Reconstruction Cases knee osteoarthritis
A 57-year-old female presents to the office with atraumatic knee pain. Her pain is worse at the beginning of activities as well as the end of the day. She has trouble ascending and descending stairs. She uses anti-inflammatories intermittently with mild relief. On examination she has pain along the medial joint line but full range of motion. X-rays show characteristic medial joint space narrowing, subchondral sclerosis, and cysts.
All of the following are modifiable risk factors for knee osteoarthritis, except:
- Patient weight
- Hard labor
- Trauma
- Gender
- Muscular weakness
Discussion
The correct answer is (D). Modifiable risk factors associated with arthritis include obesity, trauma, occupations involving hard labor, and overall deconditioning. Women are at higher risk for arthritis. White and Hispanics have higher rates of arthritis compared to African-American males and some Asian populations.
All the following are viable initial management options recommended by the AAOS, except:
- Weight loss and diet control for BMI >25
- Physical therapy for quadriceps/hamstring strengthening/stretching
- Hyaluronic acid injections
- Corticosteroid injections
- Activity modification
Discussion
The correct answer is (C). The recent AAOS guidelines on osteoarthritis of the knee endorse the use of self-management programs, strengthening, low-impact aerobic exercises, and neuromuscular education. They also recommend weight loss for knee osteoarthritis patients with BMI >25 and activity modification. The committee could not recommend for or against the use of steroids due to inconclusive data, but the guidelines advise against the use of hyaluronic acid.
The patient asks regarding other modalities or intervention for her knee before considering total knee replacement. The following modalities have been ruled inconclusive except:
- Acupuncture
- Electrostimulation
- Chondroitin sulfate
- Tylenol
- Valgus directing sports brace
Discussion
The correct answer is (C). The committee has found inconclusive evidence to recommend for or against acupuncture, electrostimulation, Tylenol and pain patches, as well as a valgus directing sports brace. Nevertheless, they have had a strong recommendation against the use of chondroitin sulfate due to the limited support in the literature for its use.
When comparing knee arthroscopy and lavage to placebo in the setting of knee arthritis, knee arthroscopy results in:
- Complete reversal of symptoms
- Improved symptom control and no progression to total knee arthroplasty
- 50% improved symptoms at 3 months that remained consistent at 1 year
- Significant improvement over 1 year followed by recurrence
- No improvement of arthritis pain
Discussion
The correct answer is (E). The AAOS guidelines strongly recommend against the use of either needle lavage or arthroscopic lavage. No significant benefit has been documented. Nevertheless, the guidelines could not recommend for or against meniscectomy.
You explain to the patient that a total knee replacement is an elective procedure and that she should decide when her symptoms are negatively affecting her quality of life. The patient inquires about outcomes and any predisposing factors. You tell her that:
- Preoperative range of motion typically determines postoperative range of motion
- The risk of infection goes up the longer they wait for surgery
- The improvement and patient satisfaction is worse if symptoms are worse
- The sooner they have the replacement the higher the satisfaction rate
- Recovery takes 6 weeks with return to full mobility
Discussion
The correct answer is (A). Total knee arthroplasty is a complex procedure with overall functional outcomes reported lower compared to the total hip. Even though patients report overall good outcomes, most studies have shown some patient bias in reported higher perceived outcomes compared to their actual functional status. It takes patients at least 6 months to regain their mobility and sustain full relief of symptoms. The overall improvement and patient satisfaction is better the worse their scores are before the surgery, with patients with minimum symptoms being most unsatisfied with overall outcomes. No link with infection and delay in surgery has been documented, even though complex surgery and the operative time may have a correlation. Preoperative range of motion and stiffness is linked to the postoperative range of motion, even if full range of motion is achieved
intraoperatively in an anesthetized patient.
The AAOS guidelines show inconclusive support for or against a tibial osteotomy. Compared to a total knee arthroplasty, a high tibial osteotomy:
- Has shorter recovery compared to a total knee arthroplasty
- Works better in obese, inactive patients in which TKA has higher risk
- Works better in older males compared to total knee arthroplasty
- Can provide significantly improved symptom relief compared to TKA
- Works similarly to TKA in thin, active individuals
Discussion
The correct answer is (E). Recommendation 14 of the AAOS guidelines suggests “The practitioner might perform a valgus producing proximal tibial osteotomy in patients with symptomatic medial compartment osteoarthritis of the knee.” Classic indications include a younger, active, thin patient with a stable knee examination in whom the outcomes may approach the outcomes of a total knee replacement.
Osteoarthritis is a disease of cartilage. The matrix disruption and subchondral sclerosis results in:
- Decreased water content
- Increased collagen content
- Decreased proteoglycan quantity
- Decreased chondrocyte activity
- Loss of chondrocytes
Discussion
The correct answer is (C). Osteoarthritis (OA) is a process that is pathophysiologically distinct from normal physiologic aging. In osteoarthritis, collagen changes include: increased water content, decreased collagen content, increased enzymatic activity, and increased chondrocyte numbers. There is also a decreased proteoglycan content in OA. Conversely in normal aging, cartilage changes include: decreased water content, normal collagen content with increased cross-linking, and decreased chondrocyte numbers.
The patient returns to you a year later stating worsening symptoms, associated instability, and decreased range of motion. Anti-inflammatory medication has provided minimal pain relief. X-rays show progressive medial as well as
patellofemoral arthritis. The most reliable intervention in this case is:
- Corticosteroid injection
- Hyaluronan injection
- High tibial osteotomy
- Unicondylar knee replacement
- Total knee replacement
Discussion
The correct answer is (E). In a patient with multicompartmental knee arthritis who has failed nonoperative treatment, a total knee replacement would provide the most reliable and reproducible results. Osteotomy or unicondylar knee replacements provide limited benefit in multicompartmental knee arthritis with associated instability.
Helpful Tip:
In 2013 the American Academy of Orthopaedic Surgeons (AAOS) published the second edition of clinical practice guidelines on the treatment of osteoarthritis of the knee. This evidence-based guideline indicated that anti-inflammatories, weight loss, and aerobic low-impact exercise have a strong support in the initial treatment of osteoarthritis. Acupuncture, other modalities, Tylenol, steroid injections, and bracing were found to be inconclusive. In contrast, the guidelines could not recommend the injection of hyaluronan or the use of arthroscopic lavage. Meniscectomies and tibial osteotomies have inconclusive and limited results, respectively.
Objectives: Did you learn...?
Recognize arthritis?
Follow AAOS guidelines for nonoperative management? Follow AAOS guidelines for early operative management?