Reinforcement Device Research Articles

Acetabular reconstruction with a reinforcement device and bone grafting in revision arthroplasty—a mean five years of follow-up

To evaluate the clinical and radiological outcomes of acetabular reconstruction using a reinforcement device (RD) in combination with bone grafting in Paprosky type 2 and 3 acetabular bone defects. Morselised bone grafts were used to fill cavitary defects and a structural graft placed in the superior part of the acetabulum in cases of cranial bone defects, with a proximally fixed RD (Protetim, Hódmezővásárhely, Hungary) implanted in all cases. Construct stability, device positioning, hip centre of rotation and medial acetabular wall thickness were evaluated radiologically. Survival rates were estimated with aseptic loosening and revision for any reason as endpoints. The 28 patients (29 hips) were followed for 4.8 ± 2.7years (range, 2-10.4years). Hip centre of rotation was lowered in all cases, with no significant differences between the mean values obtained post-operatively and at the last follow-up. Medial acetabular wall thickness and RD abduction angle were maintained up to the last evaluation. Bone grafts integrated by twoyears post-operatively in the majority of cases. Kaplan-Meier survival rates were 85.2% and 82.1% for the two endpoints at tenyears. Acetabular reconstruction using a proximally fixed RD in combination with bone grafting offered good mid-term results in the treatment of acetabular bone defects. In cases of severe bone loss, the structural allograft allowed placement of the RD with ischial contact, rendering survival rates similar to RDs with both iliac and ilioischial fixation. The technique was successful in restoring and maintaining medial acetabular bone stock and construct stability for up to ten years.

Can cemented dual-mobility cups be used without a reinforcement device in cases of mild acetabular bone stock alteration in total hip arthroplasty?

IntroductionCemented versions of dual-mobility cups (DMCs), helpful in cases of bone stock alteration, are usually used in association with a reinforcement device. To simplify the intervention in elderly subjects or those with a poor bone stock, the cups can be cemented directly into the bone, but the long-term result remains uncertain. We conducted a retrospective study in this population so as to: (1) assess whether cemented fixation of a DMC without a reinforcement device leads to a higher loosening rate, (2) confirm its efficacy in preventing dislocations in subjects at high risk of instability, and (3) measure the functional results. HypothesisCemented fixation of a DMC is reliable in cases of moderate alteration of bone stock. Material and methodsSixty-four patients (66 hips) undergoing implantation of a cemented DMC (Saturne™) without a reinforcement device were included in this single-center retrospective study. Their mean age was 79.8 years (range, 40–95 years). The indications varied: hip osteoarthritis (30.3%), prosthesis revision (44.0%), and trauma (25.8%). The patients were evaluated radiologically and clinically at follow-up. The main evaluation criterion was the revision rate for aseptic loosening. Dislocations, the infection rate, and the Postel Merle d’Aubigné (PMA) score were noted. ResultsAt the mean follow-up of 4.2 years, three (4.6%) patients had been lost to follow-up and 22 (33.3%) had died. There was one case of aseptic loosening (1.5%). Cup survival was 98% at 5 years (95%CI [94–100]). There were no dislocations. There was one revision for infection. The mean PMA score was 15.5 (range, 9–18). DiscussionThe frequency of acetabular loosening was comparable to the frequency in cemented DMCs with a reinforcement device. A cemented DMC without a reinforcement device is possible and is a simple and viable option when there is moderate bone stock alteration. Level of evidenceIV, retrospective cohort study.

Long-Term Outcome of Acetabular Reconstruction Using a Kerboull-Type Acetabular Reinforcement Device with Hydroxyapetite Granule and Structural Autograft for AAOS type II and III Acetabular Defects

We evaluated the clinical results of the reconstruction of acetabular bone deficiency using hydroxyapatite (HA) granules and structural autografts supported by a Kerboull-type acetabular reinforcement device at a minimum of 10 years follow-up. Between 1993 and 2003, 40 consecutive THA revisions were performed in 37 patients with a mean age of 66.4 years. The mean follow-up period was 12.8 years. Radiologically, 5 hips failed, of which 2 were revised. The survival rate of the acetabular component at 10 years was 100% in type II defects and 94.9% in the type III defects, using acetabular revision for loosening as the end point. Acetabular reconstruction with HA granules, structural autografts and a Kerboull-type acetabular reinforcement device provided satisfactory clinical and radiological results at 12.8 years postoperatively.

