Congenital dislocation of the knee complicated with bilateral hip dislocation: a case report and literature review.

BACKGROUND: Congenital dislocation of the knee is characterised by excessive knee extension or dislocation and anterior subluxation of the proximal tibia, and this disease can occur independently or coexist with different systemic syndromes. Nevertheless, significant controversy surrounds treating this disease when combined with hip dislocation. This paper presents a case of a 4-month-old patient diagnosed with bilateral hip dislocation combined with this disease. The study discusses the pathophysiology, diagnosis, and treatment methods and reviews relevant literature. CASE PRESENTATION: We reported a case of a 4-month-old female infant with congenital dislocation of the right knee joint, which presented as flexion deformity since birth. Due to limitations in local medical conditions, she did not receive proper and effective diagnosis and treatment. Although the flexion deformity of her right knee joint partially improved without treatment, it did not fully recover to normal. When she was 4 months old, she came to our hospital for consultation, and we found that she also had congenital dislocation of both hip joints and atrial septal defect. We performed staged treatment for her, with the first stage involving surgical intervention and plaster orthosis for her congenital dislocation of the right knee joint, and the second stage involving closed reduction and plaster fixation orthosis for her congenital hip joint dislocation. Currently, the overall treatment outcome is satisfactory, and she is still under follow-up observation. CONCLUSIONS: Early initiation of treatment is generally advised, as nonsurgical methods prove satisfactory for mild cases. However, surgical intervention should be considered in cases with severe stiffness, unresponsive outcomes to conservative treatment, persistent deformities, or diagnoses and treatments occurring beyond the first month after birth.

No effect of dislocation status at arrival in emergency department on outcome of knee joint dislocations.

PURPOSE: Knee dislocation is a rare but severe injury of the lower extremities. The aim of this study was to report on the epidemiology, diagnostics and treatment of such injuries and to identify negative predictors of clinical outcomes. METHODS: This retrospective analysis included all knee dislocations treated at a Level I Trauma Centre in Germany between 2009 and 2021. Medical records were categorised, collected and analysed in a standardised manner. A follow-up visit 1 year after the injury focused on limitations in knee mobility. RESULTS: A total of 120 knee dislocations were included in the study. 29.3% of patients presented to the emergency department with a dislocated joint, and 17.5% (n = 21) had a neurovascular lesion. At follow-up 12 months after the injury, 65.8% of the patients reported limitations in the range of motion, and 11.7% (n = 14) reported severe limitations in daily activities. Site infections due to surgery occurred in 3.3% of patients. Increased body weight (r = 0.294; p < 0.001 and r = 0.259; p = 0.004), an increased body mass index above 25 kg/m2 (body mass index, r = 0.296; p < 0.001 and r = 0.264; p = 0.004) and deficits in peripheral perfusion as well as sensory and motor function (r = 0.231; p = 0.040 and r = -0.192; p = 0.036) were found to be negative predictive factors for clinical outcome. For posttraumatic neurovascular injury, lack of peripheral perfusion, insufficient sensory and motor function (r = -0.683; p < 0.0001), as well as a higher Schenck grade (r = 0.320; p = 0.037), were identified as independent risk factors. The status of dislocation at the site of the accident and on arrival at the emergency department had no impact on the outcome or neurovascular injury. CONCLUSION: Knee dislocation is a rare injury with a high rate of severe complications such as neurovascular lesions. In particular, the initial status of neurovascular structures and injury classification showed a relevant negative correlation with the posttraumatic status of nerves and vessels. In particular, patients with these characteristics need close monitoring to prevent negative long-term consequences. LEVEL OF EVIDENCE: Level III.

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.

A Young Skier with Leg Pain.

