Cementless femoral revision in patients with a previous cemented prosthesis

Efficacy and safety of modular versus monoblock stems in revision total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

Both modular and monoblock tapered fluted titanium (TFT) stems are increasingly being used for revision total hip arthroplasty (rTHA). However, the differences between the two designs in clinical outcomes and complications are not yet clear. Here, we intend to compare the efficacy and safety of modular versus monoblock TFT stems in rTHA.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library databases were searched to include studies comparing modular and monoblock implants in rTHA. Data on the survivorship of stems, postoperative hip function, and complications were extracted following inclusion criteria. Inverse variance and Mantel-Haenszel methods in Review Manager (version 5.3 from Cochrane Collaboration) were used to evaluate differences between the two groups.

RESULTS

Ten studies with a total of 2188 hips (1430 modular and 758 monoblock stems) were finally included. The main reason for the revision was aseptic loosening. Paprosky type III was the most common type in both groups. Both stems showed similar re-revision rates (modular vs monoblock: 10.3% vs 9.5%, P = 0.80) and Harris Hip Scores (WMD = 0.43, P = 0.46) for hip function. The intraoperative fracture rate was 11.6% and 5.0% (P = 0.0004) for modular and monoblock stems, respectively. The rate of subsidence > 10 mm was significantly higher in the monoblock group (4.5% vs 1.0%, P = 0.003). The application of extended trochanteric osteotomy was more popular in monoblock stems (22.7% vs 17.5%, P = 0.003). The incidence of postoperative complications such as periprosthetic femoral fracture and dislocation was similar between both stems.

CONCLUSIONS

No significant difference was found between modular and monoblock tapered stems as regards postoperative hip function, re-revision rates, and complications. Severe subsidence was more frequent in monoblock stems while modular ones were at higher risk of intraoperative fracture.

LEVEL OF EVIDENCE

Level III, systematic review of randomized control and non-randomized studies.

TRIAL REGISTRATION

We registered our study in the international prospective register of systematic reviews (PROSPERO) (CRD42020213642).

[Postoperative outcomes and survival rates after aseptic revision total hip arthroplasty : What can patients expect from revision surgery?]

BACKGROUND

In 2020, more than 14,000 aseptic revision procedures for total hip arthroplasty (THA) were registered in Germany. Patient expectations of revision hip arthroplasty are not substantially different from expectations of primary hip replacement.

OUTCOME

However, revision surgery is associated with increased complication rates and a higher proportion of dissatisfied patients. In particular, poorer postoperative function and mobility as well as increased pain levels following revision THA have been described compared to the outcome after primary THA. Quality of life and return-to-work can also be impaired.

SURVIVAL RATE

Implant survival is influenced by age, BMI, and comorbidities of the patients, but also by the size and complexity of bone defects, the extent of periprosthetic soft tissue compromise and the choice of revision implant(s). In addition, the number of previous revision surgeries inversely correlates with the survival rates. Previous revisions have been shown to be associated with increased risks of aseptic loosening, instability and periprosthetic infection.

Risk factors for subsidence of modular fluted tapered stem implanted by using transfemoral Wagner approach during revision hip arthroplasty

PURPOSE

To determine clinical and radiographic risk factors for the vertical subsidence of modular fluted tapered stems implanted using the transfemoral Wagner approach in a cohort of revision hip arthroplasties.

METHODS

A retrospective review of a single-centre surgical registry was performed. Patients who underwent a revision total hip arthroplasty, in which the uncemented modular fluted tapered stem (REVISION Hip/Anca-Ti6Al4V, LimaCorporate, Udine, Italy) was implanted using the transfemoral Wagner approach, were identified. Patient's demographic data, clinical and radiographic outcomes and post-operative complications were assessed. As a significant subsidence, a 5-mm cut-off was chosen.

