Can Vascular Injury be Appropriately Assessed With Physical Examination After Knee Dislocation?

The current epidemiology of vascular injuries associated with knee dislocation in the United States from 2010 to 2022

Introduction

Despite the recognized importance of managing vascular injury associated with knee dislocation, studies have been limited by small patient sizes, data older than five years, and lack of inclusion of newer procedural and diagnoses codes. This has been reflected in the reported frequency of knee dislocation associated with vascular injury ranging from 1.6 % to 64 %. As such, we sought to determine: (1) the frequency of knee dislocations associated with vascular injuries; (2) the frequency of knee dislocations associated with vascular injuries that required repair; as well as (3) independent risk factors for knee dislocation with vascular injury that require repair, across different age groups, sexes, and United States geographic regions.

Methods

A national, all-payer database was queried from January 1, 2010 to June 31, 2022. The frequency of a vascular injury was calculated by dividing the number of vascular injuries within 30 days of all knee dislocations by the total number of knee dislocations in each category. The frequency of a vascular injury that required repair was calculated by dividing the number of vascular injuries that required repair associated with knee dislocation by the total number of vascular injuries associated with knee dislocations. Patients were categorized by year of diagnosis, age, sex, and US geographic region. Multivariable logistic regressions were calculated to determine independent risk factors for knee dislocation with vascular injury.

Results

From 2010 to 2022, there were 99,688 knee dislocations. Of the total knee dislocations, there were 1066 (1.1 %) vascular injuries associated with knee dislocations, 96,530 (96.8 %) were closed dislocations, and 3158 (2.2 %) were open dislocations. Of the 1066 vascular injuries associated with knee dislocations, 262 (24.6 %) vascular injuries required repair. Male sex (P < 0.001), Elixhauser Comorbidity Index (ECI) > 3 (P < 0.001), alcohol abuse (P = 0.006), congestive heart failure (P = 0.01), hypothyroidism (P = 0.003), and obesity (P < 0.001), were independent risk factors for knee dislocation with vascular injuries.

Conclusion

Our study provides a refined understanding of the historically low incidence of knee dislocation with vascular injury as well as an increase in vascular injuries requiring repair from 2010 to 2022. Given the large expense of irreversible injury in these patients, vulnerable patient populations identified in our study, such as obese patients with additional comorbidities, should be a focus of future intervention. These findings can guide physicians in a clinical setting to appropriately manage the expectations of patients as well as minimize the morbidity and mortality associated with this presentation.

The known and unknown reality of knee dislocations: A systematic review

BACKGROUND

Knee dislocations (KD) are limb threatening injuries known to cause significant dysfunction and disability. This review aims to summarize KD knowledge and uncover areas where more research is needed.

METHODS

The published literature was queried according to PRISMA guidelines. Studies eligible for inclusion were clinical studies of knee dislocations. Studies published before 1990, or that focused on patellofemoral dislocation were excluded.

RESULTS

A total of 132 studies involving 43,869 knee dislocations were analyzed. The majority of patients were young adult males, with high-velocity trauma, particularly motor vehicle accidents, being the most common cause. Substance use and alcohol involvement were commonly reported. The predominant KD types were KD III (54.8 %) and KD IV (20.5 %). Meniscal tears were observed in over 50 % of cases, while cartilage injuries were present in 26.7 %. Neurovascular complications were significant, with popliteal artery injuries in 7.8 % and peroneal nerve injuries in 15.3 % of patients. Acute ligament repairs (64.2 %) were more common than delayed repairs (35.8 %), although the average time to repair was 56.1 days. Complications included amputations (2.3 %), fatalities (1.9 %), compartment syndrome (2.7 %), deep infection (5.3 %), and heterotopic ossification (21.6 %). Despite these severe injuries, a substantial loss to follow-up (19 %) and underreporting of functional outcomes were noted, limiting the comprehensive assessment of long-term recovery. A notable percentage of patients did not return to work or sports, with many requiring a change in profession due to their injuries, but these outcomes were only reported in 10 or fewer studies.

CONCLUSION

This study highlights the significant gaps in understanding the treatment strategies, financial burden, and long-term outcomes of knee dislocations. The incomplete data, particularly the high loss to follow-up rates and underreported functional outcomes, hinders the ability to make comprehensive assessments. Available results should thusly be interpreted with an understanding of the gaps in data, however return to sport and prior employment is often not achieved. Additionally, the potential influence of socioeconomic factors and substance abuse on treatment decisions and outcomes remains inadequately explored. Future research should focus on these areas to improve the management and prognosis of patients with knee dislocations, ensuring more accurate and thorough evaluations of long-term recovery and quality of life.

Vascular Injuries in Multiligament Knee Injuries (MLKIs)

Purpose

Vascular injuries are rarely associated with severe knee injuries; nonetheless, it is imperative to efficiently detect this condition and plan for either immediate or definitive treatment at later stages. The diagnosis and management of multiligament knee injuries still present unresolved issues, particularly in the early detection of vascular issues and the sequential stabilisation of ligaments. High-energy trauma is a frequently encountered cause, however, even low-energy trauma in those who are morbidly obese might pose a significant risk. Advancements in detection and management methods have greatly decreased the occurrence of vascular complications and amputation rates over time. MLKIs after transient knee dislocations are frequently misdiagnosed for vascular injuries, underscoring the necessity for improved diagnostic techniques to avoid avoidable amputations.

Methods

This article is a new conceptual review of vascular injuries associated with MLKIs. It provides a full overview of these conditions and includes a review of the most recent literature. We have included pertinent citations from the literature, together with suggestions derived from the latest studies. This review article had additional evaluation by proficient specialists with commendable outcomes and more than a decade of expertise in surgical techniques.

Results

This article offers a detailed overview of orthopaedic management, including new definitions and summaries of the causes, evaluation of patients, clinical assessment, identification of vascular injuries, and initial management in patients with vascular impairment following major limb and joint injuries (MLKIs).

