Impact of Selective Posterior Cruciate Ligament Fiber Release on Femoral Rollback in Cruciate-Retaining Total Knee Arthroplasty: A Computational Study

BACKGROUND

Partial or total release of the posterior cruciate ligament (PCL) is often performed intraoperatively in cruciate-retaining total knee arthroplasty (CR-TKA) to alleviate excessive femoral rollback. However, the effect of the release of selected fibers of the PCL on femoral rollback in CR-TKA is not well understood. Therefore, we used a computational model to quantify the effect of selective PCL fiber releases on femoral rollback in CR-TKA.

METHODS

Computational models of nine cadaveric knees (age: 63 years, range 47 to 79) were virtually implanted with a CR-TKA. Passive flexion was simulated with the PCL retained and after serially releasing each individual fiber of the PCL, starting with the one located most anteriorly and laterally on the femoral notch and finishing with the one located most posteriorly on the medial femoral condyle. The experiment was repeated after releasing only the central PCL fiber. The femoral rollback of each condyle was defined as the anterior-posterior (AP) distance between tibiofemoral contact points at 0° and 90° of flexion.

RESULTS

Release of the central PCL fiber in combination with the anterolateral (AL) fibers, reduced femoral rollback a median of 1.5 [0.8, 2.1] mm (P = 0.01) medially and by 2.0 [1.2, 2.5] mm (P = 0.04) laterally. Releasing the central fiber alone reduced the rollback by 0.7 [0.4, 1.1] mm (P < 0.01) medially and by 1.0 [0.5, 1.1] mm (P < 0.01) laterally, accounting for 47 and 50% of the reduction when released in combination with the AL fibers.

CONCLUSION

Releasing the central fibers of the PCL had the largest impact on reducing femoral rollback, either alone or in combination with the release of the entire AL bundle. Thus, our findings provide clinical guidance regarding the regions of the PCL that surgeons should target to reduce femoral rollback in CR-TKA.

A Novel Predictor of the Length and Size of ACL Grafts in Chinese Han Adults for ACL Reconstruction: An MRI Study

OBJECTIVE

Currently, there is no simple and valid method to predict the length and size of the native anterior cruciate ligament (ACL) in each adult patient who will undergo ACL reconstruction. This study aimed to develop an imaging prediction method that can predict the length and size of ACL grafts using the intact posterior cruciate ligament (PCL), in order to enhance the graft preparation individualized sizing.

METHODS

Three hundred and nineteen patients aged 18 years or older who underwent magnetic resonance imaging (MRI) of the knee at an orthopaedic clinic between September 9, 2021, and February 5, 2023, were included. The length, sagittal diameter, and coronal diameter of the ACL and PCL were measured in all patients, and F-test were performed to explore linear relationship between ligament measurements.

RESULTS

Equations were established to predict a variable of the native ACL for the corresponding variable of the intact PCL (i.e., sagittal diameter of the ACL = 4.32 + 1.08 × sagittal diameter of the PCL, and coronal diameter of the ACL = 2.45 + 0.59 × coronal diameter of the PCL, length of the male ACL = 10.92 + 0.64 × length of the male PCL, length of the female ACL = 11.76 + 0.58 × length of the female PCL) (R2  = 0.532; R2  = 0.417; R2  = 0.488; R2  = 0.509; respectively).

CONCLUSIONS

The length and size of the intact PCL in cases without PCL buckling are predictors of the length and size of the native ACL in adults, respectively. The use of this information to optimize graft diameter may lower the rates of ACL graft failure in the future.

POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION: ARE THE RESULTS SIMILAR TO ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION?

Objective

To report and compare the results of posterior cruciate ligament (PCL) and anterior cruciate ligament (ACL) reconstructions.

Methods

In total, 42 patients were retrospectively evaluated, 20 with isolated PCL injuries (group 1) and 22 with isolated ACL ones (group 2) who were subjected to arthroscopic ligament reconstruction with autologous grafts and followed up for at least two years. To evaluate the results in group 1, objective IKDC and Lysholm scores, posterior drawer tests, and evaluations by a KT-1000 arthrometer were used, whereas for group 2, subjective IKDC and Lysholm score and the Lachman test were employed. To compare groups, objective IKDC and Lysholm scores and assessment via a KT-1000 arthrometer were considered.

