Objectives. We aimed to further evaluate the biomechanical characteristics of two locking screws versus three standard bicortical screws in synthetic models of normal and osteoporotic bone. Methods. Synthetic tubular bone models representing normal bone density and osteoporotic bone density were used. Artificial fracture gaps of 1 cm were created in each specimen before fixation with one of two constructs: 1) two locking screws using a five-hole locking compression plate (LCP) plate; or 2) three non-locking screws with a seven-hole LCP plate across each side of the fracture gap. The stiffness, maximum displacement, mode of failure and number of cycles to failure were recorded under progressive cyclic torsional and eccentric axial loading. Results. Locking plates in normal bone survived 10% fewer cycles to failure during cyclic axial loading, but there was no significant difference in maximum displacement or failure load. Locking plates in osteoporotic bone showed less displacement (p = 0.02), but no significant difference in number of cycles to failure or failure load during cyclic axial loading (p = 0.46 and p = 0.25, respectively). Locking plates in normal bone had lower stiffness and torque during torsion testing (both p = 0.03), but there was no significant difference in rotation (angular displacement) (p = 0.84). Locking plates in osteoporotic bone showed lower torque and rotation (p = 0.008), but there was no significant difference in stiffness during torsion testing (p = 0.69). Conclusions. The mechanical performance of locking plate constructs, using only two screws, is comparable to three non-locking screw constructs in osteoporotic bone. Normal bone loaded with either an axial or torsional moment showed slightly better performance with the non-locking construct

Acetabular fractures present a challenge. Anatomical reduction can be achieved by open reduction and internal fixation (ORIF). However, in elderly patients with complex fracture patterns and osteoporotic bone stock, “fix and replace” has become an option in the management of these injuries. This involves ORIF of the acetabulum to enable insertion of a press fit cup and subsequent cemented femoral stem at the index surgery. A Retrospective analysis of all operatively managed acetabular fractures by a regional Pelvic and Acetabular Trauma service (01/01/2018-30/05/2023) STATA used for analysis. 34 patients undergoing “fix and replace” surgery. Of the 133 patients managed with ORIF, 21 subsequently required Total Hip Arthroplasty (THA). Mean follow up was 2.7 years versus 5.1. There was no statistical significance between the two groups with regards to BMI or sex. Mean age in the “fix and replace” group was 68 compared to 48 in the ORIF and subsequent THA group. This reached statistical significance between the two groups (p=0.001).ASA and Charlson Comorbidity Index (3 and 3 in “fix and replace” and 2 and 1.2 in ORIF to THA group) and Charlson Comorbidity Index both were statistically significantly different (p=0.006 and p=0.027, respectively). High energy mechanism of injury accounted for 56% of the “fix and replace” group compared to 48% in the ORIF to THA. 74% of “fix and replace” were associated fractures compared to 53% of ORIF to THA. Wait to surgery was 3 days for “fix and replace” while 186 days was the mean wait time from listing to THA for the ORIF to THA group. Complication rate was 41% versus 43% in the two groups. 14% in the ORIF to THA group developed PJI versus 6% in “fix and replace”. Fix and replace allows early mobilisation in frailer, elderly patients. Our results show fewer returns to theatre and less PJI in patients having arthroplasty as part of “fix and replace” than subsequent to Open reduction internal fixation

Introduction. The objective of this study was to determine if a synthetic bone substitute would provide results similar to bone from osteoporotic femoral heads during in vitro testing with orthopaedic implants. If the synthetic material could produce results similar to those of the osteoporotic bone, it could reduce or eliminate the need for testing of implants on bone. Methods. Pushout studies were performed with the dynamic hip screw (DHS) and the DHS Blade in both cadaveric femoral heads and artificial bone substitutes in the form of polyurethane foam blocks of different density. The pushout studies were performed as a means of comparing the force displacement curves produced by each implant within each material. Results. The results demonstrated that test material with a density of 0.16 g/cm. 3. (block A) produced qualitatively similar force displacement curves for the DHS and qualitatively and quantitatively similar force displacement curves for the DHS Blade, whereas the test material with a density of 0.08 g/cm. 3. (block B) did not produce results that were predictive of those recorded within the osteoporotic cadaveric femoral heads. Conclusion. This study demonstrates that synthetic material with a density of 0.16 g/cm. 3. can provide a good substitute for cadaveric osteoporotic femoral heads in the testing of implants. However we do recognise that no synthetic material can be considered as a definitive substitute for bone, therefore studies performed with artificial bone substrates may need to be validated by further testing with a small bone sample in order to produce conclusive results

