Heat-Related Complications from Radiofrequency and Electrocautery Devices Used in Arthroscopic Surgery: A Systematic Review

Thermal Damage in Orthopaedics

There are numerous potential sources of thermal damage encountered in orthopaedic surgery. An understanding of the preclinical mechanisms of thermal damage in tissues is necessary to minimize iatrogenic injuries and use these mechanisms therapeutically. Heat generation is a phenomenon that can be used to a surgeon's benefit, most commonly for hemostasis and local control of tumors. It is simultaneously one of the most dangerous by-products of orthopaedic techniques as a result of burring, drilling, cementation, and electrocautery and can severely damage tissues if used improperly. Similarly, cooling can be used to a surgeon's advantage in some orthopaedic subspecialties, but the potential for harm to tissues is also great. Understanding the potential of a given technique to rapidly alter local temperature-and the range of temperatures tolerated by a given tissue-is imperative to harness the power of heat and cold. In all subspecialties of orthopaedic surgery, thermal damage is a relevant topic that represents a direct connection between preclinical and clinical practice.

Intravenous Tranexamic Acid Significantly Improved Visualization and Shortened the Operation Time in Arthroscopic Rotator Cuff Repair: A Systematic Review and Meta-analysis of Level I and II Studies

PURPOSE

To further clarify the role of tranexamic acid (TXA) in arthroscopic rotator cuff repair (ARCR), especially visual field clarity and operation time.

METHODS

We searched the PubMed, Cochrane Library, and Embase databases to find prospective randomized controlled clinical trials (RCTs) examining the use of TXA in ARCR. All included RCTs were evaluated for methodological quality using the Cochrane Collaboration's risk of bias tool. We used Review Manager 5.3 for meta-analysis and calculated the weighted mean difference (WMD) and 95% confidence interval (CI) of the related outcome indicators. The GRADE system was used to evaluate the strength of the clinical evidence provided by the included studies.

RESULTS

Six RCTs (3 Level I, 3 Level II) from four countries or regions were included in this study: 2 studies used intra-articular (IA) TXA, and 4 studies used intravenous TXA. A total of 451 patients underwent ARCR, including 227 patients in the TXA group and 224 patients in the non-TXA group. In 2 RCTs evaluating good visualization, intravenous TXA achieved a better surgical field of view in ARCR compared to the control group (P =.036; P = .045). Meta-analysis showed that compared with non-TXA, intravenous TXA shortened the operation time (WMD = -12.87 min, 95% CI: -18.81 to -6.93). These two RCTs did not reveal a statistically significant difference in the impact of intravenous TXA and non-TXA on mean arterial pressure (MAP) (P = .306; P = .549). Compared with epinephrine (EPN), IA TXA had no significant effects on improving the visual field clarity under arthroscopy, shortening the operation time or reducing the total amount of irrigation fluid (P > .05). Compared with saline irrigation, IA TXA improved the surgical field of vision and shortened the operation time (P < .001). No adverse events were reported for either intravenous TXA or IA TXA.

CONCLUSIONS

Intravenous TXA can shorten the operation time of ARCR, and the conclusions of existing RCTs suggest that intravenous TXA can improve visual field clarity during ARCR, thus supporting the application of intravenous TXA in ARCR. Compared with EPN, IA TXA was not better at improving the visual field clarity under arthroscopy and shortening the operation time, but it was better than saline irrigation.

LEVEL OF EVIDENCE

Level II, systematic review and meta-analysis of Level I and II studies.

Infra-patellar fat pad-derived mesenchymal stem cells maintain their chondrogenic differentiation potential after arthroscopic harvest with blood-product supplementation

PURPOSE

Mesenchymal stem cells/medicinal signaling cells (MSCs) possess therapeutic potential and are used in regenerative orthopaedics. The infra-patellar fat pad (IFP) is partially resected during knee arthroscopy (KASC) and contains MSCs. Heat, irrigation, and mechanical stress during KASC may decrease MSC's therapeutic potential. This study assessed MSCs' regenerative potential after arthroscopic IFP harvest and potential effects of two blood products (BP) (platelet-rich plasma (PRP), hyperacute serum (HAS)) on MSCs' viability and chondrogenic differentiation capacity.

