Posterior Stabilization Research Articles

Poster 175: Beach Chair Versus Lateral Decubitus Positioning for Primary Arthroscopic Posterior Shoulder Stabilization

Objectives:There are no studies that directly compare beach chair (BC) versus lateral decubitus (LD) position for arthroscopic treatment of posterior instability. In the few systematic reviews evaluating BC vs. LD, no difference had been demonstrated in regard to recurrence and revision rates. Additionally, bone loss was not accounted for in the recurrence rate. The purpose of this study is to identify predictors of shoulder instability recurrence and revision after posterior shoulder stabilization surgery in a young, high demand population and evaluate surgical position and glenoid bone loss as independent predictors of the outcomes of interest, recurrence and revision at short- and mid- term follow-up.Methods:A consecutive series of 147 arthroscopic posterior stabilization procedures were performed by sports medicine certified and fellowship trained orthopaedic surgeons from 2005-2019 in either the BC or LD position. Patients were included if they underwent an isolated primary arthroscopic posterior capsulolabral repair. Patients were excluded if concomitant anterior labral repair was performed at the time of surgery. Shoulders were additionally excluded if magnetic resonance imaging (MRI) was not available at the time of preoperative evaluation, or the patient was lost to follow up. All shoulders were evaluated for glenohumeral bone loss using the best-fit circle technique on the sagittal enface MRI. The primary outcomes of interest were recurrent instability and revision stabilization. Recurrent instability was defined as the presence of a recurrent pain limiting activities with physical exam consistent with recurrent posterior instability per clinical notes in the electronic medical record. Rates of recurrence and revision were calculated among the full cohort among patients with available 1-year or 5-year follow up. Patient and procedure characteristics were compared by BC or LD group using two sample t-tests or Chi-square tests.Results:A total of 147 shoulders with a mean age of 22.6 years (4.82 SD) underwent isolated arthroscopic repair and were followed for a mean 6.93 (3.29 SD) years. The overall recurrent instability and revisions rates were 16% (23/147) and 12% (18/147), respectively. With respect to surgical position, there was no significant difference in recurrence or revision (p-value >0.05). With respect to patient age, anchor number, and bone loss there was no significant difference in recurrence or revision with respect to patient age (p-value >0.05).Conclusions:Among fellowship-trained orthopaedic surgeons, there was no difference in rates of recurrent instability and revision surgery after performing arthroscopic stabilization for isolated posterior shoulder instability in a high demand population in either the BC or LD position.

Paper 05: The Role of the Long Head of the Biceps Tendon in Posterior Shoulder Stabilization during Forward Flexion

Objectives:The incidence of long head of the biceps tendon (LHBT) procedures is increasing, yet the role of the LHBT in glenohumeral stability is not fully understood. People lift most objects in the sagittal plane with forward flexion, which stresses the posterior aspect of the unconstrained glenohumeral joint. Determining the mechanism by which the shoulder maintains stability with functional motions is important to understanding the pathoanatomy of degenerative shoulders. We hypothesize that the LHBT resists posterior translation of the humeral head (HH) during forward flexion by tensioning the posterior capsuloligamentous complex.Methods:Ten fresh-frozen cadaveric shoulders were tested using an established shoulder simulator, which loads the rotator cuff, deltoid and LHB tendons through a system of pulleys and weights. A motion tracking system recorded glenohumeral translations with an accuracy of ±0.2mm. In each subject, the scapula was fixed and the humerus was tested in 6 positions: 30 and 60 degrees of glenohumeral forward flexion at i) maximum internal rotation (IR), ii) neutral rotation and iii) maximum external rotation (ER) (Figure 1). The deltoid was loaded with 100N, and the infraspinatus and subscapularis were loaded with 22N each. The difference in glenohumeral translation was calculated at each position comparing the LHBT loaded with 45N or unloaded.Results:When comparing the two states of LHBT loading vs unloading, unloading the LHBT led to an overall increase in posterior and superior translation of the humeral head (Figure 2) in all tested positions (neutral, maximum internal rotation, maximum external rotation in both 30 and 60 degrees of forward flexion). At 30 degrees of glenohumeral forward flexion, unloading the LHBT increased HH posterior translation by 2.46mm (±0.92mm) (p<0.001), 1.71mm (±1.02mm) (p<0.001) and 1.02mm (±0.88mm) (p=0.014) at maximum ER, neutral rotation, and maximum IR, respectively (Figure 3). At 60 degrees of glenohumeral forward flexion, unloading the LHBT increased HH posterior translation by 2.77mm (±1.16mm) (p<0.001), 2.43mm (±1.56mm) (p<0.001) and 1.66mm (±1.42mm) (p<0.001) at maximum ER, neutral rotation and maximum IR, respectively (Figure 4). Unloading the LHBT led to more posterior translation at 60 degrees of glenohumeral forward flexion compared to 30 degrees (p=0.013).Conclusions:LHBT loading resists posterior translation of the humeral head during forward flexion. This data supports the role of the LHBT as a posterior stabilizer of the shoulder, specifically when a person is carrying objects in front of them. Biceps tenotomy or tenodesis may contribute to microinstability of the glenohumeral joint and shift contact pressure posteriorly. Further work is needed to determine if unloading the LHBT, as is done with biceps tenotomy or tenodesis, may eventually contribute to the posterior glenoid wear seen with osteoarthritis.

