120 EEXOT Volume 59, (2):120-125, 2008 Knee dislocation A report on 9 patients S. PARASHOU1, H. KRYSTALLIS2, P. FLEGAS1, A. KARANIKOLAS1, N. ROUSSIS3 1 A' Orthopaedic Clinic - General Hospital of Kilkis, 2B' Orthopaedic Clinic - General Hospital of Kilkis, 3Orthopaedic Clinic - General Hospital of Agrinio ABSTRACT INTRODUCTION The aim of our work is to present our relatively limited The first description of knee dislocation was made by Sir experience from the treatment of 9 patients with knee Astley Gooper in 1824. It is so rare that many orthopaedic dislocation, an extremely serious although, fortunately, surgeons end their careers having seen one, two or even no 1 rare injury. In the period of 1980-2005, 9 patients with knee dislocations at all . They concern 0.02% of all injuries, knee dislocation were treated, 8 of whom were male and though perhaps their occurrence is higher than reported, 1 female. The causes were: car accidents in the cases of since they are either reduced automatically or immediately 2 6 patients (one with multiple injuries), a fall in another in the emergency room, therefore not being reported . patient and injuries during sports activities in another Shields reports 26 knee dislocations in 28 years, while Mayers 3,4 two patients. The age of the patients ranged between 53 knee dislocations in a period of 10 years . It seems that 18 and 47 years old, with an average of 31 years. Of the knee dislocation occurrence has risen, due to an increase above, 8 dislocations were closed and one open with an in car accidents, participation in sports activities as well as accompanying fracture of the medial femoral condyle. No its better diagnosis - report. neurovascular damage was identified in any patient. At the time of their hospital admission to the emergency room, 3 knee dislocations had been automatically reduced, 4 were MATERIAL AND METHOD reduced closed with gentle manipulation under general In the period of 1980-2005, 9 patients with equal in num- anaesthesia, while the remaining two open, one due to a ber knee dislocations were treated, 8 of whom were male failed closed reduction attempt and one because it was and 1 female. The age of the patients ranged between 18 open. Following the reduction, all patients were subjected and 47 years old, with an average of 31 years. The causes to a new neurovascular evaluation, radiological examina- were: car accidents in 6 patients (one with multiple fractures tion, as well as immobilization with brace to 8 patients and injuries), a fall in one patient and an injury due to partici- external fixation to the patient with the open fracture. The pation in sports activities in two patients. Only one out of knee instability treatment was effected immediately to 1 the 9 knee dislocations was open, with an accompanying patient, in 3 weeks from the injury to 4 patients, within 2 fracture of the medial femoral condyle (figure 1). The clinical months to 2 patients and within 5 months to 2 patients examination identified knee edemas due to hemathrosis in (multiple injuries, open dislocation). The outcome was all patients, knee instability in all 9 patients, as well as knee judged as satisfactory in all 3 patients. deformity in 6 patients, since in the remaining 3 there was an automatic reduction. No neurovascular damage was Key-words: knee dislocation, neurovascular damage, identified in any patient. Out of 9 dislocations, 3 had been knee instability, treatment. automatically reduced at the time of the patients’ admis- sion to the emergency room, 4 were reduced closed with gentle manipulation under general anaesthesia and 2 open Mailing Address under general anaesthesia: the first after a failed attempt Stamatios Parashou of a closed reduction due to medial femoral condyle intus- A' Orthopaedic Department, G.H. of Kilkis 9E Em. Papa Str., Retziki 57010 Thessaloniki susception in the medial capsule, and the second because it Tel.: 6946524411, e-mail: email@example.com was an open dislocation. Following the reduction, all patients S. PARASHOU et al. KNEE dISlOCATION. A REPORT ON 9 PATIENTS 121 Table 1. PATIENTS TABLE Sex Mechanism/Type Injuries Diagnosis Treatment Outcome of dislocation M Car accident-Closed- AC+PC+MC R+MRI Ar 5/12 P Multiple injuries M Car accident-Open AC+PC+MC R+d+MRI Ar 5/12 M M Car accident-Closed AC+PC+MC R+MRI O immediately VG M Car accident-Closed