Conclusion

MLKIs (patients with lower limb ischaemia) who have vascular damage necessitate meticulous physical assessment and sophisticated treatments in order to decrease amputation rates. Prompt identification and timely treatment of vascular lesions, namely in the popliteal artery, can substantially reduce the occurrence of amputations. Emerging research suggests that there is a heightened risk in low-energy situations, particularly amongst individuals who are extremely obese. Progress in vascular intervention has led to a reduction in amputation rates, whilst the implementation of new guidelines has enhanced identification. Thorough patient assessment is essential, utilising physical examinations and imaging techniques such as Computed tomography angiography, magnetic resonance angiography (CTA or MRA) to guide treatment decisions. MRA, in particular, is capable of identifying both vascular and knee structural damage.

Level of Evidence

Level IV, Literature reviews.

Vascular complications after a multiligament knee reconstruction: A case report highlighting the role of preoperative imaging

Vascular injuries are serious complications of multiligament knee injuries and can result in catastrophic outcomes. These injuries can range from intimal flaps with no compromise of the distal perfusion to a complete occlusion or transection requiring emergent vascular intervention. Several diagnostic tests, including the measurement of the ankle-brachial index (ABI), conventional angiography, and computed tomography angiography (CTA), are commonly used as diagnostic tools to identify vascular injuries in the context of a multiligament knee injury. In this report, the authors discuss the case of a patient with a normal ABI and palpable distal pulses on physical examination who developed limb ischemia after a multiligament knee reconstruction under tourniquet. The patient underwent emergent embolectomy and had a favorable postoperative outcome. During vascular exploration, there was no evidence of injury to the popliteal artery. The two working diagnoses were that either the patient had an intimal flap complicated by the development of a thrombus during surgery or that the initial vascular injury was not detected by ABI and clinical examination. Therefore, intimal flaps in multiligament knee injuries can lead to limb threatening ischemia in the context of reconstructive knee surgery and are likely underdiagnosed with ABI assessment. The utilization of preoperative CTA may help identify these injuries in patients indicated for reconstructive surgeries.

Tibiofemoral Dislocation Management in a Rural High School Football Scenario: Development of a Popliteal Artery Injury Suspicion Index

OBJECTIVE

This study evaluated the knowledge and preparedness of athletic trainers (ATs) for diagnosing and managing an anterior tibiofemoral knee dislocation in a rural or limited-resource high school football setting scenario. The study hypothesis was that more experienced ATs would display greater preparedness than less experienced ATs. A secondary objective was to develop evidence-based guidelines to help the AT provide better emergency triage care.

METHODS

This prospective cross-sectional study distributed a rural high school football game scenario survey electronically to a random sample of 2000 certified ATs to determine their perceptions of readiness to diagnose and manage an anterior tibiofemoral knee dislocation with signs or symptoms of possible popliteal artery injury.

RESULTS

A total of 249 surveys (12.5%) were completed. Years of athletic training experience were ≤5 years (n = 82, group 1) and ≥6 years (n = 167, group 2). Both groups perceived that they could not "rule out" an arterial injury and had similar "red flag" sign and symptom rankings. Group 2 perceived a more serious situation than group 1 (77.5 ± 15 vs 70.8 ± 14, P < 0.0001) and were more likely to activate the emergency action plan (74.5 ± 25 vs 64.4 ± 26, P = 0.005). Both groups were "neutral" about their ability to diagnose the condition or manage the case, had poor ankle-brachial index test familiarity, and agreed that evidence-based guidance was needed.

CONCLUSIONS

More experienced ATs perceived a more serious situation than less experienced ATs and were more likely to activate the emergency action plan. Both groups were neutral about their ability to diagnose the condition or manage the case, had poor ankle-brachial index test familiarity, and agreed that they would benefit from evidence-based guidance. Proposed guidelines provide the AT with a more measured, evidence-based index of suspicion for potential popliteal artery injury in anterior tibiofemoral dislocation cases. This will complement existing hospital emergency department-based management algorithms, decreasing the likelihood of this condition progressing to limb loss or death.

Open injuries and obesity as emerging risk factors for vascular injury in knee dislocations: A retrospective study

PURPOSE

Knee dislocations (KDs) are rare in orthopaedic trauma but can have devastating effects. Failing to diagnose a concomitant vascular injury can lead to amputation. Different methods are used for the diagnosis of a vascular injury and the best approach is under debate. This study aims to examine the risk factor(s) of vascular injury in patients with KDs, examine variables that differ between obese patients and non-obese patients with KDs, and analyse the modalities used to identify vascular injuries in the KD population.

METHODS

The electronic patient medical record system at a major trauma centre was retrospectively reviewed to identify knee dislocations from 2015 to 2022. These were stratified based on age, gender, BMI, mechanism of injury, vascular injury, non-vascular complications, and laterality. Co-variates were inputted into a univariable regression analysis, followed by a multivariable regression analysis to identify risk factors of vascular injury in patients with knee dislocations. Co-variates were also compared between obese and non-obese patients using two-tailed t-tests for continuous variables and chi-squared test for categorical variables.

RESULTS

Forty patients were identified with a KD, with twenty-eight males and twelve females. The average age was 42.9 years, seventeen patients had a BMI of thirty or over, and eleven patients (27.5%) had a vascular injury. Open injuries (OR: 2.21; 95% CI: 1.19-11.30; p = 0.038) and obesity (OR: 2.66; 95% CI: 1.45-18.69; p = 0.027) are risk factors for vascular injury in patients with knee dislocation. Compared to non-obese patients, obese patients had a higher rate of open injury (p = 0.028), vascular injury (p = 0.017), low-energy injuries (p = 0.014), non-vascular complications (p = 0.017), and amputation (p = 0.036).

