Introduction. Our unit has extensive experience with the use of Ilizarov circular frames for acute fracture and nonunion surgery. We have observed and analysed fracture healing patterns which question the role of relative stability in fracture healing and we offer limb mechanical axis restoration as a more important determinant. Aim. To assess for the presence of external callus, when only relative stability has been achieved but with anatomical restoration of the mechanical axis (ARMA). Methods. We retrospectively reviewed diametaphyseal proximal and distal tibial fractures treated with Ilizarov frame fixation in our unit between 2009 and 2017. We also reviewed cases where the Ilizarov frame technique had been used for complex femoral and humeral non-unions. Radiographs in 4 views were reviewed to assess bone healing, the presence of external callus and correction of lower limb mechanical axis. Results. 45 tibial plateau fractures, 42 distal tibial fractures and 20 humeral and 3 femoral non-unions were reviewed. Where ARMA was achieved, bone healing was observed to occur without external callus. ARMA proved more challenging in the distal tibia and where ARMA was not achieved external callus was visible during fracture healing. Conclusion. ARMA bone healing is reliable and occurs without formation of external callus, despite relative stability. This would suggest that external callus is produced not in response to just the magnitude of strain but also the direction of strain. Restoration of the mechanical axis is an important step in achieving union and needs to be considered when fixing fractures or treating non-unions

Despite multiple published reviews, the optimum method of correction and stabilisation of Blount's disease remains controversial. The purpose of this study is to evaluate the clinical and radiological outcomes of acute correction of late-onset tibial vara by percutaneous proximal tibial osteotomy with circular external fixation using two simple rings. This technique was developed to minimise cost in a context of limited resources. This study was conducted between 2016 and 2020. We retrospectively reviewed the clinical notes and radiographs of 30 patients (32tibiae) who had correction of late-onset tibia by proximal tibial osteotomy and Ilizarov external fixator. All cases were followed up to 2 years. The mean proximal tibial angle was 65.7° (±7.8) preoperatively and 89.8° (±1.7) postoperatively. The mean mechanical axis deviation improved from 56.2 (±8.3) preoperatively to 2.8 (±1.6) mm postoperatively. The mean femoral-tibial shaft angle was changed from – 34.3° (±6.7) preoperatively to 5.7° (±2.8) after correction. Complications included overcorrection (9%) and pin tract infection (25%). At final follow up, all patients had full knee range of motion and normal function. All cases progressed to union and there were no cases of recurrence of deformity. This simple procedure provides secure fixation allowing early weight bearing and early return to function. It can be used in the context of health care systems with limited resources. It has a relatively low complication rate. Our results suggest that acute correction and simple circular frame fixation is an excellent treatment choice for cases of late-onset tibia vara, especially in severe deformities

Background. Ilizarov hip reconstruction is a salvage option traditionally done with fixators, which often face limited compliance. We aimed at reviewing our early results of a novel technique with internal devices. Material and Methods. Retrospective evaluation of 7 patients was done that underwent Milch Batchelor procedure with dual plates followed by a second stage femoral lengthening by retrograde magnetic nail. The mean patient age was 13.8 years. A mean valgus of 410 (range, 300 to 550) and extension of 220 (range, 100 to 300) were created proximally. Results. At their mean recent follow-up of 19 months, all extremities were aligned with a mean Pelvic Mechanical Axis Angle (PMAA) of 83.80 and lateral Mechanical Axis Deviation (MAD) of 25.3 mm. The mean Lower-extremity Length Discrepancy (LLD) improved from 3.7 cm (range, 3 to 5 cm) preoperatively to 0.7 cm (range, 0 to 2 cm). The Trendelenburg sign was eliminated in five and delayed in 2. According to a predesigned clinical scoring system, there were 3 (43%) excellent, 2 (28.5%) good, 2 (28.5%) fair, and no poor results. One patient at 9 weeks broke plates, however went for healing. Conclusion. PSHR with internal devices is a patient-friendly alternative to fixators

