Low-Velocity Knee Dislocations in Obese and Morbidly Obese Patients

Abstract

Background:Knee dislocations from minor trauma have been reported sparsely in the literature. The consensus is that these injuries tend not to be associated with neurovascular compromise.Purpose:To present a series of atraumatic knee dislocations in obese and morbidly obese patients and to compare operative versus conservative treatment.Study Design:Case series; Level of evidence, 4.Methods:This study included 19 patients (21 knees) who presented with knee dislocation from a low-velocity or ultra low–velocity incident. Charts, radiographs, and magnetic resonance images (MRIs) were reviewed, and patients were reviewed based on their latest follow-up. We included patients in our database from 2001 to 2011 and compared knees of patients who had ligament repair or reconstruction (9 total knees) verses nonoperative treatment (12 total knees). Range of motion, activity levels, and knee laxity information were collected as outcome measures to compare operative and nonoperative results.Results:The mean age at presentation was 30.3 years (range, 15-74 years), with 5 men and 14 women. The average body mass index (BMI) was 41.4 kg/m2 (range, 30-64.4 kg/m2), with an average follow-up of 31 months (range, 12-72 months). Five patients (27%) had a popliteal artery injury, and 7 (44.4%) had a peroneal nerve injury at presentation. Four had a vascular repair, 1 had an amputation, and 3 of 7 patients had return of peroneal nerve. Ligament reconstruction was performed on 9 individuals. The average operating time for ligament reconstruction was 183% of that with injury-matched normal-weight patients. Eight operative patients who complied with therapy had an average range of motion of 91.4° (range, 60°-110°). The nonoperative patients had an average range of motion of 60.45° (range, 0°-120°). Two of these patients later required a total knee arthroplasty (3 total knee arthroplasties overall).Conclusion:Knee dislocations from minor falls occur in obese patients and are often accompanied by neurovascular complications. While surgical reconstruction is more time consuming and more difficult than that in normal-weight individuals, it may be preferable to nonoperative treatment.

The Role of Body Mass Index in High and Low Velocity Trauma Causing Knee Injury Associated to Popliteal Artery Lesions.

“…Both patients affected by low-velocity trauma had a BMI greater than 35 kg/m2 while patients affected by high-velocity trauma had a BMI between 18.7 and 31.5 kg/m2. The advanced age of patients affected by low-velocity trauma could represent a predisposing factor with regard to diseases associated with aging such as osteoporosis, arthrosis, and ligamentous laxity, rendering them prone to fractures or dislocations, even of the knee joint, as body weight represents a strong risk factor for low-velocity trauma fractures and dislocations 8,14,26 . In three cases of our experience patients had a knee prosthesis dislocation, a rare but possible cause of popliteal artery injury, especially in posterior dislocations; with this condition the disruption of ligaments, is also described by Bonnevialle et coll.…”

“…Because of its anatomical position in the popliteal fossa, because of which it is anteriorly protected by the knee joint, it is barely affected by isolated traumas. It is more frequently associated with knee fractures (Gustillo IIIC) 5,6 or knee dislocation 7,8 . Ligation of arterial injuries of the leg in World War II led to an amputation rate of 72% 9 , and experience with arterial repair or reconstruction in the Korean War lowered the amputation rate to 32%10.…”

The Role of Body Mass Index in High and Low Velocity Trauma Causing Knee Injury Associated to Popliteal Artery Lesions.

“…A high-velocity injury was one in which the trauma involved a motorized vehicle, such as motor vehicle collisions, motorcycle collisions, moped collisions, motorized vehicle collisions, or crush injuries. A lowvelocity injury was de ned as trauma occurring secondary to a fall, a sport, or an assault 8,14 . Clinical and operative data were retrospectively collected from the emergency and operating rooms' electronic medical reports at Tor Vergata Hospital between 1 January 2005 and 1 May 2018.…”

“…Because of its anatomical position in the popliteal fossa, because of which it is anteriorly protected by the knee joint, it is barely affected by isolated traumas. It is more frequently associated with knee fractures (Gustillo IIIC) 5,6 or knee dislocation 7,8 . Ligation of arterial injuries of the leg in World War II led to an amputation rate of 72% 9 , and experience with arterial repair or reconstruction in the Korean War lowered the amputation rate to 32%10.…”

Relationship Between Body Mass Index and Trauma Causing Knee Injury Associated With Popliteal Artery Injury. Monocentric Experience in a High Volume Surgery Center

“…A high-velocity injury was one in which the trauma involved a motorized vehicle, such as motor vehicle collisions, motorcycle collisions, moped collisions, motorized vehicle collisions, or crush injuries. A low-velocity injury was de ned as trauma occurring secondary to a fall, a sport, or an assault 8,14 . Clinical and operative data were retrospectively collected from the emergency and operating rooms' electronic medical reports at Tor Vergata Hospital between 1 January 2005 and 1 May 2018.…”