Allograft-prosthesis Composite Research Articles

The Use of Allograft Prosthesis Composite for Extensive Proximal Femoral Bone Deficiencies: A 2- to 9.8-Year Follow-Up Study

We report here results for 15 hips that we repaired using allograft prosthesis composite (APC) and monitored for a mean of 4.2 years. Two hips underwent repeat revisions with new APCs after a mean of 83.7 months. The average Harris Hip Score improved from 21.8 before revision surgery to 83.2 afterward, and 12 stems showed good stability. Of the 15 hips repaired with APC, 13 had good junctional union. One of the 2 remaining hips showed nonunion, which was repaired with an onlay graft 3.3 years later, and the other hip showed both infection and nonunion. There was 1 dislocation, and 2 hips had complications related to the greater trochanter. Our findings demonstrate that the use of APC produces satisfactory results.

Proximal Femur Allograft-prosthesis with Compression Plates and a Short Stem

Proximal femur allograft-prosthesis composites (APCs) performed with compression plates and a short stem theoretically could minimize the resorption or nonunion that reportedly occurs with long stems bypassing the diaphyseal osteotomy. To confirm this theoretical consideration, we retrospectively reviewed 34 patients with 38 proximal femoral APCs using a short-cemented femoral stem and compression plates for diaphyseal osteotomy fixation. In 26 patients, the plate fixation extended over at least half the femoral stem and in 12, it did not. We reinserted the abductor mechanism with two techniques: in 10 cases the host trochanter was reattached to the APC, and in 28 the host tendons were sutured to the tendinous insertion of the allograft. The overall survival of the entire series was 72% at 5 years and 69% at 10 years. Eleven of the 38 (29%) APCs were removed: three for infection, one for local recurrence of tumor, and seven for fractures. Trendelenburg gait occurred in four of 21 patients with direct tendon-to-tendon suture of the abductor mechanism and in three of six patients with trochanteric osteotomy. The overall APC survival rate was greater in patients in whom the allograft was adequately protected with internal fixation than in patients in whom it was not. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Massive Bone Loss from Fungal Infection after Anterior Cruciate Ligament Arthroscopic Reconstruction

Although there are numerous reports of septic pyogenic arthritis after arthroscopic anterior cruciate ligament (ACL) reconstruction, there is limited information regarding the outcomes of fungal infection. We determined the outcomes of six patients with mycotic infection after regular ACL reconstruction. There were four males and two females with a mean age of 33 years. We determined the number of procedures performed, bone loss originating to control infection, and final reconstruction in these patients. An average of five arthroscopic lavage procedures had been performed at the referring centers. Fungal infection was diagnosed based on pathologic samples; five infections were the result of mucormycosis and one was Candida. After final débridement, the mean segmental bone loss was 12.8 cm. All patients were treated with intravenous antifungal coverage and cement spacers before final reconstruction. At final followup, all patients were free of clinical infection. Three had reconstruction with an allograft-prosthesis composite, two with hemicylindrical allografts, and one with an intercalary allograft arthrodesis. Despite the extremely unusual presentation of this complication, surgeons should be aware of potential and catastrophic consequences of this severe complication after ACL reconstruction.

Non-Vascularised Fibular Grafting After Resection of Distal Femoral Tumours: An Initial Observation.

Background: Vascularized fibular grafting, allografting, megaprosthesis and allograft-prosthesis composite are suitable limb salvage techniques after resection of the whole of distal femur but are not easily available in underdeveloped countries. This difficulty prompted the use of non-vascularized fibular grafting in bridging wide distal femoral defects that have resulted from excision of tumours. Objective: To study the incorporation of long non- vascularized fibular autografts in arthrodesis of the knee as a limb salvage technique in a developing country. Method: Non-vascularized fibular grafts were used in spanning wide bone defects that had resulted from excision of distal femoral tumours in two patients. One of the defects was 10cm and the other was 15cm. long. A customized external fixator was used for initial immobilization of the limbs after surgery. Later the limbs were immobilized with re-enforced plaster-of-Paris cast. Result: The grafts showed a peculiar mode of avascular necrosis. In one patient 2cm and in the other patient 3cm of one of the ends of graft was not incorporated. Conclusion: Although the two patients were lost to follow-up, the initial observation showed such a wide non-vascularized fibular grafting for arthrodesis of the knee after resection of the distal femoral tumours is a feasible limb salvage technique in resource poor countries. Keywords: limb salvage; non-vascularized fibular graftNigerian Journal of Orthopaedics and Trauma Vol. 6 (2) 2007: pp. 83-85

