Wound complications in total knee arthroplasty. Which flap is to be used? With or without retention of prosthesis?

Successful Management of Impending Skin Necrosis After a Posterolateral Knee Dislocation

Incarcerated medial soft tissue after posterolateral knee dislocations has been described, but limited information pertaining to the etiology and management of cutaneous injuries from incarceration exists. We present the case of a 64-year-old man, where reduction of a posterolateral knee dislocation resulted in incarceration of medial ligamentous structures and impending skin necrosis. The patient avoided full-thickness skin necrosis, which could have complicated treatment options. Careful consideration of the soft-tissue envelope of the knee for preventing additional skin injury in the perioperative period should be considered to potentially avert additional necrosis in patients with a 'pucker' sign after knee dislocations.

Risk factors for failure after rotational muscle flap coverage for prosthetic knee infections

INTRODUCTION

Soft tissue defects are a devastating complication of prosthetic joint infections (PJI) after total knee arthroplasty (TKA). Rotational flaps are commonly utilized to address these defects with variable reports of success. This study aimed to identify predictors of poor outcomes in rotational muscle flap placement after prosthetic knee infections. The authors hypothesized that outcomes may vary based on infecting pathogen and treatment characteristics.

METHODS

44 cases of rotational muscle flaps for prosthetic knee infection were retrospectively evaluated at a tertiary referral hospital from 2007 to 2020. Muscle flap types included 39 medial and four lateral gastrocnemius, and one anterior tibialis. Minimum follow-up was 1 year (median: 3.4 years). Primary outcome was flap-related complications. Secondary outcomes included recurrent infection requiring additional surgery, final joint outcomes, and mortality.

RESULTS

One-year complication-free flap survivorship was 83.9%, recurrent infection-free survivorship was 65.7%, and amputation-free survivorship was 79%. Multivariable cox regression revealed that rheumatoid arthritis diagnosis (HR: 3.4; p = .028) and methicillin-resistant Staphylococcus aureus-positive culture (HR: 4.0; p = .040) had increased risk, while Coagulase-negative Staphylococcus infections had reduced risk for recurrent or persistent infection (HR: 0.2; p = .023). Final joint outcome was retained TKA implant in 18 (40.9%), amputation in 15 (34.1%) patients, and definitive treatment with articulating spacer in 10 (22.7%). 5-years survivorship from death was 71.4%.

CONCLUSION

Rotational muscle flaps for soft tissue coverage of the knee are often performed in limb salvage situations with poor survivorship from flap complications, reinfections, and amputation. When considering surgical options for limb salvage, patients should be counseled on these risks.

Outcome following soft tissue coverage with a medial gastrocnemius flap of an exposed or infected total knee arthroplasty

BACKGROUND

Soft tissue defects or periprosthetic infections after total knee arthroplasty (TKA) are severe complications that may lead to loss of the arthroplasty or the limb. Reconstructions with medial gastrocnemius flaps (MGF) are occasionally used to provide soft tissue coverage around the knee.

AIMS

The study aimed to establish the rate of implant survivorship after MGF reconstruction for soft tissue coverage in the treatment of exposed or infected TKA and to establish functional outcome.

METHODS

A retrospective analysis was performed on all patients who received soft tissue coverage with an MGF of an exposed or infected TKA between 2000 and 2017 at the Department of Hand and Plastic Surgery at Umeå University Hospital. The outcomes were implant survivorship and patient-reported outcome measures (PROMs) using the five-level EQ-5D version and The Knee Injury and Osteoarthritis Outcome Score.

RESULTS

Forty-seven patients (mean age = 67 years, 30 women) were included. The mean time between flap coverage and follow-up was 6.7 (±3.4) years. Implant survivorship was observed in 28 of 47 (59.6%) patients at follow-up. Flap failure was rare, with only 3 of 47 (6.4%) cases. Of the 20 patients who answered the PROMs, 10 of 20 experienced moderate to severe pain or discomfort.

CONCLUSIONS

Due to unfavorable underlying conditions, MGF reconstruction after TKA is often associated with a compromised functional outcome. Because donor site morbidity is limited and flap failure is unusual, the procedure can be considered prophylactically in a small subset of patients with risk factors to prevent soft tissue defects and periprosthetic joint infection.

Medial gastrocnemius rotational flap for the reconstruction of extensor mechanism disruption in periprosthetic knee infections: a retrospective series with minimum two year follow-up

PURPOSE

Extensor mechanism disruption following total knee arthroplasty has a prevalence ranging from 0.3 to 3%. Its management is challenging, especially in case of associated infection of the prosthetic implant. Surgical options are limited due to the septic process, and the use of allograft or synthetic mesh are not recommended. The aim of this study was to report clinical outcomes, complications, survival, and surgical technique of medial gastrocnemius flap for the treatment of extensor mechanism disruptions associated with periprosthetic knee infection.

METHODS

This is a retrospective study from a prospectively collected arthroplasty registry from 2012 to 2019. Patients who received the gastrocnemius flap in the setting of a two-stage knee replacement for periprosthetic infection were included. Results of physical examination, Knee Society Score, Oxford Knee Score, and measurement of the range of motion registered pre-operatively were compared to those obtained at last follow-up. Survival was analysed through Kaplan-Meier curve.

