Aims. Olecranon fractures are usually caused by falling directly on to the olecranon or following a fall on to an outstretched arm. Displaced fractures of the olecranon with a stable ulnohumeral joint are commonly managed by open reduction and internal fixation. The current predominant method of management of simple displaced fractures with ulnohumeral stability (Mayo grade IIA) in the UK and internationally is a low-cost technique using tension band wiring. Suture or suture anchor techniques have been described with the aim of reducing the hardware related complications and reoperation. An all-suture technique has been developed to fix the fracture using strong synthetic sutures alone. The aim of this trial is to investigate the clinical and cost-effectiveness of tension suture repair versus traditional tension band wiring for the surgical fixation of Mayo grade IIA fractures of the olecranon. Methods. SOFFT is a multicentre, pragmatic, two-arm parallel-group, non-inferiority, randomized controlled trial. Participants will be assigned 1:1 to receive either tension suture fixation or tension band wiring. 280 adult participants will be recruited. The primary outcome will be the Disabilities of the Arm, Shoulder and Hand (DASH) score at four months post-randomization. Secondary outcome measures include DASH (at 12, 18, and 24 months), pain, Net Promotor Score (patient satisfaction), EuroQol five-dimension five-level score (EQ-5D-5L), radiological union, complications, elbow range of motion, and re-operations related to the injury or to remove metalwork. An economic evaluation will assess the cost-effectiveness of treatments. Discussion. There is currently no high-quality evidence comparing the clinical and cost effectiveness of the tension suture repair to the traditional tension band wiring currently offered for the internal fixation of displaced fractures of the olecranon. The Simple Olecranon Fracture Fixation Trial (SOFFT) is a randomized controlled trial with sufficient power and design rigour to provide this evidence for the subtype of Mayo grade IIA fractures. Cite this article: Bone Jt Open 2023;4(1):27–37

Abstract. A study was done to test the strength of various configurations of tension band wiring (TBW) and we report clinical results of ‘Horizontal Figure of Eight TBW’ (H – 8 TBW). In an experimental lab, a model of the fractured patella was mounted on a Nene tensile testing machine and various configurations of TBWs were tested in different positions of Kirschner wires. The strength of TBW and various knots securing the ends of wires were analysed on load/displacement graphs. The experimental results were compared with the theoretical results using trigonometry and mathematical equations. Since 1986, H – 8 TBW (Sonanis and Bhende modification) was used clinically in 42 patients (40 fractured patella, and 2 greater trochanteric osteotomies) in 26 males and 16 females and all patients were followed up to average 18 months. Experimentally H – 8 TBW (0.8mm wire) could resist maximum distraction force of 700 N and achieved maximum compression. Placement of the two Kirschner wires at the mid way between centre and edge of patella at the level of fracture site achieved optimum rotational stability and compression. Crimping method of gripping the ends of wires was the most secured method (120 N). Clinically bony union using H-8 TBW was achieved in all 41 patients. Complications seen were wire discomfort in 3 patients and one death. We conclude that H – 8 TBW achieved maximum compression, optimum K wire placement was at the 1/4th distance from the edge of the patella, and crimping the ends of wire secured best fixation

Treatment of simple and complex patella fractures represents a challenging clinical problem. Controversy exists regarding the most appropriate fixation method. Tension band wiring, aiming to convert the pulling forces on the anterior aspect of the patella into compression forces across the fracture site, is the standard of care, however, it is associated with high complication rates. Recently, anterior variable-angle locking plates have been developed for treatment of simple and comminuted patella fractures. The aim of this study was to investigate the biomechanical performance of the novel anterior variable-angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Sixteen pairs of human cadaveric knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized with a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral and an inferior fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws, or an anterior variable-angle locking core plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or an anterior variable-angle locking three-hole plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range from 90° flexion to full knee extension. Interfragmentary movements were captured by motion tracking. For both fracture types, the articular displacements, measured between the proximal and distal fragments at the central aspect of the patella between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the anterior variable-angle locked plating compared with the tension band wiring, p < 0.01. From a biomechanical perspective, anterior locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring

