【Abstract】 Objective To explore the flexibil ity and rel iabil ity of cementless total knee arthroplasty (TKA) without patellareplacement through a retrospective study of the mid-term therapeutic effect of the treatment of the patients. Methods FromJune 1997 to March 2000, a consecutive series of 152 (152 knees) cementless TKA performed in Hessing-Stiftung was studied. Among them, there were 63 males and 89 females, with 70 left knees and 82 right knees. Their ages ranged from 51 years to 72 years, with an average of 59 years. There were 146 cases of osteoarthritis and 6 cases of traumatic arthritis. The course of the disease lasted for 1.0 years to 3.5 years. The EFK prostheses of German Plus company were used in all the cases. The HSS score before the operation was 41.5 ± 12.3, and the average range of motion was 55º (ranging from 30º to 90º). Results Five patients underwent anterior knee pain, and the pain was released after the appropriate treatment. No deep infection happened in all cases. A total of 145 patients (145 knees) were followed up for 5 years to 8 years. The HSS score was 87.5 ± 8.2 at the end of the follow-up, showing significant difference (P lt; 0.05). The average range of motion was 95º (ranging from 90º to 110º). Partial radiolucencies occurred at the tibia side in 18knees 3 to 6 months after the operation. Among them, the width was less than 2 mm in 15 knees without symptom, and more than 2 mm in 3 knees. There were 2 of the 3 knees which were revised at the tibia side because of the aseptic loosing, while 1 patient had only mild pain in the knee during the follow-up, with no sign of loosing. Conclusion The mid-term effect of cementless TKA is satisfactory. The ingrowth of femur and tibial bones is rel iable. The early stage migration of the component is the main reason of loosing. Satisfying outcomes can also be achieved without patella replacement during TKA.
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.
ObjectiveTo observe the effectiveness of arthroscopic reconstruction of medial patellofemoral ligament (MPFL) with a single bundle of autogenous half peroneal longus tendon, and medial displacement of lateral hemitibial tuberosity for the treatment of recurrent dislocation of patella.Methods Retrospectively analyse the clinical data of 24 patients (24 knees) with recurrent patellar dislocation with tibial tuberosity-trochlear groove distance (TT-TG) values more than 15 mm who were admitted between September 2014 and September 2018. Of which 7 were male and 17 were female; aged 16-35 years old with an average of 25.8 years. The disease duration ranged from 15 to 46 months, with an average of 26.7 months. All patients had a history of knee trauma, and a positive result of apprehension test on the affected knee. All patients underwent the surgery of arthroscopic reconstruction of MPFL with a single bundle of autogenous half peroneal longus tendon, and medial displacement of lateral hemitibial tuberosity. Before and after operation, Kujala score was used to evaluate patellofemoral joint function, Lysholm score was used to evaluate knee joint function; CT and MRI were used to measure and compare the changes of congruence angle (CA), patellar tilt angle (PTA), and lateral patella displacement (LPD) in order to evaluate patella stability.ResultsAll incisions healed by first intention, and no infection or neurovascular injury occurred. Deep vein thrombosis of the lower extremities occurred in 2 cases at 4 and 7 days after operation respectively, and the thrombosis disappeared after symptomatic treatment. All the 24 patients were followed up 12-14 months (mean, 12.9 months). During follow-up, no patellar dislocation reoccurred in the affected knee. At last follow-up, the apprehension test was negative in every patients. The TT-TG, CA, PTA, and LPD were significantly improved when compared with those before operation (P<0.05). The Kujala score and Lysholm score at 1 month and last follow-up were significantly better than those before operation, and the above scores at last follow-up were significantly better than those at 1 month after operation (P<0.05). According to Lysholm score, the patients’ knee joint functions were excellent in 13 cases, good in 10 cases, and fair in 1 case, and the excellent and good rate was 95.8%.ConclusionArthroscopic reconstruction of MPFL with a single bundle of autogenous half peroneal longus tendon combined with medial displacement of lateral hemitibial tuberosity has the advantages of minimal invision and reliable effectiveness. It can be used as one of the effective surgical methods for the treatment of recurrent dislocation of patella.