The best method of managing a fracture of the distal humerus in a frail low-demand patient with osteoporotic bone remains controversial. Total elbow arthroplasty (TEA) has been recommended for patients in whom open reduction and internal fixation (ORIF) is not possible. Conservative methods of treatment, including the ‘bag of bones’ technique (acceptance of displacement of the bony fragments and early mobilisation), are now rarely considered as they are believed to give a poor functional result. We reviewed 40 elderly and low-demand patients (aged 50 to 93 years, 72% women) with a fracture of the distal humerus who had been treated conservatively at our hospital between March 2008 and December 2013, and assessed their short- and medium-term functional outcome. . In the short-term, the mean Broberg and Morrey score improved from 42 points (poor; 23 to 80) at six weeks after injury to 67 points (fair; 40 to 88) by three months. . In the medium-term, surviving patients (n = 20) had a mean Oxford elbow score of 30 points (7 to 48) at four years and a mean Disabilities of the Arm, Shoulder and Hand score of 38 points (0 to 75): 95% reported a functional range of elbow flexion. The cumulative rate of fracture union at one year was 53%. The mortality at five years approached 40%. . Conservative management of a fracture of the distal humerus in a low-demand patient only gives a modest functional result, but avoids the substantial surgical risks associated with primary ORIF or TEA. Cite this article: Bone Joint J 2015;97-B:1132–8

Background. In elderly patients with complex proximal humerus fractures and osteoporotic bone reconstruction is not always possible. Although hemiarthroplasty is an alternative, non-union or tuberosity migration can lead to inferior functional results. Implantation of a Reverse Total Shoulder Arthroplasty (RTSA) seems to be an interesting alternative. In the present study we retrospectively analyzed the short-term results of RTSA for complex proximal humerus fractures in the elderly. Methods. From 31.10.2005 to 20.07.2010 RTSA was performed in 29 patients (average age 80 years [67;90], 25 women, 4 man) with subcapital, three- or four-part fracture of the proximal humerus as a primary treatment. All procedures were performed using the Anatomical Inverse Shoulder (Zimmer) with fracture stem. A deltopectoral approach was used in every case with reattachment of the tuberosities. Pain, range of motion, subjected shoulder value (SSV) as well as the Constant score (CS) were used to evaluate shoulder function. Implant positioning and signs of loosening were analyzed on standard x-rays. Results. Included were 23 patients with a minimal follow-up of 12 month. The average follow-up was 17 month (12 month to 5 years). The mean SSV was 81% [40;100]. The absolute CS averaged 67 points [34;84] and the relative CS 97% [52;139]. The mean pain score (VAS) was 13.7 of 15, the mean activity score 18.4 of 20, the mean mobility score 28.6 of 40 and the mean strength score 5.1 of 25. The mean active anterior elevation was 130° [80;160], the mean active abduction 128° [80;170] and the mean active external rotation in 0° abduction 21° [-30;70]. All patients reached the same activity level as before surgery and could return to independent living. The results after 12 month were already comparable to those after 24 month (10 patients). Radiographically no signs of loosening were detected. There was a total of 3 complications and reoperations, two due to a hematoma and one because of a periprosthetic fracture. Conclusions. In elderly patients with complex proximal humerus fractures and osteoporotic bone RTSA seems to be a very satisfactory procedure. The short-term clinical results are excellent and predictable with a rapid postoperative recovery of daily comfort. The complication rate is low and acceptable

