Is a C‑arm fluoroscope used during anterior cruciate ligament reconstruction surgery?

C-Arm Fluoroscopy in ACL Reconstruction

C-arm fluoroscopy is not routinely necessary for ACL reconstruction surgery, though it can be used selectively to improve tunnel placement accuracy—particularly for less experienced surgeons or in complex cases—but arthroscopic visualization alone is sufficient for confirming proper graft positioning in most cases.

Current Use and Indications

C-arm fluoroscopy is used in some ACL reconstruction procedures, primarily for:

• Confirming femoral and tibial tunnel positioning before final reaming, with studies showing surgeons change their initial pin placement based on fluoroscopic findings in approximately 15% of cases 1
• Verifying femoral button placement after suspensory fixation, though recent evidence demonstrates arthroscopic visualization is equally reliable 2
• Improving anatomic tunnel placement in double-bundle reconstruction, where fluoroscopy-assisted technique produces significantly deeper femoral anteromedial bundle positioning compared to fluoroscopy-free procedures 3

Evidence for Routine Use

The evidence does not support mandatory fluoroscopy for all ACL reconstructions:

• Arthroscopic visualization alone is highly reliable for confirming proper femoral button placement, with 97% accuracy when surgeons have high confidence (≥9/10) from both intra-articular and extra-articular perspectives 2
• No difference in clinical outcomes exists between fluoroscopy-assisted and fluoroscopy-free double-bundle ACL reconstruction in terms of knee laxity, pivot-shift grade, or functional scores at final follow-up 3
• Surgeon experience does not eliminate the need for confirmation techniques, as both experienced staff surgeons (16% pin repositioning rate) and fellows (14% rate) changed femoral pin placement based on fluoroscopy/isometry findings at similar frequencies 1

Radiation Safety Considerations

When fluoroscopy is used, radiation exposure is minimal and safe:

• Mean effective dose is 0.001 ± 0.002 mSv with entrance skin dose of 0.0015 ± 0.0029 Gy—well below the 2 Gy threshold for skin damage 4
• Lifetime cancer risk is less than 0.0001% from intraoperative fluoroscopy during ACL reconstruction 4
• Radiation exposure does not contraindicate the procedure when fluoroscopy is deemed beneficial for surgical accuracy 4

Practical Algorithm for Decision-Making

Use fluoroscopy when:

• Performing revision ACL reconstruction with altered anatomy
• Surgeon has lower confidence in tunnel positioning based on anatomic landmarks alone
• Double-bundle reconstruction requiring precise anteromedial bundle placement 3
• Teaching cases where confirmation enhances learning

Fluoroscopy is unnecessary when:

• Surgeon has high confidence (≥9/10) in button placement from both arthroscopic perspectives 2
• Primary single-bundle reconstruction with clear anatomic landmarks
• Standard suspensory fixation with good arthroscopic visualization 2

Common Pitfalls

• Over-reliance on fluoroscopy when arthroscopic visualization provides adequate confirmation, adding unnecessary radiation exposure and operative time 2
• Assuming experience eliminates positioning errors, as even experienced surgeons reposition pins 16% of the time when using confirmation techniques 1
• Failing to use any confirmation method in complex cases where tunnel malposition significantly impacts outcomes 3, 1

The C-arm remains a valuable adjunct tool in orthopaedic surgery 5, but for routine ACL reconstruction, arthroscopic visualization combined with sound anatomic technique is sufficient for most cases, reserving fluoroscopy for situations requiring additional confirmation 2.