Poster 160: Outcomes of Revision Posterior Shoulder Capsulolabral Repair in Adolescents

Objectives:Posterior arthroscopic capsulolabral repair has been shown to be successful in the athletic population. Adolescents provide a unique set of challenges to the surgeon due to their young age and potential length of time remaining in competitive athletics. Small studies have identified risk factors for failure, but there a paucity of literature evaluating adolescent specifically. The purpose of this study was to determine failure rates of adolescents who underwent arthroscopic posterior capsulolabral repair and to compare clinical outcomes and return to play between adolescents who required revision versus those who did not. It was hypothesized that adolescent athletes who require revision arthroscopic posterior unidirectional capsulolabral repair will have poorer outcomes and return to play and will undergo revision surgery at a higher rate than adults.Methods:A total of 718 patients who underwent posterior shoulder stabilization between 2000-19 with a minimum of 2-year follow-up were reviewed. Patients <11 years and >19 years of age and those with multidirectional instability were excluded. Revision surgery was defined as repeat arthroscopic posterior capsular repair. The ability to return to play, clinical outcomes scores (American Shoulder and Elbow Surgeons scoring system (ASES) and Visual Analog Scale (VAS)), and patient reported perception of range of motion, strength, and whether the surgery was worthwhile were recorded. Comparisons were made using the Chi-square or the Mann-Whitney U tests with P <0.05.Results:184 patients met inclusion criteria, with an average follow-up of 6.1 years. Nineteen patients required revision surgery, for an overall revision rate of 10.3%. At final follow-up, patients who underwent revision surgery returned to sport less frequently (86.7% vs 68.4%, p=0.04) and less likely to return to their pre-surgery level of play (Table 1). Non-revision patient had higher ASES score, as well as greater strength and range of motion. However, both groups had similar pain scores and reported that surgical repair was worthwhile (93.2% vs. 89.5%, p=0.55).Conclusions:Adolescent patients underwent revision posterior capsulolabral repair at a slightly higher rate (10.3%) when compared with athletes of all ages. Patients requiring revision had poorer outcomes scores when compared to those who did not undergo revision surgery but were able to return to sport at a high level and had a high level of satisfaction. Adolescent athletes return to play at high levels following arthroscopic posterior capsulolabral repair with a low rate of revision; however, those that require revision have poorer outcomes but high satisfaction.Table 1.Comparison of postoperative outcomes between non-revision and revision posterior shoulder arthroscopic capsulolabral repair

Arthroscopic Repair of a “Floating” Posterior Inferior Glenohumeral Ligament

Background: Combined posterior glenoid labrum lesions with posterior humeral avulsion of the glenohumeral ligament, also known as the “floating” posterior inferior glenohumeral ligament (PIGL), occur infrequently. These combined lesions are frequently missed on magnetic resonance imaging in the workup of posterior shoulder instability. Correct identification of the “floating” PIGL lesion allows for appropriate preoperative planning and treatment to decrease the risk of recurrent posterior shoulder instability. Indications: A “floating” PIGL lesion is a cause of posterior shoulder instability and demonstrates increased translation when compared with isolated labral lesions. Surgical repair of an acute “floating” PIGL lesion with concomitant superior labral tear is described. Technique Description: The patient is placed in the lateral decubitus position. Standard posterior and anterior portals are created. In this case, a superior labral tear with anterior labral tear extension was also identified and repaired. The posterior labrum was repaired prior to the posterior humeral avulsion of the glenohumeral ligament (HAGL). The torn posterior labrum is mobilized and glenoid bony bed prepared. Short, 2.9-mm biocomposite knotless suture anchors loaded with suture tape are used for labral fixation. A 70° arthroscope is used to visualize the posterior HAGL from the anterior cannula and an additional posterior inferior portal established. The footprint of PIGL on the humerus is identified, debrided, and two 3.0-mm anchors loaded with suture placed. The sutures are passed through the capsule and PIGL and tied in a mattress pattern external to the capsule and ligament. The posterior portals are closed with nonabsorbable suture. Results: While few outcomes are described in the literature for the “floating” PIGL, the literature suggests good outcomes following surgical repair. Conclusion: The “floating” PIGL lesion is a rare cause of posterior shoulder instability. It is important to perform a thorough evaluation for concomitant pathology in patients with posterior shoulder instability as multiple structures can be injured. Arthroscopic repair of the posterior labrum and posterior humeral avulsion of the glenohumeral ligament can be performed to restore posterior stability to the shoulder in the setting of a “floating” PIGL.

Lower limb musculoskeletal profiling in Malaysian professional footballers during pre-season pre-competition medical assessments

Background: Lower limb musculoskeletal profiling is important in pre-competition medical assessment (PCMA) as it helps to identify musculoskeletal pathologies that need rehabilitation and risk factors for injury that need specific prevention programme. However, a normative value is needed to identify which is normal or pathological. Our objective in this study is to establish a normative value for football-specific adaptation of lower limb musculoskeletal examination among Malaysian professional footballers. Materials and Methods: This is a prospective cross-sectional examining 83 Malaysian footballers from a single club during PCMA from 17 January 2022 to 17 February 2022. We included anthropometric assessments using body impedance analysis, objective lower limb muscle strength assessments using handheld dynamometer, range of motion and objective dynamic balance test using the Biodex system. Results: The mean age of our study was 20.3 ± 3 years. Goalkeepers and defenders have a higher body mass index and a higher skeletal muscle mass. Strikers and midfielders have a higher quadriceps and hamstring strength. Non-dominant leg has a better overall stability and anterior posterior stability index compared to dominant leg. Defender has a better overall stability. Sixty-six footballers (80%) have at least 1 low Add: Abd ratio of less than 0.9, which requires preventive programme for groin injury. Conclusion: This study demonstrates a position-specific adaptation in different positions in football.