RESULTS

A total of 15 patients were included, with a mean age of 63.4 years (range 36-77). The reconstruction of the extensor mechanism demonstrated a success rate of 73.3%. The mean extension lag at final follow-up was 7.5° (range, 0-30). The mean Knee Society Score and Oxford Knee Score improved from 29.0 (range, 21-36) and 17.5 (range, 13-22) respectively, to 82.9 (range, 74-89) and 36.0 (range, 33-39).

CONCLUSION

Medial gastrocnemius rotational flap is a reliable option for joint and limb salvage in case of periprosthetic knee infection associated with wide soft tissue degeneration and extensor mechanism disruption. The technique and surgical protocol presented in this study are reproducible and guaranteed good clinical outcomes and infection control.

Biofilms: Formation, Research Models, Potential Targets, and Methods for Prevention and Treatment

Due to the continuous rise in biofilm-related infections, biofilms seriously threaten human health. The formation of biofilms makes conventional antibiotics ineffective and dampens immune clearance. Therefore, it is important to understand the mechanisms of biofilm formation and develop novel strategies to treat biofilms more effectively. This review article begins with an introduction to biofilm formation in various clinical scenarios and their corresponding therapy. Established biofilm models used in research are then summarized. The potential targets which may assist in the development of new strategies for combating biofilms are further discussed. The novel technologies developed recently for the prevention and treatment of biofilms including antimicrobial surface coatings, physical removal of biofilms, development of new antimicrobial molecules, and delivery of antimicrobial agents are subsequently presented. Finally, directions for future studies are pointed out.

The distance between new and previous incisions does not affect skin necrosis in total knee arthroplasty: a parallel-randomized controlled clinical trial

Background

To avoid skin necrosis, an 8 cm distance between the new and previous incision is recommended in patients undergoing total knee arthroplasty (TKA). It was hypothesized that making a new incision less than 8 cm of the prior scar does not increase the risk of skin complications, and the new incision can be made anywhere, regardless of the distance from the previous scar. This study investigated how making a new incision, irrespective of the previous scars, affects skin necrosis.

Methods

In this parallel, randomized clinical trial, by simple randomization method using a random number table, 50 patients with single longitudinal knee scars were randomly assigned to two groups with a 1:1 ratio and 25 participants in each group. Patients with a minimum age of 60 and a single longitudinal previous scar on the knee were included. The exclusion criteria were diabetes mellitus, hypertension, morbid obesity, smoking, vascular disorders, cardiopulmonary disorders, immune deficiencies, dementia, and taking steroids and angiogenesis inhibitors. TKA was performed through an anterior midline incision, regardless of the location of the previous scar in the intervention group. TKA was performed with a new incision at least 8 cm distant from the old incision in the control group. Skin necrosis and scar-related complications were evaluated on the first and second days and first, second, and fourth weeks after the surgery. Knee function was assessed using the Knee Society Score (KSS) six months after the surgery.

Results

The baseline characteristics of the groups did not differ significantly. The average distance from the previous scar was 4.1 ± 3.2 cm in the intervention group and 10.2 ± 2.1 cm in the control group. Only one patient in the control group developed skin necrosis (P-value = 0.31). Other wound-related complications were not observed in both groups. The mean KSS was 83.2 ± 10.2 and 82.9 ± 11.1 in the intervention and control groups, respectively (P-value = 0.33).

Conclusions

It is possible that in TKA patients, the new incision near a previous scar does not increase the risk of skin necrosis and other complications.

Free Flap Coverage for Complex Primary and Revision Total Knee Arthroplasty

BACKGROUND

Free flap coverage in the setting of a total knee arthroplasty is rare. The purpose of the current study was to evaluate the outcome of patients who underwent a free flap to assist with soft-tissue coverage following a complex total knee arthroplasty.

METHODS

The authors used their institutional total joint registry to retrospectively review patients undergoing a free soft-tissue flap in the setting of complex primary and revision total knee arthroplasty. Among 29,069 primary and 6433 revision total knee arthroplasties from 1994 to 2017, eight (0.02 percent) required a free flap for wound coverage. This included three primary total knee arthroplasties (0.01 percent) for posttraumatic arthritis and five revision total knee arthroplasties (0.07 percent) in the setting of infection. Median follow-up was 4 years.

RESULTS

Free flaps included vertical rectus abdominis (n = 3), anterior lateral thigh (n = 2), latissimus (n = 2), and transverse rectus abdominis (n = 1). There were no total flap losses; however, one patient required additional skin grafting. Reoperation occurred in six patients, of which four were revisions of the total knee arthroplasty for infection (n = 2) and tibial component loosening (n = 2). One patient ultimately underwent transfemoral amputation for persistent infection. Following reconstruction, there was improvement in the median Knee Society Score (49 versus 82; p = 0.03) and total range of motion between preoperative and postoperative assessments (70 degrees versus 85 degrees; p = 0.14).

