Satisfactory mid-term clinical outcomes of endoscopic tenotomy for iliopsoas tendinopathy following total hip arthroplasty.

PURPOSE: To report 5-year outcomes of endoscopic iliopsoas tenotomy in patients with iliopsoas tendinopathy following total hip arthroplasty (THA) and determine whether clinical scores are associated with cup position. METHODS: Patients who underwent endoscopic iliopsoas tenotomy for iliopsoas tendinopathy following THA (2014-2017) were contacted. Indications for endoscopic iliopsoas tenotomy after THA were groin pain during active hip flexion, exclusion of other causes of groin pain, and no pain relief after 6 months of conservative treatment. Pretenotomy cup inclination and anteversion were measured on radiographs; axial and sagittal cup overhang were measured on computed tomography (CT) scans. Oxford hip score (OHS), modified Harris hip score (mHHS), and groin pain were assessed. RESULTS: The initial cohort comprised 16 men (17 hips) and 31 women (32 hips), aged 60.7 ± 10.6 years. Cup inclination and anteversion were, respectively, 46.2 ± 6.2° and 14.6 ± 8.4°, while axial and sagittal cup overhang were, respectively, 4.4 ± 4.0 mm and 6.9 ± 4.5 mm. At ≥5 years follow-up, four hips underwent cup and stem revision, two underwent isolated cup revision and one underwent secondary iliopsoas tenotomy. OHS improved by 23 ± 10 and mHHS improved by 31 ± 16. Posttenotomy groin pain was slight in 20.0%, mild in 17.5% and moderate in 12.5%. Regression analyses revealed that net change in mHHS decreased with sagittal cup overhang (ß = -3.1; 95% confidence interval [CI] = -4.6 to -1.7; p < 0.001), but that there were no associations between cup position and net change in OHS. CONCLUSIONS: Endoscopic iliopsoas tenotomy provides good mid-term clinical outcomes in patients with iliopsoas tendinopathy following THA. Furthermore, improvements in mHHS were found to decrease with increasing sagittal cup overhang, in cases for which adequate preoperative imaging was available. LEVEL OF EVIDENCE: Level IV.

Oblique Lumbar Interbody Fusion at L5-S1 Segment Through an Approach Between the Psoas Muscle and the Great Vessels.

Over the years, the oblique lateral interbody fusion (OLIF) technique has gained significant recognition for treating various spinal conditions in lumbar segments L2-L5. However, the adoption of OLIF for the L5-S1 segment has not been widely embraced by the spinal surgery community, given that significant concerns remain regarding the applicability of OLIF for lumbosacral fusion. In this study, a cohort of 20 patients underwent interbody fusion at the L5-S1 level using the OLIF technique through a single retroperitoneal oblique approach positioned between the Psoas muscle and the great vessels. The procedure involved discectomy and endplate preparation accomplished through a surgical window created on the anterolateral side of the L5-S1 disc. For secure interbody fusion cage placement, a supplementary cage insertion approach was employed. All patients were followed up for a minimum of 12 months. The mean preoperative visual analog scale (VAS) score for lower back pain was 6.3 ± 1.5 and experienced a significant reduction to 1.2 ± 0.8 at 12 months. The VAS score for lower limb pain significantly decreased from 5.6 ± 1.4 preoperatively to 0.8 ± 0.3 at 12 months after the surgery. Furthermore, the preoperative Oswestry disability index (ODI) improved from 82.4% ± 16.2% to 8.1% ± 2.0% at 12 months. Radiographic evaluations after surgery confirmed improved lumbosacral junction reconstruction for all patients. At the final follow-up, successful bony fusion was observed in all cases. Based on these findings, the OLIF technique for L5-S1 fusion represents an attainable approach for lumbosacral reconstruction. The procedure's success hinges on a comprehensive preoperative plan and precise intraoperative techniques.

Removal of schwannoma from the psoas muscle with intraoperative neurophysiological monitoring: A case report.

