## 10 Variations in Thermal Properties Among Different PMMA Bone Cements  
Discrepancies exist in the reported temperatures and necrosis thresholds during the application of PMMA bone cement from variations in the methodology of studies conducted, different cement formulations, and mixing and application techniques.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Study/Trial** & \multicolumn{2}{c}{**Key Focus**} & \multicolumn{2}{c}{**Findings**} & \multicolumn{2}{c}{**Clinical Implications**} \\ \hline \multirow{3}{*}{[PERSON] and [PERSON] [21]} & \multirow{3}{*}{-} & Computational models of temperature distribution & - & Peak temperatures above 70 \({}^{\circ}\)C at thick mantles & - & Emphasized optimal mantle thickness to reduce necrosis risk \\  & & & & & \\  & & & & & \\ \hline \multirow{3}{*}{[PERSON] et al. [22]} & \multirow{3}{*}{-} & Effects of cement handling on temperature & - & Pre-cooling components & - & Recommended pre-cooling techniques for improved necrosis \\  & & & & & \\  & & & & & \\ \hline \multirow{3}{*}{[PERSON] et al. [23]} & \multirow{3}{*}{-} & Use of phase-change materials (PCMs) & - & PMMA with PCMs reduced peak temperatures by 20-30\% compared to standard formulations & - & Suggested PCMs for safer cement applications, especially in vulnerable patients \\  & & & & & \\ \hline \multirow{3}{*}{[PERSON] et al. [25]} & \multirow{3}{*}{-} & Thermal properties of different PMMA brands & - & Brands showed significant variation in thermal properties; some exceeded necrosis thresholds & - & Advocated for careful selection of PMMA based on thermal properties \\  & & & & \\ \hline \multirow{3}{*}{[PERSON] et al. [48]} & \multirow{3}{*}{-} & Cooling effects on femoral prosthesis cementing & - & Pre-cooled prosthesis and cement reduced peak polymerization & - & Highlighted pre-cooling as an effective and simple intraoperative strategy \\  & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 6: Clinical case studies and trial comparisons.  
Some studies state that certain PMMA bone cements exceed the 56 \({}^{\circ}\)C threshold, which is associated with immediate thermal necrosis in the bone tissue [50]. Other studies report peak temperatures ranging from 44 \({}^{\circ}\)C to 113 \({}^{\circ}\)C, with a varied period in which the cement mantle maintains a temperature above 50 \({}^{\circ}\)C, posing a risk for thermal necrosis [82]. Preparation and application techniques also play a role in affecting the thermal profile of the cement used [24; 83].  
There needs to be a consensus on the safe application of PMMA bone cement to minimize the risk of thermal necrosis while also ensuring a proper fixation of the implant. Standardizing the preparation and application technique could help mitigate the risk of thermal necrosis by mitigating the peak temperatures of the polymerization reaction while also ensuring that the cement keeps its mechanical properties. For this consensus to be achieved, several factors, such as the amount of cement used, the method of mixing, and the initial temperature of the components, need to be taken into consideration [22; 69; 84].  
The peak temperature values during polymerization of PMMA bone cement may vary depending on whether or not the bone cement has an antibiotic in its composition (Figure 5).  
[PERSON] et al. have observed that the addition of antibiotics such as vancomycin and ceftazidime to PMMA does not significantly alter the peak temperature during curing, although the specific temperature differences for antibiotic-loaded bone cement compared to bone cement without antibiotics were not observed. They focused on the impact of these temperatures on the antimicrobial activity of the antibiotics after heat exposure [85].