EXHIBIT 21.1

|                                                         |  | STATE OF
INCORPORATION/ORGANIZATION
|-------------------------------------------------------- |  | -----------------------------------
|Amedicorp, Inc.                                          |  | Delaware                           
|Arlington Surgicare Partners,
Ltd.                       |  | Texas                              
|Aspen Healthcare Holdings
Limited                        |  | UK                                 
|Aspen Healthcare Limited                                 |  | UK                                 
|Austintown Sugery Center, LLC                            |  | Ohio                               
|Bagley Holdings, LLC                                     |  | Ohio                               
|Baptist Surgery Center, L.P.                             |  | Tennessee                          
|Baptist Plaza Surgicare, L.P.                            |  | Tennessee                          
|Central Virginia Surgi-Center,
L.P.                      |  | Virginia                           
|Centro de Patologia Celular y
Diagnostico Prenatal, S.A. |  | Spain                              
|Clinica Maternal Nuestra
Senora de la Esperanza, S.A.    |  | Spain                              
|Clinica Sagrado Corazon S.L.                             |  | Spain                              
|Coast Surgery Center, L.P.                               |  | California                         
|Corpus Christi Holdings, LLC                             |  | Nevada                             
|Corpus Christi Surgicare, L.P.                           |  | Texas                              
|Creekwood Surgery Center, L.P.                           |  | Missouri                           
|                                                         |  |                                    

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|Dallas Surgical Partners, L.L.P.          |  | Texas     
|----------------------------------------- |  | ----------
|Day-Op Management Company,
Inc.           |  | New York  
|Day-Op Surgery Consulting
Company, LLC    |  | Delaware  
|Decatur Surgery Center, L.P.              |  | Delaware  
|Densitometria Oseo
Computorizada, S.L.    |  | Spain     
|Denton Surgicare Partners, Ltd.           |  | Texas     
|Desoto Surgicare Partners, Ltd.           |  | Texas     
|Destin Surgery Center, Ltd.               |  | Florida   
|Diagnosticos y Tratamientos
Medicos, S.A. |  | Spain     
|Doctors Outpatient
SurgiCenter, Ltd.      |  | Texas     
|East Brunswick Surgery
Center, LLC        |  | New Jersey
|East-West Surgery Center, L.P.            |  | Georgia   
|Estudios Functionales, S.A.               |  | Spain     
|Ft. Worth Surgicare Partners              |  | Texas     
|Frisco Medical Center, L.L.P.             |  | Texas     
|Garland Surgicare Partners, Ltd.          |  | Texas     
|Georgia Musculoskeletal
Network, Inc.     |  | Georgia   
|                                          |  |           

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|Global Healthcare Partners, Ltd.                 |  | UK        
|------------------------------------------------ |  | ----------
|Grapevine Surgicare Partners, Ltd.               |  | Texas     
|Health Horizons of Decatur, Inc.                 |  | Tennessee 
|Health Horizons of Kansas
City, Inc.             |  | Tennessee 
|Health Horizons of
Murfreesboro, Inc.            |  | Tennessee 
|Health Horizons of Nashville, Inc.               |  | Tennessee 
|Hospitalizacion y Servicios, S.A.                |  | Spain     
|Imagenes Diagnosticas, S.A.                      |  | Spain     
|Instituto Policlinico Santa
Teresa, S.A.         |  | Spain     
|Irving-Coppell Surgical Hospital, L.L.P.         |  | Texas     
|KSF Orthopaedic Surgery Center, L.L.P.           |  | Texas     
|Las Cruces Surgery Center, LLC                   |  | New Mexico
|Lawrenceville Surgery Center, L.L.C.             |  | Georgia   
|MCSH Real Estate Investors, Ltd.                 |  | Texas     
|MedCenter Management Services, Inc.              |  | Delaware  
|Memorial Hermann/USP Surgery Center, L.L.P.      |  | Texas     
|Metroplex Surgicare Partners, Ltd.               |  | Texas     
|Middle Tennessee Ambulatory
Surgery Center, L.P. |  | Delaware  
|Mountain Empire Surgery
Center, L.P.             |  | Georgia   
|                                                 |  |           

