Greater trochanteric fixation using a cable system for partial hip arthroplasty: a clinical and finite element analysis

Biofilm Growth on Orthopaedic Cerclage Materials: Nonmetallic Polymers Are Less Resistant to Methicillin-Resistant Staphylococcus Aureus Bacterial Adhesion

BACKGROUND

Data on bacterial adhesion to cerclage cables are sparse. We aimed to compare 5 cerclage products for methicillin-resistant Staphylococcus aureus (MRSA) adhesion to determine the claim: Are nonmetallic polymer cables more resistant to bacterial adhesion than common metallic wires and cables?

METHODS

The following 5 cerclage products were compared: (1) monofilament stainless steel (SS) wires; (2) multifilament SS cables; (3) multifilament cobalt chrome cables; (4) multifilament Vitallium alloy (cobalt-chrome-molybdenum [Co-Cr-Mo]) cables; and (5) multifilament nonmetallic polymer cables. Each was cut into 2 cm lengths and placed into 12-well plates. Of the wells, 5 were wire or cables in trypticase soy broth with MRSA, with the remaining wells being appropriate controls incubated for 24 hours at 37° C and 5% CO2 with shaking. Wires and cables were prepared and randomly imaged via scanning electron microscopy, with bacterial counts performed on 3 images of 3 different wires or cables per study group. The scanning electron microscopy technician and counting investigator were blinded. Additionally, SS wire and polymer cables were analyzed by microcalorimetry for metabolic activity and bacterial load.

RESULTS

Bacterial attachment differed significantly between study groups in the middle section (P = .0003). Post hoc comparison showed no difference between groups individually (all P > .05) apart from polymer cables (median 551 bacteria) having significantly increased attached bacteria compared to the Vitallium alloy cable (157, P = .0004), SS cable (101, P = .0004), and SS wire (211, P = .0004). There was no difference between polymer and cobalt chrome cables (133, P = .056). Microcalorimetry supported these results, as polymer cables had a shorter time to max heat flow (6.2 versus 7.5 hours, P = .006), increased max heat flow (117 versus 64 uW, P = .045), and increased colony-forming units, indicating an increased bacterial load compared to SS wires.

CONCLUSIONS

This in vitro study demonstrated that polymer cables have increased MRSA adhesion compared to common metallic wires and cables. Future studies are necessary to confirm the translation of increased bacterial adherence on polymer cables to increased rates of orthopaedic infections.

Bilateral hip stability variation in the functional ambulation and kinetic parameters after total hip arthroplasty during leveled walking

Objectives

This study determines gender variation, comparing the significance level between men and women related to functional ambulation characteristics after hip arthroplasty. The study focuses on the broader female pelvis and how it affects the rehabilitation regimen following total hip arthroplasty.

Materials and Methods

In this cross-sectional study, 20 cases of right hip arthroplasty were divided into 10 male and 10 female cases, aged 40-65 years. The functional ambulation parameters (walking cadence, gait speed, stride length, and gait cycle time) were acquired from the GAITRite device, as well as kinematic values for hip frontal plane displacement and kinetic parameters for ground response force in the medial-lateral direction.

Results

An independent t-test showed a significant difference in the kinematic parameter variables for the anterior superior iliac spine, more significant trochanter displacement, and hip abduction angle between the operated and non-operated limbs for each group separately. Regarding the functional ambulation parameters, there was a significant difference in the walking cadence between the operated and non-operated limbs of both male and female groups. Moreover, the output variables of ground reaction force measures revealed significant differences between their operated and non-operated limbs. The linear regression model used was consistent with the current results, demonstrating a weak negative correlation between the abduction angle of the operated hip and gait speed for both male and female groups.

Conclusion

Based on the findings, we draw the conclusion that improving a rehabilitated physical therapy program for the abductors of both male and female patients' operated and non-operated limbs is essential for normalizing the ground reaction force value, avoiding focus on the operated hip, and reducing the amount of time that the operated hip's abductors must perform. This involves exposing the surgically repaired limb to the risk of post-operative displacement or dislocation, particularly in female patients.

