Osseous morphology of the medial epicondyle: an anatomoradiological study with potential clinical implications.

PURPOSE: The cubital tunnel is limited anteriorly by the medial epicondyle (ME), laterally by the medial collateral ligament, and superiorly by Osborne's fascia and the cubital tunnel retinaculum. Previous studies were mostly dedicated to the roof of the cubital tunnel, in the way that the study of the groove for ulnar nerve and ME anatomy is relatively scarce in the literature. We sought to describe the radiological anatomy of the groove for ulnar nerve and ME in healthy volunteers with multiplanar computed tomography (CT). METHODS: We analyzed 3D CT images of 30 healthy volunteers (mean age 39 years, range 18-66 years). Nine variables were measured from the right elbow, including sizes, areas and angles in two different planes (coronal and axial). RESULTS: Mean ME width and length were 17.3 ± 3.5 mm and 31.7 ± 4.5 mm, respectively. According to categorical correlation studies, ME width (X) was deemed the most representative morphological characteristic because of the positive correlation to five other different anatomical measurements. A three-tiered anatomical classification was proposed based on data distribution. CONCLUSION: Large individual variation is found in the shape of ME, both in coronal and axial planes. The knowledge of individual osseous morphology is of great value potentially contributing to the surgical decision-making in patients affected by cubital tunnel syndrome.

Patient selection protocols for endoscopic transforaminal, interlaminar, and translaminar decompression of lumbar spinal stenosis.

BACKGROUND: The indications of different endoscopic and endoscopically assisted translaminar approaches for lumbar spinal stenosis are not well-defined, and validated protocols for the use of the transforaminal over the interlaminar approach are lacking. METHODS: We performed a retrospective study employing an image-based patient stratification protocol of stenosis location (type I-central canal, type II-lateral recess, type III-foraminal, type IV-extraforaminal) and clinical outcomes on 249 patients consisting of 137 (55%) men and 112 (45%) women with an average age of 56.03±16.8 years who underwent endoscopic surgery for symptomatic spinal stenosis from January 2013 to February 2019. The average follow-up of 38.27±27.9 months. The primary clinical outcome measures were the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), and modified Macnab criteria. RESULTS: The frequency of stenosis configuration in decreasing order was as follows: type I-121/249; 48.6%, type III-104/249; 41.8%, type II-15/249; 6%, and type IV-9/249; 3.6%. The transforaminal approach (137/249; 55.0%) was used in most type II to IV lesions followed by the interlaminar approach (78/249; 31.3%), and the full endoscopic approach (12/249; 4.8%), and the endoscopically assisted translaminar approach (8/249; 3.2%) which was exclusively used for type I lesions. Macnab outcomes analysis showed Excellent in 47 patients (18.9%), Good in 178 (71.5%), Fair in 18 (7.2%) and Poor in 6 (2.4%), respectively. Paired two-tailed t-test showed statistically significant VAS (5.46±2.1; P<0.0001) and ODI (37.1±16.9; P<0.0001) reductions as a result of the endoscopic decompression surgery. Cross-tabulation of the Macnab outcomes versus the endoscopic approach and surgical technique confirmed beneficial association of the approach selection with Excellent (P=0.001) and Good (P<0.0001) outcomes with statistically significance. CONCLUSIONS: This study suggests that in the hands of skilled endoscopic spines surgeon use of an image-based stenosis location protocol may contribute to obtaining Excellent and Good clinical outcomes in a high percentage (93%) of patients suffering from lumbar stenosis related radiculopathy. Additional comparative studies should examine the prognostic value of choosing the endoscopic approach on the basis of the proposed four-type stenosis protocol by correlating its impact on outcomes with preoperative diagnostic injections and intraoperative direct visualization of symptomatic pain generators under local anesthesia and sedation.