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Official Description

Bone length studies (orthoroentgenogram, scanogram)

© Copyright 2025 American Medical Association. All rights reserved.

Common Language Description

Bone length studies, as defined by CPT® Code 77073, are specialized radiographic procedures aimed at measuring the lengths of long bones in the skeletal limbs. This method is particularly useful for assessing limb length discrepancies, which can be critical for diagnosing various orthopedic conditions. Unlike external observational measurements, which may lack precision, bone length studies provide a more accurate assessment through the use of radiographic films. The classic technique known as the orthoroentgenogram involves taking three separate radiographic exposures of the hip, knee, and ankle joints, allowing for a comprehensive evaluation of limb length. Alternatively, a scanogram is employed, which utilizes a reduced exposure size to capture all three joint images on a single film cassette, streamlining the process. Additionally, the teleoroentgenogram is a variation that consists of a single anteroposterior radiograph that incorporates a ruler within the image, facilitating direct measurement of the bone lengths. These methodologies are essential for clinicians to determine the extent of limb length inequality and to plan appropriate interventions.

© Copyright 2025 Coding Ahead. All rights reserved.

1. Indications

Bone length studies are indicated for various clinical scenarios where accurate measurement of limb lengths is necessary. The following conditions may warrant the use of this procedure:

  • Limb Length Discrepancy - This condition involves a noticeable difference in the lengths of the limbs, which can lead to functional impairments and may require surgical or non-surgical interventions.
  • Congenital Limb Deformities - Patients born with limb deformities may benefit from bone length studies to assess the extent of the discrepancies and to guide treatment options.
  • Post-Traumatic Limb Length Changes - Following trauma, such as fractures or surgical interventions, bone length studies can help evaluate any resultant changes in limb length.
  • Growth Disorders - Conditions affecting growth, such as achondroplasia or other skeletal dysplasias, may necessitate bone length studies to monitor growth patterns and plan for future interventions.

2. Procedure

The procedure for conducting bone length studies involves several key steps to ensure accurate measurements of the long bones. Each step is critical for obtaining reliable radiographic images.

  • Step 1: Patient Positioning - The patient is positioned in a supine or standing position, depending on the specific type of study being performed. Proper alignment is crucial to ensure that the joints of interest (hip, knee, and ankle) are accurately captured in the radiographic images.
  • Step 2: Radiographic Exposure - For an orthoroentgenogram, three separate exposures are taken: one for the hip joint, one for the knee joint, and one for the ankle joint. Each exposure must be carefully aligned to ensure that the anatomical landmarks are clearly visible. In the case of a scanogram, a single film cassette is used to capture all three joint images with reduced exposure size, allowing for a more efficient process.
  • Step 3: Image Processing - After the exposures are taken, the radiographic films are processed to produce clear images. The images must be evaluated for quality to ensure that all necessary anatomical details are visible for accurate measurement.
  • Step 4: Measurement - Once the images are available, the clinician measures the lengths of the long bones using the radiographic images. In the case of a teleoroentgenogram, the integrated ruler within the image aids in direct measurement, enhancing accuracy.

3. Post-Procedure

After the completion of bone length studies, the patient may be advised on any necessary follow-up care or additional imaging if required. Typically, there are no specific post-procedure restrictions, and patients can resume normal activities immediately. The clinician will review the radiographic findings and measurements with the patient, discussing any implications for treatment or further evaluation based on the results. It is essential to document the findings accurately in the patient's medical record for future reference and to guide ongoing management of any identified limb length discrepancies.

