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.

Lumbar Sympathetic Chain Tract and Mobility of Oblique Lumbar Interbody Fusion Approach: A Cadaveric Study.

OBJECTIVE: We sought to assess the lumbar sympathetic chain (LSC) relation to the surgical corridor for the oblique lumbar approach and the ability to mobilize the LSC. METHODS: Forty-three cadavers were included. A left-sided anterior retroperitoneal approach was performed in supine position. The distances between the great vessels and psoas muscle (oblique corridor) and distance between great vessels and LSC at the L2/3, L3/4, and L4/5 disk levels were measured. Mobilization of LSC at each disk level was done either close to or away from the psoas muscle, and each mobilization distance was measured. RESULTS: The presence rates of LSC in oblique corridor were 19.5%, 43%, and 75.7% at L2/3, L3/4, and L4/5 levels, respectively. At the L2/3 disk level, the mean distance between the psoas muscle and LSC and its mobility were 0.61 mm ± 1.31 mm and 2.72 mm ± 1.24 mm, respectively. At the L3/4 disk level, the mean distance between the psoas muscle and LSC and its mobility were 1.72 mm ± 2.53 mm and 3.11 mm ± 1.02 mm, respectively. At the L4/5 disk level, the mean distance between the psoas muscle and LSC and its mobility were 2.94 mm ± 3.52 mm and 2.53 mm ± 1.03 mm, respectively. The mean width of corridor of L2/3, L3/4, and L4/5 were 10.73 mm ± 5.82 mm, 12.63 mm ± 5.02 mm, and 15.43 mm ± 6.31 mm, respectively. CONCLUSIONS: The LSC tract usually lies in the oblique corridor in L4/5 but keeps decreasing in prevalence when approaching L3/4 and L2/3 levels. It can be mobilized a few millimeters close to or away from the psoas muscle. Care should be taken to prevent an LSC injury, particularly when the LSC needs to be retracted along with the psoas muscle.

Ultrasound-Guided Iliopsoas Bursal Injections for Management of Iliopsoas Bursitis After Total Hip Arthroplasty.

BACKGROUND: Iliopsoas tendonitis can cause persistent pain after total hip arthroplasty (THA). Nonoperative management of iliopsoas tendonitis includes anti-inflammatory drugs and image-guided corticosteroid injections. This study evaluated the efficacy of ultrasound-guided corticosteroid injections (US-CSIs) for iliopsoas tendonitis following THA. METHODS: We retrospectively reviewed 42 patients who received an US-CSI for iliopsoas tendonitis after primary THA between 2009 and 2020 at a single institution. Outcomes including reoperation, groin pain at last follow-up, additional intrabursal injection, and Harris Hip Score (HHS) were evaluated at a minimum of 1 year. Cross-table lateral radiographs (36 patients) or computed tomography scans (6 patients) were reviewed to determine if anterior cup overhang was present, indicating a mechanical etiology of iliopsoas tendonitis. Descriptive statistics and univariate comparison of HHS preinjection and postinjection were performed, with alpha < 0.05. RESULTS: Among the 22 patients who did not have cup overhang, four (18.2%) had persistent groin pain at mean follow-up of 40 months (range, 14-94) after US-CSI. Three patients had a second injection; none had groin pain at most recent follow-up. No patients required acetabular revision. Mean HHS improved from 74 points (range, 52-94 points) to 91 points (range, 76-100 points; P < .001) at last follow-up. Among the 20 patients who had anterior cup overhang, five underwent acetabular revision after only temporary pain relief from injection. Groin pain was resolved in all revised patients at mean follow-up of 43 months (range, 12-60) after revision. Of the remaining 15 patients, five had persistent groin pain at mean follow-up of 35 months (range, 12-83). Mean HHS improved from 69 points (range, 50-96 points) preinjection to 81 (range, 56-98 points; P = .007) at last follow-up. CONCLUSION: Resolution of groin pain was demonstrated in 78.6% of patients in the cohort; however, those who did not have acetabular overhang had higher rates of success. The overall revision rate was 11.9%. US-CSI appears to be safe and effective in the diagnosis and treatment of iliopsoas tendonitis following primary THA. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.

