Knee Dislocation in the Morbidly Obese Patient

Abstract

Though a relatively rare orthopedic injury, knee dislocation in the morbidly obese population has been increasingly reported in the literature. These injuries are often referred to as "ultralow-velocity knee dislocations" since they commonly occur after a seemingly trivial injury, such as a ground level fall. As a result, these injuries are often underappreciated and initially misdiagnosed. Even though these injuries are low-velocity, they should still be regarded as a high energy injury because of the large amount of mass contributing to the dislocating force. Knee dislocations in the morbidly obese are associated with a particularly high rate of neurovascular injury. A timely and accurate diagnosis is crucial to avoid serious limb-threatening complications, including the need for amputation. Therefore, evaluating physicians should maintain a high suspicion for a knee dislocation in any morbidly obese patient who presents with knee pain following a seemingly innocuous injury. Management of these injuries is controversial. Associated vascular injuries must be identified promptly and appropriately managed by a vascular surgery team. There is no consensus on the ideal orthopedic treatment of knee dislocations in the morbidly obese patient. Operative treatment can be fraught with complications, including a higher rate of neurovascular injury, increased surgical complications, and poor subjective patient outcome scores compared with nonobese patients sustaining a high-velocity knee dislocation. It is paramount that treating physicians are familiar with the unique challenges of treating knee dislocations in the morbidly obese patient when discussing risks and benefits of treatment options. This article presents a review of the existing literature on knee dislocations in the morbidly obese population, including diagnosis, management, and outcomes.

Morbid obesity and 1-year costs after elbow dislocation

“…Morbid obesity has been well studied within the knee dislocation population as a cause of devastating, "low-velocity" injuries with significant consequences. Carr et al 2 noted that when compared with nonobese patients, operative treatment of morbidly obese patients with knee dislocations is fraught with increased incidence of complications, including neurovascular injury, intraoperative and postoperative surgical complications, and worse patient outcome scores. Severity of injuries associated with low velocity trauma in the obese population is similar to those seen only with high velocity trauma in the non-obese population.…”

“…1 Morbid obesity has been associated with devastating low velocity knee dislocations. 2 While similar injuries occur in this patient population following dislocations of the elbow, no study has looked at the effects of obesity on elbow dislocations, and no study has focused on the financial impact of morbid obesity on the cost of managing dislocations. These elbow dislocations can be quite challenging to manage, as joint reduction, maintenance of elbow stability, methods of immobilization and surgical intervention all have unique challenges related to the arm weight and size.…”

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

“…Recently, a number of publications highlighted low-velocity mechanisms in obese individuals as novel and separate mechanism causing ligamentous knee injuries [7][8][9][10]. According to our data, low energy falls contributed to only 4.9% of all ligamentous knee injuries, and the vast majority of complex knee injuries were associated with high-energy trauma.…”

“…The incidence for knee dislocations is very low and has been estimated to be 1.2 per million person-years, mainly from high-energy trauma [7]. However, recent publications also reported knee dislocations as a result of low-energy mechanisms, including ground level falls in obese individuals [8][9][10]. The prompt identification, dedicated evaluation, and a comprehensive management of knee injuries have a high impact on long-term functional outcomes [11][12][13][14].…”

Multiligamentäre Kniegelenkverletzungen – Epidemiologie, Diagnostik und Klassifikation

“…Während die Diagnose der HV durch die Schwere des Traumas und der Begleitverletzungen eventuell verzögert wird, kann bei der ULV-Luxation der durch die Adipositas verstärkte Weichteilmantel eine MLKV maskieren [5] [11]. Um ligamentäre Schäden und andere Weichteilverletzungen des Knies nach einer Luxation zu detektieren, ist die Magnetresonanztomografie-(MRT-)Bildgebung die Methode der Wahl [15] und wird von uns grundsätzlich empfohlen (▶ Abb.…”