolucent lines or migration. We do think at last, that the best positionning of the socket in the A.P. view should approach 35 degrees.

Prospective serial technetium diphosphonate and indium-111 white blood cell labeled imaging in primary uncemented total hip arthroplasty

Although technetium diphosphonate (TcMP) and Indium-111 white blood cell labeled (Ind-WBC) imaging are reported useful in identifying aseptic and septic loosening in cemented hip arthroplasty, their usefulness has not been identified in uncemented porous coated hip arthroplasty. We attempted to define the natural history of TcMP and Ind-WBC imaging in primary P.C.A. uncemented total hip arthroplasty. Twenty-five hips in 21 patients were scanned immediately postoperatively, at 3 months, 6 months, 12 months, 18 months, and 24 months after surgery with both TcMP and Ind-WBC tracers. Clinical and radiographic follow-up were also obtained at each interval. Intensity and distribution of tracer activity were recorded as well as the time when stabilization occurred around the acetabulum, femoral porous surface areas, and femoral stem tip. Acetabular cup and femoral porous surface areas stabilized in the first year on both TcMP and Ind-WBC imaging. Focal femoral hip activity continued at 24 months in 72% of TcMP and 24% of Ind-WBC images. TcMP and Ind-WBC images used to assess uncemented total hip arthroplasty should not be over interpreted. Although persistent intense activity after one year around the acetabulum and porous surface femoral areas should be considered abnormal for both TcMP and Ind-WBC scans, femoral tip activity is present in the majority of patients, with or without thigh pain, at 24 months on TcMP scans. Tip activity can also persist at 24 months on Ind-WBC images and should be interpreted in conjunction with TcMP images.

Hospital- and patient-related characteristics determining length of hospital stay for hip and knee replacements

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are among the most prestigious health care technologies. Their popularity has grown rapidly, and an increasing proportion of health care resources is allocated to them. We studied patient- and hospital-related factors that cause variation in a major determinant of hospital costs, the length of hospital stay (LOS) for THA and TKA. We gathered data on 10,288 hip and 5,173 knee patients with primary or secondary arthrosis from the Finnish Arthroplasty Register, which we linked with the Finnish Hospital Discharge Register. Patient- and hospital-related variations in LOS were explained using regression models. Of the patient-related factors, complications caused the greatest prolongation of hospital stay, but patient's age, gender, and charge category also influenced LOS. Hospital-related factors were major causes of LOS variation. In the hospitals the average case-mix-adjusted LOS ranged from less than a week to 3 weeks. The number of arthroplasties performed in hospital was inversely related to LOS. The within-hospital LOS figures for THA and TKA were strikingly similar and persistent.

Minimum four-year radiographic and clinical evaluation of results following femoral revision surgery with the S-ROM modular hip system

Thirty-four patients were reviewed following revision modular cementless reconstruction for proximal femoral deficiency. One patient underwent a Girdlestone conversion for sepsis at 3 years postoperatively, leaving 33 patients with an average follow-up of 51 months (range 48 to 62 months). The average age at surgery was 60 years, and there were 17 right and 16 left hips. Patients were assessed clinically using the Merle d'Aubigné and Postel hip rating system. Radiographic assessment was performed on preoperative and postoperative films. Femoral assessment was performed using the Engh fixation stability score, Gruen zonal system for radiolucencies and observing for the presence or absence of osteolysis. The average pain score was 5.4/6 with 88% having slight or no pain. Only one patient (3%) had thigh pain. Radiographically, the average fixation stability score was 21.7 with features of bony ingrowth present in 97%, and one case with features of stable fibrous ingrowth. There was no evidence of osteolysis.

