Background Effective 1 January 2017, single-level endoscopic lumbar discectomy received a Category I Current Procedural Terminology (CPT) code 62380. However, no work relative value units (RVUs) are currently assigned to the procedure. An international team of endoscopic spine surgeons conducted a study, endorsed by several spine societies, analyzing the learning curve, difficulty, psychological intensity, and estimated work RVUs of endoscopic lumbar spinal decompression compared with other common lumbar spine surgeries. Methods A survey comparing CPT 62380 to 10 other comparator CPT codes reflective of common spine surgeries was developed to assess the work RVUs in terms of learning curve, difficulty, psychological intensity, and work effort using a paired Rasch method. Results The survey was sent to 542 spine specialists. Of 322 respondents, 150 completed the survey for a 43.1% completion rate. Rasch analysis of the submitted responses statistically corroborated common knowledge that the learning curve with lumbar endoscopic spinal surgery is steeper and more complex than with traditional translaminar lumbar decompression surgeries. It also showed that the psychological stress and mental and work effort with the lumbar endoscopic decompression surgery were perceived to be higher by responding spine surgeons compared with posterior comparator decompression and fusion surgeries and even posterior interbody and posterolateral fusion surgeries. The regression analysis of work effort vs procedural difficulty showed the real-world evaluation of the lumbar endoscopic decompression surgery described in CPT code 62380 with a calculated work RVU of 18.2464. Conclusion The Rasch analysis suggested the valuation for the endoscopic lumbar decompression surgery should be higher than for standard lumbar surgeries: 111.1% of the laminectomy with exploration and/or decompression of spinal cord and/or cauda equina (CPT 63005), 118.71% of the laminectomy code (CPT 63047), which includes foraminotomy and facetectomy, 152.1% of the hemilaminectomy code (CPT 63030), and 259.55% of the interlaminar or interspinous process stabilization/distraction without decompression code (CPT 22869). This research methodology was endorsed by the Interamerican Society for Minimally Invasive Spine Surgery (SICCMI), the Mexican Society of Spinal Surgeons (AMCICO), the International Society For Minimally Invasive Spine Surgery (ISMISS), the Brazilian Spine Society (SBC), the Society for Minimally Invasive Spine Surgery (SMISS), the Korean Minimally Invasive Spine Surgery (KOMISS), and the International Society for the Advancement of Spine Surgery (ISASS). Clinical Relevance This study provides an updated reimbursement recommendation for endoscopic spine surgery. Level of Evidence Level 3.

Endoscopic surgery of the cervical spine is constantly evolving and the spectrum of its indications has expanded in recent decades. Full-endoscopic techniques have standardized the procedures for posterior and anterior access. The full-endoscopic approach was developed to treat degenerative diseases with the least possible invasion and without causing instability of the cervical spine. The posterior full-endoscopic approach is indicated for the treatment of diseases of the lateral part of the vertebral segment, such as herniations and stenoses of the lateral recess and vertebral foramen. There has been little discussion of this approach to the treatment of central stenosis of the cervical spine. This technical note describes a step-by-step surgical technique for central and over-the-top full-endoscopic decompression in the cervical spine, using a 3.7 mm working channel endoscope. This technique has already been shown to be effective in a recent case series with a 4.7 mm working channel endoscope, and may represent a new treatment option for central or bilateral lateral recess stenosis. There is also the possibility of a bilateral full-endoscopic approach, but this may be associated with greater muscle damage and a longer operative time. Case series and comparative studies should be encouraged to confirm the safety and utility of this technique.

Cauda Equina Syndrome (CES) is a severe neurological emergency resulting from the compression of the lumbosacral nerve roots, potentially causing motor and sensory deficits, as well as sphincter dysfunctions. Early surgical intervention is essential to prevent permanent neurological sequelae. Traditionally, open laminectomy has been the treatment of choice for decompression. Still, minimally invasive techniques, such as endoscopic discectomy, are gaining popularity due to lower morbidity, smaller incisions, and faster recovery. This study reports three cases of patients with CES treated with endoscopic discectomy. Two cases were caused by a large, extruded disc herniation and one by an intracanal facet cyst. Pain intensity was assessed using the Visual Analog Scale (VAS), and functional disability was measured with the Oswestry Disability Index (ODI) in the preoperative period and at follow-ups of 1, 6, and 12 months. All three patients showed significant improvement in symptoms, with pain reduction and functional improvement. At 12 months, the patients maintained their functional and neurological recovery without reported complications. The endoscopic technique proved to be a safe and effective method for treating CES in these cases, offering early recovery and fewer postoperative complications. Future studies with larger populations are needed to validate these findings. Level of Evidence IV; Case Report.

To study the measurements and anatomical relationships of the patellofemoral joint using magnetic resonance imaging, and to evaluate the variation in the morphology of the medial patellofemoral ligament (MPFL) according to patients' heights and ages and the variation in measurements on other structures that are known to be involved in predisposition to patellar instability. Twenty-three knees (18 patients) underwent magnetic resonance imaging and their interepicondylar distance, patellar height, trochlear depth, ventral trochlear prominence, trochlear groove angle, lateral facet tilt, lateral patellar tilt and size of the lateral and medial facets and their ratio were measured. These measurements were compared with the length and thickness of the MPFL. The average length of the MPFL was 46.4 mm, while the average thicknesses of its patellar insertion, middle third and femoral insertion were, respectively, 1.7 mm, 1.4 mm and 1.2 mm. The thickness of the MPFL correlated positively with the lateral condyle and interepicondylar distance measurements, and negatively with the patients' ages. The morphology of the MPFL varies with the interepicondylar distance and the lateral condyle distance, and with patients' ages.

We describe the use of an endoscopic approach to fix a pars interarticularis defect in a 33-yearold man with a 7-year history of refractory low back pain, whose case had been previously diagnosed as spondylolysis. The advantage of using this technique lies in minimum muscle trauma, since it only requires a single 6-mm transverse incision. Neither intraoperative nor postoperative complications were observed. The patient reported nocturnal pain improvement and presented favourable clinical recovery after 3.5 years of follow-up. He recorded an 8% Oswestry Disability Index and visual analogue scale scores of 2 and 0 for low back and lower-limb pain, respectively. Therefore, the endoscopic technique described herein is a feasible approach to treating spondylolysis.

The treatment for symptomatic pars interarticularis spondylolysis remains controversial. Since most affected patients are young, minimally invasive techniques, have been reported to minimize tissue damage and provide an early return to daily activities. We report a clinical case of a patient with a lesion of the pars, a lesion of the contralateral pedicle, and a herniated disc who underwent surgical treatment by endoscopy one time. Due to the low level of evidence of the case report/series, further studies should be carried out to confirm this hypothesis. Level of Evidence IV; Case Report.