Avulsion of the tibial tuberosity: muscles too strong for a growth plate

PURPOSE

To ascertain whether there were significant knee extension strength differences between two adolescent male gymnasts (patient 1: age, 14.5 years; height, 159.3 cm; weight, 52.2 kg; patient 2: age, 15 years; height, 160.6 cm; weight, 54.8 kg) with avulsion of the tibial tuberosity associated with avulsion of the patellar tendon.

CASE SUMMARY

Two adolescent male gymnasts underwent open reduction and internal fixation for avulsion of the tibial tuberosity associated with avulsion of the patellar tendon. Isometric extension strength of the contralateral uninjured knee and of the operated knee was significantly greater than for nonathletic adolescents of the same age (one-way analysis of variance [ANOVA], p = 0.001), and was at a higher part of normal strength than their gymnastic peers.

DISCUSSION

A maximal contraction of the quadriceps is able to overcome the strength of the upper tibial epiphysis disrupting the extensor mechanism of the knee.

RELEVANCE

Greater-than-usual strength, although normally of no undesired consequence, may play a role in avulsion injuries of major muscles.

Bundle pattern of the flexor digitorum profundus tendon in zone II of the hand: a quantitative assessment of the size of a laceration

Assessing the cross-sectional area of a partial laceration of a flexor digitorum profundus tendon based on its width, using magnification and calipers, is often inaccurate. As the threshold for repairing a partial laceration for most surgeons is the involvement of 50% of the tendon area, an accurate method of naked-eye evaluation to detect a 50% (or larger, or smaller) laceration was developed. This assessment is based on the size of the radial and ulnar bundles in the tendon. The relative area of the two bundles at four levels in zone II in the index, middle, ring, and small fingers was measured. In the index and small fingers, the ulnar bundle had a mean area consistently greater than and the radial bundle consistently less than 50% of the total tendon area. In the middle finger, the mean areas of both bundles were close to 50% of the total tendon area, but the radial bundle was reduced at the level of the proximal interphalangeal joint and distally. In the ring finger, both bundles remained close to 50% of the total tendon area at all levels. The bundles involved in a laceration can be easily identified with the naked eye; the data provided by this study may improve the accuracy of partial laceration size assessment.

Does the internal thoracic artery graft delay the recovery of myocardial metabolism?

BACKGROUND

The left internal thoracic artery (LITA) bypass graft to the left anterior descending artery has greater long-term patency than a saphenous vein graft. However, surgeons may be reluctant to use the LITA graft in some patients because they are unable to deliver cardioplegia to the left anterior descending artery territory.

METHODS

We compared the myocardial levels of high-energy phosphates and their metabolites in patients who received an LITA graft with those in patients who received a saphenous vein graft to the left anterior descending artery territory during elective coronary artery bypass grafting. Right and left ventricular biopsy specimens were obtained at three times: before aortic cross-clamping, after cross-clamp removal, and after 10 minutes of reperfusion.

RESULTS

No differences were found between the LITA graft group and the saphenous vein graft group in any right ventricular metabolites. There was an improvement in myocardial protection over time and a higher proportion of LITA graft patients in the late time period (early group, 63% versus late group, 80%; p < 0.01). Within each time period, there were no differences between the LITA and saphenous vein graft groups. Among patients receiving cold antegrade cardioplegia, the myocardial levels of high-energy phosphates were better preserved in those receiving an LITA graft.

CONCLUSIONS

Advances in myocardial protection have led to improved preservation of high-energy phosphate levels after cardioplegic arrest. In patients undergoing elective coronary artery bypass grafting, the use of an LITA graft does not adversely affect myocardial metabolism. Further investigations are required to determine the effects of the use of the LITA during urgent or emergent procedures.

Tensile properties of the interosseous membrane of the human forearm

The interosseous membrane is a structure deep in the forearm that joins the radius and the ulna. It is made up of membranous and ligamentous regions. Two main ligamentous structures have been described: a prominent central fiber group, the "central band," and a smaller proximal fibrous band, the "oblique cord." Many authors believe that the central band plays a biomechanical role in the normal and fractured forearm and that it may function much like a ligament. The objective of this study was to determine the tensile properties of the central band. Eighteen fresh frozen forearms from cadavers (45-70 years of age, both sexes) were used. A fiber bundle of the central band was subjected to a uniaxial tensile test to failure in a materials testing machine, and its tensile properties were calculated. Stiffness, ultimate load, and energy absorbed to failure were expressed as a function of specimen width. The central band structure had a stiffness of 13.1 +/- 3.0 N/mm per mm width and an ultimate load of 56.6 +/- 15.1 N per mm width (mean +/- SD). The tissue of the central band displayed a modulus of 608.1 +/- 160.2 MPa, ultimate tensile strength of 45.1 +/- 10.3 MPa, and strain at failure of 9.0 +/- 2.0%. This study demonstrated that the central band is comprised of strong tissue. The material properties of the central band compare with those of patellar tendon: modulus is 120% and ultimate tensile strength is 84% that of patellar tendon. As a structure, the interosseous membrane is stiff and capable of bearing high loads. Although load distribution across the central band is unknown, a 1.7 cm wide, evenly loaded homogenous portion of the central band would possess a stiffness comparable with that of the anterior cruciate ligament. The results of this study provide a basis for future analyses of radioulnar stability and load transfer.

