BACKGROUND: The correlation between the morphological structure of the patellofemoral joint (PFJ) and the severity of knee joint osteoarthritis (KOA) remains uncertain. This study aims to investigate the correlation between the severity of knee joint osteoarthritis and the alignment of patellofemoral and patellar height on radiographs. METHODS: This multi-center, retrospective study analyzed the magnetic resonance imaging (MRI) scans and anteroposterior radiographs of 534 adult outpatients with KOA. To evaluate the radiographic severity of KOA, anteroposterior radiographs of the knee and the Kellgren-Lawrence (K-L) grade were used. Knee MRI scans were used to measure the patellar length ratio (PLR), sulcus angle (SA), lateral patellar tilt angle (LPTA), and the distance between tibial tuberosity and trochlear groove (TT-TG). We examined the association between the configuration of the PFJ, arrangement, and harshness of the KOA. Information on participants' demographics, such as age, sex, side, height, and weight, was collected. A chi-squared test was used for the correlation of radiographic severity of KOA with sex and the affected side. Spearman correlation was used for patellofemoral alignment or morphology and the radiographic severity of lateral KOA. Multiple linear regression models were used for the association between LPTA, SA, TT-TG, and severity of KOA after accounting for demographic variables. RESULTS: The study comprised of 534 patients; of these, 339 (63%) were female. A total of 586 knees were evaluated in this study. Age showed a strong positive correlation with KOA severity ( r  = 0.516, P <0.01), whereas LPTA showed a strong negative correlation ( r  = -0.662, P <0.01). Additionally, SA ( r  = 0.616, P <0.05), and TT-TG showed a strong positive correlation ( r  = 0.770, P <0.01) with tibiofemoral osteoarthritis (TFOA) severity. Multiple linear regression analysis indicated that knee osteoarthritis severity (β = -2.946, P <0.001) and side (β = -0.839, P  = 0.001) was associated with LPTA; knee osteoarthritis severity (β = 5.032, P <0.001) and age (β = -0.095, P <0.001) was associated with SA; knee osteoarthritis severity (β = 2.445, P <0.001), sex (β = -0.326, P  = 0.041), body mass index (β = -0.061, P  = 0.017) and age (β = -0.025, P <0.001) was associated with TT-TG. CONCLUSION Radiographic severity of KOA was positively associated with age, SA, and TT-TG but negatively associated with LPTA.
Humans ; Female ; Male ; Osteoarthritis, Knee/pathology* ; Middle Aged ; Retrospective Studies ; Aged ; Patellofemoral Joint/pathology* ; Magnetic Resonance Imaging ; Adult ; Patella/pathology* ; Radiography

OBJECTIVE: To review the research progress on the lower limb biomechanical characteristics of patients with discoid lateral meniscus (DLM) injury after surgery. METHODS: By searching relevant domestic and international research literature on DLM, the postoperative characteristics of knee joint movement biomechanics, tibiofemoral joint stress distribution, lower extremity force line, and patellofemoral joint changes in patients with DLM injury were summarized. RESULTS: Surgical treatment can lead to varying degrees of changes in the lower limb biomechanical characteristics of patients with DLM injury. Specifically, the kinematic biomechanics of the knee joint can significantly improve, but there are still problems such as extension deficits in the affected knee joint. The peak stress of the tibiofemoral joint decreases with the increase of the residual meniscus volume, and the degree of change is closely related to the residual meniscus volume. Preserving a larger volume of the meniscus, especially the anterior horn volume, helps to reduce stress concentration. The lower extremity force line will deviate outward after surgery, and the more meniscus is removed during surgery, the greater the change in the lower extremity force line after surgery. There are conditions such as cartilage degeneration, position and angle changes in the patellofemoral joint after surgery. CONCLUSION The changes in the lower limb biomechanical characteristics after DLM injury are closely related to the choice of surgical methods and rehabilitation programs. However, the mechanisms of biomechanical changes in multiple lower limb joints and individual differences still need to be further studied and clarified.
