A new and simple method for patellar height measurement: Fibula-condyle-patella angle.

OBJECTIVES: This study aims to evaluate the inter-observer reliability of fibula-condyle-patella angle measurements and to compare it with other measurement techniques. PATIENTS AND METHODS: Between January 01, 2023 and January 31, 2023, a total of 108 patients (20 males, 88 females; mean age: 47.5±12.0 years; range, 18 to 72 years) who underwent X-rays using the fibula-condyle-patella angle, Insall-Salvati, Caton-Deschamps, Blackburne-Pell, and plateau-patella angle (PPA) methods were retrospectively analyzed. Knee lateral radiographs taken in at least 30 degrees of flexion and appropriate rotation were scanned. All measurements were made by two orthopedic surgeons who were blinded to measurement methods. RESULTS: Right knee patellar height measurements were conducted in 56 patients, while left knee patellar heights were assessed in 52 patients. The highest inter-observer concordance was found in the fibula-condyle-patella angle. The second highest concordance was found in the Insall-Salvati. The highest concordance correlation was found with PPA in the measurements of both researchers. CONCLUSION: The fibula-condyle-patella angle is a reliable technique with a good inter-observer reliability for measuring patellar height. We believe that this study will inspire future research to establish comprehensive reference values for clinical applications.

Evaluation of the relationship between the anatomical characteristics of the vastus medialis obliquus muscle and the patella chondral lesion occurrence.

OBJECTIVES: The study aims to investigate the relationship between the vastus medialis obliquus (VMO) muscle distal insertion features and patellar chondral lesion presence. PATIENTS AND METHODS: This cross-sectional study included a total of 100 patients (18 males, 82 females, mean age 67.2±7.1 years; range, 50 to 86 years) who underwent total knee arthroplasty (TKA). Radiological assessments, including merchant view and standing orthoroentgenograms, were conducted. The current osteoarthritis stage, varus angle, quadriceps angle (Q angle), patella-patellar tendon angle (P-PT angle), congruence angle, and sulcus angle were calculated. The VMO tendon length, muscle fiber angle, tendon insertion width measurements, and patellar chondral lesion localization data were obtained intraoperatively. Grouping was done according to the distal insertion width of the VMO tendon to the medial edge of the patella. The medial rim of the patella was divided into three equal-sized sectors. The first group (Group 1, n=31) consisted of patients who had an insertion from the quadriceps tendon into the upper one-third of the patella. The second group (Group 1, n=48) consisted of patients with a distal insertion expanding into the middle one-third of the patella. The third group (Group 3, n=21) consisted of patients who had a distal insertion extending into the distal third region of the medial patella margin. The patella joint surface was divided into sectors, and the presence and location of cartilage lesions were noted in detail. RESULTS: The mean tendon insertion width rate was 45.99±16.886% (range, 16.7 to 83.3%). The mean muscle fiber insertion angle was 51.85±11.67º (range, 20º to 80º). The mean tendon length was 12.45±3.289 (range, 4 to 20) mm. There was no significant difference between the mean age, weight, height, body mass index, BMI, fiber angle, tendon length, varus angle, Q angle, sulcus angle, and congruence angle data among the groups. In terms of the P-PT angle, Groups 1 and 2 had a significant relationship (p=0.008). No relationship was found between the mean fiber insertion angle, mean tendon length, or the presence of chondral lesions. There was a statistically significant difference among the groups regarding the presence of chondral lesions. The highest percentage of chondral lesion frequency was observed in Group 3 (95.24%), followed by Group 1 (90.3%) and Group 2 (89.6%), respectively. Compared to the other two groups, Group 3 had a higher average ratio of lesion areas per patient. CONCLUSION: Our study results demonstrate that the formation and localization of the patellar chondral lesions are affected by the insertion width type of the VMO muscle into the patella. Group 2-type insertion is associated with a lower lesion frequency rate than Groups 1 and 3.

Gerdy's tubercle as a novel anatomical landmark for the proximal tibial cut in total knee arthroplasty.