Treatment of both simple and complex patella fractures is a challenging clinical problem. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Twelve pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34C1 or five-part complex AO/OTA 34C3 patella fractures by means of osteotomies, with each fracture model created in six pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws, or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full knee extension. Interfragmentary movements were captured via motion tracking. For both fracture types, the longitudinal and shear articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p<0.01. Lateral rim locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading

Aims: Tension band wiring is a widely accepted method for internal þxation of olecranon fractures. Plate þxation is suggested for the more complex olecranon fractures, but little is known about the speciþc risk factors for failure of tension band wiring. The aim of this study was to analyze the inßuence of fracture comminution, associated elbow instability and fracture extension into the coronoid process on the outcome of tension band wiring for olecranon fractures. Methods: From 1996 to 1998, forty-four olecranon fractures were treated consecutively at out institution using tension band wiring. All patients returned for a clinical and radiographic exam performed by two observers independent of the treating surgeon. Pain and satisfaction were determined using visual-analogue scales (VAS) and clinical results were graded using the Mayo Elbow Performance Score (MEPS) and the DASH questionnaire. Patients were followed for 3 to 6 years. Results: At most recent follow-up, the mean VAS score for pain was 2.0, mean extension was 3.6û and mean ßexion was 137.2û. According to the MEPS the results were graded as good or excellent in 78% of the patients. Five patients were disabled for activities of daily living according to the DASH questionnaire. All but one fracture healed. Fracture comminution did not affect the outcome. Worse results were associated with elbow instability and fracture extension into the coronoid. Conclusions: Tension band wiring provided satisfactory results for the treatment of olecranon fractures in the presence of fracture comminution, but worse results were obtained in the presence of elbow instability and fracture extension into the coronoid

Aims: to evaluate the outcome following internal þxation of olecranon fractures using the techniques of tension band wiring and plating with a minimum follow up of two years. Methods:Design: retrospective evaluation and clinical review. Setting: regional trauma centre. Patients and participants: 48 consecutive patients with fractures of the olecranon were treated over a twenty month period (may 1993 to december 1994). 25 fractures were þxed using a tension band wiring technique and 23 underwent plating; the selection of method was based on agreed radiological fracture pattern criteria. Main outcome measurements: radiographic evaluation of the quality of reduction. Clinical outcome (broberg and morrey functional rating index). Results: clinical evaluation of 39 patients was carried out. In the tension band wiring group 17 (85 percent) patients had an excellent or good outcome and 11 (55 percent) patients underwent a second procedure for symptomatic metalwork. In the plating group 16 (84 percent) patients had an excellent or good outcome and 2 (11 percent) patients underwent a second procedure for symptomatic metalwork. The latter group had more complex and associated fractures and included the only poor result. Conclusion: internal þxation of fractures of the olecranon results in good functional outcome. Fixation with a plate is effective and produces good outcome even though selected for the more complex olecranon fractures. Patients who have tension band wiring more often require a second procedure for removal of symptomatic metalwork

