| Following knee replacement surgery, patients | | | | the surgeon works to optimize range of motion and |
| sometimes report hearing clicks or a clicking sound | | | | joint stability through proper alignment and sizing of |
| during certain activities or at a certain point or points | | | | the implant. |
| during their gait cycle. In most cases, this sound is | | | | The resulting tension in the replaced joint can, |
| believed to be benign and is not associated with pain | | | | therefore, vary slightly from patient to patient and |
| or other adverse consequences. | | | | can be different within the range of motion of a |
| So what causes this clicking? | | | | single patient. That is, some patients may have |
| To answer this question, it is helpful to understand a | | | | "tighter" knees or "looser" knees or a single knee can |
| little bit about the nature of total knee replacement. | | | | be "tight" in flexion, but "loose" in extension and vice |
| In knee replacement, the ends of the bones that | | | | versa, but in general, some degree of laxity is |
| make up the knee joint are "resurfaced" with metal | | | | desirable to allow for adequate motion. |
| and plastic components. The surgeon uses specialized | | | | Because there is almost always some laxity in a |
| instrumentation and surgical technique to properly | | | | replaced knee, clicking can sometimes be heard as a |
| align the implants to the bones and the bones to one | | | | result of contact between the metal and plastic |
| another. | | | | components during activity. Often it is heard during a |
| This alignment is not straightforward because in the | | | | transition from low or non-weight bearing to weight |
| replaced knee joint, as in the normal knee, the bones | | | | bearing. For example, a patient may hear the click |
| are not "mechanically interconnected"; rather the joint | | | | while walking as the leg comes out of swing phase |
| is constrained by the remaining soft tissue (ligaments, | | | | and makes contact at heal strike. For the most part, |
| muscles/tendons) and the conformity of the implant | | | | the clicking is usually not associated with any adverse |
| components. During the knee replacement operation, | | | | conditions. |