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Ann R Coll Surg Engl. 2009 September; 91(6): 520–521.
PMCID: PMC2966214
Technical Notes and Tips
Bruce Campbell, Section Editor

Use of a Dental Tool to Remove Excess Cement in Unicompartmental Knee Arthroplasty


Excess retained cement following unicompartmental knee arthroplasty (UKA) is a well-recognised complication. It may result in pain,1,2 impingement,1,3 loose body symptoms,2 vascular problems3 and damage to the prosthesis or structures within the lateral compartment.4 Symptomatic patients require additional surgery to manage such complications.15 We describe the use of a tool normally used in dental surgery in order to avoid these problems.


The senior author (NWB) uses a ‘flat plastic’ dental instrument. The tool has blunt ends aligned at 90° to each other (Fig. 1) which are perfectly angled to allow the rapid removal of excess cement from the femoral component and the posterior aspect of the tibial tray during prosthesis insertion (Fig. 2). It can be manoeuvred easily to break off excess bits of cement and also to retrieve them by sweeping around the prosthesis from back to side. It is also used to assess alignment of the tibial tray medially and posteriorly to feel for over or under hang.

Figure 1
The tool has ends angled at 90° to each other and can be manoeuvred under the femoral prosthesis to the posterior aspect of the knee easily.
Figure 2
Excess cement being removed from the posteromedial aspect of the tibia during cementation of a medial unicompartmental knee arthroplasty.


The removal of cement becomes technically difficult because there is limited surgical exposure. Consequently, the incidence of retained excess cement can be high. In a study of 120 UKAs, 25 postoperative radiographs showed loose or attached excess cement.1 The ‘flat plastic’ dental tool helps to avoid retained excess cement and its associated complications in UKA, and is applicable in other minimally invasive arthroplasty procedures.


1. Hauptmann SM, Weber P, Glaser C, Birkenmaier C, Jansson V, Muller PE. Free bone cement fragments after minimally invasive unicompartmental knee arthroplasty: an underappreciated problem. 2008;16:770–5. [PubMed]
2. Howe JR, Taunton D, Jr, Engh GA. Retained cement after unicondylar knee arthroplasty. 2004;86:2283–6. [PubMed]
3. Auyeung J, Doorgakant A, Shand JEG, Orr MM. An unusual case of locking after total knee replacement. 2007;89:1249–51. [PubMed]
4. Jung KA, Lee SC, Song MB. Lateral meniscus and lateral femoral condyle cartilage injury by retained cement after medial unicondylar knee arthroplasty. 2008;23:1086–9. [PubMed]
5. Kim WY, Shafi M, Kim YY, Kim JY, Cho YK, Han CW. Posteromedial compartment cement extrusion after unicompartmental knee arthroplasty treated by arthroscopy: a case report. 2006;14:46–9. [PubMed]

Articles from Annals of The Royal College of Surgeons of England are provided here courtesy of The Royal College of Surgeons of England