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

Total Knee Arthroplasty Periprosthetic Joint Infection With Concomitant Extensor Mechanism Disruption and Soft-Tissue Defect: The Knee Arthroplasty Terrible Triad

BACKGROUND

Periprosthetic infection (PJI) with concomitant extensor mechanism disruption (EMD) and soft-tissue defect-hereinafter termed the "Terrible Triad"-is a devastating complication following total knee arthroplasty. The purpose of this study was to define the surgical and clinical outcomes following management of a cohort of patients who have the Terrible Triad.

METHODS

From 2000 to 2022, 127 patients underwent operative management for PJI alone, 25 for PJI with soft-tissue defects (defined as defects requiring flap reconstruction or being a factor contributing to the decision of performing above-knee amputation or arthrodesis), 14 for PJI with EMD, and 22 for the Terrible Triad. A composite outcome of infection status, range of motion, extensor lag, and ambulatory status at final follow-up was used to compare the proportion of patients in each group with a favorable overall knee outcome. Differences between groups were determined using one-way analyses of variance with post hoc Tukey's tests and Pearson's Chi-square tests or Fisher's exact tests with post hoc Bonferroni adjustments, where applicable. Odds ratios (OR) were calculated for comparison of the overall knee outcome between groups. A Kaplan-Meier survival analysis for patient mortality was performed.

RESULTS

The mean follow-up was 8.4 years and similar between groups (P = .064). Patients who had the Terrible Triad had a 45.5% incidence of above-knee amputation, or arthrodesis, and an 86.4% incidence of an unfavorable outcome. Compared to patients in the PJI group, patients in the PJI who had a soft-tissue defect (OR = 5.8, 95% CI [confidence interval] 2.2 to 15.7), PJI with EMD (OR = 3.7, 95%CI 1.0 to 12.9), and Terrible Triad groups (OR = 11.6, 95% CI 3.3 to 41.5) showed higher odds of an unfavorable knee outcome.

CONCLUSIONS

This study demonstrates that the total knee arthroplasty Terrible Triad is a dreaded diagnosis with poor outcomes. Clinicians and patients might consider early treatment with amputation or arthrodesis.

LEVEL OF EVIDENCE

III.

Utilization of the gastrocnemius flap for post-traumatic knee reconstruction: a systematic review

PURPOSE

High-energy injuries to the knee may lead to extensive soft tissue loss, fractures, and potential loss of extensor function. The gastrocnemius flap is a prominent reconstructive option for patients with injuries involving the knee and proximal third of the lower extremity. To the best of our knowledge, there has not been an informative review that has evaluated outcomes of patients who have undergone post-traumatic knee reconstruction with a pedicled medial or lateral gastrocnemius flap. The goal of this study is to assess outcomes in patients who have undergone gastrocnemius flap reconstruction after traumatic injuries to the knee.

METHODS

The review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) methodology. Four databases were utilized including PubMed, Cochrane Reviews, Embase, and CINAHL. Our search criteria consisted of the following keywords: gastrocnemius, flap, knee, and traum*.

RESULTS

A total of 204 studies were imported for screening, from which five papers met our final inclusion/exclusion criteria. The most common studies utilized in this review were case series followed by retrospective chart reviews. In total, 43 patients with traumatic soft tissue knee defects were included with an average patient age of 27.28 years. All patients had successful and clinical viable flaps post-operatively, and there were a total of five patients who had complications.

CONCLUSION

The gastrocnemius flap has demonstrated to be an effective option for individuals undergoing post-traumatic knee reconstruction. Infection rates, loss of mobility, and scarring represent a minority of complications that may be seen when this reconstructive technique is utilized. Still, additional randomized controlled trials and retrospective studies are required in order to further evaluate for other potential complications that may occur in this patient population.