Humans ; Biomechanical Phenomena ; Tibial Meniscus Injuries/physiopathology* ; Menisci, Tibial/physiopathology* ; Knee Joint/surgery* ; Lower Extremity/physiopathology* ; Patellofemoral Joint/physiopathology* ; Range of Motion, Articular ; Knee Injuries/physiopathology*

OBJECTIVE: To exploring the efficacy of modified patellar triple surgery (including arthroscopic lateral retinaculum release, modified medial patellofemoral ligament reconstruction, and modified Fulkerson osteotomy) in the treatment of early patellofemoral osteoarthritis. METHODS: A retrospective analysis was conducted on 57 patients with patellofemoral arthritis admitted from March 2018 to June 2022, including 22 males and 35 females;aged 22 to 45 years old, average (31.5±5.7) years old; disease course 2 to 8 years (3.7±2.2) years;19 on the left side and 38 on the right side. The tendon graft was taken from the long tendons of the ipsilateral tibia, and the lateral patellar support band release was performed arthroscopically, combined with modified medial patellofemoral ligament reconstruction and modified Fulkerson osteotomy. The changes of Q angle, patellar tilt angle, tibial tuberosity-femoral trochlear groove (TT-TG) and Lysholm knee joint scores before and 12 months after surgery were compared. RESULTS: All patient incisions healed in stageⅠ, and 57 patients were followed up for 12 to 36 with an average of (22.1±2.5) months. The Q angle, patellar inclination angle, and TT-TG values improved from (22.7±1.9)°, (29.2±2.0)°, and (23.3±1.4) mm before surgery to (14.6±2.2)°, (7.6±3.2)°, and (11.8±1.7) mm one year after surgery, with statistically significant differences (P<0.05). The Lysholm score increased from preoperative (65.1±8.7) to postoperative (86.8±7.2) at 1 year (P<0.05), with 41 cases being excellent, 15 cases being good, and 1 case being average. CONCLUSION The improvement of medial patellofemoral ligament reconstruction and lateral retinaculum release can correct the Q angle in early patellofemoral osteoarthritis, while the improvement of Fulkerson osteotomy can correct the TT-TG value, elevate the patella, relieve pressure on the patellofemoral joint, and alleviate anterior knee pain. The clinical efficacy is definite, providing ideas for the clinical treatment of patellofemoral osteoarthritis.
Humans ; Male ; Female ; Adult ; Middle Aged ; Retrospective Studies ; Osteoarthritis, Knee/surgery* ; Patellofemoral Joint/surgery* ; Patella/surgery* ; Young Adult ; Osteotomy ; Arthroscopy

OBJECTIVE: To investigate the midterm clinical efficacy of medial patellofemoral complex (MPFC) reconstruction for recurrent patellar dislocation with high-grade trochlear dysplasia. METHODS: A retrospective analysis was carried out among adult patients who underwent arthroscopically assisted MPFC reconstruction between January 2014 and December 2020. Dejour classification was evaluated to grade trochlear dysplasia; tibial tubercle-trochlear groove (TT-TG) distance and Insall-Salvati index were measured. Preoperative and postoperative patient-reported outcome measures (PROMs) were compared, including International Knee Documentation Committee (IKDC) score, Kujala score, Lysholm score and Tegner score. Information regarding returning-to-sport rate, re-instability events and complications was collected. Patellar tilt (PT), lateral patellar displacement (LPD) and bisect offset (BSO) ratio were measured based on axial computed tomography before and after surgery to assess the patellofemoral congruence. RESULTS: A total of 46 MPFC reconstructions in 43 patients were enrolled, including 16 male and 27 female. Mean age at surgery was (22.2±7.6) years (range: 14-44 years). Mean follow-up was (49.9±22.6) months (range: 18-102 months). The percentages of Dejour B, C and D dysplasia were 37.0% (17/46), 43.5% (20/46), and 19.6% (9/46), respectively. Mean Insall-Salvati index was 1.2±0.2 (range: 0.85-1.44), and mean TT-TG distance was (19.6±3.5) mm (range: 10.6-28.7 mm). At latest follow-up, there were significant improvements in all PROMs (P < 0.001): IKDC score, from 56.3±15.1 to 86.2±8.1; Kujala score, from 58.9±15.6 to 92.6±5.4; Lysholm score, from 63.7±15.0 to 94.0±5.7; Tegner score, from 3.1±1.4 to 4.7±1.4, and there were no significant differences in the improvements of the scores between the patients with Dejour B, C and D dysplasia. Overall, ninety percent of the patients returned to their preoperative sports level. One patient reported a postoperative subluxation, while no cases of infection, limited range of motion or patella fracture were observed. PT, LPD and BSO ratio were all significant altered (P < 0.001) after MPFC reconstruction. CONCLUSION Arthroscopically assisted MPFC reconstruction yielded satisfactory midterm clinical results for recurrent patellar dislocation with high-grade trochlear dysplasia. No significant differences of improvements in knee function were observed among the three types of high-grade trochlear dysplasia.