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|Neurosurgical Associates, Inc.                       |  | New Mexico
|---------------------------------------------------- |  | ----------
|New Mexico Orthopaedic Surgery
Center, L.P.          |  | Georgia   
|Northside-Cherokee/USP Surgery
Centers, LLC          |  | Georgia   
|Northside/USP Surgery Centers, LLC                   |  | Georgia   
|Northwest Georgia Orthopaedic
Surgery Center, L.L.C. |  | Georgia   
|NYCAS Administrative Services, LLC                   |  | Delaware  
|Ortho Excel, Inc.                                    |  | Delaware  
|OrthoLink ASC Corporation                            |  | Tennessee 
|OrthoLink/Baptist ASC, LLC                           |  | Tennessee 
|OrthoLink of Colorado, Inc.                          |  | Colorado  
|OrthoLink/Georgia ASC, Inc.                          |  | Georgia   
|OrthoLink/Murfreesboro ASC, LLC                      |  | Tennessee 
|OrthoLink/New Mexico ASC, Inc.                       |  | Georgia   
|OrthoLink Physicians
Corporation                     |  | Delaware  
|OrthoLink Radiology
Services Corporation             |  | Tennessee 
|OrthoLink/TN ASC, Inc.                               |  | Tennessee 
|OrthoLink/TOC, LLC                                   |  | Tennessee 
|OrthoLink/WY ASC, Inc.                               |  | Wyoming   
|Orthopedic and Surgical
Specialty Company, LLC       |  | Arizona   
|Orthopedic South Surgical
Partners, LLC              |  | Georgia   
|Paracelsus England Limited                           |  | UK        
|                                                     |  |           

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|Parkway Surgery Center, LLC                     |  | Nevada    
|----------------------------------------------- |  | ----------
|Parkwest Surgery Center, L.P.                   |  | Tennessee 
|Pasadena Holdings, LLC                          |  | Nevada    
|Physicians Data Professional, Inc.              |  | Texas     
|Physicians Pavilion, L.P.                       |  | Delaware  
|Physicians Surgery Center of Longview, LLC      |  | Texas     
|Radsource LLC                                   |  | Delaware  
|Resonancia Nuclear Magnetica
Santa Teresa, S.L. |  | Spain     
|Resurgens Surgery Center, LLC                   |  | Georgia   
|Roswell Surgery Center, LLC                     |  | Georgia   
|Saint Thomas Campus Surgicare, L.P.             |  | Tennessee 
|Saint Thomas Hendersonville
Surgicare, L.P.     |  | Tennessee 
|Saint Thomas/USP Surgery
Centers, L.L.C.        |  | Tennessee 
|San Gabriel Valley Surgical
Center, L.P.        |  | California
|Sarasota Surgicare, Ltd.                        |  | Florida   
|Shrewsbury Surgery Center, LLC                  |  | New Jersey
|Southwest Spine Center, Inc.                    |  | New Mexico
|Specialists Surgery Center, LLC                 |  | Oklahoma  
|Sugar Land Surgical Hospital,
LLP               |  | Texas     
|Surgery Center of Georgia, LLC                  |  | Georgia   
|Surgicoe of Texas, Inc.                         |  | Texas     
|Surgicoe Real Estate, LLC                       |  | Georgia   
|Surgicoe Corporation                            |  | Georgia   
|Tennessee Musculoskeletal,
Network, Inc.        |  | Tennessee 
|Teton Outpatient Services, LLC                  |  | Wyoming   
|Texas Health Venture
Arlington, L.P.            |  | Texas     
|Texas Health Venture Bellaire, L.P.             |  | Texas     
|Texas Health Venture Denton L.P.                |  | Texas     
|Texas Health Venture DSP L.P.                   |  | Texas     
|Texas Health Venture Fort
Worth, L.L.C.         |  | Texas     
|                                                |  |           

