There are well-established associations between tobacco use and early wound-healing complications, postoperative medical complications, and implant failure due to infection or aseptic loosening. In a large case series, Møller et al. demonstrated that active smokers had a twofold risk of wound complications following primary knee or hip arthroplasty as well as increased risk of postoperative medical complication, increased length of stay, or postoperative admission to an intensive care unit [22]. In a case-control study by Kapadia et al., compared to nonsmokers, active tobacco users had a higher rate of failure of primary TKA (90% survivorship over 4 years compared to 99%) and had a higher rate of postoperative medical complications [23]. Nwachakwu reported a similarly elevated TKA revision rate among smokers (Odds Ratio 2.87) with the most common failure modes being infection (30%) followed by aseptic loosening (18%) and stiffness (18%) [24]. Additionally, a significantly higher rate of deep infection was noted among active tobacco users (Hazard Ratio 2.37) after primary TKA or THA in a large cohort study by Singh et al. [25] Tobacco use is a modifiable risk factor, and in our opinion, smoking cessation should be mandatory prior to revision knee arthroplasty; we recommend requiring a negative urine or serum cotinine as confirmation of smoking cessation prior to surgery .

Dental clearance prior to total joint arthroplasty has historically been common practice, although recent data suggest it may be of limited efficacy in the primary arthroplasty population. In several recent studies, the incidence of dental pathology noted on screening varies from 8 to 23% [26–28]. In a prospective study by Lampley et al., 8.8% of elective arthroplasty patients had dental pathology noted on dental screening though there was no significant reduction in infection rates compared to a control group of hip fractures treated with arthroplasty who did not receive dental screening [28].

Nonetheless, an appropriate dental history (history of recent dental procedures) should be a part of the evaluation of any patient in whom revision TKA is contemplated. Waldman et al., noted that 11% of knee arthroplasties presenting with late infections were later attributed to hematogenous seeding from a dental procedure [29]; Kaar et al. also report on a late infection in an arthroplasty patient after a simple teeth cleaning [30].

More than 8% of patients undergoing primary and revision TKA have been diagnosed with diabetes mellitus [31]. The 2007 American Diabetes Association position statement recommends that adult patients with diabetes mellitus have a hemoglobin A1c level of <7% (normal, 4–7%), a preprandial capillary plasma glucose level of 90–130 mg/dL, and a peak postprandial capillary plasma glucose level of <180 mg/dL [32]. Diabetes is frequently associated with obesity and other comorbidities that may contribute to the increased risk of complications after TKA.

Patients with diabetes mellitus are at increased risk for perioperative complications including myocardial infarction, CVA, ileus, UTI, pneumonia, need for transfusion, and mortality [32]. They have increased likelihood of postoperative infections, wound complications, and revisions [14]. Wound complications including bulla formation, erythema with drainage, and skin necrosis are all associated with diabetes [14]. Diabetic patients may also experience nonroutine or delayed discharge and higher hospital charges [33]. Diabetes has been found to be independently associated with poorer functional outcome after TKA , significantly decreased subjective outcome scores and limitations in activities of daily living compared to nondiabetic patients [13].

Glycemic markers are important risk assessment tools in the preoperative evaluation prior to TKA. While glycemic control is important in preventing the short- and long-term complications of diabetes, it is unclear what ideal perioperative glucose range or maximum hemoglobin A1c level should be employed to optimize patients prior to TKA [34]. There have been positive correlations between certain markers including HbA1c ≥ 8 and/or fasting blood glucose ≥200 mg/dL and surgical site infection [14].

It is noteworthy that elevated preoperative glucose levels in patients without a prior diagnosis of diabetes are also associated with increased risk for PJI [35]. Glycemic variability may be more important than hemoglobin A1c or actual blood glucose values [34]. Other studies have found, however, when comparing patients to those without diabetes undergoing TKA that there was no increased risk of revision arthroplasty, deep infection, or deep venous thrombosis [36]. Consultation with an endocrinologist should be pursued for preoperative blood glucose control that is difficult to manage or outside the established limits of ADA guidelines .

Cardiovascular comorbidities are a significant risk factor for major systemic adverse events and deaths following total joint arthroplasty [4]. Cardiovascular complications comprise 42–75% of adverse events following total joint arthroplasty [37, 38]. Independent predictors of cardiac complications after TJA include revision TKA, a history of coronary artery disease, myocardial infarction, congestive heart failure, valvular heart disease, and arrhythmia [39]. Cardiovascular complications including pulmonary embolism, fatal arrhythmias, acute coronary syndrome, and cardiopulmonary arrest are the most common causes of death after TJA [37]. Thirty-day cardiac-related mortality has been reported in 0.18% of patients after TKA [40]. Ninety-day cardiac complication rates after TKA are increased in patients >65 years old, with and without known cardiac disease, and higher ASA class [41]. Patients who have had a previous acute myocardial infarction (AMI) with and without stent placement are at increased risk of having another AMI after TKA within 1 year [40, 42]. These events may extend the length of hospital stay by an average of 11 days [40]. Elective TKA should be performed at least 1 year after an episode of AMI or stent placement [40].