Results

Intragroup analysis showed improved results for all variables (p < 0.001) in both groups. Comparisons between groups showed a significant difference in objective IKDC scores (p < 0.001), but no such disparities for Lysholm ones (p = 0.052), clinical tests (p = 0.058) or evaluation by KT-1000 (p = 0.129).

Conclusion

Treatment restored knee stability and function in both groups. Comparisons between groups showed that PCL reconstructions had inferior results than ACL ones according to patients' objective IKDC scores. Level of Evidence II, Retrospective Study.

THE OUTCOMES OF POSTERIOR CRUCIATE LIGAMENT TIBIAL AVULSION FIXATION WITH A SCREW USING A DUAL POSTEROMEDIAL PORTAL TECHNIQUE

Objectives

Our purpose was to evaluate the clinical results of PCL tibial avulsion fracture fixation performed with 4 mm cancellous screws using a dual posteromedial (PM) portal technique.

Methods

In a prospective study, we followed 12 patients submitted to PCL tibial insertion avulsion arthroscopic fixation using dual PM portals with cancellous screws from March 2014 to Jan 2020. The proximal higher PM portal served as an instrument portal and provided an optimal trajectory for arthroscopic screw fixation of larger PCL avulsion fractures. The lower PM portal was used as a viewing portal.

Results

Significant improvements were found between the preoperative and postoperative mean Lysholm scores at six months. The preoperative IKDC score mean of 10.13 increased to 89.3 at the end of six months. Minor adverse results with this technique were: grade I on posterior sag in five knees (41.6%), temporary stiffness in two cases (16.7 %), delayed union in one patient (8.3 %), and difficulty squatting at the end of six months in one patient (8.3%). Temporary extension lag was present in two individuals (16.7%), and fixed subtle flexion deficit of 3-5 degrees occurred in one individual (8.3 %).

Conclusion

The outcomes obtained with the proposed technique were similar to those obtained with open techniques, although mild flexion deficits and discreet posterior sag may be present in a significant number of cases. Level of Evidence II; Prospective Cohort Study .

Cutting-Edge Posterior Cruciate Ligament Reconstruction Principles

The posterior cruciate ligament (PCL) is the primary stabilizer to posterior tibial translation of the knee. PCL injuries classically occur as the result of a posteriorly directed force against the anterior part of the tibia. They frequently occur as multiligament injuries or with concomitant cartilage or meniscal injuries. The posterior drawer test is highly sensitive and specific for PCL injuries. Posterior stress radiography is critical for objective assessment of posterior tibial translation and grading of PCL injuries. Grade I and II injuries may be treated nonoperatively, but in general isolated grade III injuries and multiligament injuries require surgical intervention due to the inevitable development of osteoarthritis. Anatomical and biomechanical studies have led to the development of an anatomic double-bundle reconstruction, which has been reported in clinical outcome studies to result in better functional and objective outcomes than single-bundle reconstructions. This article focuses on the clinically and surgically relevant anatomy and biomechanics of the PCL, diagnosis and treatment of PCL injuries, and a description of the anatomic double-bundle PCL reconstruction technique.

QUANTIFICATION OF NEURAL ELEMENTS IN POSTERIOR CRUCIATE LIGAMENT: COMPARISON BETWEEN HEALTHY KNEES AND WITH PRIMARY OSTEOARTHROSIS

Objective:

To quantify the neural elements in the posterior cruciate ligament (PCL) in healthy knees and with primary osteoarthrosis (OA).

Methods:

In two groups with OA, one of cadavers and another of individuals, the area of neural elements identified in histological sections of PCL with anti-S100 immunohistochemistry was quantified.