CONCLUSION

Free flap coverage in the setting of total knee arthroplasty was associated with a high rate of reoperation; however, the limb was able to be preserved in the majority of patients, with a reasonable functional outcome.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Comparison of single-stage and delayed gastrocnemius flap procedures for soft-tissue defects of the knee and proximal tibia

PURPOSE

Gastrocnemius flaps provide reliable reconstructive solutions to soft-tissue loss of the knee and proximal tibia following orthopedic procedures. While this technique has been used and studied, little is known about its prophylactic application. Single-stage and delayed approaches were compared with respect to the timing of débridement, complications, and relationship between microorganisms and complications.

METHODS

Gastrocnemius flaps for soft-tissue defects of the knee joint were retrospectively reviewed. Success of the flap procedure was defined as a healed soft-tissue envelope, no evidence of infection, a good blood supply to the flap, and adherence of the flap to its bed. Independent sample t test was used to compare the corresponding parameters (level of statistical significance was 0.05).

RESULTS

Of 43 flaps (43 patients), 18 were performed during a single-stage procedure along with the orthopedic procedure and 25 were delayed. Success of the single-stage (100%) and delayed flaps (88%) was not significantly different (p = 0.083). Complication rate did not differ significantly for single-stage (11%) and delayed flaps (24%) (p = 0.272). We were unable to establish a relationship between complications and microorganisms.

CONCLUSION

Results indicate both approaches are reliable. Single-stage gastrocnemius flaps may eliminate the need for a second surgery.

LEVEL OF EVIDENCE

Level III (Therapeutic, Retrospective cohort).

A Novel Fasciocutaneous Flap Design for Reconstructions in Scarred Tissue: A Case Report

This article aims to introduce a technically easy and reliable flap design for the coverage of soft tissue defects in areas where traditional flap options are limited by trauma or scarring. We applied the boomerang design in cases with defects around the knee and also extrapolated it to other regions like the wrist and sacrum. Patients with soft tissue defects in regions with scarred tissues or limited flap reconstructive options were recruited. The procedures resulted in uneventful recovery and excellent cosmetic outcomes for the patients. The authors of this article recommend the usage of this uncomplicated flap design in areas with otherwise limited flap options due to restricted vascularity or surrounding scar tissue.

Treatment of posttraumatic patella osteomyelitis with MRSA infection and knee stiffness: a case report

Background

Posttraumatic patella osteomyelitis is rare, and the treatment of osteomyelitis remains to be challenging. Control of the infection commonly costs a long time, and it is easily to cause knee stiffness. In addition, there is no unified protocol for the treatment of knee stiffness.

Case presentation

We reported a case of posttraumatic patella osteomyelitis that successive infected with methicillin-resistant staphylococcus aureus (MRSA) after multiple surgeries. We successfully treated osteomyelitis by one-staged surgery, but the patient present knee stiffness after treatment. Thus Ilizarov external fixation system was further used to gradually adjust the mobility by exerting mechanical stress to the joint. After adjusting the frame under a scheduled plan, the patient successfully restored satisfactory knee function.

Conclusions

Adequate debridement is the key to control infections of posttraumatic osteomyelitis. Control the infection of posttraumatic patella osteomyelitis by one-staged surgery is achievable and could shorten the knee immobilization period. When knee stiffness occurs, scheduled range of motion (ROM) adjustment using Ilizarov frame with hinges might be a safe and useful method to restore function.

One-staged surgical management of large-scale skin necrosis after total knee arthroplasty: a case report (CARE-compliant)

Total knee arthroplasty (TKA) is a common surgical procedure performed in clinical settings. However, postoperative skin necrosis surrounding the incision can be a devastating complication. A large area of black necrotic skin was observed at the incision and anterolateral side of the right knee in a 78-year-old female patient after TKA. Skin necrosis surrounding the incision site was confirmed. Deep joint infection was excluded by synovial fluid analysis. We performed extensive debridement, joint capsule was opened, the knee prosthesis was exposed and partial synovectomy was performed. Then massive soft tissue defect (about 18 cm × 10 cm) was developed with exposed implants. After irrigation, the medial and lateral gastrocnemius muscle flaps were both released and transferred to completely fill the soft tissue defect, and the muscle flaps were then covered with split-thickness skin graft. The wound defect was reconstructed by single-staged surgery. The surgical incisions were healing well with no incisional complications. No swelling, tenderness, or evidence of knee infection was noted during follow-up. The right knee maintained good function and the range of motion was 0° to 130° at 1-year follow-up after the operation. Massive skin necrosis after TKA is rare but manageable. One-stage surgical treatment is also applicable if there is no deep infection, which could shorten the treatment period and achieve early rehabilitation.