BACKGROUND: Proximal tibiofibular joint (PTFJ) dislocation is a rare injury that can disrupt the proximal tibia-fibula joint. The abnormalities in knee x-ray imaging can be subtle and difficult to detect, requiring careful assessment. This rare cause of lateral knee pain requires a high level of suspicion for diagnosis. Treatment is closed reduction; unstable PTFJ dislocations often require surgical intervention. CASE REPORT: A 17-year-old young man presented to the emergency department (ED) with right lateral knee pain and difficulty walking after colliding with another skier 2 days prior. The examination showed right lateral ecchymosis and tenderness over the lateral proximal fibula. He remained neurovascularly intact with a full passive and active range of motion. X-ray studies were obtained. The patient was referred by his outpatient orthopedic surgeon after the initial knee x-ray study was concerning for PTFJ dislocation and unsuccessful reduction. In the ED, the patient underwent moderate sedation and successful orthopedic-guided reduction via medial force on the lateral fibular head, while hyper-flexing the knee and holding the foot dorsiflexed and everted. Post-reduction radiographs showed improved proximal tibiofibular alignment without fracture. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: PTFJ dislocation is a rare injury that can be missed easily and requires a high level of suspicion when presented with an acute traumatic knee pain. Closed reduction of PTFJ dislocation can be achieved in the ED and early identification can prevent long-term sequelae.

Epidemiology of complete knee dislocations: an updated classification system.

INTRODUCTION: Current classifications of complete knee dislocations do not capture the extent of the complex concomitant ligamentous and bony injuries, which may have an impact on future outcomes. The purpose of this retrospective study was to evaluate the epidemiology of complete knee dislocations as well as to present an updated classification system based on the author's experience at a Level-I trauma center. MATERIALS AND METHODS: Only patients with complete loss of contact of the articulating bones and ≥ 18 years of age who admitted in our level-I trauma center between 2002 and 2019 were included. Patients were identified using a retrospective systematical query in the Hospital Information System (HIS) using the International Statistical Classification of Diseases and Related Health Problems Version10 (ICD-10) codes of the German Diagnosis Related Groups (G-DRG). RESULTS: Final data included 80 patients, with the majority of patients being male (n = 64; 80.0%). Mean age was 34.9 years (range: 18-70 years). External protective fixation was applied in 32 patients (40.0%). Reconstruction of the posterior cruciate ligament and the anterior cruciate ligament were performed in 56.3% (n = 45) and 55.0% (n = 44) of cases, respectively. The lateral collateral ligament complex was surgically addressed in 47.5% (n = 38), while the medial collateral ligament complex was reconstructed in 40% (n = 32). Surgery of the lateral meniscus and the medial meniscus was needed in 31.1% (n = 25) and 30.0% (n = 24). Neurovascular surgery occurred in 13.8% (n = 11). From the characteristic injury-patterns the authors of this study present a new classification system that ranks the injuries from Grade-A to Grade-D according to their severity. CONCLUSION: This retrospective study demonstrates that the historically used classification systems for dislocations of the knee are insufficient for these severe injuries. Concomitant ligamentous, neurovascular, bony, and meniscal injuries were frequent, and required several staged procedures. Consequently, an updated classification system is proposed.

Knee dislocation and associated injuries: an analysis of the American College of Surgeons National Trauma Data Bank.

PURPOSE: Knee dislocations (KDs) are potentially devastating injuries, leading to loss of function or limb in often young patients. This retrospective database review aims to determine the relative incidence and risk factors for KDs presenting to North American Level I and II trauma centers. METHODS: The National Trauma Data Bank (NTDB) was retrospectively interrogated using ICD-9-CM codes to identify KDs between 2010 and 2014 to derive KD incidence. KDs were stratified by age, sex, Injury Severity Score (ISS), Glasgow Coma Scale (GCS), drug and alcohol use, injury mechanism, open vs. closed KD, vascular injury and fracture. Each co-variate was tested against different mechanisms of injury, using Chi-squared tests and risk adjusted analyses to derive risk factors for KD. The same calculations were done for secondary outcomes (vascular and neurological injuries, compartment syndrome, amputation, and mortality). RESULTS: A total of 6454 KDs met the inclusion criteria (18/10,000 admissions). KDs occurred most commonly amongst men, aged 20-39, with an ISS score 1-14 and following motor vehicle collision (MVC). A vascular investigation was performed in 29%, with injury documented in 15% of KDs and 10.8% receiving a vascular procedure. Associated fractures were observed in 41.4% of KDs. Open injuries in 13.6%. Neurological injury documented in 6.2%, compartment syndrome in 2.7%, amputation in 3.8% (> 50% had vascular injury) and 2.8% died. MVC was the most common mechanism of injury (p < 0.001), significantly more common in young, male patients, associated with higher ISS and lower GCS, especially when drugs or alcohol were involved (p < 0.0001). Being male, having a vascular injury or open KD were all risk factors for compartment syndrome, amputation and neurological injuries. CONCLUSIONS: KDs are rare injuries, but their relative incidence may be increasing. Young, male patients involved in MVCs are risk factors for KDs and their associated injuries, such as neurological injuries, amputations and compartment syndrome. Vascular injury occurs at a frequency of around 15%. The findings of the current study may guide future research and help to inform clinicians on the expected rates of associated injuries in patients identified to have KD in a trauma center population. It informs regarding risk factors for KD, which may improve diagnosis rates of spontaneously reduced knee dislocations by increasing index of suspicion in high-risk patients and identifies specific links with impaired driving. LEVEL OF EVIDENCE: IV.