Background. Computer-assisted navigation systems for total knee arthroplasty (TKA) were introduced to improve implantation accuracy and to optimize ligament balancing. Several comparative studies in the literature confirmed an effect on the component position and other studies could not confirm these results. For ligament balancing most studies found no significant influence on the clinical outcome using a navigation system for TKA. In the literature there were no reports of mid-term results after navigated TKA. With our study we wanted to show if the use of a navigation system for TKA will have an influence on the component's position and on the clinical results at 5-year follow up. Methods. We enrolled 200 patients in a prospective randomized study with a minimum follow up of 5 years. 100 TKA were operated on without using a navigation system (Group A) and 100 surgeries (Group B) were done with computer assistance. Radiological investigation by standard radiographs including a long-leg X-ray was performed with a follow up rate in Group A of 86.2% versus 80.2% in Group B. We measured the mechanical axis of the leg, lateral distal femoral angel (LDFA), medial proximal tibial angle (MPTA), tibial slope and the alpha-angle of the patella. Clinical investigation was performed with a follow up rate in Group A of 85.7% versus 79.8% in Group B including the parameters for the range of motion (ROM), ligament balancing, anterior drawer test, feeling of instability, anterior knee pain, effusion, WOMAC Score, Insall Score and HSS Knee Score. Results. In both groups there was no aseptic loosening or difference in TKA survival rate (Group A 95.4% versus Group B 98.85% 5-year survival rate, p = 0.368). With the navigation technique the mechanical axis of the limb in the frontal plane was improved (p = 0.015; Group B: 1.67 ° ± 1.6° versus 2,44 ° ± 2.2 ° in Group A). 90% of the Group B and 81% of the Group A were within 3 ° varus/valgus deformity of the mechanical axis of the limb (p = 0.157). The accuracy of tibial slope was higher in the Group B (p = 0.001). More patients of the Group B (95% versus 79%) were within a deviation of 3 °, −7 ° tibial slope (p = 0.007). The mean deviation of 90 ° LDFA was higher (p = 0.034) in the Group A (1.89 ° versus 1.36 ° in Group B). Mean deviation of 90 ° MPTA, mean MPTA, mean LDFA and patella alpha angle were similar in both groups (p 0.253). There was no difference in ROM, ligament balancing, anterior drawer test, anterior knee pain or feeling of instability (p 0.058). Insall Knee Score total (181 Group A/191 Group B) and HSS Knee Score total (91 Group A/93 Group B) was higher with the navigated procedure in Group B (p 0.026). WOMAC total and HSS grades were similar in both groups (p 0.070). Conclusions. The accuracy of the mechanical axis of the limb and the tibial slope was higher with the navigated procedure. TKA survival rate and clinical outcomes were similar in both groups at 5-year follow up

Kinematic alignment has increased in popularity over the last few years in an attempt to improve clinical outcomes following total knee arthroplasty (TKA). In our unit kinematic alignment has been used with patient-specific cutting guides as part of on-going clinical trials. We performed a retrospective analysis on all the TKA which had been planned to be implanted outside of the mechanical axis (0° ± 3°) based on pre-operative MRI scans and looked at their radiographic and clinical outcomes. We identified 21 knees which had been implanted as ‘planned outliers’. All had clinical and radiographic follow up to a mean 11.6 months post op. All had a standard long leg alignment radiograph performed at 6 weeks post op to confirm alignment. All patients had a good improvement in their Oxford Knee Scores with mean improvement from 23 pre-op to 42 at 1 year. Of our patients none had a poor clinical outcome due to the alignment of their TKA, 1 patient had a poor outcome because of a quadriceps rupture which occurred 4 months post-op. There were no post-operative radiographic abnormalities. In our unit kinematic alignment outside of the mechanical axis is not associated with an increased rate of short term complications