Multimodal Conservative Treatment of Complicated Open Wound After Total Knee Replacement Arthroplasty in Patients With Comorbidities

Total knee replacement arthroplasty is a common procedure and postoperative wound complications are sometimes inevitable. Although invasive reconstructive surgery may be an option for nonhealed wounds, such procedures can limit early rehabilitation, adversely affecting the range of joint motion. Patients can achieve a wider range of motion if they undergo early rehabilitation with a conservative approach. From 2015 to 2017, 5 patients with comorbidities who underwent total knee replacement arthroplasty were referred to the reconstructive surgery department for nonhealed open wounds. Depending on their comorbidities and conditions, the patients underwent negative-pressure wound therapy based on multimodal conservative treatment. During the treatment, the patients continued rehabilitation. In the 5 patients, the mean duration of complete wound healing was 65.2 days (range = 57-81), during which all open wounds were well healed. For final wound closure, the patients underwent skin grafting, dermatotraction, or collagen dressing. Four patients achieved ranges of joint motion over 100 degrees after treatment. We believe that early coverage is important for open wounds. For complicated open wounds after total knee replacement arthroplasty in patients with comorbidities, less invasive multimodal treatment along with early rehabilitation may be more effective to achieve adequate final range of joint motion.

Hemostatic techniques to reduce blood transfusion after primary TKA: a meta-analysis and systematic review

PURPOSE

To investigate the efficacy of non-tranexamic acid (TXA) on reducing blood loss and requirements of allogeneic blood transfusion (ABT) in total knee arthroplasty (TKA).

METHODS

The PubMed, EMBASE, and the Cochrane Library databases were researched since incipiency to June 2018. Only randomized controlled trials (RCTs) involved with non-TXA hemostatic techniques in TKA met the inclusion criteria.

RESULTS

A total of 36 RCTs, including 1511 patients, were recruited for analysis. The results of subgroup analysis revealed that hemostatic techniques, which could substantially decrease the rate of ABT, were cell salvage with the transfusion trigger of 9 mg/dl, fibrin sealant with a dosage of 10 ml, and postoperative flexion position.

CONCLUSION

The available evidence in this meta-analysis suggests that postoperative flexion position, fibrin sealant, and cell salvage can substantially decrease the rate of ABT in TKA. Further studies, including more hemostatic methods and high-quality research, are expected.

Total Knee Arthroplasty Wound Complication Treatment Algorithm: Current Soft Tissue Coverage Options

BACKGROUND

Wound complications associated with soft tissue defects following total knee arthroplasty present challenges for the orthopedic surgeon. The scale of early complications include less morbid problems, such as quickly resolving drainage and small superficial eschars, to persistent drainage and full-thickness tissue necrosis, which may require advanced soft tissue coverage.

METHODS

This review outlines current wound management strategies and provides an algorithm to help guide treatment and clinical decision-making.

CONCLUSION

A surgeon's understanding of soft tissue coverage options is essential in protecting the knee prosthesis from a deep infection and to obtain an optimal functional outcome.

Central sensitization is a risk factor for wound complications after primary total knee arthroplasty

PURPOSE

Postoperative wound complication is a significant risk factor for subsequent deep periprosthetic joint infection after total knee arthroplasty (TKA). Central sensitization is an abnormal enhancement of pain mechanism involving the central nervous system. Although psychological disorder is widely considered as a risk factor, the relationship between central sensitization and wound complication is currently unclear. Therefore, the purpose of this study was to investigate whether central sensitization was associated with high wound complication rate after primary TKA.

MATERIALS AND METHODS

Between January and June 2016, 161 patients undergoing unilateral TKA were prospectively divided into two groups based on central sensitization inventory score of 40 points after excluding cases with known risk factors such as physical comorbidities, health-related behaviors, and psychological disorders. Group 1 consisted of 112 patients (112 knees) whose central sensitization inventory score was < 40 points and group 2 consisted of 49 patients (49 knees) whose central sensitization inventory score was ≥ 40 points. Wound complications were defined as wound dehiscence, suture granuloma, prolonged wound oozing after postoperative day 5, significant hematoma formation, or surgical site infection recorded during the initial 90-day postoperative period. Demographic data, visual analog scale (VAS), central sensitization inventory score, and wound complications were compared between the two groups.

RESULTS

Wound complications developed in 3 (2.7%) knees in group 1 and 14 (28.6%) knees in group 2 (p < 0.001). Multivariate logistic regression analysis showed that the odds of postoperative wound complications were increased 15.7 times in patients with central sensitization inventory score ≥ 40 (95% CI 4.1-60.0, p < 0.001).

CONCLUSION

Central sensitization is a risk factor for the development of postoperative wound complication after primary TKA.

LEVEL OF EVIDENCE

II.

Ipsilateral Arteriovenous Loop and Latissimus Dorsi Free Flap for Knee Reconstruction in an Elderly Patient: A Case Report

Herein, we report an unusual indication of an arteriovenous (AV) loop with a latissimus dorsi free flap after wound-edge necrosis in an 81 year old patient. The patient underwent multiple revision procedures after total knee arthroplasty and total hip arthroplasty. After a dramatic reduction of femoral bone, a total femoral replacement was performed. The lateral knee incision wound was broke down and the hardware became exposed. Local flaps were not available and a free flap with an ipsilateral AV loop from the great saphenous vein was used to cover the large defect. The functional status of the hip and knee joints was good after 6 months, and enough the patient was able to ambulate without any assistance. The patient did not show any signs of infection.

