Hip Joint Research Articles

Use of a Novel Reverse Hip Replacement System to Address Dislocation and Instability.

While total hip arthroplasty (THA) is an enormously successful treatment for patients with end-stage degenerative arthritis of the hip, and surgeons have optimized existing hip implants and techniques, dislocation and instability persist as a leading cause of failure. Given the tremendous success of reverse total shoulder arthroplasty in enhancing the stability of shoulder reconstruction by reversing the anatomic seating of the ball and socket components, one manufacturer (Hip Innovation Technology, LLC, Woodstock, Georgia) has developed a novel Reverse Hip Replacement System (Reverse HRS) to address the need for greater stability in reconstruction of the arthritic hip joint. Rather than the traditional anatomic components that replace the head of the femur with a spherical ball and the acetabulum with a socket with polyethylene liner mounted into the pelvis, the Reverse HRS features a cup with polyethylene liner attached to the femoral stem and a spherical metal head attached to a central trunnion inside of the porous-coated acetabular shell fixed into the pelvis. This design provides dramatically enhanced stability and improved range of motion. This article reviews relevant published literature, including results from a Canadian clinical trial and case reports from a multicenter American clinical trial monitored by the U.S. Food and Drug Administration. It also describes the components and surgical technique of reverse THA.

Effect of Sclerosis Bands in Femoral Head Necrosis on Non-Vascularized Fibular Grafting-A Finite Element Study.

Femoral head necrosis is a challenging condition in orthopaedics, and the occurrence of collapse is an important factor affecting the prognosis of femoral head necrosis. Sclerosis bands are known to influence the collapse of the femoral head, yet there is a lack of research on the biomechanical role of sclerosis bands in non-vascularized fibular grafting surgery. This study aims to evaluate the biomechanical impact of sclerosis bands in femoral head necrosis and their role in non-vascularized fibular grafting surgery (NVFG) using finite element analysis. We constructed 11 finite element models based on CT scan data of a normal hip joint, simulating different sclerosis band thicknesses and defect scenarios. The models were analyzed for changes in femoral head displacement and von Mises stress. We constructed a hip joint model based on CT data from a normal hip joint, and after reconstruction, assembly, and optimization using 3-matic. We created five groups consisting of 11 finite element analysis models of the hip joint. Mesh partitioning and mechanical parameter settings were performed in ANSYS. The changes and differences in femoral head displacement and von Mises stress of these models were analyzed. Increasing sclerosis band thickness led to reduced peak displacement of the femoral head by 28.6%, 42.9%, and 47.6%, and increased surface von Mises stress by 28.3%, 13.8%, and 13.0%, respectively. Post-surgery, peak displacement decreased in all groups compared to pre-surgery levels. Increasing sclerosis band thickness post-surgery resulted in decreased maximum von Mises stress of the femoral head by 13.9%, 3.0%, and 8.1%. Defect volume in the defect groups correlated with increased peak displacement of the femoral head by 10.0%, 30.0%, and 100.0%, and increased surface maximum von Mises stress of the femoral head by 9.3%, 14.0%, and 15.1%. Sclerosis band formation exacerbates von Mises stress concentration on the femoral head surface. However, thicker sclerosis bands improve post-NVFG stability and mechanical performance. Larger anterior lateral sclerosis band defects significantly compromise postoperative stability, increasing the risk of collapse. Protecting the anterior lateral sclerosis band during NVFG surgery is crucial.

Femoral version and its clinical relevance in adult hip preservation surgery for developmental dysplasia of the hip.