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|Texas Health Venture Frisco, L.P.                  |  | Texas     
|-------------------------------------------------- |  | ----------
|Texas Health Venture Garland L.P.                  |  | Texas     
|Texas Health Venture
Grapevine, L.L.C.             |  | Texas     
|Texas Health Ventures Group, L.L.C.                |  | Texas     
|Texas Health Ventures Group Holdings, LLC          |  | Nevada    
|Texas Health Venture Irving-
Coppell, L.P.         |  | Texas     
|Texas Outpatient Surgicare
Center, Inc.            |  | Texas     
|Texas Spine and Joint Hospital, LLP                |  | Texas     
|The Center for Ambulatory
Surgical Treatment, L.P. |  | California
|The Surgery Center,
an Ohio limited partnership    |  | Ohio      
|The Surgery Center Laboratory, Inc.                |  | Ohio      
|The Surgery Center Radiology, Inc.                 |  | Ohio      
|THVG Arlington GP, LLC                             |  | Delaware  
|THVG Bedford GP, LLC                               |  | Delaware  
|THVG Bedford, L.P.                                 |  | Texas     
|THVG Bellaire GP, LLC                              |  | Delaware  
|THVG Denton GP, LLC                                |  | Delaware  
|THVG DeSoto GP, LLC                                |  | Delaware  
|THVG DeSoto, L.P.                                  |  | Texas     
|THVG DSP GP, LLC                                   |  | Delaware  
|THVG Fort Worth GP, LLC                            |  | Delaware  
|THVG Fort Worth, L.L.P.                            |  | Texas     
|THVG Frisco GP, LLC                                |  | Delaware  
|THVG Garland GP, LLC                               |  | Delaware  
|THVG Grapevine GP, LLC                             |  | Delaware  
|THVG/HealthFirst Holdings, LLC                     |  | Nevada    
|THVG/HealthFirst L.L.C.                            |  | Texas     
|THVG Irving-Coppell GP, LLC                        |  | Delaware  
|THVG Valley View GP, LLC                           |  | Delaware  
|THVG Valley View L.L.P.                            |  | Delaware  
|Toms River Surgery Center, L.L.C.                  |  | New Jersey
|TOPS Specialty Hospital, Ltd.                      |  | Texas     
|                                                   |  |           

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|TSH Holdings, LLP                              |  | Texas     
|---------------------------------------------- |  | ----------
|Unidad de Recuperacion del
Suelo Pelvico, S.L. |  | Spain     
|United Surgery
Center-Southeast Ltd.           |  | Texas     
|United Surgical of Atlanta, Inc.               |  | Georgia   
|United Surgical Partners Barcelona, S.L.       |  | Spain     
|United Surgical Partners
Europe, S.L.          |  | Spain     
|United Surgical of Torrance, Inc.              |  | California
|United Surgical Partners GP, Inc.              |  | Delaware  
|United Surgical Partners Holdings, Inc.        |  | Delaware  
|United Surgical Partners
Madrid S.L.           |  | Spain     
|United Surgical Partners
Malaga S.L.           |  | Spain     
|University Surgery Center, Ltd.                |  | Florida   
|USP Austintown, Inc.                           |  | Ohio      
|USP Baton Rouge, Inc.                          |  | Louisiana 
|USP Bellaire, Inc.                             |  | Texas     
|USP Central New Jersey, Inc.                   |  | New Jersey
|USP Chandler, Inc.                             |  | Arizona   
|USP Cleveland, Inc.                            |  | Ohio      
|USP Coast, Inc.                                |  | California
|USP Corpus Christi, Inc.                       |  | Texas     
|USP Cottonwood, Inc.                           |  | Arizona   
|USP Dermoestetica S.L.                         |  | Spain     
|USP Destin, Inc.                               |  | Florida   
|USP Domestic Holdings, Inc.                    |  | Delaware  
|USP Fredericksburg, Inc.                       |  | Virginia  
|USP Hospital San Carlos Murcia, S.L.           |  | Spain     
|USP Houston, Inc.                              |  | Texas     
|USP Instituto Dexeus, S.A.                     |  | Spain     
|USP International Holdings, Inc.               |  | Delaware  
|USP Las Cruces, Inc.                           |  | New Mexico
|USP Long Island, Inc.                          |  | Delaware  
|USP Lyndhurst, Inc.                            |  | Ohio      
|                                               |  |           

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|USP Manhattan, Inc.                  |  | New York  
|------------------------------------ |  | ----------
|USP Nevada Holdings, LLC             |  | Nevada    
|USP Nevada, Inc.                     |  | Nevada    
|USP New Jersey, Inc.                 |  | New Jersey
|USP North Texas, Inc.                |  | Delaware  
|USP Oklahoma, Inc.                   |  | Oklahoma  
|USP Pasadena, Inc.                   |  | Texas     
|USP Sarasota, Inc.                   |  | Florida   
|USP Securities Corporation           |  | Tennessee 
|USP South Houston, Inc.              |  | Texas     
|USP Tennessee, Inc.                  |  | Tennessee 
|USP Texas, L.P.                      |  | Texas     
|USP Texas Air, LLC                   |  | Texas     
|USP West Covina, Inc.                |  | California
|USP Westwood, Inc.                   |  | California
|USP Winter Park, Inc.                |  | Florida   
|USPE Holdings Limited                |  | UK        
|Valley View Surgicare
Partners, Ltd. |  | Texas     
|Warner Park Surgery Center, L.P.     |  | Arizona   
|Zeeba Surgery Center, L.P.           |  | Ohio      

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