Geniculate Artery Injury During Primary Total Knee Arthroplasty

ANALYSIS OF GENICULATE ARTERY INJURY

The senior authors critically evaluated the GA during the primary TKAs and documented the presence or absence of injury in the operative reports. GA injury was reported if there was intraoperative visualization of pulsatile bleeding or visualization of arterial lumen in the anatomic areas of the middle and lateral inferior GAs. At 3 separate occasions during the operation, the surgeon looked specifically for pulsatile bleeding or arterial lumen in the areas of the middle and lateral inferior GAs, including after all the femoral and tibial bone cuts were completed, immediately before preparing to cement (before the tourniquet was inflated if there was not one inflated from the start of the procedure), and immediately after the tourniquet was deflated (Figure 1). All bleeding GAs that were visualized were effectively coagulated by cautery. Details regarding the use of TXA (topical or IV), intraoperative blood loss, postsurgical drain output for 24 hours after surgery, and blood transfusion were collected from the patients’ medical records (Table 1).

Operative variables other than geniculate artery injury. Data presented as mean (range) or n (%). TXA = tranexamic acid.

STATISTICAL METHODS

Statistical analysis was performed using the JMP software version 10.0.0 (SAS Institute, Inc). The overall rate of GA injury was determined, including the rates of GA injury based on location, time point, and method of diagnosis (pulsatile bleeding or arterial lumen visualization). If >1 GA injury occurred in the same knee, only 1 GA injury was calculated for the overall rate; however, each injury was specified separately when calculating the injury rate for the specific GA. Intraoperative blood loss, postoperative drain output, and the use of TXA were compared between cases in which a GA injury was detected and those in which it was not detected. Before conducting the retrospective review, a power analysis determined that we would require 100 patients to detect a difference in GA injury between Groups 1 and 2 (33 in Group 1 and 67 in Group 2), assuming a 30% rate in Group 1 and a 5% rate of GA injury in Group 2 using Fisher’s exact test. The Fisher’s exact test was used to compare categorical variables, and the Wilcoxon rank sum test was used to compare continuous variables. An alpha value of .05 was considered as statistically significant.

RESULTS

RATE OF GENICULATE ARTERY INJURY

The overall rate of any GA injury was 38% (38/100). Lateral inferior GA injury was more frequently detected than middle GA injury (31% vs 15% of TKAs, respectively; Table 2). Among the 31 lateral inferior GA injuries, 14 were identified as pulsatile bleeding, 7 as lumen visualizations, and 6 as both pulsatile bleeding and lumen visualization; 4 were detected by methods not recorded in the operative report. Of the lateral inferior GA injuries, 11 were identified after the bone cuts, 7 during meniscus removal, 3 during exposure, 1 after tourniquet deflation, and 9 at a time not recorded in the operative report. Of the 15 middle GA injuries, 9 were identified as pulsatile bleeding, 2 as lumen visualizations, and 4 as both pulsatile bleeding and lumen visualization. In addition, 7 of these GA injuries were identified after the bone cuts, 3 during cruciate removal, 1 after meniscus removal, 1 during exposure, and 3 at a time not recorded in the operative report (Table 3).

Rates of geniculate artery injury based on location and method of diagnosis. Data presented as n (%). There were 4 additional lateral inferior and 9 middle GA injuries identified by a method not specified in the operative report. GA = geniculate artery.

Rates of geniculate artery injury based on time point and method of diagnosis. GA = geniculate artery. Data presented as n (%).

FACTORS ASSOCIATED WITH GENICULATE ARTERY INJURY

Mean intraoperative estimated blood loss was 186 mL (standard deviation [SD], 111; range 50–500 mL) in those with a GA injury versus 147 mL (range, 82.25–400 mL) in those without injury (P = .14). Postoperative drain output in the 24 hours after surgery was 467 mL (SD 253, range 100–1105 mL) versus 502 mL (SD 378, range 75–1980 mL) in TKAs with and without GA injury, respectively (P = .82). Total estimated blood loss (combined intraoperative blood loss and 24-hour postoperative drain output) was 613 mL (SD 252, range 150–1105 mL) in TKAs with GA injury versus 620 mL (SD 393, range 75–2130 mL) without injury (P = .44) (Table 4). Overall, there was no statistical difference in blood loss, drain output, or combined output when analyzed according to lateral inferior or middle GA injury (P = .24–.82) (Table 5 and Table 6). No patients required blood transfusion postoperatively after TKA.

Differences in outcomes based on presence or absence of GA injury. Note that there were no significant differences. Values are reported as average (range). GA = geniculate artery.

Differences in outcomes based on presence or absence of LIGA injury. Note that there were no significant differences. Values are reported as average (range). LIGA = lateral inferior geniculate artery.

Differences in outcomes based on presence or absence of MGA injury. Note that there were no significant differences. Values are reported as average (range). MGA = middle geniculate artery.

IV administration of TXA was associated with a 37% (31/84) rate of GA injury, whereas topical TXA administration was associated with a 43% (6/14) rate of GA injury (P = .77). The rate of overall or isolated GA injury was not significantly different (P = .35–1.0) between IV and topical TXA administration (Table 7). In addition, total combined output was not significantly different (P = .1032) when comparing GA injury and noninjury in the subgroup analysis based on TXA use (IV or topical); however, topical administration was associated with lower intraoperative blood loss than IV administration (P = .0489), whereas IV administration was associated with lower 24-hour postoperative drain output than topical administration (P = .0169). There was no difference in blood loss, 24-hour drain output, or total output between those who did and did not sustain a GA injury in the group of patients who received IV TXA administration (Table 8, P = .2118–.7091). The same was true for those receiving topical TXA administration (Table 9, P = .0912–.9485).

Differences in outcomes based on presence or absence of MGA injury. Note that there were no significant differences. Values are reported as n (%) or average (range). TXA = tranexamic acid, GA = geniculate artery, LIGA = lateral inferior geniculate artery, MGA = middle geniculate artery. *denotes statistical significance (P < .05).

Differences in outcomes of those patients who received IV TXA based on presence or absence of GA injury. Note that there were no significant differences. Values are reported as average (range). GA = geniculate artery, TXA = tranexamic acid.

Differences in outcomes based on presence or absence of GA injury. Note that there were no significant differences. Values are reported as average (range). GA = geniculate artery.

Continue to: TOURNIQUET USE