Best of Both Worlds? Fixation of Distal Femur Fractures with the Nail-Plate Construct.

OBJECTIVES: Distal femoral fractures are a significant injury sustained by low- and high-energy trauma. Common treatment practices are lateral locking plate or intramedullary nail fixation, with disadvantages including risk of non and malunion and limited post-operative weightbearing status. Combining both techniques as a nail-plate construct (NPC) theoretically achieves enhanced fixation to allow immediate weightbearing. The aim of this study is to examine radiographic union, malunion and patient-reported outcomes in distal femur NPC fixation. METHODS: Single-center retrospective study including all patients >18 years who sustained distal femur fractures treated with NPC. Primary outcomes were radiographic union, malunion and patient reported outcome measures at minimum 1-year follow-up. Secondary outcome measures included post-operative mobility, length of stay and complications. Relevant variables of normality are reported as mean with standard deviation. Subgroup analysis of patients aged <65 and ≥65 years are provided. RESULTS: Sixteen patients were included in the study. Rate of radiographic union was 100%. There was no case of malunion. All patients were allowed to bear full weight immediately post-operatively. Mean length of stay was 9.50 days, with 37.5% of patients discharged directly home. The majority (85.7%) of patients returned to pre-injury mobility. Early post-operative complications occurred in three patients. Three patients returned to theater. The mean EQ-5D-5L index value was 0.713, with 71.4% describing no problems with self-care and 85.7% reporting no or slight problems with usual daily activities. CONCLUSION: The NPC provided stable fixation permitting full weightbearing post-operatively with no cases of non or malunion. Return to pre-injury mobility and activity are encouraging. Based on these results we support the use of nail-plate construct fixation in the management of distal femur fractures.

Biomechanical Performance of Total Wrist Arthrodesis Plates With and Without Arthrodesis of the Carpometacarpal Joint.

BACKGROUND: It is unknown whether total wrist arthrodesis (TWA) should be performed with or without arthrodesis of the carpometacarpal joint (CMCJ). The aim of this study is to compare CMCJ-spanning TWA plates using 3D printed wrist arthrodesis model with and without arthrodesis of the CMCJ. METHODS: Total wrist arthrodesis plates mounted to 3D printed models were tested under a 4-N bending load at 4 Hz for 50 000 cycles, increased by 15% every 10 000 cycles until failure. RESULTS: Plates with arthrodesis CMCJ were stiffer and failed at a significantly greater load and number of cycles than plates mounted to models without CMCJ arthrodesis. The Synthes stainless steel locking TWA plate performed better than the Trimed plate applied to the model without CMCJ arthrodesis and the Acumed plate applied to the model with CMCJ arthrodesis. Based on these findings, we recommend arthrodesis of the CMCJ in TWA. CONCLUSIONS: Incorporation of the CMCJ in TWA may protect against plate failure. If arthrodesis of the CMCJ is not performed, plate removal should be considered before breakage occurs. LEVEL OF EVIDENCE: IV.

Plating vs Closed Reduction for Fractures in the Distal Radius in Older Patients: A Secondary Analysis of a Randomized Clinical Trial.