The objective of this study was to compare differences in alignment following robotic arm-assisted bi-unicompartmental knee arthroplasty (Bi-UKA) and conventional total knee arthroplasty (TKA). This was a prospective, randomised controlled trial of 70 patients. 39 TKAs were implanted manually, as per standard protocol at our institution, and 31 Bi-UKA patients simultaneously received fixed-bearing medial and lateral UKAs, implanted using robotic arm-assistance. Preoperative and 3-month postoperative CT scans were analysed to determine hip knee ankle angle (HKAA), medial distal femoral angle (MDFA), and medial proximal tibial angle (MPTA). Analysis was repeated for 10 patients by a second rater to validate measurement reliability by calculating the intra-class correlation coefficient (ICC). Mean change in HKAA towards neutral was 2.7° in TKA patients and 2.3° in Bi-UKA patients (P=0.6). Mean change in MDFA was 2.5° for TKA and 1.0° for Bi-UKA (P<0.01). Mean change in MPTA was 3.7° for TKA and 0.8° for Bi-UKA (P<0.01). Mean postoperative MDFA and MPTA for TKAs were 89.8° and 89.6° respectively, indicating orientation of femoral and tibial components perpendicular to the mechanical axis. Mean postoperative MDFA and MPTA for Bi-UKAs were 91.0° and 86.9° respectively, indicating a more oblique joint line orientation. Inter-rater agreement was excellent (ICC>0.99). Early functional activities, according to the new Knee Society Scoring System, favoured Bi-UKAs (P<0.05). Robotic arm-assisted, cruciate-sparing Bi-UKA better maintains the natural anatomy of the knee in the coronal plane and may therefore preserve normal joint kinematics, compared to a mechanically aligned TKA. This has been achieved without significantly altering overall HKAA

Aim. The purpose of this study was to analyze the patellofemoral kinematics in neglected adult developmental dysplasia of the hip patients with patellofemoral symptoms and tried to clarify the affect of the severity of dislocation, the amount of limb length discrepancy, the deviation of mechanical axis and the changes in femoral anteversion on patellofemoral alignment. Methods. The dynamic patellofemoral CT results of 39 patients with DDH suffering from knee pain were reviewed. The mean age was 40.07 (range: 22–61). 14 of them were bilateral and 25 were unilateral neglected DDH patients. The CT results of 12 patients suffering from unilateral patellofemoral pain following the treatment of locked intramedullary nailing was taken as control group. In this patients atraumatic and asymptomatic normal site was taken as control group. Results. In unilateral neglected DDH patients there was significantly higher medial patellar displacement in 0, 15, 30, 60 degrees flexion in the knee at the site of dislocation. Again in uninvolved site medial patellar displacement in 15, 30, 60 degrees flexion was higher with respect to control group. In the involved extremity the PTA angle in 0, 15, 30, 60 degrees flexion were significantly higher than in control group. This increase in PTA angle corresponding to medial patellar tilt was observed only in involved extremity. In the knees of patients with bilateral DDH there was significant medial patellar displacement in every flexion degrees with respect to control group. Besides in bilateral DDH patients, the PTA angle in 15, 30, 60 degrees flexion were significantly higher than control group corresponding to medial patellar tilt. The amount of leg length discrepancy and the severity of dislocation as well as mechanical axis deviation were not affecting the patellofemoral parameters in both unilateral and bilateral DDH patients. Conclusion. Both in unilateral and bilateral DDH patients there are major changes in patellar tracking on femur during knee flexion. Increased medial shift and medial patellar tilt were seen in these patient groups. The neglected DDH patients suffering from knee pain should be analyzed not only for tibiofemoral abnormalities but also for patellofemoral malignment

