Medium term results of per-operative knee arthroscopy in confirming suitability for unicompartmental arthroplasty.

INTRODUCTION: The status of the lateral compartment of the knee is a determining factor in the long-term outcome of medial unicompartmental arthroplasty (UKA). Various methods of assessing the lateral compartment have been used including stress radiography, radioisotope bone scanning, magnetic resonance imaging and visualisation at the time of surgery. Arthroscopy is another means of directly assessing the integrity of the articular cartilage and the meniscus in the lateral compartment. PURPOSE: This study aims to show that per-operative arthroscopy is a safe and effective means of deciding whether to proceed with UKA or convert to total knee arthroplasty (TKA). METHOD: We have used arthroscopy of the lateral compartment to assess suitability for UKA in 151 knees over 8 years. RESULTS: At time of arthroscopy 34 knees underwent a change of surgical plan from UKA to TKA (22.5%). There has been one revision to TKA and 2 bearing exchanges for dislocation. CONCLUSION: Immediate per-operative arthroscopy is a reliable method for assessing the suitability of a knee for UKA, in particular the lateral compartment.

A new valid and reliable windtrainer VO2max protocol.

AIM: Maximal oxygen uptake (VO(2max)) cycling protocols usually require expensive laboratory ergometers where the athlete is unaccustomed to the cycling position. Recently, we developed a VO(2max) speed-ramped protocol with an indoor cycling simulator (Cateye Windtrainer WT) allowing cyclists to use their own bicycles during the VO(2max) test. The aim of this study was to test the validity of the WT protocol by comparing it with a traditional (TD) resistance-ramped protocol using an electronically braked ergometer. In addition, the retest reliability of the WT protocol was also determined. METHODS: Twenty experienced cyclists randomly completed 6 VO(2max) protocols consisting of one familiarization trial and two tests on the WT and TD protocols. RESULTS: There were minimal differences in maximal oxygen uptake values between protocols (WT 64.1+/-7.1, TD 63.3+/-7.4 mL/kg/min). The variability in the difference of the means between the two protocols was 0.8 mL/kg/min (95% confidence interval CI: -0.26-2.02), the coefficient of variation (CV) was 2.8% (95%CI: 2.2-4.2%) and the interclass correlation was r=0.94 (P<0.01; 95%CI: 0.86-0.98). The intratest difference within the WT protocol was 1.5% (95%CI: -1.9-5%), CV=5.3% (95%CI: 4.1-8%) and the retest correlation was r=0.81 (P<0.01; 95%CI: 0.57-0.92). CONCLUSION: The WT speed-ramped protocol is a valid and reliable method to assess VO(2max).

The meniscal flounce: a valuable arthroscopic sign.

PURPOSE: The purpose of this study was to characterise the incidence and significance of the meniscal flounce. TYPE OF STUDY: Prospective Cohort Study. METHOD: A prospective study of 1088 consecutive knee arthroscopies. RESULTS: Intact menisci tended to have a flounce of characteristic size and position. The presence of this 'normal' flounce was closely correlated with an intact meniscus (p<0.0001). For the medial meniscus with a small flounce in zone 3 the sensitivity, specificity, and positive predictive value (PPV) for an intact medial meniscus were 68.5%; 92.9%; and 92.1% respectively. Conversely the presence of meniscal pathology correlated closely with either an absent or abnormal flounce (p<0.0001). The absence of a medial flounce had sensitivity, specificity, and PPV for a meniscal tear of 82.8%; 84.9%; and 81.9% respectively. CONCLUSIONS: The findings of this study are useful for arthroscopists especially when there is difficulty visualising all of the posterior half of the meniscus. In this situation the presence of a normal flounce is likely to signify an intact meniscus. However the presence of an abnormal or absent flounce may be the sign of an occult meniscal tear requiring better exposure.

A comparison of peak power in the shoulder press and shoulder throw.

