Pre-operative patient education
Pre-operative patient education has been identified as an integral component of clinical pathways for lower limb arthroplasty, and comprises group education classes covering a host of topics. These encompass: the surgical procedure and its benefits, symptoms management, operative risks and complications, the concept of early discharge planning, discharge destinations, and post-acute services. Patient education materials ranging from a simple booklet or pathway manual to educational videos have been used successfully. These clinical pathways could be an effective tool for improving patient's journey and financial outcomes following arthroplasty .
The patient's expectations should be considered during this process. Measures include psychological and organizational preparation, and arranging support and assistance post-operatively, which may be best achieved through an extended pre-operative consultation with anesthetist and surgeon. It is necessary to understand patient expectations in order to ensure optimal patient-reported outcome measures . Conversely, dissatisfaction can result from unmet expectations . There is often a discrepancy between the expectations of patients and surgeons. In a comparative study, patients had higher expectations than surgeons with regard to their ability to engage in sporting activities and exercise after undergoing arthroplasty, and patients with higher levels of disability were found to expect better outcomes than those anticipated by their surgeons . Effective pre-operative education and communication are required to clarify these concepts.
There is a strong correlation between patient satisfaction and fulfillment of expectations about pain relief and functional improvement . Scott et al. found that THA was more likely to meet important patient expectations, whereas TKA did not meet patient expectations of kneeling, squatting, and stair negotiation, despite procedural booklets explaining these limitations being given preoperatively to patients .
Yoon et al. examined how an individualized pre-operative teaching program, either by phone or in person, can affect the hospital length of stay (LOS) after TKA and THA . They found that pre-operative education alone reduced LOS by 24 hours . By contrast, a Cochrane Review failed to identify any significant difference in LOS between patients who had and those who had not received the education .
In a randomized trial, anxiety and pain levels were assessed in patients receiving pre-operative multidisciplinary standardized information sessions versus the normally provided verbal information. There was a significant pre-operative reduction in both anxiety and pain in the intervention group, but no difference in post-operative levels . These findings were confirmed by McDonald et al., who found in a meta-analysis of nine studies that patient education moderately reduced pre-operative anxiety . Daltroy et al. reported that a pre-operative psychoeducational program focusing on avoidance of unpleasant events reduced LOS, post-operative medication usage, and anxiety .
Siggeirsdottir et al. compared an intervention group (who received pre-operative and post-operative education by physiotherapists/occupational therapists and home visits from an outpatient team) with a control group (receiving 'conventional' rehabilitation often augmented by a stay at a rehabilitation center). They found that the intervention group had a significantly shorter hospital stay and achieved superior Oxford hip scores compared with the control group .
Patient education can therefore be effective in reducing LOS; however, it will be necessary to conduct further studies to evaluate the cost-effectiveness of these programs in order to justify their use.
Pre-operative nutritional status
The effects of nutritional status on outcomes after TKA and THA are not clear. Malnutrition can lead to wound infection, delayed healing, prolonged hospitalization, and increased rehabilitation time and mortality [6, 15–18].
Pre-operative biochemical indicators of nutrition status such as low albumin, total lymphocyte count and transferrin levels have been found to predict longer recovery times and hospital stay after joint arthroplasty [6, 19]. Anthropometric parameters such as triceps skin fold can also be used to assess malnutrition, and has been shown to have an inversely proportional relationship with post-operative infection risk after TKA .
There is limited evidence showing an association between body mass index (BMI) and outcomes after arthroplasty. Although a low BMI in older patients was found to have a weak correlation (r = 0.246) with increased LOS after TKA in one study , Husted et al. did not find BMI to be a predictor of LOS in 712 patients undergoing TKA and THA . Morbidly obese patients may present technical difficulties, such as requirement for special equipment, difficulties in pre-operative positioning and in anesthesia, and presence of excessive subcutaneous fat making the initial approach to a joint such as the hip more difficult. The cumulative effect of these factors may increase operative time and intra-operative blood loss in patients with a BMI of 40 m2/kg and over [23, 24]. However a high BMI has not been shown to delay either early functional recovery from surgery or discharge from hospital following THA [23, 24].
Pre-operative anemia can affect hospital LOS. The prevalence of anemia in patients undergoing TKA and THA is estimated at 25%  There is ample evidence that a low pre-operative hemoglobin (Hb) level increases transfusion requirement, infection risk, and LOS after joint arthroplasty [25–27] The absolute blood loss itself during surgery does not seem to delay discharge , reinforcing the notion that it may well be the patients starting point (the pre-operative Hb level) which is a more important determinant of LOS. Interestingly, a recent study did not find any correlation between postoperative Hb and early physical function recovery after TKA and THA , suggesting that factors other than fatigue may be responsible for delaying discharge in patients with anemia.
There may be a role for pre-operative erythropoietin and iron supplementation in patients with anemia who are about to undergo major orthopedic surgery. Iron therapy has been shown to reduce blood-transfusion rates and incidence of postoperative infection significantly, although its effects on LOS have been less clear-cut [29, 30].
Pre-operative nutritional assessment may be necessary in a selected group of patients who are morbidly obese and severely malnourished. Correction of pre-operative anemia is an important measure that is gaining popularity in the orthopedic community and can potentially improve outcomes for both TKA and THA.
Pain is a distressing symptom that can affect functional recovery, reduce patient satisfaction, and prolong hospitalization. Patient anxiety related to pain perception is another factor that can affect outcome.