Long-Term Clinical and Radiologic Outcome Following Surgical Treatment of Lumbar Spondylodiscitis: A Retrospective Bicenter Study.

Spinal instrumentation for spondylodiskitis (SD) remains highly controversial. To date, surgical data are limited to relatively small case series with short-term follow-up data. In this study, we wanted to elucidate the biomechanical, surgical, and neurologic long-term outcomes in these patients. A retrospective analysis from two German primary care hospitals over a 9-year period (2005-2014) was performed. The inclusion criteria were (1) pyogenic lumbar SD, (2) minimum follow-up of 1 year, and (3) surgical instrumentation. The clinical and radiologic outcome was assessed before surgery, at discharge, and at a minimum of 12 months of follow-up. Follow-up included physical examination, laboratory results, CT and MRI scans, as well as assessment of quality of life (QoL) using short-form health survey (SF-36) inventory, Oswestry Disability Questionnaire, and visual analog scale (VAS) spine score. Complete data were available in 70 patients (49 males and 21 females, with an age range of 67±12.3 years) with a median follow-up of 6.6 ± 4.2 years. Follow-up data were available in 70 patients after 1 year, in 58 patients after 2 years, and in 44 patients after 6 years. Thirty-five patients underwent posterior stabilization and decompression alone and 35 patients were operated on in a two-stage 360-degree interbody fusion with decompression. Pre- and postoperative angles of the affected motion segment were 17.6 ± 10.2 and 16.1 ± 10.7 degrees in patients with posterior instrumentation only and 21.0 ± 10.2 and 18.3 ± 10.5 degrees in patients with combined anterior/posterior fusion. Vertebral body subsidence was seen in 12 and 6 cases following posterior instrumentation and 360-degree instrumentation, respectively. Nonfusion was encountered in 22 and 11 cases following posterior instrumentation and 360-degree instrumentation, respectively. The length of hospital stay was 35.0 ± 24.5 days. Surgery-associated complication rate was 18% (12/70). New neurologic symptoms occurred in 7% (5/70). Revision surgery was performed in 3% (2/70) due to screw misplacement/hardware failure and in 3% (2/70) due to intraspinal hematoma. Although patients reported a highly impaired pain deception and vitality, physical mobility was unaffected and pain disability during daily activities was moderate. Surgical treatment of SD with a staged surgical approach (if needed) is safe and provides very good long-term clinical and radiologic outcome.

Percutaneous cortical bone trajectory screw fixation versus traditional open pedicle screw fixation for type A thoracolumbar fractures without neurological deficit.

Retrospective matched-cohort comparative study. Cortical bone trajectory screw (CBT) technique is a new insertion technique in terms of fixation strength and less invasiveness. The purposes of this study were to compare the clinical and radiological outcomes of percutaneous CBT fixation (PCBT) with traditional open posterior pedicle screw fixation (OPPS) technique. Between September 2019 and October 2020, patients undergoing posterior stabilization were matched for age, sex, diagnosis, fractured level, and AO classification. 24 control patients with OPPS were identified and appropriately matched to 24 consecutive patients with PCBT technique. Clinical outcomes and radiographic assessments including vertebral wedge angle (VWA) and sagittal index were recorded and compared between the two groups. Incision length, intraoperative blood loss and hospital stay in the PCBT group were significantly better than the OPPS group (P < 0.05). The VAS scores 5days after operation for PCBT patients were significantly lower than those for OPPS patients (P = 0.003), but these differences lost significance at last follow-up. There was no significant difference in VWA and sagittal index between OPPS and PCBT group (P > 0.05). While no complications were noted in the PCBT group, there were four cases with complications in the traditional OPPS group. The present study showed that PCBT is a safe and feasible method for the treatment of thoracolumbar fractures without neurological deficits. This new surgical treatment was more minimally invasive, yet yielded equivalent or superior clinical and radiographic outcomes compared to the traditional open pedicle screw fixation surgery.

Correlation between neurologic status and spinal injury at the Cervicothoracic Junction.

With limited studies on spinal injuries occurring at the cervicothoracic junction, there is currently a knowledge gap regarding the correlation between morphology of injury and neurology and whether surgery provides a favorable neurological outcome. The primary objective was to determine whether the neurological deficit correlated with the severity of injury at this region of the spine. All patients with injuries at the cervicothoracic junction from December 2015 to December 2020 in a government trauma hospital were included. Patient demographics, characteristics of the injury, neurological score, imaging findings, surgery details and neurological outcomes were analyzed. All patients had a minimum follow up of 2 years. Of the total 30 patients, 23 were male and 7 female with mean age 42.4 years. 90% had fall injuries with 76.7% sustaining AO type C injury and 10% with AO B2 injury.73.4% had injury at C6-C7 level followed by 13.3% , C7-T1. Only 16.7% patients presented with intact neurology. Plain x-rays failed to detect cervicothoracic junction, injuries in 63.3% patients. Posterior stabilization was performed in 56.7%. Neurological improvement was observed in 9 patients. Though cervicothoracic junction injuries are uncommon, they are highly unstable injuries and difficult to diagnose by plain x-rays. These injuries also result in profound neurological deficit. Surgical stabilization of these injuries should be considered for a favorable neurological and functional outcome.

