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

Introduction: Use of a variable angle sliding hip screw is an interesting therapeutic option in pathological trauma of the proximal femur. It has successfully been used in cases of loosening of previously implanted hardware and non-union. Materials and methods: In this study we present 26 cases treated consecutively in our department between 2001 and 2005. The majority of patients in this group had suffered complications in the treatment of proximal femoral fractures, including non-unions and nail cut-outs. Results: We treated 12 male patients and 14 female patients; mean age was 72 years. Mean hospital stay was 14.3 days. The patients were examined in our consulting offices and had a minimum 6 months follow-up, with controls of their evolution at 3 and 6 months and 1 year. During the study period functional and x-ray assessments were performed. No relevant alterations were found in any of the patients; all cases resolved successfully. Conclusions: The variable angle sliding hip screw has been successfully used in cases of severe complications in patients with proximal femur fractures. We have tried to summarize our 4 years’ experience in this study by presenting a series of different cases that went from failure of a previous osteosynthesis to other techniques applied to the fracture failure such as the use of autologous grafts to resolve non-unions. The variable angle sliding hip screw is a very useful and versatile tool in the hands of the orthopedic surgeon in certain cases where rescue surgery is necessary

The study looked at early outcomes of 55 patients who underwent open reduction and internal fixation of distal radius fracture with a single variable angle volar locking plate (Variax, Stryker), by a single surgeon (GS), between May 2007 and December 2008. A retrospective review of notes and radiographs was performed. Twenty-nine women and 26 men were included. The mean age was 52 years. Mean follow up time was 3 months. The dominant wrist was involved in 38 patients. The mechanism of injury was of low energy in 38 patients and of high energy in 17 patients. All patients had comminuted fractures and 52 patients had intraarticular fractures. Seven patients underwent intraoperative carpal tunnel decompression. At latest follow up, active wrist motion averaged 37° extension, 40° flexion, 70° pronation, and 56° supination. Grip strength averaged 64% and pinch grip 77% of the contralateral wrist. Postoperative complications included one flexor pollicis longus rupture, one malunion and three patients with loosening of screws. There was a higher rate of complications seen in patients with high energy injuries. These early results suggest that volar plating with a variable angle plate is an effective treatment option, especially for complex intraarticular distal radius fractures. A medium term outcomes study of a larger number of patients is planned

Purpose: We present a new basilar osteotomy we have called TRADE. This osteotomy uses a single flat-oblique cut to achieve lateral basimetatarsal translation with lowering and derotation. Material: The ATLAS system was used. This system includes a four point axial staple for the phalanx and a staple plate for the metatarsus. The staple plaque was designed around the tibial osteotomy plates. It is composed of a straight plate screwed to the diaphysis. It carries two spikes at variable angles that penetrate the epiphysis perpendicularly. The desired angle is measured peroperatively and the plate is bent appropriately using a graduated template. Application of the staple plate then imposes the exact correction. Method: We tested the basal osteotomy on five anatomic hallux valgus specimens, including one fresh specimen. We also reviewed 125 files of patients who underwent double flat-oblique osteotomy fixed with the system. Each type of hallux valgus was defined pre- and postoperatively, clinically and radiologically: four views, three to determine the orientation of the deformity in the three planes and a fourth one to assess reducibility. The operative technique involved four times. The first was often not necessary: lateral release, depending on the degree of retraction on the reduction view. The second time, the medial chevron osteotomy of the first phalanx, was almost always needed. The third time was the basimetatarsal ostetomy; the flat-oblique direction was determined from an abacus taking into account three variables: varus, rotation, lowering. The fourth time, exostosectomy with capsule retention, was not always needed. The patients experienced little pain postoperatively when the procedure was limited to the two osteotomies without affecting the soft tissues. For the 125 cases, intermetatarsal deviation was improved from 18°67 to 6°86, metatarsophalangeal angle from 33°59 to 11° and pronation from 13°42 to 0°72. Conclusion: The TRADE osteotomy allows correction in all three planes. Correction is particularly precise in the frontal plane where the risk of undercorrection and recurrence is high. The procedure can be modulated according to the radiological presentation and can be limited to two osteotomies using short skin incisions without opening the joint

Reviewing 40 consecutive cases over a two-year period, we tested the efficacy of variable screw plate fixation postoperatively.

