Traumatic anterior dislocation of a prosthetic knee, from trauma to delayed onset of vascular injury

Abstract

Anterior dislocation of a prosthetic knee is a rare event. Only few episodes have been described in the past and have never been linked with neurovascular injury. This could lead orthopaedic surgeons to focus on the implant instability factors and underrate other complications. The authors report a case of a patient who experienced popliteal artery dissection 80 hours after traumatic anterior knee dislocation of a previously well-functioning total knee arthroplasty. Given that there is a lack of clinical cases that have established guidelines for management of this problem, the authors have focused on the importance of performing computed tomography angiography in the management of an anterior traumatic knee dislocation of a prosthetic knee.

Knee-Spanning External Fixation for Recurrent Traumatic Anterior Prosthetic Knee Dislocation With Associated Vascular Injury

“…Posterior dislocation has occurred in prior reports in posterior stabilized designs with a combined flexion and varus moment that causes the femoral component to “jump the post.” The incidence for a posterior stabilized TKA dislocation was 1%-2%, but this has decreased to below 0.5% with redesigned components and techniques [ 2 ]. Anterior prosthetic knee dislocation is limited to several small case series and reports [ [3] , [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] ] and represented only 11% of all prosthetic knee dislocations in one recent systematic review [ 1 ]. It occurs by a different mechanism of combined valgus, external rotation, and hyperextension [ 8 ].…”

“…Anterior prosthetic knee dislocation is limited to several small case series and reports [ [3] , [4] , [5] , [6] , [7] , [8] , [9] , [10] , [11] , [12] ] and represented only 11% of all prosthetic knee dislocations in one recent systematic review [ 1 ]. It occurs by a different mechanism of combined valgus, external rotation, and hyperextension [ 8 ]. This causes medial collateral and posterior cruciate ligament failure, resulting in anterior instability [ 8 ].…”

“…It occurs by a different mechanism of combined valgus, external rotation, and hyperextension [ 8 ]. This causes medial collateral and posterior cruciate ligament failure, resulting in anterior instability [ 8 ]. Contributing factors include flexion instability, component malpositioning, extensor mechanism dysfunction [ 5 ], and polyethylene wear [ 4 , 9 , 11 , 12 ].…”

“…reported a case of anterior prosthetic knee dislocation that presented with symptoms of vascular compromise approximately 80 hours after injury and subsequent reduction [ 8 ]. The patient had popliteal dissection and thrombosis on CT angiography and required emergent revascularization and subsequent fasciotomies for reperfusion compartment syndrome [ 8 ]. A high degree of suspicion, serial examinations, and a low threshold for CT angiography can help prevent missed vascular injuries.…”

Vascular injury and orthopaedics

“…Although majority of these injuries occur as a result of trauma leading to fracture or dislocation of joints, such as the case reported by Addevico et al. [1] in this issue of Arthroplasty Today , injuries to vascular structures can also occur during elective orthopaedic procedures.…”