Knee injuries in cyclists are often thought to result from an imbalance of load during the cycling motion as a consequence of inappropriate bike set-up. Recently, it has been postulated that incorrect foot positioning may be a significant factor in lower limb injury and poor cycling performance. The purpose of this study is to assess the effect of changing the foot position at the shoe-pedal interface on Vastus Medialis (VM) and Vastus Lateralis (VL) activity (mean and mean peak), knee angle and knee displacement. Maximum power tests were completed on a first visit, with data collection on a second visit recorded at 60% of the subjects maximum. Video footage and surface electromyography (SEMG) from VM and VL muscles was obtained. Data was recorded over 10 crank cycles in 3 experimental conditions; neutral, 10 degrees inversion and 10 degrees eversion using Ethylene Vinyl Acetate (EVA) wedges fitted between the cyclists shoe and the shoe cleat. Raw data (mean SEMG, mean peak SEMG) was obtained using Noraxon and SiliconCOACH measured knee angle and knee displacement. Data was analyzed using Friedmans test with appropriate post hoc tests. 12 male subjects (range 26-45, mean 35.9 years) completed the study. Mean and mean peak SEMG data showed no significant differences between the 3 experimental conditions for VM and VL. VM:VL ratios from raw mean SEMG data demonstrated a decrease in synchronicity in inversion and eversion compared to neutral. Pronators demonstrated most synchronicity in inversion and least synchronicity in eversion. There were statistically significant differences in knee angle and knee displacement between neutral, inversion and eversion (p<0.05). Inversion promoted smaller knee valgus angles and greater knee displacement from the bike. Eversion promoted larger knee valgus angles and a smaller displacement from the bike. By altering the foot position to either 10 degrees inversion or 10 degrees eversion, knee angle and knee displacement can be significantly influenced. Clinically, subjects who foot type is classified as pronating may benefit from some degree of forefoot inversion posting. Further research on subjects with knee pain needs to be undertaken.
Between 1993 and 2002 7 allografts/joint replacement combinations have been used to treat massive bone loss at the elbow. The original 4 procedures (2 humeral and 2 ulna allografts) used a standard Stanmore total elbow replacement. Of these the 2 humeral allografts failed and revision surgery was necessary. The 2 grafts on the ulna side of the joint remain in situ (average 6 years after surgery) with one of the patients subsequently having a primary joint replacement on the contra-lateral side. More recently a further humeral and a further ulna allograft/joint replacement have been performed together with one patient having humeral and ulna allografts on both sides of the joint for extensive bone loss. In these cases the Coonrad-Morrey total elbow arthroplasty was used as the joint implant. The philosophy behind the use of allografts is discussed and the management principles outlined. The possible reasons for failure of the early humerus allograft/joint replacement combinations is addressed and future developments considered.
The average follow up period was 6 years (range 4.5 – 9 years). The Oxford Shoulder Score revealed that 72% had good to excellent results, 16% remained unchanged and 12% were worse than prior to surgery. The corresponding DASH scores were 28% excellent, 40% good, 16% fair and 16% poor respectively. In addition 81% of patients were independent with daily activities, with 48% of them living alone and the remaining 33% living with their partners. Only 19% of patients needed significant help with their activities of daily living. These results were irrespective of whether surgery was performed on the dominant or non-dominant shoulder.
The long term results of the ulnohumeral arthroplasty have not previously been reported using a recognised elbow scoring system. Kashiwagi reported his results in 1986 but no validated scoring system was used in the publication. Morrey in 1992 evaluated his results using the Mayo Elbow Performance Score but the mean follow-up interval was only 33 months. Between 1990 and 1996 twenty consecutive ulnohumeral arthroplasties were performed for primary degenerative disease of the elbow. Outcome assessment using the DASH questionnaire and the Mayo Elbow Performance Score was taken at a mean follow-up of 75 months (range 58 to 132). Excellent or good results were identified in 85% (17/20) using the DASH questionnaire, and 65% (13/20) on assessment with the Mayo Elbow Performance Score (correlation coefficient 0.79). Eighty percent (16/20) felt that the benefits of surgery had been maintained, and of those working at the time of surgery, 75% (12/16) were still employed in the same vocation. There was no correlation between radiographic recurrence and the degree of fixed flexion deformity, flexion arc or elbow scores.