RESULTS

We identified 278 revision hip arthroplasties with a mean follow-up of 35 months. The median of subsidence in the group of 5 mm and less was 2 mm, and 17 mm in the group of subsidence of 5 mm and more. A negative correlation was found between the stem subsidence and the length of good contact between the medial and lateral cortical bone and the stem (medial, - 0.248; P < 0.001, lateral, 0.284; P < 0.001). For 200 mm stems, the percentage of good contact between femoral parts of stem and bone on medial side was 40.5% (81.0 mm) for patients with subsidence of five or less mm, and 30% (60.0 mm) for lateral side. For 140 mm stems, the percentage was 52.86% (74.0 mm) for medial side and 40.36% (56.5 mm) for lateral side. A neck length was shown to correlate significantly with the stem subsidence (P = 0.004).

CONCLUSION

It is crucial to provide good contact between the bilateral cortical bone and stem, and, if possible, to select implant constructs with shorter femoral necks, in order to reduce subsidence and to ensure longer implant survivorship.

Effect of patient-specific instrument on lowering threshold for junior physicians to perform total hip arthroplasty on developmental dysplasia of the hip patients

PURPOSE

To create a patient-specific instrument (PSI) in lowering the surgical experience requirement for junior physicians to perform total hip arthroplasty (THA) on developmental dysplasia of the hip (DDH) patients.

METHODS

Combined with rapid prototyping technology, we created a PSI and established DDH hip model in vitro. We enrolled 48 junior physicians and randomly assigned them into two groups. After creation of the PSI, they performed simulated THA surgery on a full-scale hip model with or without PSI on DDH models. The planned prothesis orientation, post-operative prothesis orientation, and surgery time were recorded.

RESULTS

The final cup inclination was 42.0 ± 0.8° in PSI group and 37.8 ± 2.0° in control group, while final cup anteversion was 16.0 ± 0.7° in PSI group and 24.7 ± 3.5° in control group. The △inclination in PSI group was smaller than that in control group (4.2 ± 0.5° vs 9.5 ± 1.4°, P < 0.01), so does △inclination (2.9 ± 0.4° in PSI group vs 15.2 ± 2.5° in control group, P < 0.01). The outlier percent was 8.3% in PSI group and 70.8% in control group (P < 0.01). At the same time, the PSI group did not prolong the operation time (P = 0.551).

CONCLUSION

The PSI can greatly increase the accuracy of placing the cup orientation and lower the threshold for junior physicians to perform THA on DDH patients. It could be a training tool for them to increase their THA surgical skills.

Minimum 8-year follow-up of revision THA with severe femoral bone defects using extensively porous-coated stems and cortical strut allografts

Background

Revision total hip arthroplasty (THA) with severe femoral bone defects remains a major challenge. The purpose of this study is to report the minimum 8-year clinical and radiographic results of revision THA with severe femoral bone defects treated with extensively porous-coated stems and cortical strut allografts.

Methods

We retrospectively identified 44 patients diagnosed with Paprosky type III and IV femoral bone defects between January 2006 and July 2011. The exclusion criteria were patients not eligible for surgery, revised with extensively porous-coated stems alone, lost to follow-up and deceased. A total of 31 patients treated with extensively porous-coated stems and cortical strut allografts were finally included in this study. The degree of femoral bone defects was categorized as Paprosky type IIIA in 19 patients, type IIIB in 9 patients and type IV in 3 patients. The mean duration of follow-up was 11.0 ± 1.5 (range, 8.1–13.5) years.

Results

The mean Harris Hip Score improved significantly from 43.4 ± 10.5 points to 85.2 ± 6.6 points (P < 0.001). Similarly, WOMAC and SF-12 scores also significantly improved. Twenty-eight stems achieved stable bone ingrowth, two stems showed stable fibrous ingrowth, and one stem was radiologically unstable. Complete union and bridging between cortical strut allografts and host bone was achieved in all 31 patients. The femoral width was augmented with cortical strut allografts after revision surgery (an increase of 10.5 ± 0.5 mm) and showed a slight decrease of 2.5 ± 4.8 mm after the 10-year follow-up. Using re-revision for any reason as an endpoint, the Kaplan-Meier cumulative survival rate of the stem was 96.2% (95% confidence interval, 75.7–99.5%) at 10 years.

Conclusion

Our data demonstrate that the use of extensively porous-coated stems combined with cortical strut allografts in revision THA with Paprosky type III and IV femoral bone defects can provide satisfactory clinical and radiographic outcomes with a minimum follow-up of 8 years.