The value of fibular fixation in patients with stabilized distal tibia fractures

PURPOSE

There is currently no consensus regarding the need for fixation of concomitant fibula fractures in patients with surgically treated distal tibia fracture. Although studies have shown it to be beneficial for fractures involving the syndesmosis, it remains unclear for suprasyndesmotic fractures. This study evaluates what effect the fixation of such suprasyndesmotic fibula fractures had on patients who underwent fixation of distal tibia fractures.

METHODS

This retrospective cohort study included all consecutive adult patients who received surgical treatment for an extra-articular or simple intraarticular distal tibia fracture between 2012 and 2020 and had a concomitant fibula fracture proximal to the syndesmosis. Two groups were formed depending on whether the fibula was stabilized. The need for revision surgery, the occurrence of complications, fracture healing, rotational and angular malalignment were evaluated for both groups.

RESULTS

This study included 120 patients, of which 40 (33.3%) had operative treatment of the fibula fracture. Of those with stabilized fibula fractures, 28 (70%) were treated with a plate and 12 (30%) with a titanium elastic nail. The group of patients with surgically treated fibula fractures had significantly more angular malalignments (10% vs 1.2%, p = 0.042), while there was no difference regarding rotational malalignment or fracture healing. Further, infections of the fibular surgical site occurred in 15% of surgically treated patients leading to significantly more revision surgeries in this group (40% vs 20%, p = 0.03). All infections occurred when a plate was used.

CONCLUSION

This study was unable to show any benefit from stabilizing concomitant, suprasyndesmotic fibula fractures in surgically treated distal tibia fractures. On the contrary, infection, revision surgery and angular malalignment were more frequent when the fibula was fixed. Therefore, such concomitant fibula fractures should not routinely be fixed and if stabilization is deemed necessary, the implant should be chosen carefully.

Fibula fractures management

Isolated distal fibula fractures represent the majority of ankle fractures. These fractures are often the result of a low-energy trauma with external rotation and supination mechanism. Diagnosis is based on clinical signs and radiographic exam. Stress X-rays have a role in detecting associated mortise instability. Management depends on fracture type, displacement and associated ankle instability. For simple, minimally displaced fractures without ankle instability, conservative treatment leads to excellent results. Conservative treatment must also be considered in overaged unhealthy patients, even in unstable fractures. Surgical treatment is indicated when fracture or ankle instability are present, with several techniques described. Outcome is excellent in most cases. Complications regarding wound healing are frequent, especially with plate fixation, whereas other complications are uncommon.

Minimally invasive plate osteosynthesis (MIPO) versus open reduction and internal fixation (ORIF) in the treatment of distal fibula Danis-Weber types B and C fractures

Background

Minimally invasive plate osteosynthesis (MIPO) has been reported to be superior to open reduction and internal fixation (ORIF) in the treatment of different long bone fractures. Nevertheless, in distal fibula fractures, the evidence of MIPO remains scarce. The aim of this retrospective study was to compare the clinical and radiological outcomes of the minimally invasive techniques applied to the distal fibula with open reduction and internal fixation within a 12 months follow-up.

Methods

A consecutive series of patients who underwent surgery using either ORIF or MIPO for the treatment of distal fibula fractures between 2010 and 2014 were retrospectively analyzed. All distal fibular fractures requiring an operative treatment (Danis-Weber type B ≙ AO type 44 B1, 2, 3 and Danis-Weber type C ≙ AO type 44 C1, 2) were included (ORIF n = 35, MIPO n = 35). Patients were assessed for postoperative pain using a visual analog scale (VAS) for pain (ranging from 0 to 10) and classified into 4 groups: “no pain” for VAS = 0, “low” for VAS = 1–3, “moderate” for VAS = 3–5, and “severe” for VAS = 5–10. In addition, complications of postoperative fracture-related infection, wound healing disorders, vascular and nerve injury and development of nonunion were evaluated and analyzed. Radiologic outcome measures assessing the talocrural angle, lateral and medial clear space, tibiofibular overlap, and talar tilt angle were evaluated postoperatively.

