Vacuum therapy as an intermediate phase in wound closure: a clinical experience

For severely crushed, contaminated, infected or chronic wounds, vacuum therapy can act as an intermediate phase in wound closure. In this article, our clinical experience with the vacuum system is presented. The aim of this study is to evaluate vacuum therapy in wound healing in a clinical setting. From January 1997 until May 1998, we treated 26 wounds in 26 patients with a vacuum system. Eight acute, seven subacute and 11 chronic wounds were included. The wound cavity was filled with a polyurethane (PU) or a polyvinylalcohol (PVA) foam and vacuum sealed with a PU foil. A subatmospheric pressure of 125 mm mercury was maintained by a vacuum pump. Wounds were eligible for wound closure if the bacterial load score was one or less, ranging from zero to four. The median suction time was 17 days (6–55), while the median hospital stay was 49 days (9–92). Twelve wounds were closed with a split skin graft, six with a local or pedicled flap and seven with a free musculocutaneous flap. Vacuum therapy was discontinued in one patient, because of sepsis. Successful closure was achieved in 23 wounds. Vacuum therapy seems to be benificial in complicated wounds with impaired wound healing. A prospective randomized clinical trail, in which vacuum therapy is compared to conventional dressing, is in progress. Received: 31 January 2000 / Accepted: 14 February 2000     

创伤性软组织缺损的负压封闭治疗

目的　探讨创伤致软组织缺损负压封闭 (VS)治疗的临床效果。　方法　 1 998年 8月～ 2 0 0 1年 1 2月 ,对 49例 55个大面积软组织缺损或 /和感染者 ,创面范围为 1 0 cm× 1 0 cm～ 30 cm× 30 cm;清创后将 Vacuseal材料覆盖在相应大小的创面上或填入创腔内 ,持续 50～ 60 k Pa负压引流 ,5～ 7天后二期缝合、植皮或皮瓣移位修复。1 2 6例采用传统换药或引流的患者为对照组。　结果　治疗组有 4例 (4个创面 )死亡未完成治疗 ,余 45例 51个创面治愈 ,无全身和局部并发症。在二期缝合时间、换药次数、创面缩小程度及总体治疗费用等方面 ,与对照组比较 ,均有统计学意义 (P<0 .0 1 )。创面或创腔直接通过 VS治愈 6个 ,采用游离皮瓣修复 4个 ,局部皮瓣移位修复 8个 ,植皮覆盖 2 7个 ,二期缝合 6个。　结论　 VS能充分引流和刺激创面肉芽组织快速生长 ,缩短治愈时间和消除感染。是治疗创伤后急、慢性软组织缺损的一种简便、有效方法     

Subatmospheric pressure dressings in the temporary treatment of soft tissue injuries associated with type III open tibial shaft fractures in children

PURPOSE: This study was designed to evaluate the use of subatmospheric pressure dressings on high-energy open tibial shaft fractures in children. We hypothesized that the use of a negative-pressure dressing in these fractures would result in a decreased incidence of infection and decreased need for pedicled muscle flaps and free tissue transfer. METHODS: A retrospective case series of 15 consecutive pediatric patients with 16 type III open tibial shaft fractures (8 type IIIA, 7 type IIIB, and 1 type IIIC). The patients' age ranged from 2 to 17 years. All patients underwent a standard protocol of serial irrigation and debridement of the open wound with bony stabilization. Temporary coverage of the open wound was obtained with the use of a subatmospheric pressure dressing until definitive wound coverage or closure. RESULTS: Infection occurred in 5 of 16 fractures, 2 requiring antibiotics alone (1 type IIIA and 1 type IIIB) and 3 requiring surgical intervention (2 type IIIB and 1 type IIIC). Seven of 16 (3 type IIIA, 3 type IIIB, and 1 type IIIC) fractures required repeat surgical intervention to facilitate bony healing. Only 3 patients required free tissue transfers or rotational muscle flaps for coverage, a 50% decrease compared with the initial classification. CONCLUSIONS: Compared with other described methods, the use of subatmospheric pressure dressings in the temporary treatment of soft tissue wounds associated with high-energy open tibial shaft may reduce the need for major soft tissue coverage procedures. Its effect on infection and fracture healing rates requires further study. SIGNIFICANCE: A reduction in the need for major soft tissue coverage procedures with the use of negative-pressure dressings in this setting should result in decreased morbidity for these patients and in decreased social and financial costs.     

