Metal ion levels after metal-on-metal Ring total hip replacement: a 30-year follow-up study.

Metal-on-metal bearings for total hip replacement (THR) are becoming increasingly popular. Improved wear characteristics mean that these articulations are being inserted into younger patients in the form of THR and resurfacing procedures. This has led to concerns regarding potential carcinogenicity because of the increased exposure to metal ions that the procedure brings. We have studied the serum cobalt and chromium concentrations in patients who had primary, well-fixed Ring metal-on-metal THRs for more than 30 years. The levels of cobalt and chromium were elevated by five and three times, respectively compared with those in our reference groups. Metal-on-metal articulations appear to be the source of metal ions throughout the life of the prosthesis. In three patients who had undergone revision of a previous metal-on-metal THR to a metal-on-polyethylene replacement the levels of metal ions were within the normal range. The elevations of cobalt and chromium ions seen in our study were comparable with those in patients with modern metal-on-metal THRs.

Lessons learned from cervical pseudoarthrosis in ankylosing spondylitis.

This case report illustrates three learning points about cervical fractures in ankylosing spondylitis, and it highlights the need to manage these patients with the neck initially stabilised in flexion. We describe a case of cervical pseudoarthrosis that is a rare occurrence after fracture of the cervical spine with ankylosing spondylitis. This went undetected until the development of myelopathic symptoms many months later. The neck was initially stabilised in flexion using tongs, and then slowly extended before anterior and posterior fixation was performed. The myelopathic symptoms resolved, and the patient had a good result at 18 months. We conclude that any increased movement of the spine after trauma in ankylosing spondylitis must be considered suspect and fully investigated.

Tensile strength of the medial patellofemoral ligament before and after repair or reconstruction.

The tensile strength of the medial patellofemoral ligament (MPFL), and of surgical procedures which reconstitute it, are unknown. Ten fresh cadaver knees were prepared by isolating the patella, leaving only the MPFL as its attachment to the medial femoral condyle. The MPFL was either repaired by using a Kessler suture or reconstructed using either bone anchors or one of two tendon grafting techniques. The tensile strength and the displacement to peak force of the MPFL were then measured using an Instron materials-testing machine. The MPFL was found to have a mean tensile strength of 208 N (SD 90) at 26 mm (SD 7) of displacement. The strengths of the other techniques were: sutures alone, 37 N (SD 27); bone anchors plus sutures, 142 N (SD 39); blind-tunnel tendon graft, 126 N (SD 21); and through-tunnel tendon graft, 195 N (SD 66). The last was not significantly weaker than the MPFL itself.

When is a meniscal cyst not a meniscal cyst?

Two patients are presented where lesions adjacent to the joint line of the knee were diagnosed clinically and on magnetic resonance imaging (MRI) as meniscal cysts. No concomitant meniscal tears were seen, and the MRI signal was not completely homogenous. The diagnostic imaging influenced the surgical management in a manner inappropriate for the definitive diagnoses of fibromyxoid sarcoma and monophasic synovial sarcoma. Not all cysts produce a purely homogenous signal on MRI due to haemorrhage or high protein content fluid, and not all meniscal cysts are associated with a meniscal tear. In the absence of a meniscal tear and with mixed signal on MRI we advise caution in the diagnosis of a meniscal cyst and advocate shared management with either orthopaedic or radiological colleagues with a special interest in oncology to obtain a tissue diagnosis before definitive treatment.

Anatomy and biomechanics of the medial patellofemoral ligament.

The medial patellofemoral ligament (MPFL) is a band of retinacular tissue connecting the femoral medial epicondyle to the medial edge of the patella. The MPFL is approximately 55 mm long, and its width has been reported to range from 3 to 30 mm. The MPFL is overlaid by the distal part of vastus medialis obliquus to a variable extent, and fibres of MPFL merge into the deep aspect of the muscle. Despite the MPFL being very thin, it had a mean tensile strength of 208 N, and has been reported to be the primary passive restraint to patellar lateral displacement. Lateral patellar displacement tests in vitro showed that the patella subluxed most easily at 20 degrees knee flexion. The contribution of the MPFL to resisting patellar lateral subluxation was greatest in the extended knee. This finding was linked to the retinaculae being tightest in full knee extension, and slackening with flexion.

Prevention of postoperative wound haematomas and hyperperfusion following carotid endarterectomy.

