Objective To analyze the reasons for internal fixation failure after internal fixation of nickel-titanium memory alloy patella claw for patella fracture, and to explore the countermeasures. Methods The clinical data of patients with patellar fracture treated by internal fixation of nickel-titanium memory alloy patella claw in the Second Orthopedic Ward of Chongqing Orthopedic Hospital of Traditional Chinese Medicine from May 2015 to April 2020 were analyzed retrospectively. Patients with postoperative internal fixation failure were identified. The reasons for internal fixation failure were analyzed. Results A total of 436 patients were included. Internal fixation failure occurred in 10 patients. There were 6 cases (1.38%) of patellar claw detachment, and 4 cases of simple fracture block displacement witharticular surface displacement≥2 mm (0.92%). Internal fixation failure occurred 4 to 48 days postoperatively, with an average of (18.20±10.86)days. The analysis showed that the reason for internal fixation failure in 4 patients was improper early postoperative functional exercise. The reason for 3 patients was that the auxiliary internal fixation was not selected. The reason for 2 patients was that the size of the patellar claw was too small. The reason for 1 patient was the improper fixation of the auxiliary internal fixation. Conclusion The failure of internal fixation after patella fracture with nickel-titanium memory alloy patella claw is mainly related to whether the model of the patella claw is appropriate, whether the auxiliary internal fixation is selected, whether the auxiliary internal fixation is properly fixed, and whether the early postoperative functional exercise is appropriate.
Objective To investigate the clinical effect of chitosan in prevention of knee dysfunction due to adhesion after operation for patellar fracture. Methods From March to October 1999, 40 cases of patellar fracturewere treated by internal fixation, with intraarticular injection of 2% chitosan in only 24 cases after fixation and with no chitosan injection in 16 cases(control group). The function of the knee joint, including extension and flexion, was evaluated 1month and 1 year after operation respectively. Results One month after operation, the knees with chitosan injection could actively move in the average range of 104°±23°, and the knees in the control group could move in the average range of72°±16°, which showed significant difference between two groups(P＜0.01); 1 year after operation, the range of movement of the knees with injection was 165°±38° on average, and that of the knees in the control group was 110°± 31°, which also indicated significant difference between two groups (P＜0.05). Conclusion Medical chitosan could effectively prevent or reduce the post-operative adhesion of knee joint after patellar operation.
Objective To investigate the effectiveness of three-dimensional strapping reduction in treatment of patellar fracture. Methods Between January 2015 and June 2015, thirty-two patients were randomly allocated to three-dimensional strapping reduction group (trial group) and towel clamp reduction group (control group). There was no significant difference in age, gender, damage side, interval from injury to opreration, fracture pattern, and cause of injury (P>0.05). The operation time, fluoroscopy time, fracture healing time, postoperative Hospital for Special Surgery (HSS) scores, and complications were collected and analysed. Results All incisions healed at stage I. All patients of 2 groups were followed up 10-14 months (mean, 12.4 months). The operation time and fluoroscopy time of trial group were both shorter than those of control group (t=6.212, P=0.000; t=6.585, P=0.000). X-ray films showed that the fractures in both groups healed successfully and there was no significant difference in healing time between groups (t=1.973, P=0.058). Bone nonunion, infection, and failure fixation were not found in both groups. HSS scores of trial group (91.6±3.8) was higher than that of control group (86.4±5.5) (t=–3.105, P=0.004). Conclusion Compared with towel clamp reduction, the three-dimensional strapping reduction in treatment of patellar fracture has the advantages of shorter operation time and fluoroscopy time, better knee function after operation, and satisfactory fracture healing.
