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

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.

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.

Combined articular and ligament reconstructions in neglected fracture-dislocation of the knee

Background

The management of neglected traumatic knee dislocations is challenging and is commonly associated with suboptimal outcomes. In this article we present two cases of neglected knee dislocations in two young trauma victims who presented late due to restrictions during the COVID-19 pandemic.

Methods

Two young patients presented at our center with neglected knee fracture-dislocations after eight weeks and six months of trauma. Comprehensive evaluation was performed using radiographs, computed tomography scans, and magnetic resonance imaging. Surgical intervention included open reduction and internal fixation of the mal-aligned intra-articular fracture fragments. Additionally, articular congruency was restored and repair or reconstruction of the posterior cruciate ligament, anterior cruciate ligament, and meniscus was conducted using suitable tendinous autografts and implants. Following surgery, the knees were immobilized for six weeks, followed by aggressive physical therapy.

Results

After three months of surgical intervention, fracture union and joint stability were achieved. At the >36-month follow-up appointments, both patients were pain-free at rest with a stable knee joint, achieving ≥90 degrees of knee flexion and without extensor deficits. Concurrent with radiographic evidence of osteoarthritic changes in the knee joint, there was mild pain (VAS 2) after prolonged knee movement activities and walking for long distances (>1 km).

Conclusion

Open reduction and internal fixation, along with simultaneous menisco-ligamentous reconstructions in neglected fracture-dislocations of the knee result in satisfactory clinical outcomes. This approach proves to be an effective joint preservation procedure in young patients, even in delayed and neglected conditions.

Magnetic resonance imaging quality in the context of a knee-spanning external fixator placed inside the MR bore: a literature review

After emergent assessment of potentially limb-threatening injuries in knee dislocation or multi-ligament knee injury patients, magnetic resonance imaging is necessary to visualize ligamentous structures and plan for soft tissue repair. However, the application of a knee-spanning external fixator may introduce artifact and reduce overall image quality, which can limit the evaluation of soft tissue injury. As a result, the utility of MRI in the context of a knee-spanning external fixator has been called into question. Signal-to-noise ratio, contrast-to-noise ratio, and qualitative scales have been used to assess image quality of MRI in the context of a knee-spanning external fixator. Despite the potential for artifact, studies have demonstrated that useful diagnostic information may be obtained from MRI in the presence of an external fixator. This review examines the general principles of anatomical assessment, magnetic field strength, device composition and design, radiofrequency coil use, and MRI sequences and artifact reduction as they pertain to MRI in the presence of a knee-spanning external fixator.

Perspectives and institutional policies on patient safety and image quality regarding the use of knee-spanning external fixators in MRI: A survey study of the Society of Skeletal Radiology

OBJECTIVE

Concerns regarding patient safety and image quality have made the use of knee-spanning external fixators in MRI a challenging clinical scenario. The purpose of our study was to poll practicing musculoskeletal radiologists on their personal experiences regarding the use of knee-spanning external fixators in MRI in an effort to consolidate practice trends for the radiologists' benefit.

METHODS

A 27-item survey was created to address the institutional use, safety, adverse events, quality, and perspectives of the radiologist related to MRI of an externally fixated knee. The survey was distributed to 1739 members of the Society of Skeletal Radiology.

RESULTS

A total of 72 members of the Society of Skeletal Radiology completed the survey. Most notably, 40 of 72 (55.56%) respondents are permitted to place a knee-spanning external fixator inside the MR bore at their institution, while19 of 72 (26.39%) respondents are not permitted to do so. Fourteen of 32 (43.75%) respondents have institutional guidelines for safely performing an MRI of an externally fixated knee. Twenty-five of 32 (78.13%) respondents are comfortable permitting an MRI of an externally fixated knee.

CONCLUSION

We found a general lack of consensus regarding the decision to scan a patient with a knee-spanning external fixator in MRI. Many institutions lack safety guidelines, and providers rely upon a heterogeneous breadth of resources for safety information. A re-examination of the FDA device labeling nomenclature and expectations of the individual manufacturers may be needed to bridge this gap and help direct management decisions placed upon the provider.

