This video presentation serves to illustrate the pertinent aspects of bone preparation and implant insertion in cementless total knee arthroplasty (TKA) utilizing porous tantalum as a fixation surface integral to the success of the procedure.

The patient is typical of the surgical candidate frequently encountered for arthroplasty—a 60-year-old female with three compartment osteoarthritis of the knee, and manifesting a 10-degree varus deformity and 5-degree flexion contracture. She is a limited community ambulator without the use of support.

A standard surgical exposure is utilised and the bone preparation is identical to that used in the fixation of cemented implants—no alignment guides, cutting guides, or referencing instrumentation is used that is unique in the femoral or tibial bone preparation. The principal difference is in the patellar preparation. Instrumentation unique to the cementless porous tantalum patella is utilised in order to achieve three goals: a composite implant/residual bone thickness that replicates the thickness of the native patella, the generation of a planar patellar resection that is parallel to the anterior cut of the femur, and secure initial stability of fixation.

Keys to the initial fixation of the porous tantalum tibial and patellar components include the high surface friction of the material against bone, as well as the interference between the hexagonal pegs of each implant within the fixation holes (which are dimensionally smaller in diameter than the major and minor dimensions of the peg geometry). Care must be instituted to ensure that no bone or soft tissue debris is interposed at the mating surfaces of the implants that would compromise interface contact, and to carefully suction the peg holes to ensure that no debris impedes the complete seating of the pegs and the prosthesis. Lastly, all mating surfaces at the implant/bone interface must approach each other in a parallel fashion to optimise contact between the fixation surfaces and the bone resection surfaces.

The procedure is simply, easily performed, and is time saving. Total elapsed time for insertion of all three TKA implants in this video is 90 seconds.

Total knee arthroplasty (TKA) is a successful operation associated with a high rate of clinical success and long-term durability. Cementless technology for TKA was first explored 30 years ago with the hope of simplifying the performance of the procedure and reducing an interface for potential failure by eliminating the use of cement. Poor implant design and the use of first generation biomaterials have been implicated in many early failures of these prostheses due to aseptic loosening and reflected the failure of either the tibial or patellar component. Despite this, many excellent intermediate and long-term series have clearly demonstrated the ability of cementless TKA to perform well with good to excellent survival, comparable to that of cemented designs.

Lessons learned from the initial experiences with cementless technology in TKA have led to improvements in prosthetic design and materials development. One of the most innovative biomaterials introduced into orthopaedics for cementless fixation is porous tantalum. Compared to other commonly used materials for cementless fixation, porous tantalum has the highest surface friction against bone, optimizing initial stability at the implant-bone interface as a prerequisite for long-term stability of the reconstruction.

At the 2013 AAOS Annual Meeting, Abdel presented the 5-year Mayo Clinic experience with cementless TKA utilizing a highly porous monoblock tibial component in 117 knees and found NO difference in survivorship compared to cemented fixation with a re-operation rate of 3.5% in both groups. They had no revisions for aseptic loosening. These early to intermediate results reflect our own experience with all cementless TKA utilizing a cobalt-chromium fibermesh femoral component, as well as monoblock porous tantalum tibial and patellar components with up to 11-year follow up. In that series of 115 patients, there was a 95.7% survival of implants, with no revisions of any components for aseptic loosening.

Further advantages to using cementless fixation include the elimination of concerns with regard to monomer-induced hypotension, thermal necrosis from PMMA polymerization, and third body wear secondary to retained or fragmented cement. Savings are also realised from elimination of the costs of cement, a PMMA mixing system, cement gun, pulse lavage system, and irrigation solution. Perhaps the greatest cost savings is derived from the reduction in operating room time. At our institution–a Level 1 county trauma center with an orthopaedic residency training program–we typically spend an average of 19 minutes of operating room time for the cementing of a total knee arthroplasty. Our average time expended for insertion of all three cementless implants is 47 seconds–representing a significant savings in the hospital operating room time charge. From the standpoint of the patient, the shorter operating time reduces the time under anesthesia, the blood loss, the risk of venous thromboembolism, as well as the infection risk–optimizing the conditions for a reduction in post-operative complications, directly impacting a potential reduction in morbidity and mortality.

Overall, the performance of all cementless TKA at our facility is cost-saving, is easily performed and reproduced by orthopaedic residents, and brings potential advantages to the patient in the form of a reduction in complications and an improvement in outcomes. Cementless fixation is the wave of the future, and the future is now.

Our American Academy of Orthopaedic Surgeons (AAOS) and the American College of Chest Physicians (ACCP) have come to a consensus that the use of routine prophylaxis against venous thromboembolism (VTE) is indicated for our patients undergoing total joint arthroplasty. The new guidelines acknowledge differences in efficacy of the various agents and the variable risk of VTE among patients. Agents include warfarin, low molecular weight heparin, aspirin, oral Xa inhibitors, and direct thrombin inhibitors. The use of pneumatic compression devices have been found to be effective in decreasing risk of deep vein thrombosis (DVT) as a stand-alone strategy after total knee arthroplasty (TKA) and is given a level 1C recommendation by ACCP while the data is less strong for use following total hip arthroplasty (THA). Mechanical devices are not associated with an increased bleeding risk, and address the concerns of some surgeons with regard to post-operative bleeding. The availability of mobile compression devices has expanded the indications for use as a result of portability.

While the use of mobile pump technology in DVT prophylaxis adds to the armamentarium of tools available for use in VTE risk mitigation, it does not eliminate the need for pharmacologic prophylaxis. While all arthroplasty patients are at elevated risk of VTE, the highest risk is associated with those having a prior history of DVT or pulmonary embolism (PE), having had prior surgery within the preceding three months, or requiring prolonged immobilization post-operatively for any reason. In these patients, thromboprophylaxis with any of a number of agents will play a valuable role in VTE risk reduction. Additionally, not all patients tolerate the use of the pump device. Those individuals with chronic peripheral arterial disease or arterial ulcers in the legs are also poor candidates for mechanical compression strategies which may exacerbate existing vascular compromise and perfusion of the limb. Assessment of the medical comorbidities of the patient may also stratify them to higher risk where the demonstrated benefits of pharmacologic prophylaxis outweigh the considerations of bleeding associated with their use (such as in the morbidly obese/high BMI patients).

Mobile pump technology is a valuable adjunct to our VTE reduction strategies, but do not eliminate the need for pharmacologic agents. The judicious selection of DVT prophylaxis strategies based on the totality of the constellation of orthopaedic and medical factors unique to each patient allows us to make clinical decisions tailored to their needs, their risk of VTE, and their reliability in functioning as an active partner in their own post-operative care.