We present an alternative method to extract the $t\bar{t}$ cross-section from the muon plus jets channel in $pp$ collisions at $sqrt{s}$ = 7 TeV. In addition to a standard baseline selection, we also study the use of

topological constraints to impove the measurement. Using the full 2010 dataset we obtain a result of 160.4

$pm$ 15.0(stat) $^{+43.9}_{-42.0}$ (syst) $pm$ 6.4(lumi) pb from our baseline analysis. By applying two different additional topological constraints this becomes

153.3 $pm$17.3(stat) $^{+35.4}_{-30.4}$ (syst) $pm$ 6.1(lumi) pb

and 156.5 $pm$23.7(stat) $^{+29.9}_{-30.3}$ (syst) $pm$ 6.3(lumi) pb