Importance: Distal radius fractures are common and are managed with or without surgery. Current evidence indicates surgical treatment is not superior to nonsurgical treatment at 12 months. Objective: Does surgical treatment for displaced distal radius fractures in patients 60 years or older provide better patient-reported wrist pain and function outcomes than nonsurgical treatment at 24 months? Design, Setting, and Participants: In this secondary analysis of a combined multicenter randomized clinical trial (RCT) and a parallel observational study, 300 patients were screened from 19 centers in Australia and New Zealand. Of these, 166 participants were randomized to surgical or nonsurgical treatment. Participants who declined randomization (n = 134) were included in the parallel observational group with the same treatment options and follow-up. Participants were followed up at 3, 12, and 24 months by a blinded assessor. The 24-month outcomes are reported herein. Data were collected from December 1, 2016, to December 31, 2020, and analyzed from February 4 to October 21, 2021. Interventions: Surgical treatment consisting of open reduction and internal fixation using a volar-locking plate (VLP group) and nonsurgical treatment consisting of closed reduction and cast immobilization (CR group). Main Outcomes and Measures: The primary outcome was patient-reported function using the Patient-Rated Wrist Evaluation (PRWE) questionnaire. Secondary outcomes included health-related quality of life, wrist pain, patient-reported treatment success, patient-rated bother with appearance, and posttreatment complications. Results: Among the 166 randomized and 134 observational participants (300 participants; mean [SD] age, 71.2 [7.5] years; 269 women [89.7%]), 151 (91.0%) randomized and 118 (88.1%) observational participants were followed up at 24 months. In the RCT, no clinically important difference occurred in mean PRWE scores at 24 months (13.6 [95% CI, 9.1-18.1] points for VLP fixation vs 15.8 [95% CI, 11.3-20.2] points for CR; mean difference, 2.1 [95% CI, -4.2 to 8.5]; P = .50). There were no between-group differences in all other outcomes except for patient-reported treatment success, which favored VLP fixation (33 of 74 [44.6%] in the CR group vs 54 of 72 [75.0%] in the VLP fixation group reported very successful treatment; P = .002). Rates of posttreatment complications were generally low and similar between treatment groups, including deep infection (1 of 76 [1.3%] in the CR group vs 0 of 75 in the VLP fixation group) and complex regional pain syndrome (2 of 76 [2.6%] in the CR group vs 1 of 75 [1.3%] in the VLP fixation group). The 24-month trial outcomes were consistent with 12-month outcomes and with outcomes from the observational group. Conclusions and Relevance: Consistent with previous reports, these findings suggest that VLP fixation may not be superior to CR for displaced distal radius fractures for patient-rated wrist function in persons 60 years or older during a 2-year period. Significantly higher patient-reported treatment success at 2 years in the VLP group may be attributable to other treatment outcomes not captured in this study. Trial Registration: ANZCTR.org Identifier: ACTRN12616000969460.

Increased orthopaedic presentations as a result of COVID-19-related social restrictions in a regional setting, despite local and global trends.

BACKGROUND: The coronavirus (COVID-19) pandemic has affected the utilisation of emergency department (ED) services worldwide. The aim of this study was to assess the impact of COVID-19-related public health measures on orthopaedic presentations to a regional Australian hospital. METHODS: A case-control study was performed at a regional trauma hospital in New South Wales (NSW), Australia. Data was collected prospectively from patients that required orthopaedic review in the period corresponding to a declaration of a global pandemic to the end of the NSW lockdown, and compared with retrospective data from the corresponding period in 2019. The five-year average of orthopaedic presentations to ED during the study period were obtained for comparison. The primary outcomes were overall number of presentations, mechanism and anatomical location of injuries, operative versus non-operative management and disposition. RESULTS: During the study period in 2020, presentations requiring orthopaedic review were significantly more frequent than 2019 (496 vs. 280, p < 0.0001), with more requiring admission in 2020 (p < 0.0001). The absolute number of patients managed operatively was higher (p = 0.0002) and significantly more patients were referred for community follow-up (p < 0.0001). There was a 20% increase of consults in 2020 compared to the average number of referrals during the same period in the previous five years. CONCLUSIONS: Contrary to other published literature, lockdown conditions imposed during the COVID-19 pandemic resulted in a surprising 77% increase in orthopaedic presentations to this regional Australian hospital. These findings can be used to better direct resources, preparation and staff education in the current and for future pandemics.

Surgical Plating vs Closed Reduction for Fractures in the Distal Radius in Older Patients: A Randomized Clinical Trial.

