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.
ObjectiveTo investigate the effectiveness of anterior knee incision by the patellar longitudinal approach for osteotomy in treating type C fractures of the distal femur. MethodsBetween March 2010 and June 2014, 36 patients with type C fractures of the distal femur underwent fracture reduction and internal fixation by patellar longitudinal approach for osteotomy. There were 25 males and 11 females, aged 26-72 years (mean, 49 years). Injury causes included traffic accident injury (19 cases), falling injury from height (8 cases), and crushing injury (9 cases). There were 34 cases of closed fracture and 2 cases of open fracture. Associated fractures included 2 cases of patellar fracture and 4 cases of clavicular fracture; combined injuries included 4 cases of anterior cruciate ligament injury, 1 case of posterior cruciate ligament injury, 12 cases of meniscus injury, and 9 cases of medial and lateral collateral ligament injuries. It was 3-11 days from injury to operation (mean, 6 days). ResultsAmong 36 patients, 29 were followed up 12-24 months (mean, 18 months). Primary healing of incision was obtained, without infection or lower limb deep venous thrombosis. X-ray films showed fracture healing at 12-32 weeks (mean, 16.4 weeks). Neither loosening of screw and plate breakage nor valgus and varus knee occurred. Pain and stiff of the knee joint were observed in 4 and 2 cases, respectively; 4 cases walked with a cane. According to Hospital for Special Surgery (HSS) scoring system, the results were excellent in 21 cases, good in 7 cases, and fair in 1 case; and the excellent and good rate was 96.55%. The internal fixation was removed at 10-14 months after operation, and there was no re-fracture. ConclusionThe patellar longitudinal approach has the advantages of sufficient exposure, easy reduction, short operation time, good internal fixation, less damage of soft tissue, and less complication. So it is the appropriate approach to treat type C fractures of the distal femur.
Objective To explore the cl inical effectiveness of arthroscopic reconstruction of medial patellofemoral l igament (MPFL) with trabs of medial soft tissues in the treatment of patellar instabil ity of adolescence. Methods From January 2005 to December 2006, 23 cases of patellar instabil ity were treated, including 10 males and 13 females with an average age of 16 years old (13 to 20 years old). The locations were left knee in 11 cases, right knee in 12 cases. The disease course was 1-28 weeks (mean 15 weeks). All patients had patellar instabil ity sense and knee arthralgia during strenuous exercise. Preoperative, the International Knee Documentation Committee (IKDC) score and Lysholm score were 48.30 ± 5.77 and 50.80 ± 7.61. The congruence angle, lateral patellar angle, and Q angle were (9.00 ± 2.46), (2.94 ± 2.55) and (19.10 ± 4.16)°. All of the patients experienced the operation of reconstruction of MPFL with trabs of medial soft tissues (medial patellar retinaculum, joint capsule and vastus medial is obl ique muscle fiber) through arthroscope. Results All the wounds healed by first intention, and no postoperative early compl ication occurred. All cases were followed up 19 months on average (12 to 24 months). Apprehensive test and patella tilt test were negative. The range of motion returned to normal. There was no recurrence of dislocation after operation. At 12 months after operation, the congruence angle, lateral patellar angle, and Q angle were (—7.03 ± 0.60), (11.00 ± 3.47) and (11.30 ± 1.90)°; the IKDC score and Lysholm score were 93.20 ± 3.51 and 94.10 ± 4.26. There were statistically significant differences between preoperation and postoperation (P lt; 0.05). Conclusion Arthroscopic reconstruction of MPFL with trabs of medial soft tissues can improved obviously the affected limb function in treatment of patellar instabil ity of adolescence.
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 observe the morphological characteristic by implanting domestic porous tantalum in rabbit patellar tendon and to evaluate biocompatibility features so as to provide experimental basis for porous tantalum used as interface fixation between tendon and bone. MethodsA total of 48 adult New Zealand white rabbits, male or female, weighing 2.5-3.0 kg, were selected. Porous tantalum flake (5 mm×5 mm×2 mm) was implanted in the left patellar tendon (experimental group) and the same size porous titanium flake in the right patellar tendon (control group). The animals were sacrificed at 2, 4, 8, and 12 weeks after implantation, then the specimens were harvested for gross observation, HE staining, scanning electron microscope (SEM) observation, and hard slices observation. ResultsNo animal died after operation. Porous tantalum was bonded closely with host tendon and no inflammatory reaction was found. Loose and thick fibrous capsule was observed at the beginning and became density and thinner in the end by microscope, showing significant difference between different time points in 2 groups (P<0.05), but no significant difference was found between 2 groups at different time points (P>0.05). The SEM observation showed that fibrous tissue attached to the surface and inner walls of porous tantalum at early stage, and extended on the material to reach confluence at late period, but the experimental group was more than the control group. Hard slices observation showed that the collagen fibrils were seen on porous tantalum interface with host tendon, and blood vessels grew into the pores. The control group and the experimental group showed no significant difference. ConclusionThe domestic porous tantalum has good biocompatibility. Connection and integration can be established between tendon and porous tantalum, and therefore it could be used in reconstruction of tendon-bone fixation device.
Objective To investigate effectiveness of suture anchor fixation combined with Nice knot strapping via longitudinal patellar drilling in the treatment of patellar inferior pole fractures. Methods A clinical data of 37 patients with unilateral patellar inferior pole fracture who met the selection criteria between June 2017 and June 2021 was retrospectively analyzed. Among them, 17 cases were treated with the suture anchor fixation combined with Nice knot strapping via longitudinal patellar drilling (group A), and 20 cases were treated with the traditional Kirschner wire tension band technique (group B). There was no significant difference in terms of gender, age, body mass index, fracture side, combined medical disease, and preoperative hemoglobin between the two groups (P>0.05). Operation time, intraoperative blood loss, postoperative complications, fracture healing time, knee range of motion, and knee function Bostman score (range of motion, pain, daily work, muscle atrophy, walking aids, knee effusion, soft leg, and stair climbing) and grading were recorded in both groups at last follow-up. Results There was no significant difference in operation time and intraoperative blood loss between the two groups (P>0.05). All incisions healed by first intention. All patients were followed up 1-2 years, with an average of 1.7 years. X-ray films reexamination showed that all fractures in group A healed, while 2 cases in group B did not heal. There was no significant difference in bone healing time between the two groups (P>0.05). At last follow-up, the knee range of motion, the range of motion score of Bostman score, total score and effectiveness grading in group A were significantly better than those in group B (P<0.05). There was no significant difference in the other items of Bostman scores between the two groups (P>0.05). During follow-up, 2 cases of internal fixation failure and 1 case of internal fixator irritation occurred in group B, and no complication related to internal fixation occurred in group A. The occurrence of complications was significantly lower in group A than in group B (P<0.05). ConclusionCompared with the traditional Kirschner wire tension band technique, the suture anchor combined with Nice knot strapping via longitudinal patellar drilling for the patellar inferior pole fractures has the advantages of simple operation, reliable fixation, early flexion and extension activity, and better functional recovery of knee joint.