Introduction: Traditionally the fixation of choice as recommended by the AO ASIF group for transverse fractures of the Olecranon and the Patella is the tension band wiring technique. The concept of tension band wiring is based on the fact that the distractive force applied to one surface of the bone will result in compression on the opposite articular surface. Clinical outcomes of TBW are not equivocal. It is associated with significant morbidity such as non union, failure of fixation, especially in osteoporotic bone and infection which sometimes leads to amputation. Often a second procedure for removal of prominent metal work is required. In our biomechanical study we investigated this concept as we believe that the forces generated by TBW construct do not generate significant compressive forces required for healing of fracture. Materials and Methods: We used 4th generation composite bones (Sawbones. ®. , Malmoe, Sweden.). These bone analogues have been validated to closely simulate human bone characteristics for fracture toughness, tensile strength, compressive strength, fatigue crack resistance and implant subsidence. The advantage of using 4th generation composite bone model is that it provides uniformity which is not achievable in cadaveric studies. Two different bone models representative of Olecranon and patella were used. Transverse fractures were created in the bones and fixed with TBW technique as described in A.O. manual. Two 0.062-inch Kirschner wires and figure of eight configuration of 18G Stainless steel wire with single knot technique was used. Micro motion transducers (DVRT: MicroStrain, Williston, Vermont) with an accuracy of ± 1μm were placed across the fracture site both anteriorly and posteriorly. Continuous information regarding fracture distraction and compression, as determined by the transducers was recorded from both sites simultaneously during the experiment. The tension band wire construct was loaded up to a maximum force of 4000 Newtons for patella and 500 for the olecranon. The fractures were subjected to cyclic loading at 1Hz using a servo hydraulic materials-testing system (model 8500; Instron, Canton, Massachusetts). The results were analysed on a computer and statistical analysis performed. Results: During the application of cyclical loading, we noted a gap at the articular surface ranging from 1.1± 0.4mm and 2.1± 0.6mm for Olecranon and patella constructs respectively. During most of the duration of the experiment no transducer displacements were recorded at the articular surface. Conclusion: The concept that distractive forces at one end could be converted to compression at the other end through the TBW does not hold true in our biomechanical study. A simpler construct may suffice for fixation of patellar and Olecranon fractures which can reduce the complications associated with TBW fixation

Background: Tension Band wiring technique is commonly used to treat transverse patella fractures. The commonly used configuration has parallel K wires and a stainless steel wire loop oriented as a figure of 8. Use of non-metallic suture materials as reliable fixation materials have been reported. We investigated the properties of composite polyester suture (Fibre wire) when used in Tension band wiring of patella. Methods: A wooden model of a transversely fractured patella was used. The fracture was fixed using two K wires and a loop of horizontally oriented stainless steel wire or fibre wire. Two wire twists placed at corners were used for SS wire loops. For fibre wire samples a tensioning device was used and the knots placed at one corner. Interfragmentary compression at the point of wire breakage and fracture displacement on physiologic cyclic loading was measured for each fixation construct. The reliability of tensioning device (Arthrex) and the effect of using multiple strands of wire were assessed. Results: Use of the tensioning device produced interfragmentary compression that could be repeated reliably. The addition of a further strand increased the interfragmentary compression developed by 94%. There was no significant difference between interfragmentary compression developed between groups (p> 0.05). The average interfragmentary compression produced for three repetitions for the individual groups, Fibre wire (1394N), SS wire of 1.0mm diameter (1320N), SS Wire of 1.25mm diameter (1594N) were comparable. This increased significantly when a second loop of fibre wire was used (2566N). Permanent fracture displacement at physiologic loads were, Fibre wire (9.7mm, SD 2.7mm), SS wire of 1.0mm diameter (7.0mm, SD 1.0mm) and SS Wire of 1.25mm diameter (7.4mm, SD 2.3mm). The addition of the second strand of fibre wire decreased the displacement significantly (4.8mm, SD 0.6mm). The effect of second strand of fibre wire decreased the displacement by 97% while the decrease on addition of the second strand of stainless steel wire was only 14%. Discussion: Interfragmentary compression produced to failure was comparable between a single strand of fibre wire, 1.0mm SS wire and 1.25mm SS wire, the commonly used SS wire diameters in fixation of fractured patella. The standard deviations of final permanent displacement were higher with the larger diameter of SS wire, indicating that the use of a thicker wire would require some preloading before it is uniformly tensioned. Amongst the SS wire diameters tested, 1.0mm resulted in least variations (SD 1.0mm). The addition of second strand resulted in a marked improvement in displacement with Fibre wire and variations between different samples were smaller than in any other group tested (SD 0.6mm). Conclusions:. Fibre wire has similar strength to failure when compared the commonly used thickness of stainless steel wire for fixation of patella. Use of tensioning device produces interfragmentary compression in a reliable and reproducible manner. The addition of second loop of fibre wire, separately tensioned results in significant improvements in interfragmentary compression and resistance against displacement