The surgical treatment of three- and four-part fractures of the proximal humerus in osteoporotic bone is difficult and there is no consensus as to which technique leads to the best outcome in elderly patients. Between 1998 and 2004 we treated 76 patients aged over 70 years with three- or four-part fractures by percutaneous reduction and internal fixation using the Humerusblock. A displacement of the tuberosity of > 5 mm and an angulation of > 30° of the head fragment were the indications for surgery. Of the patients 50 (51 fractures) were available for follow-up after a mean of 33.8 months (5.8 to 81). The absolute, age-related and side-related Constant scores were recorded. Of the 51 fractures, 46 (90.2%) healed primarily. Re-displacement of fragments or migration of Kirschner wires was seen in five cases. Necrosis of the humeral head developed in four patients. In three patients a secondary arthroplasty had to be performed, in two because of re-displacement and in one for necrosis of the head. There was one case of deep infection which required a further operation and one of delayed healing. The mean Constant score of the patients with a three-part fracture was 61.2 points (35 to 87) which was 84.9% of the score for the non-injured arm. In four-part fractures it was 49.5 points (18 to 87) or 68.5% of the score for the non-injured arm. The Humerusblock technique can provide a comfortable and mobile shoulder in elderly patients and is a satisfactory alternative to replacement and traditional techniques of internal fixation

Aims

Despite limited clinical scientific backing, an additional trochanteric stabilizing plate (TSP) has been advocated when treating unstable trochanteric fractures with a sliding hip screw (SHS). We aimed to explore whether the TSP would result in less post operative fracture motion, compared to SHS alone.

Aims. Periprosthetic femoral fractures (PFF) following total hip arthroplasty (THA) are devastating complications that are associated with functional limitations and increased overall mortality. Although cementless implants have been associated with an increased risk of PFF, the precise contribution of implant geometry and design on the risk of both intra-operative and post-operative PFF remains poorly investigated. A systematic review was performed to aggregate all of the PFF literature with specific attention to the femoral implant used. Patients and Methods. A systematic search strategy of several journal databases and recent proceedings from the American Academy of Orthopaedic Surgeons was performed. Clinical articles were included for analysis if sufficient implant description was provided. All articles were reviewed by two reviewers. A review of fundamental investigations of implant load-to-failure was performed, with the intent of identifying similar conclusions from the clinical and fundamental literature. Results. In total 596 articles were initially identified, with 34 being eligible for analysis. Aggregate analysis of 1691 PFFs in 342 719 primary THAs revealed a significantly higher number of PFFs with cementless femoral implants (p < 0.001). Single-wedge and double-wedge (fit-and-fill) femoral implants were associated with a threefold increase in PFF rates (p < 0.001) compared with anatomical, fully coated and tapered/rounded stems. Within cemented stems, loaded-taper (Exeter) stems were associated with more PFFs than composite-beam (Charnley) stems (p = 0.004). Review of the fundamental literature revealed very few studies comparing cementless component designs. Conclusion. Very few studies within the PFF literature provide detailed implant information. Cementless implants, specifically those of single-wedge and double-wedge, have the highest PFF rates in the literature, with most investigations recommending against their use in older patients with osteoporotic bone. This review illustrates the need for registries and future PFF studies to record implant name and information for future analysis. Furthermore, future biomechanical investigations comparing modern implants are needed to clarify the precise contribution of implant design to PFF risk. Cite this article: Bone Joint J 2017;99-B(1 Supple A):50–9

Aims

The aim of this study was to investigate the rate of revision for distal femoral arthroplasty (DFA) performed as a primary procedure for native knee fractures using data from the Australian Orthopaedic Association National Joint Arthroplasty Registry (AOANJRR).

The management of distal humeral fractures in low-demand patients with osteoporotic bone remains controversial. Total elbow arthroplasty (TEA) has been recommended for cases where achieving stable ORIF can be difficult. The ‘bag of bones’ technique, (early movement with fragments accepted in their displaced position), is now rarely considered as it is commonly believed to confer a poor functional result. The aim of this study was to present the short- and medium-term functional outcomes following the primary conservative treatment of distal humeral fractures in elderly and low-demand patients. We carried out a retrospective case note and radiograph review of all patients (n=40) aged 50 years or more, with distal humeral fractures treated conservatively at our institution over a six-year period. Short-term function was assessed using the Broberg and Morrey (B&M) score. Medium term function was assessed by telephone interview (n=20) using the Oxford Elbow Score (OES), QuickDASH and a pain questionnaire. The mean post-injury B&M score improved from 42 points at 6 weeks to 67 points by 3 months. By four years, surviving patients had a mean OES of 30 points, a mean QuickDASH of 38 points, and 95% reported a functional range of elbow flexion. Those with fracture non-union experienced greater pain on repetitive elbow activities, but no difference in rest pain, compared with patients whose fractures had united. The cumulative 1-year rate of fracture union was 53%, while the 5-year mortality approached 40%. Conservative management of distal humeral fractures confers a reasonable functional result to the patient whilst avoiding the substantial surgical risks associated with primary ORIF or TEA

