What "outpatient" means here
An ambulatory surgical center is a licensed surgical facility built for operations that don't need an overnight hospital stay. You check in the morning of surgery, have your hip or knee replaced, recover with our therapists until you can walk safely, and go home the same day with a written plan and a next-morning check-in. The surgeons are the same ones you meet in clinic; the therapy team that gets you up afterward is the same one that runs your rehab.
Why outpatient
The American Association of Hip and Knee Surgeons, with the Hip Society, Knee Society and AAOS, states that outpatient joint replacement is safe and effective for properly selected patients, with selection based on medical conditions, home support and the complexity of the case. A systematic review of 41 studies found no difference in complications, readmissions or outcomes between outpatient and inpatient joint replacement, at roughly $6,800 lower cost (Bemelmans et al., 2022). A 66,971-patient analysis of hip replacement found complications of 3.0% outpatient versus 4.7% inpatient and readmissions of 1.4% versus 3.0%, which the authors rated low-certainty evidence because the healthiest patients are the ones selected for outpatient surgery (Bordoni et al., 2022).
Medicare removed total knee replacement from its inpatient-only list in 2018 and total hip replacement in 2020. Across 3.7 million registry cases, the average stay after joint replacement fell from 2.9 days in 2012 to 1.1 days in 2023 (AJRR 2024 Annual Report). The practical reasons patients give are simpler: you sleep in your own bed, you avoid a hospital floor, and the people who put the joint in are the people who see you the next week.
Who is a candidate
- Medically stable with a straightforward primary hip or knee replacement and a capable adult at home for the first nights. Age matters less than health status.
- Blood sugar under control. The 2023 AAOS guideline update advises a hemoglobin A1c below 6.5 before knee replacement (AAOS, 2023); we apply the same thinking to hips.
- Weight. The same guideline notes a BMI above 40 raises infection risk (AAOS, 2023). That usually moves surgery to a hospital and into a preparation conversation first, not out of reach.
- Better served in a hospital: significant heart or lung disease, untreated sleep apnea, kidney disease, bleeding disorders, long-term opioid use, no home support, or a complex or revision case. Being told "hospital for you" is the screening working. The longer version is on Is outpatient joint replacement safe?
What the day looks like
- Before
Pre-op visit and prehab
Medical clearance, labs, a CT scan for robotic planning, a meeting with the therapy team, and your home set up before you need it.
- Morning
Check in at 750 Fish Creek Thoroughfare
Pre-op nursing, a last conversation with your surgeon, and the anesthesia team reviewing your options with you.
- Surgery
Robotic-assisted hip or knee replacement
Your surgeon executes the CT-based plan with robotic assistance. The evidence is balanced: robotic knee replacement produces fewer alignment outliers with no meaningful difference in function or revision (Ruangsomboon et al., 2023); robotic hip replacement puts more cups in the target zone with no difference in patient scores and longer operating time (2025 meta-analysis).
- Recovery room
Up and walking
Pain control, then a therapist gets you standing and walking. Discharge criteria are specific: walking safely with a walker, stairs if you have them at home, pain controlled by mouth, eating and drinking, passing urine.
- Evening
Home
Written instructions, your prescriptions, a direct number, and a next-morning call from the team.
- Week 1 on
Therapy on the same campus
Clinic follow-up and physical therapy here at Woodforest, with aquatic therapy once the incision is sealed. Timelines are on our hip and knee recovery pages.
What it costs
Your plan sets your share, and we verify benefits and give you an estimate before anything is scheduled. As a national reference, labeled honestly: these are Medicare averages, facility only, with surgeon and anesthesia billed separately. In 2024 the Medicare allowed amount for an outpatient total hip replacement (CPT 27130) averaged $12,476, with Medicare paying $10,847; for an outpatient total knee replacement (CPT 27447) it was $12,381 allowed and $10,750 paid (CMS Medicare Outpatient Hospitals, 2024). For comparison, an inpatient hip or knee replacement without major complications (DRG 470) carried an average hospital charge of $93,184 and an average total payment of $17,364 (CMS Medicare Inpatient Hospitals, 2024). We're in-network with major plans, and the full conversation is on Cost & Insurance and Self-Pay Pricing.
The surgeons who operate here
Sterling Ridge is one of the leading joint replacement practices in the Houston area, and this center is where most of that work happens. Three surgeons operate at the center:
- Dr. Paul C. Chin, MD, PhD, FAAOS, FAANA — robotic knee replacement, partial knee, shoulder replacement, hip arthroscopy. First Texas surgeon to use the Medacta NextAR augmented-reality shoulder platform.
