Anatomic Total Shoulder Replacement (Anatomic Total Shoulder Arthroplasty)

Overview

In an anatomic total shoulder replacement, the worn surfaces of the shoulder are replaced with implants shaped like the natural joint: a smooth metal ball on the top of the arm bone (humerus) and a plastic (polyethylene) lining for the socket (glenoid). Because the design copies normal anatomy, it relies on the patient's own rotator cuff muscles to move and stabilize the shoulder.

It is the most common replacement for glenohumeral osteoarthritis when the rotator cuff is intact, and it is also used for some cases of inflammatory arthritis, arthritis after an old injury, and avascular necrosis when the socket is also damaged. The American Academy of Orthopaedic Surgeons (AAOS) guideline on shoulder arthritis rates the evidence as strong that anatomic total shoulder replacement gives better function and pain relief than replacing the ball alone (hemiarthroplasty) for osteoarthritis ^[1].

Dr. Joshi performs anatomic, reverse, hemiarthroplasty and pyrocarbon hemiarthroplasty, as well as navigated and robotic-assisted shoulder replacement, and helps each patient choose the type that fits their shoulder, age and goals.

Benefits

• Reliable relief of arthritis pain
• Best potential for rotation and a natural-feeling shoulder when the rotator cuff is healthy
• Preserves the option of a reverse replacement later if needed

Who is a Candidate?

Anatomic Shoulder Replacement may be appropriate for patients who meet certain criteria. Ideal candidates include:

• Shoulder osteoarthritis with a working rotator cuff
• Pain that limits sleep, work or daily activities despite injections, therapy and medications
• Enough healthy socket bone to support the plastic glenoid component
• Patients who value rotation, such as reaching behind the back, overhead work, or sports like golf and tennis

Anatomic or Reverse?

Reverse replacement is usually the better option when the rotator cuff is torn or not working, when there is major socket bone loss or the ball sits off-center, and for some complex fractures and failed earlier replacements. Some X-ray findings also matter: a high critical shoulder angle (35° or more) has been linked to later revision of anatomic replacements, and some surgeons choose a reverse replacement in those shoulders ^[6].

Range of Motion: Anatomic vs. Reverse

Both replacements reliably relieve pain and improve function in arthritis with an intact rotator cuff. The main differences are in rotation:

• External rotation (turning the arm outward) tends to be better after anatomic replacement. In a multicenter study of top-performing patients followed at least 5 years, anatomic replacements had better active external rotation than reverse replacements, while other outcome scores, complications and revisions were similar ^[2].
• Internal rotation (reaching behind the back) also tends to favor anatomic replacement, especially in stiff shoulders. In patients who were stiff before surgery, anatomic replacement produced greater internal rotation (score 4.8 vs. 4.2) and external rotation (40° vs. 28°) than reverse replacement, with similar overall outcome scores ^[3].
• Overhead elevation is similar. In patients 70 and older, 98% after anatomic and 100% after reverse replacement rated their forward elevation as full or nearly full, with no difference in pain, satisfaction or outcome scores ^[4].
• A 2024 meta-analysis of 10 studies (544 anatomic and 329 reverse replacements) found similar improvements in elevation, rotation and patient-reported scores between the two ^[5].

In plain terms: if your rotator cuff is healthy, an anatomic replacement gives the best chance of near-normal rotation. A reverse replacement gives similar pain relief and overhead elevation and is the dependable choice when the rotator cuff or bone is compromised.

How Long Does It Last?

• A systematic review in The Lancet Rheumatology estimated 10-year survival of about 95% for total shoulder replacement in published case series, and 92% in national registry data ^[7].
• Long-term studies in specific groups report good durability. For example, total shoulder replacement in patients with juvenile idiopathic arthritis had 93% implant survival at 10 years and about 89% at 20 years ^[8].
• Smoking matters. About 10 years after anatomic replacement, revision rates were 7.7% in non-smokers, 20.4% in former smokers and 37.5% in current smokers ^[9].

Revision Risk Compared With Reverse Replacement

Studies disagree, and the answer depends on the patient:

• In patients 70 and older, a study of 3,791 patients found no significant difference in revision risk between anatomic and reverse replacement ^[10].
• Other studies, which include more younger and active patients in the anatomic group, report higher revision rates after anatomic replacement: 4.1% vs. 0.5% in one large database study ^[11], and 8.8% vs. 0.9% in a 2024 meta-analysis ^[5].
• In an Australian national registry of patients younger than 55, there was no significant difference in revision rate between anatomic and reverse replacement at mid-term follow-up ^[12].

Most Common Reasons for Revision

• Rotator cuff failure over time: the rotator cuff can thin or tear years after an anatomic replacement. More than half of revisions after anatomic replacement in patients 70 and older were for rotator cuff tears ^[10]. In a 10-center European study, shoulders remained free of secondary rotator cuff dysfunction in 84% at 10 years and 45% at 15 years ^[13].
• Loosening of the plastic socket component (glenoid loosening): a well-known long-term problem, where implant design matters. Metal-backed and some stemless designs have had high loosening rates ^{[14, 15]}, and the AAOS guideline advises against metal-backed cementless glenoid components ^[1].
• Instability or dislocation: in young patients in the Australian registry, revisions after total shoulder replacement were most often for instability or dislocation (20.6%) or loosening (18.6%) ^[12].
• Less common causes include infection, fracture around the implant and stiffness ^[16].

