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 fractures above well-fixed components, internal fixation is preferred. Fixation options include retrograde nailing or lateral 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. 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 and nailing techniques, however, biplanar fluoroscopic vigilance is required to prevent malalignments, typically valgus, distraction, and distal fragment hyperextension. For certain fractures, distal femoral replacement (DFR) is a wise choice. The author reserves DFR for situations where internal fixation is likely to fail (severe distal osteolysis, severe osteopenia) or for cases where it has already failed (nonunion). Obviously, if the implant is loose, revision is indicated, and typically the distal bone loss is so severe that a distal femoral replacement is indicated. The author prefers cemented constructs and routinely adds antibiotics to the cement mixture. Careful attention to posterior dissection of the distal fragment is recommended to avoid neurovascular injury. Cementing the femoral component in the proper amount of external rotation is important to allow central patellar tracking. The available literature demonstrates excellent functional results with these reconstructions, however, complications are not uncommon. Infection and extensor mechanism complications are the most frequent complications and are best avoided. In summary, ORIF remains the treatment of choice for these fractures, however, for cases where ORIF is likely to fail, or has failed, DFR remains a predictable salvage option.
Uncemented acetabular component fixation remains the gold standard for managing various defects in the revision hip setting. Multiple series have demonstrated over 90% ten-year survivorship of these constructs. Modern “enhanced” metals such as trabecular tantalum and titanium continue to perform well and are growing in popularity. So called “jumbo” cups, diameters >=62mm in females and >=66mm in males have demonstrated excellent survivorship. Good bony support with viable bone and stable initial fixation is necessary for long-term success. It is unknown how much remaining bone is necessary for reliable ingrowth with modern enhanced metals. The location of the remaining bone is probably more important than the absolute amount remaining. Occasionally, the uncemented cup must be augmented with metal augments or even a so-called “cup cage” construct. Even in these situations, the uncemented cup remains the workhorse of revision THA due to its ingrowth potential and excellent track record. Augments are commercially available in various shapes and sizes to assist in the management of cavitary, segmental and combined defects while restoring the desired cup position. Trials are available to ensure good approximation of the augment to remaining bone. The constructs are typically “unitised” to the cup via bone cement. Available data show excellent survivorship of augmented constructs for these challenging reconstructions.
The vast majority of intertrochanteric fractures treated with cephalomedullary nails (CMN) will heal. Occasionally even though bony union occurs excessive lag screw sliding can cause persistent pain and soft tissue irritation and return to surgery for hardware removal. The purpose of this study was to evaluate if fracture stability, lag screw tip-apex distance (TAD), and quality of reduction have any impact excessive lag screw sliding and potential cutout. As part of our level one trauma center's institutional hip fracture registry, a retrospective analysis identified 199 intertrochanteric fractures fixed with CMN between 2009 and 2015 with follow up to union or a minimum of three months. The mean follow-up was 22 months (3 to 94 months). Mean patient age was 75 years (50 to 97 years) and 72% were women. Postoperative radiographs were used to measure the TAD, quality of reduction, neck-shaft angle (NSA), and lateral lag screw prominence. Follow-up radiographs were reviewed to assess fracture union, translation, and progression of lateral lag screw prominence. Complications and reoperations were recorded.Introduction
Methods
Uncemented acetabular component fixation remains the gold standard for managing various defects in the revision hip setting. Multiple series have demonstrated over 90% ten-year survivorship of these constructs. Modern “enhanced” metals such as trabecular tantalum and titanium continue to perform well and are growing in popularity. So called “jumbo” cups, diameters >=62mm in females and >=66mm in males have demonstrated excellent survivorship. Good bony support with viable bone and stable initial fixation is necessary for long-term success. It is unknown how much remaining bone is necessary for reliable ingrowth with modern enhanced metals. The location of the remaining bone is probably more important than the absolute amount remaining. Occasionally, the uncemented cup must be augmented with metal augments or even a so-called “cup cage” construct. Even in these situations, the uncemented cup remains the workhorse of revision THA due to its ingrowth potential and excellent track record. Augments are commercially available in various shapes and sizes to assist in the management of cavitary, segmental and combined defects while restoring the desired cup position. Trials are available to ensure good approximation of the augment to remaining bone. The constructs are typically “unitised” to the cup via bone cement. Available data show excellent survivorship of augmented constructs for these challenging reconstructions.