Primary Arthroplasty for Unstable and Failed Intertrochanteric Fractures: Role of Multi-Planar Trochanteric Wiring Technique

Purpose

The primary objective of the current study is to demonstrate the trochanteric wiring technique. A secondary objective is to evaluate the clinico-radiological outcomes of use of the wiring technique during primary arthroplasty for treatment of unstable and failed intertrochanteric fractures.

Materials and Methods

A prospective study including follow-up of 127 patients with unstable and failed intertrochanteric fractures who underwent primary hip arthroplasty using novel multi-planar trochanteric wiring was conducted. The average follow-up period was 17.8±4.7 months. Clinical assessment was performed using the Harris hip score (HHS). Radiographic evaluation was performed for assessment of union of the trochanter and any mechanical failure. P<0.05 was considered statistically significant.

Results

At the latest follow-up, the mean HHS showed significant improvement from 79.9±1.8 (at three months) to 91.6±5.1 (P<0.05). In addition, no significant difference in the HHS was observed between male and female patients (P=0.29) and between fresh and failed intertrochanteric fractures (P=0.08). Union was achieved in all cases of fractured trochanter, except one. Wire breakage was observed in three patients. There were five cases of limb length discrepancy, three cases of lurch, and three cases of wire-related bursitis. There were no cases of dislocation or infection. Radiographs showed stable prosthesis in situ with no evidence of subsidence.

Conclusion

Use of the proposed wiring technique was helpful in restoring the abductor level arm and multi-planar stability, which enabled better rehabilitation and resulted in excellent clinical and radiological outcomes with minimal risk of mechanical failure.

Treatment Outcomes for Periprosthetic Femoral Fractures in Cementless Press-Fit Total Hip Replacement

OBJECTIVE

 The aim of this study was to report outcomes in dogs with periprosthetic femoral fractures associated with a press-fit cementless femoral total hip replacement implant.

MATERIALS AND METHODS

 Electronic medical records and digital radiographs were used to identify dogs with periprosthetic femoral fractures associated with press-fit cementless total hip replacement. Data collected included signalment, weight, time of fracture, cause of fracture, presence of intra-operative fissure, fracture type, repair technique, and clinical and radiographic outcomes. Long-term patient outcome was assessed by communication with owners or referring veterinarians.

RESULTS

 Twenty-eight dogs with femoral fracture repair associated with cementless press-fit total hip replacement were identified. Eight of the fractures occurred intraoperatively and 20 occurred at a median of 2 days postoperatively. An oblique or spiral configuration was noted in 19 cases and 15 occurred at the distal end of the femoral stem (type B), with thirteen type B1, one type B2 and one type B3 fractures. Fractures were repaired with non-locking (18/28) or locking-plate fixation (10/28). Cerclage wire was applied around the plate and proximal bone segment in 17/28 dogs. Major complications occurred in 7/28 cases (five deep infection, two mechanical failures). Bone healing was noted in 21/23 cases, for which follow-up radiographic interpretation was available. Return to function was complete in 17 cases, acceptable in 8 cases and unacceptable in 3 cases.

CONCLUSIONS

 While cementless total hip replacement periprosthetic femoral fractures can be successfully repaired with lateral plate fixation, the risk of infection appears to be high.

Fixation Options Following Greater Trochanteric Osteotomies and Fractures in Total Hip Arthroplasty: A Systematic Review

BACKGROUND

The optimal system for greater trochanteric fixation following osteotomy or fracture remains unknown. This systematic review aims to synthesize the available English-language literature on 5 commonly reported trochanteric fixation methods to quantify and compare rates of complications and reoperation.