- Dr. N. Brian Flowers, MD, MPT, FAAOS — primary hip and knee replacement, anterior-approach hip. Fellowship at the Hospital for Special Surgery, Fellow of the American Association of Hip and Knee Surgeons, Mako certified, former physical therapist.
- Dr. Rohan A. Gheewala, MD — primary, complex and revision hip and knee replacement; second opinions. Adult reconstruction fellowship, Baylor College of Medicine.
Meet the surgeons
Board-certified, fellowship-trained, and in the office every week — read their story, then decide.
Paul C. Chin, MD, PhD, FAAOS, FAANA
Brian Flowers, MD, FAAOS
Rohan Gheewala, MDAddress, hours and how to reach us
Sterling Ridge / Woodforest Ambulatory Surgical Center
750 Fish Creek Thoroughfare, Montgomery, TX 77316
(936) 272-0790
Surgery days follow each surgeon's schedule and are set at your consult. Questions, scheduling and benefits checks go through any office, Monday–Friday, 8:00 AM–5:00 PM: The Woodlands (281) 364-1122, Spring (832) 698-0111, or Woodforest (936) 272-0790. Same-day injury visits are available at the clinics, and no referral is needed for a consult.
We serve the whole corridor — Conroe/Lake Conroe, Willis, and Magnolia — from the Woodforest campus, with the clinic, surgery center, physical therapy and pool on one campus.
Common questions
Where is the surgery center?
On the Woodforest campus at 750 Fish Creek Thoroughfare, Montgomery, TX 77316, the same address as our Woodforest clinic, physical therapy and aquatic therapy. Phone (936) 272-0790. It's minutes from Conroe, Lake Conroe, Willis and Magnolia.
Is it as safe as having my joint replaced in a hospital?
For properly selected patients, the AAHKS, Hip Society, Knee Society and AAOS position statement calls outpatient joint replacement safe and effective, and a review of 41 studies found no difference in complications, readmissions or outcomes compared with a hospital stay (Bemelmans et al., 2022). The center was built with Memorial Hermann, and a hospital transfer pathway exists for the rare case that needs it. Patients who don't meet the criteria have surgery in a hospital.
Which surgeons operate there?
Dr. Paul Chin, Dr. N. Brian Flowers and Dr. Rohan Gheewala perform knee and hip replacement at the Sterling Ridge / Woodforest Ambulatory Surgical Center. It is our main surgical home, but not the only one: our surgeons also hold privileges at several area hospitals, so when your insurance plan or your medical history calls for a hospital setting, surgery is scheduled there instead. Surgery days follow each surgeon's schedule; your date is set at the consult.
What does surgery at the center cost?
Your plan sets your share. As a national reference, the 2024 Medicare allowed amount for an outpatient total hip replacement (CPT 27130) averaged $12,476 and for a total knee (CPT 27447) $12,381, facility only, with surgeon and anesthesia billed separately (CMS, 2024). We verify your benefits and give you an estimate before anything is scheduled; see Cost & Insurance.
How do I ask a question or schedule?
Call any office Monday–Friday, 8:00 AM–5:00 PM: The Woodlands (281) 364-1122, Spring (832) 698-0111, or Woodforest (936) 272-0790. Consults happen at any of the three offices, no referral needed, and surgery is scheduled from there.
Sources
- AAHKS, Hip Society, Knee Society, AAOS. Position Statement on Outpatient Joint Replacement (2024 update).
- Bemelmans YFL et al. Safety and efficacy of outpatient hip and knee arthroplasty: systematic review of 41 studies. 2022.
- Bordoni V et al. Outpatient versus inpatient total hip arthroplasty: meta-analysis of 66,971 patients. 2022.
- AAHKS. Removal of TKA from the Medicare inpatient-only list (2018).
- CMS. CY 2020 OPPS/ASC final rule fact sheet (THA removed from inpatient-only list).
- American Joint Replacement Registry. 2024 Annual Report highlights.
- AAOS. Clinical practice guideline update, surgical management of knee osteoarthritis (2023).
- Ruangsomboon P et al. Robotic-assisted versus conventional TKA: meta-analysis of 12 RCTs. 2023.
- Robotic versus manual total hip arthroplasty: meta-analysis. 2025.
- CMS. Medicare Outpatient Hospitals by Geography and Service, 2024 (CPT 27130, 27447).
- CMS. Medicare Inpatient Hospitals by Geography and Service, 2024 (DRG 470).
Medically reviewed by Keith W.V. Johnson, MD, FAAOS · Updated October 20, 2026