Despite its clinical significance, metaphyseal fracture healing has received little attention in research and experimental models have been limited. In particular it is not known to what extent the mechanical environment plays a role in metaphyseal fracture healing. Recently, a new murine internal fixation plate has been developed to stabilise fractures in the distal femur under highly standardised conditions. Goal of the current study was to modify this design, in order to be able to evaluate the influence of the fixator bending stiffness on metaphyseal fracture healing in mice. Adapting the existing single body design, resulting in low flexibility fixation, two new plates were developed with a decreased bending stiffness of approximately 65% and 45% of the original implant (100%). Pilot experiments were performed on 54 animals, whereas the mice were sacrificed and fracture healing assessed radiologically and biomechanically after 14 and 28 days. MicroCT evaluation confirmed that the osteotomy was created in the trabecular, metaphyseal bone of the distal mouse femora. All bones showed progressive fracture healing over time, with decreased implant stiffness leading to increased periosteal callus formation. These implants represent an important new research tool to study molecular and genetic aspects of metaphyseal fracture healing in mice under standardized mechanical conditions, in order to improve clinical treatment in challenging situations, such as in osteoporotic bone

Background. Distal radial fractures in the elderly population have been traditionally managed by closed techniques, primarily due to their poor bone quality and low functional demands. Since the introduction of the volar locking plate (VLP), which provides a good fixation in osteoporotic bones, there maybe an increased use of open reduction and internal fixation (ORIF) in the elderly population. Aim. We aimed to determine the changes in the management of these fractures in Scotland, and whether this differs between specialist regional centres and district general centres. Patients and Methods. We retrospectively analysed distal radius fractures, in patients aged over 70 years in the period between 1989 and 2008. Data were obtained from the national statistical centre based on admission code and from discharge summaries. Data included patient demographics and treatment method; either open reduction and internal fixation (ORIF), Kirschner wire, or manipulation under anaesthetic (MUA). Results. Incidence of distal radius fractures has increased by 75% from 1989 to 2008. In 2003 there were 94 (13.6%) ORIF, 109 (15.1%) K-wire and 492 (71.3%) MUA. In 2008 there were 131 (22.5%) ORIF, 81 (14.2%) K-wire and 361 (63.3%) MUA. There has been a 34% increase in the number of ORIF and a 26% decrease in K-wire procedures. There is a difference in the proportion treated by ORIF in university hospital and district general hospital trusts; 11.8% more fractures are treated by ORIF in university hospitals (p<0.5). Conclusion. There has been an increasing tend to use VLP in the place of K wire fixation. However a vast majority of elderly patients are still treated primarily with MUA. There is an increased tendency to use VLP in university hospital trusts than in distict general hospitals. This may be a reflection of the availability and preferences of specialist orthopaedic hand surgeons

Introduction. A review of the literature showed a discrepancy between biomechanical and clinical studies on fracture fixation failure in patients with poor bone quality. The objective of the present study is to assess the influence of local bone status on complications after surgical treatment of proximal humerus fractures. Methods. A prospective cohort study was initiated in 2007. The inclusion criteria were closed displaced fractures of the proximal humerus, primary fracture treatment with a Philos plate, patients aged 50 to 90, normal pre-trauma function of both shoulders in accordance to age, and monotrauma. There was active follow-up for one year with radiological assessment at clinical centers from four countries. Bone quality at the proximal humerus was determined preoperatively for the contralateral side of the fracture by CT scan, and at the contralateral radius within six weeks post-surgery by DXA. The occurrence of complications was monitored up to one year post-surgery. Independent x-ray evaluation and final classification of all complications will be performed at the end by a study review board using anonymous data and x-rays. Preliminary Results. 157 patients, 127 female (79%) met the inclusion criteria. Their mean age at time of surgery is 69 (range 50–89). 119 patients (100%) attended the 1-year follow-up assessment, 64 (96%) the one at 3 months, and 148 (99%) the 6 week follow-up examination. According to the WHO criteria, 107 patients (71%) suffered from either osteopenia or osteoporosis, while 43 patients (29%) had a normal T-score. The overall reported complication rate was 39%. However, the number of intraoperative complications was 0.6%, bone/fracture complications 19.1%, implant complications 15.3%, and general complications 14.6%. Discussion. Fixation of proximal humerus fractures with Philos plates in elderly people with osteoporotic bone is associated with a high rate of fixation failure. Final results will be reported after x-rays, local BMD (CT- based) and complications assessment have been conducted

