Pin Fixation Research Articles

Operative Intervention of Supracondylar Humerus Fractures More Complicated in July: Analysis of the July Effect.

The "July Effect" involves the influx of new interns and residents early in the academic year (July and August), which may have greater potential for poorer patient outcomes. Current orthopaedic literature does not demonstrate the validity of this concept in arthroplasty, spine, hand, and arthroscopy. No study has investigated the possibility of this effect on common pediatric orthopaedic procedures, such as closed reduction and percutaneous pin fixation of supracondylar humerus fractures. A retrospective review of all type II or III supracondylar humerus fractures that underwent primary closed reduction and percutaneous pin fixation (CPT code 24538) at a single pediatric level 1 trauma center from July 2009 to June 2013. Patients were grouped according to time in the academic year: early (July and August) and late (May and June). Demographic data included length of follow-up, age at surgery, sex, side of injury, and Wilkin's modified Gartland classification. Outcomes included length of operation, number of pins used, length of stay, complications, and the need for repeat surgery. There were 245 patients, 101 in the early and 144 in the late group. There was no increase in surgical time [33.32±24.74 (early) vs. 28.63±10.06 (late) min, P=0.07) or complication rates [7.0% (early) vs. 2.1% (late), P=0.06) between the early and the late groups. Cases performed with junior residents demonstrated longer operative (31.72±17.07 vs. 28.96±18.71 min, P=0.02) and fluoroscopy (48.63±30.96 vs. 34.12±27.38 s, P=0.01) times. The academic orthopaedic surgeon must ensure the education of residents, while providing the highest level of safety to patients. Our study shows that education of young residents early in the academic year results in no increase in operative times, radiation exposure, or complications. Level III.

Outcomes Following Operative Treatment of Adolescent Mallet Fractures.

Many surgeons advocate for surgical intervention of adult mallet fractures that involve either subluxation of the distal interphalangeal (DIP) joint or those that involve more than one-third of the articular surface. However, the efficacy of operative treatment and complication rates are unclear regarding the adolescent population. The goal of this study is to evaluate the clinical outcomes following operative fixation of bony mallet fractures in the adolescent population. Seventeen patients with bony mallet fractures treated surgically were retrospectively reviewed. Twelve patients were treated by closed reduction with extension block pinning. The other patients underwent an open reduction and pin fixation. The average age was 15.2years (13-18). Most injuries were sport related. The average time from injury to presentation was 17days and from injury to surgery was 24.5days. Nine patients had subluxation at the DIP joint and all involved at least one-third of the articular surface. The average time from surgery to pin removal was 28days (19-46). All distal phalanx physis were closed or nearly closed. One patient reported pain at the final follow-up. Two patients (11.8%) had major complications. One had an extension contracture postoperatively, did not attend therapy, and re-fractured 5months later requiring reoperation. The second was treated delayed (32days) and lost fixation, requiring revision surgery and antibiotics for a superficial infection. Two patients with delayed treatment (32 and 44days) had an extensor lag (11.8%). Operative treatment of mallet fractures with subluxation or involving more than one-third of the articular surface appears effective. Pin removal 4weeks postoperatively appears adequate. Complications occurred with delayed presentation and non-compliance.

Novel Use of Active Leptospermum Honey for Ringed Fixator Pin Site Care in Diabetic Charcot Deformity Patients.

