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.
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.
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.
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.
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 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.