Traumatic proximal tibiofibular fracture and dislocation.

BACKGROUND: Traumatic proximal tibiofibular fracture and dislocation (PTFD) have been rarely studied and are easily missed in clinical practice. PTFD is considered a marker of severely traumatized knees. The purpose of this study was to retrospectively analyze the incidence and impact of PTFD in traumatized knees with vascular injury. METHODS: Patients with knee trauma and vascular injury were included from January 2022 to October 2023. X-rays and CT scans of included patients were retrospectively analyzed to determine the presence of PTFD. Patients were further divided into PTFD group and non-PTFD group for further comparative analysis. RESULTS: A total of 27 patients (28 limbs) were included. Incidence of PTFD was 39.3% (11/28) in traumatic knee with vascular injury, including 8 anterolateral dislocations and 3 posteromedial dislocations. PTFD group had significantly more limbs with open injuries compared with non-PTFD group (10/11 VS 7/17, p<0.05). Amputation rate of PTFD group was as high as 40% (4/10), compared to 23.5% (4/17) in non-PTFD group. However, the difference between two groups was not statistically significant (p>0.05). CONCLUSIONS: PTFD was easily overlooked or missed. In traumatized knees with vascular injury, incidence of PTFD was high. The presence of PTFD might indicate severe knee trauma and the possibility of open injury. Although there was no significant difference compared with non-PTFD group, PTFD group had a relatively high amputation rate of 40%.

An examination from 1990 to 2019: investigating the burden of knee dislocation on a global scale.

Background: The literature on the disease burden of knee dislocation is lacking. The aim of the study is to systematically assess the global burden, trends, causes, and influencing factors of knee dislocation. Methods: The incidence and years lived with disability (YLDs) of knee dislocation were assessed globally, as well as at the regional and national levels from 1990 to 2019. Subsequent analyses focused on the age and gender distribution related to knee dislocation. An investigation into the main causes of knee dislocation followed. Finally, the Pearson correlation between age-standardized rates and social-demographic index (SDI) was calculated. Results: Although the age-standardized incidence and YLDs rate of knee dislocation decreased over the past 30 years, the incidence and YLDs number increased. The disease burden remained higher in males compared to females. Males and females showed different patterns of incidence rates in each age group, but their YLDs rates were similar. Over the past 30 years, the disease burden of knee dislocation increased in the older population while declining in the younger population. Falls had consistently emerged as the most important cause for both incidence and YLD rates. Additionally, a positive correlation between SDI and the disease burden of knee dislocation was found. Conclusion: The disease burden of knee dislocation remains heavy. It is essential to recognize the evolving epidemiology of knee dislocation. Utilizing data-driven assessments can assist in formulating public health policies and strategies to improve overall well-being.

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.

Clinical and Functional Outcomes of Documented Knee Dislocation Versus Multiligamentous Knee Injury: A Comparison of KD3 Injuries at Mean 6.5 Years Follow-up.

