Knee dislocation is a relatively uncommon injury accounting for about 0.02% of all orthopedic injuries [1] its true incidence is underestimated however, because a knee that was dislocated or subluxed at the time of trauma will very often spontaneously reduce prior to assessment [2] . It is usually a high energy injury except in obese patients where a simple fall from standing height may result in knee dislocation [3] .

High energy knee dislocations are usually associated with other injuries and these include vascular and nerve injuries 18%, fractures 57% (including open fractures 27%), and other life-threatening injuries 27% [4] [5] , hence all patients sustaining high energy injuries warrant thorough examination following ATLS protocol to detect associated life-threatening injuries and a methodical neurovascular exam of the limb. In the setting of knee dislocation prompt diagnosis of vascular injury and intervention is essential for limb survival. time of ischemia is a crucial factor determining the outcome of the limb and some recommend less than 8 hrs while others 4 - 6 hours, beyond which is considered delayed and the likely hood of limb loss is so high [6] [7] , this window is usually not met for the majority of patients in resource limited settings like our own [8] .

This case underscores the importance of limb revascularization, even when ischemic time is beyond 8 hours, particularly in non-gangrenous limbs, however, clinicians should ideally aim to initiate revascularization within 8 hours of vascular injury.

The incidence of vascular injury in knee dislocation varies between studies, ranging from 22% to 32% [1] Vascular injuris are commonly seen in KDIIIL type (32%) and posterior types (25%) of knee dislocations [1] , according to modified Schenk and Kenedy classification see Table 1. The most commonly injured vessel in knee dislocation is the popliteal artery, primarily due to its anatomical predisposition [6] [9] . The popliteal artery is closely associated with the distal femur and proximal tibia, with ligamentous fixations both proximally and distally, making it relatively immobile. It originates at the tendinous hiatus of the Adductor Magnus muscle and is firmly anchored by the tendinous arch of the Soleus muscle distally [6] .

Timely diagnosis and intervention are crucial in determining whether to salvage or amputate a limb. Literature suggests that a prognosis becomes poor if the ischemia time exceeds 8 hours, leading to irreversible damage and potential reperfusion injury upon limb revascularization [7] . Total ischemic time has a direct correlation with the rate of amputation [10] and 86% amputation rate has been reported when ischemic time exceeds 8 hours [7] .

Therefore, quick and accurate diagnosis is vital, the diagnostic approach to vascular injuries following trauma remains a subject of ongoing debate. Conventional angiography has traditionally been regarded as the gold standard for diagnosis in this context [6] . Some studies recommend routine angiography for all patients with knee dislocation [11] [12] , while newer studies advocate for selective angiography in patients with abnormal pulses or ankle-brachial indexes (ABIs) [13] . The rationale behind this approach is that routine angiography may lead to side effects such as hematoma, pseudoaneurysm, arteriovenous fistula formation, and contrast-induced nephropathy, as well as increased hospital costs and delayed diagnosis. Ankle Brachial Index (ABI) is a more cost-effective, reliable, and quick investigation which has demonstrated sensitivity of 95% to 100% and specificity of 80% to 100% in detecting vascular injuries requiring surgical repair [14] , relying on pulse examination can sometimes be misleading and the presence of palpable distal pulse does not exclude the possibility of a major vascular injury requiring surgical repair [15] .

In cases where “hard” signs (Table 2) of ischemia are present, and the injury zone is clearly defined (e.g., knee dislocation with involvement of the popliteal

artery), it is advisable for the vascular surgeon to proceed with immediate arterial exploration at the knee level without the need for additional diagnostic studies. However, in situations where the precise injury zone is uncertain, such as a gunshot wound to the lower extremity with a wide “blast zone,” arteriography is typically conducted to pinpoint the exact location of the vascular lesion. This approach helps guide further treatment decisions and interventions.

Regarding the sequence of treatment in the operating room, especially the order between vascular repair and skeletal stabilization, there is no definitive consensus. One perspective emphasizes vascular repair as the initial step to reduce ischemic time, followed by skeletal stabilization. On the other hand, an alternative viewpoint suggests, skeletal stabilization should come first to prevent stretching and further injury to the repaired vessel. However, it’s important to note that a meta-analysis has shown that this sequence does not significantly affect amputation rate [16] .

In resource limited settings, patients rarely meet the 8-hour window for timely intervention due to delays in accessing well-equipped trauma centers, delayed diagnosis, and unavailability of proper equipment for vascular repair [8] [17] , all of which were contributing factors in our patient’s case. In a recent study conducted in India where the mean time of limb revascularization was 30.8 hours, 95% of the patients with >8 hours delay had good outcome [8] . The study recommended revascularizing viable limbs in otherwise stable patients, even with prolonged periods of ischemia.

It is crucial to emphasize the need for improving prompt diagnosis and timely referral for limb revascularization, ideally within the first 8 hours following injury. However, we acknowledge in resource-limited settings, meeting this timeframe may be challenging. In cases where patients with vascular injury arrive at referral centers after 8 hours have elapsed since the injury, a thorough assessment of limb viability should be conducted. If the limb is found to be viable, revascularization procedures should be initiated without delay.

To enhance patient outcomes in similar cases, hospitals should prioritize equipping their emergency care physicians with the necessary tools and equipment for vascular repair. This proactive approach ensures that healthcare providers can promptly and effectively address vascular injuries, thus optimizing the chances of limb salvage and reducing the risk of complications associated with delayed intervention.

The authors declare no conflicts of interest regarding the publication of this paper.

Jimmy, O. and Abdulmajid, S. (2023) Delayed Management of Popliteal Artery Injury Following Knee Dislocation—A Case Report. Open Journal of Orthopedics, 13, 427-434. https://doi.org/10.4236/ojo.2023.1310042