Revision total knee arthroplasty of bone grafts versus implant supplementation

Small contained bone defects can be managed by cement either with or without screws. Larger contained defects should be managed using morsellized allograft bone. Uncontained bone defects can be managed with implant supplements or structural grafts depending on the size and location of the defect. In the salvage situation, custom implants and arthrodesis may need to be considered.

Acute polyethylene fracture in an uncemented acetabular cup

The smaller acetabular components used in total hip replacement may have a polyethylene liner that is too thin, resulting in higher polyethylene stress and an increased potential for wear. The authors present a case that highlights the problem of acute polyethylene fracture. To compensate for the thinness of the polyethylene, the authors recommend the use of a smaller head size to allow polyethylene thickness of at least 8 mm.

Sarcoma of bone-cement membrane: a case report and review of the literature

The development of a cancerous tumour at the site of total joint replacement is a rare but virtually always fatal event. The previously unreported scenario of a patient who was found to have a malignant fibrous histocytoma at the bone-cement membrane after revision for a loose total hip prosthesis is reported. Recent biologic information evaluating the response of mesenchymal cells to metallic debris suggests that the environment surrounding a loosened prosthesis may provide conditions appropriate for the development of a sarcoma.

Reconstruction of massive bone defects with allograft in revision total knee arthroplasty

Allograft bone was used to reconstruct a defect in the proximal aspect of the tibia or the distal aspect of the femur, or both, in thirty knees of twenty-eight patients who had a revision total knee arthroplasty. The average age of the patients at the time of the index procedure was 65.8 years (range, twenty-four to eighty-nine years). At an average of fifty months (range, twenty-four to 132 months; median, thirty-six months) postoperatively, the score for twenty-three knees (twenty-one patients) had increased by at least 20 points, and these knees did not need additional operative treatment. Thus, the rate of success was 77 per cent. The procedure was considered a failure for the remaining seven knees because of infection (three), loosening of the tibial component (two), fracture of the graft (one), and non-union at the allograft-host junction (one). Properly applied allograft can be used to reconstruct massive bone defects, provide stability and support for implants, and restore bone stock in the event that additional operative treatment is necessary.

Immediate surgery versus waiting list policy in revision total hip arthroplasty. An economic evaluation

An economic evaluation was carried out using a decision tree that models the costs and consequences of surgery at the point of consultation versus a waiting list policy for candidates in need of revision hip arthroplasty. The theoretical scenarios looked at a 2-year period wherein the immediate surgery patients incurred costs for 2 years after surgery, whereas the waiting list patients incurred costs for 1 year before and 1 year after surgery. Outcome probabilities were defined and applied to each treatment group, as derived from the literature and expert opinion. Expenditures were derived from the literature, based on conservative estimates of predicted pre- and postsurgical behavior for each scenario. This analysis indicates the potential for both substantial savings in resources and improved patient outcome for immediate surgery over waiting lists. These savings would begin at the inception of the immediate surgery protocol. Sensitivity analysis indicates that the conclusion is valid over a wide range of expenditures and probabilities.

Varus osteotomy of the distal part of the femur. A survivorship analysis

Varus osteotomy of the distal part of the femur is often the procedure of choice for the treatment of osteoarthrosis of the lateral compartment associated with genu valgum. We followed twenty-one knees (twenty patients) long term or until failure. At the most recent evaluation (average, 133 months; range, ninety-seven to 240 months), thirteen osteotomies were still successful, seven had failed, and one patient (in whom the knee had remained functional) had died. Of the seven failures, three occurred early (at twelve or twenty-four months) and four occurred late (between seventy-two and ninety-eight months). The probability of survival at ten years was 64 per cent (95 per cent confidence interval, 48 to 80 per cent), as determined with use of the Kaplan-Meier method. We concluded that, with proper selection of patients, this procedure is effective for the treatment of gonarthrosis of the lateral compartment associated with valgus deformity.

Titanemia from total knee arthroplasty. A case resulting from a failed patellar component

The subject of this case report is a patient with elevated serum levels of titanium (77 parts/billion [ppb]; normal, 3.3 ppb) and vanadium (0.38 ppb; normal, 0.17 ppb) resulting from excessive wear of a metal-backed patellar component in a total knee arthroplasty. The patellar component was worn through both its polyethylene and metal backing as a result of abnormal contact between the patellar and femoral components. Scanning electron microscopic examination of the ingrowth surface of the patellar component indicated that particle debonding occurred as a result of overloading of the sintered neck regions at the particle-substrate interface, suggesting a possible damage during initial insertion of the device, which may have predisposed it to loosening and abnormal contact with the femoral component. Wear particles resulted in staining of the tissues within the knee and an inflammatory and immune response in the synovium consisting of giant cells and T lymphocytes. The serum metal levels were reduced 22 weeks after replacing the patellar component; however, the titanium level was still slightly elevated (8 ppb).