German S2e-Guideline "Knee Dislocation"

Knee dislocation is a devastating form of multiligament injury of the knee. Due to its high complexity, there is a large number of different diagnostic and treatment strategies. With the aim of providing evidence-based treatment recommendations, the S2e guideline on knee dislocation is aimed at all professional groups involved in diagnostics and therapy (orthopaedic and trauma surgeons, physiotherapists, outpatient/inpatient surgeons, sports physicians, etc.) as well as those affected (patients with knee dislocation) and service providers (health insurance companies, pension insurance companies). In addition to the presentation of conceptual differences between the injury entities, this includes the special features of diagnostic testing, options for conservative and surgical therapy as well as aspects of follow-up treatment - against the background of the interdisciplinary treatment approach to a severe knee injury.

Irreducible knee dislocation: improved clinical outcomes of open and arthroscopic surgical treatment. A systematic review of the literature

PURPOSE

Irreducible knee dislocations (IKDs) are a rare rotatory category of knee dislocations (KDs) characterized by medial soft tissue entrapment that requires early surgical treatment. This systematic review underlines the need for prompt surgical reduction of IKDs, either open or arthroscopically. It describes the various surgical options for ligament management following knee reduction, and it investigates their respective functional outcome scores to assist orthopedic surgeons in adequately managing this rare but harmful KD.

METHODS

A comprehensive search in four databases, PubMed, Scopus, Embase, and MEDLINE, was performed, and following the PRISMA guidelines, a systematic review was conducted. Strict inclusion and exclusion criteria were applied. Studies with LoE 5 were excluded, and the risk of bias was analyzed according to the ROBINS-I tool system. This systematic review was registered on PROSPERO. Descriptive statistical analysis was performed for all data extracted.

RESULTS

Four studies were included in the qualitative analysis for a total of 49 patients enrolled. The dimple sign was present in most cases. The surgical reduction, either open or arthroscopically performed, appeared to be the only way to disengage the entrapped medial structures. After the reduction, torn ligaments were addressed in a single acute or a double-staged procedure with improved functional outcome scores and ROM.

CONCLUSIONS

This systematic review underlines the importance of promptly reducing IKDs through a surgical procedure, either open or arthroscopically. Moreover, torn ligaments should be handled with either a single acute or a double-staged procedure, leading to improved outcomes.

LEVEL OF EVIDENCE

IV.

[Multiligament instabilities of the knee in sports injuries : An update of the Hamburg concept]

BACKGROUND

Knee dislocation (KD) is a rare but severe injury of the knee joint, with a high rate of concomitant neurovascular injuries. The severity of the ligamentous injury, which is classified according to the Schenck classification, the mechanism of injury, concomitant injuries and individual factors determine the treatment strategy in KD.

TREATMENT STRATEGY

Furthermore, a clear differentiation between high-velocity (HV) and low-velocity (LV) injuries is necessary. Generally, surgical treatment within 7-10 days should be aspired. Herein, the one-stage hybrid treatment using augmented ligament sutures (ligament bracing) in combination with primary ligament reconstruction (posterolateral and ACL) leads to very good functional results in the mid-term. Ultra-low-velocity (ULV) dislocations and those with concomitant peroneal lesions require a modified approach, due to a limited prognosis. During rehabilitation, the individual progress must be closely monitored and follow an early functional approach. In approximately 20% of all cases, early arthroscopic arthrolysis shows a high success rate.

Patient Safety in MRI with the Use of a Joint-Spanning External Fixator for Knee Dislocation: A Critical Analysis Review

» Universal safety guidelines for the use of a knee-spanning external fixator in magnetic resonance imaging (MRI) are unlikely to be established considering the high variability in device construct configurations.» Per the US Food and Drug Administration, manufacturers are to provide parameters for safe MRI scanning for "MR Conditional" devices; however, such labeling may be limited in detail. Physicians should reference manufacturer labels as a starting point while making an educated clinical decision.» Scanning of a knee-spanning external fixator inside the MR bore has been safely demonstrated in previous studies, although with small sample sizes.» When considering MRI in a patient treated with a knee-spanning external fixator, physicians should use all available resources and coordinate with their medical team to make a clinically reasonable decision contrasting patient benefit vs. potential harm.

