Unicompartmental Knee Replacement

One Patients Story to Treatment and Recovery

““Orthopedic injuries can only bear a certain amount of weight. With this machine, we can gauge how much weight and be compliant with the doctor’s orders. The patient can exercise without as much pain."”

Trent Leonard, Rehabilitation Service Manager, Life Care Center

One Patients Recovery from a Unicompartmental Knee Replacement Procedure

David Nissenbaum, MPT, MA, LAT


69-year-old active male with long history of DJD to the medial compartment of his right knee underwent elective right unicompartmental knee replacement.

  • The patient is very active. He plays pickleball (version of tennis) and is a member of a hiking club.
  • At 3 months post-op, the patient will be going hiking in Nova Scotia for one month.


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  • Initiate early weight bearing to prepare for hiking trip
  • Develop a normal gait pattern
  • Progressively improve hip, knee, and core strength
  • Return to a normal walking program and be able to walk on even and uneven surfaces and multiple speeds and angles

History / Progression

I. Plan

  • Patient is a retired surgeon. He was very active throughout his whole life and played tennis for many years, but was eventually unable to do so secondary to knee pain. Patient then started pickleball, which causes less stress on his joints and played pickleball until symptoms increased to the point where he was unable to do any lateral movements
  • Patient had Synvisc® injection series with no noticeable improvement in knee symptoms
  • Consulted with MD and elected to undergo R partial medial knee arthroplasty
  • Underwent 4 days of inpatient care post-op, followed by 10 days of inpatient rehabilitation, then started outpatient rehabilitation
  • Patient initially had significant medial knee pain with any active or passive flexion beyond 90 degrees. Discussed case with patient’s MD and surgeon subsequently released medial collateral ligament which resulted in decreased medial knee pain
  • 2 weeks post-op, the patient initiated a walking program on the AlterG physical therapy equipment at 40% of his body weight at 1.7 mph and no incline
  • This patient’s treatment protocol included gait training(on AlterG), soft tissue mobilization, patellar mobilization, joint mobilization, knee strength and stability exercises and proprioceptive drills
  • Program duration was 3 months

II.  Considerations

  • Pain, swelling and soreness were monitored when progressing ambulation on the AlterG
  • Speed and incline were increased as patient’s pain level improved

III. Progression

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The patient was seen 3x/wk x 4 weeks, then 2x/wk x 4 weeks, then 1x/wk x 4 weeks until month 4 post-op. The patient initially had increased medial knee pain with flexion, but did not have pain while ambulating. The patient did achieve all of his functional goals and has returned back to an exercise program, but not pickleball currently. At the time of this case study, the patient was leaving for Nova Scotia.

The AlterG Anti-Gravity Treadmill was incorporated early in the physical theraphy rehabilitation program as a way to restore his normal gait. We also used the AlterG as a way to prepare the patient for the extreme amount of walking that he was going to do in Nova Scotia. We kept his unloading to a maximum of 75% as a way to improve patient’s cardiovascular endurance without stressing his knee. The patient was discharged, ready for his hiking trip. He will be seen as needed when he returns.