CONCLUSION

Open injuries and obesity are risk factors for vascular injury in patients with KD. Compared to non-obese patients, obese patients have low-energy injuries and an increased rate of non-vascular complications, meaning that clinicians could err on the side of caution when investigating vascular injury.

LEVEL OF EVIDENCE

IV.

Diagnosis and treatment strategies of the multiligament injured knee: a scoping review

OBJECTIVE

To map the current literature evaluating the diagnosis and treatment of multiligament knee injuries (MLKIs).

DESIGN

Scoping review.

DATA SOURCES

Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews and Arksey and O'Malley frameworks were followed. A three-step search strategy identified relevant published literature comprising studies reporting on at least one aspect in the diagnosis or treatment of MLKI in adults. Data were synthesised to form a descriptive analysis and thematic summary.

RESULTS

Overall, 417 studies were included. There was a substantial chronological increase in the number of studies published per year, with 70% published in the last 12 years. Of included studies, 128 (31%) were narrative reviews, editorials or technical notes with no original data. The majority of studies (n=239, 57%) originated from the USA; only 4 studies (1%) were of level I evidence. Consistent themes of contention included clinical assessment, imaging, operative strategy, timing of surgery and rehabilitation. There was a lack of gender and ethnic diversity reported within patient groups.

CONCLUSIONS

There remains insufficient high-level evidence to support definitive management strategies for MLKI. There is considerable heterogeneity in outcome reporting in current MLKI literature, precluding robust comparison, interpretation and pooling of data. Further research priorities include the development of expert consensus relating to the investigation, surgical management and rehabilitation of MLKI. There is a need for minimum reporting standards for clinical studies evaluating MLKI.

Vascular Injury After Knee Dislocation: A Meta-Analysis Update

INTRODUCTION

Multisystem injuries affecting vasculature and nerves can be detrimental sequelae of knee dislocations (KDs). The purpose of this study was to provide an update of the current literature since the conducted search used in the publication of Medina et al on May 3, 2013, to evaluate (1) the frequency of vascular and neurologic injury after KD, (2) the frequency with which surgical intervention was conducted for vascular injury in this setting, and (3) the frequency with which each imaging modality was used to detect vascular injury.

METHODS

A two-author screening process was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the MEDLINE database. Frequency of vascular injury, surgical intervention, and amputation after KD were analyzed. Diagnostic modalities used in the acute-care setting were also evaluated.

RESULTS

Nineteen articles were analyzed for a total of 37,087 KDs. Of these, 10.7% sustained vascular injuries and 19.6% sustained nerve injuries. Overall, 62.2% of patients with vascular injury underwent surgical repair and 2.2% limbs resulted in amputation. Angiography was the most frequently used diagnostic modality (91.7%).

DISCUSSION

This review updates our understanding on the clinical implications of KDs including frequency of vascular injury (10.7%), amputation (2.2%), and nerve injuries (19.6%). Compared with prior literature, there was an increased prevalence of KD1 (32.4%) and lateral KDs (80.4%). Most vascular injuries after KD undergo surgical repair (62.2%).

Inclusion of open injuries in an updated Schenck classification of knee dislocations based on a global Delphi consensus study

OBJECTIVES

Knee dislocations (KDs) are complex injuries defined as incongruity of the tibiofemoral joint, which leads to tears of two or more of the main stabilising knee ligaments, and they are often associated with damage to surrounding soft tissue or neurovascular structures. A classification system for these injuries should be simple and reproducible and allow communication among surgeons for surgical planning and outcome prediction. The aim of this study was to formulate a list of factors, prioritised by high-volume knee surgeons, that should be included in a KD classification system.

METHODS

A global panel of orthopaedic knee surgery specialists participated in a Delphi process. The first survey employed 91 orthopaedic surgeons to generate a list of patient- and system-specific factors that should be included in a KD classification system that may affect surgical planning and outcomes. This list was subsequently prioritised by 27 identified experts (mean 15.3 years of experience) from Brazil (n = 9), USA (n = 6), South Africa (n = 4), India (n = 4), China (n = 2), and the United Kingdom (n = 2). The items were analysed to find factors that had at least 70% consensus for inclusion in a classification system.

RESULTS

Of the 12 factors identified, four (33%) achieved at least 70% consensus for inclusion in a classification system. The factors deemed critical for inclusion in a classification system included vascular injuries (89%), common peroneal nerve injuries (78%), number of torn ligaments (78%), and open injuries (70%).

CONCLUSION

Consensus for inclusion of various factors in a KD classification system was not easily achieved. The wide geographic distribution of participants provides diverse insight and makes the results of the study globally applicable. The most important factors to include in a classification system as determined by the Delphi technique were vascular injuries, common peroneal nerve injuries, number of torn ligaments, and open injuries. To date, the Schenck anatomic classification system most accurately identifies these patient variables with the addition of open injury classification. The authors propose to update the Schenck classification system with the inclusion of open injuries as an additional modifier, although this is only a small step in updating the classification, and further studies should evaluate the inclusion of more advanced imaging modalities. Future research should focus on integrating these factors into useful existing classification systems that are predictive of surgical treatment and patient outcomes.

Vascular Complications in Sports Surgery: Diagnosis and Management

Orthopedic sports surgery of the knee and shoulder is generally considered to be safe and effective. Vascular complications can occur during or after arthroscopy of either joint. A thorough understanding of anatomy, particularly when placing portals in non-routine locations, is extremely important. Prompt recognition of any vascular complication is of significant importance. This review will discuss the potential vascular complications for both knee and shoulder sports surgery, review the relevant anatomy, and discuss the treatment and expected outcome of each.