Dislocation of modern design rotating hinge total knee arthroplasty : case series and narrative review.

Knee dislocation is an infrequent complication after rotating hinge total knee arthroplasty (RHTKA). The aim of the present study was to describe our experience with dislocating RHTKA in a consecutive prospective large series, its occurrence rate, causative mechanisms and to perform a review of available literature. In total, six dislocations were observed in 303 RHTKA procedures (NexGen RHK, ZimmerBiomet, Warsaw, Indiana, US) at a mean of 10 (range, 2 - 24) months after surgery. This results in a 2% dislocation rate, which is lower than the 3.1% cumulative rate reported earlier in literature. Men and women were distributed equally, with a mean age of 56 years old. The indication for RHTKA among the six dislocations was revision in 4 cases and primary arthroplasty for the other 2 cases. Analysis revealed that the main mechanism of hinge dislocation was forced knee flexion with concomitant extensor mechanism insufficiency (4/6 cases). The second cause was unscrewing of the locking pin (2/6 cases). This is probably caused by the screw home mechanism that results in a counterclockwise torque -and therefore a loosening- effect on locking bolts, specifically in right-sided RHTKA. Obesity probably predisposes to hinge dislocation since 83% of patients in this series were obese (BMI, range 34 to 52). The findings of this study suggest that dislocation of RHTKA is a rare complication that could happen to obsese patients without an adequate extensor mechanism. Level of evidence : IV.

Posterior dislocation following revision total knee replacement arthroplasty: a case report and literature analysis.

Knee dislocation following total knee replacement arthroplasty is a rare but serious complication. The incidence of dislocation following primary total knee arthroplasty with posterior stabilized implants ranges from 0.15 to 0.5%, and posterior dislocation after revision total knee arthroplasty is even rarer. Here, we report the case of a 76-year-old male who presented with posterior dislocation after posterior stabilized revision total knee arthroplasty.

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.

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

BACKGROUND: Knee dislocations are rare injuries with potentially devastating vascular complications. An expeditious and accurate diagnosis is necessary, as failing to diagnose vascular injury can result in amputation; however, the best diagnostic approach remains controversial. QUESTIONS/PURPOSES: We asked: (1) What patient factors are predictors of vascular injury after knee dislocation? (2) What are the diagnostic utilities of palpable dorsalis pedis or posterior tibial pulses, and the presence of an ankle-brachial index (ABI) of 0.9 or greater? METHODS: A database at a Level I trauma center was queried for patients with evidence of knee dislocation, demographic information (age at the time of injury, sex, Injury Severity Score, BMI, mechanism of injury), and the presence of open injury were recorded. One-hundred forty-one patients underwent screening at initial presentation, of whom 26 (24%) underwent early vascular exploration based on an abnormal physical examination. One-hundred five (91%) of the remaining 115 patients were available at a minimum followup of 6 months (mean, 19 ± 10 months). In total, 31 unique patients were excluded, including 10 patients (7%) who were lost to followup before 6 months. Among the 110 patients who met inclusion criteria, the mean age and SD was 37 ± 13 years, and the Injury Severity Score was 15 ± 9. There were 71 males (65%). Logistic regression was used to determine independent correlates of vascular injury. The vascular examination was reviewed for the presence of a palpable pulse in the dorsalis pedis artery, the presence of a palpable pulse in the posterior tibial artery, and whether the ABI in the dorsalis pedis was 0.9 or greater. Contingency tables were generated to assess the sensitivity, specificity, and accuracy of physical examination maneuvers. The physical examination was collectively regarded as "normal" when both pulses were palpable and the ABI was 0.9 or greater. The initial physical examination as just described was considered the diagnostic test being evaluated in this study; "positive" tests were evaluated by and confirmed at vascular surgery, and 6 months clinical followup without symptoms or progressive signs of vascular injury confirmed the absence of injury in the remainder of the patients. Contingency tables were generated again to assess the sensitivity, specificity, and accuracy of the combined physical examination. RESULTS: Increased BMI (odds ratio [OR], 1.077; 95% CI, 1.008-1.155; p = 0.033) and open injuries (OR, 3.366; 95% CI, 1.008-11.420; p = 0.048) were associated with vascular injury. No single physical examination maneuver had a 100% sensitivity for ruling out vascular injury. A normal physical examination (palpable pulses and ABI ≥ 0.9) had 100% sensitivity for ruling out vascular injury. CONCLUSIONS: Increased BMI and the presence of open dislocation are associated with a greater risk for vascular injury after knee dislocation. The combination of a palpable dorsalis pedis and posterior tibial pulse combined with an ABI of 0.9 or greater was 100% sensitive for the detection of vascular injury based on clinical followup at 6 months. LEVEL OF EVIDENCE: Level III, diagnostic study.