Femoral version (FV) is more widely adopted with the definition as the angle between the long axis of the femoral neck and the tangent line of the posterior femoral condyles on the axial plane, and the normal range between 5 and 20°. FV can be measured by imaging and functional tests. Cross-sectional CT including both the hip and the knee is the typically used imaging technique, yet variation exists according to the different landmarks used. As MRI investigations are routinely performed preoperatively, and protocols can be easily adopted to include version measurement, they are frequently used as an alternative to CT and offers several advantages. Abnormal FV has adverse effects on the biomechanics and musculoskeletal health of the whole lower limb. It affects the lever arm of muscles and the forces that the hip and patellofemoral joints suffer, and can lead to disorders such as osteoarthritis and impingement. In adult hip preservation surgery for developmental dysplasia of the hip (DDH), abnormal FV is sometimes accompanied by other morphological abnormities of the hip, a more severe DDH, and can help predict postoperative range of motion (ROM), and postoperative impingement. Currently, the most frequently used surgical technique for abnormal FV is femoral derotational osteotomy. Many controversies are left to be solved, including the specific origin of FV, the indication for femoral derotational osteotomy, especially in patients with combined DDH and abnormal FV, and the explicit compensation mechanism of abnormal FV by tibial torsion.

Success rate of single versus multiple debridement, antibiotics, and implant retention (DAIR) in hip and knee periprosthetic joint infection: a systematic review and meta-analysis.

This systematic review aimed to compare outcomes between multiple and single debridement, antibiotics, and implant retention (DAIR) procedures for early periprosthetic joint infection (PJI) in hip and knee arthroplasty. Four databases were searched from inception till January 2024 for original studies investigating the outcomes of multiple DAIR in hip and knee PJI. The primary outcome was the success rate in eradicating joint infection. This review was conducted per PRISMA guidelines. A total of 9 observational studies with 1104 participants were included, with a mean age and BMI of 58.37years (95%CI: 25.77-90.98) and 31.43kg/m2 (95%CI: 28.89-34.98), respectively. The mean follow-up period was 58.37months (95%CI: 25.77-90.98), and the average MINORS score assigned to the review was 17.6 ± 3.46, indicating a low overall risk of bias. An equivalent success rate between single and double DAIR was observed, at 67% (95%CI: 64-71%) and 70% (95%CI: 48-86%), respectively, with no statistically significant difference between the two treatment modalities (p = 0.740). Additionally, the success rate for triple DAIR ranged from 50 to 60%. This study suggests that double DAIR is a valid treatment option for acute PJI after TKA and THA, with a success rate comparable to single DAIR (70% vs. 67%, p = 0.740). Triple DAIR achieved success rates ranging from 50 to 60%. However, caution is warranted when interpreting these results due to heterogeneity in host comorbidity factors, DAIR protocols, and antibiotic regimens. Therapeutic, Level III.

The Superior Approach in Hemiarthroplasty for Femoral Neck Fracture: A Comparative Analysis with the Posterior Approach.

The concept of a superior approach (SA) involves the use of a tissue-sparing posterior approach (PA), with exposure of the piriformis muscle and gluteus medius/minimus muscles. The objective of this study was to clarify the features of hip hemiarthroplasty (HA) using a SA in regard to early recovery and mid-term outcomes, with a comparison of the outcomes of SA-HAs and HAs using a PA (PA-HAs). A total of 120 HAs for treatment of primary femoral neck fracture with a healthy opposite hip joint were performed in our hospital from 2013 to 2018. Propensity score matching in regard to age, sex, body mass index, walking ability before injury, place of residence, time to surgery, and American Society of Anesthesiologists-Physical Status was performed for 79 patients with SA-HAs and 41 patients with PA-HAs. The final analysis included 34 patients who underwent SA-HAs and 34 patients who underwent PA-HAs. The duration of surgery was 57.1 minutes and 72.1 minutes (P=0.001) for SA-HAs and PA-HAs, respectively. The scores for walking ability at postoperative one week were 4.9±1.4 and 4.2±1.0 (P=0.021) for SA-HAs and PA-HAs, respectively. The Barthel index (BI) at the start of rehabilitation was 26.2±18.7 and 17.4±16.3 (P=0.042) for SA-HAs and PA-HAs, respectively. The 4-year complication-free survival rates were 74.2% and 56.3% for SA-HAs and PA-HAs, respectively (P=0.310). SA-HA can be performed without torsion of the muscles and ligaments around the hip joint. Early recovery of walking ability and BI was a significant feature of SA-HAs.

