Oblique femoral osteotomy in cementless total hip arthroplasty. Prospective consecutive series with a 3-year minimum follow-up period

Success of total hip arthroplasty using cementless implants is dependent on intimate contact of the prostheses with viable host-bone and achievement of optimal fit and rigid implant fixation. A technique of oblique femoral osteotomy has been used to correct proximal femoral deformity and to facilitate difficult revision surgery in selected cases. This prospective study included 26 osteotomies performed in 25 consecutive patients with a minimum follow-up period of 3 years. The median follow-up period was 50 months. Eighty-four percent of the reconstructions remained in situ at the final follow-up examination, with 81% of them rated clinically excellent or good. Three stems were revised for aseptic loosening at a mean interval of 46 months. One additional femoral revision was necessary for nonunion of the osteotomy. Two of the remaining stems were classified as radiographically loose. Although oblique femoral osteotomy serves as a useful adjunct surgical technique in difficult femoral reconstructions, nearly 25% of the hips in this study either failed or were loose at the medium-term follow-up examination. Long-term success of this technique with cementless prostheses remains to be defined.

Migration of uncemented, long-stem femoral components in revision hip arthroplasty. A 2-8 year clinical follow-up of 45 cases and radiostereometric analysis of 13 cases

We reviewed after 48 (24-90) months the clinical results in 45 cases of revision hip arthroplasties where an uncemented, long-stem femoral prosthesis (BIAS, Zimmer) had been used. A subgroup of 13 cases was followed with radiostereometric analysis (RSA) for 2 years. 3/45 cases had been revised, another 12 had unsatisfactory pain scores. The median Harris score was 69 (26-99). 12/13 stems migrated; 11 subsided 4.1 (0.4-7.9) mm, and 8 migrated posteriorly 2.9 (1.9-9.6) mm. The poor clinical results and large migrations speak against the use of this prosthesis in revision hip arthroplasty.

Endoprostheses for osteonecrosis of the femoral head. A comparison of four models in young patients

Eighty-eight hip arthroplasties were carried out in 75 patients, all aged 50 years or less, with osteonecrosis. All the operations were carried out by one surgeon. Four different methods were used: a standard cemented arthroplasty; a cemented THARIES surface replacement; an uncemented surface replacement; a cemented titanium femoral surface hemiarthroplasty. Comparable clinical improvement occurred in all 4 groups initially. Aseptic loosening, with intersurface degradation and osteolytic lesions, was the most common cause of failure in the 3 types which had a polythene bearing. Polyethylene is the major contributor to bone loss around the endoprosthesis and loosening. Fixation of the surface hemiarthroplasty remained intact in every patient and failure was secondary to wear of the acetabular cartilage. We recommend surface hemiarthroplasty as an interim solution for young patients with stage III or early stage IV osteonecrosis because this procedure conserves bone stock, there is little osteolysis and it can easily be revised.

Loss of bone stock with cementless hip arthroplasty

One hundred four porous-coated anatomic cementless hip arthroplasties followed from 2 to 6.5 years (mean, 50 months) were studied. Ninety-four percent had excellent clinical results. Thigh pain occurred in 23% of patients, but was severe in only two. "Cancelization" and rounding off of the calcar were noted in 83% of hips, whereas localized osteolysis occurred in 24 femurs and one acetabulum. Ten of these measured more than 10 mm, and all of those in the femur were located proximally. None of these patients were symptomatic and none have come to revision. Ultrahigh-molecular-weight polyethylene wear and plastic debris were implicated as the cause of osteolysis. Lytic lesions were seen only after 3 years and occurred only in patients with 32-mm femoral heads in whom the outer diameter of the acetabular component was 52 mm or less. Use of excessively thin ultrahigh-molecular-weight polyethylene in these patients may have predisposed them to accelerated wear. Section modulus mismatch resulting in stress protection is considered as an alternate mechanism of proximal bone resorption.

Cemented revision for aseptic acetabular loosening. A review of 387 hips

We reviewed the records and radiographs of 387 cemented revisions of aseptic loose sockets after total hip replacement at a mean follow-up of 5.5 years. The clinical results were satisfactory, but at the last radiological assessment 38 sockets (9.8%) had a continuous zone of demarcation greater than 1 mm thick and another 35 (9%) showed migration. Poor acetabular bone stock had a profound influence on the outcome of revision surgery, but the results of cemented revision were comparable to those reported for cementless revision at similar mean follow-up.

Poor results of the Ribbed Hip System for cementless replacement

We reviewed 12 patients six years after they had undergone total hip replacement with a cementless prosthesis, the Ribbed Hip System (Waldemar Link GmbH & Co, Hamburg, Germany). Aseptic loosening of one or both components had necessitated revision surgery in seven patients, in five within two years of operation. In view of our experience we question the wisdom of allowing the uncontrolled use of new prosthesis without postoperative surveillance.

Effect of preoperative autologous blood donation and intraoperative and postoperative blood recovery on homologous blood transfusion requirement in cementless total hip replacement operation

BACKGROUND

Blood transfusion is often necessary in operations for total hip replacement (THR). This study was done to investigate the efficacy of three different methods of autologous blood conservation and transfusion in patients undergoing primary THR without cement.

STUDY DESIGN

One hundred fifty-five patients with osteoarthritis underwent unilateral cementless THR using normotensive general anesthesia performed by a single surgeon. The patients were divided into four groups depending on which conservation method was used. Ten different demographic and hematologic parameters were recorded and analyzed by using analysis of the variance and multiple regression methods.