AC+PC+MC R+MRI Ar 2/12 G M Car accident-Closed AC+PC+MC R+MRI Ar 2/12 M M Car accident-Closed AC+PC+MC R+MRI O 3/52 VG M Fall-Closed AC+PlC R+MRI O 3/52 G M Football-Closed AC+PlC R+MRI O 3/52 G F Ski-Closed AC+PlC R+MRI O 3/52 G M: male, F: female, AC: anterior cruciate ligament, PC: posterior cruciate ligament, MC: medial collateral ligament, PlC: posterior lateral corner, O: openly, Ar: arthroscopically, VG: very good, G: good, M:medium, P: poor, d: during operation were subjected to a new neurovascular evaluation of the and a patella tendon autograft from the healthy crus in 5 crus, 8 patients to knee immobilization with brace and the patients. The average duration of follow-ups was 11 years. open dislocation patient to external fixation. A new radio- All patients had quadriceps atrophy, flexion limitation by logical examination with anteroposterior and lateral X-ray 5-15 degrees, extension limitation by 4 degrees, as well as radiographs followed to confirm the reduction. In order to a mild knee arthritis. The mean term in lynsholm score was evaluate the ligament damages, 8 patients had a magnetic 90 for those operated within the 3 first weeks and 79 for tomography in the knee. Intraoperative rupture of the those operated later. The mean terms for every day activity anterior cruciate ligament, the posterior cruciate ligament were 88 and 77, while the mean terms for sports activity and the medial collateral ligament (figure 2) was identified were 85 and 66 correspondingly. in the patient with the open reduction. As for the other 8 patients who were subjected to an MRI, we identified a rupture of the anterior cruciate ligament in all of them, a DISCUSSION rupture of the posterior cruciate ligament in 5 patients, a The deformity observed in a knee dislocation usually makes rupture in the medial collateral ligament in 5 and a rupture diagnosis easy. Many times, though, there is an automatic of the posterior lateral corner in 3 patients. The magnetic dislocation reduction and the only indirect indication is tomography was conducted within 3 weeks from the injury in knee instability, accompanied with damage to at least 3 6 of the patients, while in the remaining two (multiple-injury knee ligament elements. Knee dislocations are classified as and open-dislocation patients) it was conducted 5 months closed or open, reducible or irreducible and according to after the injury, after the fracture union. The knee instability the tibia deviation in relation to the femoral bone. A large rehabilitation was immediate in one patient (open reduction series of studies monitoring 245 knee dislocations reported due to failure of the closed one), open within 3 weeks from an anterior dislocation from hyperextension in a 40% occur- the injury in 4 patients, arthroscopically within 2 months rence, posterior dislocation from the knee impact on the from the injury in two patients and arthroscopically within 5 car dashboard in a 33% occurrence, a lateral dislocation in months from the injury in two patients (multiple-injury and 18% and a medial dislocation in 4% from a violent impact open-dislocation cases), (figure 3). For the rehabilitation of with valgus or varus directions. The rotatory dislocation, the posterior cruciate ligament, we used achilloallograft in a quite rare case, was reported in a 5% occurrence7. The 4 patients, as well as immediate stitching and anchorage irreducible dislocation is owed to the interposition of the in 2 patients; for the rehabilitation of the anterior cruciate medial femoral condyle in the medial articular capsule3,10,11. ligament we used a patella tendon allograft in 4 patients The open knee dislocation occurrence is reported to be 122 E.E.X.O.T., Volume 59, Number 2, 2008 A Β C D Figure 1. A. Open knee dislocation after a car accident, B. We can observe the accompanying fracture of the medial femoral condyle, C. Immediate postoperative X-rays. We can observe the condyle fixation with 2 K-W as well as the knee stabilization with external fixation, D. instability rehabilitation 5 months after the surgery. 