Medium-term outcomes of the S-ROM modular femoral stem in revision hip replacement

Dissociation and Subsequent Stable Malrotation of Femoral Stem Within Sleeve After Sivash-Range of Motion Total Hip Arthroplasty: A Case Report

CASE

A 78 year-old man fell 6 months after Sivash-range of motion (S-ROM) total hip arthroplasty (THA), after which he developed hip pain and external rotation deformity. Imaging showed stem malrotation in relative retroversion. Revision THA was delayed because of medical issues, occurring 1.5 years after the fall. No corrosion was observed intraoperatively at the stem-sleeve interface. His symptoms resolved after revision THA.

CONCLUSION

We present a rare complication of S-ROM THA-dissociation of the femoral stem from the proximal sleeve, with subsequent re-engagement in static malrotation. No corrosion was observed, suggesting that the stem had stably reseated within the sleeve.

Long-Term Survivorship of Modular Cementless Femoral Stem in Complex Primary Total Hip Arthroplasty: A Concise Minimum 15-Year Follow-Up Report

BACKGROUND

S-ROM hip is a well-established and versatile prosthesis that offers extensive metaphyseal and diaphyseal geometries providing solutions for a variety of surgical scenarios. The aim of this study is to report on long-term survivorship and radiographic outcomes of complex primary total hip arthroplasty (THA) using a modular cementless stem (S-ROM).

METHODS

Retrospective consecutive study was conducted of 167 patients (167 hips): 97 males and 70 females with average age at the time of surgery of 55 years (range 22-76). All patients underwent complex THA by the senior author from 1987 to 1999. Patients were identified using a prospective database. Demographic, clinical, and surgical data were collected from health records. All patients received a cementless acetabular component with a standard polyethylene liner. The primary outcome measure was survivorship beyond 15 years using stem revision for any cause as an end point. Secondary outcome measure was rate of radiographic loosening using Engh classification.

RESULTS

Only 3 patients required stem revision for aseptic loosening and 1 for periprosthetic fracture. Isolated acetabular revision was undertaken in 23 of 167 patients (13.8%) due to polythene wear, osteolysis, and aseptic loosening. Proximal femoral stress shielding (zone 1, 7) was noted in 34 of 167 hips (20.4%). Stable bony ingrowth was noted in 144 hips (86.2%) and the remaining 23 hips had stable fibrous ingrowth (13.8%). Using stem "any-cause revision" as an endpoint, the mean stem survivorship was 31.5 years (95% confidence interval 31.007-31.985) with 30-year estimated survivorship of 97.6%.

CONCLUSION

In a single designer surgeon series, S-ROM stem has stood the test of time with long-term, 30-year survivorship of 97.6% and continues to play an important role in modern hip surgery providing longevity and versatility. However, further comparative long-term studies from independent centers are needed for a definitive conclusion.

LEVEL OF EVIDENCE

IV.

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.

Promising results of revision total hip arthroplasty using a hexagonal, modular, tapered stem in cases of aseptic loosening

Background

Modular stems are widely used in revision total hip arthroplasty (THA) with aseptic loosening being a common reason for revision. Despite the good results reported on the use of modular stem designs, there are only few studies focusing on aseptic revisions and few studies on a hexagonal stem design. The goal of this study is to determine stem survival, clinical and functional outcome along with possible risk factors for implant failure in aseptic revision THA.

Methods

We retrospectively identified 53 patients with aseptic THA revision using a modular hexagonal stem with a minimum follow-up of two years. Femoral bone loss, radiographic and clinical outcomes as well as function measured using the Harris Hip Score (HHS) was assessed. Patients’ previous medical history was analyzed for comorbidities and the body mass index. Stem survival was calculated using the Kaplan-Meier method. Possible risk factors for implant failure were analyzed using the log-rank test. The median age at revision was 69 (IQR 62–73) with a median follow up of 74 months.

Results

Implant survival rates amounted to 90.4% at 3 and 5 years. The median HHS improved by 47 points (34 (IQR 22–47) vs 81 (IQR 59–90) p<0.001). There was a reduced implant survival after 5 years when the revision stem was used following a previous cemented stem (83.4% vs 100%, p = 0.04).

Conclusion

A modular, hexagonal stem can be successfully used in aseptic revision THA with remarkable functional results and excellent survivorship. Revision of a cemented stem using this implant might result in reduced survival which must be considered when planning treatment.

[Revision reasons and prosthesis selection of Crowe developmental dysplasia of hip after total hip arthroplasty]

OBJECTIVE

To investigate revision reasons and prosthesis selection of Crowe Ⅳ developmental dysplasia of the hip (DDH) after total hip arthroplasty (THA).

METHODS

A clinical data of 14 patients (15 hips) with Crowe Ⅳ DDH, who underwent a revision hip arthroplasty between January 2008 and May 2018, was retrospectively reviewed. There were 1 male (1 hip) and 13 females (14 hips). The age ranged from 27 to 63 years (mean, 45.0 years). There were 7 cases of left hip, 6 cases of right hip, and 1 case of bilateral hips. The prosthetic interfaces of primary THA were metal-on-polyethylene (MOP) in 9 hips, ceramic-on-ceramic (COC) in 4 hips, ceramic-on-polyethylene (COP) in 1 hip, and ceramic-on-metal in 1 hip. The time from primary THA to revision was 3-204 months (mean, 65.0 months). The causes of revision included aseptic loosening in 7 hips, dislocation in 3 hips, periprosthetic joint infection in 2 hips, osteolysis in 1 hip, nonunion of osteotomy in 1 hip, and a small-angle of femoral anteversion in 1 hip. Preoperative Harris score was 54.1±17.8 and the range of motion (ROM) of flexion was (92.7±20.2)°. Preoperative X-ray films showed the acetabular bone defect in 11 hips and osteolysis of femoral side in 4 hips. During the revision, the prostheses with COP and COC interfaces were used in 5 hips and 10 hips, respectively. Both acetabular and femoral revisions were performed in 11 hips and only femoral revision was performed in 4 hips.

RESULTS

The mean operation time was 3.7 hours (range, 1.5-6.0 hours). The mean intraoperative blood loss was 940.0 mL (range, 200-2 000 mL). All patients were followed up 16-142 months (mean, 73.9 months). Postoperative X-ray films showed no difference in inclination and anteversion between primary THA and revision ( P>0.05). The height of rotation center and offset after revision were higher than those after primary THA, and the difference in offset was significant ( P<0.05). At last follow-up, the Harris score and ROM of flexion were 85.0±7.3 and (115.0±17.0)°, respectively, which were significantly higher when compared with those before revision ( t=8.909, P=0.000; t=4.911, P=0.000). Three hips underwent a re-revision operation. All protheses were fixed well and no radiolucent line, loosening, or subsidence was observed at last follow-up.

CONCLUSION

The most common reason for revision in patients with Crowe Ⅳ DDH after THA was aseptic loosening. Due to high activity demand of this population, the prosthesis with MOP interface should be prevented and the prosthesis with COC interface could be alternative. Metal block, cup-cage, and reinforcement ring were reasonable solutions for reconstruction of acetabulum with severe bone defects and have satisfactory effectiveness. S-ROM prosthesis should be the preferred stem for neither primary THA or revision.