A Codman plate was used in all cases. We compared radiological preoperative measurements of the kyphotic angle and disc height with immediate postoperative measurements and measurements at a mean of eight months postoperatively. In no case was there an increase in kyphotic angle. Disc height remained within two mm of that shown on immediate postoperative radiographs.

We concluded that satisfactory results are obtained with variable screw plate fixation, with no compromised stability.

The aim of this study was to determine the effect of a Galeazzi fracture on the strength of pronation and supination at a mean of two years after surgical treatment. The strength of pronation and supination was measured in varying rotational positions of the forearm of ten male patients (mean age 38.9 years (21 to 64)) who had undergone plate fixation for a Galeazzi fracture. The stability of the distal radioulnar joint was assessed, and a clinical assessment using the quick-Disabilities of the Arm Shoulder and Hand (quickDASH) questionnaire and patient-related wrist examination (PRWE) scores was undertaken. In addition, the strength of pronation and supination was measured in a male control group of 42 healthy volunteers (mean age 21.8 years (18 to 37)).

The mean absolute loss of strength of supination in the injured compared with the non-injured arm throughout all ranges of forearm rotation was 16.1 kg (sem 5.3), corresponding to a relative loss of 12.5% (95% confidence interval (CI) 3.6 to 21.4). For the strength of pronation, the mean loss was 19.1 kg (sem 4.5), corresponding to a relative loss of 27.2% (95% CI 14.2 to 40.1). Loss of strength of supination following a Galeazzi fracture correlated with poor quickDASH (p = 0.03) and PRWE scores (p < 0.01).

Loss of strength of pronation (27.2%), and of supination (12.5%) in particular, after a Galeazzi fracture is associated with worse clinical scores, highlighting the importance of supination of the forearm in function of the upper limb.

Cite this article: Bone Joint J 2013;95-B:1508–13.

Recently, a new generation of superior clavicle plates was developed featuring the variable-angle locking technology for enhanced screw positioning and optimized plate-to-bone fit design. On the other hand, mini-fragment plates used in dual plating mode have demonstrated promising clinical results. However, these two bone-implant constructs have not been investigated biomechanically in a human cadaveric model. Therefore, the aim of the current study was to compare the biomechanical competence of single superior plating using the new generation plate versus dual plating with low-profile mini-fragment plates. Sixteen paired human cadaveric clavicles were assigned pairwise to two groups for instrumentation with either a 2.7 mm Variable Angle Locking Compression Plate placed superiorly (Group 1), or with one 2.5 mm anterior plate combined with one 2.0 mm superior matrix mandible plate (Group 2). An unstable clavicle shaft fracture AO/OTA15.2C was simulated by means of a 5 mm osteotomy gap. All specimens were cyclically tested to failure under craniocaudal cantilever bending, superimposed with bidirectional torsion around the shaft axis and monitored via motion tracking. Initial stiffness was significantly higher in Group 2 (9.28±4.40 N/mm) compared to Group 1 (3.68±1.08 N/mm), p=0.003. The amplitudes of interfragmentary motions in terms of craniocaudal and shear displacement, fracture gap opening and torsion were significantly bigger over the course of 12500 cycles in Group 1 compared to Group 2; p≤0.038. Cycles to 2 mm shear displacement were significantly lower in Group 1 (22792±4346) compared to Group 2 (27437±1877), p=0.047. From a biomechanical perspective, low-profile 2.5/2.0 dual plates demonstrated significantly higher initial stiffness, less interfragmentary movements, and higher resistance to failure compared to 2.7 single superior variable-angle locking plates and can therefore be considered as a useful alternative for diaphyseal clavicle fracture fixation especially in unstable fracture configurations

