Femoral revision surgery using a fully hydroxyapatite-coated stem: a cohort study of twenty two to twenty seven years

Clinical and radiographic outcomes of long monoblock, hydroxyapatite-coated stem in revision hip arthroplasty with extended trochanteric osteotomy: a multicenter study

BACKGROUND

The distally fixed stem used in revision total hip arthroplasty (rTHA) with extended trochanteric osteotomy (ETO) is subject to periprosthetic fracture, stem subsidence, and stress shielding. The prospective multicentric study aimed to assess the clinical and radiographic outcomes, and complications of using the Corail revision stem in rTHA with ETO.

METHODS

Sixty-four patients undergoing rTHA with ETO using the Corail revision stem between 2019 and 2020 were enrolled in the study. We performed a postoperative follow-up of the patient and obtained radiographs and Harris hip scores (HHSs). These results were used to analyze ETO union, Engh scores, bone remodeling, stem stability and hip function.

RESULTS

The mean follow-up duration was 34 months (range 23-41). Sixty-two patients who underwent ETOs achieved complete healing at the final follow-up. Fifty-nine hips had bony ingrowth from the osteotomy fragment to the stem without radiolucent lines. The postoperative Engh score was 21.3 ± 3.59 (range 15.5-27.0). Forty-three hips had regeneration in the proximal femur. Two patients had transient thigh pain postoperatively. The postoperative HHS improved from 40.7 ± 16.67 (range 0-67) preoperatively to 82.1 ± 6.83 (range 73-93).

CONCLUSION

Corail revision stems are a viable and reliable option in rTHA with ETO. This stem had excellent clinical and radiographic outcomes, resulting in a high rate of ETO union and stem survival. The revision stem enabled restoration of proximal bone stock in femurs with prerevision bone defects, which were prepared for the next revision operation. Level of evidence Level IIb, Prospective self-control study.

There Are over 60 Ways to Produce Biocompatible Calcium Orthophosphate (CaPO4) Deposits on Various Substrates

A The present overview describes various production techniques for biocompatible calcium orthophosphate (abbreviated as CaPO4) deposits (coatings, films and layers) on the surfaces of various types of substrates to impart the biocompatible properties for artificial bone grafts. Since, after being implanted, the grafts always interact with the surrounding biological tissues at the interfaces, their surface properties are considered critical to clinical success. Due to the limited number of materials that can be tolerated in vivo, a new specialty of surface engineering has been developed to desirably modify any unacceptable material surface characteristics while maintaining the useful bulk performance. In 1975, the development of this approach led to the emergence of a special class of artificial bone grafts, in which various mechanically stable (and thus suitable for load-bearing applications) implantable biomaterials and artificial devices were coated with CaPO4. Since then, more than 7500 papers have been published on this subject and more than 500 new publications are added annually. In this review, a comprehensive analysis of the available literature has been performed with the main goal of finding as many deposition techniques as possible and more than 60 methods (double that if all known modifications are counted) for producing CaPO4 deposits on various substrates have been systematically described. Thus, besides the introduction, general knowledge and terminology, this review consists of two unequal parts. The first (bigger) part is a comprehensive summary of the known CaPO4 deposition techniques both currently used and discontinued/underdeveloped ones with brief descriptions of their major physical and chemical principles coupled with the key process parameters (when possible) to inform readers of their existence and remind them of the unused ones. The second (smaller) part includes fleeting essays on the most important properties and current biomedical applications of the CaPO4 deposits with an indication of possible future developments.

A bone-conserving revision stem for unstable intertrochanteric fractures of the geriatric osteoporotic population

Purpose

Primary hemiarthroplasty is gaining popularity for the treatment of unstable intertrochanteric fractures in geriatric patients with severe osteoporosis. This study evaluated early clinical and radiographic outcomes by using a bone-conserving revision stem for unstable intertrochanteric fractures in the geriatric osteoporotic population.

Methods

A retrospective study involving 31 patients with unstable intertrochanteric fractures was conducted. The patients were aged 82.1 years on average. All patients underwent primary hemiarthroplasty using bone-conserving, fully porous-coated revision stem. The operative time, intraoperative blood loss, length of hospitalization, and need for blood transfusion were noted during the hospital stay. Postoperative complications, including dislocations, deep venous thrombosis, infections, peri-prosthetic fractures, and frontal thigh pain were also recorded. Koval's category was used to quantify activity level, and Harris hip score (HHS) was used for functional assessment. Radiographic outcomes, including osteolysis, bone ingrowth, subsidence of the femoral component, lower limb length discrepancy, and heterotopic ossification, were collected at each follow-up.

