Anteroinferior 2.7-mm versus 3.5-mm plating of the clavicle: A biomechanical study

IntroductionLower patient satisfaction and high rates of plate prominence has led to the use of lower profile, smaller plates in the treatment of midshaft clavicle fractures. Specifically regarding the use of 2.7 mm reconstruction plates, there lacks biomechanical comparison to its more robust 3.5 mm counterpart. This study was designed to compare the mechanical properties of anteroinferior plate fixation on a clavicle fracture model using either 2.7 mm or 3.5 mm reconstruction plates.MethodsForty-eight synthetic left clavicles were divided into two groups based on the type of fixation: 3.5 mm or 2.7 mm pelvic reconstruction plate fixed in the anteroinferior position. Fixation was tested on AO/OTA 15B1.3 transverse midshaft fractures. Each specimen underwent the following three mechanical tests: axial compression, torsion, and four-point bending.ResultsSignificant differences were observed in axial (p = 0.016) and torsional (p = 0.00097) stiffness between the two groups. The average bending rigidity (EI) was found to be significantly lower for the 2.7-mm plates as compared to the 3.5-mm plates (p = 0.03). The loading scenarios performed in the mechanical tests did not lead to failure of any implants.ConclusionWhile our results show clear mechanical superiority of 3.5-mm reconstruction plates over 2.7-mm plates, superior results in the clinical setting may not necessarily translate. With exceptional mechanical strength also noted for the 2.7 mm plate, well above the biomechanical properties of an intact clavicle, these results may obviate the need for robust plates in general.     

Non-union in lateral locked plating for distal femoral fractures: A systematic review

IntroductionThis study aims to identify patient and intra-operative factors that contribute to non-union in locked lateral plating for distal femoral fractures.MethodsSystematic searches of English-language articles in Ovid Medline, PubMed, Embase, Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews were undertaken in February 2018 according to the PRISMA guidelines. The search terms were (fracture or fracture*) AND (distal femur or distal femoral) AND (malunion or non-union). Eligible studies published at any time reported non-union rates and compared patient and intraoperative factors in patients who underwent locked lateral plating for traumatic distal femoral fractures. The quality of included papers was assessed using The Journal of Bone and Joint Surgery levels of evidence (Wright et al., 2003), and further appraised using the Downs and Black score (Downs and Black, 1998).ResultsEight studies investigating 1380 distal femoral fractures were found to satisfy the inclusion and exclusion criteria. These studies analysed a variety of patient and intra-operative factors that may contribute to non-union. These include high BMI, open fracture, comminution, fracture infection, stainless steel plate material, shorter working length, open reduction and internal fixation when compared with minimally invasive plate osteosynthesis, high construct rigidity scores and purely locking screw constructs.ConclusionThis review has identified multiple factors which potentially contribute to non-union including stainless steel plate material, high construct rigidity scores and purely locking screw constructs. These findings may reflect that overly rigid plating constructs can contribute to non-union. However, they should be taken in the context of heterogeneity amongst included studies, with further research necessary to support these findings.     

Predictive factors of distal femoral fracture nonunion after lateral locked plating: A retrospective multicenter case-control study of 283 fractures

Introduction

Reported initial success rates after lateral locked plating (LLP) of distal femur fractures have led to more concerning outcomes with reported nonunion rates now ranging from 0 to 21%. Reported factors associated with nonunion include comorbidities such as obesity, age and diabetes. In this study, our goal was to identify patient comorbidities, injury and construct characteristics that are independent predictors of nonunion risk in LLP of distal femur fractures; and to develop a predictive algorithm of nonunion risk, irrespective of institutional criteria for clinical intervention variability.

Patients and methods

A retrospective review of 283 distal femoral fractures in 278 consecutive patients treated with LLP at three Level1 academic trauma centers. Nonunion was liberally defined as need for secondary procedure to manage poor healing based on unrestricted surgeon criteria. Patient demographics (age, gender), comorbidities (obesity, smoking, diabetes, chronic steroid use, dialysis), injury characteristics (AO type, periprosthetic fracture, open fracture, infection), and management factors (institution, reason for intervention, time to intervention, plate length, screw density, and plate material) were obtained for all participants. Multivariable analysis was performed using logistic regression to control for confounding in order to identify independent risk factors for nonunion.