Electromagnetic navigation versus conventional Total Knee Arthroplasty: Clinical improvements Optical and electromagnetic (EM) tracking systems are widely used commercially. However in orthopaedic applications optical systems dominate the market. Optical systems suffer from deficiencies due to line of sight. EM trackers are smaller but are affected by metal. The accuracy of the two tracker systems has been seen to be comparable1. Recent advancements in optical navigated TKA have shown improved overall limb alignment, implant placement and reduce outliers when compared to conventional TKA2-4. This study is the first RCT to compare EM and conventional TKA. Two groups of 100 patients underwent TKA using either the EM navigation system or the conventional method. Frontal, sagittal and rotational alignment was analysed from a CT scan. Clinical scores including Oxford Knee Score (OKS) and Knee/Function American Knee Society Score (AKSS) were recorded pre-op, and at 3 and 12 months post-op. 3 month data presented includes 180 patients (n = 90). The 12 months data presented includes 140 (n = 70). The two groups had similar mean mechanical axis alignments (EM 0.31o valgus, conventional 0.15o valgus). The mechanical axis alignment was improved in the EM group with 92% within +/-3o of neutral compared to 84% of the conventional group (p = 0.90). The alignment of the EM group was improved in terms of frontal femoral, frontal tibial, sagittal femoral, sagittal tibial and tibial rotation alignment. However, only the sagittal femoral alignment was significantly improved in the EM group (p = 0.04). Clinically, both TKA groups showed significant improvements in OKS and AKSS scores between both pre-op to 3 month post-op and 3 months to 12 months post-op (p<0.001). The OKS and the AKSS knee score for the EM group was significantly better at 3 months post-op (OXS p = 0.02, AKSS knee p = 0.04). However there was no difference between the groups at 12 months. The mean pre-op range of motion (ROM) for both groups was 105o. This decreased to 102o in the EM group and 99o in the conventional group at 3 months. There was a significant improvement at 12 months post-op, EM = 113o (p = 0.012) and conventional = 112o (p = 0.026). There was no significant difference in ROM between the two groups at 3 or 12 months post-op. Therefore the alignment outcome of the EM TKA group was improved compared to the conventional group. The EM group also showed clinical improvements at 3 months post-op however these were not seen again at 12 months post-op. ROM was seen to decrease at 3 months post-op but then significantly improve by 12 month post-op

Introduction. Femorotibial malalignment exceeding ±3° is a recognised contributor of early mechanical failure after total knee replacement (TKR). The angle between the mechanical and anatomical axes of the femur remains the best guide to restore alignment. We investigated where the femoral head lies relative to the pelvis and how its position varies with respect to recognised demographic and anatomic parameters. We have tested the hypothesis of the senior author that the position of the centre of the femoral head varies very little, and if its location can be identified, it could serve to outline the mechanical axis of the femur without the need for sophisticated imaging. Patients & Methods. The anteroposterior standing, plain pelvic radiographs of 150 patients with unilateral total hip replacements were retrospectively reviewed. All patients had Tönnis grade 0 or 1 arthritis on the non-operated hip joint. All radiographs were obtained according to a standardised protocol. Using the known diameter of the prosthetic head for calibration, the perpendicular distance from the centre of the femoral head of the non-operated hip to the centre of pubic symphysis was measured with use of TraumaCad software. Anatomic parameters, including, but not limited to, the diameter of the intact femoral head, were also measured. Demographic data (gender, age, height, weight) were retrieved from our database. Results. There were 72 men and 78 women with a mean age of 67.0 years. The mean distance of the centre of the femoral head to the pubic symphysis was 89.1 mm (standard deviation [SD], 5.8 mm). This distance was higher in men (mean, 90.5 mm; SD, 5.6 mm) than in women (mean, 87.7 mm; SD, 5.8 mm) (p=0.003). No statistically significant correlations between this distance and body-mass index or age (p=0.57 and p=0.28, respectively) were revealed. However, height was strongly correlated with this distance (r=0.52, p < 0.01), as was the diameter of the femoral head (r=0.61, p < 0.01). The latter was significantly larger in men than in women (p < 0.01). Conclusion. This is the first study to demonstrate that the position of the centre of the femoral head has very little variability, irrespective of patient age or body-mass index. As expected, it varies with patient's height and gender. Although statistically significant, the difference between genders is < 3 mm and can be explained by the smaller femoral head size of females. Our findings should prove useful during TKR surgery, as they facilitate intra-operative identification of the centre of the femoral head. Based on these results, simple trigonometry shows that if a surgeon measures 9 cm from the symphysis pubis, a line from this point to the centre of the knee will be within 2° and 2.2° of the true mechanical axis in 98% (i.e. ± 3 SD of the mean) of male and female patients, respectively