A rare variant of knee dislocation.

Knee dislocation is a rare injury. It represents less than 0.2% of orthopaedic injuries. This case reports a rare form of knee dislocation caused by the impact of a high-energy trauma. In these cases the appropriate assessment and management is needed to ensure that patient receives the proper treatment.

Ultrasound assessment of medial meniscal extrusion: a validation study using MRI as reference standard.

OBJECTIVE. The purpose of this article is to validate both semiquantitative and quantitative ultrasound assessment of medial meniscal extrusion using MRI assessment as the reference standard. SUBJECTS AND METHODS. Ninety-three consecutive patients with chronic knee pain referred for knee MRI were evaluated by ultrasound and MRI on the same day. Two musculoskeletal radiologists assessed meniscal extrusion on ultrasound and MRI separately and independently and graded it semiquantitatively as follows: 0 (< 2 mm), 1 (≥ 2 mm and < 4 mm), and 2 (≥ 4 mm). Agreement between the ultrasound and MRI evaluations was determined using weighted kappa statistics. Intraclass correlation coefficients were used to evaluate agreement using the absolute values of extrusion (quantitative assessment). We further evaluated the diagnostic performance of ultrasound for the detection of medial meniscal extrusion using MRI as the reference standard. RESULTS. For semiquantitative grading, agreement between ultrasound and MRI was moderate for reader 1 (κ = 0.57) and substantial for reader 2 (κ = 0.64). Substantial agreement was found for both readers (intraclass correlation coefficients, 0.73 and 0.70) when comparing quantitative assessment of meniscal extrusion between ultrasound and MRI. Ultrasound showed excellent sensitivity (95% and 96% for each reader) and good specificity (82% and 70% for each reader) in the detection of meniscal extrusion. CONCLUSION. Ultrasound assessment of meniscal extrusion is reliable and can be used for both quantitative and semiquantitative assessment, exhibiting excellent diagnostic performance for the detection of meniscal extrusion compared with MRI.

Radiological assessment of irreducible posterolateral knee subluxation after dislocation due to interposition of the vastus medialis: a case report.

Knee dislocation is a serious and relatively uncommon traumatism that every emergency room is supposed to diagnose and treat rapidly. Most of the time these dislocations reduce spontaneously or with closed reduction. If a subluxation persists, an incarceration of soft tissue in the joint must be suspected. Irreducible knee subluxations after dislocation are rare entities better described in the orthopaedic than in the radiological literature. However, the initial radiological assessment is an important tool to obtain the correct diagnosis, to detect neurovascular complications, and to plan the most suitable treatment. In cases of delayed diagnosis, the functional prognosis of the joint and even the limb may be seriously compromised primarily because of vascular lesions. Thereby, vascular imaging is essential in cases of dislocation of the knee, and we will discuss the role of angiography and the more recent use of computed tomography angiography or magnetic resonance angiography. Our patient presented with an irreducible knee subluxation due to interposition of the vastus medialis, and we will review the classical clinical presentation and 'do not miss' imaging findings on conventional radiography, computed tomography angiography, and magnetic resonance imaging. Finally, we will also report the classical imaging pathway indicated in knee dislocation, with a special emphasis on the irreducible form.

Intra-articular peroneal nerve incarceration following multi-ligament knee injury.

