The medial parapatellar approach in total knee arthroplasty is arguably the most common approach, but the subvastus approach is less insulting to the quadriceps mechanism.

A single centre, randomized controlled trial was conducted in a metropolitan hospital to investigate whether the subvastus approach afforded better outcomes than the medial parapatellar approach. Ninety participants with knee osteoarthritis were randomized to either the subvastus or medial parapatellar approach. The primary outcome was the American Knee Society Score and secondary outcomes reported included pain, extension and flexion range of motion, quadriceps lag, girth, Oxford Knee Score, 3 meter timed up and go test, days to straight leg raise, surgeon perceived difficulty, operation duration, tourniquet duration and length of stay. Data were collected preoperatively, intra-operatively, days 1,2,3, discharge, 6 weeks and 6, 12 and 18 months post operatively.

Analysis was undertaken on 76 participants revealing no significant difference with the primary outcome (p=0.076; MP 167.3±36.6; SV 153.1±36.6) or any other outcome except for surgeon perceived difficulty, which favored the medial parapatellar approach (p=0.001; MP 3.3/10±1.9; SV 5.4/10±2.3) and days to straight leg raise, which favoured the subvastus approach by 0.9 days (p=0.044; MP 2.8±1.9; SV 1.9±1.6).

The subvastus approach is technically more difficulty and offers no clinical benefit over the medial parapatellar approach.

Introduction: Magnetic Resonance Imaging (MRI) is the gold standard for imaging muscle and fatty infiltrate has featured in low back pain. However, there is little knowledge about in vivo features of neck muscles in chronic WAD. The purpose of this study was to quantitatively compare fatty infiltrate in the cervical extensors in patients with chronic WAD and controls across muscle and segmental level.

Methods: Volunteer subjects were gained through referral from local practitioners and the local university fraternity. A previously established MRI measure was performed in 113 female subjects (79- WAD & 34 healthy controls). Subjects with chronic WAD (> three months – < three years) were included if, classifiable as WAD II per the Quebec Task Force. The cohort was restricted to females (18–45 years) as they best represent those with chronic WAD. Volunteers were excluded when

classified as WAD I, III or IV

The measure was performed for the rectus capitis minor/major, multifidus, semispinalis cervicis/capitis, splenius capitis and upper trapezius. The values for all muscles were plotted for level and side and linear regression analysis was used to determine segmental trends (C3-7). A multi-factorial analysis of variance (MANOVA) was applied to investigate group means of whiplash and controls for fat indices across muscle, side and level. Bonferroni post-hoc comparisons were used to compare group by muscle interactions at each level. Multiple regression analyses were performed to determine if the score on the Neck Disability Index (NDI), age, Body Mass Index (BMI), compensation status and duration influenced fatty infiltrate. Significance was set at p < 0.05. Data presented as mean ± SD.

Results: The demographic characteristics of the two groups are: WAD (n = 79): age: 29.7 ± 7.8 years, BMI (kg/m2): 25.1 ± 5.7; duration: 20.3 ± 9.6 months and NDI: 45.5 ± 15.9. Healthy Controls (n = 34): Age: 27.0 ± 5.6 years, BMI: 23.0 ± 4.4.. NDI was not collected in controls.

MANOVA revealed significant main effects for group, muscle, segmental level and side (p < 0.0001), and significant interactions between Group:Muscle, Group:Level, Muscle:Level and Group:side (p < 0.0001). Sides were averaged for each muscle and level for post-hoc analysis.

There was a linear decrease in the fat indices from C3 – C7 for each muscle in both groups. No significant differences in fat indices across muscle, levels and side were noted in controls (p = 0.09). For the WAD subjects, the multifidus muscle had significantly higher fat content at each level compared to the other segmental muscles (p < 0.0001) and was highest at C3 (p < 0.0001).

There were higher fat indices in the whiplash group compared to the controls for the rcpmin and rcpmaj muscles (p < 0.0001).

