From 1974 to 1993, 20 patients with dislocation of patella in 26 knees were treated by surgical technique, including 11 males and 9 females, aged from 10 to 67,averaged 31 year old. Thirteen cases (16 knees) were available for followup with an average period of 6.4 years. Using the criteria of Insall, the result were excellent in 5 knees, good in 5 knees, fair in 3 knees and poor in 3 knees with a success rate of 62%. Based on the biomechanism of patella movement and the findings in this study, the mechanism of dislocation of patella and its biomechanical reconstruction principle as well as the factors influencing the operative results were discussed.
Objective To introduce a new fluoroscopic method for assessing the quality of medial and lateral joint surface reduction during internal fixation of patellar fractures and to summarize the clinical outcomes of patients treated using this method. Methods A retrospective analysis was conducted on the clinical data of 52 patients with patellar fractures treated between January 2018 and January 2022 who met the inclusion criteria. There were 27 male and 25 female patients, aged 21-75 years, with an average age of 62 years. The types of patellar fractures included 9 transverse fractures, 37 comminuted fractures, and 6 longitudinal fractures. According to the AO/Orthopaedic Trauma Association (AO-OTA)-2018 fracture classification, there were 21 cases of type 34A, 6 cases of type 34B, and 25 cases of type 34C. The time from injury to operation ranged from 1 to 5 days, with an average of 2.3 days. Treatments included internal fixation with hollow screws or hollow screw tension bands, with or without anchor repair. During operation, the medial and lateral joint surfaces of the patella were observed using the tangential fluoroscopic method to assess the smoothness of reduction of the median ridge, lateral joint surface, medial joint surface, and lateral joint edge. Patients were followed up regularly, and X-ray films were taken to observe fracture healing. Knee joint range of motion, Böstman score, and Lysholm score were used to evaluate functional recovery. Results The tangential fluoroscopic method for the medial and lateral joint surfaces of the patella during operation showed satisfactory reduction of the joint surfaces and good positioning of the implants. All patients were followed up 12-16 months, with an average of 13.4 months. During the follow-up, fracture displacement occurred in 1 case and titanium cable breakage in 1 case. All patella fractures healed successfully, with a healing time of 8-16 weeks (mean, 11.4 weeks). At last follow-up, knee joint range of motion ranged from 120° to 140°, with an average of 136°. The Böstman score ranged from 20 to 30, with an average of 28, yielding excellent results in 45 cases and good results in 7 cases. The Lysholm score ranged from 88 to 100, with an average of 93, yielding excellent results in 40 cases and good results in 12 cases. Conclusion The intraoperative application of the tangential fluoroscopic method for the medial and lateral joint surfaces of the patella can quickly determine the fluoroscopic plane of the patella, accurately assess the quality of fracture reduction and the position of internal fixator, thereby improving effectiveness.
To investigate the feasibility of using the pedicled patella for repaire of the superior articular surface of the medial tibial condyle, 37 lower limbs were studied by perfusion. In this series, there were 34 obsolete specimens and 3 fresh specimens of lower legs. Firstly, the vessels which supply to patella were observed by the methods of anatomy, section and casting mould. Then, the form and area of the patellar and tibial medial conylar articular surface were measured in 30 cases. The results showed: (1) the arteries supplied to patella formed a prepatellar arterial ring around patella, and the ring gave branches to patella; (2) medial inferior genicular artery and inferior patellar branches of the descending genicular arterial articular branch merge and acceed++ to prepatellar ring at inferior medial part of patella; (3) the articular surface of patella is similar to the superior articular surface of the tibial medial condyle on shape and area. It was concluded that the pedicled patella can be transposed to medial tibial condyle for repaire of the defect of the superior articular surface. The function of the knee can be reserved by this method.
Objective To investigate the effectiveness of anatomical locking plate in the treatment of Rockwood type Ⅰ-Ⅲ patella fractures. Methods The clinical data of 16 patients with patella fractures who were admitted between November 2021 and January 2023 and met the selection criteria was retrospectively analyzed. There were 14 males and 2 females, with an average age of 44.5 years (range, 19-72 years). Causes of injuries included tumble in 12 cases and traffic accident in 4 cases. The fractures were rated as type Ⅰ in 2 cases, type Ⅱ in 9 cases, and type Ⅲ in 5 cases according to Rockwood classification criteria. The time from injury to operation ranged from 6 to 15 days, with an average of 9 days. After fracture reduction, an appropriate anatomical locking plate was selected for internal fixation. The operation time, intraoperative blood loss, and incision healing were recorded; the Lysholm score, Böstman patella fracture efficacy score, knee joint mobility, and pain visual analogue scale (VAS) score were used to evaluate the knee joint function and pain degree; X-ray films were used to review the fracture reduction and healing. Results The operation time was 65-100 minutes (mean, 75.3 minutes); the intraoperative blood loss was 10-35 mL (mean, 25.6 mL). All incisions healed by first intention after operation. All patients were followed up 11-26 months (mean, 19.7 months). X-ray films showed that the fractures were reduced satisfactorily, and all achieved bony healing with healing time of 3-5 months. At last follow-up, the Lysholm score was 90-95 (mean, 93.0); the Böstman patella fracture efficacy score was 27-30 (mean, 28.8), of which 12 cases were excellent and 4 were good; the VAS score was 0-1 (mean, 0.3). There was no significant difference in the range of motion of the knee joint between the healthy and affected sides [145° (140°, 150°) vs 145° (140°, 145°); Z=1.890, P=0.059]. Conclusion Choosing anatomical locking plates for Rockwood typeⅠ-Ⅲ patella fractures can achieve strong fixation with minimal surgical trauma, rapid recovery of knee joint function, and mild pain after operation.
