Abrasive three-body wear of polyethylene caused by broken multifilament cables of a total hip prosthesis. A report of these cases

Cerclage performance analysis - a biomechanical comparison of different techniques and materials

BACKGROUND

Wire cerclages play a fundamental role in fracture fixation. With an increasing variety of designs being commercially available the question arises which cerclage should be used. This study investigates the biomechanical properties of metallic and non-metallic cerclages and their different application-types. Furthermore, potential influence of muscular interposition between bone and cerclage constructs was tested.

METHODS

Samples of the following four different cerclage types were tested on 3D printed models of human humeri as well as on human cadaveric humeri with and without muscular interposition: Titanium Cable Cerclage (CC), Steel Wire Cerclage (SWC), Suture Tape (ST), Suture Tape Cerclage (STC) with both single- (sSTC) and double-loop application (dSTC). A preinstalled self-locking mechanism secured by the provided tensioner in the STCs being the main difference to the STs. Cyclic loading was performed to 1 kN and then linearly to a maximum load of 3 kN. Statistical analysis was performed using either one-way ANOVA and post-hoc Tukey or Kruskal-Wallis and post-hoc Dunn test depending on normalization of data (p < 0.05).

RESULTS

Whilst all cerclage options could withstand high loads during failure testing, only within the CC and dSTC group, all samples reached the maximal testing load of 3000 N without any failure. The SWC reached 2977.5 ± 63.6 N, the ST 1970.8 ± 145.9 N, and the sSTC 1617.0 ± 341.6 N on average. Neither muscular interposition nor bone quality showed to have a negative influence on the biomechanical properties of the cerclage constructs, presenting no significant differences.

CONCLUSION

All tested cerclage constructs produce reliable stability but differ in their resulting compression forces, in a simplified fracture model. Therefore, non-metallic cerclage alternatives can provide similar stability with less compression and stiffness to metallic cable constructs, but they may offer several advantages and could possibly provide future benefits. Especially, by offering more elasticity without losing overall stability, may offer a biologic benefit. Installing any cerclage constructs should be performed carefully, especially if poor bone quality is present, as the tightening process leads to high forces on the construct.

Experimental Study to Evaluate the Wear Performance of UHMWPE and XLPE Material for Orthopedics Application

The main objective of this study is to perform an abrasive wear resistance study of UMHWPE and XLPE by using different grades of abrasive paper (grade 100 (190 µm), grade 220 (50 µm), and grade 400 (40 µm)) with minor (10 N) and major (15 N) loading conditions. In this article, wear performance of the UMHWPE and XLPE materials compared to the bio-tribological data as reported earlier in the clinical studies has been investigated. The experimental result shows that the loss of materials for the XLPE was much higher than the UHMWPE under similar loading conditions. UHMWPE shows a 34% reduction in wear at minor loading conditions and a 53% reduction in wear at major loading conditions. From experimental results it was concluded that Cross-link PE has better wear resistance than UHMWPE in minor wear conditions, whereas UHMWPE shows better wear resistance under major loading conditions. Based upon these results, UHMWPE and XLPE have been recommended for use as bearing materials in orthopedics. The experimental results of this study were validated using results from the available literature.

Metallic versus Non-Metallic Cerclage Cables System in Periprosthetic Hip Fracture Treatment: Single-Institution Experience at a Minimum 1-Year Follow-Up

Metallic cerclage cables are reliable and cost-effective internal fixation devices, which are largely used in surgical practice for the treatment of periprosthetic fractures. Nevertheless, complications connected with their use have been described in the literature, including the following: third-body generation, failure and consequent migration, fraying, allergies, and injury to the surgical team. The development of new materials offers alternatives to traditional metallic cables. This study compares the outcomes between two groups of patients affected by periprosthetic hip fractures, treated with titanium cables or with ultra-high-molecular-weight polyethylene (UHMWPe) iso-elastic cables. Our retrospective study aims to compare the clinical and radiological outcomes of titanium cables and UHMWPe iso-elastic cables, isolated or associated with dedicated plates, for the surgical treatment of periprosthetic fractures with stable implants. Two groups of 30 (group A-metallic cables) and 24 (group B-UHMWPe iso-elastic cables) patients have been surgically treated in our institution for hip periprosthetic fractures, between September 2017 and June 2020. The mean age of the patients was 81 years in group A and 80 years in group B. In our study, we included fractures classified as B1 or C, according to the Vancouver postoperative fractures classification; the patients were evaluated retrospectively at 1 year postoperatively, regarding the following: surgery time, blood loss, partial weight-bearing time, radiographical healing time, Harris hip score, and postoperative complications. Comparable outcomes were observed in patients from both groups. Group A showed a higher complication rate compared to group B, at 1 year postoperatively. Non-metallic nylon fiber and ultra-high-molecular-weight polyethylene (UHMWPe) cerclage cables could represent a reliable fixation device, ensuring comparable healing and complication rates with traditional titanium cerclage cables.