Acute Femoropopliteal Bypass Graft Occlusion After Knee Manipulation Under Anesthesia: A Case Report and Review of Current Literature

Bilateral tibiofemoral knee dislocations are a relatively rare injury, and there is a scarcity of literature on its appropriate evaluation and treatment. Even less knee dislocations with concomitant popliteal artery injury have been described. Postoperative graft occlusion accounts for approximately half of the overall complication rate, occurring in up to 18% of the patients undergoing femoropopliteal bypass grafting. Furthermore, anticoagulation and antiplatelet therapy after graft placement is a point of contention. Here, we describe a case of a knee dislocation with associated popliteal artery transection treated initially with successful knee-spanning external fixation and arterial grafting, respectively. At 6 weeks after injury, the patient underwent external fixation removal and closed manipulation of the knee for arthrofibrosis. After manipulation, yet still under anesthesia, distal pulses were acutely diminished and subsequent CTA demonstrated femoropopliteal graft thrombosis. This case demonstrates successful recognition, thrombectomy, and restoration of arterial blood flow, which has since been maintained. Written consent by the patient involved in this case report was obtained.

Knee Dislocation With Vascular and Nerve Injury in a Professional Football Player: Return to Play

Traumatic knee dislocations are serious and complex injuries, defined as clinical and/or radiological loss of tibiofemoral congruence, which may represent real emergencies to the integrity of the affected limb. This lesion is responsible for multi-ligament tears but the most serious possible complications are related to vascular and peripheral nerve injuries.

Recent studies show that surgical treatment has better functional results and higher return rates to sports practice compared to conservative treatment. However, there is still no consensus on the ideal surgical technique and the timing of surgery. After conservative management or surgical treatment, rehabilitation treatment plays a key role in the recovery process. There are few studies evaluating the return to competition after traumatic knee dislocation and those athletes who return have difficulty reaching the pre-injury level.

Here, we report the case of a professional football player who suffered a traumatic knee dislocation, with multiple ligament tears associated with vascular and neurological damage. Three hours after the initial lesion a double interposition bypass was done with the great saphenous vein, returning flow distally. It was decided not to perform ligament surgery. Two years after a long and intense rehabilitation program the athlete successfully returned to competition.

Knee joint dislocation: overview and current concepts

Knee joint dislocation is a relatively uncommon injury but its management is important because of the associated high risk of vascular, neurological and multi-ligamentous knee injuries. Clinicians must be aware that not all knee dislocations are diagnosed on plain X-rays; a high index of suspicion is required based on clinical evaluation. Multidisciplinary specialist care is required in all cases to achieve best outcomes. Early one-stage or multiple staged ligament repair and reconstruction offer better outcomes, but most patients have some long-term functional limitation. This article provides insights into the epidemiology and management of this injury and its devastating effects.

Comparison of computed tomography angiography and physical exam in the evaluation of arterial injury in extremity trauma

BACKGROUND

CT angiography (CTA) is increasingly used in the evaluation of arterial injury in extremity trauma. While it may provide additional objective data, it comes with inherent risks and expense. The purpose of this study was to compare CTA to physical exam in the evaluation of arterial injury in extremity trauma.

METHODS

We performed a retrospective review of patients who underwent CTA for evaluation of upper or lower extremity trauma at a Level 1 trauma center over a 10 month period. Patients were classified based on initial vascular exam (normal, soft signs, hard signs), and arterial injury on CTA was classified as major (named arteries) or minor (un-named arteries). We evaluated rates of vascular intervention in each group and compared the sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV) for physical exam and CTA in identifying arterial injury requiring intervention.

RESULTS

A total of 135 CTA studies were included. On initial vascular exam, 71% of patients had a normal exam, 22% had soft signs, and 6% had hard signs. The NPVs for arterial injury requiring intervention of a normal physical exam and negative CTA were both 100%. The PPVs for arterial injury requiring intervention of major injury on CTA and hard signs on physical exam were 35% and 50%, respectively.

CONCLUSION

A normal physical exam can likely rule out the need for vascular intervention and eliminate the need for CTA. Additionally, the presence of hard signs on physical exam is potentially superior to CTA in predicting the need for vascular intervention.

Initial Evaluation and Classification of Knee Dislocations

The traumatic knee dislocation (KD) is a complex condition resulting in injury to >1 ligament or ligament complexes about the knee, termed multiligament knee injuries. Typically, KDs result in injury to both cruciate ligaments with variable injury to collateral ligament complexes. Very rarely, KD may occur with single cruciate injuries combined with collateral involvement but it is important to understand that not all multiligament knee injuries are KDs. Patients can present in a wide spectrum of severity; from frank dislocation of the tibiofemoral joint to a spontaneously reduced KD, either with or without neurovascular injury. The initial evaluation of these injuries should include a thorough patient history and physical examination, with particularly close attention to vascular status which has the most immediate treatment implications. Multiple classification systems have been developed for KDs, with the anatomic classification having the most practical application.

Prioritised challenges in the management of acute knee dislocations are stiffness, obesity, treatment delays and associated limb-threatening injuries: a global consensus study

OBJECTIVES

Heterogeneous patient factors and injury mechanisms result in a great variety of injury patterns encountered in knee dislocations (KD). Attempts to improve outcome can focus on a wide range of challenges. The aim of this study was to establish and prioritise a list of challenges encountered when treating patients with acute KD.

METHODS

A modified Delphi consensus study was conducted with international knee specialists who generated a prioritised list of challenges. Selected priorities were limited to half of the possible items. Agreement of more than 70% was defined as consensus on each of these items a priori.

RESULTS

Ninety-one international surgeons participated in the first round. The majority worked in public hospitals and treated patients from low-income and middle-income households. Their propositions were prioritised by 27 knee surgeons from Europe, Africa, Asia, as well as North and South America, with a mean of 15.3 years of experience in knee surgery (SD 17.8). Consensus was reached for postoperative stiffness, obesity, delay to presentation and associated common peroneal nerve injuries. Challenges such as vascular injuries, ipsilateral fractures, open injuries as well as residual laxity were also rated high. Most of these topics with high priority are key during the initial management of a patient with KD, at presentation. Topics with lower priority were postsurgical challenges, such as patient insight, expectations and compliance, rehabilitation programme, and pain management.