Medial Gastrocnemius Flap in the Course of Treatment for an Infection at the Site of a Total Knee Arthroplasty

Introduction

The pedicled medial gastrocnemius flap provides a robust coverage option for most soft-tissue deficiencies over the distal anterior aspect of the knee encountered in the setting of an infection after total knee arthroplasty.

Indications & Contraindications

Step 1 Patient Positioning

Position the patient supine with an ipsilateral sterile thigh tourniquet to allow room for harvest of a split-thickness skin graft as needed.

Step 2 Revision Arthroplasty for Infection

Perform the arthroplasty to address the underlying deep infection (e.g., irrigation and debridement with exchange of modular components, component removal with antibiotic spacer placement, antibiotic spacer exchange, or second-stage reimplantation) prior to the medial gastrocnemius flap that is utilized for soft-tissue coverage.

Step 3 Incision and Approach for the Medial Gastrocnemius Flap

Use one of two different surgical approaches for the exposure and elevation of the medial gastrocnemius muscle and the identification of its vascular pedicle: the medial approach or the posterior midline approach.

Step 4 Elevation of the Medial Gastrocnemius Flap

Protect the sural artery pedicle in the popliteal fossa because it is key to raising a viable medial gastrocnemius flap.

Step 5 Transposition and Insetting of the Flap Over the Defect

Rotate the flap and transpose it anteriorly over the defect either through a subcutaneous tunnel or by dividing the intervening skin bridge.

Step 6 Closure Skin-Grafting and Dressing Application

Complete the layered skin closure and place a split-thickness skin graft over the remaining exposed muscle flap and a nonadherent compressive bolster dressing or negative-pressure device over the skin graft to prevent hematoma under the skin graft.

Step 7 Postoperative Care

Progress range of motion of the knee once the flap and graft show evidence of survival, while an appropriate antibiotic regimen is completed.

Results

We recently reported the largest English-language series, to our knowledge, of medial gastrocnemius flaps performed for soft-tissue coverage in the course of treatment for infection after total knee arthroplasty¹³.

Pitfalls & Challenges

Systematic Review and Comparative Meta-Analysis of Outcomes Following Pedicled Muscle versus Fasciocutaneous Flap Coverage for Complex Periprosthetic Wounds in Patients with Total Knee Arthroplasty

Background

In cases of total knee arthroplasty (TKA) threatened by potential hardware exposure, flap-based reconstruction is indicated to provide durable coverage. Historically, muscle flaps were favored as they provide vascular tissue to an infected wound bed. However, data comparing the performance of muscle versus fasciocutaneous flaps are limited and reflect a lack of consensus regarding the optimal management of these wounds. The aim of this study was to compare the outcomes of muscle versus fasciocutaneous flaps following the salvage of compromised TKA.

Methods

A systematic search and meta-analysis were performed to identify patients with TKA who underwent either pedicled muscle or fasciocutaneous flap coverage of periprosthetic knee defects. Studies evaluating implant/limb salvage rates, ambulatory function, complications, and donor-site morbidity were included in the comparative analysis.

Results

A total of 18 articles, corresponding to 172 flaps (119 muscle flaps and 53 fasciocutaneous flaps) were reviewed. Rates of implant salvage (88.8% vs. 90.1%, P=0.05) and limb salvage (89.8% vs. 100%, P=0.14) were comparable in each cohort. While overall complication rates were similar (47.3% vs. 44%, P=0.78), the rates of persistent infection (16.4% vs. 0%, P=0.14) and recurrent infection (9.1% vs. 4%, P=0.94) tended to be higher in the muscle flap cohort. Notably, functional outcomes and ambulation rates were sparingly reported.

Conclusions

Rates of limb and prosthetic salvage were comparable following muscle or fasciocutaneous flap coverage of compromised TKA. The functional morbidity associated with muscle flap harvest, however, may support the use of fasciocutaneous flaps for coverage of these defects, particularly in young patients and/or high-performance athletes.

Prosthetic knee infection by resistant bacteria: the worst-case scenario

PURPOSE

The aim of the present paper was to determine (1) the incidence of failure (defined as the persistence or the recurrence of the infection), (2) the incidence of prosthesis (or even limb) loss (defined as the final need for an arthrodesis, resection arthroplasty or amputation) and (3) what factors could influence the failure in patients treated with a two-stage reimplantation for periprosthetic knee infections caused by resistant bacteria.

METHODS

The authors retrospectively reviewed 29 total knee arthroplasties infected by resistant bacteria in 29 patients who underwent a two-stage revision. Between the stages, intravenous-targeted antibiotics were administered for a median period of 8 (range 6-12) weeks. Median follow-up was 10 (range 7-14) years.

RESULTS

The authors found that failure occurred in 5 of 29 patients (17.2 %). When methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative staphylococci (MR-CoNS) were involved, failure rate was 10 % (2 of 20). When vancomycin-resistant enterococcus (VRE), multidrug-resistant (MDR) Acinetobacter baumannii and MDR Pseudomonas aeruginosa were involved, the failure rate was 33.3 % (3 of 9). Of those five patients, two underwent amputations, one chronic suppressive antibiotic therapy, one arthrodesis and one resection arthroplasty; among them, three lost the limb (10.3 % of the overall group). Timing of reimplantation and patient comorbidities did not significantly influence the failure.