Open reduction with external fixation (OREF) utilizing fine wire ringed fixators for correction of Charcot deformity has gained popularity over the past decade. Pin site infections are a well-documented complication of external fixation as well as a driver of escalating health care costs. We aimed to demonstrate the safety and efficacy of a novel method of pin site care utilizing active Leptospermum honey-impregnated dressings (MediHoney) in diabetic patients undergoing deformity correction with OREF. Twenty-one diabetic patients with Charcot deformities of the lower extremity were prospectively enrolled and followed for pin site complications following OREF for deformity correction. Active Leptospermum honey dressings were applied at metal-cutaneous interfaces at the end of the OREF procedure and replaced weekly for a total of 8 weeks. Patients were monitored for pin site infections from the time of surgery until external fixator removal. Sixteen consecutive patients receiving standard OREF for Charcot deformities were evaluated retrospectively to serve as a control group. Of the 21 enrolled patients, 19 underwent OREF and followed up throughout the study period. Treated patients had a mean age of 58.5 years and mean body mass index measuring 33.3 kg/m2 as documented prior to surgery. The 15 patients with hemoglobin A1c labs drawn in the 3 months preceding surgery averaged 7.5. Fixators were removed at an average of 12.1 weeks after adequate bony healing. Of the 244 pin sites in 19 patients, 3 pin sites (1.2% of pins) in 2 patients (10.5% of patients) showed evidence of superficial infection. All infections resolved with oral antibiotics. Infection rates were significantly reduced when compared to the standard care control group. Pilot data in a prospectively collected case series demonstrate safety and efficacy of active Leptospermum honey-impregnated dressings when used for fine wire ringed fixator pin site care in diabetic Charcot deformity patients. Further investigation in the form of a prospective randomized controlled study is warranted to demonstrate the potential value of this novel intervention. Level IV.

Unstable fragility fractures of the ankle in the elderly: Transarticular Steinmann pin or external fixation

IntroductionBecause of poor skin conditions and comorbidity, open reduction and internal fixation in ankle fractures is frequently contra-indicated in the elderly. This study reports the results of two temporary fixation types in fragility fractures in the older patient: transarticular Steinmann pin fixation and external fixation. MethodsPatients aged over 60 treated with a Steinmann pin or external fixation were retrospectively included. Patient, fracture and treatment characteristics were collected. ResultsFifteen patients were included. Nine were managed using a Steinmann pin and six by external fixation. All reached fracture consolidation. Patients treated with a Steinmann pin underwent a median of 2 operations and the pin was left in situ for 80 days. Three patients suffered from superficial wound infection. X-ray showed malreduction in 67% and only two patients returned to pre-injury mobility.A median of 2 operations with 32 fixation days was reported in the external fixation group. This group showed one deep infection. In 50% there was malreduction, one patient experienced disability in ambulation at the end of treatment. ConclusionBoth techniques show few complications, but have, as expected, poor results in fracture reduction and functional outcome. External fixation and subsequent internal fixation could result in better functional outcome.

Closed pinning for paediatric supracondylar fractures: does timing really matter?

<p><strong>Background:</strong> Management guidelines and comparative studies are not yet clear for those patients who present early and late with widely displaced supracondyle humerus fracture in children.</p><p><strong>Methods:</strong> A total of 74 children were included in this study, 30 patients presenting early within 24 hours as group 1, and 44 patients who presented late i.e. after 24 hours and within a week as group 2 underwent closed reduction and pinning.<strong></strong></p><p><strong>Results: </strong>In group one 24 had excellent, 6 had good results, according to modified Flynn’s criteria. One patient developed ulnar nerve palsy which was iatrogenic, and improved completely after wire removal. Another was brachial artery injury which was explored and recovered completely. In group 2 the average delay in presentation was 57.56 hours; mean time to surgery after presentation was 9.83 hours. Sixteen patients (36.36%) had neurologic complications at presentation to the emergency room of which three had median nerve palsy (6.81%) whereas seven (15.90%) had isolated anterior interosseous nerve palsy and six (13.6%) had radial nerve palsy all patients showed total neurological recovery at 12 weeks. Six patients (13.63%) had vascular compromise at initial presentation of which five patients had feeble radial pulse and one had absent radial pulse, but capillary filling was adequate in all. The pulse was restored within 24 hours in all patients following reduction. There were 37 excellent, 6 good and 1fair results.</p><p><strong>Conclusions:</strong> Our results support, closed reduction and Percutaneous pin fixation as an effective treatment option for grossly displaced supracondylar fractures presenting early and late but requires good and careful judgment and also technique.</p>

Conceptual design and implantation of an external fixator with improved mobility for knee rehabilitation