RATIONALE: The incidence of a schwannoma within the psoas muscle is rare, and only a few cases have been reported. The surgical approach to removing schwannomas present in the psoas muscle is challenging because of its anatomical proximity to the lumbar plexus. PATIENT CONCERNS: A 31-year-old man experienced right lower back pain and anterolateral thigh numbness for 2 months. DIAGNOSIS: Magnetic resonance imaging of the patient's lumbar spine revealed a mass lesion, which was radiologically diagnosed as a well-demarcated schwannoma. INTERVENTIONS: The patient underwent surgery for excision of the schwannoma in the right psoas muscle at the second to fourth lumbar vertebrae levels. During surgery, intraoperative neurophysiological monitoring modalities, free-running and triggered electromyography and evoked potentials, from the target muscles were recorded. OUTCOMES: There was no neurotonic discharge corresponding to neuronal injury. Compound motor nerve action potential was detected in the triggered electromyography of muscles around the medial margin of the tumor. However, direct integration of the motor nerve was not observed in the intra-tumor region. LESSONS: We report that schwannoma removal in the psoas muscle, which is adjacent to the lumbar plexus, can be safely performed using intraoperative neurophysiological monitoring.

Editorial Commentary: For Post-Hip Arthroplasty Iliopsoas Tendonitis, Psoas Tenotomy Is the Preferred First-Line Treatment, Even in Cases of Cup Overhang.

Iliopsoas impingement pathology is one of the causes of persistent pain after total hip arthroplasty. It is reported as occurring in approximately 4% of cases; this may be significantly greater (in cases of postarthroplasty pain of unknown etiology). Inflammation is a result of impingement of the tendon against the acetabular component. This may occur with anteroinferior prominence when the cup is properly positioned in anteversion or when the cup is oversized. Other causes of impingement include a cup-reinforcement ring or acetabular cage, a collared femoral component, screws penetrating through the ilium, cement extrusion, anterior wall hypoplasia, or increased femoral offset. When conservative treatment does not achieve the best outcome, the 2 main therapeutic options are psoas tenotomy or revision of the cup component. Tenotomy can be performed either arthroscopically or by an open approach and may be considered the best option for many patients, even in cases with anterior component prominence, as it is less invasive, presents fewer complications, and has faster recovery. The debate is open. The level of tenotomy remains controversial, with risks and benefits of both a lesser trochanter and transcapsular approach.

Approach-related anatomical differences in patients with lumbo-sacral transitional vertebrae undergoing lumbar fusion surgery at level L4/5.

INTRODUCTION: Lumbo-sacral transitional vertebrae (LSTV) are accompanied by changes in soft tissue anatomy. The aim of our retrospective study was to evaluate the effects of LSTV as well as the number of free lumbar vertebrae on surgical approaches of ALIF, OLIF and LLIF at level L4/5. MATERIAL AND METHODS: We assessed the CTs of 819 patients. Of these, 53 had LSTV from which 11 had six (6LV) and 9 four free lumbar vertebrae (4LV). We matched them for sex and age to a control group. RESULTS: Patients with LSTV had a higher iliac crest and vena cava bifurcation, a greater distance between the common iliac veins and an anterior translation of the psoas muscle at level L4/5. In contrast, patients with 6LV had a lower iliac crest and aortic bifurcation, no differences in vena cava bifurcation and distance between the iliac veins compared to the control group. CONCLUSIONS: For patients with LSTV and five or four free lumbar vertebrae, the LLIF approach at L4/5 may be hindered due to a high riding iliac crest as well as anterior shift of the psoas muscle. Whereas less mobilization and retraction of the iliac veins may reduce the risk of vascular injury at this segment by ALIF and OLIF. For patients with 6LV, a lower relative height of the iliac crest facilitates lateral approach during LLIF. For ALIF and OLIF, a stronger vessel retraction due to the deeper-seated vascular bifurcation is necessary during ALIF and is therefore potentially at higher risk for vascular injury.

L4/5 accessibility for extreme lateral interbody fusion (XLIF): a radiological study.