Versatile use of vacuum-assisted healing in fifty patients

Context:

Wound management can often be a challenging experience, especially in the presence of diabetes mellitus, vascular or immunological compromise. While no single technique can be considered by itself to be ideal, vacuum-assisted healing, which is a recent innovation, is fast becoming a necessary addition as adjuvant therapy to hasten wound healing.

Aims:

To determine the efficacy of vacuum-assisted healing.

Settings and Design:

Plastic surgery centre. Ministry of Health Hospital, Kuwait.

Materials and Methods:

Patients from Kuwait in a wide variety of clinical situations were chosen for study: Patients (n=50) were classified by diagnosis: Group 1: pressure sore- sacral (n= 3), trochanteric (n=6), ischial (n= 2); Group 2: ulcers (n= 11); Group 3: traumatic soft tissue wounds (n =15); Group 4: extensive tissue loss from the abdominal wall perineum, thigh and axilla (n =5); Group 5: sternal dehiscence wounds (n =4) and Group 6: wounds from flap necrosis (n =4). All wounds were subjected to vacuum by wall unit or portable unit, using pressure of 100-125 mm - continuous or intermittent. Closure of wounds, significant reduction in size and refusal by patient for continuation of vacuum-assisted closure therapy were end points of vacuum application.

Results:

Sixteen per cent of patients showed complete healing of the wound. Seventy per cent of patients showed 20-78% reduction in wound size. In 14% of patients treatment had to be discontinued. All patients showed improvement in granulation tissue and reduction in bacterial isolates and tissue oedema.

Conclusions:

The application of subatmospheric pressure or negative pressure promotes healing in a wide range of clinical settings and is an advanced wound healing therapy that can optimize patient care, promote rapid wound healing and help manage costs. It may be used in most instances in both hospital and community settings.     

Comparing conventional gauze therapy to vacuum-assisted closure wound therapy: a prospective randomised trial.

BACKGROUND: Vacuum-assisted closure wound therapy (vacuum therapy) has been used in our department since 1997 as a tool to bridge the period between debridement and definite surgical closure in full-thickness wounds. We performed a prospective randomised clinical trial to compare the efficacy of vacuum therapy to conventional moist gauze therapy in this stage of wound treatment. METHODS: Treatment efficacy was assessed by semi-quantitative scoring of the wound conditions (signs of rubor, calor, exudate and fibrinous slough) and by wound surface area measurements. Tissue biopsies were performed to quantify the bacterial load. Besides this, the duration until 'ready for surgical therapy' and complications encountered during therapy and postoperatively were recorded. RESULTS: Fifty-four patients were included (vacuum n=29, conventional n=25). With vacuum therapy, healthier wound conditions were observed. Furthermore, a tendency towards a shorter duration of therapy was found, which was most prominent in late-treated wounds. In addition, the wound surface area reduced significantly faster with vacuum therapy. Surprisingly, these results were obtained without a decrease in the number of bacteria colonising the wound. Complications were minor, except for one case of septicaemia and one case of increased tissue necrosis, which compelled us to stop vacuum therapy. For the treatment of full-thickness wounds, vacuum therapy has proven to be a valid wound healing modality.     

Negative pressure wound therapy for the treatment of infected wounds with exposed knee joint after patellar fracture

Treatment of soft tissue defects with exposed bones and joints, resulting from trauma, infection, and surgical complications, represents a major challenge. The introduction of negative pressure wound therapy has changed many wound management practices. Negative pressure wound therapy has recently been used in the orthopedic field for management of traumatic or open wounds with exposed bone, nerve, tendon, and orthopedic implants. This article describes a case of a patient with a large soft tissue defect and exposed knee joint, in which negative pressure wound therapy markedly improved wound healing. A 50-year-old man presented with an ulceration of his left knee with exposed joint, caused by severe wound infections after open reduction and internal fixation of a patellar fracture. After 20 days of negative pressure wound therapy, a granulated wound bed covered the exposed bones and joint.To our knowledge, this is the first report of negative pressure wound therapy used in a patient with a large soft tissue defect with exposed knee joint. Despite the chronic wound secondary to infection, healing was achieved through the use of the negative pressure wound therapy, thus promoting granulation tissue formation and closing the joint. We suggest negative pressure wound therapy as an alternative option for patients with lower limb wounds containing exposed bones and joints when free flap transfer is contraindicated. Our result added to the growing evidence that negative pressure wound therapy is a useful adjunctive treatment for open wounds around the knee joint.     

