Receiving protein can affect the bone formation and maintenance by providing a structural matrix of the bone, optimizing the level of IGF-1, increasing intestinal calcium absorption, transferring phosphorous, and improving muscle strength.Therefore, protein may be effective on vertebral fusion by such mechanisms. In this trial patients undergoing elective posterior spine fusion surgery are divided into two groups of intervention or control.

A randomized, double blind, controlled trial will be conducted in patients undergoing elective posterior spine fusion surgery in Tehran, Iran. After a full review of the inclusion and exclusion criteria and explanation of the risks and benefits of the study, written consent form will be completed. The participants are 80 eligible posterior spine fusion surgery patients, aged ≥ 18 years. Intervention patients will be received 36 grams of protein supplement along with diet containing 1.2 g/kg/day of protein for 30 days after surgery and control patients will be received Carbo Mass along with diet containing 1.2 g/kg/day of protein 30 days after surgery. Patients will be evaluated for occurrence of vertebral fusion and enhanced recovery after 3 months surgery.

Inclusion criteria:

• Adult patients 18-65 years
• Body mass index 18.5-30
• Candidate for the elective posterior spine fusion
• Without history of severe liver disorder
• Without history of Kidney disorder
• Without history of diabetes
• Without history of trauma and fracture of the vertebral
• Without history of osteoporosis
• Without history of Gastrointestinal malabsorption
• Without history of Parathyroid gland disorders
• Without taking medications that affect the metabolism of bone, such as calcitonin,
• bisphosphonate, corticosteroid
• No smoking
• serum level of vitamin 25 (OH) D ≤20 ng/l

Exclusion Criteria:

• Allergy or intolerance to protein or maltodextrine supplement
• Unwillingness to continue cooperation

Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)