Male porcine stifle joint: Insights into osteology and meniscus anatomy for orthopaedic research.

INTRODUCTION: Utilizing large animal model like male pig for biomechanical studies offers a cost-effective approach to understanding human joint and tissue mechanics. Our study explores the osteology and meniscus anatomy of the male porcine stifle joint and compares it to human knee joint parameters, aiming to provide a valuable reference for orthopaedic research and surgical training. METHODS: We examined 60 male porcine stifle joints and analyzed their menisci and bones. Dissections were meticulously performed, with measurements taken using digital Vernier calipers and ImageJ software. These dimensions included bone morphology and meniscal width, height, and volume, followed by statistical analysis using unpaired Student's t-tests. RESULTS: The various measurements of bones and menisci indicated a high degree of anatomical similarity to human knees. The anterior width of the medial meniscus was 12.545 ± 1.763 mm, while the lateral meniscus was 14.99 ± 1.720 mm. The middle width of the medial meniscus was 12.065 ± 1.691 mm, compared to the lateral meniscus at 14.375 ± 1.732 mm. The posterior width was 15.25 ± 1.741 mm for the medial meniscus and 16.39 ± 1.662 mm for the lateral meniscus. The femoral intercondylar notch dimensions widened and became shallower with age, resembling the maturation patterns seen in human knee development. The average volume of the medial meniscus was 4.30 ± 0.13 ml, while the lateral meniscus was 5.9 ± 0.29 ml. The aspect ratio of the femoral condyles was 1.04 ± 0.04 (0.95-1.11), while the aspect ratio of the tibial condyles was 0.65 ± 0.02 (0.61-0.70), measured via digital Vernier calipers. These findings were statistically significant, showcasing the male porcine model's relevance in replicating human knee mechanics (p < 0.05). CONCLUSION: Male porcine stifle joints present a valid and accessible model for knee anatomy research. Our study underscores the value of the male porcine model in understanding human knee joint biomechanics and supports its continued use in orthopaedic research and training. These findings have significant implications for advancing orthopaedic research methodologies and enhancing surgical training practices by providing a reliable and anatomically comparable model.

Anterior variable angle locking neutralisation plate superiority over traditional tension band wiring for treating transverse patella fractures.

Purpose: This paper investigates the biomechanical benefits of using hybrid constructs that combine cannulated screws with tension band wiring (TBW) cerclage compared to cannulated screws with anterior Variable Angle locking neutralisation plates (VA LNP). These enhancements can bear heavier loads and maintain the repaired patella's integrity, in contrast to traditional methods. Method: Eighteen fresh-frozen human cadaver patellae were carefully fractured transversely at their midpoints using a saw. They were then divided into two groups of nine for subsequent utilisation. Fixation methods included Cannulated Screw Fixation added with either TBW or VA LNP Fixation Technique. Cyclic loading simulations (500 cycles) were conducted to mimic knee motion, tracking fracture displacement with Optotrak. After that, the constructs were secured over a servo-hydraulic testing machine to determine the load-to-failure on axial mode. Results: The average fracture displacement for the anterior neutralisation plate group was 0.09 ± 0.12 mm, compared to 0.77 ± 0.54 mm for the tension band wiring with cannulated screw group after 500 cyclic loading. This result is statistically significant (p = 0.004). The anterior neutralisation plate group exhibited a mean load-to-failure of 1359 ± 21.53 N, whereas the tension band wiring group showed 780.1 ± 22.62 N, resulting in a significant difference between the groups (p = 0.007). Conclusion: This research highlights the superior biomechanical advantage of VA LNP over TBW for treating simple transverse patella fractures with two cannulated screws. It also highlights how the TBW is still a valuable option considering the load-to-failure limit. Level of Evidence: Not Applicable.

Effects of various load magnitudes on ACL: an in vitro study using adolescent porcine stifle joints.