A Tensionable Suture-based Cerclage Is an Alternative to Stainless Steel Cerclage Fixation for Stabilization of a Humeral Osteotomy During Shoulder Arthroplasty

INTRODUCTION

Fixation of periprosthetic humeral fractures is most commonly obtained with steel-based wires or cables; however, disadvantages with these constructs are numerous. Suture-based cerclages offer the advantage of easy handling, less radiographic interference, and risk of metallosis, as well as decreased risk of cutting into the soft humeral bone. Therefore, the purpose of this study was to compare a suture-based cerclage to a stainless steel wire cerclage (SSWC) for stabilization of the humerus during shoulder arthroplasty.

METHODS

In part I of the study, SSWC fixation was compared with single-looped tape cerclage and a double-looped tape cerclage (DLTC) fixation. In part II, a subsidence test was performed on 12 cadaveric humeri. After an osteotomy, the humeri were secured with either a SSWC or DLTC. Subsequently, a metal wedge was introduced into the humerus to simulate the stem of a shoulder arthroplasty.

RESULTS

In part I, load to 2-mm displacement was significantly higher for the DLTC construct compared with the SSWC construct (2,401 ± 483 N versus 750 ± 33 N; P < 0.0001). Load to failure was 935 ± 143 N with the SSWC, 1,737 ± 113 N with the single-looped tape cerclage, and 4,360 ± 463 N with the DLTC constructs, and all differences were statistically significant (P < 0.05). In part II, load at 20-mm subsidence was higher for the DLTC (320 ± 274 N) compared with the SSWC (247 ± 137 N), but no significant difference was observed (P > 0.05). However, gap displacement at 20 mm subsidence was significantly lower with the DLTC construct (0.33 ± 0.31 mm versus 0.77 ± 0.23 mm; P = 0.009). Load to failure was higher with the DLTC construct compared with the SSWC construct (4,447 ± 2,325 N versus 1,880 ± 1,089 N; P = 0.032), but the final gap displacement did not differ significantly (DLTC 5.23 ± 6.63 mm versus SSWC 6.03 ± 8.82 mm; P > 0.05).

DISCUSSION

A DLTC has higher load to failure and trends toward lower gap displacement compared with a SSWC. The DLTC construct may therefore be a viable alternative for fixation of periprosthetic fractures or osteotomies of the humeral shaft during shoulder arthroplasty.

Trochanteric Fixation With a Third-Generation Cable-Plate System: An Independent Experience

BACKGROUND

Greater trochanteric fracture/nonunion can be a devastating complication with significant functional impact after total hip arthroplasty, and their fixation remains a challenge because of the significant forces being transmitted as well as the poor bone quality often associated with these fractures. The objective of this study is to investigate the rates of reoperation and trochanteric nonunion using a third-generation cable-plate system at one center.

METHODS

Thirty-five patients, mean age 72.9 years (range 46-98 years) with 24 women and 11 men, underwent fixation of their fractured greater trochanter using a third-generation cable-plate system. The indications were: periprosthetic fracture (n = 17), complex primary arthroplasty (n = 5), and complex revision arthroplasty (n = 13). Primary outcomes included rates of reoperation and radiographic union.