RESULTS

All three methods were effective in reducing the need for homologous blood transfusions. The greatest benefit was realized when both preoperative autologous blood donation and intraoperative salvage using the Cell Saver were combined. The addition of postoperative salvage and retransfusion of wound drainage blood using the Solcotrans System did not significantly reduce further the chance of homologous blood transfusions.

CONCLUSIONS

The data from this study were similar to previously published reports. Regression analysis confirmed the correlation among the different variables studied. We currently offer preoperative donation and intraoperative salvage with the Cell Saver to patients undergoing cementless total hip replacement.

Blood coagulation and fibrinolytic activity during femoral neck prosthetic replacement using bone cement

To assess the blood coagulative and fibrinolytic responses during cemented femoral neck replacement, we measured these parameters in 9 patients, including anti-thrombin III (AT-III), prothrombin time (PT) and activated partial thromboplastin time (APTT) before surgery, just before packing bone cement and after the insertion of the prosthesis. We also measured thrombin-anti-thrombin III complex (TAT), plasmin-alpha 2-plasmin inhibitor complex (PIC), and D-dimer. A significant increase in APTT, and decrease in AT-III and PT were observed before the insertion of bone cement and prosthesis. The value of TAT and D-dimer increased significantly after the insertion of the prosthesis, but there were no significant changes in PIC. The data suggest that blood coagulation is activated after the insertion of bone cement and prosthesis into the femoral shaft, and in addition, the fibrinolysis is also accelerated secondary to the activation of the coagulation. Further investigations are needed to establish whether the activation of the coagulation induced by the cemented replacement exerts a great influence on the appearance of pulmonary thrombosis or circulatory depression.

Cemented Charnley revision arthroplasty for severe femoral osteolysis

We reviewed prospectively cemented stem revision in 106 patients with severe femoral endosteal bone lysis without infection. Bone grafts were not used in any of the patients. The minimum follow-up was three years (mean 6 years 4 months). At the last review 76.4% of the patients were free of pain and 17.9% had only mild or occasional discomfort; radiographs showed well-fixed stable stems in 101 (95.3%). An intramedullary cement plug was used at revision to improve stability in 97.7%. There was new endosteal osteolysis after revision in 17 patients; only two had severe changes. Seven hips (6.6%) required a second revision; only four of these (3.8%) were for stem loosening. Survivorship of the revised stem, using radiological evidence of stem loosening as the end point, was 95.8% at seven years. The results of stem revision arthroplasty using cement in the presence of massive endosteal cavitation are satisfactory.

[Monitoring of bone marrow spilling and cardiopulmonary changes in fat embolism syndrome]

After long bone fractures, as well as hip or knee total arthroplasty, the increase in intramedullary pressure induces bone marrow release into the circulation in more than 90% of patients. Three to four percent of the patients reveal fat embolism syndrome with pulmonary and cerebral involvement and a petechial rash. In about 20% of these patients a fulminant and fatal course is possible. Although fat embolism syndrome was described more than a century ago, there is still no sufficient therapeutic strategy. Because of these facts we try to prevent fat embolism syndrome and monitor patients at risk perioperatively. We have evaluated different diagnostic methods and monitoring facilities and recommend pulse oximetry, capnography, ECG, blood pressure controls and, if indicated, blood gas analyses for perioperative monitoring. Patients at risk and patients who are suffering from fat embolism syndrome require more intensive monitoring, such as transesophageal echocardiography and a pulmonary artery catheter to obtain more detailed information about the hemodynamic and oximetric variables. Furthermore, these patients must be admitted to an intensive care unit.

Total hip replacement with bone grafting using the removed femoral head in severe acetabular dysplasia

We carried out total hip replacement and femoral head bone-grafting in 21 hips with congenital dysplasia or dislocation, obtaining as much support of the cup by the host bone as was possible. A Charnley small or extra small cup was implanted in 20 cases and a miniature femoral component in 15. The results of 20 hips were reviewed prospectively at an average of 10 years. Nineteen patients had no pain. Three cups showed radiological signs of loosening, one was causing other symptoms. All the stems, except one, were radiologically stable and were symptomless. The graft had fused without resorption in 18 cases. Two grafts showed severe resorption with loosening of the cup. Satisfactory long term results of total hip replacement and femoral head bone-grafting can be achieved using special surgical techniques and the appropriate components. Medialisation of the hip and the use of small cups are important in allowing sufficient support of the prosthesis by bone so that the distribution of load on the graft is minimised. The grafted femoral head provides suitable bone stock for reconstruction of the acetabulum.

Extensile anterior column acetabular reconstruction in revision total hip arthroplasty

The extensile triradiate approach, with anterior-column plate reconstruction using structural allografts, was used in 12 cases. Pelvic discontinuity requiring posterior-plate application was present in eight of these cases. Allograft reconstructions seemed to be radiographically incorporated by approximately 8 months postoperatively and all discontinuities united. The results were excellent in four cases, good in two cases, fair in three cases, and poor in three cases. Two cups were revised for loosening. Deep sepsis resulted in graft and component removal in two cases. At reexploration, discontinuity and allografts were noted to be healed in these cases.