CONCLUSION

This consensus study has a wide geographical footprint of experts around the world practising in various settings. These participants prioritised stiffness, obesity, treatment delays and associated limb-threatening injuries as the most important challenges when managing a patient with acute KD. This list calls for applicable and feasible solutions for these challenges in a global setting. It should be used to prioritise research efforts and discuss treatment guidelines.

LEVEL OF EVIDENCE

V.

Knee Dislocations in the Morbidly Obese Patient

Ultra-low-velocity knee dislocations are historically rare but increasingly common events. They occur most frequently in obese, morbidly obese, and super obese patients during everyday activities, but they can be as severe or more severe than high-velocity knee dislocations. Ultra-low-velocity knee dislocations frequently are associated with neurovascular injury and other complications. Diagnosis, early reduction, and identification and treatment of vascular injuries are critical to reducing the risk of limb ischemia and possibly amputation. Given the size of the limb, maintenance of reduction in these patients almost always requires external fixation. Although surgery on morbidly obese patients may be technically challenging, surgical reconstruction leads to improved subjective and objective results and is recommended.

Controversies in acute multiligamentary knee injuries (MLKI)

Multiligament injuries of the knee (MLKI), remain an infrequent pathology especially in developed countries compared to mono-ligament lesions. In Colombia, MLKI is frequent due to the high accident rate on motorcycles. In the city of Bogota alone, about 160 motorcycle accidents have been estimated daily, being one of the cities that proportionately use this means of transport less compared to small cities. The term MLKI, include all ruptures of two or more major ligaments and therefore it has a broad spectrum of clinical presentation which creates a great challenge for the orthopedists and the surgeons envolved in this topic. The literature is rich in studies level IV but very poor in level I and level II, which generates controversies and little consensus in the diagnosis and treatment of this pathology. However there has been a gradual and better understanding of all factors involved in the treatment of MLKI that has improved the functional results of these knees in our patients, in fact we currently are more precise to achieve accurate diagnosis, evolved from not surgical approach to operate most, applying new anatomical and biomechanical concepts, with specialized and skill surgical techniques with more stable and biocompatible fixation implants, which allow in most cases to initiate an early integral rehabilitation program. Nevertheless due to the complexity and severity of the lesions, in some patients the functional results are poor. The goal of this revision is to identify the most frequent controversies in the diagnosis and treatment of MLKI, defining which of them are agreed according to what is reported in the literature and share some concepts based from the experience of more than 25 years of the senior author (MM) in the management of these injuries. LEVEL OF EVIDENCE: V - Expert Opinion.

The outcomes of one-stage treatment for multiple knee ligament injuries combined with extensor apparatus rupture

Background

Multiple knee ligament injuries combined with extensor apparatus rupture are serious and complex knee injuries that are rare in clinical practice. The management is extremely challenging and controversial.

The aim of this study is to describe a patient collective with multiple knee ligament injuries combined with extensor apparatus injuries in detail and to report the mid-term outcomes of a one-stage surgical treatment regarding subjective outcome scores, complications, knee instability, and ROM.

Methods

Eleven of 425 patients with multiple knee ligament injuries combined with extensor apparatus injuries admitted to our hospital were reviewed from July 2008 to May 2017. All patients underwent one-stage repair and reconstruction of multiple knee ligaments and extensor apparatus. The Lysholm knee score and the International Knee Documentation Committee (IKDC) score were adopted to evaluate the surgical effect preoperatively and at a minimum of 2 years’ follow-up. Clinical data, including range of motion and knee stability, were also recorded at the final follow-up.

Results

Ten patients were followed up with a mean time of 40 (range, 24–60) months. At the last follow-up, 8 patients had joint flexion range of motion greater than or equal to120 degrees, 2 patients had joint flexion range of motion of 100–120 degrees, and 1 patient had active knee extension limitation of 5 degrees. Stress radiographs showed that the mean differences in posterior displacement were reduced from 10.8 ± 3.0 mm preoperatively to 2.0 ± 2.5 mm at the last follow-up. There were significant improvements in stress radiographs from pre- to postoperative states for all patients with multiple knee ligament injuries. The Lysholm score ranged from 85 to 96, with a mean of 92.1 (compared with 33 before surgery, P < 0.05). The final IKDC scores were A in 2 patients (20%), B in 7 (70%), and C in 1 (10%). Nine of the 10 patients (90%) returned to their former activity level.

Conclusion

Multiple knee ligament injuries combined with extensor apparatus rupture are rare. Single-stage management of the repair and reconstruction of multiple knee ligaments and extensor apparatus with proper rehabilitation is an effective and reliable procedure to restore knee stability and function.

Level of evidence

Level IV, therapeutic case series.

Which Risk Factors Predict Knee Ligament Injuries in Severely Injured Patients?-Results from an International Multicenter Analysis