Allograft-Prosthetic Composite in the Proximal Tibia After Bone Tumor Resection

We consider an allograft-prosthesis composite in the proximal tibia one of the better reconstructive options in this site because it combines the mechanical stability of a prosthesis with the biologic reconstruction of the extensor mechanism. We retrospectively reviewed 62 patients who had proximal tibia reconstructions with allograft-prosthesis composites to ascertain the complications and functional outcomes. By combining an allograft with a prosthesis, placing cement in the graft, and press-fitting the prosthesis in the tibial diaphysis, we obtained satisfactory Musculoskeletal Tumor Society scores in 90.4% of patients, with a 5-year survival rate (73.4%) comparable to that of reconstruction with a modular prosthesis. However, we observed high infection rates (24.2%) and rotation of the medial gastrocnemius seemed not to reduce this complication. For this reason, we do not recommend using this reconstructive technique in patients who will receive postoperative chemotherapy or in patients in whom a previous reconstructive method failed. We believe the ideal candidate is the young patient with a benign aggressive or malignant low-grade tumor who has not undergone previous surgery. Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Function, disability, and health‐related quality of life after allograft‐prosthesis composite reconstructions of the proximal femur

Factors affecting function, disability and health-related quality of life after allograft-prosthesis composite reconstructions have been poorly studied. Retrospective study of eighteen patients who underwent reconstruction with proximal femoral allograft-prosthesis composites and answered questionnaires to assess hip function (Postel and Merle d'Aubigné, self-reported Harris Hip Score), disability (Toronto Extremity Salvage Score), and health-related quality of life (SF-36). The median Toronto Extremity Salvage Score was 76 (IQR: 48-85), the median self-reported Harris Hip Score was 90 (IQR: 48-95) and the median Postel and Merle d'Aubigné score was 17 (IQR: 12-17). Older age, female gender, and presentation with a pathologic fracture were associated with increased disability and poorest function. The median Physical Component Summary score was 44 (IQR: 39-45) and Mental Component Summary scores were 49 (IQR: 46-56). Male gender and recurrence of disease were associated with poorer health-related quality of life. There was a high degree of correlation between function, disability scores and Physical Component Summary score. Patients' characteristics at presentation such as age, gender, and occurrence of a pathologic fracture play an important role in determining disability, function, and health-related quality of life after allograft-prosthesis composite reconstruction of the proximal femur.

Salvage procedures and implant selection for periprosthetic femoral fractures

Periprosthetic femoral fractures with severe bone loss are challenging to treat. There are various treatment options, depending on the severity of the bone loss, age and activity of the patient and experience of the surgeon. This review focuses on the treatment of these Vancouver type B3 fractures with long-stem implants, proximal femoral replacements, allograft-prosthesis composites and cortical strut grafting.