[Modified surgical technique for reduction of bone marrow spilling in cement-free hip endoprosthesis]

Since 1970 the fat embolism syndrome (FES) has been recognised as a severe complication of cemented total hip arthroplasty (THA). Initially and still today the toxicity of bone cement has been though to be responsible for the cardiorespiratory problems. Meanwhile several reports have confirmed the causal relationship between intramedullary pressure (IMP), bone-marrow release into the circulation and subsequent cardiorespiratory deterioration during cemented THA. In recent publications it has been reported that bone-marrow release due to increased IMP also occurs during cementless THA. The clinical implication of these observations is controversial. For this reason in the first part of this paper two autopsy-proven FES deaths and five further clinically manifest FES cases are presented. In the second part of the study, IMP courses during four different surgical techniques (2 conventional, 2 modified) are compared. The aim of the modified surgical technique developed in our department was to minimize IMP peaks and bone-marrow release during cementless THA. Both modified techniques showed significantly lower IMPs during opening of the medullary canal, preparation with rasps, and implantation of the prosthesis than the conventional techniques. The observed FES cases for the first time strongly confirm the clinical relevance of the FES, also during cementless THA. On the basis of the data presented we recommend the modified surgical technique to reduce bone-marrow release during cementless THA.

Cementless total hip arthroplasty with AML, PCA and HGP prostheses

Two hundred and fourteen patients who had 270 cementless hip prostheses were followed for 2 to 8 years. PCA (Porous-Coated Monatomic), AML (Monatomic Medullary Locking) and HGP (Harris-Galante-Porous) femoral stems and acetabular cups were used without any preference for the prostheses. The overall clinical results were similar for the three prostheses with average Harris hip scores of 93, 93 and 91 respectively. Four PCA prostheses had radiological aseptic loosening and one was revised because of polyethylene wear. There was no loosening in the AML and HGP prostheses. Pain in the thigh, usually slight, occurred in 17% of AML, 21% of PCA and 19% of HGP prostheses. Five years after operation, radiological changes such as migration, calcar remodelling and radiolucent lines were the same for the 3 prostheses, but bony ingrowth was greater with the AML femoral stems.

Transfusion practice in support of surgery during introduction of a hospital-based autologous presurgical blood donor program

OBJECTIVES

To assess blood use in support of elective surgery during the introduction of a hospital-based presurgical autologous blood donor program and to identify changes in transfusion practice.

DESIGN

Case series over a 3-year period.

SETTING

A tertiary-care, university-affiliated hospital.

PATIENTS

All patients (887) who underwent, electively, one of four major surgical procedures between Apr. 1, 1990, and Mar. 31, 1993, during introduction of the hospital's autologous blood transfusion program. The criteria for donation were wide.

INTERVENTIONS

Hip and knee arthroplasty, radical hysterectomy and radical prostatectomy.

MAIN OUTCOME MEASURES

Increase or decrease in the use of autologous or allogeneic blood for transfusion for the four surgical procedures over the study period.

RESULTS

For hip arthroplasty, the use of blood decreased significantly overall. The use of blood in support of radical hysterectomy and prostatectomy decreased but not significantly. In knee arthroplasty, blood use increased for reasons still under investigation. The contribution of autologous blood for the four procedures increased over the 3 years of the study from 17% to 55%, and constituted 3.8% of red cell and whole blood transfusions. Avoidance of allogeneic transfusion in the 3rd year of the study was 64% for patients who underwent hip arthroplasty, 71% for those who underwent radical prostatectomy and 77% for those who underwent knee arthroplasty and radical hysterectomy.

CONCLUSIONS

Hospital-based autologous blood collection with wide eligibility criteria can contribute significantly to the availability of blood for elective surgery and can prevent allogeneic blood exposure in about 75% of patients who undergo, electively, one of four common procedures. Compared with other centres, there is room for further reduction in allogeneic blood exposure.

Avascular necrosis of the hip treated by hemiarthroplasty. Results in renal transplant recipients

Osteonecrosis of the femoral head is common complication in renal transplant recipients. Despite the young age of these patients, replacement arthroplasty is often used in treating symptomatic individuals. Between 1983 and 1990, 22 cemented biarticular hemiarthroplasties were performed in 16 consecutive patients with advanced osteonecrosis of the hip. The average interval from initial transplant to arthroplasty was 28 months (range, 11-63 months). The mean age at the time of arthroplasty was 40 years (range, 21-66 years), and all patients were treated with steroids and immunosuppressants at the time of surgery. The average preoperative Harris hip score was 27 points (range, 4-46 points). The mean follow-up period was 40 months (range, 24-71 months). All patients had improvement in pain. Eighty percent of the patients reported a slight or mild limp, although only 25% demonstrated a positive Trendelenburg sign. The average postoperative Harris hip score was 88 points (range, 71-96 points), with 9 hips rated excellent, 12 good, and 1 fair. One patient fractured her acetabulum 26 months after arthroplasty, which resulted in progressive subluxation of the prosthesis. It was revised to a total hip arthroplasty. Another patient developed symptomatic aseptic loosening after 30 months. Apart from this patient there was no other radiologic evidence of loosening in the remainder of the series. Only one patient had demonstrable acetabular protrusion. Twenty percent of the hips had asymptomatic heterotopic ossification. The early results of using a cemented, biarticular hemiarthroplasty in this young group of renal transplant recipients appear encouraging. There was no evidence that this prosthesis causes accelerated acetabular erosion or early loosening.(ABSTRACT TRUNCATED AT 250 WORDS)

Total hip replacement after intertrochanteric osteotomy

From 1980 to 1993 we inserted 216 total prostheses into hips which had been treated by varus and valgus-extension intertrochanteric osteotomy. The technique of the operation was more difficult than in hips operated on for the first time because of anatomical changes produced by the osteotomy in the surrounding structures. We have had complications which taught us how to prevent and deal with these problems.