Preliminary biomechanical study of different acetabular reinforcement devices for acetabular reconstruction.

BackgroundAcetabular reinforcement devices (ARDs) are frequently used as load-sharing devices to allow allograft incorporation in revision hip arthroplasty with massive acetabular bone loss. The key to a successful reconstruction is robust fixation of the device to the host acetabulum. Interlocking fixation is expected to improve the initial stability of the postoperative construct. However, all commercially available ARDs are designed with non-locking fixation. This study investigates the efficacy of standard ARDs modified with locking screw mechanisms for improving stability in acetabular reconstruction.MethodsThree types of ARDs were examined to evaluate the postoperative compression and angular stability: i) standard commercial ARDs, ii) standard ARDs modified with monoaxial and iii) standard ARDs modified with polyaxial locking screw mechanisms. All ARDs were implanted into osteomized synthetic pelvis with pelvic discontinuity. Axial compression and torsion tests were then performed using a servohydraulic material testing machine that measured load (angle) versus displacement (torque). Initial stability was compared among the groups.ResultsEquipping ARDs with interlocking mechanisms effectively improved the initial stability at the device/bone interface compared to standard non-locked ARDs. In both compression and torsion experiments, the monoaxial interlocking construct demonstrated the highest construct stiffness (672.6 ± 84.1 N/mm in compression and 13.3 ± 1.0 N·m/degree in torsion), whereas the non-locked construct had the lowest construct stiffness (381.4 ± 117.2 N/mm in compression and 6.9 ± 2.1 N·m/degree in torsion) (P < 0.05).ConclusionsOur study demonstrates the potential benefit of adding a locking mechanism to an ARD. Polyaxial ARDs provide the surgeon with more flexibility in placing the screws at the cost of reduced mechanical performance. This in vitro study provides a preliminary evaluation of biomechanical performance for ARDs with or without interlocking mechanisms, actual clinical trial deserves to be further investigated in future studies.

Tissue Reinforcement in Implant-based Breast Reconstruction.

Background:Tissue reinforcement with allogeneic or xenogeneic acellular dermal matrices (ADMs) is increasingly used in single-stage (direct-to-implant) and 2-stage implant-based breast reconstruction following mastectomy. ADMs allow surgeons to control implant position and obviate the need for submuscular implant placement. Here, we review the benefits and risks of using ADMs in implant-based breast reconstruction based on available data.Methods:A comprehensive analysis of the literature with focus on recent publications was performed. Additional information regarding the proper use of ADMs was based on our institutional experience.Results:ADM use may improve definition of the lateral confines of the breast and lower pole projection. It may facilitate direct-to-implant procedures and improve aesthetic outcomes. The effect of ADMs on complication rates remains controversial. Known patient risk factors such as obesity, smoking, and radiotherapy should be considered during patient selection. For patients with healthy, well-vascularized skin envelopes, ADM-assisted direct-to- implant reconstruction is a safe and cost-effective alternative to 2-stage implant reconstruction, with low complication rates. ADMs may be used to treat capsular contracture, and limited available data further suggest the possibility that ADMs may reduce the risk of capsular contracture. Novel synthetic or biosynthetic tissue reinforcement devices with different physical and ease-of-use properties than ADMs are emerging options for reconstructive surgeons and patients who seek to avoid tissue products from human or mammalian cadavers.Conclusions:ADM-assisted implant-based breast reconstruction may improve aesthetic outcomes. However, appropriate patient selection, surgical technique, and postoperative management are critical for its success, including minimizing the risk of complications.

