Opening wedge distal femoral varus osteotomy for lateral compartment osteoarthritis in the valgus knee.

INTRODUCTION: Osteotomy aims to reduce pain and the rate of progression of arthritis by correcting deformity and offloading the affected compartment. This study reports the results of a case series of opening wedge distal femoral varus osteotomies for valgus lateral osteoarthritis of the knee. PATIENTS AND METHODS: Eighteen patients underwent osteotomy surgery (21 knees) with the aim of correcting the mechanical axis to 48-50% from medial to lateral. RESULTS: The mean follow-up for the study population was 4.5 years (range 1.6 to 9.2 years). Four patients underwent conversion to arthroplasty at a mean time of 3.3 years postosteotomy. Kaplan-Meier analysis demonstrates a cumulative survival of 79% at 5 years. In the remaining 17 osteotomies, all patients reported that outcome measures improved from baseline. However, only the IKDC and pain subdomain of KOOS showed a statistically significant and clinically relevant difference. Re-operation for non-arthroplasty related surgery was common. In part this was due to symptoms related to prominence of metalwork (10). Other reasons included non-union (1), loss of correction (2), infection (1), and persistent symptoms (2). CONCLUSION: Cumulative survival of opening wedge DFVO is comparable with that reported in closing wedge series. Clinically relevant differences in the IKDC and KOOS pain scores suggest that opening wedge DFVO is a useful option in the management of valgus gonarthrosis. However, DFVO is a technically demanding procedure and re-operation, particularly for removal of metalwork, is common.

Absorbable or non-absorbable sutures? A prospective, randomised evaluation of aesthetic outcomes in patients undergoing elective day-case hand and wrist surgery.

INTRODUCTION: We prospectively evaluated aesthetic outcomes in a group of randomised patients who underwent elective day-case hand and wrist surgery using either absorbable or non-absorbable sutures. PATIENTS AND METHODS: A cohort of 100 adult patients were randomised using sealed envelopes to receive either absorbable or non-absorbable sutures for their wound closure. Clinical review was carried out at 6 weeks. A postal questionnaire was sent to all patients 3 months following surgery comprising a visual analogue scale (VAS) for wound satisfaction, a validated 6-point patient scar assessment tool and the shortened version of the disabilities of the arm, shoulder and hand questionnaire (QuickDASH). RESULTS: From the postal questionnaire, 70 responses were received. There was no statistically significant difference between the two groups in terms of VAS, patient scar assessment tool and quick DASH. CONCLUSIONS: For elective day-case hand and wrist surgery, either suture material can be used confidently with respect to overall aesthetic appearance in such patients.

Recurrent total hip arthroplasty dislocation in combination with massive osteolysis: an outline of management using a proximal femoral replacement.

Recurrent dislocation of a total hip arthroplasty is a most distressing complication for both patient and surgeon. The situation is worsened when massive osteolysis occurs in combination with recurrent dislocation. Management options become more limited in this situation. We present such a case along with a discussion of the management options utilised.

Magnetic tracking: a novel method of assessing anterior cruciate ligament deficiency.

INTRODUCTION: The Lachman test is commonly performed as part of the routine assessment of patients with suspected anterior cruciate ligament (ACL) deficiency. A major drawback is its reliance on the clinician's subjective judgement of movement. The aim of this study was to quantify Lachman movement using a magnetic tracking device thereby providing a more accurate objective measure of movement. PATIENTS AND METHODS: Ten patients aged 21-51 years were assessed as having unilateral ACL deficiency with conventional clinical tests. These patients were then re-assessed using a Polhemus Fastrak magnetic tracking device. RESULTS: The mean anterior tibial displacement was 5.6 mm (SD = 2.5) for the normal knees and 10.2 mm (SD = 4.2) for the ACL-deficient knees. This gave an 82% increase in anterior tibial displacement for the ACL deficient knees. This was shown to be highly significant with P = 0.005. CONCLUSIONS: The magnetic tracking system offers an objective quantification of displacements during the Lachman test. It is convenient, non-invasive and comfortable for the patient and is, therefore, ideally suited for use as an investigative tool.