ObjectiveTo compare the biomechanical difference between petal-shaped poly-axial locking plate and tension band wire cerclage in fixing star-shaped 6-part patellar fractures in cadaver model, and provide the experimental data for clinical use.MethodsThe paired 12 knee specimens from 6 human cadavers were randomly divided into 2 groups (the control group and the test group) after a star-shaped 6-part patellar fracture model was established. The specimens were weighted, and the control group was fixed with tension band wire cerclage and the test group was fixed with petal-shaped poly-axial locking plate. The specimens were connected to CMT5105 biomechanics test machine by a customized fixture, the total fracture gap of patellar fracture blocks was measured before testing. The knee extensor load test was performed to record the extensor load of knees at 90° flexion to extension. Then the anti gravity physiological knee extension process at 90° flexion was stimulated according to the knee extensor load. The cyclic times until failure and the total fracture gap of patellar fracture blocks after failure were recorded.ResultsThe specimens weight and the total fracture gap of patellar fracture blocks before testing between 2 groups had no significant difference (t=0.410, P=0.690; t=0.650, P=0.530). In the biomechanical test, there was no significant difference of knee extension load between 2 groups (t=0.490, P=0.638). The total fracture gap after failure in test group was significantly smaller than that in control group (t=3.026, P=0.013), and the cyclic times until failure in test group was significantly more than that in control group (t=2.277, P=0.046). The failure reasons in control group were all the wires slipped off the Kirschner wires, while the failure reasons in test group were the screws pulled out from the upper pole in 5 cases (83.3%) and from the lower pole in 1 case (16.7%).ConclusionThe petal-shaped poly-axial locking plate has better biomechanical stiffness to fix the star-shaped 6-part patellar fractures when compared with tension band wire cerclage method. However, this type of fracture is a serious comminuted type, and the early excessive activity still carries the risk of displacement.
OBJECTIVE To evaluate the results of free auto-periosteal graft in primary repair of cartilage defect accompanying severe comminuted fractured of patella. METHODS From January 1992 to August 1998, seventeen cases with extensive cartilage defect due to severe comminuted fracture of patella were primarily repaired with free auto-periosteal graft. In these cases, there were whole patellar fracture in 9 patients, upper two third patellar fracture in 3 patients and lower two third patellar fracture in 5 patients. During operation, "S"-shaped incision along medial side of knee through intra-cavity pathway were used. After fixation of the patellar fracture and clearance of the residual cartilage in the fracture area, the cancellous bone was exposed and trimmed. The free periosteum was incised from the anterior medial side of upper tibia and then transplanted to the region of cartilage defect. The size of grafted periosteum ranged from 3 cm x 4 cm 5 cm 6 x cm. The knee joint was received passive motion at 7 days after operation. RESULTS All cases were followed up 8 to 74 months. There were excellent recovery in 12 patients and the function of knee joint was normal, better recovery in 4 patients and the function of knee joint was nearly normal, and moderate recovery in 1 patient and the function of knee joint was limited mildly. CONCLUSION Free auto-periosteal graft is a simple and effective treatment in primary repair of cartilage defect accompanying patellar fracture. It is valuable to apply in clinical practice.
Objective To explore the surgical method and cl inical short-term outcomes of internal fixation combined closed reduction with arthroscope aid in treating patellar fracture. Methods From June 2004 to July 2008, 42 patients with fresh simple patellar fracture underwent internal fixation combined closed reduction with arthroscope aid, included28 males and 14 females, aged 16-59 years (35 years on average). The locations were 19 left knees and 23 right knees. Injury was by traffic accident in 21 cases, by fall ing in 11 cases, by sports in 7 cases and by crush in 3 cases. All the patients had fresh closed fracture, including 38 cases of transverse fracture and 4 cases of stellate fracture. The Lysholm score was 68.60 ± 15.20; the proprioceptive function of the knee joints was (3.72 ± 0.12)°. The time from injury to operation was 3-42 hours (12 hours on average). After the treatment of affil iated injury under the arthroscope, patellar fracture was reduced with manipulation method, fracture was fixed with tensile force screw or modified tension band. Results All incisions obtained heal ing by first intention after operation, 42 patients were followed up for 12-39 months (16 months on average). The X-ray films showed callus at the fracture and the smooth cartilage surface 6-9 weeks (7 weeks on average) after operation. The flexed motion range of knee joint at last follow-up was at normal range in 38 cases, was l imited in 4 cases. Circumference of suffered l imbs 15 cm above the patella was the same as normal ones in 23 cases, atrophied 0.7 cm in 19 cases. There were no breakage of internal fixation and shift of fracture and patellofemoral arthritis at last follow-up. The proprioceptive function of the knee joints was (2.06 ± 0.11)° and the Lysholm score was 95.10 ± 3.92; all showing statistically significant differences when compared with preoperation (P lt; 0.05). Conclusion This treatment method has advantages as follows: mini-wound, early exercises and few compl ications, which can rinse articular cavity and repair the affil iated injury at the same time.
