Retrospective cohort study of union rate in tarsometatarsal joint arthrodeses

N. Carroll, R. Martin, J. Coorsh, R. Kakwani, A. Murty, D. Townshend

Background: The aim of this study was to assess type of fixation on success of tarsometatarsal joint arthrodesis. Primary outcome was union at 3 and 12 months.

Methods: Medical records were reviewed for demographics, diabetes and smoking status, implant, and indication for surgery. There were 139 consecutive tarsometatarsal joint (TMTJ) fusions in 134 patients. 27 male:111 female, average age 60.9. 75 were isolated TMTJ fusions, 64 multiple TMTJ fusions. 70 used compression plates (43 Stryker Claw2, 27 Synthes VA), 22 used compression screws across the joint, 47 used a combination of the above. The overall union rate at 3 months and 12 months was 85% (118/139) and 89% (124/139) respectively.

Results: The overall rate of broken metalware was 8% (11/139), and revision rate was 2% (4/139). Diabetes was a predictor of non-union (3 months OR 3.78 p=.034; 12 months OR 3.77 p=.023 respectively). The rate of union was greater in single joint fusion vs multiple joint fusion (3 months OR 5.0 p=.003, 12 months OR 6.1 p=.003 respectively). There was no significant difference in the rate of union for the use of bone graft (3 months OR 0.29 p=0.09, 12 months OR 0.2 p=0.11 at 12 months), or smoking (OR 0 at 3 and 6 months), as independent variables. We found no significant difference in rate of union based on indication for surgery. Claw2 used in isolation were found to have a higher rate of non-union at 3 months and at 12 months compared to other methods (10/35 and 8/35 respectively; chi square= 3.87 and 4.90 respectively; p=.049 and 0.026 respectively). We found no significant difference in union rates between other methods of fixation.

Conclusion: In this series, multiple TMTJ fusion, diabetes, and the use of the Claw 2 system without adjunct compression screws were independent predictors of non-union.