OBJECTIVES: This study aimed to explore the use of Gerdy's tubercle (GT) as an innovative and dependable anatomical landmark for the proximal tibial cut in total knee arthroplasty (TKA) in cases with extensive knee degeneration. MATERIALS AND METHODS: One hundred dry tibia bones and 10 formalin-fixed cadaveric knee specimens of both sexes were examined. A Zimmer NexGen tibial cutting guide and a Mitutoyo digital caliper were utilized to align the guide with the tibia's mechanical axis. The procedure was replicated on cadaver knees using a standardized medial parapatellar arthrotomy approach. Measurements included the distance from GT superior border to the resection line and the length of the tibia. A radiological study involving magnetic resonance imaging examinations of 48 patients, which were evaluated focusing on the upper border of GT and the least degenerated segment of the posterolateral part of the lateral tibial condyle, was conducted. RESULTS: Anatomical measurements of GT and proximal tibial areas in 110 specimens showed slight but consistent variations with cadaver measurements. Magnetic resonance imaging analysis of 48 patients revealed notable sex differences in the distance between the superior border of GT and the tibia's posterolateral surface. There was also a significant negative correlation between the distance from GT to the posterolateral corner and cartilage thickness. CONCLUSION: Proper alignment in TKA is crucial for success, but identifying an extra-articular landmark for horizontal tibial resection remains challenging, particularly in severely arthritic knees. This study introduces GT as a novel anatomical landmark for TKA, offering a more reliable reference for achieving desired joint levels in knees with significant degenerative changes.

A comparative analysis of 3D bioprinted gelatin-hyaluronic acid-alginate scaffold and microfracture for the management of osteochondral defects in the rabbit knee joint.

OBJECTIVES: This study aims to compare the radiological, biomechanical, and histopathological results of microfracture treatment and osteochondral damage repair treatment with a new scaffold product produced by the three-dimensional (3D) bioprinting method containing gelatin-hyaluronic acid-alginate in rabbits with osteochondral damage. MATERIALS AND METHODS: A new 3D bioprinted scaffold consisting of gelatin, hyaluronic acid, and alginate designed by us was implanted into the osteochondral defect created in the femoral trochlea of 10 rabbits. By randomization, it was determined which side of 10 rabbits would be repaired with a 3D bioprinted scaffold, and microfracture treatment was applied to the other knees of the rabbits. After six months of follow-up, the rabbits were sacrificed. The results of both treatment groups were compared radiologically, biomechanically, and histopathologically. RESULTS: None of the rabbits experienced any complications. The magnetic resonance imaging evaluation showed that all osteochondral defect areas were integrated with healthy cartilage in both groups. There was no significant difference between the groups in the biomechanical load test (p=0.579). No statistically significant difference was detected in the histological examination using the modified Wakitani scores (p=0.731). CONCLUSION: Our study results showed that 3D bioprinted scaffolds exhibited comparable radiological, biomechanical, and histological properties to the conventional microfracture technique for osteochondral defect treatment.

Simultaneous medial closing wedge distal femoral varus osteotomy and double-bundle anterior cruciate ligament reconstruction in the symptomatic femoral valgus deformity: A case report.

Distal femoral varus osteotomy (DFVO) is a widely recognized surgical procedure used to address valgus malalignment in patients with knee joint disorders. However, it still remains unclear whether anterior cruciate ligament (ACL) reconstruction can be performed in a single procedure along with DFVO. Herein, we present a 73-year-old female patient who developed lateral osteoarthritis of the knee with valgus alignment due to chronic ACL deficiency following a twisting injury during skiing. She was physiologically very active, and strongly demanded to return to sports. We performed a combined procedure involving a medial closing wedge DFVO using an anatomical locking plate, along with double-bundle ACL reconstruction. The postoperative radiograph confirmed successful correction of knee alignment, specifically achieving varus alignment with precise conformance of the anatomical plate to the medial contour of the distal femur following the osteotomy. The patient resumed her previous sports activities without experiencing knee pain. The operated knee demonstrated restored anterior stability, as indicated by negative Lachman test results, and regained full range of motion. Both the Knee Injury and Osteoarthritis Outcome Score and the 2011 Knee Society score demonstrated continuous postoperative improvements over the three-year follow-up period, indicating positive functional outcomes and joint preservation. To the best of our knowledge, this is the first case of medial closing wedge DFVO with anatomic double-bundle ACL reconstruction in the symptomatic femoral valgus deformity with chronic ACL deficiency in the literature.

Impact of postoperative femorotibial axis on functional outcomes in unicompartmental knee arthroplasty.