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.

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.

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.

Anatomical positional changes in the lateral lumbar interbody fusion.

INTRODUCTION: ALIFs and LLIFs are now becoming more utilized for adult spinal disease. As technologies advance, so do surgical techniques, with surgeons now modifying traditional supine-ALIF and lateral-LLIF to lateral-ALIF and prone-LLIF approaches to allow for more efficient surgeries. The objective of this study is to characterize the anatomical changes in the surgical corridor that occur with changes in patient positioning. METHODS: MRIs of ten healthy volunteers were evaluated in five positions: supine, prone with hips flexed, prone with hips extended, lateral with hips flexed, and lateral with hips extended. All lateral scans were in the left lateral decubitus position. The anatomical changes of the psoas muscles, inferior vena cava, aorta, iliac vessels were assessed with relation to fixed landmarks on the disc spaces from L1 to S1. RESULTS: The most anteriorly elongated ipsilateral to approach psoas when compared to supine was seen in lateral-flexed position (- 5.82 mm, p < 0.001), followed by lateral-extended (- 2.23 mm, p < 0.001), then prone-flexed (- 1.40 mm, p = 0.014), and finally supine and prone-extended (- 0.21 mm, p = 0.643). The most laterally extending or "thickest" psoas was seen in prone-flexed (- 1.40 mm, p = 0.004) and prone-extended (- 1.17 mm, p = 0.002). The psoas was "thinnest" in lateral-extended (2.03 mm, p < 0.001) followed by lateral-flexed (1.11 mm, p = 0.239). The contralateral psoas did not move as anteriorly as the ipsilateral. 3D volumetric analysis showed that the greatest changes in the psoas occur at its proximal and distal poles near T12-L1 and L4-S1. In lateral-flexed compared to prone-extended, the IVC moves medially to the left (p < 0.001). The aorta moves laterally to the left (p = 0.005). The venous structures appeared more full and open in the lateral positions and flattened in the supine and prone positions. The arteries remain in full calibre. CONCLUSION: The MRI anatomical evaluation shows that the psoas, and therefore lumbar plexus, and vasculature move significantly with changes in positioning. This is important for preoperative planning for proper intraoperative execution from preoperative supine MRI. Understanding that the psoas and vessels move the most anteriorly in the lateral-flexed position and to a least degree in the prone-extended is essential for safe and efficient utilization of techniques such as the traditional LLIF, traditional ALIF, prone-LLIF.

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.

Physical therapy management of a patient with persistent groin pain after total hip arthroplasty and iliopsoas tenotomy: a case report.

Background: Hip impingement syndrome can occur after total hip arthroplasty (THA). Nonoperative treatment is inconsistently recommended, and surgical options include iliopsoas tenotomy. The current case report describes the unique case of a patient with persistent groin pain after THA and iliopsoas tenotomy.Case Description: The 72-year-old male had persistent groin pain after right THA and an unsuccessful iliopsoas tenotomy. He had pain and limited right hip range of motion during active and passive hip flexion, abduction, and external rotation. Treatment consisted of high-grade joint mobilization to improve the range of motion of the right hip and an exercise program.Outcomes: The patient was treated for six visits over 3 weeks. Clinically important improvements were noted in pain, function, and perceived level of improvement. Pain during hip flexion improved on the Numeric Pain Rating Scale, and function improved on the Lower Extremity Functional Scale. Improvements in the range of motion and strength were also observed. At 6-month follow-up, he reported maintenance of improvements.Discussion: Joint mobilization and exercise were effective for improving range of motion, groin pain, and function in a patient with a 4-year history of persistent groin pain after THA and subsequent iliopsoas tenotomy.

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.