Spinal canal stenosis in children with achondroplasia: the role of augmentation laminoplasty-a 15-year single institution experience.

Achondroplasia typically results in compressive spinal canal stenosis in one-third of children, but rare under the age of 15years. Laminectomy is the mainstay of treatment but this leads to instability and progressive deformity requiring complex fixation. In order to reduce that risk, we developed a novel modified augmented laminoplasty that increases spinal canal diameter while preserving the posterior column stability. All laminoplasty cases for spinal compressive achondroplasia from 2006 to 2020 were included. Ten augmentation laminoplasty procedures were performed in 7 children with regular clinical and radiological post-operative follow-up. Kyphotic deformity and clinical outcomes (neurological and urological) were evaluated. At presentation, clinical features included radiculopathy, neurogenic claudication or acute cauda equina compression with sphincter dysfunction. The average age at initial surgery was 11.2 (range 5-16) with a mean follow-up of 5 (range 2-8) years. All patients demonstrated improvement in neurogenic claudication symptoms after surgery; however, bladder dysfunction persisted in some children. In one child, cervical and lumbar augmentation laminoplasties were performed for concomitant disease. Augmentation laminoplasty effectively prevented deformity progression over time in all cases except one where a further revision laminoplasty with extension was required for screw loosening. Despite this, progressive symptomatic kyphotic deformity led to a 360° fixation. Minor complications included one dural breach (repaired intraoperatively) and one superficial wound infection. Augmentation laminoplasty is a viable surgical option following laminectomy in achondroplasia patients as an alternative to surgical fixation. Fixation can be reserved for cases where there is progressive deformity and kyphosis.

Increased Prevalence of Posterior Cruciate Ligament Dysfunction Noted With 3-Dimensional Intraoperative Kinematic Evaluation in Total Knee Arthroplasty.

Poor restoration of cruciate-driven kinematics after total knee arthroplasty may result from technical difficulties, but the ligament may also be functionally compromised by the presence of arthritis. We asked whether the function of the posterior cruciate ligament (PCL) could be assessed intraoperatively to predict the quality of the resulting posterior cruciate kinematics. PCL integrity was assessed using intraoperative infrared trackers to monitor knee kinematics in 73 patients. Three-dimensional images of the femur and tibia were projected onto a screen, allowing the surgeon to visualize kinematic relationships in real time. We measured femoral rollback (distance of femoral contact as a percentage of antero-posterior tray width) from images captured by the robotic system during initial kinematic assessment, gap balancing, and assessment of the final construct and from lateral flexion radiographs obtained 2 years after surgery. Associations were characterized using Pearson's correlation and graphical methods. Thirty-six knees (49%) showed rollback <60% during gap balancing, indicative of PCL insufficiency. The rollback during gap balancing was positively correlated with that seen in the final cruciate retaining constructs (r= 0.60, P < .001), which in turn predicted rollback 2 years after surgery on lateral flexion X-rays (r= 0.50, P= .006). Intraoperative functional evaluations can allow the surgeon to identify cases where rollback is not consistent with desirable knee kinematics, and posterior stabilization may lead to a better outcome for those patients.

The role of the long head of the biceps tendon in posterior shoulder stabilization during forward flexion.

The role of the long head of the biceps tendon (LHBT) in glenohumeral stability is not fully understood. Most objects are lifted in the sagittal plane with forward flexion, which stresses the posterior aspect of the unconstrained glenohumeral joint. Determining the mechanism by which the shoulder maintains stability with functional motions is important to understanding the pathoanatomy of degenerative shoulders. Our hypothesis was that the LHBT resists posterior translation of the humeral head (HH) during forward flexion by tensioning the posterior capsuloligamentous complex. Ten fresh-frozen cadaveric shoulders were tested using an established shoulder simulator that loads the LHBT, rotator cuff, and deltoid tendons through a system of pulleys. A motion tracking system recorded glenohumeral translations with an accuracy of ±0.2 mm. In each subject, the scapula was fixed and the humerus was tested in 6 positions: 30° and 60° of glenohumeral forward flexion at (1) maximum internal rotation (IR), (2) neutral rotation, and (3) maximum external rotation (ER). The deltoid was loaded with 100 N, and the infraspinatus and subscapularis were loaded with 22 N each. The difference in glenohumeral translation was calculated at each position comparing the LHBT loaded with 45 N or unloaded. At 30° of glenohumeral forward flexion, unloading the LHBT increased HH posterior translation by 2.5 mm (±0.9 mm; P<.001), 1.7 mm (±1.0 mm; P<.001), and 1.0 mm (±0.9 mm; P=.01) at maximum ER, neutral rotation, and maximum IR, respectively. At 60° of glenohumeral forward flexion, unloading the LHBT increased HH posterior translation by 2.8 mm (±1.2 mm; P<.001), 2.4 mm (±1.6 mm; P<.001), and 1.7 mm (±1.4 mm; P<.001) at maximum ER, neutral rotation, and maximum IR, respectively. LHBT loading resists posterior translation of the HH during forward flexion. These data support the role of the LHBT as a posterior stabilizer of the shoulder, specifically when a person is carrying objects in front of them. Further work is needed to determine if unloading the LHBT, as is done with biceps tenotomy or tenodesis, may eventually lead to posterior labral pathology, or to the posterior glenoid wear commonly seen with osteoarthritis.

