Lateral unicondylar knee arthroplasty can help patients return to sport

One prospective study covers patients that undergo unicompartmental arthroplasty from 2000-2005 : nineteen patients underwent lateral unicompartmental (uni) knee replacements, with an average age of 68 years for the lateral unicompartmental group.

Assessments included preoperative and postoperative range of motion, subjective testing, radiographic evaluation and MRI.

Only one patient was converted to a total knee arthroplasty, and none were lost to follow-up.

Successful outcomes are reported in the majority of cases over an average follow-up of 33 months…

Physical examination and subjective questioning along with MRI correlation would help  predict successful outcomes.

Overall, patients reported a return to skiing in 5 months, tennis in 4 months and walking and jogging within 1 to 2 months.

He also reports that long-term results have to be followed and adds that the procedure has shown it is worth consideration.

“You can preserve bone stock, you can get near-normal kinematics, you have low cost and blood loss during surgery is less,” he says.

Reference

Plancher KD, Bishai SK, Ibrahim T. Patients undergoing lateral unicondylar knee arthroplasty: Can we guarantee success and return to sport? Paper SS-38. Presented at the 2010 Annual Meeting of the Arthroscopy Association of North America. May 20-23, 2010. Hollywood, Fla.

Researchers cite potential of bacteria to improve implants

While current implant manufacturing methods involve spraying HA on the device, the researchers noted that the bacteria can facilitate adhesion in hard-to-reach areas that spray-on techniques may miss.

They also noted that bacterial-produced HA nanocrystals are smaller than chemically produced HA nanocrystals and, therefore, have a high mechanical strength, according to the release.

No difference in outcomes seen at 1 year follow-up when using navigation for TKA

This patient’s knee is representative of those randomized to undergo standard or computer-navigated TKA surgery in a study designed to identify differences between the techniques.

Investigators found average surgical time increased 12 minutes for navigated TKAs.

Full-length standing radiographs were taken postoperatively in all cases and some patients had knee CT scans. Investigators found few differences in the groups’ results at 1 year postop.

Good ROM

The navigated group’s SF-36 general health scores were better than in the traditionally operated group, but none of the functional outcomes differed at 1 year postoperative. Range of motion and total arc of motion were also similar, according to the results.

Also, what causes the navigated group’s slight increase in varus alignment ?

One may speculate it may be due to landmarking issues at the surgery’s start or slightly internally rotating the tibial cut in conjunction with implanting the tibial base plate with added slope.

Surgeons’ skill level

All the investigators completed 20 navigated knees, minimum, with this system; two had done many more cases than that.

Further long-term follow-up studies will be required to assess the impact of surgical navigation on knee implant survival.