BACKGROUND: Previous research has found that the incidence of neurovascular injury is greatest among multiligamentous knee injuries (MLKIs) with documented knee dislocation (KD). However, it is unknown whether there is a comparative difference in functional recovery based on evidence of a true dislocation. PURPOSE: To determine whether the knee dislocation-3 (KD3) injury pattern of MLKI with documented tibiofemoral dislocation represents a more severe injury than KD3 MLKI without documented dislocation, as manifested by poorer clinical outcomes at long-term follow-up. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: A multicenter retrospective cohort study was performed of patients who underwent surgical treatment for KD3 MLKI between May 2012 and February 2021. Outcomes were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm score, Tegner activity scale, and visual analog scale (VAS) for pain. Documented dislocation was defined as a radiographically confirmed tibiofemoral disarticulation, the equivalent radiology report from outside transfer, or emergency department documentation of a knee reduction maneuver. Subgroup analysis was performed comparing lateral (KD3-L) versus medial (KD3-M) injuries. Multivariable linear regression was conducted to determine whether documented dislocation was predictive of outcomes. RESULTS: A total of 42 patients (25 male, 17 female) were assessed at a mean 6.5-year follow-up (range, 2.1-10.7 years). Twenty patients (47.6%) were found to have a documented KD; they reported significantly lower IKDC (49.9 vs 63.0; P = .043), Lysholm (59.8 vs 74.5; P = .023), and Tegner activity level (2.9 vs 4.7; P = .027) scores than the patients without documented dislocation. VAS pain was not significantly different between groups (36.4 vs 33.5; P = .269). The incidence of neurovascular injury was greater among those with documented dislocation (45.0% vs 13.6%; P = .040). Subgroup analysis found that patients with KD3-L injuries experienced a greater deficit in Tegner activity level than patients with KD3-M injuries (Δ: -3.4 vs -1.2; P = .006) and had an increased incidence of neurovascular injury (41.7% vs 11.1%; P = .042). Documented dislocation status was predictive of poorer IKDC (ß = -2.15; P = .038) and Lysholm (ß = -2.85; P = .007) scores. CONCLUSION: Patients undergoing surgical management of KD3 injuries with true, documented KD had significantly worse clinical and functional outcomes than those with nondislocated joints at a mean 6.5-year follow-up. The current MLKI classification based solely on ligament involvement may be obscuring outcome research by not accounting for true dislocation.

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.

Traumatic Dislocation of the Proximal Tibiofibular Joint: A Systematic Review and 10-year Experience From a Level 1 Trauma Center.

INTRODUCTION: Traumatic proximal tibiofibular joint dislocations occur infrequently and are typically the result of high-energy trauma. These injuries can be a marker of limb injury severity because patients often sustain vascular injury and are at high risk of amputation. The purpose of this study was to present a systematic review of traumatic proximal tibiofibular joint dislocations and compare rates of associated injuries with a retrospective series of patients at a level 1 trauma center. The secondary objective was to report rates and clinical predictors of limb amputation. METHODS: A systematic review was conducted, identifying three studies meeting eligibility criteria. A retrospective chart review was conducted identifying 17 skeletally mature patients with proximal tibiofibular dislocation treated from January 2010 to February 2021. A chart review extracted patient demographics, fracture patterns, open fracture, preoprative and postoperative peroneal nerve injury, vascular injury, and amputation. Binary logistic regression analysis was used to identify clinical predictors of outcomes. RESULTS: Sixteen of 17 proximal tibiofibular injuries (94.1%) were associated with fracture, most commonly tibial shaft (n = 11, 68.75%). Twelve of 17 fractures (76.5%) were open. Five vascular injuries (29.4%) occurred requiring surgical intervention. Seven (41.2%) preoperative peroneal nerve deficits were noted; six had persistent deficits postoperatively or underwent amputation (average follow-up 31.3 ± 32.6 months). Two patients in the sample without preoperative peroneal nerve deficits were noted to exhibit them after fixation. Eight patients (47%) underwent an amputation, 7 (87.5%) of whom had an open fracture and 4 (50%) of whom had documented vascular injury. DISCUSSION: Traumatic proximal tibiofibular fractures indicate severe injury to the lower extremity with high risk for nerve injury and possible amputation. Patients who present with vascular injury and open fracture in association with proximal tibiofibular joint disruption may be at elevated risk of amputation.

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.

Demographic analysis of knee dislocation: A rare mechanism of injury.

