Knowledge Base Article

ICD-10-CM Chapter 13 Musculoskeletal System – Part 1
In the last I-10 Corner article we covered Infectious and Parasitic Diseases. Our next chapter to review is the Musculoskeletal System which we will cover in two parts. Part one will cover ICD-10-CM and Part two will address ICD-10-PCS. In ICD-10-CM, we will highlight some changes we thought were important for you to be aware of. For instance, The Musculoskeletal System chapter received numerous code expansions partly due to ‘laterality’ being required for code assignment.

Example: Right Medial Epicondylitis

First, take a look below and see how the subchapters or blocks have expanded.

This chapter contains the following blocks:

M00-M02        Infectious Arthropathies

M05-M14        Inflammatory Polyarthropathies

M15-M19        Osteoarthritis

M20-M25        Other Joint Disorders

M26-M27        Dentofacial Anomalies [including malocclusion] and Other Disorders of Jaw

M30-M36        Systemic Connective Tissue Disorders

M40-M43        Deforming Dorsopathies

M45-M49        Spondylopathies

M50-M54        Other Dorsopathies

M60-M63        Disorders of Muscles

M65-M67        Disorders of Synovium and Tendon

M70-M79        Other Soft Tissue Disorders   

M80-M85        Disorders of Bone Density and Structure

M86-M90        Other Osteopathies

M91-M94        Chondropathies

New in Chapter 13

• Big code expansion in this chapter to identify type, site and laterality
• Clarifications for coding joint vs. specific affected bone (see coding guideline)
• Acute traumatic vs. chronic/recurrent conditions are defined with coding instructions
• Osteoporosis and Pathological Fracture information now included in ICD-10-CM Coding Guidelines
• Many codes relocated from other chapters in ICD-9-CM, i.e., Gout, Osteomalacia and Malocclusion
• Lots of other instructions such as:
• Use an external cause code
• Code first underlying disease
• Code also any associated underlying condition
• Use additional code to identify
• Code first poisoning due to drug or toxin
• Code first underlying neoplasm
• Use additional code to identify infectious agent
• Instructions for coding pathological fractures, needs 7th digit extension to identify episode of care (see below)
  Example:
  A Initial encounter for fracture
  D Subsequent encounter for fracture with routine healing
  G Subsequent encounter for fracture with delayed healing
  K Subsequent encounter for fracture with nonunion
  P Subsequent encounter for fracture with Malunion
  S Sequela
• Intraoperative and Postprocedural Complications of the Musculoskeletal System located within this chapter
• Acute traumatic fractures reassigned to Chapter 19 Injury, Poisoning and Certain Other Consequences of External Causes

ICD-10-CM Coding Guidelines

1. Site and laterality
   Most of the codes within Chapter 13 have site and laterality designations. The site represents the bone, joint or the muscle involved. For some conditions where more than one bone, joint or muscle is usually involved, such as osteoarthritis, there is a “multiple sites” code available. For categories where no multiple site code is provided and more than one bone, joint or muscle is involved, multiple codes should be used to indicate the different sites involved.
2. Bone versus joint
   For certain conditions, the bone may be affected at the upper or lower end, (e.g., avascular necrosis of bone, M87, Osteoporosis, M80, M81). Though the portion of the bone affected may be at the joint, the site designation will be the bone, not the joint.
3. Acute traumatic versus chronic or recurrent musculoskeletal conditions
   Many musculoskeletal conditions are a result of previous injury or trauma to a site, or are recurrent conditions. Bone, joint or muscle conditions that are the result of a healed injury are usually found in chapter 13. Recurrent bone, joint or muscle conditions are also usually found in chapter 13. Any current, acute injury should be coded to the appropriate injury code from chapter 19. Chronic or recurrent conditions should generally be coded with a code from chapter 13. If it is difficult to determine from the documentation in the record which code is best to describe a condition, query the provider.
4. Coding of Pathologic Fractures
   Seventh (7th) character A is for use as long as the patient is receiving active treatment for the fracture. Examples of active treatment are: surgical treatment, emergency department encounter, evaluation and treatment by a new physician. Seventh (7th) character D is to be used for encounters after the patient has completed active treatment. The other 7th characters, listed under each subcategory in the Tabular List, are to be used for subsequent encounters for treatment of problems associated with the healing, such as malunions, nonunions, and sequelae.
   Care for complications of surgical treatment for fracture repairs during the healing or recovery phase should be coded with the appropriate complication codes.
   See Section I.C.19. Coding of traumatic fractures.
5. Osteoporosis
   Osteoporosis is a systemic condition, meaning that all bones of the musculoskeletal system are affected. Therefore, site is not a component of the codes under category M81, Osteoporosis without current pathological fracture. The site codes under category M80, Osteoporosis with current pathological fracture, identify the site of the fracture, not the osteoporosis.
6. Osteoporosis without current pathological fracture
   Category M81, Osteoporosis without current pathological fracture, is for use for patients with osteoporosis who do not currently have a pathologic fracture due to the osteoporosis, even if they have had a fracture in the past. For patients with a history of osteoporosis fractures, status code Z87.310, Personal history of (healed) osteoporosis fracture, should follow the code from M81.
7. Osteoporosis with current pathological fracture
   Category M80, Osteoporosis with current pathological fracture, is for patients who have a current pathologic fracture at the time of an encounter. The codes under M80 identify the site of the fracture. A code from category M80, not a traumatic fracture code, should be used for any patient with known osteoporosis who suffers a fracture, even if the patient had a minor fall or trauma, if that fall or trauma would not usually break a normal, healthy bone.

Musculoskeletal System examples of why you need to brush up on your Anatomy and Physiology

Infectious Arthropathy - may also be referred to as Pyogenic or Septic Arthritis. Organisms invade the joint by:

• direct infection of joint; example: infected surgical hip wound
• indirect contamination; infection in bloodstream

Enteropathic Arthropathy - diseases of joints linked to gastrointestinal tract inflammation such as Inflammatory Bowel Disease or Crohn’s Disease.

Palindromic Rheumatism - is a sudden onset of inflammation in one or several joints. Lasts a few hours to a few days and is suddenly gone.

Dorsopathies - is a general term referring to conditions affecting the back or spine. Conditions such as Scoliosis, Spondylosis and Intervertebral disc disorders are included here.

Fragility Fracture -sustained with trauma no more than a fall from a standing height or less that occurs under circumstances that would not cause a fracture in a normal healthy bone.

Skeletal Fluorosis - this is excessive intake of fluoride causing the bones to become hardened and vulnerable to fractures.

In closing, the more you study this chapter the less you will feel overwhelmed. Once you do this, you will become familiar with the clinical information so that you can educate your physicians of what is required for more specific documentation.

Don’t forget to consult Coding Clinic for ICD-10-CM/PCS information!