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.
Humans ; Patellar Dislocation/surgery* ; Joint Dislocations ; Joint Instability/surgery* ; Lower Extremity ; Osteotomy

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*

Ankle Fractures ; Femoral Fractures ; Fracture Fixation, Internal ; Humans ; Patella/surgery* ; Patellar Dislocation/surgery*

Fracture Fixation, Internal ; Humans ; Patella/surgery* ; Patellar Dislocation/surgery*

Humans ; Joint Dislocations ; Patella ; Patellar Dislocation ; Reconstructive Surgical Procedures

BackgroundPatellar dislocation is one of the most common knee injuries in the adolescent population. It is often combined with osteochondral fracture. The purpose of this study was to compare the outcomes between fixation and excision of osteochondral fractures not involving the bearing surface in adolescent patients with patellar dislocations.

MethodsPatients who underwent surgery for osteochondral fracture following patellar dislocation in our institution from 2007 to 2014 were retrospectively evaluated. Visual analog scale (VAS) of pain and the International Knee Documentation Committee (IKDC) form were used to assess knee pain and function at follow-up. Patient satisfaction was evaluated. Differences in the values of variables among groups were assessed using t-test if equal variance or Mann-Whitney U-test if not equal variance. The Pearson's Chi-square test was applied for dichotomous variables if expected frequency was >5 or Fisher's exact test was applied if not. A value of P < 0.05 was considered statistically significant.

ResultsForty-three patients were included, with the average age of 14.1 ± 2.3 (range, 9.0-17.0) years. Nineteen underwent fixation of osteochondral fractures and 24 did not. The average follow-up time was 28 ± 10 months. There was no significant difference in age, gender, follow-up time, causes of injury, times of dislocation, and location of osteochondral fracture between fixation and excision groups. The fixation group had a significantly longer surgery time (82 ± 14 min) and larger size of osteochondral fracture (2.30 ± 0.70 cm) than the excision group (43 ± 10 min, 1.88 ± 0.62 cm, respectively, t = 10.77, P < 0.01 and t = 0.84, P < 0.05). At the last follow-up, the average IKDC score in the fixation group (82.52 ± 8.71) was significantly lower than that in the excision group (89.51 ± 7.19, t = 2.65, P < 0.01). There was no significant difference in VAS of pain and patients' satisfaction. There were 7 (16%) patients with recurrent dislocation.

ConclusionExcision of osteochondral fractures has equivalent or better outcomes compared to fixation in adolescent patients with patellar dislocations when these fractures do not involve the bearing surface.

Adolescent ; Child ; Female ; Femoral Fractures ; surgery ; Humans ; Knee Injuries ; surgery ; Male ; Patellar Dislocation ; surgery ; Retrospective Studies

OBJECTIVE: To evaluate the correlation between the injury patterns of the medial patellofemoral ligament (MPFL) on magnetic resonance imaging in an acute first-time lateral patellar dislocation (LPD) and incidence of a second-time LPD. MATERIALS AND METHODS: Magnetic resonance images were prospectively analyzed in 147 patients after an acute first-time LPD with identical nonoperative management. The injury patterns of MPFL in acute first-time LPDs were grouped by location and severity for the analysis of the incidence of second-time LPD in a 5-year follow-up. Independent t tests, chi-square tests and Kruskal-Wallis tests were performed as appropriate. RESULTS: Forty-six cases (46/147, 31.3%) of second-time LPD were present at the 5-year follow-up. Fourteen (14/62, 22.6%) and 31 cases (31/80, 38.8%) were present in the partial and complete MPFL tear subgroups, respectively. Twenty-five cases (25/65, 38.5%), 11 cases (11/26, 42.3%), and 8 cases (8/47, 17%) were present in the isolated femoral-side MPFL tear (FEM), combined MPFL tear (COM), and isolated patellar-side MPFL tear (PAT) subgroups, respectively. Compared with the partial MPFL tears, complete tears showed higher incidence of a second-time LPD (p = 0.04). The time interval between the two LPDs was shorter in the complete MPFL tear subgroup (24.2 months) than in the partial tear subgroup (36.9 months, p = 0.001). Compared with the PAT subgroup, the FEM and COM subgroups showed a higher incidence of a second-time LPD (p = 0.025). The time intervals between the two LPDs were shorter in the FEM and COM subgroups (20.8 months and 19.2 months) than in the PAT subgroup (32.5 months, p = 0.049). CONCLUSION: A complete MPFL tear, isolated femoral-side tear and combined tear in a first-time LPD predispose a second-time LPD.
Follow-Up Studies ; Humans ; Incidence* ; Knee ; Ligaments* ; Magnetic Resonance Imaging* ; Patellar Dislocation* ; Prospective Studies ; Recurrence ; Tears