OBJECTIVES: This study aimed to compare the functional outcomes of patients undergoing fixed-bearing medial unicompartmental knee arthroplasty (UKA) classified as either varus or neutral based on their postoperative femorotibial angle (FTA), with the goal of evaluating the impact of FTA on functional results. PATIENTS AND METHODS: A total of 38 knees of 35 patients (27 females, 8 males; mean age: 63.6±7.1 years; range, 52 to 75 years) were included in this retrospective study. The data was collected between December 15, 2020, and January 15, 2021. Patients were categorized into two groups based on their postoperative FTA. The neutral group consisted of patients with an FTA range of 5.1° to 7.4°, while the varus group included patients with an FTA range of 0.1° to 4.8°. Knee Outcome Osteoarthritis Score (KOOS), Visual Analog Scale (VAS) scores, sit to stand test results, and six minute walk test data were analyzed. RESULTS: The mean follow-up was 42.0±19.3 months. The postoperative VAS score for the varus group was 0.95±0.99, whereas the neutral group had a VAS score of 2.19±1.83 (p=0.021). The mean KOOS for the varus group was 88.01±7.88, whereas the neutral group had a mean KOOS score of 78.46±13.69 (p=0.006). CONCLUSION: In patients undergoing UKA, mild varus alignment could yield superior early and midterm functional outcomes compared to a neutral femorotibial angle.

Unicompartmental knee arthroplasty combined with posterior cruciate ligament reconstruction: a case report.

BACKGROUND: In this study, we present the unique case of a patient with knee osteoarthritis (OA) of the medial compartment and posterior cruciate ligament (PCL) deficiency who underwent simultaneous medial unicompartmental knee arthroplasty (UKA) and PCL reconstruction. CASE PRESENTATION: A 49-year-old male patient presented with a 1-year history of pain and instability in the left knee. The patient had previously experienced a trauma-related injury to the PCL of the left knee that was left untreated. Imaging and physical examination confirmed the presence of left medial knee OA along with PCL rupture. To address these issues, the patient underwent UKA combined with PCL reconstruction. The patient's Lysholm score was 47 before surgery and 81 three months after surgery, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was 29 before surgery and 18 three months after surgery, and the International Knee Documentation Committee (IKDC) subjective score was 56.3 before surgery and 74.7 three months after surgery. Six months after surgery, the patient's gait returned to normal, and he was able to jog. CONCLUSION: This case report presents the first instance of UKA combined with PCL reconstruction and introduces a novel treatment approach for patients suffering from medial knee OA and ligament injury.

Survivorship and Outcomes of Robotic Arm-Assisted Medial Unicompartmental Knee Arthroplasty at a Minimum of 5-Year Follow-Up.

PURPOSE: This study aimed to evaluate implant survivor-ship, complications, and re-operation rates following robotic arm-assisted unicompartmental knee arthroplasty (UKA) at mid-term follow-up. METHODS: Patient satisfaction, clinical outcome, and knee alignment restoration were evaluated. All patients undergo-ing robotic arm-assisted medial UKA during a 2-year period were prospectively enrolled. Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, varus-valgus deformity, and knee range of motion were studied pre- and postoperatively. Revisions and surgery-related complications were recorded. RESULTS: Eighty-five patients were included in the study (mean age: 71.2 years). The mean follow-up was 74.7 months. One conversion to total knee arthroplasty was performed due to periprosthetic fracture 4.5 years after initial surgery result-ing in a survivorship rate of 98.8%. Overall satisfaction was excellent; 97.7% of patients were satisfied or very satisfied, while none was dissatisfied or very dissatisfied. WOMAC score in total, as well as in each component, exhibited sig-nificant improvement postoperatively. Additionally, knee alignment in the coronal plane as well as flexion contracture were significantly improved following the procedure. CONCLUSIONS: The outcomes of the present cohort revealed that precise prosthesis implantation through the robotic arm-assisted system in UKA provided excellent overall satisfac-tion rates and clinical outcomes at mid-term follow-up.

Matrix-Induced Autologous Chondrocyte Implantation Versus Autologous Chondrocyte Implantation of the Knee A Retrospective Comparison.