Results

The overall complication rate showed to be lower in the MIPO group compared to the ORIF group (14% vs. 37%, p = 0.029). Even though not statistically significant, specific surgery-related complications such as skin necrosis (3% vs. 9%, p = 0.275), nonunion (0% vs. 6%, p = 0.139), infections and wound healing disorders (9% vs. 20%, p = 0.141), as well as postoperative pain (17% vs. 26%, p = 0.5) were found more frequently in the ORIF group. The tibiofibular overlap demonstrated to be significantly lower in the ORIF group (3.3 mm vs. 2.7 mm, p = 0.033). The talocrural angle, talar tilt angle, and lateral and medial clear space showed to be equivalent in both groups.

Conclusion

In this retrospective single-center consecutive series, MIPO was superior to ORIF in the surgical treatment of distal fibula fractures with respect to the overall complication rate.

Trial registration

EKNZ Project-ID: 2019-02310, registered on the 20th of December 2019 with swissethics

Treating AO/OTA 44B lateral malleolar fracture in patients over 50 years of age: periarticular locking plate versus non-locking plate

Background

The role of locking plate in lateral malleolar fracture fixation for the elderly remains unclear. The aim of our study is to compare radiological and functional outcomes in older patients (> 50 years) with AO/OTA 44B lateral malleolar fractures after locking plate (PLP) or one-third non-locking tubular plate (TP) lateral fixation.

Methods

We retrospectively reviewed the medical records of 72 patients (PLP group, 34 patients; TP group, 38 patients; mean age, 61.9 ± 7.6 years; range, 51–80 years; follow-up, 1 year). Patients with open fractures, syndesmosis injuries, and a previous ankle trauma or surgery were excluded. Demographic data, union rate, complications, radiographic outcomes, visual analog scale (VAS) scores, and foot and ankle outcome scores (FAOSs) between the groups were recorded and compared. We also investigated the association of clinical features with pain and function. Statistically, the Fisher’s exact test was used for categorical variables and the Mann-Whitney U test for the continuous variables. The final model for the multiple regression analysis was used to predict factors related to functional outcomes.

Results

There were no significant between-group differences in demographic data, complication rates, immediately postoperative distal fibula lengths, ankle osteoarthritis (OA) grades, talar tilt angles (TTAs) ≥ 2°, or reduction accuracy. All fractures achieved union. The PLP group had significantly lower rates of distal screw loosening, fibula shortening > 2 mm, OA grade progression, and TTAs ≥ 2°, and better FAOSs and VAS scores than was the case for the TP group after 1 year of follow-up (all p < 0.05). The severity of OA, TTA ≥ 2°, and distal screw loosening were positively associated with VAS scores, and negatively associated with FAOSs.

Conclusions

When treating AO/OTA 44B fractures in patients over 50 years of age, PLPs provided better VAS scores, FAOSs, and radiological outcomes, including less fibula shortening > 2 mm, less osteoarthritic (OA) ankle progression, less implant removal rate, and fewer TTAs ≥ 2° than was the case for TPs after a 1-year follow-up.

Level of evidence

Therapeutic level III

Nailing the fibula: alternative or standard treatment for lateral malleolar fracture fixation? A broken paradigm

PURPOSE

Despite the fact that open reduction and internal fixation with a plate, either non-locked or locked, is the standard of care for managing lateral malleolus fractures, intramedullary (IM) fixation of the fibula has been recently introduced as an alternative, mainly for some potential complicated situations. We hypothesized that almost all patterns of distal fibula fracture can be safely fixed with an IM device, with the potential benefit of providing biomechanical efficiency, but using a soft-tissue friendly implant. Here, we present a multicenter case series based on a proposed algorithm.

PATIENTS AND METHODS

Sixty-nine consecutive patients were managed with fibular IM fixation for closed malleolar fractures. Twenty patients were managed by IM screw fixation and 49 by fibular nailing. Outcome was measured both according to the American Orthopaedic Foot and Ankle Society (AOFAS) score for ankle and hindfoot, and the time to bone union.

RESULTS

The mean AOFAS for Group I was 99.35 ± 1.95 points and that for Group II was 89.30 ± 16.98 points. There were no significant differences between the fracture pattern, according to the Lauge-Hansen classification, and post-operative levels of pain and functional activity among patients in both groups (p > 0.05). All fractures healed uneventfully in both groups. The mean time to union for Group I was 8.15 weeks and for Group II was 8.25 weeks (p > 0.05).