A hinged external fixator is used to allow early knee rehabilitation in case of injury or trauma, as an alternative approach to immobilization. It is mainly adopted for the treatment of dislocations, which involve tearing of the ligaments, and it basically consists of two links connected to each other by a revolute joint. Each link is fixed to the femur and tibia via pin fixation, and the revolute joint is approximately aligned to the knee flexion-extension (FE) axis. The advantage in its implantation is to protect ligament reconstruction, while allowing for an aggressive rehabilitation. Traditional fixators only accommodate the functional flexion movement in a limited range, i.e. where the anatomical movement is closer to a planar circular trajectory. This paper presents the conceptual design and implantation procedure of a double-axis fixator, which accommodates both FE and longitudinal internal-external rotation. The procedure is based on accurate knee kinematics measurements and on computer-aided multibody simulations to assist clinicians in the implantation. An experimental test is presented using an artificial knee, and guidelines are given for in vitro studies. The proposed technique may allow for a better understanding of knee kinematics and have the potential advantage to increase the range of motion in postoperative rehabilitation.

Staged minimally invasive plate osteosynthesis of proximal tibial fractures with acute compartment syndrome

PurposeHigh-energy proximal tibial fractures often accompany compartment syndrome and are usually treated by fasciotomy with external fixation followed by secondary plating. However, the initial soft tissue injury may affect bony union, the fasciotomy incision or external fixator pin sites may lead to postoperative wound infections, and the staged procedure itself may adversely affect lower limb function. We assess the results of staged minimally invasive plate osteosynthesis (MIPO) for proximal tibial fractures with acute compartment syndrome. MethodsTwenty-eight patients with proximal tibial fractures accompanied by acute compartment syndrome who underwent staged MIPO and had a minimum of 12 months follow-up were enrolled. According to the AO/OTA classification, 6 were 41-A, 15 were 41-C, 2 were 42-A and 5 were 42-C fractures; this included 6 cases of open fractures. Immediate fasciotomy was performed once compartment syndrome was diagnosed and stabilization of the fracture followed using external fixation. After the soft tissue condition normalized, internal conversion with MIPO was done on an average of 37 days (range, 9–158) after index trauma. At the time of internal conversion, the external fixator pin site grades were 0 in 3 cases, 1 in 12 cases, 2 in 10 cases and 3 in 3 cases, as described by Dahl. Radiographic assessment of bony union and alignment and a functional assessment using the Knee Society Score and American Orthopedic Foot and Ankle Society (AOFAS) score were carried out. ResultsTwenty-six cases achieved primary bony union at an average of 18.5 weeks. Two cases of nonunion healed after autogenous bone grafting. The mean Knee Society Score and the AOFAS score were 95 and 95.3 respectively, at last follow-up. Complications included 1 case of osteomyelitis in a patient with a grade IIIC open fracture and 1 case of malunion caused by delayed MIPO due to poor wound conditions. Duration of external fixation and the external fixator pin site grade were not related to the occurrence of infection. ConclusionsStaged MIPO for proximal tibial fractures with acute compartment syndrome may achieve satisfactory bony union and functional results, while decreasing deep infections and soft tissue complications.

Preventing Seal Leak During Negative Pressure Wound Therapy Near External Fixators: A Technical Tip

Negative pressure wound therapy is an effective tool for the treatment of open wounds. Occasionally these wounds are associated with injuries or procedures that require treatment with an external fixator. This article shows how a simple, inexpensive, and commercially available product can be used to prevent loss of suction around external fixator pins within the negative pressure wound treatment area.

Plate Fixation versus Percutaneous Pinning for Unstable Metacarpal Fractures: A Meta-analysis.

Whether percutaneous pinning or plate fixation is more appropriate for metacarpal fractures is still open to debate. Our study purpose was to review the current literature in an attempt to determine the optimal treatment modality for metacarpal fractures on the basis of functional outcomes, radiographic outcome and rates of complications. We selected Pubmed, Cochrane library, EMBASE and the relevant English orthopedic journals and pooled data from eligible trials including four comparative studies and one retrospective review. Overall, the studies contained 222 patients with 231 fractures, 143 treated with pinning and 88 treated with plates and screws. Mean follow up was 7.5 months (4-12 months). Data were analyzed and the fixed effects are assumed for meta-analysis. Patients undergoing pinning for metacarpal fractures have higher motion scores when compared to open reduction and internal fixation with plate and screws. Functional scores, grip strength, radiographic parameters, time to union and complications were found not to be significantly different between the two groups. There is evidence to support the use of pins over ORIF with plates and screws in the treatment of metacarpal fractures. This may have practical advantages, including minimal dissection, easier insertion and availability of the pins. The limitations of this study include the small number of eligible studies, lack of reporting of standard deviation value, and the lack of DASH score assessments at follow up. Further randomized controlled trials that include a larger patient numbers with longer follow up are needed to substantiate the superiority of one fixation method over another.