Management of Bone Loss in Revision Total Knee Arthroplasty: An International Consensus Symposium

The evaluation, classification, and treatment of significant bone loss after total knee arthroplasty (TKA) continue to be a complex and debated topic in revision TKA (rTKA). Despite the introduction of new evidence and innovative technologies aimed at addressing the approach and care of severe bone loss in rTKA, there is no single document that systematically incorporates these newer surgical approaches. Therefore, a comprehensive review of the treatment of severe bone loss in rTKA is necessary. The Stavros Niarchos Foundation Complex Joint Reconstruction Center Hospital for Special Surgery, dedicated to clinical care and research primarily in revision hip and knee replacement, convened a Management of Bone Loss in Revision TKA symposium on June 24, 2022. At this meeting, the 42 international invited experts were divided into groups; each group was assigned to discuss questions related to 1 of the 4 topics: (1) assessing preoperative workup and imaging, anticipated bone loss, classification system, and implant surveillance; (2) achieving durable fixation in the setting of significant bone loss in revision TKA; (3) managing patellar bone loss and the extensor mechanism in cases of severe bone loss; and (4) considering the use of complex modular replacement systems: hinges, distal femoral, and proximal tibial replacements. Each group came to consensus, when possible, based on an extensive literature review and interactive discussion on their group topic. This document reviews each these 4 areas, the consensus of each group, and directions for future research.

Complex periprosthetic wound coverage in patients undergoing revision total knee arthroplasty: a single plastic surgeon study

INTRODUCTION

Options for soft tissue coverage in revision total knee arthroplasty (rTKA) range from primary wound closure to complex muscle flap reconstructions. The purpose of this study was to investigate the institutional experience of wound coverage options for complex soft tissue defects in rTKA.

MATERIALS AND METHODS

77 patients undergoing rTKA with complex wound closure by a single plastic surgeon were retrospectively reviewed. The average follow-up was 30.1 months. In 18 (23.4%) patients, an intraoperative decision for primary closure was made. Fifty-nine patients (76.6%) received either a local fasciocutaneous (N = 18), a medial gastrocnemius (N = 37), a free latissimus dorsi (N = 3) or a lateral gastrocnemius flap (N = 1). Revision-free survival and complication rates were assessed and risk factors were analyzed with Cox-regression analysis.

RESULTS

Medial gastrocnemius flaps had significant lower cumulative revision-free survival rates than local fasciocutaneous flaps (P = 0.021) and primary closures (P < 0.001) (42.5% vs. 71.5% vs. 100%,respectively). Comparing the most common complex closure procedures medial gastrocnemius flaps had the highest rate of prolonged wound healing (29.7%) and infection/reinfection (40.5%). Infection-associated flap procedures had significant lower cumulative revision-free survival rates (30.5%) than non-infection associated flap procedures (62.8%,P = 0.047). A history of more than two prior surgeries (HR = 6.11,P < 0.001) and an age ≥ 65 years (HR = 0.30,P = 0.018) significantly increased the risk of revision.

CONCLUSIONS

The results of this study indicate that primary closure -if possible- should be preferred to early proactive muscle flap coverage. Even in the hands of an experienced plastic surgeon muscle flaps have high revision and complication rates. The study highlights the need to clarify flap indications and to investigate alternative approaches.

Global mapping of institutional and hospital-based (Level II-IV) arthroplasty registries: a scoping review

PURPOSE

Four joint arthroplasty registries (JARs) levels exist based on the recorded data type. Level I JARs are national registries that record primary data. Hospital or institutional JARs (Level II-IV) document further data (patient-reported outcomes, demographic, radiographic). A worldwide list of Level II-IV JARs must be created to effectively assess and categorize these data.

METHODS

Our study is a systematic scoping review that followed the PRISMA guidelines and included 648 studies. Based on their publications, the study aimed to map the existing Level II-IV JARs worldwide. The secondary aim was to record their lifetime, publications' number and frequency and recognise differences with national JARs.