Few will disagree that the best femoral head that a young patient can have is his or her own, native femoral head. In the active, healthy patient under age 60 with a displaced femoral neck fracture, well-done, timely ORIF presents the best chance of preserving the patient's native femoral head. Arthroplasty is generally reserved for older patients, over age 60, where attempts at ORIF in this setting have demonstrated failure rates over 40%. “Physiologic age” is a somewhat nebulous term that takes into account the health and ambulatory status of the patient. For example, a 52-year-old with end-stage renal failure, severe osteoporosis, and a displaced femoral neck fracture may best be treated with arthroplasty. However, in reality, such situations are quite rare. Recent studies have documented that approximately 80% of young patients with displaced femoral neck fractures treated with ORIF will keep their own femoral head for 10 years after injury. The variables under the surgeon's control include timing of fixation, quality of reduction, accurate implant placement and implant selection, and capsulotomy. All of these variables potentially affect outcomes. Fractures in this young age group are frequently high shear angle (vertical) Pauwels type 3 fractures, and benefit from fixed angle fixation. The author prefers anatomic reduction and stabilization with a sliding hip screw and a superiorly placed derotation screw. Careful attention to detail is important to obtain an anatomic reduction, which is the most important variable in the outcome of these challenging injuries.
The vast majority of fractures around the knee will heal with well-done internal fixation. TKA has a role in several scenarios. Acute TKA can be effective for fractures of the distal femur (especially periprosthetic) in very elderly patients where internal fixation attempts are likely to fail. Acute TKA for tibia plateau fractures may have a role in fractures in the elderly with pre-existing DJD and relatively simple fracture patterns. There is very little published literature regarding the outcomes of TKA for acute tibial plateau fracture and caution is advised until more data is available. TKA is commonly indicated for failed fixation and post-traumatic arthritis. Challenges include managing retained hardware, soft tissue injury and contracture, unusual ligamentous imbalances, and multiple prior incisions and/or flaps. Occasionally, a partial hardware removal may be appropriate. If extensive or multiple incisions are needed for hardware removal it may be wise to stage the reconstruction after soft tissue recovery. The available data on TKA for post-traumatic reconstructions generally demonstrate predictable functional improvement but higher complications.
There is a paucity of available literature to guide the surgeon treating postoperative fractures of the greater trochanter after femoral component revision. Between 2009 and 2016, 133 patients underwent femoral component revision by the senior author utilizing a modular tapered fluted titanium stem. 17 patients died or had inadequate follow-up. Therefore, 116 patients were included in the final analysis. There were 58 males and 58 females with a mean age of 64 (range 23 to 91 years old). Clinical and radiographic data were analyzed for postoperative greater trochanteric fracture (GTfx). Mean clinical follow up was 21 months (range 3 to 77 mos). Age, BMI, preoperative diagnosis, comorbidities, reason for revision, use of Extended Trochanteric Osteotomy (ETO), fixation method of ETO, presence of prior hardware, post-operative trauma (falls), femoral component size and offset, change in leg length were analyzed to determine potential risk factors for postoperative GT fracture. There were 7 postoperative greater trochanteric fractures in 7 patients (6%). Of these, 1 occurred as a result of a postoperative fall, 1 occurred after dislocation, and 1 occurred after a fall with a subsequent dislocation. The mean time to diagnosis of the fracture was 10.7 weeks postoperatively (range one day to 37.4 weeks). 52 of 116 patients had their revision performed through an ETO. Of those, 6 had a postoperative fracture of the GT. The use of an ETO significantly increased the likelihood of postoperative GT fx (p=0.035). Regarding femoral component size, use of a longer proximal body (+10 or greater) was associated with an increased risk of postoperative GT fx (p=0.07). Two fractures were minimally (<1cm) or non-displaced and were treated non-operatively. Of these fractures, 1 united. The other fracture further displaced and resulted in recurrent instability. This was treated with excision of the fragment and a constrained liner. 5 fractures were displaced and were treated with ORIF. 3 were fixed with a cable grip device, 1 was plated, and 1 was treated with a cable grip device and a constrained liner. Of those treated with some form of ORIF, all 5 healed. Of those that underwent surgical fixation initially, 3 reported residual trochanteric pain and 1 patient had their hardware removed (trochanteric claw). 2 of these patients have a residual limp and require a cane for use as a gait aid. The patient treated non-surgically required a cane as did the patient that failed non-surgical treatment. Post-operative greater trochanteric fractures are a rare complication of femoral component revision. The use of an ETO significantly increased the rate of post of GTfx. The mean time to diagnosis of was 11 weeks. Displaced fractures of the greater trochanter treated with ORIF all healed, both cable grip devices and plates were effective. Residual limp requiring gait aids and residual trochanteric pain were common outcomes after fixation of these fractures despite successful union.
