Introduction:: Various reference axes are used in total knee arthroplasty to determine the femoral rotation including transepicondylar axis, posterior condylar axis and Whiteside’s line. However, there are currently no golden standards as to the ideal axes to determine the true femoral rotation.

Materials and Methods: A prospective observational study was performed to analyse the various axes used to determine femoral rotation during total knee replacement. All consecutive patients who underwent MRI of the knee between December 2006 and May 2007 were considered to be included in the study. Patients below the age of 20 years, above the age of 40 years and mass lesions obscuring the bony landmarks were excluded. The transepicondylar, posterior condylar, posterior femoral cortical, anterior femoral cortical and tibial anteroposterior axes were measured on the PACS system.

Results: Of the 100 patients, there were 75 males and 25 females with a mean age of 31(20–39) years. The mean relation between the posterior condylar axes and transepicondylar axes was 3.9 (SD−1.71, 95% CI 3.58–4.26), posterior condylar axes and posterior femoral cortical axes was 5.85 (SD−2.76, CI 5.3–6.4), posterior condylar axis and anterior cortical axis was 6.21 (SD−3.09, CI 5.6–6.8) and posterior condylar axes and tibial anteroposterior axes was 89.6 (SD−5.18, CI 88.5–90.6).

Conclusion: The transepicondylar axis appears to be the most consistent amongst the landmarks used to determine femoral rotation. However even the transepicondylar axis shows a significant variation. If transepicondylar axis is not available we suggest the use of femoral anterior cortical axes as a reference landmark

Background: Arthrodesis is still the recommended treatment for end-stage hallux rigidus in young and active patients. Silicone implant arthroplasty of great toe was first described back in 1979 by Swanson et. al. Over the years, total joint replacement arthroplasty has taken over, as the apparent complication rate with silicone appeared high.

Objective: The objective of this retrospective study was to analyse medium to long-term clinical outcomes and patient satisfaction of patients with silastic implant arthroplasty of great toe.

Methods: Between May 1996, and December 2004, 65 patients totalling 76 first metatarsophalangeal silastic implants were evaluated both subjectively and objectively. The group comprised of 25 males and 40 females with average age 56 years (26–86). The average time of follow-up was 6 years (2–11). 12 patients (18%) has previous metatarsal osteotomy with bunionectomy for hallux valgus.

Outcomes were assessed by overall subjective satisfaction, Visual Analogue Scale (VAS) for pain, functional scores, range of motion and radiographic evaluation.

Results: Overall success rate was over 80%. 90% patients reported good pain relief after the operation. All patients regained satisfactory range of movement in the joint. The average flexion was 110 (5–200) and extension 200 (10–300). None of the patients reported difficulty in walking or slow running.

6 patients (9%) complained of persisting mild to moderate pain and swelling in the joint. 2 patients (3%) were not happy with the level of deformity correction. All the above 8 patients declined to have joint arthrodesed. 2 patients (3%) had deep infection requiring implant removal. 1 patient had osteolysis on the x-rays but remain asymptomatic. Although radiographic deterioration of the implant was demonstrated in a lot of implants, this deterioration did not correlate with patient satisfaction.

We conclude that silastic first metatarsophalangeal joint replacement is a proven procedure that not only provides long- term pain relief but also satisfactory range of movement. Therefore it should still be considered as an option in patients with end-stage hallux rigidus.

To analyse the intra-operative variation in mechanical axes of the lower limb at various stages during navigated total knee replacement. A prospective study was performed to analyse the intra-operative variation in the mechanical axes of the lower limb during navigated total knee replacement. All consecutive patients who underwent navigated total knee replacement were included and patients with inadequate data were excluded from the study. The intra-operative initial, trial and the final mechanical hip-knee-ankle axes were recorded from the navigation system. The differences between these axes were calculated and analysed. There were forty patients, of which 24 were females and 16 males with the age ranging from 37–89 (average 68.4) years. The right knee was replaced in 27 and the left knee in 13 patients. The average initial mechanical axes alignment was 0.03° valgus (3° varus to 3° valgus), trial alignment 0.64° varus (3° varus to 1.5° valgus) and final alignment 0.25° varus (4° varus to 4° valgus). Average deviation from initial to trial axes was 0.97°, trial to final axes was 0.74° and initial to final axes was 1.08°. The cor-relation co-efficient between the initial and the trial axes was 0.25, trial and final axes was 0.43 & initial and final axes was 0.09.

This study highlights a significant variation in mechanical axes between the different stages of navigated total knee replacement. The potential sources of intra-operative errors causing these changes could be soft tissue imbalance, variations in implant placement and possible tracker micro motion. Execution of bony cuts in near normal neutral alignment does not guarantee achievement of near normal final alignment. We advocate surgeons to be vigilant to avoid potential malalignment during navigated total knee replacement.

AIM: The purpose of this retrospective study was to assess the results of a novel surgical technique for chronic lateral ankle instability using dynamic extensor digitorum brevis (EDB) muscle transfer.

METHODS: 15 patients underwent dynamic EDB muscle transfer for symptomatic chronic lateral ankle instability. All patients were quite fit and physically very active. 9 male and 6 female patients, mean age 27 (range, 22–32) were operated by single surgeon (ALP) between March 2003 and August 2005. All patients had standard procedure involving proximal transfer of the origin of EDB muscle whilst preserving its neuro-vascular pedicle. All patients went through a standard post-operative physiotherapy protocol including pro-prioceptive training. Mean follow-up was 24 months (range, 12–36 months). The mean functional Karlsson scores improved from 26.5 before surgery to 86.5 at 12 months after surgery. At follow-up, all patients had normal range of ankle movements and were functionally stable. All patients regained their pre-injury activity level at 12 months after surgery. There were no early or late complications in our series.

