What are the recommendations for a patient with potential underlying conditions requiring Computer-Assisted Manufacture (CAM) implant treatment, particularly those with compromised bone health?

CAM Impingement Treatment

For femoroacetabular impingement (FAI) with cam morphology, MR arthrography or CT arthrography should be performed after initial radiographs to confirm the diagnosis and guide surgical planning, with computer-assisted surgery available to precisely resect the cam lesion according to a prescribed plan. 1

Diagnostic Imaging Algorithm

Initial evaluation:

• Plain radiographs of the pelvis and hip are the mandatory first imaging study for any patient with chronic hip pain and suspected cam impingement 1

Confirmatory imaging when impingement is suspected:

• MR arthrography or CT arthrography is the appropriate next step after radiographs when cam-type FAI is suspected 1
• These contrast studies are superior to non-contrast MRI for evaluating the labrum and detecting cartilage damage associated with cam impingement 1

Advanced surgical planning:

• CT data can be used for computer-navigated surgery to define exact bony anatomy and instrument positioning 1
• Cross-sectional CT or MRI data enables virtual surgery modeling, allowing surgeons to plan the precise parameters of cam lesion resection before the actual procedure 1
• Computer-assisted surgery can pair with 3-D models to resect the cam lesion according to a prescribed surgical plan 1

Surgical Considerations

Computer-guided cam resection:

• Virtual surgery models created from CT or MRI data allow surgeons to perform the cam resection on a computed model first, then execute the planned resection during actual surgery 1
• This approach differs from simple templating and provides precise control over the amount and location of bone removal 1

Special Populations Requiring Additional Evaluation

Patients with compromised bone health:

• If the patient has risk factors for osteoporosis (glucocorticoid use, transplant recipient, metabolic bone disease), bone density assessment and metabolic workup should be completed before any surgical intervention 1
• For patients on chronic glucocorticoids at moderate-to-high fracture risk, oral bisphosphonates are the preferred first-line osteoporosis treatment due to safety, cost, and proven efficacy 1

Renal transplant recipients:

• Evaluation by a metabolic bone disease expert is recommended for all renal transplant patients before orthopedic surgery 1
• Bisphosphonates should generally not be used if eGFR <35 mL/min 1

Common Pitfalls to Avoid

• Do not proceed with surgical planning based on radiographs alone when cam impingement is suspected—arthrography (MR or CT) is necessary to fully evaluate labral tears and cartilage damage 1
• Do not assume computer-guided surgery eliminates all complications; strict adherence to system protocols is essential, as bony interference preventing complete seating of prostheses remains a recognized early complication 2
• In patients with metabolic bone disease or chronic glucocorticoid use, do not perform elective orthopedic procedures without first optimizing bone health and addressing modifiable fracture risk factors 1