No relationship was found for fat indices in all WAD muscles and NDI scores (p = 0.81), age (p = 0.14), duration (p = 0.99), compensation (p = 0.37) or BMI (p = 0.74).

Discussion: There is significantly greater fatty infiltration in neck extensors, especially in the deeper muscles, in females with chronic WAD when compared with controls. Future studies are required to investigate relationships between muscular degeneration and symptoms.

Introduction and Aims: Cyclic pneumatic pressure applied to the musculature proximal to a fracture of the distal radius has been shown to produce compressive loading of the fracture. The aim of this randomised controlled in vivo study in an ovine model was to investigate the effect of the pneumatic pressure on fracture healing.

Method: Thirty-seven sheep underwent a transverse osteotomy of the right radius. All sheep were managed in a plaster cast and splint to ensure non-weight bearing during rehabilitation. Nineteen of the sheep were randomised to receive cyclic loading by the application of a pressure cuff around the muscles of the proximal forearm deep to the cast. The other 18 sheep acted as controls. The sheep in the experimental group received 120 cyclic loads over two 10-minute sessions each day starting one week post-osteotomy. Sheep from both groups were sacrificed at either four or six weeks. X-rays, ultrasonography, biomechanical testing and histomorphometry were used to assess differences between the groups.

Results: The area of periosteal callus on lateral and antero-posterior x-ray, the peak torsional strength, the fracture stiffness, the energy absorbed over the first 10 degrees of torsion and histomorphometric analysis all showed that the fractures in the group treated with the cyclic pneumatic pressure achieved the same level of union at four weeks as the control group fractures at six weeks (not significantly different p> 0.05). The density of the woven bone in the periosteal callus of the treated sheep was significantly greater than the controls (p< 0.01). Ultrasonography showed no significant difference (p> 0.05) in the amount of muscle wasting between the treated group and the control group.

Conclusion: This study has shown that the rate of healing is enhanced when cyclic pneumatic pressure is applied to the musculature proximal to a transverse fracture of the distal radius in an adult sheep model. There is potential for this treatment to be used in a human population.

Introduction and Aims: The radiographic appearance of fractures is often used as an evaluative tool when assessing the status of healing fractures. The aim of this study was in the first instance to assess the reliability of orthopaedic surgeons to measure the area of periosteal callus and secondly to compare the area with the biomechanical strength of the fractures.

Method: Thirty-seven sheep underwent a transverse osteotomy of the right radius. All sheep were managed in a plaster cast and splint to ensure non weight-bearing during rehabilitation. Nineteen of the sheep were ran-domised to receive cyclic loading by the application of a pressure cuff around the muscles of the proximal forearm deep to the cast. The other 18 sheep acted as controls. Sheep from both groups were sacrificed at either four or six weeks. Fractures were x-rayed and subjected to biomechanical testing following sacrifice. X-rays were transferred to a Labview program from which the area of callus was measured. Biomechanical testing of the fractures was a torsional test to failure. The peak torque, stiffness and energy absorbed over the first 10 degrees of torsion were measured for each fracture.

Results: The two orthopaedic surgeons who measured the area of callus showed a positive correlation (r = 0.85). When the four-week fractures that were treated with cyclic loading were compared with the four-week control fractures, the periosteal callus measurement along with the peak torque, fracture stiffness and energy absorbed over the first 10 degrees of torsion all showed a significant difference (p < 0.05). In addition, when the six-week fractures that were treated with cyclic loading were compared with the six-week control fractures, the periosteal callus measurement along with the peak torque, fracture stiffness and energy absorbed over the first 10 degrees of torsion were not significantly different (p > 0.05).

Conclusion: The results show that the area of periosteal callus on radiographs can be related to the biomechanical status of a healing fracture. Further research is required to determine if other characteristics of the periosteal callus plus quantification of the callus area is able to accurately predict fracture strength.