Revision of the acetabular component of a total hip arthroplasty with a massive structural allograft. Study with a minimum five-year follow-up

The results of the placement of a massive structural acetabular allograft in conjunction with a revision total hip arthroplasty in thirty-two patients (thirty-tree hips) were evaluated at a minimum of five years. The graft supported more than 50 percent of the cup in all of the patients. The goals of a revision operation in a hip that has massive loss of bone are to provide support for the cup, to approximate the normal anatomy, to restore the length of the lower limb, and to restore bone stock should a future revision be necessary. Clinical and radiographic review at an average of seven years (range, five to eleven years) after the revision revealed that eighteen hips had needed no additional operation, seven hips had needed a repeat revision but the structural allograft was intact and had been used to support the cup at the repeat revision, and eight hips had had failure of both the prosthesis and the allograft. The result was considered a clinical and radiographic success when the hip score had increased at least 20 points, the cup was stable, the allograft had united, and no additional operation was necessary. According to these criteria, the rate of success was 55 percent (eighteen of thirty-three hips.) The only factor that was found to be clinically important with respect to outcome was the method of reconstruction. Seven of the eight hips that had been reconstructed with use of a roof-reinforcement ring and a structural allograft had a successful result at an average of 7.5 years (range, five to eleven years). The findings of the present study support the use of a structural allograft in the presence of massive loss of bone in order to achieve the goals of a revision hip replacement. Because of the high rate of success with acetabular reinforcement rings, we now use this method of reconstruction whenever a massive allograft is employed on the acetabular side.

Revision of the acetabular component of a total hip arthroplasty with a massive structural allograft. Study with a minimum five-year follow-up

The results of the placement of a massive structural acetabular allograft in conjunction with a revision total hip arthroplasty in thirty-two patients (thirty-tree hips) were evaluated at a minimum of five years. The graft supported more than 50 percent of the cup in all of the patients. The goals of a revision operation in a hip that has massive loss of bone are to provide support for the cup, to approximate the normal anatomy, to restore the length of the lower limb, and to restore bone stock should a future revision be necessary. Clinical and radiographic review at an average of seven years (range, five to eleven years) after the revision revealed that eighteen hips had needed no additional operation, seven hips had needed a repeat revision but the structural allograft was intact and had been used to support the cup at the repeat revision, and eight hips had had failure of both the prosthesis and the allograft. The result was considered a clinical and radiographic success when the hip score had increased at least 20 points, the cup was stable, the allograft had united, and no additional operation was necessary. According to these criteria, the rate of success was 55 percent (eighteen of thirty-three hips.) The only factor that was found to be clinically important with respect to outcome was the method of reconstruction. Seven of the eight hips that had been reconstructed with use of a roof-reinforcement ring and a structural allograft had a successful result at an average of 7.5 years (range, five to eleven years). The findings of the present study support the use of a structural allograft in the presence of massive loss of bone in order to achieve the goals of a revision hip replacement. Because of the high rate of success with acetabular reinforcement rings, we now use this method of reconstruction whenever a massive allograft is employed on the acetabular side.

Classification and reconstruction in revision acetabular arthroplasty with bone stock deficiency

Revision acetabular surgery with bone stock loss is a difficult problem. Defects are classified into contained cavitary (Type-1) defects and noncontained defects (Type 2A and 2B) based on preoperative radiographs and intraoperative findings. Fifty-four hips with Type-1 defects were treated with morsellized allograft. The overall success rate was 90% at 6.78 year followup. Type-2 defects are reconstructed with structural grafts. Twenty-nine hips with Type-2A defects (the allograft supports <50% of the cup) were reviewed at 7.1 years' followup. The success rate was 90)%. In all but 1 case the allograft united to host bone. No resorption or minor resorption was seen in 26 of 29 hips with minor column structural grafts. Type-2B defects all had structural allografts that supported >50% of the cup. There were 33 hips in this group observed for an average of 7.1 years. The rerevision rate in this group was 45%. However, 7 of 15 hips were reconstructed without additional graft at rerevision. The only factor that was clinically significant for success in Type-2B defects was choice of acetabular component. In hips that received roof rings with cemented cups, the success rate was 100% (excluding 1 infection). The authors support the use of allograft bone in revision acetabular surgery. When structural grafts are required, every attempt should be made to achieve >50% support from host bone. If this is not possible, then a roof reinforcement ring with a cemented cup is the acetabular component of choice.

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.