INTRODUCTION: Potential advantages of the Extreme Lateral Interbody Fusion (XLIF) approach are smaller incisions, preserving anterior and posterior longitudinal ligaments, lower blood loss, shorter operative time, avoiding vascular and visceral complications, and shorter length of stay. We hypothesize that not every patient can be safely treated at the L4/5 level using the XLIF approach. The objective of this study was to radiographically (CT-scan) evaluate the accessibility of the L4/5 level using a lateral approach, considering defined safe working zones and taking into account the anatomy of the superior iliac crest. METHODS: Hundred CT examinations of 34 female and 66 male patients were retrospectively evaluated. Disc height, lower vertebral endplate (sagittal and transversal), and psoas muscle diameter were quantified. Accessibility to intervertebral space L4/5 was investigated by simulating instrumentation in the transverse and sagittal planes using defined safe zones. RESULTS: The endplate L5 in the frontal plane considering defined safe zones in the sagittal and transverse plane (Zone IV) could be reached in 85 patients from the right and in 83 from the left side. Through psoas split, the safe zone could be reached through psoas zone II in 82 patients from the right and 91 patients from the left side. Access through psoas zone III could be performed in 28 patients from the right and 32 patients from the left side. Safe access and sufficient instrumentation of L4/5 through an extreme lateral approach could be performed in 76 patients of patients from the right and 70 patients from the left side. CONCLUSION: XLIF is not possible and safe in every patient at the L4/5 level. The angle of access for instrumentation, access of the intervertebral disc space, and accessibility of the safe zone should be taken into account. Preoperative imaging planning is important to identify patients who are not suitable for this procedure.

Evaluation of iliopsoas tendon using shear wave elastography after open reduction surgery for developmental dysplasia of hip.

OBJECTIVES: The aim of this study was to investigate the wholeness, thickness, and elastography measurements of the iliopsoas tendon using shear wave elastography who underwent open reduction surgery for unilateral developmental dysplasia of the hip. PATIENTS AND METHODS: Between January 2011 and December 2016, a total of 15 patients (2 males, 13 females; mean age: 24.6±26.3 months; range, 3 to 98 months) who underwent surgical treatment for unilateral DDH were retrospectively analyzed. In addition to demographic data, clinical findings such as muscle strength, range of motion, and the presence of limping were recorded. Ultrasound elastography was used to examine the thickness, shear wave velocity and elasticity of the iliopsoas tendons. RESULTS: The mean follow-up was 92.6±30.2 (range, 44 to 120) months. Full range of motion of the hips was observed in all patients. Hip flexor muscles' strength was 5/5 in bilateral. No hip dislocation or limping was not detected in any of the patients. Ultrasound examinations revealed that tenotomized iliopsoas tendons were intact in all patients. The mean muscle thickness was lower in operated sides, indicating no statistically significant difference. The mean velocity and elasticity were statistically significantly higher in the operated sides. CONCLUSION: This is the first study using shear wave ultrasonography for iliopsoas tenotomy of the patients underwent open reduction for developmental hip dysplasia. Re-adhesion of the iliopsoas tendons provided wholeness while healing as a more rigid and thinner structure compared to the intact sides.

Psoas weakness following oblique lateral interbody fusion surgery: a prospective observational study with an isokinetic dynamometer.

BACKGROUND CONTEXT: Although the surgical corridor used for oblique lateral interbody fusion (OLIF) protects the intrapsoas nerves by causing minimal compression, transient weakness remains the most commonly reported postoperative complication. PURPOSE: Using a dynamometer to evaluate how the hip flexor strength changes following OLIF. STUDY DESIGN/SETTING: A prospective observational study. PATIENT SAMPLE: Forty-six patients who underwent single or multi-level OLIF for lumbar spondylolisthesis. OUTCOME MEASURES: Isokinetic dynamometer values (peak torque, total work, average power), visual analogue scale (VAS) scores for leg pain, hypoesthesia, subjective weakness of the left hip flexor muscle, Oswestry disability index, body mass index, bone mineral density, radiologic findings of the psoas muscle (cross-sectional area, Hounsfield unit (HU), fat portion grade), and psoas retraction time. METHODS: The isokinetic muscle strength of the hip flexor was measured five times (preoperatively and postoperatively at 2 days, 1 week, 1 month, and 3 months) for both legs. The peak torque was defined as the postoperative strength of the left hip flexor muscles, and was compared to the preoperative baseline value. The strength of the left and right hip flexor muscles were also compared at each time point. For logistic regression analysis, when the peak torque was below the median value, it was defined as lower peak torque. RESULTS: Up to 1 week after surgery, the strength of the left hip flexor muscle decreased significantly (paired difference in peak torque was 22.6%, p<.001). In the results of multivariate logistic regression analysis, diabetes (odds ratio [OR]=8.43, p=.020) and the HU of the psoas muscle (OR=0.916, p=.034) were associated with lower peak torque 1 week after surgery. From 1 month after surgery, postoperative weakness of the psoas muscle was not significant. In the questionnaire survey, subjective left hip flexion weakness was reported in 8.5% (4/47) of patients 1 week after surgery, and it remained in only 2.1% (1/47) of patients after 3 months of operation. The frequency of left anterior thigh pain and hypoesthesia decreased from 85.1% (40/47) at 1 week to 2.1% (1/47) at 3 months after surgery. The mean VAS score for left anterior thigh or groin pain decreased significantly at 1 month after surgery (PO2D: 4.04±1.84, PO1M: 1.67±1.10, p<.001). CONCLUSIONS: Dynamometer measurement showed that psoas strength declined significantly up to 1 week after OLIF surgery. Patients with diabetes or lower HU of the psoas muscle showed delayed recovery from postoperative weakness of the psoas muscle. However, the weakness was insignificant from 1 month after surgery. At 3 months after surgery, the other psoas-related problems (left anterior thigh pain and hypoesthesia) also disappeared.

