Single-bone forearm reconstruction for malignant and aggressive tumors.

UNLABELLED: Limb-salvage surgery for malignant and aggressive forearm tumors presents a unique surgical challenge. We performed single-bone forearm reconstructions after extensive resections of the radius and ulna in four patients for such tumors. Radiocarpal arthrodesis was performed in three patients. We recorded the presence of metastases or local recurrences, Musculoskeletal Tumor Society upper extremity scores, and complications. One patient had local recurrence and one died of metastases. The average Musculoskeletal Tumor Society score at the last followup was 26 of 30 (88%; range, 24-28). Complications included wound infection/necrosis, delayed union, nonunion, and acute carpal tunnel syndrome. Single-bone forearm reconstructive surgery provided satisfactory functional outcomes in these four patients, and we believe it is a reasonable treatment option for individuals with malignant or aggressive tumors of the forearm requiring massive bone resection. LEVEL OF EVIDENCE: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Physiological characteristics of top level off-road motorcyclists.

OBJECTIVES: The study aims to analyse the physiological characteristics of top level off-road motocross, enduro, and desert rally motorcyclists to facilitate the design of a specific training program. METHODS: Twenty seven off-road top level riders participated in this study which measured anthropometric data, maximum aerobic power with incremental tests of both arms and legs, isokinetic dynamometry of the knee and elbow, handgrip strength, heart rate, and blood lactate concentrations during competition. RESULTS: The physical demands of the various races appear to influence the development of distinct musculoskeletal characteristics, as well as aerobic and anaerobic metabolism. Motocross riders have more muscle mass, higher isokinetic handgrip strength, and greater aerobic power than enduro and desert rally riders. However, there are no significant anthropometric and physiological differences between desert rally and enduro riders. Desert rally riders tend to be overweight with maximum aerobic power similar to that of healthy individuals. The mechanical characteristics of the motorcycle and the technical and tactical skills of the riders seem to be more important for race success than the metabolic capabilities of the rider. CONCLUSIONS: Desert rally and enduro riders present similar anthropometric and physiological characteristics. Both have a maximum aerobic power similar to that of healthy normal individuals, although desert rally riders tend to be overweight. Motocross riders on the other hand, have more muscle mass, more strength, and greater aerobic power. The differences observed suggest the need for a specific training program to address the requirements of different riders to reduce the possibility of injury.

Reoperation after autologous chondrocyte implantation. Indications and findings.

We have reviewed 22 patients from a total of 135 treated by autologous chondrocyte implantation (ACI) who had undergone further surgery for pain in the knee and mechanical symptoms after a mean of 10.5 months. There were 31 grafted lesions. At operation the findings included lifting (24/31) and detachment (3/31) of periosteal patches for which arthroscopic shaving was performed. Chondroplasty was undertaken on two new lesions, another required an ACI and a further patient required trimming of a meniscus. The mechanical symptoms resolved within two weeks. At the last review, two to 14 months from reoperation; 68% had improved, and 86% had normal or nearly normal IKDC scores. Of the 31 lesions, 30 (97%) had normal or nearly normal visual repair scores. Biopsy showed good integration with subchondral bone and the marginal interface in all specimens, most of which showed hyaline or hyaline-like cartilage (70%). Troublesome mechanical symptoms required surgery in 13% of ACI-treated patients and were attributed to periosteal extrusion. Simple arthroscopic debridement was curative.

Prospective clinical study of autologous chondrocyte implantation and correlation with MRI at three and 12 months.

In order to determine the usefulness of MRI in assessing autologous chondrocyte implantation (ACI) the first 57 patients (81 chondral lesions) with a 12-month review were evaluated clinically and with specialised MRI at three and 12 months. Improvement 12 months after operation was found subjectively (37.6 to 51.9) and in knee function levels (from 85% International Cartilage Repair Society (ICRS) III/IV to 61% I/II). The International Knee Documentation Committee (IKDC) scores showed an initial deterioration at three months (56% IKDC A/B) but marked improvement at 12 months (88% A/B). The MRI at three months showed 82% of patients with at least 50% defect fill, 59% with a normal or nearly normal signal at repair sites, 71% with a mild or no effusion and 80% with a mild or no underlying bone-marrow oedema. These improved at 12 months to 93%, 93%, 94% and 91%, respectively. The overall MR score at 12 months suggested production of normal or nearly normal cartilage in 82%, corresponding to a subjective improvement in 81% of patients and 88% IKDC A/B scores. Second-look surgery and biopsies in 15 patients (22 lesions) showed a moderate correlation of MRI with visual scoring; 70% of biopsies showed hyaline and hyaline-like cartilage. Thus, MRI at 12 months is a reasonable non-invasive means of assessment of ACI.

Structural glycoproteins from rabbit aortic media.

Rabbit aortic intima-media fragments were incubated with [14C]mannose and [3H]fucose for 6 h to detect glycoproteins synthesized in situ. The radioactively labelled and the non-labelled samples were extracted with 0.2 mM-CaCl2/0.5 mM-dithiothreitol/0.5 mM-ATP and chloroform/methanol/water (4:4:1, by vol.). The delipidated residue was extracted with 5 M-guanidinium chloride/0.05 M-dithiothreitol/0.1 M-Tris/0.4% Na2EDTA, pH 7.5, before (extract 1) and after hydrolysis with collagenase (extract 2). The proteins in extracts 1 and 2 were S-carboxamidomethylated and separated by molecular-sieve chromatography, polyacrylamide-gel electrophoresis and isoelectric focusing in sucrose gradients in urea. The apparent molecular weights of glycoproteins were 36 000 (glycoprotein I) from extract 1, 50 000 (glycoprotein II) and 130 000 (glycoprotein III) from extract 2. The molecular weights of the non-labelled and radioactively labelled glycoproteins were identical. Glycoproteins I, II and III contain large amounts of polar amino acids and methionine. They contain neither hydroxyproline nor 3-methylhistidine. A hydroxyproline-containing component of 160 000-apparent-mol.wt. relatively rich in polar amino acids and labelled with incorporated sugars was isolated from extract 1. The incorporation in vitro of radioactive sugars into glycoproteins I, II, III and collagenous glycoproteins indicates that they are synthesized in the surviving aorta by the smooth-muscle cells.