ACL Knee Brace vs ROM Knee Brace: Key Differences in Stability and Motion Control

ACL knee braces and ROM knee braces are both hinged knee orthoses with adjustable flexion and extension, but they are built for different purposes and fall under different HCPCS codes.

A ROM knee brace, or range of motion knee brace, is a positional orthosis. It limits flexion and extension to clinician-set ranges, typically to protect the knee during early rehabilitation after surgery or injury. An ACL knee brace is a functional orthosis designed for knee instability. Along with adjustable motion control and medial-lateral support, it provides rotation control.

For providers, rotation control is the key distinction. Both brace types can control range of motion and provide medial-lateral support. What separates L1845/L1852 from L1832/L1833 is rotation control and the construction that delivers it.

What Is a ROM Knee Brace?

A ROM knee brace is a knee orthosis with adjustable joints that sets limits on knee flexion and extension while permitting movement within those limits. It is commonly used during early rehabilitation following knee surgery or injury.

The Coretech ROM Knee Brace Elite features bilateral adjustable hinges, aluminum frame, adjustable length, and a universal design for either leg. It is associated with HCPCS codes L1832 and L1833.

L1832 and L1833 describe prefabricated knee orthoses with adjustable knee joints (unicentric or polycentric) that serve as rigid positional orthoses. L1832 is custom fitted and L1833 is off-the-shelf. Braces in this category often use uprights that provide medial-lateral support, but rotation control is not part of the code description.

What is an ACL Knee Brace?

An ACL knee brace is a functional knee orthosis used for knee instability, including ligament injuries and post-reconstruction care. It combines adjustable motion control with medial-lateral and rotation control, typically through double uprights, rigid thigh and calf cuffs, and condylar pads.

The Coretech ACL Knee Brace features a rigid frame with bilateral uprights and polycentric hinges. Flexion stops adjust from 0° to 120°, extension stops adjust from 0° to 45°, and the brace includes varus/valgus adjustment. It is associated with HCPCS codes L1845 and L1852.

L1845 and L1852 describe prefabricated double-upright knee orthoses (thigh and calf) with adjustable flexion and extension joints, medial-lateral and rotation control, with or without varus/valgus adjustment. L1845 is custom fitted and L1852 is off-the-shelf.

ACL Knee Brace vs ROM Knee Brace

Key Construction and Control Differences

Controlled Range of Motion 

A defining feature of a ROM knee brace is the ability to set permitted limits for flexion and extension while allowing movement within those settings.

This makes the hinge system the central component of a hinged ROM knee brace or adjustable ROM knee brace. The Coretech ROM Knee Brace Elite uses bilateral adjustable hinges within a rigid frame to provide controlled range of motion. ACL knee braces also offer adjustable motion stops, so range of motion settings alone do not distinguish the two categories.

Medial-Lateral Control

In both categories, medial-lateral control generally comes from the rigid uprights on either side of the knee. Medial-lateral support alone does not make a knee orthosis an L1845/L1852 device.

Rotation Control

Rotation control is what sets ACL-style functional knee orthoses apart. Under Medicare coding guidance for L1845 and L1852, rotation control is achieved by the combination of rigid material in the anterior portion of the thigh and calf cuffs and condylar pads. Rotation at the knee occurs during weight bearing and ambulation, which is when this control matters.

This distinction is relevant when providers compare an ACL brace, knee brace for ACL tear, or other knee orthosis where rotation control is part of the prescribed support strategy. The term derotational knee brace may also be used, but providers should evaluate the documented features and HCPCS classification of the specific orthosis rather than the product name.

HCPCS & Provider Considerations

For orthopedic practices, O&P providers, and DME suppliers, the distinction between these knee orthoses involves more than the presence of an adjustable hinge.

Under Medicare's Knee Orthoses LCD (L33318) and related policy article (A52465), both code families can be covered after a recent injury or surgical procedure on the knee, or for an ambulatory patient with documented knee instability. Because the clinical indications overlap, the code billed must match the brace's actual construction.

Several of these codes have been included on CMS's Required Prior Authorization List. Providers should confirm the current list before dispensing.

Providers should also consider:

• Required flexion and extension control.
• Need for rotation control, not only medial-lateral support.
• Patient measurements and fitting complexity.
• Custom-fitted versus off-the-shelf classification and the fitting actually performed.
• Current PDAC coding verification and product documentation.
• Current payer, DME MAC, and prior authorization requirements.
• The prescribed rehabilitation protocol.

A post-op knee brace, post-operative knee brace, or knee rehabilitation brace may require different types of motion control depending on the rehabilitation protocol. A post-operative ACL brace or ACL rehabilitation brace may incorporate rotation control in addition to adjustable flexion and extension, while a ROM knee orthosis emphasizes controlled range of motion.

Frequently Asked Questions

Can a ROM knee brace provide medial-lateral control without being classified as L1845 or L1852?

Yes. Many L1832/L1833 braces use uprights that provide medial-lateral support. L1845 and L1852 also require rotation control, along with adjustable flexion and extension and double-upright construction.

Providers should evaluate the complete brace construction and the applicable HCPCS description rather than any single feature.

Why can two knee braces have similar ROM settings but different HCPCS codes?

Hinge adjustability is only one part of the HCPCS description. An ACL knee brace and a ROM knee brace may both offer adjustable flexion and extension while differing in rotation control, structural design, and fitting classification.

Does calling a product an ACL brace or derotational knee brace determine its HCPCS classification?

No. Product terminology does not determine the HCPCS code. Providers should verify the documented construction, mechanical function, current PDAC coding information, and product-specific documentation before selecting a billing code.

Can the same knee brace model be associated with both custom-fitted and off-the-shelf HCPCS codes?

Yes. Some models have documentation supporting paired codes, and the correct code depends on how the orthosis is provided and fitted.

• L1832: prefabricated, custom fitted.
• L1833: prefabricated, off-the-shelf.
• L1845: prefabricated, custom fitted.
• L1852: prefabricated, off-the-shelf.

Custom-fitted codes require that the prefabricated orthosis be modified to fit the specific patient by an individual with expertise, and that the fitting be documented. Off-the-shelf codes apply when the orthosis requires only minimal self-adjustment.

Is a custom-fitted knee brace the same as a custom-fabricated knee brace?

No. L1832 and L1845 are prefabricated braces that are custom fitted. A custom-fabricated orthosis is built for an individual patient and is billed under different codes, such as L1846.

Compare Coretech Knee Braces

Compare the Coretech ROM Knee Brace Elite, Coretech ACL Knee Brace, and other Coretech knee orthoses by construction, controlled range of motion, rotation control, sizing, fitting requirements, HCPCS classification, and available product documentation.

Coretech ROM Knee Brace Elite
Coretech ACL Knee Brace
Coretech Product Resources

Coretech Product Resources includes manuals, brochures, PDAC letters, billing sheets, and other provider documentation.

Disclaimer: This article is provided for general product education and does not replace the prescribing healthcare professional's clinical judgment or model-specific Coretech user instructions. Coverage, coding, documentation, and reimbursement requirements can vary and change. Providers and suppliers are responsible for confirming current requirements with CMS, the applicable DME MAC, PDAC, and the patient's payer.