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Patellar tracking disorder is recognized as one of the major causes of the pathophysiological mechanism in patellofemoral pain syndrome. This paper reviewed the results of patellofemoral kinematic analyses and summarized the motion characteristics of six-degrees-of-freedom (6DOF) of patellofemoral joints under different functional activities. Patella has a relatively unified trend in lateral, anterior and posterior translation, tilt and flexion. However, different measurements limit an in-depth comparison between studies. In the future, widely applying magnetic resonance(MRI) or/and dual fluoroscopic imaging system (DFIS), standardizing the establishment of coordinate system or definition and use of morphological parameters, and increasing sample size will contribute to explicating the 6DOF motion characteristics of patellofemroal joints in vivo and improve the clinical evaluation on kinematic function of patellofemroal joints.
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Objective: To investigate the effect of three-dimensional (3D) printing guide plate on improving femoral rotational alignment and patellar tracking in total knee arthroplasty (TKA). Methods: Between January 2018 and October 2018, 60 patients (60 knees) with advanced knee osteoarthritis who received TKA and met the selection criteria were selected as the study subjects. Patients were randomly divided into two groups according to the random number table method, with 30 patients in each group. The TKA was done with the help of 3D printing guide plate in the guide group and following traditional procedure in the control group. There was no significant difference in gender, age, disease duration, side, and preoperative hip-knee-ankle angle (HKA), posterior condylar angle (PCA), patella transverse axis-femoral transepicondylar axis angle (PFA), Hospital for Special Surgery (HSS) score, and American Knee Society (AKS) score ( P>0.05). Results: All incisions healed by first intention and no complications related to the operation occurred. All patients were followed up 10-12 months, with an average of 11 months. HSS score and AKS score of the two groups at 6 months after operation were significantly higher than those before operation ( P0.05). Postoperative X-ray films showed that the prosthesis was in good position, and no prosthesis loosening or sinking occurred during follow-up. HKA, PCA, and PFA significantly improved in the two groups at 10 months after operation compared with those before operation ( P<0.05). There was no significant difference in HKA at 10 months between the two groups ( t=1.031, P=0.307). PCA and PFA in the guide group were smaller than those in the control group ( P<0.05). Conclusion: Application of 3D printing guide plate in TKA can not only correct the deformity of the knee joint and alleviate the pain symptoms, but also achieve the goal of the accurate femoral rotation alignment and good patellar tracking.
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Purpose To determine the incidence,degree and radiographic characteristics of knee Jsign in recurrent patella dislocation patients.Method It was a retrospective review of a consecutive series of 59 recurrent patella dislocation patients.The knee J-sign was classified into negative (-),positive one degree(mild,l+)and positive two degree(gross,2+)based on the severity of patellar lateral translation at the extreme extension of knees with quadriceps contracted actively.The computed tomography(CT)examination at 0° extension of the knee was performed to quantify the degree of patellar lateral translation and tilt,with three CT parameters measured and calculated in axial slices:patella bisect offset index (BOI),patella trochlear-groove (PTG) distance and patella lateral tilt (PLT) angle.Results In all the 59 patients,72.9％(43/59)showed positive J-sign,27.1％(16/59)of positive one degree(1+) and 45.8％(27/59)of positive two degree(2+).All the three CT parameters increased with the severity of Jsign(P＜0.05).Conclusion Among 59 recurrent patella dislocation patients,we have found 72.9％ of positive knee J-sign.The severity of J-sign has a positive correlation with the degree of patellar lateral translation and tilt.
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Objective To identify related anatomical parameters and the strongest risk predictor leading to patients with recurrent patellar instability.Methods 52 young patients with recurrent patellar instability that failed of conservative treatment were retrospec-tively evaluated by MRI.Measurements included parameters of patellar tracking,which was characterized by bisect offset index (BSO),trochlear congruence angle (CA)and patellar lateral tilt (PTA),and anatomical parameters of patellofemoral joint,which were characterized by the sulcus angle (SA),lateral trochlear inclination (LTI),trochlear facet asymmetry,trochlear depth,Insall-Salvati Ratio (ISR),Caton-Deschamps index (C-D)and tibial tuberosity-trochlear groove (TT-TG)distance.The collection data were analyzed including the Pearson's correlation and multiple stepwise regression analysis.Results The patellofemoral joint ma-lalignment was significantly correlated with LTI,TT-TG distance and ISR,but not or partly with the trochlear depth,SA,trochlear facet asymmetry and C-D.Linear regression models including LTI,TT-TG distance and ISR explained 0.58,0.47 and 0.43 of the va-riance in BSO,CA and PTA,respectively (P<0.001).And the standardized beta coefficient was largest for LTI,then were TT-TG distance and ISR.Conclusion At full extension of the knee,anatomical related factors measured on MRI explain some degree of re-current lateral patella shift and tilt,the strongest predictor among anatomical related factors that could lead to maltracking is LTI, and then are TT-TG distance and ISR.
