I'm surprised to see the restrictions that some surgeons appear to be placing on rowing. At my post-op appointment (about 5 weeks after my BHR), I got the all-clear from my surgeon (Fares Haddad) to do anything that didin't involve running or jumping - with no weight, flexion or other restricitions. As it happens, I used the rower for the first time just yesterday (8 weeks post-op). It felt better than when I rowed pre-surgery! On the concept 2, I did 5K in just under 23 minutes, which is just off my old times, so I was pretty happy about that. And I feel great today.
I don't think my surgeon is a cowboy on the recovery score - like McMinn, he recommends waiting a year before running again. McMinn also includes rowing as as one of the good exercises to undertake after the soft-tissue healing phase. Here's what he has to say about the risks on the FAQ section of his website:
"The first six weeks after the operation you are in the phase of soft tissue healing. Therefore you will be advised not to put your hip through extreme ranges of movement in order to avoid a dislocation.
After this period, the degree of soft tissue healing is adequate to protect your hip during any voluntary movement. As a matter of fact, the tendency of the healing scar is now to contract in order to gain strength. Contracting scar has the potential to create a stiff and sore hip unless the hip is subjected to regular exercise during this period. Hence you will be encouraged to progressively increase your range of hip movements and increase the strength in the muscles around the hip by resorting to activities like swimming and non-impact exercises in the gym (such as using the bicycle, rowing machine, cross-trainers etc). Any exercise that does not result in excessive loading of the hip is good at this stage. You should try and avoid high impact-loading exercises like running, jogging, football, squash etc for at least a year after the operation.
As your hip improves in flexibility and stability, you may gradually resume your hobbies over the next few months. You may start playing a gentle game of golf after around 4 months and doubles tennis around 6 months. During the next few months, as you find improvement in the strength of your hip, you will be able to play more rigorously. If you are very keen on resuming impact loading sports then please start jogging on the treadmill with good footwear for a few months starting around the eleventh month before moving on to outdoor jogging or high-impact sports."