The ability to generate peak power is central for performance in many sports. Currently two distinct resistance training methods are used to develop peak power, the heavy weight/slow velocity and light weight/fast velocity regimes. When using the light weight/fast velocity power training method it was proposed that peak power would be greater in a shoulder throw exercise compared with a normal shoulder press. Nine males performed three lifts in the shoulder press and shoulder throw at 30% and 40% of their one repetition maximum (1RM). These lifts were performed identically, except for the release of the bar in the throw condition. A potentiometer attached to the bar measured displacement and duration of the lifts. The time of bar release in the shoulder throw was determined with a pressure switch. ANOVA was used to examine statistically significant differences where the level of acceptance was set at p < 0.05. Peak power was found to be significantly greater in the shoulder throw at 30% of 1 RM condition [F, (1, 23) = 2.325 p < 0.051 and at 40% of 1 RM [F, (1, 23) = 2.905 p < 0.05] compared to values recorded for the respective shoulder presses. Peak power was also greater in the 30% of 1 RM shoulder throw (510 +/- 103W) than in the 40% of 1 RM shoulder press (471 +/- 96W). Peak power was produced significantly later in the shoulder throw versus the shoulder press. This differing power reflected a greater bar velocity of the shoulder throw at both assigned weights compared with the shoulder press.

Inhibition of experimental vasospasm with anti-intercellular adhesion molecule-1 monoclonal antibody in rats.

BACKGROUND AND PURPOSE: Inflammation may play a role in delayed chronic vasospasm after aneurysmal subarachnoid hemorrhage. We investigated the role of intercellular adhesion molecule-1 (ICAM-1) and macrophage/granulocyte infiltration in the rat femoral artery model of vasospasm using systemic administration of a murine anti-ICAM-1 monoclonal antibody (MAb). METHODS: The femoral arteries (n = 72) in Sprague-Dawley rats (n = 36) were enclosed in latex pouches bilaterally. Autologous blood was injected into the pouch on one side, and saline was injected on the contralateral side. Chronic vessel narrowing was evaluated with the use of 29 rats, which were randomized into one of three groups for intraperitoneal injections: (1) anti-ICAM-1 MAb (2 mg/kg per dose, n = 10), (2) isotype-matched MAb (2 mg/kg per dose, n = 9), or (3) saline (n = 10), given at 3 hours and 3, 6, and 9 days after blood exposure. These rats were killed 12 days after blood exposure, and femoral artery lumen cross-sectional areas were determined by computerized image analysis. Saturation of ICAM-1 binding sites with this dosing schedule was evaluated by fluorescence-activated cell sorter (FACS) analysis of splenocytes. Immunohistochemical studies with objective cell counts were performed to evaluate macrophage/granulocyte infiltration at 24 hours in 7 rats, comparing anti-ICAM-1 MAb treatment (n = 4) with isotype-matched control MAb (n = 3). RESULTS: Animals treated with anti-ICAM-1 MAb showed a significant inhibition of arterial narrowing at 12 days (P = .0081), with lumen patency of 96.5 +/- 5.3% (mean +/- SEM), compared with 77.3 +/- 5.6% for isotype-matched MAb and 72.2 +/- 5.3% for saline-treated controls. FACS analysis of splenocytes from animals treated with anti-ICAM-1 MAb confirmed saturation of ICAM-1 binding sites. Vessels treated with anti-ICAM-1 MAb showed a significant decrease in inflammatory cell infiltrates, with objective macrophage/granulocyte counts of 31.3 +/- 26.6 (mean +/- SEM) per high-powered field, compared with 171.4 +/- 30.7 for isotype-matched control MAb (P = .0027). CONCLUSIONS: Anti-ICAM-1 MAb administered systemically starting 3 hours after blood exposure results in significant inhibition of chronic vasospasm in the rat femoral artery model and is correlated with a reduction in the number of infiltrating macrophages and granulocytes in the periadventitial region of blood-exposed arteries. We conclude that inflammatory changes associated with ICAM-1-mediated macrophage and granulocyte migration play an important role in the development of posthemorrhagic chronic vasospasm in this model.

Decreased gray matter in normal aging: an in vivo magnetic resonance study.

Using in vivo magnetic resonance (MR) images, the percentages of gray matter, white matter, and cerebrospinal fluid (CSF) in the brains of 8 young and 6 elderly normal male community volunteers were quantified. Compared with the young men, the elderly men had a significantly lower percentage of gray matter (p less than .01) and higher percentage of CSF (p less than .01). The percentage of white matter was not significantly different between the two groups. This finding suggests that the age-related decrease in brain tissue is chiefly due to loss of gray matter.