Is hip disarticulation (amputation of the leg at the hip), CPT (Current Procedural Terminology) code 27290, medically necessary for a patient with a destructive right pelvic mass involving the right hip and sacroiliac joints?

Hip Disarticulation (CPT 27290) for Right Hemipelvic Mass

Hip disarticulation (CPT 27290) is medically necessary for this patient with a large destructive right pelvic mass likely representing primary osseous malignancy, and inpatient admission for 7-10 days is appropriate for this procedure.

Medical Necessity Justification

Indication for Amputation

The presence of a large destructive pelvic mass involving the right hip and sacroiliac joints with characteristics of primary bone malignancy meets criteria for limb reconstruction or amputation. The MCG guideline explicitly states that "limb reconstruction or amputation needed" is an indication for musculoskeletal surgery 1. This patient's imaging demonstrates:

• Destructive right pelvic mass with hip and sacroiliac joint involvement on MRI [@case presentation]
• Large heterogeneous hypermetabolic mass on PET/CT consistent with osseous primary malignancy [@case presentation]
• Sclerosis and stippled calcified mass occupying the right hemipelvis [@case presentation]

Surgical Approach Decision

Hip disarticulation is the appropriate surgical procedure when the tumor involves the acetabulum, iliac wing, and sacroiliac joint as demonstrated in this case. For high-grade bone sarcomas involving the pelvis, complete surgical resection with wide margins is mandatory [@4@, 1]. The ESMO guidelines specify that "all patients with a suspected primary malignant bone tumor should be referred to a bone sarcoma reference center" and that "the biopsy should be carried out at the reference center, by the surgeon who is to carry out the definitive tumor resection" [@4@].

Amputation should be performed when complete tumor resection would leave the limb non-functional or when extensive compromise of major neurovascular structures cannot be preserved [@8@]. Given the extensive involvement of the right hemipelvis including the hip joint and sacroiliac joint, limb-sparing internal hemipelvectomy would likely not achieve adequate margins or preserve functional limb use [@14@].

Timing and Multidisciplinary Management

All patients must be managed by a multidisciplinary team for bone sarcomas in specialized centers, and definitive resection must be performed by a surgeon member of this team [@7@]. The case presentation indicates appropriate workup with tumor board discussion planned, which aligns with guideline recommendations [@4@, 1].

The biopsy must be completed before definitive surgery, and the biopsy tract must be excised en bloc with the resection specimen [@4@, @8@]. The plan appropriately includes biopsy coordination before proceeding to definitive surgery.

Inpatient Level of Care and Length of Stay

Inpatient Necessity

Hip disarticulation requires inpatient admission due to the magnitude of surgery, blood loss risk, need for intensive postoperative monitoring, and complex pain management [@11@, 2]. This is a radical lower extremity amputation involving careful transection of all muscles and nerves surrounding the hip joint [@11@].

Expected Length of Stay

The appropriate inpatient stay for hip disarticulation is 7-10 days, based on the following considerations:

• Hip disarticulation is associated with high rates of morbidity requiring extended monitoring [@11@]
• Military Health System data shows patients averaged 170.8 encounter days in the first 12 months post-amputation, with the initial hospitalization representing a significant portion [@12@]
• The procedure requires management of surgical drains, pain control, early mobilization assessment, and initiation of rehabilitation [@10@, 3]
• Wound care and monitoring for complications including infection and phantom limb pain necessitate extended inpatient observation [@11@, 2]

Postoperative Rehabilitation Planning

Preoperative evaluation for rehabilitation (physical and occupational therapy) is necessary, and rehabilitation should continue until maximum function is achieved [@8@]. Multidimensional and patient-tailored physical rehabilitation programs should be implemented perioperatively 4.

Critical Caveats

The definitive surgical plan cannot be fully confirmed without biopsy results. If biopsy reveals low-grade chondrosarcoma or atypical cartilaginous tumor, limb-sparing internal hemipelvectomy might be considered instead [@7@, 5]. However, the PET/CT findings of large heterogeneous hypermetabolic mass strongly suggest high-grade malignancy requiring radical resection [@case presentation].

Neoadjuvant therapy (preoperative radiotherapy 45-50 Gy or chemotherapy) should be considered for borderline resectable tumors 4. However, given the extensive involvement and likely high-grade nature, upfront surgery is typically preferred for resectable disease 1.

Adjuvant radiotherapy should be considered for close soft tissue margins (<1 cm) or microscopically positive margins 4. This decision will be made based on final pathology and margin status.