A new classification for heterotopic ossifications in total hip arthroplasty considering the surgical approach

We would like to introduce a new classification for heterotopic ossifications (HO) after total hip arthroplasty which also considers ossifications within the region of the surgical approach. Furthermore, we will point out the influence of the surgical approach on the rate of HO. We analyzed 75 cementless hip arthroplasties with consecutive HO in a prospective study. The operations were performed by three experienced orthopaedic surgeons using an identical stem and a standardized lateral approach. All patients followed an identical rehabilitation procedure. Clinical and radiological data were documented in a standardized way. We found a total of 40 HO. Only 24 could be exactly classified by the known methods. Our classification considers 3 regions and 4 grades and is relevant for all 40 HO. Electrocauterisation to dissect the muscles in the lateral approach reduced the rate of HO: overall 64.3% to 39.4%; clinically relevant ossifications were reduced to 3.0% from 16.7%. Our new classification considers all HO concerned with total hip arthroplasty, especially those localized in the intertrochanteric region. The rate of HO can be reduced by using electrocauterisation for muscle dissection in the lateral approach.

[Alloplastic replacement of the proximal femur--indications, results and experiences]

The aim of this follow-up study was to see if, by the application of a special endoprosthesis for the replacement of the proximal femur, a radical tumour resection could be achieved and/or the function of the lower limb could be preserved or restored respectively. Between 11/1986 and 12/1992 a proximal femoral endoprosthesis was implanted in 9 patients with metastases in the proximal femur. In 21 cases this special endoprosthesis was used in the revision of conventional cemented total hip arthroplasties with loosening of the implant and extreme bone loss at the proximal femur. Twenty-three patients were seen for a follow-up examination with an average follow-up period of 20 months. In all cases the walking ability was preserved or restored respectively. The majority (22/23) of the patients had complete or, nearly complete pain relief. In those patients with skeletal metastases, were no cases of local reoccurrence. The majority problem of this endoprosthesis was the increased risk of dislocation. There is a clear indication for such a special endoprosthesis in the treatment of primary and secondary bone tumours in the proximal femur. For revision of cemented total hip prostheses with loosening and bony defects a revision prosthesis with uncemented distal fixation should be used.

Femoral component fixation with and without intramedullary plug. A 6-year follow-up

A total of 113 patients underwent a cemented total hip replacement (THR) operation involving femoral component fixation either without the use of a distal intramedullary plug (n = 57, group 1) or with the plug (n = 56, group 2). We studied the femoral component fixation radiographically at on average 6 years after THR. The cement coating was assessed as technically good in 86% and 95% of groups 1 and 2, respectively. There was radiographically diagnosable loosening of the femoral component at the follow-up in 25 cases in which stems were inserted without the intramedullary plug, and in 6 cases in those with the plug (P < 0.0008), and the mean subsidence of the femoral component was 5 mm in group 1 and 1.5 mm (P < 0.0003) in group 2, respectively. Osteolytic changes around the femoral component were noticed in both groups in equal numbers and with no statistical difference. The use of a distal intramedullary plug in the cementation of the femoral stem results in a better cement coating, reduces femoral component subsidence and ameliorates the loosening rates.

A no-touch technique of loading bone cement for gun injection at total hip arthroplasty

Cement guns are widely used to introduce bone cement into the proximal femur at total hip arthroplasty. Loading these devices is cumbersome. A convenient technique for filling cement gun inserts is described.

[Stabilization of the proximal femur in hip joint replacement using M.E. Müller's acetabular roof socket]

Extreme changes of the hip joint often require individual technical supplements in addition to the endoprosthesis. But the base of success are procedures using a model of prosthesis and a technique that are matured. This is available e.g. with the old M. E. Müller curved stem hip joint prosthesis. In special cases of extreme changes or damage of the proximal femur we perform in artificial joint-replacement of the hip or changing of prostheses a special kind of operative treatment. This is a combination of the Original-M. E. Müller curved stem endoprosthesis, long or short version of the femoral part, in addition fixated by bone-cement and M. E. Müller's special metal socket--primary indicated for stabilization of the acetabular roof. The indications for this method can be changes of proximal femur and hip-joint, especially dysplasias of pelvis or hip joint, extensive fractures especially in old patients, destructions in polyarthritis, dysplasia of pelvis and coxitis caused by juvenile chronic arthritis and long time therapy with corticosteroids, destructions, loosenings and fractures in changing operations of hip-endoprostheses. Until today we treated 15 different cases by this method--one case was operated 13 years ago--with good results, prooved by Merle d'Aubigné's score.

