Our aim was to explore factors associated with early post operative infection for surgically managed base of 4th/5th metacarpal fractures. We hypothesised that K-wires crossing the 4th and 5th carpometacarpal joint (CMCJ) would be associated with an increased risk of post-operative infection.

Data from consecutive patients requiring surgical fixation for a base of 4th/5th metacarpal fracture from October 2016 to May 2021 were collected. Patient demographics, time to surgery, length of surgery, operator experience, use of tourniquet, intra-operative antibiotics, number and thickness of K-wire used, as well as whether or not the K-wires crossed CMCJ joints were recorded. Factors associated with post operative infection were assessed using Chi Squared test and univariable logistic regression using R studio.

Of 107 patients, 10 (9.3%) suffered post operative infection. Time to surgery (p 0.006) and length of operation (p=0.005) were higher in those experiencing infection. There was a trend towards higher risk of infection seen in those who had K-wires crossed (p=0.06). On univariable analysis, patients who had wires crossed were >7 times more likely to experience infection than those who didn't (OR 7.79 (95% CI, 1.39 - 146.0, p=0.056). Age, smoking, K-wire size, number of K-wires used, intraoperative antibiotics, tourniquet use and operator experience were not associated with infection.

In patients with a base of 4th/5th metacarpal fractures requiring surgical fixation, we find an increased risk of post-operative infection associated with K-wires crossing the CMCJ, which has implications for surgical technique. Larger prospective studies would be useful in further delineating these findings.