[Value of venting drilling for reduction of bone marrow spilling in cemented hip endoprosthesis]

A rise in intrafemoral pressure during the implantation of a cemented hip replacement seems to have been proven in experimental and clinical studies. The biological system of the femur equalizes this pressure by means of its venous drainage system, which is located at the linea aspera and distal metaphysis. The intravasation of bone marrow, fat and debris that follows leads to characteristic clinical signs of a more or less distinct embolism of the lung, which is indicated by an intraoperative drop in blood pressure and end expiratory pCO2. The logical therapeutic measure to avoid biological self-drainage of the femur is to create sufficient extrafemoral drainage via a unicortical venting hole distal from the expected tip of the prosthesis, which must be combined with an intramedullary plug to preserve the desired effect of the high-pressure technique for cement-bone interlocking. If it is also possible to install a vacuum in the medullar cavity of the femur to draw the cement into the cancelleous bone, an optimal cementing result in combination with minimal patient risk can be promised.

Acetabular reconstruction in revision total hip arthroplasty

Acetabular revision surgery is always associated with some degree of bone loss. Where an intact peripheral rim is present it can be used to achieve ingrowth and cementless prosthetic fixation. Where major segmental defects are present and prosthetic stability is not possible in host bone, structural allografts may be necessary to satisfy the principles of acetabular reconstruction. Using quality bone, proper fixation, and buttressing of structural allografts against host bone, a high degree of success can be expected. The majority of acetabular revisions can be reconstructed with large hemispherical sockets and adjuvant screw fixation and the use of bulk allografts should be reserved for those reconstructions where no good alternative exists.

Single-stage, bilateral, cementless total hip arthroplasty

Single-stage, bilateral, cementless total hip arthroplasties were performed in 92 patients (184 arthroplasties) between March 1984 and December 1989. The clinical and radiographic findings were retrospectively evaluated, and the effects of weight bearing on the clinical and radiographic outcomes of the patients' prostheses were assessed. With a follow-up period ranging from 24 to 77 months (average, 44 months), the postoperative Harris hip scores averaged 94.6. Radiographic assessment at the most recent follow-up examination showed that 70% of the femoral components were optimally fixed, 26% were stable, and 4% had failed. Ninety-six percent of the acetabular components were optimally fixed. There were six acetabular component failures. These results indicate that single-stage, bilateral, cementless total hip arthroplasty can be performed without compromise to either hip if initial fit is achieved in both the metaphyseal and diaphyseal portions of the femur. Moreover, weight bearing did not adversely affect the initial stability and possible bone ingrowth, further implicating initial rigid fixation as paramount among the factors influencing the amount of ingrowth into the prosthesis.

Current attitudes to cementing techniques in British hip surgery

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The canine cemented modular total hip prosthesis

Total hip replacement (THR) is well established as a treatment modality for dogs with noninfectious, nonneoplastic, disabling conditions of the coxofemoral joint. Since the mid 1970s, a fixed-head prosthesis has been used in this procedure. A modular prosthesis, which is based on many of the technical advances found in human prostheses, now is available for use in veterinary medicine. The prosthesis, surgical instrumentation, surgical technique, and clinical results have been evaluated in a prospective study conducted at The Ohio State University's College of Veterinary Medicine. The modular prosthesis provides results equal to or better than the fixed-head prosthesis.

Hydroxyapatite clay for gap filling and adequate bone ingrowth

In uncemented total hip arthroplasty, a complete filling of the gap between femoral prosthesis and the host bone is difficult and defects would remain, because the anatomy of the reamed intramedullary canal cannot fit the prosthesis. Therefore, it seems practical to fill the gap with a clay containing hydroxyapatite (HA), which has an osteoconductive character. The clay (HA clay) is made by mixing HA granules (size 0.1 mm or more) having a homogeneous pore distribution and a porosity of 35-48 vol%, and a viscous substance such as a saline solution of sodium alginate (SSSA). In the first experiment, the ratio of HA granules and sodium alginate in SSSA is set for the same handling properties of HA clay and polymethylmethacrylate bone cement (standard viscosity) before hardening. As a result, the ratio is set for 55 wt% of HA in the clay and 12.5 wt% of sodium alginate in SSSA (i.e., HA:sodium alginate:saline solution = 9.8:1:7). In the second study, the gap between the femoral stem and bone model is completely filled with HA clay. However, the gap is not filled only with HA granules or HA granules mixed with saline solution. In the third animal experiment, using an unloaded model, histology shows that HA clay has an osteoconductive property bridging the gap between the implant and the cortical bone without any adverse reaction. HA clay is considered a useful biomaterial to fill the gap with adequate bone ingrowth.

Reaming technique of the femoral diaphysis in cementless total hip arthroplasty

Distal fixation enhances initial torsional stability of cementless femoral components in primary and revision total hip arthroplasty. Surgical technique affects the quality of distal fixation, and too aggressive a technique can cause femoral fracture during insertion of the stem. Thirty-five adult human cadaveric femoral specimens were implanted with either a standard or long femoral stem. Control specimens were reamed 0.5 mm less than the diameter of the distal cylindrical portion of the stem and were broached line to line proximally. The proximal femur was removed from the remaining specimens to allow assessment of distal fixation. The controls outperformed the distal-only fixation groups in all testing modes, illustrating that proximal and distal fixation work in concert to resist torsional load. The average failure torque in underreamed specimens with only distal fixation was 23.6 Nm for standard length stem specimens and 41.3 Nm for long stem specimens, whereas the average failure torque for specimens with only distal fixation prepared by a line-to-line reaming technique was only 6 Nm. The estimated length of tight distal fit should be 10 to 40 mm to obtain sufficient initial torsional stability of the stem and still avoid intraoperative femoral fracture.