Objective To investigate the advance in surgical treatment of inferior pole fracture of patella and to explore the existing problems and further research directions. Methods Domestic and foreign l iterature in recent years on patella fracture was extensively reviewed, the surgical treatment of inferior pole fracture of patella was summarized by combining the research findings with cl inical experience. Results The surgical treatment of inferior pole of patella fractures included retaining the integrity of the patella and partial patellectomy of inferior pole of patella and extending knee installationreconstruction. There were kinds of ways to retain the integrity of the patella, such as circular wire fixation, tension bandfixation, NiTi-patella concentrotor fixation, basket plate fixation, reforming McLaughl in way and polydioxanone suture netfixation; the latter category is partial patellectomy and extensor device reconstruction. Every surgical way had its advantages and l imitations. Conclusion Most studies tend to retain the integrity of the patella, but some researches have shown that partial resection of inferior pole of patella had no significant effect on knee function. It is important to obtain the security excisional range and elongation range postoperative by experiment for regulating the treatment of comminuted fractures of inferior pole of patella.
ObjectiveTo investigate the effectiveness of arthroscopic medial patellofemoral ligament (MPFL) reconstruction combined with tibial tuberosity transfer for recurrent patellar dislocation.MethodsBetween February 2012 and December 2013, 24 patients (24 knees) with recurrent patellar dislocation were treated with arthroscopic MPFL reconstruction combined with tibial tuberosity transfer. There were 7 males and 17 females, with a mean age of 23.2 years (range, 18-37 years). One patient had recurrence dislocation after operation in the other hospital, and the others were the first operation. The disease duration ranged from 6 months to 20 years (mean, 5.6 years). The patellar apprehension tests were positive. The preoperative Lysholm score was 49.79±11.67 and the Kujala score was 49.63±6.28. X-ray films showed that 13 patients had dysplasia of the patella and femoral trochlea; 8 patients had high tibia (Caton-Deschamps index>1.2); the congruence angle was (23.96±5.54)°. CT examination showed that the tibial tuberosity-trochlear groove distance (TT-TG) value was (23.71±2.35) mm.ResultsAll incisions healed by first intention. Twenty-two patients were followed up 59-81 months, with an average of 66.8 months. No dislocation occurred during the follow-up period. The patellar apprehension tests were negative. At 1 week after operation, the results of X-ray films and CT showed that the congruence angle angle was (–1.96±4.65)°, and the TT-TG value was (13.75±1.89) mm, which were significantly lower than those before operation (P<0.05). At 6 months, 1 year, and last follow-up, Lysholm scores were 81.13±17.76, 91.35±3.60, and 92.23±2.71, respectively; and Kujala scores were 84.04±3.98, 91.48±3.64, and 91.45±3.29, respectively. The Lysholm and Kujala scores were significantly increased after operation when compared with the preoperative scores (P<0.05). At last follow-up, the effectiveness was excellent in 11 cases, good in 8 cases, and fair in 3 cases, with an excellent and good rate of 86%.ConclusionArthroscopic MPFL reconstruction combined with tibial tuberosity transfer for recurrent patellar dislocation can effectively improve the patellofemoral joint matching relationship and has a satisfactory short- and medium-term 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.
ObjectiveTo investigate biomechanical effects of pseudo-patella baja on stress of patellofemoral joint after total knee arthroplasty (TKA) by using finite element analysis (FEA).MethodsA series of CT and MRI of the left knee joint of two healthy volunteers and three-dimensional (3D) scanned data of TKA prosthesis were taken, and the 3D models of knee before and after TKA were established. The finite element model of pseudo-patella baja, normal patella, and alta patella after TKA were constructed by Insall-Salvafi (IS) ratio and Blackburne-Peel (BP) ratio. The load was applied along the direction of quadriceps femoris. After testing the validity of the finite element model, the high contact stress of patellofemoral joint was measured on the von Mise stress nephogram of pseudo-patella baja, normal patella, and alta patella after TKA when the knee flexion was 30°, 60°, and 90°. The average contact area was calculated according to two volunteers’ data.ResultsOn the finite element model of the normal patella after TKA with knee flexion 30°, 475 N pressure was applied along the direction of quadriceps femoris. The contact stress of patellofemoral joint was (1.29±0.41) MPa, which was similar to the results reported previously. The finite element model was valid. The von Mise stress nephogram showed that the stress mainly focused on the medial patellofemoral articular surface during knee flexion, and the contact point gradually moved up with the knee flexion deepened. The stress on the medial and lateral patellofemoral articular surface increased with the knee flexion deepened but decreased with the increase of patellar height. The effects of patellar height and knee flexion on the high contact stress of patellofemoral joint were similar among the finite element models after TKA based on the data of two volunteers. The high contact stress of patellofemoral joint increased with the knee flexion deepened in the same patellar height models (P<0.05), but decreased with the increase of patellar height in the same knee flexion models (P<0.05). The high contact stress of patellofemoral joint of pseudo-patella baja model was significantly higher than normal and alta patella models (P<0.05). The average contact area of patellofemoral joint of pseudo-patella baja was bigger than normal and alta patella models with the knee flexion deepened.ConclusionThe pseudo-patella baja after TKA has an important effect on the biomechanics of patellofemoral joint. Reserving the joint line and avoiding the occurrence of pseudo-patella baja can decrease the risk of anterior knee pain, patellar arthritis, and other complications caused by the increasing of contact stress of patellofemoral joint.
