We compared the early complication rates of total hip (THA) and total knee (TKA) arthroplasty carried out at a regional orthopaedic hospital (AOC) and two Independent Sector Treatment Units (ISTUs) (WGH and CNH). After THA, reoperation rates were higher at CNH (9%) than AOC (0.6%) or WGH (1.4%). After TKA, reoperation rates at CNH were (8%) higher than AOC (1%) and WGH (1.9%).

5% of patients undergoing TKR at CNH underwent 2 stage revision for deep infection.

After THA, dislocation rates at CNH (6%) were higher than AOC and WGH (1.8%). Readmission from CNH (13%) was higher than AOC (1.2%) and WGH (0.6%).

Major wound problems at CNH (20%) were higher than WGH (3.8%) and AOC (0.4%).

After TKA, major wound problems were higher at CNH (19%) compared to WGH (1.9%) and AOC (1.1%). Readmission rates not requiring surgery from CNH (13%) were higher than AOC. (1.1%) and WGH (1%). AOC and WGH audited their outcomes. None were available from CNH. WGH initially missed many of their complications because they presented at base hospitals elsewhere.

ISTUs performed approximately 2/3rds of procedures for which patients had been referred from base hospitals.

At CNH, 23% were rejected on grounds of potential co-morbidity. Audit from ISTUs is inferior to NHS hospitals and the results in one of those audited significantly worse.

Patients offered surgery at ISTUs should be told that the audited outcome of the surgeon who will be treating them is not known and that, in some, results are inferior to surgery in the NHS.