[MCL tear with intra-articular dislocation]

A 48-year-old male patient presented with inner skin retraction after a sports accident involving the knee. In a multi-ligament injury it must be assumed that knee dislocation has occurred. Inner skin retraction after knee distortion can result from an intra-articular dislocation of the ruptured medial collateral ligament. Prompt reduction and exclusion of concomitant neurovascular injuries is thus obligatory. After surgical reconstruction of the medial collateral ligament, instability was no longer apparent 3 months postoperatively.

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%).

Simultaneous ipsilateral knee dislocation and hip fracture: A case report

Hip fracture is one of the main causes of medical attendance in trauma centers. By contrast, knee dislocation is a challenging and limb-threatening injury. We report a case of a 68-year-old male who sustained a simultaneous ipsilateral hip fracture and knee dislocation after a low-energy fall. Popliteal artery and common peroneal nerve injuries were associated. Knee dislocation treatment included closed reduction, external fixation and popliteal artery repair. Hip hemiarthroplasty was performed using a direct anterior approach. Revision multiligament knee reconstruction surgery was not considered. A rehabilitation program achieved a good long-term functional outcome. Simultaneous ipsilateral knee dislocation and associated proximal femoral injuries are rare and challenging, potentially requiring long-term staged management. The direct anterior approach to the hip is worth consideration when additional lower limb injuries are present, especially in the setting of a knee spanning external fixator.

Arthrofibrosis is a common but poorly defined complication in multiligament knee injuries: a systematic review

PURPOSE

The purpose of this study is to systematically review multiligament knee injury (MLKI) outcome studies to determine definitions of arthrofibrosis (AF) and provide information about incidence, management as well as potential risk factors.

METHODS

A systematic literature search was performed (PubMed and Cochrane library) following the PRISMA guidelines of operatively treated MLKI (Schenck II-IV) studies reporting the incidence of AF. Twenty-five studies met the inclusion criteria. Injury pattern, timing of surgery, surgical technique, treatment of AF, rehabilitation programs and PROMS were inquired. Risk of bias and quality of evidence were assessed using the Coleman methodological score.

RESULTS

Twenty-five studies with a total of 709 patients with a mean age of 33.6 ± 4.8 years were included and followed 47.2 ± 32.0 months. The majority of studies (22/25) used imprecise and subjective definitions of AF. A total of 86 patients were treated for AF, resulting in an overall prevalence of 12.1% (range 2.8-57.1). Higher-grade injuries (Schenck III-IV), acute treatment and ROM (range of motion) limiting rehabilitation programs were potential risk factors for AF. The time from index surgery to manipulation anesthesia (MUA) and arthroscopic lysis of adhesions (LOA) averaged at 14.3 ± 8.8 and 27.7 ± 12.8 weeks. Prior to MUA and LOA, the ROM was 51.7° ± 23.5 and 80.2° ± 17.0, resulting in a total ROM gain after intervention of 65.0° ± 19.7 and 48.0° ± 10.6, respectively; with no reports of any complication within the follow-up. The overall methodological quality of the studies was poor as measured by the Coleman score with average 56.3 ± 12.5 (range 31-84) points.

CONCLUSIONS

AF is a common but poorly defined complication particularly in high-grade MLKI. Early postoperative and intensified physiotherapy is important to reduce the risk of AF. MUA and LOA are very effective treatment options and result in good clinical outcome. Prospective studies with bigger study population are needed to optimize treatment algorithms of further patients after MLKI. The protocol of this systematic review has been prospectively registered with PROSPERO (CRD42021229187, January 4th, 2021).