Introduction: Ligament injuries around the knee joint and knee dislocations are rare but potentially complex injuries associated with high-energy trauma. Concomitant neurovascular injuries further affect their long-term clinical outcomes. In contrast to isolated ligamentous knee injuries, epidemiologic data and knowledge on predicting knee injuries in severely injured patients is still limited. Methods: The TraumaRegister DGU^® (TR-DGU) was queried (01/2009–12/2016). Inclusion criteria for selection from the database: maximum abbreviated injury severity ≥ 3 points (MAIS 3+). Participating countries: Germany, Austria, and Switzerland. The two main groups included a “control” and a “knee injury” group. The injury severity score (ISS) and new ISS (NISS) were used for injury severity classification, and the abbreviated injury scale (AIS) was used to classify the severity of the knee injury. Logistic regression analysis was performed to evaluate various risk factors for knee injuries. Results: The study cohort included 139,462 severely injured trauma patients. We identified 4411 individuals (3.2%) with a ligament injury around the knee joint (“knee injury” group) and 1153 patients with a knee dislocation (0.8%). The risk for associated injuries of the peroneal nerve and popliteal artery were significantly increased in dislocated knees when compared to controls (peroneal nerve from 0.4% to 6.7%, popliteal artery from 0.3% to 6.9%, respectively). Among the predictors for knee injuries were specific mechanisms of injury: e.g., pedestrian struck (Odds ratio [OR] 3.2, 95% confidence interval [CI]: 2.69–3.74 p ≤ 0.001), motorcycle (OR 3.0, 95% CI: 2.58–3.48, p ≤ 0.001), and motor vehicle accidents (OR 2.2, 95% CI: 1.86–2.51, p ≤ 0.001) and associated skeletal injuries, e.g., patella (OR 2.3, 95% CI: 1.99–2.62, p ≤ 0.001), tibia (OR 1.9, 95% CI: 1.75–2.05, p ≤ 0.001), and femur (OR 1.8, 95% CI: 1.64–1.89, p ≤ 0.001), but neither male sex nor general injury severity (ISS). Conclusion: Ligament injuries and knee dislocations are associated with high-risk mechanisms and concomitant skeletal injuries of the lower extremity, but are not predicted by general injury severity or sex. Despite comparable ISS, knee injuries prolong the hospital length of stay. Delayed or missed diagnosis of knee injuries can be prevented by comprehensive clinical evaluation after fracture fixation and a high index of suspicion is advised, especially in the presence of the above mentioned risk factors.

Varus mechanism is associated with high incidence of popliteal artery lesions in multiligament knee injuries

PURPOSE

This study aims to identify multiple ligament knee injury patterns that possess a high-risk of vascular lesion.

METHODS

We retrospectively compared torn ligament patterns and the presence of vascular lesions confirmed by magnetic resonance imaging and computed tomography angiography from 122 consecutive patients with diagnoses of multiple ligament knee injury made at the emergency department between January 2012 and December 2017. Patients were not eligible if they had an ipsilateral lower extremity lesion (dislocations or fractures at another level), initial evaluation at another hospital, or follow-up for less than 12 months. The primary outcomes were the comparison between the imaging findings of torn structures patterns and the presence of a vascular lesion.

RESULTS

We identified 48 eligible patients (50 knees) with multiligamentary knee lesions, of whom eight had popliteal artery damage, yielding an incidence of 16%. Our clinical examination detected six of these patients that were classified, according to the Schenck system, as KD-IIIL (6 knees) and KD-IIIM (2 knees). The odds of having a popliteal artery injury is 4.69 to 1 with a KD-IIIL injury that with any other type of injury on that classification (95% CI 0.960-22.98).

CONCLUSIONS

This data suggests that varus forces causing enough energy to produce a KD-IIIL lesion possess a higher popliteal artery injury risk, making recommendable a thorough examination of the vascular integrity when diagnosing a KD-IIIL lesion.

Outcomes and Predictors of Popliteal Artery Injury in Pediatric Trauma

BACKGROUND

Popliteal artery injury (PAI) is a rare occurrence in pediatric patients with significant consequences. Delays in diagnosis lead to severe complications such as lifelong disability and limb loss. We sought to identify outcomes and clinical predictors of PAI in the pediatric trauma population.

METHODS

The Pediatric Trauma Quality Improvement Program (2014-2016) was queried for patients ≤17 years old with PAI. Patient demographics and outcomes were characterized. A comparison of patients sustaining blunt versus penetrating PAI was performed. A multivariable logistic regression analysis was used to identify predictors of PAI.

RESULTS

From 119,132 patients, 58 (<0.1%) sustained a PAI with 74.1% from blunt trauma. Most of the patients were male (75.9%) with a median age of 15 and median Injury Severity Score of 9. A majority of the patients were treated with open repair (62.1%) in comparison to endovascular repair (10.3%) and nonoperative management (36.2%). The rates of open and endovascular repair and nonoperative management were similar between blunt and penetrating PAI patients (P = not significant). Concomitant injuries included popliteal vein injury (PVI) (12.1%), posterior tibial nerve injury (3.4%), peroneal nerve injury (3.4%), and closed fracture/dislocation of the femur (22.4%), patella (25.9%), and tibia/fibula (29.3%). Overall complications included compartment syndrome (8.6%), below-knee amputation (6.9%), and above-knee amputation (3.4%). The overall mortality was 3.4%. Patients with PAI secondary to penetrating trauma had a higher rate of concomitant PVI (26.7% vs. 7%, P = 0.04) and posterior tibial nerve injury (13.3% vs. 0%, P = 0.02) but a lower rate of closed fracture/dislocation of the patella (0% vs. 34.9%, P = 0.008) and tibia/fibula (0% vs. 39.5%, P = 0.004) compared to patients with PAI from blunt trauma. Predictors for PAI included PVI (odds ratio [OR] 296.57, confidence interval [CI] = 59.21-1,485.47, P < 0.001), closed patella fracture/dislocation (OR 50.0, CI = 24.22-103.23, P < 0.001), open femur fracture/dislocation (OR 9.05, CI = 3.56-22.99, P < 0.001), closed tibia/fibula fracture/dislocation (OR 7.44, CI = 3.81-14.55, P < 0.001), and open tibia/fibula fracture/dislocation (OR 4.57, CI = 1.80-11.59, P < 0.001). PVI had the highest association with PAI in penetrating trauma (OR 84.62, CI = 13.22-541.70, P < 0.001) while closed patella fracture/dislocation had the highest association in blunt trauma (OR 52.01, CI = 24.50-110.31, P < 0.001).

