Medial condyle hypoplasia in adolescent and young adult patients with trochlear dysplasia: a retrospective study / Hipoplasia do côndilo medial em pacientes adolescentes e adultos jovens com displasia troclear: estudo retrospectivo

Abstract Objective: To determine the association between medial femoral condyle hypoplasia and trochlear dysplasia by analyzing the knee magnetic resonance imaging scans of young patients with or without trochlear dysplasia. Materials and Methods: This was a retrospective analysis of magnetic resonance imaging scans of the knees of young individuals (16-35 years of age): 30 patients with trochlear dysplasia and 30 individuals with no signs of patellofemoral instability. The ratios between the depth, width, and height of the medial and lateral femoral condyles (dLC/dMC, wLC/wMC, and hLC/hMC, respectively) were calculated, as was the ratio between the width of the medial condyle and the total width of the femur (wMC/FW). All of the values were determined in consensus by two radiologists. Results: We evaluated 60 patients: 30 with trochlear dysplasia and 30 without. The mean dLC/dMC, wLC/wMC, and hLC/hMC ratios were higher in the patients than in the controls (p < 0.05), whereas the mean wMC/FW ratio was lower in the patients (p < 0.05). The optimal cutoff values, obtained by calculating the areas under the receiver operating characteristic curves, were 1.0465 for the dLC/dMC ratio (76% sensitivity and 63.3% specificity), 0.958 for the wLC/wMC ratio (80% sensitivity and 73.3% specificity), and 1.080 for the hLC/hMC ratio (93.3% sensitivity and 93.3% specificity). Conclusion: Our findings confirm our hypothesis that trochlear dysplasia is associated with medial condyle hypoplasia.

Resumo Objetivo: Determinar a associação entre hipoplasia do côndilo femoral medial e displasia troclear mediante análise de ressonância magnética do joelho de pacientes jovens com displasia troclear e sem displasia troclear. Materiais e Métodos: Análise retrospectiva de exames de ressonância magnética de joelhos de indivíduos jovens (16 a 35 anos de idade), sendo 30 pacientes com displasia troclear e 30 indivíduos sem sinais de instabilidade femoropatelar. As razões entre a profundidade, largura e altura dos côndilos femorais mediais e laterais (dLC/dMC, wLC/wMC e hLC/hMC, respectivamente) foram calculadas, assim como a razão entre a largura do côndilo medial e a largura total do fêmur (wMC/FW). Todos os valores foram determinados em consenso por dois radiologistas Resultados: Foram incluídos no estudo 60 adolescentes e adultos jovens, 30 com displasia troclear e 30 sem displasia troclear. A média das razões dLC/dMC, wLC/wMC, hLC/hMC foi maior nos pacientes do que nos controles (p < 0,05), enquanto a média da razão wMC/FW foi menor nos pacientes (p < 0,05). Os valores de corte ótimos obtidos da área sob a curva característica de operação do receptor foram 1,0465 para dLC/dMC (sensibilidade de 76% e especificidade de 63,3%), 0,958 para wLC/wMC (sensibilidade de 80% e especificidade de 73,3%) e 1,080 para hLC/hMC (sensibilidade de 93,3% e especificidade de 93,3%). Conclusão: Nossos resultados confirmam nossa hipótese de que a displasia troclear está associada a hipoplasia do côndilo medial.

Simultaneous rupture of the patellar and contralateral quadriceps tendons in a nephropathy patient / Ruptura simultânea de tendão patelar e quadricipital contralateral em paciente nefropata

ABSTRACT Simultaneous rupture of the patellar and contralateral quadriceps tendons in patients with chronic renal failure is an extremely rare condition, with few cases described in the medical literature. Several systemic pathological conditions that lead to a decline in kidney function can predispose individuals to spontaneous tendon rupture, such as rheumatological and endocrine diseases, and even gestational conditions, such as eclampsia. Objective: In this case report, we describe the case of a 39-year-old woman with chronic renal failure on dialysis due to a previous history of eclampsia that caused the simultaneous rupture of the patellar and contralateral quadriceps tendons. Methods: Data were collected by interviews, direct observation, and medical examinations, and include information about the case history, the patient's characteristics, the former interventions, and the results obtained. Results: The surgery to repair the patellar and contralateral quadriceps tendons was performed by transosseous tunnels and the Krackow technique with nonabsorbable sutures was used. The semitendinosus tendon was removed and used as reinforcement. Conclusion: Patient under follow-up with good functional results in both knees. Level of Evidence V, Expert Opinion.

RESUMO A ruptura simultânea de tendão patelar e tendão quadricipital contralateral em paciente com insuficiência renal crônica é uma condição extremamente rara, havendo poucos casos descritos na literatura médica. Diversas condições patológicas sistêmicas que levam ao declínio das funções renais podem predispor à ruptura tendinosa espontânea, como doenças reumatológicas e endócrinas, até mesmo condições gestacionais, como a eclâmpsia. Objetivo: Neste relato de caso, descrevemos o caso de uma mulher de 39 anos com insuficiência renal crônica dialítica decorrente de quadro pregresso de eclâmpsia que culminou na ruptura simultânea de tendão patelar e tendão quadricipital contralateral. Métodos: Estudo realizado com dados coletados por meio de entrevista, observação direta e exames médicos. Os dados incluem informações sobre o histórico do caso, as características do paciente, as intervenções realizadas e os resultados obtidos. Resultados: A cirurgia para reparo da lesão de tendão patelar contralateral e tendão quadricipital foi realizada por túneis transosseos e a rafia foi feita com pontos Krakow utilizando fios não absorvíveis. Além disso, o tendão semitendinoso foi retirado e usado como reforço. Conclusão: A paciente apresentou bons resultados funcionais em ambos os joelhos operados. Nível de Evidência V, Opinião do Especialista.