Results

The 31 patients were followed for an average time of 23 months postoperatively. The average operative time lasted for 74.2 min, while the mean intraoperative blood loss was 200.1 ml, with an average hemoglobin decrease of 11.1 g/L after the procedure. The mean visual analog scale (VAS) score for pain dropped from 7.4 preoperatively to 2.4 at the 4-week follow-up. At the latest follow-up, the mean Harris hip score was 82.1, and the VAS was 1.7. No intraoperative or postoperative peri-prosthetic fractures were noted. Postoperative complications included one case of thrombosis formation in the posterior tibial vein and one case of congestive heart failure. Both patients were discharged uneventfully after treatment. Radiographically, none of the hips had evidence of stem loosening or osteolysis. Within the follow-up period of 23 months, the mortality rate was 3.2% (1/31), and no revision surgeries were required.

Conclusion

Primary hemiarthroplasty using a bone-conserving, cementless revision stem could serve as a reliable alternative for the treatment of unstable intertrochanteric fractures in the geriatric population with osteoporosis.

Influence of Geometry and Extent of Coating on Survival of Cementless Distal-Locking Revision Stems at 7 to 18 Years

BACKGROUND

We aimed to compare the long-term clinical outcomes, complications, and survival of 2 revision stems with different geometries, extents of coating, and distal-locking mechanisms.

METHODS

We retrospectively compared outcomes at a minimum of 7 years following revision THA using 2 proximally coated distal-locking stems: 98 Ultime first-generation (G1) and 116 Linea second-generation (G2) stems. Ten-year Kaplan-Meier survival was assessed considering stem re-revision for any reason and for aseptic reasons. At final follow-up, Harris Hip Score and Oxford Hip Score were collected, and any thigh pain or complications were noted.

RESULTS

Considering re-revision for any reason, survival was 69% for G1 stems and 91% for G2 stems. Considering re-revision for aseptic reasons, survival was 77% for G1 stems and 92% for G2 stems. Re-revisions were due to fracture of 6 G1 stems but no G2 stems. Complications that required reoperation without stem or cup removal occurred in 3 of the G1 stems and 1 of the G2 stems. Compared to the G1 stems, the G2 stems resulted in better Harris Hip Score (83 vs 71, P = .001), Oxford Hip Score (22 vs 27, P = .019), less thigh pain (4% vs 39%, P < .001), and fewer nonoperated complications (9% vs 15%).

CONCLUSION

The second-generation stem had significantly better survival and clinical outcomes than the first-generation stem. The differences in survival and clinical outcomes could be attributed to the larger coated surface of the G2 stem and to the fact that the G1 stem was originally intended as a temporary implant to be followed by de-escalation.

High Revision Rates of a Cementless Beta-Titanium Alloy Stem with Contamination-Free Roughened Surface in Primary Total Hip Arthroplasty

Optimal osseointegration of cementless total hip arthroplasty is essential for high stability and long-term survival. The purpose of this follow-up study was to evaluate the clinical and radiological outcome, the complications, and survival rates of a beta-titanium alloy stem with a specific grit-blasted-free surface. In 192 patients (mean age of 64.4 years), 202 consecutive primary total hip arthroplasties were performed using a cementless Hipstar^® stem (Stryker, Duisburg, DE). The Harris Hip Score (HHS) was assessed pre-operatively and post-operatively. Radiolucent lines were evaluated and the implant survival rate was calculated using Kaplan-Meier analysis. The mean follow-up was 7.71 years (range of 5.0–14.0 years). Overall, 15 revisions were performed. Early aseptic stem loosening was observed in six cases (2.97%). Radiolucent-lines adjacent to the stem were detected in 73 cases (83.02%), especially (70.46%) in the Gruen zones 1, 7, 8, and 14. The mean postoperative HHS was 92.65 points (range 42–100). The cumulative survival probability of the stem was 94.4% (95% CI 90.3 to 98.5%). Considering aseptic failure as an endpoint, the cumulative survival rate of the stem was 95.3% (95% CI 0.914 to 0.992) at six years of follow-up. Overall, an inferior mid-term implant survival was observed in comparison to well-established cementless stem designs.

