Low Reinfection Rates But a High Rate of Complications in THA for Infection Sequelae in Childhood: A Systematic Review
Authors: D’Apolito Rocco , Bandettini Guido , Rossi Gregorio , Jacquot Filippo Piana , Zagra Luigi 
Published: February 2021

Abstract

Background
Childhood hip infections can result in serious sequelae during adulthood, including persistent pain, functional limitations, and premature THA. When THA is performed in patients who had hip joint infections during childhood, surgeons surmise these arthroplasties are at an increased risk of complications and incomplete recovery. However, the degree to which this is true is not well characterized and has varied across a large number of small, retrospective studies.

Questions/purposes
(1) What proportion of THAs performed in patients who had pediatric septic arthritis result in periprosthetic joint infection? (2) What are the Harris hip scores associated with these reconstructions? (3) What proportion of these patients develop complications after THA? (4) What proportion of patients undergo revision after these THAs?

Methods
For this systematic review, we searched the MEDLINE (PubMed), Scopus, and CINAHL (EbscoHost) electronic databases. We evaluated studies published in English between 1980 and 2020 that had a minimum of 10 patients (with a minimum of 2 years of follow-up) in whom sequelae of septic arthritis of the hip were treated with single-stage THA. We also evaluated studies reporting clinical outcomes by means of the Harris hip score, along with a radiographic assessment of the prosthesis. Updates of previous studies using the same database, case reports, surgical technique reports, systematic reviews, and expert opinions were excluded. No restrictions were applied regarding study design and loss to follow-up. A total of 430 studies were identified through the initial search, and 11 studies were included after applying the inclusion and exclusion criteria. All but two studies, which included a historical control group, were retrospective case series. A total of 691 patients with a mean age of 45 years were involved. A total of 599 patients underwent cementless THAs, 84 patients underwent hybrid THA (cemented stems), and the remaining eight patients received a cemented THA. A total of 287 additional procedures were performed on the acetabulum, including autografting, allografting, and medial wall osteotomies; in three hips, tantalum augments were used. Three hundred thirty-five additional procedures were performed on the femora, including 223 shortening osteotomies and 112 greater trochanter osteotomies. The mean follow-up duration ranged from 5.5 to 15.2 years (minimum follow-up range 2-13 years). To assess the quality of the studies, we used the Methodological Index for Non-randomized Studies and the Assessment of Quality in Lower-limb Arthroplasty, for which a higher score represents a better study quality. The mean Methodological Index for Non-randomized Studies score for case series was 9 of 16 (range 6-12), and 19 and 18 of 24 for the two comparative studies. The mean reporting quality of the Assessment of Quality in Lower Limb Arthroplasty score was 6 of 8 (range 3-8).

Results
Because of loss to follow-up, which was not consistently reported in the source studies, we caution the reader that the estimates provided here likely underestimate the risks of adverse events and overestimate the mean hip scores. The pooled proportion of patients in whom infections developed was 1% (seven of 691 THAs). Considering only studies published in the past 10 years, the proportion was 0.7% (two of 276 THAs). The Harris hip score increased from a mean of 52 ± 6 points before THA to a mean of 88 ± 2 points after THA. The pooled proportion of complications, including sciatic nerve palsy, femoral nerve palsy, intraoperative periprosthetic fracture, deep venous thrombosis, and dislocation, was 11% (76 complications among 691 THAs). The pooled proportion of patients who underwent revision was 8% (53 revisions of any components for any reason among 691 THAs) at a mean follow-up interval of 9.1 ± 3 years.

Conclusion
In THAs for sequelae of childhood septic arthritis, reinfections were uncommon, whereas generally, infection rates were slightly higher than those reported for conventional primary THAs. However, the duration of follow-up might have been insufficient to identify all patients in whom infections later developed, and the available data were not adequate to precisely detect the minimum quiescent period to avoid reinfections. Moreover, the studies in this systematic review were retrospective, and selection bias, transfer bias, and assessment bias likely influenced our findings. The general effect of these biases is to cause an underestimation of the harms of the intervention. Complications, especially intraoperative fracture and nerve palsy, were common in patients with the most-severe infections. Further data on this topic are needed, ideally from multicenter or registry studies with even longer follow-up durations.

Level of Evidence
Level IV, therapeutic study.