Although the vast majority of fractures of the proximal femur will heal with well-done internal fixation, occasionally failure of fixation will occur. Having effective salvage options is important to restore function and minimise complications. In general, it is logical to separate salvage options into those for fractures of the femoral neck, and those for fractures of the intertrochanteric region. Additionally, patient age and remaining bone stock should be considered. Femoral neck fracture fixation failure salvage, young patients: All efforts are focused on preserving the native femoral neck. Valgus producing osteotomy is typically indicated, and can be successful even with small patches of AVN. Femoral neck fracture fixation failure salvage, older patients: Total hip arthroplasty is generally most predictable. Be prepared for very poor bone quality. Supplement uncemented acetabular component with multiple screws. Be prepared to cement femoral component, if necessary. Intertrochanteric fracture fixation failure salvage, young patients: Repeat internal fixation attempts with fixed angle devices (such as a 95-degree blade plate) and bone grafting generally preferred. Avoid varus of proximal fragment and target inferior femoral head bone. Intertrochanteric fracture fixation failure salvage, older patients: Total hip arthroplasty preferred. Long stems to bypass femoral shaft stress risers and “calcar replacement” stems may be necessary due to proximal bone defects. Trochanteric fixation must be stable. Results are generally good but trochanteric complaints are common.
Periprosthetic fractures around a TKA typically involve the distal femur above a well-fixed femoral component. ORIF is typically indicated, using a retrograde nail or some form of locked plating. Tibial fractures after TKA are quite rare. In distinction to femoral fractures, fractures around a tibial component are typically associated with a loose prosthesis. Revision is indicated in this situation. Dealing with bone loss with augments, sleeves, cones, or allograft as well as stem bypass is typically necessary. Varus malalignment is often noted in these situations and should be corrected. More distal fractures can be managed with closed treatment if displacement and angulation is acceptable. A period of time in a long leg cast followed by conversion to a short leg or so-called PTB cast can be effective. More unstable fractures can be managed with plating techniques. Percutaneous so called MIPPO techniques can be particularly useful. Modern locking plates allow polyaxial proximal fixation that can be effective around the keels of tibial components. Malalignments are common so careful fluoroscopic scrutiny is necessary when using percutaneous techniques.
Instability remains a common reason for revision after primary TKA. Careful preoperative examination is necessary to determine the exact direction of and reason for the instability. Radiographs and CT can be useful to evaluate component alignment and rotation. Obviously, ruling out concurrent infection should be a part of the routine preoperative workup. PCL insufficiency can be treated by conversion to a more “dished” insert if available, and all other component issues are acceptable. If dished inserts are not available, then revision to a posterior stabilised component can be effective. Flexion instability can occur with PCL substituting designs, and may require revision as well. Up-sizing, and posteriorising the femoral component (often requiring posterior augmentation) to tighten the flexion gap can be an effective strategy. With collateral ligament problems, so called CCK or “constrained” implants can be effective. While ligament advancement or augmentation techniques have been described, few surgeons are familiar with these techniques, and most “back up” such reconstructions with constrained implants. With more severe collateral ligament deficiencies, multi-directional instabilities, or massive flexion-extension gap mismatches, the use of so-called “hinged” implants can be effective. It is wise to have various levels of constraint available preoperatively when undertaking these challenging revisions.
