Bone defects in revision total knee arthroplasty: classification and management

The goal of bone reconstruction in revision total knee arthroplasty is to provide a stable support for the implant and to re-establish the correct joint line. Therefore, a useful, therapy-based classification of the defects is necessary. According to Stockley et al. (1992), the defects are classified into contained and uncontained defects. Uncontained defects can be reconstructed using structural allografts or metal wedges. In contained defects, cancellous allograft can be used. For aseptic loosening of total knee arthroplasty, the defect classification according to Engh and Parks (1994) can be helpful because of its recommendations for reconstruction. In case of the more common first or second graded defects, reconstruction is performed using modular revision components or allografts. For the rare third graded defects, bulk allografts or modular tumour endoprostheses are recommended. On the basis of more than 150 revision total knee arthroplasties performed in our hospital the classification of bone defects and their clinical consequences are presented in this review.     

Impaction grafting and wire mesh for uncontained defects in revision knee arthroplasty

The current authors review the results of 17 revision total knee arthroplasties in 14 patients in whom large uncontained defects were treated with impaction allografting and molded wire mesh for containment. Knee Society clinical scores increased from an average of 47 points to 95 points and function scores increased from 48 points to 73 points at the most recent followup. No patients required revision surgery, although, nonprogressive tibial radiolucency has been observed in three patients. One patient required open reduction and internal fixation of a periprosthetic supracondylar femur fracture. One patient with an acute postoperative infection with Staphylococcus epidermidis was treated successfully with irrigation and debridement with retention of the implant. Impaction grafting with wire mesh containment for large uncontained defects in revision total knee arthroplasty is an effective method of treating massive uncontained bone loss in revision total knee arthroplasty.     

Reconstruction of severe uncontained bone defects in revision total knee arthroplasty in a patient with rheumatoid arthritis

We report on a 54-year-old rheumatoid arthritic female patient with uncontained type-III tibial and femoral bone defects at the time of revision total knee arthroplasty (TKA). The knee was reconstructed using a structural distal femoral allograft and a stemmed, semi-constrained knee prosthesis. We achieved the re-alignment of a severe preoperative valgus deformity of 40 degrees. Due to postoperative wound complications we had to perform a gastrocnemius muscle flap. At two-year follow-up the patient was free of pain and the Knee Society Score improved from 18 to 156 (p < 0.01). Radiographs revealed no loosening of the prosthetic components and progressive incorporation of the graft. Reconstruction of extensive uncontained bone defects in revision of TKA in rheumatoid arthritis can be managed by structural allografts; however, wound complications in those patients might necessitate soft tissue techniques.     

Distal femoral allograft reconstruction for massive osteolytic bone loss in revision total knee arthroplasty

Massive osteolytic bone loss in revision total knee arthroplasty has been an uncommon challenge. From 2001 to 2002, 11 knees in 10 patients underwent revision of failed modular PFC (Johnson and Johnson Orthopaedics, Raynham, Mass) total knee arthroplasties with distal femoral allografts and long-stemmed revision implants for massive osteolytic induced femoral bone loss. The mean follow-up was 42 months (range, 36-48 months). Radiographic graft incorporation was demonstrated in all 11 knees with no cases of loosening. The Knee Society Pain Scores improved by an average of 25.4 points, and the function scores improved by an average of 23.3 points. The outcomes of distal femoral allografts in the reconstruction of massive osteolytic bone loss associated with failed modular PFC (Johnson and Johnson Orthopaedics) total knee arthroplasties are favorable.     

Revision unikondylärer Knieprothesen

Despite the good midterm survivorship reported for unicondylar knee arthroplasty, an increase in revision surgery has to be expected due to increased replacement rates. The reasons for failure as well as distribution are different for unicondylar knee arthroplasty compared to total knee arthroplasty. The main reasons for revision are aseptic loosening and the progression of osteoarthritis. In most cases, unicondylar knee arthroplasty will be revised to total knee arthroplasty. To obtain good revision results, the cause of implant failure has to be analysed carefully. In the case of contained bone defects, the reconstruction can be supported with bone grafting. For those cases with uncontained defects, implants with augmentation and, in some cases, stem extensions are needed. The modularity of the revision implant should cover different intraoperative requirements.     