Patellar fracture in anterior cruciate ligament reconstruction: in vitro analysis / Fratura patelar na reconstrução do ligamento cruzado anterior: análise in vitro

ABSTRACT Objective: To determine, by biomechanical analysis, safe patellar cut limits in anterior cruciate ligament (ACL) reconstruction that minimize fracture risks. Methods: From three-dimensional reconstruction, triangular cuts were made in the patella, with a depth of 6.5 mm and variable width and length (10 to 20 mm and 8 to 12 mm, respectively, both with an interval of 1 mm). The combinations of cuts constituted 55 models for tests, with five variations in width and 11 variations in length, tested with the finite element method (FEM). Results: The mean of the localized principal maximum (traction force) values was 4.36 Pa (SD 0.87 ± 0.76) and the localized principal minimum (compression force) was −4.33 Pa (SD 1.05 ± 1.11). Comparing width and length to the tension force of the values of the main maximum, we found statistical significance from 11 mm for width and 13 mm for length. Conclusion: In ACL reconstruction, the removal of the patellar bone fragment is safe for fragments smaller than 11 mm in width and 13 mm in length, which corresponds to 24% of the width and 28% of the length of the patella used. Level of Evidence II, Comparative Prospective Study.

RESUMO Objetivo: Determinar, por meio de análise biomecânica, os limites de corte patelar seguros para a reconstrução do ligamento cruzado anterior (LCA) e que minimizem riscos de fratura. Métodos: A partir de reconstrução tridimensional, foram feitos cortes triangulares na patela, com profundidade de 6,5 mm e largura e comprimento variáveis (8 a 12 mm e 10 a 20 mm), respectivamente, com intervalo de 1 mm). As combinações dos cortes constituíram 55 modelos para ensaios, com 5 variações de largura e 11 variações de comprimento, ensaiados por meio do método dos elementos finitos (MEF). Resultados: A média dos valores da máxima principal localizada (força de tração) foi de 4,36 Pa (DP 0,87 ± 0,76), e a mínima principal localizada (força de compressão) foi de −4,33 Pa (DP 1,05 ± 1,11). Comparando largura e comprimento à força de tensões dos valores da máxima principal, houve significância estatística a partir de 11 mm para largura e 13 mm para comprimento. Conclusão: Na reconstrução do LCA, a retirada do fragmento ósseo patelar mostrou-se segura para fragmentos menores que 11 mm de largura e 13 mm de comprimento, o que corresponde a 24% da largura e 28% do comprimento da patela utilizada. Nível de Evidência II, Estudo Prospectivo Comparativo.

Fibroma of the Patellar Tendon Sheath: A New Paradigm / Fibroma da bainha do tendão patelar: Um novo paradigma

Abstract The authors present a case of fibroma of the tendon sheath with intra-articular location in the knee, more specifically in the infrapatellar fat; with this specific location, this is the fourth case described of an entity that rarely affects large joints. Clinical and epidemiologi-cal aspects, but especially the imaging findings on magnetic resonance imaging scans, are essential for the differential and definitive diagnosis, which was nevertheless established only after a histological study of the excised mass by miniarthrotomy.

Resumo Os autores apresentam um caso de um fibroma da bainha de tendão com localização intra-articular no joelho e origem na gordura infrapatelar. Esta localização específica é extremamente rara, sendo este o quarto caso descrito de uma entidade que raramente afeta grandes articulações. Para o seu diagnóstico aspetos clínicos, epidemiológicos e sobretudo achados imagiológicos da ressonância magnética são fundamentais. Neste caso o diagnóstico definitvo foi apenas estabelecido após estudo histológico da massa excisada por mini-artrotomia.

The interpretation of the American Academy of Orthopaedic Surgeons "management of anterior cruciate ligament injuries evidence-based clinical practice guideline (2022)" / 中华骨科杂志

The anterior cruciate ligament (ACL) injury is a common sports injury, which can lead to the knee unstable, make it difficult for the patient to return to sports, and cause post-traumatic osteoarthritis. The difficulty of its clinical diagnosis and treatment has always been the focus of sports medicine research. In August 2022, the American Association of Orthopaedic Surgeons updated and published "evidence-based clinical practice guideline on management of ACL injuries (2022 version)" based on the "evidence-based clinical practice guideline on management of ACL injuries (2014 version)". In the prevention, diagnosis and treatment of ACL injuries, the new guideline offers 8 recommendations and 7 options according to different evidence strength. To assist clinicians in the diagnosis and treatment of ACL injuries, this article provides an interpretation of the new guideline. In comparison to the 2014 version, the new guideline does not recommend allografts any more, shortens the time for reconstruction after ACL injury from 5 months to 3 months, adds advice that ACL reconstruction can be combined with anterolateral ligament reconstruction or lateral extra-articular tenodesis, and does not recommend ACL repair. The new guideline also shares many similarities with the domestic "clinical evidence-based guideline for the diagnosis and treatment of anterior cruciate ligament injury (2022 version)", both of which advocate history and physical examination at diagnosis, early reconstruction, the use of autologous bone-patellar tendon-bone or hamstring tendon, and either single-bundle or double-bundle ACL reconstruction. The new ACL guidelines of the American Association of Orthopaedic Surgeons lack specific recommendations on artificial ligaments, techniques for bone tunnel creation, and rehabilitation programs, all of which are of concern to domestic physicians because they are based on evidence-based research from abroad. Therefore, in order to improve the diagnosis and treatment of ACL injuries in China, clinicians should not only follow the new ACL guidelines of the American Association of Orthopaedic Surgeons, but also combine the characteristics of Chinese patients, clinical practice, and pertinent domestic guidelines when diagnosing and treating ACL injuries.

