Cartilage Lesions and the Development of Osteoarthritis After Internal Fixation of Ankle Fractures
Reference: Sjoerd A Stufkens, MD, Markus Knupp MD, Monika Horisberger, MD, Christoph Lampert, MD, and Beat Hintermann, MD, J Bone Joint Surg Am 2010; 92: 279-86.
Scientific Literature Review
Reviewed by: Carissa Sharpe, DPM
Residency Program: Ohio College of Podiatric Medicine/University Hospitals Cleveland, Ohio
The evaluation of cartilage lesions and osteoarthritis development after internal fixation of ankle fractures is an important factor to consider when performing this type of trauma surgery. Podiatrists perform open reduction internal fixation of ankle fractures quite frequently and need to be aware of any possible consequences such as osteoarthritis due to osteochondral defects in the ankle joint that could be problematic in the future.
A long term study was performed in which 109 patients were evaluated after being treated operatively for ankle fractures according to AO principles. The mean follow up was 12.9 years. Sixty-one patients were male (mean age of 37.4 years) and forty-eight patients were female (mean age of 50.2 years). In all patients, ankle arthroscopy was performed followed by open reduction internal fixation. All cartilage lesions found via arthroscopy were identified and adequately documented and graded according to the individual parameters. The main focus on evaluation of the cartilage defects was on the depth and location. Anteroposterior and lateral radiographs of the ankle were then evaluated by a radiologist to determine the severity of osteoarthritis.
The Weber classification system was used to classify the ankle fractures, in which 15% were type A, 68% were type B, and 17% were type C. During arthroscopy, a cartilage lesion was found in 65% of the patients. The talus was only involved in 17% of patients, the tibia in 8%, and the fibula in 6%. All three surfaces were involved in 21% of the patients. Final evaluation showed initial cartilage damage in the ankle joint in 81% of patients directly after the ankle fracture. Clinical signs of osteoarthritis were found in 39%.
It is known that open reduction internal fixation of ankle fractures leads to more favorable results. However, post-traumatic arthritis is still reported in 14-50% of patients status post ankle fracture fixation. Factors contributing to the osteoarthritis include malunion, varus or valgus alignment of the distal tibia, ligament damage causing ligamentous instability, and arthrofibrosis. The hypothesis of this article is that the more extensive the initial cartilage damage, the higher chance that osteoarthritis would develop later. This study reveals that cartilage damage at the time of an ankle fracture does contribute to the development of osteoarthritis. There was no correlation found between the total number of osteochondral lesions and the development of osteoarthritis, but rather the location in the joint to be important. Lesions found on the anterior and lateral aspect of the talus and medial malleolus were found to significantly increase the risk of posttraumatic arthritis. Lesions found on the fibula did not correlate with an unfavorable outcome. Therefore, the severity and location of osteochondral lesions should be considered when determining the prognosis of osteoarthritis following ankle fractures treated with open reduction internal fixation.