Surgical risk factors that could have contributed to the complication in this case include the surgical skin preparation solution (ChloraPrep; CareFusion), use of adhesive antimicrobial drape (Ioban, 3M), tourniquet time, dressing choice, and DVT prophylaxis regimen. While the skin preparation solution is an unlikely culprit since the presentation is not consistent with contact dermatitis, inappropriate strapping or removal of the adhesive drape could result in stretch injury of the skin, shearing the dermoepidermal junction and causing tension blisters.9 There were no intraoperative complications and the tourniquet time was appropriate (78 minutes). Postoperatively, no compressive or adhesive dressings were used. With regards to DVT prophylaxis, the patient received a single dose of enoxaparin on the first postoperative day. While heparin-induced hemorrhagic blisters have been reported,10 I do not feel that the use of enoxaparin was a contributing factor. Heparin-induced blisters have been described as systemic blisters,10 whereas the blisters in this case were confined to the operative extremity. The patient was not taking any nutritional supplements (eg, fish oil, vitamin E) that could have increased his risk of bleeding. Throughout his hospital stay, he was hemodynamically stable and did not require blood transfusion.
Management of fracture blisters is controversial, and there is no consensus on appropriate soft-tissue handling. In this patient, the blisters were left intact. Blister fluid has been shown to be sterile, containing growth factors, opsonins, and activated neutrophils that aid in healing and infection prevention.1 Giordano and Koval11 found no difference in the outcome of 3 soft-tissue treatment techniques: (1) aspiration of the blister, (2) deroofing of the blister followed by application of a topical antibiotic cream or coverage with nonadherent dressing, or (3) keeping the blister intact and covered with loose dressing or exposed to air. In contrast, Strauss and colleagues12 found that deroofing the fracture blister to healthy tissue followed by twice-daily application of silver sulfadiazine antibiotic cream promoted reepithelialization and resulted in better cosmetic appearance and higher patient satisfaction.
The optimal dressing for fracture blisters remains elusive. Madden and colleagues13 showed that the use of occlusive nonadherent dressing was associated with significantly faster healing and less pain compared with semiocclusive, antibiotic-impregnated dressings. In another study, Varela and colleagues1 found no differences in blister healing between patients treated with either (1) dry dressing and casting, (2) Silvadene dressing (King Pharmaceuticals), or (3) whirlpool débridement and Silvadene dressing.
Infection is perhaps the most dreaded complication of fracture blisters after TKA. Varela and colleagues1 showed that, while the fluid in intact blisters was a sterile transudate, polymicrobial colonization with skin flora often occurred soon after blister rupture and persisted until reepithelialization. Our patient received a 10-day course of prophylactic antibiotics and no superficial or deep infection developed; however, the real contribution of antibiotic prophylaxis to the absence of infection cannot be established based solely on 1 case.
Pain is another concern associated with fracture blisters. Our patient had significant pain that limited his ability to participate in PT, resulting in limited knee range of motion and eventual discharge to a short-term rehabilitation facility. Fortunately, after resolution of the fracture blisters, he was able to participate in an aggressive rehabilitation program. By 6 weeks after surgery, he had significant improvement in his knee motion, avoiding the need for manipulation under anesthesia.
This case represents the first reported fracture blisters after primary TKA. The risk of deep surgical site infection, a devastating complication after TKA, is perhaps the most frightening concern of this rare complication. While the etiology and the management are controversial, there is evidence to recommend prophylactic antibiotics after blister rupture and skin desquamation. The decision to withhold DVT prophylaxis should be based on individual patient risk factors and blister type (blood-filled vs clear fluid–filled). Patients should be encouraged to continue knee exercises during reepithelialization to avoid stiffness.