Treatment of soft tissue defects in pediatric patients using the V.A.C. system

Twenty-seven consecutive pediatric patients presenting to the orthopaedic surgery or plastic surgery services were reviewed after completion of wound care with the Vacuum Assisted Closure (V.A.C.) system. Each patient presented with complex soft tissue wounds requiring coverage procedures. Patients with acute wounds and wounds present after nonsuccessful attempts at surgical closure (dehisced incisions and failed flaps) were treated. All soft tissue defects healed without extensive coverage procedures using the V.A.C. system. In the majority of patients, use of the V.A.C. system produced a profuse bed of granulation tissue over all exposed bone, tendon, joint, and/or hardware, which could be covered with split thickness skin graft. Other patients were treated successfully with delayed primary closure, local flap advancement (one patient underwent a pedicled cross-leg flap), or by secondary intention. Use of the V.A.C. device is valuable in increasing the rate of granulation tissue formation and healing of extensive soft tissue injuries in pediatric patients. This vacuum system aids in the debridement of necrotic tissue and local soluble inflammatory mediators that may inhibit the proliferation of granulation tissue. These improvements in the local wound environment seem to accelerate wound healing compared with traditional methods. Before the development of the V.A.C. system, a minimum of nine patients within this group would have required free tissue transfer to obtain adequate coverage. The V.A.C. device seems to permit earlier coverage with local tissue or split-thickness skin grafting techniques, thereby decreasing the need for extensive microvascular tissue transfers in pediatric patients.     

Mechanics of wound healing and importance of Vacuum Assisted Closure in urology

PURPOSE: We discuss the mechanisms of wound healing and our experience with the Vacuum Assisted Closure device (Kinetic Concepts, Inc., San Antonio, Texas) for complex urogenital wounds. MATERIALS AND METHODS: The literature obtained from a Medline search on wound healing, wound failure and vacuum assisted closure was reviewed. In addition, we reviewed our experience with negative pressure wound therapy. RESULTS: Wound healing is a complex interaction between the reticuloendothelial and immune systems, in addition to correctable internal and external factors. Understanding the healing process improves outcomes and decreases patient morbidity. Negative pressure wound therapy has hastened wound healing and it adds significant improvement in the arsenal of choices available. CONCLUSIONS: Vacuum Assisted Closure is a therapeutic alternative that complements surgical and medical intervention in patients with complex wounds.     

VAC therapy to promote wound healing after surgical revascularisation for critical lower limb ischaemia

Vacuum‐assisted closure (VAC) therapy is a new emerging non‐invasive system in wound care, which speeds up wound healing by causing vacuum, improving tissue perfusion and suctioning the exudates, and facilitating the removal of bacteria from the wound. The application of sub‐atmospheric pressure on the lesions seems to alter the cytoskeleton of the cells on the wound bed, triggering a cascade of intracellular signals that increase the rate of cell division and subsequent formation of granulation tissue. The aim of this study is to analyse the results of VAC therapy used as an adjuvant therapy for the treatment of foot wounds in patients affected by critical limb ischaemia (CLI) (Rutherford 6 class) after distal surgical revascularisation, to promote and accelerate the healing of ulcers. Twenty‐nine patients (20 males, 9 females; mean age 68·4) affected by CLI of Rutherford 6 class, after surgical revascularisation of the lower limb, underwent VAC therapy in order to speed up wound healing. Complete wound healing was achieved in 19 patients (65·51%), in an average period of 45·4 ± 25·6 days. VAC therapy is a valid aid, after surgical revascularisation, to achieve rapid healing of foot lesions in patients with CLI.     