Background. Humerus fracture non-union is a challenge for which a wide range of treatments exist. We present our experience of managing these by hybrid Ilizarov frame fixation, without bone graft or debridement of the non-union site. Methods. Case notes review of a consecutive series of 20 patients treated for aseptic humeral non-union between 2004 and 2016. Eighteen patients had previous plate or intramedullary nail fixations, and 2 had no prior surgery. During Ilizarov application, any existing metalwork preventing dynamisation of the fracture site was removed through minimal incisions before compression of the fracture site was then achieved. Only 3 patients had open debridement or osteotomy of the non-union site, otherwise all other patients had no debridement of their non-union. Results. Bony union was achieved in 17 patients (85%), with a further 2 achieving a functional fibrous union. The remaining patient subsequently had successful open surgery. Union rates were 66% (2/3) and 88% (15/17) for the debridement/osteotomy and non-debridement groups respectively. Mean frame duration was 193 days. One patient was treated for pin-site infection. The Chertsey Outcome Score for Trauma was used to assess patient reported outcomes. Conclusions. Simple changes to the physical properties acting upon a humeral non-union, such as adequate control of its strain environment and restoration of the mechanical axis, are enough on their own to initiate healing. In our practice, this eliminates any morbidity associated with extensive fracture debridements or donor harvest sites

The 8-plate (Orthofix, SRL, Italy) is a titanium extraperiosteal plate with 2 screws which acts as a hinge at the outer limits of the physis. It has been used for correction of both angular and sagittal deformity around the knee. To our knowledge this is the first study describing the use of 8-plates in leg length discrepancy (LLD) correction. We aimed to evaluate outcomes of temporary 8-plate epiphysiodesis in LLD, and to assess the complications associated with its usage. This retrospective study included 30 patients between 2007 and 2010 whom underwent 8-plate epiphysiodesis to address LLD. Leg length measurements were recorded using erect full leg length scanograms and comparison made between pre-operative, interval and final scanograms. Any deviations of the mechanical axis were also recorded. During the study period 34 epiphysiodeses were performed on 30 patients. There were 17 males and 14 females. The average age at the time of procedure was 10.7 years (range 3–15). Average time to final follow-up was 24 months (range 52–10). The average pre-operative LLD was 2.5 cm (range 1.5–6 cm). The mean overall rate of correction was 1.0 cm per year. The mean residual LLD at end of treatment was 1.1 cm (range 0–4.5 cm). Two patients experienced genu recurvatum deformity. This was associated with placement of distal femoral plates anterior to the mid-lateral line. Based on our experience 8-plate epiphysiodesis is a reversible, minimally invasive procedure with reliable results in length correction. However, careful device placement is required to prevent deformity

Accurate measurement of the alignment of the tibia is important both clinically and in research. The conventional method of measuring the angle of malunion after a fracture of the shaft of the tibia is potentially inaccurate because the mechanical axis of the normal bone may not pass down the centre of the medullary canal. An alternative method is described in which a radiograph of the opposite tibia is used as a template. A sample of 56 sets of standard radiographs of healed fractures of the shaft of the tibia was evaluated. The 95% limits of agreement between this and the conventional method were wide, being −6.2° to +5.5° for coronal angulation and −6.7° to +8.1° for sagittal angulation. These results suggest that the conventional method is inaccurate. The new method has good inter- and intraobserver reliability