Results

28 of the 283 fractures were treated for nonunion, 13 were referred to us from other institutions. Obesity (BMI > 30), open fracture, occurrence of infection, and use of stainless steel plate were significant independent risk factors (P < 0.01). A predictive algorithm demonstrates that when none of these variables are present (titanium instead of stainless steel) the risk of nonunion requiring intervention is 4%, but increases to 96% with all factors present. When a stainless plate is used, obesity alone carries a risk of 44% while infection alone a risk of 66%. While Chi-square testing suggested no institutional differences in nonunion rates, the time to intervention for nonunion varied inversely with nonunion rates between institutions, indicating varying trends in management approach.

Discussion

Obesity, open fracture, occurrence of infection, and the use of stainless steel are prognostic risk factors of nonunion in distal femoral fractures treated with LLP independent of differing trends in how surgeons intervene in the management of nonunion.     

Comminuted supracondylar femoral fractures: a biomechanical analysis comparing the stability of medial versus lateral plating in axial loading

The aim of this study was to compare the biomechanical properties of medial and lateral plating of a medially comminuted supracondylar femoral fracture. A supracondylar femoral fracture model comparing two fixation methods was tested cyclically in axial loading. One-centimetre supracondylar gap osteotomies were created in six synthetic femurs approximately 6 cm proximal to the knee joint. There were two constructs investigated: group 1 and group 2 were stabilized with an 8-hole LC-DCP, medially and laterally, respectively. Both construct groups were axially loaded. Global displacement (total length), wedge displacement, bending moment and strain were measured. Medial plating showed a significantly decreased displacement, bending moment and strain at the fracture site in axial loading. Medial plating of a comminuted supracondylar femur fracture is more stable than lateral plating.     

Low risk of nonunion with lateral locked plating of distal femoral fractures—A retrospective study of 191 consecutive patients

Introduction

The reported rate of nonunion of distal femoral fractures varies in the literature. Several risk factors for nonunion following lateral locked plating (LLP) have been described. We aimed to study the rate of nonunion, and risk factors thereof, in a Swedish population where fragility fractures are common. A secondary aim was to study risk factors for reoperation for any cause.

A novel technique for approximation of the symphysis pubis in bladder exstrophy without pelvic osteotomy

PURPOSE: We evaluated the outcome of pubic bone approximation and internal fixation using a miniature metal plate and screws without osteotomy in children with bladder exstrophy. MATERIALS AND METHODS: A total of 17 children with bladder exstrophy underwent surgery. Mean patient age was 27 months. Of the patients 15 had a history of 1 or more failed bladder closures with or without osteotomy. All children underwent bladder closure and complete posterior and anterior urethroplasty with bladder neck wrap. Both ureteral orifices were brought together by the Gil-Vernet antireflux procedure. The pubes were brought together with 3 deeply placed 1 mm polyglactin sutures through the bone and fixed by placing a miniature metal plate with 6 to 7 screws. Patients remained in a frog leg bandage for 1 to 3 weeks. The plate was removed during additional surgery. Median followup was 61 months (range 14 to 71). RESULTS: All children had an uneventful postoperative period without any serious complications, except for skin erosion caused by a screw without bone infection in 1 patient, and miniature plate subluxation following cystoscopy for reinsertion of urethral catheter 3 days after initial surgery in 1. Operating time and hospital stay were significantly lower than in children undergoing osteotomy or Bryant's traction. Overall continence rate was 53.8%. CONCLUSIONS: Although the number of patients is low, these results are promising. Pubic bone adaptation with miniature plate fixation without any type of osteotomy or leg traction is safe and less invasive than bilateral osteotomy and postoperative leg traction or plaster.     