RESULTS

At a mean follow-up of 2.5 years, trochanteric union rate was 62.9% with nonunion rate of 31.4%, and fibrous union in 5.7%. In regard to quality of initial apposition, only 40% achieved a perfect bone on bone reduction. Ten patients (28.6%) had evidence of wire breakage. Five patients (14.3%) required reoperation and removal of the internal fixation because of lateral hip pain.

CONCLUSION

Fixation of the trochanteric fractures remains a challenge with a relatively high reoperation rate. Poor bone quality and capacity to maintain a stable reduction continue to make this complication after total hip arthroplasty a difficult problem to solve.

Use of locking plates for fixation of the greater trochanter in patients with hip replacement

BACKGROUND

Fixation of the greater trochanter with total hip replacement is challenging and associated with short- and long-term complications. Locking plate technology has been used for fixation of other bones and may be applied successfully in trochanteric fixation. The purpose of this retrospective study was to analyze the utility of the use of trochanteric locking plates in total hip arthroplasty (THA) patients.

METHODS

From 2004 to 2014, 32 procedures were performed to fix the greater trochanter in patients with trochanteric fracture, osteotomy, or nonunion in the setting of THA. The median age at the time of surgery was 69 years. This was a primary arthroplasty in 8 of the patients, conversion from prior hip surgery in 5, and a revision in 19. The greater trochanter was fixed with locking plate alone in 15 hips and with the addition of a single cerclage cable in 17 hips. Patients were followed clinically and radiographically until healing occurred. The median duration of radiographic follow-up was 41.6 months (range: 10-112 months).

RESULTS

Osseous union occurred in 29 (90.6%) of 32 hips. The median Harris hip score was 94 (range 54-100, standard deviation = 10.4) at latest follow-up. Complications included broken hardware in 5 (15.6%) patients, of which 3 underwent subsequent hardware removal. Two additional patients elected hardware removal due to trochanteric pain.

CONCLUSIONS

Locking plate technology is a successful method of fixation of the greater trochanter in patients with THA. Postoperative trochanteric pain and reoperation for hardware-related issues remain a challenge.

Oxinium femoral head damage generated by a metallic foreign body within the polyethylene cup following recurrent dislocation episodes

Oxinium femoral heads are supposed to be more scratch-resistant thanks to their oxidized layer. However, damages to this thin layer can jeopardize implant's properties. Following revision total hip arthroplasty performed for recurrent posterior dislocations, the Oxinium femoral head initially implanted was observed to be dramatically damaged. A metallic foreign body from a trochanteric fixation wire was found within the polyethylene cup. Only few cases of damaged Oxinium femoral heads have been reported and all were related to either dislocation or reduction of THA. The aim of this report is to describe a non-reported mechanism of damaged Oxinium femoral head due to a broken trochanteric fixation wire device. Any broken metallic wire from a transtrochanteric approach should be carefully followed to detect migration within the polyethylene cup. If such a migration occurs, revision surgery should be rapidly scheduled.

Comparison of the outcome following the fixation of osteotomies or fractures associated with total hip replacement using cables or wires: the results at five years

There are no recent studies comparing cable with wire for the fixation of osteotomies or fractures in total hip replacement (THR). Our objective was to evaluate the five-year clinical and radiological outcomes and complication rates of the two techniques. We undertook a review including all primary and revision THRs performed in one hospital between 1996 and 2005 using cable or wire fixation. Clinical and radiological evaluation was performed five years post-operatively. Cables were used in 51 THRs and wires in 126, and of these, 36 THRs with cable (71%) and 101 with wire (80%) were evaluated at follow-up. The five-year radiographs available for 33 cable and 91 wire THRs revealed rates of breakage of fixation of 12 of 33 (36%) and 42 of 91 (46%), respectively. With cable there was a significantly higher risk of metal debris (68% vs. 9%; adjusted relative risk (RR) 6.6; 95% confidence interval (CI) 3.0 to 14.1), nonunion (36% vs. 21%; adjusted RR 2.0; 95% CI 1.0 to 3.9) and osteolysis around the material, acetabulum or femur (61% vs 19%; adjusted RR 3.9; 95% CI 2.3 to 6.5). Cable breakage increased the risk of osteolysis to 83%. There was a trend towards foreign-body reaction and increased infection with cables. Clinical results did not differ between the groups. In conclusion, we found a higher incidence of complications and a trend towards increased infection and foreign-body reaction with the use of cables.