15 20-25%. Rarely are there in the literature knee dislocation an angiography should be made . If the crus is ischemic, reports without an accompanying rupture of the anterior there should be reduction with gentle manipulation under 12 cruciate ligament . There should always be a neurovascular intravenous regional anaesthesia, immobilization in braces and examination of the crus, both clinically and with doppler new vascular check. If the flow is restored, radiographs and system. The ankle-branchial index (ABI) is also useful. Any an angiograph should be conducted, otherwise there should rate lower than 0.90 is an indication for an angiography, be immediate operation. The popliteal artery rehabilitation is while higher than 0.90 suggests a normal flow in the ves- effected with a venous graft from the contralateral saphen- 13,14 sels, though it should be accompanied with pulpation . ous, with simultaneous stitching of the capsule-ligament We should note that the existence of a pulse does not rule system and immobilization with external fixation. Both the out the possibility of vascular damage. If in suspicion of instability check through a magnetic tomography and re- vascular damage, an angiosurgeon should be consulted and habilitation are effected in a second phase, usually after 12 S. PARASHOU et al. KNEE dISlOCATION. A REPORT ON 9 PATIENTS 123 B Figure 2. A. Knee dislocation after a fall, B. Failure in closed reduction, C. Open reduction with a simultaneous ligament rehabilitation (allograft for the anterior cruciate ligament, posterior cruciate ligament fixation on the tibia and medial collateral stitching on the femur, D. Immediate postoperative X- ray. A C months, so that there has been vascular damage restoration the simultaneous dislocation reduction and immobilization 16,17,18,19 and ischemic bandaging can be used . The peroneal with braces or external fixation for 6 weeks. Instability reha- 22 nerve damage has an occurrence of approximately 25% and bilitation is effected after the fracture union . If a closed varies from complete neurotmesis to simple neuroapraxia. reduction fails, the treatment involves either an open or an 6,20 The rate of full or partial rehabilitation reaches 40-50% . arthroscopic reduction, though the latter is best avoided 8,3,10,11 In an open dislocation with a peroneal nerve damage, the due to the high risk of compartment syndrome . The recommended treatment involves examination, its immedi- instability restoration is effected either immediately or in a ate stitching with the simultaneous stitching of the capsule, second phase. In the case of a successful closed reduction, immobilization with external fixation and nerve monitoring. In instability can be treated either conservatively or surgically. a closed dislocation with peroneal nerve damage, the closed Conservative treatment is recommended for eldery patients reduction, immobilization for 6 weeks and monitoring the with low survival expectancy and a bad general condition. nerve function are favoured. If we have indications of nerve Prolonged immobilization time leads to a stable but inflex- function, we can proceed with the instability rehabilitation ible knee, while short time leads to a flexible but unstable 23,24,25,26 after the total function of the nerve; if not, we proceed with knee . There is a dispute over the time of surgical exploration and nerve rehabilitation with the use of a graft. instability rehabilitation, the surgical technique to be used, In the case of permanent damage, we proceed with tendon the type of grafts and the rehabilitation program. The best 21 transfers or triple arthrodesis . For open knee dislocations, results have been given by the open rehabilitation of the the recommended course involves open reduction, stitching ligaments within 3 weeks from the injury. If rehabilitation the capsule system and stabilization with EX-F for 6 weeks, delays for more than 3 weeks, then preferably it should be while instability rehabilitation follows in a second phase. If done arthroscopically in 6-12 weeks after we have full move- there are accompanying fractures, they are treated with ment of the knee and healing of the capsule. difficulties will 124 E.E.X.O.T., Volume 59, Number 2, 2008 B C Picture 3. A. Anterior knee dislocation in a multiple-fracture patient, B. Magnetic tomography showing rupture of the anterior cruciate ligament, posterior cruciate ligament, medial collateral A ligament and medial meniscus, C. Instability rehabilitation 6 months after surgery. be encountered in stitching the medial collateral ligament tion of the Knee. 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