Comparative Cohort Study for Expansion of Lateral Recess and Facet Joint Injury after Biportal Endoscopic Ipsilateral Decompression and Contralateral Decompression.

STUDY DESIGN: This was a retrospective longitudinal study of patients operated on consecutively in a single center from May to October 2019. PURPOSE: The aim in biportal interlaminar endoscopic decompression surgery for lumbar stenosis is to compare the clinical and radiological outcome of lateral recess decompression and facet preservation, employing ipsilateral (IL) versus contralateral (CL) approaches. OVERVIEW OF LITERATURE: There is scant literature comparing the radiological outcome of lateral recess decompression and facet preservation via IL versus CL approaches in patients undergoing biportal interlaminar endoscopic decompression surgery. METHODS: In this retrospective study, we reviewed 37 IL and 34 CL approaches. Postoperative magnetic resonance imaging of the segment involved was carried out on the same day as the operation for comparison with preoperative imaging. Radiological assessments of recess angle, recess height, facet length, and recess dural sac diameters were compared. In addition, pre- and postoperative Visual Analog Scale (VAS) pain scores for the lower limb were analyzed. RESULTS: For IL versus CL approaches, we observed statistical differences in the postoperative recess angle (36.0° vs. 43.7°), recess height (4.27 vs. 5.06 mm), and the dural sac expansion ratio for recess diameter (1.54 vs. 2.17). There was better preservation of facet length in the CL approach than in the IL approach (91.9% vs. 83.7%). There was no difference in VAS improvement between the groups (69.3% vs. 63.6%). CONCLUSIONS: Unilateral biportal decompression via the CL interlaminar approach may offer better lateral recess clearance and facet preservation than can be achieved via the IL approach. Larger-scale studies are needed for better delineation and for correlation of radiological features with clinical manifestations.

Rapidly progressive osteoarthritis of hip: establishing and validating diagnostic criteria in the Southeast Asian population.

BACKGROUND: The study aimed to establish quantitative diagnostic criteria for rapidly progressive osteoarthritis (RPOA) of the hip and to compare the criteria with those for other pathological hip entities in the Asian population. METHODS: From July 2011 to September 2019, 126 patients who had undergone hip replacement were retrospectively recruited from a fast-track joint replacement list. Patient demographics and radiological parameters were evaluated. Diagnosis of hip RPOA was established based on Lequesne et al's criteria. The patients with RPOA, hip dysplasia, avascular necrosis, and primary osteoarthritis were allocated to the corresponding groups separately and compared. The diagnostic criteria of RPOA were established and validated in the sample population. RESULTS: Diagnosis of hip RPOA was confirmed in 18 patients. Their mean age at surgery (72 years) was significantly higher in this group than in the dysplasia and avascular necrosis groups. The mean pelvic tilt parameter (0.485) of RPOA group was significantly lower than those of other groups. The mean initial Tonnis angle (8.35°) of RPOA group was significantly higher than those of avascular necrosis and osteoarthritis groups. The differences were statistically significant between RPOA and non-RPOA groups in limb shortening rate, superior joint space narrowing, acetabular destruction, and head destruction (P < 0.05). Tonnis angle and lateral subluxation also increased significantly during the disease progression. CONCLUSION: Posterior pelvic tilt and increased Tonnis angle may contribute to the pathogenesis of RPOA, leading to progressive acquired acetabular obliquity and lateral subluxation. We propose the modern comprehensive diagnostic criteria be based on the existing literature and the current findings. Further external validation is recommended.

Unilateral Bi-portal Endoscopic Decompression via the Contralateral Approach in Asymmetric Spinal Stenosis: A Technical Note.

We discuss the technical details and operative advantages of approaching pathologies from the contralateral side in cases of asymmetric spinal stenosis. The contralateral approach offers better manipulative freedom and a more accessible target approach along the plane of the pathology, allowing safer decompression and facet preservation; further, this approach is ergonomic for surgeons. We recommend the adoption of this approach in decompressing asymmetric spinal stenosis.

Delayed Neurological Deficits after Osteoporotic Vertebral Fractures: Clinical Outcomes after Surgery.

STUDY DESIGN: Retrospective cohort. PURPOSE: To review the clinical presentation of operated patients with delayed neurological deficits after osteoporotic vertebral fractures (OVFs). OVERVIEW OF LITERATURE: Delayed neurological deficits can occur from 1 week to 5.7 months after OVFs. Baba has reported 78% good-to-excellent improvement (i.e., ≥50%) after 20 posterior (Cotrel-Dubousset) and 7 anterior (Kaneda in 4, Zielke ventral derotational spondylodesis in 2, and un-instrumented anterior fusion in 1) fusions. Predictive factors for neurological deficits include burst type, vacuum sign, kyphosis, angular instability, and retropulsion. METHODS: Patients with neurological deficits after OVF who received spinal operations between 2000 and 2016 were included. RESULTS: Totally, 28 patients with a mean age of 77 years underwent surgery. Neurological deficits occurred at an average of 5.4 weeks after the onset of back pain. The most common site was L1. Burst fracture was present in 14 patients and vacuum sign in seven. Surgery was performed within an average of 3.9 days of the onset of neurological deficit. Baba's score improved significantly from 5.96 to 9.81, with good-to-excellent improvement in 18 (64%) patients. Better outcomes based on Baba's scores (improvement>60% [median]) were associated with compression fractures, preoperative retropulsion of <41%, and correction of >16%. Poor improvement in Baba's scores (<25%) was associated with surgical complications and burst fracture type. Twenty-two patients (79%) regained walking ability, and seven of 15 (47%) patients demonstrated improved sphincter control at the latest follow-up. Six Frankel grade B patients did not achieve neurological recovery, four of whom exhibited postoperative surgical complications and died at 2 years because of medical problems. Implant migration occurred in six patients, albeit this was of no clinical significance. CONCLUSIONS: Although OVFs are commonly considered benign, delayed neurological deficits can occur. The significant improvement in clinical function after surgery for neurological deficits is associated with compression (and not burst) fractures, lack of surgical complications, and optimal restoration of retropulsion.