OBJECTIVES. In elderly patients the temporary loss of function of the upper extremity due to immobilization for treatment of unstable proximal humeral fractures is a very disabling condition. Stable fixation of such fractures allowing immediate functional aftercare may contribute to early social reintegration in this group of patients. Aim of this study is to present the surgical technique of humeral blade plate fixation and the clinical and radiographic results after fixation of unstable surgical neck fractures with this implant followed by immediate functional treatment in patients older than 60 years. PATIENTS. 20 patients (4 male, 16 female) with a mean age of 74 years (59y–93y) were included in this study and treated consecutively for an unstable/displaced surgical neck fracture with a humeral blade plate. Postoperatively functional treatment was allowed. All but one patient had a clinical and radiographic follow-up 6 weeks po. At an average final follow-up of 18,8 months (12–24 months) 4 patients had died from causes unrelated to surgery. RESULTS. Surgery was performed in all patients without local or general complications despite comorbidities. In all patients anatomic reduction and stable fixation could be achieved. 6 weeks po all patients (N=20) were free of pain at rest, 7 patients had low pain (VAS < 4) when actively moving the arm. All patients used their operated arm for ADL and were back home or in the institution they came from at the time of trauma. All fractures were deamed to be healed without implant failure. In two cases a clinically asymptomatic 1–2mm protrusion of the blade through the subchondral bone was observed, but did not required further surgery. At final follow-up (N=8) the average absolute Constant/Murley Score was 68,6 points (contralateral 71,4). Radiographically all fractures had healed without complications. Implant removal was not required. CONCLUSION. Humeral blade plate fixation combined with suture tension-banding of the rotator cuff allows indirect reduction, dynamic and stable osteosynthesis of unstable surgical neck fractures even in osteoporotic bone. In our small series, this technique has shown to be a safe and reliable therapeutic option allowing immediate functional treatment and thus early social reintegration in elderly patients

Introduction. Total knee replacement has been well-established form of treatment both for osteoarthritis and inflammatory arthritis. Both cemented and uncemented TKR have been used successfully. Since 1977 low contact stress (LCS) mobile bearing knee replacement has been in extensive use. Most of the intermediate and long term results reported are in osteoarthritis1–7. Though there are several studies reporting short term performance of TKR in rheumatoid arthritis8–19 there have been rare reports31 of intermediate to long-term performance of LCS uncemented TKR in rheumatoid arthritis. Methods. Retrospective, non-randomised and consecutive study. Case notes and radiological assessment done. Kaplan meyer survival analysis used. Radiological assessment between initial and final xrays done using T test statistics. Assessement done by two independent observer. Results. 108 knees in 67 patients are collected. 21 patients with 36 knees have died. Only 65 knees in 42 patients had both case notes and xrays which are included in this study. Of this 11 knees in 7 patients were dead. All 65 knees in 42 patients are sero-positive rheumatoid arthritis. Pre-operative bone loss was seen only in 4 knees. Bone loss was in the medial side in 3 knees (4,5 and 8mm respectively) and lateral in 1 knee (1 cm). None of these bone loss needed bone grafting or any special procedures. There was no subsidence in any of the 65 knees. Survival of uncemented LCS TKR in inflammatory arthritis patients is 100%. Aseptic failure is 0%. No infective failure. There is no significant change in the implant position. This is the longest follow for uncemented TKR in inflammatory arthritis ever reported in the literature. Conclusion and Discussion. In conclusion, our study has uniformity, as a single surgeon performed/supervised with senior trainees all the operations and all patients received the same level of post-operative care. Survival of LCS uncemented TKR in inflammatory arthritis patients is 100% up to 15years. This is the longest follow up in this patient population ever reported in the literature. Our study shows excellent survival and comparable to other cemented TKRs in this patient population reported in the literature. This study proves contrary to the general belief that uncemented TKR do poor in inflammatory arthritis due to osteoporotic bone

