We present the Jenkins classification for Bertolotti syndrome or symptomatic lumbosacral transitional vertebra (LSTV) and compare this with the existing Castellvi classification for patients presenting for treatment. We performed a retrospective cohort study of 150 new patients presenting for treatment of back, hip, groin, and/or leg pain from July 2012 through February 2022. Using magnetic resonance imaging, computed tomography, and radiography, the patients with a radiographic finding of LSTV, an appropriate clinical presentation, and identification of LSTV as the primary pain generator via diagnostic injections were diagnosed with Bertolotti syndrome. Patients for whom conservative treatment had failed and who underwent surgery to address their LSTV were included in the present study. The Castellvi classification excludes 2 types of anatomic variants: the prominent anatomic side and the potential transverse process and iliac crest contact. Of 150 patients with transitional anatomy, 103 (69%) were identified with Bertolotti syndrome using the Jenkins classification and received surgery (46 men [45%] and 57 women [55%]). Of the 103 patients, 90 (87%) underwent minimally invasive surgery. The patients presented with pain localized to the back (n = 101; 98%), leg (n = 79; 77%), hip (n = 51; 49%), and buttock (n = 52; 50%). Only 84 of the Jenkins classification patients (82%) met any of the Castellvi criteria. All 19 patients for whom the Castellvi classification failed had had type 1 anatomy using the Jenkins system and underwent surgery (decompression, n = 16 [84%]; fusion, n = 1 [5%]; fusion plus decompression, n = 2 [11%]). Of these 19 patients, 17 (89%) had improved pain scores. The 19 patients exclusively diagnosed via the Jenkins classification had no significant differences in improved pain compared with those diagnosed using the Castellvi classification. The Jenkins classification improves on the prior Castellvi classification to more comprehensively describe the functional anatomy, identify uncaptured anatomy, and better predict optimal surgical procedures to treat those with Bertolotti syndrome.

Using the Jenkins classification, we propose a strategy of shaving down hypertrophic bone, unilateral fusion, or bilateral fusion procedures to achieve pain reduction and improve quality of life for patients with Bertolotti syndrome. We reviewed 103 patients from 2012 through 2021 who had surgically treated Bertolotti syndrome. We identified 56 patients with Bertolotti syndrome and at least 6 months of follow-up. Patients with iliac contact preoperatively were presumed to be more likely to have hip pain that could respond to surgical treatment, and those patients were tracked for those outcomes as well. Type 1 patients (n = 13) underwent resection. Eleven (85%) had improvement, 7 (54%) had good outcome, 1 (7%) had subsequent surgery, 1 (7%) was suggested additional surgery, and 2 (14%) were lost to follow-up. In Type 2 patients (n = 36), 18 underwent decompressions and 18 underwent fusions as a first line. Of the 18 patients treated with resection an interim analysis saw 10 (55%) with failure and needing subsequent procedures. With subsequent procedure, 14 (78%) saw improvement. For fusion surgical patients, 16 (88%) saw some improvement and 13 (72%) had a good outcome. In Type 4 patients (n = 7), 6 (86%) did well with unilateral fusion, with durable benefit at 2 years. In patients who had hip pain preoperatively (n = 27), 21 (78%) had improvement of hip pain postoperatively. The Jenkins classification system provides a strategy for patients with Bertolotti syndrome who fail conservative therapy. Patients with Type 1 anatomy respond well to resection procedures. Patients with Type 2 and Type 4 anatomy respond well to fusion procedures. These patients respond well in regard to hip pain.

Although neurologic symptoms occur in two-thirds of lysosomal storage disorders (LSDs), for most we do not understand the mechanisms underlying brain dysfunction. A major unanswered question is if the pathogenic hallmark of LSDs, storage accumulation, induces functional defects directly or is a disease bystander. Also, for most LSDs we do not know the impact of loss of function in individual cell types. Understanding these critical questions are essential to therapy development. Here, we determine the impact of genetic rescue in distinct cell types on neural circuit dysfunction in CLN3 disease, the most common pediatric dementia and a paradigmatic neurodegenerative LSD. We restored Cln3 expression via AAV-mediated gene delivery and conditional genetic rescue in a CLN3 disease mouse model. Surprisingly, we found that low-level rescue of Cln3 expression in neurons alone normalized clinically relevant electrophysiologic markers of network dysfunction, despite the presence of substantial residual histopathology, in contrast to restoring expression in astrocytes. Thus, loss of CLN3 function in neurons, not storage accumulation, underlies neurologic dysfunction in CLN3 disease. This impliesies that storage clearance may be an inappropriate target for therapy development and an ineffectual biomarker.

