ICD code S82.033C – Displaced transverse fracture of unspecified patella

Key takeaways

S82.033C is a billable FY2026 ICD-10-CM code in the S82.0 patella fracture subcategory.

The 7th character C means a Gustilo type IIIA, IIIB, or IIIC open fracture on initial encounter.

Character A covers the closed-fracture initial encounter, and character B covers open type I or II.

Unspecified laterality means S82.033C applies only when the record omits which side was fractured.

Pabau’s claims management software flags incomplete laterality and 7th-character documentation before a claim is submitted.

What is ICD-10 Code S82.033C?

ICD-10 Code S82.033C is the specific, billable ICD-10-CM diagnosis code for a displaced transverse fracture of unspecified patella.

The 7th character C narrows it to an initial encounter for open fracture type IIIA, IIIB, or IIIC. The code is valid for FY2026 and sits within the S82.0 (fracture of patella) subcategory of category S82, fracture of lower leg including ankle.

The code’s position in the ICD-10-CM hierarchy matters for both coding accuracy and payer editing. A coder who selects S82.033C asserts four points at once:

• The fracture is displaced.
• The fracture line runs transversely across the patella.
• Laterality is not specified in the medical record.
• This is the patient’s first encounter for active treatment of a Gustilo type III open fracture.

Code description and clinical meaning of S82.033C

Each word in the descriptor of ICD-10 Code S82.033C carries a coding obligation. Misreading any element produces an incorrect code selection that payers will reject.

• Displaced — the fracture fragments have separated from their normal anatomical alignment. If the fragments remain in position, the correct code shifts to the nondisplaced series (S82.036x).
• Transverse — the fracture line runs perpendicular to the long axis of the patella. A comminuted pattern (multiple fragments) maps to S82.04x instead.
• Unspecified patella — neither right nor left side is identified in the medical record. This does not mean the coder is uncertain. It means the documentation genuinely lacks laterality.
• Initial encounter — the patient is actively receiving treatment for this fracture. Subsequent visits during the healing phase use 7th character D or the appropriate healing-status extension, not C.
• Open fracture type IIIA, IIIB, or IIIC — the skin is broken and the fracture meets the Gustilo-Anderson criteria for a high-energy open injury. The 7th character C encompasses all three type III sub-classifications.

A displaced transverse patellar fracture in the open type III category is a high-energy injury. Motor vehicle collisions, falls from height, and direct blunt trauma are the most common mechanisms.

Wound contamination, soft tissue loss, and possible vascular involvement characterize Gustilo type III injuries. That combination sets this fracture apart from lower-grade open fractures and almost always calls for surgery.

Understanding the 7th character for S82.033: A, B, and C explained

The 7th character is the most coding-sensitive component of ICD-10 Code S82.033C. Three 7th characters apply to initial encounters in the S82.033 subcategory. Choosing the wrong one is the single most common denial trigger for patellar fracture claims. The same encounter-type logic runs through the whole S82 category, so the table below transfers to every lower-leg fracture code.

Gustilo-Anderson classification: What type IIIA, IIIB, and IIIC mean

The Gustilo-Anderson classification grades open fractures by wound size, contamination, periosteal stripping, and vascular involvement. ICD-10-CM groups all three type III sub-classes under a single 7th character C, because the code set does not sub-divide them further. The clinical distinction still matters for operative planning, but the coding outcome is the same for all three.

The operative report or emergency department note must document the Gustilo grade explicitly. Without a documented grade, the coder has no basis for character C and must default to character B instead. When grading is absent, query the attending surgeon before assigning a higher-acuity character.

Laterality and code specificity: S82.031C, S82.032C, and S82.033C

The 5th character in S82.033 encodes laterality. Character 1 is the right patella, 2 is the left patella, and 3 is unspecified. ICD-10 Code S82.033C should only be assigned when the medical record provides no laterality information. Medicare and many commercial payers run automated edits that flag unspecified laterality codes when a more specific alternative exists.

If the operative report names the side, such as “right knee explored,” the coder must use S82.031C. Using S82.033C when laterality is documented but overlooked is a specificity error. Some payers treat that error as a medical necessity mismatch.

When in doubt, query the surgeon rather than defaulting to “unspecified.” The wound grade and the documented side are the only two questions that decide the code, and they resolve like this.

Adjacent patella fracture codes in the S82.0 subcategory

The S82.0 subcategory contains several displaced patellar fracture codes. Picking the wrong descriptor, whether transverse, comminuted, or osteochondral, is a common specificity error. ICD-10-CM uses parallel logic across every fracture site, so the same displaced, nondisplaced, and laterality conventions apply throughout.

Imaging determines whether the pattern is transverse or comminuted, and the operative note confirms it. Imaging language such as “stellate fracture,” “butterfly fragment,” or “multi-fragment” signals comminuted and rules out S82.033C.

Documentation requirements for S82.033C

Six documentation elements must appear in the medical record before a coder can confidently assign ICD-10 Code S82.033C. Missing any one of them requires a physician query before claim submission.

