Case Study: Diagnostic and Therapeutic Considerations in Advanced Knee Osteoarthritis Requiring Total Knee Replacement

Abstract

A 67-year-old male presented with progressively worsening bilateral knee pain, functional decline, and difficulty walking over the past four years. Radiographic evaluation demonstrated end-stage osteoarthritis with joint space narrowing, osteophyte formation, and subchondral sclerosis, most severe in the medial compartments. Conservative management including NSAIDs, corticosteroid injections, physical therapy, and activity modification provided limited relief. Given his escalating disability and reduced quality of life, he underwent right total knee arthroplasty (TKA). Postoperative recovery was favorable, with significant reduction in pain and improved mobility by the three-month follow-up. This case highlights the decision-making process, surgical considerations, and rehabilitative strategies essential for optimizing outcomes in patients undergoing knee replacement.

Introduction

Knee osteoarthritis (OA) is a prevalent degenerative joint disorder and a major cause of pain, disability, and reduced mobility among older adults. As the disease progresses, structural deterioration of the articular cartilage and surrounding bone contributes to chronic pain and functional impairment.
When conservative therapies fail to provide adequate symptom relief, total knee arthroplasty (TKA) becomes the treatment of choice, offering improved joint function and enhanced quality of life.
This case study explores the evaluation, diagnostic workup, perioperative planning, and postoperative outcomes in a patient requiring knee replacement due to severe osteoarthritis.

Patient Information

Age / Gender: 67-year-old male
Occupation: Retired bank manager
Marital Status: Married
Medical History: Hypertension (on amlodipine 5 mg daily), Type 2 diabetes mellitus (metformin 500 mg twice daily)
Surgical History: None
Family History: Father with osteoarthritis; no autoimmune disease history
Social History: Non-smoker, occasional alcohol consumption
Current Medications: Amlodipine, metformin, acetaminophen as needed for pain
Chief Complaints: Bilateral knee pain, stiffness, and difficulty climbing stairs for four years, worsening over the past six months.

Clinical Findings

General Examination:

• Mild antalgic gait

• Difficulty weight-bearing on the right knee

• No gross deformities of the lower limbs

Inspection and Palpation:

• Joint line tenderness (medial > lateral)

• Mild effusion in the right knee

• Crepitus during flexion-extension

Range of Motion:

• Flexion limited to 90°

• Extension deficit of 10°

Vital Signs:
Temperature: 98.6°F
Pulse: 88 bpm
BP: 132/80 mmHg
Respiratory Rate: 18/min

Initial Impression:
Advanced osteoarthritis with significant pain and functional disability.

Timeline

• Year 1–2: Patient reports intermittent knee pain managed with NSAIDs and lifestyle modifications.

• Year 3: Onset of frequent stiffness and swelling; physical therapy initiated.

• Year 3.5: Corticosteroid and hyaluronic acid injections provide temporary relief.

• Year 4: Pain intensifies, stair climbing and standing >20 minutes become difficult.

• Month 48: Orthopedic referral made due to impaired mobility.

• Month 49: Imaging confirms severe OA; surgical planning begins.

• Month 50: Patient undergoes right total knee replacement.

• Month 53: Significant improvement in pain, mobility, and daily functioning.

Diagnostic Assessment

Laboratory Investigations

• CBC, ESR, CRP: Within normal limits

• HbA1c: 6.8% (acceptable for surgery)

• Renal and liver function tests: Normal

Radiographic Findings

X-ray Knee (AP, Lateral, Standing):

• Severe joint space narrowing in medial compartment

• Marginal osteophytes

• Subchondral sclerosis and cysts

• Varus deformity of 7°

MRI Findings (if obtained):

• Near-complete cartilage loss

• Degenerative meniscal changes

• Moderate effusion

• Intact cruciate ligaments

Diagnosis:

End-stage primary osteoarthritis of the right knee requiring total knee arthroplasty.

Differential Diagnosis

• Rheumatoid arthritis

• Post-traumatic arthritis

• Meniscal degeneration

• Osteonecrosis of the knee

• Crystal arthropathy (ruled out via labs and history)

Therapeutic Intervention

Step 1 – Conservative Management

• NSAIDs and acetaminophen

• Weight reduction counseling

• Physiotherapy focusing on quadriceps strengthening

• Intra-articular corticosteroid injections

• Activity modification

These strategies provided incomplete and diminishing symptom control.