Analysis of factors affecting the change in relative patellar height after robotic-assisted primary total knee arthroplasty / 中华骨科杂志

Objective:To analyze the factors affecting the relative height change of the patella after primary robotic-assisted total knee arthroplasty (R-TKA).Methods:The data of 97 patients with osteoarthritis of the knee treated with R-TKA admitted from June 2021 to March 2022 were retrospectively analyzed, including 15 males and 82 females, aged 70.0±5.4 years (range, 58-80 years). The bone resection parameters of the robotic system were recorded intraoperatively, including the bone resection amount of the medial and lateral distal femur, medial and lateral posterior femoral condyle and medial and lateral tibial plateau. The Blackburne-Peel index (BPI) and Caton-Deschamps index (CDI) were used to measure the preoperative and postoperative relative patellar height on lateral radiographs, as well as the posterior tibial slope (PTS) and the change in patellar ligament length before and after surgery. The relationship between the change in relative patellar height and the variables of interest was analyzed using partial correlation and multiple linear regression.Results:The mean postoperative CDI was lower than preoperatively (0.79±0.15 vs. 0.91±0.13, t=9.69, P<0.001), and the percentage of patients with postoperative CDI<0.6 was higher than preoperatively (9.3% vs. 0; χ 2=12.92, P<0.001); the differences in mean postoperative BPI and percentage of patients with postoperative BPI<0.45 were not statistically significant compared to preoperatively (0.69±0.13 vs. 0.71±0.17, t=1.35, P=0.182; 11.3% vs. 17.5%, χ 2=1.50, P=0.220). The mean patellar ligament length on the first postoperative day was 2.29 mm shorter than preoperatively, there was a statistically significant difference ( t=5.90, P<0.001). Partial correlation analysis showed that the amount of patellar ligament length change was positively correlated with the amount of BPI and CDI change ( r=0.84, P<0.001; r=0.70, P<0.001), and the amount of PTS change and the mean distal femoral bone resection were negatively correlated with the amount of BPI ( r= -0.41, P<0.001; r=-0.32, P=0.002) and CDI ( r=-0.23, P=0.029; r=-0.25, P=0.017) change. In contrast, the amount of posterior femoral condyle bone resection and tibial plateau bone resection did not correlate with the change of BPI and CDI. Multiple linear regression analysis showed that the amount of patellar ligament length change, PTS change and the distal femoral bone resection were factors influencing the change of BPI ( β=0.03, P<0.001; β=-0.01, P<0.001; β=-0.02, P=0.021) and CDI ( β=0.02, P<0.001; β=-0.01, P=0.001; β=-0.02, P=0.008). Conclusion:Amount of patellar ligament length change, PTS change and the distal femoral bone resection are factors affecting the BPI. In order to obtain a better relative patellar height in the primary R-TKA, attention should be paid to the adjustment of the distal femoral bone resection and PTS, while taking the necessary measures to reduce the postoperative patellar ligament length changes.

Modified all-arthroscopic reconstruction of medial patellofemoral ligament for the treatment of recurrent patellar dislocation / 中华创伤杂志

Objective:To evaluate the clinical efficacy of modified all-arthroscopic reconstruction of medial patella femoral ligament (MPFL) for the treatment of recurrent patellar dislocation.Methods:A retrospective case series study was conducted to analyze the clinical data of 38 patients (46 knees) with recurrent patellar dislocation, who were treated at First Affiliated Hospital of Shenzhen University from January 2017 to January 2020. The patients included 12 males (12 knees) and 26 females (34 knees), aged 14-40 years [(24.6±5.4)years]. All patients underwent the modified all-arthroscopic MPFL reconstruction procedure. The femoral tunnel locations were assessed by 3D-CT immediately after surgery. The MRI was performed at 6 and 12 months after operation to assess the healing morphology of the reconstructed MPFL. The Lysholm score and Kujala score were used to assess the knee function before operation, at 6 months after operation, at 12 months after operation and at the last follow-up. The time to return to sports as well as complications were observed.Results:All patients were followed up for 26-48 months [(32.4±8.6)months]. Postoperative 3D-CT examination showed that the femoral tunnels were located in the groove area of the medial epicondyle of the femur and the adductor tubercle. At 6 and 12 months after operation, MRI T2 images showed that the reconstructed MPFL had a low signal and well tensioned ligament tissue, indicating that the MPFL was healed well. The Lysholm scores at 6 and 12 months postoperatively and at the last follow-up were (81.1±12.0)points, (91.2±3.8)points, and (92.2±9.8)points, respectively, being significantly higher than the preoperative (52.4±10.6)points (all P<0.01). The Kujala scores at 6 and 12 months postoperatively and at the last follow-up were (85.4±3.9)points, (91.4±3.6)points, and (93.1±8.5)points, respectively, being significantly higher than the preoperative (55.2±6.8)points (all P<0.01). Compared with 6 months postoperatively, the Lysholm score and Kujala score were significantly improved at 12 months postoperatively and at the last follow-up (all P<0.05). All patients returned to sports, with the time to return to sports for 3-12 months [(8.7±2.3)months] after operation. One patient had poor wound healing but was healed after dressing changes. No wound infection, nerve injury, joint stiffness, patella re-dislocation or other complications occurred. Conclusion:For recurrent patellar dislocation, the modified all-arthroscopic MPFL reconstruction has advantages of accurate bone tunnel positioning, good ligament healing, good function recovery, early return to sports, and less postoperative complications.

3D printed guide plate assisted and C-arm X-ray fluoroscopic positioning for femoral tunnel reconstruction of medial patellofemoral ligament in treating recurrent patellofemoral dislocation: a comparison of efficacies / 中华创伤杂志