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 compare the effectiveness of improved and traditional Kirschner wire tension band fixation in treatment of type C patellar fractures.MethodsBetween January 2017 and January 2019, 26 patients with type C patellar fractures were treated with improved Kirschner wire tension band fixation (group A), and 24 patients were treated with traditional Kirschner wire tension band fixation (group B). There was no significant difference in gender, age, injury cause, disease duration, and side and type of fracture between 2 groups (P>0.05). The operation time, intraoperative blood loss, the visual analogue scale (VAS) scores at 1 and 3 days after operation, the fracture healing time, and the occurrence of complications (skin irritation of Kirschner wires, failure of internal fixation, fracture reduction loss) were recorded, and the knee function was evaluated by Lysholm scoring standard in 2 groups.ResultsThe operation time in group A was significantly less than that in group B (t=−4.742, P=0.000). There was no significant difference in the intraoperative blood loss and VAS scores at 1 and 3 days after operation between 2 groups (P>0.05). All incisions healed by first intention. All patients were followed up 8-15 months, with an average of 11 months. The fracture healing time was (3.3±0.6) months in group A and (3.2±0.6) months in group B, showing no significant difference (t=0.589, P=0.559). At last follow-up, the knee joint function was evaluated according to Lysholm scoring standard. And there were 15 cases of excellent, 8 cases of good, and 3 cases of fair, with an excellent and good rate of 88.5% in group A; there were 8 cases of excellent, 7 cases of good, 7 cases of fair, and 2 cases of poor, with an excellent and good rate was 62.5%. The difference between 2 groups was significant (Z=2.828, P=0.005). The internal fixators were removed after the fracture healed in 2 groups. At last follow-up, no skin irritation of Kirschner wires occurred in group A, but 3 cases in group B. X-ray films reexamination showed that 5 cases of internal fixation failure and no fracture reduction loss were found in group A, while 9 cases of internal fixation failure and 1 case of fracture reduction loss in group B. The incidence of complications in group A was 19.2% (5/26), which was significantly lower than that in group B (54.2%, 13/24) (χ2=6.611, P=0.010).ConclusionCompared with the traditional Kirschner wire tension band fixation, the improved Kirschner wire tension band fixation in treatment of type C patellar fracture can shorten the operation time, reduce the incidence of complications, and benefit the functional recovery of knee joint.
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.
ObjectiveTo investigate the effectiveness of internal fixation using Kirschner with hole and tension band system with wire winding and pressure in the treatment of patellar fracture. MethodsBetween February 2008 and January 2010, 39 patients with patellar fracture were treated using Kirschner with hole and tension band system with wire winding and pressure. The average age was 37 years (range, 18-65 years), including 23 males and 16 females. The left side was involved in 21 cases and the right side in 18 cases. The causes were falling injury in 21 cases, traffic accident injury in 11 cases, and striking injury in 7 cases. The injury to operation time was 5 hours to 6 days (mean, 3.5 days). Twelve cases had open fractures, and 19 cases had comminuted fractures. ResultsAll incisions healed by first intention, and no deep venous thrombosis of lower limbs formed. Thirty-nine patients followed up 12-21 months (mean, 14 months). There was no wire breaking during operation and after operation. X-ray film showed no re-fracture, fracture displacement, or needle displacement; fracture healed well, fracture line disappeared at 6-8 weeks (mean, 7.5 weeks) after operation. After 12 months, the internal fixation was removed; according to the Lysholm knee score standard, the results were excellent in 22 cases, good in 16 cases, fair in 1 case, and the excellent and good rate was 97.4%. ConclusionInternal fixation using Kirschner with hole and tension band system with wire winding and pressure has satisfactory effectiveness for the treatment of patellar fracture, with the following advantages: wire is not easy to break, the needle does not fall off, and the pressure strength is powerful.