CONCLUSION

In this multicenter case series, intramedullary fixation for the lateral malleolus fracture presented itself as a viable and safe option for the treatment of almost all patterns of fibula fracture in adults. Overall, we were able to demonstrate the potential indications of the proposed algorithm for the choice of IM implant for the lateral malleolus fracture in terms of the Lauge-Hansen staged classification.

Safety and efficacy of surgical fixation of fibula fractures using an intramedullary nail: a retrospective observational cohort study in 30 patients

Background

Open reduction and internal fixation remains the standard treatment for displaced unstable ankle fractures. Plate fixation represents the most frequently used instrumentation option in fibula fractures and favourable outcomes have been reported. Recently, intramedullary nailing techniques have been suggested as a viable alternative resulting in less soft tissue disruption. The objectives of this study are to describe the surgical technique and to evaluate the safety and efficacy of using an intramedullary nail in patients undergoing surgical fixation of their fibula fracture.

Methods

A total of 30 skeletally mature patients with unstable ankle fracture who underwent intramedullary fixation of their fibula fractures from February 2016 to July 2017 were included in this retrospective study. Patients were evaluated using the Short Form-36 (SF-36) and the American Orthopaedic Foot and Ankle Society (AOFAS) at 18 months after surgery.

Results

All patients went on to fracture union. Two patients required a secondary surgical procedure. No patient included in this series developed any wound complications. The mean Physical Component Summary (PCS) of the SF-36 was 53.90 ± 13.3 and the mean Mental Component Summary Score (MCS) was 52.63 ± 11.12. The AOFAS subscale scores were 34.67 ± 1.03 for pain, 42.40 ± 0.2997 for function and 9.50 ± 0.2785 for alignment.

Conclusions

Our study demonstrates promising outcomes associated with intramedullary nail fixation of unstable fibula fractures. We recommend intramedullary nail fixation of fibula fractures to be a safe procedure with a low complication rate.

Level of evidence

Level 4 retrospective case series.

Ankle torque-related fractures and its echo-fast diagnosis protocol

Ankle torque is the most frequent injury mechanism encountered in traumatology. It usually develops as an ankle sprain, and often produces an ankle fracture. Signs and symptoms are very unspecific on the differential diagnosis, and conventional radiographs must be obtained to confirm it. This study compares ultrasound and standard X-ray images values found in ankle sprain-related fracture diagnoses. A 3-month prospective study was carried out on 52 patients with ankle torque. First, an ultrasound diagnosis was made by the first researcher at their arrival to the emergency department, usually consisting of a longitudinal section of the fibula, tibia, and V metatarsal. Then, a blinded independent investigator carried out the usual diagnosis protocol using traditional radiographs. When the required number was obtained, a third independent investigator evaluated the results. A Chi-squared test was used to contrast the outcomes between sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) comparing a non-inferiority hypothesis of our protocol against standard X-ray images screening. Echography showed to be at least as good as standard radiographs on the screening of ankle torque-related fractures (p = 0.02). In our series of patients, nearly 8% of fractures are misdiagnosed with plain radiographies, which concurs with the lower limit found in the bibliography. All the false negatives on radiographs were true positives in the first ultrasound assessment. The average time for the ultrasound protocol was 42 s. An ultrasound is at least as effective as conventional X-ray images when used in diagnosing ankle sprain-related fractures, regardless of age or sex and could in fact be better. The use of echography could reduce the number of radiographies performed when diagnosing these kinds of fractures, thereby reducing the amount of radiation exposure and expediting the diagnostic process as well as the "in situ diagnosis".Level of clinical evidence 2 [prospective cohort (N > 30 patients) study].

Non-ossifying fibroma with a pathologic fracture in a 12-year-old girl with tricho-rhino-phalangeal syndrome: a case report

Background

Tricho-rhino-phalangeal syndrome (TRPS) is a rare autosomal dominant genetic disorder characterized by distinctive craniofacial and skeletal abnormalities, while non-ossifying fibroma (NOF) is a common benign bone tumour in children and adolescents. To date, no case of TRPS coexisting with NOF has been reported. This report presents a 12-year-old girl who had the characteristic features of tricho-rhino-phalangeal syndrome and non-ossifying fibroma with a fibula fracture.