OBJECTIVE: The purpose of this study was to compare the short-term clinical outcomes of matrix-induced autologous chondrocyte implantation (MACI) to those seen following traditional autologous chondrocyte implantation (ACI) in the management of symptomatic cartilage lesions of the knee. METHODS: This was a retrospective cohort study of patients who underwent either ACI or MACI from January 2011 to March 2018. Patients with a minimum postoperative follow-up of 18 months were contacted. Demographic information, intraoperative findings, and patient-reported functional outcomes scores were collected. Comparisons were made between the two cell-based cartilage repair techniques. RESULTS: Fifty-six patients were included in the study (39 ACI, 17 MACI). Visual analog scale (VAS) for pain scores improved significantly in both groups, with MACI patients demonstrating significantly lower postoperative pain scores compared to those treated with ACI. In the ACI group, there was a decrease in the Tegner Activity score compared to the preoperative baseline, while no significant difference was seen between pre- and postoperative activity levels in the MACI group. Patients were generally satisfied with the outcome of their procedures, and there was no significant difference in satisfaction between groups. No patients re-quired additional surgery during the follow-up period. CONCLUSION: Both ACI and MACI demonstrated good short-term postoperative clinical results with improved pain and activity levels compared to the preoperative baseline. Patients treated with the MACI technique demonstrated greater reductions in pain scores compared to ACI, and while ACI resulted in a decrease in levels of postoperative activity, activity levels for MACI remained stable.

The Vega advanced third generation posterior stabilized total knee arthroplasty system enables the restoration of range of motion for high demanding daily activities - A 5-years follow-up study.

BACKGROUND: The Vega System® PS (Aesculap AG, Tuttlingen, Germany) is an advanced, third generation fixed implant that aims to mimic natural knee kinematics by optimizing pivotal motion while reducing surface stress. This study evaluated mid-term survival and clinical outcomes, including range of motion (ROM) of the modern posterior stabilized implant in order to analyse whether this biomechanically successful implant reaches good results in situ. METHODS: The first 100 patients to receive the Vega PS System for total knee arthroplasty were invited to take part in this single centre, single surgeon study. Of these, 84 patients were clinically assessed 5-6 years postoperatively. Data which was obtained during this follow-up examination included revision data, range of motion and clinical scores. RESULTS: The 5-year survival rate for exchange of any component was 97.6%, whereby two patients required replacement of the polyethylene gliding surface. Secondary patella resurfacing was performed in 7 patients. Significantly improved results in comparison to the preoperative state could be obtained at the follow-up: KOOS improved from 39.4 to 78.8, SF-12 PCS improved from 32.1 to 42 SF-12 MCS improved from 46 to 53.8 and patella pain improved from 2.7 to 0.3. The mean ROM of the 84 patients after 5 years was 133.1° and mean total KSS was 189.9. DISCUSSION & CONCLUSIONS: This study demonstrates a high survival rate of the Vega PS System® and significant improvements in clinical outcomes 5 years after implantation. The obtained mean ROM indicates that this implant provides good flexibility of the knee joint, allowing a high number of activities. However, due to the rate of secondary patella implantation, routine resurfacing of the patella for all PS TKA cases is highly recommended. CLINICAL TRIALS REGISTRATION: The study was registered at clinicaltrials.gov (NCT02802085).

Effect of soft tissue tension around the knee joint on medio-lateral patellar position.

Patellofemoral pain (PFP) is one of the most common sports injuries of the knee joint and has a high persistence and recurrence rate. Medio-lateral patellar position in the knee extension position during contraction is associated with PFP. However, soft tissue tension that most influences the medio-lateral patellar position in the knee extension position during contraction in vivo is unclear. We aimed to clarify the relationship between medio-lateral patellar position and soft tissue tension around the knee joint. Twelve patients with PFP and 20 healthy participants were included. Medio-lateral patellar position and tension of the rectus femoris, vastus lateralis (VL), vastus medialis, iliotibial band (ITB), lateral patellofemoral ligament, and medial patellofemoral ligament were measured during contraction and rest. The tensions of the VL and ITB during contraction and the medio-lateral patellar position at rest were significantly associated with medio-lateral patellar position during contraction (ß = 0.449, 0.354, and 0.393, respectively). In addition, the tension of ITB was significantly associated with the medio-lateral patellar position at rest (ß = 0.646). These relationships were not affected by the presence of PFP. These findings suggest that the patellar position during contraction became more lateral as the tension in the VL and ITB increased, regardless of the presence of PFP. These results may facilitate the prevention and treatment of PFP.

Combining enhanced spectral resolution of EMG and a deep learning approach for knee pathology diagnosis.

