Sathish Muthu

models, and a survey conducted with the AO Spine Knowledge Forum Degenerative to assess current clinical practices and highlight gaps in knowledge. Additionally, this critical review explores future strategies to reduce the biological impact of wear particles and improve the safety and longevity of spinal implants through better therapeutics and design innovations. By combining literature and clinical insights, this paper aims to guide future research in addressing the complexities of spinal implant wear and its biological consequences.

OBJECTIVE: The objective of this paper was to determine the interobserver reliability and intraobserver reproducibility of the AO Spine Upper Cervical Injury Classification System based on surgeon experience (< 5 years, 5-10 years, 10-20 years, and > 20 years) and surgical subspecialty (orthopedic spine surgery, neurosurgery, and "other" surgery). METHODS: A total of 11,601 assessments of upper cervical spine injuries were evaluated based on the AO Spine Upper Cervical Injury Classification System. Reliability and reproducibility scores were obtained twice, with a 3-week time interval. Descriptive statistics were utilized to examine the percentage of accurately classified injuries, and Pearson's chi-square or Fisher's exact test was used to screen for potentially relevant differences between study participants. Kappa coefficients (κ) determined the interobserver reliability and intraobserver reproducibility. RESULTS: The intraobserver reproducibility was substantial for surgeon experience level (< 5 years: 0.74 vs 5-10 years: 0.69 vs 10-20 years: 0.69 vs > 20 years: 0.70) and surgical subspecialty (orthopedic spine: 0.71 vs neurosurgery: 0.69 vs other: 0.68). Furthermore, the interobserver reliability was substantial for all surgical experience groups on assessment 1 (< 5 years: 0.67 vs 5-10 years: 0.62 vs 10-20 years: 0.61 vs > 20 years: 0.62), and only surgeons with > 20 years of experience did not have substantial reliability on assessment 2 (< 5 years: 0.62 vs 5-10 years: 0.61 vs 10-20 years: 0.61 vs > 20 years: 0.59). Orthopedic spine surgeons and neurosurgeons had substantial intraobserver reproducibility on both assessment 1 (0.64 vs 0.63) and assessment 2 (0.62 vs 0.63), while other surgeons had moderate reliability on assessment 1 (0.43) and fair reliability on assessment 2 (0.36). CONCLUSIONS: The international reliability and reproducibility scores for the AO Spine Upper Cervical Injury Classification System demonstrated substantial intraobserver reproducibility and interobserver reliability regardless of surgical experience and spine subspecialty. These results support the global application of this classification system.

Introduction: With the extreme range of movements, the shoulder joint is prone for dislocations. This could be due to traumatic or atraumatic, though the majority are atraumatic. With each subsequent episode of dislocation, humeral head, the glenoid, capsule, labrum and the ligaments undergoes progressive degeneration which further worsens the situation. Selecting an optimal and efficient surgical procedure for patients with anterior glenohumeral instability and associated glenoid bone loss is a complex problem. Among the coracoid transfer procedures, open laterjet procedure offers good clinical outcomes even with engaging Hill sach’s along with glenoid bone loss. The purpose is to study the clinical outcome of Open Laterjet procedure in anterior glenohumeral instability and even with Hill Sach’s lesion. Materials & Methods: Twenty patients with recurrent dislocation were performed Open Laterjet Procedure. All patients were screened by arthroscopy through standard portals of the shoulder before open procedure. Patients were followed up for mean period of 22 months. The functional outcome was measured with Walch Duplay and Visual analog scores. Results: All twenty patients had solid bone union. 90% of the patients had excellent to good outcomes. 10% of these patients had developed Grade 1 Humeral Arthropathy and this is due to improper instrument selection. One patient had transient axillary nerve weakness which recovered fully within 3 months period. During the first 10 months, there is significant loss of external rotation. But during 18 to 20 months period, there is significant improvement in the range of external rotation. None of the patient developed recurrent dislocation or positive apprehension. All patients have resorted back to routine work after 6 months period. Conclusion: Open latarjet procedure offers a good surgical method of management of recurrent anterior shoulder dislocation with significant bone loss and our study showed good functional outcome as measured by Walch Duplay and VAS scores.

BACKGROUND Knee osteoarthritis (OA) is a degenerative joint disease traditionally viewed through the lens of cartilage degradation. However, emerging evidence positions subchondral bone pathology - particularly bone marrow lesions (BMLs) - as a key contributor to pain, progression, and structural deterioration. Mesenchymal stem cell exhaustion within the osteoarthritic subchondral zone further impairs intrinsic repair mechanisms, reinforcing the rationale for biologic interventions. AIM To evaluate the clinical efficacy of bone marrow aspirate concentrate (BMAC) therapy for knee OA, comparing subchondral vs intra-articular delivery routes, and elucidating the therapeutic impact on symptom relief and structural preservation. METHODS Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, five clinical studies were included - comprising three randomized controlled trials and two prospective cohorts - with pooled data from 298 knees. Data on functional outcomes, imaging findings, and progression to total knee arthroplasty (TKA) were extracted and qualitatively synthesized. RESULTS Subchondral BMAC injections demonstrated superior improvements compared to intra-articular injection or placebo: Knee Injury and Osteoarthritis Outcome Score improved from 49.1 ± 1.9 to 61.2 ± 6.3 at 12 months (P &lt; 0.05), Knee Society Score increased from 57 ± 12 to 87.3 ± 12 at two years, and Western Ontario and McMaster Universities Arthritis Index scores showed significant improvement favoring combined approaches. Magnetic resonance imaging analyses revealed mean BML volume regression of 2.1 cm3, with 80% of knees avoiding TKA over 13-year follow-up. Magnetic resonance imaging analyses revealed regression of BMLs and increased cartilage preservation in subchondral-treated knees. Long-term data indicated delayed progression to TKA and biomechanical improvements (e.g. , Hip-Knee-Ankle angle correction). No major adverse events were reported. CONCLUSION Targeting subchondral bone with BMAC addresses underlying OA pathology and may offer disease-modifying potential beyond symptom relief. These findings support a paradigm shift toward whole-joint biologic therapy, positioning the subchondral matrix as a therapeutic epicenter in OA management.