Total Knee Arthroplasty to Treat Acute Knee Dislocation Associated With Osteoarthritis: a Case Report

Background: Knee dislocation (KD) is a common disease in the young people. It is rare to report treatment of the KD associated with osteoarthritis (OA) in the old population. In this case report, we present two cases in which total knee arthroplasty (TKA) was performed to treat acute KD associated with osteoarthritis (OA) in two female patients. Methods: The two patients underwent knee injuries and limited range of motion (ROM). After diagnosing acute KD, including KD II and KD III-M, associated with OA with X-ray, computed tomography (CT) and magnetic resonance imaging (MRI) investigations, we considered TKA to be the best management. Results: TKA was successfully used to treat acute KD associated with OA, and the patients achieved signicant improvements in their clinical and functional outcomes. Conclusion: Acute KD associated with OA could be an indication for TKA. However, early TKA procedures can lead to a risk of arthrobrosis and joint stiffness.


Background
Knee dislocation (KD) is a severe multiligament knee injury 1-3 that accounts for approximately 0.02-0.2% of orthopaedic injuries. 3 Arthroscopic and open ligament reconstruction and repair procedures for acute KD are routine surgeries in young patients. 1,3 To the best of our knowledge, total knee arthroplasty (TKA) is similarly considered to be a procedure that can successfully manage chronic KD. [4][5][6] However, TKA for the management of acute KD associated with osteoarthritis (OA) has not been reported.
Furthermore, TKA for acute KD associated with OA is challenging because the complicated natures of multiligament injuries could result in risks for an intraoperative gap imbalance and postoperative knee instability. 7 In the current case report, two cases of TKA for the treatment of two elderly female patients with KD associated with OA are reported.

Case 1
A 67-year-old woman suffered an injury to her left knee joint in a tra c accident while crossing a crosswalk, and no additional injuries or conditions were found. The patient requested ligament reconstruction and was transferred to our orthopaedic department from another hospital. Additionally, she presented with a history of bilateral knee pain before the accident. She had irreversible varus deformities of 8° and 10° in her left and right knees, respectively. The bilateral knee range of motion (ROM) was 5° to 85°. The anterior drawer test (ADT) and posterior drawer test (PDT) were positive in the left knee. On both sides, the knee was severely degenerated with medial substantial bone loss on plain radiographs (►Fig. 1a, b), and anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears were found in the left knee on magnetic resonance imaging (MRI) (►Fig. 1c, d). KD II (ACL and PCL tears) associated with OA (Kellgren-Lawrence IV) 8 was diagnosed in the left knee according to the Schenck classi cation system, 9 and we decided to perform TKA on the eighth day after injury.
A cemented, posterior-stabilized (PS) prosthesis (Genesis II, Smith & Nephew, USA) was utilized during conventional surgery. After administering spinal anaesthesia, the patient was placed in the supine position with an upper-thigh tourniquet, a medial parapatellar approach was selected. In this case, a defect was present in the medial plateau of the tibia that was not completely removed by the proximal cut in the tibia. A cancellous screw was positioned into the tibial defect to improve the medial support for the tibial tray. Owing to the presence of medial instability (► Fig. 2g, h), the left knee was xed to allow for full extension and exion using an unlocked hinged brace for 6 weeks, 10 and then the patient was allowed to start weight bearing.
Manipulative release was performed under general anaesthesia at 10 weeks postoperatively because of knee stiffness. No additional complications, such as infection or deep venous thrombosis, occurred. The VAS, OKS, WOMAC, and ROM signi cantly improved at the latest follow-up compared with the preoperative values (►Table 1) (►Fig. 2k). The postoperative radiographs of the left knee joint showed good alignment (►Fig. 2i, j).

Discussion
The important ndings in these two cases were that acute KD associated with OA could be managed by TKA, with good functional outcomes. These cases showed that TKA could be indicated for acute KD associated with OA. However, early TKA procedures could lead to a risk of arthro brosis and joint stiffness.
KD is mainly caused by traumas, congenital anomalies, 11,12 secondary lesions 13 and so on. Both patients developed disabilities due to serious KD and severe OA. In the two cases, knee instability and pain with limited ROM were observed. Because of severe degenerative changes in the knee in both cases, the advantages and disadvantages of ligament reconstruction or repairs and joint arthroplasty were discussed and communicated with the patients who chose to undergo TKA over ligament reconstruction or single repair. TKA was chosen for these two patients because of severe knee OA, which is already an indication for TKA. The advantages of TKA include satisfactory outcomes, minimal complications, rapid postoperative rehabilitation, and early joint motion. 4,14,15 A few studies have reported TKA for the treatment of KD, [3][4][5][6] although all of these studies only reported TKA as treatment for chronic multiligament knee injury. Jabalameli et al. 5 reported TKA with a constrained hinged prosthesis for patients with CMKI, and recently, Goyal et al. 3 reported that two patients with KD III injuries underwent TKA with PS prostheses because of progressive OA that developed after the ligament reconstruction procedures. These patients achieved improved functional ability and returned to their previous jobs. Our two patients also achieved signi cant improvements in their VAS, OKS, and WOMAC postoperatively, which is similar to the results obtained in the aforementioned studies. One-stage TKA can reduce complications and costs and allow for early mobility. Our procedure was nished within the tourniquet time, as ligament reconstruction and repair procedures, with no increased intraoperative bleeding or postoperative infusion. Therefore, we consider that TKA is a favourable treatment for KD associated with OA. However, there were better functional outcomes and higher satisfaction for the right knee than for the left knee in case 1, and the patient in case 2 sustained stiffness of the left knee. Acute TKA could be related to stiffness and arthro brosis. 3 It may be more appropriate to perform TKA after soft tissue and bone marrow oedema has subsided.
There are some limitations in this case report. First, we initially considered the two cases to be ordinary cases, and few intraoperative images were collected. Second, this surgical procedure can only be performed by highly experienced and specialized surgeons using the knee arthroplasty technique. Third, TKA may only be indicated in some cases of KD with severe OA and for elderly patients.
In conclusion, TKA could be indicated for acute KD associated with OA. However, early TKA procedures could lead to a risk of arthro brosis and joint stiffness. Ethics approval and consent to participate The patients signed an informed consent. They agreed to allow the images and details of the case to be made public.

Consent for publication
The publication was done with the consent of the participants  shows ACL, PCL, and MCL tears as well as peri-knee soft tissue and femoral marrow oedema. g-h Intraoperative images show an MCL tear, gap imbalance and knee instability. i-j Postoperative radiographs of the right knee joint show good alignment.