There are many different ways to approach the problem of an anterior cruciate ligament (ACL) injury of the knee. A partial tear may respond well to conservative (nonoperative) care. But if rehab doesn’t yield the desired results (or in the case of a competitive athlete), the ligament may need surgical repair. The surgeon stitches the ends of the ligament back together.
A fully ruptured ACL often requires surgical reconstruction. It doesn’t work to try and pull the ends of the ruptured ligament back together — instead, a piece of tendon is taken from another area of the knee and used as a graft to replace the damaged ligament. The donor graft comes from one of two places: either the patellar tendon (just below the knee cap) or the hamstrings (behind the knee).
There are many ways to compare which type of graft works best. There are a lot of variables to work through in making the comparison. For example, patients of all ages, sizes, and shapes injure the ACL and need this treatment. Athletes have very different needs than older, less active adults.
It sounds like you are pursuing the patellar tendon graft. And you are right, residual knee pain when kneeling has been reported by many patients who have this graft type. How difficult is that? As you have pointed out, kneeling for long periods of time at church or at home is not a part of your daily activity.
It might be helpful for you to find out (before surgery) how often you use the kneeling position. And while you are evaluating that, you can pay attention to the importance of the activity . In other words, could you find a different way to accomplish the same task without kneeling? Is it something you do often such that not being able to kneel is going to be a big deal?
You can do a self-assessment by just observing your activities for a day or two and judge for yourself how often you use the kneeling position. If you don’t think you’ll remember, you can always tie something around your knee to alert you when you are kneeling. It could be something as simple as a small stone held against your knee with a bandana or as elaborate as a buzzer that would go off everytime pressure was applied to the knee.
To summarize a recent study from Australia on the long-term effects of patellar-tendon grafts for ACL ruptures: results are good-to-excellent. A few problems can crop up such as pain with kneeling, arthritis, and further knee injuries. Efforts to find ways to reduce knee pain after patellar tendon grafting are underway. Patients agree a little knee pain when kneeling is a small price to pay for the excellent long-lasting results they got otherwise.