Outcomes of long tapered hydroxyapatite-coated stems in revision total hip arthroplasty

Clinical and Radiographic Outcomes of a Long Cementless Monobloc Stem for Revision Total Hip Arthroplasty Due to Chronic Periprosthetic Infection

BACKGROUND

A long cementless monobloc stem is widely used for aseptic loosening, with satisfactory 5- to-10-year outcomes reported. Nonetheless, related studies on chronic periprosthetic joint infection (PJI) are scant. This study evaluated the clinical and radiographic outcomes of the stem in 2-stage revisions due to PJI.

METHODS

This prospective multicenter cohort study consisted of patients from three medical centers who were enrolled in a single arm from January 2017 to May 2022. All patients were diagnosed with chronic PJI based on the International Consensus Meeting criteria and underwent 2-stage revisions using a long monobloc cementless revision stem. Among 44 patients, 37 (12 women and 25 men) completed an average follow-up of 35.6 months (range, 14 to 75). The primary outcome was the stability of the stem; secondary outcomes included infection eradication, Harris Hip Score, leg length discrepancy, major complications, and isolated pathogens at intraoperative cultures.

RESULTS

At 1 year after revision, the infection-free prosthesis survival rate was 97.3% (95% confidence interval: 96.4 to 98.2). At the last follow-up, the mean subsidence was 2.9 ± 2.1 mm (range, 0.8 to 4.8). Postoperative leg length discrepancy averaged -4.6 ± 4.9 mm (range, -16 to 0). The Engh score averaged 14.1 ± 6.9 (range, zero to 22). The Harris Hip Score improved from a preoperative average of 35.7 ± 8.5 (range, 12 to 50) to 80.4 ± 9.3 (range, 58 to 92) at the 1-year postoperative follow-up (P < 0.01).

CONCLUSIONS

The long cementless monobloc stem used in the current study presents a feasible option for 2-stage revision in cases of chronic PJI. The bone ingrowth and stability could be observed within the short follow-up time.

LEVEL OF EVIDENCE

Level IV, prospective cohort study.

Clinical and functional outcomes of a modular fluted titanium stem in complex hip surgery with femoral bone loss

Background

The tapered fluted titanium stem is a viable option for complex hip reconstruction. We therefore, evaluate the results of complex hip arthroplasty for femoral bone loss (Paprosky type IIIA to type IV femoral defect), using a modular fluted titanium stem.

Methods

Data for this retrospective study was collected from the medical records of the 2 participating orthopaedic units from December 2018 to December 2021. Twenty-seven patients who underwent reconstruction of femoral bone loss with a modular fluted titanium stem were included in this study. General, demographic and clinical data including patient's age, comorbidities, ambulatory status before and after surgery, blood transfusion, surgical complications, rehabilitation after surgery, length of stay in hospital (in days), readmission after surgery, implant details and mortality rate were recorded. Clinical evaluation was performed using the oxford hip score and 12-item short-form health survey (SF-12). Complications and survivorship were evaluated using Kaplan-Meier survival rate with 95 % confidence interval.

Results

The mean age for the cohort was 60.14 ± 11.58 years, with mean follow-up of 3.2 years for the study. The median pre-operative OHS was 10 (8), which improved to 39 (12) and 41 (4) at 1 and 2-year postoperative follow-up, respectively (P < 0. 001). The quality of life measures (SF-12 scores) in both mental and physical components showed progressive improvement at 2 years follow-up with P- value < 0.001. A total of five patients (18.5 %) had postoperative complications, including deep venous thrombosis in one patient, dislocations in two patients and one patient each with superficial and deep infection. The implant survival rate was 100 % at mean follow-up of 3.2 years.

Conclusions

Proximal femur reconstruction with a modular fluted titanium stem restores mobility, improves the quality of life and reduces pain significantly. It can be considered as a good option as a salvage procedure.

Femoral revision in total hip arthroplasty using a cementless modular stem: clinical and radiological results with a 8-year follow-up

INTRODUCTION

Modular femoral components allow for patient-specific restoration of hip joint geometry and the reconstruction of extensive bone defects in revision total hip arthroplasty (THA); however, potential problems of modular implants such as taper corrosion and the risk of implant fracture continue to be of concern. The aim of the present study was to evaluate the clinical and radiological results of a cementless modular revision stem following revision surgery due to aseptic loosening and periprosthetic fracture and to assess patient-reported outcome measures (PROMs) in these patients at mid-term follow-up.