Knee dislocation with a common peroneal nerve injury is a serious problem. A case of multi-ligamentous knee injury with the unusual and interesting finding of a common peroneal nerve rupture incarcerated within the knee joint is presented. MRI and arthroscopic images are used to document this occurrence. To date, there are no published reports of a similar finding in the English orthopaedic literature. Level of evidence IV.

[Complete rupture of the peroneal nerve by knee distortion]. / Komplette N.-peronaeus-Ruptur bei Kniedistorsion.

This report describes a case of complete rupture of the peroneal nerve as a consequence of low velocity trauma. A 54-year-old physically fit patient suffered a complex trauma with complete nerve discontinuity as a result of knee joint distortion without external force. The initial medical findings were unremarkable, in particular neither the accident medical history nor the initial sensitivity impairment suggested the presence of serious knee damage; however, during clinical diagnostics a complex trauma with rupture of the peroneal nerve was found. Accordingly, an extensive revision with nerve suturing was carried out.

Insert dissociation after fixed bearing PS constrained Genesis II total knee arthroplasty. A case series of nine patients.

Dissociation of the polyethylene insert after fixed bearing posterior stabilized Genesis II total knee arthroplasty has been rarely described. We present a case series of nine patients with a dissociation of the insert within a period of two years after surgery. Revision surgery was performed in all patients. In this report we discuss clinical presentation, patient characteristics and possible etiologies for tibial insert dissociation seen in the presented cases. In conclusion, tibial insert dissociation does not lead to a uniform clinical presentation. Therefore, in this point of view regular physical examination and imaging after TKA regardless the presence of symptoms seems to be indicated.

Superficial femoral artery transposition repair for traumatic popliteal rupture.

Closed dislocation of the knee with complete popliteal rupture is an uncommon injury. It requires prompt recognition and treatment to prevent limb loss. We describe a case of acute ischemia caused by complete knee dislocation with rupture of the popliteal artery that was successfully repaired with superficial femoral artery transposition. To the best of our knowledge, this is the first reported clinical experience of the use of an arterial autograft for revascularization of traumatic popliteal artery rupture.

Vascular and nerve injury after knee dislocation: a systematic review.

BACKGROUND: Vascular injury is a devastating complication of acute knee dislocation. However, there are wide discrepancies in the reported frequency of vascular injury after knee dislocations, as well as important differences among approaches for diagnosis of this potentially limb-threatening problem. QUESTIONS/PURPOSES: We determined (1) the frequency of vascular and neurologic injury after knee dislocation and whether it varied by the type of knee dislocation, (2) the frequency with which surgical intervention was performed for vascular injury in this setting, and (3) the frequency with which each imaging modality was used to detect vascular injury. METHODS: We searched the MEDLINE(®) literature database for studies in English that examined the clinical sequelae and diagnostic evaluation after knee dislocation. Vascular and nerve injury incidence after knee dislocation, surgical repair rate within vascular injury, and amputation rate after vascular injury were used to perform a meta-analysis. Other measures such as diagnostic modality used and the vessel injured after knee dislocation were also evaluated. RESULTS: We identified 862 patients with knee dislocations, of whom 171 sustained vascular injury, yielding a weighted frequency of 18%. The frequency of nerve injuries after knee dislocation was 25% (75 of 272). We found that 80% (134 of 160) of vascular injuries underwent repair, and 12% (22 of 134) of vascular injuries resulted in amputation. The Schenck and Kennedy knee dislocation classifications with the highest vascular injury prevalence were observed in knees that involved the ACL, PCL, and medial collateral liagment (KDIIIL) (32%) and posterior dislocation (25%), respectively. Selective angiography was the most frequently used diagnostic modality (61%, 14 of 23), followed by nonselective angiography and duplex ultrasonography (22%, five of 23), ankle-brachial index (17%, four of 23), and MR angiography (9%, two of 23). CONCLUSIONS: This review enhances our understanding of the frequency of vascular injury and repair, amputation, and nerve injuries after knee dislocation. It also illustrates the lack of consensus among practitioners regarding the diagnostic and treatment algorithm for vascular injury. After pooling existing data on this topic, no outcomes-driven conclusions could be drawn regarding the ideal diagnostic modality or indications for surgical repair. In light of these findings and the morbidity associated with a missed diagnosis, clinicians should err on the side of caution in ruling out arterial injury.