Extensor mechanism complications following total knee arthroplasty

Extensor mechanism complications following 281 knee arthroplasties that included patellar resurfacing, performed by two surgeons in one hospital over a 6-year period, were reviewed. The mean follow-up period was 42 months. There were 28 (10%) extensor mechanism complications: 3 quadriceps tendon ruptures, 5 patellar fractures, 4 patellar tendon ruptures, 11 recurring patellar subluxations, 4 cases of patellar pain, and 1 malrotated patella. Nine (3%) required further surgery. Surgical technique may have contributed to the tendon ruptures; patellar fractures occurred mainly in patients who had rheumatoid arthritis. Patients with patellar subluxation had abnormal preoperative valgus deformities of their knees and presented with this subluxation problem an average of 4 months after surgery, but it appeared to cause them less discomfort with time. Patellar resurfacing as part of a knee arthroplasty procedure is recommended but should be performed with care to the integrity and vasculature of the extensor mechanism.     

Intrafollicular blood flow during human ovulation.

Transvaginal ultrasonography with color flow mapping has been used to study changes in intrafollicular blood flow and morphology during follicular rupture and presumed ovulation in one human volunteer. Detailed monitoring started on day 11 of the menstrual cycle and the follicle began to rupture at 14.30 on day 13. This event was preceded by a defined rise and peak in the level of immunoreactive serum luteinizing hormone (LH) by 42 h and 17 h 20 min, respectively. Blood vessels were clearly visible in the inner ring of the follicle (the granulosa layer) at the time of the LH peak and part of the granulosa (probably containing the oocyte) started to detach before the follicle ruptured. The maximum value for the peak blood velocity in the inner vessels was observed 10 s after the start of follicular rupture and there was a concurrent increase in the impedance to blood flow, as reflected by the resistance index and the pulsatility index. The follicle took 14 min 29 s to empty and the corpus haemorrhagicum started to form about 1 min later. These preliminary data suggest that intrafollicular angiogenesis and changes in blood flow can be monitored by a relatively non-invasive technique. Changes in vascularity might be used to predict imminent ovulation and could possibly be identified or modified biochemically to help achieve or avoid a pregnancy.     

Endothelial function and aqueous humor flow rate in patients with Fuchs' dystrophy

Using a two-dimensional scanning fluorophotometer, we studied 50 subjects with symmetric ocular involvement of Fuchs' dystrophy without epithelial edema. Twenty-six subjects with confluent or nearly confluent cornea gutata with increased corneal thickness and 24 subjects with mild to moderate cornea guttata with normal corneal thickness were compared to normal control subjects. There were no statistically significant differences in endothelial permeability between the three groups. Corneal thickness was significantly increased in the subjects with confluent to nearly confluent guttae, however. These results suggest that endothelial pump function may be affected in subjects with advanced cornea guttata with stromal edema.     

Corneal crystals, myopathy and nephropathy: a new syndrome?

A case with ocular (corneal crystals and retinal pigment epithelial mottling), muscle (oropharyngeal and hand weakness and atrophy), and renal (proteinuria and hypertension) abnormalities is described. We believe that this represents a previously unrecognized syndrome.     

Perforated colorectal neoplasms: correlation of clinical, contrast enema, and CT examinations

Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm.     

In-vivo comparison of four absorbable sutures: Vicryl, Dexon Plus, Maxon and PDS

Absorbable sutures are initially equal or superior to nonabsorbable sutures in terms of tensile strength but are absorbed at variable rates by the action of hydrolysis. This study demonstrated that the in-vivo half-life tensile strength of the braided absorbable sutures polyglycolic acid (Dexon Plus) and polyglactin 910 (Vicryl) is 2 weeks, whereas those of the monofilament absorbable sutures polyglyconate (Maxon) and polydioxanone (PDS) are 3 and 6 weeks respectively. The addition of a single hitch or six knots reduced the in-vitro tensile strength by 30% to 35%. Polyglyconate (Maxon) suture demonstrated the best in-vitro knot security.