Purpose. To observe the follow-up results of standard cemented bipolar hemiarthroplasty with double loop and tension band wiring technique for treatment of unstable intertrochanteric hip fractures in elderly patients with osteoporosis. Materials and Methods. From May 2000 to May 2006, 86 cemented bipolar hemiarthroplasties were performed in elderly patients who had unstable intertrochanteric fractures. The mean age at the time of surgery was 82 years old. The average follow-up period were 5.3 years. We evaluated post-operative results after operation by clinical and radiographic methods. Results. Clinically, the final follow-up of Harrsi hip score was noted 79.2. The mean time needed for full weight bearing following surgery was 4.2 weeks and 82.5% of patients regained their preoperative ambulatory level. All patients achieved union in lesser trochanter fracuture, but great trochanter displacement were observed in 4 cases. There was one case of acetabular erosion. Post-operative superficial infections were found in 2 cases. 1 case with stem subsidence(<5 mm) showed satisfactory results without further subsidence in follow-ups. Conclusion. If we properly apply indications in technique with cemented bipolar hemiarthroplasty in the treatment of unstable intertrochanteric hip fracture in elderly, we will achieve systematic postoperative rehabilitation, pain control and handy nursing which is its one of merits

Introduction: The most common method for internal fixation of olecranon fractures is AO tension band wiring (TBW). A number of complications related to this technique have been described, such as subcutaneous prominence of the device, skin irritation, infection, loss of extension in the elbow joint and non-union. To avoid those complications Dr. Robert J. Medoff has designed a new device, the ulnar sled, which will be shown on a picture. The objective of this cadaver study was to determine the stability of olecranon fracture fixation with the ulnar sled and compare it with AO method. Methods: In six matched pairs of fresh-frozen arms a fracture of the olecranon was created and stabilized with either TBW or the ulnar sled. The ulnar sled (US) group: The two free legs of the sled were inserted into two pre-drilled holes from the tip of the olecranon into the ulna medullary cavity of the ulna. The washer was then placed with its slot over the prominence of the sliding plate and with a screw fixed bicortically into the ulna, through the distal part of the proximal oval washer hole. Compression over the fracture site could be observed visually and the washer was finally fixed with another bicortical screw in its distal hole. The TBW group: In the TBW group the AO technique with oblique bicortical K-wires and the two-knot-modification was used. Mechanical Testing: First the brachialis and then the triceps muscle were sequentially loaded with 5 kg (50N) for 20 cycles in three different angles: 45, 90 and 135. The fracture displacement was measured before and after loading. Results: The increase in the fracture gap after 20 cycles of loading for the two fixation techniques will be shown in a table. There was no significant increase of the fracture gap for either device when loading the brachialis muscle at any of the three flexion angles. The fracture displacement in 90 in triceps loading was 0.23mm in the the US group and in 0.19mm in the TBW group. This difference was not significant (p> 0.05). Similar results were obtained for the other flexion angles. Almost no displacement was observed in brachialis loading with either method. Discussion: The results suggest that the ulnar sled method is a stable surgical method for fixation of uncommuted olecranon fractures when compared to TBW

INTRODUCTION – Tuberosity fractures of the calcaneum are rare injuries. The traditional operative treatment involves open reduction and internal fixation with a tension band wire construct. We have developed a new technique of fixing these fractures with internal fixation using cannulated screws and a figure of eight wire. This paper describes the new technique outlining its advantages and compares the 2 methods of fixation biomechanically to determine their properties with respect to fracture fixation.

METHOD – 20 sections of bovine bone were taken to act as an experimental model for the calcaneum. They were osteotomised to create the posterior process fracture model. 10 were fixed using a traditional tension band wire construct and 10 were fixed using the cannulated screw and wire construct. Each construct was subjected to biomechanical testing to identify the stiffness, energy to failure and load to failure.