Importance: The burden of injury and costs of wrist fractures are substantial. Surgical treatment became popular without strong supporting evidence. Objective: To assess whether current surgical treatment for displaced distal radius fractures provided better patient-reported wrist pain and function than nonsurgical treatment in patients 60 years and older. Design, Setting, and Participants: In this multicenter randomized clinical trial and parallel observational study, 300 eligible patients were screened from 19 centers in Australia and New Zealand from December 1, 2016, until December 31, 2018. A total of 166 participants were randomized to surgical or nonsurgical treatment and followed up at 3 and 12 months by blinded assessors. Those 134 individuals who declined randomization were included in a parallel observational cohort with the same treatment options and follow-up. The primary analysis was intention to treat; sensitivity analyses included as-treated and per-protocol analyses. Intervention: Surgical treatment was open reduction and internal fixation using a volar-locking plate (VLP). Nonsurgical treatment was closed reduction and cast immobilization (CR). Main Outcomes and Measures: The primary outcome was the Patient-Rated Wrist Evaluation score at 12 months. Secondary outcomes were Disabilities of Arm, Shoulder, and Hand questionnaire score, health-related quality of life, pain, major complications, patient-reported treatment success, bother with appearance, and therapy use. Results: In the 300 study participants (mean [SD] age, 71.2 [7.5] years; 269 [90%] female; 166 [81 VLP and 85 CR] in the randomized clinical trial sample and 134 [32 VLP and 102 CR] in the observational sample), no clinically important between-group difference in 12-month Patient-Rated Wrist Evaluation scores (mean [SD] score of 19.8 [21.1] for VLP and 21.5 [24.3] for CR; mean difference, 1.7 points; 95% CI -5.4 to 8.8) was observed. No clinically important differences were found in quality of life, wrist pain, or bother at 3 and 12 months. No significant difference was found in total complications between groups (12 of 84 [14%] for the CR group vs 6 of 80 [8%] for the VLP group; risk ratio [RR], 0.53; 95% CI, 0.21-1.33). Patient-reported treatment success favored the VLP group at 12 months (very successful or successful: 70 [89%] vs 57 [70%]; RR, 1.26; 95% CI, 1.07-1.48; P = .005). There was greater use of postoperative physical therapy in the VLP group (56 [72%] vs 44 [54%]; RR, 1.32; 95% CI, 1.04-1.69; P = 0.02). Conclusions and Relevance: This randomized clinical trial found no between-group differences in improvement in wrist pain or function at 12 months from VLP fixation over CR for displaced distal radius fractures in older people. Trial Registration: http://anzctr.org.au identifier: ACTRN12616000969460.

Radiation Exposure in Patients with Isolated Limb Trauma: Acceptable or Are We Imaging Too Much?

The aim of our study was to investigate the cumulative effective dose of radiation resulting from medical imaging in orthopaedic patients with isolated extremity trauma. Deidentified radiology records of consecutive patients without age restriction with isolated extremity trauma requiring operative treatment at a regional hospital were reviewed retrospectively over a 1-year period, and the effective dose per patient for each study type of plain film X-ray, computed tomography, and operative fluoroscopy was used to calculate cumulative effective dose. Values were summarised as mean, ± standard deviation, maximum, and proportion with overdose (>20 mSv). The study cohort included 428 patients (193 male and 235 female) with an average age of 44 years (±28). There were 447 procedures performed, i.e., all involved operative fluoroscopy, 116 involved computed tomography, and 397 involved X-ray. The mean cumulative effective dose per patient was 1.96 mSv (±4.98, 45.12). The mean cumulative effective dose for operative fluoroscopy was 0.32 mSv (±0.73, 5.91), for X-ray was 1.12 mSv (±3.6, 39.23) and for computed tomography was 2.22 mSv (±4.13, 20.14). The mean cumulative effective dose of 1.96 mSv falls below the recommended maximum annual exposure of 20 mSv. This study can serve as a guide for informing clinicians and patients of the acceptable radiation risk in the context of isolated extremity trauma.

Safe and rapid implementation of telemedicine fracture clinics: the impact of the COVID-19 pandemic.