Techniques of bone grafting in total knee arthroplasty

Bone grafting of osseous defects in primary or secondary total knee arthroplasty remains a popular and often indispensable solution to reconstructive problems. Solutions to contained, uncontained, and massive defects of both the tibia and femur are presented, as well as several options for reconstruction of deficient or ruptured extensor mechanisms.     

Strukturelle Femurkopfallografts in der Revisionschirugie von gelockerten Hüftendoprothesenpfannen

BACKGROUND: Treatment of acetabular bone defects presents a great challenge in revision total hip arthroplasty (THA). Many methods of acetabular reconstruction have been described. The purpose of this study was to evaluate the midterm results of structural femoral head allografts for acetabular reconstruction. METHODS: Thirty-six patients (33 females and 3 males) with acetabular defects ranging from type 2C to type 3B according to Paprosky's classification were included in the study. In all cases acetabular defects were closed using allografts from femoral heads. In 13 cases an uncemented press-fit cup, in 17 cases a cemented polyethylene socket, and in 6 cases a Burch-Schneider antiprotrusion cage was implanted. The mean follow-up period was 84.2 months (range: 5-147). RESULTS: Four acetabular components failed. All 36 grafts were osseointegrated radiographically and formed a mechanically stable construction. The mean Harris Hip Score at the most recent follow-up was 79.8 points. The distance from the obturator line to the prosthesis head center was 3.73 cm (1.17-5.80 cm) preoperatively and 2.79 cm (0.85-4.8 cm) postoperatively (p<0.05). The distance from the teardrop figure to the prosthesis head center was 3.02 cm (1.0-5.8 cm) preoperatively and 3.25 cm (1.6-4.8 cm) postoperatively (p<0.001). CONCLUSIONS: Closure of acetabular defects of types 2C to 3B according to Paprosky's classification can be satisfactorily accomplished using femoral head allografts. These allografts may facilitate future revision surgery. Femoral heads are readily available due to widespread primary total hip replacement surgery. However, the use of structural femoral head allografts for acetabular reconstruction is cost intensive. Individual patient-related aspects, such as the function of revision arthroplasty, have to be considered when planning revision arthroplasty using femoral head allografts.     

Pelvic reconstruction with a free vascularized distal femur for revision total hip arthroplasty

The reconstruction of massive structural acetabular defects after revision arthroplasty presents a unique challenge to the orthopedic surgeon. This report describes such a salvage procedure where an autologous vascularized distal femur was used to reconstruct acetabular bone stock with subsequent implantation of a total femoral endoprosthetic replacement that uses a constrained cup and a hinged total knee system. At 2 years of follow-up, there is a good functional result with full incorporation of the graft.     

Direct exchange endoprosthetic reconstruction with tumour prosthesis for periprosthetic knee infection associated with segmental bone defects

Revision knee arthroplasty for infection poses a treatment challenge. The presence of massive osteolysis limits the treatment options in this cohort. Controversy exists in the management of these patients. Direct exchange arthroplasty has provided good results in the presence of infection, but whether this is appropriate in the presence of massive bone defects associated with the infection is undetermined. We present our experience in revision knee arthroplasty for infection associated with massive bone defects. The aim of the study is to present the preliminary results of a direct exchange endoprosthetic reconstruction with tumour prosthesis for periprosthetic infection associated with segmental bone defects. This is a retrospective study of prospectively collected data, involving six patients with periprosthetic infection and massive bone defects treated by direct exchange tumour prostheses between 2003 and 2007 (four distal femoral replacements and two total femoral replacements). The mean age and follow-up were 74.2 (±5.2) years and 32.5 (±8.2) months respectively. Each patient had an infected revised knee arthroplasty at the time of referral to our institution. Staphylococcus aureus was the most common causal organism. The mean duration of antibiotics was 6 weeks intravenous therapy followed by 3.5 months oral. The recurrences of infection, pain or immobility were outcome criteria considered failures. Our success rate was 80%. Salvage of infected revised knee arthroplasty by direct exchange endoprosthetic reconstruction has provided an effective means of pain relief, joint stability and improved mobility in our cohort. It reduces morbidity through earlier mobilisation and avoids a second major operation.     