PURPOSE: The aim of this study was to present to the literature a rare injury mechanism that causes knee dislocation (KD) and describe its characteristics. METHODS: A retrospective review of patients with KD who were treated between January 2014 and December 2019 at our hospital was performed. Patients with KD due to rotavator machine injury were included in Group 1 and all patients with KD due to other etiological reasons were included in Group 2. Patients' age, gender, side, injury mechanism, time to surgery, length of stay (LOS), operation time, follow-up time, neurological injury status, vascular injury status, open injury status, and surgical interventions were evaluated. RESULTS: A total of 34 patients were evaluated in the study. There was no statistically significant difference between the groups in terms of age, gender, side, or follow-up time (p = .915, p = 1.000, p = .682, p = .374, respectively). However, LOS and time to surgery were statistically significantly longer in Group 1 (p = .037, p = .010, respectively). Moreover, neurovascular damage was statistically significantly more common in Group 1. CONCLUSION: As a rare injury mechanism for KD, rotavator machine injuries cause more neurovascular injuries in patients compared to other injury mechanisms and increase the time to surgery and LOS due to preoperative soft tissue damage.

[Diagnosis, Treatment and Complications of Knee Dislocation: a Retrospective Study]. / Diagnostika, terapie a komplikace luxace kolenního kloubu: retrospektivní studie.

PURPOSE OF THE STUDY Acute knee dislocation is a less common injury of the knee joint. It is, however, a serious injury with a high rate of nerve and vascular damage and it is considered a limb threatening injury with long-term functional disability, which can ultimately lead to amputation. Knee dislocations constitute less than 0.5% of all joint dislocations. Most of these injuries occur in highenergy traumas and careful diagnosis can identify the patient at risk of this injury. MATERIAL AND METHODS The total number of patients with knee dislocation was 37. The incidence of knee dislocation was 2.5 patients per year. The mean age of patients was 49 years. After the evaluation of blood supply to the limb and before the examination of the ligament injury, routine X-ray views of the affected joint were performed. It was necessary to confirm good blood supply of the limb, in which knee dislocation had been suspected. In patients with reduced knee joint and asymmetric pulses in the lower limb, CT angiography was indicated. The absence of peripheral pulses and the presence of serious clinical signs of peripheral blood supply disruption in case of the reduced knee or irreducible knee dislocation necessitated immediate revision by a vascular surgeon performed in the operating room. RESULTS Dislocation of the knee without TKA (a total of 34 cases) was caused by a high-energy trauma in 19 cases (56%) and in 7 cases (21%) it was a part of polytrauma. The most common was a motorcycle accident, namely in 7 cases (21%). In 12 cases (35%), it was a low-energy trauma, a fall or a slip while walking. In three cases (9%), the patients suffered an open knee dislocation. In 18 patients (47%), no knee surgery was performed. The knee ligament injury was treated non-operatively through knee brace fixation. An open revision with sutures of injured ligament structures and knee capsule was performed in 16 patients (42%). In two cases, above-the-knee amputation was done. External fixation was performed in two polytrauma patients. Three cases of infectious complications were reported. Nerve lesions were observed in 9 cases (25%). Vascular lesions were recorded in 9 cases (25%). Deep vein thrombosis was observed in three cases in our study group. The Lysholm knee questionnaire was used to assess subjective difficulties. DISCUSSION In agreement with the literature, these injuries occur most frequently when riding on motorcycle. The patients, in whom a vascular lesion was identified and revascularisation performed within 8 hours, showed a significantly lower incidence of amputations (11%) compared to those who underwent surgery after 8 hours (86%). Majority of vascular surgeons consider 6 hours to be the time limit for the performance of vascular reconstruction since a surgery performed after 6 hours is accompanied by a higher complication rate. Currently, the aim of the final treatment is to perform anatomic suture or reconstruction of knee ligaments and meniscus to achieve a stable, pain-free, functional knee and to prevent any complications. CONCLUSIONS Knee joint dislocation ranks among less common injuries that can be accompanied by a vascular injury in 20% on average and a nerve lesion in 10-40% (around 25% on average). A negative X-ray in spontaneous reduction of knee dislocation can be misleading for proper diagnosis. It is crucial to rule out a vascular injury that might be a limb threatening. In case of a vascular lesion, an early reconstruction of vascular supply is necessary within 6 hours after the injury. The revascularisation performed later is accompanied by a high risk of complications and can ultimately lead to above-the-knee amputation. It is most appropriate to refer such serious injuries to specialised trauma centres that avail of necessary equipment and experience with treating the patients who sustained such complicated orthopaedic injuries. As to the ligament reconstruction, most surgeons prefer to postpone the procedure in majority of cases by 10-14 days. Key words: knee dislocation, vascular injury, neurologic injury, ligament reconstruction, irreducible dislocation.