BACKGROUND: The coronavirus disease outbreak in December 2019 rapidly spread around the world with profound effects on healthcare systems. In March 2020, all elective surgery and elective outpatient clinics were cancelled in our institution, a regional hospital in Northern New South Wales, Australia. With regard to orthopaedic fracture clinics, a telehealth system was implemented on an emergency basis for patient and staff safety to prevent disease transmission. The aim of our study was to investigate whether rapid implementation of telehealth for orthopaedic fracture clinics resulted in an increase in complications. METHODS: A retrospective cohort study of all patients with orthopaedic fracture clinic appointments at a regional New South Wales hospital between 17 March and 8 May 2020 was undertaken. There were 191 patients, including 390 appointments of which 23.1% were conducted via telehealth, namely by phone call. Complications requiring phone calls to the orthopaedic team, presentations to the emergency department, admission to hospital or return to theatre, were recorded. RESULTS: There was no increase in complications following emergent implementation of telehealth for orthopaedic fracture clinic follow-up in our institution. Patients in the telehealth group were significantly older than those in the clinic group. CONCLUSION: The study demonstrates that application of telehealth fracture clinics in a regional Australian setting can be achieved without increasing complication rates and can be used to formulate a rapid telehealth implementation plan if a similar scenario occurs in the future.

A Combined Randomised and Observational Study of Surgery for Fractures In the distal Radius in the Elderly (CROSSFIRE): a statistical analyses plan.

BACKGROUND: We are performing a combined randomised and observational study comparing internal fixation to non-surgical management for common wrist fractures in older patients. This paper describes the statistical analysis plan. METHODS/DESIGN: A Combined Randomised and Observational Study of Surgery for Fractures In the distal Radius in the Elderly (CROSSFIRE) is a randomised controlled trial comparing two types of usual care for treating wrist fractures in older patients, surgical fixation using volar locking plates and non-surgical treatment using closed reduction and plaster immobilisation. The primary aim of this comparative-effectiveness study is to determine whether surgery is superior to non-surgical treatment with respect to patient-reported wrist function at 12 months post treatment. The secondary outcomes include radiographic outcomes, complication rates and patient-reported outcomes including quality of life, pain, treatment success and cosmesis. Primary analysis will use a two-sample t test and an intention-to-treat analysis using the randomised arm of the study. Statistical analyses will be two-tailed and significance will be determined by p < 0.05. Sensitivity analyses will be conducted to assess for differences in intention-to-treat, per-protocol and as-treated analyses. Sensitivity analyses will also be conducted to assess selection bias by evaluating differences in participants between the randomised and observational study arms, and for bias relating to any missing data. An economic analysis will be conducted separately if surgery is shown to provide superior outcomes to a level of clinical significance. DISCUSSION: This statistical analysis plan describes the analysis of the CROSSFIRE study which aims to provide evidence to aid clinical decision-making in the treatment of distal radius fractures in older patients. TRIAL REGISTRATION: CROSSFIRE was approved by The Hunter New England Human Research Ethics Committee (HNEHREC Reference No: 16/02/17/3.04). Registered on 22 July 2016 with The Australian and New Zealand Clinical Trials Registry (ANZCTR Number; ACTRN12616000969460 ). This manuscript is based on v.11 of the statistical analysis plan. A copy of v.11, signed by the chief investigator and the senior statistician is kept at the administering institution.

Screw placement is everything: Risk factors for loss of reduction with volar locking distal radius plates.

AIM: To determine factors correlated with postoperative radial shortening in patients with distal radius fractures treated with volar locking distal radius plates. METHODS: A total of 250 patients with a distal radius fracture stabilised with volar locking plates between January 2010 and December 2014 were included in a multicentre retrospective cohort study. We measured the distance of the distal locking screws to the joint line immediately postoperatively and then measured radial shortening after six to eight weeks using the change in ulnar variance. RESULTS: Multivariate linear regression analysis showed that there was a significant linear association between the distance of the screws from the joint line and radial shortening. No other patient, injury, or treatment-related characteristic significantly influenced radial shortening in multivariate analysis. CONCLUSION: Distal locking screws should be placed as close as possible to the subchondral joint line to prevent postoperative loss of reduction.

A combined randomised and observational study of surgery for fractures in the distal radius in the elderly (CROSSFIRE)-a study protocol.

