Convert to ICD-10-CM: 
728.4 converts approximately to:
- 2015/16 ICD-10-CM M24.20 Disorder of ligament, unspecified site
 
 ICD-9-CM Volume 2 Index entries containing back-references to 
728.4:
- Lax, laxity - see also Relaxation
ligament 728.4
 - Relaxation
back ligaments 728.4