Distraction Arthroplasty: Adjuvant Procedures May Be Doing More Harm Than Good

Distraction Arthroplasty (DA) is an alternative for select patients in the treatment of ankle osteoarthrosis. Distraction offloads the joint and facilitates biologic repair, while allowing restoration of the subchondral bone to near normal architecture at 2 years following frame removal.

Bone marrow stimulation (BMS) using microfracture (MFX) and intra-articular biologic adjuncts, such as concentrated bone marrow aspirate (CBMA), have been reported to stimulate chondrogenesis and facilitate an immune modulatory benefit.

Therefore, DA with adjuvant procedures theoretically makes sense. Or, does it?

The study

“Effect of Microfracture on Functional Outcomes and Subchondral Sclerosis Following Distraction Arthroplasty of the Ankle Joint,” a retrospective comparative case series by Gianakos et al. in Foot and Ankle International, presents the results of 78 patients who underwent DA using a hinged frame, with adjuvant procedures.

Interventions were divided into four groups for comparison: DA+MFX (n = 8); DA+MFX+CBMA (n = 35); DA+CBMA (n = 22); and DA alone (n = 13). Demographic data, patient reported outcome measures, functional activity levels, complications, and radiographs were reviewed.

The data

• MFX yielded no benefit when compared to DA alone. In-fact, interventions which included MFX had less improvement in joint space, reduced range of motion, and lower outcome scores. This suggests damage induced to the subchondral plate during drilling may reduce chondrogenesis.

• CBMA allowed earlier return to activity, without any additional benefit.

• Twenty-seven patients (34.6%) experienced a complication, with postoperative pain being the most common (10%).

• Overall complication rates: DA+MFX (12.5%); DA+MFX+CBMA (40%); DA+CBMA (31.8%); and DA alone (30.7%).