The role of pre-emptive analgesia in reducing postoperative pain is still controversial. Mallory et al. compared three multimodal analgesic regimens , all using peri-operative intravenous dexamethasone and ondansetron. The first included: discontinuation of the epidural during recovery, initiation of regular oral doses of opioids for 48 hours, and use of intravenous hydromorphone for breakthrough pain. The second and third regimens used a similar protocol that differed from that of the first, and included: discontinuation of the epidural (second) or spinal (third) during recovery; initiation of patient-controlled analgesia for 24 hours during recovery, followed by oral doses of opioid medications every 4 hours through to discharge; use of intravenous hydromorphone, similar to the first regimen; and administration of cyclooxygenase-2 inhibitors for 2 weeks preoperatively and for 10 days post-operatively. The second and third regimens resulted in significantly shorter hospital stays. Pain scores during the first and second postoperative days were significantly better for patients who received the second regimen than for those who received either of the other two options .
However, a systematic review of the existing evidence comparing pre-emptive to post-incisional analgesia was published in the same year, which failed to show any significant improvement in postoperative pain scores recorded within 24 h after surgery in patients who had the pre-emptive treatment. This review included pre-emptive analgesia for both orthopedic and non-orthopedic operations .
This method also needs to be tested in the context of fast-track pathways with hip and knee arthroplasty.
Local infiltration analgesia
Local infiltration analgesia (LIA) is an 'enabling' process that was initially developed by Kerr and Kohan in 2008, and comprises injection of a local anesthetic mixture (ropivacain, ketorolac, and epinephrine) systematically throughout the operative field . The authors evaluated 325 patients who had undergone THA or TKA, and found patients had satisfactory postoperative pain control allowing mobilization within 4 hours of surgery, early discharge, and no serious complications or side effects . Although this was a non-randomized study, the methods and drug mixture used became popular for modeling future randomized clinical trials (RCTs). A later RCT involving bilateral TKAs reported effective analgesia post-operatively with LIA compared with placebo , but in a second study, postoperative subcutaneous bolus LIA produced no improved analgesic effect . Another study reported reduced pain and morphine consumption, shorter LOS, and increased patient satisfaction with LIA compared with no LIA after TKA . However, in a different study, LIA was not found to provide additional analgesic or outcome benefits in the context of a comprehensive multimodal analgesic approach .
LIA can therefore be useful in efforts to enhance functional recovery and reduce the LOS, however further research is required in this field.
Neuromuscular electrical stimulation
Neuromuscular electrical stimulation (NMES) involves applying transcutaneous current to neuromuscular junctions in order to stimulate muscle contractions [38, 39]. It is used in both prehabilitation and rehabilitation programs for TKA, and as an adjunct to these programs to strengthen quadriceps muscle function [38, 39].
Muscle stimulation failure and pre-operative muscle atrophy are factors contributing to quadriceps muscle weakness, especially in patients with osteoarthritis. Further weakness following surgery can affect the patient's overall functional recovery ; evidence shows that quadriceps muscle strength is reduced by 85% after TKA  and by 30 to 40% after THA .
A systematic review that examined the effectiveness of NMES in the context of muscle strengthening in TKA failed to draw any conclusion, because the included studies were biased and sample sizes were not large enough to allow for statistically robust conclusions . A randomized study  comparing the effects of NMES on patients undergoing TKA evaluated pre-operative and post-operative quadriceps muscle strength, cross-sectional area, and clinical function against a standard rehabilitation protocol. The study found significant pre-operative gains in walking, stair-climbing, and chair-rise times in the NMES group, and similar objective functional recovery from 6 to 12 weeks post-operatively. There was no difference in the LOS between the groups . Patient-reported compliance with this treatment after TKA was 99.4%, and stimulator-recorded compliance was 99% .
An RCT comparing the combined use of NMES and conventional physiotherapy (including extension-resisted exercises) against conventional physiotherapy alone in patients receiving total hip replacement (THR) showed significant improvement in quadriceps strength in the NMES group. There were no significant differences in walking speed or LOS between the two groups in the short term . Interestingly, the extension-resisted exercises alone were found to reduce the LOS and to improve the muscle strength and functional performance significantly compared with NMES alone or conventional physiotherapy alone in a three-armed RCT .
This procedure should therefore be tested further in the context of fast-track recovery following TKA and THA.
Pulsed electromagnetic fields
Local joint swelling, inflammation, and pain following THA and TKA are factors affecting patient recovery and joint function [44, 45]. Holm et al. showed that decreased knee-extension strength, which decreases functional performance in the short term after TKA, is caused in part by post-operative knee swelling, and recommended interventions to help reduce joint swelling and improve functional recovery .
Use of pulsed electromagnetic fields (PEMFs) is a safe and non-invasive treatment to facilitate endogenous bone repair and reduce inflammation [45, 47]. PEMFs act as an adenosine agonist on the A2a receptors of inflammatory cells. This has the strongest anti-inflammatory effect, and can reduce joint swelling and inflammation, the need for analgesics, and the time to functional recovery. This approach to treatment is also well accepted by patients [44, 47].
Many studies have shown a positive effect of PEMF after knee surgery [44, 47, 48], but there are limited data on the effect of PEMFs after hip arthroplasty. A randomized double-blinded study on patients who had undergone revision hip surgery found that PEMFs helped to improve functional recovery and restore bone stock .
Another study showed that PEMFs reduced the use of non-steroidal anti-inflammatory drugs, improved functional recovery, and were well accepted by patients. No side effects were reported by patients who had undergone knee arthroscopy . Similar findings were reported for patients who had undergone arthroscopic anterior cruciate ligament repair .
This treatment may be considered for enhanced rapid recovery; however, well-designed studies on use of PEMFs and arthroplasty are required.