Background. Adequate rotation of femoral component in total knee arthroplasty(TKR) is mandatory for preventing numerous adverse sequelae. The transepicondylar axis has been a well-accepted reference for femoral component rotation in the measured resection technique. In this technique, measured resection is performed referenced off the tibial cut - perpendicular to the tibial mechanical axis with the knee in 90 ° of flexion. However, to the best of our knowledge, it is not known whether this technique apply well to a knee with tibia vara. This study evaluates the reliability of the transepicondylar axis as a rotational landmark in knees with tibia vara. Methods. We selected 101 osteoarthritis knees in 84 symptomatic patients(mean age: 69.24 ± 5.68) with proximal tibia vara (Group A). Group A was compared with 150 osteoarthritic knees without tibia vara in 122 symptomatic patients (mean age: 69.51 ± 6.01) (Group B). The guide line for selection of all these knees were based on the degree of tibia vara angle (TVA) which was formed by line perpendicular to epiphysis and by anatomical axis of the tibia - all measured in radiographs of the entire lower limb. Magnetic resonance imaging (MRI) axial images with most prominent part of both femoral condyles were used for measurement of transepicondylar axis(TE), anteroposterior axis(AP) and posterior condylar axis(PC). Results. The mean TVA of group A was 8.94° ± 3.11 and group B was 1.24° ± 0.85. The TE line in Group A showed 6.09 ° ± 1.43 of external rotation, relative to PC. This did not show statistical difference compared with 5.95 ° ± 1.58 in Group B (p=0.4717). The AP line in Group A showed 6.06 ° ± 1.93 of external rotation, relative to the line perpendicular to PC. This was statistically significant when compared to 5.44 ° ± 2.13 in Group B (p=0.020). Conclusion. There is no difference between knees without tibia vara compared those with tibia vara with regards to transepicondylar axis. In addition, both groups have almost identical external rotation of approximately 6 °. The AP axis was only approximately 0.5 ° difference between the two groups. The distal femoral geometry was not affected by tibia vara deformity, that is, there were no hypoplastic or hyperplastic deformities of medial femoral condyle in osteoarthritic knees with tibia vara. The use of transepicondylar axes in determining femoral rotation may produce flexion asymmetry in knees with proximal tibia vara. So, It should be pointed out that more attention should be paid on femoral component rotation and flexion gap balancing in knees with proximal tibial vara

Introduction. Patellar tracking in total knee replacements has been extensively studied, but little is known about patellar tracking in isolated patellofemoral replacements. We compared patellar tracking and the position of the patellar groove in the natural knee, followed by implantation of the femoral component of a PFR (patella unresurfaced) and after implantation of the femoral & patellar component of the PFR. Methods. Computer navigation was used to track the patella in eight whole lower extremities of four cadavers in the natural knee, in the same knee with the femoral component of the PFR (PFR-P) and with the femoral and patellar component of the PFR (PFR+P, patella resurfaced) (Depuy Sigma PFR). The form and position of the trochlea in the natural knee and the patellar groove of the femoral component was also analysed. Values are means+/−SD, two tailed Student's t-test for paired samples. Results. With a PFR-P the patella had a slightly more lateral tilt (0.8+/−0.8° to 2.8+/−2.5° at 40–100° of flexion, p<0.05 vs. Nat), this was more pronounced with the PFR+P (2.0+/−0.7° to 4.9+/−1.8° at 20–90° flexion, p<0.05 vs. Nat., p<0.05 vs. PFR-P at 20–80° flexion). No differences in patella rotation were seen between the three groups. In the PFR-P group the patella tracked a little more medially compared to the natural knee (0.6+/− 0.7mm to 1.3+/−2.6mm, p<0.05 at 20°,80°,90° flexion). The difference was more pronounced after patella resurfacing (PFR+P) (2.1+/−2.0mm to 3.0+/−2.2mm, p<0.05 vs. Nat. at 10°–100°, p<0.05 vs. PFR-P from 10–100°). When analysed relative to the patellar groove of the trochlea/femoral component the patella in the natural knee tracked slightly lateral to the groove (2.0+/−1.7mm to 2.9+/−2.0mm at 50–100° p<0.05), so did the patella of PFR-P (2.0+/−2.3mm to 2.3+/−2.3mm at 60–90° flexion, p<0.05), whilst the PFR+P tracked right on the groove (0.6+/−3.7mm medially to 0.6+/−2.9mm laterally, p<0.05 vs Nat at 10–30° & 70–100°, p<0.05 vs. PFR-P at 10–100°). Distance from the patellatot the epicondylar axis was slightly larger in the PFR-P group (0.6+/− 0.7mm to 1.3+/−1.4mm, p<0.05 vs. Natu at 20,80 & 90°. This was more pronounced with patellar resurfacing (2.1+/−2.0 to 3.0+/−2.2mm, p<0.05 vs. Nat at 10–100°, p<0.05 vs. PFR-P at 20–100°) The patella groove on the natural knee and the implanted femoral component of the implanted PFR had the same radius, inclination relative to the femoral mechanical axis, antero-posterior position and medio-lateral orientation. As intended by the designers the groove of the patellar component extended about 13mm further superiorly and 0.5mm more inferiorly. Discussion. The patella groove on the femoral component of the PFR reproduces the natural trochlear anatomy well. Patella tracking in the PFR-P shows only minor differences compared to the natural knee. Resurfacing of the patella in the PFR+P group causes the patella to tilt a little more laterally and track a little more medially, the distance to the epicondylar axis is slightly larger but this allows the patella to engage better in the patellar groove of the femoral component