Soft Tissue Management in Open Fractures of the Lower Leg: The Role of Vacuum Therapy

Abstract   The management of severe open fractures of the lower leg continues to challenge the treating surgeon. Major difficulties include high infection rates as well as adequate temporary soft tissue coverage. In the past, these injuries were commonly associated with loss of the extremity. Today, vacuum therapy provides not only safe temporary wound coverage but also conditioning of the soft tissues until definitive wound closure. Amongst other advantages, bacterial clearance and increased formation of granulation tissue are attributed to vacuum therapy, making it an extremely attractive tool in the field of wound healing. However, despite its clinical significance, which is underlined by a constantly increasing range of indications, there is a substantial lack of basic research and well-designed studies documenting the superiority of vacuum therapy compared to alternative wound dressings. Vacuum therapy has been approved as an adjunct in the treatment of severe open fractures of the lower leg, complementing repeated surgical debridement and soft tissue coverage by microvascular flaps, which are still crucial in the treatment of these limb-threatening injuries. Vacuum therapy has in general proven useful in the management of soft tissue injuries and, since it is generally well tolerated and has low complication rates, it is fast becoming the gold standard for temporary wound coverage in the treatment of severe open fractures of the lower leg.     

Problem-adapted application of vacuum occlusion dressings: case report and clinical experience

Vacuum-assisted closure (VAC), a technique using subatmospheric pressure dressings, has been widely used for treatment of various chronic and complicated wounds. In addition to the advantages of an occlusive dressing therapy, the VAC therapy has proved effective in evacuating wound fluid, increasing tissue oxygen tension, decreasing bacterial contamination, and stimulating granulation tissue formation. This leads to more rapid re-epithelialization of wounds compared to conventional dressings. A two-phase VAC technique to provide enhanced coverage of an ischemic ulcer of the lower leg in a diabetic patient is presented. The refined VAC therapy scheme is described in detail and the results in a further 19 patients with complicated wounds of the lower leg and feet are reported. Received: 26 January 2000 / Accepted: 11 May 2000     

Vacuum-assisted closure versus conventional wound care in the treatment of wound failures following inguinal lymphadenectomy for penile cancer: a retrospective study

OBJECTIVES: Impaired wound healing is a frequent event in inguinal surgery and very common after lymphadenectomy for penile cancer. Although vacuum therapy has been reported to expedite the healing of complex wound failures, vacuum-assisted closure (VAC) has been reported to be contraindicated in malignancy. In the present study we evaluated the use of VAC in the treatment of complex wound failures following inguinal lymphadenectomy for penile cancer in comparison to conventional wound care (CWC) implying debridement and saline-soaked gauze. METHODS: We retrospectively identified six inguinal wounds following inguinal lymphadenectomy for penile cancer and subsequent use of VAC from 2003 to 2006 at our institution. Data on surgical interventions, complications, length of time required for closure, and outcome were compared to 10 inguinal defects treated with CWC between 2000 and 2003. RESULTS: Wound volume was comparable for both groups. Wound breakdown occurred at a median of 7.4 d after inguinal lymphadenectomy and was treated by CWC for a mean of 69.8 d. In the VAC group, the median duration until complete closure was 38.9 d. Thus, VAC was shown to result in complete wound healing in less time (p<0.001). No local recurrence in the VAC group was noted despite positive lymph nodes. CONCLUSIONS: VAC therapy is effective in complex inguinal wound failures following lymphadenectomy for penile cancer and appears to be superior to CWC. VAC seems to offer adequate safety concerning local recurrence.     

Vacuum-assisted closure therapy leads to an increase in plasma fibronectin level

An extensive research has been performed to investigate the mechanisms of action by which the application of subatmospheric pressure to wounds increases the rate of healing. Increased blood flow with vacuum-assisted closure (VAC) use is the most popular aspect. Fibronectin, which is an adhesion molecule, has several functional domains mediating chemotaxis, adhesion and migration. This is thereby involved in differentiation, proliferation, inflammation and thus in wound healing. In this study, plasma fibronectin levels were measured before and after VAC in patients with wounds. The results showed that there was an increase in pre- and post-VAC levels of plasma fibronectin. This statistically significant increase could be another explanation of how VAC therapy promotes wound healing.     