Bearing dislocation of mobile bearing unicompartmental knee arthroplasty in East Asian countries: a systematic review with meta-analysis.

BACKGROUND: Bearing dislocation is a common postoperative complication of mobile-bearing unicompartmental knee arthroplasty, and East Asian patients tend to be at higher risk. However, whether this high dislocation rate is common in all East Asian populations remains unclear. This meta-analysis was performed to explore this issue and describe various features of dislocation in East Asians, including the onset time, dislocation direction, and re-dislocation rate. METHODS: The literature was searched in PubMed, Embase, Ovid, and Cochrane Library up to May 2020. Studies were scrutinized by two independent authors, and the bearing dislocation rate, onset time, direction, and re-dislocation rate were specifically analyzed. RevMan 5.3 was used for the statistical analysis. RESULTS: Seven case series from Korea, China, and Japan were included. The pooled analysis showed that the total dislocation rate was 2.37%, while the subgroup analysis showed that the dislocation rate in Korea and other countries was 4.50% and 0.74%, respectively (P < 0.01). Another subgroup analysis of the onset time showed a significant difference before and after the first 5 years postoperatively (P < 0.01). Anterior and posterior dislocations were more frequent than medial and lateral dislocations (P < 0.01). The average re-dislocation rate was 32.45%, which was approximately seven times higher than the primary dislocation rate (P < 0.01). CONCLUSION: Our meta-analysis demonstrated that Korea had a higher bearing dislocation rate among East Asian countries, especially in the first 5 years after primary UKA. Anterior and posterior dislocations were common. The most important finding is that the re-dislocation rate can be much higher than the initial dislocation rate.

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.

Surgical management of the congenital dislocation of the knee and hip in children presented after six months of age.

PURPOSE: Congenital dislocation of the knee and hip is a rare congenital disorder. The specific aim of the study was to evaluate the clinical and radiological outcomes of the children with congenital dislocation of the knee and hip who presented after six months of age. METHODS: All the consecutive children with congenital dislocation of the knee and hip joints were retrospectively reviewed. We included cases that were treated after six months of age and followed up for a minimum of two years. Twenty-four children with congenital dislocation of the knee and hip (thirteen with ligamentous laxity, eleven children with stiff joints) were included. The knee was dislocated in 45 limbs; the hip was dislocated in 40 instances. The knee joint dislocation was treated with quadricepsplasty in all twenty-four children (45 knees). The hip dislocation (n = 32) was addressed with either closed reduction (n = 8) or open reduction of the hip (n = 24). Eight hip dislocations were not addressed. The outcome of the hip and knee was evaluated. RESULTS: The clinical and radiological outcomes were better in children with ligamentous laxity than without laxity. Twenty-two children were community walkers. An orthosis was needed in eight children. The frequency of spontaneous reduction of unreduced dislocation of the hip was noted in three children (5/8 hips). CONCLUSION: Outcome in combined dislocation of knee and hip is good in most cases with surgical interventions. The outcome is better in children with ligamentous laxity. Spontaneous reduction of the dislocated hips might be achieved after gaining knee flexion following knee surgery for congenital the knee in a few cases.

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.

Association of Injury Energy Level and Neurovascular Injury Following Knee Dislocation.