This study examined pre-operative measures to predict post-operative biomechanical outcomes in total knee arthroplasty (TKA) patients. Twenty-eight patients (female=12/male=16, age=63.6±6.9, BMI=29.9±7.4 kg/m2) with knee osteoarthritis scheduled to undergo TKA were included. All surgeries were performed by the same surgeon (GD) with a subvastus approach. Patients visited the gait lab within one-month prior to surgery and 12 months following surgery. At the gait lab, patients completed the knee injury and osteoarthritis outcome score (KOOS), a timed up and go (TUG), maximum knee flexion and extension strength evaluation, and a walking task. Variables of interest included the five KOOS sub-scores, TUG time, maximum knee flexion and extension strength normalized to body weight, walking speed, and peak knee biomechanics variables (flexion angle, abduction moment, power absorption). A Pearson's correlation was used to identify significantly correlated variables which were then inputted into a multiple regression. No assumption violations for the multiple regression existed for any variables. Pre-operative knee flexion and extension strength, TUG time, and age were used in the multiple regression. The multiple regression model statistically significantly predicted peak knee abduction moment, post-operative walking speed, and post-operative knee flexion strength. All four variables added statistically significantly to the prediction p<.05. Pre-operative KOOS values did not correlate with any biomechanical indicators of post-operative success. Age, pre-operative knee flexion and extension strength, and TUG times predicted peak knee abduction moment, which is associated with medial knee joint loading. These findings stress the importance of pre-surgery condition, as stronger individuals achieved better post-operative biomechanical outcomes. Additionally, younger patients had better outcomes, suggesting that surgeons should not delay surgery in younger patients. This delay in surgery may prevent patients from achieving optimal outcomes. Future studies should utilize a hierarchical multiple regression to identify which variables are most predictive

One in five patients remain unsatisfied due to ongoing pain and impaired mobility following total knee arthroplasty (TKA). It is important if surgeons can pre-operatively identify which patients may be at risk for poor outcomes after TKA. The purpose of this study was to determine if there is an association between pre-operative measures and post-operative outcomes in patients who underwent TKA. This study included 28 patients (female = 12 / male = 16, age = 63.6 ± 6.9, BMI = 29.9 ± 7.4 kg/m2) with knee osteoarthritis who were scheduled to undergo TKA. All surgeries were performed by the same surgeon (GD), and a subvastus approach was performed for all patients. Patients visited the gait lab within one-month of surgery and 12 months following surgery. At the gait lab, patients completed the knee injury and osteoarthritis outcome score (KOOS), a timed up and go (TUG), and walking task. Variables of interest included the five KOOS sub-scores (symptoms, pain, activities of daily living, sport & recreation, and quality of life), completion time for the TUG, walking speed, and peak knee biomechanics variables (flexion angle, abduction moment, power absorption). A Pearson's product-moment correlation was run to assess the relationship between pre-operative measures and post-operative outcomes in the TKA patients. Preliminary analyses showed the relationship to be linear with all variables normally distributed, as assessed by Shapiro-Wilk's test (p > .05), and there were no outliers. There were no statistically significant correlations between any of the pre-operative KOOS sub-scores and any of the post-operative biomechanical outcomes. Pre-operative TUG time had a statistically significant, moderate positive correlation with post-operative peak knee abduction moments [r(14) = .597, p < .001] and peak knee power absorption [r(14) = .498, p = .007], with pre-operative TUG time explaining 36% of the variability in peak knee abduction moment and 25% of the variability in peak knee power absorption. Pre-operative walking speed had a statistically significant, moderate negative correlation with post-operative peak knee abduction moments [r(14) = -.558, p = .002] and peak knee power absorption [r(14) = -.548, p = .003], with pre-operative walking speed explaining 31% of the variability in peak knee abduction moment and 30% of the variability in peak knee power absorption. Patient reported outcome measures (PROMs), such as the KOOS, do indicate the TKA is generally successful at relieving pain and show an overall improvement. However, their pre-operative values do not correlate with any biomechanical indicators of post-operative success, such as peak knee abduction moment and knee power. Shorter pre-operative TUG times and faster pre-operative walking speeds were correlated with improved post-operative biomechanical outcomes. These are simple tasks surgeons can implement into their clinics to evaluate their patients. Future research should expand these findings to a larger sample size and to determine if other factors, such as surgical approach or implant design, improves patient outcomes