Long-term successful arthroscopic repair of large and massive rotator cuff tears with a functional and degradable reinforcement device

Rotator cuff repair is a procedure with varying outcomes, and there has been subsequent interest in devices that reinforce the repair and enhance structural and functional outcomes. The objective of this study was to determine these outcomes for arthroscopic repair of large and massive rotator cuff tears augmented with a synthetic absorbable mesh designed specifically for reinforcement of tendon repair by imaging and clinical assessments. Consecutive arthroscopic repairs were performed on 18 patients with large to massive rotator cuff tears by use of a poly-l-lactic acid synthetic patch as a reinforcement device and fixation with 4 sutures. Patients were assessed preoperatively and at 6 months, 12 months, and a mean of 42 months after surgery by the American Shoulder and Elbow Surgeons (ASES) shoulder score to evaluate clinical performance and at 12 months by ultrasound to assess structural repair. Ultrasound showed that 15 of 18 patients had intact rotator cuff repair at 12 months; at 42 months, an additional patient had a failed repair. Patients showed improvement in the ASES shoulder score from 25 preoperatively to 71 at 12 months and 70 at 42 months after surgery. Patients with intact rotator cuff (n = 14) at 42 months had an ASES shoulder score of 82. The poly-l-lactic acid bioabsorbable patch designed specifically to reinforce the surgical repair of tendons supported successful repair of large to massive rotator cuff tears in 83% of patients at 12 months after surgery and 78% of patients at 42 months after surgery, with substantial functional improvement.

Supercharging irradiated allografts with mesenchymal stem cells improves acetabular bone grafting in revision arthroplasty

The procedure of bone allografting associated with a reinforcement device is widely used for acetabulum revision. However in absence of biologic fixation of the allograft, failure of the reconstruction may occur. We made the hypothesis that it would be possible to load these grafts with bone marrow derived mesenchymal stem cells (MSC) to rescue the osteogenic capacity of an allogenic dead bone and therefore enhance incorporation of allografts with the host bone and decrease the number of failures related to the allograft. We identified 60 patients who had undergone acetabular component revision for aseptic failure of cemented implants associated with massive periacetabular osteolysis and Paprosky type 3A or 3B classification (without pelvic discontinuity) between 1996 and 2001. The study group of 30 patients received MSCs in the allograft and at the host graft junction. The average total number of MSCs received by each patient was 195,000 cells (range 86,000-254,000 cells). The control group of 30 patients had no MSCs in the allograft. Patients were matched for the size of periacetabular osteolysis (Paprosky type 3A or 3B). We compared the evolution of the allografts and evaluated cup migration and revision of the hips as end points at a minimum of 12 years or until failure. Better radiographic graft union rates and less allograft resorption were observed with allografts loaded with stem cells. Allograft resorption was significantly decreased in the group with allograft loaded with MSCs (1.2 cm(2) -range 0-2.3 cm(2)-of resorption on radiographs in the group with MSCs; versus 6 cm(2), range 2.1-8.5 cm(2) in the group without MSCs). The rate of mechanical failure was highest (p = 0.01) among the 30 patients with allograft without stem cells (9/30; 30 %) compared with no failures for patients with allograft loaded with stem cells. Revision of the cup was necessary in nine patients in the control group. No revision was performed in the 30 patients of the study group with MSCs. For acetabular defect reconstruction, loading the allograft with MSCs has resulted in a lower rate of failure as compared with allograft without MSCs.

Options for Managing Severe Acetabular Bone Loss in Revision Hip Arthroplasty. a Systematic Review

Revision hip arthroplasty in the presence of severe acetabular bone loss is challenging and requires a solid understanding of current techniques. A literature search of multiple databases applying specific criteria revealed a total of 50 articles of level IV scientific evidence comprising 2415 patients (2480 hips) managed with reinforcement devices (roof-reinforcement rings and anti-protrusio cages), custom-made triflanged acetabular components (CTACs), jumbo cups and tantalum metal (TM) systems. Overall, patients had improved postoperative hip scores for each technique. The use of reinforcement devices resulted in a mean revision rate of 8.2% and a mean complication rate of 29.21%. CTACs were associated with a revision rate of 15.9% and had a complication rate of 24.5%. Jumbo cups were revised in 8.8% of patients and had a complication rate of 18.4%. TM systems had an overall revision rate of 8.5% with complications seen in 18.5% of patients. CTACs had considerably higher revision rates compared to the other techniques. Jumbo cups and TM systems had lower complication rates compared to the use of reinforcement devices and CTACs. The most frequently occurring complications seen throughout the series were aseptic loosening, dislocation and infection.

