MAKO Surgical (UNKNOWN:UNKNOWN), purveyor of a robot-assisted system used for performing both knee and hip surgical procedures, released third quarter results shortly after the market closed. Revenue grew 46% to $29.2 million to beat analyst estimates of $27.5 million. Earnings per share came in a penny ahead of expectations.

The revenue upside was driven by systems sales. Fifteen placements led to systems-related revenue of $14.4 million, ahead of my personal expectations and an encouraging sign of progress on the sales front. On the flip side, procedural volumes grew by a somewhat disappointing 33% to 2,413, driving overall utilization down to 6.2 procedures per system.

Going forward, strong sales execution gave management the confidence to maintain full year guidance of 42 to 48 systems. However, the company lowered expectations for full year procedures to between 10,200 to 10,600 from between 11,000 to 12,000.

The earnings call just began, and I'm sure investors will be curious as to what caused the soft procedure numbers. We'll be covering the story in depth as more details unfold.

Brenton Flynn has no positions in the stocks mentioned above. The Motley Fool owns shares of MAKO Surgical. Motley Fool newsletter services recommend MAKO Surgical . Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.