Analysing lower limb motion and muscle activation in athletes with ankle instability during dual-task drop-jump

ABSTRACT This study investigates the impact of chronic ankle instability (CAI) on athletes’ lower extremity mechanics during bounce drop-jump landings with divided attention. Thirty Division I physical education voluntarily participated in the study. They performed two sets of bounce drop jumps: one set with a divided attention task and the other without. The obtained data were analysed using a paired t-test to compare the outcomes between the divided attention (DA) and non-divided attention (NDA) tasks. Athletes with CAI, during the DA task, displayed higher vertical landing forces, increased ankle inversion velocity, and greater range of motion of the ankle, knee, and hip in the frontal and transverse planes. They also exhibited insufficient neuromuscular preparation of the rectus femoris muscle. Notably, distinct kinematic alterations were observed in the ankle, knee, and hip joints regarding frontal and transverse lower-extremity kinematics. The findings suggest that athletes with CAI experience decreased activation of the rectus femoris muscle, which may impact their dynamic postural stability from pre-landing to ascending phases. Furthermore, the results indicate that individuals with CAI closely replicate the injury mechanisms encountered during a drop-jump landing task with divided attention. These insights offer valuable information about the real-time challenges faced by athletes with CAI.

Modeling the effects of common types of arm swing on muscle forces of the hip and knee joints

Modeling the effects of common types of arm swing on muscle forces of the hip and knee joints

Are Anthropometric Measures, Range of Motion, or Movement Control Tests Associated with Lumbopelvic Flexion during Barbell Back Squats?

Resistance training with the barbell back squat (BBS) exercise is practiced in sports, recreation, and rehabilitation. Although extensively debated, it is commonly believed and recommended that maintaining a neutral lumbopelvic alignment during BBS is an important technical aspect that might reduce the risk of injury. There is limited knowledge of how objectively measurable factors affect the extent to which the lumbopelvic region moves into flexion during a BBS. The aim of the study was to investigate the association among anthropometric measurements, range of motion in the hips and ankle joints, lumbopelvic movement control tests, and flexion of the lumbopelvic region during execution of the BBS. Observational, cross sectional. Eighteen experienced powerlifters and Olympic weightlifters were included and measurements of lumbopelvic movements were collected with inertial measurement units during BBS performed at 70 % of 1RM. Examination of anthropometric properties, range of motion in the hip and ankle joints, and lumbopelvic movement control tests were collected as independent variables. Linear regression analysis was used to investigate which independent variables were associated with lumbopelvic flexion during a BBS. The linear regression showed that a higher range of motion in ankle dorsiflexion could statistically significantly explain an increased amplitude of lumbopelvic flexion during the BBS. Anthropometrics, range of motion of the hips, and performance in lumbopelvic movement control tests did not show any statistically significant associations. The results suggest that strength and conditioning professionals and clinicians who instruct and assess lifting technique in the BBS and/or use the BBS to assess performance or as an intervention should recognize that a higher range of motion in the ankle joints might affect lumbopelvic flexion during the BBS. In practice, the value of an individual assessment of lifting technique focusing on the goal of the movement should be emphasized. 3.

Improving Biological Joint Moment Estimation During Real-World Tasks With EMG and Instrumented Insoles.