Fractures of the distal radius are common and occur in all age groups. The incidence is high in older populations due to osteoporosis and increased falls risk. Considerable practice variation exists in the management of distal radius fractures in older patients ranging from closed reduction with cast immobilisation to open reduction with plate fixation. Plating is currently the most common surgical treatment. While there is evidence showing no significant advantage for some forms of surgical fixation over conservative treatment, and no difference between different surgical techniques, there is a lack of evidence comparing two of the most common treatments used: closed reduction and casting versus plating. Surgical management involves significant costs and risks compared with conservative management. High-level evidence is required to address practice variation, justify costs and to provide the best clinical outcomes for patients. METHODS AND ANALYSIS: This pragmatic, multicentre randomised comparative effectiveness trial aims to determine whether plating leads to better pain and function and is more cost-effective than closed reduction and casting of displaced distal radius fractures in adults aged 60 years and older. The trial will compare the two techniques but will also follow consenting patients who are unwilling to be randomised in a separate, observational cohort. Inclusion of non-randomised patients addresses selection bias, provides practice and outcome insights about standard care, and improves the generalisability of the results from the randomised trial. ETHICS AND DISSEMINATION: CROSSFIRE(Combined Randomised and Observational Study of Surgery for Fractures In the distal Radius in the Elderly) was reviewed and approved by The Hunter New England HREC (HNEHREC Reference No: 16/02/17/3.04). The results of the trial will be published in a peer-reviewed journal and will be disseminated via various forms of media. Results will be incorporated in clinical recommendations and practice guidelines produced by professional bodies. REGISTRATION: CROSSFIRE has been registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR: ACTRN12616000969460).

U-type bilateral sacral fracture with spino-pelvic dissociation caused by epileptic seizure.

Sacral fracture with spino-pelvic  dissociation is a rare and unstable injury caused by high-energy trauma, often with serious haemodynamic and neurological implications. Diagnosis is easily delayed or missed as it is often masked by severe associated injuries. Here, we present an unusual case of spino-pelvic dissociation sustained during a seizure episode in a young epileptic patient on long-term anticonvulsant therapy with previous thoracolumbar spinal arthrodesis. This unique case brings to light the need for clinicians to consider sacral fractures in patients presenting with low back pain with no preceding trauma who otherwise may have risk factors for pathological fractures.

Volar locking distal radius plates show better short-term results than other treatment options: A prospective randomised controlled trial.

AIM: To compare the outcomes of displaced distal radius fractures treated with volar locking plates and with immediate postoperative mobilisation with the outcomes of these fractures treated with modalities that necessitate 6 wk wrist immobilisation. METHODS: A prospective, randomised controlled single-centre trial was conducted with 56 patients who had a displaced radius fracture were randomised to treatment either with a volar locking plate (n = 29), or another treatment modality (n = 27; cast immobilisation with or without wires or external fixator). Outcomes were measured at 12 wk. Functional outcome scores measured were the Patient-Rated Wrist Evaluation (PRWE) Score; Disabilities of the Arm, Shoulder and Hand and activities of daily living (ADLs). Clinical outcomes were wrist range of motion and grip strength. Radiographic parameters were volar inclination and ulnar variance. RESULTS: Patients in the volar locking plate group had significantly better PRWE scores, ADL scores, grip strength and range of extension at three months compared with the control group. All radiological parameters were significantly better in the volar locking plate group at 3 mo. CONCLUSION: The present study suggests that volar locking plates produced significantly better functional and clinical outcomes at 3 mo compared with other treatment modalities. Anatomical reduction was significantly more likely to be preserved in the plating group. Level of evidence: II.

Treatment of distal femur fractures in a regional Australian hospital.

