Vascular Complications after Anterior Cruciate Ligament Reconstruction and Deep Venous Thrombosis Prophylaxis

Arterial Complications

Knee arthroscopy is generally a safe procedure with a low incidence of complications. The two largest studies to date report complication rates of 0.54% and 0.8%. Penetrating popliteal artery injuries were described by DeLee in 6 out of 118,540 arthroscopies. Small noted nine cases (out of 375,000 arthroscopic procedures) of penetrating trauma to the popliteal artery. A subsequent study of 8741 cases done by experienced arthroscopists showed no vascular complications. Pseudoaneurysm is the most frequently published popliteal artery lesion after arthroscopy of the knee. It is associated with direct violation of the posterior capsule or previous (open) knee surgery. However, it is still rare and published in case reports only.

The incidence of arterial lesions after arthroscopic ACL reconstruction is unknown. Case reports have been published using various techniques of ACL reconstruction. Table 134.1 presents the details of the published arterial complications after ACL reconstruction. Most case reports found a correlation between vascular injuries and surgical complications related to ACL reconstruction. ^{, , ,} Three studies related their vascular complications to concurrent lateral meniscectomy, posterior cruciate ligament (PCL) reconstruction, and preexistent intimal popliteal artery injury due to a previous knee dislocation.

Arterial complications can be observed in the form of occlusion, avulsion, penetrating injury, arteriovenous fistula, or pseudoaneurysm. Pseudoaneurysm is the most frequently reported arterial complication after ACL reconstruction, irrespective of graft type or method of fixation. Pseudoaneurysms differ from true aneurysms in that they do not contain all the layers of an artery. They resemble organized hematomas that have internal arterial flow. A direct arterial trauma by a drill bit, shaver, hardware, or fixation device for ACL reconstruction may cause a pseudoaneurysm. This condition usually presents with repeated hemarthrosis and a pulsatile mass within days to weeks after ACL reconstruction. Their growth may lead to neuropraxia and deep vein thrombosis due to compression of nerves and nearby veins, respectively. Patients with poor collateral development may have severe ischemia and poor prognosis, even leading to amputation. It should be noted that most case reports described palpable dorsalis pedis and posterior tibial arterial pulses at time of clinical presentation, with swelling and pain around the popliteal area. These findings have misled surgeons to underestimate vascular complications after ACL reconstruction.

In our consecutive series of 1961 arthroscopic ACL reconstructions (1998–2014), three arterial complications have occurred (incidence 0.15%). In these cases, a quadruple hamstring graft was fixed with a Bone Mulch Screw on the femoral side and a WasherLoc bicortical screw in the tibia (Arthrotek, Inc., Warsaw, Indiana).

Our first case was a 44-year-old male with a previous history of open medial and lateral ligament repair of the same knee 15 years previously (motor accident). The hospital recovery was uneventful after ACL reconstruction. On the 17th day postsurgery, he experienced pain and swelling in the popliteal fossa of the knee. The complaints partially resolved with physiotherapy. Two days later, the fossa pain returned with alterations of skin color, sensory loss, and an increasingly cold foot. Adequate dorsal pedal and posterior tibial pulses were noted. Duplex ultrasound examination showed no sign of venous thrombosis. Angiography revealed a subtotal occlusion of the popliteal artery at the level of the superior genicular artery ( Fig. 134.1 ). An embolectomy was performed using a Fogarty catheter inserted in the femoral artery. The pedal pulses were diminished after embolectomy and a second angiography performed. The occlusion at the level of the popliteal artery was no longer detected. No further emboli were noted; however, the peripheral flow qualified as too slow and suspect of small distal occlusions. Anticoagulant therapy with intravenous heparin and epidural analgesia was administered until there was complete recovery of peripheral circulation. The patient developed a superficial infection of the groin wound, treated by antibiotics. He was mobilized and discharged after 8 days. Sensory loss of the foot slowly recovered after 4 months. Vascular analysis in rest and strenuous activity was performed at 4 months. He had no more complaints, symmetrical ankle-brachial index in both legs, and intact pulses at the foot and ankle. Our hypothesis of the cause was the traumatic knee dislocation 15 years previously. Precursors could have been preexistent intimal vascular damage or adhesions of the artery at the level of the superior genicular artery in combination with the use of the tourniquet.