Scratching vulnerability of conventional vs highly cross-linked polyethylene liners because of large embedded third-body particles

The hypothesis of this study was that acetabular liner vulnerability to scratching from femoral heads, roughened by third bodies embedded in the liner, is not significantly lower for highly cross-linked polyethylene (HXPE) than for conventional polyethylene (CPE). Six CPE and 6 HXPE acetabular liners were each reproducibly embedded with 5 cobalt-chromium-molybdenum (CoCrMo) beads then run for 10,000 cycles in a joint simulator. By visual rank ordering, there was low association between liner scratch severity and polyethylene type. The CPE and HXPE liner scratches were not significantly different in scratch peak-valley height or width or in liner roughness in the vicinity of the embedded beads. This model indicated that high cross-linking of polyethylene does not offer appreciable protection against severe scratching induced by large embedded third-body particles.

Trochanteric fixation using a third-generation cable device--minimum follow-up of 3 years

Third-generation trochanteric fixation cable systems are designed to overcome implant breakage, nonunion, and bony escape. The study prospectively assessed the functional and radiologic outcomes using such an implant. Forty-seven trochanteric fixations in 46 patients were performed over 4 years at 2 institutions using the Accord Cable Plate system (Smith and Nephew, Memphis, Tenn). Serial evaluation at a mean follow-up of 57 months demonstrated that the mean Harris hip scores improved from 52.3 preoperatively to 88.2 postoperatively (P < .001), and the mean pain score improved from 6.2 to 2.3, respectively (P < .001). No cable breakage, fretting, or fraying occurred. There were 2 cases of nonunion. A third-generation cable system appears to improve upon early-generation implants and provide favorable outcomes for reattachment of a trochanteric fragment in a variety of clinical scenarios.

Utility of polymer cerclage cables in revision shoulder arthroplasty

Revision shoulder arthroplasty often requires humeral osteotomy for stem extraction or is complicated by periprosthetic fracture. In these situations, various modes of fixation are used, including cerclage wires, cable plates, and allograft strut augmentation. The use of metal wires and cables, however, has been associated with soft tissue irritation, sharps injuries, and accelerated wear of joint arthroplasty bearing surfaces. As an alternative to traditional metal cables, the SuperCable (Kinamed Inc, Camarillo, California) contains braided ultra-high molecular-weight polyethylene fibers surrounding a nylon core. To date, no studies have examined the use of nonmetallic cerclage cables in shoulder arthroplasty.A retrospective review was performed of 11 patients who underwent shoulder arthroplasty for which nonmetallic cerclage cables were used. Clinical and radiographic data were examined regarding patient age, procedure performed, indication for cerclage cabling, time to healing of osteotomy or fracture, and any complications associated with the use of these cerclage cables. Minimum follow-up was 1 year. Ten patients underwent reverse total shoulder arthroplasty, and 1 patient underwent revision unconstrained total shoulder arthroplasty. Mean follow-up was 20.5 months. Ten patients required humeral osteotomy for stem or cement removal. Allograft augmentation was performed in 7 patients. Mean time to healing was 3.2 months. No patients experienced loosening or migration of hardware or allograft, and no complications directly related to the use of nonmetallic cerclage cables were identified.

Early experience with a novel nonmetallic cable in reconstructive hip surgery

BACKGROUND

Metallic wires and cables are commonly used in primary and revision THA for fixation of periprosthetic fractures and osteotomies of the greater trochanter. These systems provide secure fixation and high healing rates but fraying, third-body generation, accelerated wear of the bearing surface, and injury to the surgical team remain concerning.

QUESTIONS/PURPOSES

We determined the rate of cable failure, union, and complications associated with a novel, nonmetallic cerclage cable in periprosthetic fracture and osteotomy fixation during THA.

METHODS

We retrospectively reviewed 29 patients who had primary and revision THAs using nonmetallic cables. Indications for use included fixation of an extended trochanteric osteotomy, intraoperative fracture of the proximal femur, strut allograft fixation, and a Vancouver B1 periprosthetic fracture of the femur. All patients were evaluated clinically and radiographically immediately postoperatively, at 3 weeks, 6 weeks, 3 months, and then annually thereafter. The minimum followup was 13 months (mean, 21 months; range, 13-30 months).