Humans ; Patellar Dislocation/surgery* ; Male ; Female ; Adult ; Arthroscopy/methods* ; Retrospective Studies ; Adolescent ; Young Adult ; Patellofemoral Joint/surgery* ; Recurrence ; Plastic Surgery Procedures/methods* ; Patella/surgery* ; Treatment Outcome

OBJECTIVE: To review the research progress of Schöttle's method in medial patellofemoral ligament reconstruction (MPFLR), and provide the latest knowledge and suggestions for surgical treatment. METHODS: The studies on Schöttle's method at home and abroad in recent years were extensively collected, then summarized the problems affecting the accuracy of Schöttle's method and the new ideas to improve the accuracy of localization. RESULTS: It's vital to accurately locate the femoral tunnel during MPFLR. Malposition of the femoral tunnel is the main cause of postoperative complications and surgical failure. Schöttle's method is the most well studied and most reproducible method for femoral tunnel localization, which is widely used as the "gold standard". However, there are still problems that affect the accuracy of Schöttle's method, including the impact of the internal/external rotation and varus/valgus of the knee on localization accuracy, unclear requirements for X-ray imaging and anatomical landmark reference line drawing standards, no suitable for patients with anatomical variations, and lack of further research on pediatric patients. In recent years, some new ideas are proposed to improve the Schöttle's method to improve the localization accuracy. CONCLUSION Future research should combine new technologies such as three-dimensional (3D) printing and intraoperative navigation to develop personalized and intelligent Schöttle's method, further improving their localization accuracy.
Humans ; Femur/surgery* ; Plastic Surgery Procedures/methods* ; Patellofemoral Joint/surgery* ; Patellar Ligament/surgery* ; Postoperative Complications ; Knee Joint/surgery* ; Ligaments, Articular/surgery* ; Tomography, X-Ray Computed/methods*

BACKGROUND: Patellofemoral joint (PFJ) degeneration has traditionally been regarded as a contraindication to unicompartmental knee arthroplasty (UKA). More recently, some researchers have proposed that PFJ degeneration can be ignored in medial UKA, and others have proposed that this change should be reviewed in PFJ degenerative facets and severity. This study aimed to systematically evaluate the effect of PFJ degeneration on patient-reported outcome measures (PROMs) and revision rates after medial UKA. METHODS: Electronic databases (PubMed, Embase, Web of Science, etc.) were searched for studies assessing the influence of PFJ degeneration on medial UKA. A random-effects meta-analysis was conducted for the Oxford knee score (OKS), Knee society score (KSS), and revision rates and stratified by PFJ degenerative facets (medial/lateral/trochlear/unspecified), severe PFJ degeneration (bone exposed), and bearing type (mobile/fixed). Heterogeneity was assessed by the Cochran Q test statistic and chi-squared tests with the I-squared statistic. RESULTS: A total of 34 articles with 7007 knees (2267 with PFJ degeneration) were included (5762 mobile-bearing and 1145 fixed-bearing and 100 unspecified). Slight to moderate degenerative changes in the medial and trochlear facets did not decrease the OKS and KSS, and only lateral facets significantly decreased the OKS (mean difference [MD] = -2.18, P   <  0.01) and KSS (MD = -2.61, P   <  0.01). The severity degree of PFJ degeneration had no additional adverse effect on the OKS, KSS, or revision rates. For mobile-bearing UKA, only lateral PFJ degeneration significantly decreased the OKS (MD = -2.21, P  < 0.01) and KSS (MD = -2.44, P  < 0.01). For fixed-bearing UKA, no correlation was found between PROMs/revision rates and PFJ degeneration. CONCLUSION For medial mobile-bearing UKA, slight to moderate degenerative changes in the PFJ, except lateral facet, did not compromise PROMs or revision rates. For medial fixed-bearing UKA, although it might not be conclusive enough, PROMs or revision rates were not adversely affected by PFJ degeneration (regardless of the facet).