CONCLUSIONS

Two-stage protocol resulted in a viable option for patients with infections by some resistant organisms (MRSA and MR-CoNS). However, when highly resistant organisms were involved (VRE, MDR Acinetobacter Baumannii and MDR Pseudomonas aeruginosa), the failure rate was much higher. In all cases of failure of the two-stage reimplantation, prosthesis (or even limb) loss occurred. Consequently, patients should be counselled that when highly resistant bacteria are involved, two-stage reimplantation could not be successful, with high final risk of prosthesis (or even limb) loss.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.

Soft Tissue Reconstruction and Flap Coverage for Revision Total Knee Arthroplasty

BACKGROUND

Total knee arthroplasty is a successful operation for treatment of arthritis. However, devastating wound complications and infections can compromise the knee joint, particularly in revision situations.

METHODS

Soft tissue loss associated with poor wound healing and multiple operations can necessitate the need for reconstruction for wound closure and protection of the prosthesis.

RESULTS

Coverage options range from simple closure methods to complex reconstruction, including delayed primary closure, healing by secondary intention, vacuum-assisted closure, skin grafting, local flap coverage, and distant microsurgical tissue transfer.

CONCLUSION

Understanding the advantages and pitfalls of each reconstructive option helps to guide treatment and avoid repeated operations and potentially devastating consequences such as knee arthrodesis or amputation.

Orthopedic Prosthetic Infections: Plastic Surgery Management

Orthopedic prosthetic infections are potentially devastating complications. Plastic surgeons are frequently consulted to aid in the management of the soft tissue defects that are created by these infections. A review of the existing literature was performed to identify established treatment methods for soft tissue coverage of orthopedic hardware infections for a variety of anatomic locations. The following treatment guidelines and soft tissue reconstructive options were identified as viable options for the management of exposed or infected orthopedic hardware. This review provides descriptions of the various soft tissue reconstructive options available as well as adjunctive treatment methods.

Orthopedic Prosthetic Infections: Diagnosis and Orthopedic Salvage

Orthopedic hardware infections are much feared and costly complications that can occur when these devices are implemented both in traumatic cases as well as in joint replacement surgery. Because these infections can lead to great morbidity, it is important to understand their pathophysiology as well as the principles behind their diagnosis and initial treatment. Plastic surgeons are frequently consulted as part of a multidisciplinary team to provide stable soft tissue coverage of the associated defects that result from these infections. A review of the existing literature was performed to identify the potential causes of these infections, to provide established diagnostic criteria guidelines, and to explain how these prosthetic infections are managed from an orthopedic surgery perspective prior to consulting the plastic surgery team.

[Quadriceps tendon insufficiency and rupture : Treatment options in total knee arthroplasty]

Quadriceps tendon injuries and insufficiencies in total knee arthroplasty are rare, but are followed by a devastating complication that left untreated leads to a complete loss of function of the knee. This review article summarizes the functional anatomy, risk factors, and the prevalence and diagnosis of quadriceps tendon injuries, in addition to the possible management options for partial and complete ruptures. The treatment options are adapted according to the extent of the loss of function (partial, complete) and the duration of the injury (acute vs chronic). Furthermore, the choice of treatment should take into account the quality and availability of primary tissue, the patient's general health, along with their likely functional requirements. Conservative treatment is often justified in partial ruptures with good results. Complete ruptures require surgical intervention and multiple operative techniques are described. Treatment options for acute ruptures include direct primary repair with autogenous or synthetic tissue augmentation. In the case of chronic insufficiency and a lack of soft-tissue surroundings, reconstruction with the aid of a muscle flap or allograft tissue can be considered. All surgical intervention techniques used so far have been fraught with complications and rarely lead to satisfactory results. A new surgical approach to the reconstruction and augmentation of the extensor mechanism consists of the use of a synthetic mesh. The technique is described here in detail.

What Factors Influence the Success of Medial Gastrocnemius Flaps in the Treatment of Infected TKAs?

BACKGROUND

Soft tissue defects after TKA are a potentially devastating complication. Medial gastrocnemius flaps occasionally are used to provide soft tissue coverage, most commonly with a periprosthetic joint infection.

QUESTIONS/PURPOSES

We asked: (1) What were the rates of persistent or recurrent infection, implant survivorship, flap-related complications, and reoperation for patients who underwent medial gastrocnemius flap reconstruction for soft tissue coverage after TKA? (2) What were the Knee Society clinical and functional scores for patients who underwent medial gastrocnemius flap reconstruction for soft tissue defects after TKA? (3) What were the risk factors for failure of medial gastrocnemius flap reconstruction after TKA, with failure defined as recurrent or new periprosthetic joint infection or inability to reimplant the TKA prosthesis?