Filling of segmental bone defects in revision knee arthroplasty using morsellized bone grafts contained within a metal mesh

For revision knee surgery with uncontained tibial bone defects, the authors report the containment of compacted morsellized allograft using metal-wire mesh, followed by implantation of a cemented total knee prosthesis. This method is comparable to the "impaction grafting technique" described for revision hip surgery and could be an alternative to metal wedges, augmented components, custom-made implants, polymethyl-methacrylate or structural bone grafts to solve some problems of cavitary and segmental bone defects in revision total knee arthroplasty.     

Femoral reconstruction by massive allografts in revision of hip prostheses with major bone defects

Summary Major bone defects are commonly encountered in revision of total hip arthroplasties. We reconstruct both the acetabular and femoral component with bone allografts to allow successful implantation of a new prosthesis. Frozen femoral heads are used for all kinds of acetabular defects and for small femoral defects, and irradiated massive cortical allografts have been used since 1985 for major deficiencies of the femur. The femoral reconstruction technique differed according to the type of surgery: —After removal of a failed massive femoral prosthesis, a long-stem Charnley prosthesis was cemented in the proximal allograft and the distal host femoral shaft. —When revision of standard arthroplasties was performed, different surgical procedures were used according to the type of bone deficiency encountered, the goal being to preserve as much host bone as possible. We used either segmental allografts covered with the remaining host femoral cortex preserved with its soft tissue attachments, or segmental allografts impacted into an enlarged residual shaft. In other cases, a semi-circular allograft strut was used for replacing or reinforcing a deficient cortex. A cemented longstem Charnley prosthesis was generally used, but whenever possible a standard stem was implanted.From 1985 to the end of 1992, 102 upper femoral reconstructions for major revision arhtroplasties were performed in our department. Onlay struts had excellent results, always united, and complications were rare. Segmental allografts had a higher complication rate. The frequency of trochanteric complications (20%) implies firm initial fixation, apparently better ensured by plates, though screwing through the graft risks damaging it, as occurred once. Graft or prostheses failures were rare, and occurred mainly with large segmental allografts used in custommade massive prosthesis replacement, the conditions then being comparable with malignant tumor reconstruction surgery. When complications occurred, the benefit of initial bone stock repair was preserved in most cases, allowing easy further revision.Massive irradiated allografts appear to be an effective method in major femoral reconstructions. These results rely on safe bone banking procedures, which require predefined and strictly controlled methods. Good results also depend on suitable surgical techniques, particularly efficient graft stability, secure muscle reattachment, and reliable prostheses. The aim of the different surgical technics we used in revision arthroplasties was to obtain good anatomic situation, alignment and length, while preserving as much as possible of the residual host bone.     

Reconstruction of the failed femoral component and proximal femoral bone loss in revision hip surgery

Advances in implant technology and surgical techniques have greatly improved the results of femoral stem revision in total hip arthroplasty. The 10-year results obtained with extensively coated noncemented revision stems parallel those obtained with cemented stems revised by using contemporary techniques. Proximal femoral bone loss is an important consideration when planning and performing revision arthroplasty. Proximal femoral bone defects can be managed with either metal or bone. Insignificant defects can be reconstructed by using primary hip arthroplasty techniques. Proximal femoral replacement prostheses are best restricted to sedentary elderly patients. Cortical strut grafts can be used reliably to reconstruct noncircumferential segmental defects. Calcar allografts are associated with unacceptably high rates of resorption. Proximal femoral allografts with either noncemented or cemented long-stem prostheses have the potential advantage of biologic soft-tissue attachment and restoration of bone stock. Impaction allografting with cement is indicated for cavitary defects and may also restore bone stock.     