RESULTS

One hundred five Level II-IV JARs were identified. Forty-eight hospital-based, 45 institutional, and 12 regional JARs. Fifty JARs were found in America, 39 in Europe, nine in Asia, six in Oceania and one in Africa. They have published 485 cohorts, 91 case-series, 49 case-control, nine cross-sectional studies, eight registry protocols and six randomized trials. Most cohort studies were retrospective. Twenty-three per cent of papers studied patient-reported outcomes, 21.45% surgical complications, 13.73% postoperative clinical and 5.25% radiographic outcomes, and 11.88% were survival analyses. Forty-four JARs have published only one paper. Level I JARs primarily publish implant revision risk annual reports, while Level IV JARs collect comprehensive data to conduct retrospective cohort studies.

CONCLUSIONS

This is the first study mapping all Level II-IV JARs worldwide. Most JARs are found in Europe and America, reporting on retrospective cohorts, but only a few report on studies systematically.

Comparisons of the morbidities of a double gastrocnemius flap and a medial gastrocnemius flap in the orthoplastic reconstruction around the knee

BACKGROUND

The pedicled gastrocnemius flap is commonly used to treat lower limb defects. Either the medial, lateral, or both heads can be used. When extended soft tissue defects are present, a double gastrocnemius (DG) flap may be used. However, no data of the additional donor site morbidity compared to a medial gastrocnemius (MG) flap are available. The aim of this study was to compare the donor site morbidity of a DG with that of a MG.

METHODS

Patients with a soft tissue defect around the knee, treated with a gastrocnemius flap between 2018 and 2021 at the University Hospital of Lausanne and Bari, with a minimum follow-up of 12 months, were included. According to the size and the position of the defect, it was decided whether one (10 patients) or two (9 patients) heads of the gastrocnemius were necessary for the coverage. The mean age was 61 years (range 42-82) in DG, and 63 years (range 45-78) in MG. The average defect size was 89.8 cm2 in the DG group and 53.4 cm2 in the MG group. The etiologies were trauma (n = 10), infection (n = 7) and sarcoma (n = 2). A medial approach or a posterior midline approach was used for the harvesting of the gastrocnemius muscle. Once the flap was harvested, it was rotated and transposed anteriorly over the defect, either through a subcutaneous tunnel or by dividing the intervening skin bridge, depending on the soft tissue defect. A split-thickness skin graft was used to close the skin over the remaining exposed muscle flap. The active range of motion of the ankle and knee joints was measured. Muscle strength was assessed with a hand-held dynamometer and by the ability to stand on tiptoe. Physical function was evaluated through the Lower Extremity Functional Scale (LEFS).

RESULTS

The two groups were homogeneous, with no significant difference in age, sex, and BMI. All flaps survived in both groups. Both groups showed lower values in strength and range of motion of the operated leg, when compared to contralateral side. In plantar flexion, this accounted for a reduction in MG by 3.8 ± 1.0 kg of strength and 8 ± 3° of ROM, and in DG by 4.7 ± 1.7 kg and 16 ± 4°, respectively. For knee flexion, the reduction in MG was 4.4 ± 0.6 kg and 16 ± 7°, while in DG 5.6 ± 1.0 kg and 28 ± 6°. In the MG group, 60% were able to stand on the tiptoe of the operated leg, as opposed to 0% in DG. The average LEFS score in DG was lower by 10.9 points (p < .05). Questions concerning running and jumping had a lower score in DG (p < .01).

CONCLUSIONS

The harvesting of both gastrocnemii led to significant additional donor site morbidity compared to the harvesting of the medial gastrocnemius alone. However, the additional morbidity did not have an impact on activities of daily living and walking, even though it limited the ability to perform more demanding tasks such as running and jumping. Therefore, based on our study, the choice of a DG flap should be critically assessed in younger, more demanding patients.

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.

