BACKGROUND Anterior cruciate ligament(ACL)reconstruction using bone-patellar tendon-bone(BPTB)autografts remains the gold standard for young,active individuals due to its superior biomechanical strength and bone-to-bo...BACKGROUND Anterior cruciate ligament(ACL)reconstruction using bone-patellar tendon-bone(BPTB)autografts remains the gold standard for young,active individuals due to its superior biomechanical strength and bone-to-bone healing.However,donor site morbidity,particularly anterior knee pain(AKP),limits its utilization despite its advantages.Various techniques have been proposed to reduce AKP,but they show variable outcomes and several limitations.AIM To assess the incidence and severity of AKP following BPTB ACL reconstruction using an autologous bone grafting technique.METHODS We conducted a retrospective observational study of 24 patients aged 20-45 years,who had primary ACL reconstruction with BPTB grafts.During surgery,autologous cancellous bone generated from tunnel drilling was used to fill the patellar and tibial donor site voids after graft fixation.All patients were followed up for at least twelve months.Using the Kujala Anterior Knee Pain Score,clinical outcomes were evaluated,including the pain-specific subcomponent.RESULTS With scores ranging from 86 to 100,the average overall Kujala score was 95.67±4.01.No patient scored below 85.There was no complication such as patellar fracture,tibial tuberosity fracture,or infection.Grouped data showed 20.8%of patients scored 100,whereas 54.2%scored between 95 and 99,and 25%scored between 86 and 94.One patient(4.2%)had an 8/10 pain subcomponent,whereas 23 patients(95.8%)had a 10/10.CONCLUSION This procedure is easy to incorporate into routine surgical practice,cost-effective and reproducible without requiring extra incisions or raising the patient’s surgical expenses.Excellent short-term results back up this technique.展开更多
BACKGROUND Total knee arthroplasty(TKA)is a mature procedure recommended for correcting knee osteoarthritis deformity,relieving pain,and restoring normal biomechanics.Although TKA is a successful and cost-effective pr...BACKGROUND Total knee arthroplasty(TKA)is a mature procedure recommended for correcting knee osteoarthritis deformity,relieving pain,and restoring normal biomechanics.Although TKA is a successful and cost-effective procedure,patient dissatisfaction is as high as 50%.Knee pain after TKA is a significant cause of patient dissatisfaction;the most common location for residual pain is the anterior region.Between 4%and 40%of patients have anterior knee pain(AKP).AIM To investigate the effect of various TKA procedures on postoperative AKP.METHODS We searched PubMed,EMBASE,and Cochrane from January 2000 to September 2022.Randomized controlled trials with one intervention in the experimental group and no corresponding intervention(or other interventions)in the control group were collected.Two researchers independently read the title and abstract of the studies,preliminarily screened the articles,and read the full text in detail according to the selection criteria.Conflicts were resolved by consultation with a third researcher.And relevant data from the included studies were extracted and analyzed using Review Manager 5.4 software.RESULTS There were 25 randomized controlled trials;13 were comparative studies with or without patellar resurfacing.The meta-analysis showed no significant difference between the experimental and control groups(P=0.61).Six studies were comparative studies of circumpatellar denervation vs non-denervation,divided into three subgroups for meta-analysis.The two-subgroup meta-analysis showed no significant difference between the experimental and the control groups(P=0.31,P=0.50).One subgroup meta-analysis showed a significant difference between the experimental and control groups(P=0.001).Two studies compared fixed-bearing TKA and mobile-bearing TKA;the results meta-analysis showed no significant difference between the experimental and control groups(P=0.630).Two studies compared lateral retinacular release vs non-release;the meta-analysis showed a significant difference between the experimental and control groups(P=0.002);two other studies compared other factors.CONCLUSION Patellar resurfacing,mobile-bearing TKA,and fixed-bearing TKA do not reduce the incidence of AKP.Lateral retinacular release can reduce AKP;however,whether circumpatellar denervation can reduce AKP is controversial.展开更多
