Surgical debridement to optimise wound conditions and healing

Abstract

Different treatment strategies are available for bone, joint and soft tissue infections, including use of local antibiotics; negative pressure wound therapy; one‐stage, two‐stage or multi‐stage revisions; or open wound therapy. All methods have one principle in common: adequate surgical debridement is the prerequisite for successful treatment of bone, joint and soft tissue infections. According to the different textures of healthy, infected or necrotic tissue, special techniques are used. In this article we will describe the clinical presentation of necrotic and non‐vital tissue in skin, soft tissue and bone and appropriate techniques of debridement.

Introduction

Debridement is defined as ‘the removal of sequestrate and resection of infected bone and soft tissue to improve the healing potential of the remaining healthy tissue’ 1. This treatment has been known and utilised for hundreds of years. The first mention of surgical debridement is found in the script of the Roman physician Aulus Cornelius Celsus in the first century AD 2. Currently the goal of surgical debridement is to remove as much necrotic tissue as possible in order to reduce the bacterial bioburden.

There are different concepts for treatment of bone, joint and soft tissue infections [e.g. use of local antibiotics, negative pressure wound therapy (NPWT), one‐stage, two‐stage or multi‐stage revisions or open wound therapy]. Each method has its advantages and disadvantages with a much controversial discussion in the literature. All authors agree that adequate surgical debridement is the prerequisite for all treatment modalities 3.

To highlight the importance of this surgical intervention, debridement has often been called ‘radical’ or ‘extensive’; but not further defined 4. In our opinion, ‘radical’ is not the appropriate term. All necrotic and scarred tissues have to be removed, but on the other hand, as much of healthy, non‐infected tissue as possible has to be retained to enable undisturbed wound healing. The term ‘radical’ implies the risk of removing too much healthy tissue.

Therefore, we suggest calling this calculated, meticulous surgical technique ‘intelligent’ debridement.

In this article we will describe the clinical presentation of necrotic and non‐vital tissue (skin, soft tissue and bone) and the appropriate methods of debridement. All patient photographs and data were collected according to institutional protocols. Informed consent was obtained from all patients.

Methods of surgical debridement

Skin

Non‐vital skin initially becomes white/pale (ischaemic), then turns dark purple and finally black 5. Final necrosis is easy to recognise and can be excised with a scalpel. Borderline poorly perfused to non‐vital, necrotic skin is sometimes difficult to differentiate. In this situation, excision should be carried out in a stepwise fashion until there is bleeding from the small vessels, thereby indicating vital and perfused tissue 5. The skin defect may be covered by a mesh graft. After debridement, NPWT (V.A.C.^® Therapy, KCI Medizinprodukte GmbH, Wiesbaden, Germany) can be used to produce granulation tissue in order to optimise wound conditions.

Case report I

Patient was a 79‐year‐old female who presented with a haematoma of the right forearm after a fall. Patient had rheumatoid arthritis and was treated with prednisolone. The following is a timeline of treatment:

• 5 January 2012: debridement of a subcutaneous haematoma of the right forearm.

• 10 January 2012: skin and soft tissue necrosis developed (Figure 1).

• 11 January 2012: debridement of skin and soft tissue, local antibiotic therapy with polymethylmethacrylate (PMMA)‐gentamicin‐beads (Septopal^®, Biomet, Berlin, Germany) and Epigard^® (Medisave, Wiesbaden, Germany) for 7 days (Figure 2).

• 19 January 2012: second debridement, NPWT with polyurethane foam dressing for 7 days, continuous therapy, 75 mmHg (Figure 3).

• 26 January 2012: split‐thickness skin graft (STSG; 0·4 mm, 1:1·5) from right thigh (Figure 4).

• 31 January 2012: clinical outcome after 5 days (Figure 5).

Figure 1.

Skin and soft tissue necrosis of right elbow (10 January 2012).

Figure 2.

Clinical result after debridement and local antibiotics for 7 days (18 January 2012).

Figure 3.

Clinical result after 7 days of negative pressure wound therapy (NPWT; 26 January 2012).

Figure 4.

Intra‐operative site after split‐thickness skin graft (STSG; 26 January 2012).

Figure 5.

Clinical outcome 5 days after split‐thickness skin graft (STSG; 31 January 2012).

Subcutaneous tissue

As fat tissue necroses, its structure alters, becoming a liquid, deliquescent substance, which can be easily removed by a curette 5. In early fatty necrosis, when the tissue is still firm, it should be removed with a scalpel until bleeding from small vessels appears.

