Proximal first metatarsal opening wedge osteotomy: geometric analysis on saw bone models.

BACKGROUND: For hallux valgus correction, distal first metatarsal osteotomy is generally used for minor to moderate deformities, diaphyseal osteotomy for moderate deformities and basal osteotomy or arthrodesis for severe deformities. With the advent of locking plates, there has been renewed interest in opening wedge basal osteotomy. OBJECTIVE: We undertook this study in order to understand the power and limitations of this osteotomy. METHOD: Proximal opening wedge osteotomies were performed on saw bone models in four orientations, with three different wedge sizes: (1) perpendicular to the ground (PG); (2) perpendicular to the shaft (PS); (3) perpendicular to shaft with 30° declination (DEC); (4) 30° oblique (OB). Pre- and post-osteotomy measurements were made of axial and plantar translation and inter-metatarsal angle. RESULTS: Plantar translation and intermetatarsal angle correction increased with increasing wedge size. The DEC osteotomy produced the greatest increase in length of metatarsal shaft, while the PS osteotomy gave the least. The most plantar translation was achieved with the DEC osteotomy. Overall, the PS osteotomy gave the largest correction of the intermetatarsal angle. CONCLUSION: Although there are several published clinical case series of the proximal opening wedge osteotomy, this is the first study to fully evaluate its geometry.

Footwear and orthopaedics.

Footwear is the oldest known fashion accessory in use. Footwear is often implicated in orthopaedic problems affecting lower limbs and back. Hence footwear modifications have a major role in management of these pathologies as well. This review explores footwear and its role in causation and management of orthopaedic problems. Based on our observations we recommend that children with flexible flatfeet should be encouraged to walk barefoot to help in developing their arches. Women with risk factors for secondary arthritis of knee or back pain may be advised to avoid heels. Commercial shoes which decrease hind foot loading may be used in symptomatic management of hindfoot and mid foot problems. Similarly shoes which decrease forefoot loading may be useful in managing forefoot pathology. Flip-flops should be avoided by diabetics as they do not protect from injuries.

A small rise in CEA is sensitive for recurrence after surgery for colorectal cancer.

OBJECTIVE: Rise in carcinoembryonic antigen (CEA) above normal limits can indicate recurrent colorectal cancer. The aim of this study was to evaluate whether a small rise in CEA, even within normal limits was a sensitive indicator of recurrence. METHOD: 150 patients aged 22-87 years were followed up for a mean of 27 months after colorectal surgery with CEA 3 and 6 monthly computerized tomography. We analysed whether a rise in CEA > 1 ng/ml correlated with recurrence of metastases. RESULTS: Forty-six of 139 patients in final analysis had recurrent disease. A rise in CEA > 1 had a predictive value of 74% for recurrence or metastases (sensitivity 80%, specificity 86%). These findings were similar whether or not the CEA was normal preoperatively. CONCLUSION: If CEA is measured after surgery for colorectal cancer, a rise of >1 in the patient's postoperative value is predictive for recurrence or metastases with an overall sensitivity of 80% and specificity of 86%. Previous studies have recognized the role of large rises in CEA in predicting recurrence but this study shows that small changes in CEA may be significant even if these levels would be traditionally within 'normal' limits.

Nucleophilic substitution induced by electron transfer at the bridgehead of polycyclic alkanes: competition between polar and radical pathways.

A series of 2,5(or 1,4)-dihaloadamantanes (4 and 5, X = Y = halogens) and 9,10-dihalotriptycenes (7, X = Y = halogens) as well as two 5-halo (X) adamantan-2-ones (6, Y = O, X = Br and I) have been treated with Me(3)SnLi in THF in the absence and presence of tert-butylamine (TBA) and dicyclohexylphosphine (DCHP). The product distributions of these reactions have been established by (13)C and (119)Sn NMR spectroscopy, vapor-phase chromatographic analyses, and GC/MS. The former compounds (4 and 5) appear to react exclusively by a free-radical chain process (S(RN)1 mechanism) to yield tin substitution products. By contrast, the triptycenes react predominantly by a polar mechanism initiated by the formation of a carbanion. In the case of the halo ketones (6, Y = O, X = Br and I), a mechanistic divergence of the reaction was unexpectedly encountered. Whereas the bromo ketone provides the substitution product (6, Y = O, X = SnMe(3)) in good yield (ca. 75%), apparently by a radical pathway, the iodo ketone yields a fragmentation product (ca. 95% yield) by a polar mechanism. This mechanistic switch highlights the importance of the electronegativity of the leaving group as well as substituent-induced electron delocalization as molecular factors governing the competition between radical and polar pathways.

Small peptides Do not inhibit human non-pancreatic secretory phospholipase-A(2) (Type IIA).

Seven small peptides, that are among the most potent reported inhibitors of secreted mammalian phospholipases A(2), were found not to inhibit processing of a small phospholipid substrate by human non-pancreatic secretory phospholipase A(2) (type IIa), under conditions where certain non-peptides are potent inhibitors at nanomolar concentrations.

Objectives of basic surgical training.

There are a range of skills to be learned in basic surgical training. These include communication and patient management, operating and other technical skills, and audit. Surgical tutors might use such a framework to facilitate education and assessment of their trainees.

Donor cell infiltration of recipient tissue as an indicator of small bowel allograft rejection in the rat.

This study assessed whether screening of host tissues for graft cells could be used as an effective monitor of rejection following small bowel transplantation. Allogeneic rat small bowel transplantation was performed with or without cyclosporin (CyA) immunosuppression and cellular infiltration of host tissues assessed by immunohistological staining. Without immunosuppression, grafts were completely rejected within 1 week. CyA treatment for 7 days preserved the graft for 28 days although there was histological evidence of mild rejection in some of the animals studied. Continuous CyA treatment preserved the graft for up to 56 days. The peripheral lymph nodes and spleens of untreated animals were transiently infiltrated by low numbers of donor cells that disappeared by day 6. There was a marked donor cell infiltration of the lymph nodes and spleens of 7-day. CyA-treated animals that was maintained during the administration of immunosuppressive therapy but that declined thereafter. Continuous CyA treatment sustained donor cell infiltration up to day 56. These findings suggest the presence of donor cells in recipient lymph nodes and spleen to be indicative of effective control of rejection and their disappearance to be predictive of developing rejection responses. Examination of recipient peripheral tissues for donor cells may provide an improved technique for monitoring clinical small bowel transplantation.