Ankle function after reconstruction of post-traumatic soft tissue defects with soleus and/or gastrocnemius local muscle flaps

Local muscle flaps are especially advantageous when treating soft tissue defects, but one disadvantage is the potential functional deficits associated with the muscle transfer. In this study, we evaluated ankle function among patients (cases) who underwent reconstruction of soft tissue defects in the leg using local flaps of the gastrocnemius and/or soleus muscle. Function was compared between the affected and contralateral non-affected limb and against patients (controls) with open tibial fractures who required no soft tissue reconstruction. In a retrospective cohort study, ankle function was accessed as range of motion (ROM) and plantar flexion strength, and using American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot summation and subscale scores. Among 31 patients who underwent soft-tissue reconstruction, 19 were available for functional evaluation. Controls were 23 patients with open tibial fractures not requiring flaps. Among cases, reconstruction was performed with a soleus flap in nine patients, a medial gastrocnemius flap in seven, a lateral gastrocnemius in one, and with both gastrocnemius and soleus flaps in one patient each. One patient developed partial flap necrosis. In cases, ankle dorsiflexion and plantar flexion were significantly decreased on the affected versus normal side. However, no deficit in plantar flexion strength was detected; nor any significant difference in AOFAS ankle-hindfoot scores in cases versus controls. Local muscle flaps are useful for reconstructing post-traumatic soft tissue defects in the leg. Some loss of ankle ROM should be expected, but likely no clinically-measurable deficit in overall ankle strength and function.

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.

A comparison of healing and complication rates between common flaps utilized in total knee arthroplasty: a review of the literature

Background

Flap reconstruction with perforator, fasciocutaneous, muscular, and/or free microvascular flaps is utilized to cover wound defects and improve vascularization and antibiotic/nutrient delivery. Flap use in revision procedures for total knee arthroplasty has been explored previously; however, current data are limited and studies comparing healing and complication rates between different flap types are lacking.

Methods

A literature review was performed using PubMed on 13 January 2022. Studies were included if they reported healing and complication rates for either gastrocnemius, rectus abdominis, latissimus dorsi, fasciocutaneous, chimeric, or gracilis flaps in the setting of revision total knee arthroplasty (TKA).

Results

The final cohort included gastrocnemius (n = 421, healing rate 73.8%, complication rate 59.9%), gracilis (n = 9, healing rate 93%, complication rate 55.6%), latissimus dorsi (n = 41, healing rate 67%, complication rate 46.3%), rectus abdominis (n = 3, healing rate 100%, complication rate 0%), fasciocutaneous (n = 78, healing rate 70%, complication rate 19.2%), and chimeric flaps (n = 4, healing rate 100%, complication rate 25%). There was no significant difference when comparing healing rates across flap types (p = 0.39). There was a significant difference when comparing complication rates across flap types (p < 0.0001), with a significant difference being noted between gastrocnemius and fasciocutaneous complication rates (p < 0.0001). All other comparisons between flap types by complication rate were not significantly different.

Conclusions

Gastrocnemius flaps are the workhorse flap in the setting of revision TKA, as evidenced by this review. Healing rates did not vary significantly across flap types, which suggests that determining the appropriate flap for coverage of soft-tissue defects in revision TKA should be driven by defect size and location as well as physician experience and patient tolerance.

Soft Tissue Procedures in the Multiply Operated on Knee Replacement Patient

In the multiply operated on knee replacement, no one soft tissue procedure is vastly superior to another. The most extensive literature available is in relation to muscle flaps, which will continue to be the workhorse technique for orthopedic and plastic reconstructive surgeons for the foreseeable future. Closed incision negative pressure wound therapy may prove to be a superior method in time but further large-scale studies are required to expand our understanding of this technique. The continued use of a combination of these techniques, tailored to the specific patient, is likely to be the best approach to the multiply operated on knee into the future.