METHODS

Between 2003 and 2011, four surgeons at one institution performed 31 medial gastrocnemius flaps for soft tissue coverage over an infected TKA. Of those, 27 (87%) were available for followup at a minimum of 2 years (mean, 4 years; range, 2-6 years), although patients experiencing complications or treatment failures before two years were included. The study group consisted of 15 men and 12 women with a mean age of 61 years at the time of surgery (range, 36-86 years). The general indication for using a gastrocnemius flap in this setting was full-thickness soft tissue deficiency over the anterior knee during the course of treatment for concomitant deep infection. Six flaps were performed at prosthetic explantation and antibiotic spacer placement, eight at a spacer exchange, eight at second-stage TKA prosthesis reimplantation, and five at débridement with polyethylene exchange. The decision regarding when during staged treatment to place the flap was based solely on when the soft tissues were deemed insufficient, and not based on a belief that placement at one stage versus another was advantageous. Failure was defined as inability to undergo reimplantation of a TKA prosthesis or recurrence of periprosthetic joint infection. Patient and procedural characteristics were tested for association with failure. Survivorship was calculated by Cox proportional hazards modeling. Outcomes scores were drawn from a longitudinal institutional registry.

RESULTS

Fourteen of 27 (52%) patients had a persistent or recurrent infection; survivorship of the TKA prosthesis at 4 years was 48% (95% CI, 31%-66%). Although there were no flap-related complications, 12 patients had a total of 19 reoperations during the study period. Overall, the mean (± SD) Knee Society knee (38 ± 18 vs 65 ± 20; p < 0.001) and function (20 ± 22 vs 37 ± 25; p = 0.002) scores were improved at most recent followup. No factors were identified as associated with failure when a Bonferroni correction was applied.

CONCLUSIONS

Gastrocnemius flaps were used to address difficult soft tissue defects in this series, in the presence of deep infections; the high proportion of patients experiencing persistent or recurrent infections reflects the case complexity and not necessarily a problem with the flaps. However, this series highlights the need to continue to explore alternative approaches to managing this difficult clinical problem. Future studies should aim to establish an evidence-based reconstructive algorithm, focusing on host, wound, and timing characteristics that may maximize outcomes.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

A clinical study of the rotational alignment of the femoral component in total knee arthroplasty

[Purpose] The reasons for femorotibial rotational malalignment after total knee arthroplasty (TKA) were analyzed to provide evidence for clinical knee joint surgery and to reduce complications. [Subjects and Methods] Ninety knees of 60 patients were selected and randomly divided into two groups (n=30). For one group, rotational alignment of the femoral component was determined by the transepicondylar axis and TKA was performed. For the other group, rotational alignment of the femoral component was conducted through 3° external rotation of the posterior femoral condyles. Knee joint specimens were operated with TKA and various biomechanical indices were measured. [Results] The femoral epicondylar axis was a constant, reliable reference for femoral component rotational alignment. When the femoral component was rotated by 0° versus the epicondylar axis, the peak contact pressure on the patellofemoral joint was optimal. When the femoral component was arranged in parallel with Whiteside's line, the peak contact pressure on the patellofemoral joint varied largely. The patellofemoral contact areas of the two groups were similar. [Conclusion] Axial rotational alignment of the femoral component influenced the contact pressure of patellofemoral joints in TKA more significantly than external rotation of the femoral condyles. It is more reliable to use the femoral epicondylar axis as the reference for the rotational alignment of the femoral component.

Vacuum-assisted closure for skin necrosis after revision total knee arthroplasty

Although skin necrosis following total knee arthroplasty or revision total knee arthroplasty is rare, it may cause severe complications. Skin changes begin with superficial infections and may result in removal of the prosthesis. Treatment of skin necrosis is an important factor, which determines the prognosis of the prosthesis. Several techniques have been defined for sufficient closure. In this article, we present the case of a patient who was treated for skin necrosis that developed after knee revision arthroplasty, using serial debridement, convergence sutures and an intermittent vacuum-assisted closure device (KCI Inc., San Antonio, TX).

Flap reconstruction of the knee: A review of current concepts and a proposed algorithm

A literature search focusing on flap knee reconstruction revealed much controversy regarding the optimal management of around the knee defects. Muscle flaps are the preferred option, mainly in infected wounds. Perforator flaps have recently been introduced in knee coverage with significant advantages due to low donor morbidity and long pedicles with wide arc of rotation. In the case of free flap the choice of recipient vessels is the key point to the reconstruction. Taking the published experience into account, a reconstructive algorithm is proposed according to the size and location of the wound, the presence of infection and/or 3-dimensional defect.

Knee flexion after total knee arthroplasty reduces blood loss

PURPOSE

Extensive blood loss after total knee arthroplasty (TKA) may be a potential problem since it leads to anaemia, increased need for transfusion and prolonged hospitalization. Aim of this study was to investigate the effects of postoperative knee flexion after TKA on blood loss and the need for transfusion.

METHODS

One hundred consecutive patients undergoing primary TKA from 2012 to 2013 were randomizely divided into two groups. In one group, the knee was extended for the first 6 h after surgery, whereas in the other was flexed at 90° for the same time. Two doses of endovenous tranexamic acid were administered in all subjects. Patients were homogeneous for all the possible confounding factors.