Percutaneous screw configuration versus perimeter plating of calcaneus fractures: a cadaver study

BACKGROUND: Percutaneous screw configuration has been used clinically to reduce the high rate of wound complications associated with the extensile approach of standard open reduction and internal plate fixation. The aim of this cadaveric biomechanical study was to compare the strength of the standard perimeter plating with that of the percutaneous screw configuration for a Sanders type-2B calcaneus fracture. MATERIALS AND METHODS: Ten pairs of fresh-frozen cadaveric lower limbs were prepared and osteotomized to create a Sanders type-2B fracture. Of each pair, one specimen underwent open reduction and internal fixation with standard perimeter plating; the other was stabilized with the percutaneous screw configuration. Each foot was compressed axially via the talar dome (1 mm/sec) until failure occurred. Differences in treatment groups were analyzed for significance (p < 0.05) using paired t-tests. RESULTS: Construct stiffness was 158 +/- 85 and 113 +/- 60 N/mm for the plate and percutaneous fixation, respectively (p = 0.18). Failure occurred at an average of 1156 +/- 513 and 1064 +/- 540 N for the plate and percutaneous construct, respectively (p = 0.65). CONCLUSION: The results suggest that open reduction and internal fixation with percutaneous screw configuration for Sanders type-2B calcaneus fractures provides a strength similar to that of perimeter plating. CLINICAL RELEVANCE: Percutaneous screw fixation of calcaneus fractures may provide fracture reduction similar to plate fixation.     

Additional fixation of medial plate over the unstable lateral locked plating of distal femur fractures: A biomechanical study

IntroductionLateral locked plating is a standard treatment option for distal femur fractures. However, the unstable conditions after lateral locked plating are increasing. The objective of this study was to investigate the biomechanical strength of additional medial plate fixation over the unstable lateral locked plating of distal femur fractures.Materials and methodsA distal femur fracture model (AO/OTA 33-A3) was created with osteotomies in the composite femur. Three study groups consisting of 6 specimens each were created for single-side lateral locked plating with 6 distal locking screws (LP-6), single-side lateral locked plating with 4 distal locking screws (LP-4), and additional medial locked plating on LP-4 construct (DP-4). A compressive axial load (10 mm/min) was applied in the failure test. Mode of failure, load to failure, and ultimate displacement were documented.ResultsAll single-side lateral locked plating (LP-4 and LP-6) showed plate bending at the fracture gap, while none of the DP-4 showed plate bending at the fracture gap. Load to failure of DP-4 (mean 5522 N) was 17.1% greater than that of LP-6 (mean 4713.3 N, p < 0.05) and 29.2% greater than that of LP-4 (mean 4273.2 N, p < 0.05). Ultimate displacement of DP-4 (mean 5.6 mm) was significantly lower than that of LP-6 (mean 8.8 mm, p < 0.05) and LP-4 (mean 9.1 mm, p < 0.05).ConclusionsAdditional fixation of medial plate significantly increased the fracture stability in distal femur fractures fixed with the lateral locked plating. Especially in the clinical situations where sufficient stability cannot be provided at the distal segment, the medial plate may be considered as a useful biomechanical solution to obtain adequate stability for fracture healing.     

Comparison of Locked Volar Plating Versus Pinning and External Fixation in the Treatment of Unstable Intraarticular Distal Radius Fractures

INTRODUCTION: We retrospectively compared the outcomes of open reduction and internal fixation (ORIF) with volar locking plate versus standard external fixation and percutaneous pinning in treating similar unstable distal radius fractures with a minimum 2-year follow-up. METHODS: The ORIF group included 41 patients with an average follow-up of 29 months. The external fixation group comprised 14 patients with an average follow-up of 33 months. Average age at presentation was 45 years in the external fixation group and 48 years in the ORIF group. The male/female ratios were 16:25 among the ORIF group and 6:8 in the external fixation group. The two groups were compared for clinical and functional outcomes measured by the disabilities of the arm, shoulder, and hand (DASH) score. Pain scores were similar. Radiographic measurements were also evaluated between groups. RESULTS: Final ranges of motion and grip strengths were similar between the two groups. The mean DASH score of the locked volar plate group was 9 compared to 23 for the external fixation group. Radiographically, volar tilt and radial length were significantly better in the patients treated with ORIF. The ORIF group required less therapy visits. No complications occurred in the locked volar plate group whereas two patients had pin tract infections and one had prolonged finger stiffness in the external fixation group. CONCLUSION: Locked volar plating compares favorably to external fixation and pinning for amenable fracture patterns. Whereas grip and range-of-motion data were similar, DASH scores, frequency of rehabilitation, and some radiographic parameters were superior in patients treated with ORIF.     