Versatility of Medial Sural Artery Islanded Pedicled Perforator Flap for Resurfacing Areas Around the Knee

ABSTRACT

Soft tissue defects with exposed tendon, bones, and joints around the knee are difficult and challenging to treat because of its location over a joint, requires a stable cover that is supple and stretchable. For any knee defects, the gastrocnemius muscle flap is the first choice for the reconstruction, although it causes less functional deficit; however, because of its less reach, it is difficult to cover the defect in the superolateral aspect of knee joint and anterior to the tibial tuberosity with the other disadvantage being the bulkiness. The medial sural artery perforator flap (MSAPF) provides thin fasciocutaneous tissue similar to the adjacent normal soft tissue in the knee and so, its use leads to an improved reconstruction of contour and eliminating the need of a skin graft over the primary defect. Here, we will be discussing a case series using MSAPF to cover the defects around the knee.

Outcomes of the gastrocnemius flap performed by orthopaedic surgeons in salvage revision knee arthroplasty

Introduction: The gastrocnemius myofascial flap is used to manage soft-tissue defects over the anterior aspect of the knee in the context of a patient presenting with a sinus and periprosthetic joint infection (PJI) or extensor mechanism failure. The aim of this study was twofold: firstly, to evaluate the outcomes of gastrocnemius flaps performed by appropriately trained orthopaedic surgeons in the context of PJI and, secondly, to evaluate the infection-free survival of this patient group. Patients and methods: We retrospectively reviewed 30 patients who underwent gastrocnemius flap reconstruction during staged revision total knee arthroplasty for prosthetic joint infection (PJI). All flaps were performed by an orthopaedic surgeon with orthoplastics training. Patients had a mean age of 68.9 years (range 50-84) and were followed up for a mean of 50.4 months (range 2-128 months). A total of 29 patients (97 %) were categorized into Musculoskeletal Infection Society (MSIS) local extremity grade 3 (greater than two compromising factors), and 52 % of PJIs were polymicrobial. The primary outcome measure was flap failure, and the secondary outcome measure was recurrent infection. Results: Flap survival was 100 % with no failures or early returns to theatre for flap problems such as necrosis or haematoma. Overall infection-free survival during the study period was 48 % (13 of 27 infected cases). Using limb salvage as the outcome, 77 % (23 of 30 patients) retained the limb. Infection recurrence occurred in 48 % (10 patients) in the type B3 cohort and 67 % (4 patients) in the type C3 cohort ( p = 0.65 ). Conclusions: The surgical technique for a gastrocnemius myofascial flap is reliable and reproducible when performed by appropriately trained orthopaedic surgeons, even in high-risk groups. However, the risks of recurrent infection and amputation remain high within our series due to poor host and extremity factors.

The Versatility of the Pedicled Medial Sural Artery Perforator Flap: From Simple to Its Chimeric Pattern and Clinical Experience with 37 Cases

BACKGROUND

Defects in the knee area, popliteal fossa region, and upper third of the lower extremity can pose a challenge for reconstructive plastic surgeons. The purpose of this article is to report the authors' experience with the use of the pedicled medial sural artery perforator flap in its simple and chimeric form for reconstruction of defects in three different regions: knee, popliteal fossa, and proximal lower leg.

METHODS

From April of 2018 to April of 2019, 37 patients (29 men and eight women) with a mean age of 51 years (range, 18 to 78 years) underwent reconstruction with 37 pedicled medial sural artery perforator flaps. All flaps were harvested as pedicled perforator flaps in conventional or chimeric fashion and were based on one or two perforators. The defect locations included the knee (18 cases), popliteal fossa (seven cases), and proximal lower leg (12 cases). The cause of reconstruction was trauma in 22 patients (59 percent), tumor in 10 patients (27 percent), and donor-site closure of free medial sural artery perforator in five patients (14 percent).

RESULTS

The flap sizes varied from 3.5 × 5 cm to 5 × 10 cm. All but one flap, which showed distal tip necrosis, survived completely after surgery. The donor sites were all closed primarily. Minor complications included flap dehiscence (two cases) and minor wound infection delaying the healing process (four cases). All complications were treated conservatively. Follow-up observations were conducted for 3 to 12 months, and all patients had good functional recovery with satisfactory cosmetic results.