Step 2 – Preoperative Optimization

• Glycemic control monitored

• Blood pressure stabilized

• Smoking status confirmed negative

• Prehabilitation exercises introduced

• Patient educated about surgical procedure, implants, and postoperative expectations

Step 3 – Surgical Intervention

Procedure: Right total knee arthroplasty
Implant Type: Cemented posterior-stabilized prosthesis
Anesthesia: Spinal with sedation
Intraoperative Notes:

• Osteophytes removed

• Balanced flexion-extension gaps

• Achieved neutral mechanical alignment

• No complications

Step 4 – Postoperative Management

• Analgesia (multimodal)

• Thromboprophylaxis with low-molecular-weight heparin

• Early mobilization on postoperative day 1

• Physiotherapy for range of motion and gait training

• Wound care and infection surveillance

Challenges Faced

• Pre-existing diabetes requiring tight perioperative glycemic control

• Managing patient expectations regarding postoperative activity

• Initial limitation in knee flexion due to stiffness

• Motivation barriers for adhering to physiotherapy

Follow-Up and Outcomes

At the 2-week follow-up, wound healing was satisfactory and staples were removed.
At 6 weeks, the patient achieved:

• Flexion: 110°

• Full extension

• Pain score reduced from 8/10 preoperatively to 2/10

At the 3-month evaluation:

• Able to walk without assistive devices

• Minimal discomfort during prolonged standing

• X-rays showed well-aligned implants with no loosening

The patient resumed routine activities, including morning walks and light household tasks.

Discussion

Total knee replacement remains the gold standard for managing end-stage osteoarthritis that no longer responds to conservative measures, providing substantial and often life-changing relief from chronic pain and disability. Successful outcomes depend heavily on careful patient selection, comprehensive perioperative optimization, precise surgical technique, and a well-structured rehabilitation program tailored to individual needs. This case illustrates the progressive nature of osteoarthritis and emphasizes how early implementation of conservative strategies can delay the need for surgery, although they may eventually lose effectiveness as joint degeneration advances. Following total knee arthroplasty, patients often experience remarkable improvements in mobility, function, and overall quality of life, highlighting the procedure’s transformative potential. Equally important is the critical role of postoperative physiotherapy, which facilitates restoration of joint motion, strengthens supporting musculature, and ensures a stable, functional gait. Long-term follow-up remains essential to monitor implant integrity, detect potential complications such as infection, loosening, or polyethylene wear, and guide ongoing activity modification to preserve joint longevity. Overall, the case reinforces the importance of a coordinated, multidisciplinary approach to knee osteoarthritis, ensuring that patients receive not only effective surgical care but also the necessary rehabilitation and surveillance to achieve optimal long-term outcomes.

Multidisciplinary Approach

Orthopedic Team: Diagnostic evaluation, surgery, follow-up
Physiotherapists: Prehabilitation and postoperative rehabilitation
Endocrinologists: Diabetes optimization
Nursing Team: Wound care, patient support
Pain Specialists: Postoperative analgesic strategies

Key Takeaways

• Total knee replacement is effective for patients with end-stage OA who fail conservative treatment.

• Radiologic severity correlates with functional impairment and guides decision-making.

• Optimal outcomes require coordinated perioperative and rehabilitative care.

• Physiotherapy plays a critical role in restoring knee function.

• Patient education and expectation management improve satisfaction.

Patient’s Perspective

“I struggled to walk even short distances before the surgery. The pain affected my daily routines and independence. After the knee replacement and physiotherapy, I can move much more comfortably. I feel like I have regained my freedom.”

Conclusion

This case highlights the multifaceted clinical, diagnostic, and therapeutic considerations involved in managing advanced knee osteoarthritis and guiding a patient through total knee replacement. As demonstrated, osteoarthritis is not merely a condition of joint degeneration but a progressive disorder that significantly affects mobility, independence, and overall quality of life. When conservative management fails, timely transition to surgical intervention becomes essential to prevent further functional deterioration and decline in daily living capacity.

Total knee arthroplasty offers a reliable and durable solution for patients with end-stage disease, provided that a comprehensive preoperative evaluation is undertaken to address comorbidities, functional limitations, and patient expectations. In this case, the combination of careful surgical planning, optimal implant selection, and meticulous intraoperative technique ensured biomechanical stability, proper alignment, and restoration of joint function. Equally important was the structured postoperative rehabilitation program, which played a pivotal role in regaining range of motion, strengthening periarticular muscles, and facilitating early return to independent mobility.

The patient’s positive recovery underscores the importance of a multidisciplinary approach, uniting orthopedic specialists, physiotherapists, anesthesiologists, nursing staff, and rehabilitation experts to achieve the best possible clinical outcomes. Long-term surveillance remains crucial to monitor implant integrity, prevent complications, and sustain joint function over time.

Ultimately, this case illustrates that with appropriate clinical decision-making, patient-centered planning, and dedicated rehabilitation, total knee replacement can transform a severely debilitating condition into one with renewed mobility, reduced pain, and restored quality of life.

References

1. American Academy of Orthopaedic Surgeons (AAOS). Management of Osteoarthritis of the Knee.

2. Kerkhof F, et al. Total Knee Arthroplasty Outcomes. J Arthroplasty. 2020.

3. Skou ST, et al. Non-surgical vs surgical treatment of knee OA. NEJM.

4. Knee replacement guidelines. International Society for Arthroplasty.

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