Background. Digital planning of implants in regard to position and size is done preoperatively in most cases. Intraoperative it can only be made by navigation systems. With the development of the VIPS-method (Virtual Implant Planning System) as an application for mobile C-arms, it is possible to do an intraoperative virtual planning of the screws near the joint in treatment of distal radius fractures by plating. Screw misplacement is a well known complication in the operative treatment of these fractures. The aim of this prospective randomised trial was to gain first clinical experiences and to compare VIPS with the conventional technique. The study hypothesis was that there will be less screw misplacement in the VIPS group. Methods. We included 40 patients with distal radius fractures type A3, C1 and C2 according to the AO-classification. In a pilot study the first 10 Patients were treated by the VIPS method to gain experience with VIPS in a clinical set-up. The results of the pilot-study are not part of this analysis. Then 15 Patients were web-based randomised into two groups. After diaphysial fixation of a 2.4 mm Variable Angle Two-Column Volar Distal Radius Plate and fracture reduction matching of a three-dimensional virtual plate to the two-dimensional image of the plate in the fluoroscopy shots in two plains was performed automatically in the VIPS group. The variable angle locking screws were planed in means of direction and length. Drilling was done by the use of the Universal Variable Angle Locking Drill Guide that was modified by laser marks at the rim of the cone to transfer the virtual planning. The drill guide enables drilling in a cone of 30°. In the control group the same implant was used in a conventional technique that means screw placement by the surgeon without digital planning. After implant placement an intraoperative three-dimensional scan was performed to check the position and length of the screws near the joint. OR- and fluoroscopy-time was documented. In addition the changes of misplaced screws were engaged. Results. In the VIPS group six A3-fractures, one C1-fracture and eight C2-fractures were included. In the control group six A3-fractures and nine C2-fractures were included. The intraoperative fluoroscopy time was 2.53 min (SD 1.44, range 1.27–7.14) in the VIPS group and 2.26 min (SD 0.51, range 1.55–3.39) in the control group (p=0.40). The OR-time was 53.33 min (SD 34.49, range 34–171) in the VIPS group and 42.27 min (SD 8.76, range 20–58) in the control group (p=0.23). In the VIPS group we changed three screws (two were too long, one was borderline near the joint) and two screws in the control group (one was too long, one was borderline near the joint) (p=0.24). Conclusions. The Virtual Implant Planning System is a reliable method that can be integrated easily in the workflow in treatment of distal radius fractures. There is a tendency that the virtual implant planning needs additional time, but there are no significant differences between the two groups. Further development is necessary to make the VIPS method beneficial

We present the results of a bi-centre, retrospective study examining the clinical, functional and radiological outcomes of distal radius fracture fixation with the Aptus locking plates and Tri-Lock® variable angle locking screws. We assessed 61 patients with distal radius fractures with a minimum of six months follow-up. Functional assessment was made using the DASH score. We measured wrist range of movement and grip strength, and reviewed radiographs to assess restoration of anatomy, fracture union and complications. All fractures united within six weeks. Mean ranges of movement and grip strength were only mildly restricted compared to the normal wrist. The mean DASH score was 18.2. Seven patients had screws misplaced outside the distal radius although 3 of these remained asymptomatic. Five other patients developed minor complications. Variable angle locking systems benefit from flexibility of implant positioning and may allow enhanced inter-fragmentary reduction for accurate fixation of intra-articular fractures. However, variable-angle systems may lead to increased rates of screw misplacement

The ITS volar radial plate (Implant Technology Systems, Graz/Austria) is a fixation device that allows for the distal locking screws to be fixed at variable angles (70°-110°). This occurs by the different material properties, with the screws (titanium alloy) cutting a thread through the plate holes (titanium). We present our experience with the ITS plate. We retrospectively studied 26 patients who underwent ITS plate fixation for unstable multifragmentary distal radial fractures (AO types A3, B2, B3, C2, C3). The surgery was performed either by a consultant orthopaedic hand surgeon or senior registrar. A volar approach was used every time and 10 cases required synthetic bone grafting. Post-operatively they were immobilised for an average of 2.5 weeks. The 26 patients had a mean age of 58 and the dominant side was affected in 46% of cases. 5 cases were open fractures and 10 cases followed failed manipulation under general anaesthesia. The average interval between injury and surgery was 7 days. Union was achieved in all cases. No implant infections, failure or tendon rupture/irritation occurred. There were two fractures which loss reduction, of which one required revision surgery. There was one case of CRPS. The six month average DASH score was 27.5. We consider the ITS plate a technically easy plate to use and a reliable implant at early follow-up. We value the versatility of its variable angle screw fixation ability for complex intra-articular distal radial fractures

Aims

Proper preoperative planning benefits fracture reduction, fixation, and stability in tibial plateau fracture surgery. We developed and clinically implemented a novel workflow for 3D surgical planning including patient-specific drilling guides in tibial plateau fracture surgery.