MATERIALS AND METHODS

In this study, a consecutive cohort of 75 patients who underwent primary revision THA at our institution using a modular cementless stem design (MRP-TITAN stem) was retrospectively evaluated at a mean follow-up of 7.7 years. Kaplan-Meier survivorship analyses were performed with revision of the femoral component for any reason as the end point. The Harris-Hip Score, the UCLA Activity Score, the Forgotten Joint Score and the SF-12 Score were used for clinical assessment. We used the Wilcoxon signed rank test to compare pre- and postoperative clinical scores.

RESULTS

Overall stem survival with the endpoint stem re-revision for any reason was 85.4% at a mean follow-up of 7.7 years (range 2.4-14 years). Stem survival was 89.5% in the aseptic loosening group and 78.3% in the periprosthetic fracture group with no statistically significant difference between both groups (p = 0.107). One patient had to be revised due to taper fracture. PROMs improved significantly up to the latest follow-up, and radiographic evaluation showed full osseointegration of all stems in this cohort.

CONCLUSIONS

Revision THA using a modular cementless titanium revision stem demonstrated adequate clinical and radiological results at mid- to long-term follow-up in this cohort. Cementless revision stems are a useful treatment option to restore the anatomy, especially in deformed hips and in complex revision hip arthroplasty. However, there are some significant disadvantages related to an increased risk of mechanical failure such as corrosion/fretting damage and implant fracture. Future high-quality prospective studies with longer follow-up are necessary to confirm the supposed advantages.

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.

Mid- to Long-Term Outcomes of Cementless Modular, Fluted, Tapered Stem for Massive Femoral Bone Loss in Revision Total Hip Arthroplasty

OBJECTIVE

To evaluate mid- to long-term results of revision total hip arthroplasty for massive femoral bone loss using a cementless modular, fluted, tapered stem.

METHODS

This is a retrospective study performed at a single hospital. During the period of January 2007 to January 2015, 33 patients (34 hips) underwent primary revision surgery with cementless modular, fluted, tapered stems due to femoral bone loss. Sixteen men and 17 women were included in the study, with an average age of 63.9 ± 11.7 years (range, 27 to 88 years). Operative data including operative duration, length of incision, drainage volume and duration, blood loss and transfusion, cases of bone graft and extended trochanteric osteotomy were recorded. Clinical evaluation was performed using Harris hip score (HHS), visual analogue scale (VAS), and patients' satisfaction. Radiographic data including femoral stem fixation, subsidence, integrin of allograft bone, and leg length discrepancy were assessed. Complications and survivorship were evaluated using Kaplan-Meier survival rate.

RESULTS

The mean follow-up was 9.1 ± 2.5 years (range, 5-13 years). The Harris hip score was 43.6 ± 11.5 preoperatively and maintained at 86.5 ± 6.6 at the time of latest follow-up (P < 0. 05). The X-ray showed bone ingrowth fixation in 30 hips (88%), fibrous stable fixation in three hips (9%), and instability in one hip (3%). The average stem subsidence was 3.9 ± 2.2 mm (range, 1 to 10 mm). The mean difference in leg length in our study was 3.3 ± 2.7 mm (range, 0 to 10 mm), and the leg length discrepancy in 28 (82%) patients was within 5 mm. No case of junction fracture was observed. Seven (21%) intraoperative fractures occurred in our study. Three (9%) cases with infection were observed after revision. Six (18%) patients had lower limb vein thrombosis. The survivorship of prostheses with re-revision for any reason was 95% (95% CI, 12.0 to 13.0) at the 10-year follow-up. Three (9%) re-revisions were needed, including one for aseptic loosening, one for dislocation, and one for infection.

CONCLUSION

The mid- to long-term results of revision total hip arthroplasty with the cementless modular, fluted, tapered stems are encouraging for massive femoral bone loss.

Results of hydroxyapatite ceramic coated primary femoral stem in revision total hip replacement

PURPOSE

The purpose of this study was to assess survival rate, functional and radiological outcomes when using a hydroxyapatite-ceramic fully coated primary femoral stem in revision total hip arthroplasty.

METHODS

Patients who underwent revision total hip arthroplasty using the Furlong hydroxyapatite-ceramic (HAC)-coated (Joint Replacement Instrumentation Ltd., Sheffield, UK) primary stem were retrospectively identified between 2013 and 2017. A total of 30 hips in 27 patients were identified and the mean follow-up duration was 44 months. Post-operative radiographs were scrutinized for signs of component loosening by two independent assessors. Patient's functional outcomes were assessed using the Oxford hip score and compared pre- and post-operatively. The prevalence of thigh pain was assessed at the latest follow-up.

RESULTS

The most common cause of revision was adverse reactions to metal debris (ARMD) (46.6%). The overall complication rate was 13.3%. Results at final follow-up demonstrated 100% survival rate and no reported incidence of thigh pain. Using paired t test, all patients had a statistically significant (P < 0.05) improvement in post-operative mean Oxford hip score of 35 compared to a mean pre-operative score of 14. Radiographic analysis of the latest follow-up radiographs revealed no signs of component loosening or component subsidence.