A Prospective Cohort Study of the Therapeutic Patterns, Challenges and Outcomes of Paediatric Femoral Fractures in a Cameroonian Tertiary Center.

Background:Knowledge of the therapeutic patterns, challenges and outcomes of treatment of paediatric femoral fractures (PFF) helps to better choose the ideal therapeutic modality which is still controversial. However, this data is scarce in the sub-Saharan African literature.Objective:To determine the therapeutic patterns, treatment challenges and outcomes of treatment of PFF in a tertiary care centre in Cameroon.Method:We conducted a prospective cohort study of all consenting consecutive cases of femoral fractures in patients younger than 16 years managed between 2011 and 2015 at the surgical unit of Yaoundé University Teaching Hospital, Cameroon. We analysed demographic data, injury characteristics, fracture patterns, treatment details, therapeutic challenges and outcomes of treatment at 12 months using Flynn’s criteria.Results:We enrolled 30 femoral fractures from 29 children with mean age was 4.2 ± 3.3 years. The male gender, diaphyseal locations and spiral fracture lines were predominant. Main mechanisms of injury were accidental falls, road traffic accidents and game injuries. Fracture management entailed 12 tractions followed by casting, 10 casting alone, four closed reductions followed by casting, two cannulated screw fixations, one pin fixation and one external fixation. The mean duration of consolidation was 10.3 ± 3.9 weeks. The outcome was rated excellent in 28 cases. Limited resources precluded fluoroscopy use, proper anaesthetic management, early rehabilitation and patient-parent satisfaction.Conclusion:Conservative management of PFF yields a good outcome in our setting. However, an improvement in surgical, radiology and anaesthetic infrastructure is needed for optimal PFF care.

RapidNAM: generative manufacturing approach of nasoalveolar molding devices for presurgical cleft lip and palate treatment.

Nasoalveolar molding (NAM) is an accepted treatment strategy in presurgical cleft therapy. The major drawbacks of the treatment listed in the literature relate to the time of the treatment and the coordination of the required interdisciplinary team of therapists, parents, and patients. To overcome these limitations, we present the automated RapidNAM concept that facilitates the design and manufacturing process of NAM devices, and that allows the virtual modification and subsequent manufacture of the devices in advance, with a growth prediction factor adapted to the patient's natural growth. The RapidNAM concept involves (i) the prediction of three trajectories that envelope the fragmented alveolar segments with the goal to mimic a harmonic arch, (ii) the extrusion from the larger toward the smaller alveolar segment along the envelope curves toward the harmonic upper alveolar arch, and (iii) the generation of the NAM device with a ventilation hole, fixation pin, and fixation points for the nasal stents. A feasibility study for a vector-based approach was successfully conducted for unilateral and bilateral cleft lip and palate (CLP) patients. A comparison of the modified target models with the reference target models showed similar results. For further improvement, the number of landmarks used to modify the models was increased by a curve-based approach.

Metacarpal fractures in the athlete.

To describe current evaluation and treatment of metacarpal fractures in athletes RECENT FINDINGS: Biomechanical and clinical studies involving lower-profile, locking, shorter length, and double-row or separate-dual plate configurations, as well as intramedullary screw fixation, have demonstrated the potential benefits of internal fixation with promising results. Treatment should be customized to the specific athlete and injury, and is often successful without surgery, or with percutaneous pin fixation. Internal fixation of metacarpal fractures has improved with new hardware and new techniques, and may expedite return to play, although further clinical studies are needed.