RESULTS

Two of the 29 patients (7%) developed a nonunion; all remaining osteotomies, fractures and allografts had healed at the time of most recent evaluation. Four patients (14%) dislocated postoperatively; two were treated successfully with closed reduction, while the other two required reoperation. We identified no evidence of breakage or other complications directly attributable to the cables.

CONCLUSIONS

The nonmetallic periprosthetic cables used in this series provided adequate fixation to allow for both osteotomy and fracture healing. We did not observe any complications directly related to the cables. Level of Evidence Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

"Severe" wear challenge to 36 mm mechanically enhanced highly crosslinked polyethylene hip liners

Our purpose was to compare the wear performance of mechanically enhanced 5Mrad highly crosslinked polyethylene (MEP, ArComXL) hip liners to (control) 3Mrad UHMWPE liners (ArCom) in 36 mm head size. As a more severe synergy of clinically relevant test models, we contrasted wear with custom roughened Co-Cr surfaces (Ra 500 nm) to the standard pristine Co-Cr heads (Ra < 20 nm) using a severe microseparation test mode in our hip simulator. We adopted a previously published model to estimate potential biological activity. On new Co-Cr heads, the MEP liners showed a 47% reduction in volumetric wear a 13% reduction in wear particle size and a 27% reduction in Functional Biological Activity (FBA) compared to our control. On rough Co-Cr heads, the MEP liners showed little advantage in terms of volumetric wear compared with the control. However, the MEP liners overall showed a 38% reduction in FBA compared to the control owing to a larger volume fraction of larger particles. Thus overall the MEP liners appeared to offer advantages in terms of reduced FBA indices.

Comparison of complications in transtrochanteric and anterolateral approaches in primary total hip arthroplasty

Three surgical approaches to primary total hip arthroplasty (THA) have been in use since Charnley popularized the transtrochanteric approach. This study was designed to examine the difference in morbidity between the transtrochanteric approach and the anterolateral approach in primary THA. Information on 891 patients who underwent primary THA performed by a single surgeon was collected prospectively between 1998 and 2003 using a modified SF-36 form, preoperatively, intraoperatively, and at 3 months postoperatively. The transtrochanteric group had higher morbidity and more patients who were dissatisfied with their THA. There was a greater range of motion in the anterolateral group.

Fixation systems of greater trochanteric osteotomies: biomechanical and clinical outcomes

The development of cerclage systems for fixation of greater trochanteric osteotomies has progressed from monofilament wires to multifilament cables to cable grip and cable plate systems. Cerclage wires and cables have various clinical indications, including fixation for fractures and for trochanteric osteotomy in hip arthroplasty. To achieve stable fixation and eventual union of the trochanteric osteotomy, the implant must counteract the destabilizing forces associated with pull of the peritrochanteric musculature. The material properties of cables and cable grip systems are superior to those of monofilament wires; however, potential complications with the use of cables include debris generation and third-body polyethylene wear. Nevertheless, the cable grip system provides the strongest fixation and results in lower rates of nonunion and trochanteric migration. Cable plate constructs show promise but require further clinical studies to validate their efficacy and safety.

[Mechanisms of damage to metal-on-polyethylene articulating surfaces of total hip prostheses: influence of intra-articulate migration of metallic debris]

PURPOSE OF THE STUDY

The objective of this work was to identify the mechanisms leading to deterioration of the polyethylene acetabular surface in total hip prostheses.

MATERIAL AND METHODS

We conducted an in vivo analysis of damage caused to articulating surfaces of metal-on-polyethylene total hip prostheses. This analysis was performed on three of the 45 explants of Harris-Galante prostheses available to use from our series of 1480 implantations performed between 1985 and 1996. These three pieces were selected because large-sized fibers of metallic debris were identified on the polyethylene surface and because the explants had been performed for reasons other than loosening in aseptic patients. Macroscopic examination was combined with scan electron microscopy to analyze morphological changes.