Bipolar hip arthroplasty without acetabular bone-grafting for dysplastic osteoarthritis. Results after 6-9 years

The authors report the clinical and radiographic results of 36 bipolar hip arthroplasties after performing excavation of the steep and shallow acetabulum without acetabular bone-grafting for dysplastic osteoarthritis. The procedures were carried out between 1981 and 1985. Survivorship analysis showed that 84.6 of the bipolar hip arthroplasties were retained for 8 years. Twenty-nine patients, which were followed for 6-9 years after surgery, were reviewed. Severity of acetabular dysplasia was classified according to the method of Crowe. Class 1 included 17 hips and class 2 included 12 hips. The average preoperative clinical score was 49 points. The average postoperative clinical hip score improved to 87 points after 6 years. Twenty-seven of the 29 hips assessed were classified as either excellent or good by Charnley's function score. Stress fracture, due to excessive acetabular excavation at the time of surgery, and femoral component loosening were major symptomatic complications. The cessation of radiographic evidence of migration of the bipolar socket was recognized in 25 of 29 procedures at 6 years after surgery (86.2%). Cineradiographic study demonstrated that the abduction motion under standing position for 20 of 24 hip joints functioned dominantly at the inner-bearing and metallic-stem interface.

The cemented acetabular component of a total hip replacement. All polyethylene versus metal backing

The increasing use of a cementless acetabular component with a total hip replacement requires the need for metal backing, but metal backing with cement in the author's use has been less than optimal. The intention, therefore, was to evaluate all cemented acetabular components, with and without metal backing, used by the author, to offer a standard by which other acetabular components can be compared. From 1969 to 1983, 238 Charnley, 141 Mueller, 555 T-28, 100 Miami Orthopaedic Surgical Clinic total hip replacements with cemented all-polyethylene acetabula, and 134 Miami Orthopaedic Surgical Clinic total hip replacements with a cemented metal-backed acetabula were performed and followed from 1 to 22 years. The cemented acetabular component failure rates for the Charnley, T-28, and all-polyethylene Miami Orthopaedic Surgical Clinic were 14%, 10%, and 9%, respectively. There was a 20% failure rate in the Mueller and metal-backed Miami Orthopaedic Surgical Clinic acetabular components. The Charnley (p < 0.0001), T-28 (p < 0.0001), all-polyethylene Miami Orthopaedic Surgical Clinic (p < 0.0001), and Mueller (p < 0.012) total hip replacements demonstrated statistically improved survival rates as compared with the metal-backed Miami Orthopaedic Surgical Clinic acetabular components. The Charnley (p < 0.0001) and T-28 (p < 0.0003) sockets survived statistically better than the Mueller sockets.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical approach and nerve palsy in total hip arthroplasty

A prospective study of the relation between nerve palsy and the surgical approach used for total hip arthroplasty was performed on 1,000 consecutive patients. A postoperative neuropathy was diagnosed in eight patients for an overall prevalence of 0.8%. The overall prevalence of nerve palsy with the posterior approach was 0.6% and 1.0% with the lateral transtrochanteric approach. In both primary and revision surgeries, there were no statistical differences between the two approaches. Our data suggest that it is the anatomic variations and complexity of the reconstruction that are associated with nerve injury and not the surgical approach per se. The increased prevalence of nerve palsy seen in revision surgeries (1.4%) regardless of the approach supports this position.

Atrophy of the proximal part of the femur after total hip arthroplasty without cement. A quantitative comparison of cobalt-chromium and titanium femoral stems with use of dual x-ray absorptiometry

The purpose of this study was to compare the density of periprosthetic bone about titanium and cobalt-chromium stems that had been inserted without cement. The analysis was done, three to four years after a total hip arthroplasty, in a retrospectively matched cohort of thirty patients. Fifteen patients had a stem that was collarless, proximally coated, and made of titanium; the other fifteen had a stem of similar design that was made of cobalt-chromium. The criteria for selection in the study included an excellent clinical and radiographic result and separately calculated modified Harris and Mayo hip scores of more than 94 points. All stems had radiographic evidence of osseous ingrowth. A comparison of the bone-mineral density about the two different types of stem with dual-energy x-ray absorptiometry revealed a significant difference only along the calcar of the femur. There was no significant difference about the remaining, preponderant portion of the proximal part of the femur. Our data suggest that the difference in the modulus of elasticity between the two types of stem had little effect on the loss of bone-mineral density in most of the proximal part of the femur after arthroplasty without cement.

Total hip replacement for developmental dysplasia of the hip

Total hip arthroplasty relieves pain and improves function for many patients with endstage arthritis secondary to developmental dysplasia of the hip. Acetabular dysplasia, however, presents a special problem for total hip reconstruction in these patients. Structural bone grafting with femoral head autografting to the dysplastic acetabulum and cementing acetabular components into the graft provides satisfactory short-term results, but longer-term followup data show high acetabular component failure rates. At a mean followup period of 7 years, 20% of components were loose, and at a mean followup period of 12 years, 46% were loose. Noncemented porous-coated hemispherical acetabular components have considerably expanded the success of total hip replacement without the need for structural bone grafting in such patients. At a mean followup period of almost 7 years, none of the acetabular components were reported to be loose in 1 series. For most patients, the acetabular dysplasia can be managed by techniques such as reaming deeper, using small-diameter porous-coated acetabular components, using screws to provide rigid initial stability for the components, increasing the height of the prosthetic hip center, and covering small portions of the components with bone graft chips if necessary.

