Acetabuloplasty with resection of the femoral head — the Girdlestone procedure — performed to relieve pain when infection or bone quality precludes joint reconstruction.

Verified May 8, 2026 · 7 sources ↓

Medicare: $1,010.71
Total RVUs: 30.26
Global, days: 90
Region: Hip

Drawn from CMSAAPCNIHWorkerscompAAOS

Documentation requirements

What must appear in the operative or office note to support the claim.

Source · Editorial brief grounded in 7 cited references ↓

Operative note must explicitly confirm femoral head resection and describe the acetabular modification performed — 'standard approach' language is insufficient.
Document the clinical indication driving the resection choice: active hip infection, failed prior arthroplasty with poor bone stock, or another reason reconstruction was contraindicated.
Confirm no prosthetic implant was placed — any implant charge on the same claim will trigger a mismatch audit.
If a staged conversion to THA is anticipated, document that intent in the original operative note before appending modifier 58 to the future procedure.
Pathology or intraoperative culture results should be referenced if infection is the primary indication — supports medical necessity under the applicable ICD-10 code.
Assistant surgeon participation requires documentation of active intraoperative role; primary surgeon signature on the operative report is sufficient per CMS Claims Processing Manual.

Applicable modifiers

Modifiers commonly billed with this code.

Source · AMA CPT modifier descriptors · CMS NCCI Policy Manual

22 Increased complexity 24 Unrelated E/M during global 25 Significant separate E/M 50 Bilateral procedure 51 Multiple procedures 57 Decision for surgery 58 Staged or related 59 Distinct service 78 Unplanned return — related 79 Unrelated during global 80 Assistant surgeon AS PA/NP/CNS assistant LT Left side RT Right side

What this code covers

Source · Editorial summary grounded in 7 cited references ↓

CPT 27122 covers acetabuloplasty combined with femoral head resection, commonly called the Girdlestone procedure. The surgeon reshapes the acetabulum and removes the femoral head entirely — there is no prosthesis placed. The indication is typically a severe hip infection that has destroyed the joint or a patient whose bone stock cannot support reconstructive arthroplasty. The result is a resection arthroplasty: the patient ambulates on soft tissue rather than a reconstructed joint, often with a Trendelenburg gait.

This is a 90-day global procedure. Every routine post-op visit, wound check, and dressing change through day 90 is bundled. Separately billable services in that window require modifier 24 (unrelated E/M) or 78 (unplanned return to OR for a related complication). If a staged conversion to total hip arthroplasty is planned, use modifier 58 on the subsequent procedure — this resets the global clock and signals the staged intent documented in the original operative note.

Do not confuse 27122 with 27120 (acetabuloplasty without femoral head resection) or 27125 (hemiarthroplasty with prosthesis placement). The operative note must confirm both components — acetabular modification and femoral head removal — with no implant placed. Payers audit this code for implant claims submitted on the same date, which is a red flag.

RVU & reimbursement

Component RVUs and Medicare national rate. Actual payment varies by GPCI locality.

Source · CMS Physician Fee Schedule, RVU26A · January 2026

Work RVU	15.69
Practice expense RVU	11.24
Malpractice RVU	3.33
Total RVU	30.26
Medicare national rate	$1,010.71
Global period	90 days

Payment by site of service

Medicare pays different rates by setting. HOPD typically pays substantially more than ASC for the same procedure.

Source · CMS OPPS Addendum B·ASC HCPCS payment rates·2026

Setting	Medicare rate (national)
Office (PFS non-facility) Procedure performed in physician's office	$1,010.71
HOPD (APC 5114) Hospital outpatient department	$7,413.38
ASC (PI G2) Ambulatory surgical center (freestanding)	$3,695.53

Common denial reasons

The recurring reasons claims for CPT 27122 get rejected.

Source · Editorial brief grounded in CMS NCCI edits, AAOS coding appeals, and cited references ↓

Wrong code selected — 27120 (acetabuloplasty without resection) or 27125 (hemiarthroplasty with prosthesis) billed when 27122 is the correct code for resection arthroplasty without implant.
Medical necessity not established — payers require documentation of why reconstruction or arthroplasty was contraindicated; missing infection records or bone quality narrative leads to denial.
Implant charges submitted on the same date conflict with the no-prosthesis nature of the Girdlestone procedure and trigger automatic review.
Post-op services billed without modifier 24 or 25 during the 90-day global period are bundled and denied.
Unplanned return to OR for a related complication billed without modifier 78 — payers deny the second claim as already included in the global.

Frequently asked questions

Source · Generated from the editorial pipeline, verified against 7 cited references ↓

01Is 27122 the right code for a Girdlestone procedure?

Yes. CPT 27122 — acetabuloplasty with femoral head resection — is the standard code for the Girdlestone procedure. The key is that no prosthesis is placed. If an implant is inserted, you're looking at a different code family (27125 for hemiarthroplasty, 27130 for THA).

02What's the difference between 27120 and 27122?

27120 is acetabuloplasty alone — the acetabulum is reshaped but the femoral head remains. 27122 adds femoral head resection. Both components must be documented in the operative note to support 27122.

03Can you bill 27122 and 27125 together on the same date?

No. 27122 is a resection arthroplasty without implant; 27125 is a hemiarthroplasty with prosthesis. They are mutually exclusive by definition. Billing both on the same date will generate an edit and likely a fraud flag.

04How do you handle a planned conversion to THA after a Girdlestone?

If conversion to total hip is planned at the time of the Girdlestone, document that intent in the original operative note. When the THA is performed, append modifier 58 to 27130 or 27132 — this signals a staged related procedure and resets the 90-day global clock.

05Does the 90-day global include treatment of a post-op infection?

Routine wound care is bundled. But if the patient returns to the OR for an unplanned irrigation and debridement of a post-op infection, that's a complication requiring modifier 78 on the return procedure. An E/M visit for the same complication still needs modifier 24 to be separately billable.

06When is modifier 22 appropriate for 27122?

Use modifier 22 when the procedure required substantially greater work than typical — for example, an extensively scarred surgical field from prior infection, hardware removal complicating access, or a morbidly obese patient with anatomic distortion. The operative note must quantify the extra time and describe the specific obstacles. Modifier 22 without supporting documentation is a common audit target.

Sources & references

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

Mira AI Scribe

Mira's AI scribe captures the specific acetabular modification technique, confirmation of femoral head removal, absence of implant placement, and the clinical rationale (infection severity, bone stock quality) from the surgeon's dictation. That detail prevents the two most common denials: upcoding flags from reviewers who confuse 27122 with 27125, and medical necessity rejections when the operative note fails to explain why reconstruction was not performed.

See how Mira captures CPT 27122 documentation