Objective To evaluate an improving operative procedure and the cl inical results of arthroscopically assisted treatment for acute patellar dislocation. Methods Between April 2006 and March 2009, 22 patients (25 knees) with primary acute complete dislocation of the patella underwent an improving arthroscopic operation, release of lateral retinaculum and suture of medial capsule and retinaculum structure. There were 5 males and 17 females with an average age of 23.6 years (range, 14-34 years). Three patients had bilateral procedure. Eleven left knees and 14 right knees were involved. The disease duration was 1-10 days with an average of 5.9 days. All patients had lateral dislocation; of them, 14 patients showed reduction without treatment, and 8 patients showed dislocation at admission and were given close manipulative reduction. The results were positive for apprehension test in all patients with the l imitation of passive motion and for Ballottable Patella Sign in 15 cases. Lysholm score, visual analogue scale (VAS) score, and Insall scale were adopted to evaluate the effect. Results All incisions healed by first intention. All the patients were followed up 12-36 months (17 months on average). During the first 3 months after operation, sunken skin in the puncture point medial to the patella was observed in 12 knees; 10 knees suffered pain of the soft tissue lateral to the patella; 15 knees felt tense in the soft tissue medial to the patella, however, all these problems disappeared or recovered gradually after rehabil itation and conservative treatment. No recurrence of dislocation was observed during the follow-up. Lysholm score was significantly improved from preoperative 67.3 ± 5.7 to postoperative 96.6 ± 4.5 (t=3.241, P=0.003) and VAS score from 6.5 ± 0.5 to 1.8 ± 0.4 (t=2.154, P=0.040). According to Insall scale, the results were excellent in 18 knees, good in 5 knees, and fair in 2 knees at 1 year after operation with an excellent and good rate of 92%. Conclusion The improving procedure of arthroscopically assisted treatment for acute patellar dislocation is a minimally invasive operation and has a number of benefits. Its short-term cl inical outcome was satisfactory.
Objective To investigate the effectiveness of reconstructing medial patellofemoral l igament with hamstring tendon autografts for the treatment of recurrent patellar dislocation under arthroscopy. Methods Between January 2005 and January 2010, 22 cases of recurrent patellar dislocation were treated by lateral retinacular release and reconstructionof the medial patellofemoral ligament with hamstring tendon autografts under arthroscopy. There were 5 males and 17 females, aged 15-19 years (mean, 17.3 years). The average number of dislocation was 4 (range, 3-8). The main cl inical symptoms were pain and swell ing of knee joint, weakness in the leg, and limited range of motion (ROM). The patellar tilt test, pressing pain of patellofemoral ligament insertion, and apprehension sign showed positive results. According to International Knee Documentation Committee (IKDC) scoring criteria, the subjective IKDC score was 36.7 ± 4.7, and the Lysholm score was 69.3 ± 3.8. X-ray films showed that the patella inclined outwards. Results All incisions healed by first intention. Twenty-two cases were followed up 18-49 months (mean, 34 months). Pain and swelling of knee joint and weakness were improved obviously. No recurrence was found during follow-up. The ROM of knee in flexion and extension was improved when compared with preoperative ROM. The subjective IKDC score was 92.4 ± 5.3 and the Lysholm knee score was 91.7 ± 5.2, showing significant differences when compared with preoperative scores (P lt; 0.05). Conclusion Reconstruction of the medial patellofemoral ligament with hamstring tendon autografts under arthroscopy is an effective method to treat recurrent patellar dislocation.
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 summarize the surgical treatment methods and progress of inferior patellar pole fractures and provide reference for clinical application. Methods The literature on surgical treatment of inferior patellar pole fractures was extensively reviewed, and the relevant research progress, advantages, and limitations were summarized. Results The inferior pole of the patella is an important part of the knee extension device, which can strengthen the force arm of the quadriceps. Inferior patellar pole fractures are relatively rare and often comminuted, usually requiring surgical treatment. At present, there are various methods to treat inferior patellar pole fractures, including patellectomy of inferior pole, tension-band wiring technique, plate internal fixation, suture anchor fixation, claw-like shape memory alloy, separate vertical wiring technique. Different methods have their own characteristics, advantages, and disadvantages. The single internal fixation method has more complications and is easy to cause fixation failure. Therefore, the trend of combining various internal fixation methods is developing at present. Conclusion When the main fragment of the inferior patellar pole fracture is large and mainly distributed transversely, the combination protocol based on tension-band wiring technique can be regarded as an ideal choice. When the fragments are severely damaged and small, the comprehensive protocol based on suture fixation can result in a better postoperative functional recovery.