The Bateman bipolar prosthesis: a prospective study in primary osteoarthritis

We present a prospective study of Bateman bipolar prosthesis performed over 5 years in Perth. All patients were treated for primary osteoarthritis using a cementless straight Moore stem and the bipolar acetabular component. Assessment was made at 6-monthly intervals. Harris hip scores were calculated and radiological parameters of inner bearing movement, component migration and proximal osteoporosis were assessed. The group comprised 76 prostheses in 72 patients. The mean Harris hip score at 3 years follow-up was 85, however with a wide range between 55 and 99. A total of 30% of patients at 3 years follow-up had a Harris hip score at less than 70. Twenty-seven per cent of the prostheses at 3 years had restriction of movement at the inner bearing and 43% were judged to have moderate or severe stress shielding around the proximal femur. The clinical results were unpredictable with thigh pain being a significant problem. Because of the unpredictable results we would not advocate the use of the Bateman prosthesis in primary osteoarthritis.

The case for cementing all femoral components in total hip replacement

Two important new observations underlie the recommendation that it is advisable to cement all femoral components of total hip replacement (THR). First, it is now clear that improved cementing techniques have remarkably extended the durability of the cemented fermoral fixation and markedly reduced the incidence of lysis. Second, the incidence of femoral lysis around all noncemented femoral components that have been reported with minimum 5-year follow-up is high, increasing and alarming. With good cementing in primary THR, the incidence of femoral revision for aseptic loosening at 15 to 18 years after the initial operation is only 2% to 3%, even in those 50 years of age and younger. Moreover, lysis is rare. Similarly, with improved femoral cementing, femoral revision is also far more effective. The juxtaposition of the excellent results with improved cementing and the high and rising lysis rates around noncemented femoral components clearly mandate the use of contemporary cementing procedures for all femoral components, regardless of the age or sex of the patient, the diagnosis and whether the procedure is a primary or revision one.

Total hip replacement: the case for noncemented femoral fixation because of age

Both noncemented fixation and improved cemented fixation of total hip replacements emerged to counteract the clinical and radiographic failures of early cemented procedures. A randomized clinical trial comparing a second-generation cemented with a second-generation noncemented total hip replacement demonstrated that in the medium term both implants allow excellent, disease-specific, global and functional capacity outcome measures. No significant differences existed between the cemented and noncemented implants in terms of these parameters or revision rate. Cost-to-utility analyses of both types of replacements revealed that total hip replacement is one of the most cost-effective medical interventions. Noncemented total hip replacements seem as efficacious as cemented devices in patients younger than 70 years.

Choosing the socket in total hip arthroplasty

Significant improvements have been made in the long-term results of cemented femoral components, but there has been little improvement in the results of cemented acetabular components. Polyethylene wear debris has been proposed as the most important factor causing loosening of cemented acetabular components. Polyethylene thickness and femoral-head size affect the rate of acetabular wear and loosening. The early results of total hip arthroplasty with noncemented acetabular components are promising, and many feel that they represent the state of the art. The hemispheric components with a porous coating have proven superior to most of the screw ring designs. There are potential disadvantages with the use of screws to augment fixation of the hemispheric components, and recently it has become popular to under-ream the acetabulum and press-fit the oversized acetabular component without the use of screws.

The surgical approach to total hip arthroplasty: complications and utility of a modified direct lateral approach

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Osteointegrated porous-coated titanium implants

The study deals with the bone-prosthesis interface using an in vivo experimental animal model in relation to loading and walking on the prosthetized hip, studied by force plate analysis. The interface is studied from a histological and morphometric point of view by means of a LECO 2001 system. Results show that titanium favors osteointegration according to the criteria of Branemark even in conditions of physiological loading; bone ingrowth (that cannot be considered a true process of osteointegration) was 27.6%; furthermore, we quantified two models of periprosthetic bone growth in an osteointegrative sense: total bone bonding (27.4%) and core bone bonding (bone that grows in direct contact with the prosthesis) that was 16.1%. Finally, osteointegration tends to be greater where contact between the bone and the prosthetic is closer, regardless of the type of prosthetic coating.

Comparison of healing of allograft/endoprosthetic composites with three types of gluteus medius attachment

This study compared three methods of gluteus medius tendon attachment to an allograft/endoprosthetic composite of the proximal 25% of the femur in a canine model. The three methods were bone to bone, tendon to bone, and tendon to tendon attachment. In an in vivo study, 24 dogs were assigned to three groups of eight dogs each, and serial radiography and weight-bearing analyses were performed throughout the study. The dogs were killed at 6 months, and the specimens were tested in tension to failure and were analyzed histologically. In an in vitro study, each repair was done on six limbs, with a contralateral limb serving as a control for each. In these specimens, the bone to bone attachments were significantly stronger (99.1% of the controls) than the tendon to bone attachments (71.8% of the controls) and the tendon to tendon attachments (40.0% of the controls); there were no differences in tensile stiffness among the three types of attachment. By 6 months, the tensile strength of the tendon to tendon attachments increased significantly and that of the tendon to bone attachments decreased significantly. There were no significant differences in tensile strength among the three types of attachment. The tensile stiffness of the bone to bone attachments (91.0% of the controls) was significantly greater than that of the tendon to bone attachments (40.8% of the controls) but not significantly different from that of the tendon to tendon attachments (63.2% of the controls). The bone to bone attachment was associated with increased bone resorption, bone remodeling, and bone porosity, accompanied by thinner allograft cortices, when compared with the other types of attachment. In dogs with a bone to bone attachment, weight-bearing increased more slowly than in dogs with either of the other two attachments. These changes associated with the bone to bone attachment may merely be secondary to healing of the bone to bone attachment to the greater trochanter; therefore, they may only be temporary phenomena or they may be the portents for long-term complications. Longer term studies of at least 1-2 years must be performed before these questions can be answered.