Background/Objectives: Utilization of polyetheretherketone (PEEK) cages for spinal fusion has surged in the U.S., yet comprehensive comparisons evaluating its postoperative effectiveness with alternative materials remain limited. This systematic review investigates the efficacy of PEEK cages against traditional fusion materials across various surgery types, elucidating PEEK’s impact on fusion rates, postoperative outcomes, and long-term success. Methods: A systematic search of PubMed, CINAHL, Scopus, Embase, and Web of Science was conducted through 14 October 2024. Included studies were randomized controlled trials (RCTs) comparing PEEK cages with titanium, silicon nitride, and metal-coated PEEK cages for anterior cervical discectomy and fusion (ACDF), posterior lumbar interbody fusion (PLIF), and transforaminal lumbar interbody fusion (TLIF). Article quality was assessed using GRADE criteria. Results: From 288 initially screened articles, 25 RCTs involving 2046 patients (mean follow-up 23.1 ± 18.2 months) met inclusion criteria and were determined as moderate (n = 21) or high (n = 4) quality. Fusion rates by cage material for PEEK (n = 1041), Ti-PEEK (n = 291), and titanium (n = 53) were 85.63 ± 18.00%, 80.05 ± 19.9%, and 92.75 ± 11.31%, respectively. In ACDF, titanium cages achieved higher fusion rates than PEEK (100% vs. 94%). In PLIF and TLIF, coated PEEK outperformed uncoated PEEK (75% vs. 71% and 94% vs. 84%, respectively). Uncoated PEEK achieved fusion rates of 94.04 ± 5.04% for ACDF, 71.21 ± 21.93% for PLIF, and 83.50 ± 24.66% for TLIF, with titanium outperforming PEEK in early fusion outcomes. Coated PEEK demonstrated potential improvements in fusion rates over uncoated PEEK in PLIFs and TLIFs. Conclusions: Selection of cage material for spinal fusions should be tailored to surgical requirements and patient needs. While titanium and PEEK are effective, their performance varies across contexts. New materials and surface modifications may enhance these outcomes further, warranting future research in long-term studies and development of novel materials. These findings can help surgeons choose cage materials according to procedure type, patient characteristics, and imaging needs.

Background/Objectives: The success of lumbar interbody fusion depends on the implant design and the surgical approach used. This study evaluated the clinical and radiographic outcomes of lateral lumbar interbody fusion (LLIF) and anterior lumbar interbody fusion (ALIF) using a 3D-printed porous titanium interbody cage system. Methods: A retrospective, single-center review of 48 patients treated for degenerative lumbar spine disease was conducted. Patients underwent LLIF, ALIF, or a combination of both using a 3D-printed titanium cage system (J&J MedTech, Raynham, MA, USA). The Oswestry disability index (ODI) and Patient-Reported Outcomes Measurement Information System (PROMIS) metrics were assessed after 6 weeks, 3 months, 6 months, and 12 months. Linear mixed-effects models evaluated the pre- and post-operative differences. Fusion performance and complications were assessed using the Bridwell grading system over 24 months. Results: A total of 78 levels (62 LLIF and 16 ALIF) were analyzed. Fusion rates were 90.3% (56/62) for LLIF levels and 81.3% (13/16) for ALIF levels by the end of 12 months. ODI scores improved significantly after 3 months (MD −13.0, p < 0.001), 6 months (MD −12.3, p < 0.001), and 12 months (MD −14.9, p < 0.001). PROMIS Pain Interference scores improved after 3 months (MD −6.1, p < 0.001), 6 months (MD −3.4, p < 0.001), and 12 months (MD −5.8, p < 0.001). PROMIS Physical Function scores improved after 3 months (MD +3.4, p = 0.032) and 12 months (MD +4.9, p < 0.001). Conclusions: This novel interbody cage demonstrated high fusion rates, significant pain and function improvements, and a favorable safety profile, warranting further comparative studies.