The Wagner revision stem in alloarthroplasty of the hip

Forty-one Wagner revision stems were implanted at the Orthopedic Department of the University of Tübingen between July 1990 and January 1993. We report the results of 37 patients at an average follow-up of 27 months (13-48 months) postoperatively. The main indication was stem loosening with considerable loss of bone. In addition, we used the implant 4 times in primary arthroplasty. At follow-up examination 33 patients (89%) were satisfied with the postoperative outcome. According to the Merle D'Aubigné score (12-point scale), 32 patients showed a poor functional result of less than 6 points preoperatively. Postoperatively, the results of 36 patients could be classified as very good to good. To categorise the radiological destruction of the implant bed, we used the femoral shaft defect classification of the DGOT (Deutsche Gesellschaft für Orthopädie und Traumatologie) in conjunction with the classification of Pak and Paproski [5, 11]. Twenty patients presented with trochanteric and calcar defects, and 11 patients with a combination of a calcar and shaft defect. We found a circular shaft defect in 2 patients. In 7 cases we assessed the bone remodelling postoperatively as very good, with strong newly formed bone structures, and in 25 cases as good, with remodelling of the old stem bed and bony structuring of the osteolyses. A secondary sinking in of the Wagner stem was seen in 7 cases. Only one stem had to be revised because of pain symptoms and loosening; in all other cases a secondary stabilisation of the revision-stem took place. With the Wagner revision stem, there is the possibility of achieving mechanical stability even in situations with massive bone loss. The evacuation of bone cement and granulation tissues is facilitated by the transfemoral approach, bony remodelling is accelerated, and bone grafting is often not necessary. As our short-term results show, the concept is a promising one. Nevertheless, we will be very careful in following these patients in the long term, as we have noticed stem sinkage in a small percentage of cases.

[Total hip prosthesis for chronic juvenile arthritis. A review of a series of 34 prosthesis]

PURPOSE OF THE STUDY

The purpose of this study was to analyse the results of total hip arthroplasty for chronic juvenile arthritis in order to evaluate risks, problems and benefits of this procedure.

MATERIAL AND METHODS

Between 1984 and 1992, 34 total hip prostheses were implanted for chronic juvenile arthritis in 20 patients. Most prosthesis were Zweymuller cementless prosthesis. Mean follow up was 5 years.

RESULTS

Results were good. In 85 per cent of cases, patients had a normal activity recovery. Pain relief was very good since in 80 per cent cases patients had a total indolence.

DISCUSSION

Beyond these good clinical results at this mean follow-up, the main interest of this study is to characterize two different periods in the surgical technique. The first period when cemented prosthesis was employed and the second one when cementless femoral implants with screwed acetabular component were used. Cementless prostheses appear to be a satisfying solution in this disease, preserving bones and showing very good radiological and functional results.

CONCLUSION

Furthermore, the very low complication rate despite general discomfort may prompt us to use total hip arthroplasty for the treatment of chronic juvenile arthritis.

The ROBODOC clinical trial: a robotic assistant for total hip arthroplasty

Operating room teams at three U.S. hospitals are participating in a controlled clinical trial to evaluate the use of a surgical robot in total hip arthroplasty. The robot, called the ROBODOC Surgical Assistant System, precisely prepares the femoral canal for the placement of a "press fit" cementless prosthesis. The Food and Drug Administration (FDA) requires that the robot, as an investigational device, be tested in a controlled clinical trial to demonstrate safety and efficacy. The clinical trial will include 300 patients who must meet specific criteria before enrollment and randomization. This article describes the need for new surgical technology, ROBODOC's development history, hardware and software components of the system, the patient population and surgical protocol for the clinical trial, special nursing care requirements, and considerations for patient rehabilitation.

Failure of trochanteric osteotomy in total hip replacement: a comparison of two methods of reattachment

A retrospective study was undertaken to assess the rate of trochanteric union after a primary Charnley total hip replacement. In one group the trochanter was reattached with Wrobleski spring wire, and in the second group with a Dall-Miles clamp. Non-union occurred in 29% of each group. The high rate of failure may have implications for morbidity and function. Alternative surgical approaches for total hip replacement should be considered.