Knee osteoarthritis (OA) is a prevalent, debilitating joint condition primarily affecting the elderly. This investigation aims to develop an electromyography (EMG)-based method for diagnosing knee pathologies. EMG signals of the muscles surrounding the knee joint were examined and recorded. The principal components of the proposed method were preprocessing, high-order spectral analysis (HOSA), and diagnosis/recognition through deep learning. EMG signals from individuals with normal and OA knees while walking were extracted from a publicly available database. This examination focused on the quadriceps femoris, the medial gastrocnemius, the rectus femoris, the semitendinosus, and the vastus medialis. Filtration and rectification were utilized beforehand to eradicate noise and smooth EMG signals. Signals' higher-order spectra were analyzed with HOSA to obtain information about nonlinear interactions and phase coupling. Initially, the bicoherence representation of EMG signals was devised. The resulting images were fed into a deep-learning system for identification and analysis. A deep learning algorithm using adapted ResNet101 CNN model examined the images to determine whether the EMG signals were conventional or indicative of knee osteoarthritis. The validated test results demonstrated high accuracy and robust metrics, indicating that the proposed method is effective. The medial gastrocnemius (MG) muscle was able to distinguish Knee osteoarthritis (KOA) patients from normal with 96.3±1.7% accuracy and 0.994±0.008 AUC. MG has the highest prediction accuracy of KOA and can be used as the muscle of interest in future analysis. Despite the proposed method's superiority, some limitations still require special consideration and will be addressed in future research.

Association of Preoperative Subchondral Bone Marrow Oedema with Outcomes after Lateral Unicompartmental Knee Arthroplasty.

OBJECTIVE: To determine whether the presence of preoperative subchondral bone marrow oedema (SBME) is associated with inferior outcomes after lateral unicompartmental knee arthroplasty (LUKA). STUDY DESIGN: Descriptive study. Place and Duration of the Study: Department of Orthopaedic Surgery, Chongqing Orthopaedic Hospital of Traditional Chinese Medicine, Chongqing, China, from January 2019 to June 2022. METHODOLOGY: Data on patients treated with LUKA were obtained from the Medical Registry Database. Two groups were made based on the presence and absence of SBME on preoperative magnetic resonance imaging (MRI). The visual analogue scale (VAS), American Knee Society Scores (AKSS), and rate of patient satisfaction were compared between the two groups. RESULTS: A total of 20 patients treated with LUKA were reviewed. The SBME was present in 9 cases and absent in 11 cases. Patients with SBME had inferior scores at preoperative evaluation and at 1, 3, and 6 months postoperatively. However, there was no significant difference between the groups at the 12-month follow-up. Eight (88.9%) patients with SBME were satisfied with the LUKA surgery versus 9 (81.8%) patients without SBME, showing no significant differences between groups. CONCLUSION: Presence of preoperative SBME is associated with inferior functional outcomes after LUKA within six months of follow-up. KEY WORDS: Bone marrow, Oedema, Knee, Arthroplasty, Outcome, Patient satisfaction.

Anesthesia for the Patient Undergoing Knee Procedures.

Anesthesia for patients undergoing knee procedures encompasses a large patient population with significant variation in patient age, comorbidities, and type of surgery. In addition, these procedures are performed in vastly different surgical environments, including large academic hospitals, private hospitals, and out-patient surgical centers. These variabilities require a thoughtful and individualized anesthetic approach tailored toward the medical and surgical needs of each patient. This article discusses anesthetic approaches to patients with acute, subacute, and chronic knee-related pathology requiring surgery. We will also review pertinent knee anatomy and innervation and discuss regional nerve blocks and their applications to knee-related surgical procedures.

Knee and ankle range of motion and spasticity from childhood into adulthood: a longitudinal cohort study of 3,223 individuals with cerebral palsy.