RESULTS – During loading the cannulated screw and wire constructs showed a significant increase in stiffness and energy to failure compared to the tension band wire constructs

CONCLUSION – The increased stability of the cannulated screw construct demonstrated by the testing offers biomechanical benefit over the traditional tension band wire construct. This, as well as the improved technical aspects of the cannulated screw fixation, may be beneficial for clinical use.

Introduction:

Mayo 2A Olecranon fractures are traditionally managed with a tension band wire device (TBW) but locking plates may also be used to treat these injuries.

Compression and absolute stability are important in the management of intra-articular fractures. We compared tension band wiring with plate fixation for the treatment of fractures of the olecranon by measuring compression within the fracture. Identical transverse fractures were created in models of the ulna. Tension band wires were applied to ten fractures and ten were fixed with Acumed plates. Compression was measured using a Tekscan force transducer within the fracture gap. Dynamic testing was carried out by reproducing cyclical contraction of the triceps of 20 N and of the brachialis of 10 N. Both methods were tested on each sample. Paired t-tests compared overall compression and compression at the articular side of the fracture. The mean compression for plating was 819 N (. sd. 602, 95% confidence interval (CI)) and for tension band wiring was 77 N (. sd. 19, 95% CI) (p = 0.039). The mean compression on the articular side of the fracture for plating was 343 N (. sd. 276, 95% CI) and for tension band wiring was 1 N (. sd. 2, 95% CI) (p = 0.038). During simulated movements, the mean compression was reduced in both groups, with tension band wiring at −14 N (. sd. 7) and for plating −173 N (. sd. 32). No increase in compression on the articular side was detected in the tension band wiring group. Pre-contoured plates provide significantly greater compression than tension bands in the treatment of transverse fractures of the olecranon, both over the whole fracture and specifically at the articular side of the fracture. In tension band wiring the overall compression was reduced and articular compression remained negligible during simulated contraction of the triceps, challenging the tension band principle

We investigated whether an alternative tension band wire technique will produce greater compression and less displacement at olecranon (elbow) fracture sites compared to a standard figure of eight tension band technique. Olecranon fractures are commonly treated with tension band wiring using stainless steel wire in a figure of eight configuration. However recently published studies have raised doubts over the validity of the tension band concept proving that the standard figure of eight configuration does not provide fracture compression when the elbow is flexed. We propose an alternative tension band technique where the figure of eight is applied in a modified configuration producing greater compression across the fracture. An artificial elbow joint was simulated using artificial forearm (ulna) and arm (humerus) bones. The design simulated the action of the muscles around the elbow joint to produce flexion and extension. There were two arms to this investigation. (1) Standard tension band wire configuration with stainless steel. (2) Modified tension band wire configuration with stainless steel. The simulated elbow was put through a range of movement and sensors measured the compression at the articular and non-articluar surfaces of the fracture. Measurements were taken for compression with different weights applied to challenge both the techniques of tension band wiring. Measurements from the non articular surface of the fracture demonstrated greater compression with alternative tension band technique. However it was not statistically significant (ANOVA). Compression at the articular surface of the fracture exhibited statistically significant (p<0.05) greater compression with the alternative technique. Neither technique produced greater compression during flexion of the simulated elbow. The alternative tension band wiring technique proved superior in providing greater compression over the fracture site