CONCLUSION

The pedicled medial sural artery perforator flap can be considered an optimal method of reconstruction for covering defects not only in the knee area but also in the popliteal fossa and upper lower leg.

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).

Gastrocnemius Muscle Flaps for Soft Tissue Coverage in Periprosthetic Knee Joint Infection

BACKGROUND

Soft tissue deficiency in total knee arthroplasty infection is a potentially devastating complication. Gastrocnemius muscle flaps can be used to address this problem. We aim at reporting survival rates of these reconstructions and identify risk factors for failure.

METHODS

A retrospective evaluation of all flaps performed at a single center between 2006 and 2019 was performed. Clinical and microbiological results were assessed in 43 cases after a median follow-up period of 53 months (25%-75% interquartile range 18-79). Function was assessed using the Oxford Knee Score. We analyzed the infection-free survival and identified risk factors using survival comparison and (non-)parametric testing.

RESULTS

Infection-free survival was 71% at 2 years and 63% at 5 years. The rate of subsequent amputation was 16% with a mortality rate of 26% during follow-up. Four patients did not undergo reimplantation and 11 patients received an arthrodesis implant. There were no failures of the flap itself. The Charlson Comorbidity index was the only relevant risk factor for reinfection. Coagulase-negative staphylococci were most common organisms identified. Postoperative function was limited with a mean Oxford Knee Score of 20.

CONCLUSION

Gastrocnemius flap coverage is a valid option for soft tissue reconstruction in periprosthetic infections to retain a functioning limb despite a high complication rate and the risk of subsequent amputation.

Effectiveness of circular hexapod external fixation with soft tissue reconstruction in treating severe knee dislocation due to burn scarring: a case report

Background

Severe varus deformity and soft tissue injury caused by a burn around a complex knee dislocation is a rare injury. Soft tissue reconstruction and deformity correction with circular hexapod external fixation of the knee and hinged total knee arthroplasty (TKA) are challenging and can lead to major complications if not performed appropriately. We present a case in which a combination of soft tissue reconstruction, circular hexapod external fixation, and TKA was used treat severe knee dislocation due to burn scarring.

Case presentation

We report the case of a 58-year-old woman who presented for knee surgery with soft tissue reconstruction, deformity correction with circular hexapod external fixation, and hinged TKA for a severe complex deformity and soft tissue injury caused by a burn injury at 6 months of age. The left leg was shorter by 35 mm in terms of functional leg length discrepancy. She walked with a limp, with a marked varus deformity of the left knee during the stance phase of walking. After a 3-stage repair, the patient was able to walk without assistance, confirming improvement of mobility.

Conclusion

The treatment method was an effective use of a combination of soft tissue reconstruction, circular hexapod external fixation, and rehearsal surgery using a 3D printed bone model of the modular rotating hinge component of TKA, which was successfully used to treat a severe knee dislocation due to burn scarring. This staged surgery maintained the leg length and ultimately achieved a satisfactory alignment.

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.

Treatment of Periprosthetic Knee Infection With Concurrent Rotational Muscle Flap Coverage Is Associated With High Failure Rates

BACKGROUND

Soft-tissue deficiency is a potentially devastating complication of the infected total knee arthroplasty (TKA). Rotational muscle flaps are commonly used to address these defects. However, reported success rates vary widely.

METHODS

We reviewed 26 consecutive patients who underwent rotational muscle flap surgery for full-thickness anterior soft-tissue defect during treatment of an infected TKA. Twenty-four cases used a medial gastrocnemius rotational flap, 1 used a lateral gastrocnemius flap, and 1 used a rectus femoris-vastus intermedius flap. Implant survival, recurrence of infection, and limb survival were reported. Patient and procedural characteristics were tested for association with failure using χ² and Student t-test. Kaplan-Meier analysis was used to estimate the failure-free survival function.