OBJECTIVE: To study the incidence of wound haematomas and hyperperfusion following carotid endarterectomy and the effect of changes in perioperative management. METHODS: We undertook a prospective audit of the postoperative outcome of 300 consecutive carotid endarterectomies performed for a symptomatic stenosis of the internal carotid artery, under the care of a single consultant. RESULTS: audit of the first 100 operations between 1990-93 resulted in 4 changes to clinical practice. These included the use of Dacron instead of vein because of 3 vein patch blowouts, invasive postoperative monitoring of blood pressure, and the use of intravenous beta-blockers to control hypertension, because of 4 hyperperfusion injuries. The use of 10F suction drains was discontinued, because they did not prevent 8 wound haematomas. The results of the second 100 cases between 1994-97 and the third 100 cases between 1998-2000 confirmed no further hyperperfusion injuries or patch blowouts (p =0.01 and 0.04 respectively). Larger 14F suction drains were reintroduced for the third series because of thirteen haematomas in the second series (p =0.09). Only 4 haematomas occurred in the third series ( p =0.05). The need for beta-blockers fell in the third series due to the introduction of local anaesthesia (p =0.0001). CONCLUSION: The use of Dacron patches and postoperative control of hypertension has reduced the incidence of haemorrhage and hyperperfusion after carotid endarterectomy. Larger suction drains may also help.

Saphenous neuralgia after coronary artery bypass grafting.

OBJECTIVE: To determine the incidence, extent and site of saphenous neuralgia (anaesthesia, hyperaesthesia and pain) in the lower limb after harvesting of great saphenous vein (GSV) for coronary artery bypass grafting (CABG). METHODS: Thirty-two consecutive patients (39 lower limbs) aged 58+/-16 years undergoing CABG were prospectively reviewed. All patients were assessed pre-operatively to establish the presence of normal sensation, then at 3 days, 6 weeks and 20+/-4 months post-operatively for symptoms or signs of saphenous neuralgia. The data were recorded on serial diagrammatic representations, and the area of sensory loss for each site was recorded at each review. The decrease in areas of sensory loss over time was investigated with statistical analysis. RESULTS: Thirty-five (90%) of the lower limbs examined showed some degree of anaesthesia at 3 days with 23 (72%) still symptomatic at a mean follow up of 20 months. Hyperaesthesia and pain were infrequently noted. Anaesthesia was generally confined to three main areas, which were denoted sites A, B and C for descriptive purposes. The mean area of sensory loss in the lower limb at 3 days post-surgery was 53.4 cm2, for an incision of mean length 42+/-22 cm from the medial malleolus. This area reduced to 31.7 cm2 by 20 months, and the decrease in area over time for each site was found to be statistically significant using analysis of variance for repeated measures and the Freidman-Rubin test. CONCLUSIONS: This study demonstrates that saphenous neuralgia after harvest of GSV for CABG is common. The main symptom is anaesthesia and certain areas may persist for some considerable time post-operatively.

Free tendon interposition grafting for the repair of ruptured extensor tendons in the rheumatoid hand. A clinical and biomechanical assessment.

Sixteen ruptured extensor tendons were repaired in seven rheumatoid hands using autogenous palmaris longus tendon as a free interposition graft. The patients were reviewed at an average of 17 months (range, 5-45) after repair. Subjectively all patients were satisfied with the clinical results, and achieved a return to their level of ability before tendon rupture. A biomechanical model suggests that tendon repair using an interposition graft, rather than a traditional end-to-side tendon transfer retains the anatomical axis of tendon function, and achieves greater forces during active finger extension.

Scar quality from partial or complete wound closure using the Cincinnati incision for clubfoot surgery.

The method of skin closure in using the Cincinnati incision for clubfoot surgery may influence the quality of the scar obtained and the postoperative outcome. We retrospectively reviewed two groups of patients who underwent either primary skin closure (14 feet in 11 patients) or partial wound closure and healing by secondary intention (15 feet in 11 patients). The quality of the scars from both of these methods were equally acceptable cosmetically, and neither technique predisposed the patient to any long-term wound complications. In addition, we noted that closing the skin may act as a soft tissue tether, and that the initial position of the postoperative splinting of the foot may influence the surgical outcome. Both of these factors may contribute to the recurrence of equinovarus deformity.

Giant hydronephrosis--a diagnostic dilemma.

We report a complex case in which the left kidney had undergone giant hydronephrotic change after chronic obstruction at the vesicoureteric junction. Minor blunt abdominal trauma caused rupture of the parenchyma of this expanded and dilated kidney, with bleeding into its collecting system. The mixture of blood and urine remained contained within the kidney's structural layers, so producing a tense, cystic, fluid-filled mass arising from the left hypochondrium. Pathogenesis, differential diagnosis and investigation of giant hydronephrosis and its rupture are discussed. The observation is made that gross distortion of the renal parenchyma by rupture or hydronephrosis impairs arterial inflow to the kidney.

Atorvastatin: an effective lipid-modifying agent in familial hypercholesterolemia.

Hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors are the drugs of choice in heterozygous familial hypercholesterolemia (FH), which has a high risk of ischemic heart disease. An open-label study was conducted to test the efficacy and safety of atorvastatin, a new synthetic HMG-CoA reductase inhibitor in proven FH. After a 4-week placebo phase, 22 subjects were randomized to either 80 mg atorvastatin at night (n = 11) or 40 mg twice a day for 6 weeks. The two dosage groups were well matched and had no difference in lipoprotein responses. After 6 weeks, the LDL cholesterol concentration was reduced by 57%, from 8.16 +/- 1.15 to 3.53 +/- 0.99 mmol/L (P < .001). The total cholesterol concentration decreased from 9.90 +/- 1.32 to 5.43 mmol/L (P < .001). HDL cholesterol concentration increased from 1.19 +/- 0.31 to 1.49 +/- 0.43 mmol/L (P < .001). Triglyceride concentrations decreased from 1.34 +/- 0.66 to 0.88 +/- 0.36 mmol/L (P < .01). Three subjects had single, transient increases of serum transaminase of up to twice the upper limit of normal. Apolipoprotein B concentration decreased significantly by 42%. Changes in apolipoproteins AI and (a) were not statistically significant. Nondenaturing gradient gel electrophoresis revealed increases in the size of smaller LDL particles in four subjects. Plasma fibrinogen concentration increased by 44%. The drug was well tolerated. One subject withdrew for personal reasons. Atorvastatin is a powerful and safe lipid-modifying agent for LDL cholesterol; it also modifies HDL cholesterol and triglyceride concentrations, and may suffice as a single agent for many subjects with heterozygous FH.

Inflammatory pseudotumour of the lung mimicking thymoma.

A 36 year old man presented with chest symptoms had a radiological left upper mediastinal lesion, that was interpreted as an anterior mediastinal tumour, consistent with a thymoma. At operation an inflammatory pseudotumour was found in the left upper lobe of the lung, that was projecting across and in front of the mediastinum. The investigation and surgical management of these tumours are reviewed in the light of the presenting symptoms and radiological imaging.

Pancreatic metastases from breast cancer: an unusual cause of biliary obstruction.

Metastatic tumour deposition within the pancreas is a rare cause of biliary obstruction. We present a case in which obstructive jaundice was the first sign of dissemination of a breast cancer, the cause being intrapancreatic obstruction to the biliary tree by tumour.

A mechanism for entrapment of the tibialis posterior tendon in lateral subtalar dislocation.

The entrapment of the tibialis posterior tendon causing a block to reduction of lateral subtalar dislocation is recognized. The mechanism which allows tendon excursion is less clearly understood. We present a case in which extensive tearing of the musculotendinous junction of the tibialis posterior muscle occurred during tendon displacement and entrapment in lateral subtalar dislocation. In view of this previously poorly recognized finding the two theories regarding entrapment are discussed. Recognition of the cause of the tendon lengthening with an intact flexor retinaculum allows appropriate early treatment.

Plasma mevalonic acid, an index of cholesterol synthesis in vivo, and responsiveness to HMG-CoA reductase inhibitors in familial hypercholesterolaemia.

Fasting plasma mevalonic acid (MVA), an indicator of in vivo cholesterol synthesis, was measured in 35 patients with familial hypercholesterolaemia (FH) of whom 7 were treated with pravastatin 10-40 mg/day, 7 with simvastatin 10-40 mg/day and 21 with atorvastatin 80 mg/day. Reductions in low density lipoprotein (LDL) cholesterol and MVA on maximal dose therapy differed significantly between the three drugs: 34.7%, 42.9% and 54.0% (P = 0.0001), and 31.6%, 48.9% and 58.8% (P = 0.004), respectively. Patients on atorvastatin were subdivided according to whether their reduction in LDL cholesterol on treatment was above or below the mean percentage change for the whole group. Basal values of LDL cholesterol did not differ significantly, but above average responders had a significantly higher mean pre-treatment level of MVA (6.2 +/- 0.60 vs. 4.3 +/- 0.61 ng/ml, P < 0.05) than below average responders. When all three drug groups were pooled above average responders showed a significantly greater absolute decrease in MVA on treatment than below average responders (3.85 +/- 0.48 vs. 2.33 +/- 0.40 ng/ml, P < 0.05). However, there was no significant correlation between the magnitude of the decreases in LDL cholesterol and MVA. These findings suggest that FH patients who responded well to statins had a higher basal level of plasma MVA, i.e. a higher rate of cholesterol synthesis, which was more susceptible to pharmacological inhibition. The more marked cholesterol lowering effect of atorvastatin 80 mg/day presumably reflects, at least in part, its ability to inhibit HMG-CoA reductase to a greater extent than maximal recommended doses of pravastatin and simvastatin of 40 mg/day.