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Successful Nonoperative Treatment of Persistently Painful Knees Following Total Knee Arthroplasty—A Case Series

An estimated 20% of patients with total knee arthroplasty will report pain following the procedure. Careful examination of the structures around the knee can reveal tendonitis, bursitis, and soft tissue pain that respond to usual care.
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Case 1—Complex Regional Pain Syndrome?

A 63-year-old woman presented to our office 15 months after undergoing bilateral total knee arthroplasties (TKA). The patient reported that the initial surgeries were uncomplicated, with no adverse events. However, with time, the patient suffered from continued pain and, more recently, from a gradual loss of range of motion. She was treated with manipulation under anesthesia (MUA), which successfully restored some of the range of motion, but she continued to have diffuse, debilitating pain that significantly limited her daily function. The pain was mostly intense in the distal quadriceps, and was more prominent in the right knee than in the left knee.

Physical Examination
The patient’s right knee showed no skin discoloration, erythema, or hyperalgesia to light touch. The patient had a well-healed surgical incision. There was some typical periarticular warmth, but no erythema. Range-of-motion examination revealed that the patient lacked 20 degrees of extension and had flexion to only 75 degrees. Functional testing demonstrated decreased strength activation of the quadriceps on the right side, with considerable extensor lag of approximately 15 degrees. Palpation of the periarticular soft tissues revealed mild tenderness in the pes bursa. The patient was extremely sensitive at the insertion of the quadriceps tendon. She would withdraw from light to moderate pressure in this area. There was a small joint effusion, and distally the neurovascular exam was intact. There was some decrease in sensation around the incision.

Examination of the left knee demonstrated relatively poor range of motion as well, but better than that of the right knee. The patient lacked 10 degrees of extension, with flexion to 85 degrees. The surgical incision of this knee also was well healed. There were no significant skin changes identified. The distal neurovascular exam was intact. Again, there was considerable tenderness at the insertion of the quadriceps tendon. Activation of the quadriceps muscle was near normal.

Prior Treatment
Treatment had consisted of physical therapy and aggressive pain management, which included hydromorphone (Dilaudid), pregabalin (Lyrica), and amitriptyline (Elavil). This regimen would help her sleep, but her days remained difficult, with considerable pain upon ambulation and limited range of motion. The patient presented with a working diagnosis from a consulting orthopedic surgeon of complex regional pain syndrome (CRPS). The surgery was deemed technically sound and the implants properly positioned (Figure 1).

Figure 1. Postoperative radiographs of successful bilateral total knee arthroplasty. The implant position and operative technique were deemed technically sound.  (Image courtesy of Joseph J. Ruane, DO.)

Differential Diagnosis

  • CRPS
  • Failed total knee arthroplasty
  • Lumbar radiculopathy
  • Multifocal soft tissue pain

Final Diagnosis
Quadriceps tendonitis and periarticular soft tissue pain with muscle inhibition

Based on this diagnosis, a conservative treatment plan was initiated. A physical therapist with extensive experience in treating patients who have undergone TKA also participated in the patient’s evaluation. This combined medical and physical therapy evaluation concluded the quadriceps tendonitis with resultant muscle inhibition was the primary influence in this patient’s disability.

The quadriceps tissue tendonitis was treated with iontophoresis to the distal quadriceps tendon using dexamethasone 4 mg/mL solution. Light local soft tissue effleurage and muscle activation techniques also were included. She was also given a prescription for diclofenac patches (Flector) to use daily over the distal quadriceps.

Medication treatment included increasing the dosage of pregabalin to a maximum of 300 mg per day, with careful titration, to aid with the generalized hyperalgesia that had developed. She was encouraged to take hydromorphone prior to each physical therapy visit to maximize her ability to work aggressively on range of motion.

The addition of physical therapy modalities and local treatments to the extensor mechanism resulted in a pain reduction of 50% (based on a Numeric Pain Intensity Scale [NPIS]) in the first 3 weeks. This facilitated a more aggressive approach to achieving the therapy goals. Once her pain inhibition was removed, her motion improved rapidly. Her gait pattern also normalized. After 6 weeks of treatment, the patient was discharged with an average NPIS rating of 1 to 2 out of 10 and full extension in both knees with flexion beyond 110 degrees bilaterally.

Case 2—“Failed Total Knee Arthroplasty”

A 63-year-old woman presented 2 years after undergoing an uncomplicated right TKA. The surgery and immediate postoperative period were uneventful. Approximately 6 weeks after surgery, the patient began to experience daily, lateral, and anterior knee pain. The pain was worse when she climbed stairs and decreased with prolonged periods of non–weight bearing. She reported no significant night pain.

The surgeon who performed the index TKA informed the patient that the implant appeared radiographically sound and that the surgery had been performed with appropriate technique. The patient was then informed that post-surgical pain of uncertain etiology is an unfortunate risk of the procedure and that she would have to live with her current symptoms. The contralateral knee had mild medial compartment osteoarthritis that did not interfere with activity.

Physical Examination
Examination of the right knee revealed minimal effusion. The patient had full range of motion, but had pain when passing into full extension. The incision was well healed with no dehiscence or defects. The pesancerine bursa, patellar tendon, and quadriceps tendon were unremarkable to palpation. The patient was tender to palpation in the area of the lateral retinaculum and the lateral femoral condyle. A musculoskeletal ultrasound obtained in the office with demonstrated no significant tissue changes (Figure 2).

Figure 2. Longitudinal musculoskeletal ultrasound of distal iliotibial band. The tendon displays normal, homogeneous fibrillar architecture, and normal bony contour is also seen. It is not unusual for there to be a lack of significant tissue changes in patients who present with a convincing clinical diagnosis. (Image courtesy of Joseph J. Ruane, DO.)

Last updated on: February 9, 2012
First published on: November 1, 2011