Irrigation with water under pressure (jet lavage) can also be used to remove fat necrosis. The water jet creates a plane of cleavage which excises the non‐vital tissue while leaving vital tissue intact.

Fascia

Necrotic fascia also becomes liquid, changes colour becoming yellow or grey and loses its integrity. Such fascia must be excised with a scalpel until bleeding from small vessels appears. This is vital in the life‐threatening necrotising fasciitis, where the only chance of survival is to remove the necrotic fascia completely. This often involves extensive incisions and the removal of virtually all fascia of the involved extremity 6.

Muscle

As muscle tissue becomes necrotic, its appearance changes to that similar to ‘overcooked’ meat and can be removed with a curette. The necrotic tissue is yellowish, doughy and shows almost no bleeding. The structure of infected, yet vital, muscle is intact, but loosened and bleeds extensively. This tissue can be left in situ.

Bone

The discussion of bone tissue should be divided into cortical and cancellous bone.

Cortical bone

Necrotic cortical bone is white and looks like it is painted. It can appear like ivory or porcelain/china 5. Normal cortical bone has small spots from small blood vessels, which gives it a ‘dotted’ appearance. To distinguish between vital and non‐vital cortical bone, a chisel can be used tangentially. In healthy bone, bleeding appears when chips are removed from the surface 7. This is sometimes called the ‘paprika sign’, as the bleeding looks like a sprinkle of paprika 8. Non‐vital bone is brittle and splits like porcelain.

The extent of the bone necrosis must be determined by X‐ray and/or computer‐assisted tomography (CT) in association with the intra‐operative signs discussed above. Depending on the size of the wound, fenestration of the bone, excision or a segmental resection may be necessary. External fixation is required for stabilisation of the bone, if instability of bone fragments results. In such a situation, an original Ilizarov ring fixator (Litos GmbH, Ahrensburg, Germany) 9 or Taylor Spatial Frame (Smith & Nephew GmbH, Marl, Germany) is preferred.

Cancellous bone

Necrotic cancellous bone becomes soft, has granulation tissue between the trabeculae 5 and can be removed with a curette. Distinguishing between necrotic, infected bone and vital, cancellous bone is often difficult. When any doubt exists, extensive debridement must be performed, especially if the tibial plateau or tibial head is involved.

Case report II

Patient was a 69‐year‐old male who presented with a fracture of the left distal tibia (June 2011; pilon tibiale AO 43–C3; Figure 6). The following is a timeline of treatment:

• 20 June 2011: closed reduction and external fixation with AO‐fixator (frame–fixator; ex domo).

• July 2011: additional open reduction and internal fixation with screws and plate (ex domo).

• July 2011 to February 2012: non‐union of distal tibia developed (8 months, Figure 7).

• 22 February 2012: first surgery in our hospital: Removal of all hardware (screws, plate and external fixator), debridement, excision of sequesters (Figure 8), open reduction and external fixation with original Ilizarov ring fixator (Litos GmbH) plus autologous bone graft from left dorsal iliac crest (Figure 9).

• February to May 2012: mobilisation with original Ilizarov ring fixator with 10 kg weight bearing for 12 weeks (Figure 10).

• 24 May 2012: second surgery: removal of ring fixator.

• May to July 2012: mobilisation in soft cast with 10 kg weight bearing for 8 weeks.

• 23 July 2013: mobilisation with full weight bearing (Figures 11 and 12).

Figure 6.

X‐ray of left ankle joint after accident (20 June 2011).

Figure 7.

X‐rays of left ankle joint and left knee joint: Non‐union developed after 8 months (21 February 2012).

Figure 8.

Surgical site with sequesters of distal tibia (22 February 2012).

Figure 9.

Postoperative X‐rays of left ankle and knee joint (24 February 2012).

Figure 10.

Correct position of ring fixator 12 weeks after surgery (23 May 2012).

Figure 11.

Radiographic control: bony union 6 months after debridement and external fixation (10 August 2012).

Figure 12.

Clinical outcome: full weight‐bearing, satisfactory range of motion of left ankle joint (3 August 2012).

Conclusion

Adequate surgical debridement is the prerequisite for the successful treatment of skin, soft tissue, and bone infections. It is crucial to distinguish between healthy, vital tissue and infected, necrotic tissue. Clinical signs during surgery are mainly used for this differentiation.

Diefenbeck M, Haustedt N, Schmidt HGK. Surgical debridement to optimise wound conditions and healing.