Arthroscopic debridement can improve function due to post-ankle fracture arthrofibrosis

Investigators found that patients with grade A1 and A2 chondral damage had significant improvements in AOFAS scores after arthroscopic debridement of fibrous tissue.

Arthroscopic debridement can be effective for removing the fibrous tissue that often forms after surgically repairing ankle fractures, which in turn can help improve articular function, according to a study by researchers in Japan.

Kiyomi Utsugi, MD, and colleagues at Saitama Medical University, Saitama, investigated the relationship between arthrofibrosis and ankle function in 33 patients with ankle fractures managed by open reduction and internal fixation at an average 40.2 years of age.

Using the American Orthopaedic Foot and Ankle Society (AOFAS) classification system, one patient had a 43A fracture, eight had 43B fractures, three had 43C fractures, four had 44A fractures, 10 had 44B fractures and seven had 44C fractures. In all cases, surgeons performed arthroscopy at the time of implant removal and after radiographically confirming bone union.

In addition to AOFAS scores, the researchers used their own four-point scale to grade articular function from G1 to G4 (G4 having worst function), focusing on squatting ability. Specifically, the scale evaluated pain during squatting, pain during daily activities (except for squatting) and range of motion limitations greater than 5° as compared to patients' unaffected sides, according to the study, published in Arthroscopy.

"In the Japanese lifestyle, squatting is a common daily activity, and difficulty in squatting presents a great limitation during everyday life," the authors said.

Fibrosis was graded from B0 to B2, with B0 being no fibrosis, B1 being mild fibrosis but no evidence of impingement and B2 being extensive fibrosis with impingement during passive ankle dorsiflexion, according to the study.

Prior to arthroscopy, AOFAS scores averaged 90.3 points, with 22 patients rated as excellent, four as good and seven as fair. Also, 22 patients were rated as G1 for articular function, two as G2, seven as G3 and two as G4.

Overall, 11 patients had chondral damage — nine patients demonstrated A1 damage and two patients had A2 damage. Patients rated as G3 or G4 for articular function were significantly more likely to have chondral damage, with 78% of these patients showing such damage (P=.0122), the authors noted.

Investigators found arthrofibrotic tissue formation in 73% of patients, with 16 patients graded as B1 and eight graded as B2. "All B0 cases showed favorable G1 articular function, whereas all G3 and G4 cases had arthrofibrosis, and seven of eight B2 cases (88%) were rated G3 or higher (P=.0005)," the authors said in the study.

After arthroscopy, all nine patients graded as B0 for fibrosis had no change in their clinical score — 100 points for the AOFAS scale and G1 for articular function, the authors said.

Surgeons performed arthroscopic debridement in the remaining patients. After surgery, AOFAS scores averaged 98.7 points in patients with B1 arthrofibrosis and 91.4 points in patients with B2 fibrosis, according to the study. Only patients treated for B2 arthrofibrosis showed a significant improvement after surgery (P=.0036), the authors noted.

Arthroscopic debridement also significantly improved AOFAS scores in patients with grade A1 and A2 chondral damage. AOFAS scores improved to 93.3 points from 79.9 points preoperatively (P=.0384) for patients with A1 damage, and improved to 92.5 points from 71 points preoperatively (P=.0443) for patients with A2 damage, according to the study.

"The principal findings ... were that a correlation was found between joint function and formation of arthrofibrosis after surgical reduction of ankle fractures, that formation of arthrofibrosis was observed at high rates in cases of poor ankle function, and that function was improved by removal of fibrous tissue," the study authors said.

For more information:
Utsugi K, Sakai H, Hiraoka H, et al. Intra-articular fibrous tissue formation following ankle fracture: The significance of arthroscopic debridement of fibrous tissue. Arthroscopy. 2007;23:89-93.