A bicortical tibial drill bit caused the pseudoaneurysm of the popliteal artery in our second case report. A 24-year-old man had an ACL reconstruction and was allowed full weight bearing with aggressive rehabilitation. The hospital stay was uneventful. Twelve days after surgery, the patient complained of progressive pain in the popliteal fossa that had started on the 5th day postsurgery. On physical examination, a pulsating mass was felt in the popliteal fossa, with sensory loss of the medial foot as well as the plantar heel. The dorsal pedal and posterior tibial pulses were intact. Duplex analysis and computed tomography (CT) angiography demonstrated a pseudoaneurysm of the infragenicular popliteal artery near the site of the bicortical tibial screw ( Fig. 134.2 ). The pseudoaneurysm measured 3.5 × 1.5 cm on the sagittal view and 3.5 × 4 cm in the frontal aspect ( Figs. 134.3 and 134.4 ). Surgical exploration was immediately performed. A vascular defect (3 mm) of the infragenicular popliteal artery was found just proximal to the origin of the anterior tibial artery ( Fig. 134.5 ). The tip of the bicortical screw was not in direct contact with the arterial lesion. Apparently, the 3.2-mm drill bit used for the bicortical screw had caused perforation of the popliteal artery. An arteriotomy was performed and an intimal lesion repaired. A venous patch was used to close the arterial defect. A Fogarty catheter was inserted to remove small clots present in the tibioperoneal trunk. Aspirin was prescribed for 3 months. No complications occurred after the vascular repair. Functional treatment using continuous passive motion started the day after surgery. Brace-free, accelerated rehabilitation was initiated after wound healing occurred. At 4-months follow-up, there was full range of motion of the knee. Lachman and anterior drawer test were 0–2 mm (according to International Knee Documentation Committee), with an absent pivot-shift test. Neurological evaluation by a neurologist showed a sensory loss of the saphenous and medial plantar nerves, and to a lesser degree sensory loss of the superficial peroneal nerve of the right leg. There was no loss of motor function. The dorsal pedal and posterior tibial pulses were intact.

Our third case was a 50-year-old woman with a pseudoaneurysm of the popliteal artery after ACL reconstruction. She was seen 1-week postsurgery with pain in the popliteal fossa, absent foot pulses, and sensory loss in the foot. Doppler examination showed weak signals in the foot. Magnetic resonance imaging (MRI) angiography revealed a pseudoaneurysm of the supragenicular popliteal artery and a 4-cm occlusion proximal to the tibioperoneal trunk ( Fig. 134.6 ). Surgical exploration on the 9th day postsurgery showed damage to the artery in line with the tibial bicortical screw. Just as in our previous case, the tip of the bicortical screw was not in direct contact with the artery. The drill bit used for the bicortical screw had caused perforation of the popliteal artery. There was no hematoma around the pseudoaneurysm, nor was it in line with the Bone Mulch Screw fixation of the femur. The vascular surgeon thought this lesion to be preexistent and not related to the ACL surgery. The pseudoaneurysm was ligated and a saphenous bypass performed. A 5-day course of intravenous heparin was administered in combination with aspirin. Aspirin was continued after discharge. At final follow-up, sensory loss of the plantar foot and decreased motor function of the flexor hallucis longus muscle were still present.

Post and King studied the relative position of the neurovascular structures at risk when drilling bicortical screws for tibial fixation in ACL reconstruction. Arthroscopic tibial tunnels were made in cadaver human knees, using lateral Roentgen graphs for accurate positioning. A 4.5-mm bicortical drill hole was placed perpendicular to the tibial surface, 1 cm distal to the tibial tunnel. The distances from the posterior tibial drill exit point to the nearby neurovascular structures were measured with a caliper. The closest structure to the exit point was the bifurcation of the popliteal artery/vein (11.4 ± 0.6 mm). The next closest was the anterior tibial vein (11.7 ± 1.6 mm). The closest any individual hole came to a neurovascular structure was 3.5 mm from the anterior tibial vein. They concluded that bicortical screw and spiked washer fixation of soft tissue ACL grafts appear to be relatively safe. Curran et al. performed an in vitro study comparing two techniques for ACL tibial fixation with a bicortical screw. They concluded that aiming the screw toward the fibula reduced the risk of vascular injury compared with screws drilled perpendicular to the cortex. Other possible recommendations to prevent neurovascular damage are the use of a drill bit stop for bicortical screws or a single cortex fixation on the tibia without compromising stability of fixation. We have adapted these recommendations, and no further arterial injuries occurred in the consecutive series of ACL reconstructions.

In accordance with our three cases, most case reports in our systematic review showed a certain delay in diagnosis (1–6 weeks postsurgery up to 8 years). ^{, ,} Damage to the popliteal artery occurred even with all-inside techniques of arthroscopic ACL reconstruction and fixation, as well as any type of graft. Other than the Gore-Tex rupture ligament case, all patients maintained adequate ACL stability after vascular surgery. The neurological deficits, however, may be permanent.