Efficacy and safety of a modified lateral lumbar interbody fusion in L4-5 lumbar degenerative diseases compared with traditional XLIF and OLIF: a retrospective cohort study of 156 cases.

BACKGROUND: The authors designed a modified lateral lumbar interbody fusion (LLIF) procedure named as XOLIF and compared the efficacy and safety with traditional LLIF procedures. METHODS: Patients were divided into XLIF, OLIF, and XOLIF group according to the surgical approach. Cases of psoas major and vascular space stenosis, psoas major muscle elevation, psoas major muscle hypertrophy, and high iliac crest were recorded. Basic information, composition ratio of specific cases, Visual analog scale (VAS), Oswestry Disability Index (ODI), interbody fusion rate and complications were compared between the 3 groups. RESULTS: The study included 156 cases of L4-5 LLIF. There was no statistical difference in age, gender, BMI among the three groups. Cases with stenosis between psoas muscle and artery accounted for 11.8 and 18.4% of the XLIF and XOLIF group, respectively, while no case of this type had undergone OLIF surgery, the difference was statistically significant (P < 0.05). The proportions of high iliac crest cases in the OLIF and XOLIF group were 12.5 and 18.4%, respectively, while the XLIF group with vertical approach is not suitable for cases with high iliac crest. The postoperative VAS and ODI of the three groups were significantly improved compared with those before operation. There were 51 cases (32.7%) of complications including 21cases in XLIF group, 20 cases in OLIF Group and 10 cases in XOLIF group. XOLIF group has more advantages in reducing lumbar plexus injury and the risk of vascular injury. CONCLUSIONS: XOLIF showed good clinical efficacy and technical advantages with a low incidence of intraoperative and postoperative complications, especially in the specific cases.

Results after arthroscopic treatment of iliopsoas impingement after total hip arthroplasty.

BACKGROUND: A cause of groin pain after total hip arthroplasty (THA) is mechanical irritation or impingement of the iliopsoas tendon. The incidence is about 4%. If conservative therapy fails, an arthroscopic release of the iliopsoas tendon can be performed. The aim of the study was to assess the mid-term clinical outcome after arthroscopic release. We hypothesize that good results can be achieved by a minimally invasive endoscopic procedure. METHODS: Using our in-house database, all patients who received an endoscopic release of the iliopsoas tendon due to mechanical irritation after THA were identified. Inclusion criteria were mechanical irritation of the iliopsoas tendon after cementless THA with minimal acetabular component prominence. Exclusion criteria were marked prominence of the acetabular component and groin pain after THA for any other reason. In these patients, the modified Harris Hip Score (mHHS), the pain level using the numerical analogue scale and the UCLA Activity Score were measured. The mean follow-up period was 7 ± 3.8 (2.6-11.7) years. RESULTS: 25 patients were identified in whom an arthroscopic release of the iliopsoas tendon had been performed since 2007. The data of 20 patients were available at follow-up. The gender ratio was 1:1, the average age at the time of arthroscopy was 59 ± 27.7 (52-78) years. The average interval between THA and arthroscopy was 6.3 ± 4.0 (1.7-15) years. The mHHS showed a significant improvement from preoperative 31.2 ± 9.8 (17.6-47.3) to 82.0 ± 9.8 (46.2-100) points (p = 0.001). The pain level on the NAS decreased significantly from 8.5 ± 1.2 (7-10) to 2.5 ± 1.8 (0-6) points (p = 0.001). The activity level based on the UCLA Activity Score raised from 4.0 ± 2.7 (0-7) to 6.5 ± 1.8 (3-9) (p = 0.09). CONCLUSION: Mechanical irritation and impingement of the iliopsoas tendon is an important diagnosis to be considered in persistent groin pain after total hip arthroplasty. In failure of non-operative treatment, good clinical results can be achieved with arthroscopic release and the pain level can be significantly reduced. LEVEL OF EVIDENCE: IV.