Objective To establish the finite element model of Y-shaped patellar fracture fixed with titanium-alloy petal-shaped poly-axial locking plate and to implement the finite element mechanical analysis. Methods The three-dimensional model was created by software Mimics 19.0, Rhino 5.0, and 3-Matic 11.0. The finite element analysis was implemented by ANSYS Workbench 16.0 to calculate the Von-Mises stress and displacement. Before calculated, the upper and lower poles of the patella were constrained. The 2.0, 3.5, and 4.4 MPa compressive stresses were applied to the 1/3 patellofemoral joint surface of the lower, middle, and upper part of the patella respectively, and to simulated the force upon patella when knee flexion of 20, 45, and 90°. Results The number of nodes and elements of the finite element model obtained was 456 839 and 245 449, respectively. The max value of Von-Mises stress of all the three conditions simulated was 151.48 MPa under condition simulating the knee flexion of 90°, which was lower than the yield strength value of the titanium-alloy and patella. The max total displacement value was 0.092 8 mm under condition simulating knee flexion of 45°, which was acceptable according to clinical criterion. The stress concentrated around the non-vertical fracture line and near the area where the screws were sparse. Conclusion The titanium-alloy petal-shaped poly-axial locking plate have enough biomechanical stiffness to fix the Y-shaped patellar fracture, but the result need to be proved in future.
ObjectiveTo explore the effectiveness of high strength suture fixation in treatment of patellar transverse fracture.MethodsBetween June 2014 and June 2016, 38 patients with the patellar transverse fracture were treated with high strength suture internal fixation. There were 24 males and 14 females with the age of 26 to 64 years (mean, 45 years). There were 6 cases of accident injury and 32 cases of crashing injury. The time interval between injury and surgery was 2-8 days (mean, 5 days). The preoperative visual analogue scale (VAS) score, Lysholm score, and range of motion (ROM) of patients were 84.3±8.4, 44.5±7.2, and (62±12)°, respectively.ResultsAll patients’ incisions healed by first intention after operation. There was no neurovascular injury, deep venous thrombosis of lower limbs, or local foreign matter irritation reaction. The X-ray films showed that the reduction of patella and the location of internal fixator were good at 2 days after operation. All the 38 patients were followed up 12-18 months (mean, 16 months). All fractures healed and the healing time was 2-4 months (mean, 3 months). At last follow-up, according to the Böstman criteria, 36 patients were rated as excellent and 2 as good, with an excellent and good rate of 100%. The VAS score, Lysholm score, and ROM of patients were 10.2±6.6, 93.1±6.4, and (124±14)°, respectively, showing significant differences when compared with preoperative ones (t=42.759, P=0.000; t=31.099, P=0.000; t=20.727, P=0.000).ConclusionApplication of high strength suture fixation in the treatment of patellar transverse fracture has advantages of simple to operate, effective fixation, and less complication. It can avoid reoperation of removing the internal fixators. The satisfied ROM and function of the knee joint can be obtained after operation.
Objective To investigate the effectiveness of transosseous suture in medial patellofemoral ligament (MPFL) double bundle reconstruction. Methods The clinical data of 75 patients with recurrent patella dislocation who met the selection criteria between January 2014 and December 2017 were retrospectively analyzed. All of them were treated with MPFL double bundle reconstruction, and divided into study group (39 cases, using new transosseous suture technique) and control group (36 cases, using traditional suture anchor fixation) depending on the intraoperative fixation technique. There was no significant difference in gender, age, body mass index, affected knee side, preoperative tibial tuberosity-trochlear groove distance, Insall-Salvati ratio, knee range of motion, Kujala score, International Knee Documentation Committee (IKDC) score, congruence angle, and tilt angle between the two groups (P>0.05). The operation time, intraoperative blood loss, hospital stay, and postoperative complications were recorded and compared between the two groups. Kujala score, IKDC score, and knee range of motion were used to evaluate the functional improvement of patients before and after operation. The congruence angle and tilt angle were measured on X-ray films. Results There was no significant difference in operation time, intraoperative blood loss, and hospital stay between the two groups (P>0.05). Patients in both groups were followed up 24-36 months, with an average of 29.4 months. There was no complication such as incision infection, fat liquefaction, patellar redislocation, and prepatellar pain during follow-up. At last follow-up, the Kujala score, IKDC score, knee range of motion, congruence angle, and tilt angle of two groups significantly improved when compared with those before operation (P<0.05), while there was no significant difference between the two groups (P>0.05). ConclusionThe application of suture anchor or transosseous suture to complete MPFL double bundle reconstruction can restore patellar stability, and there is no significant difference in the short-term effectiveness between them.
