The relationship between early-onset chondromalacia and the position of the patella

Harvest of All-Soft Tissue Quadriceps Tendon Autograft for Anterior Cruciate Ligament Reconstruction With or Without Closure of Resulting Defect Has No Effect on Patellar Height

Purpose

To evaluate the radiographic effect of quadriceps tendon harvest on patellar height and to determine whether closure of a quadriceps graft harvest defect resulted in a significant change in patellar height compared to nonclosure.

Methods

We conducted a retrospective review of prospectively enrolled patients. The institutional database was queried and all patients who underwent quadriceps autograft anterior cruciate ligament reconstruction between 2015 and March 2020 were included. Graft harvest length in millimeters and final graft diameter after preparation for implantation were obtained from the operative record and demographic data were obtained from the medical record. Radiographic analysis was performed of eligible patients using standard ratios of patellar height: Insall-Salvati (IS), Blackburn-Peele (BP), and Caton-Deschamps (CD). Measurements were performed using digital calipers on a digital imaging system by 2 postgraduate fellow surgeons. Preoperative and postoperative radiographs were performed at 0° according to a standard protocol. Postoperative radiographs were performed 6 weeks postoperatively in all cases. Preoperative patellar height ratios were compared with postoperative patellar height ratios for all patients using t-tests. Subanalysis was then performed to compare the effect of closure of with nonclosure on patellar height ratios using repeated-measures analysis of variance. Interrater reliability between the 2 reviewers was assessed using an intraclass correlation coefficient calculation.

Results

In total, 70 patients met final inclusion criteria. There were no statistically significant changes from pre- to postoperative values for either reviewer for IS (reviewer 1, P = .47; reviewer 2, P = .353), BP (reviewer 1, P = .98; reviewer 2, P = .907), or CD (reviewer 1, P = .107; reviewer, 2 P = .188). The closure and nonclosure groups were adequately powered and no statistically significant demographic differences between the closure and nonclosure groups was identified for sex (P = .066), age (P = .343), weight (P = .881), height (P = .42), laterality (P = 1), meniscal repair (P = .332), graft diameter (P = .068), or graft length (P = .183). According to the repeated measures analysis of variance, closure of the quadriceps defect had no significant impact on any of the knee ratios. However, reviewer identity had a significant influence on the CD ratio. Intraclass correlation coefficient analysis revealed excellent agreement between reviewers for the IS (0.982) and BP (0.954) ratios, but only moderate-to-good agreement for the CD (0.751) ratio.

Conclusions

Harvest of quadriceps tendon graft does not result in radiographic changes in patellar height. Furthermore, closure of the quadriceps defect does not appear to result in radiographic changes in patellar height.

Level of Evidence

III, retrospective comparative trial.

Knee Diameter and Cross-Section Area Measurements in MRI as New Promising Methods of Chondromalacia Diagnosis-Pilot Study

Background and Objectives: Chondromalacia often affects the knee joint. Risk factors for the development of cartilage degenerative changes include overweight, female sex and age. The use of radiological parameters to assess the knee joint is rarely reported in the literature. Materials and Methods: The study involved 324 patients, including 159 (49%) women and 165 (51%) men, with an age range between 8−87 years (mean: 45.1 ± 20.9). The studied group had a body mass index (BMI) in the range of 14.3−47.3 (mean: 27.7 ± 5.02). A 1.5 Tesla and 3.0 Tesla (T) MRI scanner was used to assess the cartilage of the knee joint using the Outerbridge scale. The radiological parameters analyzed were the Insall−Salvati index, knee surface area, knee AP (antero-posterior) maximal diameter and knee SD (sinistro-dexter) maximal diameter. Results: Parameters such as the knee surface area, knee AP maximal diameter and knee SD maximal diameter showed a significant correlation with Outerbridge Scale (p < 0.014). The age of the patients showed a significant correlation with each knee parameter (p < 0.004). Results of knee AP and SD maximal diameter measurements strongly depended on BMI level. Conclusions: A significant relationship was found between the knee surface area, knee AP maximal diameter and knee SD maximal diameter and the advancement of chondromalacic changes in the knee joint, age and BMI.

MODELING OF PATELLA HEIGHT WITH DISTAL FEMUR AND PROXIMAL TIBIA REFERENCE POINTS WITH ARTIFICIAL NEURAL NETWORK

The patellofemoral joint is one of the parts of the knee extension mechanism that plays a role in the stability of the knee by enlarging the force arm of the quadriceps muscle and changing the direction of the muscle strength. For the entire knee joint to perform its task painlessly and functionally, the positions and strength of the muscles, the strength of the ligaments, and their reaction to movement must be compatible. The Insall–Salvati (Ins-Sal) index is useful for showing changes in patellar height produced by repositioning the tibial plateau, in other words, showing changes in patellar tendon length. Patella height is an important value to be taken into account in knee prosthesis surgery, tibial osteotomy, and anterior cruciate ligament reconstruction. The morphometric relationship between the reference measurements of the distal femur and proximal tibia and the position of the patella will be useful in determining the natural anatomy. In this study, we aimed to determine the relationship between patella height and distal femur and proximal tibia reference areas by using the artificial neural network method as an alternative approach method. In order to assess the performance of the estimation of the Ins-Sal index, the four ANN model with six input combinations which included age, gender and the reference measurements for the right and left sides have been constructed and tested. The MSE and [Formula: see text] values are calculated for every four models for the training and test phase. The results show that the proposed approach for modeling of relation between reference measurements and the Ins-Sal index is a powerful approach.

Relation of the chondromalatia patellae to proximal tibial anatomical parameters, assessed with MRI

Background Magnetic resonance imaging (MRI) is a non-invasive highly sensitive tool for diagnosing chondromalacia patellae in the early stages. Many studies have evaluated patellar and trochlear morphology with different radiologic indices. We aimed to assess the discriminative power of tibial, patellar, and femoral indices in MRI for chondromalacia patellae. Patients and methods 100 cases of chondromalacia, as well as 100 age-matched controls among the patients who underwent knee MRI between February 2017 and March 2019, were included. The standard protocol of knee MRI was applied and the diagnosis of chondromalacia was made on MRI findings. Chondromalacia subjects were also classified as grade 1 to 4 according to the Modified Outerbridge's MRI grading system. We measured 25 MRI parameters in the knee and adjacent structures to determine the relation between chondromalacia patellae and anatomical MRI parameters. Results Tibial slope, trochlear depth, lateral trochlear inclination, and lateral patellar tilt angle had significant correlation with chondromalacia. Any increase in lateral trochlear inclination and lateral patellar tilt angle could increase the probability of the disease (Odds ratio [OR] 1.15, 1.13; 95% CI: 1.03-1.30; 1.02-1.26, respectively), while any increase in medial tibial slope and trochlear depth could decrease the probability of chondromalacia (OR 0.85, 0.06; 95% CI: 0.73-0.98, 0.02-0.17, respectively). We also designed a model for the severity of disease by using the patellar height index (relative odds ratio: 75.9). Conclusions The result of this study showed the novelty role of tibial anatomy in developing chondromalacia and its mechanism. We also concluded that patellar height might be an important factor in defining disease severity.