Aims

Several previously identified patient-, injury-, and treatment-related factors are associated with the development of nonunion in distal femur fractures. However, the predictive value of these factors is not well defined. We aimed to assess the predictive ability of previously identified risk factors in the development of nonunion leading to secondary surgery in distal femur fractures.

In Total Knee Arthroplasty (TKA) restoring the mechanical alignment of the knee joint is essential. This can be improved by considering the individual variability in the angle between the mechanical and anatomical axes of the femur (FMA angle). However with the traditional instrumentation and the use of the most common fixed distal femoral resection angle of 6° we assume little or no variation in the FMA angles in different patients. In a previous study we showed that the FMA angle had a wide distribution and that there was a good correlation between the FMA angle and the pre-operative lower limb alignment in the coronal plane. Our hypothesis was that improved post operative limb alignment would be achieved with traditional instrumentation by individual measurement of the FMA angles pre-operatively and adjusting the distal femoral resections accordingly. In the study we compared the post-operative coronal limb alignment for a cohort of patients with a variable distal femoral resection angle to the previous cohort of fixed distal femoral resection angle. The study consisted of 103 patients undergoing 103 consecutive primary TKAs between October 2008 and March 2009. All patients had pre- and post-operative Hip-Knee-Ankle digital radiographs and had TKAs performed using a variable distal femoral cut angle. The FMA angle and the mechanical femoro-tibial (MFT) angles were measured in all cases. Inter-observer variation was measured by second observer readings. We compared our results with the group of 158 consecutive patients undergoing 174 primary TKAs operated between January and October 2007 using fixed distal femoral resection angle. Patient demographics of the two cohorts (age, gender, BMI) were similar. The pre-operative coronal deformity for the variable cohort was less than the fixed, mean 3.7° varus (SD 5.8°) compared to 4.7° varus (SD 7.9°). The FMA angles for the variable cohort ranged from 4° to 8°, (the fixed cohort from 2° to 9°). The variable valgus resection angles cohort showed a correlation between FMA and pre-operative MFT angles as had previously been shown in the fixed cohort (r = −0.499 and r = −0.346 respectively). Post op alignment showed that accuracy within ±5° increased from 86% (fixed resection angle group) to 96% (variable resection group). When using the more commonly quoted accuracy of within ±3°, this changed from 67% (fixed resection angle group) to 85% (variable resection group). These improvements were statistically significant (chi-squared 0.025 and 0.002, respectively). To further evaluate the effect of using variable angles we analysed the improvement of each of the different groups of deformity identified in the previous study (> 8° varus, 8° varus to 1° valgus, > 2° valgus). The range was reduced in both the extreme varus and valgus groups with the variable angles. The most significant improvement was found in the valgus group with the median reducing from 3° to 2° and range from 14° to 8°. It seems logical to use a variable distal femoral resection angle based on the patient’s individual anatomy. By doing so, our results show significant improvement of postoperative limb alignment compared to traditional method of using fixed distal femoral resection angle. In units where preoperative long leg film radiographs are available, measuring the FMA angle and setting the distal femoral resection angle guide accordingly improves the postoperative limb alignment. However, where long leg radiographs are not available, changing the distal femoral resection angle according to the pre-operative varus-valgus deformity is likely to improve the post operative limb alignment. (e.g. 4°–5° distal femoral resection angle for preoperative valgus, 6° for preoperative mild/moderate varus, and 7°–8° for preoperative severe varus).Computer navigation, however, enables us not only to use customised distal femoral cut for each patients, but it also provides many other useful information such as dynamical limb alignment through motion, component rotation, soft tissue balancing

Aims

Historically, patients undergoing surgery for adolescent idiopathic scoliosis (AIS) have been nursed postoperatively in a critical care (CC) setting because of the challenges posed by prone positioning, extensive exposures, prolonged operating times, significant blood loss, major intraoperative fluid shifts, cardiopulmonary complications, and difficulty in postoperative pain management. The primary aim of this paper was to determine whether a scoring system, which uses Cobb angle, forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and number of levels to be fused, is a valid method of predicting the need for postoperative critical care in AIS patients who are to undergo scoliosis correction with posterior spinal fusion (PSF).