Multiligamentous Knee Injuries: Acute Management, Associated Injuries, and Anticipated Return to Activity

Multiligamentous knee injuries (MLKIs) are devastating injuries. The energy and severity of these injuries encompass a wide range from low-energy single-joint mechanisms to high-energy polytrauma settings. Currently, there is no consensus on surgical treatment approach, surgical timing, or the return to preinjury activity levels after injury. There does appear to be a difference in the rate of return to activity and level of activity based on whether the injury was sustained during sport, in a trauma setting, or while on active military duty. The purpose of this descriptive review was to summarize current concepts related to (1) the acute management of MLKIs; (2) the effect of concomitant neurovascular, meniscal, and chondral injury on MLKI outcomes; (3) the effect of surgical versus nonsurgical treatment of MLKI on outcomes; and (4) rates and predictors of return to sport, work, and active military service after an MLKI.

Treatment of Knee Dislocation With Primary Repair and Suture Augmentation: A Viable Solution

Background:

Different surgical techniques have been described for the treatment of knee dislocation (KD). Nonoperative approaches are frequently combined with surgical reconstruction using auto- or allograft.

Purpose:

To evaluate the midterm results of primary surgical repair and suture augmentation to treat KD.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 22 patients (5 women, 17 men; mean age, 45 ± 15 years) with KD were evaluated at a mean of 49 ± 16 months after surgical treatment that included primary repair and suture augmentation. Magnetic resonance imaging, stress radiographs, and outcome scores were obtained at the follow-up. Clinical examination including hop tests and force measurements for flexion and extension was performed.

Results:

The mean difference in pre- to postinjury Tegner scores was –2 ± 1. The outcome scores showed mean values of 84 ± 15 (Lysholm), 73 ± 15 (International Knee Documentation Committee) and 65 ± 25 (Anterior Cruciate Ligament–Return to Sport after Injury scale). Compared with the uninjured knee, the range of motion of the injured knee was reduced by 21° ± 12°. Twelve patients felt fit enough to perform hop tests and showed a mean deficit of 7% ± 17%° compared with the uninjured leg. The mean force deficit was 19% ± 18% for extension and 8% ± 16% for flexion. Stress radiographs revealed an 11 ± 7–mm higher anteroposterior translation on the injured side. Four patients had secondary ligament reconstructions due to persistent instability and 7 underwent arthroscopic arthrolysis due to stiffness. A significant increase of osteoarthritis was found for the medial, lateral, and patellofemoral compartments (P = .007, .004, and .006, respectively).

Conclusion:

Primary repair and suture augmentation of KD led to satisfactory clinical midterm results despite persistent radiological instability and a significant increase in osteoarthritis. This technique allows the return to activities of daily living without subjective instability in most nonathletic patients. Secondary ligament reconstructions should be performed if relevant instability persists to decrease the risk of secondary meniscal and cartilage damage.

Total Knee Arthroplasty as the Primary Surgical Treatment After Knee Dislocation

Traumatic knee dislocation (KD) is a rare but serious injury, and a missed diagnosis or incorrect treatment can be limb-threatening due to a significant risk of neurovascular injury. The mechanism of injury is often high-energy trauma, but there is a rising tendency of KD after low-energy trauma in the obese patient. KD often results in multiligament injury which can be a complicated surgical task with long recovery time, especially in older patients. This report presents 4 cases where patients older than 50 years with traumatic KD have been treated with a total knee arthroplasty of revision type as an alternative to multiligament reconstruction.

An Evidence-Based Approach to Multi-Ligamentous Knee Injuries

Multi ligament knee injuries (MLKIs) are highly complex injuries with associated complications and often present with difficult management strategies. MLKIs may affect the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (or posteromedial corner (PMC)), and lateral collateral ligament (or posterolateral corner (PLC)) in addition to other structures including the menisci, common peroneal nerve, and popliteal artery. MLKIs are highly associated with the male sex and are commonly seen in high-velocity motor vehicle accidents and low-velocity sports injuries. Given the multiple planes of movement in the knee and various primary and secondary stabilizers throughout those planes, there is great heterogeneity in an injury pattern and most involve the ACL and PCL. Initial evaluation of this injury includes assessment of lower extremity sensation, distal pulses, and ankle-brachial index (ABI). If vascular compromise is suspected, computed tomography angiography (CTA) or magnetic resonance angiography (MRA) are indicated to evaluate the vasculature. As opposed to CTA, MRA offers visualization of the soft-tissue structures that are commonly damaged in MLKIs. Initial management typically includes closed reduction of the knee with subsequent external fixation. Classification systems guide initial assessments; however, further management is unclear and leads the surgical team to decide the best, individualized management option for each patient. As a result, optimal surgical and postoperative treatment options remain complicated, and clinical outcomes remain difficult to predict. The purpose of this review is to consolidate the most up-to-date practices of the diagnostic workup, management, and treatment of MLKIs.