Allograft-prosthesis Composites after Bone Tumor Resection at the Proximal Tibia

The survival of irradiated allograft-prosthesis composites at the proximal tibia is mostly unknown. However, allograft-prosthesis composites have proved beneficial at other reconstruction sites. We presumed allograft-prosthesis composites at the proximal tibia would improve survival and facilitate reattachment of the extensor mechanism compared with that of conventional (megaprostheses) reconstructions. We retrospectively reviewed 26 patients who underwent resection of proximal tibia tumors followed by reconstruction with allo-graft-prosthesis composites. Patients received Guepar massive custom-made fully constrained prostheses. Allografts were sterilized with gamma radiation, and the stems were cemented into the allograft and host bone. The minimum followup was 6 months (median, 128 months; range, 6-195 months). Fourteen patients had one or more components removed. The median allograft-prosthesis composite survival was 102 months (95% confidence interval, 64.2-infinity). Of the 26 allografts, seven fractured, six showed signs of partial resorption, and six had infections develop. Seven allografts showed signs of fusion with the host bone. Six extensor mechanism reconstructions failed. Allograft-prosthesis composites sterilized by gamma radiation yielded poor results for proximal tibial reconstruction as complications and failures were common. We do not recommend irradiated allograft-prosthesis composites for proximal tibia reconstruction.

Gluteal muscle attachment during proximal femoral reconstruction in a canine model

In this 18 month in vivo canine study we compared three methods of attaching the gluteal muscles to the proximal femur during hip reconstruction with an allograft-prosthesis composite (APC). All three methods are commonly practiced in human hip revision surgery and data on their effectiveness in dogs is directly relevant to human treatment. The methods compared were host gluteal tendon sutured to allograft tendon, host greater trochanter apposed to allograft using a cable grip system, and host cortical bone shells around the allograft secured with cerclage wires. For each method, we assessed changes in allograft-host bone fusion, weight bearing, gluteal muscle mass, and structural properties through qualitative radiography, gait analysis, histology, and biomechanical testing. Hip reconstruction using the WRAP method resulted in the greatest limb use with complete resolution of gluteal muscle atrophy 18 months after surgery. This method yielded a stronger, more stable hip joint that allowed for more normal limb function. These hips had the more rapid rate of bony union at the host bone-allograft junction and little resorption of the graft. The increased limb use and resultant larger gluteal muscle mass conferred to the WRAP hip composites the greatest tensile strength and stiffness when tested 18 months after reconstruction. There was a large amount of new bone formation on the periosteal surface where the WRAP reconstructions had an overlay of live bone that resulted in a more rapid union and increased cortical width at the level of the osteotomy. New bone also penetrated into the allograft a greater distance from the osteotomy in the WRAP group.

SURVIVAL OF TOTAL KNEE REPLACEMENT WITH A MEGAPROSTHESIS AFTER BONE TUMOR RESECTION

Background: The use of a megaprosthesis has become the method of choice for reconstruction after bone tumor resection at the knee. However, the long-term survival of megaprostheses is poor. In this study, we sought to identify factors that were associated with implant failure and amenable to interventions designed to improve implant survival. Methods: A retrospective review of the charts of ninety-one patients who had undergone resection of a tumor of the knee followed by reconstruction with a custom-made megaprosthesis was performed. The distal part of the femur was resected in fifty-six patients and the proximal part of the tibia, in thirty-five patients. The reconstruction was performed with an allograft-prosthesis composite in thirty-three patients and with metal or plastic sleeves in fifty-eight patients. Reconstruction of the extensor mechanism was necessary in all thirty-five patients with a tibial tumor. Results: The median duration of follow-up was sixty-two months. The extensor mechanism was significantly less likely to rupture when partial continuity had been preserved at the time of the resection. Intra-axial laxity (an arc of motion of >5° in the frontal plane) was significantly more common when the prosthesis had an antirotation pin than when it did not have an antirotation pin (p = 0.0023). There was mechanical failure of ten allograft-prosthesis composites and ten sleeve reconstructions. Thirty-six patients had removal of at least one component of the prosthesis. When revision due to local tumor recurrence was excluded, the median duration of prosthetic survival was 130 months following the distal femoral resections and 117 months following the proximal tibial resections. The median duration of survival was 117 months for the allograft-prosthesis composites and 138 months for the sleeve reconstructions. Body weight and activity level were independent predictors of early revision. Conclusions: The long-term survival of the knee megaprostheses in this study was poor. Mechanical failure was multifactorial and the leading cause of revision. Use of allograft-prosthesis composites and use of bushings or an antirotation pin appeared to have no mechanical benefits. We recommend that weight control programs and advice about adapting their activity level be offered to patients preoperatively. Level of Evidence: Prognostic Level II. See Instructions to Authors for a complete description of levels of evidence.