Comparison of Prone Transpsoas and Standard Lateral Lumbar Interbody Fusion Surgery for Degenerative Lumbar Spine Disease: A Retrospective Radiographic Propensity Score-Matched Analysis.

BACKGROUND: Prone transpsoas lateral lumbar interbody fusion (PTP-LLIF) is a recently introduced modification to standard LLIF. To date, no study has compared the radiographic outcomes of standard LLIF and PTP-LLIF. We performed a radiographic parameter-based propensity score-matched analysis to compare postoperative clinical and radiographic outcomes between PTP-LLIF and standard LLIF for degenerative lumbar spine disease. METHODS: A total of 30 consecutive patients met the inclusion criteria. The preoperative standing scoliosis radiographs were retrospectively reviewed for global and segmental sagittal alignment. Propensity score matching was calculated using the baseline radiographic parameters. One-to-one matching of patients who had undergone PTP-LLIF with those who had a similar propensity score but had undergone standard LLIF was performed to compare the radiographic (primary) and clinical (secondary) outcomes. RESULTS: Propensity score matching resulted in 10 pairs of PTP-LLIF and standard LLIF patients. The PTP-LLIF group had had significantly better improvement in lumbar lordosis (P = 0.047). The difference in the improvement in pelvic incidence minus lumbar lordosis mismatch approached statistical significance for the PTP-LLIF group (P = 0.05). This led to better improvement in the short-form 12-item physical score (P = 0.03) and Oswestry disability index (P = 0.1) in the PTP-LLIF group. No significant differences were found between the 2 groups in the other clinical and radiographic outcomes. The PTP-LLIF group had a shorter operative time (P = 0.4) and hospital stay (P = 0.1), without a statistically difference, and shorter radiation exposure time (P = 0.5). The standard LLIF group had experienced less intraoperative bleeding, without a statistically significant difference (P = 0.3). The mean follow-up time was 10.2 ± 5.2 months in the PTP-LLIF group and 30.9 ± 17.2 months in the standard LLIF group (P < 0.05). CONCLUSIONS: The PTP-LLIF group showed significantly better improvement in lumbar lordosis and short-form 12-item physical score.

Radiographs assessment of changes in the psoas muscle at L4-L5 level after single-level lateral lumbar interbody fusion in patients with postoperative motor weakness.

The purposes of this study were (1) to investigate postoperative changes in cross-sectional area (CSA) and signal intensity (SI) of the psoas muscle (PS) using magnetic resonance imaging (MRI) and (2) to compare the CSA and SI of the PS between patients with and without motor weakness after single-level lateral lumbar interbody fusion (LLIF) at level L4-L5. Sixty patients were divided into two groups-those with postoperative motor weakness and those without-and the two groups were compared. Baseline demographics and clinical characteristics, such as operation time and blood loss, length of hospital stay, and postoperative complications, were recorded. The CSA and SI of the PS were obtained from the MRI regions of interest defined by manual tracing. Patients who developed motor weakness after surgery were significantly older (p = 0.040). The operation time (p = 0.868), LLIF operative time (p = 0.476), and estimated bleeding loss (p = 0.168) did not differ significantly between groups. In both groups, the CSA and SI of the left and right PS increased after surgery. The change in the CSA of the left PS was significantly higher in patients with weakness (247.6 ± 155.2 mm2) than without weakness (152.2 ± 133.1 mm2) (p = 0.036). The change in SI of the left PS did not differ between the two groups (p = 0.530). To prevent postoperative motor weakness regardless of the operation time, surgeons should be aware of the potential for surgical invasive of the PS during LLIF in older people.

Anteroinferior Psoas Technique for Oblique Lateral Lumbar Interbody Fusion.