CONCLUSIONS

A higher index of suspicion should be present for PAI in pediatric trauma patients presenting with a closed patella fracture/dislocation after blunt trauma. PVI is most strongly associated with PAI in penetrating trauma. Prompt recognition of PAI is crucial as there is a greater than 10% amputation rate in the pediatric population.

Management of the Floating Knee: Ipsilateral Fractures of the Femur and Tibia

The "floating knee" is defined as fractures of the ipsilateral femur and tibia, which consists of a spectrum of injury, and may be in isolation or part of multiple system trauma for a given patient. A floating knee may compromise limb viability due to severe soft-tissue and vascular injury. Expeditious fracture reduction and patient resuscitation are crucial, while type and timing of provisional and definitive management is guided by the extent of injury to the involved extremity and associated systemic injuries. Numerous surgical techniques are available to treat the floating knee, including external fixation and internal fixation with plates or intramedullary nails. Fracture complexity and severity of soft-tissue injury present challenges, with articular injuries potentially more debilitating in the long term. Complications such as infection, deep vein thrombosis, knee stiffness, nonunion, malunion, and posttraumatic arthrosis after these injuries should be considered.

Evaluation and Management of Knee Dislocation in the Emergency Department

BACKGROUND

Knee dislocations are a potentially limb-threatening injury, and it is essential that emergency medicine clinicians are aware of them.

OBJECTIVE

This article provides a review of the diagnosis and management of knee dislocation for the emergency provider.

DISCUSSION

Knee dislocations are uncommon injuries with the potential for significant morbidity. A thorough history and examination are important, because 50% of dislocations may have reduced before arrival to the emergency department. Knee dislocations should be quickly reduced in the emergency department setting. The presence of equal pulses does not exclude vascular injury, and all patients should undergo serial vascular examinations and evaluation with ankle-brachial indices. Those with abnormal ankle-brachial indices should receive computed tomographic angiography. Radiographs are important to identify any fractures, while magnetic resonance imaging may be deferred until after admission.

CONCLUSION

Knee dislocation is a potentially dangerous medical condition requiring rapid diagnosis and management. It is essential for emergency clinicians to know how to diagnose and treat this disorder.

Hoffa fracture accompanied by dissection of the popliteal artery

After a high-energy trauma, a 37-year-old motorcyclist presented to the emergency ward with a Hoffa fracture of the lateral femoral condyle of the right knee. Following admission, the patient developed a pale, cold and pulseless right foot. CT angiography scan showed a 5 cm dissection of the popliteal artery. Emergency arterial reconstruction was performed and the Hoffa fracture was repaired in a second stage. To our knowledge, this is the first report of a patient with a Hoffa fracture accompanied by a popliteal artery dissection.

Importance of Early Diagnosis and Care in Knee Dislocations Associated with Vascular Injuries

BACKGROUND

Arterial injury secondary to acute knee dislocation (KD) is a rare but devastative complication. The aim of this study is to evaluate functional sequelae and factors of poor prognosis.

METHODS

A retrospective monocentric series of consecutive KD with acute ischemia by popliteal artery injury was analyzed between 2005 and 2017. The main outcome was the amputation rate.

RESULTS

Sixteen dislocations were included. Nine (56%) were due to public road accidents, 5 (31%) were due to falls from height, and 2 (13%) were due to sports injuries. Dislocation had occurred in the posterior location in 8 (50%) cases. Regarding arterial injury, there were 7 (44%) ruptures, 7 (44%) dissections, and 2 (13%) isolated thromboses. Eleven (69%) KDs with vascular trauma were associated with signs of acute ischemia. Revascularization was achieved by anatomical venous bypass in 14 (88%), resection and direct anastomosis in one (6%), and isolated thrombectomy in one (6%). Median time to surgery (time between trauma and vascular repair) was 7 hours (3.25-60.92 hours). Primary revascularization was performed in 12 (75%) cases. In three cases (19%), orthopedic reduction and stabilization were performed first. In one case, (6%) three-step management with vascular shunt at first, then with knee stabilization, and finally vascular bypass was carried out. Stabilization was achieved by using an external fixator in 13 (82%) cases, by open reduction and internal fixation in one case (6%), by ligamentoplasty in one (6%), and by using a long leg cast in one (6%). Fasciotomy was required in 12 (75%) cases. Two patients had early vascular complications, and 2 had early systemic complications. Three secondary transfemoral amputations were performed. Median follow-up duration was 23 months. No secondary amputation was recorded. At the end of follow-up, functional outcomes were evaluated using the Oxford Knee Score (OKS). The median OKS was 30 versus the pretrauma median OKS of 47 (P < 0.00028). No risk factor associated with limb amputation has been highlighted.

CONCLUSIONS

Analysis of these results provided indications for therapeutic management of this condition. This study shows poor functional outcomes because of severity of vascular lesion in patients with orthopedic trauma but with healthy arteries.

Multidisciplinary team approach in the management of popliteal artery injury

Popliteal artery injuries (PAIs) remain a challenging entity and carry the greatest risk of limb loss among traumatic lower extremity vascular injuries. Operative management of traumatic popliteal vascular injuries continues to evolve. Improved diagnostic imaging and the introduction of endovascular techniques offered alternative modalities to traditional surgical management. Despite major efforts in establishing protocols and guidelines in the management of vascular trauma, optimal strategies of traumatic PAIs are still under investigation. Herein, we discussed the role of multidisciplinary team, involving trauma and endovascular surgeons, emergency department personnel, and interventional radiologists in the management of complex PAIs.