AIM: To review our outcomes and compare the results of the Less Invasive Stabilization System (LISS) to other implants for distal femur fracture management at a regional Australian hospital. METHODS: The LISS is a novel implant for the management of distal femur fractures. It is, however, technically demanding and treatment results have not yet been assessed outside tertiary centres. Twenty-seven patients with 28 distal femur fractures who had been managed surgically at the Mackay Base Hospital from January 2004 to December 2010 were retrospectively enrolled and assessed clinically and radiologically. Outcomes were union, pain, Lysholm score, knee range of motion, and complication rates. RESULTS: Twenty fractures were managed with the LISS and eight fractures were managed with alternative implants. Analysis of the surgical techniques revealed that 11 fractures managed with the LISS were performed according to the recommended principles (LISS-R) and 9 were not (LISS-N). Union occurred in 67.9% of fractures overall: 9/11 (82%) in the LISS-R group vs 5/9 (56%) in the LISS-N group and 5/8 (62.5%) in the alternative implant group. There was no statistically significant difference between pain, Lysholm score, and complication rates between the groups. However, there was a trend towards the LISS-R group having superior outcomes which were clinically significant. There was a statistically significant greater range of median knee flexion in the LISS-R group with compared to the LISS-N group (P = 0.0143) and compared with the alternative implant group (P = 0.0454). CONCLUSION: The trends towards the benefits of the LISS procedure when correctly applied would suggest that not only should the LISS procedure be performed for distal femur fractures, but the correct principle of insertion is important in improving the patient's outcome.

More is not necessarily better. A biomechanical study on distal screw numbers in volar locking distal radius plates.

INTRODUCTION: Currently available volar locking plates for the treatment of distal radius fractures incorporate at least two distal screw rows for fixation of the metaphyseal fragment and have a variable-angle locking mechanism which allows placement of the screws in various directions There is, however no evidence that these plates translate into better outcomes or have superior biomechanical properties to first generation plates, which had a single distal screw row and fixed-angle locking. The aim of our biomechanical study was to compare fixed-angle single-row plates with variable-angle multi-row plates to clarify the optimal number of locking screws. MATERIALS AND METHODS: Five different plate-screw combinations of three different manufacturers were tested, each group consisting of five synthetic fourth generation distal radius bones. An AO type C2 fracture was created and the fractures were plated according to each manufacturer's recommendations. The specimens then underwent cyclic and load-to-failure testing. An optical motion analysis system was used to detect displacement of fragments. RESULTS: No significant differences were detected after cyclic loading as well as after load-to-failure testing, neither in regard to axial deformation, implant rigidity or maximum displacement. The fixed-angle single-row plate showed the highest pre-test rigidity, least increase in post-testing rigidity and highest load-to-failure rigidity and least radial shortening. The radial shortening of plates with two distal screw rows was 3.1 and 4.3 times higher, respectively, than that of the fixed-angle single-row plate. CONCLUSION: The results of our study indicate that two distal screw rows do not add to construct rigidity and resistance against loss of reduction. Well conducted clinical studies based on the findings of biomechanical studies are necessary to determine the optimal number of screws necessary to achieve reproducibly good results in the treatment of distal radius fractures.

Adherence to Canadian C-Spine Rule in a regional hospital: a retrospective study of 406 cases.

INTRODUCTION: Cervical spine radiography may be over-utilised in an emergency department setting. The Canadian C-Spine Rule has been developed to reduce unnecessary radiography. Our aim was to retrospectively determine the proportion of cervical spine radiographs requested through the emergency department for trauma patients that were clinically indicated, according to the Canadian C-Spine Rule. METHODS: This was a cross-sectional survey conducted at a regional centre in Northern Queensland, Australia. All cervical spine radiographs for trauma, performed at the Mackay Base Hospital from 1 January 2009 to the 31 December 2009, were reviewed. The relevant patient charts were audited for evidence of indications for radiography. RESULTS: Of 406 patients in the study, 155 patients (38%) (95% confidence interval 33.3%, 42.7%) had cervical spine imaging performed that was not indicated according to the Canadian C-Spine Rule. None of these patients had a significant cervical spine injury on radiography. CONCLUSION: Applying the Canadian C-Spine Rule would have safely reduced the incidence of cervical spine radiography by 38%. This would also reduce costs, patient morbidity and radiation exposure.

Risk factors for surgical site infection after dermatological surgery.