RESULTS

We found that identical damage could be observed on the polyethylene explants despite the different sizes of the metallic heads and different metal-on-polyethylene combinations. Our analysis confirmed the deleterious effect of metallic foreign bodies trapped in contact with the articulate surfaces. These foreign bodies resulted in one case from rupture of a multifilament wire used for the trochanteric fixation and in two cases from the surfacing of the non-cemented Harris-Galante cups. The microscopic analysis demonstrated several successive localizations of the foreign bodies on the polyethylene surface before becoming deeply encrusted in the polyethylene where they deteriorated the femoral head surface (rough) and wore the polyethylene surface (abrasion). When the fibers came from the surfacing of the Harris-Galante cups, the metallic debris remained unrecognized during the revision procedure and were only identified later during the systematic examination of prosthetic explants.

DISCUSSION AND CONCLUSION

These findings emphasize the importance of quality surface treatments for non-cemented prostheses and argue in favor of particular precautions during operative manipulation of these components. A systematic analysis of the prosthetic explants is advisable, particularly for components explanted because of wear or unexplained osteolysis. Use of multifilament trochanteric wires should be avoided because rupture raises the risk of intra-articulate migration of metallic debris. If the prosthesis involves a polyethylene acetabular surface, ceramic heads should be preferred to improve resistance to abrasion, particularly to limit the deleterious effect of a third body.

Fixation of Chevron trochanteric osteotomy with two wire loops in isolated acetabular component revision

The use of two wire loops for fixation of the trochanteric fragment after Chevron osteotomy in revision THA achieves stable fixation with minimal hardware.

Third-body wear of highly cross-linked polyethylene in a hip simulator

The wear performance of a radiation cross-linked melted ultrahigh-molecular-weight polyethylene (UHMWPE) articulating against 28-mm cobalt chrome femoral heads in the presence of third-body particulate debris was investigated in a hip simulator and compared with the wear of conventional UHMWPE. Particles of aluminum oxide or bone cement containing barium sulfate were added to the serum. In the presence of aluminum oxide particles, the incremental wear rates of conventional UHMWPE averaged as high as 149 +/- 116 mg/million cycles compared with 37 +/- 38 mg/million cycles for the highly cross-linked components. The difference in the average weight loss was statistically significant at P <.01. With bone cement particles, the conventional UHMWPE components had an average incremental wear rate of 19 +/- 5mg/million cycles, and the wear rate of the highly cross-linked UHMWPE components was 0.5 +/- 0.7 mg/million cycles.

Reattachment of the ununited greater trochanter following total hip arthroplasty. The use of a trochanteric claw plate

BACKGROUND

The purpose of this retrospective study was to analyze the utility of a trochanteric claw plate in the treatment of an ununited greater trochanter following total hip arthroplasty.

METHODS

From 1986 through 1999, seventy-two consecutive procedures to reattach an ununited greater trochanter were performed in seventy-one patients. The average age at the time of the index arthroplasty was 66.2 years. The arthroplasty that resulted in the nonunion of the greater trochanter was primary in fifty-four hips, a first revision in sixteen hips, and a second and third revision in one hip each. The mean duration between the hip replacement and the treatment of the nonunion was 8.1 months. The greater trochanter was fixed with the trochanteric plate alone in forty-eight hips and with the plate in conjunction with vertical wires in the remaining twenty-four hips. The average duration of follow-up was 5.1 years.

RESULTS

Osseous union occurred in fifty-one of the seventy-two hips. There was a persistent nonunion in twelve hips and fibrous consolidation in the remaining nine hips. The mean time to osseous consolidation was 3.7 +/- 2.1 months (range, two to twelve months). The mean Merle d'Aubigné hip score was 16.1 +/- 2.4 points at the time of the latest follow-up. A highly significant improvement in function was achieved only in the group with osseous consolidation (p < 0.0001). The highest rate of osseous union was achieved when vertical wires had been used in conjunction with the claw plate. Union occurred in twenty-one of the twenty-four hips in that group (p = 0.025).

CONCLUSIONS

Nonunion of the greater trochanter following total hip arthroplasty can be successfully treated with a trochanteric claw plate. The use of adjunctive vertical wires results in better osseous contact and union.