Case presentation

A 12-year-old girl was admitted to the Department of Endocrinology and Diabetes for evaluation of brachydactyly and a right fibula fracture. Clinical examination revealed sparse scalp hair, a characteristic bulbous pear-shaped nose, and brachydactyly with significant shortening of the fourth metatarsal. Neither intellectual disability nor multiple exostoses were observed. Radiography of both hands showed brachydactyly and cone-shaped epiphyses of the middle phalanges of the digits of both hands with deviation of the phalangeal axis. Genetic analysis of TRPS1 identified a heterozygous germline sequence variant (p.Ala932Thr) in exon 6 in the girl and her father. Approximately 1 month before being admitted to our department, the girl experienced a minor fall and suffered a fracture of the proximal fibula in the right lower limb. The pathological cytological diagnosis of the osteolytic lesion was NOF. Ten months following the surgery, the lesion on the proximal fibula of the girl disappeared.

Conclusions

In conclusion, the present study is the first to report a rare case of NOF with a pathologic fracture in the fibula of a girl with TRPS. The identification of a missense mutation, (p.Ala932Thr), in exon 6 of TRPS1 in this kindred further suggested that the patient had type I TRPS and indicated that mutations in this exon may be correlated with more pronounced features of the syndrome. Radiological techniques and genetic analysis played key roles in the definitive diagnosis.

Electronic supplementary material

The online version of this article (10.1186/s12881-018-0732-4) contains supplementary material, which is available to authorized users.

Screw distraction technique for gaining fibular length

Shortening of fibular length is most commonly secondary to fracture, especially in cases of malreduction, malunion or nonunion. In the presence of deltoid ligament incompetence, a shortened fibula causes lateral talar shift, widening of the mortise, decreased tibiotalar contact area and increased incidence of post-traumatic arthrosis. Restoring fibular length is important for normal anatomic relationships and kinematics of the ankle joint. While several techniques have been described for restoring length, some limitations exist. We describe an alternative surgical technique that is straightforward and reproducible that allows for restoration of fibular length and rotation.

Ipsilateral stress fracture of the proximal fibula after total knee arthroplasty in a patient with severe valgus knee deformity on a background of Rheumatoid arthritis

•

Stress fracture of the fibula after TKA is extremely rare.

•

A severe valgus knee can be associated with a fibular stress fracture.

•

Fibular fracture after a TKA has a risk of joint instability or aseptic loosening.

•

Watchful waiting and close clinico-radiographic observation is essential in the follow-up of all post-operative TKA patients, especially those whom have had a TKA for a significant valgus knee deformity correction, as in this case.

Introduction

Previous studies have reported a lower extremity stress fracture after total knee arthroplasty (TKA). However, a fibular fracture after TKA is quite rare. We report a case of proximal fibula fracture after TKA in a patient with rheumatoid arthritis (RA).

Presentation of case

A 45 year old woman with RA had severe knee and foot pain with an antalgic gait disturbance. There was a significant joint deformity in many of lower limb joints. Interval bilateral TKAs were performed two weeks apart. Right TKA was performed using a constraint-type prosthesis, through lateral parapatellar approach. Left TKA was performed using a posterior-stabilized (PS) prosthesis through the more commonly employed, medial parapatellar approach. Seven weeks after the right TKA, the patient was found to have an atraumatic proximal fibular fracture. The fracture went on to heal conservatively.

Discussion

The fracture was considered to have occurred after the TKA. The callus appeared eleven weeks after the TKA. The factors that contributed to the fracture were thought to be overload of the fragile bone secondarily to disuse osteopaenia, RA or potentially the significant valgus malalignment correction. The surgical approach, the implant or implantation or the persisting joint deformity, were thought to be contributing factors to the aetiology of the stress fracture. The resultant change in clinical outcome/course is outlined in this case report.

Conclusion

A stress fracture of the proximal fibula has the potential in the aetiology of may cause other stress fractures, joint other instability, and/or malalignment of the total lower extremity.

