New York Physical Therapy 36-Hour Ebook Continuing Education

PREOPERATIVE PHASE

Planning and preparation for a TKA procedure can facilitate the desired outcomes following surgery. Patients will undergo evaluations to ensure they are medically ready for surgery, will Pre-surgical planning Because TKA is an elective procedure, the patient will undergo a number of medical tests prior to admission to the hospital and will have time to prepare their home to facilitate recovery. The surgeon will perform a detailed history and physical examination, obtain baseline blood work as well as an electrocardiogram, urinalysis, and chest x-ray to determine the patient’s ability to cope with a major operation. If needed, updated x-rays of the knee will be taken for surgical planning. The physical examination will include assessment of the patient’s gait pattern and whether an assistive device is necessary, areas of knee tenderness upon palpation, ligamentous stability, limb alignment, and neurovascular health of the limb to be operated on (Williams et al., 2010). Prior to surgery, the surgeon will measure the patient’s knee for the proper implant size via x-rays. This is generally done by using plastic overlay templates that are positioned over the preoperative x-rays in both anterior-posterior and lateral views, to estimate the best fit. Plain radiographs are normally used for this purpose; however, accuracy may be enhanced by using digital radiography (Fitzpatrick, FitzPatrick, Auger, & Lee, 2007). When preoperative plans are made using digital images, approximately 97% of femoral implants and 95% of tibial implants may be measured to within one size of the actual implant used on the day of surgery (Wongsak, Kawinwonggowit, Mulpruck, Channoom, & Woratanarat, 2009). The final determination on the best fit of the prosthetic implant is made during surgery itself, once the bones are directly measured. Because of the nature of the surgery, TKA may result in significant perioperative blood loss and the need for postsurgical blood transfusion, although advances in surgical techniques have reduced the amount of blood loss that occurs during surgery. Historically, patients were advised to bank their own blood in advance of their surgical date. Autologous blood donation minimizes the risk of transferring bloodborne illnesses, allergic reactions, and eliminates the risk of blood type incompatibility. Recent studies have demonstrated that preoperative blood banking should be done selectively, only in patients with a low hematocrit, as the transfusion rate of allogenic blood is not increased in patients with normal hematocrit levels and preoperative banking may actually increase the need for Surgical decisions Based on the patient presentation and their radiographic results, the surgeon must decide whether to replace one compartment (unicondylar knee replacement) or all three compartments (total knee replacement) as a means to improve pain and function (Figure 5). To aid the surgeon’s decision, detailed analysis of the three compartments is necessary to determine whether the medial compartment, lateral compartment, and/or anterior compartments are affected. A unicondylar replacement may be appropriate for a patient with early degenerative changes affecting only the medial or lateral compartment of the knee. Advantages of this procedure include preservation of bone stock, smaller incision and less surgical dissection, normal knee mechanics, less blood loss, faster recovery, and shorter inpatient length of stay. Careful patient selection is key to successful outcomes, as TKA appears to be a more dependable procedure in which there is a lower revision rate (Arirachakaran, Choowit, Putananon, Muangsiri, & Kongtharvonskul, 2015). Survival rates for unicondylar replacements compared to those for a TKA are presented in Table 2.

finalize with their surgeon which procedure is best suited for them, and initiate some components of their rehabilitation prior to surgery to best prepare for their recovery.

postoperative transfusions. Routine preoperative blood banking for patients undergoing TKA is not cost effective and contributes to a significant waste, because many patients do not utilize their banked blood postoperatively (Blazekovic, Bicanic, Hrabac, Tripkovic, & Delimar, 2014; Monsef et al., 2013). Patients who are obese (BMI > 30 kg/m 2 ) or morbidly obese (BMI > 40 kg/m 2 ) are advised to lose weight before TKA surgery because obesity is associated with an increased risk of complications, including infection (Crowe et al., 2015; D’Apuzzo et al., 2015; Mulhall, Ghomrawi, Mihalko, Cui, & Saleh, 2007; Si et al., 2015). Samson, Mercer, and Campbell (2010) reported a prevalence of deep prosthetic infection in the morbidly obese patient three to nine times greater than in controls, plus a higher incidence of wound complications. Overall, complications occur in 35.1% of morbidly obese patients and 22.6% of obese patients, as compared with 14.2% of patients who are not obese (BMI < 30; Dowsey, Liew, Stoney, & Choong, 2010). An important part of patient preparation for TKA surgery during the preoperative period is making sure that the home environment is properly set up to receive the patient upon hospital discharge. Physical therapists typically play an integral role in discharge planning and should be prepared to discuss practical adaptations of the home environment with the patient and family members. Simple environmental modifications that will reduce the risk of falls and facilitate home rehabilitation and recovery following TKA include ensuring adequate lighting is available, that strategically placed grab bars are installed in bathrooms and showers, and that floors are easily navigable for assistive devices and contain no throw rugs or thick, loose sections of carpeting (AAOS, 2011). Chairs that are stable, sturdy, and designed with two arms will facilitate independent transfers, as will the use of a raised toilet seat during the early days of recovery. The addition of a shower bench or chair is also a necessity, and when possible, patients may practice accessing the shower on a “dry run” prior to surgery. When all these parameters are set in place, patients will be able to leave for the hospital knowing that their recovery will be optimal when they return home.

Figure 5: Types of knee replacements

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Unicompartmental

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Book Code: PTNY3622B

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