Objective To review the progress in the prevention and repair of patellar ligament injury in total knee arthroplasty. Methods Recent literature about the prevention and repair of patellar ligament injury in total knee arthroplasty was reviewed and analyzed. Results Increased exposure can prevent the patellar ligament injury, and treatments of acute patellar ligament rupture can be obtained by simple repair, reconstruction with allograft materials or artificial materials, and auxiliary strengthening. Conclusion Patellar ligament injury in total knee arthroplasty should not be ignored. Active prevention and repair of patellar ligament injury can obtain better function of knee joint.
ObjectiveTo investigate the effectiveness of the arthroscopic lateral retinacular release combined with medial patellofemoral ligament (MPFL) reconstruction for patellar dislocation.MethodsBetween January 2016 and March 2017, 28 cases (32 knees) with patellar dislocation were treated by arthroscopic lateral retinacular release and MPFL reconstruction. There were 6 males (6 knees) and 22 females (26 knees) with an average age of 21 years (range, 17-29 years). The disease duration ranged from 2 days to 2 years (mean, 8 months). Apprehension test of all patients were positive. The preoperative Lysholm score was 68.34±12.26. Anteroposterior X-ray film showed the patellar subluxation or dislocation. The Q angle was (17.67±4.21)° and the distance of tibia tuberosity-trochlear groove was less than 20 mm. The femoral attachment of retinacular were fixed by the interference screws (16 knee) or the anchors (16 knee), respectively.ResultsAll incisions healed by first intention. All patients were followed up 6 months. The function of knee joint was significantly improved at 6 months after operation. The Lysholm score was 92.88±6.42 and the Q angle was (12.15±3.68)° at 6 months. There were significant differences in the Lysholm score and the Q angle between pre- and post-operation (t=–3.408, P=0.006; t=–2.317, P=0.004). Apprehension test of all patients were negative. No knee pain, knee weakness, and patellar dislocation occurred during follow-up. There was no significant difference in the Lysholm score and the Q Angle between the anchor group and interference screw group (t=–3.254, P=0.820; t=–3.576, P=0.940). ConclusionLateral retinacular release combined with MPFL reconstruction under arthroscopy can effectively improve the function of the knee joint for patients with Q angle less than 20° and TT-TG less than 20 mm, and the early effectiveness is good. There is no significant difference in knee function between the anchor and interference screw internal fixation.
Objective To review research progress on femoral attachment positioning during medial patellofemoral ligament (MPFL) reconstruction, so as to provide a reference for accurate positioning in clinic. Methods The literature at home and abroad on femoral attachment positioning during MPFL reconstruction was extensively reviewed and summarized. Results MPFL is the main ligament that restricts patellar outward migration, so MPFL reconstruction is the main treatment for patellar dislocation, but the accuracy of intraoperative femoral attachment positioning will significantly affect the effectiveness. At present, there are three main methods for femoral attachment positioning in MPFL reconstruction, including imaging positioning, bony landmark positioning, and new technology. Among them, the main imaging positioning method is the “Schöttle point” method, but it has high requirements for fluoroscopic positioning, and can only be accurately positioned under standard lateral fluoroscopy of the femur. The bony landmark positioning method mainly locates the femoral attachment by touching or dissecting the bony landmarks such as adductor tubercles and medial epicondyle of femur, but its disadvantages are that the positioning is not accurate enough, the intraoperative visual field exposure requirements are high, and a large incision is required. In order to avoid the problem that the simple bony landmark positioning method, in recent years, the combination of bony landmarks combined with arthroscopy, three-dimensional (3D) printing technology, and robot-assisted positioning methods have begun to be used in clinical practice. New technology localization methods have shown good results by preparing guides before operation, planning positioning paths in advance, or directly using robots to assist positioning during operation. Conclusion The accurate positioning of the femoral attachment in MPFL reconstruction is crucial, and the method of accurate and rapid intraoperative determination needs to be further improved and optimized. In the future, it is expected that the combination of computer image recognition correction technology and intraoperative position assistance will solve this problem.