Despite improvements in technique and technology for total knee arthroplasty(TKA),anterior knee pain impacts patient outcomes and satisfaction.Addressing the prosthetic and surgical technique related causes of pain af...Despite improvements in technique and technology for total knee arthroplasty(TKA),anterior knee pain impacts patient outcomes and satisfaction.Addressing the prosthetic and surgical technique related causes of pain after TKA,specifically as it relates to anterior knee pain,can aid surgeons in addressing these issues with their patients.Design features of the femoral and patellar components which have been reported as pain generators include: Improper femoral as well as patellar component sizing or designs that result in patellofemoral stuffing; a shortened trochlear groove distance from the flange to the intercondylar box; and then surgical technique related issues resulting in: Lateral patellar facet syndrome; overstuffed patella/flange combination; asymmetric patellar resurfacing,improper transverse plane component rotation resulting in patellar subluxation/tilt.Any design consideration that allows impingement of extensor mechanism anatomical elements has the possibility of impacting outcome by becoming a pain generator.As the number of TKA procedures continues to increase,it is increasingly critical to develop improved,evidence based prostheses that maximize function and patient satisfaction while minimizing pain and other complications.展开更多
Total Knee Arthroplasty has been shown to be a successful procedure for treating patients with osteoarthritis,and yet approximately 5%-10%of patients experience residual pain,especially in the anterior part of the kne...Total Knee Arthroplasty has been shown to be a successful procedure for treating patients with osteoarthritis,and yet approximately 5%-10%of patients experience residual pain,especially in the anterior part of the knee.Many theories have been proposed to explain the etiology of this anterior knee pain(AKP)but,despite improvements having been made,AKP remains a problem.AKP can be described as retropatellar or peripatellar pain,which limits patients in their everyday lives.Patients suffering from AKP experience difficulty in standing up from a chair,walking up and down stairs and riding a bicycle.The question asked was:"How can a‘perfectly’placed total knee arthroplasty(TKA)still be painful:what can cause this pain?".To prevent AKP after TKA it is important to first identify the different anatomical structures that can cause this pain.Greater attention to and understanding of AKP should lead to significant pain relief and greater overall patient satisfaction after TKA.This article is a review of what pain is,how nerve signalling works and what is thought to cause Anterior Knee Pain after a Total Knee Arthroplasty.展开更多
AIM To compare rotating versus fixed-bearing Press-Fit Condylar(PFC) Sigma posterior stabilized(PS) total knee arthroplasty(TKA) with the new "J curve"femoral design in terms of clinical outcomes and anterio...AIM To compare rotating versus fixed-bearing Press-Fit Condylar(PFC) Sigma posterior stabilized(PS) total knee arthroplasty(TKA) with the new "J curve"femoral design in terms of clinical outcomes and anterior knee pain.METHODS We retrospectively analyzed 39 patients who underwent primary total knee replacement surgery for knee osteoarthritis using the PFC Sigma PS TKA with either fixed(FP group, 20 cases) or rotating platform(RP group, 19 cases) treated between 2009 and 2013 by the same surgeon. The two groups were homogeneous for age, gender, weight, American Society of Anesthesiologists status, preoperative clinical and functional scores, and prosthetic alignment at two years after surgery. We analyzed clinical outcomes score at two years follow-up using Knee Society Score(KSS), Knee Injury and Osteoarthritis Outcome Score(KOOS),Knee Performance Score, Short Form(SF) 36, and anterior knee pain assessed by the Hospital for Special Surgery(HSS) patellar score.RESULTS No differences were found in KSS, Knee Performance Score, and SF-36 outcome scores. A statistically significant difference was found in the HSS Patella score objective(FP: 22.36; RP: 28.75; P < 0.05), HSS Patella score total(FP: 73.68; RP:86.50; P < 0.05), and KOOS symptoms(FP: 73.49; RP: 86.44; P < 0.05).CONCLUSION Rotating platform in PFC Sigma PS TKA appears to reduce the short-term incidence of anterior knee pain compared to the fixed platform.展开更多
Background:Dynamic knee valgus(DKV)is an abnormal movement pattern visually characterized by excessive medial movement of the lower extremity during weight bearing.Differences in hip and knee kinematic components of D...Background:Dynamic knee valgus(DKV)is an abnormal movement pattern visually characterized by excessive medial movement of the lower extremity during weight bearing.Differences in hip and knee kinematic components of DKV may explain the emergence of different pain problems in people who exhibit the same observed movement impairment.Using a secondary analysis of exiting data sets,we sought to determine whether hip and knee frontal and transverse plane angles during a functional task differed between women with patellofemoral pain and women with chronic hip joint pain and the relationship between joint-specific kinematics and pain in these 2 pain populations.Methods:In the original studies,3-dimensional hip and knee kinematics during a single-limb squat were obtained in 20 women with patellofemoral pain and 14 women with chronic hip joint pain who demonstrated visually classified DKV.Pain intensity during the squat was assessed in both groups.For