METHODS

IFP was arthroscopically harvested, isolated, and counted (n = 5). Flow cytometry was used to assess cell viability via staining with annexin V/7-AAD and stemness markers via staining for CD90, CD73, and CD105. MSCs were incubated with blood products, and metabolic activity was determined via an XTT assay. Deposition of cartilage extracellular matrix was determined in histologic sections of chondrogenically differentiated 3D pellet cultures via staining with Alcian Blue. Expression of cartilage-specific genes (SOX9, MMP3/13, ACAN, COL1/2) was analyzed via quantitative PCR.

RESULTS

MSC isolation from IFP yielded 2.66*106 ± 1.49*106 viable cells from 2.7 (0.748) g of tissue. MSC markers (CD 90/105/73) were successfully detected and annexin V staining showed 81.5% viable cells. XTT showed increased metabolic activity. Within the BP groups, this increase was significant (days 0-14, p < 0.05). PCR showed expression of cartilage-specific genes in each group. COL2 (p < 0.01) as well as ACAN (p < 0.001) expression levels were significantly higher in the HAS group. Histology showed successful differentiation.

CONCLUSION

Arthroscopic harvest of IFP-MSCs yields sufficient cells with maintained regenerative potential and viability. Blood products further enhance MSCs' viability.

Temperature change of epidural space by radiofrequency use in biportal endoscopic lumbar surgery: safety evaluation of radiofrequency

PURPOSE

Articles evaluating radiofrequency (RF) safety are insufficient. Thus, the purpose of this study was to investigate RF safety during biportal endoscopic lumbar decompressive laminotomy by measuring epidural temperature after RF use.

METHODS

Both in vitro cadaveric study and in vivo study were performed. The epidural temperature was measured at epidural space after RF use in three cadavers. The epidural temperature was measured and analysed according to RF mode, RF power, RF usage time, and saline irrigation patency. In the in vivo study, the epidural temperature was measured after biportal endoscopic surgery. Epidural temperatures were measured around ipsilateral and contralateral traversing nerve roots after 1-s use of RF.

RESULTS

In the in vivo study, epidural space temperature was increased by 0.31 ± 0.16 °C ipsilaterally and 0.29 ± 0.09° contralaterally after RF use in coagulation mode 1. The epidural temperature of epidural space was increased by 0.21 ± 0.13 °C ipsilaterally and 0.15 ± 0.21 °C contralaterally after RF use in high mode 2. In the in vitro study, epidural temperature was significantly increased with a long duration of RF use and a poor patency of irrigation fluid.

CONCLUSION

The use of RF in biportal endoscopic spine surgery might be safe. In order to reduce indirect thermal injuries caused by RF use, it might be necessary to reduce RF use time and maintain continuous saline irrigation patency well.

Effect of Thermal Ablation on Growth Plates: A Study to Explore the Thermal Threshold of Rabbit Growth Plates During Microwave Ablation

PURPOSE

To explore the temperature threshold of thermal damage to growth plates.

METHODS

Nine rabbits were divided into three groups for femoral ablation, exposing the growth plate to different temperatures (T1 = 43-45 °C; T2 = 46-48 °C; T3 = 49-51 °C). After 5 weeks, the changes in the femurs were assessed by macroscopic images, micro-CT, haematoxylin and eosin staining, and immunohistochemistry of Col2a1 (type II collagen). At the cellular level, rabbit epiphyseal chondrocytes were exposed to 37 °C, 44 °C, 47 °C and 50 °C for 5 min. Then, proliferation and chondrogenic differentiation were detected.

RESULTS

The rabbits in the T2 and T3 groups developed length discrepancies and axial deviations of femurs, abnormal newly formed bone in the marrow cavity, disorganized growth plates and decreased Col2a1 expression. At the cellular level, the cells exposed to 47 °C and 50 °C for 5 min showed decreased viability, increased apoptosis, decreased extracellular matrix synthesis and decreased matrix mineralization. However, the changes in rabbits in the T1 group and cells at 44 °C did not show a significant difference.

CONCLUSION

The ablation of growth plates at temperatures above 45 °C for 5 min results in decreased chondrocyte viability and disorganized growth plates, leading to growth disturbances. Further studies are warranted to confirm these promising initial results.