Patient injuries in primary total hip replacement

Abstract

Background and purpose - Although the results of primary total hip replacements (THRs) are generally excellent, sometimes serious complications arise. Some of these severe complications are considered to be patient injuries. We analyzed primary THR-related patient injuries in a nationwide setting. Patients and methods - We evaluated all the primary THR-related patient injury claims in Finland between 2008 and 2010. We used the original medical records and 2 nationwide registries, the Care Register for Social Welfare and Health Care and the Patient Injury Claim Register. Results - We identified 563 claims, 44% of which were compensated (n = 250). Of these 250 compensated claims, 79% were considered to be avoidable (treatment injuries) and 21% were severe unexpected infections (with a preoperative infection risk of less than 2%). The most common type of technical error was cup malposition (31%). High-volume hospitals (with an annual primary THR volume ≥ 400) had a lower patient injury rate. In lower-volume hospitals (with an annual primary THR volume of < 400), the relative risks (RRs) of patient injury for any reason, due to technical errors, or because of cup malposition were 2-fold (95% CI: 1.6-3.1), 4-fold (95% CI: 2.3-6.2), and 9-fold (95% CI: 3-28), respectively, compared to high-volume hospitals. Interpretation - Our study provides the first comprehensive nationwide data on THR-related patient injury types. Hospital volume was associated with the quality and quantity of errors detected. An annual hospital volume of ≥ 400 primary THRs was established as a protective factor against patient injuries.

Figure 1.

Flow chart of data collection. NFB: any primary hip arthroplasty operation; NFC: any hip revision operation; NFJ: any hip fracture operation; NGB: any primary knee arthroplasty; NGC: any revision knee arthroplasty. ^a 2 claims of 10 were from high-volume hospitals (group 4). 9 claims were treatment injury claims, and 1 was an infection claim (group 3).

Figure 2.

Types of patient injury. a Nerve or vascular lesions/injuries. b Percentage (%) of all perioperative technical errors. c Unplanned leg length difference of > 2 cm due to stem malposition. d Two patients had 3 errors.

Figure 3.

Hospital volume and patient injuries. A. The association between high THR volume and lower incidence of claims filed, compensated claims, and perioperative technical errors. B. The number of compensated claimants with avoidable technical errors in each individual hospital performing total hip replacements (THRs) relative to hospital volume. Hospitals with over 50 primary THRs per year were included. The thick red line represents the average rate of compensated claimants with perioperative technical errors in Finnish hospitals. Hospitals below the line performed better than the national average.