Medium Term Radiographic and Clinical Outcomes Using a Modular Tapered Hip Revision Implant.

BACKGROUND: The rate of revision hip arthroplasty surgery is rising. Surgeons must use implants with proven outcomes to help overcome the technical challenges faced during revision surgery. However, outcome studies using these implants are limited. The aim of this study is to investigate the radiographic and clinical outcomes of the Stryker Restoration stem, the most commonly used hip revision stem in the United Kingdom (UK). METHODS: A retrospective review of a single surgeon case series was performed. Immediate postoperative radiographs were analyzed for offset and leg length discrepancy. Radiographic evidence of subsidence was assessed using follow-up radiographs. Kaplan-Meier survival analysis was applied using explantation and reoperation as endpoints. Patient-reported outcomes were measured using the Oxford Hip Score and EQ-5D-5L. RESULTS: One hundred ninety-eight cases were identified. Mean follow-up duration was 51.8 months (range: 24-121). Stem survival during this period was 98%. Reoperation for any reason was 13%. Mean subsidence was 4.18 mm. Analysis of variance testing showed no difference in mean subsidence between revision indications. Mean offset and leg length discrepancies were measured at 4.5 mm and 4.3 mm, respectively. The mean Oxford Hip Score for participants was 27.6. CONCLUSIONS: This series demonstrates excellent implant survival, with radiographic parameters for reconstruction and subsidence levels comparable to those in the existing literature. The tapered modular hip revision stem provides surgeons with the intraoperative flexibility to overcome some of the anatomical difficulties encountered during revision surgery; this is reflected in the radiographic and clinical outcomes of the cohort in this study.

Subsidence Following Revision Total Hip Arthroplasty Using Modular and Monolithic Components.

BACKGROUND: The ideal femoral component in revision total hip arthroplasty (rTHA) remains undetermined; however, tapered, fluted, titanium (TFT) stems are now widely used with favorable results in all types of revision scenarios. With both modular and monoblock TFT stem options, neither has been proven to be superior. Femoral stem subsidence has been linked to aseptic loosening, instability, and leg length discrepancy. This study aims to assess stem subsidence of modular and monoblock TFT stems at a single urban orthopedic specialty hospital within a tertiary academic medical center. METHODS: Electronic medical records of rTHAs performed between January 2013 and March 2018 utilizing modular and monoblock TFT stems were examined. Data collected included baseline demographics, surgical indication, femoral Paprosky classification, and stem subsidence at most recent follow up (3 months to 3 years). Two-sample t-tests and chi-squared tests were used for statistical analysis. RESULTS: A total of 186 patients (106 modular, 80 monoblock) were included in the analysis. Modular stems underwent significantly greater subsidence than monoblock stems at latest radiographic follow-up (3.9 ± 2.6 vs 2.3 ± 2.5 mm, P < .001). A significantly greater proportion of modular stems underwent >5 mm of subsidence at latest follow-up (29.2% vs 11.3%, P < .001). CONCLUSION: Monoblock TFT stems have displayed promising clinical results in prior studies, and now have been shown to decrease the incidence of postoperative subsidence. With the potential for stem subsidence to lead to aseptic loosening, limb length discrepancy, and instability, the orthopedic surgeon should weigh the risks and benefits of utilizing modular vs monoblock TFT stems in rTHA.

Nonmodular Stems Are a Viable Alternative to Modular Stems in Revision Total Hip Arthroplasty.

BACKGROUND: Nonmodular and modular femoral stems have been associated with complications after revision total hip arthroplasty (rTHA). As such, the ideal femoral component for rTHA remains undecided. This study aims to report outcomes of titanium, tapered-fluted, modular and nonmodular femoral components in rTHA. METHODS: From January 1, 2013 to September 30, 2017, all rTHAs using modular or nonmodular femoral stems were identified. Demographic data including age, gender, and American Society of Anesthesiologists scores were collected. Surgical details including operative time and implant cost were also collected. Clinical outcomes including length of stay, dislocation, infection, fracture, reoperation, and re-revision were collected. Statistical analysis was performed using chi-square test and Student's t-test for all categorical and continuous variables, respectively. RESULTS: One hundred forty-six rTHA cases (103 modular and 43 nonmodular) were identified with an average follow-up of 29 months (range 3-59 months). Nonmodular stems had a significantly lower cost when compared to modular implants (modular stems 120.8% higher cost; P < .001). The surgical time of nonmodular components was significantly greater (193 minutes vs 163 minutes; P = .029). There were no differences observed in any other surgical details or clinical outcomes assessed, including length of stay (P = .323), rate of re-revision of the femoral implant (P = .389), rate of re-operation (P = .383), and postop complications (P = .241), including infection (P = .095), dislocation (P = .778), and fracture (P = .959). CONCLUSIONS: Nonmodular components provide encouraging clinical results with significantly lower costs compared to modular implants in rTHA. The use of titanium, tapered-fluted, nonmodular components may offer a more cost-effective approach to rTHA compared to their modular counterparts.

What Is the Difference Between Modular and Nonmodular Tapered Fluted Titanium Stems in Revision Total Hip Arthroplasty.

BACKGROUND: Both modular and nonmodular tapered fluted titanium stems are used in revision total hip arthroplasty (THA), with follow-up showing good results for both stems. We aimed to determine whether there were any differences in clinical outcomes, survivorship, or frequency of complications. METHODS: A retrospective review of 160 consecutive THAs (153 patients) revised with a tapered fluted modular titanium stem from 2002 to 2014 and 129 consecutive THAs (128 patients) revised with a tapered fluted nonmodular titanium stem between 2008 and 2014 was conducted. The patient's level of satisfaction, clinical assessment, and complications were examined. A Kaplan-Meier survivorship analysis was performed with the endpoint defined as any reoperation due to septic/aseptic complications. RESULTS: Mean duration of follow-up was longer in the modular group (6.3 years) than the nonmodular group (5.0 years; P = .003). No significant group differences were found in the postoperative Harris Hip Score, the level of overall satisfaction, the 8-year cumulative survival, the rate of infection, dislocation, or postoperative periprosthetic fractures. However, intraoperative fractures occurred significantly more frequently in the modular group (16.9%) than in the nonmodular group (7.0%; P = .011), and stem subsidence was significantly less in the modular group (0.95 mm) than in the nonmodular group (1.93 mm; P = .001). Two mechanical failures associated with the modular design occurred in the modular group. CONCLUSION: Both modular and nonmodular tapered fluted titanium stems provide satisfactory midterm results in revision THA. Although tapered fluted modular stems are gaining in popularity in revision THA, tapered fluted nonmodular stems should not be disregarded as a viable alternative, especially for relatively straightforward cases.

A comparison of modular tapered versus modular cylindrical stems for complex femoral revisions.

The effect of distal geometry in modular stems in revision THA remains unclear. The purpose of this study is to compare femoral revisions with modular tapered versus modular cylindrical stems in high-grade defects. A multicenter review of 105 femoral revisions with Paprosky III/IV defects using modular titanium stems (61 tapered; 44 cylindrical) was performed with an average follow-up of 5 years. Demographic data was comparable between groups. The tapered group had more IIIB and IV defects (51% vs. 20%; P < .01). The failure rate for component osseointegration was 1.6% in the tapered group and 15.9% in the cylindrical group (P = <.01). The rate of femoral component re-revision for any reason was 4.9% in the tapered group and 22.7% in the cylindrical group (P = .013). Modular tapered stems were associated with lower rates of stem failure and improved bone ongrowth compared to cylindrical stems despite being used in femurs with greater defects.