Few will disagree that the best femoral head that a young patient can have is his or her own, native femoral head. In the active, healthy patient under age 60 with a displaced femoral neck fracture, well-done, timely ORIF presents the best chance of preserving the patient's native femoral head. Arthroplasty is generally reserved for older patients, over age 60, where attempts at ORIF in this setting have demonstrated failure rates over 40%. “Physiologic age” is a somewhat nebulous term that takes into account the health and ambulatory status of the patient. For example, a 52-year-old with end stage renal failure, severe osteoporosis, and a displaced femoral neck fracture may best be treated with arthroplasty. However, in reality, such situations are quite rare. Recent studies have documented that approximately 80% of young patients with displaced femoral neck fractures treated with ORIF will keep their own femoral head for 10 years after injury. The variables under the surgeon's control include timing of fixation, quality of reduction, accurate implant placement and implant selection, and capsulotomy. All of these variables potentially affect outcomes. Fractures in this young age group are frequently high shear angle (vertical) Pauwels Type 3 fractures, and benefit from fixed angle fixation. The author prefers anatomic reduction and stabilisation with a sliding hip screw and a superiorly placed derotation screw. Careful attention to detail is important to obtain an anatomic reduction, which is the most important variable in the outcome of these challenging injuries.
There are many challenges facing the revision knee surgeon. Bony defects, ligamentous imbalance, and difficult gap balancing scenarios are common and require practical management strategies. Typically, an implant with the least amount of constraint necessary to provide a well-aligned, well-balanced arc of motion is preferred. Constraint in implants increases the stresses on both the bearing surfaces and the bony interfaces and may result in earlier mechanical failure of the implant. Despite this fact, there are situations where one cannot rely on a simple larger polyethylene post (such as found in CCK type devices) to balance gaps. The author prefers to choose hinge-type devices in situations that demonstrate massive gap imbalance (typically huge flexion gaps), situations with deficient extensor mechanisms that can result in recurvatum stresses, or in situations of global ligamentous instability. Techniques of supporting the bony interfaces with stems and sleeves may improve the longevity of these constructs. Complications are common, including extensor mechanism problems. Multiple studies have demonstrated reasonable results of hinged implants for these challenging revision scenarios, and the hinge should remain in the armamentarium of the revision surgeon.
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. Typically a megaprosthesis is required. Well-fixed components, internal fixation is preferred. Fixation options include retrograde nailing or lateral 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.
There are many challenges facing the revision knee surgeon. Bony defects, ligamentous imbalance, and difficult gap balancing scenarios are common and require practical management strategies. Typically, am implant with the least amount of constraint necessary to provide a well-aligned, well-balanced arc of motion is preferred. Constraint in implants increases the stresses on both the bearing surfaces and the bony interfaces and may result in earlier mechanical failure of the implant. Despite this fact, there are situations where one cannot rely on a simple larger polyethylene post (such as found in CCK type devices) to balance gaps. The author prefers to choose hinge type devices in situations that demonstrate massive gap imbalance (typically huge flexion gaps), situations with deficient extensor mechanisms that can result in recurvatum stresses, or in situations of global ligamentous instability. Techniques of supporting the bony interfaces with stems and sleeves may improve the longevity of these constructs. Complications are common, including extensor mechanism problems. Multiple studies have demonstrated reasonable results of hinged implants for these challenging revision scenarios, and the hinge should remain in the armamentarium of the revision surgeon.
