From 1980–2004 a total of 928 uni knees were performed using the link “St. Georg” and “Endo-Modell” as well as the “Allegretto” device. Our last follow up concerning the first group 1980–1984 revealed an average survival rate of more than 15 years for 94,6 % of the patients, including cases of 24 years without any complaints. Since 2001 the uni knee also was performed as 1-day-surgery in out-patients. Is there any benefit in comparison with In-patients having the same surgery?

Since 2001 53 patients got a uni knee as out-patients. Exclusion criteria: body overweight, cardio-respiratory disease, diabetes, coagulopathy, allergy, malposition of the patella and insufficiency to use crutches. Socially excluded were patients with deficits in emergency supply, home care, personal compliance, local rehabilitation network and insurance problems. Our standards of the surgical procedure: Tourniquet, no cutting guides, antibiotic single shot, general anaesthetica, cemented components, heparine, compression stockings and a controlphone in the evening. At the first ambulatory follow up the second day after surgery we changed the compression stockings after removal of the drainage and started physiotherapy with lymphatic drainage and a special movement splint for exercise at home 3hours/day.

X-ray results and clinical investigation did’nt show a siginificant difference between In- and Out-patients. Out-patients had an average postoperative stay at the unit of 4,7 hours. 24 patients left by wheelchair and 29 by crutches. 46 used a private car for the transport and 7 an ambulance. At the beginning we saw only two “out-patient-specific-complications” in form of drainage disconnections, however without any consequences for the patients. We got 17 emergendy calls because of postoperative pain within the first 28 hours.

The follow up comparison of In- and Out-patients performing minimally invasive unicondylar knee prosthesis did not reveal benefits for ambulatory surgery concerning blood loss, pain, recovery, infections, thrombosis, personal care and surgical procedure. Insurance savings, however, were tremendous: 3800,- EUR for general insured patients and 7900,- EUR for private insurance.

From 01/1988 to 04/2001 224 THR were performed assisted by a surgical robot (ROBODOC). The short term run of 5 years should reveal, if any benefit ore disadvantage could be detected comparing Robodo chips with hand -broached hips.

In all 224 cases a straight stem prosthesis with a proximal sleeve was used (S-Rom-Prosthesis). The cup was implanted manually (RM-Cup). The average follow up has been 5 years (4,0–6,2 years). At the last investigation 3 patients had died, 6 patients could not be reached. 215 patients (96%) were examined. According to Merle d’Aubigné pain and walking ability were mesured with a maximal score of 12 points.

Robot assisted hip surgery surely offers an improved primary stability of the stem because of the outstanding precision.