Glossary · Clinical

Hemiarthroplasty

Hemiarthroplasty is a partial joint replacement in which only one articular surface is resurfaced with a prosthesis—most commonly the femoral head in the hip or the proximal humerus in the shoulder—while the native opposing surface is left intact.

Verified May 8, 2026 · 5 sources ↓

Drawn from CMSAAPC

Definition

Source · Editorial summary grounded in 5 cited references ↓

In a hemiarthroplasty, the surgeon removes and replaces a single side of a joint rather than both articular surfaces. At the hip, this typically means excising the femoral head and neck and implanting a femoral stem with a prosthetic head that articulates against the patient's natural acetabulum. The procedure is most frequently performed after femoral neck fracture in elderly patients, where the blood supply to the femoral head is compromised and internal fixation failure rates are high. Hip hemiarthroplasty may use a unipolar (fixed head) or bipolar (inner-bearing) design, a distinction that affects implant selection but does not change the primary CPT code.

At the shoulder, hemiarthroplasty replaces only the proximal humerus. It is indicated when the humeral head is damaged or fractured but the glenoid cartilage remains serviceable, and it is also used in selected cases of avascular necrosis or irreparable rotator cuff arthropathy where glenoid replacement would be unreliable.

From a coding standpoint, the term hemiarthroplasty appears explicitly in CPT descriptors, and correct code selection depends on both the joint treated and the clinical indication. A hip hemiarthroplasty performed to manage a femoral neck fracture is captured under the fracture-treatment code, not the elective arthroplasty code—a distinction that directly affects reimbursement and audit defensibility.

Why it matters

Choosing the wrong CPT code for hip hemiarthroplasty is one of the most audited errors in orthopedic billing. When the procedure is performed to treat an acute femoral neck fracture, the correct code is 27236 (open treatment of proximal femoral neck fracture with prosthetic replacement), not 27125 (elective hip hemiarthroplasty). These two codes carry different RVUs, different global periods, and different ICD-10-CM linkage requirements. Submitting 27125 with a fracture diagnosis—or 27236 with a degenerative-disease diagnosis—creates a medical-necessity mismatch that triggers claim denial or post-payment audit. Similarly, for shoulder hemiarthroplasty (CPT 23470), NCCI 2026 policy explicitly bundles prosthesis-removal codes 23333, 23334, and 23335 into the arthroplasty code; billing them separately when the prior implant is removed as part of the same procedure will result in automatic denial.

Common mistakes

Where people most often go wrong with this concept.

Source · Editorial brief grounded in cited references ↓

Reporting CPT 27125 (elective hip hemiarthroplasty) instead of CPT 27236 when the operative indication is an acute femoral neck fracture—these codes are not interchangeable and carry different medical-necessity requirements.
Billing CPT 23334 or 23335 separately alongside CPT 23470 for shoulder hemiarthroplasty when an existing prosthesis is removed during the same operative session; NCCI policy bundles removal into 23470.
Using CPT 27125 for a bipolar hip implant placed for fracture and assuming 'bipolar' in the operative report means the elective arthroplasty code applies—it does not; the clinical indication drives code selection, not implant design.
Failing to link the correct ICD-10-CM fracture code (e.g., S72.001A for displaced femoral neck fracture, initial encounter) to CPT 27236, causing a medical-necessity denial when a degenerative-disease code is submitted instead.
Omitting documentation of why total arthroplasty was not performed (e.g., intact glenoid, patient physiologic status), leaving the hemiarthroplasty choice uncorroborated in the operative record.

Related codes

Codes commonly involved when this concept appears in practice.

CPT

ICD-10

M16.11

Modifiers

RT Right side LT Left side 59 Distinct procedural service

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 5 cited references ↓

01What is the difference between CPT 27125 and CPT 27236 for hip hemiarthroplasty?

CPT 27236 is used when hemiarthroplasty is performed as treatment for an acute proximal femoral neck fracture. CPT 27125 applies when the procedure is done electively for conditions such as osteoarthritis or avascular necrosis without an acute fracture. Using the wrong code relative to the documented diagnosis creates a medical-necessity mismatch and invites claim denial or audit.

02Can I bill separately for removing an old shoulder prosthesis when performing hemiarthroplasty under CPT 23470?

No. Per NCCI 2026 policy, CPT 23470 includes removal of a native joint or a failed prior prosthesis. CPT codes 23333, 23334, and 23335 may not be billed separately with 23470 for removal performed during the same operative session on the same shoulder.

03Does a bipolar implant design change which CPT code I report for hip hemiarthroplasty?

No. Implant design (unipolar vs. bipolar) does not determine the CPT code. Code selection is driven by the clinical indication and whether the procedure treats a fracture (27236) or an elective condition (27125). The operative report should describe the implant type, but that description alone does not override indication-based code selection.

04What ICD-10-CM codes support medical necessity for hip hemiarthroplasty after femoral neck fracture?

Displaced and non-displaced femoral neck fracture codes in the S72.0 subcategory (e.g., S72.001A for displaced femoral neck fracture, initial encounter) are the primary supporting diagnoses for CPT 27236. The fracture must be documented as acute, with imaging correlation, and the seventh-character encounter indicator must match the episode of care.

05When is shoulder hemiarthroplasty preferred over total shoulder arthroplasty?

Shoulder hemiarthroplasty is generally preferred when the glenoid cartilage is intact and healthy, when glenoid bone stock is inadequate to seat a glenoid component, or in certain high-demand patients where glenoid component longevity is a concern. The operative report should explicitly document the condition of the glenoid to justify the choice of hemiarthroplasty over total shoulder replacement.

Sources & references

Editorial content was developed using the following public sources. Last verified May 8, 2026.

Mira AI Scribe

When Mira detects documentation of a hemiarthroplasty, it evaluates two decision points before suggesting a code. 1. JOINT AND INDICATION CHECK: For the hip, Mira checks whether the operative note references an acute fracture (femoral neck, displaced or non-displaced) or a chronic/degenerative condition (osteoarthritis, AVN without acute fracture). Fracture indication → flags CPT 27236 with the appropriate fracture ICD-10-CM code (e.g., S72.001A). Degenerative or elective indication → flags CPT 27125 with a disease-based ICD-10-CM code (e.g., M16.11). For the shoulder, Mira maps hemiarthroplasty language to CPT 23470 and cross-checks for glenoid involvement; if both surfaces are documented as replaced, it escalates to 23472. 2. BUNDLING ALERT: If the operative note includes language indicating removal of a prior hip or shoulder prosthesis during the same session, Mira suppresses separate removal codes (23333, 23334, 23335 for shoulder; analogous removal codes for hip) and inserts an alert that NCCI policy bundles removal into the primary arthroplasty code. A modifier-bypass note is appended only when the removal and replacement involve separate anatomic sites or contralateral joints. 3. LATERALITY: Mira auto-appends modifier RT or LT based on laterality language in the note. If laterality is absent or ambiguous, a documentation gap alert fires before the claim is finalized.

See Mira's approach

Related terms

Total hip arthroplasty (THA) Clinical

Total hip arthroplasty (THA) is a surgical procedure that removes damaged bone and cartilage from the acetabulum and femoral head, replacing both with prosthetic components to relieve pain and restore hip function. It is also called total hip replacement (THR).

Total shoulder arthroplasty (TSA) Clinical

Total shoulder arthroplasty (TSA) is a surgical procedure that replaces both the proximal humerus (ball) and glenoid (socket) with prosthetic components to relieve pain and restore function in a severely damaged shoulder joint. It is the third most commonly replaced joint in the U.S., after the hip and knee.