Peri-prosthetic fractures above a TKA are becoming increasingly more common, and typically occur at the junction of the anterior flange of the femoral component and the osteopenic metaphyseal distal femur. In the vast majority of cases the TKA is well-fixed and has been functioning well prior to fracture. For loose components, revision is typically indicated. Often, distal femoral mega prostheses are required to deal with metaphyseal bone loss. Good results have been reported in small series, however, complications, including infection remain concerning, and these implants are incredibly expensive. Although performing a mega prosthesis in the setting of a well-fixed TKA is not unreasonable due to immediate full weight bearing, in my opinion, prosthetic replacement should be limited to cases of failed ORIF (rare), or in cases where fixation is likely to fail (i.e., severe osteolysis distally). For the majority of fractures above well-fixed components, internal fixation is preferred for the main reason that the overwhelming majority of these fractures will heal. Fixation options include retrograde nailing or lateral locked plating. Nails are typically considered in arthroplasties that allow intercondylar access (“open box PS” or CR implants) and have sufficient length of the distal fragment to allow multiple locking screws to be used. This situation is rare, as most distal fragments are quite short. If a nail is chosen, use of a long nail is preferred, since it allows the additional fixation and alignment that diaphyseal fill affords. Short nails should be discouraged since they can “toggle” in the meta-diaphysis and do not engage the diaphysis to improve coronal alignment. Plates can be used with any implant type and any length of distal fragment. The challenge with either fixation strategy is obtaining stable fixation of the distal fragment while maintaining length, alignment, and rotation. Fixation opportunities in the distal fragment can be limited due to obstacles caused by femoral component lugs, boxes, stems, cement mantles, and areas of stress shielding or osteolysis. Modern lateral locked plates can be inserted in a biologically friendly submuscular extra-periosteal fashion. More recent developments with polyaxial locked screws (that allow angulation prior to end-point locking) may offer even more versatility when distal fragment fixation is challenging. The goal of fixation is to obtain as many long locked screws in the distal fragment as possible. High union rates have been reported with modern locked plating techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension.
Despite our best efforts, occasionally, certain patients will have multiply operated, failed reconstructions after TKA. There are situations where further attempts at arthroplasty are unwise, for example, chronic infections with multiple failed staged reconstructions. A careful pre-operative evaluation of the patient is critical to guide decision-making. An assessment of medical comorbidity, functional demands, and expectations is important. Regarding the extremity, the severity of bone loss, soft tissue defects, ligamentous competency, and neurovascular status is important. The next step is to determine whether the knee is infected. The details of such a workup are covered in other lectures, however, the author prefers to aspirate all such knees and obtain C reactive protein and sedimentation rates. For equivocal cases, PCR may be helpful. If no infection is present, complex reconstruction is considered. Segmental megaprosthesis and hinged prostheses may be helpful. Often, soft tissue reconstruction with an extensor mechanism allograft or muscle flap is required. Obviously, these are massive undertakings and should be done by experienced surgeons. If a prosthesis is not a good option, other options include definitive resection, knee arthrodesis, or above knee amputation. A careful discussion with the patient about the pros and cons is necessary to allow them to partner with the surgeon in the decision-making. Definitive resections are reserved for minimal to non-ambulators with significant comorbidity that do not desire an AKA. AKA is often the best option, however, it should be noted that the majority of these patients will never ambulate with a prosthesis due to the energy requirements necessary to do so. High complication rates and reoperation rates have been reported with AKA after TKA. Functional outcome studies have generally shown better function with arthrodesis than with AKA. Arthrodesis can be effective and can be accomplished with several methods. If active infection is present, an external fixator is typically chosen. If no infection is present then plating or long intramedullary nailing is considered. Plating requires healthy anterior soft tissues due to the bulk associated with double plating techniques. The highest union rates have been reported with long nails. The author therefore prefers to use long nails after eradicating infection with a staged procedure (interval spacer) rather than to use an external fixator. Union rates are higher with nails, but the risk of re-infection is slightly higher as well. Careful attention to detail is necessary to minimise complications.
Peri-prosthetic fractures of the femur around a THA remain challenging injuries to treat. The Vancouver Classification helps to guide decision making, and is based on fracture location, implant fixation status, and remaining bone quality. It is critical to determine fixation status of the implant, even if surgical dislocation is necessary. Type A fractures involve the trochanters, and are usually due to osteolysis. Revision of the bearing surface and bone grafting of the lesions can be effective. Type B1 fractures occur around a well fixed stem, typically at the stem tip. Internal fixation with laterally based locked cable plates is effective. Optimising proximal fixation is important, typically with locked screws and cables. Allograft struts are probably unnecessary with modern angle stable plates. Type B2 and B3 fractures are treated with revision, either with a fully coated cylindrical or a modular fluted tapered titanium stem. Distal fixation should be optimised, while preserving vascularity to proximal bony fragments. The « internal scaffold » technique has been described with excellent results. Rarely, a proximal femoral replacement is necessary. Careful attention to detail and clear knowledge of stem fixation status is necessary for a good outcome.