DISCUSSION: Ankle sprains are the most common injuries sustained during sports and physical exercise. Treatment is usually conservative because most of these injuries heal without consequence. However, symptomatic chronic lateral ankle instability is a difficult problem to treat and several surgical techniques have been described. EDB muscle not only acts as a dynamic substitute for the deficient ligament but also overcomes the problem of over-tightening of the ligament leading to restricted supination.

CONCLUSION: Dynamic EDB muscle transfer is a safe, clinically effective and reliable surgical option for symptomatic chronic lateral ankle instability.

Significant concerns remain in computer navigated surgery regarding potential errors due to inadequate tracker or array fixation, cutting guide block movements, saw blade deviation, variable component seating and standardisation and validity of radiographic measurements of alignment for outcome assessment. There are no studies in the literature comparing computer generated axes at different steps of operation as well as radiographic axes using scanograms to our knowledge. Long leg films involve significant radiation, which can be minimised by the use of scanograms.

A prospective study was performed to compare the per-operative and post-operative alignment of the lower limbs after navigated total knee replacements. All consecutive patients who underwent navigated total knee replacement between May 2006 and November 2006 were included in the study. Patients with inadequate data, patients who refused to participate in the study or lost contact, obvious measurement errors and patients having had recent operations were excluded. The intra-operative initial, trial and the final axes were recorded from the navigation system. Post-operatively a CT (Computer Tomogram) scanogram of the lower limbs was performed as per the scanogram protocol. Measurement of the mechanical hip-knee-ankle axis of the lower limb was performed on the computer. Results were analysed using appropriate statistical methods and comparison made between initial, trial, final and scanogram axes with assessment of their correlation coefficients.

Twenty-five patients were initially recruited in the study, of which, 15 were available with completed data. There were four males and 11 females with the age ranging from 57–80 (average 70) years. The right knee was replaced in 12 and the left knee in three patients. The average initial alignment was 0.09° valgus (0.5° varus to 1° valgus), trial alignment 0.59° varus (2° varus to 1° valgus), final alignment 0.56° varus (4° varus to 1.5° valgus) and average radiographic alignment was 0.52° varus (3.1° varus to 1.8° valgus) in maximum possible extension. Average deviation from initial to trial alignment was 0.69° varus, trial to final was 0.03° varus and final to radiographic alignment was 0.12° valgus.

Correlation co-efficient of 0.62 between the initial and final axes with average difference of 0.72° varus (p= 0.11, unequal variance 2 tailed) demonstrates reasonable reproducibility of the alignment with computer-guided surgery, also confirming the fact that there is some variation between the initial cut angles and final mechanical axes. Correlation co-efficient of 0.92 between final axes and radiographic axes suggests that scanogram is an imaging modality with reasonable accuracy for measuring mechanical limb alignment despite significantly low radiation and relatively low resolution. Potential errors in radiographic measurements due to rotational malposition combined with flexion deformity is highlighted.

This study aimed to A) establish a protocol for measuring periprosthetic bone mineral density (BMD) of the proximal humerus following implant arthroplasty, and B) compare the differences in the periprosthetic BMD values 4–9 years after surface replacement and stemmed arthroplasties of the proximal humerus. The study design was of retrospective independent samples cohorts, of patients who had received a proximal humeral arthroplasty between January 1992 and December 1996 in a tertiary referral shoulder unit of a UK hospital. The exclusion criteria were A) patient unavailable for study, B) patient refusal, C) inadequate information of dependent and independent variables, or D) obvious measurement errors.

All available patients underwent DEXA scanning of the proximal humerus using a Lunar DPXL scanner fitted with Orthopaedic Hip software version 1.3. Replicable patient positioning with a special jig was used. On a predetermined format of Gruen equivalent zones and sub-zones, BMD values in gm/cm² were plotted. Cortical thickness on plain radiographs was recorded for each zone. Femoral neck DEXA scan was performed to obtain a proportionate value of BMD of the proximal humerus, in order to eliminate the effect of confounding variables. Confounding variables accounted for were age, gender, height, weight, activity level, indication for surgery, duration of implantation, dominance, type of arthroplasty (hemi or total) and use of cemented or uncemented stemmed implants. Statistical analysis was performed using Microsoft excel as well as SPSS software.

Initially, 58 shoulders in 52 patients were recruited. 6 patients declined to participate for ill health, 6 had moved out of the area and 8 did not attend or reply. Of the remaining 31 shoulders in 25 patients, 2 patients had an obviously erroneous DEXA reading. 29 shoulders in 23 patients were finally analysed, which included 10 male and 19 female shoulders. Average age was 67.5 years and average time since surgery was 6 years 2 months. Indications for surgery were RA in 14, OA in 8 and other reasons in 7. Of 29 shoulders, 20 received a total replacement, 9 a hemiarthroplasty.

The inevitable obliquity of the image caused some difficulties in maintaining accuracy and difficulties were observed due to limitation of the software to measure thin cortices and to distinguish between the cement and bone. There was no significant correlation between gross cortical thickness and BMD values, and the average periprosthetic BMD was 0.54 g/cm². Surface replacement implants were associated with relative preservation of proximal medial cortex and higher BMD values in this region. BMD values were consistently higher at the level of stem tip for the stemmed implants. No such phenomenon was observed for the surface replacement prostheses. Hemiarthroplasty was associated with relatively higher BMD values in the proximal medial cortical region than total arthroplasty.

Traumatic posterior dislocation of the sternoclavicular joint is an unusual injury. We report a rare, late complication in the form of a thoracic outlet syndrome. Resection of the first rib resulted in prompt and complete resolution of the symptoms and would appear to be the appropriate treatment, avoiding the complications associated with resection of the clavicle.