Real-time measurement of biological joint moment could enhance clinical assessments and generalize exoskeleton control. Accessing joint moments outside clinical and laboratory settings requires harnessing non-invasive wearable sensor data for indirect estimation. Previous approaches have been primarily validated during cyclic tasks, such as walking, but these methods are likely limited when translating to non-cyclic tasks where the mapping from kinematics to moments is not unique. We trained deep learning models to estimate hip and knee joint moments from kinematic sensors, electromyography (EMG), and simulated pressure insoles from a dataset including 10 cyclic and 18 non-cyclic activities. We assessed estimation error on combinations of sensor modalities during both activity types. Compared to the kinematics-only baseline, adding EMG reduced RMSE by 16.9% at the hip and 30.4% at the knee (p < 0.05) and adding insoles reduced RMSE by 21.7% at the hip and 33.9% at the knee (p < 0.05). Adding both modalities reduced RMSE by 32.5% at the hip and 41.2% at the knee (p < 0.05) which was significantly higher than either modality individually (p < 0.05). All sensor additions improved model performance on non-cyclic tasks more than cyclic tasks (p < 0.05). These results demonstrate that adding kinetic sensor information through EMG or insoles improves joint moment estimation both individually and jointly. These additional modalities are most important during non-cyclic tasks, tasks that reflect the variable and sporadic nature of the real-world. Improved joint moment estimation and task generalization is pivotal to developing wearable robotic systems capable of enhancing mobility in everyday life.

Posterior Labral Suture of Hip Joint by a 2-Step Camera Rotation Switching for Establishment of Bird’s-Eye View

Labral tear of the hip joint is an important factor causing joint pain and locking, as well as mobility disturbance. Although femoroacetabular impingement syndrome often results in anterior labral tears, posterior labral tears are present in a subset of patients, especially those with a history of posterior hip dislocation. Posterior labral repair under arthroscopy usually requires switching between the viewing approach and the operating approach, but this undoubtedly increases the operative time and the destruction of soft tissue. This article introduces a technique for rapid posterior labral suture by rotating the arthroscopic camera without switching the surgical approach.

Anti-Shortening Screw for the Prevention of Postoperative Shortening in Displaced Femoral Neck Fractures: A Retrospective Cohort Study.

Early femoral neck shortening after femoral neck system (FNS) fixation for displaced femoral neck fractures can occur in 22.3%-39.1% of cases, leading to decreased hip joint function. This study aimed to investigate the effectiveness of using an anti-shortening screw (ASS) in FNS fixation to prevent postoperative femoral neck shortening in displaced femoral neck fractures. We retrospectively analyzed 106 cases of displaced femoral neck fractures treated with FNS at the Hospital from April 2020 to April 2023. Patients were divided into two groups based on the use of an ASS: the traditional group and the ASS group, each consisting of 53 cases. The ASS group was age-matched with the traditional group treated during the same period without an ASS. The study variables included age, sex, body mass index (BMI), smoking and drinking history, injury mechanism, side of injury, fracture type, surgical time, intraoperative blood loss, Harris Hip Score (HHS) at the final follow-up, radiographic assessment (femoral neck shortening), and complications (infection, femoral head necrosis, nonunion, and secondary surgery). Statistical analysis was performed using SPSS software, with continuous and categorical variables analyzed using appropriate parametric (t-test) and nonparametric (Mann-Whitney U test) tests, and chi-square or Fisher's exact tests, respectively. A p-value <0.05 was considered significant. There were no significant differences in background characteristics between the traditional and ASS groups. The shortening distance at postoperative day 1 did not differ significantly between the two groups (0 vs. 0 mm, p = 0.120). However, at 1, 3 months, and 1 year postoperatively, the femoral neck shortening in the ASS group was significantly less than that in the traditional group (1 month: 2.3 vs. 3.1 mm, p = 0.007; 3 months: 2.6 vs. 3.5 mm, p = 0.005; 1 year: 2.6 vs. 3.5 mm, p = 0.002). The ASS group also had a significantly lower shortening distance during the fracture healing process (0.9 vs. 2.7 mm, p = 0.005). The incidence of moderate to severe shortening (≥5 mm) at 1 year postoperatively was lower in the ASS group compared with the traditional group (15.1% vs. 37.7%, p = 0.001). The ASS group had a longer surgical time (63.0 ± 13.4 vs. 73.0 ± 23.2 min, p = 0.008) and a higher HHS (90.7 vs. 94.8, p = 0.008). There was no significant difference in fracture healing time or postoperative complications between the two groups. The traditional group had 3.8% cutouts, 7.5% nonunions, 5.7% avascular necrosis, and 7.5% secondary hip replacements. The ASS group saw 0% cutouts, 1.9% nonunions, 3.8% avascular necrosis, and 3.8% hip replacements. No significant differences in complication rates (p > 0.05). The use of an ASS in FNS fixation for displaced femoral neck fractures can reduce the degree of postoperative shortening and improve hip joint function.