Management of acute knee dislocation with vascular injury: the use of the external fixator. A systematic review

INTRODUCTION

Vascular injuries after traumatic knee dislocation pose a potential limb threat for the patient. The benefits of external fixation have been described by many authors. However, the usefulness of the external fixator during acute management of knee dislocations with vascular injuries is a controversial aspect that has no consensus in the literature. The purpose of the present study was to provide data from the current literature on the utility of the external fixator and to investigate the percentage of knee dislocations with vascular injuries treated with an external fixator, the timing between external fixator and vascular repair, and the total time of external fixator.

MATERIAL AND METHODS

The present systematic review was conducted according to the PRISMA checklist. MEDLINE (Pubmed), Web of Science, and SCOPUS databases were searched for articles from 1 January 2000 to 6 February 2019. Studies reporting outcomes of treatment of knee dislocations with vascular injuries were included. Exclusion criteria included studies investigating chronic knee dislocations, knee arthroplasties, editorials, case reports, and expert opinions. Two authors independently extracted data and appraised the quality of evidence and risk of bias using the Methodological quality and synthesis of case series and case reports.

RESULTS

Descriptive statistics were used to report the outcome of our findings. Seven studies related to the usefulness of the external fixator during acute management of knee dislocations with vascular injuries were included. The external fixator had been used in the majority of knee dislocations with vascular lesions (72%). Timing between external fixator and vascular repair was reported on four studies (57%), two studies performed external fixation before vascular repair, and two studies performed external fixation after vascular repair. Total time of external fixator was only reported on three studies, ranging from 3 weeks to 3 months. These studies reported acute management, without referring to long-term results and without comparative groups.

CONCLUSIONS

External fixator was used in the majority of knee dislocations with vascular injuries but the justification for its use remained unclear. Larger studies are needed to fully understand the merit of the external fixator in knee dislocations with vascular injuries. Joint protocols between vascular surgeons and trauma surgeons are necessary to agree on the aspects related to the management of knee dislocations with vascular injuries.

LEVEL OF EVIDENCE

IV.

Triple dislocation around the knee joint: a case report

BACKGROUND

Dislocation of the knee is a serious and potentially limb-threatening injury. There are three types of dislocation around the knee joint: patellofemoral, tibiofemoral, and tibiofibular. Tibiofemoral dislocation is the variant that is deemed the most serious, with a higher risk of compromise to the popliteal artery and common peroneal nerve. Although simultaneous dislocations of two types have been described, there has been no such description of all three types occurring simultaneously.

CASE PRESENTATION

We present a case of a 40-year-old hairdresser who suffered a fall off her moped in Spain, and simultaneously dislocated all three articulations around the knee. Diagnosis was achieved with clinical examination, plain films, and computed tomography and magnetic resonance imaging scans. Management consisted of initial surgical debridement and reduction with stabilization of the affected joints.

CONCLUSION

Dislocation of the knee is an uncommon but life changing and potentially limb-threatening injury. It should always be suspected in trauma patients who present with multiligamentous knee injuries. The main concern is of neurovascular compromise to the lower leg, namely, the popliteal artery and common peroneal nerve. The treatment of multiligamentous knee injuries for most patients is surgical treatment with physiotherapy and adequate stabilization of the knee joint. Close monitoring of progress of the knee in terms of persistent laxity, range of movement, and functional status is required for at least 1-year post injury. Current evidence suggests that, despite good functional outcomes for knee dislocations in the short term, the prevalence of post-traumatic osteoarthritis is high in the long term.

External fixation increases complications following surgical treatment of multiple ligament knee injuries

PURPOSE

The purpose of this study was to review post-operative complications after surgical intervention of MLKIs within the first 6 months to be better able to counsel patients before surgical intervention.