Ligamentous contributions to pelvic stability in a rotationally unstable open-book injury: A cadaver study

Introduction

Due to the orientation of the sacroiliac joint (SIJ), as the symphysis widens in an open-book pelvic ring disruption, it should displace inferiorly. The purposes of this study were to reconfirm this inferior displacement and to evaluate the relative contributions of the pubic symphysis (PS), the sacrotuberous/sacrospinous ligament complex (STL/SSL) and the anterior sacroiliac ligament (ASIL) to pelvic ring stability in a rotationally unstable open-book injury.

Methods

For each of 6 cadaver pelves, the right hemipelvis was fixed to a table and the PS was sectioned. Under fluoroscopy, a manual external rotational force was then applied through the unfixed, left ilium. At the point of maximal displacement, a permanent AP image was obtained. With magnification corrected, horizontal (H) and vertical (V) displacements were measured. The pelves were then divided into two groups of three each. In Group 1, the PS release was followed by sectioning of the STL/SSL, and then the ASIL. In Group 2, the PS release was followed by sectioning of the ASIL and then the STL/SSL. The above described technique of manual manipulation and radiographic measurement was repeated after each stage of ligament release.

Results

The displacement after initial PS sectioning was not significantly different when comparing Group 1 to Group 2. In both groups, a significant and progressive increase in displacement was noted when the PS (H and V; p < 0.05) and ASIL (H and V; p < 0.05) were sectioned. However, there was no significant change with SSL/STL sectioning in either group. Vertical displacements were all directed inferiorly.

Conclusions

The PS and ASIL are important in maintaining pelvic ring external rotational stability. However, the SSL/STL has little, if any, effect in this regard. Due to the orientation of the SIJ, external rotation of the hemipelvis, as in open-book injury, will show inferior vertical, as well as horizontal, displacement on the AP radiograph, despite the PSIL being intact.     

Distal radius fractures and the volar lunate facet fragment: Kirschner wire fixation in addition to volar-locked plating

Background

The volar lunate facet fragment of a distal radius fracture may not be stabilized with volar-locked plating alone due to the small size and distal location of the fragment. Identification and stabilization of this small fragment is critical as unstable fixation may result in radiocarpal and radioulnar joint subluxation. The addition of spring wire fixation with volar plating can provide stable internal fixation of this critical fracture fragment.

Methods

A retrospective review (2006–2011) identified nine patients with distal radius fractures with an associated volar lunate facet fragment that were treated with volar-locked plating and spring wire fixation of the volar lunate facet fragment. Radiographic indices, range of motion, grip strength, and postoperative Patient-related wrist evaluation (PRWE) scores were obtained to assess pain and function.

Results

All distal radius fractures healed, and the volar lunate facet fragment reduction was maintained. The mean follow-up was 54 weeks. Mean active range of motion was 46° wrist flexion, 51° wrist extension, 80° pronation, and 68° supination. The mean grip strength was 21 Kg, achieving 66 % of the uninjured limb. The average PRWE score was 17. No patient required removal of hardware or had evidence of tendon irritation.

Conclusions

The addition of spring wire fixation to volar-locked plating provided stable fixation of the volar lunate facet fragment of distal radius fractures without complication. This technique addresses a limitation of volar-locked plating to control the small volar lunate facet fragment in distal radius fractures otherwise amenable to volar plating.

