Reverse total shoulder arthroplasty (rTSA)

In a conventional total shoulder replacement, the humeral head is the ball and the glenoid is the socket. Reverse TSA flips that relationship: a metal hemisphere (glenosphere) is fixed to the glenoid, and a polyethylene cup is placed on the resected proximal humerus. This geometric inversion shifts the center of rotation medially and inferiorly, lengthening the deltoid moment arm so the deltoid can power shoulder elevation even when the rotator cuff is absent or non-functional.

The primary indications include rotator cuff tear arthropathy (CTA), massive irreparable rotator cuff tears with pseudoparalysis (active forward elevation below 90° despite intact passive range of motion), and complex proximal humerus fractures in older patients. Secondary indications recognized in payer policy include failed prior shoulder arthroplasty with rotator cuff deficiency, inflammatory arthropathy with cuff compromise, and certain tumors requiring proximal humeral reconstruction. CMS LCD L39956 (Palmetto GBA) specifies that pseudoparalysis reversal—defined as restoration of active forward elevation above 90°—is achieved in roughly 96% of rTSA cases, supporting medical necessity when conservative care has failed.

From a coding standpoint, rTSA is captured by the same CPT code used for conventional total shoulder arthroplasty (23472). There is no standalone CPT code that distinguishes the reverse design from an anatomic total shoulder. The operative report must clearly document the reverse configuration—glenosphere fixation, humeral cup placement, and the rationale for choosing the reverse design—so that the claim survives medical review. Revision of a prior rTSA to new components is coded with 23473 (single component) or 23474 (both components), depending on what is exchanged intraoperatively.

Because rTSA and anatomic total shoulder arthroplasty share CPT 23472, payers rely entirely on ICD-10 diagnosis codes and operative documentation to validate medical necessity for the reverse design. Submitting a rotator cuff tear arthropathy diagnosis (M19.011–M19.019, or the appropriate M75.1x cuff codes) paired with a generic osteoarthritis indication—or vice versa—creates a mismatch that triggers pre-payment medical review or post-payment audit. A denied or downcoded claim for rTSA represents a substantial reimbursement loss given the higher implant costs relative to anatomic arthroplasty. Separately, misidentifying a revision rTSA as a primary procedure (23472 instead of 23473/23474) undercodes the service and misrepresents the actual complexity, exposing the practice to compliance risk if the pattern recurs across cases.