Objective:To compare the efficacies of 3D printed guide plate assisted positioning and C-arm X-ray machine fluoroscopic positioning for femoral tunnel reconstruction of medial patellofemoral ligament in treating recurrent patellofemoral dislocation.Methods:A retrospective cohort study was performed on the clinical data of 60 patients with recurrent patellar dislocation admitted to the First Affiliated Hospital of Kunming Medical University from January 2018 to December 2022. The patients included 29 males and 31 females, with age range of 14-40 years [(28.6±7.6)years]. The 3D printed guide plate was used to locate the femoral tunnel in 30 patients for medial patellofemoral ligament reconstruction (3D guide group), and C-arm X-ray machine was used for another 30 patients (conventional group). (1) CT data of the knee joint were collected before surgery and at 7 days after surgery. Mimics 19.0 software was introduced to measure the distance between the center of femoral tunnel and Sch?ttle point after surgery. (2) Knee Lysholm score and Kujala score were used to evaluate the knee function before and at 3, 6, 9 and 12 months after surgery. (3) At the same time points, Opti-Knee TM 3D knee kinematics analysis system was used to collect the forward and backward displacement, up and down displacement, internal and external displacement, internal and external flipping angle, internal and external rotation angle, and flexion and extension angle of the affected knee joint. The range of each freedom degree was calculated and 6 freedom degree items of 30 healthy people were subjected to knee kinematics analysis. Results:All patients were followed up for 12-15 months [(12.3±0.7)months]. (1) The distance between the center of femoral tunnel and Sch?ttle point in the 3D guide group was (5.5±2.3)mm, smaller than that in the conventional group [(7.6±2.5)mm] ( P<0.01). (2) The Lysholm score and Kujala score of the 3D guide group and conventional gruop gradually increased after surgery (all P<0.01). There were no significant differences in the Lysholm score or Kujala score between the 3D guide group and conventional gruop before surgery and at 12 months after surgery (all P>0.05). At 3, 6 and 9 months after surgery, the Lysholm score of the 3D guide group [(70.4±4.5)points, (86.4±3.1)points, (91.2±3.2)points] and Kujala score [(74.2±5.3)points, (80.9±3.5)points, (85.2±3.2)points] were higher than those of the conventional group [Lysholm score: (67.3±5.2)points, (81.8±2.5)points, (86.2±1.9)points; Kujala score: (69.8±5.2)points, (77.6±2.1)points, (82.7±2.6)points] ( P<0.05 or 0.01). (3) Before surgery, the forward and backward displacement in the 3D guide group and conventional group [(0.6±0.1)cm, (0.6±0.2)cm], up and down displacement [(0.5±0.1)cm, (0.6±0.0)cm], internal and external displacement [(0.7±0.1)cm, (0.6±0.2)cm], and flexion and extension angle [(50.6±10.3)°, (51.6±8.5)°] were less than those in the healthy controls [(1.6±0.3)cm, (1.7±0.5)cm, (1.0±0.4)cm, (63.2±5.1)°] (all P<0.05), while the internal and external flipping angle [(17.5±4.0)°, (17.1±3.8)°] and internal and external rotation angle [(17.9±1.9)°, (17.5±1.5)°] were greater than those in the healthy controls [(11.8±3.6)°, (15.8±4.9)°] (all P<0.05). At other time points, the results of front and back displacement, up and down displacement, internal and external displacement, internal and external rotation angle in the 3D guide group and conventional group were not significantly different compared with the healthy controls (all P>0.05). The flexion and extension angle in the 3D guide group and conventional gruop were smaller than those in the healthy controls at 3 months after surgery (all P<0.05). At 6 and 9 months after surgery, the flexion and extension angle in the conventional group [(55.0±3.7)°, (57.7±4.8)°] were smaller than those in the healthy controls [(63.2±5.1)°, (63.2±5.1)°] (all P<0.05), but no significant difference was found between the 3D guide group [(61.0±4.8)°, (61.8±4.9)°] and the healthy controls (all P>0.05). The flexion and extension angle in the 3D guide group and conventional gruop was similar with that in the healthy controls at 12 months after surgery (all P>0.05). Conclusions:Compared with the C-arm X-ray machine, the 3D printed guide plate assisted positioning of femoral tunnel is more simple and accurate for the medial patellofemoral ligament reconstruction in treating recurrent patellofemoral dislocation, together with better early knee function recovery, better satisfaction of the patients, and better and faster restoration of the flexion and extension angle of knee joint kinematic function.

Association between posterior tibial slope and tibial torsion angle and recurrent patellar dislocation based on the full-length CT of the lower limbs / 解剖学报

Objective To measure and compare the lateral posterior tibial slope (LPTS) , medial posterior tibial slope ( MPTS) and tibial torsion angle ( TTA) between the patients of recuiTent patellar dislocation and the heathy people, and to analyze the correlation between LPTS, MPTS and TTA and the risk factors of recuiTent patellar dislocation. Methods A total of 33 patients (44 knees) with recuiTent patellar dislocation in our hospital from July 2019 to June 2021 were selected and listed as the stud)' group. Twenty-three subjects (46 knees) who were suspected iliac vascular and lower limb vascular diseases during the same period were selected and listed as the control group. All the enrolled researchers had fulllength CT scans date of the lower limbs. Three-dimensional models were reconstructed using Mimics 21. 0 software and then imported into 3-matic software. The LPTS, MPTS and TTA were measured and compared between the two groups. Results In the study group, the LPTS, MPTS and TTA were (7. 69} 1. 42) ° , ( 10. 06} 1. 71) ° , ( 36. 42}8. 13 ) ° , respectively while the control group, the LPTS, MPTS and TTA were ( 8. 42 } 1. 65 ) ° , ( 10. 44 } 0. 86 ) ° , ( 25. 77} 3. 90 ) ° , respectively. There were no signiiicant differences in the LPTS, MPTS and TTA between different genders and sides both in the stud)' group and the control group ( P > 0. 0 5 ) . Compared with the control group, the LPTS in the stud)' group was smaller, and the difference was statistically significant (P0. 05). Compared with the control group, the TTA in the stud)' group was higher, and the difference was statistically significant (P< 0. 0 5 ) . Compared with the control group, the LPTS and MPTS in the study group were significant asymmetry, and the difference was statistically significant ( P < 0 . 0 5 ). Conclusion The lateral posterior tibial slope of patients with recurrent patellar dislocation is significantly smaller than that in the healthy people, while there is no significant difference in the medial posterior tibial slope; The tibial torsion angle of patients with recurrent patellar dislocation is significantly larger than in the healthy people; The lateral posterior tibial slope and tibial torsion angle have certain correlation with recurrent patellar dislocation, which can conduct the diagnosis of recurrent patellar dislocation.