Sacral fractures in geriatric patients

Sacral fractures in geriatric patients are increasing and form a distinct entity. Clinical findings can be unspecific, which is why they are easily overlooked. It is mandatory to analyze the whole pelvic ring for evaluation of pelvic stability and for making treatment decisions. The primary diagnostics are made using plain X‑radiography; however, for assessment of the posterior pelvic ring an examination using sectional imaging is regularly necessary. The fragility fractures of the pelvis (FFP) classification is suitable as a guideline for the surgical treatment to be used. Stable fractures without relevant displacement after initial mobilization should be treated conservatively. Instability, failure of mobilization and persistent pain are, however, common reasons for surgical treatment. Fracture displacement determines if minimally invasive procedures for posterior and anterior pelvic ring stabilization are possible. Otherwise, complex open procedures such as spinopelvic fixation may be necessary.

Posterior cruciate ligament reconstruction with independent internal brace reinforcement: surgical technique and clinical outcomes with a minimum two year follow-up

PurposeWe developed an augmentation technique for PCL reconstruction with independent internal brace reinforcement and evaluated the functional outcome after PCL reconstruction employing autologous hamstrings augmented with an internal brace system for patients with isolated or combined grade 3 posterior instability who were treated with this technique.MethodsFrom January 2016 to January 2018, patients with isolated or combined grade 3 PCL tears who underwent single-bundle PCL reconstruction using autologous hamstrings augmented with independent internal braces were studied. The function of the operated knee was evaluated according to the International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity score. The patients were asked the level of returned to their previous sport. Posterior knee laxity was examined with a KT-1000 arthrometer, and data on range of motion (ROM), re-operation, and other complications were collected.ResultsA total of 33 consecutive patients who received single-bundle PCL reconstruction using autologous hamstrings augmented with independent internal braces with a minimum two years follow-up were included in this study. Two patients had undergone this procedure during the study period and were not included in this study (one had combined bone fractures, and one patient had previous meniscus surgery). Thirty-one patients were available for final analysis. The mean follow-up was 45.35 ± 10.88 months (range 29–66 months). The average IKDC subjective knee evaluation scores from 51.65 ± 12.35 to 84.52 ± 6.42, the Lysholm score from 53.90 ± 11.86 to 85.68 ± 4.99, and the Tegner score from 2.81 ± 0.79 to 6.71 ± 1.83 (P < 0.05 for all). The mean total posterior side-to-side difference in knee laxity, assessed using a KT-1000 arthrometer, decreased from 12.13 ± 2.66 mm pre-operatively to 1.87 ± 0.56 mm post-operatively at 70° (P < 0.05). Most patients (29/31) had normal or near normal knee ROM post-operatively; two patients revealed a 6–15° loss of knee flexion compared with the contralateral knee. Twenty-nine patients (93.55%) returned to a normal daily exercise level. Twenty-three patients (74.19%) returned to competitive sports with high-level sports (Tegner score of 6 or above; eleven patients (35.48%) reported to be on the same level as well as the Tegner level); six patients (19.35%) returned to recreational sports (Tegner score of 4 or 5). Two patients had Tegner scores of 2 and 3, indicating poor function level. No patient needed PCL revision surgery during the follow-up period.ConclusionSingle-bundle PCL reconstruction with internal brace augmentation for PCL injury exhibited satisfactory posterior stability and clinical outcomes in patients with isolated or combined grade 3 PCL injuries at a minimum two year follow-up.

Preliminary Results of a Prospective Clinical and Radiological Study with Roentgen Stereophotogrammetric Analysis (RSA) after Implantation of a Posterior Dynamic Stabilization Device in the Lumbar Spine

Introduction: Posterior dynamic stabilization (PDS) can be based on interspinous distraction devices (IDD). The goals of these implants are maintaining or restoring intervertebral range of motion (ROM) in a controlled fashion and avoiding a complete restriction of mobility. Clinical and radiological data with the Wallis® spacer as one type of IDD have been rarely reported. The goal of this study was to present clinical and radiological data including roentgen stereophotogrammetric analysis (RSA) after a short- to mid-term follow-up period.&#x0D; Patients and Methods: 10 patients were included in this prospective monocentric study and had PDS of the lumbar spine with an IDD (Wallis® spacer). Before and soon after operation and 3, 6, and 12 months later clinical and radiological evaluations were performed. Pain and disability were analyzed by use of visual analog scale for back and leg pain, Oswestry Disability Index, Roland-Morris Disability Questionnaire and Short-Form-36 Health Survey. The ROM of the operated levels and the total lumbar spine was determined by use of lateral functional x-ray images with calculation of the differences of the segmental and total lumbar spine angles in flexion and extension. Furthermore, RSA was used to measure the segmental ROM.&#x0D; Results: After a follow-up of 12 months, the results of the pain intensity and the disability and health related quality of life scores showed statistical significant improvement. The segmental angles of the operated levels demonstrated statistical significant reduction in ROM during the different follow-up examinations. The discrepancy of the conventionally determined segmental angles and the data measured by RSA were low with a mean of 1.77°. The mean total lumbar spine angles did not change statistically significantly during the postoperative controls.&#x0D; Conclusions: According to the radiological results of this study, the used implant leads to a posterior dynamic stabilization. The clinical findings are promising, but they are to be interpreted with caution because of the small number of patients and the lack of a control group.