METHODS

All patients who underwent surgical reconstruction for a MLKI at one institution from 2009 to 2018 were included in this study. A retrospective review was performed of all patients and post-operative complications were recorded, including motion loss (which included > 10 degree flexion loss or > 3 degree extension loss), hematoma formation, infection, iatrogenic vascular or nerve injury, deep vein thrombosis (DVT), pulmonary embolism (PE), skin lesions, symptomatic hardware, recurrent ligamentous laxity, and need for additional surgery. Knee ligament injuries were classified based on the Schenck Knee Dislocation (KD) Classification.

RESULTS

A total of 136 patients were included in this study, 83 with KD I injuries, 40 with KD III injuries, 9 with KD IV injuries, and 4 with KD V injuries. Of these total patients, 48 (35.5%) sustained a post-operative complication: 11 out of 133 (8.3%) from 0 to 1 week, 46 out of 132 (34.8%) from 1 week to 1 month, 28 out of 124 (22.6%) from 1 to 3 months, and 26 out of 121 (21.5%) from 3 to 6 months. Out of the total complications, 99 (78.5%) occurred at 1 week-3 months post-operation. Patients who had an external fixator placed at initial injury were more likely to sustain a post-operative complication. The most common complication was motion loss in 39 (28.6%) patients. There was a significant difference in mean number of complications between the KD I and KD III groups, as well as the KD III and KD IV-V groups. There was no significant difference in the overall prevalence of post-operative complications or occurrence of motion loss with KD grade.

CONCLUSION

The main finding of this study was 48 (35.5%) patients sustained a complication after surgical treatment of MLKIs, with 99 (78.5% of all complications) complications occurring at 1 week-3 months post-operation. Patients who had an external fixator placed at initial injury were more likely to sustain a post-operative complication. The most common post-operative complication was motion loss in 39 (28.6%) patients. The KD grade was not associated with post-operative development of motion loss, but KD III had a significantly greater mean number of complications than KD I or KD IV-V grades.

LEVEL OF EVIDENCE

IV.

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.

Deep Learning-Based Magnetic Resonance Imaging Image Features for Diagnosis of Anterior Cruciate Ligament Injury

To study and explore the adoption value of magnetic resonance imaging (MRI) in the diagnosis of anterior cruciate ligament (ACL) injuries, a multimodal feature fusion model based on deep learning was proposed for MRI diagnosis. After the related performance of the proposed algorithm was evaluated, it was utilized in the diagnosis of knee joint injuries. Thirty patients with knee joint injuries who came to our hospital for treatment were selected, and all patients were diagnosed with MRI based on deep learning multimodal feature fusion model (MRI group) and arthroscopy (arthroscopy group). The results showed that deep learning-based MRI sagittal plane detection had a great advantage and a high accuracy of 96.28% in the prediction task of ACL tearing. The sensitivity, specificity, and accuracy of MRI in the diagnosis of ACL injury was 96.78%, 90.62%, and 92.17%, respectively, and there was no considerable difference in contrast to the results obtained through arthroscopy (P > 0.05). The positive rate of acute ACL patients with bone contusion and medial collateral ligament injury was substantially superior to that of chronic injury. Moreover, the incidence of chronic injury ACL injury with meniscus tear and cartilage injury was notably higher than that of acute injury, with remarkable differences (P < 0.05). In summary, MRI images based on deep learning improved the sensitivity, specificity, and accuracy of ACL injury diagnosis and can accurately determined the type of ACL injury. In addition, it can provide reference information for clinical treatment plan selection and surgery and can be applied and promoted in clinical diagnosis.