Results:

The overall mean area of the neural elements was 0.96% ± 0.67%, with the value in the cadaver group of 1.02% ± 0.67% and in the OA group of 0.80% ± 0.64%, with a significant statistically difference (p = 0.001). No correlation was observed between neural element quantification and the age of the individuals (p > 0.05). There was no difference in the quantification of neural elements between the sexes in the cadaver group (p = 0.766), but in the OA group there was a statistically significant reduction in males (p = 0.003). Also, in the osteoarthrosis group there was no difference in the quantification of neural elements in the knees with varus or valgus alignment (p = 0.847).

Conclusion:

There was a decrease in neural element quantification in PCL of individuals affected by OA in relation to non-arthritic individuals, with this quantification not related to age or with the axis of the lower limb. However, this quantification is not related to age or the axis of the lower limb.Level of Evidence III, Case control study.

IS THE "U-SIGN" RADIOLOGIC FEATURE OF A POSTERIOR CRUCIATE LIGAMENT TIBIAL AVULSION FRACTURE?

Objective:

By analyzing our cases of posterior cruciate ligament (PCL) tibial avulsion fracture, we noted that a U-shaped image was present in the anteroposterior plain radiographs view of the affected knee, even in cases where the profile view of the knee had been inconclusive as to tibial PCL avulsion fracture, a “hidden” fracture. Therefore, we aimed to investigate whether there was an anatomical correlation between this radiological U sign and the tibial insertion of the PCL and to ascertain the intra- and inter-rater reliability of this sign in clinical practice.

Methods:

The data of the widths and heights area of the PCL tibial insertion area, and the U sign area were measured and compared to the largest width of the tibia. Two moreover, the reliability and reproducibility of this imaging were analyzed.

Results:

The areas height of the U-sign area and the anatomical insertion area of the posterior cruciate ligament showed no difference, and both were topographically located in the two central quarters of the proximal end of the tibia. The radiographic assessment showed excellent Kappa agreement rates between interobserver and intraobserver, with high reliability and reproducibility.

Conclusion:

The U sign is a radiographic feature of PCL tibial avulsion fracture seen on the radiograph AP view, there is a high association between the ratios of the U-sign area height in the X-ray and the anatomical height of the PCL tibial insertion site MRI with the largest width of the proximal tibia. The radiographic U sign showed excellent rates of interobserver and intraobserver agreement with Kappa values higher than 0.8. Level of Evidence IV; Dignostic Studies - Investigating a Diagnostic Test.

CLINICAL OUTCOMES AFTER TWO-STAGE BICRUCIATE KNEE LIGAMENT RECONSTRUCTION

Objective:

To correlate clinical and intraoperative findings with the postoperative evaluation of two-stage bicruciate knee ligament reconstruction.

Methods:

The study was conducted with 25 patients (20 men and 05 women) with mean age of 32.3 years, mean body mass index (BMI) of 26.2, and mean lesion duration of 18.3 months. The treatment consisted of an Inlay reconstruction of the posterior cruciate ligament (PCL) followed by the anterior cruciate ligament (ACL) reconstruction, at least 3 months after the first surgical procedure. Four patients required additional procedures: patellar tendon (02), medial collateral ligament (MCL) (02).

Results:

With an average follow-up of 24.8 months, 60% of the patients scored zero or + at the posterior drawer test, while 40% scored ++; 60% of patients were evaluated as good/excellent according to the Lysholm scale. Only one patient reached the pre-injury Tegner activity level. Injury duration had a negative influence on functional limitation, vitality, and mental health (SF-36).

Conclusion:

Although two-stage bicruciate knee ligament reconstruction improved knee stability and self-assessment, 96% of patients did not recover their pre-injury state. In the 36-item short form survey (SF-36), injury duration was inversely correlated with self-assessment of functional capacity, physical limitation, vitality, and mental health. Level of Evidence II, retrospective study.

Similar functional outcomes of arthroscopic reconstruction in patients with isolated Posterior Cruciate Ligament (PCL) and combined Anterior Cruciate Ligament (ACL) and PCL tears

BACKGROUND

Posterior Cruciate Ligament (PCL) injuries seldom occur in isolation and majority occurs in conjugation with other ligament injuries. Posterior Cruciate Ligament (PCL) reconstruction continues to be taken into consideration as a complicated surgical procedure, with heterogeneity in literature regarding clinical and functional outcomes in isolated PCL and combined ACL and PCL injuries.

