How do we miss bone related risks in joint arthroplasty & How bone health fits in

A Wake-Up Call for Every TKA Program

Members, if you manage or influence a total knee arthroplasty (TKA) service line, this study demands your immediate attention.

Published in the Journal of Orthopaedic Surgery and Research (2025), Feng et al. conducted a 10-year retrospective analysis of 1,330,099 TKA cases from the National Inpatient Sample (NIS) database (2010–2019). Their objective: to quantify the independent impact of preoperative osteoporosis on perioperative complications, length of stay (LOS), and hospital costs.

The verdict?

Osteoporosis is not just a comorbidity—it's a surgical risk multiplier.

Study Design: Gold Standard Methodology

The researchers identified 56,888 patients (4.28%) with a preoperative diagnosis of osteoporosis. To eliminate confounding, they executed 1:1 propensity score matching across:

• Age

• Sex

• Race

• Payer status

• Hospital type (urban vs. rural, teaching vs. non-teaching)

• 29 Elixhauser comorbidity indices

This produced a balanced cohort of 113,686 patients (56,843 per group). Multivariable logistic regression then calculated adjusted odds ratios (aOR) with 95% confidence intervals for a comprehensive set of outcomes.

Full Results: A Cascade of Elevated Risks

Outcome        Adjusted Odds Ratio (aOR)              (95% CI)        {P-value}

Periprosthetic fracture           2.13 aOR                       (1.31-3.45)    {<0.001}

Prosthetic loosening               1.26 aOR                       (1.11-1.43)    {<0.001}

Postoperative hemorrhage    1.41 aOR                       (1.15-1.72)    {<0.001}

Blood transfusion                     1.23 aOR                       (1.18-1.28)    {<0.001}

Stroke                                           1.26 aOR                       (1.10-1.44)    {<0.001}

Urinary tract infection            1.10 aOR                       (1.02-1.18)    {0.013}

Pressure ulcer                           1.53 aOR                       (1.09-2.15)    {0.015}

Muscle atrophy                         2.77 aOR                       (1.59-4.82)    {<0.001}

Lower limb peripheral nerve injury

                                                        1.30 aOR                       (1.01-1.14)    {0.041}

Prolonged LOS (>75th percentile)

                                                        1.11 aOR                       (1.07-1.14)    {<0.001}           

Higher total hospitalization cost (>75th percentile)

                                                        1.07 aOR                       (1.04-1.10)    {<0.001}

Deep Dive: The Most Clinically Significant Risks

1. Periprosthetic Fracture (aOR 2.13)

• Mechanism: Compromised bone stock reduces implant fixation and increases stress riser formation.

• Clinical Impact: Often requires revision surgery, extended rehab, and carries a >20% risk of infection.

• Cost: $50,000–$100,000+ per case. At 4.28% prevalence, a program performing 100 TKAs/year faces 2–3 expected fractures annually—$100K–$300K in avoidable spend.

2. Prosthetic Loosening (aOR 1.26)

• Mechanism: Micromotion at the bone-implant interface due to poor trabecular support.

• Long-Term Risk: Aseptic loosening is the leading cause of late TKA failure.

• Prevention: Cemented components, longer stems, or augmented fixation in BMD <0.6 g/cm².

3. Postoperative Hemorrhage (aOR 1.41)

• Mechanism: Fragile cortical bone increases bleeding risk during canal preparation and reaming.

• Management: Pre-op tranexamic acid, meticulous hemostasis, and consideration of tourniquet protocols.

4. Muscle Atrophy (aOR 2.77)

• Mechanism: Prolonged immobility due to pain, poor bone healing, or fear of weight-bearing.

• Functional Impact: Delays return to ADLs, increases fall risk, and compromises rehab outcomes.

Resource Utilization: The Hidden Financial Burden

• Prolonged LOS: Osteoporotic patients had 11% higher odds of exceeding the 75th percentile LOS. In bundled payment models (CJR, BPCI), this directly erodes margins.

• Total Cost: 7% higher odds of exceeding the 75th percentile cost. For an average TKA at $27,500, this adds ~$1,925 per case—scaling to $96,250 across 50 osteoporotic patients.

Why this matters for ASOP providers and health systems:

1. Screening is non-negotiable. Every TKA candidate over 50 should be assessed for osteoporosis. Missing it means accepting preventable complications.

2. Pre-op optimization saves downstream disasters. Early identification and treatment can improve bone quality before surgery. The ROI? One avoided periprosthetic fracture can save $50,000–$100,000 in revision costs.

3. Surgical planning must adapt. Consider cemented components, longer stems, or augmented fixation in osteoporotic bone. This isn't preference — it's becoming evidence-based risk mitigation.

4. Bone Health belongs in ortho workflows. Patients will flow from both Primary (pre-op bone health risk assessments) and Secondary fracture prevention (reducing the risk of another fracture in patients who have recently fractured).

5. Document osteoporosis as a comorbidity. It strengthens the medical necessity for bone health programs, supports higher-complexity coding, and justifies investment in provider education and virtual care platforms.

6. Education on how osteoporosis is defined. It's not just low bone mass (low T-score); it also includes a history of low-energy fracture, high fracture risk, history of prior fractures, or direct intraoperative observation (which should be documented in the operative note).

The financial lens:

• Average TKA cost: ~$25,000–$30,000

• Add osteoporosis-related excess: +7% total cost, +11% LOS

• Scale that across 50–100 TKAs/year? The Bone Health service line can save the practice tens to hundreds of thousands in avoidable spend annually!

Financial Modeling: Your Program's Return on Investment (ROI)

Examine 100 patients undergoing total knee arthroplasty. Based on this data, you would have:

4.28% Rate of Osteoporosis Prevalence

2.1        Expected Fractures resulting in $50K - $100K of revision surgery costs

<1         Expected fractures with the ASOP model with $0 cost of revision surgery

Add LOS reduction (0.3 days average) and cost savings ($1,300/case), and a modest program delivers $150K-$350K in annual profit.

Discussion: Why This Study Changes Everything

1. Osteoporosis is underdiagnosed in TKA candidates

• Only 4.28% coded, but population prevalence in women >65 is >20%, with some studies indicating up to a 60% rate of osteoporosis in the total joint replacement population.

2. Current guidelines are reactive, not proactive

• AAOS and ACR focus on post-fracture care.

• Pre-TKA optimization is the new frontier.

3. Technology can identify these patients early in the workflow of orthopedics. 

• Identifying and referring patients before they are TKA candidates streamlines workflows and improves patient satisfaction.

4. Value-based care demands bone health integration.

• CMS penalties for readmissions in TEAMS

• Value-based care is here to stay. Let's move in that direction now.

Final Word

This study isn't just data—it's a mandate. It's a blueprint for building profitable, high-impact bone health programs inside orthopedic service lines.

Orthopedics can continue performing TKAs on fragile bone and pay the price in revisions, readmissions, and lost margins.

Or we can act now—screen, optimize, adapt, and document.

Stop treating osteoporosis as a silent comorbidity and start treating it like the profit and outcomes driver it can be.

The evidence is on your screen. Let's build Bone Health Programs that improve TKA programs - don't just replace joints, preserve lives.

Citation:
Feng Y, Lin J, Zheng C, Wang J, Yang Q, Wang J. Osteoporosis exacerbates perioperative complications in total knee arthroplasty: a 10-year nationwide analysis. J Orthop Surg Res. 2025;20:995. doi:10.1186/s13018-025-06340-8