Where to start? 

I. Think about the Functions of the musculoskeletal System

• Mineral homeostasis (Calcium, phosphorus)
• Housing for haematopoietic bone marrow elements
• Mechanical functions

  • Protect viscera
  • Movement and locomotion
  • Body structure and size

II. Next, it may be helpful to begin by classifying the conditions into:

• BONE vs JOINT diseases

and

• FOUR major aetiologic categories: Inflamatory, Infectious, Metabolic and Neoplastic
• There are of course conditions that fall into other aetiologic categories (eg. traumatic, vascular, congenital, etc), however, we will focus on these four, in accordance with your lecture material.

Here's a simple framework to start with:

• I. Bones

  • Infectious diseases (osteomyelitis) 
  • Metabolic diseases (osteoporosis; osteomalacia/rickets; hyerparathyroidism; Paget's disease)
  • Neoplasms (Benign vs Malignant primary neoplasms; Metastatic malignancy)

• II. Joints

  • Inflammatory diseases (eg. osteoarthritis - degenerative and inflammatory; rheumatoid arthritis; crystal arthropathies) 
  • Infectious diseases affect both bones (osteomyelitis) and joints (septic arthritis)

This mindmap explains a systematic Approach to Bone and Joint Diseases.