Comparison of a minimally invasive osteosynthesis technique with conventional open surgery for transverse patellar fractures / 中华创伤杂志(英文版)

PURPOSE@#The study aims to compare the efficacy and safety of a new minimally invasive osteosynthesis technique with those of conventional open surgery for transverse patellar fractures.@*METHODS@#It was a retrospective study. Adult patients with closed transverse patellar fracture were included, and with open comminuted patellar fracture were excluded. These patients were divided into minimally invasive osteosynthesis technique (MIOT) group and open reduction and internal fixation (ORIF) group. Surgical time, frequency of intraoperative fluoroscopy, visual analogue scale score, flexion, extension, Lysholm knee score, infection, malreduction, implant migration and implant irritation in two groups were recorded and compared. Statistical analysis was performed by the SPSS software package (version 19). A p < 0.05 indicated statistical significance.@*RESULTS@#A total of 55 patients with transverse patellar fractures enrolled in this study, the minimally invasive technique was performed in 27 cases, and open reduction was performed in 28 cases. The surgical time in the ORIF group was shorter than that in the MIOT group (p = 0.033). The visual analogue scale scores in the MIOT group were significantly lower than those in the ORIF group only in the first month after surgery (p = 0.015). Flexion was restored faster in the MIOT group than that in the ORIF group at one month (p = 0.001) and three months (p = 0.015). Extension was recovered faster in the MIOT group than that in the ORIF group at one month (p = 0.031) and three months (p = 0.023). The recorded Lysholm knee scores in the MIOT group were always greater than those in the ORIF group. Complications, such as infection, malreduction, implant migration, and implant irritation, occurred more frequently in the ORIF group.@*CONCLUSION@#Compared with the ORIF group, the MIOT group reduced postoperative pain and had less complications and better exercise rehabilitation. Although it requires a long operation time, MIOT may be a wise choice for transverse patellar fractures.

Clinical application and effectiveness of patellar tunnel locator in medial patellofemoral ligament reconstruction surgery / 中国修复重建外科杂志

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.

Advances in peripatellar osteotomy for treating recurrent patellar dislocation / 中国修复重建外科杂志

OBJECTIVE@#To summarize the progress of research related to the surgical treatment of recurrent patellar dislocation by peripatellar osteotomy in clinical practice, in order to provide reference for clinical treatment.@*METHODS@#The recent literature on peripatellar osteotomy for recurrent patellar dislocation at home and abroad was reviewed, and the bony structural abnormalities, imaging diagnosis, and treatment status were summarized.@*RESULTS@#Abnormalities in the bony anatomy of the lower limb and poor alignment lead to patellofemoral joint instability through the quadriceps pulling force line and play an important role in the pathogenesis of recurrent patellar dislocation. Identifying the source of the deformity and intervening with peripatellar osteotomy to restore the biomechanical structure of the patellofemoral joint can reduce the risk of soft tissue surgical failure, delay joint degeneration, and achieve the target of treatment.@*CONCLUSION@#In the clinical diagnosis and treatment of recurrent patellar dislocation, the factors causing patellofemoral joint instability should be comprehensively evaluated to guide the selection of surgery and personalized treatment.

Effectiveness of suture anchor fixation combined with Nice knot strapping via longitudinal patellar drilling in treatment of patellar inferior pole fracture / 中国修复重建外科杂志

OBJECTIVE@#To investigate effectiveness of suture anchor fixation combined with Nice knot strapping via longitudinal patellar drilling in the treatment of patellar inferior pole fractures.@*METHODS@#A clinical data of 37 patients with unilateral patellar inferior pole fracture who met the selection criteria between June 2017 and June 2021 was retrospectively analyzed. Among them, 17 cases were treated with the suture anchor fixation combined with Nice knot strapping via longitudinal patellar drilling (group A), and 20 cases were treated with the traditional Kirschner wire tension band technique (group B). There was no significant difference in terms of gender, age, body mass index, fracture side, combined medical disease, and preoperative hemoglobin between the two groups ( P>0.05). Operation time, intraoperative blood loss, postoperative complications, fracture healing time, knee range of motion, and knee function Bostman score (range of motion, pain, daily work, muscle atrophy, walking aids, knee effusion, soft leg, and stair climbing) and grading were recorded in both groups at last follow-up.@*RESULTS@#There was no significant difference in operation time and intraoperative blood loss between the two groups ( P>0.05). All incisions healed by first intention. All patients were followed up 1-2 years, with an average of 1.7 years. X-ray films reexamination showed that all fractures in group A healed, while 2 cases in group B did not heal. There was no significant difference in bone healing time between the two groups ( P>0.05). At last follow-up, the knee range of motion, the range of motion score of Bostman score, total score and effectiveness grading in group A were significantly better than those in group B ( P<0.05). There was no significant difference in the other items of Bostman scores between the two groups ( P>0.05). During follow-up, 2 cases of internal fixation failure and 1 case of internal fixator irritation occurred in group B, and no complication related to internal fixation occurred in group A. The occurrence of complications was significantly lower in group A than in group B ( P<0.05).@*CONCLUSION@#Compared with the traditional Kirschner wire tension band technique, the suture anchor combined with Nice knot strapping via longitudinal patellar drilling for the patellar inferior pole fractures has the advantages of simple operation, reliable fixation, early flexion and extension activity, and better functional recovery of knee joint.

Uso de placa malla en el manejo de fracturas conminutas de patela: reporte de caso / Use of mesh plate for the treatment of comminuted patellar fractures: case report

OBJETIVOS Describir la técnica quirúrgica para el uso de placa malla en un caso de fractura conminuta de patela y sus resultados en el seguimiento a mediano plazo. MATERIALES Y MÉTODOS Presentamos un caso de fractura conminuta de patela manejada con el uso de una placa malla y un tornillo canulado asociado, evitando de esta forma la patelectomía parcial y sus posibles complicaciones. RESULTADOS El paciente presentó una evolución satisfactoria, con rango de movimiento de rodilla completo y en condiciones de alta laboral a los cuatro meses desde la cirugía, sin complicaciones ni reintervenciones. DISCUSIÓN El uso de placas malla permite el manejo de fracturas conminutas de patela preservando stock óseo y restaurando la indemnidad del aparato extensor, con una osteosíntesis estable y poco prominente. Casos en que antiguamente la única alternativa era la patelectomía parcial y reinserción del tendón patelar ahora tienen etas placas como opción de manejo. CONCLUSIÓN El uso de placas malla en fracturas conminutas de patela es una alternativa atractiva por la estabilidad que brindan, la capacidad de reservar stock óseo, y la baja tasa de reintervenciones

OBJETIVE To describe the surgical technique for the use of a mesh plate in a case of comminuted patellar fracture and the mid-term follow up outcomes. MATERIALS AND METHODS We present a case of comminuted patella fracture managed with the use of a mesh plate and an associated cannulated screw, thus avoiding partial patellectomy and its possible complications. RESULTS Four months postoperatively, the patient presented full knee range of motion and could be discharged to return to work, with no complications or reinterventions. DISCUSSION The use of mesh plates enables the management of comminuted patellar fractures preserving bone stock and restoring the extensor mechanism with a stable and little prominent osteosynthesis. Cases which previously would only have been treated by partial patellectomy and patellar tendon reinsertion can be treated with these plates. CONCLUSION The use of mesh plates for comminuted patellar fractures is an attractive option due to their stability, their ability to preserve bone stock, and the low rates of reintervention.