Perforated Meckel's diverticulum presenting as subphrenic abscess.

Meckel's diverticulum is known to present with myriad complications. However, its perforation followed by development of subphrenic abscess has not been reported in literature. We report this complication in an eleven-month-old child.

Asparagine-linked oligosaccharides protect Lamp-1 and Lamp-2 from intracellular proteolysis.

Lysosomes contain several integral membrane proteins (termed Lamps and Limps) that are extensively glycosylated with asparagine-linked oligosaccharides. It has been postulated that these glycans protect the underlying polypeptides from the proteolytic environment of the lysosome. Previous attempts to test this hypothesis have been inconclusive because they utilized approaches that prevent initial glycosylation and thereby impair protein folding. We have used endoglycosidase H to remove the Asn-linked glycans from fully folded lysosomal membrane proteins in living cells. Deglycosylation of Lamp-1 and Lamp-2 resulted in their rapid degradation, whereas Limp-2 was relatively stable in the lysosome in the absence of high mannose Asn-linked oligosaccharides. Depletion of Lamp-1 and Lamp-2 had no measurable effect on endosomal/lysosomal pH, osmotic stability, or density, and cell viability was maintained. Transport of endocytosed material to dense lysosomes was delayed in endoglycosidase H treated cells, but the rate of degradation of internalized bovine serum albumin was unchanged. These data provide direct evidence that Asn-linked oligosaccharides protect a subset of lysosomal membrane proteins from proteolytic digestion in intact cells.

Wortmannin retards the movement of the mannose 6-phosphate/insulin-like growth factor II receptor and its ligand out of endosomes.

The effect of wortmannin on the trafficking of the mannose 6-phosphate/insulin-like growth factor II receptor (Man-6-P/IGF-II receptor) and its ligand beta-glucuronidase has been determined in murine L cells and normal rat kidney cells. The drug induced a 90% decrease in the steady-state level of the Man-6-P/IGF-II receptor at the plasma membrane without affecting the rate of internalization, indicating that the return of receptor from endosomes to the plasma membrane is retarded. Wortmannin also slowed the movement of receptor from endosomes to the trans-Golgi network by about 60%. Such a kinetic block would dramatically reduce the number of Man-6-P/IGF-II receptors in the trans-Golgi network, which could account for the previously described hypersecretion of procathepsin D induced by wortmannin. In addition, the drug slowed delivery of endocytosed beta-glucuronidase from endosomes to dense lysosomes. These data, taken together with the published reports of others, indicate that wortmannin inhibits membrane trafficking out of multiple compartments of the endosomal system and suggest a role for phosphatidylinositol 3-kinase in regulating these processes.

Formation of liquid crystals from actin filaments.

Actin is cross-linked by actin-binding proteins in the cytoplasm to form either isotropic or highly oriented anisotropic structures. The inherent orientation among actin filaments could influence whether an isotropic or highly oriented anisotropic structure is formed. A highly oriented state can arise spontaneously through the formation of liquid crystals as predicted by polymer theory. In this study, the ability of filamentous actin to form liquid crystalline domains was detected using the anisotropic component of scattered light and by observation of birefringence. As liquid crystalline domains formed, the intensity of the anisotropic component of scattered light increased, and birefringent macroscopic oriented domains were directly observed. The formation of liquid crystalline domains was dependent on the concentration of actin filaments and on the average filament length controlled by varying the ratio of gelsolin to actin monomers. The concentration of actin filaments required to form liquid crystalline domains increased moderately as the average length was decreased. At a fixed actin concentration, orientation among the filaments attained a maximum value at a ratio of actin to gelsolin in the range from 1500 to 2000 and decreased as the ratio was increased or decreased from this range. The results are not well explained by theoretical treatments for liquid crystal formation by monodisperse, charged worm-like chains. Differences from the theoretical predictions for formation of liquid crystals are most likely due to the polydisperse filament length of actin. This phenomenon may have important effects on the structural and rheological properties of the cytoplasm in living cells.