The American Heart Association and the American College of Cardiology have published guidelines for perioperative cardiovascular evaluation [43]. Any patient with active cardiac conditions should undergo specialist evaluation and treatment before consideration of total joint arthroplasty (Table 27.1) [43]. Expert recommendations should be obtained for thrombotic prophylaxis and cardiac medications both pre- and postoperatively [43].

In the initial evaluation of a patient presenting for possible revision TKA one should (1) assume there is an infection until proven otherwise, and (2) once convinced there is no current infection, evaluate the patient’s risk for future infection. It is prudent to obtain serum inflammatory markers on all patients presenting for revision arthroplasty and investigate the cause of any elevated results (ESR greater than 30 mm/h and CRP greater than 10 mg/L) [44]. If there is clinical suspicion for infection, synovial aspiration is indicated. Synovial fluid culture is worthwhile but is not sufficiently sensitive to rule out infection as clinically infected cases can have negative cultures due to prior antibiotic use, the presence of a slow-growing organism, or the presence of biofilms [45]. Synovial alpha-defensin (part of the commercially available Synovasure assay, CD Diagnostics) has shown good sensitivity and specificity [46]. Normal laboratory results may in the immunocompromised patient and are critically evaluated in the patient with a highly suspicious clinical history, exam, or radiographic findings. Further imaging such as MRI with the use of a metal artifact reduction sequence (MARS) [47] or alternatively a tagged white blood cell scan can be utilized [48]. Finally, in a patient in whom all previous testing is negative but there is lingering suspicion for infection, an open biopsy can be performed; in this circumstance we recommend adhering to Musculoskeletal Infection Society (MSIS) guidelines and obtaining multiple synovial tissue samples (3–5 in total) for frozen section with positive result defined as greater than five neutrophils in five high-power fields at 400× magnification [49].

Vascular complications following total knee arthroplasty are rare, but the sequelae may be dire and threaten both life and limb. The reported incidence of vascular complications in patients undergoing TKA ranges from 0.03 to 0.17% [50, 51]. However, the majority of acute perioperative vascular complications occur in patients with preexistent, chronic arterial insufficiency, and these patients can, with some effort, be identified preoperatively as being at increased risk. In an analysis of 1182 consecutive TKA’s, 24 cases or 2% were found preoperatively to have chronic lower extremity ischemia based upon a careful history, physical, and ancillary studies including ankle-brachial indices and ankle pulse volume recordings [50]. In the same series, ischemic complications following TKA occurred in 6 knees or 0.5% of the entire cohort (6/1182). However, all complications occurred in the group with preexistent ischemia, representing an incidence of 25% (6/24) in these patients, who were all identified as high risk preoperatively.

Screening for patients at risk for vascular complications begins with a thorough, focused history. The likelihood of vascular compromise increases with age. Thus, a high index of suspicion is maintained for the elderly and those with other known risk factors. Those factors include a history of any prior vascular reconstruction, including lower extremity reconstruction, coronary artery bypass grafting, carotid endarterectomy, or resection of an abdominal aortic aneurysm [50]. Other risk factors are smoking, diabetes mellitus, and hypertension [50]. Patients are queried for symptoms of claudication, ischemic rest pain, or a history of vascular ulcers.

The physical examination begins with inspection for telltale signs of skin discoloration, hairlessness, or dystrophic nails. Pulses are palpated for the presence and strength as well as asymmetry. Popliteal fullness warrants evaluation for the presence of popliteal aneurysm. Routine preoperative radiographs are evaluated for calcification of the femoral/popliteal arterial tree. Based upon the information described above, noninvasive vascular studies such as ankle-brachial indexes and pulse volume recordings are ordered. At the author’s institute, we have an extremely low threshold for referring at-risk patients to vascular medicine/surgery to direct such studies, which may include arteriography .

The incidence of osteoarthritis of the knee increases with age. Concomitantly, bone health tends to decline. In one study [56] 199 patients awaiting total hip or knee arthroplasty were evaluated with DEXA scan. Osteoporosis was found in 23%, and an additional 43% of patients met World Health Organization criteria for osteopenia. Thus, poor bone quality should always be suspected in patients undergoing revision TKA. This is in addition to actual bone loss secondary to osteolysis and possibly during implant removal. Osteopenia is a known risk factor for periprosthetic fracture following total knee arthroplasty [57–59] and should be suspected in patients revised for that reason.

Risk factors for osteopenia include rheumatoid arthritis, corticosteroid use, smoking, increasing age, and female sex. The role of poor bone quality in aseptic loosening has not been firmly established. A relationship may be inferred from the observation that the incidence of aseptic loosening after TKA has been shown to be lowered by the perioperative administration of bisphosphonates [59, 60]. As such, we recommend the use of long-stemmed revision components in patients with significant osteopenia. Likewise, patients with both osteopenia and obesity are, in the authors’ experience, prone to insufficiency fractures (Fig. 27.3). Long-stem prostheses are recommended to enhance the stability of revision constructs in these patients as well .