An intact fibula may contribute to allow early weight bearing in surgically treated tibial plateau fractures

PURPOSE

The role of the proximal tibiofibular joint (PTFJ) in tibial plateau fractures is unknown. The purpose of this study was to assess, with finite-element (FE) calculations, differences in interfragmentary movement (IFM) in a split fracture of lateral tibial plateau, with and without intact fibula. It was hypothesized that an intact fibula could positively contribute to the mechanical stabilization of surgically reduced lateral tibial plateau fractures.

METHODS

A split fracture of the lateral tibial plateau was recreated in an FE model of a human tibia. A three-dimensional FE model geometry of a human femur-tibia system was obtained from the VAKHUM project database, and was built from CT images from a subject with normal bone morphologies and normal alignment. The mesh of the tibia was reconverted into a geometry of NURBS surfaces. The fracture was reproduced using geometrical data from patient radiographs, and two models were created: one with intact fibula and other without fibula. A locking screw plate and cannulated screw systems were modelled to virtually reduce the fracture, and 80 kg static body weight was simulated.

RESULTS

Under mechanical loads, the maximum interfragmentary movement achieved with the fibula was about 30% lower than without fibula, with both the cannulated screws and the locking plate. When the locking plate model was loaded, intact fibula contributed to lateromedial forces on the fractured fragments, which would be clinically translated into increased normal compression forces in the fractured plane. The intact fibula also reduced the mediolateral forces with the cannulated screws, contributing to stability of the construct.

CONCLUSION

This FE model showed that an intact fibula contributes to the mechanical stability of the lateral tibial plateau. In combination with a locking plate fixation, early weight bearing may be allowed without significant IFM, contributing to an early clinical and functional recovery of the patient.

The Role of Fibular Fixation in the Treatment of Combined Distal Tibia and Fibula Fracture: A Randomized, Control Trial

Background:

This randomized, parallel-group, non-blinded study was designed to determine the role of fibular fixation in the treatment outcomes of combined distal tibia and fibula fractures.

Materials and Methods:

Sixty patients with distal tibial and fibular fractures were randomly divided in two groups of case and controls. In the case group, fibula was fixed prior to the fixation of tibia. In the control group, tibia was fixed without fibular fixation. Primary outcomes were varus–valgus angulation, anterior–posterior angulation, union and side effects. Follow-up visit and radiographs were taken 2 and 4 weeks as well as 3, 6 and 9 months after surgery.

Results:

During the follow-up, 11 out of 60 patients in case and control groups were excluded. We recruited 24 and 25 patients in the case and control group, respectively. Intramedullary nailing was used in 8 patients of case and 11 patients of control group. Plate and screw were used in 16 patients in the case and 14 patients in the control group. Varus/valgus and anterior–posterior angulation were not statistically significant between two groups (P ≥ 0.05). The frequency of tibial and fibula union after 1, 3, 6 and 9 months in case and controls groups were not statistically significant (P ≥ 0.05). The frequency of nonunion of tibia and fibula, infection and nerve injury in studied groups were not statistically significant (P ≥ 0.05).

Conclusion:

We did not observe any significant improvement using fibular fixation in the treatment outcomes of tibia distal fractures.

Antiglide versus lateral plate fixation for Danis-Weber type B malleolar fractures caused by supination-external rotation injury

PURPOSE

The purpose of this study was to evaluate functional results and the frequency of complications in the distal fibula Danis-Weber type B fractures caused by supination-external rotation injury in a group of lateral and antiglide plate fixation.

METHODS

This prospective study evaluated 44 patients with a minimum of one-year follow-up. Patients were divided into two groups: one lateral plate group (24 patients) and group with an antiglide plate (20 patients). The patients of both groups were always positioned supine, and lateral approach was used. In the lateral plate group, the fracture was anatomically reduced, an optional anteroposterior lag screw was placed perpendicular to fracture line, and then the one-third tubular plate was applied on the lateral fibular site. In the antiglide group, the palate was implemented on the posterolateral surface of the fibula and the fracture was anatomically reduced. An optional lag-screw was used. Distal screw fixation was applied deliberately. Functional assessment according to the American Orthopaedic Foot and Ankle Society hind foot-ankle score (AOFAS) were performed at one year after surgery. The complications were recorded.