Oblique lateral lumbar interbody fusion (OLIF) has been extensively used, with satisfactory outcomes for the treatment of degenerative lumbar disease. This article aims to demonstrate a modified lateral approach, also known as the anteroinferior psoas (AIP) technique for OLIF, which is expected to enhance security by operating under direct vision. The core procedures of our technique are as follows. First, a minimal skin incision is recommended 2 cm backward compared with the normal incision of OLIF, facilitating the oblique placement of the working channel and the orthogonal maneuver for the cage placement. Second, two special custom-made retractors, as an alternative to the index finger, are used to pull the psoas muscle to the dorsal side and pull the abdominal organs together with extraperitoneal fate to the ventral side under direct visualization, making the exposure of the working channel convenient and safe and avoiding radiation exposure. Third, the anterior border of the psoas is bluntly dissected and retracted backwards, obviously enlarging the retroperitoneal anatomic corridor and then expanding clinical indications of OLIF. The benefits of this technique include that it has a short learning curve, satisfactory clinical outcomes, and low risk of perioperative complications.

Single-Position Prone Transpsoas Lateral Interbody Fusion Including L4L5: Early Postoperative Outcomes.

BACKGROUND: The lateral lumbar interbody fusion (LLIF) was a revolutionary approach devised by Luiz Pimenta that allowed the surgeon to access the lumbar spine through the major psoas muscle. Although the traditional LLIF had enabled enormous advances, the technique has its drawbacks. A new concept to perform the traditional LLIF has been proposed, with the patient being prone to decubitus with slightly extended legs. Our study aims to analyze the early outcomes of patients who had undergone the prone transpsoas (PTP) for degenerative spine pathologies including the L4/5 level. METHODS: This study was multicentric, retrospective, nonrandomized, noncomparative, and observational. Only participants who received PTP in L4/5, with no more than 3 levels of intersomatics and fixation no further than S1, were included. The primary outcomes were the onset of new neurologic deficits and postoperative complications. Also, surgery details, such as blood loss and surgery duration, were measured. Neurologic deficits were accessed at the postoperative visit, which ranged from 7 to 14 days after surgery. RESULTS: Twenty-seven patients fulfilled the inclusion and exclusion criteria, with the majority receiving PTP only in L4/5 (66.6%). The mean surgery time was 182, with 29 minutes of mean transpsoas time. Of the patients, only 1 presented the onset of a motor deficit, while 3 patients presented a new sensory deficit. Five complications occurred, none intraoperative and 5 postoperative, with only 1 directly correlated with the access. CONCLUSIONS: The prone transpsoas is safe and feasible for approaching the L4/5 disk, presenting with a low rate of complication and new-onset neurologic deficits.

Artificial Intelligence-enabled, Real-time Intraoperative Ultrasound Imaging of Neural Structures Within the Psoas: Validation in a Porcine Spine Model.

STUDY DESIGN: Experimental in-vivo animal study. OBJECTIVE: The aim of this study was to evaluate an Artificial Intelligence (AI)-enabled ultrasound imaging system's ability to detect, segment, classify, and display neural and other structures during trans-psoas spine surgery. SUMMARY OF BACKGROUND DATA: Current methodologies for intraoperatively localizing and visualizing neural structures within the psoas are limited and can impact the safety of lateral lumbar interbody fusion (LLIF). Ultrasound technology, enhanced with AI-derived neural detection algorithms, could prove useful for this task. METHODS: The study was conducted using an in vivo porcine model (50 subjects). Image processing and machine learning algorithms were developed to detect neural and other anatomic structures within and adjacent to the psoas muscle while using an ultrasound imaging system during lateral lumbar spine surgery (SonoVision,™ Tissue Differentiation Intelligence, USA). The imaging system's ability to detect and classify the anatomic structures was assessed with subsequent tissue dissection. Dice coefficients were calculated to quantify the performance of the image segmentation. RESULTS: The AI-trained ultrasound system detected, segmented, classified, and displayed nerve, psoas muscle, and vertebral body surface with high sensitivity and specificity. The mean Dice coefficient score for each tissue type was >80%, indicating that the detected region and ground truth were >80% similar to each other. The mean specificity of nerve detection was 92%; for bone and muscle, it was >95%. The accuracy of nerve detection was >95%. CONCLUSION: This study demonstrates that a combination of AI-derived image processing and machine learning algorithms can be developed to enable real-time ultrasonic detection, segmentation, classification, and display of critical anatomic structures, including neural tissue, during spine surgery. AI-enhanced ultrasound imaging can provide a visual map of important anatomy in and adjacent to the psoas, thereby providing the surgeon with critical information intended to increase the safety of LLIF surgery.Level of Evidence: N/A.

Robotic-assisted ureteral reimplantation and psoas hitch after ureteral injury during cesarean section.