• Fracture pattern: The note must describe the fracture as transverse, meaning perpendicular to the long axis. Synonyms such as “horizontal” are acceptable in a patellar context. “Stellate” and “comminuted” are not.
• Displacement status: The record must confirm the fragments are separated. Radiology reports usually state “displaced” outright. Where they do not, operative findings describing a reduction establish it.
• Bone affected: The patella must be named. “Knee fracture” without anatomical specificity does not support S82.033C.
• Laterality, or its confirmed absence: Right, left, or an explicit statement that the record does not identify a side. Laterality found in imaging, the operative report, or even the referral letter satisfies this element.
• Open fracture: Wound documentation confirming a skin breach at the fracture site. Operative notes describing wound irrigation and debridement confirm an open injury.
• Gustilo grade: The surgeon must document IIIA, IIIB, or IIIC explicitly. A grade of I, II, or “open NOS” maps to character B, not C.

When documentation is incomplete, query the attending surgeon before submission rather than defaulting to a lower-specificity code. An S82.033A submitted in place of S82.033C understates clinical severity and may affect case-mix weighting, DRG assignment, and quality reporting.

Getting all six elements onto the record the first time is what makes a clean claim submission possible for this code. A query answered before submission takes minutes. An appeal after a denial takes weeks.

CPT codes commonly reported with S82.033C

Open fractures of the patella at Gustilo type III severity almost always require surgical management. The CPT code on the claim must be clinically consistent with the ICD-10 diagnosis.

A payer that sees S82.033C paired with CPT 27520, closed treatment without manipulation, will flag the combination as a medical necessity mismatch. Verify current CPT descriptors and RVU values against the CMS Physician Fee Schedule before billing.

The AAPC ICD-10-CM and CPT crosswalk lists the procedure codes that pair with each diagnosis. Bundling edits between debridement codes and the primary fracture CPT vary by payer. Review your MAC’s local coverage determination before appending a -59 modifier.

Common claim denial reasons for S82.033C and how to fix them

Denials on ICD-10 Code S82.033C cluster around six predictable errors, and each has a clear correction path. Reading the common denial codes a payer returns tells you which edit fired before you start rebuilding the claim.

External cause codes (V00-Y99) are strongly recommended by the CDC/NCHS ICD-10-CM guidelines for all traumatic injuries. A growing number of commercial payers now require them. Common pairings for a patellar fracture are:

• W19.xxxx for an unspecified fall
• W18.xx for a fall on the same level
• V-codes for a motor vehicle collision

Activity codes (Y93.xx) and external cause status codes (Y99.xx) may also be appended where the payer’s LCD requires them. Review the current CMS ICD-10 coding guidelines and your MAC’s LCD for the requirements in your jurisdiction.

For appeals, read the CARC denial reason codes returned in your ERA to identify which edit fired. Then build the appeal around the documentation correction rather than the code itself. Fracture care also carries a 90-day global period, which changes how follow-up visits are billed alongside the initial encounter code.

How Pabau catches S82.033C coding errors before submission

In most practices the coder finds a missing Gustilo grade or an absent laterality statement after the claim has already gone out. The denial comes back weeks later, and the correction competes with that week’s new work.

Practice management software like Pabau moves that check forward. Its cleaner claims management workflow compares the diagnosis and procedure codes on a claim against the documentation attached to the encounter. Where the 7th character, the laterality statement, or the Gustilo grade is missing, the claim is held for review instead of submitted.

Claims then go out through Claim.MD, our US clearinghouse partner, which runs its own payer edits before the file reaches the insurer. Orthopedic and urgent care teams get the correction request while the surgeon is still reachable.

Reduce patellar fracture claim denials before they happen

Pabau’s claims management software flags incomplete laterality documentation and 7th-character mismatches before a claim leaves your practice. See how orthopedic and urgent care teams use Pabau to submit cleaner claims on the first pass.

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Conclusion

S82.033C is a narrow code, and most of the work that earns it happens before the coder opens the chart. The surgeon’s Gustilo grade and one explicit line about the injured side decide whether the claim clears on the first pass.

The trade-off worth remembering is timing. A query sent while the patient is still in the department takes one message. The same query after a denial takes a resubmission, an appeal, and a month of held revenue.

Pabau checks documentation against the codes on the claim while the encounter is still open. Book a demo to see how orthopedic and urgent care teams cut S82.033C denials before submission.

Continue your research

Need to understand how clearinghouse edits catch coding errors before payers do? Claim.MD clearinghouse overview explains how real-time claim validation works for ICD-10 fracture codes.

Want to reduce denial turnaround time on complex fracture claims? Electronic remittance advice (ERA) guide covers how to read CARC denial codes and build targeted appeals.

Looking for ICD-10-CM eligibility verification before treatment? Insurance eligibility verification outlines how pre-visit checks reduce fracture care claim rejections.

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