High Incidence of Intraoperative Fractures With a Specific Cemented Stem Following Intracapsular Displaced Hip Fracture

BACKGROUND

To reduce costs of orthopedic implants, the government decided to standardize implants used across different specialties in a group of hospitals located in the same geographic area. The usual cemented stem used in the context of intracapsular displaced geriatric hip fractures was replaced by another stem. Abnormal intraoperative calcar and trochanteric fractures were noted. The purpose of this study is to determine the incidence of intraoperative periprosthetic fractures following an intracapsular displaced hip fracture treated with this specific cemented stem compared to the previous implant.

METHODS

This is a retrospective cohort study comparing an historic cohort of hip fractures treated with the OmniFit EON (Stryker, Kalamazoo, MI) cemented stem with a new cohort of patients who received the Corail (DePuy Synthes, Warsaw, IN) cemented stem. Four orthopedic surgeons reviewed operative reports and postoperative radiographs.

RESULTS

The treatment group included 348 patients who received the Corail stem. The control group included 77 patients. The 2 groups had similar baseline characteristics (P > .05) except for the presence of dementia. Incidence of intraoperative calcar or greater trochanteric fracture was 15.5% for the Corail group and 2.7% for the control group (P < .05). No patient-related factors or surgeon-related factors were related to a higher number of fractures in the treatment group (P > .05).

CONCLUSION

The Corail cemented stem presents an abnormal number of iatrogenic intraoperative fractures following displaced femoral neck fracture in our geriatric population. No external factor seems to explain this high number of fractures. Implant design should be questioned.

LEVEL OF EVIDENCE

III.

Use of the Corail stem for revision total hip arthroplasty: evaluation of clinical outcomes and cost

Background

With the growing number of total hip arthroplasty (THA) procedures performed, revision surgery is also proportionately increasing, resulting in greater health care expenditures. The purpose of this study was to assess clinical outcomes and cost when using a collared, fully hydroxyapatite-coated primary femoral stem for revision THA compared to commonly used revision femoral stems.

Methods

We retrospectively identified patients who underwent revision THA with a primary stem between 2011 and 2016 and matched them on demographic variables and reason for revision to a similar cohort who underwent revision THA. We extracted operative data and information on in-hospital resource use from the patients’ charts to calculate average cost per procedure. Patient-reported outcomes were recorded preoperatively and 1 year postoperatively.

Results

We included 20 patients in our analysis, of whom 10 received a primary stem and 10, a typical revision stem. There were no significant between-group differences in mean Western Ontario and McMaster Universities Osteoarthritis Index score, Harris Hip Score, 12-Item Short Form Health Survey (SF-12) Mental Composite Scale score or Physical Composite Scale score at 1 year. Operative time was significantly shorter and total cost was significantly lower (mean difference –3707.64, 95% confidence interval –5532.85 to –1882.43) with a primary stem than with other revision femoral stems.

Conclusion

We found similar clinical outcomes and significant institutional cost savings with a primary femoral stem in revision THA. This suggests a role for a primary femoral stem such as a collared, fully hydroxyapatite-coated stem for revision THA.

Outcome evaluation of new calcium titanate schanz-screws for external fixators. First clinical results and cadaver studies

OBJECTIVE

External fixators are important for correcting length discrepancies and axis deformities in pediatric or trauma orthopedic surgery. Pin loosening is a common pitfall during therapy that can lead to pain, infection, and necessary revisions. This study aims to present clinical data using calcium titanate (CaTiO₃) Schanz screws and to measure the fixation strength.

PATIENTS AND METHODS

22 titanate screws were used for external fixators in 4 pediatric patients. Therapy was initiated to lengthen or correct axial deformities after congenital abnormalities. The maximum tightening torque was measured during implantation, and the loosening torque was measured during explantation. In addition, screws of the same type were used in a cadaver study and compared with stainless steel and hydroxyapatite-coated screws. 12 screws of each type were inserted in four tibias, and the loosening and tightening torque was documented.

RESULTS

The fixation index in the in vivo measurement showed a significant increase between screw insertion and extraction in three of the four patients. The pins were in situ for 91 to 150 days, and the torque increased significantly (P = 0.0004) from insertion to extraction. The cadaveric study showed lower extraction torques than insertion torques, as expected in this setting. The calculated fixation index was significantly higher in the CaTiO₃ group than in the other groups (P = 0.0208 vs. HA and P < 0.0001 vs. steel) and in the HA group vs. plain steel group (P = 0.0448).

CONCLUSION

The calcium titanate screws showed favorable fixation strength compared to HA and stainless steel screws and should be considered in long-term therapy of external fixation.