Proximal femoral allografts in revision hip arthroplasty

We followed prospectively 69 patients with 78 proximal femoral allografts performed for revision of total hip arthroplasty for an average of 36 months (range 29 to 68). Large fragment proximal femoral allografts and cortical strut allografts were successful in 85%. Grafts smaller than 3 cm in length (calcar grafts) were clinically successful in 81%, but 50% underwent significant radiographic resorption. We conclude that large proximal femoral allografts and cortical strut allografts provide dependable reconstruction of bone stock deficiencies during revision total hip arthroplasty.     

Clinical experience in allogeneic vascularized bone and joint allografting

The allotransplantation of vascularized femoral diaphyses and total knee joints is a novel approach in orthopedic surgery. Allogeneic femoral diaphyses were transplanted into three patients suffering from chondrosarcoma or posttraumatic defects. Total knee joints allografts were transplanted in five patients with large bone defects of the knee and loss of the extensor apparatus caused either by major trauma alone or infection after a major trauma. Bone segments and total joints were harvested from multi-organ donors, perfused with UW-solution and transplanted within cold ischemia times of 18-25 h. Patients were immunosuppressed postoperatively primarily with cyclosporine (Cyclosporin A) and azathioprine. Two allografts (1 femur, 1 knee) were lost due to infections. Seven of the eight patients are able to walk with full weight-bearing posttransplant. Two of the patients with transplanted joint allografts subsequently received total knee arthroplasty implantations. Vascularized bone and joint allotransplantation may serve as a last line of defense treatment before considering lower limb amputation.     

The use of structural allograft for uncontained defects in revision total knee arthroplasty. A minimum five-year review

BACKGROUND: To our knowledge, the medium to long-term outcome after revision knee arthroplasty with structural allograft augmentation for reconstruction of uncontained defects has not been determined. The purpose of the present study was to assess the outcome for patients managed with such a procedure. METHODS: We prospectively followed fifty patients who had fifty-two revision knee replacements with sixty-six structural grafts performed at three institutions. Twenty-nine knees (twenty-seven patients) were independently evaluated at a mean of 96.9 months (range, sixty to 189 months) by an investigator who had not been involved in the index procedure. Twelve knees (23%) had a repeat revision at a mean of 70.7 months (range, twenty-six to 157 months). The allograft was retained in two of these patients. Eleven patients died at a mean of ninety-three months (range, sixty-one to 128 months) after the procedure; the structural allograft and implants were intact, and the patients were not awaiting revision at the time of death. RESULTS: Clinical evaluation revealed that the mean modified Hospital for Special Surgery knee score had improved from 32.5 points preoperatively to 75.6 points at the time of the review and the mean range of motion had increased from 60.5 degrees preoperatively to 88.6 degrees. Failure was defined as an increase of less than 20 points in the modified Hospital for Special Surgery knee score at the time of the review or the need for an additional operation related to the allograft. Thirteen knee replacements failed, yielding a 75% success rate. Five knees had graft resorption, resulting in implant loosening. Four knee replacements failed because of infection, and two knees had nonunion between the host bone and the allograft. Two knees (one patient) did not have a 20-point improvement in the knee score. The survival rate of the allografts was 72% (95% confidence interval, 69% to 75%) at ten years. On radiographic analysis, none of the surviving grafts had severe resorption, one had moderate resorption, and two had mild resorption. One knee had a loose tibial component, and three knees had nonprogressive tibial radiolucent lines. All four knees were asymptomatic. CONCLUSIONS: Our results demonstrate that allografts used in revision knee replacement in patients with the difficult problem of massive bone loss have an encouraging medium-term rate of survival.     