Posterior stabilization with polyetheretherketone (PEEK) rods and transforaminal lumbar interbody fusion (TLIF) with titanium rods for single-level lumbar spine degenerative disease in patients above 70 years of age

BackgroundGiven the lack of guidelines regarding the operative management of elderly patients needing lumbar spine fusion for degenerative disease, it is often difficult to balance between invasiveness respecting the fragile spine and geriatric comorbidities.AimTo compare reoperation rates and clinical outcome in patients above 70 years of age undergoing Transforaminal Lumbar Interbody Fusion (TLIF) with titanium rods or posterior stabilization with Polyetheretherketone (PEEK) rods for the treatment of one-level lumbar spine degenerative disease.MethodsRetrospective review of baseline characteristics, reoperation rates as well as the clinical and radiological outcomes of patients, older than 70 years, undergoing posterolateral fusion with PEEK rods (n = 76, PEEK group) or TLIF with titanium rods (n = 67, TLIF group) for a single-level lumbar degenerative disease from 2014 to 2020. Additional subanalysis on the patients above 80 years of age was performed.ResultsOur results showed similar reoperation rates and outcomes in the TLIF and PEEK groups. However, intraoperative blood loss, administration of tranexamic acid, and operation time were significantly higher in the TLIF group. In patients older than 80 years, reoperation rates at first follow-up were significantly higher in the TLIF group, too.ConclusionAccording to our results, posterior stabilization with PEEK rods is less invasive and was associated with significantly lower blood loss, administration of blood products and shorter operation time. Moreover, in patients above 80 years of age reoperations rates were lower with PEEK rods, as well. Nevertheless, the benefits of PEEK rods for foraminal stenosis still have to be investigated.

Paper 10: Long-Term Outcomes Following Arthroscopic Posterior Shoulder Stabilization: Minimum 10 Year Follow-up

Objectives:Posterior shoulder instability accounts for approximately 2-12% of shoulder instability cases and represents a debilitating if not potentially career-ending injury in athletic populations. Arthroscopic posterior shoulder stabilization through capsulolabral reconstruction has been shown to reduce pain and improve function, facilitating return to sport at short- to medium-term follow-up. However, few long-term follow-up studies (exceeding 10 years) have been performed to assess the persistent benefit in shoulder function achieved by surgical intervention. Therefore, the purpose of this study was to investigate the objective and subjective clinical outcome measures of shoulder function in patients who underwent arthroscopic posterior shoulder stabilization with a minimum follow-up time of 10 years. It was hypothesized that current shoulder function would remain statistically superior to preoperative shoulder function, with diminishing benefit for those who required revision surgery.Methods:A group of 183 patients (200 shoulders) who underwent arthroscopic capsulolabral reconstruction for isolated posterior shoulder instability between January 1998 and December 2009 were recruited via existing contact information within the electronic medical record at a single academic medical institution. Institutional review board approval was obtained prior to study initiation, and all patients signed informed consent. Patient characteristics including age, gender, hand dominance, sports played, level of participation, and length of follow-up, were obtained. Patients completed an online questionnaire containing the American Shoulder and Elbow (ASES) shoulder score and the Kerlan-Jobe Orthopaedic Clinic (KJOC) shoulder and elbow score. Subjective scores of pain, stability, range of motion (ROM), and strength were also obtained. The level of sporting participation after treatment was determined and patients assessed whether the initial surgery was worthwhile. Current shoulder status, as compared to preoperative (but post-injury) shoulder status, was compared according to the above metrics. Subgroup analyses were performed comparing outcomes between athletes whose primary sport did or did not involve overhead throwing. Subgroup analyses were also performed for patients who underwent revision surgery, as compared to those who did not, including additional evaluation of shoulder function after failure but preceding revision surgery. Group means for continuous variables were compared using ANOVA and student’s t tests as appropriate, while ordinal or categorical data were compared with Wilcoxon signed rank tests or Fisher’s exact test when suitable.Results:53 patients (55 shoulders) with a mean age of 23 years at surgery were included, with an average follow-up time of 15.4 years. 49 of 53 patients were right-hand dominant, with right shoulder injury in 35 cases. Patient characteristics for subgroup analyses based upon position and need for revision surgery are shown in Table 1. Across all patients (55 shoulders) there was significant improvement in all outcome measures, including scores of ASES, KJOC, pain, stability, ROM, and strength, comparing current to preoperative shoulder status (Table 2). Similar trends were found in subgroup analyses, with throwers and non-throwers demonstrating equivalent improvements. In contrast, patients who underwent revision surgery (n=8) possessed a current shoulder status equivalent to preoperative status, across all outcome measures, although significantly improved when compared to shoulder status after initial failure (Table 2). Across all patients, 60% returned to sport at any level, with 34.5% returning to sport an the same level as prior to injury. 89% of patients felt the initial surgery was worthwhile. Subgroup analysis demonstrated a trend towards compromised return to sport at pre-injury levels in throwing athletes, but statistical significance was not achieved (p = .09).Conclusions:The main finding of this study was that arthroscopic capsulolabral reconstruction produced significant pain relief and improved shoulder function at long-term follow-up, that is, at a mean of 15.4 years following surgery. Of the limited patient population that underwent revision surgery (n=8), current shoulder status did not differ statistically from preoperative status (i.e., no significant improvement compared to preoperative function). Both findings support the hypothesis. No differences in throwing athletes were found in comparison to non-throwing athletes according to the outcome measures explored. The majority of patients were able to return to sport following surgery, but only 64% of non-throwers returned to sport at the same level as prior to injury, with only 21% of throwers returning to pre-injury levels. While some of these findings are attributed to a discontinuation or reduction in sporting activity due to expected life circumstances (e.g. graduation), the results suggest continued opportunity to improve shoulder function following injury entailing a posterior instability event. This study is also limited by the absence of a group that did not undergo operative intervention. While this study is limited by a relatively small sample size, it does represent one of the longest follow-up periods for posterior shoulder stabilization, demonstrating sustained benefit in shoulder pain and function following arthroscopic surgery.