A closing wedge distal femoral osteotomy is a procedure to reduce pain and delay the progression of degenerative arthritis of knee by moving the weight bearing line from the lateral compartment to the medial side while preserving the knee joint. Age, weight bearing line, and the degree of arthritis are the essential factors to be considered at the time of surgery. The indications for distal femoral osteotomy are as follows. All patients are aged less than 65 years old, normal medial compartment of the knee with normal patello femoral joint, valgus deformity with lateral degenerative arthritis, younger patients with lateral osteochondritis, congenital osteochondrosis, and recurrent patellar dislocation with genu valgum. The distal femoral osteotomy provides the advantages of rapid pain reduction and short rehabilitation in young and active patients and patients who are subjected to heavy loads on the knee.
Arthritis ; Congenital Abnormalities ; Femur* ; Genu Valgum ; Humans ; Joints ; Knee ; Knee Joint ; Osteoarthritis ; Osteochondritis ; Osteochondrosis ; Osteotomy* ; Patellar Dislocation ; Rehabilitation ; Weight-Bearing

BACKGROUND: The tibial tuberosity-trochlear groove (TT-TG) distance is used to determine the necessity of tibial tubercle osteotomy. We conducted this study to determine the extent to which each of the tibial tuberosity lateralization, trochlear groove medialization, and knee rotation angle affects the TT-TG distance in both normal and patella dislocated patients and thereby scrutinize the rationale for tuberosity transfer based on the TT-TG distance. METHODS: Retrospective analysis of rotational profile computed tomography was done for patella dislocated and control group patients. Femoral anteversion, tibial torsion, knee rotation angle, tuberosity lateralization, and trochlear groove medialization were assessed in all patients. Relationship of these parameters with the TT-TG distance was investigated to evaluate their effects on the TT-TG distance. RESULTS: We observed that the patellar dislocation group, compared to the control group, had increased TT-TG distance (mean, 19.05 mm vs. 9.02 mm) and greater tuberosity lateralization (mean, 64.1% vs. 60.7%) and tibial external rotation in relation to the femur (mean, 7.9° vs. −0.81°). CONCLUSIONS: Tuberosity lateralization and knee rotation were factors affecting patellar dislocation. These factors should be considered in addition to the TT-TG distance to determine the need for tibial tubercle osteotomy in patients with patellar dislocation.
Femur ; Humans ; Knee ; Osteotomy ; Patella ; Patellar Dislocation* ; Retrospective Studies

BACKGROUNDNumerous studies have investigated the influence of osseous factors on patellofemoral joint instability, but research on the influence of dynamic muscle factors in vivo is still in the exploratory stage. This study aimed to use magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) to evaluate vastus medialis oblique (VMO) fiber bundles in patients with recurrent patellar dislocation to explore the changes in muscle morphology and function.

METHODSThis prospective study involved 30 patients (7 males and 23 females; average age, 21.4 ± 3.8 years) clinically diagnosed with recurrent patellar dislocation in Peking University Third Hospital and 30 healthy volunteers matched for age, sex, and body mass index in our medical school between January 2014 and October 2014. None of the patients had a recent history of traumatic patellar dislocation or transient patellar dislocation. All patients underwent conventional MRI and DTI of the knee. The cross-sectional area of the VMO on MRI and the fractional anisotropy (FA), apparent diffusion coefficient (ADC), and primary (λ1), secondary (λ2), and three-level characteristic (λ3) values on DTI were measured. The independent-samples t-test was used to compare these parameters between the two groups.

RESULTSCompared with the control group, the patient group showed significantly higher FA values (0.39 ± 0.05 vs. 0.33 ± 0.03) and significantly lower ADC (1.51 ± 0.13 vs. 1.58 ± 0.07), λ2 (4.96 ± 0.13 vs. 5.04 ± 0.07), and λ3 values (4.44 ± 0.14 vs. 4.58 ± 0.07; t = 5.99, t = -2.58, t = -3.02, and t = -4.88, respectively; all P < 0.05). Cross-sectional VMO area and λ1 values did not differ between the two groups (t = -1.82 and t = 0.22, respectively; both P > 0.05).

CONCLUSIONSThe functional status of the VMO is closely associated with recurrent patellar dislocation. MRI, especially DTI (FA, ADC, λ2, and λ3), can detect early changes in VMO function and might facilitate the noninvasive monitoring of the functional status of the VMO in patients with recurrent patellar dislocation.

Adolescent ; Adult ; Child ; Diffusion Tensor Imaging ; methods ; Female ; Humans ; Knee Joint ; pathology ; Magnetic Resonance Imaging ; Male ; Patella ; pathology ; Patellar Dislocation ; diagnosis ; Prospective Studies ; Quadriceps Muscle ; pathology ; Sensitivity and Specificity ; Young Adult