INTRODUCTION: The escalating incidence of anterior cruciate ligament (ACL) injuries, particularly among adolescents, is a pressing concern. The study of ACL biomechanics in this demographic presents challenges due to the scarcity of cadaveric specimens. This research endeavors to validate the adolescent porcine stifle joint as a fitting model for ACL studies. METHODS: We conducted experiments on 30 fresh porcine stifle knee joints. (Breed: Yorkshire, Weight: avg 90 lbs, Age Range: 2-4 months). They were stored at - 22 °C and a subsequent 24-h thaw at room temperature before being prepared for the experiment. These joints were randomly assigned to three groups. The first group served as a control and underwent only the load-to-failure test. The remaining two groups were subjected to 100 cycles, with forces of 300N and 520N, respectively. The load values of 300N and 520N correspond to three and five times the body weight (BW) of our juvenile porcine, respectively. RESULT: The 520N force demonstrated a higher strain than the 300N, indicating a direct correlation between ACL strain and augmented loads. A significant difference in load-to-failure (p = 0.014) was observed between non-cyclically loaded ACLs and those subjected to 100 cycles at 520N. Three of the ten samples in the 520N group failed before completing 100 cycles. The ruptured ACLs from these tests closely resembled adolescent ACL injuries in detachment patterns. ACL stiffness was also measured post-cyclical loading by applying force and pulling the ACL at a rate of 1 mm per sec. Moreover, ACL stiffness measurements decreased from 152.46 N/mm in the control group to 129.42 N/mm after 100 cycles at 300N and a more significant drop to 86.90 N/mm after 100 cycles at 520N. A one-way analysis of variance (ANOVA) and t-test were chosen for statistical analysis. CONCLUSIONS: The porcine stifle joint is an appropriate model for understanding ACL biomechanics in the skeletally immature demographic. The results emphasize the ligament's susceptibility to injury under high-impact loads pertinent to sports activities. The study advocates for further research into different loading scenarios and the protective role of muscle co-activation in ACL injury prevention.

Arthroscopic and Radiographic Features Distinguish Femoral Head Deformity from Idiopathic Cam, Slipped Capital Femoral Epiphysis, and Recurrent Cam After Slipped Epiphysis.

Introduction: Hip impingement from slipped epiphysis and idiopathic cam is well known but not fully differentiated. Idiopathic cam can be a result of an undiagnosed slip. The mechanism of remodeling of slipped epiphysis deformity has also been controversial. The causes of recurrent femoral head deformity and new impingement beyond progression of the slip have not been studied. Materials and Methods: A consecutive series of hips treated by arthroscopic femoral neck osteoplasty for impingement from slipped epiphysis were compared with a series of hips treated for idiopathic cam impingement. Demographics and clinical, radiographic, and arthroscopic features were retrospectively retrieved. The same parameters were studied in another consecutive series of hips treated for slipped epiphysis and developed recurrent pain from impingement. The deformity was analyzed to understand the causes of recurrence in these hips. The medial most point where the femoral head sphericity ended was called the Alpha point and the tissue covering the bone at the Alpha point was identified. Results: Children with idiopathic cam were older, had less pain and limp, and less clinical deformity compared to those with slipped epiphysis. The damage pattern was chondrolabral separation and acetabular cartilage debonding from the subchondral bone by an articular cartilage covered bump in idiopathic cam impingement, while it was labral crushing and labral and cartilage abrasion by metaphyseal bone in slip impingement. Recurrent cam deformities after initial slips were from epiphyseal extension similar to the idiopathic cam deformity in 7 out of 9 hips. Discussion: Slipped epiphysis and idiopathic cam seem to be distinct entities at the time of presentation. They were different in all findings except for having pain with flexion and internal rotation in both groups. Remodeling of slip deformity seems to occur by wear of the metaphyseal prominence on the acetabulum. Recurrence or worsening of cam deformity in slips occurred by growth of the epiphysis on to the neck anteriorly which can appear as a decrease in the posterior slip. The relationship of the Alpha point to the physeal scar and the tissue covering the femoral head at the Alpha point help differentiate between epiphyseal and metaphyseal cam deformities. Level of Evidence: Level 3 retrospective comparative study.

