Should a 60-year-old woman with a torn anterior cruciate ligament (ACL) and a history of multiple falls due to instability wear a knee brace, despite concerns that it may weaken the knee's strength?

Knee Brace Recommendation for ACL Tear with Instability and Falls

Yes, this 60-year-old woman with a torn ACL and multiple falls due to instability should absolutely wear a functional knee brace—the concern about "weakening the knee" is not supported by evidence and should not prevent bracing in a patient with documented functional instability and fall risk. 1

Why the Provider's Concern is Misplaced

The fear that bracing will weaken the knee is not substantiated in the medical literature. While functional knee braces have limitations, causing muscle weakness is not among the documented risks. 1 The actual documented limitations include:

• Increased energy expenditure during prolonged athletic activities 1
• Potential false sense of confidence (relevant for athletes, not for fall prevention) 1
• Decreased agility in high-level sports (not applicable to this patient) 1

None of these concerns outweigh the immediate safety risk of recurrent falls in a 60-year-old woman. 1

Evidence-Based Rationale for Bracing

Primary Indication Met

• Functional knee braces are specifically indicated for "additional support after ACL surgery" and "support for mild to moderate PCL or MCL instability" 1
• Most critically, functional braces provide "control of knee hyperextension," which is essential for preventing the giving-way episodes that cause falls 1, 2

Age-Appropriate Treatment Strategy

The American Academy of Orthopaedic Surgeons guidelines for a 56-year-old man with ACL tear (nearly identical age to this patient) rated "ACL functional knee brace without reconstruction" as "May Be Appropriate" (score 5-6) alongside non-surgical rehabilitation 1. For a 60-year-old woman with documented instability and falls, bracing becomes even more appropriate as a safety measure while pursuing rehabilitation.

Documented Benefits in ACL-Deficient Knees

• Sleeve-style functional braces decreased knee joint laxity by 33% in ACL-deficient patients 3
• Bracing significantly increased dynamic balance after perturbation by 20% 3
• Bracing increased dynamic lower limb peak rate of force development by 17% 3
• These improvements in balance and dynamic stability directly address the fall risk 3

Specific Brace Selection and Fitting

Optimal Brace Design

• Select a functional knee brace with a hinge-post-shell design (molded plastic and foam enclosures), which provides superior tibial-displacement control, greater rigidity, enhanced durability, and better soft tissue contact compared to strap designs 2, 4
• Alternatively, a sleeve-style functional brace may provide additional proprioceptive benefits that specifically improve dynamic balance—this may be particularly valuable given her fall history 3

Critical Fitting Requirements

• Choose the longest brace length that fits comfortably—shorter braces provide inadequate protection 2, 5
• Measure thigh circumference 6 inches above the mid-patella to determine proper size 4
• Position hinges precisely relative to the femoral condyles—this is essential for optimal performance 2, 5
• Ensure regular tightening of straps to prevent unwanted brace migration 5

Off-the-Shelf vs. Custom

• Start with an off-the-shelf (presized) brace—these are generally sufficient, more cost-effective, and immediately available 5, 4
• Custom braces provide few additional benefits over off-the-shelf models 2

Essential Treatment Context: Bracing is NOT Standalone Therapy

Critical caveat: The brace is a safety adjunct, not a replacement for rehabilitation. The most important interventions for ACL injury management are:

• Supervised rehabilitation program (rated "Appropriate" with score of 7 for this age group) 1
• Strength training, particularly hamstring strengthening 1, 2
• Conditioning and flexibility exercises 1, 2
• Activity modification 1

The American Academy of Orthopaedic Surgeons explicitly recommends supervised rehabilitation and activity modification as "Appropriate" (score 7) for patients in this age group with ACL tears 1. The brace serves to prevent falls during the rehabilitation process, not to replace it.

Addressing the "Weakening" Myth Directly

The evidence shows that:

• Bracing does not cause muscle weakness or atrophy 1
• The documented effect on muscle function is increased energy expenditure during prolonged athletic activities (not relevant for daily activities or fall prevention) 6
• Bracing should be combined with appropriate rehabilitation exercises—the exercises prevent weakness, not the absence of a brace 2, 5

Practical Implementation Algorithm

1. Immediately fit with an off-the-shelf functional knee brace (hinge-post-shell or sleeve design) for fall prevention 2, 3
2. Simultaneously initiate supervised physical therapy focusing on hamstring strengthening, quadriceps strengthening (avoiding terminal extension exercises initially), and proprioceptive training 1, 7
3. Wear the brace full-time during all weight-bearing activities until functional stability improves and fall risk decreases 7
4. Reassess brace positioning and structural integrity regularly; replace if damaged 5, 4
5. Gradually wean from brace use only after achieving adequate strength (at least 75% of contralateral leg), improved proprioception, and absence of giving-way episodes for several months 7

Common Pitfall to Avoid

The most dangerous pitfall is prioritizing theoretical concerns about "weakening" over the immediate, documented risk of falls in an older adult with knee instability. Falls in 60-year-old women can result in fractures, head injuries, and loss of independence—risks that far outweigh any theoretical concerns about brace dependency. 1