Few will disagree that the best femoral head that a young patient can have is his or her own, native femoral head. In the active, healthy patient under age 60 with a displaced femoral neck fracture, well-done, timely ORIF presents the best chance of preserving the patient's native femoral head. Arthroplasty is generally reserved for older patients, over age 60, where attempts at ORIF in this setting have demonstrated failure rates over 40%. “Physiologic age” is a somewhat nebulous term that takes into account the health and ambulatory status of the patient. For example, a 52-year-old with end stage renal failure, severe osteoporosis, and a displaced femoral neck fracture may best be treated with arthroplasty. However, in reality, such situations are quite rare. Recent studies have documented that approximately 80% of young patients with displaced femoral neck fractures treated with ORIF will keep their own femoral head for 10 years after injury. The variables under the surgeon's control include timing of fixation, quality of reduction, accurate implant placement and implant selection, and capsulotomy. All of these variables potentially affect outcomes. Fractures in this young age group are frequently high shear angle (vertical) Pauwels type 3 fractures, and benefit from fixed angle fixation. The author prefers anatomic reduction and stabilization with a sliding hip screw and a superiorly placed derotation screw. Careful attention to detail is important to obtain an anatomic reduction, which is the most important variable in the outcome of these challenging injuries.
The orthopaedic surgeon is often consulted to manage pathologic fractures due to metastatic disease, even though he or she may not be an orthopaedic oncologist. A good understanding of the principles of management of metastatic disease is therefore important. The skeleton remains a common site for metastasis, and certain cancers have a predilection for bone, namely, tumors of the breast, prostate, lung, thyroid, and kidney. Myeloma and lymphoma also often involve bone. The proximal femur and pelvis are most commonly affected, so we will focus on those anatomic sites. The patient may present with pain and impending fracture, or with actual fracture. Careful preoperative medical optimization is recommended. If the lesion is solitary, or the primary is unknown, the diagnosis must be made by a full workup and biopsy before definitive treatment is planned. For patients with known metastasis (the most common situation), the options for treatment of pathologic lesions of the proximal femur generally center on internal fixation versus prosthetic replacement. Patients with breast or prostate metastasis can live for several years after pathologic fracture, so constructs must be relatively durable. If fixation is chosen, it must be stable enough to allow full weight bearing, since the overwhelming majority of pathologic fractures will never heal. In general, long constructs are chosen to protect the entire length of the bone. Nails should protect the femoral neck as well, so cephalomedullary devices are typically chosen. Megaprostheses can be useful in situations where bony destruction precludes stable internal fixation. Postoperative radiation is recommended after wound healing. Acetabular involvement typically requires reinforcement rings or cement augmentation with the Harrington technique. Careful multi-disciplinary medical management is recommended to minimise complications.
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.
Few will disagree that the best femoral head that a young patient can have is his or her own, native femoral head. In the active, healthy patient under age 60 with a displaced femoral neck fracture, well-done, timely ORIF presents the best chance of preserving the patient's native femoral head. Arthroplasty is generally reserved for older patients, over age 60, where attempts at ORIF in this setting have demonstrated failure rates over 40%. Recent studies have documented that approximately 80% of young patients with displaced femoral neck fractures treated with ORIF will keep their own femoral head for 10 years after injury. The variables under the surgeon's control include timing of fixation, quality of reduction, accurate implant placement and implant selection, and capsulotomy. All of these variables potentially affect outcomes. Fractures in this young age group are frequently high shear angle (vertical) Pauwels type 3 fractures, and benefit from fixed angle fixation. The author prefers anatomic reduction and stabilization with a sliding hip screw and a superiorly placed derotation screw. Careful attention to detail is important to obtain an anatomic reduction, which is the most important variable in the outcome of these challenging injuries.