Level of Evidence

A retrospective case series, Level IV.     

Symphyseal internal rod fixation versus standard plate fixation for open book pelvic ring injuries: a biomechanical study

Purpose

This study investigates the biomechanical stability of a novel technique for symphyseal internal rod fixation (SYMFIX) using a multiaxial spinal screw-rod implant that allows for direct reduction and can be performed percutaneously and compares it to standard internal plate fixation of the symphysis.

Methods

Standard plate fixation (PLATE, n = 6) and the SYMFIX (n = 6) were tested on pelvic composite models with a simulated open book injury using a universal testing machine. On a previously described testing setup, 500 consecutive cyclic loadings were applied with sinusoidal resulting forces of 200 N. Displacement under loading was measured using an optoelectronic camera system and construct rigidity was calculated as a function of load and displacement.

Results

The rigidity of the PLATE construct was 122.8 N/mm (95 % CI: 110.7–134.8), rigidity of the SYMFIX construct 119.3 N/mm (95 % CI: 105.8–132.7). Displacement in the symphyseal area was mean 0.007 mm (95 % CI: 0.003–0.012) in the PLATE group and 0.021 mm (95 % CI: 0.011–0.031) in the SYMFIX group. Displacement in the sacroiliac joint area was mean 0.156 mm (95 % CI: 0.051–0.261) in the PLATE group and 0.120 mm (95 % CI: 0.039–0.201) in the SYMFIX group.

Conclusions

In comparison to standard internal plate fixation for the stabilization of open book pelvic ring injuries, symphyseal internal rod fixation using a multiaxial spinal screw-rod implant in vitro shows a similar rigidity and comparable low degrees of displacement.

     

Anteroinferior versus superior plating techniques for displaced midshaft clavicle fractures: A retrospective single centre cohort study from Northern Nigeria

BackgroundClavicle fractures are common injuries accounting for up to 5% of all fractures in adults. Most clavicle fractures heal well with nonoperative treatment, some however, require surgical intervention especially when they are displaced. While plating remains the most popular and most successful method of clavicle fixation; the optimal position of the plate is yet to be agreed upon.PurposesThe purpose of this study was to compare the functional outcomes of displaced clavicle fractures fixed with superior and anteroinferior plating techniques.Patients and methodsThis retrospective cohort study of 69 patients (45 males and 24 females) was carried out between January 2014 and December 2018 at a government orthopaedic hospital in north-western part of Nigeria. The study involved all consecutive patients who sustained a displaced mid-shaft clavicle fracture and had open reduction and internal fixation (ORIF) with either superior plating (SP) or anterior-inferior plating (AIP) and were followed up for at least one year. Data analyzed include: age, sex, laterality, mode of injury, the time from initial injury to surgery, type of plate used, position of the plate, union rate, functional outcome and peri-operative complications.ResultsFourty-two patients had SP and twenty seven patients had AIP. Fourty one (97.6%) patients had fracture union in SP group while all the twenty seven patients (100%) in the AIP group had fracture union. The mean QuickDASH scores was 3.2 ± 4.6 and 3.6 ± 4.7 in AIP and SP groups respectively. There was no significant difference in the union rates and functional outcome between the two groups.ConclusionBoth superior and anteroinferior plating techniques are safe and effective in the surgical management of displaced mid-clavicle fractures.Level of evidenceLevel 3, retrospective cohort study.     

Mono- versus polyaxial locking plates in distal femur fractures: a prospective randomized multicentre clinical trial

Purpose

Treatment of complex fractures of the distal femur utilizing monoaxial locking plates (e.g. Less Invasive Stabilisation System, LISS®, Synthes) is considered to be superior to conventional plating systems. Due to the limitation that the thread forces the screw into pre-determined positions, modifications have been made to allow screw positioning within a range of 30° (Non Contact Bridging, NCB®-DF, Zimmer). For the first time, this multicenter prospective randomized clinical trial (RCT) investigates the outcome of LISS® vs. NCB®-DF treatment following complex fractures of the distal femur.