A study of rock bolting failure modes

Rock bolting has advanced rapidly during the past 4decades due to a better understanding of load transfer mechanisms and advances made in the bolt system technology. Bolts are used as permanent and temporary support systems in tunnelling and mining operations. A review of has indicated that three systems of reinforcement devices have evolved as part of rock bolt and ground anchor while the rock is not generally thought of as being a component of the reinforcement system. A classification of rock bolting reinforcement systems is presented, followed by the fundamental theory of the load transfer mechanism. The failure mode of two phases of rock bolting system is formularised. The failure modes of cable bolting are discussed using a bond strength model as well as an iterative method. Finally, the interfacial shear stress model for ribbed bar is introduced and a closed form solution is obtained using a tri-line stress strain relationship.

Load Dispersion Effects of Acetabular Reinforcement Devices Used in Revision Total Hip Arthroplasty: A Simulation Study Using Finite Element Analysis

Several types of acetabular reinforcement devices are used to prevent the collapse of grafted bone in revision total hip arthroplasty. However, it remains unclear how the stress is reduced by different devices. We used finite element analysis to evaluate 4 types of acetabular reinforcement devices: Kerboull-type device, Burch-Schneider anti-protrusio cage, Mueller ring, and Ganz ring. The control was a socket fixed with bone cement without any reinforcement devices. The stress distribution on the inner surface of each socket was calculated by binarization image processing. For all 4 reinforcement devices, the stress was reduced to less than one-half of that in the control. All the devices were useful for preventing the collapse of bulk bone grafts applied to load-bearing defects.

Mid-term results of acetabular reconstruction using a Kerboull-type acetabular reinforcement device

The purpose of this study was to investigate the mid-term results of 32 acetabular reconstructions performed using a Kerboull-type acetabular reinforcement device and bone graft between June 1997 and January 2009. The mean age of the patients at the time of surgery was 71.4 years (range 55-85). Patients were followed-up for a mean of 7.5 years (range 2.1-13.7). The acetabular bone defects according to the American Academy of Orthopaedic Surgeons system was type III for 29 hips and type IV for three hips. Bulk allografts were performed in 30 hips and morselised autografts (iliac bone) were performed in two hips. Clinical evaluations were made according to the criteria of Postel/Merle d'Aubigné. The mean pre-operative Postel/Merle d'Aubigné hip score was 7.0 ± 2.9, and the final follow-up hip score was 12.6 ± 2.8. Six hips showed radiographic loosening, and two hips required further revision. A Kaplan-Meier analysis showed that the five-year and ten-year survival rates were 96.9% and 92.3%, respectively, using further revision of the acetabular device as an end point. Acetabular reconstruction using a Kerboull-type acetabular reinforcement device and bone graft gives satisfactory mid-term results.

Pelvic Discontinuity Caused by Acetabular Overreaming during Primary Total Hip Arthroplasty

Intraoperative acetabular fracture is a rare complication of primary total hip arthroplasty (THA), typically occurring during impaction of the cementless acetabular component. Here we report an unusual case of pelvic discontinuity caused by overreaming of the acetabulum during primary THA. Restoration of posterior columnar continuity was achieved with an autologous fibular graft and a reconstruction plate. Wall defects and cavitary defects were reconstructed with metal mesh and femoral head allograft, followed by placement and fixation of a Kerboull-type acetabular reinforcement device. Previous reports of acetabular fracture during THA have indicated that it has a relatively good prognosis without extensive treatment. However, to our knowledge, there has been no report of pelvic discontinuity necessitating acetabular reconstruction surgery as an intraoperative complication of primary THA.

Revision Total Hip Arthroplasty of an Acetabular Cup with Acetabular Bone Defects

Recently, the incidence of revision total hip arthroplasty (THA) has increased following primary THA. Bone stock deficiency presents the major challenge in acetabular reconstruction during revision hip arthroplasty. The reasons for such acetabular defects include osteolysis, bone resportion following cup loosening, iatrogenic damage resulting from cup or cement removal during revision THA, and cup migration. The pre-operative assessment of acetabular bone stock, including the amount and location of pelvic osteolysis before revision surgery, is a critical preoperative preparation for the treatment of bone deficiency. In cases with mild acetabular defects, a variety of surgical options are available for treating. However, in cases with severe segmental, cavitary, or combined acetabular defects, controversies have existed so far about the most optimal treatment. Thereby, we tend to introduce the most commonly-adopted classification system of acetabular defects and management options using high hip center cups, oblong cups, structural allografts, morselized allografts with bipolar cups, morselized allografts with cementless cups, morselized allografts with acetabular reinforcement devices, and revisions with trabecular metal augmentations.