Survival of Total Knee Replacement with a Megaprosthesis After Bone Tumor Resection

The use of a megaprosthesis has become the method of choice for reconstruction after bone tumor resection at the knee. However, the long-term survival of megaprostheses is poor. In this study, we sought to identify factors that were associated with implant failure and amenable to interventions designed to improve implant survival. A retrospective review of the charts of ninety-one patients who had undergone resection of a tumor of the knee followed by reconstruction with a custom-made megaprosthesis was performed. The distal part of the femur was resected in fifty-six patients and the proximal part of the tibia, in thirty-five patients. The reconstruction was performed with an allograft-prosthesis composite in thirty-three patients and with metal or plastic sleeves in fifty-eight patients. Reconstruction of the extensor mechanism was necessary in all thirty-five patients with a tibial tumor. The median duration of follow-up was sixty-two months. The extensor mechanism was significantly less likely to rupture when partial continuity had been preserved at the time of the resection. Intra-axial laxity (an arc of motion of >5 degrees in the frontal plane) was significantly more common when the prosthesis had an antirotation pin than when it did not have an antirotation pin (p = 0.0023). There was mechanical failure of ten allograft-prosthesis composites and ten sleeve reconstructions. Thirty-six patients had removal of at least one component of the prosthesis. When revision due to local tumor recurrence was excluded, the median duration of prosthetic survival was 130 months following the distal femoral resections and 117 months following the proximal tibial resections. The median duration of survival was 117 months for the allograft-prosthesis composites and 138 months for the sleeve reconstructions. Body weight and activity level were independent predictors of early revision. The long-term survival of the knee megaprostheses in this study was poor. Mechanical failure was multifactorial and the leading cause of revision. Use of allograft-prosthesis composites and use of bushings or an antirotation pin appeared to have no mechanical benefits. We recommend that weight control programs and advice about adapting their activity level be offered to patients preoperatively.

Proximal femoral allografts for bone deficiencies in revision hip arthroplasty: A medium-term follow-up study

Fifteen patients who had undergone hip reconstruction using a proximal femoral allograft-prosthesis composite because of failed total hip arthroplasty were reviewed retrospectively. The average length of allograft was 11 cm. The average follow-up period was 7.6 years. Ten patients retained the allograft-prosthesis construct, yielding a success rate of 67% for the procedure. The average preoperative Harris Hip Score of all patients was 21.7 points. At the latest follow-up, the average hip score for 10 patients with retained allograft-prosthesis composite was 81 points. Complications included junction nonunion (13%), allograft fracture (6.7%), loosening of acetabular component (6.7%), trochanteric escape (26.7%), allograft infection (20%), and allograft resorption (20%). Although proximal femoral allograft-prosthesis composite achieved good clinical results in most of the patients at medium-term follow-up, the late development of infection and resorption of the allograft warranted continued observation of patients who had undergone such procedures.

ALLOGRAFT-PROSTHESIS COMPOSITE FOR REVISION OF CATASTROPHIC FAILURE OF TOTAL ELBOW ARTHROPLASTY

Revision of a failed total elbow arthroplasty is a challenging procedure, often associated with bone deficiency. The purpose of this investigation was to review our experience with a composite allograft-implant reconstruction for patients with a failed total elbow arthroplasty. Thirteen patients (thirteen elbows) in whom a total elbow arthroplasty had failed, primarily as a result of loosening of the humeral or ulnar component, were operated on with use of an allograft-prosthesis composite; the composite was placed on the humeral side in four of these patients and on the ulnar side in nine. The delay between the last total elbow arthroplasty and the allograft-prosthesis-composite procedure averaged eight years. At an average of forty-two months after the revision, the Mayo Elbow Performance Score was excellent for four elbows, good for three, fair for one, and poor for five. Nine of the thirteen patients had no or only slight pain in the elbow. The mean arc of flexion was 97 degrees, with an average of 28 degrees (range, 0 degrees to 60 degrees ) of extension to 125 degrees (range, 100 degrees to 140 degrees ) of flexion. There were seven complications affecting seven elbows, and five of the seven required a revision procedure. Deep infection developed in four elbows, and the allograft-prosthesis composite had to be removed from three. Two nonunions occurred at the allograft-humeral junction. An allograft-prosthesis composite can be a valuable option in selected patients with a failed total elbow arthroplasty with massive bone loss. The union and implant survival rates are high. Deep infection remains the main complication. Hence, we recommend the pursuit of other revision options, such as strut graft reconstruction, whenever possible before resorting to the use of an allograft-prosthesis composite in the surgical treatment of a failed total elbow arthroplasty with massive bone loss.

