Joint Instability after Total Knee Arthroplasty Volume 62- Issue 2

Takatomo Mine*, Kazuhiro Yamazaki, Michio Shinohara, Ryutaro Kuriyama, Tetsu Tsubone and Kouichiro Ihara

• Department of Orthopaedic Surgery, National Hospital Organization Kanmon Medical Center, Shimonoseki, Japan

Received: June 06, 2025; Published: June 13, 2025

*Corresponding author: Takatomo Mine, Department of Orthopaedic Surgery, National Hospital Organization Kanmon Medical Center, 1-1 Choufusotoura, Shimonoseki, Yamaguchi 752-8510 Japan

DOI: 10.26717/BJSTR.2025.62.009725

Abstract PDF

Background: Tibiofemoral instability is an increasing complication of prime total knee arthroplasty (TKA). It can arise from component loosening and breakage, polyethylene wear, ligamentous instability, or surgical error related to implant size or knee balancing. A 77-year-old woman underwent revision TKA for acquired instability after primary TKA. The instability was noted because of poor ligament balancing. The exchange of isolated polyethylene insert eliminated the instability, and the symptoms disappeared.
Conclusion: Treatment of tibiofemoral instability after TKA must be tailored to its specific cause.

Keywords: Total Knee Arthroplasty; Tibiofemoral Instability; Polyethylene Insert

Abbreviations: HSS: Hospital for Special Surgery; ROM: Range of Motion; TKA: Total Knee Arthroplasty; PS: Posterior Stabilizer; CS: Cruciate Substituting

Total knee arthroplasty (TKA) has achieved good clinical outcomes, but some cases still experience complications, requiring revision procedures. Infection, loosening, polyethylene wear, and instability are the common reasons for the revisions. Instability is one of the most common failures in primary TKA, accounting for 11-26% of failures [1-3]. Instability can arise from component loosening and component breakage, polyethylene wear, ligamentous instability, or surgical error in relation to implant size or knee balancing [4]. Wilson, et al. [5] reported that certain subgroups may develop a form of acquired instability after initially successful TKA [5]. We present a case of revision TKA for acquired instability after primary TKA.

A 77-year-old woman with osteoarthritis in her left knee underwent Zimmer Persona posterior stabilizer type TKA in another hospital about 3.5 years ago. Three years later, she experienced severe pain and a locking sensation in her left knee while shopping. A swelling and tenderness were observed in the left knee. A joint puncture was then performed. The aspirated fluid resembled blood. The bacterial culture was negative. Subsequently, severe pain and a locking sensation in the knee appeared occasionally. Therefore, she was referred to our department for surgery. Her history was unremarkable. A physical examination revealed swelling and slight local heat of the left knee. Anterior instability was not observed, but varus and valgus instability were eminent. The range of motion (ROM) was 0 to 123o. The knee-rating scale of the Hospital for Special Surgery (HSS) was 53. Radiographs showed that the tibiofemoral joint was not dislocated, and loosening of the implants was not found (Figures 1A & 1B). In the stress radiographs, varus and valgus instabilities (ext. 0o, flex. 30o) were noted (Figures 2A-2D).

Figure 1

Figure 2

A mid-parapatellar incision was made in surgery. In the intra-articular space, the synovial membrane was characterized by marked proliferation. There was an amount of hematoma, but no metallosis caused by contact between the tibial and femoral components. The polyethylene was withdrawn, but not damaged. Since the thickness of the initial posterior stabilizer (PS) type polyethylene was 10mm, a 14mm version was inserted. However, the instability remained, necessitating the cruciate substituting (CS) type 14mm polyethylene, and the instability disappeared (Figures 3A & 3B). The knee was not immobilized for postoperative care, ROM exercises were initiated using continuous passive motion. Partial weight bearing was allowed as soon as she could. The symptom disappeared postoperatively. Her postoperative HSS score was 97. The ROM was 0 to 120o.