RESULTS

Calculated blood loss was 846 ± 197 (ml) in the flexion group and 1,242 ± 228 (ml) in the extension group (p < 0.05). Drop of haemoglobin levels at 24 h in the study group and the control group was 1.9 ± 0.8 (g/dl) and 3.0 ± 0.5 (g/dl), respectively (p < 0.01). Drop of haematocrit at 24 h was 4.5 ± 0.2 (%) in the flexion group and 6.7 ± 0.3 (%) in the extension group (p < 0.05). Blood transfusion was necessary in 5 patients in the control group and was not necessary in any patient of the study group. Average knee flexion at day 7 was 105° ± 4° in the flexion group and 98° ± 7° in the extension group.

CONCLUSION

Knee flexion at 90° after TKA, associated with the intraoperative use of tranexamic, acid is an effective method to reduce blood loss and the need for blood transfusion. The routine use of the present protocol is effective in reducing social costs and length of hospitalization of TKA procedures.

Flaps for closure of soft tissue defects in infected revision knee arthroplasty

PURPOSE

Total knee arthroplasty revision has wound healing deficits of up to 20 %. Defects in the knee region of multimorbid patients are hard to treat as complete explantation and revision arthroplasty is often too burdensome for them. In this study, we present our results with flaps for the treatment of defects after knee replacement, arthrodesis or osteosynthesis.

METHODS

Twenty-five patients (26 knees) with defects in the knee region were treated with flaps. Mean follow-up was 37 months (13-61) and the patients had a mean age of 72 years (49-85). A total of 39 flaps were performed (27 muscle flaps, seven fascio-cutaneous flaps and five free flaps).

RESULTS

Patients with more than three comorbidities showed higher risk of complications after surgery. Fifteen patients showed no infection at last follow up. Five patients received an arthrodesis of the knee, two showed persistent infection of the implant with fistula, and three were amputated above the knee.

CONCLUSIONS

Amputation could be avoided in 22 cases (85 %). The gastrocnemius muscle flap showed good results in the treatment of defects after arthroplasty or arthrodesis of the knee in multimorbid patients. This procedure can be used if further revision surgery is not indicated.

Reverse gracilis muscle flap: an alternative means of skin coverage for recurrent infection after TKA

PURPOSE

Poor wound-healing and skin necrosis are serious but not unusual complications after total knee arthroplasty, and when skin or soft tissue necrosis occurs, reconstructions in the knee area need thin, pliable, tough skin flaps.

METHODS

A 62-year-old man, who previously underwent multiple TKR operations due to recurrent infection, was transferred from another hospital after a gastrocnemius muscle rotation flap failed. We decided to treat the affected area with a reverse gracilis muscle flap. After confirming that the secondary pedicle was intact by Doppler sonography, muscle dissection was extended to the entry of the secondary pedicle. The proximal tendon of the gracilis muscle was transected, and the muscle was rotated 180° and placed at the recipient site.

RESULTS

The aim is to report a case of reconstruction at the anterior knee using a reverse gracilis muscle flap that achieved an excellent final clinical result.

CONCLUSION

This case suggests that the indications for a reverse gracilis muscle flap could be broadened when other flaps are not available for knee prosthesis coverage.

Surgical technique: vastus medialis and vastus lateralis as flap transfer for knee extensor mechanism deficiency

BACKGROUND

Loss of the quadriceps tendon, patella, and patellar tendon leaves a major anterior defect that is difficult to close and compromises knee extension strength. Gastrocnemius muscle transfer does not sufficiently cover such major defects. This paper describes a new surgical technique that addresses these defects and the results of eight cases of revision TKA managed with this new technique.

DESCRIPTION OF TECHNIQUE

The new procedure transfers the vastus medialis or the vastus lateralis and their tibial attachments or both muscles and their distal expansions combined with gastrocnemius and soleus flaps to cover major deficiencies in the anterior knee. Nine cadaver knee specimens were dissected to determine the effect of the transfer on nerve and blood supply of the muscles.

METHODS

Eight patients underwent the new procedure between 2005 and 2009. Four knees had vastus medialis transfer, two vastus medialis and vastus lateralis transfer, two vastus medialis and medial gastrocnemius transfer, and two medial gastrocnemius and medial ½ of the soleus muscle transfer. Minimum followup was 15 months (mean, 43 months; range, 15-74 months). Patients were evaluated for anterior knee pain, quality of knee closure, ROM, extensor lag, walking ability, use of assistive devices, and ability to climb stairs with the operated extremity.

RESULTS

All patients achieved closure of the knee without synovial leaks by 10 days postoperatively. Mean flexion contracture at last followup was 3° (range, 0°-7°). Mean extension lag was 22° (range, 5°-65°). Extension lag was less in those knees that included gastrocnemius or soleus muscle transfer. None of the flaps developed necrosis.

CONCLUSIONS

The vastus medialis and vastus lateralis muscles provide adequate coverage for anterior soft tissue deficits of the knee.

Wound closure

In this paper, we consider wound healing after total knee arthroplasty.