Functional Complications of Patellar Instability Treatment with Medial Patellofemoral Ligament Reconstruction with the Medial Third of the Patellar Tendon with a Minimum 5-Year Follow-Up / Complicações funcionais do tratamento da instabilidade patelar com reconstrução do ligamento femoropatelar medial com terço medial do tendão patelar com acompanhamento mínimo de 5 anos

Abstract Objective To evaluate major complications after a minimum of 5 years of follow-up after acute or recurrent patellar dislocation treated with medial patellofemoral ligament (MPFL) reconstruction with the medial third of the patellar tendon, with or without associated medialization of the tibial anterior tuberosity (TAT). Methods A total of 50 patients were included, with a minimum follow-up of 5 years. The patients were evaluated regarding complications such as joint stiffness, recurrence of patellar dislocation, subjective instability reported by patients, and inability to return to the previous level of physical activity. Results The mean follow-up was of 8.9 2.6 years, with a minimum of 6 and maximum of 15 years; 64% of the patients were women, with a mean age of 27 11.2 years old; 24% were submitted to TAT osteotomy for simultaneous medialization; and 46% were acute cases. Only 9 poor results (18%) were found, all resulting from recurrence of dislocation (12%) and complaint of subjective instability (6%) at between 36 and 60 months of follow-up. No other complications occurred. Among the poor results, five occurred in cases of acute dislocation, and four in recurrent cases, and only one had undergone TAT osteotomy. Conclusion Reconstruction of the MPFL with the medial third of the patellar tendon, associated or not with TAT medialization osteotomy, is an alternative in the treatment of acute or chronic patellar instability, with a failure rate of only 18% in at least 5 years of follow-up. In addition, it is safe treatment, that does not present other complications.

Resumo Objetivo Avaliar complicações maiores após um mínimo de 5 anos de acompanhamento após luxação aguda ou recidivante da patela tratada com reconstrução do ligamento femoropatelar medial (LFPM) com terço medial do tendão patelar, com ou sem medialização da tuberosidade anterior da tíbia (TAT) associada. Métodos Um total de 50 pacientes foram incluídos, com acompanhamento mínimo de 5 anos. Os pacientes foram avaliados em relação à ocorrência de complicações como rigidez articular, recidiva de luxação patelar ou instabilidade subjetiva relatada pelos pacientes, e incapacidade de retorno ao nível prévio de atividades físicas. Resultados O acompanhamento médio foi de 8,9 2,6 anos, com mínimo de 6 e máximo de 15 anos; 64% dos pacientes eram mulheres, com média de idade de 27 11,2 anos; 24% dos pacientes foram submetidos a osteotomia da TAT para medialização concomitantemente; e 46% eram casos agudos. Foram constatados apenas 9 maus resultados (18%), todos decorrentes de recidiva da luxação (12%) e de queixa de instabilidade subjetiva (6%), ocorridos entre 36 e 60 meses de acompanhamento. Não ocorreram outras complicações. Dentre os maus resultados, cinco ocorreram em casos de luxação aguda, e quatro em casos recidivantes, e apenas um havia sido submetido a osteotomia da TAT. Conclusão AreconstruçãodoLFPMcomterçomedialdotendãopatelar,associadaounãoà osteotomia de medialização da TAT, é uma alternativa no tratamento da instabilidade patelar aguda ou crônica, com falha de apenas 18% em acompanhamento mínimo de 5 anos. Além disso, é um tratamento seguro, sem apresentar outras complicações.

Manejo de fracturas conminutas del polo distal de la patela con asas verticales de alambre: reporte de casos / Management of comminuted fractures of the distal pole of the patela with vertical wire loops: case report

INTRODUCCIÓN Las fracturas conminutas del polo distal de la patela representan un desafío para el cirujano de rodilla, pues no existe un tratamiento estándar que permita una rehabilitación acelerada. Recientemente se han descrito la osteosíntesis y la reinserción del polo distal utilizando asas de alambre verticales. MATERIALES Y MÉTODOS Presentamos dos casos de fractura conminuta del polo distal de la patela resueltos con asas de alambre verticales y modificaciones de esta técnica. RESULTADOS Se realizó osteosíntesis del polo distal de la patela, y se logró una reducción radiográfica satisfactoria, lo que permitió una rehabilitación acelerada, con un rango de movilidad progresivo a tolerancia desde el día siguiente tras la cirugía. Los pacientes lograron recuperar el rango de movimiento completo a los dos y tres meses de operados, evolucionaron satisfactoriamente, sin complicaciones relacionadas a esta técnica y sus variaciones, y recibieron el alta médica tras cuatro meses de la reducción y osteosíntesis. DISCUSIÓN Las técnicas tradicionales para el manejo de fracturas del polo distal implican consideraciones especiales en la rehabilitación y complicaciones asociadas. Se utilizó la técnica de asas de alambres verticales en dos pacientes: en uno de ellos, el procedimiento fue complementado con sutura tipo Krackow; y, en el otro, con una placa para minifragmentos, lo que permitió una rehabilitación acelerada y retorno precoz a sus actividades laborales. CONCLUSIÓN El uso de asas de alambre vertical aparece como una técnica segura, que permite una rehabilitación acelerada y un reintegro laboral precoz.