Revision total hip arthroplasty with shelf bulk allografts. A long-term follow-up study

A series of 29 shelf ( < 50% of the acetabulum) structural allografts were done in conjunction with acetabular revision with a minimum follow-up period of 5 years (average, 7.1 years). At the latest follow-up examination, 86% of the hips were successful both clinically and radiologically. Only four patients required further surgery, with two of these being revised with no additional grafts. The use of bulk allograft in conjunction with acetabular revision is supported, provided that at least 50% support of the cup can be obtained with host-bone. This type of reconstruction provides support for the cup and restores anatomy, leg length, and bone stock should future revision be necessary.

Total hip arthroplasty with shelf grafts using uncemented cups. A long-term follow-up study

A series of 33 hips treated with cementless cups and structural autograft or allograft were reviewed at a minimum follow-up period of 5 years. Seventeen hips received a shelf autograft during primary hip arthroplasty and 16 received an allograft at revision. In the hips receiving autografts, the average preoperative hip score was 45.1 and the score at final review was 87.5, whereas in the revisions reconstructed with allografts, the average preoperative hip score was 44.4 and the score at final review was 82. Overall, only 2 of 33 hips were considered failures, giving a success rate of 94% at an average follow-up period of 6.6 years. Leg-length discrepancy greater than 2 cm was seen in 27 of 33 hips, and at final review only 4 of 33 hips had a leg-length discrepancy greater than 2 cm. All grafts united to host-bone. Resorption, when seen, was minor, with only three grafts showing moderate resorption. Our data support the use of cementless cups with structural allografts and autografts, provided the graft supports less than 50% of the cup.

Proximal femoral allografts for reconstruction of bone stock in revision arthroplasty of the hip

Proximal femoral allografts have been used to restore uncontained circumferential defects of the multiply revised total hip arthroplasty. These grafts are used with long stem components that are cemented to the graft but not the host. The junction of host and graft is stabilized by the stem and a step cut with cerclage wires. Autograft bone is placed at the junctions to induce union. Full weightbearing is delayed until union occurs between the graft and the host femur, usually by 3 months. One hundred sixty-eight structural femoral allografts were done; average followup was 4.8 years as of January 1, 1995. Success was defined as an increase in the clinical score of at least 20 points, a stable implant, and no need for further surgery related to the allograft. The success rate in 130 patients with at least 2 years followup is 85%. There have been 17 revisions in 16 patients: 3 revisions for infection, 8 for dislocation, 5 for nonunion, and 1 for pain. The revision rate is 10.1%. Radiographic analysis showed 7 nonunions, minor resorption in 6 patients, and significant resorption in 1 patient. All implants are stable with no lucent lines. The results support using this technique for full circumferential segmental proximal femoral defects in revision hip arthroplasty.

Fresh osteochondral allografts for advanced giant cell tumors at the knee

Sixteen patients with advanced giant cell tumors presenting at the knee were treated with complete tumor resection and reconstruction using fresh osteochondral allografts. All patients had one or more of the following indications for tumor resection (as opposed to curettage): tumor recurrence, pathologic fracture, or destruction of the subchondral bone plate. At the 3-15-year follow-up period (mean, 9 years), two grafts have been revised to second fresh grafts because of fracture and one graft has been converted to an allograft-implant composite reconstruction. One joint was fused because of late infection. Functional assessment was carried out in 13 patients, and 8 were good or excellent, 4 were fair, and 1 was poor. The authors conclude that the fresh osteochondral allograft is a viable treatment alternative to prosthetic arthroplasty in advanced, benign, aggressive bone tumors.

The use of femoral head autograft shelf reconstruction and cemented acetabular components in the dysplastic hip

In view of the controversy about bulk autografts to provide support for the acetabular cup in reconstruction of the dysplastic hip, a series of 15 dysplastic hips were investigated as follows: Femoral head autograft shelf reconstruction and cemented acetabular components were evaluated at an average follow-up period of 99 months after operation (range, 27-141 months). Hip rating scores and radiographic assessments were done on each patient before surgery and at postoperative examinations. The average preoperative hip score was 43.6 points (range, 22-82). The average hip score at review was 72.3 points (range, 48-100). The increase in hip scores was 29 points (range, -10 to +69). All grafts showed radiographic evidence of union to the pelvis at review. There was no resorption in five cases. The graft showed some resorption in eight cases, six of which were minor. None of the grafts or the acetabular components showed any signs of migration. Although the number of cases is small, the results show that bulk acetabular allografts can survive beneath cups in reconstructed dysplastic hips.