Implant selection in revision total knee arthroplasty.

Revision total knee arthroplasty implants have evolved from fully constrained (fixed-hinge) to semiconstrained to contemporary constrained designs. The latter category includes nonlinked constrained (total condylar-III) designs ( Fig. 1) and rotating-hinge designs ( Figs. 2-A and 2-B). Fig. 1: Postoperative anteroposterior radiograph illustrating a nonlinked constrained knee design that was used to revise a failed primary total knee arthroplasty in a patient with rheumatoid arthritis. Figs. 2-A and 2-B: Preoperative (Fig. 2-A) and postoperative (Fig. 2-B) radiographs of the knee of a low-demand seventy-nine-year-old woman who was managed with a rotating-hinge knee prosthesis because of a comminuted periprosthetic supracondylar fracture of the femur. Additionally, the advent of limb-salvage procedures following tumor resection and other instances in which there is massive segmental bone loss, such as that seen after multiple failed arthroplasties (particularly following failed reimplantation for infection), has stimulated the development of modular or custom segmental replacement and the use of allograft-prosthesis composites. Segmental modular megaprostheses are rotating-hinge components with modular stems of varying lengths that are used to replace segmental femoral or tibial diaphyseal bone loss ( Fig. 3). Fig. 3: Lateral radiograph illustrating reconstruction of segmental bone defects of the distal part of the femur and proximal part of the tibia. On the femoral side a custom segmental distal femoral rotating-hinge prosthesis was used, and on the tibial side an allograft-prosthesis composite was used. Use of the proximal tibial allograft facilitated reattachment of the extensor mechanism. An allograft-prosthesis composite consists of a structural allograft, usually the distal part of a donor femur or the proximal part of a donor tibia, into which a stemmed prosthesis is cemented. The composite structure is attached to the remaining host bone with use of matching step-cuts at the junction of the allograft and the host bone. The construct is stabilized with an intramedullary stem ( Figs. 4-A …

The structural allograft composite in revision total knee arthroplasty

Options in revision total knee arthroplasty with massive bone loss include arthrodesis, custom total knee arthroplasty, amputation, and revision with structural allograft–prosthesis composites. Advantages of structural allografts include their biologic potential, versatility, relative cost-effectiveness, bone stock restoration, and potential for ligamentous reattachment. Disadvantages include the risk of disease transmission and graft nonunion, malunion, collapse, or resorption. Extensive preoperative planning is required to rule out infection and to select properly the type and size of allograft and prosthetic implant. Implant designs with diaphyseal-engaging stems and increased prosthetic constraint often are required. The host site and allograft require meticulous preparation to maximize surface contact and mechanical interlock of the allograft and host. Allograft fixation must be rigid to allow for incorporation. Ligamentous reattachment to the allograft is most successful when done by a bone block technique. Common complications include instability and graft collapse. Copyright 2002, Elsevier Science (USA). All rights reserved.

Long intramedullary stems of prosthetic components reduce complications, when allograft-prosthesis composite is used in tumor reconstruction

Long intramedullary stems of prosthetic components reduce complications, when allograft-prosthesis composite is used in tumor reconstruction

Total knee arthroplasty in patients who have massive osteoarticular allografts.