Humans ; Arthroplasty, Replacement, Knee ; Patellofemoral Joint/surgery* ; Treatment Outcome ; Osteoarthritis, Knee/surgery* ; Knee Prosthesis ; Bone Diseases ; Knee Joint/surgery* ; Retrospective Studies

OBJECTIVE: To evaluate the operability and effectiveness of a self-developed patellar bone canal locator (hereinafter referred to as "locator") in the reconstruction of the medial patellofemoral ligament (MPFL). METHODS: A total of 38 patients with recurrent patellar dislocation who met the selection criteria admitted between January 2022 and December 2022 were randomly divided into study group (the patellar canal was established with a locator during MPFL reconstruction) and control group (no locator was used in MPFL reconstruction), with 19 cases in each group. There was no significant difference in baseline data between the two groups ( P>0.05), such as gender, age, body mass index, disease duration, patella Wiberg classification, constituent ratio of cartilage injury, Caton index, tibia tubercle-trochlear groove, and preoperative Lysholm score, Kujal score, Tegner score, visual analogue scale (VAS) score, and so on. The Lysholm score, Kujal score, Tegner score, and VAS score were used to evaluate knee joint function before operation and at 3 days,1 month, 3 months, and 6 months after operation. The ideal prepatellar cortical thickness and canal length were measured before operation, and the actual prepatellar cortical thickness and canal length after operation were also measured, and D1 (the distance between the ideal entrance and the actual entrance), D2 (the ideal canal length minus the actual canal length), D3 (the ideal prepatellar cortical thickness minus the actual prepatellar cortical thickness) were calculated. RESULTS: Patients in both groups were followed up 6-8 months (mean, 6.7 months). The incision length and intraoperative blood loss in the study group were smaller than those in the control group, but the operation time was longer than that in the control group, the differences were significant ( P<0.05). There was no complication such as incision infection, effusion, and delayed healing in both groups, and no further dislocation occurred during follow-up. One patient in the study group had persistent pain in the anserine area after operation, and the symptoms were relieved after physiotherapy. The VAS score of the two groups increased significantly at 3 days after operation, and gradually decreased with the extension of time; the change trends of Lysholm score, Kujal score, and Tegner score were opposite to VAS score. Except that the Lysholm score and Kujal score of the study group were higher than those of the control group at 3 days after operation, and the VAS score of the study group was lower than that of the control group at 3 days and 1 month after operation, the differences were significant ( P<0.05), there was no significant difference in the scores between the two groups at other time points ( P>0.05). Patellar bone canal evaluation showed that there was no significant difference in preoperative simulated ideal canal length, prepatellar cortical thickness, and postoperative actual canal length between the two groups ( P>0.05). The postoperative actual prepatellar cortical thickness of the study group was significantly smaller than that of the control group ( P<0.05). D1 and D3 in the study group were significantly higher than those in control group ( P<0.05), but there was no significant difference in D2 between the two groups ( P>0.05). CONCLUSION The locator can improve the accuracy of MPFL reconstruction surgery, reduce the possibility of intraoperative damage to the articular surface of patella and postoperative patellar fractures.