RESULTS

Mean follow-up time was 3.3 years. Eighteen of 26 patients (69.2%) experienced recurrent infection requiring an average of 5.3 additional operations (range, 1-20). Five (19.2%) required arthrodesis while 6 (23.1%) eventually underwent above-the-knee amputation. Two patients (7.7%) died due to complications of revision surgery or persistent infection. Eleven patients (42.3%) were infection free with a retained prosthesis after treatment at a mean follow-up of 5.3 years (range, 0.7-18.0 years).

CONCLUSION

Rotational muscle flap coverage of soft-tissue defects in the setting of the infected TKA remains a viable salvage option. However, despite adequate tissue coverage, many patients experience recurrent infection requiring additional surgical treatment. Patients and surgeons should be aware of the potential high failure rates observed when treating these complex problems.

The Effect of Positive Postdebridement Cultures on Local Muscle Flap Reconstruction of the Lower Extremity

Background

Local muscle flaps are a reconstructive option for wound coverage in the distal lower extremity, particularly in high-risk patients who are poor candidates for free tissue transfer. At our institution, chronic and infected wounds are managed with serial debridement before definitive reconstruction. There is a paucity of data on optimal timing for reconstruction in this patient population. This study investigates the relationship of positive postdebridement cultures (PDC) and wound closure rates at 90 days.

Methods

A retrospective review of patients undergoing local muscle flap coverage of chronic distal lower extremity wounds between 2006 and 2012 was performed. All patients were managed with serial debridement until negative PDC were obtained. In some cases, PDC remained positive or exhibit delayed culture growth in the day(s) following closure. Data recorded include demographics, flap type/location, culture data, and wound closure at 90-day follow-up.

Results

Of 76 patients, 60 met inclusion criteria with minimum 90-day follow-up. Despite 100% flap survival, 17 patients (28.3%) had failure of wound closure at 90 days and 22 patients (36%) had positive PDC. Multivariate analysis identified positive PDC (odds ratio, 29.6; 95% CI, 3.6-246.4; P = 0.002) and smoking (odds ratio, 8.9; 95% CI, 1.4-57.6; P = 0.02) as independent predictors of nonclosure at 90 days.

Conclusions

In this series of local muscle flap coverage of distal lower extremity wounds, positive PDC were a strong independent predictor of failure of wound closure at 90 days. This study demonstrates the importance of serial debridement to negative cultures before definitive coverage in this patient population.

Long-Term Outcomes of Pedicled Gastrocnemius Flaps in Total Knee Arthroplasty

BACKGROUND

Deficient soft tissue following total knee arthroplasty (TKA) can jeopardize outcome. The gastrocnemius flap is an important means of providing coverage of a knee with deficient soft tissue. There is a paucity of long-term studies on the use of the gastrocnemius flap in the setting of TKA. The purpose of this study was to review the outcomes after the use of pedicled gastrocnemius flaps for coverage of a soft-tissue defect at the time of TKA.

METHODS

Eighty-three patients in whom a gastrocnemius flap had been used to cover the site of a primary (n = 18) or revision (n = 65) TKA over a 25-year period were identified. There were 48 women (58%) and 35 men (42%) with a mean age and body mass index (BMI) of 65 years and 32.6 kg/m. The mean wound size was 49 cm, and the wound was most commonly located over the anterior aspect of the knee/patellar tendon (n = 33). Patients were followed to the time of implant or flap revision, amputation, or death or for a minimum of 2 years (mean, 8 years). Clinical outcomes were assessed using the Knee Society Score (KSS) for pain and the KSS for function. The Kaplan-Meier method was used to assess revision and amputation-free survival. Risk factors for amputation and revision were identified with Cox regression.