Autogenous bone grafting of uncontained bony defects of tibia during total knee arthroplasty a 10-year follow up

Autogenous bone grafting of uncontained tibial bony defects was carried out in 18 patients during a cemented total knee arthroplasty. American Knee Society scores were used to compare the results of the grafted group with those of a control group of 132 total knee arthroplasty patients without a significant tibial bony defect. The patients were followed up for 10 years. There was a statistically significant difference in the mean knee scores of the 2 groups at the preoperative assessment. Postoperative results were comparable between the 2 groups, indicating a significant and similar improvement in the knee scores of the grafted and control groups. Autogenous bone grafting is an easy and reproducible method of dealing with uncontained tibial bony defects during a total knee arthroplasty.     

Evolution of the rotating hinge for complex total knee arthroplasty.

Initial rotating hinge total knee designs were associated with a high failure rate. More recent designs have improved the patellofemoral articulation and the rotating hinge mechanism, added modular canal filling slotted fluted stems and metaphyseal sleeves, and improved the articulation between the mobile-bearing element and the tibial component. A series of patients with complex problems was studied. They underwent knee arthroplasty using a second generation rotating hinge component incorporating the design features listed above. Indications for surgery included medial collateral ligament disruption, revision of a previous hinged component with a massive bone loss, comminuted distal femur fracture or distal femoral nonunion in elderly patients, extensor mechanism disruption requiring reconstruction in an unstable knee, and ankylosis requiring femoral peel exposure with moderate residual flexion extension gap imbalance. A series of 23 knees in 22 patients was evaluated at the 2- to 9-year followup. The clinical results, range of motion, and satisfaction were comparable with that of a standard condylar revision knee arthroplasty despite the fact that the cases were more complex. These results warrant continued investigation of the role of rotating hinge in complex total knee arthroplasty.     

The use of porous metal cones in revision total knee arthroplasty

Massive bone defects represent a major problem in revision total knee arthroplasty. Traditionally, structural allograft has been used for this purpose; however, this is technically demanding and is associated with a failure rate. Metaphyseal tantalum cones have been a major advancement. They have made surgery easier and have yielded better results when compared to reconstruction with allograft. Adding the ability to comfortably use these implants to one’s armamentarium should be a priority for surgeons who regularly revise total knee replacements. These implants have completely replaced the use of structural allografts in the authors’ practice.     

Structural allografting in revision total knee arthroplasty

Between 1985 and 1991, 15 patients underwent structural allografting as part of revision total knee arthroplasty. All patients had large segmental, cavitary, or combination defects of the femur and/or tibia. Seven distal femurs and 12 proximal tibias required allografting. Patients were evaluated with physical examination, radiographs, and The Hospital for Special Surgery knee rating scale. Three patients died, leaving 15 allografts for follow-up study. The average age at surgery was 63 years. The follow-up period averaged 47 months (range, 30–101 months). Average range of motion before surgery was 4° to 93°, and after surgery, 2° to 104°. Average knee score was 47 before and 86 after surgery. Preoperative alignment averaged 5° varus, ranging from 25° valgus to 20° varus, and postoperative alignment averaged 4° valgus, ranging from neutral to 6° valgus. All patients, except one, had improvement of pain and stability. All of the 15 allografts healed to host—bone and 13 showed evidence of incorporation. There were no infections or fractures of the allografts. One complication directly related to the allograft occurred; that patient had a tibial component fracture over a proximal tibial allograft 3 years after surgery. Three other complications occurred. One was tibial loosening in a patient who received a distal femoral allograft, the second was a proximal tibial fracture in a patient who received a distal femoral allograft, and the third was an intraoperative patellar tendon avulsion. These results suggest that structural allografting can provide a satisfactory method of managing large bone defects in the failed total knee arthroplasty.     

The bipolar endoprosthesis and bone graft in the management of aseptic acetabular component loosening

Ten patients with large acetabular defects underwent hip arthroplasty revision with the use of allografts in conjunction with a bipolar prosthesis. Six patients had solid femoral head allografts and the others, morselized allografts. Radiographs at 2-year follow up showed an average of 8 mm of superior migration and 4 mm of medial migration. Our experience has shown that bipolar revision arthroplasties tend to migrate against the allograft. We recommend that bipolar revisions be limited to small acetabular defects that give the bipolar prosthesis full rim contact.