Introduction. Although tension band wiring fixation of patellar fracture has been the most widely used technique, the metal implants related complications including implant loosening, postoperative pain are very common and additional surgeries are often necessary. Hypothesis. A totally metal free technique of transosseous suturing method could outperform the traditional fixation technique. Materials & Methods. A total of 25 patients (mean age of 59.60 years) with displaced patellar fracture treated by transosseous suturing technique were compared with a 1:1 matched historical control group who underwent modified tension band wiring fixation of patellar fracture. Union time, union rate, operation time, number of procedures, mean hospitalization days and the complications were compared between cases and controls. Results. Union time (8.43 ±2.92 weeks versus 8.64 ±2.82 weeks) and operation time (69.00 ±19.31 versus 64.89 ±14.27 minutes) were not different between two groups. Mean hospitalization days (4.04 ±1.40 versus 5.76 ±1.50 days; P < 0.001), number of procedures and the frequency of complications were significantly lower among transosseous suturing group (P< 0.001). Conclusions. Transosseous suturing technique is safe and effective in the transverse or comminuted fractures of patella. The complication rate is significantly lower than that of conventional tension band wiring technique

Purpose: Tension band wiring is the most common surgical procedure for fixation of fractures of the Olecranon, but it is associated with high rate of metal work complications and implant failure leading to re-operation. Method: We present a new fixation technique for olecranon fractures that avoids reoperation to remove hardware as compared with the standard fixation technique with Kirschner wires and tension band wiring as advocated by the AO technique. We describe fixation of displaced transverse and oblique olecranon fractures with anchor sutures, each of which has two pairs of suture strands. Prior to the insertion of the anchor sutures, the fracture is reduced through a standard open approach. Results: Twelve patients have been treated with this technique so far, with a mean follow-up of 6 months. The mean age of the patients was 46.7 years (range 14–75 yrs). We have followed all these patients till union of the fractures. No immediate complications have been noted. Radiographic results are good, with no loss of reduction. Conclusion: This technique avoids the need for reop-eration for hardware removal without compromising the quality of reduction. It may be argued that anchor sutures may cost more than tension band wiring which is a very low cost procedure. At the same time, we should also consider the future cost involved because of reoperation rate and morbidity. Our newly described technique would be particularly useful in dealing with olecranon fractures in children where it is undesirable to cross the physeal plate by metal work. It would also be of great value in dealing with intra articular distal humeral fractures where fixation is planned initially but conversion to total elbow replacement becomes essential intra-operatively. In such cases an olecranon osteotomy can be fixed by this technique, even in presence of a total elbow replacement

The aim of this study was to compare the primary fixation stability and initial fixation stiffness of two commonly used fixation techniques, the tension band wiring technique and interfragmentary screw fixation, with an innovative mini-screw fragment fixation system in a model of transverse fracture of the patella. It was hypothesized that the biomechanical performance of the fragment fixation system would not significantly differ from the loading characteristics of the two established methods currently investigated. Materials and Methods: A standardized transverse patella fracture was induced in ninety-six calf patella and three different fixation methods, including the mod-ified tension band wiring technique, interfragmentary screw fixation, and the mini-screw fragment fixation system, were used for fragment fixation. Specimens were mounted to a loading rig which was integrated within a material testing machine. In each fixation group, eight specimens were loaded to failure at varying simulated knee angles of either 0° or 45°. Another eight specimens were submitted to polycyclic loading consisting of 30 cycles between 20 N and 300 N at a simulated knee angle of either 0° or 45°. The residual displacement between the first and the last cycle was recorded. Differences in the biomechanical performance between the three fixation groups were evaluated. Results: With monocyclic loading, no significant differences between the three groups were observed in the parameters maximum load to failure and linear fixation stiffness. Specimens loaded at 45° showed significantly lower maximum failure loads and linear stiffness when compared with 0° knee angle. With polycyclic loading, no significant differences in the residual displacement were observed between the groups at 0° loading angle, while at 45°, residual displacement was significantly higher with tension band fixation when compared with interfragmentary screw fixation or the fragment fixation system. Conclusion: This study confirmed that the biomechanical performance of the fragment fixation system was comparable to interfragmentary screw fixation and superior to the tension band wiring technique. As the fragment fixation system combines the advantages of providing interfragmentary compression with percutaneous pin insertion after closed reduction, we believe the fragment fixation system to be an adequate alternative in the osteosynthesis of transverse patella fractures