Rotator cuff tears are the most common cause of shoulder disability, affecting 10% of the population under 60 and 40% of those aged 70 and above. Massive irreparable rotator cuff tears account for 30% of all tears and their management continues to be an orthopaedic challenge. Traditional surgical techniques, that is, tendon transfers are performed to restore shoulder motion, however, they result in varying outcomes of stability and complications. Superior capsular reconstruction (SCR) is a novel technique that has shown promise in restoring shoulder function, albeit in limited studies. To date, there has been no biomechanical comparison between these techniques. This study aims to compare three surgical techniques (SCR, latissimus dorsi tendon transfer and lower trapezius tendon transfer) for irreparable rotator cuff tears with respect to intact cuff control using a clinically relevant biomechanical outcome of rotational motion. Eight fresh-frozen shoulder specimens with intact rotator cuffs were tested. After dissection of subcutaneous tissue and muscles, each specimen was mounted on a custom shoulder testing apparatus and physiologic loads were applied using a pulley setup. Under 2.2 Nm torque loading maximum internal and external rotation was measured at 0 and 60 degrees of glenohumeral abduction. Repeat testing was conducted after the creation of the cuff tear and subsequent to the three repair techniques. Repeated measures analysis with paired t-test comparisons using Sidak correction was performed to compare the rotational range of motion following each repair technique with respect to each specimen's intact control. P-values of 0.05 were considered significant. At 0° abduction, internal rotation increased after the tear (intact: 39.6 ± 13.6° vs. tear: 80.5 ± 47.7°, p=0.019). Internal rotation was higher following SCR (52.7 ± 12.9°, intact - SCR 95% CI: −25.28°,-0.95°, p=0.034), trapezius transfer (74.2 ± 25.3°, intact – trapezius transfer: 95% CI: −71.1°, 1.81°, p=0.064), and latissimus transfer (83.5 ± 52.1°, intact – latissimus transfer: 95% CI: −118.3°, 30.5°, p=0.400) than in intact controls. However, internal rotation post SCR yielded the narrowest estimate range close to intact controls. At 60° abduction, internal rotation increased after the tear (intact: 38.7 ± 14.4° vs. tear: 49.5 ± 13°, p=0.005). Internal rotation post SCR did not differ significantly from intact controls (SCR: 49.3 ± 10.1°, intact – SCR: 95% CI: −28°, 6.91°, p=0.38). Trapezius transfer showed a trend toward significantly higher internal rotation (65.7 ± 21.1°, intact – trapezius transfer: 95% CI: −55.7°, 1.7°, p=0.067), while latissimus transfer yielded widely variable rotation angle (65.7 ± 38°, intact – latissimus transfer: 95% CI: −85.9°, 31.9°, p=0.68). There were no significant differences in external rotation for any technique at 0° or 60° abduction. Preliminary evaluation in this cadaveric biomechanical study provides positive evidence in support of use of SCR as a less morbid surgical option than tendon transfers. The cadaveric nature of this study limits the understanding of the motion to post-operative timepoint and the results herein are relevant for otherwise normal shoulders only. Further clinical evaluation is warranted to understand the long-term outcomes related to shoulder function and stability post SCR