METHODS

A comprehensive search of MEDLINE and Embase databases from January 1946 to June 2017 was performed for articles in English describing fixation of trochanteric osteotomies and fractures using wires, cables, cable-plate devices, claw or locking plates, and trochanteric bolts. Pooled mean rates of complications and reoperation with 95% confidence intervals (CIs) were analyzed using a random-effects model.

RESULTS

Fifty-seven studies involving 10,956 hips were eligible for inclusion. Five studies had Level-III evidence and 52 had Level-IV evidence. The pooled mean rate of nonunion was 4.17% (95% CI, 3.21% to 5.13%; I = 79%) for wires, 5.07% (95% CI, 0.37% to 9.77%; I = 74%) for cables, 16.11% (95% CI, 10.85% to 21.37%; I = 89%) for cable-plate systems, 9.60% (95% CI, 2.23% to 16.97%; I = 59%) for claw or locking plates, and 12.42% (95% CI, 3.41% to 21.43%; I = 75%) for trochanteric bolts. Substantial heterogeneity in the data precluded formal statistical comparison of outcomes and complications between implants.

CONCLUSIONS

Available literature on the various trochanteric fixation implants is heterogeneous and consists primarily of retrospective case series. Based on the current literature, it is difficult to support the use of one implant over another. Despite superior mechanical properties, rates of complication and reoperation following cable-plate fixation remains suboptimal, especially in complex revision scenarios. Additional rigorous prospective randomized and cohort studies are needed to make definitive recommendations regarding the most reliable method of trochanteric fixation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Is rigid fixation of the greater trochanter necessary for arthroplasty of intertrochanteric fractures?

INTRODUCTION

Stable fixation of the greater trochanter fracture fragments is necessary in arthroplasty of intertrochanteric hip fractures, as nonunion of the greater trochanter fracture comminution may result in impaired function or dysfunction of the abductor lever arm.

HYPOTHESIS

The ethibond suture technique is an efficient method for fixation of the greater trochanter fracture fragments.

MATERIALS AND METHODS

A total of 47 cases were studied. The mean age of the patients was 80.6 years, and the minimum follow-up was 6 months. Radiologic evaluation was done by examination of greater trochanter healing and measurement of migration of the greater trochanter fragment. Functional evaluation was done by comparison of pre-injury and postoperative ambulation status.

RESULTS

The mean migration of the greater trochanter fragment with ethibond sutures was 5.98mm. Union was achieved in 76.6%, and the nonunion rate was 23.4%. 86.9% of patients had no difference in ambulation or had a difference of only 1 level by the Koval score after treatment compared to their pre-injury status.

DISCUSSION

The ethibond suture technique provides good fixation of the greater trochanter fragments in arthroplasty of intertrochanteric hip fractures.

LEVEL OF EVIDENCE

IV, Case series.

Evaluation of Risk Factors for Second Hip Fractures in Elderly Patients

Background

Hip fracture is a worldwide public health problem that primarily affects osteoporotic individuals and the elderly. A second hip fracture can occur in elderly patients who have already suffered an initial hip fracture. The aim of this study was to investigate possible risk factors for second hip fractures in elderly patients with hip fractures.

Methods

Between 2010 and 2014, 230 patients who underwent uncemented bipolar hemiarthroplasty for hip fractures were retrospectively analyzed. The patients were divided into two groups: those with a first hip fracture (group 1) and those with a second hip fracture (group 2).

Results

The mean time from the first hip fracture to second hip fracture was 22 months. There were no significant differences in the American Society of Anesthesiologist scores, comorbidities were observed in the two groups. The mean length of hospitalization was not significantly different between the two groups. The mean postoperative functional scores after second hip fractures were significantly lower in group 2 than in group 1.

Conclusions

Although there are not certain risk factors for second hip fractures in elderly patients with hip fractures, to prevent second hip fractures, elderly patients should be provided with physical and medical therapy as well as orthotic support and their functional activity should be maintained.

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.