Methods

Since June 2008, 27 patients with a fracture of the distal femur (AO ASIF 33-A-C and periprosthetic fractures) were enrolled in this study by four university trauma centres in southern Germany. Clinical (e.g. range of motion, Oxford knee score, Tegner score) and radiological (e.g. axis deviation, secondary loss of realignment) follow-ups were conducted one and six weeks, as well as three, six, and 12 months after the operation.

Results

This study comprises data of 27 patients (8 male, 19 female; 15 NCB®-DF, 12 LISS®). Polyaxial osteosynthesis using the NCB® system tended to result in better functional knee scores and a higher range of motion. Interestingly, fracture union tended to be more rapid using the polyaxial plating system.

Conclusions

We present the analysis of a multicenter prospective RCT to compare the monoaxial LISS® vs. the polyaxial NCB®-DF treatment following complex fractures of the distal femur. NCB®-DF treatment tended to result in better functional and radiological outcomes than LISS® treatment.

Level of Evidence

Level I     

The Outcome and Complications of the Locked Plating Management for the Periprosthetic Distal Femur Fractures after a Total Knee Arthroplasty

Background

The osteosynthesis of the periprosthetic fractures following a total knee arthroplasty (TKA) can be technically difficult with the relatively small satisfactory outcomes and the high complication rates. The purpose of the study is to analyze the mid-term radiological and functional outcomes following the locked plating of the distal femur periprosthetic fractures after a TKA.

Methods

Records of 20 patients with a periprosthetic distal femur fracture following TKA treated by the locked plate osteosynthesis were retrospectively evaluated. The union rate, complications and functional outcome measures were analyzed.

Results

Successful union was achieved in 18 of the 19 patients available for the follow-up. The mean follow-up was 39 ± 10 months. Significant reductions (p < 0.05) in the range of motion and Western Ontario and McMaster Universities Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores were evident in the follow-up. Secondary procedures were required in 5 patients to address the delay in union and the reduced knee range of motion. The osteosynthesis failed in 1 patient who underwent a revision TKA.

Conclusions

The satisfactory union rates can be achieved with the locked plate osteosynthesis in the periprosthetic distal femur fractures after TKA. Prolonged rehabilitation coupled with the un-modifiable risk factors can decrease the activity and satisfaction levels, which can significantly alter the functional outcome.     

Percutaneous pins versus volar plates for unstable distal radius fractures: a biomechanic study using a cadaver model

PURPOSE: A biomechanic study using a cadaver model of a dorsally unstable distal radius fracture was used to compare the stability of percutaneous pinning and volar fixed-angle plating. Among the many surgical options for treating distal radius fractures are percutaneous pinning and internal plate fixation. Although percutaneous pin fixation requires less soft-tissue trauma and has low complication rates, plate fixation allows for early active movement with good clinical results. The biomechanic stability of these 2 methods was studied by using a cadaver model of a dorsally unstable intra-articular distal radius fracture. METHODS: This study was performed on 7 fresh-frozen cadaver arms, in each of which an unstable intra-articular fracture with dorsal comminution was created. The fracture was first fixed with 0.062-mm K-wires inserted in standard crossed fashion and was tested in a pneumatic loading device that indirectly loaded the wrists through the 5 motor tendons 3 times at each level of force in flexion and extension. Testing was then repeated after removal of the pins and fixation with a fixed-angle DVR distal volar radius plate system (Hand Innovations, Inc., Miami, FL). Testing was performed in flexion up to 68 N and in extension up to 100 N, and the distance across the fracture site was measured. RESULTS: Volar plating was significantly more stable than pinning, with an average movement across the fracture site of 2.51 mm for pin fixation and 1.07 mm for plate fixation. The pins also showed a substantial degree of slipping after repeated stressing, but the plates remained stable. CONCLUSIONS: These results show the superior biomechanic stability of internal fixation using plates for dorsally comminuted intra-articular distal radius fractures in this cadaver model. Further clinical correlations are needed.