Although the vast majority of fractures of the proximal femur will heal with well-done internal fixation, occasionally failure of fixation will occur. Having effective salvage options is important to restore function and minimise complications. In general, it is logical to separate salvage options into those for fractures of the femoral neck, and those for fractures of the intertrochanteric region. Additionally, patient age and remaining bone stock should be considered. Femoral neck fracture fixation failure salvage, young patients: All efforts are focused on preserving the native femoral neck. Valgus producing osteotomy is typically indicated, and can be successful even with small patches of AVN. Femoral neck fracture fixation failure salvage, older patients: Total hip arthroplasty is generally most predictable. Be prepared for very poor bone quality. Supplement uncemented acetabular component with multiple screws. Be prepared to cement femoral component, if necessary. Intertrochanteric fracture fixation failure salvage, young patients: Repeat internal fixation attempts with fixed angle devices (such as a 95 degree blade plate) and bone grafting generally preferred. Avoid varus of proximal fragment and target inferior femoral head bone. Intertrochanteric fracture fixation failure salvage, older patients: Total hip arthroplasty preferred. Long stems to bypass femoral shaft stress risers and “calcar replacement” stems may be necessary due to proximal bone defects. Trochanteric fixation must be stable. Results are generally good but trochanteric complaints are common.
Despite our best efforts, occasionally, certain patients will have multiply operated, failed reconstructions after TKA. There are situations where further attempts at arthroplasty are unwise, for example, chronic infections with multiple failed staged reconstructions. A careful preoperative evaluation of the patient is critical to guide decision-making. An assessment of medical comorbidity, functional demands, and expectations is important. Regarding the extremity, the severity of bone loss, soft tissue defects, ligamentous competency, and neurovascular status is important. The next step is to determine whether the knee is infected. The details of such a workup are covered in other lectures, however, the author prefers to aspirate all such knees and obtain C reactive protein and Sedimentation Rates. For equivocal cases, PCR may be helpful. If no infection is present, complex reconstruction is considered. Segmental megaprosthesis and hinged prostheses may be helpful. Often, soft tissue reconstruction with an extensor mechanism allograft or muscle flap is required. Obviously, these are massive undertakings and should be done by experienced surgeons. If a prosthesis is not a good option, other options include definitive resection, knee arthrodesis, or above knee amputation. A careful discussion with the patient about the pros and cons is necessary to allow them to partner with the surgeon in the decision-making. Definitive resections are reserved for minimal to non-ambulators with significant co-morbidity that do not desire an AKA. AKA is often the best option, however, it should be noted that the majority of these patients will never ambulate with a prosthesis due to the energy requirements necessary to do so. High complication rates and reoperation rates have been reported with AKA after TKA. Functional outcome studies have generally shown better function with arthrodesis than with AKA. Arthrodesis can be effective and can be accomplished with several methods. If active infection is present, and external fixator is typically chosen. If no infection is present then plating or long intramedullary nailing is considered. Plating requires healthy anterior soft tissues due the bulk associated with double plating techniques. The highest union rates have been reported with long nails. The author therefore prefers to use long nails after eradicating infection with a staged procedure (interval spacer) rather than to use an external fixator. Union rates are higher with nails, but the risk of re-infection is slightly higher as well. Careful attention to detail is necessary to minimise complications.
Vancouver A: If minimal displacement and prosthesis stable can treat nonoperatively. If displacement is unacceptable and/or osteolysis is present consider surgery. AL: Rare, avulsions from osteopenia and lysis. If large, displaced and include large portion of calcar-can destabilise stem and prompt femoral revision. AG: More common. Often secondary to lysis. Does not usually affect implant stability. Minimal displacement. Treat closed × 3 months. Revise later is needed to remove the particle generator, debride defects and bone graft. Displaced with good host bone stock. Consider early ORIF and bone grafting. Vancouver B: B1: Rarely non-operative. ORIF with femoral component retention. Need to carefully identify stem fixation. B2's classified as B1's are doomed to fail. B1's correctly identified treated with plate, allograft struts or both. High union rates with component retention. B2: Femoral revision +/− strut allograft. Best results seen with patients revised with uncemented, extensively porous coated femoral stems. May use modular, fluted taper stems. B3: Proximal femoral replacement - Tumor prosthesis, Allograft Prosthetic Composite (APC). Uncemented femoral stem - Extensively porous coated, Fluted, tapered stem, Allograft strut. Vancouver C: Treat with standard fracture techniques. These fractures are away from the femoral prosthesis. Rarely nonoperative. Fixation options – Cerclage, Strut Allograft, Plate fixation, Retrograde IM nail, or a Combination thereof. Avoid stress risers between implants. Bypass (overlap) fixation. Consider allowing 2.5 cortical diameters between devices.