OBJECTIVE: To describe the associations between mechanism of injury energy level and neurovascular injury (NVI) following knee dislocation (KD) using a large representative sample of trauma patients and to examine risk factors within these groups. DESIGN: Retrospective cohort study. SETTING: Trauma centers participating in the American College of Surgeons National Trauma Data Bank. PARTICIPANTS: Adult patients with KD without lower extremity fracture. INTERVENTION: Patients were grouped as ultra-low, low, or high-energy based on injury mechanism. Univariate/multivariate analyses assessed associations of energy level with NVI and of patient characteristics with NVI within energy-level groups. MAIN OUTCOME MEASUREMENTS: Rate of nerve and blood vessel injury. RESULTS: One hundred twenty-four patients with KD were identified; 181 sustained ultra-low-energy mechanisms, 275 low-energy, and 868 high-energy. Nerve injury occurred in 6% of ultra-low-energy injuries, 7% in low-energy, and 3% in high-energy (P = 0.03). Vessel injury occurred in 21% of ultra-low-energy injuries, 17% in low-energy, and 13% in high-energy (P = 0.01). On multivariate analyses, obesity was associated with nerve injury in the ultra-low-energy group (OR 4.9; 95% CI 1.0-24.0) but not with other energy levels. Obesity was also associated with vessel injury in the ultra-low-energy group (OR 4.0; 95% CI 1.6-9.7). Smoking, hypertension, and diabetes were not associated with NVI. CONCLUSIONS: NVI following KD is more common after lower energy-level mechanisms. Obesity is associated with NVI in lower energy-level mechanisms. Physicians should be vigilant in screening for NVI in the setting of KD even with seemingly benign mechanisms of injury, especially in patients with obesity. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Epidemiology and outcomes of traumatic knee dislocations: Isolated vs multi-trauma injuries.

BACKGROUND AND PURPOSE: Traumatic dislocation of the knee (TKD) is a rare injury, accounting for approximately 0.02% of orthopaedic injuries. They are a challenging entity for orthopaedic surgeons to manage, and can have devastating consequences. The aim of this study was to describe the epidemiology of traumatic knee dislocations (TKD'S) and contrast the incidence of neurovascular injury between isolated and multi-trauma dislocations as well as key patient reported outcomes achieved between these groups. MATERIAL AND METHODS: Patients who had a traumatic disruption of the tibiofemoral articulation between March 1 2007 and February 31, 2015 were identified from the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Data was cross-checked with medical records and radiological reports to confirm true multi-ligamentous dislocation. VOTOR collects information pertaining to orthopaedic injuries, treatment, complications and outcomes from four adult hospitals in Victoria, Australia, including the major trauma centers. Patient-reported outcomes are collected by VOTOR at 12 months post-injury including the EQ-5D-3L (EQ-5D) and Glasgow Extended Outcome Scores (GOS-E) and return to work status. Patient reported functional and quality of life outcomes at 12 months after injury were analysed. RESULTS: A cohort of 88 patients were identified that fit the inclusion criteria for the study, and at 12 months post-injury there was data available for 80 patients (90.9%). There were 38 (42.9%) patients who experienced an isolated traumatic knee dislocation and 52 (57.1%) who experienced a traumatic knee dislocation in association with another injury. Of the 88 patients identified as eligible for the study, two had bilateral knee dislocations, hence there were 90 multi-ligamentous knee injuries. Those who were injured at a higher velocity were more likely to have additional injuries. Dislocations that occurred at a lower velocity were shown to have better overall outcomes, as did dislocations that occurred in isolation. CONCLUSIONS: Traumatic knee dislocations that occur in isolation typically result in better outcomes than those that occur with associated injuries. TKD's are a rare but severe injury that requires further research in order for functional outcomes to be optimized.

Knee dislocation and vascular injury: 4 year experience at a UK Major Trauma Centre and vascular hub.