Relationship of Kinematic Variables with the Performance of uprise on rings in Men’s Artistic Gymnastics

An investigationwas done to find the relation between selected kinematic variables and theperformance of uprise on rings in men’s artistic gymnastics.The study was conducted on national-levelgymnasts. The data on angular kinematic variables were collected on four different phases of uprise onrings. Linear kinematic variables were identifiedon two different phases of uprise on rings.The angular kinematic variables did not show any significant relationship at the 0.05 level at theDislocation Phase.Duringthe Vertical Line Cross Phasea significant relationship was found between angle atthe ankle andthe hipangle. InKicking and Pulling Phase angle at the left hip joint and the performance of Uprisehasshown a significant relationship.During the Supporting phase angle at the neck and the performance ofUprisewas showing a significant relationship, and also the angle of the left Wrist correlated significantlywith the angle of the Hip.Results also reveal that none of the linear kinematic variables at different Phases of Uprise showed anysignificant relationship at 0.05 level

Assessing hip joint-related structure and patient-reported outcomes in people with Marfan syndrome.

People with Marfan syndrome (MFS) have clinical symptoms of hip pain, but to date, there is limited knowledge about hip-related structural abnormalities in these patients. Therefore, the purpose of this cross-sectional study was to assess hip-related structural abnormalities and patient-reported outcomes (PRO) in a cohort of patients with MFS compared to healthy controls. Nineteen individuals with MFS(17 females, 39.8±11.5 years) and 19 age, sex, and body mass index-matched healthy, asymptomatic individuals (17 females, 36.2±12.5 years)underwent radiographic imaging and unilateral hip MRI. The Scoring Osteoarthritis with MRI (SHOMRI) technique was used to assess hip-related morphological abnormalities between the MFS and control groups. All participants completed the Hip disability and Osteoarthritis Outcome Score (HOOS) to assess hip-related symptoms, pain, and function during activities of daily living (ADL) and quality of life (QOL). The MFS group exhibited higher lateral center edge angles (p < .001). Despite similar severity of femoral cartilage damage (p = 1.0), the MFS group exhibited a higher severity (p = 0.046)of acetabular cartilage degeneration (1.21±1.08) compared to the controls(0.53±1.02). There were no between-group differences in severity of labral pathology, subchondral cysts, or edema. Individuals with MFS also self-reported significantly lower HOOS symptoms (p = 0.003), pain (p = 0.014), ADL (p = 0.028), and QOL (p = 0.014) sub-scores, indicating worse hip-related PRO in MFS. Our study results suggest that individuals with MFS exhibit early signs of acetabular cartilage degeneration and poor hip-related clinical outcomes compared to healthy individuals. Future work should investigate the underlying biomechanical mechanisms associated with hip joint degeneration in the MFS population.

Importance of hip capsular repair in total hip arthroplasty (THA) via the posterior lateral approach: a five year retrospective cohort study.