MRI of Traumatic Knee Dislocation: A Study to Evaluate Safety and Image Quality for Patients with Knee-Spanning Stabilization Devices

This study evaluated safety and image quality of MRI exams performed for patients with traumatic knee dislocations in knee-spanning stabilization devices. It is an IRB-approved retrospective design with waived informed consent that included 63 patients with traumatic knee dislocation. 56 patients had metallic external fixators, and 7 patients had non-metallic knee immobilizers. 7 patients had bilateral dislocations yielding a total of 70 knee MRIs. 1.5 Tesla MRI exams were performed for all patients who were awake and alert at the time of imaging. All knee-spanning external fixators were considered "MR conditional" by the FDA. The electronic medical record was reviewed for notes from the technologist and nursing staff documenting any patient complaints or adverse events during the MRI exam as required by departmental protocol. Qualitative analysis of the six most frequently performed sequences were independently conducted by 2 musculoskeletal radiologists using a 5-point Likert scale. Overall image quality and select time intervals between the two groups were compared using an independent sample t test and the Mann-Whitney U test, respectively. No adverse events were reported for a 40-minute average estimated patient scan time with the stabilization devices in the MR gantry. Mean values of Likert scale scores were generated from two readers' data for comparison between the external fixation and the immobilizer groups. Most knee MRI exams with external fixators were within diagnostic quality despite artifacts (grade 3). MRI exams generally were of higher diagnostic quality in the immobilizer group than the external fixator group (p < 0.05). The external fixator models included DePuy Synthes, Smith and Nephew, Stryker Hoffman III, Zimmer FastFrame, and Zimmer XtraFix. MRI examinations in patients with external fixators for traumatic knee dislocations can be safely performed under certain conditions and provide diagnostic quality images.

Increased Neurovascular Morbidity Is Seen in Documented Knee Dislocation Versus Multiligamentous Knee Injury

This article was updated on May 19, 2021 because of previous errors, which were discovered after the preliminary version of the article was posted online. In the legend for Figure 3-A, the phrase that had read "T1-weighted coronal MRI showing a right knee" now reads "T1-weighted coronal MRI showing a left knee." On page 924, in the section entitled "Materials and Methods," the sentence that had read "If there was no radiographic evidence or if there was a clinical note that documented visible deformity around the knee with no reduction maneuver being performed, then the patient was classified into the non-dislocated MLKI group." now reads "If there was no radiographic evidence or if there was no clinical note that documented visible deformity around the knee with no reduction maneuver being performed, then the patient was classified into the non-dislocated MLKI group." On page 925, in the section entitled "Analysis," the sentence that had read "Our study included 78 dislocated MLKIs and non-dislocated MLKIs, so both cohorts were adequately powered for the overall analysis." now reads "Our study included 45 dislocated MLKIs and 78 non-dislocated MLKIs, so both cohorts were adequately powered for the overall analysis." Finally, on page 927, in the section entitled "Discussion," the sentence that had read "Interestingly, we found that MLKIs with a documented knee dislocation had a substantially higher rate of vascular injury (23%) compared with those without (3%)." now reads "Interestingly, we found that MLKIs with a documented knee dislocation had a substantially higher rate of vascular injury (18%) compared with those without (4%)."

Anterior Tibial Tendon Side-to-Side Tenorrhaphy after Posterior Tibial Tendon Transfer: A Technique to Improve Reliability in Drop Foot after Common Peroneal Nerve Injury

Common peroneal nerve injury is present in 40% of knee dislocations, and foot drop is the principal complication. Posterior tibial tendon transfer is a viable solution to replace the function of the anterior tibial tendon (ATT) in the mid-foot. Several techniques for posterior tibial tendon transfer exist today, with variable results reported. However, adding augmentation with side-to-side tenorrhaphy of ATT to the transferred posterior tibial tendon (PTT) enhances anterior tissue balance and load sharing stress between native ATT enthesis and PTT tenodesis, allowing early rehabilitation and improving functional outcomes. Side-to-side tenorrhaphy is performed after PTT tenodesis in the lateral cuneiform to improve reliability in foot drop. This technique allows shorter immobilization time (from 6 to 2 weeks), earlier rehabilitation, sooner weight-bearing, and decreased risk of arthrofibrosis, scar formation, and muscle atrophy.

