Proximal femoral arthroplasty in patients undergoing revision hip arthroplasty

The survivorship of revision total hip replacement with severe proximal bone deficiency using a modular taper fluted prosthesis

Contemporary uncemented femoral revision hip systems have become commonly used over the past decade and have enabled the reconstruction of leg length, offset and anteversion as independent variables through the use of modular junctions. Modular junction failures between the proximal body and distal stem have been described with revision systems, although this is rare. We sought to identify the survivorship of one revision system in a salvage arthroplasty scenario where no host bone support of the modular junction was present. From a series of 136 patients, 15 patients (16 hips) were identified without host bone support of the modular junction with a mean radiological follow up of over 6 years (76 months +/- 35 months). There have been no cases of prosthetic fracture over the follow-up duration, with two revisions performed for reasons of aseptic loosening and infection. The mean BMI of the study group was 30.2 with 78% of the cohort classified as overweight or obese. It is well recognised that, host bone support of the modular junction is preferable, however the satisfactory outcomes over the midterm in these complex patients suggests that modular revision systems remain an option.

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.

First application of three-dimensional designing total hip arthroplasty with long uncemented stem for fibrous dysplasia patients combined with hip joint osteoarthritis

Background

In order to treat proximal femur fibrous dysplasia (FD) patients combined with hip joint osteoarthritis (OA), the three-dimensional (3D) designing osteotomy and implantation of femoral component was firstly used for deformity correction and total hip arthroplasty (THA). The purpose is to present the detailed design, perioperative management and evaluate short-term clinical outcomes of this novel therapeutic method.

Method

A retrospective study was performed in twelve FD patients combined with hip joint OA who were treated in our hospital between July 2013 and April 2015. Seven patients received 3D designing combined osteotomy and THA, and the other five patients underwent 3D designing THA only.

Results

All patients were followed-up with an average duration of 47 months (range, 35–56 months). There was no infection, dislocation, postoperative wound problems or mechanical failures. For the seven patients receiving 3D designing corrective osteotomy, the mean extremity lengthening was 2.8 (range, 1.5–4) cm. The average duration of bone union was 4.2 months. The average Harris Hip Score was improved from 46.08 (range, 13–67) points preoperatively to 93.72 (range, 83–100) points at the last follow-up. The average modified criteria of Guille was improved from 3.2 (range, 1–7) points preoperatively to 8.6 (range, 6–10) points at the last follow-up.

Conclusions

The 3D designing THA with long uncemented stem, including 3D designing corrective osteotomy and implantation of long prosthesis stem, seems to be a reliable method for FD patients combined with hip joint OA. Through preoperative 3D design, corrective osteotomy and implantation of long prosthesis stem can be precise to re-store alignment, uttermost preserve host bone, obtain primary stem stability and provide necessary condition for long-term stem survival, finally leading to better limb function. Besides, perioperative management should be abided strictly for late stability. Nevertheless, the outcomes of long-term follow-up and larger cases are still required.

A novel use of a tibial cone in a proximal femoral replacement

Revision total hip arthroplasty in the setting of severe femoral bone loss can be challenging, with salvage options often limited to modular tapered stems, allograft prosthetic composites, and megaprostheses. This case highlights a 79-year-old woman with 2 years of thigh pain who is 8 years status post a revision proximal femoral allograft prosthetic composite reconstruction. Radiographs demonstrated significant stem subsidence into the femoral condyle. In an attempt to avoid a total femoral replacement and spare her functioning native knee, a tibial cone was used in conjunction with a proximal femoral replacement to structurally fill the flaring femoral canal and serve as a stable pedestal for the megaprosthesis body and provide the potential for biologic ingrowth. At 12-month follow-up, she ambulates with a cane, and radiographs reveal stable implant position.

Midterm Outcomes of Revision Total Hip Arthroplasty Using a Modular Revision Hip System

BACKGROUND

The growth in hip arthroplasty surgery has meant a corresponding escalating revision burden with increasing challenges for the orthopaedic surgeon. The purpose of this study was to review clinical outcomes of a modular revision hip system within a single institution.

METHODS

We retrospectively reviewed a cohort of modular revision hip system stems performed in our institution between January 2005 and October 2012 giving a potential minimum follow-up of 2 years. Clinical outcomes data on complications, Oxford Hip Score (OHS, 0-48) and patient satisfaction were collected. Radiographic outcomes including subsidence were assessed. Implant survival was estimated using Kaplan Meier analysis.

RESULTS

115 stems in 106 patients were identified. All cause survival was 82% (95%CIs: 73%-89%) at 6.1 years; survival excluding infection being 99% (95%CIs: 93%-100%). There was a low incidence of subsidence (seven stems) and no peri-prosthetic fractures. Primary cause of re-revision in this series was re-infection with only one re-revision for mechanical failure. Median Oxford Hip Score at mean follow up 4.1 years (2-9) was 40 (14-48) and 93% of patients reported being satisfied with their revision surgery.

CONCLUSION

This study showed good clinical outcomes and survival using a modular revision stem with low mechanical failure and subsidence. Recurrence of infection remains a challenge in revision surgery.