Infection after TKA remains a common reason for reoperation, and represents a significant burden for the patient and health care system. Having effective treatment strategies, therefore, is important to ensure the highest possible rate of success, and the lowest possible rate of reoperation due to treatment failure. This lecture will focus on the chronically infected TKA, where treatment options include either one stage exchange or two stage exchange. Proponents of one stage exchange cite lower costs, less morbidity, and reasonable success rates when compared to two stage exchange protocols. One must realise that strict selection criteria are generally used by proponents of single stage exchange. Favorable pathogens, healthy hosts, good soft tissues, minimal bone loss, etc. are generally used as indications to consider one stage exchange. Such “ideal” clinical situations, however, are exceedingly rare. The overwhelming majority of infected TKA in my practice involve resistant bacteria, significant bone loss, hosts with medical comorbidity, and often, poor soft tissues. In these situations, two stage exchange remains the gold standard to which all other interventions should be compared. With few exceptions, the published success rates for two stage procedures have been better, albeit slightly, than those published for one stage exchanges. Both static and articulating cement spacers have been used with good results. Further research is needed to better define the most effective treatment protocols, however, until further information is available, two stage exchange, with success rates of 80–90%, remains the most successful intervention for chronically infected TKA.
Pelvic discontinuity remains one of the most difficult reconstructive challenges during acetabular revision. Bony defects are extremely variable and remaining bone quality may be extremely poor. Careful pre-operative imaging with plain radiographs, oblique views, and CT scanning is recommended to improve understanding of the remaining bone stock. It is wise to have several options available intra-operatively including metal augments, jumbo cups, and cages. Various treatment options have been used with variable success. The principles of management include restoration of acetabular stability by “connecting” the ilium to the ischium, and by (hopefully) allowing some bony ingrowth into a porous surface to allow longer-term construct stability. Posterior column plates can be useful to stabilise the pelvis, and can supplement a trabecular metal uncemented acetabular component. Screws into the dome and into the ischium are used to span the discontinuity. More severe defects may require so-called “cup-cage” constructs or trabecular metal augmentation distraction techniques. The most severe defects typically necessitate custom triflange components. Triflange constructs allow broad based contact with remaining bone stock, and can span surprisingly large defects. Recent cost analyses have shown that custom triflange constructs are comparable to cup-cage-augment reconstructions. The results of these various solutions to manage pelvic discontinuity is extremely variable, however, it is fair to conclude that constructs that allow some bony ingrowth have demonstrated improved survivorship when compared to historical treatments such as bulk allografts protected by cages. The author prefers a posterior column plate and a trabecular metal cup for simple discontinuities, a cup-cage for larger defects, and a custom triflange for the most severe defects. Pre-operative imaging is critical to guide this decision-making, and careful attention to detail is important to obtain a stable, durable construct.
Although the vast majority of fractures of the proximal femur will heal with well-done internal fixation, occasionally failure of fixation will occur. Having effective salvage options is important to restore function and minimize complications. In general, it is logical to separate salvage options into those for fractures of the femoral neck, and those for fractures of the intertrochanteric region. Additionally, patient age and remaining bone stock should be considered. Femoral neck fracture fixation failure salvage, young patients: All efforts are focused on preserving the native femoral neck. Valgus producing osteotomy is typically indicated, and can be successful even with small patches of AVN. Femoral neck fracture fixation failure salvage, older patients: Total hip arthroplasty is generally most predictable. Be prepared for very poor bone quality. Supplement uncemented acetabular component with multiple screws. Be prepared to cement femoral component if necessary. Intertrochanteric fracture fixation failure salvage, young patients: Repeat internal fixation attempts with fixed angle devices (such as a 95 degree blade plate) and bone grafting generally preferred. Avoid varus of proximal fragment and target inferior femoral head bone. Intertrochanteric fracture fixation failure salvage, older patients: Total hip arthroplasty preferred. Long stems to bypass femoral shaft stress risers and “calcar replacement” stems may be necessary due to proximal bone defects. Trochanteric fixation must be stable. Results are generally good but trochanteric complaints are common.
