Glossary · Anatomy

Femoral head

The femoral head is the spherical proximal end of the femur that articulates with the acetabulum to form the hip joint. It is the 'ball' in the ball-and-socket structure of the hip.

Verified May 8, 2026 · 6 sources ↓

Drawn from CMSApsmedbillAbosAAOS

Definition

Source · Editorial summary grounded in 6 cited references ↓

The femoral head sits atop the femoral neck and is covered almost entirely by hyaline cartilage, except at the fovea capitis—a small central depression where the ligamentum teres attaches. Its blood supply is predominantly retrograde via the medial femoral circumflex artery, a detail that directly explains why displaced femoral neck fractures carry such high risk of avascular necrosis (AVN): disruption of that arterial pathway can leave the head ischemic.

In clinical and coding contexts, the femoral head is the focal anatomical structure in a wide range of pathology: AVN, osteoarthritis, femoral head fractures (Pipkin classification), slipped capital femoral epiphysis (SCFE), and developmental dysplasia of the hip (DDH). Each condition has its own ICD-10-CM code family, and the specific anatomical site—head versus neck versus intertrochanteric region—drives both diagnosis coding and procedure code selection.

Surgically, the femoral head may be preserved (core decompression, osteotomy), replaced with a hemiarthroplasty prosthesis, or removed entirely as part of a total hip arthroplasty (THA). When a femoral head specimen is sent to pathology after removal, CPT pathology codes differentiate between a non-fractured head removed during elective replacement and a fractured head removed after trauma—a distinction that changes the laboratory CPT code assigned.

Why it matters

Precisely identifying the femoral head as the anatomical site—rather than the femoral neck, intertrochanteric region, or acetabulum—determines which ICD-10-CM S72 fracture subcategory applies, which CPT surgical code is selected, and which MS-DRG the case groups to. Misidentifying the site can shift a case from DRG 480/481/482 (Hip and Femur Procedures Except Major Joint) to a major joint DRG or vice versa, producing a reimbursement discrepancy that exposes the claim to post-payment audit. On the pathology side, submitting CPT 88304 (femoral head, no fracture) when the bone was fractured—or billing 88305 for a joint resection when only the isolated femoral head was received—is a common source of laboratory claim denials and compliance flags.

Common mistakes

Where people most often go wrong with this concept.

Source · Editorial brief grounded in cited references ↓

  • Coding a femoral neck fracture (S72.0x) when documentation clearly states the fracture involves the femoral head (S72.05x)—the two subcategories are distinct and non-interchangeable.
  • Selecting pathology CPT 88304 (femoral head, other than fracture) for a specimen that is fractured; the correct code is 88305 (femoral head, fracture), which requires an actual structural break, not merely a pathologic fracture.
  • Billing 88305 (femoral head, fracture) when the specimen also includes a significant portion of the acetabulum or femoral neck—that specimen requires 88305 coded as joint resection instead.
  • Assigning total hip arthroplasty codes when only a hemiarthroplasty (femoral head replacement only) was performed; the two procedures carry different CPT codes, different RVUs, and different coverage criteria.
  • Omitting laterality on ICD-10-CM femoral head fracture codes (right: S72.051x; left: S72.052x; unspecified: S72.059x)—incomplete laterality coding renders the code invalid under ICD-10-CM rules.

Related codes

Codes commonly involved when this concept appears in practice.

CPT

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 6 cited references ↓

01What is the difference between a femoral head fracture and a femoral neck fracture for coding purposes?
They occupy separate ICD-10-CM subcategories. Femoral head fractures code to S72.05x (with laterality and encounter characters), while femoral neck fractures code to S72.0x variants. Using the wrong subcategory misrepresents the anatomical injury, can affect DRG grouping, and may trigger a medical-necessity review because treatment protocols—and implant choices—differ between the two.
02When should CPT 88304 be used instead of 88305 for a femoral head specimen?
Use 88304 when the femoral head is removed during elective hip replacement and is not fractured. Use 88305 when the head contains an actual structural fracture (a true break or crack). Whether the specimen arrives in fragments does not change the code; the determining factor is whether a fracture existed in the patient, not how the specimen was handled after removal.
03Does replacing only the femoral head (hemiarthroplasty) code the same as a total hip arthroplasty?
No. Hemiarthroplasty—replacement of the femoral head without addressing the acetabulum—maps to CPT 27125, while total hip arthroplasty maps to CPT 27130 (primary) or 27132 (conversion). The two procedures carry different relative value units and may have different payer coverage criteria, so using the wrong code produces both a reimbursement error and a compliance risk.
04Why does avascular necrosis of the femoral head matter for coding and reimbursement?
AVN of the femoral head (ICD-10-CM M87.05x) is a recognized indication for hip arthroplasty under CMS coverage policy. Documenting the specific site—femoral head rather than a generic 'hip'—is required to satisfy medical necessity for arthroplasty coverage, particularly under Local Coverage Determinations tied to total hip arthroplasty billing article A57683.
05What MS-DRGs are associated with femoral head procedures?
Procedures on the hip and femur that do not involve a major joint replacement typically group to DRGs 480, 481, or 482 (Hip and Femur Procedures Except Major Joint), stratified by MCC, CC, or neither. Major joint replacements such as THA group to different DRGs. Accurate anatomical coding of the femoral head versus adjacent structures ensures the case groups to the correct DRG family.

Mira AI Scribe

When Mira captures documentation referencing the femoral head, the scribe layer should flag laterality immediately—right (RT/LT modifier; ICD-10 S72.051x vs. S72.052x) and confirm whether the pathology involves the head proper versus the neck or intertrochanteric zone, because downstream CPT and DRG assignment diverge at that split. For fracture encounters: confirm Pipkin classification if documented; map to the correct S72.05x subcategory with the appropriate 7th-character encounter qualifier (A = initial, D = subsequent, S = sequela). Prompt the provider to document whether the fracture is open or closed and fracture type (I/II vs. IIIA/IIIB/IIIC) to satisfy full ICD-10-CM code validity. For surgical encounters: distinguish hemiarthroplasty (femoral head replacement only, CPT 27125) from total hip arthroplasty (CPT 27130/27132) based on whether the acetabular component was addressed. If the femoral head is excised without prosthetic replacement (Girdlestone), CPT 27122 applies. For pathology: automatically populate CPT 88304 when the operative note describes elective hip replacement without fracture; escalate to CPT 88305 when the note documents an actual fracture of the femoral head. Alert the coder if the pathology note references accompanying acetabular tissue or femoral neck, as that shifts the specimen category to joint resection under 88305.

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