The evaluation of subatmospheric pressure and hyperbaric oxygen in ischemic full-thickness wound healing

We evaluated the efficacy of subatmospheric pressure and hyperbaric oxygen (HBO) as adjuncts in the treatment of hypoxic full-thickness wounds in a rabbit model. We hypothesized that subatmospheric pressure and HBO independently are effective in improving wound healing in the ischemic wound model and that when they are used in combination there is an increased positive effect on wound healing. Using a standard ischemic wound model four full-thickness wounds were created on each ear of 41 male New Zealand white rabbits (N = 82 ears). On each rabbit one ear was dressed with the vacuum-assisted closure (VAC) device and connected to suction; the other was dressed identically without the suction and suction tubing. Twenty rabbits were treated with HBO daily for 10 days at 2.0 atmospheres absolute for 90 minutes plus descent and ascent times. Necropsy on all rabbits was performed on postoperative day 10. Four ischemic wound treatment groups were evaluated: Group 1 (N = 21) VAC dressing alone; Group 2 (N = 20) VAC dressing plus HBO; Group 3 (N = 21) VAC dressing to suction alone; and Group 4 (N = 20) VAC dressing to suction and HBO. Using light microscopy a veterinary pathologist blinded to treatment groups quantified peak granulation tissue, granulation tissue gap, and epithelialization tissue gap. Data were analyzed by analysis of variance with significance indicated by P < 0.05. Statistical significance was found in a comparison of VAC dressing to suction and VAC dressing alone for peak granulation tissue and granulation tissue gap both with and without use of HBO. VAC device use appears to increase the rate of healing in a rabbit ischemic wound model. HBO therapy did not significantly affect the rate of healing in this model.     

Therapeutic options and postoperative wound complications after extremity soft tissue sarcoma resection and postoperative external beam radiotherapy

Soft tissue sarcomas occur most commonly in the lower and upper extremities. The standard treatment is limb salvage surgery combined with radiotherapy. Postoperative radiotherapy is associated with wound complications. This systematic review aims to summarise the available evidence and review the literature of the last 10 years regarding postoperative wound complications in patients who had limb salvage surgical excision followed by direct closure vs flap coverage together with postoperative radiotherapy and to define the optimal timeframe for adjuvant radiotherapy after soft tissue sarcomas resection and flap reconstruction. A literature search was performed using PubMed. The following keywords were searched: limb salvage, limb‐sparing, flaps, radiation therapy, radiation, irradiation, adjuvant radiotherapy, postoperative radiotherapy, radiation effects, wound healing, surgical wound infection, surgical wound dehiscence, wound healing, soft tissue sarcoma and neoplasms. In total, 1045 papers were retrieved. Thirty‐seven articles were finally selected after screening of abstracts and applying dates and language filters and inclusion and exclusion criteria. Plastic surgery provides a vast number of reconstructive flap procedures that are directly linked to decreasing wound complications, especially with the expectant postoperative radiotherapy. This adjuvant radiotherapy is better administered in the first 3–6 weeks after reconstruction to allow timely wound healing and avoid local recurrence.     

负压闭式引流加内固定治疗肢体开放性骨折

目的　探讨负压闭式引流 (VS)加一期内固定治疗开放性肢体骨折伴软组织污损的效果。　方法2 0 0 0年 5月～ 2 0 0 2年 11月对 14例 (18个创面 )开放性肢体骨折并软组织广泛污损患者进行了治疗 ,面积 10 cm×15 cm～ 2 5 cm× 90 cm,无其他头、胸、腹合并伤。其中男 9例 ,女 5例。年龄 15～ 6 8岁。受伤至手术时间 :2～ 9小时 30分钟。创面中度污染 12个 ,重度以上污染 6个。手术彻底清创 ,骨折经钢板或交锁髓内钉内固定后 ,缺损创面用多聚乙烯醇 -明胶海绵高分子复合材料 (Vacuseal)覆盖封闭 ,术后接 5 0～ 6 0 k Pa的负压 ,5～ 7天后行植皮或皮瓣修复。另选伤情、创面大致相同 ,用传统换药二期内固定手术方法治疗的 14例患者作为对照组。　结果　 VS治疗组创面均完全愈合 ,无全身及局部并发症 ,随访 4～ 6个月骨折愈合良好。与对照组比较 ,治疗时间、住院总体费用及并发症发生率等均明显降低 ,差异有统计学意义 (P<0 .0 1)。　结论　VS使创面引流充分 ,降低感染发生率 ,刺激肉芽生长 ,配合一期内固定治疗开放性骨折伴软组织广泛污损创面是一种简便、有效、经济实用的方法。     