Management of knee dislocation prior to ligament reconstruction: What is the current evidence? Update of a universal treatment algorithm

Traumatic knee dislocation is a rare but potentially limb-threatening injury. Thus proper initial diagnosis and treatment up to final ligament reconstruction are extremely important and a precondition to successful outcomes. Reports suggest that evidence-based systematic approaches lead to better results. Because of the complexity of this injury and the inhomogeneity of related literature, there are still various controversies and knowledge gaps regarding decision-making and step-sequencing in the treatment of acute multi-ligament knee injuries and knee dislocations. The use of ankle-brachial index, routine or selective angiography, braces, joint-spanning or dynamic external fixation, and the necessity of initial ligament re-fixation during acute surgery constitutes current topics of a scholarly debate. The aim of this article was to provide a comprehensive literature review bringing light into some important aspects about the initial treatment of knee dislocation (vascular injury, neural injury, immobilization techniques) and finally develop an accurate data-based universal algorithm, enabling attending physicians to become more acquainted with the management of acute knee dislocation.

Effect of Vascular Injury on Functional Outcome in Knees with Multi-Ligament Injury: A Matched-Cohort Analysis

BACKGROUND

Multi-ligament knee injury (MLKI) associated with knee dislocation can result in vascular injury. The purpose of this study was to compare knee function after MLKI between patients with a vascular injury requiring popliteal artery bypass grafting and patients without vascular involvement. Additionally, factors associated with poor knee function in patients who had MLKI with vascular injury were evaluated.

METHODS

This retrospective study identified patients with an MLKI between 1992 and 2014. Each patient who had a concomitant vascular injury requiring bypass grafting (vascular cohort, n = 16; mean age, 30.3 years) was matched to 2 patients without a vascular injury (control cohort, n = 32; mean age, 31.4 years) on the basis of age, knee dislocation (KD) grade, and peroneal nerve status. Fifteen patients in the vascular cohort and 26 patients in the control cohort had an isolated knee injury. Functional outcomes were assessed with physical examination of range of motion and ligamentous stability as well as patient-reported outcome scores.

RESULTS

The vascular cohort had a mean Lysholm score of 62.5 points (range, 16 to 100 points) and a mean International Knee Documentation Committee (IKDC) score of 59.7 points (range, 14.9 to 100 points) at a mean (and standard deviation) of 8.3 ± 5.0 years after surgery. The control cohort had a mean Lysholm score of 86.4 points (range, 51.0 to 100.0 points) and a mean IKDC score of 83.8 points (range, 35.6 to 100.0 points) at a mean of 6.0 ± 4.0 years. The vascular cohort had significantly lower Lysholm (p = 0.001) and IKDC (p = 0.002) scores than the control cohort. A body mass index (BMI) of >30 kg/m was predictive of lower IKDC (p = 0.0009) and Lysholm (p = 0.0008) scores.

CONCLUSIONS

Patients who sustain an MLKI with an associated popliteal artery injury requiring bypass grafting have significantly lower knee function scores than patients without vascular involvement. This information can be used to help counsel patients with combined multiple ligament and popliteal artery injuries.

LEVEL OF EVIDENCE

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

Clinical and Functional Results of 119 Patients With Knee Dislocations

OBJECTIVES

To describe clinical results and functional outcomes of knee dislocations treated with a consistent strategy within our institution.

DESIGN

Retrospective case series.

SETTING

Level 1 trauma center.

PATIENTS

One hundred nineteen patients were treated at one institution between 2000 and 2014 for knee dislocation.

MAIN OUTCOME MEASUREMENTS

Knee range of motion, functional instability, and complications were recorded. Musculoskeletal Function Assessment (MFA) and Lysholm scores were obtained after minimum of 1 year.

RESULTS

Sixty-three early complications were noted in 36 patients (32%), with an overall amputation rate of 9.2% (8 early and 3 late amputations). Of the patients who retained their limb, 4.5% reported instability. Open knee dislocations were associated with amputation (26% vs. 1.3%, P < 0.001). Popliteal arterial injuries were associated with more amputation (31% vs. 3.2%, P = 0 < 0.001), infection (37% vs. 8%, P = 0.002), and deep venous thrombosis (32% vs. 8.8%, P = 0.014). Patients with wound infection were more likely to develop heterotopic ossification (36% vs. 9.4%, P = 0.017) and less knee motion (77.5 vs. 117 degrees P = 0.049). Knee motion improved over time for all patients with a mean arc of 86 degrees at 3 months, 109 degrees at 6 months, and 115 degrees at 12 months. An Injury Severity Score of ≥20 was associated with less knee motion (97 vs. 121 degrees P = 0.029). Mean Lysholm score was 86.7, and mean MFA score was 35.7 after mean follow-up of 90 months and 82 months, respectively.

CONCLUSIONS

Few patients (4.5%) experienced functional instability. However, early complications occurred frequently (32%) as expected, particularly in patients with open injuries and/or arterial injury. Limitations in knee motion were associated with high Injury Severity Score, infection, and heterotopic ossification. Mean knee scores were good, consistent with reasonable knee function, although MFA scores suggest a lower level of generalized function.

LEVEL OF EVIDENCE

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

Knee Dislocation: A Case Report, Diagnostic Vascular Work-Up, and Literature Review

Knee dislocation is an uncommon, potentially limb-threatening, knee injury. Most often caused by high-velocity trauma, it can also result from low- or even ultra-low-velocity trauma. Rapid identification of the injury, reduction, and definitive management are necessary to minimize neurovascular damage. We present a case of rotatory anterolateral knee dislocation sustained during a twisting sports-related event. Special emphasis is placed on diagnosing vascular injuries associated with knee dislocations.

Knee Dislocations in Sports Injuries

Knee dislocations are devastating when they occur on the athletic field or secondary to motor sports. The complexity of presentation and spectrum of treatment options makes these injuries unique and extremely challenging to even the most experienced knee surgeons. An astute appreciation of the treatment algorithm is essential to plan individualized management since no two complex knee dislocations are ever the same. Moreover, attention to detail and finesse of surgical technique are required to obtain a good functional result and ensure return to play. Over the past 10 years, our service has treated 43 competitive sportsmen with knee dislocations, and this experience forms the basis for this narrative review.