METHODS

The retrospective evaluation of patients with isolated PCL reconstruction (group 1) and combined Anterior Cruciate Ligament (ACL) and PCL reconstruction (group 2) was performed. A total of 66 patients with either isolated PCL or combined ACL and PCL reconstruction surgeries that met the inclusion criteria, were included in the study. These patients were assessed for functional outcome scores including Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Lysholm score, International Knee Documentation Committee (IKDC) and Tegner activity score at a minimum follow-up of 5 years.

RESULTS

The mean follow-up of patients was 82.09 ± 12.43 months in group 1 and 79.36 ± 11.24 months in group 2, with a total of 29 patients in group 1 and 21 patients in group 2. Both the groups were found to be comparable in terms of age, gender, duration of injury and pre-injury Tegner activity level. Post-surgical functional outcome scores (WOMAC score, Lysholm score and Tegner score) were found to be comparable between 2 groups at a mean follow-up of 5 years. Further, 22 patients in group 1 and 16 patients in group 2 had normal or near normal objective IKDC outcome scores at a mean follow-up of 5 years.

CONCLUSIONS

No differences were observed in functional outcome scores (WOMAC score, Lysholm score, Tegner score and IKDC score) between isolated reconstructed PCL and combined ACL and PCL reconstructed patients.

Mucoid Degeneration of Posterior Cruciate Ligament with Secondary Impingement of Anterior Cruciate Ligament: A Rare Case Report

Introduction:

Mucoid degeneration of cruciate ligament is well known entity, but symptomatic lesions are rare. It is even rarer to find a symptomatic posterior cruciate ligament mucoid degeneration than anterior cruciate ligament.

Case Report:

A 65-years-old female presented to our hospital complaining of pain in right knee joint on terminal extension since 6 months. On clinical examination, there was a flexion deformity of 5 degree and a further flexion of 150 degree with mild pain exacerbated by extension. MRI of the right knee joint showed a diffusely thickened posterior cruciate ligament (PCL) with increased intra ligamentous signal intensity on T2-weighted images. The arthroscopic findings of grossly thickened PCL with a yellowish hue are characteristic and the PCL was filled with a yellowish substance. We excised the yellowish substance from the PCL as precisely as possible not to damage the remaining PCL fiber (Limited Debulking). We did notchplasty of lateral wall and roof to accommodate the Anterior Cruciate Ligament and avoid impingement.

Conclusion:

Posterior cruciate ligament may enlarge significantly and may push the Anterior Cruciate Ligament in the notch and may lead to the anterior cruciate ligament (ACL) impingement symptoms. Partial Debulking of Posterior Cruciate Ligament and notchplasty is effective treatment with immediate postoperative pain relief and good functional results.

Correlation between magnetic resonance imaging and arthroscopic findings in the knee joint

BACKGROUND

The knee joint is the largest and the most complex joint of the human body. It is not covered by any thick muscular covering anteriorly.

OBJECTIVES

The purpose of this study was to explore the diagnostic capabilities of clinical examination, magnetic resonance imaging (MRI), and arthroscopy in traumatic disorders of the knee joint, to seek correlation between clinical findings, MRI findings and arthroscopic.

PATIENTS AND METHODS

A total of 26 patients with a presentation suggestive of traumatic knee pathology were studied prospectively. A detailed history was taken and relevant clinical examination was done, which was followed by MRI of the knee. The patients were scheduled for arthroscopy under general/spinal anesthesia, whenever indicated.

RESULTS

Keeping arthroscopic examination as standard, the correlation between clinical and arthroscopy showed a sensitivity of 80%, specificity of 86%, accuracy of 63.16%, negative predictive value of 93.48%; whereas MRI vs. arthroscopy showed a sensitivity of 74.42%, specificity of 93.10%, accuracy of 84.21%, and negative predictive value of 88.04%.

CONCLUSIONS

The clinical examination is an important and accurate diagnostic modality for evaluation of traumatic derangement of the knee joint. It is noninvasive, easy, available, and valuable diagnostic modality. The MRI is an accurate diagnostic modality. It can be used whenever there is an uncertain indication for arthroscopy. However, costs have to be kept in mind, especially in patients with low socio-economic status.