Soft-tissue expansion before total knee arthroplasty in arthrodesed joints. A report of two cases

We report two cases in which arthrodesed knees were revised to total arthroplasties after the use of soft-tissue expanders. Case 1 had had multiple operations on her knee and had been arthrodesed for septic arthritis two years earlier. Case 2 had had knee arthrodesis for severe osteoarthritis 18 years before revision. In both patients, tissue expanders were used to increase the soft tissues available for cover and to help to mobilise the extensor mechanism. The operations were made much easier, and in both patients a range of motion from 0 degrees to 90 degrees was achieved at operation.

Soft-tissue expansion before total knee arthroplasty in arthrodesed joints. A report of two cases

We report two cases in which arthrodesed knees were revised to total arthroplasties after the use of soft-tissue expanders. Case 1 had had multiple operations on her knee and had been arthrodesed for septic arthritis two years earlier. Case 2 had had knee arthrodesis for severe osteoarthritis 18 years before revision. In both patients, tissue expanders were used to increase the soft tissues available for cover and to help to mobilise the extensor mechanism. The operations were made much easier, and in both patients a range of motion from 0 degrees to 90 degrees was achieved at operation.

Revision arthroplasty of the proximal femur using allograft bone

Revision arthroplasty of the hip may require restoration of bone stock on the femoral side to provide bone support for the new implant and restore anatomy and leg length. Large cortical defects can be reconstructed best with allograft bone because of the quality and quantity of the bone required. In this article, the surgical technique and results of cortical allograft as full circumferential and cortical strut grafts are presented.

Bone grafts in hip replacement surgery. The pelvic side

Replacement arthroplasty of the hip may require restoration of bone stock to provide support for the acetabular implant and to restore anatomy and leg lengths. This article discusses the indications, surgical technique, results, and controversies of using bulk autograft bone to provide cup support for primary hip replacement in hip dysplasia. In addition, the use of allograft bone to restore bone stock in the revision situation is covered. The indications, surgical technique, and results of the use of both morsellized and bulk allograft bone are presented.

[Fresh osteochondral transplants in the treatment of advanced giant cell tumors]

Eighteen patients with advanced giant cell tumors were treated with complete tumor resection and reconstruction using fresh osteochondral allografts. All patients had one or more of the following indications for tumor resection (as opposed to curettage): tumor recurrence, pathological fracture, or destruction of the subchondral bone plate. At the 4- to 16-year follow-up (mean 9 years), two grafts were revised to a second fresh graft because of fracture, one graft was converted to an allograft implant composite and two joints were fused because of infection. The functional results were assessed in 14 patients: 9 were good or excellent, 4 fair and 1 poor. We conclude that the fresh osteochondral allograft is a viable treatment alternative to prosthetic replacement in advanced benign, aggressive bone tumors.

Clinical and radiographic results of the Muller straight stem used as a press-fit

Prior to the introduction of porous coating, 21 patients had 24 ME Muller straight-stem femoral prostheses inserted as a press fit for the treatment of osteoarthrosis. Five hips have been revised for aseptic loosening; the remaining 19 prostheses are still in situ after a mean of 7.3 years (range, 6.2-8.3 years). A prospective clinical assessment has been undertaken using a modified Harris hip score, with scores increasing on average from a preoperative 43 to a postoperative 79. Eighteen of the 19 remaining hips are functioning well. Variable distances of subsidence are evident in 10 hips. Despite the use of a prosthesis that was not designed for cementless proximal wedge fitting, the results indicate an exceptionally low incidence of bone resorption and lysis. Unlike cemented and some porous-coated prostheses, stress shielding and osteopenia were not a feature in this series.

The long-term success of fresh, small fragment osteochondral allografts used for intraarticular post-traumatic defects in the knee joint

Ninety-two fresh osteochondral allografts were implanted in 91 patients with posttraumatic osteoarticular defects of the knee joint. These patients have been prospectively followed since 1972. An analysis of long-term survival of these grafts has been performed to determine their success rates: 75% at 5 years, 64% at 10 years, and 63% at 14 years. An evaluation was made between unipolar grafts, which involve only one surface of the compartment, and bipolar grafts, which involve both surfaces. The unipolar grafts had a lower failure rate at all time periods compared to bipolar grafts, with 76% survival at 5 years, 69% at 10 years, and 67% at 14 years. While investigating other factors that might affect the survival of the fresh osteochondral allografts, we calculated the influence of the anatomical location of the graft, patient sex, and patient age. There was no meaningful impact on allograft survival by either the location of the allograft or the sex of the patient. However, there was a significant effect on allograft longevity in terms of patient age, with patients under age 60 doing better. The best indication for the use of unipolar fresh osteochondral allografts is for posttraumatic defects in relatively young, active patients. Joint malalignment should be corrected to achieve best results.