Backgrounds. The rigid fixation of glenoid base plate is essential for the prevention of dissociation of the construct in the reverse total shoulder arthroplasty. For the rigid fixation, ideal placement of fixation screw is crucial but it is difficult to determine the best direction and length of screws. The purpose of this study was to determine configuration of optimal screw in cadaveric scapulae and compare with that in patient who underwent reverse total shoulder arthroplasty. Materials and methods. Seven scapulae were used and implanted using a variable angle base plate with four directions screws. Optimal screw placement was defined as that which maximized screw length, accomplished far cortical purchase. Insertion angle and length of every screw was measured from AP and axial radiograph taken after the screws fixation. In a similar manner, the insertion angles of screws were measured from radiographs of 7 postoperative patients who underwent reverse total shoulder arthroplasty. The averages of length and insertion angle of 4 screws from two groups were compared. Result. The average lengths of screws were anterior 29.4 mm, posterior 15.0 mm, superior 36.0 mm, inferior 46.7 mm in the cadavers group and 22.2 mm, 22.3 mm, 28.0 mm, 29.1 mm each in the patient group. There was statistical significance of the difference of the insertion angle of superior and inferior screws between two groups. Conclusion. Trajectory angles of superior and inferior screw were smaller than those of optimal screws. Awareness of this tendency is helpful to insert the optimal screws intraoperatively

Tightrope fixation is known method for reconstructing acromioclavicular joint and the presence of good bone stock around the two drillholes is the most important determining factor for preventing failure. Aim. Arthroscopic-assisted tightrope stabilisation involve drilling clavicle and coracoids in a straight line. This leads to eccentric drillholes with inadequate bone around it. Open tightrope fixation involves drilling holes under direct vision, independently and leading to centric hole with adequate bone around it. Our study assesses the hypothesis of tightrope fixation in relation to location of drillholes using CT-scan and cadaveric models for arthroscopic and open technique for ACJ fixation. Methods. CT-scans of 20 shoulders performed. Special software used to draw straight line from distal end of clavicle to coracoid. Bone volume around coracoid drillhole was calculated. Cadaveric shoulder specimens were dissected. The arthroscopic technique was performed under vision by drilling both clavicle and base of coracoid holes in one direction. Same specimens were used for open technique. Base of coracoid crossectioned and volume calculated. Results. 40 shoulders were included(20 cadaveric specimens&20 CT). Bone stock was adequate in both techniques. Variable angle for insertion of drillholes using arthroscopic technique were needed depending on shape of shoulder. Conclusion. Tightrope allows nonrigid anatomic fixation of acromioclavicular joint. Published studies showed high rate of fixation failure with tightrope system but with patient satisfaction and high functional results. Our study showed adequate bone stock around coracoid in both open and arthroscopic technique. Mode of failure remains unclear and we recommend further biomechanical studies to assess failure factors

The routine use of a fixed distal femoral resection angle in total knee arthroplasty (TKA) assumes little or no variation in the angle between the anatomical and mechanical femoral axes (FMA angle) in different patients. The aims of this study were threefold, firstly to investigate the distribution of FMA angle in TKA patients, secondly to identify any correlation between the FMA angle and the pre-operative coronal mechanical femoro-tibial (MFT) angle and in addition to assess post-operative MFT angle with fixed or variable distal femoral resection angles. 277 primary TKAs were performed using either fixed or variable distal femoral resection angles (174 and 103 TKAs respectively), with intramedullary femoral and extramedullary tibial jigs. The variable distal femoral resection angles were equal to the FMA angle measured on pre-operative Hip-Knee-Ankle (HKA) digital radiographs for each patient. Outcomes were assessed by measuring the FMA angle and the pre- and post-operative MFT angles on HKA radiographs. The FMA angle ranged from 2° to 9° (mean 5.9°). Both cohorts showed a correlation between FMA and pre-operative MFT angles (fixed: r = -0.499, variable: r = -0.346) with valgus knees having lower FMA angles. Post-operative coronal alignment within ±5° increased from 86% in the fixed angle group to 96% when using a variable angle, p = 0.025. For post-operative limb alignment within ±3°, accuracy improved from 67% (fixed) to 85% (variable), p = 0.002. These results show that the use of a fixed distal femoral resection angle is a source of error regarding post-operative coronal limb malalignment. The correlation between the FMA angle and pre-operative varus-valgus alignment supports the rational of recommending the adjustment of the resection angle according to the pre-operative deformity (3°-5° for valgus, 6°-8° for varus) in cases where HKA radiographs are not available for pre-operative planning