The use of fibre-based demineralised bone matrix in major acetabular reconstruction: surgical technique and preliminary results

Acetabular osteolysis associated with socket loosening is one of the main long-term complications of total hip arthroplasty. In case of major bone loss, where <50% host bone coverage can be obtained with a porous-coated cementless cup, it is generally agreed that a metal ring or cage in association with a cemented component and allograft bone should be used. In order to promote allograft bone consolidation and incorporation, we have associated demineralised bone matrix (DBM, Grafton® A Flex) to the construct ion. Here we describe the technical details of major acetabular reconstruction using the Kerboull acetabular reinforcement device with allograft bone and DBM. This device has a hook that must be placed under the teardrop of the acetabulum and a plate for iliac fixation. The main advantages of this device are help in restoring the normal centre of hip rotation, guiding the reconstruction and partially unloading the graft. The Kerboull acetabular reinforcement device has provided a 92% survival rate free of loosening at 13-year follow-up in a consecutive series of 60 type III and IV deficiencies. Our preliminary results using DBM indicate faster allograft consolidation and remodelling.

Repair of fresh open tear of Achilles tendon

Lack of the timely mechanical loading of the repaired tendon is detrimental for healing progress. The current knowledge knows the appropriate time for the mechanical loading, but need to find out a suitable tool for this purpose. Therefore we present a technique based on using of an absorbable reinforcement device for tension regulation at the suture line. 24 patients with open tear of Achilles tendon were repaired surgically, the repair was reinforced using an absorbable suture and the outcomes were prospectively assessed at 24 months. No tendon lengthening or reruptures were reported; patients returned to pre-injury daily activates by fourth month. One patient reported 1cm atrophy of the calf, scar adhesion Grade 1 and ankle dorsiflexion decreased 5°. Restoration of the continuity and actual length of repaired tendons support use of the absorbable reinforcement device for regulation of the mechanical environment at the suture line.

Repair of fresh patellar tendon rupture: tension regulation at the suture line

The reported complications of the repaired patellar tendon have been attributed to the influence of the mechanical environment on the healing process. This study postulates that the healing complications can be minimised through tension regulation at the suture line using an absorbable reinforcement device. Twelve patients with fresh patellar tendon rupture were included in the study. They were prospectively followed up for an average period of 45 months. The patients resumed their pre-injury activities at an average of 6.1 months. The active knee movement averaged 0-154.6° compared to 0-156.7° in the contralateral knee. Radiologically no patella alta, patella baja or degenerative changes in the patellofemoral joints were noted. The results support use of the absorbable reinforcement device for tension regulation at the suture line.

Five-year experience with orthodontic miniscrew implants: A retrospective investigation of factors influencing success rates

Introduction Anchorage control is important for efficient orthodontic treatment with fixed appliances. Successful osseointegration encouraged many orthodontists to use dental implants as stationary anchorage units for force application. However, their use has some drawbacks, which led to the development of miniscrew implants (MIs). Our aim was to investigate factors significantly contributing to the success rates of MIs in various orthodontic treatment procedures in white patients. Methods In total, 350 self-tapping (187 Abso Anchor [Dentos, Daegu, South Korea] and 163 Ortho Easy Pin [Forestadent, Pforzheim, Germany]) MIs used to reinforce orthodontic anchorage and placed in 130 consecutively chosen patients were assessed retrospectively. Clinical variables possibly influencing the success rates of MIs were categorized into patient-related, implant-related, location-related, and orthodontic-related. Statistical evaluation included descriptive statistics and survival analysis. The survival curves of the MIs with respect to the various factors were estimated and plotted by using the Kaplan-Meier product-limit estimate. The MI survival distributions for each factor were compared with the log rank test for simple comparisons or the Cox regression for multiple variables. Results The overall success rates of MIs that remained stable during a mean treatment time of 19.2 ± 2.3 months was 93.43%; this was considerably higher than in previous reports. Only a few factors were found to be associated with statistically significant higher success rates of MIs, including deep bites, placement in the attached gingiva of the maxilla, and en-masse distalization of teeth. Conclusions The success rates of MIs in white patients were greater than the corresponding rates reported for Asian patients. Our results confirm the effectiveness of orthodontic MIs as temporary anchorage reinforcement devices and suggest various clinical factors as potential causes of failure.

