Effect of Microfracture on Functional Outcomes and Subchondral Sclerosis Following Distraction Arthroplasty of the Ankle Joint

Abstract

Background:

Treatment for post-traumatic osteoarthritis (PTOA) of the ankle remains challenging. Distraction arthroplasty (DA) is an alternative for patients who are averse to or poor candidates for arthrodesis or joint replacement. The purpose of this study was to examine the role of microfracture (MFX) and concentrated bone marrow aspirate (CBMA) on the outcome of patients undergoing DA for end-stage PTOA of the ankle joint.

Methods:

Ninety-five patients who underwent DA for the treatment of end stage PTOA from 2009 to 2014 were selected from the hospital ankle registry. Demographic data, functional activity levels, complications, and radiographs taken at 6, 12, 24, and 36 months postoperatively were reviewed. Foot and Ankle Outcome Scores (FAOS) were obtained at the same time intervals. A total of 78 patients were included in this study. Interventions were divided into 4 groups for comparison: DA+MFX (n = 8), DA+MFX+CBMA (n = 35), DA+CBMA (n = 22), and DA alone (n = 13).

Results:

Patients undergoing DA+MFX or DA+MFX+CBMA had significantly worse motion (P = .003) when compared with DA alone. Patients undergoing MFX had significantly reduced postoperative joint space and a greater length of time to return to activity when compared to subgroups not using MFX (P = .01). The use of MFX was associated with significantly lower FAOS scores.

Conclusion:

The current study showed no benefit from MFX when combined with DA in the treatment of PTOA. CBMA may have helped mitigate the adverse effect of MFX but conferred no benefit when used with DA alone. DA remains a useful alternative to ankle arthrodesis and arthroplasty in patients with PTOA. However, MFX and biologic augmentation using CBMA appeared to have no additional benefit.

Level of Evidence:

Level III, comparative study.