Paper 11: Return to Sport Testing vs Time-Based Clearance in Posterior Shoulder Instability

Objectives:Recurrent pain, instability and loss of function is a challenging complication that can occur after arthroscopic treatment of posterior shoulder instability and SLAP tears in athletes. Many surgeons allow return to sport after a designated arbitrary postoperative time point. Recent evidence has demonstrated that a majority of athletes have residual strength and functional limitations at 6 months postoperatively – the time at which most time-based protocols allow full return to sport1. Recent data has also been presented that patients undergoing arthroscopic Bankart repair who are required to meet objective return to sport testing criteria have a 4x lower rate of recurrent anterior instability than those who return based on time elapsed since surgery2. Considering these findings, the purpose of this study is to investigate the use of a similar objective return to sport testing protocol on recurrence rates following arthroscopic surgery for posterior shoulder instability and SLAP tears. We hypothesized that patients who meet objective return to sport criteria would have a lower rate of reoperation and recurrence of symptoms compared to those who did not undergo the testing and were cleared to return based on time from surgery.Methods:Consecutive patients (Group 1) who underwent arthroscopic posterior shoulder stabilization surgery with or without SLAP repair by a single surgeon from 2016 to 2019, had a minimum of 1 year follow up, and completed functional and strength testing to evaluate readiness for return to sport were included in this retrospective case-controlled study. These patients were compared to a control group of historical consecutive cases (Group 2) from 2012-2016 who did not undergo return to sports testing and were cleared for sports after a minimum of 6 months following surgery. Failure was defined as recurrent symptoms of pain or instability requiring reoperation. Exclusion criteria were: patients undergoing isolated anterior stabilization procedures with or without concomitant SLAP tears, multidirectional instability, and open procedures. Chi-square, Fisher exact tests and two-tailed Students T-test were performed. Statistical significance was set at p<0.05.Results:There were 33 patients in Group 1 who underwent return to sport testing, and 90 patients in Group 2, the historical control. There were no differences between groups regarding sex (p=0.46), hand dominance (p=0.16), side affected (p= 0.69. The average age of Group 1 (20.8 +/- 4 yrs) was significantly younger than Group 2 (31.6 +/- 9.1 yrs, p< 0.00001). Patients who underwent return to sport criteria-based testing protocol had a rate of recurrent symptoms of pain or instability of 12.1% compared to 18.9% for those who did not (p= 0.43). Similarly, there were no reoperations for in Group 1, while three patients in group 2 (3.3%) underwent revision surgery for recurrent symptoms. This difference, however, did not reach statistical significance (p= 0.5633).Conclusions:In our cohort of young patients undergoing arthroscopic surgery for posterior shoulder instability, we detected no significant difference in reoperation rate and recurrence of symptoms between athletes who underwent objective return to sport testing and those who were released to sport on a time-based protocol. This may be related to an overall lower rate of reoperation in patients undergoing arthroscopic posterior stabilization or SLAP repairs in general compared to those undergoing arthroscopic anterior stabilization and differences in tolerance and presentation of recurrent posterior instability/SLAP tears versus anterior instability. It is possible that criteria-based return to sport testing prior to clearance to return to sport may be less critical for improving failure rates following arthroscopic posterior stabilization and SLAP repair than for anterior stabilization. Alternatively, given low reoperation rates overall, future studies investigating the role of return to sport testing after arthroscopic surgery for posterior shoulder instability and SLAP repairs may need to include more patients in order to detect differences related to the testing protocol. Objective functional testing may be a viable alternative to arbitrary, time-based criteria for returning to sport in patients who have undergone arthroscopic posterior shoulder stabilization and SLAP repairs.

Predictive factors of posterior corneal shift aftersmall incision lenticule extraction: a 5-year follow-up study.