Objectives

External fixators are the traditional fixation method of choice for contaminated open fractures. However, patient acceptance is low due to the high profile and therefore physical burden of the constructs. An externalised locking compression plate is a low profile alternative. However, the biomechanical differences have not been assessed. The objective of this study was to evaluate the axial and torsional stiffness of the externalised titanium locking compression plate (ET-LCP), the externalised stainless steel locking compression plate (ESS-LCP) and the unilateral external fixator (UEF).

This study aimed to determine the long-term functional, clinical and radiological outcomes in patients with Schatzker IV to VI fractures of the tibial plateau treated with an Ilizarov frame. Clinical, functional and radiological assessment was carried out at a minimum of one year post-operatively. A cohort of 105 patients (62 men, 43 women) with a mean age of 49 years (15 to 87) and a mean follow-up of 7.8 years (1 to 19) were reviewed. There were 18 type IV, 10 type V and 77 type VI fractures. All fractures united with a mean time to union of 20.1 weeks (10.6 to 42.3). No patient developed a deep infection. The median range of movement (ROM) of the knee was 110^o and the median Iowa score was 85.

Our study demonstrates good long-term functional outcome with no deep infection; spanning the knee had no detrimental effect on the ROM or functional outcome.

High-energy fractures of the tibial plateau may be treated effectively with a fine wire Ilizarov fixator.

Cite this article: Bone Joint J 2015;97-B:1693–7.

Radiological evidence of post-traumatic osteoarthritis (PTOA) after fracture of the tibial plateau is common but end-stage arthritis which requires total knee arthroplasty is much rarer.

The aim of this study was to examine the indications for, and outcomes of, total knee arthroplasty after fracture of the tibial plateau and to compare this with an age and gender-matched cohort of TKAs carried out for primary osteoarthritis.

Between 1997 and 2011, 31 consecutive patients (23 women, eight men) with a mean age of 65 years (40 to 89) underwent TKA at a mean of 24 months (2 to 124) after a fracture of the tibial plateau. Of these, 24 had undergone ORIF and seven had been treated non-operatively. Patients were assessed pre-operatively and at 6, 12 and > 60 months using the Short Form-12, Oxford Knee Score and a patient satisfaction score.

Patients with instability or nonunion needed total knee arthroplasty earlier (14 and 13.3 months post-injury) than those with intra-articular malunion (50 months, p < 0.001). Primary cruciate-retaining implants were used in 27 (87%) patients. Complication rates were higher in the PTOA cohort and included wound complications (13% vs 1% p = 0.014) and persistent stiffness (10% vs 0%, p = 0.014). Two (6%) PTOA patients required revision total knee arthroplasty at 57 and 114 months. The mean Oxford knee score was worse pre-operatively in the cohort with primary osteoarthritis (18 vs 30, p < 0.001) but there were no significant differences in post-operative Oxford knee score or patient satisfaction (primary osteoarthritis 86%, PTOA 78%, p = 0.437).

Total knee arthroplasty undertaken after fracture of the tibial plateau has a higher rate of complications than that undertaken for primary osteoarthritis, but patient-reported outcomes and satisfaction are comparable.

Cite this article: Bone Joint J 2015;97-B:532–8.

