Vol. 16 •Issue 4 • Page 16
Correct Coding for Knee Arthroscopies
Arthroscopies are becoming commonplace in the health care arena. Depending upon the degree of difficulty, these procedures are performed in hospitals, surgical centers and in some physician offices. Although common procedures, coders often have difficulty determining the correct ICD-9-CM and CPT codes to report. The case study below addresses a knee arthroscopic procedure. Look for another case study on knee arthroscopies in the next Coding Corner column scheduled for March 13, 2006.
Preoperative Diagnosis: Chronic left knee anterior cruciate ligament tear with medial meniscus tear; chondromalacia of the medial femoral condyle.
Postoperative Diagnosis: Same as above.
Procedures: Left knee arthroscopy, anterior cruciate ligament reconstruction with allograft, medial partial meniscectomy and notchplasty.
The patient was laid in the supine position with prepping and draping done in the usual fashion. A tourniquet was applied to the left thigh and inflated to 350 mmHg. Medial and lateral ports were made, and the scope was introduced into the knee joint. We noted the presence of an adequate patellofemoral joint with evidence of degenerative medial femur chondromalacia. The medial meniscus showed a tear extending from the posterior horn to the body of the medial meniscus.
With the basket and shaver, we did a medial partial meniscectomy and trimmed the edges with vapor. The femoral condyle showed a Grade 3 chondromalacia over a 2 cm x 2 cm area. In the notch, the anterior cruciate ligament was totally torn laterally. The compartment was adequate for the meniscus and the cartilage. With the burr, we performed a notchplasty. With the vapor and four-edge shaver, we removed the stump of the ACL. We then shaped the allograft to fit the 12-mm tunnel. With a tibial guide, the pin was introduced through an incision just medial to the tibial tuberosity.
Using a cannulated 12-mm drill, the tibial tunnel was drilled. An 8-mm offset was introduced, and we drilled a femoral tunnel. We then pulled the graft through both tunnels and locked the femur graft with a 7-mm absorbable screw from DePuy and a 9-mm absorbable screw, distally, both 25 mm long.
The knee was tested in flexion and extension, obtaining good stability. There was no impingement with full extension or flexion. The knee was irrigated, and the instruments were removed. The skin was closed with staples. Surgery was tolerated well. Blood loss was minimal.
ICD-9-CM Code Assignments
In the 2006 ICD-9-CM manual, check the index for the words Tear, torn. Then find the word “ligament,” which is followed by a direction to see also Sprain, by site. After finding the term Sprain, strain in the index, check for the term “cruciate.” Indented under this, look for the words “old,” then “anterior,” which is followed by the first code to assign–717.83 (old disruption of anterior cruciate ligament).
Again, check the term Tear, torn in the index, and review the indented terms for “meniscus (knee) (current injury).” Look at the next level of indents until you see “medial,” then “posterior horn” then “old.” Code 717.2, the second assignment, is listed.
717.2 Derangement of posterior horn of medial meniscus
Finally, check for the term Chondromalacia, and you will see code 733.92 (chondromalacia of femoral condyle).
CPT Code Assignments
Check the index of the CPT code manual for the term Arthroscopy. Then, under the term “surgical,” check for the indented term Knee, which is followed by codes 29871Ð29889.
Turn next to the Surgery/Musculoskeletal System section of the manual and review each description for the above code range. By comparing the code descriptions against the procedures described previously, you will see that the following are the correct code choices. Because the procedure was performed on the left knee, you also should assign modifier LT (left side, used to identify procedures performed on the left side of the body) to both codes.
29888LT Arthroscopically aided anterior cruciate ligament repair/augmentation or reconstruction, left knee
29881LT Arthroscopy, knee, surgical; with meniscectomy (medial or lateral, including any meniscal shaving), left knee
Some coders will be tempted to assign code 29877, which describes arthroscopy with debridement/shaving of articular cartilage (chondroplasty).
Although chondroplasty of the knee (also known as notchplasty) often is included in some of the larger knee procedures, it should not be reported. In the Correct Coding Initiative (CCI) edits, code 29877 is bundled into codes 29881 and 29888. The procedure is basically plastic surgery on cartilage (i.e., repair of lacerated or displaced cartilage), and many physicians perform this repair by removing torn or frayed articular cartilage.
If, however, the physician spends a significant amount of time (e.g., 15 minutes of time for Medicare patients) performing the chondroplasty in a separate compartment of the knee, you would assign code G0289 (instead of 29877). The use of an allograft (donor graft) is inclusive in the repair/reconstruction of the anterior cruciate ligament.
G0289 Arthroscopy, knee, surgical, for removal of loose body, foreign body, debridement/shaving of articular cartilage (chondroplasty) at the time of other surgical knee arthroscopy in a different compartment of the same knee
Peggy Hapner is manager of the health information management consulting division at Medical Learning Inc. (MedLearn®), St. Paul, MN.