Introduction. Femoral neck fractures are a large clinical and economical problem. One of the most common fixation options for femoral neck fractures are multiple cancellous screws. A previous clinical study has shown the lack of washers to be the single largest predictor of fixation failure in the treatment of femoral neck fractures with cancellous screws. This finding was somewhat surprising as washers do not prevent the screws from backing out and do not provide any increase resistance to varus collapse. Therefore a follow-up biomechanical study was designed to test this observation. The purpose was to evaluate the maximal insertional torque of screws in osteoporotic bone with and without washers. We hypothesized that the lateral cortex of an osteoporotic proximal femur does not provide sufficient counter resistance for the screw heads to obtain maximum torque upon screw insertion in the femoral head and that the use of washers would increase screw purchase by providing a larger rigid surface area and subsequent higher counter resistance thereby allowing a higher maximal screw insertion torque. Methods. We used eight matched pairs of osteoporotic fresh-frozen human cadaveric femurs (age >70 years, all female). Two screws each were inserted in each femur either with or without a washer and maximal insertional torque was measured using a 50 Nm torque transducer. The testing was performed using a customized device which allowed the torque transducer to apply a constant axial force and torque speed to the screws. A paired Student's t-test was used to compare the maximal screw insertional torque of screws with washers versus screws without washers in matched pairs. Results. Fifteen out of 16 times the maximal screw insertional torque was higher when a washer was used. The average maximal torque with a washer was 5.1 Newtonmeter (Nm) compared to 3.1 Nm without a washer (p<0.001). Conclusion. We conclude that the addition of washers increases the maximal insertion torque of cancellous screws in the treatment of osteoporotic femoral neck fractures by providing counter resistance to the screw heads at an otherwise weak lateral cortex. We have demonstrated that the washer prevents the screw heads from penetrating the lateral cortex and provides for an improved purchase of the screws in the femoral head. As a clinical reference value for interpretation of this data, the limit of torque limiting screw drivers used with locking plates is set between 4 and 6 Nm. Therefore the difference in insertion torques likely represents clinically relevant values. Since there is no apparent disadvantage in the use of washers and they are inexpensive and readily available even in less developed countries, we advocate for their routine use until larger clinical studies disprove their efficacy

Introduction. The most common treatment options for fixation of osteoporotic distal femur fractures are retrograde nails and locking plates. There are proponents of more elastic titanium plates as well as more rigid steel plates; No clear superiority of one over the other has been established. We aimed to evaluate the mechanical differences between stainless steel and titanium locking plates in the fixation of distal femur fractures in osteoporotic bone. We hypothesized that due to its higher elasticity titanium locking plates can absorb more energy and are therefore less likely to “cut” into the bone compared to stainless steel locking plates resulting in improved metaphyseal osteoporotic fracture fixation. Methods. We used eight matched pairs of osteoporotic fresh-frozen human cadaveric femurs (age >70 years, all female). Within each pair we randomized one femur to be fitted with a Less Invasive Stabilization System (LISS-Titanium locking plate) and one with a Distal Locking Condylar Plate (DLCP-Stainless steel locking plate). A fracture model simulating an AO 33-A3 fracture was created (extraarticular comminuted fracture) and specimens were subsequently subjected to step-wise cyclic axial loading to failure. We used an advanced three dimensional tracking system (Polhemus Fastrak) to monitor the movement of the distal fragment relative to the real time distal plate position allowing us to evaluate distal implant cut-out. Results. During cyclic testing, seven of the eight pairs of matched femurs, the DLCP failed before the LISS plate (p=0.03). All constructs were able to withstand cyclical loading up to 800N. The overall plastic deformation as measured by the displacement of the Instron crosshead experienced by the titanium plate constructs was significantly lower compared to the stainless steel plate construct: The plastic deformation of the LISS plates was 39% lower compared to the Locking Condylar plates after cycle testing at 400 Newtons and 70% lower at 800N. Furthermore during the 800N cycle testing the LISS plating system showed a significantly lower rate of plastic deformation not only for the entire bone-implant construct, but also between the plate and the distal fragment than the locking condylar plate (=less distal implant cut-out). Conclusions. The use of a more advanced three dimensional tracking system, fresh-frozen osteoporotic matched human specimen and the ability to test all constructs to failure allowed us a more thorough comparison of titanium versus stainless steel implants compared to previous studies. The titanium locking plates provided an overall superior fixation of osteoporotic distal femur fractures with less distal implant cut-out, a better elastic recoil, and a slower rate of residual plastic deformation

