How Soon Is Too Soon for Revision THA to Treat Instability?

    Dr. Nathanael Heckmann and Dr. Craig Della Valle answer ICJR’s questions about their study that investigated whether the amount of time between the index total hip arthroplasty and a revision procedure for instability is associated with an increased risk of complications.

    ICJR: What question did you and your co-authors want to answer with this study?

    Craig J. Della Valle, MD: Several recent studies have identified a higher complication rate among total hip arthroplasty (THA) patients who undergo revision surgery shortly after their index procedure. Our group wanted to expand on the existing data with regard to 2 main points:

    • First, we wanted to investigate the time interval between the index procedure and revision surgery with more granularity, with the goal of identifying a time point at which the risk of revision decreases.
    • Second, we wanted to examine a group of revision THA patients for whom revision surgery may reasonably be delayed, as this would allow our findings to provide actionable recommendations to the arthroplasty community.

    For those reasons, we chose an instability cohort. Instability is one of the most common reasons for revision THA, which would give us the highest likelihood of being able to power a study to provide granularity by month. A subset of early revisions in these patients could reasonably be delayed, which would allow our findings to be translatable to the revision surgeon’s practice.

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    What did you conclude about the timing of revision THA for instability?

    Dr. Della Valle: We found a higher rate of complications among patients undergoing revision THA for instability within 3 months of their index procedure. The most alarming finding was the 10.6% to 14.7% rate of periprosthetic joint infection (PJI) during this time period. Even after accounting for potential confounders, these patients were 1.35 to 1.84 times more likely to develop a PJI compared with patients who underwent revision surgery more than 1 year after their index procedure.

    How did you reach your conclusions? What was your study cohort and what did you find with your analysis?

    Nathanael D. Heckmann, MD: We identified 9298 beneficiaries in the Medicare Part A claims database who had undergone revision THA for instability between 2010 and 2017. The patients within this cohort who had revision surgery more than 1 year after the index procedure served as the baseline comparator group. We then subdivided the remaining patients into 6 early revision subgroups:

    • Less than 1 month
    • 1 to 2 months
    • 2 to 3 months
    • 3 to 6 months
    • 6 to 9 months
    • 9 to 12 months

    The PJI rate was 6.9% for patients who underwent revision THA for instability more than 1 year after the index procedure. Compared with this rate, we observed a statistically significant increase in the PJI rate for the first 3 subgroups:

    • 14.7% for revision less than a month after the index procedure
    • 12.7% for revision at 1 to 2 months after the index procedure
    • 10.6% for revision at 2 to 3 months after the index procedure

    Statistical significance persisted even after accounting for potential confounders.

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    Why is this significant for clinical practice?

    Dr. Heckmann: Our data suggest that when performed within 3 months of the index surgery, early THA revisions for instability are associated with increased rates of subsequent PJI. Although our study does not allow us to make any causal claims, this association is alarming and has led us to recommend delaying early revisions for instability when feasible.

    Our data add to a larger body of work that has found higher rates of infectious complications among patients undergoing revision total joint arthroplasty for other indications.


    Heckmann ND, Yang J, Ong K, Lau E, Fuller BC, Bohl DD, Della Valle CJ. Revision surgery for instability following total hip arthroplasty: does timing matter? (Paper 766). Presented at the 2021 Annual Meeting of the American Academy of Orthopaedic Surgeons, August 31-September 3, San Diego, California.

    Heckmann ND, Yang J, Ong KL, Lau EC, Fuller BC, Bohl DD, Della Valle CJ. Revision surgery for instability after total hip arthroplasty: does timing matter? J Arthroplasty. 2021 May;36(5):1779-1783.e2. doi: 10.1016/j.arth.2020.12.035. Epub 2020 Dec 29.

    About the Experts

    Nathanael D. Heckmann, MD, is an Assistant Professor in the Department of Orthopaedic Surgery, Adult Reconstruction Division, at the Keck School of Medicine, University of Southern California, Los Angeles.

    Craig J. Della Valle, MD, is Chief of Adult Reconstruction at Midwest Orthopaedics at Rush, Chicago, Illinois.

    Disclosures: Dr. Heckmann has disclosed that he is a paid consultant for and has stock or stock options in Intellijoint Surgical and that he is a paid consultant for MicroPort Orthopedics. Dr. Della Valle has disclosed that he has stock or stock options in Navbit, Orthophor and Surgiphor, and Parvizi Surgical Innovations; that he receives royalties from, is a paid consultant for, and receives research support from Smith & Nephew and Zimmer Biomet; that he is a paid consultant for Cardinal Health and DePuy Synthes; and that he receives research support from Stryker.