The authors treated 24 patients with total knee arthroplasty who had a massive allograft used to reconstruct the knee and who later had instability, degeneration, or a fracture near the articular surface of the graft develop. Patients then were followed up for a minimum of 2 years and a mean of 8.2 years. Overall, 96% of the patients retained a functional limb, although 46% underwent revision surgery, and an additional 12% had some other major complication. Statistical analysis showed a significant negative effect of chemotherapy on revision-free survival of the prosthesis. Patients with high-grade tumors were at significantly greater risk of fracture of the allograft-prosthesis composite. Certain technical factors were identified that seemed to predispose the allograft-prosthesis reconstructions to early failure. Total knee arthroplasty can be used to treat patients with complications of massive osteoarticular allografts and may prolong the functional life of an otherwise successful limb salvage reconstruction.

Salvage of failed femoral megaprostheses with allograft prosthesis composites.

The records of 11 consecutive adult patients who underwent revision of a failed femoral megaprosthesis (aseptic loosening, nine; periprosthetic fracture, one; and prosthesis fracture, one) to an allograft prosthesis composite were reviewed retrospectively. Complications included radiographic component subsidence in two patients (18%), hip instability in three patients (27%), deep infection in two patients (18%), and allograft fractures in two patients (18%). Five patients (45%) required subsequent reoperations; four patients underwent removal of the allograft prosthesis composite at a mean of 16 months (range, 5-41 months) and one patient (9%) with hip instability underwent revision of the failed megaprosthesis to a constrained acetabulum. Reconstruction of a failed femoral megaprosthesis is a complex problem caused by extensive bone loss and violation of soft tissue attachments. Despite a high complication rate, six patients (55%) remained ambulatory and had mild or no pain at a mean followup exceeding 5.5 years.

Revision total knee arthroplasty with a cemented posterior-stabilized or constrained condylar prosthesis: A minimum 3-year and average 5-year follow-up study

The results of 57 revision total knee arthroplasties performed for aseptic failure between 1984 and 1992 with a cemented posterior-stabilized or constrained condylar prosthesis were reviewed at follow-up examinations at a minimum of 36 and an average of 62 months (range, 36–120 months). The reason for revision was aseptic loosening of 1 or both components in 32 knees (56%), instability in 16 knees (28%), polyethylene wear and osteolysis in 4 knees (7%), supracondylar femur fracture in 2 knees (4%), and a failed allograft, pain, and arthrofibrosis in 1 knee each (5% total). The average age of the patients at the time of the revision was 74 years (range, 38–90), and the original diagnosis for the majority of patients was osteoarthritis (74%). All of the revision prostheses were cemented posterior stabilized or constrained condylar-type implants. Bone deficiencies were grafted with cancellous allograft in contained defects and cortical allograft in noncontained defects. Five knees were reconstructed with allograft-prosthesis composites. The average modified Hospital for Special Surgery knee score improved from 49 to 82 (100 points possible) at final follow-up evaluation ( P < 0.001). Seventy-nine percent of knees were graded as good or excellent. Kaplan-Meier survivorship analysis predicted 94% ± 6.2% survival at 40 months and 75% ± 25% at 99 months. There were 4 clinical failures, 3 of which were related to residual instability in patients with a posterior-stabilized prosthesis. Complications (3 knees) were exclusively related to the extensor mechanism. Radiographically, overall knee alignment improved from 0.3° varus to 3.0° valgus. Fifty-six percent of tibial components were placed in slight varus alignment. Radiolucent lines occurred in 33% of knees, but there were no complete or progressive radiolucencies. Radiolucent lines were more prevalent adjacent to press-fit intramedullary femoral stems compared with cemented stems ( P < .02), but the difference did not correlate with clinical or radiographic failure. The median bone defect score, as proposed by the Knee Society Committee on Bone Defects, was significantly greater in knees that were revisions of a failed cemented total knee arthroplasty compared with revision of a failed cementless total knee arthroplasty ( P = .02) but was not correlated with clinical or radiographic outcome ( P > .05).

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

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