INTRODUCTION: Knee dislocation is a rare but potentially devastating injury. Quoted rates of associated vascular compromise vary dramatically between 3.3% and 64%, and the best approach to investigate and diagnose such an injury remains controversial. We aim to evaluate our own 4-year experience of knee dislocation and vascular injury as a UK Major Trauma Centre and vascular hub. METHODS: Knee dislocation was defined as disruption of at least two major stabilising ligaments of the knee and gross instability requiring an operation. Patients were identified from the Department of Trauma and Orthopaedics patient database across a 4 year period from 2010 to 2014. Electronic patient records, imaging and hard notes were retrieved and reviewed retrospectively and relevant information recorded. RESULTS: Twenty-five cases of knee dislocation were identified. Male to female ratio was 11.5:1 with a mean age of 33 years (range 17-71). One patient had a vascular injury which ultimately required a femoro-popliteal bypass graft. Twenty-four patients had documented examination findings pertaining to the vascular status of the limb. Seventeen patients had specific reference to the presence or absence of pedal pulses. The remaining seven cases were documented as either "warm well perfused" or "neurovascularly in-tact". Nine patients were discharged directly from the emergency department with outpatient follow up. All admitted cases had documented vascular examination findings the following day. Two patients had additional adjunctive non-invasive investigations. No patients were examined with duplex ultrasound, although two patients had pulses confirmed with hand-held doppler ultrasound. Three patients had an angiogram. Four cases have a documented discussion with or review from a vascular surgeon. DISCUSSION AND CONCLUSIONS: Our rates of vascular injury are in line with the most recent and largest study to date. Non-invasive investigation and selective angiography has been safe in identifying significant vascular compromise, however, there is inconsistency in management pathways, and too much reassurance attributed to the presence of pedal pulses on initial examination. Safety and consistency could be improved with the introduction of a formalised evidence-based protocol for the initial evaluation of knee dislocation and vascular injury.

Traumatic Proximal Tibiofibular Dislocation: A Marker of Severely Traumatized Extremities.

OBJECTIVE: The purpose of this analysis is to report on the epidemiology and clinical implications of traumatic proximal tibiofibular dislocation (PTFD). DESIGN: Retrospective chart and radiographic review. SETTING: Level 1 regional trauma center. PATIENTS: Skeletally mature patients with a traumatic PTFD between July 1, 2006, and December 31, 2013. INTERVENTION: Open reduction internal fixation of the proximal tibiofibular joint. MAIN OUTCOME MEASUREMENTS: Patient demographics and associated musculoskeletal and neurovascular injuries were recorded as data points. RESULTS: There were a total of 30 PTFDs in 30 patients during the course of the defined study period. The incidence of PTFD was 1.5% (15 of 1013) of operative tibial shaft fractures and 1.9% (15 of 803) of operative tibial plateau fractures (P = 0.5810). Fifty percent (15 of 30) of PTFD were associated with a tibial shaft fracture, and 50% (15 of 30) with tibial plateau fractures. PTFD was associated with an open fracture in 63% (19 of 30) of cases. Two patients (6.7%) presented with a vascular injury who underwent a successful repair without vascular sequelae. Two different patients (6.7%) ultimately underwent an amputation (one above the knee and one below the knee) for a nonreconstructable extremity. In the remaining 28 patients without amputation, the incidence of compartment syndrome was 29% (8 of 28) and the incidence of peroneal nerve palsy was 36% (10 of 28). Only 30% (3 of 10) of the peroneal nerve palsies recovered clinically within the follow-up period, which averaged 11 months (range: 6 months to 4 years). CONCLUSIONS: Traumatic proximal tibiofibular joint dislocations can be found in approximately 1%-2% of both tibial plateau and shaft fractures. PTFD is associated with a high rate of compartment syndrome (29%), open fracture (63%), and peroneal nerve palsy (36%). The majority (70%) of peroneal nerve palsies do not recover. Proximal tibiofibular joint dislocation is a marker for a severely traumatized limb. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Medial patellofemoral ligament anatomy: is it a predisposing factor for lateral patellar dislocation?