INTRODUCTION Comminuted fractures of the distal pole of the patella represent a challenge for the knee surgeon, as there is no standard treatment that enables accelerated rehabilitation. Osteosynthesis and reattachment of the distal pole using vertical wire loops has recently been described. MATERIALS AND METHODS We herein present two cases of omminuted fracture of the distal pole of the patella resolved with vertical wire loops and modifications of this technique. RESULTS Osteosynthesis of the distal pole of the patella was performed, achieving a satisfactory radiographic reduction and enabling accelerated rehabilitation, with a progressive range of motion the day after the surgery. The patients achieved full range of motion two and three months after surgery. They progressed satisfactorily, without complications related to this technique and its variations, and were discharged four months after the reduction and osteosynthesis. DISCUSSION The traditional techniques for the management of distal pole fractures involve special considerations regarding rehabilitation and associated complications. The vertical wire loop technique was used in two patients: in one of them, it was supplemented with a Krackow suture; and, in the other, with a mini-fragment plate, which enabled accelerated rehabilitation and early return to work. CONCLUSION The use of vertical wire loops appears to be a safe technique, which enables accelerated rehabilitation and early return to work.

Knee MR Using a Body Coil is Equivalent to CT in Measuring the TT-TG Distance: Removing the Systematic Bias / A ressonância magnética do joelho usando a bobina de corpo é equivalente à TC na medição da distância TT-ST: Removendo o viés sistemático

Abstract Objective To compare magnetic resonance imaging (MRI) using a body coil with computed tomography (CT) in measuring the tibial tubercle-trochlear groove distance (TT-TG) and the patellar tendon-cartilaginous trochlear groove (PT-CTG) distances, and evaluate interrater reliability. Methods The study group consisted of 34 knees from 17 asymptomatic subjects with no history of knee pathology, trauma or surgery. A low-dose CT scan and an axial T1-weighted MRI sequence of the knees were performed with rigorous standardization of the positioning with full extension of the knees and parallel feet. Two musculoskeletal radiologists performed the measurements independently. The reliability of the TT-TG and PT-CTG distances on CT (17.1 ± 4.2 mm and 17.3 ± 4.2 mm) and of MRI (16.2 ± 3.7 mm and 16.5 ± 4.1 mm) was assessed by intraclass correlation coefficient (ICC [2,1]) and Bland-Altman graphs, as well as the interrater reliability for both methods. Results Good reliability and agreement was observed between CT and MRI measurements for TT-TG and PT-CTG, with an ICC of 0.774 (p< 0.001) and 0.743 (p< 0.001), respectively, and no systematic bias was observed. The interrater reliability was excellent for all measurements on both imaging methods. Conclusion This was the first study that compared MRI using a body coil with CT in measuring the TT-TG distance, with the potential clinical implication that the CT in this clinical setting could be avoided.

Resumo Objetivo Comparar a ressonância magnética (RM) usando uma bobina corporal e tomografia computadorizada (TC) na medição da distância tubérculo tibial-sulco troclear (TT-ST) e as distâncias tendão patelar-sulco troclear cartilaginoso (TP-STC), e avaliar a confiabilidade interavaliador. Métodos O grupo de estudo consistiu em 34 joelhos de 17 indivíduos assintomáticos sem história de patologia, trauma ou cirurgia no joelho. Uma tomografia computadorizada (TC) de baixa dose e uma sequência axial de RM ponderada em T1 dos joelhos foram realizadas com padronização rigorosa do posicionamento com extensão total dos joelhos e pés paralelos. Dois radiologistas musculoesqueléticos realizaram as medidas de forma independente. A confiabilidade das distâncias TT-ST e TP-STC na TC (17,1 ± 4,2 mm e 17,3 ± 4,2 mm) e RM (16,2 ± 3,7 mm e 16,5 ± 4,1 mm), foi avaliada pelo coeficiente de correlação intraclasse (CCI [2,1)]) e gráficos Bland-Altman, bem como a confiabilidade entre avaliadores para ambos os métodos. Resultados Boa confiabilidade e concordância foram observadas entre as medidas de TC e RM para TT-ST e TP-STC com um CCI de 0,774 (p< 0,001) e 0,743 (p< 0,001), respectivamente, e nenhum viés sistemático foi observado. A confiabilidade entre avaliadores foi excelente para todas as medições em ambos os métodos de imagem. Conclusão Este foi o primeiro estudo que comparou a RM usando bobina de corpo com a TC na medição da distância TT-ST, com a implicação clínica potencial de que a TC neste cenário clínico poderia ser evitada.

Efectos del autoinjerto hueso-tendón patelar-hueso sobre la posición articular y la fuerza en pacientes con reconstrucción del ligamento cruzado anterior / Effects of bone-patellar tendon-bone autograft on joint position and strength in patients with anterior cruciate ligament reconstruction

RESUMEN: El objetivo del estudio fue comparar el déficit propioceptivo a través del Joint position sense (JPS) y Force steadiness en pacientes con reconstrucción del ligamento cruzado anterior (LCA) injerto hueso-tendón patelar-hueso (HTH) 6 a 12 meses postcirugía. Participaron 15 pacientes (13 hombres y 2 mujeres, 25,5 ± 1,3 años) con reconstrucción de LCA con autoinjerto HTH y 20 personas sin lesión del LCA (19 hombres y 1 mujer, 24,1 ± 0,8 años). Para evaluar la sensación de posición de la articulación de la rodilla se midió la Joint position sense (JPS) en tres rangos: 0°-30°, 31°-60° y 61°-90° y la sensación de fuerza del cuádriceps fue evaluada con la prueba Force steadiness (FS) al 15 % de la contracción voluntaria máxima (CVM), ambas pruebas realizadas 6 a 12 meses post cirugía. Los resultados mostraron que no hubo diferencias estadísticamente significativas en la sensación de la posición articular (JPS 0°-30°) (p=0.564) y 31°-60° (p=0.681), mientras que en el rango 61°-90° (p=0.003) existieron diferencias estadísticamente significativas. En las mediciones de sensación de fuerza del cuádriceps (FS al 15 % CVM) entre los pacientes operados de LCA técnica HTH y el grupo control no hubo diferencias estadísticas (p= 0.987) La sensación de la fuerza del cuádriceps medida con la prueba FS al 15 % CVM no presentaría déficit entre los 6 a 12 meses en pacientes post operados de LCA al ser comparados con sujetos sin lesión ni cirugía de este ligamento. Se concluye que la sensación de la posición articular medida con la prueba JPS en en tres rangos articulares de pacientes con reconstrucción de LCA injerto HTH 6 a 12 meses post cirugía sólo mostró alteraciones en el rango de 61°- 90° al ser comparado con el grupo control, lo cual indica que la sensación de la posición articular presenta un déficit en este rango específico.