BACKGROUND AND PURPOSE: Reduced range of motion (ROM) and spasticity are common secondary findings in cerebral palsy (CP) affecting gait, positioning, and everyday functioning. These impairments can change over time and lead to various needs for intervention. The aim of this study was to analyze the development path of the changes in hamstring length, knee extension, ankle dorsiflexion, and spasticity in hamstrings and gastrosoleus from childhood into adulthood in individuals with CP at the Gross Motor Function Classification System (GMFCS) levels I-V. METHODS: A longitudinal cohort study was undertaken of 61,800 measurements in 3,223 individuals with CP, born 1990-2017 and followed for an average of 8.7 years (range 0-26). The age at examination varied between 0 and 30 years. The GMFCS levels I-V, goniometric measurements, and the modified Ashworth scale (MAS) were used for repeated assessments of motor function, ROM, and spasticity. RESULTS: Throughout the follow-up period, knee extension and hamstring length exhibited a consistent decline across all individuals, with more pronounced decreases evident in those classified at GMFCS levels III-V. Ankle dorsiflexion demonstrated a gradual reduction from 15° to 5° (GMFCS I-IV) or 10° (GMFCS V). Spasticity levels in the hamstrings and gastrosoleus peaked between ages 5 and 7, showing a propensity to increase with higher GMFCS levels. CONCLUSION: Passive ROM continues to decrease to 30 years of age, most pronouncedly for knee extension. Conversely, spasticity reached its peak at a younger age, with a more notable occurrence observed in the gastrosoleus compared with the hamstrings. Less than 50% of individuals had spasticity corresponding to MAS 2-4 at any age.

Demonstrating antibiotic stewardship while diagnosing and treating bilateral pseudoseptic arthritis: a case report.

INTRODUCTION: Although viscosupplementation is a commonly used treatment for osteoarthritis and is widely regarded as a safe treatment option, it is associated with the rare complication of pseudoseptic arthritis. Most existing case reports that cite this rare complication employed the use of early broad-spectrum antibiotics. CASE PRESENTATION: In this case report, we present a 61-year-old African American female patient who presented with bilateral knee pseudoseptic arthritis in the setting of viscosupplementation. She presented 3 days after bilateral viscosupplementation injections with bilateral knee swelling, discomfort, and pain with micromotion. Her white blood cell count (WBC) was 12.83 (4.5-11 normal), her C-reactive protein (CRP) level was 159 mg/L (0-10 normal), and her erythrocyte sedimentation rate (ESR) was 79 mm/hour (0-40 normal). Her left knee aspirate yielded 38,580 WBC with a negative gram stain and negative cultures. Her right knee aspirate yielded 29,670 WBC with a negative gram stain and negative cultures. Through the utilization of careful clinical monitoring, ice therapy, and non-steroidal inflammatory medication, we were able to successfully treat this patient while maintaining proper antibiotic stewardship. CONCLUSION: Pseudoseptic arthritis in the setting of viscosupplementation can be adequately treated and monitored without the use of antibiotics.

Analysis of cartilage loading and injury correlation in knee varus deformity.

Knee varus (KV) deformity leads to abnormal forces in the different compartments of the joint cavity and abnormal mechanical loading thus leading to knee osteoarthritis (KOA). This study used computer-aided design to create 3-dimensional simulation models of KOA with varying varus angles to analyze stress distribution within the knee joint cavity using finite element analysis for different varus KOA models and to compare intra-articular loads among these models. Additionally, we developed a cartilage loading model of static KV deformity to correlate with dynamic clinical cases of cartilage injury. Different KV angle models were accurately simulated with computer-aided design, and the KV angles were divided into (0°, 3°, 6°, 9°, 12°, 15°, and 18°) 7 knee models, and then processed with finite element software, and the Von-Mises stress distribution and peak values of the cartilage of the femoral condyles, medial tibial plateau, and lateral plateau were obtained by simulating the human body weight in axial loading while performing the static extension position. Finally, intraoperative endoscopy visualization of cartilage injuries in clinical cases corresponding to KV deformity subgroups was combined to find cartilage loading and injury correlations. With increasing varus angle, there was a significant increase in lower limb mechanical axial inward excursion and peak Von-Mises stress in the medial interstitial compartment. Analysis of patients' clinical data demonstrated a significant correlation between varus deformity angle and cartilage damage in the knee, medial plateau, and patellofemoral intercompartment. Larger varus deformity angles could be associated with higher medial cartilage stress loads and increased cartilage damage in the corresponding peak stress area. When the varus angle exceeds 6°, there is an increased risk of cartilage damage, emphasizing the importance of early surgical correction to prevent further deformity and restore knee function.

Robot-assisted total knee arthroplasty system provides more precise control of the femoral rotation angle: A retrospective study.