RESULTS

The 10-year revision and amputation-free survival rates following gastrocnemius flap coverage were 68% and 79%, respectively. The risk of implant failure was increased by morbid obesity (BMI of ≥40 kg/m) (hazard ratio [HR] = 2.82, 95% confidence interval [CI] = 1.09 to 7.32, p = 0.03) and ≥5 prior surgical procedures on the knee (HR = 2.68, 95% CI = 1.04 to 6.88, p = 0.04). The risk of amputation was increased in patients with ≥5 prior surgical procedures (HR = 10.76, 95% CI = 2.38 to 48.58, p = 0.002), an age of ≥65 years (HR = 4.94, 95% CI = 1.10 to 22.09, p = 0.03), and a wound size of ≥50 cm (HR = 3.29, 95% CI = 1.14 to 9.53, p = 0.02). Preoperatively the mean KSSs for pain and function were 46 and 28, and these scores significantly (p < 0.05) improved to 78 and 43, respectively, at the time of follow-up.

CONCLUSIONS

The gastrocnemius flap reliably provides coverage of components used in complex knee reconstruction. A history of multiple surgical procedures on the knee and larger soft-tissue defects increase the risk of revision TKA and of amputation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The Medial Sural Artery Perforator Flap: The First Choice for Soft-Tissue Reconstruction About the Knee

BACKGROUND

The gastrocnemius muscle flap may be considered the first choice in many cases of soft-tissue reconstruction about the knee. Limited arc of rotation and reach of the flap as well as unsightly muscle bulk are major disadvantages and were the impetus to look for a local alternative. The aim of this study is to present a consecutive series of patients with a reconstruction about the knee involving the medial sural artery perforator flap (MSAPF).

METHODS

A consecutive series of 17 cases of defect reconstructions about the knee using the MSAPF is described, with an emphasis on early postoperative complications.

RESULTS

No major flap-related complications occurred except 1 case of tip necrosis that healed uneventfully after excision and secondary suture. Two patients with direct donor-site closure had a minor complication that required no revision, and 2 had partial skin-graft loss.

CONCLUSIONS

In summary, use of this pedicled perforator flap represents a reliable technique for soft-tissue reconstruction about the knee with an acceptable complication rate and optimal contour reconstruction without the need for a skin graft and secondary debulking procedures. The range of motion associated with the MSAPF in comparison to the range associated with the gastrocnemius muscle flap is increased so that more proximal and lateral defects can be covered.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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

Medial Gastrocnemius Flap for Reconstruction of the Extensor Mechanism of the Knee Following High-Energy Trauma. A minimum 5 year follow-up

INTRODUCTION

The purpose of this study was to assess the medium-term results of reconstruction of the extensor mechanism using the medial gastrocnemius while also providing soft tissue coverage.

MATERIALS AND METHODS

This retrospective review consisted of a consecutive series of four patients (age 28-40 years) with complex high energy traumatic injuries to lower extremity including both soft tissue loss and disruption of the knee extensor mechanism. The medial gastrocnemius rotational flap was used to reconstruct the patellar tendon and restore soft tissue coverage simultaneously. Range of motion and extensor lag; functional recovery was judged by return to work and sports activity. Validated measures included the Oxford Knee Score, Knee Injury and Osteoarthritis Outcome Score, and the modified Cincinnati Score.

RESULTS

At the final follow up was 61.5 (57-66) months after reconstruction, the mean SF 12 physical component score ranged from 21.7 to 56.8 with a median of 55.3; the mental component from 42.8 to 60.7 with a median of 58.6. The KSS knee score ranged from 50 to 78 with a median of 68; the function score from 65 to 90 with a median of 85. The Oxford knee score ranged from 22 to 45 with a median of 33.5. The KOOS ranged from 28 to 82.7 with a median of 73.7 and the modified Cincinnati score from 38 to 82 with a median of 76.5. Knee range of motion ranged from 0 to 120°. Of the four patients three returned to working fulltime in their profession and returned to sports, including mountain biking and fitness training.

CONCLUSIONS

For severe traumatic knee injuries with the combination of soft tissue defects and disruption of the extensor mechanism, the medial gastrocnemius flap provides an excellent reconstructive option to address both problems simultaneously. The results of this small case series support the use of this limb salvage technique.