Human cadaveric dissection has been an essential component of medical education since the development of modern anatomy [1,2]. Beyond undergraduate anatomical teaching, cadavers have become increasingly important models for postgraduate surgical training, procedural simulation and evaluation of emerging surgical techniques [3]. Cadaver-based surgical training allows clinicians to practice complex procedures in a controlled environment without compromising patient safety [4-6].

The suitability of cadavers for surgical simulation largely depends on the preservation technique employed. The ideal embalming method should maintain anatomical structures, preserve tissue colour and consistency, prevent decomposition and microbial contamination, and provide realistic handling characteristics similar to living tissue [3,6-11]. Formalin-based embalming has been the standard preservation technique for more than a century due to its excellent fixation properties, antimicrobial activity and long-term preservation capability. However, formaldehyde cross-links tissue proteins resulting in increased rigidity, loss of elasticity, altered tissue texture and reduced joint mobility. These changes limit its effectiveness for advanced surgical simulation. In addition, formaldehyde exposure is associated with occupational health concerns among healthcare workers and anatomy personnel [3,6-11].

Thiel's embalming method, introduced by Walter Thiel, has gained popularity due to its ability to preserve natural colour, flexibility and tissue consistency. Thiel-embalmed cadavers have demonstrated usefulness in various surgical disciplines including minimally invasive surgery, orthopaedics, urology and vascular procedures. However, the technique requires multiple chemical components, prolonged preparation and specialized facilities, making it expensive and difficult to implement in resource-limited settings [4,5,8].

The saturated salt solution (SSS) embalming method has emerged as a promising alternative. It uses sodium chloride as a major preservative component along with additional antimicrobial and tissue-preserving agents. Previous studies have demonstrated that SSS-embalmed cadavers provide realistic tissue handling characteristics and are suitable for surgical skill training. The method is comparatively inexpensive, technically simpler and requires less complex preparation than Thiel embalming [1,2,6]. The present study was undertaken to compare saturated salt solution, Thiel's method and conventional formalin embalming techniques with respect to surgical training suitability and joint mobility.

This observational comparative study was conducted in the Department of Anatomy, Sri Devaraj Urs Medical College, Sri Devaraj Urs Academy of Higher Education and Research, Kolar, Karnataka, India, following approval from the Institutional Ethics Committee. Three fresh adult human cadavers obtained through the institutional body donation programme were preserved using: 1) Formalin solution (FS); 2) Saturated salt solution (SSS); and 3) Thiel's solution (TS). Exclusion criteria included previously embalmed or formalin-fixed bodies, decomposed or autopsied cadavers, and those with significant trauma.

Individual evaluator scores and mean suitability metrics demonstrated marked differences across embalming techniques (Tables 2 and 3). Formalin-fixed cadavers ranked lowest across all parameters, with an overall mean suitability score of 2.87/5 (tissue color: 3.2, consistency: 2.8, flexibility: 2.4, tactile sensation: 2.8, handling: 3.0, overall usefulness: 3.0). SSS-embalmed cadavers showed marked tissue realism with an overall score of 4.57/5 (color: 4.4, consistency: 4.6, flexibility: 4.4, tactile sensation: 4.6, handling: 4.6, usefulness: 4.8), which was comparable to Thiel preservation (overall score 4.83/5; color: 4.6, consistency: 4.8, flexibility: 4.8, tactile sensation: 5.0, handling: 4.8, usefulness: 5.0).

Goniometric range of motion (ROM) measurements across major joints demonstrated superior mobility in SSS and Thiel groups compared to formalin fixation (Table 4). Shoulder flexion reached 80-90° in SSS/TS vs. 20-35° in FS; shoulder abduction reached 100° in SSS/TS vs. 40° in FS. Hip flexion reached 60-75° in SSS/TS vs. 10-20° in FS, and knee flexion reached 70-75° in SSS/TS vs. 30° in FS. Joint mobility between SSS and Thiel cadavers showed no significant differences.

Cadaver-based surgical skill training provides an essential bridge between anatomical education and live operative practice. The efficacy of procedural simulation depends fundamentally on preservation quality [1-3]. Conventional formalin embalming creates rigid cross-linked methylene bridges among tissue proteins, resulting in excessive hardening, loss of elasticity, and restricted joint movement that hinder advanced surgical simulations and laparoscopic or flap procedures [3,6,11].

Thiel's method maintains natural color, pliability, and tissue planes, rendering it highly effective for urological, orthopaedic, and laparoscopic training [4,5,8]. However, its complex sequential formulation (stems A, B, C, morpholine, and propylene glycol), prolonged immersion requirement, and high cost restrict its widespread institutional adoption [4,6].

Saturated salt solution (SSS) embalming represents a practical, cost-effective alternative. The combination of saturated sodium chloride (osmotic preservation and microbial inhibition), glycerol (hydration and flexibility), low-concentration formaldehyde, phenol, and isopropyl alcohol yields pliable tissues, patent vascular lumens, and lifelike surgical planes [1,2,6]. Evaluators found SSS cadavers highly suitable for diverse procedures including vascular exposure/repair, tracheostomy, chest tube insertion, and flap elevation [1,2,9]. Table 5 outlines the detailed formulations utilized.

Study limitations include the pilot sample size (3 cadavers), lack of quantitative biomechanical tensile testing, and absence of long-term microbiological surveillance. Future multi-center evaluations with objective tissue testing are recommended.

Saturated salt solution embalming provides a simple, economical, and effective preservation technique for cadaver-based surgical skill training. It offers tissue pliability, tactile feedback, and joint range of motion comparable to Thiel embalming while eliminating technical complexity and excessive chemical costs, making it highly suitable for wider adoption in surgical simulation and anatomy training centres.