Anatomical Study and Morphometric Analyses on the Femoral Insertions of the Posterior Cruciate Ligament

Purpose

To provide an anatomical and morphometric basis for the femoral insertions of the posterior cruciate ligament (PCL) in order to aid in the creation of anatomical femoral tunnels in ligament surgical reconstruction. Study design: laboratory controlled study.

Material and Methods

The macroscopic details of the femoral insertions of the PCL's anterolateral (AL) and posteromedial (PM) bundles were analyzed in 24 cadaver knees. The specimens were photographed with a digital camera and the images obtained were studied using the software ImageJ. The bundles' insertion areas were measured in square millimeters, and the length of the structures and the distances between significant points were measured in millimeters.

Results

The PCL's femoral insertion average total area was 87.29 ± 31.42 mm². The mean insertion's areas of the AL and PM bundles were, respectively, 47.13 ± 19.14 and 40.67 ± 16.19 mm². In 95.8% of the examined knees was verified the presence of the medial intercondylar ridge and in 83.3% of the knees was noted the medial bifurcated ridge. The average length of the medial intercondylar ridge was 20.54 ± 2.26 mm and the medial bifurcated ridge's average length was 7.62 ± 2.35 mm.

Conclusions

The AL had a femoral insertion area larger than the PM bundle; these bundles' insertion areas were lower than those previously described in the literature. There were important individual variations related to the area of the bundles in the samples, suggesting that there should be an individual recommendation for anatomical reconstructions of the PCL with single or double femoral tunnels.

REHABILITATION PROTOCOL AFTER ISOLATED POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

To create a rehabilitation protocol following reconstruction of the posterior cruciate ligament (PCL), through a literature review. The literature review was conducted in the Medline and Embase databases, to search for data on biomechanical concepts and analyses relating to the posterior cruciate ligament of the knee. The search strategy was set up using the following rules: problem or injury in association with anatomical location terms; or surgical intervention procedure in association with rehabilitation terms. We began the process in this manner and subsequently introduced restrictions on certain terms to improve the search specificity. To design the protocol, a table was created for better data assessment, based on the time that elapsed between surgery and the start of physiotherapy. A rehabilitation protocol was created to improve weight-bearing control in the initial weeks after surgery, with the aid of a knee brace. Our aim was to achieve gains in total range of motion of the knee, which should be attained by the third month, thereby avoiding contractures resulting from the tissue healing process. Strengthening exercises and sensory-motor training were guided accordingly, thus avoiding overload on the graft and respecting the healing phases. The protocol proposed through this review was based on the current evidence relating to this subject.

POSTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH AUTOGRAFT OF THE DOUBLE SEMITENDINOSUS MUSCLES AND MIDDLE THIRD OF THE QUADRICEPS TENDON WITH DOUBLE FEMORAL AND SINGLE TIBIAL TUNNELS: CLINICAL RESULTS IN TWO YEARS FOLLOW UP

Objective: To evaluate the surgical aspects that may offer good anatomic and functional results in posterior cruciate ligament (PCL) reconstruction using an autologous graft of the quadriceps tendon and double semitendinosus through a double femoral tunnel. Methods: Fourteen patients with isolated PCL lesions, instability and pain were operated on by arthroscopy and evaluated according to the International Knee Documentation Committee (IKDC) and Lysholm scales. Posterior knee laxity was examined with a KT1000 arthrometer. Results: The mean postoperative posterior side-to-side difference was between 0-2 mm in 57.1% of patients and between 3 and 5 mm in 35.7% of cases. The average Lysholm score was 93 points in the final follow-up. In the IKDC evaluation, 3 patients were graded A, 10 were graded B, and 1 patient was graded C. Conclusions: Double bundle arthroscopic PCL reconstruction based on the anatomical positioning of the tunnels, with double semitendinosus tendon and single quadriceps, provides a clinically evident reduction in symptoms and restores satisfactory stability, although no statistically significant difference was found due to the small sample.