A total of 23 patients (16 men and 7 women) aged 23 to 55 years (mean: 40.7±9.1) underwent open reduction and internal fixation for avulsion fractures of the ALL associated with periarticular knee fractures from June 2014 to May 2017. The inclusion criteria for this study were (1) periarticular fractures of the knee, including distal femoral and proximal tibial fractures, (2) absence of injury to nerves, blood vessels, and major organs, (3) a follow-up period of ≥ 2 years, (4) the ability to walk normally using the ipsilateral knee joint before injury, and (5) no obvious osteoarthritis or any history of trauma. The exclusion criteria were (1) a simple Segond fracture, (2) concurrent injury of the common peroneal nerve, (3) concurrent osteofascial compartment syndrome, (4) pathological fractures, (5) poor adherence to rehabilitation/follow up, and (6) a pre-existing history of knee osteoarthritis. Table 1 reports the demographic details and patient characteristics of the study population.
Associated with distal femoral fracture (Group A). Of nine patients, the distal femoral fracture type was 33A2 in two patients, 33A3 in four patients, 33B2 in two patients, and 33B3 in one patient (according to the AO/OTA Fracture and Dislocation Classification).
For patients with 33A2 AND 33A3fractures, we used a standard open lateral approach to the distal femur. The incision was extended slightly distally to expose the avulsion fracture of the tibial insertion of the ALL. First, the distal femoral fracture was repaired utilizing minimally invasive plate osteosynthesis (MIPO) techniques. The ALL tibial avulsion fracture bed was cleared of intervening soft tissue under direct visualization, and dissection continued proximally until the origin of the ALL was identified. After identification of the ALL, the avulsion fracture block was accurately reduced and fixed (Figure 1). For patients with type 33B2 and 33B3 fractures, a medial incision was performed to reduce and fix the fracture of the medial femoral condyle, then a lateral incision was made to fix the ALL tibial avulsion fracture. The lateral incision was made at the midpoint between Gerdy’s tubercle and the apex of fibular head.
Associated with tibial plateau fracture (Group B). Of the 10 patients with tibial plateau fracture, six patients also had an anterior cruciate ligament (ACL) avulsion fracture. After management of the tibial plateau fracture was performed, the ACL avulsion fracture was fixed with steel wire or nonabsorbable sutures passed through the ACL insertion in a figure-of-eight and brought through a tibial tunnel. After adequate reduction and fixation of the tibial plateau and ACL avulsion fractures as confirmed by the image intensifier, the ALL tibial avulsion fracture was fixed.
Associated with the tibial intercondylar eminence avulsion fracture (Group C). Of the four patients, the ACL avulsion fracture was fixed first with nonabsorbable sutures passed in a figure-of-eight through the ACL insertion and brought through a tibial tunnel under arthroscopic assistance and anchored distally in the tibia, followed by reduction and fixation of the ALL tibial avulsion fracture via a small lateral incision.
After the associated fracture had been fixed, the pivot-shift test was performed by the senior attending surgeon prior to fixing the ALL tibial avulsion fracture [27, 28, 48, 43]. The patients were routinely followed up at 1, 3, 6, 12, and 24 months postoperatively. They were usually discharged from orthopaedic care at 24 months of follow-up. During the follow-up appointments, X-ray images were obtained, and the the fracture healing was determined based on clinical exam and imaging. The postoperative pivot-shift test, International Knee Documentation Committee (IKDC) score [27, 43], Lysholm score, and Tegner activity level  were recorded at 2 year follow up.
Statistical analysis was performed using the software package SPSS (Version 120.0, IBM Corp). Descriptive statistics including means and standard deviations were obtained from continuous data. Data are presented as mean values with ranges. Chi-square analysis was used for categorical variables, and the Mann-Whitney U test was used to compare parametric or nonparametric variables. The Kruskal-Wallis H test was used to compare was used to compare the postoperative objective IKDC evaluation. Statistical significance was defined at P < .05.