Analysis on the effect of surgical cleaning combined with external fixator for the treatment of post-traumatic heterotopic ossification of elbow joint

To evaluate the clinical efficacy of surgical treatment using a combined medial and lateral approach combined with an external fixator for the treatment of post-traumatic heterotopic ossification(HO) in patients with stiff elbow joints. Surgical release using the combined medial and lateral approach combined with external fixation for the treatment of HO and elbow stiffness in 26 patients from July 2010 to December 2013. The study group included 18 males and 8 females, with an average age 38.7 years (ranged 14 to 60 years). The time from injury to surgery averaged 9.3 (ranged 7 to 18) months. Before and after operation, the elbow range of motion and forearm rotation angle were measured, and the Mayo Elbow Performance Score (MEPS) was evaluated. The wound of all patients was well healed during the first period, except one patient who had chronic infection at the external fixation pin 3 weeks after operation. Then the external fixator was removed. All 26 patients were followed up, and the during ranged from 24 to 40 months, with an average of 34 months. HO recurrence occurred in 1 patient 8 months after operation. The range of motion, forearm rotation angle, and Mayo Elbow Performance Score of elbow joint in patients was significantly improved compared with that before surgery(P<0.05). Surgical release using the combined medial and lateral approach combined with an external fixator for the treatment of traumatic HO and elbow stiffness can effectively improve elbow function, resulting in a satisfactory effect.

Surgical management of delayed irreducible Gartland III supracondylar fractures in children: open reduction and internal fixation versus external fixation

Percutaneous pinning has been accepted as the "gold standard" for displaced supracondylar humeral fracture (SHF) in children. However, to secure an anatomic reduction and to reduce the rotated fragment, open reduction is often necessary when there is inadequate stabilization or a satisfactory reduction has failed to be achieved. The study aimed to compare the efficacy of the open reduction and bioabsorbable poly-d,l-lactic acid (PDLLA) pin fixation method with the closed reduction and lateral external fixation method in irreducible delayed Gartland type III SHF in children. In this study, 124 consecutive patients with irreducible delayed Gartland type III SHF were included between 2005 and 2013. Two different surgical methods were performed in patients separately. Group I had 64 patients undergoing bioabsorbable PDLLA pin fixation after open reduction, whereas group II had 60 patients treated by lateral external fixation after closed reduction. The outcome of treatment was evaluated by the Mayo Elbow Performance Score and the criteria of Flynn. Operation duration was longer in group I than in group II. Scoring of function showed that all patients had satisfactory results in both groups. The cosmetic result was satisfactory in all patients except 1 in group I. Both bioabsorbable PDLLA pin fixation and lateral external fixation are reliable, safe treatment alternatives for irreducible delayed SHF. Neither open nor closed reduction is linked to an increased rate of perioperative complications or unsatisfactory functional results.

Cannulated Lag Screw Fixation of Displaced Lateral Humeral Condyle Fractures Is Associated With Lower Rates of Open Reduction and Infection Than Pin Fixation.

Open reduction/internal fixation remains the most common way to surgically stabilize displaced pediatric lateral humeral condyle fractures, but closed reduction and internal fixation is being increasingly used. Our goal was to compare the clinical and functional results of treating displaced pediatric lateral humeral condylar fractures with traditional smooth or threaded pin fixation versus single cannulated screw fixation. From 1998 through 2012, the lateral humeral condyle fractures of 48 patients were treated with pin fixation (22 patients, until 2006) or cannulated, partially threaded screw fixation (26 patients, from 2006 onward). In each, closed reduction with percutaneous fixation was attempted first, followed by open reduction if anatomic reduction was not achieved. For the pin and screw groups, preoperative maximum radiographic displacement averaged 8.4 mm (range, 3.8 to 18.4 mm) and 6.3 mm (range, 2.2 to 15.5 mm), respectively; follow-up averaged 4.3 months (range, 1.5 to 20 mo) and 10.3 months (range, 2 to 30 mo), respectively. We reviewed preoperative and postoperative images and all follow-up clinical examination findings; serially assessed initial displacement, Baumann and carrying angles, range of motion limitations, and clinical alignment; evaluated functional results via the system of Hardacre and colleagues; and investigated all complications. Open reduction was required in 73% (16/22) and 15% (4/26) of the pin and screw groups, respectively (P<0.001). All fractures were reduced to <1 mm postoperative displacement. Postoperative immobilization averaged 5.9 weeks (range, 4 to 11 wk) and 4.5 weeks (range, 3 to 8 wk) for the pin and screw groups, respectively. The only significant difference in complications was the infection rate: 5 (1 deep) in the pin group and none in the screw group (P<0.05). Closed reduction and percutaneous 4.5-mm lag screw fixation of displaced pediatric lateral humeral condyle fractures is safe and reliable, enabling a higher rate of closed reduction, significantly lower infection rate, and earlier mobilization than traditional pin fixation. Level III-Therapeutic.

