Our systematic search identified 14 original studies that included patients treated with ORIF and patients treated with revision arthroplasty in the treatment of B2 and B3 PFF [5, 16, 19,20,21,22,23,24,25,26,27, 30,31,32]. The publications were mainly retrospective cohort studies which did not describe the treatment allocation, provided little information about potential predictive factors and presented diverse outcome parameters. Additionally, in most studies, the group sizes were small so that no statistical tests were performed. Table 2 provides an overview about the eligible studies including relevant outcomes and potential predictors.
Only a handful of publications provided information about the most likely prognostic factors such as type of the original stem, initial indication for THA, or implants used to treat the PFF, which have been shown to be important outcome predictors . Therefore, it was not possible to quantitatively analyze these potential prognostic factors.
Eight studies presented information on whether the PFF occurred around primary or around revision hip stems [5, 16, 22,23,24,25, 27, 31], eight presented the information whether the stem was cemented or uncemented [5, 16, 22, 24, 25, 27, 30, 31], three provided information about the fixation mechanism of the cemented stem (CCPT or CB) or the stem’s brand name for the respective treatment group [16, 22, 27], three informed about the diagnosis that had led to the initial hip replacement [22, 27, 31] and 7 provided details about the implants used for ORIF [16, 20, 22,23,24,25, 30]. One study presented some of the aforementioned parameters for some of the PFF types but did not follow a consistent pattern in doing so .
In addition to the assessment of bone quality and stem stability inherent to the Vancouver classification (B2: unstable or loose stem with good quality of the surrounding bone stock, B3: unstable or loose stem with inadequate surrounding bone stock), one study classified the bone quality around B3 fractures according to Paprosky . In this study no ORIF was used to treat B3 fractures.
Since the reported outcome measures were diverse, it was not possible to summarize them quantitatively. Some studies focused on mobility [16, 23,24,25,26,27, 30] as measured with various instruments, whereas other studies focused on union rates [16, 20, 23, 24, 26, 27, 32], reoperation rates [5, 19, 21,22,23, 30, 32], mortality [21, 22, 25, 26], or on perioperative parameters [16, 19,20,21, 23,24,25], including various combinations of these outcomes.
Success of treatment modality
Only five studies used statistical tests to compare the results of ORIF vs. stem revision in B2 or B3 fractures. Solomon et al. compared ORIF to stem revision in 21 patients whose initial stem was a CCPT stem and who had sustained B2 fractures. The results were significantly in favor of ORIF for surgical time and the need for blood transfusions. There were also non-significant (n.s.) trends in favor of ORIF for the Harris pain score and complications as well as n.s. trends in favor of revision surgery for mobility. However, the authors pointed out that the mean age in the revision group was 9 years higher and that one of the nine patients in the revision group had been evaluated for mobility directly after having received a knee replacement to explain the latter trend . Antoniadis et al. compared results of ORIF to stem revision in 53 patients who had sustained B2 fractures with an unknown fixation type of the initial stem. They found results significantly in favor of ORIF for surgical time and blood loss along with n.s. trends in favor of ORIF concerning complications and mortality . Joestl et al. compared the results of 3 treatment modalities to treat B2 PFF, one being ORIF, with a group size of only 8, and two different revision stem designs with group sizes of 14 each. They found n.s. trends in favor of ORIF for surgery time, blood units needed and the number of patients returning back to their pre-injury mobility level . Gitajn et al. analyzed the outcomes of patients with B1, B2 and B3 fractures. The results of the patients who had sustained B2 or B3 fractures were in favor of ORIF concerning blood loss and blood transfusions, showed no difference concerning mortality, and were in favor of revision surgery concerning the postoperative weight bearing instructions given by the treating practitioner . Pavlou et al. compared ORIF with and without grafting with stem revision with and without grafting, amongst other PFF types also between B2 and B3 fractures. The main outcome of the paper was that in the treatment of PFF, using a graft in addition to ORIF or a revision stem is beneficial. A comparison of all possible treatment combinations (ORIF/revision/with graft/without graft) demonstrated that in B2 fractures, treatment with a revision stem with or without graft resulted in higher union rates than treatment with ORIF without graft. No significant differences were seen in any of the other combinations, including ORIF with graft compared to revision with a stem with or without graft .
In several other publications, which had not used statistical tests to compare the results of ORIF vs. stem revision in B2 or B3 fractures, there were trends which appeared to favor ORIF for various parameters [20, 24, 25]. Other publications also showed trends for better outcomes of revision arthroplasty [22, 24]. However, the lack of appropriate statistics and the small group sizes do not allow drawing reliable conclusions.