Migration of polyethylene wear debris in hip arthroplasties: a canine model

The distal migration of polyethylene wear debris appears to be a major cause of loosening and osteolysis of cementless total hip arthroplasties. The use of modern cementing techniques, circumferential porous or hydroxyapatite (HA) coating has been advocated as a means of preventing access of the particles to the bone-implant interface. The purpose of this study was to compare the ability of different methods of implant fixation to prevent wear debris migration. Three each of smooth, porous-coated, HA-coated, and cemented hemiarthroplasties were implanted in the right hip of 12 dogs. Polyethylene particles were injected into the hip once a month for 4 months and then the femurs were sectioned. The percentage bone ingrowth was 8% for the smooth, 38% for the porous, and 83% for the HA-coated sections. Infiltration of the interface membrane by histiocytes containing polyethylene particles, and endosteal scalloping or osteolysis were found on all sections of the smooth prostheses. No particles or osteolysis were found on any sections of the other three types of prostheses. Capsular and lymph node sections from all dogs revealed histiocytic infiltration with numerous polyethylene particles present. It is concluded that the use of cement, porous, or HA coating prevents or delays access of the polyethylene wear debris to the bone-implant interface. No one of these methods of fixation proved more advantageous in the 5-month limit of this study.

Modular unipolar versus bipolar prosthesis: a prospective evaluation of functional outcome after femoral neck fracture

Between January 1, 1987, and December 31, 1992, 140 community-dwelling geriatric patients > or = 65 years of age with a displaced femoral neck fracture (Garden III-IV) underwent primary prosthetic replacement and were followed prospectively for a minimum of 1 year. Overall, 92 patients received a cemented bipolar prosthesis and 48 patients received a cemented modular unipolar prosthesis. There were no statistically significant differences between the two groups with respect to preinjury characteristics (age, sex, and number and severity of medical comorbidities) and functional ability. There were no statistically significant differences between the two groups with regard to the number of postoperative complications, length of stay, and 1 year mortality rate. An in-depth functional evaluation was obtained as follows: level of ambulation, independence in basic activities of daily living (feeding, bathing, dressing, toileting), and independence in instrumental activities of daily living (food shopping, food preparation, banking, laundry, housework, and use of public transportation). At 1 year follow-up, no statistically significant differences in functional ability were identified between the unipolar and bipolar groups. Furthermore, at a minimum of 1 year follow-up, there were no statistically significant differences between the two groups with regard to the need for revision surgery or the incidence hip pain. Based on the results of this study, there does not appear to be any advantage to the use of bipolar endoprosthesis for the treatment of femoral neck fractures in the elderly patient. The lower cost of modular unipolar prostheses compared with bipolar prostheses provides additional support for their use.

Femoral head bone grafting for reconstruction of the acetabular wall in dysplastic hip replacement

From 1980 through 1991 we screwed a preshaped cortico-cancellous bone graft onto the ileum wall to compensate acetabular deficiency in 94 consecutive total hip replacements. We report the results of 87 hips (79 patients) with an average follow-up of 30 months (12-75 months) postoperatively. Pain in dysplasia-coxarthrosis and congenital dislocation of the hip, destructive coxitis in rheumatoid arthritis and cup loosening was the main indication for surgery. According to the Merle d'Aubigné score the postoperative clinical evaluation demonstrated 77% very good and 18% good results. Due to component loosening the results had to be classified as unsatisfactory in 4 hips (2 cups and 2 stems). At the time of evaluation 90% of the arthroplasties was osseously consolidated as evidenced by trabecular bridging and structural integrity with host bone. Resorptions of the graft were noted in 32 hips. One cup was removed because of complete resorption and consecutive loosening, a further one was considered clinically and radiologically loose because of partial graft resorption. Two further complete resorptions and 28 partial lateral resorptions had no influence on the secondary stability of the implant. We are aware that these are short-term results. Nevertheless, we recommend the described method as a valuable addition to arthroplasties for acetabular rim defects both in osteoarthritis and in revision surgery.

Short-term results of hydroxyapatite-coated primary total hip arthroplasty

One hundred consecutive patients who had Howmedica ABG total hip replacements, a system in which the femoral stem and the acetabular component are hydroxyapatite coated, during the period from September 1989 to January 1991 were studied prospectively. Clinical assessment using the d'Aubigné score showed that 96 patients had an excellent score at a minimum of 2 years from the operation. Radiographic analysis, based on DeLee and Charnley criteria for the acetabular cup and on Gruen criteria for the femoral stem, showed equally good results. There was good initial stability of the cup and the metaphyseal portion of the stem, with a secondary increase of load transmission in Zones 2 and 6 with cortical and cancellous thickening.