This study aims to assess the impact of repairing the hip joint capsule during posterior-lateral approach total hip arthroplasty (THA) on postoperative hip joint function and late dislocation incidence. A retrospective cohort study included 413 patients, divided into experimental (hip joint capsule repair, n = 204) and control (hip joint capsule excision, n = 209) groups. Patients were followed for five years, evaluating postoperative hip range of motion (ROM), dislocation rate, VAS and HHS scores, inflammatory and coagulation markers, hospitalization, blood loss, and body composition. Statistical analysis included the Student's t-test, Chi-square test, and logistic regression for dislocation risk factors. Joint capsule repair improved postoperative hip flexion and extension within six months and at two years postoperatively, internal and external rotation within three months, and abduction and adduction throughout the entire follow-up period (P < 0.05). Capsular repair also reduced early and late dislocation rates (P < 0.05). Significant differences in HHS and VAS scores, inflammatory and coagulation indicators, hospitalization, blood loss, and body composition were noted (P < 0.05). Multivariate logistic regression indicated hip joint repair, rheumatoid arthritis, epilepsy, and sarcopenia as dislocation risk factors (P < 0.05). Capsular repair during posterior-lateral THA improves postoperative hip function and mobility while reducing dislocation rates, blood loss, pain, inflammation, and economic burden. Patients with rheumatoid arthritis, epilepsy, or sarcopenia require individualized planning and enhanced postoperative care to minimize complications.

Influence of texting while walking on lower extremity gait function in young adults

Texting while walking (TWW) is a dual-task activity that young adults perform in their everyday lives. TWW has been reported to affect gait characteristics such as gait speed, stride length, and cadence. However, the influence of TWW on lower extremity gait function has not been investigated. Therefore, the purpose of this study was to quantify gait function by examining gait symmetry and using a time series analysis. Twenty-eight young adults (14 males, 14 females) walked at their preferred speed for 10 m as a baseline condition and a 10 m TWW task. Three-dimensional segment tracking was achieved utilizing a lower extremity and trunk marker set and the Model Statistic was used to test for statistical differences between the hip, knee, and ankle angular joint positions. The hip yielded the most asymmetries (25 out of 101 points) throughout the gait cycle, while asymmetries for the knee and ankle joints yielded 16 out of 101 points and 11 out of 101 points, respectively. The outcomes of this study suggest there are differences between baseline and TWW gait symmetry, however, the percentage of the gait cycle affected was less than 25 % - indicating gait function is not strongly influenced by texting while walking in young adults.

AI-smartphone markerless motion capturing of hip, knee, and ankle joint kinematics during countermovement jumps.

Recently, AI-driven skeleton reconstruction tools that use multistage computer vision pipelines were designed to estimate 3D kinematics from 2D video sequences. In the present study, we validated a novel markerless, smartphone video-based artificial intelligence (AI) motion capture system for hip, knee, and ankle angles during countermovement jumps (CMJs). Eleven participants performed six CMJs. We used 2D videos created by a smartphone (Apple iPhone X, 4K, 60 fps) to create 24 different keypoints, which together built a full skeleton including joints and their connections. Body parts and skeletal keypoints were localized by calculating confidence maps using a multilevel convolutional neural network that integrated both spatial and temporal features. We calculated hip, knee, and ankle angles in the sagittal plane and compared it with the angles measured by a VICON system. We calculated the correlation between both method's angular progressions, mean squared error (MSE), mean average error (MAE), and the maximum and minimum angular error and run statistical parametric mapping (SPM) analysis. Pearson correlation coefficients (r) for hip, knee, and ankle angular progressions in the sagittal plane during the entire movement were 0.96, 0.99, and 0.87, respectively. SPM group-analysis revealed some significant differences only for ankle angular progression. MSE was below 5.7°, MAE was below 4.5°, and error for maximum amplitudes was below 3.2°. The smartphone AI motion capture system with the trained multistage computer vision pipeline was able to detect, especially hip and knee angles in the sagittal plane during CMJs with high precision from a frontal view only.