Popliteal Artery Occlusion with Collateral Blood Flow in a Reducible Knee Dislocation During Pregnancy: A Case Report

CASE

A 29-year-old healthy woman, 19 weeks pregnant, sustained a right posterolateral knee dislocation with multiligamentous injury and a complete occlusive injury to the right popliteal artery yet had adequate distal perfusion. She declined operative management for both the knee dislocation and the arterial injury, and successful collaboration between obstetrical, vascular, and orthopaedic surgical services resulted in limb preservation and restoration of function.

CONCLUSION

This is a unique case of traumatic complete popliteal artery occlusion with adequate collateral arterial perfusion after a reducible posterolateral knee dislocation in a pregnant patient that resulted in limb preservation with nonoperative management.

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.

Long term outcome of early single stage surgery in multi-ligamentous injuries of knee

BACKGROUD

Multi-ligamentous knee injuries have been a grey area due to unavailability of large scale control trials with a long term follow up. Several studies have documented good results with different protocols of management regarding time of treatment, repair versus reconstruction, choice of graft and sequence of repair. The author wishes to put forward long-term results of early (<6 weeks) single-stage surgery in multi ligamentous injuries.

METHODS

The prospective trial included 29 patients diagnosed with three or more ligaments involved. Patients having fractures involving proximal tibia, distal femur, patella, patients with history of compound trauma to knee, osteochondral lesions, associated neuro-vascular injury & poly-trauma patients were excluded from the study. The patients also underwent AP, lateral & stress skiagrams in addition to a standard 3T MR scan for pre-operative planning and confirmation of diagnosis. The pre & post-operative outcomes were assessed using KSS & Lysholm score. The patients were followed up for two years with clinical examination and stress skiagrams.

RESULTS

The mean increase in knee scores was statistically significant at both 12 months and 24 months (p < 0.05) with mean ROM of 132.8° at final follow-up. Three patients required manipulation under anaesthesia. All patients could carry out their activities of daily living at mean period of 8.2 months. Osteoarthritis was most common complication at 2 years follow-up.

CONCLUSION

The most important aspect of a single stage reconstruction lies in earlier restoration of function with a tremendous decrease in loss of medical expenses, improvement of quality of life and early & improved function in terms of both physical and psychological factors. Better restoration of kinematics from early rehabilitation is probably the factor responsible for the results. Osteoarthritis remains an important follow-up finding.

Open tibia plateau fracture with intra-osseous dislocation of the patella and quadriceps tendon rupture: a case report

Background

Both tibial plateau fractures and extensor apparatus injuries are serious injuries to the knee joint that generally do not occur in the same patient. We report a rare case of open tibial plateau fracture combined with quadriceps tendon rupture and complete displacement of the patella into the tibial plateau fracture.

Case presentation

The case involved a male who was 19 years old who had been in a motorcycle accident. The patient was admitted to our department with an open tibial plateau fracture 3 h post-injury. X-ray showed a tibial plateau fracture and complete displacement of the patella into the tibial plateau. CT showed an avulsion fracture in the patella and tibial intercondylar eminence. Concomitant quadriceps tendon injury and both anterior and posterior cruciate ligament tibial insertion avulsion fractures were considered. The operative findings of emergency surgery confirmed our preoperative diagnosis. Single-stage quadriceps tendon repair and ORIF for the tibial plateau fracture were performed. Satisfactory restoration of function was acquired at the last follow up.

Conclusion

The most difficult aspect of this case was the determination of the cause of the intra-osseous dislocation of the patella into the tibial plateau. The most likely mechanism of the injury may be that the patient experienced transient posterior dislocation of the knee during the injury. Rupture of the quadriceps tendon should be considered with posterior dislocation of the knee, and the patella was pushed into the tibial plateau fracture by force after the rupture of the quadriceps tendon.

Preoperative MRI for the Multiligament Knee Injury: What the Surgeon Needs to Know

The multiligament knee injury is devastating and potentially limb threatening. Preoperative magnetic resonance imaging for the evaluation of the multiligament knee injury is an invaluable clinical tool, and when the radiologist is familiar with how certain injury patterns influence management, optimal outcomes can be achieved. We provide a detailed description of the relationship between salient imaging features of the multiligament knee injury, focusing on the preoperative magnetic resonance imaging, and their influence on clinical decision-making.