CONCLUSION

With a 100% survival rate and excellent reported functional outcomes, we believe that our experience and results support the use of primary cementless stems in selected revision cases.

Survivorship and Radiological Analysis of a Monoblock, Hydroxyapatite-Coated Titanium Stem in Revision Hip Arthroplasty

BACKGROUND

We evaluated the survivorship, incidence of complications, radiological subsidence, proximal stress shielding, and patient-reported outcomes of a conservative, monoblock, hydroxyapatite-coated femoral stem.

METHODS

This retrospective cohort study reports on 254 revision hip arthroplasties between January 2006 and June 2016. The mean age of patients was 71 years. The mean length of follow-up was 62 months (range 12-152).

RESULTS

There were 13 stem re-revisions: infection (4), periprosthetic fracture (4), aseptic stem loosening (3), stem fracture (1), and extended trochanteric osteotomy nonunion (1). Kaplan-Meier aseptic stem survivorship was 97.33% (confidence interval 94-100) at 6 years. There were 29 intraoperative fractures. There were 6 cases of subsidence greater than 10 mm; however, none required revision. Ninety-six percent of cases showed no proximal stress shielding. Thigh pain was reported in 3% of cases.

CONCLUSION

This study confirms that this stem provides good survivorship at 6 years, acceptable complication rates, adequate proximal bone loading, low incidences of thigh pain, and reliable clinical performance in revision hip arthroplasty.

KEY MESSAGE

A monoblock, fully hydroxyapatite-coated titanium stem is reliable in revision arthroplasty with mild-moderate femur deficiencies.

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

PURPOSE

Femoral component revision with either cemented or proximally coated stems has been disappointing, but revision with extensively coated stems has been promising. Our purpose was to evaluate the long-term outcome using an extensively hydroxyapatite (HA)-coated stem in femoral revisions surgery.

METHODS

During 1988-1993 we performed 66 femoral revisions in 65 patients (49 women), mean age 58 (range, 28-86) years. We used a grit-blasted straight stem made of TiAl₆V₄ designed for press-fit insertion (Landos Corail; Landanger, Chaumont, France). In 48 hips we used primary stems of size 10 in two cases, size 11 in two, size 12 in seven, size 13 in four, size 14 in 12, size 15 in eight, size 16 in 12 and size 18 in one. In 18 cases, we used revision stems of size 12 in four cases, size 14 in seven, size 16 in five and size 18 in two.

RESULTS

During follow-up, 21 patients have died. One patient had a traumatic fracture around the stem after six years, and another patient with osteoporosis developed fatigue fracture of the femoral bone after 22 years. In one patient the cup loosened after 23 years. The cup was revised, but deep infection occurred, and the patient underwent a two-stage revision of both components. Then, 12 of the revised stems were followed for more than ten years and 24 for more than 20 years. During this time only one stem was revised due to mechanical failure. This patient had a femoral defect classified to Type IV, and a proximal fracture occurred when the prosthesis was inserted. The fracture was stabilised by wires, but primary stability of the stem could not be obtained. At control examinations no patients suffered from significant thigh pain, and we noticed a low degree of proximal bone loss and a low incidence of distal bone hypertrophy.

CONCLUSIONS

Our study suggests that a fully HA-coated stem in femoral revision surgery can provide reliable results for up to 27 years. The bone changes confirmed a well-fixed femoral component with a rather physiological transfer of stress from proximal to distal regions with no significant thigh pain.

Calcium orthophosphate deposits: Preparation, properties and biomedical applications

Since various interactions among cells, surrounding tissues and implanted biomaterials always occur at their interfaces, the surface properties of potential implants appear to be of paramount importance for the clinical success. In view of the fact that a limited amount of materials appear to be tolerated by living organisms, a special discipline called surface engineering was developed to initiate the desirable changes to the exterior properties of various materials but still maintaining their useful bulk performances. In 1975, this approach resulted in the introduction of a special class of artificial bone grafts, composed of various mechanically stable (consequently, suitable for load bearing applications) implantable biomaterials and/or bio-devices covered by calcium orthophosphates (CaPO4) to both improve biocompatibility and provide an adequate bonding to the adjacent bones. Over 5000 publications on this topic were published since then. Therefore, a thorough analysis of the available literature has been performed and about 50 (this number is doubled, if all possible modifications are counted) deposition techniques of CaPO4 have been revealed, systematized and described. These CaPO4 deposits (coatings, films and layers) used to improve the surface properties of various types of artificial implants are the topic of this review.