Range of motion
Patients recuperate from UKA more rapidly and more predictably than after TKA and do not require formal exercise regimes or outpatient physiotherapy appointments to recover knee movement. Vigorous exercises are counterproductive by making the knee more painful and swollen.
On the day of the operation, while the local anaesthetic block is providing good pain relief and the drain is in place, most patients can easily perform an active straight leg raise and flex the knee to 110°. Thereafter, the joint tends to become more swollen, pain relief is less complete, and flexion is more difficult. Exercises to encourage flexion at this stage may make the knee worse, and patients should be allowed to limit knee movement within the range that is comfortable. Education of physiotherapists may be necessary especially if the unit is new to UKA. They may well treat the patient as though they have a TKA which is understandable but counterproductive as the patient often loses confidence if pushed too hard. By the end of the first week, pain and swelling subside. Motion is gradually regained in succeeding weeks, usually recovering to what it was preoperatively after a month and often improving further thereafter.
Ambulation
Most patients can start to walk about 2–3 hours after the operation. Early walking seems to improve the pain relief. If there is quadriceps weakness, splinting the knee may help.
Early discharge
With rapid recovery, it is possible to discharge patients from hospital early. Repicci and Eberle (1999) were able to treat 80% of their patients with less than 24 hours in hospital.
We undertook a randomised study, within the setting of the UK National Health Service 10 years ago, to compare the effect of discharge on the day after operation with our practice at that stage which was discharge on day 4 or 5 (Beard et al, 2002; Reilly et al, 2005). In appropriately selected patients, discharge on the day after operation did not prejudice the speed of recovery or increase the incidence of complications. However, it did result in a significant cost saving (Shakespeare & Jeffcote, 2003). In order that patients are suitable for early discharge, they must be relatively fit and live locally, there must be a support system so that patients can telephone if they have problems and be readmitted if necessary.
Increasingly, patients having the OUKA are being discharged on the day of surgery. Up to 80% of patients undergoing UKA in some centres are discharged on the same day. These patients undergo a prior rigorous health check up, have a detailed outpatient consultation including counselling about advantages of day case surgery and are provided adequate support (including visits and 24 hour telephone service) after surgery. Education of patients and staff is essential. In addition reliable pain control and postoperative support is required. Early outcomes have been shown to be better than or as good as those with conventional discharge without any increase in readmission rates or mortality or morbidity (Gondusky et al, 2014).
Duration of recovery
The early rapid recovery of function after UKA tends to slow down in later weeks. Often, at 6 weeks, patients are disappointed that they still have symptoms (although these are usually less severe than those experienced at the same stage after TKA). Therefore, we warn patients before discharge that their rapid rate of recovery may not continue and that they may still have some pain medially, numbness laterally, swelling of the knee, stiffness and restriction of extension and flexion for three months. Night pain around the six week mark is a not uncommon complaint. The patients recover quickly, and therefore stop taking pain relief medication and become increasingly active. As a result they may have increasing symptoms. They should be warned not to stop night time medication too soon. If a patient does have increasing symptoms, they should decrease their level of activity.
Overall, most of the recovery occurs within the first three months. After that the symptoms continue to improve slowly for about a year.