Introduction. Distal radius fractures are one of the most common injuries attended in hospitals. Throughout the years the treatment has change from simple cast to ORIF. Objectives. To compare the functional and radiographic results in the treatment of the distal intrarticular radial fractures treated by volar buttress plate (T plate AO® Synthes, Oberdorf, Suiza) and fixed volar angle locking plate (DVR® Depuy, Warsaw, Indiana, USA). Material and Methods. We performed a comparative retrospective study between two series of patients treated by fixed volar angle locking plate (40 patients) or volar buttress plate (36 patients). Distal radius fractures were classified by the AO/ASIF Müller classification after X-ray study in two views (Anteroposterios and lateral views), surgical treatment was indicated by the type of fracture (unstable fractures) and open fractures. Demographic information was gathered, injury mechanism and postoperatory complications. The minimal follow-up was 10 months. We performed clinical and radiographic evaluations before surgery, postoperatory, to 3 months and at the end of the follow-up (Palmar tilt, radial inclination, radial height and the radioulnar index were measured). Lidström's and Quick Dash scale, by means of telephonic survey, were used for the functional evaluation. Results. The time from fracture to surgery was on average 3.74 days in the group of DVR ® plates and 1.69 days for the group treated with T buttress plates. Henry's approach was realized in every case and the average time spent in surgery was 74 minutes for patients treated with T buttress plate and 80 minutes for patients treated with plate DVR®. In some cases K wires had to be used in 9 cases in the DVR® group and 7 in the other group. DVR® group obtained better results in radiological evaluation except in the radial inclination. In the Quick Dash scale, conducted a telephone survey, the average for the DVR® group was 26.40 (CI: 13.6 to 81.8) and 33.37 (CI: 10.2–90) for the group of T buttress plate (p=0.055). Conclusion. The potential advantages of ORIF in the distal radius fractures are low complication rate, stable subchondral fixation and early active movement of the wrist in the postoperative period. The disadvantages are a high cost, greater complexity and surgical exposure. Locking plates were designed to prevent postoperative collapse of the fracture also allows a better fix system in osteoporotic bone. Both types of plates obtained good results radiological and functional at the end of follow-up but we have obtained better results in the patients treated with locking plates

Introduction. Locking compression plate (LCP) fixation is an established method of treatment of distal third tibial fractures. No biomechanical data exists in the literature regarding their use. Additionally no data exists on the biomechanical advantage of locking screw fixation over non-locking screw fixation for these fractures. In this study the axial and torsional stiffness, axial load to failure and fatigue performance of a 3.5 mm LCP medial distal tibia Synthes plate was evaluated for the stabilisation of distal third tibial fractures. Additionally the performance of the plate in uni and bicortical locked mode as well as non-locked mode was evaluated. Methods. A standardized oblique fracture pattern was created in the tibial metaphysis of 3rd generation composite tibias, 40 mm from the distal end of the tibia (AO 43-A2.3). A 10mm fracture gap was used to model a comminuted metaphyseal fracture. A 3.5 mm medial distal tibia LCP was applied with bi or unicortical locking or bicortical non-locking screws to 5 tibias respectively. All the bio-mechanical tests were performed on a Bose 3510 Electroforce material testing machine. A ramp to load, loading profile was used to determine the static axial and torsional performance of the construct. Fatigue testing simulated a 6 week gradual weight bearing régime with the load increasing every two weeks by 400N until either 250,000 cycles were completed or the construct failed. Results. The non-locked plate demonstrated a significantly higher load to failure than both the bicortical and unicortical locked plates, 683N vs. 575N vs. 483N respectively(p<0.01). The non locked plate also demonstrated significantly higher mean axial stiffness than the bicortical locked plate and unicortical locked plate 632±13 N/mm, 337±12N/mm and 266±6 N/mm respectively (p <0.01). The non locked plate demonstrated the highest torsional stiffness followed by the bi and unicortical locking plates 1.16 ±.08 Nmm vs. 0.79 ± .06 Nmm vs.0.40 ± 0.02 Nmm respectively (p < 0.01). The non locked plate demonstrated higher endurance than the bi and unicortical locking plates over a 6 week simulated fatigue cycle with 1.75mm, 2.10mm and 2.3mm residual displacement at 1600N respectively (p < 0.01). Discussion. This is the first study that has examined the biomechanical properties of the LCP when used for distal third tibial fractures. A review of the literature suggests LCPs outperform dynamic compression plates in osteoporotic bone but demonstrates no clear biomechanical advantage in using a locking construct in non-osteoporotic bone. In our study the non locked construct outperformed the locked constructs in all parameters assessed. We conclude there is no advantage in using a locking construct for distal third tibial fractures in good quality bone