OBJECTIVES: Surgical site infection (SSI) following minor surgery contributes to patient morbidity and compromises cosmetic outcomes. The purpose of this study was to determine the incidence of and risk factors for SSI after dermatological surgery in general practice. METHODS: A prospective, observational study which assessed infection among 972 patients was conducted in regional north Queensland, Australia. Consecutive patients presenting for minor skin excisions were invited to participate. Wounds were assessed for SSI at the time of removal of sutures. RESULTS: Infection occurred in 85 of the 972 excisions; thus, the overall incidence of infection was 8.7% (95% confidence interval 6.5-11.0). Excisions in the upper (P<0.001) or lower (P<0.001) extremities, excisions of basal cell carcinoma (BCC) (P=0.001) or squamous cell carcinoma (SCC) (P=0.001), and re-excision of skin cancer were found to be independent risk factors for wound infection. The length of the excision (P<0.001) and the patient's status as an ex-smoker (P=0.019) were additional independent risk factors for infection. Diabetes was not found to be an independent risk factor for infection (P=0.891). CONCLUSIONS: Prophylactic antibiotics are probably prescribed excessively or inappropriately for dermatological surgery, and overall we wish to discourage their use. The results of this study may encourage the more judicial use of prophylactic antibiotics by defining high-risk procedures, such as excisions from the extremities, excision of BCC or SCC, and larger excisions, and patients who are at high risk for infection, such as ex-smokers.

Influence of screw diameter and number on reduction loss after plating of distal radius fractures.

BACKGROUND: The current options for plate-screw combinations in volar locking distal radius plates used for the treatment of distal radius fractures are either plates with a single distal screw row or plates with multiple distal screw rows. Additionally, the screws themselves may have either fixed angle locking or polyaxial locking mechanisms. To date, there is no evidence or consensus regarding the optimal plate-screw combination. The aim of this study was to assess the biomechanical behaviour of different plate-screw combinations with respect to total distal screw number, number of distal screw rows and screw projection surface area of the most distal row. METHODS: Biomechanical study to assess six different plating configurations in five different volar locking plate models in a Sawbone distal radius fracture model. The specimens were loaded with 800 Newton loads for 2.000 cycles at 1 Hz. After cyclic loading, load-to-failure testing was performed. RESULTS: With cyclical testing, there was a significant and positive correlation between rigidity and a greater projection area of the most distal screws. Dorsal tilting was significantly more pronounced in plate models with a lesser projection area of the most distal screws and a smaller number of distal screws. With load-to-failure testing, there was a significant increase in rigidity with increasing screw projection area of the most distal row and total number of distal screws. CONCLUSIONS: Additional distal screw rows in volar locking distal radius plates might not add substantially to resistance against loss of reduction in the post-operative period.

Multidirectional volar fixed-angle plating using cancellous locking screws for distal radius fractures--evaluation of three screw configurations in an extra-articular fracture model.

INTRODUCTION: Volar fixed-angle plating is a popular treatment for unstable distal radius fractures. Despite the availability of plating systems for treating distal radius fractures, little is known about the mechanical properties of multidirectional fixed-angle plates. The aim of this study was to compare the primary fixation stability of three possible screw configurations in a distal extra-articular fracture model using a multidirectional fixed-angle plate with metaphyseal cancellous screws distally. MATERIAL AND METHODS: Eighteen Sawbones radii (Sawbones, Sweden, model# 1027) were used to simulate an extra-articular distal radius fracture according to AO/OTA 23 A3. Plates were fixed to the shaft with one non-locking screw in the oval hole and two locking screws as recommended by the manufacturer. Three groups (n = 6) were defined by screw configuration in the distal metaphyseal fragment: Group 1: distal row of screws only; Group 2: 2 rows of screws, parallel insertion; Group 3: 2 rows of screws, proximal screws inserted with 30° of inclination. Specimens underwent mechanical testing under axial compression within the elastic range and load controlled between 20 N and 200 N at a rate of 40 N/s. Axial stiffness and type of construct failure were recorded. RESULTS: There was no difference regarding axial stiffness between the three groups. In every specimen, failure of the Sawbone-implant-construct occurred as plastic bending of the volar titanium plate when the dorsal wedge was closed. DISCUSSION: Considering the limitations of the study, the recommendation to use two rows of screws or to place screws in the proximal metaphyseal row with inclination cannot be supported by our mechanical data.

