Surgical Wound Closure in Orthopaedic Surgery
Classically, the wound healing process is described in three phases: inflammation, proliferation, and remodeling (Figure 1). The inflammatory phase features an intense cellular response that persists for the first 48 hr. This response is mounted by neutrophils and macrophages that secrete inflammatory cytokines and growth factors, such as tumor necrosis factor-α, interleukin-6, and transforming growth factor-β. The inflammatory phase is followed by the proliferation phase, which continues through day 10. This phase is characterized by angiogenesis, connective tissue deposition, and granulation tissue formation. The remodeling phase begins at or around day 10 and persists for up to 1 yr and is characterized by remodeling of tissue collagen and extracellular matrices with restoration of tensile strength.
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Figure 1.
The three phases of wound healing: inflammatory (A), proliferative (B), and remodeling (C).
Identifying patients at risk for compromised wound healing is crucial in avoiding complications. Risk factors such as patient age, connective tissue disorder, location of incision, prior surgery or history of radiation are not modifiable. However, other risk factors, such as diabetes, obesity, smoking, and nutritional status, can and should be optimized before and after surgery (Table 1). Also, patient specific considerations, such as open fractures and poor compliance, can predispose patients to wound healing problems. Recent studies have begun to measure the effect of these risk factors on clinical outcomes in orthopaedic surgery. A retrospective analysis of diabetic patients undergoing total joint arthroplasty revealed that hemoglobin A1C values greater than 6.7 preoperatively or blood glucose levels greater than 200 postoperatively have odds ratios of greater than 3 for wound complications. Additionally, technical factors such as higher tourniquet cuff pressure (>225mm Hg) during total knee arthroplasty and prolonged operative time during ankle fracture surgery have been shown to increase wound complications and rates of infection as well. Optimization of modifiable risk factors is critical in minimizing wound complication rates.
An angiosome is a three-dimensional segment of tissue supplied by a single source artery as initially described by Taylor and Palmer. Source vessels give rise to branches that perfuse bone, muscle, fascia, and skin. Through detailed anatomical studies, the authors identified reproducible angiosomes throughout the human body (Figure 2). The angiosome concept underscores the importance of tissue perfusion, particularly in the distal extremities and should be contemplated before making a surgical incision. Attinger et al. applied this concept to reconstructive procedures of the injured extremity and highlighted a number of important principles for placing a surgical incision. The incision must provide adequate exposure for the planned procedure and have adequate blood supply on either side of the incision to optimize healing. It should also spare sensory and motor nerves, and consideration should be given to avoiding scar contractures around joints. Being mindful of these concepts, Howard et al. demonstrated that a less than 7-cm skin bridge between incisions, previously thought to be critical in avoiding soft-tissue complications in the setting of tibial plafond fractures, could be tolerated when the relevant angiosomes were understood and respected.
(Enlarge Image)
Figure 2.
The angiosome territories defined by Taylor and Palmer. (Reproduced with permission from: Inoue and Taylor).
Basic Science of Wound Healing
Classically, the wound healing process is described in three phases: inflammation, proliferation, and remodeling (Figure 1). The inflammatory phase features an intense cellular response that persists for the first 48 hr. This response is mounted by neutrophils and macrophages that secrete inflammatory cytokines and growth factors, such as tumor necrosis factor-α, interleukin-6, and transforming growth factor-β. The inflammatory phase is followed by the proliferation phase, which continues through day 10. This phase is characterized by angiogenesis, connective tissue deposition, and granulation tissue formation. The remodeling phase begins at or around day 10 and persists for up to 1 yr and is characterized by remodeling of tissue collagen and extracellular matrices with restoration of tensile strength.
(Enlarge Image)
Figure 1.
The three phases of wound healing: inflammatory (A), proliferative (B), and remodeling (C).
Risk Factors for Poor Wound Healing
Identifying patients at risk for compromised wound healing is crucial in avoiding complications. Risk factors such as patient age, connective tissue disorder, location of incision, prior surgery or history of radiation are not modifiable. However, other risk factors, such as diabetes, obesity, smoking, and nutritional status, can and should be optimized before and after surgery (Table 1). Also, patient specific considerations, such as open fractures and poor compliance, can predispose patients to wound healing problems. Recent studies have begun to measure the effect of these risk factors on clinical outcomes in orthopaedic surgery. A retrospective analysis of diabetic patients undergoing total joint arthroplasty revealed that hemoglobin A1C values greater than 6.7 preoperatively or blood glucose levels greater than 200 postoperatively have odds ratios of greater than 3 for wound complications. Additionally, technical factors such as higher tourniquet cuff pressure (>225mm Hg) during total knee arthroplasty and prolonged operative time during ankle fracture surgery have been shown to increase wound complications and rates of infection as well. Optimization of modifiable risk factors is critical in minimizing wound complication rates.
Angiosomes and Incision Placement
An angiosome is a three-dimensional segment of tissue supplied by a single source artery as initially described by Taylor and Palmer. Source vessels give rise to branches that perfuse bone, muscle, fascia, and skin. Through detailed anatomical studies, the authors identified reproducible angiosomes throughout the human body (Figure 2). The angiosome concept underscores the importance of tissue perfusion, particularly in the distal extremities and should be contemplated before making a surgical incision. Attinger et al. applied this concept to reconstructive procedures of the injured extremity and highlighted a number of important principles for placing a surgical incision. The incision must provide adequate exposure for the planned procedure and have adequate blood supply on either side of the incision to optimize healing. It should also spare sensory and motor nerves, and consideration should be given to avoiding scar contractures around joints. Being mindful of these concepts, Howard et al. demonstrated that a less than 7-cm skin bridge between incisions, previously thought to be critical in avoiding soft-tissue complications in the setting of tibial plafond fractures, could be tolerated when the relevant angiosomes were understood and respected.
(Enlarge Image)
Figure 2.
The angiosome territories defined by Taylor and Palmer. (Reproduced with permission from: Inoue and Taylor).