Introduction. Pedicle screw pullout or loosening is increased in the osteoporotic spine. Recent studies showed a significant increase of pullout forces especially for PMMA-augmentation. With application of conventional viscosity PMMA the risk of cement extravasation is associated. This risk can be reduced by using radiofrequency-responsive, ultrahigh viscosity bone cement. Method. 11 fresh-frozen lumbar vertebral bodies (VB) from 5 cadavers were collected and freed from soft-tissue and ligaments. By DEXA scan (Siemens QDR 2000) 8 VB were identified as severely osteoporotic (BMD 0.8 g/cm3), 3 VB were above this level. Two screws (6×45 mm, WSI-Expertise Inject, Peter Brehm, Weisendorf, Germany) were placed in the pedicles. Through the right screw 3ml of radiofrequency-responsive bone cement (StabiliT® ER2 Bone Cement, DFine, Germany) were injected via hydraulic cement delivery system (StabiliT® Vertebral Augmentation System, DFine, Germany). As control group, left pedicle screws remained uncemented. After potting the whole VB in technical PMMA (Technovit 4004, Heraeus Kulzer, Germany) axial pullout test was performed by a material testing device (Zwick-Roell, Zmart-Pro, Ulm, Germany). Results. The mean BMD of all specimen was 0.771 g/cm3 (min./max. 0.615/1.116, SD ± 0.170). Due to the definition of osteoporosis 8 specimens had a BMD lower than 0.8 g/cm3 (mean 0.677, min./max. 0.615/0,730, SD ±0.045). The non-osteoporotic group consisted of 3 specimens with a mean BMD of 1.020 g/cm3 (min/max 0.928/1.116, SD ±0.094). Overall we observed an increase in the mean axial pullout strength of 284% when using cement augmentated screws (non-cemented 385 N vs. cemented 1029 N, p 0,001). In the osteoporotic group the mean pullout force of the non-cemented screws was 407 N vs. 1022 N for the cemented screws (p 0.001). Similarly the pullout force rose in the non-osteoporotic group from 325 N for the non-cemented screws to 1048 N for the cemented screws p 0,001). All surgical procedures could be performed without technical problems. Conclusion. This cadaver study demonstrates the efficacy and effectiveness of pedicle-screw augmentation with ultra-high viscosity cement. Pullout forces are significantly increased, especially in osteoporotic bone. No complications like clogged in cannulated pedicle-screws or extravasation of bone cement were observed. In daily clinical routine radiation exposure to operator during cement delivery is reduced due to remote-controlled, automated delivery of radiofrequency-responsive bone cement. Furthermore availability of longer time to work with the cement (up to 30 min) is achieved; hectically injection or multiple-cement-mixing is not necessary anymore. The WSI-Expertise cannulated pedicle screws can be inserted and also augmented in a minimal-invasive technique. The PMMA then is injected through an extension adapter. PMMA augmentation of pedicle screws is already well established in spine surgery. With the combination of radiofrequency-responsive, ultra-high viscosity bone cement and cannulated pedicle screws this established procedure could become more controlled and safer for both patient and physician