the secondary analysis,kinematic data were compared between pain groups using their respective control groups as a reference.Within each pain group,correlation coefficients were used to determine the relationship between kinematics and pain during the squat.Results:Hip adduction and contralateral pelvic drop were greater in those with chronic hip joint pain compared to those with patellofemoral pain(effect sizes ≥0.40).Greater knee external rotation(r= 0.47,p= 0.04)was correlated with greater knee pain in those with patellofemoral pain,while greater hip adduction(r = 0.53,p = 0.05)and greater hip internal rotation(r = 0.55,p = 0.04)were correlated with greater hip pain in those with chronic hip joint pain.Conclusion:Hip frontal plane motion was greater in those with chronic hip joint pain compared to those with patellofemoral pain.In both groups,greater abnormal movement at the respective joint(e.g.,knee external rotation in the patellofemoral pain group and hip adduction and internal rotation in the chronic hip joint pain group)was associated with greater pain at that joint during a single-limb squat.展开更多
Patellofemoral pain(PFP)is a common overuse condition seen in high-volume runners,such as military recruits.Exercise is commonly prescribed,with benefit,for the rehabilitation of individuals with PFP.However,a sub-sta...Patellofemoral pain(PFP)is a common overuse condition seen in high-volume runners,such as military recruits.Exercise is commonly prescribed,with benefit,for the rehabilitation of individuals with PFP.However,a sub-stantial number of individuals with the condition do not achieve an optimal outcome,suggesting the condition can be difficult and complex.Given the challenging nature of the condition,and the risk of developing PFP in high-volume runners,it seems logical to investigate options for injury prevention.Eccentric exercise has been useful in the prevention of some pathologies so its utility in preventing PFP should be explored.Current evidence regarding prevention programs for PFP are limited.Preventative exercise programs for PFP have not been well described or reported,and questions remain regarding their effectiveness.Based on available evidence or lack thereof,and known physiological and clinical effects of eccentric exercise,suggestions for integration of eccentric exercise into PFP prevention programs are offered.Eccentric exercise may be useful for PFP prevention from a theoretical framework however additional longitudinal cohort studies would be useful in determining its utility.展开更多
Objective:Total knee arthroplasty(TKA)has become an effective treatment modality for end-stage osteoarthritis and rheumatoid arthritis.Postoperative problems such as anterior knee pain affect postoperative patient sat...Objective:Total knee arthroplasty(TKA)has become an effective treatment modality for end-stage osteoarthritis and rheumatoid arthritis.Postoperative problems such as anterior knee pain affect postoperative patient satisfaction.Patellar denervation has been proposed as a technique to relieve pain,but its efficacy remains controversial.This study evaluated the mid-and long-term effects of patellar denervation on postoperative knee joint functions,hoping to provide better guidance for clinical practice.Methods:This study is a prospective randomized controlled double-blind study.58 patients undergoing bilateral non-resurfaced total knee arthroplasty were included and randomized into two groups.Both groups underwent total knee arthroplasty while patellar denervation was performed only on the experimental group.Information regarding whether if patellar denervation was performed were withheld from all patients and outcome assessors.All surgeries were performed by the same high-level professional physician,and the post-stable knee prosthesis system(PS Scorpio NRG PS,Stryker)was used during the surgeries.The knee joint functions were evaluated by professional assessors before and after surgery.The evaluation indicators mainly include KSS scoring,Western Ontario and McMaster Universities(WOMAC)scoring and Visual Analogue Scale(VAS),FJS scoring,etc.The follow-up period was 3 years and 5 years after surgery.Results:The experimental group had better KSS and FJS scores than the control group,the difference was statistically significant.There was no significant inter-group difference in WOMAC and VAS scores.Conclusion:The patellar denervation in TKA patients has positive effects on the mid-and long-term recovery of knee joint functions,and the postoperative satisfaction is better.展开更多
