What advice should be given to patients after total knee replacement (TKR)?

Post-Total Knee Replacement Advice

Patients should begin immediate knee mobilization within the first week, start isometric quadriceps exercises from postoperative day 1 (if pain-free), progress to full weight-bearing as tolerated, and engage in supervised or minimally supervised rehabilitation for 9-12 months with emphasis on strength and neuromuscular training. 1

Pain Management

Implement a multimodal analgesic approach combining regional anesthesia with scheduled non-opioid medications:

• Use femoral nerve block or adductor canal block combined with general anesthesia, or alternatively spinal anesthesia with local anesthetic plus spinal morphine 2, 3
• Administer scheduled paracetamol (acetaminophen) as baseline analgesia 2, 3
• Add NSAIDs or COX-2 inhibitors for their analgesic and opioid-sparing effects unless contraindicated 1, 2
• Reserve strong intravenous opioids for breakthrough high-intensity pain, or weak opioids for moderate pain 2, 3
• Apply cryotherapy immediately after surgery and continue for the first postoperative week to reduce pain 1

Important caveat: Be cautious with bilateral nerve blocks in elderly patients or those with significant comorbidities due to increased risk of local anesthetic systemic toxicity 3

Early Mobilization and Weight-Bearing

Begin immediate mobilization and weight-bearing within the first week:

• Start immediate knee mobilization (within 1 week) to increase joint range of motion, reduce knee pain, and prevent soft tissue complications like extension deficit 1
• Progress to immediate full weight-bearing as tolerated, ensuring correct gait pattern without pain, effusion, or temperature increase 1
• Use crutches initially if needed to maintain proper gait mechanics 1

Critical point: Immediate weight-bearing reduces the incidence of anterior knee pain without affecting knee laxity 1

Exercise Prescription

Initiate a progressive, criterion-based exercise program starting from the first postoperative week:

Week 1 Onwards:

• Begin isometric quadriceps exercises from the first postoperative week if they provoke no pain 1
• Consider adding neuromuscular electrostimulation to isometric strengthening for the initial 6-8 weeks to re-educate voluntary contraction and increase quadriceps strength 1

Week 4 Onwards:

• Progress to both open kinetic chain (OKC) exercises (90-45°) and closed kinetic chain (CKC) exercises as early as 4 weeks 1
• Prioritize CKC exercises in the first postoperative month to mitigate the risk of patellofemoral pain 1
• Shift progressively from isometric to concentric and eccentric exercises in closed kinetic chain 1

Ongoing:

• Combine strength training with neuromuscular and motor control re-education exercises throughout rehabilitation 1
• Include balance training and aquatic therapy as tolerated to improve functional outcomes 4, 5

Rehabilitation Setting and Duration

Continue structured rehabilitation for 9-12 months depending on functional goals:

• Home-based rehabilitation with minimal supervision may be used in highly motivated patients who live far from a physical therapist 1
• For most patients, supervised outpatient physiotherapy in a clinical setting under a registered physiotherapist provides the best long-term outcomes, particularly for patients over 45 years of age 4, 6
• High-quality evidence supports home-based physiotherapy as comparable to inpatient rehabilitation for functional outcomes at 1 year 6

Evidence note: When comparing 19-week versus 32-week rehabilitation programs, no differences were found in laxity, ROM, self-reported knee function, or strength, but continuing rehabilitation for 9-12 months aligns with return-to-activity goals 1

What NOT to Do

Avoid interventions that lack evidence or may cause harm:

• Do NOT use continuous passive motion (CPM) routinely—three out of four studies showed no significant differences in pain scores, and it provides no functional benefit 1
• Do NOT use postoperative functional knee bracing routinely—multiple guidelines recommend against it 1
• Do NOT delay mobilization or weight-bearing beyond the first week without specific surgical contraindications 1

Functional Outcome Monitoring

Track progress using validated outcome measures:

• Use patient-reported outcome measures such as WOMAC, IKDC subjective score, or KOOS 1, 6, 7
• Measure knee pain, activities of daily living, quality of life, and functional status regularly 1
• Assess quadriceps and hamstring strength deficits, as a preoperative quadriceps strength deficit >20% predicts significant strength deficits up to 2 years post-surgery 1

Expected Outcomes

Patients should anticipate substantial improvements in pain and function:

• TKR effectively reduces pain and improves function in the vast majority of patients, with effect sizes demonstrating at least 20% improvement in outcome scores 7
• Most patients report decreased pain and successful long-term results, though recovery patterns vary 4
• Revision rates range from 0% to 13% in studies with at least 5 years of follow-up 7

Common pitfall: Over 70% of variance in TKR outcomes remains unexplained by factors like age, obesity, gender, or prosthesis design, emphasizing the importance of adherence to rehabilitation protocols 7