The regenerative potential of bone is enormous, and it is possible to lengthen limbs by bone distraction. However, there remains a major risk of fracture after lengthening the bone. Previous studies have described how the pixel value ratio may be used for determining the time for frame removal. The aim of this study was to investigate the intrarater and the interrater reliability of pixel value scores from radiographs in tibial lengthening prior to frame removal. Moreover, the study aimed to determine the overall number of X- rays obtained during circular frame treatment. Retrospective study. Patients treated with tibial lengthening by a circular frame at Aalborg University Hospital from January 1st 2000 to December 31st 2017 and a minimum of 12 months after frame removal were included. The bone was divided in proximal-, regenerate- and distal bone zone. These 3 zones were in AP x-ray divided in an anterior and posterior zone and in sagittal X-ray medial and lateral zone producing 6 zones in which the pixel value was measured. Pixel value ratio was calculated as: (Proximal pixel value+Distal pixel value)/2/Regenerate pixel value. Interrater correlations were calculated from measurements obtained by an orthopaedic registrar and an orthopaedic specialist. Intrarater correlation was calculated from repeated measurements obtained by an orthopaedic specialist. Mean duration of circular frame treatment was: 6 (+-3) months. Median number of x-ray controls during frame treatment were: 9 (+-4). Out of 90 tibial lengthening it was only possible to measure pixel value in all six areas of interest on 20 lengthening prior to frame removal. Major reasons for inability to obtain measurements were metal hardware crossing the areas of bone interest on x-rays. The mean (95 % confidence intervals) pixel ratios values were: 1) lateral: 0.96 (0.93–1.00); 2) medial: 0.95 (0.92–0.99); 3) anterior: 0.94 (0.90–0.97); 4) posterior: 0.96 (0.93–0.99). The mean (95 % confidence intervals) inter ratter ICC estimates were: 1) lateral: 0.8 (0.5–0.9); 2) medial: 0.8 (0.4–0.9); 3) anterior: 0.4 (−0.5–0.8); 4) posterior: 0.6 (0.1–0.9). The mean (95 % confidence intervals) intra ratter ICC estimates were: 1) lateral: 1.0 (0.9–1.0); 2) medial: 1.0 (1.0–1.0); 3) anterior: 0.9 (0.9–1.0); 4) posterior: 1.0 (1.0–1.0). Out of the 20 lengthening examined one fracture occurred in the bone regenerate after frame removal. Prospective studies are warranted to determine whether the pixel value ratio can be used as an indicator for frame removal

Reported rates of dislocation in hip hemiarthroplasty (HA) for the treatment of intra-capsular fractures of the hip, range between 1% and 10%. HA is frequently performed through a direct lateral surgical approach. The aim of this study is to determine the contribution of the anterior capsule to the stability of a cemented HA through a direct lateral approach. . A total of five whole-body cadavers were thawed at room temperature, providing ten hip joints for investigation. A Thompson HA was cemented in place via a direct lateral approach. The cadavers were then positioned supine, both knee joints were disarticulated and a digital torque wrench was attached to the femur using a circular frame with three half pins. The wrench applied an external rotation force with the hip in extension to allow the hip to dislocate anteriorly. Each hip was dislocated twice; once with a capsular repair and once without repairing the capsule. Stratified sampling ensured the order in which this was performed was alternated for the paired hips on each cadaver. . Comparing peak torque force in hips with the capsule repaired and peak torque force in hips without repair of the capsule, revealed a significant difference between the ‘capsule repaired’ (mean 22.96 Nm, standard deviation (. sd. ) 4.61) and the ‘capsule not repaired’ group (mean 5.6 Nm, . sd. 2.81) (p < 0.001). Capsular repair may help reduce the risk of hip dislocation following HA. Cite this article: Bone Joint J 2015;97-B:141–4

The implementation of knee arthrodesis has become synonymous with limb salvage in the presence of chronic sepsis and bone loss around the knee. This can be seen in failed trauma surgery or knee arthroplasty as an alternative to trans-femoral amputation. There is no prior literature assessing which factors affect knee arthrodesis using external fixation devices. Sixteen consecutive patients (four women and twelve men) made up of eleven infected knee implants, three internal fixations of the tibial following fractured tibial plateau as well as 2 infected native joints were identified. The mean age at initial surgery was 56 years (range 25 to 82 years). All procedures were performed under the direct supervision of the limb reconstruction teams using a standard protocol with either a Taylor spatial frame or Ilizarov frame. The patient records, microbiology results and radiographs of all patients who underwent knee arthrodesis at this institution between 1999 and 2010 were reviewed. Of the 16 patients in this study knee fusion occurred in eleven patients (69%). The five patients where arthrodesis failed all had significant bone loss on the pre-operative radiographs and confirmed at surgery. We found a relationship between a significant infection of the knee with MRSA and failure to fuse. Three of the five patients had MRSA isolated from inside the knee at some stage during their treatment. The five patients where fusion failed were on average older (mean age 63 years against 51 years) and had more extensive bone loss. Those who failed to fuse had more co-morbidities. We would conclude that where there is little or no bone loss, arthrodesis of the knee can be reliably achieved with the use of circular frame fixation. A greater number of negative factors also prolongs the amount of time spent in the external fixator. The presence of significant bone loss, infection, increased age and multiple co-morbidities requires careful evaluation and consideration of trans-femoral amputation as an alternative

Biomechanical studies involving all-wire and hybrid types of circular frame have shown that oblique tibial fractures remain unstable when they are loaded. We have assessed a range of techniques for enhancing the fixation of these fractures. Eight models were constructed using Sawbones tibiae and standard Sheffield ring fixators, to which six additional fixation techniques were applied sequentially. The major component of displacement was shear along the obliquity of the fracture. This was the most sensitive to any change in the method of fixation. All additional fixation systems were found to reduce shear movement significantly, the most effective being push-pull wires and arched wires with a three-hole bend. Less effective systems included an additional half pin and arched wires with a shallower arc. Angled pins were more effective at reducing shear than transverse pins. The choice of additional fixation should be made after consideration of both the amount of stability required and the practicalities of applying the method to a particular fracture

Objectives

The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method.