We investigated a new intramedullary locking nail that allows the distal interlocking screws to be locked to the nail. We compared fixation using this new implant with fixation using either a conventional nail or a locking plate in a laboratory simulation of an osteoporotic fracture of the distal femur. A total of 15 human cadaver femora were used to simulate an AO 33-A3 fracture pattern. Paired specimens compared fixation using either a locking or non-locking retrograde nail, and using either a locking retrograde nail or a locking plate. The constructs underwent cyclical loading to simulate single-leg stance up to 125 000 cycles. Axial and torsional stiffness and displacement, cycles to failure and modes of failure were recorded for each specimen. When compared with locking plate constructs, locking nail constructs had significantly longer mean fatigue life (75 800 cycles (sd 33 900) vs 12 800 cycles (sd 6100); p = 0.007) and mean axial stiffness (220 N/mm (sd 80) vs 70 N/mm (sd 18); p = 0.005), but lower mean torsional stiffness (2.5 Nm/° (sd 0.9) vs 5.1 Nm/° (sd 1.5); p = 0.008). In addition, in the nail group the mode of failure was either cut-out of the distal screws or breakage of nails, and in the locking plate group breakage of the plate was always the mode of failure. Locking nail constructs had significantly longer mean fatigue life than non-locking nail constructs (78 900 cycles (sd 25 600) vs 52 400 cycles (sd 22 500); p = 0.04).

The new locking retrograde femoral nail showed better stiffness and fatigue life than locking plates, and superior fatigue life to non-locking nails, which may be advantageous in elderly patients.

Cite this article: Bone Joint J 2014;96-B:114–21.

Coronal plane fractures of the posterior femoral condyle, also known as Hoffa fractures, are rare. Lateral fractures are three times more common than medial fractures, although the reason for this is not clear. The exact mechanism of injury is likely to be a vertical shear force on the posterior femoral condyle with varying degrees of knee flexion. These fractures are commonly associated with high-energy trauma and are a diagnostic and surgical challenge. Hoffa fractures are often associated with inter- or supracondylar distal femoral fractures and CT scans are useful in delineating the coronal shear component, which can easily be missed. There are few recommendations in the literature regarding the surgical approach and methods of fixation that may be used for this injury. Non-operative treatment has been associated with poor outcomes. The goals of treatment are anatomical reduction of the articular surface with rigid, stable fixation to allow early mobilisation in order to restore function. A surgical approach that allows access to the posterior aspect of the femoral condyle is described and the use of postero-anterior lag screws with or without an additional buttress plate for fixation of these difficult fractures.

Cite this article: Bone Joint J 2013;95-B:1165–71.

Filling the empty holes in peri-articular locking plates may improve the fatigue strength of the fixation. The purpose of this in vitro study was to investigate the effect of plugging the unused holes on the fatigue life of peri-articular distal femoral plates used to fix a comminuted supracondylar fracture model.

A locking/compression plate was applied to 33 synthetic femurs and then a 6 cm metaphyseal defect was created (AO Type 33-A3). The specimens were then divided into three groups: unplugged, plugged with locking screw only and fully plugged holes. They were then tested using a stepwise or run-out fatigue protocol, each applying cyclic physiological multiaxial loads.

All specimens in the stepwise group failed at the 770 N load level. The mean number of cycles to failure for the stepwise specimen was 25 500 cycles (sd 1500), 28 800 cycles (sd 6300), and 26 400 cycles (sd 2300) cycles for the unplugged, screw only and fully plugged configurations, respectively (p = 0.16). The mean number of cycles to failure for the run-out specimens was 42 800 cycles (sd 10 700), 36 000 cycles (sd 7200), and 36 600 cycles (sd 10 000) for the unplugged, screw only and fully plugged configurations, respectively (p = 0.50). There were also no differences in axial or torsional stiffness between the constructs. The failures were through the screw holes at the level of comminution.

In conclusion, filling the empty combination locking/compression holes in peri-articular distal femur locking plates at the level of supracondylar comminution does not increase the fatigue life of the fixation in a comminuted supracondylar femoral fracture model (AO 33-A3) with a 6 cm gap.