Changes in rotator movement during early gait acquisition in after total hip arthroplasty

BackgroundIn walking in healthy adults, rotation of the hip joint affects stride length and shifts the center of gravity, but these are not seen in hip osteoarthritis which affects gait. In gait of total hip arthroplasty, there are few reports on changes in the horizontal plane. This study clarified the preoperative and early postoperative gait characteristics of patients undergoing total hip arthroplasty. MethodsThe analysis included 12 females who underwent initial total hip arthroplasty using a posterolateral approach. Gait was measured pre and postoperatively using a three-dimensional motion analysis device. Statistics were compared pre and postoperative range of motion, muscle strength, walking speed, stride length, gravity movement distance, trunk angle, hip joint angle, and joint moment. FindingsThe maximum hip abduction moment and trunk flexion angle to the surgical side were lower than in healthy subjects. The angle of internal rotation during the stance phase was significantly higher in the postoperative period. The distance of the center of gravity shift in the left and right directions was significantly decreased postoperatively. InterpretationGait disturbance was seen preoperatively and remained after surgery. Walking after total hip arthroplasty provides the hip joint rotates inward which is closer to normal walking. However, no change was observed in the external rotation moment of the hip joint during walking. We suspect that the invasiveness of the posterolateral approach of total hip arthroplasty affects the muscles for external rotation of the hip joint. This can also cause in gait disturbances.

Technical analysis of basketball players' shooting movements through video images

BackgroundWith the increase in basketball competition intensity, video image analysis-based methods have been increasingly applied to improve the technical level of basketball players. MethodsTaking the example of one-handed set shoulder shooting (the basketball player spreads legs apart at shoulder width, holds the ball over the right shoulder, extends the right hand along with lower body movement, and releases the ball softly using fingers), this study compared the technical differences between 20 level 2 basketball players (level 2 group) and 20 basketball specialized students (specialized group) by capturing video images using a high-speed camera and conducting independent sample t-tests. ResultsThe level 2 group had a significantly higher shooting percentage than the specialized group (p=0.005). Additionally, the level 2 group had shorter dribbling time and longer shooting time compared to the specialized group (p=0.032; p=0.021). The amplitude of variation in the knee, hip, and elbow joints was significantly greater than that of the specialized group (p=0.008/0.016/0.031). The flexion angles of the index finger and middle finger after striking in the level 2 group were significantly higher than those of the specialized group (p=0.021/0.036). The level 2 group also had a smaller striking angle and a larger striking height and speed than the specialized group (p=0.001; p=0.005/0.006). ConclusionAthletes of different levels show differences in phase duration and joint angles when performing one-handed set shoulder shooting, providing a basis for athletes' training.

P153. PI Changes in patients with adult spinal deformity following S2AI fixation: is the hip joint involved?

P153. PI Changes in patients with adult spinal deformity following S2AI fixation: is the hip joint involved?

Recurrence of spinal schwannomas in a patient with neurofibromatosis type 1: A case report

Introduction and importance: Spinal schwannomas are benign tumors usually attached to peripheral nerves, consisting of a clonal population of Schwann cells. Neurofibromatosis type 1 is an autosomal dominant neurocutaneous disorder that predominantly affects the skin, bone and nervous system. Neurofibromatosis type 1 is a clinically and genetically distinct from neurofibromatosis type 2. This case report highlights the rare association between spinal schwannoma and neurofibromatosis type 1. Case presentation: The patient with a past medical history of spinal schwannoma, operated 1 year back, presented with back pain, weakness of lower limbs and urge incontinence. On examination, she had cutaneous features suggestive of neurofibromatosis type 1 and there was impairment of all sensory modalities below hip region. MRI revealed spinal schwannoma at D9 level for which laminectomy with removal of schwannoma was performed. Clinical discussion: The occurrence and recurrence of spinal schwannoma in neurofibromatosis type 2 is common finding. But such association has not been established between spinal schwannoma and neurofibromatosis type 1. In this case, the recurrence of spinal schwannoma has been linked to neurofibromatosis type 1 in the absence of other well-defined etiologies. Conclusion: The occurrence of spinal schwannoma can be genetic or sporadic. The recurrence is usually associated with familial tumor syndrome. The available literature has not established association between neurofibromatosis type 1 and spinal schwannoma, thus, emphasizing the need of more focused studies .