The aim of this study was to determine risk factors affecting changes in posterior corneal elevation (PCE) and predict the 5-year stability after small incision lenticule extraction (SMILE). This retrospective, longitudinal study enrolled 161 patients post-SMILE. The PCE values were measured at the apex, thinnest, maximal and 24 other prespecified preoperative points and at 6 months, 1 year and 5 years postoperatively. Posterior corneas exhibited time-dependent, region-dependent and angle-dependent changes. For every dioptre increase in the absolute preoperative spherical equivalent (SE), 10-μm decrease in the central corneal thickness (CCT), 10-μm increase in the maximum lenticule thickness (MLT), 10-μm decrease in the residual bed thickness (RBT), 10% increase in the percentage ablation depth (PAD, MLT divided by CCT) and 10% decrease in the percentage stromal bed thickness (PSBT, RBT divided by CCT), PCE exhibited average forward displacements of 0.2-0.4, 0.2-0.7, 0.1-0.2, 0.1-0.3, 0.6-1.0 and 0.5-1.1 μm, respectively (p < 0.05). PSBT was the variable with the highest accuracy in predicting 5-year stability of posterior corneas (area under curve = 0.75). The cut-off values of SE, CCT, MLT, RBT, PAD and PSBT for increased PCE were -8.00 to -8.31 D, 481.0-498.5 μm, 139.5-144.5 μm, 255.5-263.5 μm, 26.9-28.3% and 48.9-52.6%, respectively. Eyes with thinner corneas, higher myopia requiring greater MLT and lower RBT exhibited greater predispositions towards posterior protrusion. The thresholds for preventing forward posterior corneal displacement were 26.9-28.3% for PAD and 48.9-52.6% for PSBT. Prediction of posterior corneal stability is useful for assessing surgical risks post-SMILE.

Risk Factors for Postoperative Loss of Correction in Thoracolumbar Injuries Caused by High-Energy Trauma Treated via Percutaneous Posterior Stabilization without Bone Fusion.

Background and Objectives: Percutaneous pedicle screws were first introduced in 2001, soon becoming the cornerstone of minimally invasive spinal stabilization. Use of the procedure allowed adequate reduction and stabilization of spinal injuries, even in severely injured patients. This decreased bleeding and shortened surgical time, thereby optimizing outcomes; however, postoperative correction loss and kyphosis still occurred in some cases. Thus, we investigated cases of percutaneous posterior fixation for thoracolumbar injury and examined the factors affecting the loss of correction. Materials and Methods: Sixty-seven patients who had undergone percutaneous posterior fixation for thoracolumbar injury (AO classifications A3, A4, B, and C) between 2009 and 2016 were included. Patients with a local kyphosis angle difference ≥10° on computed tomography at the postoperative follow-up (over 12 months after surgery) or those requiring additional surgery for interbody fusion were included in the correction loss group (n = 23); the no-loss group (n = 44) served as the control. The degree of injury (injury level, AO classification, load-sharing score, local kyphosis angle, cuneiform deformity angle, and cranial and caudal disc injury) and surgical content (number of fixed intervertebral vertebrae, type of screw used, presence/absence of screw insertion into the injured vertebrae, and presence/absence of vertebral formation) were evaluated as factors of correctional loss and compared between the two groups. Results: Comparison between each group revealed that differences in the wedge-shaped deformation angle, load-sharing score, degree of cranial disc damage, AO classification at the time of injury, and use of polyaxial screws were statistically significant. Logistic regression analysis showed that the differences in wedge-shaped deformation angle, AO classification, and cranial disc injury were statistically significant; no other factors with statistically significant differences were found. Conclusion: Correction loss was seen in cases with damage to the cranial intervertebral disc as well as the vertebral body.

Comparing the Effect of Classical and Modified Thoracolumbar Interfascial Plane Block on Postoperative Pain and IL-6 Level in Posterior Lumbar Decompression and Stabilization Surgery

BackgroundUltrasound (US)-guided classical and modified thoracolumbar interfascial plane (TLIP) blocks are often used to provide adequate analgesia after lumbar spinal surgery. Postoperative pro-inflammatory interleukin 6 (IL-6) blood concentrations after lumbar spine surgery are related to postoperative pain and inflammation.ObjectivesThe purpose of this prospective randomized parallel controlled study was to assess postoperative pain and serum levels of pro-inflammatory IL-6 after posterior lumbar decompression and stabilization surgery with a classical and modified technique of TLIP block.MethodsThis prospective randomized, single-blinded controlled pilot study was conducted on eight patients who will undergo posterior lumbar decompression and stabilization surgery. After obtaining the ethical approval and an informed consent, all subjects were randomly allocated into the classic TLIP group and the modified TLIP group. Following general anesthesia induction, 20 mL bupivacaine 0.25% was injected on each side in interfascialis plane between m. longissimus and m. iliocostalis in modified TLIP group and between m. multifidus and m. longissimus in classical TLIP group. Intraoperative hemodynamic (blood pressure and heart rate) and noxious stimulation response level (qNOX), postoperative IL-6 level, 24-hour morphine consumption, and numerical rating score were recorded and analyzed.ResultsThe median of IL-6 level was found to be lower in the modified TLIP group 12 hours postoperatively compared to classic TLIP (29.91 (8.56 – 87.61) vs. 46.87 (2.87 – 92.35)). The mean Numerical Rating Scale (NRS) in the modified TLIP block was comparable with the classic TLIP group, although it was lower than the classic TLIP group (2.75 ± 1.5 vs. 3.75 ± 1.7 at 6 hours and 3.5 ± 1.3 vs. 4 ± 1.6 12 hours postoperatively). However, there was no difference in intraoperative hemodynamic, Qnox value, and total postoperative morphine consumption between the two groups.ConclusionsOur study showed that modified TLIP block resulted in lower IL-6 level and NRS 12 hours postoperatively compared to classical TLIP block. However, there were no differences in total postoperative morphine consumption between the two groups.