We report herein a rare case of lateral parapatellar synovial plica that developed simultaneously in both knees. A 15-year-old competitive soccer player visited our institution with a six-month history of anterolatera...We report herein a rare case of lateral parapatellar synovial plica that developed simultaneously in both knees. A 15-year-old competitive soccer player visited our institution with a six-month history of anterolateral pain and catching sensation in both knee joints. On physical examination, he complained of tenderness along the joint line of bilateral patellofemoral joint (PFJ). Visible and palpable popping was observed at the lateral margin of each patella during active knee motion. Magnetic resonance imaging showed obvious synovial soft nodules in the lateral side of the PFJ. On arthroscopy, a yellowish, thick, tongue-shaped tissue extending transversely from the lateral parapatellar synovium was identified in both knees, and parts of this tissue showed avascular hypertrophy. Arthroscopic findings of both knees are almost symmetrical in anatomical location, but no similar in size. After arthroscopic excision, the patient became asymptomatic. At 24-month follow up, he demonstrated full knee function, without evidence of local recurrence.展开更多
文摘BACKGROUND Anterior cruciate ligament(ACL)reconstruction using bone-patellar tendon-bone(BPTB)autografts remains the gold standard for young,active individuals due to its superior biomechanical strength and bone-to-bone healing.However,donor site morbidity,particularly anterior knee pain(AKP),limits its utilization despite its advantages.Various techniques have been proposed to reduce AKP,but they show variable outcomes and several limitations.AIM To assess the incidence and severity of AKP following BPTB ACL reconstruction using an autologous bone grafting technique.METHODS We conducted a retrospective observational study of 24 patients aged 20-45 years,who had primary ACL reconstruction with BPTB grafts.During surgery,autologous cancellous bone generated from tunnel drilling was used to fill the patellar and tibial donor site voids after graft fixation.All patients were followed up for at least twelve months.Using the Kujala Anterior Knee Pain Score,clinical outcomes were evaluated,including the pain-specific subcomponent.RESULTS With scores ranging from 86 to 100,the average overall Kujala score was 95.67±4.01.No patient scored below 85.There was no complication such as patellar fracture,tibial tuberosity fracture,or infection.Grouped data showed 20.8%of patients scored 100,whereas 54.2%scored between 95 and 99,and 25%scored between 86 and 94.One patient(4.2%)had an 8/10 pain subcomponent,whereas 23 patients(95.8%)had a 10/10.CONCLUSION This procedure is easy to incorporate into routine surgical practice,cost-effective and reproducible without requiring extra incisions or raising the patient’s surgical expenses.Excellent short-term results back up this technique.
基金Supported by the Capital Fund Project for Clinical Diagnosis and Treatment Technology Research and Translational Application,No.Z201100005520091and Beijing Traditional Chinese Medicine Science and Technology Development Fund Project,No.JJ-2020-67.
文摘BACKGROUND Total knee arthroplasty(TKA)is a mature procedure recommended for correcting knee osteoarthritis deformity,relieving pain,and restoring normal biomechanics.Although TKA is a successful and cost-effective procedure,patient dissatisfaction is as high as 50%.Knee pain after TKA is a significant cause of patient dissatisfaction;the most common location for residual pain is the anterior region.Between 4%and 40%of patients have anterior knee pain(AKP).AIM To investigate the effect of various TKA procedures on postoperative AKP.METHODS We searched PubMed,EMBASE,and Cochrane from January 2000 to September 2022.Randomized controlled trials with one intervention in the experimental group and no corresponding intervention(or other interventions)in the control group were collected.Two researchers independently read the title and abstract of the studies,preliminarily screened the articles,and read the full text in detail according to the selection criteria.Conflicts were resolved by consultation with a third researcher.And relevant data from the included studies were extracted and analyzed using Review Manager 5.4 software.RESULTS There were 25 randomized controlled trials;13 were comparative studies with or without patellar resurfacing.The meta-analysis showed no significant difference between the experimental and control groups(P=0.61).Six studies were comparative studies of circumpatellar denervation vs non-denervation,divided into three subgroups for meta-analysis.The two-subgroup meta-analysis showed no significant difference between the experimental and the control groups(P=0.31,P=0.50).One subgroup meta-analysis showed a significant difference between the experimental and control groups(P=0.001).Two studies compared fixed-bearing TKA and mobile-bearing TKA;the results meta-analysis showed no significant difference between the experimental and control groups(P=0.630).Two studies compared lateral retinacular release vs non-release;the meta-analysis showed a significant difference between the experimental and control groups(P=0.002);two other studies compared other factors.CONCLUSION Patellar resurfacing,mobile-bearing TKA,and fixed-bearing TKA do not reduce the incidence of AKP.Lateral retinacular release can reduce AKP;however,whether circumpatellar denervation can reduce AKP is controversial.
