Compass Point: When two procedures are related, you must determine whether the series of surgeries was planned or unplanned in order to select the proper codes and modifiers.
Surgeons perform transmetatarsal amputations (TMAs) to manage severe forefoot infections, tissue damage, or circulatory issues. While the goal is to preserve as much of the foot as possible to maintain ambulation, the complexity of these cases can lead to revisions or reamputations. Unfortunately, clinicians often misdocument or miscode these follow-up procedures, resulting in reimbursement issues and potential audits.
The Case File: When There is a Plan for Revisional Surgery
On June 26, a 72-year-old patient with type 2 diabetes mellitus and hypertension underwent a TMA of the left foot due to a chronic wound that progressed to osteomyelitis across multiple metatarsal heads. During the procedure, the surgeon did not close the surgical site due to concerns about the risk of continued infection. Instead, they packed the site open and planned to return to the operating room after the lab finalized the culture and bone biopsy results.
On July 3, the surgeon brought the patient back to surgery for additional removal of bone at the metatarsal bases and primary closure of the surgical site.
Case Challenge
What Current Procedural Terminology® (CPT) code(s) should the surgeon choose to properly represent each component of this case scenario? And what specific documentation elements should the surgeon include to support these choices?
Coding Lab Results
The medical record must clearly document that the surgeon established a “staged, related, preplanned scenario,” after the June 26 procedure, with an intended revisional surgery to be performed at the appropriate time.
This first procedure, a TMA, corresponds to CPT code 28805 (amputation, foot; transmetatarsal).1,2 The surgeon must also append an -LT modifier to this code to indicate the proper surgical side.
The second procedure, also a TMA, but more proximal, matched the definition of CPT code 28805. However, the surgeon would apply two modifiers in this instance. In addition to the -LT modifier, the surgeon would append modifier -58 to indicate that the revision was a staged, related, and preplanned procedure that the same surgeon performed during the postoperative period.1-3
If the revision involves only soft tissue debridement, secondary closure, the surgeon may instead assign codes such as 13160, which is a secondary closure of surgical wound or dehiscence, extensive or complicated, depending on the procedure’s details and complexity.3 In these cases, modifier -58 should still be appended to the correct code, and a new postoperative period begins with the second procedure.4
The Case File: When Revisions Are Unplanned
Consider an alternate scenario. On June 26, the same patient underwent a TMA of the left foot with primary closure, as the surgeon did not suspect any residual infection. In this scenario, however, the site deteriorated weeks after the patient left the hospital, presenting with redness, swelling, drainage, and pain at the incision. On July 3, the patient underwent a previously unplanned revisional surgery, which included the removal of bone across all five metatarsals more proximally due to an infection. In this second surgery, the surgeon kept the wound open.
Case Challenge
What Current Procedural Terminology® (CPT) code(s) should the surgeon choose to properly represent each component of this second case scenario? And what specific documentation elements should the surgeon include to support these choices?
Coding Lab Results
In the first procedure, CPT 28805 and the -LT modifier apply since the surgeon planned the revision scenario. However, what about the subsequent procedure in this updated scenario? At the time of the first procedure, the surgeon had not planned for a staged procedure. Therefore, the surgeon should not apply the -58 modifier to the second surgery.
When a revision is unplanned and results from complications, such as infection or stump issues, the surgeon must carefully assess the timing and details of the procedure to determine the most appropriate code. The surgeon should not use modifier -76 since it indicates a repeat procedure or service, on the same day, by the same physician or other qualified healthcare professional (QHP).5 This modifier does not apply in this case since the revisional procedure did not occur on the same day. The surgeon should use modifier -78 since it indicates an unplanned return to the operating room by the same physician for a related procedure during the postoperative period.6
The surgeon performed a second surgery on the patient’s affected foot during the postoperative period, specifically at the site of the initial TMA due to an infection. The surgeon resected the remaining five metatarsal stumps more proximally and should code this case to include CPT 28805 as well as the -LT and -78 modifiers. The key is that the second procedure was unplanned, and this statement should be included in the documentation to support the chosen coding.
Final Lab Lessons
Thorough documentation is crucial for substantiating surgical coding. Clinicians must clearly distinguish each intervention, including any revisions, from routine postoperative care. The surgeon must record these details in the operating room notes. The report should document the rationale for the procedure, specifying whether it is primary or a revision, the exact location and extent of the amputation, and any pertinent details, such as whether it is a re-amputation or a secondary closure. The report should also include the anatomical site, laterality, and the level of amputation, along with detailed intraoperative findings to support both clinical and coding decisions.