The August 2014 Trauma Roundup. 360 . looks at: On-table CT for calcaneal fractures; timing of femoral fracture surgery and outcomes; salvage arthroplasty for failed internal fixation of the femoral neck; screw insertion in osteoporotic bone; fibular intramedullary nailing on the ascendant; posterior wall acetabular fractures not all that innocent; bugs, plating and resistance and improving outcomes in olecranon tension band wiring

For the management of displaced patellar fractures, surgical fixation using cannulated screws along with anterior tension band wiring is getting popular. Clinical and biomechanical studies have reported that using cannulated screws and a wire instead of the modified tension band with Kirschner wires improves the stability of fractured patellae. However, the biomechanical effect of screw proximity on the fixed construction remains unclear. The aim of this study was to evaluate the mechanical behaviors of the fractured patella fixed with two cannulated screws and tension band at different depths of the patella using finite element method. A patella model with simple transverse fracture [AO 34-C1] was developed; the surgical fixation consisted of two 4.0-mm parallel partial-threaded cannulated screws with a figure-of-eight anterior tension band wiring using a 1.25-mm stainless steel cable. Two different locations, including the screws 5-mm and 10-mm away from the leading edge of the patella, were used. A tension force of 850 N was applied on the patellar apexes at two loading angles (45° and 0° [parallel] to the long axis) to simulate different loading conditions while knee ambulation. The proximal side (base) of the patella was fixed, and the inferior articular surface was defined as a compression-only support in ANSYS to simulate the support from distal femur condyles. Compression-only support enables the articular surfaces of the present patella to only bear compression and no tension forces. Under different loading conditions, the fixed fractured patella yielded higher stability during 0° loading of tension force than during 45° loading. When the screws were parallel placed at the depth of 5 mm away from the patellar surface, the deformation of patellar fragment and maximum gap opening at the fracture site were smaller than those obtained by screws placed at the depth of 10 mm away from the patellar surface. Compared to the superficial screw placement, the deeper placement (10 mm) increased the maximum gap opening at the fracture site by 1.56 times under 45° loading, and 1.58 times under 0° loading. The load on the tension band wire of the 10-mm screw placement was 3.12 times (from 230 to 717 N) higher than that of the 5-mm placement. Under the wire, the contact pressure on the patellar surface was higher with the 10-mm screw placement than the 5-mm screw placement. The peak bone contact pressures with the 10-mm placement were 7.7 times (99.5 to 764 MPa) higher. This is the first numerical study to examine the biomechanical effects of different screw locations on the fixation of a fractured patella using screws and tension band. Based on a higher stability and lower cable tension obtained by the superficial screws placement, the authors recommended the superficial screw placement (5 mm below the leading edge of the patella) rather than the deep screws while fixing the transverse patellar fracture with cannulated screws and cable

Ulna Styloid Fractures have been historically dismissed as a relatively benign injury. However recent clinical and biomechanical research has suggested that primary repair of displaced ulna styloid avulsion fractures is advised as a means of stabilizing the radioulnar joint and preventing the disability associated with chronic radioulnar joint instability. Optimum fixation method was examined in this study using a human cadaveric model. A custom jig was designed to allow testing in radial/ulna deviation in varying degrees of wrist flexion and extension. Universal materials testing device was used to apply a maximum load of 150 N. Eight pairs of cadaveric wrists were tested. Constructs tested were 1.6mm K-wire fixation, Tension Band wiring and Screw Fixation. Fracture displacement was measured using a venire micrometer. Results: Displacement on forced radial deviation was maximum in neutral wrist position in all construct configurations. Displacement was minimized in 20 degrees wrist flexion. The optimum fixation method was 2 k-wires with tension band wiring. This study would suggest that the optimum fixation for ulna styloid fractures is a Tension band-wiring construct. If non-operative treatment is used we suggest that the wrist is immobilized in a position of wrist flexion to reduce tension on the ulna carpal ligament and prevent fracture displacement