文摘Despite improvements in technique and technology for total knee arthroplasty(TKA),anterior knee pain impacts patient outcomes and satisfaction.Addressing the prosthetic and surgical technique related causes of pain after TKA,specifically as it relates to anterior knee pain,can aid surgeons in addressing these issues with their patients.Design features of the femoral and patellar components which have been reported as pain generators include: Improper femoral as well as patellar component sizing or designs that result in patellofemoral stuffing; a shortened trochlear groove distance from the flange to the intercondylar box; and then surgical technique related issues resulting in: Lateral patellar facet syndrome; overstuffed patella/flange combination; asymmetric patellar resurfacing,improper transverse plane component rotation resulting in patellar subluxation/tilt.Any design consideration that allows impingement of extensor mechanism anatomical elements has the possibility of impacting outcome by becoming a pain generator.As the number of TKA procedures continues to increase,it is increasingly critical to develop improved,evidence based prostheses that maximize function and patient satisfaction while minimizing pain and other complications.
文摘Total Knee Arthroplasty has been shown to be a successful procedure for treating patients with osteoarthritis,and yet approximately 5%-10%of patients experience residual pain,especially in the anterior part of the knee.Many theories have been proposed to explain the etiology of this anterior knee pain(AKP)but,despite improvements having been made,AKP remains a problem.AKP can be described as retropatellar or peripatellar pain,which limits patients in their everyday lives.Patients suffering from AKP experience difficulty in standing up from a chair,walking up and down stairs and riding a bicycle.The question asked was:"How can a‘perfectly’placed total knee arthroplasty(TKA)still be painful:what can cause this pain?".To prevent AKP after TKA it is important to first identify the different anatomical structures that can cause this pain.Greater attention to and understanding of AKP should lead to significant pain relief and greater overall patient satisfaction after TKA.This article is a review of what pain is,how nerve signalling works and what is thought to cause Anterior Knee Pain after a Total Knee Arthroplasty.
文摘AIM To compare rotating versus fixed-bearing Press-Fit Condylar(PFC) Sigma posterior stabilized(PS) total knee arthroplasty(TKA) with the new "J curve"femoral design in terms of clinical outcomes and anterior knee pain.METHODS We retrospectively analyzed 39 patients who underwent primary total knee replacement surgery for knee osteoarthritis using the PFC Sigma PS TKA with either fixed(FP group, 20 cases) or rotating platform(RP group, 19 cases) treated between 2009 and 2013 by the same surgeon. The two groups were homogeneous for age, gender, weight, American Society of Anesthesiologists status, preoperative clinical and functional scores, and prosthetic alignment at two years after surgery. We analyzed clinical outcomes score at two years follow-up using Knee Society Score(KSS), Knee Injury and Osteoarthritis Outcome Score(KOOS),Knee Performance Score, Short Form(SF) 36, and anterior knee pain assessed by the Hospital for Special Surgery(HSS) patellar score.RESULTS No differences were found in KSS, Knee Performance Score, and SF-36 outcome scores. A statistically significant difference was found in the HSS Patella score objective(FP: 22.36; RP: 28.75; P < 0.05), HSS Patella score total(FP: 73.68; RP:86.50; P < 0.05), and KOOS symptoms(FP: 73.49; RP: 86.44; P < 0.05).CONCLUSION Rotating platform in PFC Sigma PS TKA appears to reduce the short-term incidence of anterior knee pain compared to the fixed platform.
基金supported by the Washington University Institute of Clinical and Translational Sciences (No. UL1 TR000448) (Schmidt)the National Center for Advancing Translational Sciences (No. TLl TR000449) (Schmidt)+1 种基金the National Center for Medical Rehabilitation Research, National Institute of Child Health and Human Development, and National Institute of Neurological Disorders and Stroke (No. K23 HD067343,K12 HD055931) (Harris-Hayes)the National Center for Medical Rehabilitation Research, National Institute of Child Health and Human Development (No. R15HD059080)
文摘Background:Dynamic knee valgus(DKV)is an abnormal movement pattern visually characterized by excessive medial movement of the lower extremity during weight bearing.Differences in hip and knee kinematic components of DKV may explain the emergence of different pain problems in people who exhibit the same observed movement impairment.Using a secondary analysis of exiting data sets,we sought to determine whether hip and knee frontal and transverse plane angles during a functional task differed between women with patellofemoral pain and women with chronic hip joint pain and the relationship between joint-specific kinematics and pain in these 2 pain populations.Methods:In the original studies,3-dimensional hip and knee kinematics during a single-limb squat were obtained in 20 women with patellofemoral pain and 14 women with chronic hip joint pain who demonstrated visually classified DKV.Pain intensity during the squat was assessed in both groups.For the secondary analysis,kinematic data were compared between pain groups using their respective control groups as a reference.Within each pain group,correlation coefficients were used to determine the relationship between kinematics and pain during the squat.Results:Hip adduction and contralateral pelvic drop were greater in those with chronic hip joint pain compared to those with patellofemoral pain(effect sizes ≥0.40).Greater knee external rotation(r= 0.47,p= 0.04)was correlated with greater knee pain in those with patellofemoral pain,while greater hip adduction(r = 0.53,p = 0.05)and greater hip internal rotation(r = 0.55,p = 0.04)were correlated with greater hip pain in those with chronic hip joint pain.Conclusion:Hip frontal plane motion was greater in those with chronic hip joint pain compared to those with patellofemoral pain.In both groups,greater abnormal movement at the respective joint(e.g.,knee external rotation in the patellofemoral pain group and hip adduction and internal rotation in the chronic hip joint pain group)was associated with greater pain at that joint during a single-limb squat.