When an anatomic replacement fails, it is most often converted to a reverse replacement.

Recovery & Rehabilitation

Most patients stay in the hospital one night or go home the same day. A sling is worn for several weeks while the subscapularis tendon, which is released and repaired to reach the joint, heals. Therapy progresses from gentle motion to strengthening over three to six months, and improvement can continue for up to a year.

References

1. American Academy of Orthopaedic Surgeons. Management of Glenohumeral Joint Osteoarthritis: Evidence-Based Clinical Practice Guideline. 2020. aaos.org/globalassets/quality-and-practice-resources/glenohumeral/gjo-cpg.pdf
2. Anatomic versus reverse total shoulder arthroplasty for primary osteoarthritis with an intact rotator cuff: a midterm comparison of early top performers. J Am Acad Orthop Surg. 2024. doi.org/10.5435/JAAOS-D-24-00110
3. Clinical outcomes of anatomic vs. reverse total shoulder arthroplasty in primary osteoarthritis with preoperative rotational stiffness and an intact rotator cuff. J Shoulder Elbow Surg. 2023. doi.org/10.1016/j.jse.2022.12.027
4. Comparison of clinical outcomes after anatomic total shoulder arthroplasty and reverse shoulder arthroplasty in patients 70 years and older with glenohumeral osteoarthritis and an intact rotator cuff. J Am Acad Orthop Surg. 2020. doi.org/10.5435/JAAOS-D-19-00166
5. Vij N, Tummala S, Shahriary E, Tokish J, Martin S. Total shoulder arthroplasty versus reverse shoulder arthroplasty in primary glenohumeral osteoarthritis with intact rotator cuffs: a meta-analysis. Cureus. 2024;16(4):e57866. doi.org/10.7759/cureus.57866
6. The association between critical shoulder angle and revision following anatomic total shoulder arthroplasty: a matched case-control study. J Shoulder Elbow Surg. 2021. doi.org/10.1016/j.jse.2021.08.003
7. Evans JP, Evans JT, Craig RS, et al. How long does a shoulder replacement last? A systematic review and meta-analysis of case series and national registry reports with more than 10 years of follow-up. Lancet Rheumatol. 2020;2(9):e539-e548. doi.org/10.1016/S2665-9913(20)30226-5
8. Shoulder arthroplasty in patients with juvenile idiopathic arthritis: long-term outcomes. J Shoulder Elbow Surg. 2021. doi.org/10.1016/j.jse.2021.06.014
9. The impact of tobacco use on clinical outcomes and long-term survivorship after anatomic total shoulder arthroplasty. J Orthop. 2023. doi.org/10.1016/j.jor.2023.01.002
10. Similar rates of revision surgery following primary anatomic compared with reverse shoulder arthroplasty in patients aged 70 years or older with glenohumeral osteoarthritis: a cohort study of 3791 patients. J Shoulder Elbow Surg. 2023. doi.org/10.1016/j.jse.2023.03.021
11. Exactech Equinoxe anatomic versus reverse total shoulder arthroplasty for primary osteoarthritis: case-controlled comparisons using the machine learning-derived Shoulder Arthroplasty Smart score. J Shoulder Elbow Surg. 2022. doi.org/10.1016/j.jse.2022.09.029
12. Survivorship of shoulder arthroplasty in young patients with osteoarthritis: an analysis of the Australian Orthopaedic Association National Joint Replacement Registry. J Shoulder Elbow Surg. 2023. doi.org/10.1016/j.jse.2023.03.024
13. Young AA, Walch G, Pape G, Gohlke F, Favard L. Secondary rotator cuff dysfunction following total shoulder arthroplasty for primary glenohumeral osteoarthritis: results of a multicenter study with more than five years of follow-up. J Bone Joint Surg Am. 2012;94(8):685-693. doi.org/10.2106/JBJS.J.00727
14. High failure rates of polyethylene glenoid components in stemless anatomic total shoulder arthroplasty for primary and secondary OA. J Bone Joint Surg Am. 2025. doi.org/10.2106/JBJS.24.01126
15. High complication and revision rates in anatomical total shoulder arthroplasty with the combination of polyethylene and cementless convertible metal-backed glenoid components. Orthop Res Rev. 2024. doi.org/10.2147/ORR.S442128
16. Bohsali KI, Bois AJ, Wirth MA. Complications of shoulder arthroplasty. J Bone Joint Surg Am. 2017;99(3):256-269. doi.org/10.2106/JBJS.16.00935
17. AAOS OrthoInfo. Shoulder Joint Replacement. orthoinfo.aaos.org/en/treatment/shoulder-joint-replacement/