Use of Dexmedetomidine in Patients Undergoing Craniotomies.

The neuroanaesthesia ensures stable perioperative cerebral haemodynamics, avoids sudden rise in intracranial pressure and prevents acute brain swelling. The clinical characteristics of dexmeditomidine make this intravenous agent a potentially attractive adjunct for neuroanaesthesia and in the neurological intensive care unit. This study aimed to assess the effect of dexmedetomidine on intraoperative haemodynamic stability and to assess the intraoperative requirements of analgesic and other anaesthetic agents, and also to assess postoperative sedation, respiratory depression and any other side effects of dexmedetomidine as compared to placebo. This prospective randomized study was done in 60 patients of either sex, age between 18 to 60 years and American Society of Anaesthesiologist (ASA) Grade I and II undergoing elective craniotomies under General Anaesthesia (GA) for intracranial Space Occupying Lesion (SOL). These 60 patients underwent thorough history, clinical examination and laboratory investigations. They were randomly divided into two groups, Group D (received Inj. Dexmedetomidine) and Group P (received Inj. Placebo). During bolus and infusion Heart Rate (HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP), Peripheral oxygen saturation (SPO2) was recorded at every five minutes interval for first 20 minute. The mean age in Group D was 39.5 years and in Group P was 40 years. The sex distribution in two groups was in Group D, 12 patients (40%) were females and 18 (60%) patients were males. While in Group P 10 (33.3%) were females and 20 (66.7%) patients were males. The two groups were comparable with respect to diagnosis and type of surgery of patients and difference was not statistically significant. The mean HR, the mean DBP and the mean MAP was lower in Group D as compared to Group P and the difference was statistically significant. Dexmedetomidine provided intraoperative haemodynamic stability. It attenuates the haemodynamic responses to laryngoscopy, intubation, at pin fixation and the emergence from anaesthesia.

Unstable Distal Radius Fractures Treated by Volar Locking Anatomical Plates.

Fracture of the distal end of radius represents the most common fracture of the upper extremity accounting for 16-20% of all fractures. Plating is now emerging as the gold standard for management of distal radius fractures due to increased rate of complications such as malunion, subluxation/dislocation of distal radio-ulnar joint or late collapse of fracture. Procedures such as closed reduction and cast immobilization, ligamentotaxis with external fixator and percutaneous pin fixation are no longer acceptable. The purpose of the study was to evaluate the functional and radiological outcome of unstable distal radius fractures treated with the volar locking plate. We reviewed 53 patients from January 2011 to December 2015, treated for unstable distal radius fractures using a volar locking compression plate. Standard radiographic and clinical assessment after 12 months (range 12-16 months) were measured and final functional and radiological outcome were assessed using the Modified Mayo wrist scoring system and Sarmiento's modification of Lindstorm criteria respectively. There were 42 males and 11 females with an average age of 39.12±31.78 years (18-71 years). At the end of 12 months, 36 patients had an excellent radiological outcome and 10 patients had good radiological outcome as per Sarmiento's modification of Lindstorm criteria. Eleven patients had an excellent functional outcome and 26 patients had a good functional outcome as per modified Mayo wrist scoring system. There was one case of superficial wound infection which subsided with intravenous antibiotics. The volar locking plate fixation helps in early mobilization of the wrist, restores anatomy, allows early return to function, prevents secondary loss of reduction and hence is an effective treatment for unstable fractures of the distal radius.