文摘Patellofemoral pain(PFP)is a common overuse condition seen in high-volume runners,such as military recruits.Exercise is commonly prescribed,with benefit,for the rehabilitation of individuals with PFP.However,a sub-stantial number of individuals with the condition do not achieve an optimal outcome,suggesting the condition can be difficult and complex.Given the challenging nature of the condition,and the risk of developing PFP in high-volume runners,it seems logical to investigate options for injury prevention.Eccentric exercise has been useful in the prevention of some pathologies so its utility in preventing PFP should be explored.Current evidence regarding prevention programs for PFP are limited.Preventative exercise programs for PFP have not been well described or reported,and questions remain regarding their effectiveness.Based on available evidence or lack thereof,and known physiological and clinical effects of eccentric exercise,suggestions for integration of eccentric exercise into PFP prevention programs are offered.Eccentric exercise may be useful for PFP prevention from a theoretical framework however additional longitudinal cohort studies would be useful in determining its utility.
文摘Objective:Total knee arthroplasty(TKA)has become an effective treatment modality for end-stage osteoarthritis and rheumatoid arthritis.Postoperative problems such as anterior knee pain affect postoperative patient satisfaction.Patellar denervation has been proposed as a technique to relieve pain,but its efficacy remains controversial.This study evaluated the mid-and long-term effects of patellar denervation on postoperative knee joint functions,hoping to provide better guidance for clinical practice.Methods:This study is a prospective randomized controlled double-blind study.58 patients undergoing bilateral non-resurfaced total knee arthroplasty were included and randomized into two groups.Both groups underwent total knee arthroplasty while patellar denervation was performed only on the experimental group.Information regarding whether if patellar denervation was performed were withheld from all patients and outcome assessors.All surgeries were performed by the same high-level professional physician,and the post-stable knee prosthesis system(PS Scorpio NRG PS,Stryker)was used during the surgeries.The knee joint functions were evaluated by professional assessors before and after surgery.The evaluation indicators mainly include KSS scoring,Western Ontario and McMaster Universities(WOMAC)scoring and Visual Analogue Scale(VAS),FJS scoring,etc.The follow-up period was 3 years and 5 years after surgery.Results:The experimental group had better KSS and FJS scores than the control group,the difference was statistically significant.There was no significant inter-group difference in WOMAC and VAS scores.Conclusion:The patellar denervation in TKA patients has positive effects on the mid-and long-term recovery of knee joint functions,and the postoperative satisfaction is better.
文摘We report herein a rare case of lateral parapatellar synovial plica that developed simultaneously in both knees. A 15-year-old competitive soccer player visited our institution with a six-month history of anterolateral pain and catching sensation in both knee joints. On physical examination, he complained of tenderness along the joint line of bilateral patellofemoral joint (PFJ). Visible and palpable popping was observed at the lateral margin of each patella during active knee motion. Magnetic resonance imaging showed obvious synovial soft nodules in the lateral side of the PFJ. On arthroscopy, a yellowish, thick, tongue-shaped tissue extending transversely from the lateral parapatellar synovium was identified in both knees, and parts of this tissue showed avascular hypertrophy. Arthroscopic findings of both knees are almost symmetrical in anatomical location, but no similar in size. After arthroscopic excision, the patient became asymptomatic. At 24-month follow up, he demonstrated full knee function, without evidence of local recurrence.