ObjectiveTo investigate the clinical significance of Q-angle measuring under different conditions in female recurrent patellar dislocation female patients. MethodsBetween August 2012 and March 2013, 10 female patients (11 knees) with recurrent patellar dislocation were collected as trial group; 20 female patients (20 knees) with simple meniscus injury were collected as control group at the same time. Q-angle was measured in extension, 30° flexion, 30° flexion with manual correction, and surgical correction in the trial group, and only in extension and 30° flexion in the control group. Then the difference value of Q-angle between extension and 30° flexion (Q-angle in extension subtracts Q-angle in 30 flexion) were calculated. Independent sample t-test was used to analyze Q-angle degrees in extension, 30° flexion, and the changed degrees of 2 groups. The Q-angle between manual correction and surgical correction of the trial group was analyzed by paired t-test. ResultsThe Q-angle in extension, Q-angle in 30° flexion, and difference value of Q-angle between extension and 30° flexion were (17.2±3.6), (14.3±3.0), and (2.9±1.9)° in the trial group and were (15.2±3.4), (14.4±3.5), and (0.8±1.7)° in the control group. No significant difference was found in Q-angle of extension or Q-angle of 30° flexion between 2 groups (P>0.05), but the difference value of Q-angle between extension and 30° flexion in the trial group was significantly larger than that in the control group (t=3.253, P=0.003). The Q-angle in 30° flexion with manual correction and surgical correction in the trial group was (19.8±3.4)° and (18.9±3.8)° respectively, showing no significant difference (t=2.193, P=0.053). ConclusionWhen a female patient's Q-angle in 30° flexion knee changes obviously compared with Q-angle in extension position, recurrent patellar dislocation should be considered. For female patients with recurrent patellar dislocation, the preoperative Q-angle in 30° flexion with manual correction should be measured, which can help increasing the accuracy of evaluation whether rearrangement should be performed.
Objective To compare the long-term effectiveness of patellar denervation by electrotomy combined with patellar replacement and patellar denervation by electrotomy alone in primary total knee arthroplasty (TKA). Methods A retrospective analysis was conducted on the clinical data of 30 patients treated with primary TKA of both knees between July 2013 and March 2015 who met the selection criteria. There were 11 males and 19 females, aged 56-79 years, with an average age of 67.6 years. One knee was randomly selected for patellar denervation by electrotomy combined with patellar replacement during TKA (combined group), while the other knee was treated with patellar denervation by electrotomy alone (control group). All patients adopted the same type of total knee prosthesis. After surgery, the patients were followed up regularly, and the occurrence of complications was recorded. The functions of the knee and patella were evaluated using the Knee Society Score (KSS) and Feller score, respectively. The position of the prosthesis, patella trajectory, and prosthesis loosening and wear were observed by imaging examination. Results All 30 patients were followed up 81.4-103.5 months, with an average of 90.4 months. The patellar thickness of the combined group ranged from 21 to 26 mm, with an average of 23.0 mm. The position of the prosthesis and patella trajectory in the combined group and the control group were good, without obvious loosening or wear. After operation, 2 sides (6.7%) in the combined group and 3 sides (10.0%) in the control group presented joint adhesion and poor activities. No complication such as lower limb deep vein thrombosis, aseptic fractures, and infections around the prosthesis occurred in both groups. At last follow-up, the KSS clinical score, KSS function score, and Feller score showed no significant difference between the two groups (P>0.05). According to the KSS score, 24 patients (80.0%) had no obvious preference for patellar denervation combined with patellar replacement, 3 patients (10.0%) preferred patellar replacement combined with patellar denervation, and 3 patients (10.0%) preferred no patellar replacement. Anterior knee pain occurred in 6 sides (20.0%) of both groups. Conclusion There is no significant difference in the long-term effectiveness between patellar denervation combined with patellar replacement and patellar denervation alone conducted in patients with knee osteoarthritis undergoing primary TKA.
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.