The radial nerve danger zone: A cadaver study

Certain distal humerus fractures and elbow fracture dislocations warrant early fixation with an external fixator. The distal humerus is close to the radial nerve and a hazardous area for the placement of an external fixator. No known safe zone for the placement of an external fixator has been identified on the lateral border of the humerus. We record the incidence of radial nerve damage following external pin fixation and note the relation of the radial nerve to each pin. A total of 39 cadavers were dissected for this study. Two 4 mm pins were placed with a multi-pin clamp into the lateral border of the right and left humerus at 100 mm and 70 mm proximal to the lateral epicondyle. We dissected the upper limbs and recorded the incidence of radial nerve damage and the position of the nerve in relation to the two pins. Data for right and left sides were combined. The radial nerve was damaged by the proximal and distal pin in 56.4% and 20.5% respectively. The radial nerve was located anterior to the proximal pin (41%) and distal pin (79.5%). The radial nerve was located posterior to the proximal pin (2.6%) and distal pin (0.0%). We were unable to identify a safe zone from this study. We propose that pins should be placed less than 100 mm proximally from the lateral epicondyle and as posterior as possible to minimise the risk of radial nerve damage.

PP37. PATIENT EXPERIENCE AND SATISFACTION WITH DEXMEDETOMIDINE IN AWAKE CRANIOTOMY FOR BRAIN TUMOURS

INTRODUCTION: Gross total excision of high and low grade gliomas has been proven beneficial both by prolonging progress free survival and overall survival. In this context awake craniotomies for tumour resections as close as possible to eloquent brain have become popular. Patient experience has improved dramatically with the advent of the electromagnetic navigation which does not require rigid pin fixation of the head and allows conscious sedation throughout the procedure (AAA). Similarly new sedative medications like Dexmedetomidine have become available aiming to achieve the same level of sedation with less respiratory depression. METHODS: In this survey we used Dexmedetomidine intravenously to achieve conscious sedation in 40 consecutive patients who underwent awake craniotomy for an eloquently located brain tumour. After the patients recovered from the operation and were discharged, they were asked to complete a questionnaire that explored the way they experienced the awake craniotomy before, during and after the procedure. Dexmedetomidine use for awake craniotomies is standard practice in North America, but in this work we present the first UK experience of a series of patients. RESULTS: 32/40 responses received. Amongst these 19 patients remember being comfortable during the operation, 6 patients felt some discomfort, and 7 patients were not able to remember and comment on their experience during the operation. From the anaesthetic point of view none of these patients required any intraoperative airway intervention. The satisfaction results are comparable to a previous survey carried out in our unit in 2011 which looked at the level of satisfaction with Propofol and Remifentanil. CONCLUSIONS: The outcome of our survey looking at the use of dexmedetomidine +/- remifentanil matches the previous study in our institution using remifentanil+/-propofol and appears to be as equally as tolerated by patients. The use of dexmedetomidine has the added benefit of little or no respiratory depression. Larger studies are required to explore the true potential of dexmedetomidine further.

A biomechanical comparison of conventional versus cable pin fixation for transverse patellar fractures

Background: Transverse patellar fractures require fixation that anatomically restores continuity of the knee extensor complex and resiliency to the loads of early postoperative knee mobilization. The objective of this study was to evaluate the biomechanical fixation strength of three patellar osteosynthesis techniques. Methods: Transverse osteotomies were created in 24 custom fourth-generation composite left patellae, randomized into three equal groups for osteosynthesis fixation: group I, modified anterior tension wiring; group II, cannulated lag screws with anterior tension wiring; group III, cable pin fixation system. All patellae were loaded in simulated 60-degree knee flexion at 15 mm/min until complete failure. Results: Mean load to failure for group I (415.14±150.10 N) was significantly less than the load for group II (814.37±281.98 N), P=0.023 and group III (1103.64±358.70 N), P&lt;0.0001. Mean stiffness for group II and group III were 51.60±5.01 N/mm and 46.53±3.09 N/mm, respectively, and statistically higher (P&lt;0.0001) than group I (23.86±7.02 N/mm). Mean medial gapping in group III (10.33±6.50 mm) was statistically higher (P=0.041) than that in group II (4.59±3.19 mm). Conclusions: Greater compression across the fracture site was likely in the more robust constructs of cannulated lag screws with anterior tension wiring (group II) and cable pin fixation (group III), which may allow more timely and aggressive postoperative mobilization.