Total hip replacement with solid autologous femoral head graft for hip dysplasia

Acetabuloplasty with solid autologous femoral head graft for the treatment of hip dysplasia is an established method which creates the contained cavity needed to accommodate the artificial cup. In order to evaluate the medium- and long-term results of this method using a cementless hemispheric cup, 34 patients (39 hips) operated on between 1979 and 1986 were clinically and radiologically reviewed. The minimal follow-up was 5 years (average 7.6 years). The Harris hip score increased from 36 points preoperatively to 89 points 1 year postoperatively and to 85.1 at the last follow-up. On roentgenographic evaluation, all grafts had been incorporated and appeared to have tolerated the mechanical loading well. Partial resorption of the graft occurred in 22 of the 39 hips, mainly in the lateral non-loaded zone. Twenty-nine of the 39 acetabular components showed migration, on average 4.2 mm cranially and 1.8 mm medially; 92% occurred during the first 2 years, and thereafter it was not progressive. Smaller cups migrated consistently more than larger cups. A significant correlation was found between cup migration and the degree of bone coverage of the cup, and extensive migration occurred in most cases with cup coverage by the host bone of less than 40%-50% of the weight-bearing surface of the cup. Only one acetabular component was altered significantly, and another appears to have become loose. The use of the normal-sized cups and cementless fixation medially in the primary acetabulum are thought to have contributed to our favorable mid- to long-term results.(ABSTRACT TRUNCATED AT 250 WORDS)

Wound cleansing by irrigation for implant surgery

Wound irrigation is an adjunct to all implant surgeries involving surgical incisions or arthroplasties. An understanding of the physics of wound irrigation provides a scientific basis for recommending wound irrigation systems for implant surgery. When inserting implants through surgical incisions, a low-pressure irrigation system is recommended for removing blood from the wound surface. In contrast, high-pressure irrigation systems are indicated to cleanse the intramedullary canal before cemented arthroplasty. With the advent of static and dynamic pressure transducers, irrigation systems can now be specifically designed to achieve these goals.

Conversion of resection arthroplasty to total hip replacement

Conversion of Girdlestone arthroplasty is a demanding procedure dependent on adequate debridement at time of resection and appropriate long-term antibiotic therapy. Patients must be followed closely for persistent sepsis through ESR, aspiration, and physical examination. Pre-reconstruction, existing bone stock should be assessed and revision techniques utilized where appropriate. Our experience is that conversion of Girdlestone pseudoarthrosis to THR can yield good functional results and restore independence.

A multicenter 10-year study of cemented revision total hip arthroplasty in patients younger than 55 years old. A follow-up report

In 1988, the authors reported the results of 67 cemented revision total hip arthroplasties performed for aseptic loosening in patients younger than 55 years old. Both components were cemented at both the primary operation and revision. With an average follow-up period of 4 years, 14 hips (21%) required a second revision arthroplasty. Eight hips in this study group were revised using the Christiansen prosthesis, which is known to have a high failure rate and is, consequently, not in use anymore. Therefore, these eight hips have been excluded from this extended follow-up study. The authors were able to follow the remaining 59 hips for an average of 10 years (range, 8-13 years). In all, 49 hips (83%) were rerevised or radiographically loose or painful. Nevertheless, 75% of the patients, rerevisions included, were satisfied with the final result. There was an increase in bone loss at the final follow-up visit compared to the initial revision, reducing the prerequisites for a good result if further revision surgery was to be performed. After 10 years, survivorship analysis depicted a 48% survival rate when rerevision for aseptic loosening was considered a failure. The survival rate was 65% for the cup and 61% for the stem. The authors conclude that there is an increased failure rate with longer follow-up periods for cemented, revision total hip arthroplasties in young and active patients, and therefore, these patients must be followed indefinitely. The long-term results in this study provide an opportunity for valid comparisons of more sophisticated surgical techniques.

Bipolar hemiarthroplasty for primary osteoarthritis of the hip

One hundred twenty-five bipolar hemiarthroplasties of the hip were performed at the authors' hospital. Although the procedure was performed for acute femoral neck fractures, rheumatoid arthritis, revision hemiarthroplasty, and primary osteoarthritis, only the latter is the subject of this review. A modified Harris hip score (HHS) was used to evaluate the patients both preoperatively and postoperatively. Radiographs were taken preoperatively as well as postoperatively at 2-, 4-, 6-, and 24-month intervals. A total of 68 patients underwent bipolar hemiarthroplasty for primary hip osteoarthritis. The mean preoperative HHS was 35.5 (SEM = 1.86); the mean postoperative score was 81.2 (SEM = 1.64) with an average improvement of 45.7 (SEM = 2.03). The results of this review were compared to a control group of conventional total hip arthroplasties performed at the same institution. The mean postoperative HHS for the group of conventional arthroplasties was 87.2 (SEM = 1.07). The results of this review indicate a good clinical result from bipolar hemiarthroplasty, but significantly less postoperative function when compared to conventional total hip arthroplasty.

Heterotopic ossification following uncemented total hip arthroplasty. Effect of the operative approach

A consecutive series of 112 primary uncemented total hip arthroplasties using the same type of prosthesis was reviewed for the incidence and severity of heterotopic ossification (HO). Sixty-three of these patients underwent a posterior approach (group 1) and 49 underwent an anterolateral approach (group 2). The two groups were virtually identical when risk factors, such as age, sex, estimated blood loss, length of surgery, and diagnosis were compared. Patients in group 1 had a significantly lower incidence and severity of HO than those in group 2. The overall incidence of class III or IV HO was very low (8%), indicating that uncemented total hip arthroplasty in itself is not predisposed to moderate or severe degrees of HO. Patients undergoing uncemented total hip arthroplasty through an anterolateral approach had a higher incidence of HO than those undergoing a posterior approach in this series.