Short Descr BONE LENGTH STUDIES
Medium Descr BONE LENGTH STUDIES
Long Descr Bone length studies (orthoroentgenogram, scanogram)
Status Code Active Code
Global Days XXX - Global Concept Does Not Apply
PC/TC Indicator (26, TC) 1 - Diagnostic Tests for Radiology Services
Multiple Procedures (51) 0 - No payment adjustment rules for multiple procedures apply.
Bilateral Surgery (50) 0 - 150% payment adjustment for bilateral procedures does NOT apply.
Physician Supervisions 09 - Concept does not apply.
Assistant Surgeon (80, 82) 0 - Payment restriction for assistants at surgery applies to this procedure...
Co-Surgeons (62) 0 - Co-surgeons not permitted for this procedure.
Team Surgery (66) 0 - Team surgeons not permitted for this procedure.
Diagnostic Imaging Family 99 - Concept Does Not Apply
APC Status Indicator STV-Packaged Codes
ASC Payment Indicator Packaged service/item; no separate payment made.
Type of Service (TOS) 4 - Diagnostic Radiology
Berenson-Eggers TOS (BETOS) I1B - Standard imaging - musculoskeletal
MUE 1
CCS Clinical Classification 226 - Other diagnostic radiology and related techniques
26 Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number.
X5 Diagnostic services requested by another clinician: for reporting services by a clinician who furnishes care to the patient only as requested by another clinician or subsequent and related services requested by another clinician; this modifier is reported for patient relationships that may not be adequately captured by the above alternative categories; reporting clinician service examples include but are not limited to, the radiologist's interpretation of an imaging study requested by another clinician
TC Technical component; under certain circumstances, a charge may be made for the technical component alone; under those circumstances the technical component charge is identified by adding modifier 'tc' to the usual procedure number; technical component charges are institutional charges and not billed separately by physicians; however, portable x-ray suppliers only bill for technical component and should utilize modifier tc; the charge data from portable x-ray suppliers will then be used to build customary and prevailing profiles
LT Left side (used to identify procedures performed on the left side of the body)
RT Right side (used to identify procedures performed on the right side of the body)
59 Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25.
FY X-ray taken using computed radiography technology/cassette-based imaging
GC This service has been performed in part by a resident under the direction of a teaching physician
52 Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use).
XS Separate structure, a service that is distinct because it was performed on a separate organ/structure
XU Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service
CR Catastrophe/disaster related
XE Separate encounter, a service that is distinct because it occurred during a separate encounter
79 Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.)
MA Ordering professional is not required to consult a clinical decision support mechanism due to service being rendered to a patient with a suspected or confirmed emergency medical condition
X2 Continuous/focused services: for reporting services by clinicians whose expertise is needed for the ongoing management of a chronic disease or a condition that needs to be managed and followed with no planned endpoint to the relationship; reporting clinician service examples include but are not limited to: a rheumatologist taking care of the patient's rheumatoid arthritis longitudinally but not providing general primary care services
XP Separate practitioner, a service that is distinct because it was performed by a different practitioner
47 Anesthesia by surgeon: regional or general anesthesia provided by the surgeon may be reported by adding modifier 47 to the basic service. (this does not include local anesthesia.) note: modifier 47 would not be used as a modifier for the anesthesia procedures.
50 Bilateral procedure: unless otherwise identified in the listings, bilateral procedures that are performed at the same session, should be identified by adding modifier 50 to the appropriate 5 digit code. note: this modifier should not be appended to designated "add-on" codes (see appendix d).
76 Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
77 Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service.
AQ Physician providing a service in an unlisted health professional shortage area (hpsa)
CC Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed)
FX X-ray taken using film
GA Waiver of liability statement issued as required by payer policy, individual case
GV Attending physician not employed or paid under arrangement by the patient's hospice provider
GW Service not related to the hospice patient's terminal condition
GY Item or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
GZ Item or service expected to be denied as not reasonable and necessary
ME The order for this service adheres to appropriate use criteria in the clinical decision support mechanism consulted by the ordering professional
MG The order for this service does not have applicable appropriate use criteria in the qualified clinical decision support mechanism consulted by the ordering professional
MH Unknown if ordering professional consulted a clinical decision support mechanism for this service, related information was not provided to the furnishing professional or provider
PD Diagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days
Q1 Routine clinical service provided in a clinical research study that is in an approved clinical research study
Q5 Service furnished under a reciprocal billing arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
Q6 Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area
X4 Episodic/focused services: for reporting services by clinicians who provide focused care on particular types of treatment limited to a defined period and circumstance; the patient has a problem, acute or chronic, that will be treated with surgery, radiation, or some other type of generally time-limited intervention; reporting clinician service examples include but are not limited to, the orthopedic surgeon performing a knee replacement and seeing the patient through the postoperative period
Date
Action
Notes
2025-01-01 Changed Short Description changed.
2011-01-01 Changed Short description changed.
2007-01-01 Added First appearance in code book in 2007.
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