INTRODUCTION AND HYPOTHESIS: Ureteral injury during gynecological surgery can be managed in a variety of ways, from endoscopic stent placement to ureteroneocystotomy with accompanying psoas hitch and/or Boari flap. The majority of these occur during hysterectomy; therefore, gynecologic surgeons may not be as familiar with repair in women with intact uteri. Herein we present our technique for delayed robotic-assisted ureteral reimplant and psoas hitch in a woman with a ureteral injury sustained during cesarean section, which initially presented as a uretero-cervical fistula. METHODS: In this video, we describe the evaluation and surgical management of a patient with delayed recognition of a left distal ureteral injury sustained during cesarean section. We present necessary modifications to robotic-assisted laparoscopic ureteroneocystostomy and psoas hitch to accommodate an intact uterus including the need for uterine manipulation, division of the round ligament, bladder mobilization from the lower uterine segment and development of the retropubic space, reimplantation steps, and psoas hitch. CONCLUSIONS: Simple modifications to a traditional technique of robotic-assisted ureteroneocystotomy effectively compensate for the presence of a uterus. Obstetricians should maintain a high index of suspicion for ureteral injury in women with new-onset severe urinary leakage post-cesarean section.

Arthroscopic tendon release for iliopsoas impingement after primary total hip arthroplasty: a retrospective, consecutive series.

INTRODUCTION: Aim of this study was to describe the clinical outcomes of 16 patients with iliopsoas (IP) impingement after primary total hip arthroplasty (THA), treated with an arthroscopic tendon release. METHODS: 16 patients (11 females/5 males), with a mean age of 57.8 ± 11.1 years (age at THA: 54.4 ± 11 years) and a diagnosis of IP impingement after primary THA, were treated with the Wettstein tenotomy. Preoperatively, every patient underwent a diagnostic ultrasonography guided peritendinous injection and a computed tomography (CT) scan. Every patient was clinically evaluated using WOMAC score. Subjective pain relief and active hip flexion strength were measured. RESULTS: No complications related to arthroscopy were detected. Every cup was prominent with a mean axial overhang of 13 ± 4.8 mm (range 5-20 mm). At a mean follow-up of 27 ± 20.1 months (range 6-48 months), the WOMAC score was 83.7 ± 10.1 points. 13 patients out of 16 (81.3%) had a complete pain relief. 14 patients out of 16 (88%) regained full active hip flexion strength at the final follow-up. 1 patient was scheduled for cup revision after 6 months, due to persistent symptomatology. No demographic data or CT measurements about cup position statistically influenced the outcome. CONCLUSIONS: When preceded by an appropriate diagnosis, arthroscopic tenotomy proved safe and effective for IP impingement, regardless the magnitude of cup protrusion.

Outside-in arthroscopic psoas release for anterior iliopsoas impingement after primary total hip arthroplasty.

PURPOSE: 1 of the causes of groin pain after total hip arthroplasty (THA) is impingement of the iliopsoas tendon. The purpose of this study was to present our results with outside-in arthroscopic tenotomy for iliopsoas impingement after THA. METHODS: We retrospectively reviewed 12 patients treated between 2009 and 2016 with a minimum follow-up of 2 years. Anterior acetabular component prominence was measured on a true lateral hip radiograph. A transcapsular tenotomy was performed near the edge of the acetabular component through an outside-in arthroscopic approach. The primary clinical outcomes evaluated were groin pain, assessed with a visual analogue scale (VAS), and the Harris Hip Score (HHS). Secondary outcomes included strength of hip flexion, measured with the Medical Research Council (MRC) scale. RESULTS: All patients had groin pain improvement, though one patient continued to have moderate pain. The mean VAS score was significantly lower postoperatively (1.08) than preoperatively (6.2) (p < 0.001). The mean HHS improved from 58.8 (range, 37-76) to 86.1 (range, 59-98) (p = 0.001). The average postoperative MRC Scale was 4.58. The mean anterior prominence was 7.25 mm (range 3-12 mm). In patients with <10 mm of component prominence, tenotomy provided groin pain resolution in all cases (n = 8). In patients with ⩾10 mm of prominence, symptoms resolved in 3 out of 4 cases. CONCLUSIONS: Outside-in arthroscopic iliopsoas release provided a high rate of success with no complications in this study, even in patients with moderate acetabular component prominence.