Editor's Summary and Q&A: Five-year experience with orthodontic miniscrew implants: A retrospective investigation of factors influencing success rates

Anchorage control is important for efficient orthodontic treatment with fixed appliances. Successful osseointegration encouraged many orthodontists to use dental implants as stationary anchorage units for force application. However, their use has some drawbacks, which led to the development of miniscrew implants (MIs). Our aim was to investigate factors significantly contributing to the success rates of MIs in various orthodontic treatment procedures in white patients.In total, 350 self-tapping (187 Abso Anchor [Dentos, Daegu, South Korea] and 163 Ortho Easy Pin [Forestadent, Pforzheim, Germany]) MIs used to reinforce orthodontic anchorage and placed in 130 consecutively chosen patients were assessed retrospectively. Clinical variables possibly influencing the success rates of MIs were categorized into patient-related, implant-related, location-related, and orthodontic-related. Statistical evaluation included descriptive statistics and survival analysis. The survival curves of the MIs with respect to the various factors were estimated and plotted by using the Kaplan-Meier product-limit estimate. The MI survival distributions for each factor were compared with the log rank test for simple comparisons or the Cox regression for multiple variables.The overall success rates of MIs that remained stable during a mean treatment time of 19.2 +/- 2.3 months was 93.43%; this was considerably higher than in previous reports. Only a few factors were found to be associated with statistically significant higher success rates of MIs, including deep bites, placement in the attached gingiva of the maxilla, and en-masse distalization of teeth.The success rates of MIs in white patients were greater than the corresponding rates reported for Asian patients. Our results confirm the effectiveness of orthodontic MIs as temporary anchorage reinforcement devices and suggest various clinical factors as potential causes of failure.

Total Hip Arthroplasty Using Kerboull-Type Acetabular Reinforcement Device for Rapidly Destructive Coxarthrosis

We studied 20 primary cemented total hip arthroplasties performed using Kerboull-type acetabular reinforcement device for rapidly destructive coxarthrosis. The average patient age at the time of surgery was 68.3 (range, 60-77) years. The mean follow-up period was 6.3 years (3.8-11.8). The mean preoperative Japanese Orthopedic Association hip score was 38.1 (16-70) vs 85.2 (70-93) at the latest follow-up. The radiographic outcome in 20 hips showed no migration or aseptic loosening. A partial radiolucent line at the cement-bone interface was noted in 2 hips (10%), but no progression occurred. There were no major complications. No patient required repeated surgery. The use of Kerboull-type acetabular reinforcement device for rapidly destructive coxarthrosis provided satisfactory 3-year to 11-year clinical and radiographic results.

Acetabular Reconstruction with Human and Bovine Freeze- Dried Bone Grafts and a Reinforcement Device

BACKGROUNDThis is a cohort trial (1997–2005) of 49 patients submitted to an acetabular component revision of a total hip arthroplasty, using impacted human and bovine freeze-dried cancellous bone grafts (H&FDBG) and a reinforcement device.OBJECTIVETo compare clinical/radiographic graft incorporation capability between cancellous bone grafts.PATIENTS/METHODSThere were two groups: I (n=26) receiving human grafts and II (n=25) receiving bovine grafts. The average follow-up times were 55 and 49 months, respectively. Clinical analysis was based on the Merle d’Aubigné and Postel score, and the radiographic analysis involved an established score based on Conn’s et al. criteria for radiographic bone incorporation.RESULTSNo clinical/radiographic differences were found between the groups and both showed an overall rate of 88.5% and 76% of graft incorporation (p=0.424).CONCLUSIONThe results presented here are comparable to those in the literature with the use of deep-FG. Therefore, cancellous bone grafts can be safely and adequately used in acetabular component revision in total hip arthroplasty.