Humans ; Patella/surgery* ; Patellar Dislocation/surgery* ; Patellofemoral Joint/surgery* ; Knee Joint/surgery* ; Joint Dislocations ; Ligaments, Articular/surgery*

OBJECTIVE: To explore correlation between imaging classification of knee osteoarthritis (KOA) and axis angle of tibiofemoral and patellofemoral joints. METHODS: A retrospective analysis of 739 middle-aged and elderly patients with KOA (1 026 knee joints) who underwent vertical X-ray examination of both lower limbs and lateral knee joints from September 2018 to December 2020. Among them, 63 patients with K-L 0 grade (95 knee joints), 100 patients with K-L 1 grade (130 knee joints), 161 patients with K-L 2 grade (226 knee joints), 187 patients with K-L 3 grade (256 knee joints), and 228 patients of K-L 4 grade (319 knee joints). According to relative position of knee joint center and line between hip joint center and ankle joint center, the affected knee was divided into varus group(844 knees joints) and valgus group (182 knees joints). According to Install-Salvati method, the affected knee was divided into three groups, such as high patella (patella height>1.2 mm, 347 knees joints), median patella (patella height ranged from 0.8 to 1.2 mm, 561 knees joints), and low patella (patella height<0.8 mm, 118 knees joints). Lower femur angle, upper tibia angle, femoral neck shaft angle, femoral tibial angle, joint gap angle, hip-knee-ankle angle, patella-femoral angle and patella height among different groups were observed and compared. RESULTS: (1) In varus KOA group, there were statistical differnces in hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades (P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, joint space angle and K-L grade were significantly positively correlated at 0.01(P<0.05);femoral neck shaft angle and K-L grade showed negative correlation at 0.01(P<0.05). (2) In valgus KOA group, hip-knee-ankle angle, there were statistical differences in tibiofemoral angle, inferior femoral angle, superior tibial angle, joint space angle, and femoral neck shaft angle of patients with different K-L grades(P<0.05). Hip-knee-ankle angle, tibiofemoral angle, lower femoral angle, upper tibial angle, and femoral neck shaft angle showed negative correlation with K-L grades at level of 0.01 (P<0.05);joint gap angle and K-L grades showed significantly positive correlation at level of 0.01(P<0.05). (3) In high patella group, there were statistically differences in patellar height and patellar femoral angle of different K-L grades(P<0.05);there were no statistical difference in patella height and patellar femoral angle of different K-L grades in median patella group. There was no significant difference in patella heightin low patella group with different K-L grades(P>0.05), and there was statistical difference in patellofemoral angle(P<0.05). Patellar height and patella-femoral angle of high patella group were significantly positively correlated with K-L grades at the level of 0.01 (P<0.05);patella height and patella-femoral angle were not correlated with K-L grades in median patella group(P>0.05). There was no correlation between height of patella and K-L grade in low patella group (P>0.05). There was significant negative correlation between patella-femoral angle and K-L grade at level of 0.05 (P<0.05). CONCLUSION Inferior femoral angle, tibiofemoral angle, joint gap angle, hip-knee-ankle angle, femoral neck shaft angle and high patella are related to K-L classification of varus KOA, which could be used for early diagnosis and provide objective data for efficacy analysis of conservative treatment.