Few will disagree that the best femoral head that a young patient can have is his or her own, native femoral head. In the active, healthy patient under age 60 with a displaced femoral neck fracture, well-done, timely ORIF presents the best chance of preserving the patient's native femoral head. Arthroplasty is generally reserved for older patients, over age 60, where attempts at ORIF in this setting have demonstrated failure rates over 40%. “Physiologic age” is a somewhat nebulous term that takes into account the health and ambulatory status of the patient. For example, a 52-year-old with end stage renal failure, severe osteoporosis, and a displaced femoral neck fracture may best be treated with arthroplasty. However, in reality, such situations are quite rare. Recent studies have documented that approximately 80% of young patients with displaced femoral neck fractures treated with ORIF will keep their own femoral head for 10 years after injury. The variables under the surgeon's control include timing of fixation, quality of reduction, accurate implant placement and implant selection, and capsulotomy. All of these variables potentially affect outcomes. Fractures in this young age group are frequently high shear angle (vertical) Pauwels type 3 fractures, and benefit from fixed angle fixation. The author prefers anatomic reduction and stabilization with a sliding hip screw and a superiorly placed derotation screw. Careful attention to detail is important to obtain an anatomic reduction, which is the most important variable in the outcome of these challenging injuries.
Peri-prosthetic fractures above a total knee arthroplasty (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. Typically a megaprosthesis is required. For well-fixed components, internal fixation is preferred. Fixation options include retrograde nailing or lateral 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.
Stiffness remains one of the most common, and challenging post-operative complications after TKA. The exact definition of stiffness varies, and patient expectations of post-operative motion vary as well. Pre-operative motion and diagnosis (such as post-traumatic arthritis) can influence post-operative motion, and careful patient counseling about expectations is important. Post-operative stiffness should be evaluated by ruling out infection, evaluating rehabilitation efforts, and careful physical and radiographic examination. Manipulation under anesthesia (MUA) in selected cases can be helpful. The author generally prefers to perform MUA between the 6- and 8-week mark post-operatively. Careful technique is required to minimised the risk of fracture or soft tissue injury. For more chronic stiffness, revision may be indicated, especially if an etiology is identified pre-operatively (for example, an excessively thick patellar resurfacing, an oversized femoral component, gross malrotation, etc.). CT scanning can be helpful for pre-operative evaluation and planning. During revision, thorough synovectomy and release of contractures and ligamentous balancing is performed as required. Careful attention to gap balancing, component rotation, and sizing is critical. Patients should be counseled that the results of revision for stiffness are mixed and somewhat unpredictable unless a clear etiology was found intra-operatively (for example, a grossly oversized femoral component). More frequent post-operative office visits may be helpful to guide rehabilitation progress in these challenging cases.
The femoral diaphysis presents the best opportunity for fixation during revision THA. Both fully coated cylindrical and modular fluted tapered titanium stems have demonstrated excellent results. Cylindrical stems have demonstrated concerning rates of failure when used in larger, osteopenic canals or in canals with post-isthmal divergent morphologies. Modular stems offer the advantage of separating distal fixation needs from proximal version, leg length, and offset needs via a modular junction. Although early designs demonstrated some breakages at the taper or through thin proximal bodies, newer generation implants have not demonstrated such mechanical concerns. Additionally, the modular junctions do not appear to be having any problems with corrosion. Mid- to long-term data with various designs now support the safety and efficacy of these constructs that can handle a wide variety of challenges during femoral revision. Careful attention to detail is necessary to minimise the risk of subsidence and intra-operative fracture or femoral perforation.
Few will disagree that the best femoral head that a young patient can have is his or her own, native femoral head. In the active, healthy patient under age 60 with a displaced femoral neck fracture, well-done, timely ORIF presents the best chance of preserving the patient's native femoral head. Arthroplasty is generally reserved for older patients, over age 60, where attempts at ORIF in this setting have demonstrated failure rates over 40%. Recent studies have documented that approximately 80% of young patients with displaced femoral neck fractures treated with ORIF will keep their own femoral head for 10 years after injury. The variables under the surgeon's control include timing of fixation, quality of reduction, accurate implant placement and implant selection, and capsulotomy. All of these variables potentially affect outcomes. Fractures in this young age group are frequently high shear angle (vertical) Pauwels type 3 fractures, and benefit from fixed angle fixation. The author prefers anatomic reduction and stabilization with a sliding hip screw and a superiorly placed derotation screw. Careful attention to detail is important to obtain an anatomic reduction, which is the most important variable in the outcome of these challenging injuries.
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.
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.
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.
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.
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.
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.