Faziale Riss-Quetsch-Wunden

The face is a predilection site for soft tissue injuries and wound treatment of facial soft tissue injuries is one of the most frequently performed outpatient surgical procedures in oral and maxillofacial casualty departments. In this article the essential diagnostic and therapeutic steps of the wound treatment of facial soft tissue injuries will be presented. To underline the appraisal of the presented steps 75 patients exhibiting 100 facial soft tissue injuries, which were all treated at our department, were evaluated. The reason for the injury should be clarified without any doubt. Suspicion of syncope, poorly regulated diabetes mellitus or epileptic seizure should be clarified. The diagnosis of traumatic brain injury can normally be made clinically and requires further monitoring. Clinical evidence of a fracture needs to be clarified radiologically and the actuality of tetanus vaccinations should be checked. Wound morphology should be documented and the shape, depth and dimensions of the wound are essential features. A photographic documentation is recommended for forensic reasons. The surgical treatment of facial soft tissue injuries should be performed in a standardized manner. Contaminated wounds should be carefully cleaned before closure is performed and require postoperative antibiotic treatment. Preoperative anamnesis and clinical evaluation are essential in the therapy of facial soft tissue injuries. Overall facial soft tissue injuries present a good tendency to wound healing after correctly performed surgical therapy.     

Basics foundation and results of the vacuum therapy in the reconstructive surgery

Vacuum therapy (vacuum assisted wound closure (V.A.C.(R)) is a non invasive method to promote wound healing. It is based on defined, controlled negative pressure application via medical-grade reticulated polyurethane ether or polyvinyl foam dressing to wound surfaces. The technique is characterized by continuous removal of wound exudates and hence reduction of extravascular, interstitial fluid, subsequently leading to enhanced microcirculation. Experimental studies revealed a positive influence both on local microcirculation and on granulation tissue formation. Local mechanical physical factors, yet not completely understood, similar to tissue expansion, apply to the wound surface and seem to promote cell growth. In our own patients the vacuum technique has been used to pretreat chronic wounds in 139 patients, to fix split thickness skin grafts in 148 patients and to prefabricate or delay free or pedicled flaps in 11 patients so far. Thorough surgical debridement remains the mainstay of wound care. Vacuum therapy however, as an adjunctive procedure, offers significant advantages compared to conventional wound care methods, which call for further clinical and experimental studies to elucidate the basic mechanisms.     

Infected internal fixation after ankle fractures--a treatment path

In the emergency treatment of infected internal fixation after ankle fractures, the infection needs to be resolved quickly to protect the implants, bone, and tendons. Vacuum wound therapy (topical negative pressure therapy) has been used for more than 15 years to assist in closure and to accelerate healing of a wide range of wounds. In the present report, we describe the results of treatment of 7 angiopathic (dysvascular) patients who developed a deep wound infection after ankle osteosynthesis. Each patient was treated with initial surgical debridement, followed by vacuum wound therapy and meshed split-thickness skin graft transplantation. The mean inpatient length of vacuum wound therapy was 14.0 ± 4.31 days, and the mean total duration of vacuum treatment was 54.43 ± 7.74 days.     

Evaluation of vacuum‐assisted closure in patients with wound complications following tumour surgery

Covering the reconstructed area with a healthy soft‐tissue envelope is a major challenge after limb‐sparing surgery in patients with malignant bone and soft‐tissue tumours. Negative pressure wound therapy (NPWT) of open wounds hastens healing and minimises the requirement for complex reconstructive soft‐tissue surgery. The aim of this study was to investigate the effectiveness and safety of NPWT in bone and soft‐tissue malignant tumour patients with postoperative wound complications. Between January 2006 and November 2009, at a single institution, 13 patients with malignant bone and soft‐tissue tumours who had undergone wide resection were retrospectively analysed. NPWT was performed in all patients to temporarily close the soft‐tissue defects. After obtaining the culture negativity and normal infection markers, definitive soft‐tissue reconstruction was performed to close the wound with primary suturisation in two patients, split thickness grafts in four patients, full thickness grafts in two patients, rotational flaps in three patients and free flaps in two patients. Mean duration of hospitalisation was 20 (range 8–48) days and mean follow‐up period was 57·3 (range 50–74) months. There was no tumour recurrence or skip metastasis in the follow‐up period. In addition, there was no periprosthetic infection or complication associated with NPWT. In conclusion, NPWT therapy seems to be a safe and effective option in the management of local wound problems and secondary surgical site infections after musculoskeletal tumour surgery.