BACKGROUND: Rotational alignment in total knee arthroplasty (TKA) is a crucial technical point that needs attention. We conducted a retrospective study to investigate whether a new robot-assisted TKA (RA-TKA) could improve the accuracy of rotational alignment and whether rotational alignment affects postoperative pain and functional evaluation of the knee. METHODS: A total of 136 consecutive patients who underwent TKA were included in this study. Half of the patients underwent RA-TKA and the other half underwent conventional TKA (CON-TKA) by the same group of surgeons. Collect the relevant parameters. RESULTS: The postoperative femoral rotation angle (FRA) was -0.72 ± 2.59° in the robot-assisted group and 1.13 ± 2.73° in the conventional group, and were statistically significantly different (p < 0.001). CONCLUSION: This study provides preliminary evidence that the RA-TKA provides more precise control of FRA than CON-TKA, and verifies that tibial rotation angle and combined rotation angle affect postoperative knee pain and functional evaluation.

Factors influencing the posterior cruciate ligament buckling phenomenon-a multiple linear regression analysis of bony and soft tissue structures of the knee joint.

PURPOSE: To determine whether posterior cruciate ligament (PCL) buckling (angular change) is associated with anterior cruciate ligament (ACL) status (intact or ruptured), meniscal bone angle (MBA), anterior tibial translation (ATT), body weight, femoral-tibial rotation (FTR), posterior tibial slope (PTS), PCL length and femoral-tibial distance (FTD) and to identify the factors that have the greatest influence. METHODS: All enrolled participants were scanned with a 3.0 T, 8-channel coil MRI system (Magnetom Verio; Siemens). Bone and soft tissue parameters were measured by MIMICS software for each subject and each measured parameter was correlated with PCL buckling phenomena. The correlated and statistically significant parameters were then analyzed by multiple linear regression to determine the magnitude of the effect of the different parameters on the PCL buckling phenomenon. RESULTS: A total of 116 subjects (50 ACL ruptured and 66 age, weight and height matched volunteers with uninjured knees) were enrolled. Among all measured parameters, there were 8 parameters that correlated with PCL angle (PCLA), of which ACL status had the strongest correlation with PCLA (r = - 0.67, p = < 0.001); and 7 parameters that correlated with PCL-posterior femoral cortex angle (PCL-PCA), of which ATT had the strongest correlation with PCL-PCA (r = 0.69, p = < 0.001). PCLIA was not significantly correlated with any of the measured parameters. Multiple linear regression analyses revealed four parameters can explain PCLA, of which ACL status had the strongest effect on PCLA (absolute value of standardized coefficient Beta was 0.508). Three parameters can explain PCL-PCA, of which ATT had the strongest effect on PCLIA (r = 0.69, p = < 0.001), ATT has the greatest effect on PCL-PCA (absolute value of normalized coefficient Beta is 0.523). CONCLUSIONS: PCLA may be a simple and easily reproducible and important supplement for the diagnosis of ACL injury; PCL-PCA is a simple and easily reproducible and important complementary tool for the detection of ATT. The use of PCLA is more recommended to aid in the diagnosis of ACL injury.

Study on the therapeutic effect of Kirschner wire tension band combined with anchor cross-stitch technique in the treatment of comminuted patellar inferopolar fractures.

PURPOSES: Fractures of the inferior patellar pole, unlike other patellar fractures, present challenges for traditional surgical fixation methods. This article introduces the clinical technique and outcomes of using Kirschner wire tension band combined with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures. METHODS: This retrospective case series study included 14 patients with comminuted inferior patellar pole fractures treated at our institution from September 1, 2020, to April 30, 2022. All patients underwent surgery using the Kirschner wire tension band with anchor screw cross-stitch technique. Follow-up assessments involved postoperative X-rays to evaluate fracture healing, as well as clinical parameters such as healing time, Visual Analog Scale (VAS) scores, range of motion (ROM), and Bostman scores. RESULTS: All patients were followed for an average of over 12 months, with no cases of internal fixation failure. Knee joint stability and function were excellent. X-rays revealed an average healing time of approximately 10.79 ± 1.53 weeks, hospitalization lasted 5.64 ± 1.15 days, surgery took approximately 37.86 ± 5.32 minutes, and intraoperative blood loss was 33.29 ± 8.15 ml. One patient experienced irritation from the internal fixation material. At the final follow-up, the Bostman score averaged 28.29 ± 0.83, knee joint flexion reached 131.07° ± 4.88°, all patients achieved full knee extension, and the VAS score was 0.36 ± 0.63. CONCLUSION: Kirschner wire tension band with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures delivered satisfactory clinical outcomes. This surgical method, characterized by its simplicity and reliability, is a valuable addition to clinical practice.