MAUDE Adverse Event Report: UNITED ORTHOPEDIC CORPORATION USTAR II KNEE SYSTEM; KRO

Model Number	2115-3310
Medical Device Problem Code	Unintended Movement (3026)
Health Effect - Clinical Code	Hyperextension (4523)
Date of Event	10/22/2025
Type of Reportable Event	Serious Injury
Additional Manufacturer Narrative
Unknow at the time of this report.
Event or Problem Description
On (b)(6) 2024, a female patient ((b)(6)) underwent a total knee arthroplasty utilizing the ustar ii knee system.The primary procedure involved implantation of the following components: · ustar ii knee system distal femoral component, rhs, size s, left (pn: 2115-3310, lot: 22c065b).· ustar ii knee system tibial baseplate, hinged (pn: 2215-1430, lot: 23f304d) · ustar ii knee system segment part, rhs 120mm length (pn: 2915-1120, lot: 17k11713) · ustar ii knee system tibial stem 14 x 120mm (pn: 2715-7514, lot: 22g669gz) · ustar ii knee system cemented straight stem, rha non-coated 15 x 125mm (pn: 2715-3115, lot: 20e327f).· ustar ii knee system xpe tibial insert (pn: 23315-3213, lot: 23j382b).The implantation was performed according to the manufacturer's surgical technique guidelines.The surgery was completed without intraoperative complications, and the patient's initial post-operative recovery was normal.The patient was subsequently discharged following standard post-surgical evaluation.Approximately one year post-operatively, during clinical follow-up, the patient presented with excessive knee hyperextension which exceeds the manufacturer's specified range.Radiographic imaging confirmed the presence of the hyperextension anomaly.X-rays images were requested for further analysis.On october 22, 2025, the same operating surgeon performed a revision surgery using the same ustar ii knee system.During the revision procedure, the cemented straight stem implant did not require replacement, however the following implants have been replaced to facilitate the revision surgery: · ustar ii knee system distal femoral component, rhs, size s, left (pn: 2115-3310, lot: 25e746a).· ustar ii knee system xpe tibial insert s, 14mm (2315-3212, lot 24lc71a).· ustar ii knee system segment part, rhs 120 mm length (2915-1120, lot 25a072ae).· ustar ii knee system segment part, rhs 25 mm length (2915-1025, lot 17h408s).The explanted components were collected and returned to the uoc usa inc warehouse.The implant will be sent to manufacturer for investigation aiming to evaluate potential contributing factors, including but not limited to manufacturing defects, design parameters, surgical technique, and patient-specific anatomical or biomechanical considerations associated with the excessive hyperextension observed.

• Brand Name: USTAR II KNEE SYSTEM
• Common Device Name: KRO
• Manufacturer (Section D): UNITED ORTHOPEDIC CORPORATION; no 57, park ave.2,; scinece park; hsinchu city, 30075 ; TW 30075
• MDR Report Key: 23625041
• Report Number: 3009760038-2025-00002
• Device Sequence Number: 18386865
• Product Code: KRO
• UDI-Device Identifier: 04719872179436
• UDI-Public: (01)04719872179436(17)270315(10)22C065B
• Combination Product (Y/N): N
• Initial Reporter State: FL
• Initial Reporter Country: US
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2024
• Device Explanted Year: 2025
• Serviced by Third Party (Y/N): N
• Reporter Type: Importer
• Initial Reporter Occupation: Non-Healthcare Professional
• Type of Report: Initial
• Report Date (Section B): 11/20/2025
• Report Date (Section F): 11/21/2025

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Model Number: 2115-3310
• Device Catalogue Number: N/A
• Device Lot Number: 22C065B
• Was Device Available for Evaluation?: Yes
• Was the Report Sent to FDA?: Yes
• Distributor Facility Aware Date: 10/25/2025
• Event Location: Hospital
• Date Report to Manufacturer: 11/19/2025
• Initial Date Received by Manufacturer: Not provided
• Initial Report FDA Received Date: 11/22/2025
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Required Intervention
• Patient Age: 59 YR
• Patient Sex: Female
• Date Report Sent to FDA: 11/21/2025