Objective To explore the effects of changes in the length of the patella on patellofemoral contact areas and pressures, to provide a theoretical foundation for treatment of lower pole of patella fracture. Methods Using homemadeloadingequipment, pressure sensitive films of 100 mm × 100 mm in size were placed on the force platform, vertically downwardload (0-19.6 N) was given. The pressure-sensitive response curve was obtained by computer image analysis of the pressuresensitive tablets and calculation. Six male left fresh knee specimens from voluntary donation were placed in homemade-test fixed load device, and the double-layer pressure sensitive film was placed on the patellofemoral joint surface; under loading of 196 N at flexion of 0, 15, 30, 45, 60, 75, 90, 105, 120, and 135° for 2 minutes, respectively, the pressure sensitive film was removed as the control group. Patellas were transected cut and in situ fixed by Kirschner wire and steel-wire as in situ fixation group. Bone fragments obtained from the corresponding 1/6 and 2/6 of contralateral patella, were embedded in the interspace between osteotomy with internal fixation with Kirschner wire and steel-wire respectively as lengthening group. Followed by the amputating patella length of 1/6, 2/6, 3/6 from proximal to distal and internal fixation with Kirschner wire and steel wire by turns as a shortening group. Repeat the above steps of each experiment. By image analysis the pressure sensitive film, the patella joint contact area were measured, and patellar contact pressure (including the peak pressure and average pressure) was calculated according to pressure-sensitive response curve. Results The actural contact area were significantly smaller in the shortening groups than in the control group at flexion of 30-135° (P lt; 0.05); the pressure was significantly bigger in shortening 1/6 group at flexion of 0, 15, 60, and 75°, in shortening 2/6 group at flexion of 0° and 75-135°, and in shortening 3/6 group at flexion of 0-30°and 75-135° than in the control group (P lt; 0.05); the peak pressure was significantly bigger in shortening 1/6 group at flexion of0, 15, and 60-105°, in shortening 2/6 group at flexion of 0, 15, and 75-105°, and in shortening 3/6 group at flexion of 0, 30, and 60-135° than in the control group (P lt; 0.05). The actural contact area was significantly smaller in the lengthening groups than in the control group at flexion of 15, 60, and 90°, and it was bigger at flexion of 105, 135° in lengthening 2/6 group than in the control group (P lt; 0.05); the pressure was significantly bigger in the lengthening groups at flexion of 15-75° than in the control group and it was smaller in the lengthening groups at flexion of 105, 135°, and smaller in lengthening 2/6 group at flexion of 120° (P lt; 0.05); the peak pressure was significantly smaller in lengthening 1/6 group than in the control group at flexion of 0, 90, and 105° and smaller in lengthening 2/6 group at flexion of 0° (P lt; 0.05). The actural contact area was significantly bigger in all lengthening groups than in all shortening groups at flexion of 30, 45, and 75-135° (P lt; 0.05). The pressure was significantly bigger in shortening 1/6 group than in lengthening groups at flexion of 0, 60, and 90° (P lt; 0.05), in shortening 2/6 group at flexion of 0, 60, and 90-120° (P lt; 0.05), in shortening 3/6 group at flexion of 0-135° (P lt; 0.05). The peak pressure was bigger in shortening groups than in lengthening 1/6 group at flexion of 0, 90, and 105° (P lt; 0.05), bigger than lengthening 2/6 group at flexion of 0° (P lt;0.05余请见正文.....
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.