Mid-term outcomes of titanium modular neck femoral stems in revision total hip arthroplasty

Background

Modular stems have been widely studied as they allow intraoperative adjustments (offset, anteversion, limb length) to better restore hip biomechanics. Many authors reported outcomes of revision total hip arthroplasty (THA) using modular stems with metaphyseal-diaphyseal junctions, however, little is known about modular neck femoral stems (MNFS) with metaphyseal-epiphyseal junctions. We therefore aimed to report outcomes and implant survival of a MNFS in a consecutive series of revision THA at a minimum follow-up of 5 years.

Methods

We reviewed a consecutive series of 28 revision THAs performed between February 2010 and March 2012 using an uncemented MNFS. The final study cohort included 25 patients living with their original components, at a mean follow-up of 68.4±7.4 months and aged 67.7±11.6 years at index operation.

Results

The Harris Hip Score (HHS) improved from 39.1±19.2 pre-operatively to 78.1±18.3 post-operatively, and the Postel Merle d'Aubigné score (PMA) improved from 9.8±3.0 pre-operatively to 14.8±2.8 post-operatively. The postoperative limb length discrepancy (LLD) was >10 mm in 18% of the hips. There were no significant differences of femoral offset and neck shaft angle (NSA) between operated and contralateral hips. Two hips (8.0%) showed new periprosthetic radiolucent lines. Periprosthetic fractures (PPF) occurred in 3 hips (12%). No subluxations, dislocations or implant breakages were reported. One revision (3.6%) was performed with retrieval of the revision stem for infection. The Kaplan-Meier (KM) survival at 5 years, using stem revision as endpoint, was 96.0%.

Conclusions

The Optimal^® MNFS provided a satisfactory survival and clinical outcomes at 5 years, with no noticeable adverse effects resulting from the additional modular junction.

A new classification for proximal femur bone defects in conservative hip arthroplasty revisions

INTRODUCTION

In the last three decades, total hip replacement in young patient became a habitual procedure. Principles of bone preservation are pushing many surgeons to implant conservative femoral components in patient younger than 65 years. Despite an overall good survivorship and clinical outcomes of conservative implants, failed cases are reported and the need to revise a conservative femoral component became an occasional procedure (with high prevalence of failed resurfacing implants).

METHODS

During conservative femoral component revisions, we analyzed proximal bone stock preservation, considering the type of original component removed, etiology of failure, timing of revision, and femoral explantation technique.

RESULTS

We identified four patterns of proximal femoral changes (types I-IV). We suggest, for each of them, a revision strategy directed toward a "conservative revision procedure" using conservative or primary component. Out of our 21 cases, none underwent further revision due to mechanical failure (follow-up ranging from 6 to 152 months, mean 54 months). We had two case of re-operation: one for early septic loosening and one for prosthetic modular neck fracture.

CONCLUSIONS

If literature offers well-established guidelines to femoral revision of conventional stems, there is, on the other hand, a lack of data about revision strategies in presence of failed conservative implants. Although the mean follow-up of our procedures is still too short (4.5 years) to give final conclusions, we would leave a message: a conservative hip arthroplasty is not a "one-time" opportunity for young and active people. A "conservative revision" is a valid option for at least a part of them, when an early failure of primary procedure occurred.

A new classification for proximal femur bone defects in conservative hip arthroplasty revisions

INTRODUCTION

In last three decades, total hip replacement in young patients became an habitual procedure. Principles of bone preservation are pushing many surgeons to implant conservative femoral components in patient younger than 65 years. Despite an overall good survivorship and clinical outcomes of conservative implants, failed cases are reported and the need to revise a conservative femoral component became an occasional procedure (with high prevalence of failed resurfacing implants).

METHODS

During conservative femoral component revisions, we analyzed proximal bone stock preservation, considering the type of original component removed, aetiology of failure, timing of revision, and femoral explantation technique.

RESULTS

We identified four patterns of proximal femoral changes (types I-IV). We suggest, for each of them, a revision strategy directed toward a "conservative revision procedure" using conservative or primary component. Out of our 21 cases, none underwent further revision due to mechanical failure (follow-up ranging from 6 to 152 months, mean 54 months). We had two cases of re-operation: one for early septic loosening and one for prosthetic modular neck fracture.

CONCLUSIONS

If literature offers well-established guidelines to femoral revision of conventional stems, there is, on the other hand, a lack of data about revision strategies in presence of failed conservative implants. Although the mean follow-up of our procedures is still too short (4.5 years) to give final conclusions, we would leave a message: a conservative hip arthroplasty is not a "one time" opportunity for young and active people. A "conservative revision" is a valid option for at least a part of them, when an early failure of primary procedure occurred.