Aged ; Middle Aged ; Humans ; Patellofemoral Joint/diagnostic imaging* ; Osteoarthritis, Knee/diagnostic imaging* ; Retrospective Studies ; Knee Joint ; Femur/diagnostic imaging* ; Tibia

Objective: To investigate the changes of imaging parameters of patellofemoral joint after kinematic alignment total knee arthroplasty (KA-TKA) and mechanical alignment total knee arthroplasty (MA-TKA) and the effects on clinical outcomes. Methods: A retrospective analysis was performed on 227 patients diagnosed with knee osteoarthritis, 105 males and 122 females, with the age of (68.6±7.2) years (range: 52 to 86 years). The patients underwent unilateral TKA at the Department of Orthopaedic Surgery, Beijing Chaoyang Hospital, Capital Medical University, from January 2020 to July 2021. The patients were divided into the KA-TKA group (n=102) and the MA-TKA group (n=125) according to the alignment method. The Blackburne-Peel index, lateral patellofemoral angle, patellofemoral tilt angle and patellofemoral index of the two groups were recorded before and 6 months after operation. The frequency of lateral patellar retinaculum release, preoperative and postoperative knee range of motion (ROM), and Oxford knee score(OKS) were also recorded. The differences between preoperative and postoperative measurement data of each group were calculated. If the difference was in line with normal distribution, the independent sample t-test or t'-test was used for comparison between the two groups. If it did not conform to normal distribution, Mann-Whitney U test was used. Paired sample t-test was used for comparison before and after treatment. Chi-square test was used for comparation of categorical data between the two groups. Results: After 6 months of operation, the patellar tilt angles of the KA-TKA group and the MA-TKA group were (14.22±3.26)° and (13.35±2.27)°, and the lateral patellar angles were (9.73±4.86)° and (11.91±3.89)°, respectively. The change of lateral patellofemoral angle in the KA-TKA group was significantly less than that in the MA-TKA group ((1.68±4.86)° vs. (4.15±4.88)°, t=3.805, P<0.01). OKS and ROM were improved in the both groups at 6 months after operation (all P<0.05), but there were no statistic significance in preoperative and postoperative difference between the two groups (all P>0.05). The intraoperative lateral patellar retinacular release rate was 14.4% (18/125) in the MA-TKA group and 6.9% (7/102) in the KA-TKA group, with no statistical difference (χ²=3.256,P=0.071). Conclusions: There are greater patella lateral tilt at 6 months postoperatively in the KA-TKA group compared with the MA-TKA group, but this radiographic difference could not show differences of clinical outcomes and postoperative ROM, the frequency of intraoperative lateral patellar retinacular release wouldn't increase. Therefore, KA-TKA does not increase the difficulty of postoperative patellofemoral joint complications and intraoperative lateral patellar release.
Male ; Female ; Humans ; Middle Aged ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee/methods* ; Patellofemoral Joint/surgery* ; Biomechanical Phenomena ; Retrospective Studies ; Patella/surgery* ; Osteoarthritis, Knee/surgery* ; Knee Joint/surgery* ; Knee Prosthesis ; Range of Motion, Articular ; Postoperative Complications

OBJECTIVE: To observe the clinical efficacy of Kinesio Taping combined with electroacupuncture in the treatment of patellofemoral disorder in middle-aged and elderly exercise enthusiasts. METHODS: From April 2018 to April 2020, 62 middle-aged and elderly exercisers with patellofemoral disorder were selected and divided into observation group and control group. In the observation group, there were 30 cases:12 males and 18 females, aged from 35 to 66 years old, with an average age of (48.32±6.80) years old. The observation group was treated with Kinesio Taping and electroacupuncture . In the control group, there were 32 cases:12 males and 20 females, aged from 35 to 67 years old, with an averageage of (48.67±8.13) years old. The patients in the control group was treated with knee electroacupuncture. All the patients in both groups were treated once every other day, 3 times a week, for a total of 4 weeks. The VAS pain score and knee Lysholm score before and after treatment were compared between the two groups before and after treatment, and statistical analysis was conducted. RESULTS: In the control group, 2 patients were not satisfied with the curative effect after 2 weeks of treatment and gave up treatment, while the remaining 60 patients completed all the treatments. After 4 weeks of treatment, the VAS and Lyshlom scores of the control group were 2.73±1.46 and 75.63±8.62 respectively;the VAS and Lyshlom scores of the observation group were 2.02±1.85 and 83.31±5.53 respectively;the VAS and Lyshlom scores of the observation group and the control group were better than those before treatment, and the Lyshlom scores of the observation group were better than those of the control group. CONCLUSION Kinesio Taping combined with electroacupuncture is aimed at patellofemoral disorderof middle-aged and elderly sports enthusiasts. It has little trauma, can relieve pain and has a fast onset speed, which is readily accepted by patients, and promotes the rehabilitation of knee joint function of patients, thus providing a favorable reference for the promotion in clinical application.
Adult ; Aged ; Athletic Tape ; Electroacupuncture ; Female ; Humans ; Knee Joint ; Male ; Middle Aged ; Patellofemoral Pain Syndrome ; Treatment Outcome