PURPOSE: Because the medial patellofemoral ligament (MPFL) is the primary restraint to lateral dislocation of the patella, we aimed, in this controlled study, to verify whether the MPFL with different measurements could be considered another predisposing factor for patellar dislocation. METHODS: A group of 100 consecutive individuals without the criteria for patellar dislocation (trochlear dysplasia, patella alta and lateral patellar tilt) was recruited as a control group and underwent magnetic resonance imaging (MRI) study and another group of 50 patients with patellar instability. Femoral condyles, interepicondylar distance, length and thickness of the MPFL were measured. RESULTS: In the control group, the MPFL was 38-60 mm long. Individuals with patellar instability who had no episode of patellar dislocation had a 4.11-mm longer ligament than controls (p = 0.032), while patients with instability with a previous history of dislocation had a 13.54-mm longer MPFL than controls (p < 0.001). Thickness of the MPFL at the patellar insertion was lower in individuals with patellar instability with a history of dislocation (p < 0.001). An instability coefficient (IC) less than 1.3 indicates that the MPFL is insufficient. CONCLUSIONS: Individuals with patellar instability and previous patellar dislocation present with longer MPFL when compared to controls, and an associated IC less than 1.3 can be considered a predisposing factor for patellar dislocation. Treatment of patellar instability is a challenge, and it is difficult to identify what is the predisposing factor. This study has verified the measurements of the MPFL for the first time and presents values of thickness and length that can be considered as indications for surgical reconstruction. LEVEL OF EVIDENCE: III.

Epidemiology of multiligament knee reconstruction.

BACKGROUND: The multiple-ligament-injured knee represents a special challenge, being an uncommon injury that is both severe and complicated to treat. Many studies have evaluated patients treated for this injury, but most are limited in their scope. The evaluation of this injury and its treatment using an administrative database might provide a different perspective. QUESTIONS/PURPOSES: Using a large administrative database, we determined (1) the number of multiligament knee reconstructions in New York State, (2) the rate of 90-day hospital readmission, and (3) the frequency of subsequent knee surgery. We examined the rates of these outcomes as a function of diagnosis, admission type, discharge status, comorbidity burden, and patient demographic factors. METHODS: We used the New York Department of Health Statewide Planning and Research Cooperative System (SPARCS), a database with information on patient characteristics, diagnoses, and treatments, to identify patients who underwent a multiligament procedure in a nonfederal facility from 1997 to 2005 using ICD-9-CM and Current Procedural Terminology codes. SPARCS collects data from all nonfederal acute care facilities, with an estimated reporting completeness of almost 99% for the years in this study. We evaluated data on patient age, sex, admission type, discharge status, and comorbidity burden (using Elixhauser comorbidities) and developed a multivariable logistic regression model to assess the influence of confounding variables. RESULTS: We identified 1032 patients in this database who underwent multiligament knee reconstruction in New York State from 1997 to 2005. The frequency of readmission within 90 days was 4.8% (n = 49). Readmission was more likely for patients who underwent inpatient multiligament reconstruction (odds ratio [OR] = 2.3; 95% CI: 1.2-4.4; p = 0.014), had a diagnosis of dislocation (OR = 2.2; 95% CI: 1.2-3.9; p = 0.011), or had various Elixhauser comorbidities, including chronic lung disease (OR = 6.4; 95% CI: 1.5-27.2; p = 0.013), fluid and electrolyte disorders (OR = 19.7; 95% CI: 2.5-155.7; p = 0.005), and anemia deficiency (OR = 5.6; 95% CI: 1.05-29.4; p = 0.044). Two hundred eighty-seven patients (28%) underwent subsequent knee surgery between their index procedure and 2006. Subsequent surgery was more likely for patients who underwent inpatient multiligament reconstruction (OR = 1.4; 95% CI: 1.1-1.9; p = 0.011) or were readmitted within 90 days of the index surgery (OR = 4.2; 95% CI: 2.3-7.6; p < 0.001). CONCLUSIONS: Our findings have the potential to aid clinicians in identifying their patients with multiligament reconstruction at highest risk for 90-day readmission and subsequent knee surgery. Future research, particularly large prospective studies evaluating surgical approaches and timing, will be critical in advancing the treatment of multiligament knee injuries. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.