Comparative study of locking neutralization plate construct versus tension band wiring with a cannulated screw for patella fractures: experimental and finite element analysis.

Transverse patella fractures, accounting for approximately 1% of Orthopedic injuries, pose intricate challenges due to their vital role in knee mechanics. This study aimed to compare the biomechanical performance of a construct, integrating cannulated screws and an anterior locking neutralization plate, with the conventional tension band wiring technique for treating these fractures. Experimental testing and Finite Element Analysis were employed to evaluate the constructs and gain profound insights into their mechanical behavior. Sixteen cadaveric knees were prepared, and transverse patella fractures were induced at the midpoints using a saw. The plate construct and tension band wire fixation were randomly assigned to the specimens. A cyclic test evaluated the implants' durability and stability, simulating knee movement during extension and flexion. Tensile testing assessed the implants' maximum failure force after cyclic testing, while Finite Element Analysis provided detailed insights into stress distribution and deformation patterns. Statistical analysis was exclusively performed for the experimental data. Results showed the plate enhanced stability with significantly lower deformation (0.09 ± 0.12 mm) compared to wire fixation (0.77 ± 0.54 mm) after 500 cycles (p = 0.004). In tensile testing, the construct also demonstrated higher failure resistance (1359 ± 21.53 N) than wire fixation (780.1 ± 22.62N) (p = 0.007). Finite Element Analysis highlighted distinct stress patterns, validating the construct's superiority. This research presents a promising treatment approach for transverse patella fractures with potential clinical impact and future research prospects. This study presents a promising advancement in addressing the intricate challenges of transverse patella fractures, with implications for refining clinical practice. The construct's improved stability and resistance to failure offer potential benefits in postoperative management and patient outcomes.

The current trend of proximal tibiofibular ganglion cyst: A summary of 7 case series and 61 case reports.

Purpose: To review the different types of ganglion cysts surrounding the proximal tibio-fibular joint, their management options, outcomes, and recurrence. Design: Descriptive analytical review. Results: 7 case series consisting of a total of 159 patients and 61 case reports consisting of 80 patients (with three patients having bilateral pathology) were included in this review. (Total cysts 159 + 83 = 242). The mean age was 41 years, and 71 % of the patients were males. 96.5 % of the cases were managed operatively, out of which 98 % of patients felt improvement in local symptoms and 71.5 % had improvement in neurological symptoms. Complete excision of the cyst is the primary mode of operative management. Many added procedures with complete excision are to mitigate the risk of recurrence. The recurrence rate of aspiration, simple excision alone, simple excision with recurrent articular branch neurectomy, and simple excision with PTFJ procedures were 77 %, 56 %, 11.5 %, and 0 %, respectively. Outcomes beyond recurrence were poorly reported. Conclusion: There is not enough literature regarding the topic from which any formal systematic review can be done. Our summary suggests that aspiration alone or with steroid injection is associated with the highest recurrence rates among all the procedures. Complete excision with recurrent articular branch neurectomy should be the primary management. Revision cyst excision in isolation is an inadequate treatment option, therefore should be done in conjunction with PTFJ arthrodesis, which reduces the recurrence rates. Better quality studies are needed that report patient-centered outcomes and morbidities following PTFJ procedures.

Management of Chronic Patella Tendon Tear with Heterotopic Ossifications: A Case Report and Pictorial Review of Various Techniques in Contemporary Practice.