SUMMARY: The aim of the study was to compare the proprioceptive deficit through the Joint position sense (JPS) and Force steadiness in patients with anterior cruciate ligament (ACL) bone-patellar tendon-bone graft (PTH) reconstruction 6 to 12 months post-surgery. Fifteen patients (13 men and 2 women, 25.5 ± 1.3 years) with ACL reconstruction with HTH autograft and 20 persons without ACL injury (19 men and 1 woman, 24.1 ± 0.8 years) participated. To assess knee joint position sensation, Joint position sense (JPS) was measured in three ranges: 0°-30°, 31°- 60° and 61°-90° and quadriceps strength sensation was assessed with the Force steadiness (FS) test at 15 % of maximal voluntary contraction (MVC), both tests performed 6 to 12 months post surgery. The results showed that there were no statistically significant differences in joint position sensation (JPS 0°-30°) (p=0.564) and 31°-60° (p=0.681), while in the range 61°-90° (p=0.003) there were statistically significant differences. In the quadriceps strength sensation measurements (FS at 15 % CVM) between the patients operated on ACL HTH technique and the control group there were no statistical differences (p= 0.987). The quadriceps strength sensation measured with the FS test at 15 % CVM would not present a deficit between 6 to 12 months in post- operated ACL patients when compared to subjects without injury or surgery of this ligament. It is concluded that the joint position sensation measured with the JPS test in three joint ranges of patients with ACL reconstruction HTH graft 6 to 12 months post surgery only showed alterations in the range of 61°- 90° when compared to the control group, indicating that the joint position sensation presents a deficit in this specific range.

Clinical results of medial patellofemoral ligament reconstruction / Resultados clínicos da reconstrução do ligamento patelofemoral medial

ABSTRACT Objective: To assess clinical results of patients who underwent medial patellofemoral ligament (MPFL) reconstruction after a minimum of two years of follow-up. Methods: Patients' medical records were assessed for residual instability, patient satisfaction, and post-operative functional outcomes. Results: Fifty-one patients were analyzed, out of which 56.87% were women. Patients' mean age was 30.8 years (16 to 57 years). The mean follow-up time was 68.7 months (37 to 120 months). Length between first dislocation and surgery was less than 1 year for 58.82% of patients, between 1 and 5 years for 37.25%, and over 5 years for 3.93%. Patients showed a high degree of satisfaction (96.08% would undergo surgery again), with recurrence rate of 11.76%. Twenty-two patients reported knee symptoms, including pain from movements (72.72%), weakness (18.18%), constant pain (13.63%), and crepitus (4.54%). Considering dissatisfied patients, patients with dislocation recurrence, and patients with symptoms, five cannot practice physical activity, out of which only three blame their knee. Conclusion: MPFL reconstruction showed a recurrence rate of 11.7%, with high patient satisfaction, good functional results, and high rate of return to sports, after a minimum of two years of follow-up. Level of Evidence IV, Case Series.

RESUMO Objetivo: Avaliar o resultado clínico de pacientes submetidos à reconstrução do ligamento patelofemoral medial (LPFM), acompanhados por mínimo de dois anos. Métodos: Avaliação de prontuários para informações sobre instabilidade residual, satisfação do paciente e resultado funcional pós-operatório. Resultados: Foram analisados 51 pacientes. 56,87% do sexo feminino e média etária 30,8 anos (16 a 57). Tempo médio de acompanhamento de 68,7 meses (37 a 120). Intervalo entre primeira luxação e cirurgia foi menos de 1 ano em 58,82%, entre 1 e 5 anos em 37,25% e mais de 5 anos para 3,93%. Os pacientes apresentaram alto grau de satisfação (96,08% fariam a cirurgia novamente), com 11,76% de recidiva. Houve persistência de sintomas em 22 pacientes, sendo dor ao movimento o principal (72,72%), seguido de fraqueza (18,18%), dor constante (13,63%) e crepitações (4,54%). Somando os pacientes insatisfeitos aos que tiveram recidiva da instabilidade e os sintomáticos, 5 não conseguem praticar atividade física, mas apenas 3 por causa do joelho. Conclusão: A reconstrução isolada do LPFM demonstrou índice de recidiva de 11,7%, com alto nível de satisfação dos pacientes, ótimos resultados funcionais e alta taxa de retorno ao esporte, em acompanhamento mínimo de 2 anos. Nível de Evidência IV, Série de Casos.

Risk factors related to patellar dislocation combined with osteochondral fracture / 中华创伤杂志

Objective:To investigate the related risk factors related to patellar dislocation combined with osteochondral fracture (OCF).Methods:A case control study was conducted to analyze the clinical data of 278 patients with patellar dislocation admitted to Second Hospital of Lanzhou University from January 2016 to June 2020, including 98 males and 180 females; aged 12-41 years [(21.1±4.6)years]. The patients were divided into OCF group ( n=112) and non-OCF group ( n=166) according to the surgical records and occurrence of OCF or not under intraoperative arthroscopy. The data of the two groups were recorded, including basic characteristics (ie, sex, age, sides of injury, whether or not the epiphysis is closed), patella height, patellar inclination angle, tibial tubercle-trochlear groove (TT-TG), femoral trochlear shape, tibial lateral rotation angle and femoral anteversion angle. Univariate analysis was adopted to evaluate the correlation of the data with patellar dislocation combined with OCF. Multivariate Logistic regression analysis was used to determine the independent risk factors of patellar dislocation combined with OCF. Results:Univariate analysis showed that patellar dislocation combined with OCF was related to male, patellar inclination angle and femoral anteversion angle ( P<0.05 or 0.01), while not to age, epiphysis is closed or not, sides of injury, patella height, TT-TG, femoral trochlear shape and tibial lateral rotation angle (all P>0.05). Multivariate Logistic regression analysis showed that male ( OR=1.75, 95% CI 1.07-2.90, P<0.05) and increased femoral anteversion angle ( OR=3.12, 95% CI 1.89-5.17, P<0.05) were significantly correlated with patellar dislocation combined with OCF. Conclusion:Male and increased femoral anteversion angle are independent risk factors for patellar dislocation combined with OCF.