RESULTS

According to Lauge-Hansen classification of supination-external rotation injury, a total of 27 (61.4%) patients was classified as stage 2, 2 (4.5%) patients as stage 3 and 15 (34.1%) patients with stage 4. In the lateral plate group, there were 13 (54.2%) male and 11 (45.8%) female patients. In the antiglide plate group, men comprised 12 (60%) and women 8 (40%) of patients. The AOFAS in the lateral and antiglide group performed one year after surgery was, on average, 93.7 ± 6.1 (range 85-100) and 94.5 ± 6.0 (range 85-100) points respectively. There were no statistically significant differences in both groups (p = 0.37). Complications were observed in 7 (29.3%) patients of lateral plate and 3 (15%) patients of an antiglide plate (p = 0.31). There was no case of tendinopathy. Revision surgery was performed in one patient with superficial infection.

CONCLUSION

In the present study, the outcome of the surgically treated Weber type B fractures caused by supination external rotation injury was comparable in both groups. The antiglide plate fixation showed no signs of peroneal tendinopathy, low rate of complications. We believe this technique is safe and a good method of fixation as well as traditional lateral plating.

[IMPROVED DOUBLE OPERATIVE APPROACHES FOR TREATMENT OF Pilon FRACTURES ACCOMPANIED WITH FIBULA FRACTURES]

OBJECTIVE

To investigate the clinical effect of surgical treatment of Pilon fractures accompanied with fibula fractures with the improved double operative approaches.

METHODS

Between January 2012 and June 2015, 19 patients with closed Pilon fractures accompanied with fibula fractures (Rüedi-Allgöwer type Ⅲ) underwent open reduction and internal fixation with improved anterior-median incision and posterior-lateral incision. There were 13 males and 6 females, aged 35 years on average (range, 23-68 years). Injury was caused by traffic accident in 11 cases, falling from height in 7 cases, and crash injury of heavy object in 1 case. According to AO/OTA classification, there were 4 cases of type C2, and 15 cases of type C3. According to Tscherne-Gotzen classification of soft tissue defect, 6 cases were rated as grade 1 and 13 cases as grade 2. The interval of injury and operation was 6-18 days (mean, 10.3 days). After operation, reduction of Pilon fracture was evaluated by the Burwell-Charnley radiological evaluation criteria, and the ankle joint function was evaluated by the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score.

RESULTS

The operation time was 1.8-4.6 hours (mean, 2.4 hours); the intraoperative blood loss was 200-500 mL (mean, 310 mL). All the 19 patients were followed up for 13.7 months on average (range, 12-18 months). The fracture healing time was 3.6 months on average (range, 2.5-8.0 months). Postoperative complications included anterior-median incision necrosis in 2 cases, traumatic arthritis in 2 cases, and ankle instability in 1 case. According to Burwell-Charnley radiological evaluation criteria, anatomical reduction was obtained in 15 cases and satisfactory reduction in 4 cases. According to AOFAS score, the excellent and good rate was 84.2% (excellent in 11 cases, good in 5 cases, and fair in 3 cases).

CONCLUSIONS

The improved anterior-median incision combined with posterior-lateral incision is a safe and effective method to treat complex Pilon fractures accompanied with fibula fractures, which has the advantages of simple operation, adequate exposure and minimal invasion.

Does a polyaxial-locking system confer benefits for osteosynthesis of the distal fibula: A cadaver study

BACKGROUND

In plate osteosynthesis involving the distal fibula, antiglide plating is superior to lateral plating in terms of the biomechanical properties. The goal of this study was to examine whether polyaxial-locking implants confer additional benefits in terms of biomechanical stability.

METHODS

Seven pairs of human cadaveric fibulae were subjected to osteotomy in a standardized manner to simulate an uncomplicated Weber B fracture. The generated fractures were managed with a dorsolateral antiglide plate. To this end, one fibula of the pair was subjected to non-locking plating and the other to polyaxial-locking plating. Biomechanical tests included quantification of the primary bending and torsional stiffness. In addition, the number of cycles to failure in cyclic bending loading were determined and compared. Bone mineral density was measured in all specimens.

RESULTS

Bone mineral density was comparable in both groups. Primary stability was higher in the polyaxial-locking group under torsional loading, and higher in the non-locking group under bending loading. The differences, however, were not statistically significant. All specimens except for one fixed-angle construct failed the cyclic loading test. The number of cycles to failure did not differ significantly between polyaxial-locking and non-locking fixation.