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PURPOSE: The purpose of this study was to analyze the influence of rotational alignment of the femoral and patellar components on patellar tilt after total knee arthroplasty (TKA). MATERIALS AND METHODS: A total of 56 patients (76 knees) who underwent TKA using Advance Medial Pivot Knee system between May 2009 and April 2011 and were available for minimum 1-year follow-up were enrolled in this study. Whiteside's line and the transepicondylar line were used to determine the rotational alignment of the femoral component. Patella cut was aimed to be parallel to the anterior patellar cortex during surgery. Radiographic evaluation was performed using plain axial radiographs. The rotational alignment of the femoral component was measured as the angle between the anterior condylar axis and the surgical transepicondylar axis. The patellar resection angle was measured between the patellar resection axis and the anterior cortical line of the patella. Patellar tilt was evaluated to investigate the correlation with the rotation of the femoral component and patellar resection angle. RESULTS: The mean rotation of the femoral component was 0.42degrees+/-3.18degrees of internal rotation. The mean patellar resection angle was 1.82degrees+/-3.44degrees, indicating medial overresection. The mean patellar tilt was 6.12degrees+/-4.31degrees of lateral tilt. The rotational angle of the femoral component showed a negative correlation with patellar tilt in the linear regression analysis (p=0.749), but the patellar resection angle showed a positive correlation with patellar tilt (p<0.001). CONCLUSIONS: Accurate patellar resection is recommended for proper patellar tracking in TKA.
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Humans , Arthroplasty , Axis, Cervical Vertebra , Follow-Up Studies , Knee , Linear Models , PatellaABSTRACT
Objective To evaluate the effects of isokinetic quadriceps training with different ranges of motion for improving mal-patellar tracking after total knee replacement (TKR). Methods Isokinetic quadriceps training was administered to 52 TKR cases, involving 66 knee joints with poor patellar tracking. The subjects were randomly allocated into 3 groups for isokinetic training with ranges of 0-30°, 30-60° or 60-90°, with 22 knee joints in each group. The angular velocity was set at 30°/second. X-rays with loading and with 45° knee flexion were taken before and after the training. The lateral patello-femoral angle,the patella index and the patello-femoral index were recorded along with the maximum torque ( MT), the total work ( TW ), and the average work(AW) in the three different ranges of motion. Hospital for Special Surgery (HSS) scores were also recorded. Results After 3 months of training, the average lateral patello-femoral angle, patella index, and patello-femoral index in the 0-30° training group were all significantly better than before the training. However, there was no significant difference in these measures for the 30-60° and 60-90° groups. After training average MT, TW and AW increased significantly in all groups, but the improvements were significantly correlated with the differences in lateral patello-femoral angles, patella indices and patello-femoral indices only for the 0-30°group. When compared with the baseline values, a statistically significant difference in HSS score after training was observed only in the 0-30° training group. Conclusions Isokinetic quadriceps training with a 0-30° range of motion can best realign patellar tracking after TKR, and best improve knee function.
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PURPOSE: We evaluated the lateral release rate and the clinical results according to the intraoperative assessment of patellar tracking in total knee arthroplasty (TKA). MATERIALS AND METHODS: We analyzed 365 primary total knee arthroplasties in 278 patients. The knees showing good patellar tracking without tourniquet deflation were classified into group 1, those showing improved patellar tracking after tourniquet deflation were classified into group 2, those showing improved patellar tracking after the single stitch method were classified into group 3 and those showing persistent patellar maltracking, that resulted in lateral retinacular release, were classified into group 4. The postoperative patellar tilting angle was measured and the clinical results were evaluated for all the groups. RESULTS: We classified 176, 127, 57 and 5 knees into groups 1, 2, 3 and 4 respectively. Only 5 knees (1.4%) showed poor patellar tracking with the single stitch method after tourniquet deflation and this resulted in lateral retinacular release. The postoperative mean patellar tilting angle was 4.1degrees, 3.4degrees, 5.1degrees and 4.3degrees in each group, respectively, and no statistical differences were shown between the groups (p>0.05). Nine knees complained of anterior knee pain and there was no difference between groups. CONCLUSION: Lateral retinacular release in TKA may not be necessary if the patellar tracking is improved with the single stitch method after tourniquet deflation.