Volar fixed-angle plating of extra-articular distal radius fractures--a biomechanical analysis comparing threaded screws and smooth pegs.

BACKGROUND: Distal radius fractures represent the most common fractures in adult individuals. Volar fixed-angle plating has become a popular modality for treating unstable distal radius fractures. Most of the plates allow insertion of either threaded locking screws or smooth locking pegs. To date, no biomechanical studies compare locking screws and pegs under axial and torsional loading. METHODS: Ten Sawbones radii were used to simulate an AO/OTA A3 fracture. Volar fixed-angle plates (Aptus Radius 2.5, Medartis, Switzerland) with threaded locking screws (n = 5) or smooth locking pegs (n = 5) were used to fix the distal metaphyseal fragment. Each specimen was tested under axial compression and under torsional load with a servohydraulic testing machine. Qualitative parameters were recorded as well as axial and torsional stiffness, torsion strength, energy absorbed during monotonic loading and energy absorbed in one cycle. RESULTS: Axial stiffness was comparable between both groups (p = 0.818). If smooth pegs were used, a 17% reduction of torsional stiffness (p = 0.017) and a 12% reduction of minimum torque (p = 0.012) were recorded. A 12% reduction of energy absorbed (p = 0.013) during monotonic loading and unloading was recorded if smooth pegs were used. A 34% reduction of energy absorbed in one cycle (p < 0.007) was recorded if threaded screws were used. Sliding of the pegs out of the distal radius metaphyses of the synthetic bones was recorded at a mean torque of 3.80 Nm ± 0.19 Nm. No sliding was recorded if threaded screws were used. CONCLUSIONS: According to the results of this study using Sawbones, volar fixed-angle plates with threaded locking screws alone are mechanically superior to volar fixed-angle plates with smooth locking pegs alone under torsional loading.

Influence of an additional locking screw on fracture reduction after volar fixed-angle plating-introduction of the "protection screw" in an extra-articular distal radius fracture model.

BACKGROUND: Though, volar fixed-angle plating has become increasingly popular to treat distal radius fractures no studies are available comparing the mechanical properties of different screw configurations to fix the plate to the shaft. The aim of the present study was to evaluate the effect of an additional locking screw directly proximal to the fracture site and to assess if such a screw might be protective against secondary loss of reduction after volar fixed-angle plating. METHODS: Ten Sawbones radii were used to simulate an extra-articular distal radius fracture model (AO/OTA 23-A3). In the first group (n = 5), volar fixed-angle plates (Aptus Radius 2.5, Medartis, Switzerland) were fixed to the radius shaft with a single nonlocking cortex screw in the oval hole and with two locking screws in the holes proximal to the long hole (LLNx); in the second group, the plates were fixed identically as in the first group, but an additional locking screw was inserted into the plate-hole distal to the oval hole, proximal to the fracture site (LLNL). After embedding, specimens were tested with a servohydaulic material testing machine under cyclic axial loading with 800 N for 2,000 cycles. Axial stiffness, elastic axial deformation (elastic dorsal tilt angle), and plastic deformation (plastic dorsal tilt angle) were recorded. RESULTS: After 2,000 cycles, stiffness was 761.6 (+/-59.5) N/mm in group LLNx and 628.9 (+/-37.6) N/mm in group LLNL without significant difference. Elastic deformation and elastic tilt angle were 1.05 (+/-0.08) mm and 3.9 (+/-0.3) degree in group LLNx. In group LLNL, elastic deformation and elastic tilt angle were 1.27 (+/-0.08) mm and 4.7 (+/-0.3) degree, respectively. Plastic deformation and plastic tilt angle were significantly higher in group LLNx (p < 0.001). After 2,000 cycles, dorsal tilt angle was 1.9 (+/-0.3) degree in group LLNx and 0.7 (+/-1.0) in group LLNL. CONCLUSION: This study showed the mechanical superiority of volar fixed-angle plates with a "protection screw" in an extra-articular fracture model. Further clinical investigation is needed to verify the results.