CONCLUSION

In a cadaveric Weber B fracture model, we observed no differences in biomechanical properties between polyaxial-locking and non-locking fixation using an antiglide plate. Based on the biomechanical considerations, no recommendation can be made regarding the choice of the implant. Further biomechanical and clinical studies are required.

CLINICAL RELEVANCE

Information on the behavior of polyaxial-locking plates is relevant to surgeons performing internal fixation of distal fibula fractures.

Nerve and tendon injury with percutaneous fibular pinning: a cadaveric study

OBJECTIVE

The purposes of this study were to measure the average distance from a percutaneous pin in each quadrant of the distal fibula to the sural nerve and nearest peroneal tendon, and define the safe zone for percutaneous pin placement as would be used during surgery.

METHOD

Ten fresh-frozen cadavers underwent percutaneous pin fixation into four quadrants of the distal fibula. The sural nerve and peroneal tendon were identified as they coursed around the lateral ankle. Distances from the K-wire in each quadrant to the anatomic structure of interest were measured.

RESULTS

Average distances (mm) from the K-wire to the sural nerve in the anterolateral, anteromedial, posterolateral, and posteromedial quadrants were 19.1±8.9 (range, 5.1-35.5), 12.8±8.2 (range, 0.3-27.8), 12.6±6.8 (range, 3.0-27.8), and 5.9±5.5 (range, 0.1-19.9), respectively. Average distances from the K-wire to the nearest peroneal tendon in the anterolateral, anteromedial, posterolateral, and posteromedial quadrants were 15.7±4.4 (range, 9.5-23.1), 11.9±5.2 (range, 3.2-21.7), 6.3±3.9 (range, 0.1-14.4), and 1.0±1.6 (range, 0-5.6), respectively.

CONCLUSIONS

Percutaneous pinning of distal fibula fractures is a successful treatment option with minimal complications. Our anatomical study found the safe zone of percutaneous pin placement to be in the anterolateral quadrant. The sural nerve can be as close as 5.1mm and the peroneal tendons as near as 15.7mm. In contrast, the posteromedial quadrant was associated with the greatest risk of injury to both the sural nerve and peroneal tendons.

Biomechanical comparison of a lateral polyaxial locking plate with a posterolateral polyaxial locking plate applied to the distal fibula

BACKGROUND

Polyaxial locking plates are becoming popular for the fixation of distal fibula fractures. This study establishes how construct stiffness and plate loosening, measured as range of motion, differs between lateral and posterolateral plate location.

METHODS

Seven matched pairs of cadaver fibulae were osteotomized in standardized fashion to produce a Weber type B distal fibula fracture. The fragments were fixated with an interfragmentary lag screw and polyaxial locking plates, with one fibula in each pair receiving a posterolateral anti-glide-plate, and the other a lateral neutralization-plate. In a biomechanical test, the bending and torsional stiffnesses of the constructs and the ranges of motion (ROM) were measured and subjected to a paired comparison.

RESULTS

The laterally plated group had a higher median (interquartile range) bending stiffness (29.2 (19.7) N/mm) and a smaller range of motion (2.06 (1.99) mm) than the posterolaterally plated group (14.6 (20.6) N/mm, and 4.11 (3.28) mm, respectively); however, the results were not statistically significant (pbending=0.314; pROM=0.325). Similarly, the torsional stiffness did not differ significantly between the two groups (laterally plated: 426 (259) Nmm/°; posterolaterally plated: 248 (399) Nmm/°; ptorsion=0.900). The range of motion measurements between the two groups under torsional loading were also statistically insignificant (laterally plated: 8.88 (6.30) mm; posterolaterally plated: 15.34 (12.64) mm; pROM=0.900).

CONCLUSION

In biomechanical cadaver-model tests of Weber type B fracture fixation with polyaxial locking plates, laterally plated constructs and posterolaterally plated constructs performed without significantly difference. Therefore, other considerations, such as access morbidity, associated injuries, patient anatomy, or surgeon's preference, may guide the choice of plating pattern. Further clinical studies will be needed for the establishment of definitive recommendations.

CLINICAL RELEVANCE

Information on the behavior of polyaxial locking plates is relevant to surgeons performing internal fixation of distal fibula fractures.