Figure 3

Historically, common causes of failure in TKA have included infection, instability, stiffness, and osteolysis [1,4,6-9]. In the present case, the cause in this case was acquired instability after initially successful TKA. Instability can arise from component loosening and breakage, polyethylene wear, ligamentous instability, or surgical error related to implant size or knee balancing [4]. In this case, the loosening of component and polyethylene wear were not found. Ligamentous instability was the only cause. Wilson, et al. [5] reported that discussion amongst surgeons around clinical cases and presentation within the Arthroplasty Society of Australia suggested a growing awareness of instability as a mode of implant failure. It is assumed that this is due to ligamentous failure months and years after TKA [5]. The present case appears to confirm this phenomenon. Initially, in another hospital, it was thought this patient’s symptoms were of unknown cause. Wilson, et al. [5] pointed out that clinical history is the most important diagnostic factor. Patients with symptomatic instability, particularly in flexion, report a typical series of symptoms, including a feeling of insecurity in the knee without complete giving way, difficulty with stairs, recurrent knee swelling, and anterior knee pain [5]. Revising an unstable replacement joint can involve changing the polyethylene insert of posterior stabilizer or using semi-constrained type, such as that described above. Changing the 10 mm polyethylene insert to a thicker, 14mm version did not remove the instability.

Zimmer Persona’s total knee system has a cruciate retaining type, PS type, CS type and bicruciate retaining type. Therefore, when a 14 mm cruciate substituting type polyethylene was inserted, the instability disappeared. Can, et al. [10] reported that the management of tibiofemoral instability depends on the underlying cause. The pattern of instability must be determined because treatment should be tailored to its specific cause. Increasing constraints during revision TKA is essential [10]. Fortunately, in this case, isolated polyethylene insert exchange eliminated the instability and the symptoms disappeared. However, isolated polyethylene insert exchange is considered suitable only for selected case.

We performed revision TKA for acquired instability after primary TKA. Based on the characteristics of the implant model used, isolated polyethylene insert exchange was conducted. In some cases, revision of all components may be necessary instead of partial component revision.

Funding

This research was supported by the commissioned research expenses to Kanmon Medical Center (Shimonoseki, Japan) from Kyocera Japan and Japan Medical Dynamic Marketing ING.

Availability of Data and Material

Not applicable.

Consent for Publication

We have obtained consent to publish from the participants.

Competing Interests

The authors declare that they have no competing interests.

Ethics Approval and Consent to Participate

Not applicable.

Human and Animal Rights

Not applicable.

Standards of Reporting

CARE guidelines have been used for conducting this research.

Conflict of Interest

Authors declare no conflict of interest, financial or otherwise.

Acknowledgements

Declared none.

1. Sharkey RF, Lichstein PM, Shen C, Tokarski AT, Parvizi J (2014) Why Are Total Knee Arthroplasties Failing Today-Has Anything Changed After 10 Years? J Arthroplasty 29(9): 1774-1778.
2. Dalury DF, Pomeroy DL, Gorab RS, Adams MJ (2013) Why are Total Knee Arthroplasties Being Revised? J Arthroplasty 28(8): 120-121.
3. Le DH, Goodman SB, Maloney WJ, Huddleston JI (2014) Current modes of failure in TAK: Infection, instability, and stiffness predominate. Clin Orthop Relat Resa 472(7): 2197-2200.
4. Vince KG, Abdeen DJ, Sginori T (2006) The unstable total knee arthroplasty: Causes and cures. J Arthroplasty 21: 44-49.
5. Wilson CJ, Theodoulou A, Damarell RA, Krishman J (2017) Knee instability as the primary cause of failure following Total Knee Arthroplasty (TKA): A systematic review on the patient, surgical and implant characteristic of revised TKA patients. The Knee 24: 1271-1281.
6. Bozic KJ, Kurtz SM, Lau E, Ong K, Chiu V, et al. (2010) The epidemiology of revision total knee arthroplasty in the United States. Clin Orthop Relat Res 468: 45-51.
7. Callaghan JJ, O’Rourke MR, Saleh KJ (2004) Why knees fail: Lessons learned. J Arthroplasty 19: 31-33.
8. Fehring TK, Odum S, Griffin WL, Mason J, Nadaud M (2001) Early failures in total knee arthroplasty. Clin Orthop Relat Res 392: 315-318.
9. Gioe TJ, Killeen KK, Grimm K, Mehle S, Scheltema K (2004) Why are total knee replacements revised? Analysis of early revision in a community knee implant registry. Clin Orthop Relat Res 392: 100-106.
10. Can A, Erdogan F, Erdogan AO (2017) Tibiofemoral Instability After Primary Total Knee Arthroplasty: Posterior-Stabilized Implant for Obese Patients. Orthopedic 40(5): e812-819.