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Humans , Arthroplasty , Knee , Tourniquets , Track and FieldABSTRACT
PURPOSE: The pattern of patellar tracking is changed depending upon whether a tourniquet is operating or not. This study was performed to suggest the criteria of lateral retinacular release(LRR) in total knee arthroplasty(TKA) based on the lateral patellar tilt angle(LPTA). MATERIALS AND METHODS: In study 1, the LPTA was compared in 24 bilateral TKAs, one side was required LRR and performed LRR, but not required and not done LRR on the other side according to the patellar tracking status in deflating tourniquet. In the second prospective study, we performed LRR one side and not the other side intentionally in all 11 patients' knees(22 knees) those who were same situations that the patellar tracking was not good under the condition of operating tourniquet but tracking was improved after deflation of tourniquet. We compared LPTA in both studies with paired t-test of SPSS 11.0. RESULTS: The LPTA was average 4.86 degrees on the side of performed LRR and 4.83 degrees on the other side in 24 patients. There was no significant difference of LPTA between them(p=0.952) in study 1. And the LPTA was average 5.18 degrees on the side of underwent LRR based on the condition of operating tourniquet, 5.45 degree on other not LRR side knee. There were also no significant difference between them(p=0.829) in study 2. CONCLUSION: The incidence of LRR will be reduced with no detrimental effect on lateral patellar tilt angle when making decision of LRR based on the patellar tracking status in deflating tourniquet.
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Humans , Arthroplasty , Incidence , Intention , Knee , Prospective Studies , TourniquetsABSTRACT
PURPOSE: To evaluate the difference between the midvastus and median parapatellar approach in total knee arthroplasty (TKA) in terms of clinical and radiologic results. MATERIALS AND METHODS: From January to December 2003, 49 patients having bilateral TKA were randomized prospectivity-one knee having a vastus splitting approach and the other knee having a median parapatellar approach- to compare operation time, postoperative ROM and drain amount, knee society knee score and function score, return to SLR, patellar tilting and displacement. The data was collected during 2 years of follow-up period, and analyzed using paired t-test. RESULTS: The patients with the midvastus splitting approach performed active straight-leg raise sooner (mean, 1.8 day) than the patients operated on using median parapatellar approach (mean, 2.2 days). But, there was no statistically difference. Knee flexion was better at post-operative 4 weeks in midvastus splitting approach group (mean, 125.5 degrees) than the median parapatellar approach group (mean, 123.9 degree)(p=0.028). However, patellar displacement was more severe in midvastus splitting approach group (mean, 3.4 mm) than the median parapatellar group (mean, 1.6 mm) (p=0.035). There was 1 postoperative hematoma and avulsion fracture of patellar tendon in midvastus splitting approach group. CONCLUSION: Even though midvastus splitting approach could provides the advantage of early postoperative rehabilitation, The midvastus splitting surgical approach dose not consider as being superioir to median parapatellar approach due to severe injury of midvastus and limitation of surgical indication.
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Humans , Arthroplasty , Follow-Up Studies , Hematoma , Knee , Patellar Ligament , RehabilitationABSTRACT
PURPOSE: To evaluate the effect of the tourniquet on intraoperative patellar tracking and to determine how this may influence the decision to perform lateral release during primary total knee arthroplasty (TKA). MATERIALS AND METHODS: From Jan. 1998 to Feb. 1999, 126 TKAs in which patellar tracking was assesed with tourniquet inflated were chosen as a control group. From May 1999 to June 2000, a total of 221 consecutive TKAs in which patellar tracking was assessed before and after tourniquet release were selected as a study group and were placed into 1 of 3 groups: Group I (49 out of 221) were knees that tracked properly both before and after tourniquet release. Group II (150 out of 221) were knees that maltracked with the tourniquet inflated and subsequently corrected with the tourniquet deflated. Group III (22 out of 221) were knees that maltracked both before and after tourniquet release, therefore required a lateral release. The lateral release rate, patella tilt and displacement were compared among groups. RESULTS: In control group, the lateral release rate was 65.9%(83/126). The patella tilit and displacemen were 2.65+/-0.78 degree and 3.51+/-1.68 mm respectively. In study group, the lateral release rate was 10.0%(22/221). The patella tilit and displacement were 0.76+/-0.85degree and 2.96+/-1.96 mm in study group. CONCLUSION: Tourniquet application alters intraoperative patellar tracking during TKA. When contemplating lateral retinacular release, tourniquet release and reevaluation of patellar tracking should be considered.