Purpose: To review reliable techniques for reconstructing or repairing chronic patella tendon tears and describe the unique case report of chronic patellar tendon tear with heterotopic ossification (HO). Case description: A 47-year-old male presented with chronic patellar tendon tears with HO, resulting in an inability to extend the right knee fully. Krackow suture repair augmented by autograft semitendinosus and gracilis was employed after debriding intra-substance patella tendon HO and fibrotic tissue. The repair was augmented using a method described by Chen et al. Postoperative recovery was uneventful, and the patient demonstrated an excellent Knee Society Score (86/100) at 6 months of follow-up. Proximal migration of the patella, poor tissue quality, scar tissue formation, and quadriceps atrophy pose unique challenges in managing chronic patellar tendon tears. Conclusion: HO increased the probability of patella baja after the reconstruction. To alleviate that, precise pre-op planning, careful method selection, and proper execution of the selected method are very important. A comprehensive review of 14 different methodologies for managing chronic patellar tendon tears, comprising eight case series and six case reports, was conducted. The selection of an appropriate technique should be based on individual patient characteristics, resource availability, and the surgeon's expertise.

Hip Joint Instability After Surgery Performed Through the Surgical Dislocation Approach.

Background: Safe surgical dislocation of the hip is a versatile approach to the hip joint with a low complication rate. Hip joint instability is a devastating complication with poor prognosis. Methods: All hips treated surgically through the safe surgical dislocation approach were entered in a database and the complication of hip joint instability was studied prospectively from 2000 to 2021. Instability was diagnosed by intraoperative stress examination and on postoperative radiographs. The initial deformities treated, type of instability, presumed causes, treatment provided, response to the treatment, and final result were recorded as they happened during the course of the treatment. We considered patient's age, sex, body mass index (BMI), and initial diagnosis as risk factors. We evaluated the radiographs for femoral neck shortening, lack of greater trochanteric advancement, acetabular deformity, and incongruity of the hip joint. Anterior hip precautions were initiated in the middle of the study period. Results: 22/459 hips developed hip joint instability after surgical dislocation approach performed for hip preservation. Acetabular deficiency, coxa breva, coxa valga, posterior impingement, increased anteversion, lax soft tissues, medial thigh obesity and lack of postoperative precautions seemed to contribute to instability. 50% of the hips became normal. Chondrolysis and residual subluxation were common in the others. Conclusion: Surgical dislocation approach disrupts the soft tissue restraints of the hip and joint stability depends on bony morphology, abductor muscle tension, and postoperative precautions. Several risk factors were subjective and speculative, but awareness of all the potential risk factors and prevention and treatment options should decrease this complication. Level of Evidence: IV Case series.

Pediatric cervical Hemivertebrae - A Rare Case Presentation in a 3-Year-Old Child.

INTRODUCTION: Hemi vertebrae are very rarely seen at a cervical level which results in kyphotic deformity without coronal tilt. Vertebral formation defects have been the basis of congenital kyphoscoliosis deformity in the pediatric age group. Cervical spine kyphosis more than 10° along with kinking of cord at a single level results in neurodeficits which require urgent management on the lines of decompression, realignment, and bony fusion to prevent recurrence and failure and to achieve superior outcomes. However, in pediatric age group, spine surgeons face a lot challenges with respect to surgical anatomy, body landmarks, and bone anchors. CASE REPORT: A 3-year-old male patient presented to the outpatient department with complain of progressive bilateral upper and lower limb weakness and progressive deformity of the cervical spine which increased in the past 2 months. The patient earlier used to walk with support. However, for 2 months, there was progressive decrease in motor function. The clinical course, radiologic features, pathology, and treatment outcome of the patient were documented. C3 hemivertebrectomy and stabilization from C2 to C4 with fibular strut grafting and anterior cervical plating were done under neuromonitoring guidance. The neurologic symptoms of the patient were markedly improved after surgery. CONCLUSION: We have reported the first case of the management of pediatric cervical spine hemivertebrae with neurodeficit in a 3-year-old child, with anterior hemivertebrectomy, strut grafting, and plating which improved the patient neurologically and functionally.