Biomechanical properties of peripheral nerves

The biomechanical properties of peripheral nerves still are not completely understood or quantified. This is partly because of the nonhomogeneous nature of nerves and the variation in the proportions of the components of different nerves. The recognition and quantification of the in-situ stress and the viscoelastic behavior of nerves have been important stepping stones in understanding their mechanical behavior. The effects of stretch and compression on the vascular supply and conduction properties of normal animal nerves have been well studied. Similar studies in injured nerves will provide invaluable information for understanding the mechanics of nerve function and the prevention of stretch- and compression-related trauma.

The informatics superhighway: prototyping on the World Wide Web

We have experimented with developing a prototype Surgeon's Workstation which makes use of the World Wide Web client-server architecture. Although originally intended merely as a means for obtaining user feedback for use in designing a "real" system, the application has been adopted for use by our Department of Surgery. As they begin to use the application, they have suggested changes and we have responded. This paper illustrates some of the advantages we have found for prototyping with Web-based applications, including security aspects.

Genetic linkage mapping for a susceptibility locus to bipolar illness: chromosomes 2, 3, 4, 7, 9, 10p, 11p, 22, and Xpter

We are conducting a genome search for a predisposing locus to bipolar (manic-depressive) illness by genotyping 21 moderate-sized pedigrees. We report linkage data derived from screening marker loci on chromosomes 2, 3, 4, 7, 9, 10p, 11p, 22, and the pseudoautosomal region at Xpter. To analyze for linkage, two-point marker to illness lod scores were calculated under a dominant model with either 85% or 50% maximum penetrance and a recessive model with 85% maximum penetrance, and two affection status models. Under the dominant high penetrance model the cumulative lod scores in the pedigree series were less than -2 at theta = 0.01 in 134 of 142 loci examined, indicating that if the disease is genetically homogeneous linkage could be excluded in these marker regions. Similar results were obtained using the other genetic models. Heterogeneity analysis was conducted when indicated, but no evidence for linkage was found. In the course of mapping we found a positive total lod score greater than +3 at the D7S78 locus at theta = 0.01 under a dominant, 50% penetrance model. The lod scores for additional markers within the D7S78 region failed to support the initial finding, implying that this was a spurious positive. Analysis with affected pedigree member method for COL1A2 and D7S78 showed no significance for linkage but for PLANH1, at the weighting functions f(p) = 1 and f(p) = 1/sqrt(p) borderline P values of 0.036 and 0.047 were obtained. We also detected new polymorphisms at the mineralocorticoid receptor (MLR) and calmodulin II (CALMII) genes. These genes were genetically mapped and under affection status model 2 and a dominant, high penetrance mode of transmission the lod scores of < -2 at theta = 0.01 were found.

Blackened bronchoalveolar lavage fluid in crack smokers. A preliminary study

A retrospective study was performed on heavily pigmented pulmonary cytologic specimens from 14 hospital patients to determine the clinical features distinguishing these cases. The lavage fluid or sputum in each case was turbid and gray or black, exceeding the blackness usually seen in heavy tobacco smokers dwelling in the same urban environment. Excessive carbonaceous material was observed in the cytoplasm of pulmonary alveolar macrophages or the extracellular compartment of the smears. The latter feature is not seen in cigarette smokers. Many other pigmentary sources were ruled out, including melanin, hemosiderin, medicinal charcoal, India ink, and hematoxylin crystals. The common feature of the patients was that they recently or currently smoked the crack form of cocaine heavily; five patients also had positive toxicologic results for cocaine at admission. The authors suggest that blackened bronchoalveolar lavage fluid indicates the possibility of crack cocaine smoking and the associated sequelae, particularly when the carbonaceous material is present in the extracellular compartment.

Accurate charge capture and cost allocation: cost justification for bedside computing

This paper shows that cost justification for bedside clinical computing can be made by recouping charges with accurate charge capture. Twelve months worth of professional charges for a sixteen bed surgical intensive care unit are computed from charted data in a bedside clinical database and are compared to the professional charges actually billed by the unit. A substantial difference in predicted charges and billed charges was found. This paper also discusses the concept of appropriate cost allocation in the inpatient environment and the feasibility of appropriate allocation as a by-product of bedside computing.

Early migration of prostheses related to long-term survivorship. Comparison of tibial components in knee replacement

We determined the cumulative survival rates, in arthroplasty of the knee, of three designs of tibial component, using a change of position on standard radiographs or revision for aseptic loosening as criteria of failure. The average migration of each of the three designs in the first postoperative year is known from roentgen stereophotogrammetric analysis reported by other authors. The ranking order of the components as judged by cumulative survival is the same as that determined by early migration. This finding supports the view that the measurement of early migration can predict late aseptic loosening and therefore that such measurements are clinically of value.

Automated acuity scoring within a computer based medical record

This paper describes the initial development of a completely automated acuity scoring system that resides within the TMR bedside computing system at the Duke University Medical Center, Surgical Intensive Unit. The scoring system is based upon the APACHE II acuity scoring system and provides for the recalculation of acuity scoring at 12 hour intervals through the patient's ICU course. When comparing hand calculated versus computer generated acuity scores for 19 patients, discrepancies fell into three broad categories: 1) data available to the application differed from that available to the human scorer. 2) apparent transcription errors 3) data items lost or absent from the paper record. It remains to be determined if computer generated acuity scoring provides for a more accurate representation of the patient's acuity.

Bedside computerization of the ICU, design issues: benefits of computerization versus ease of paper & pen

This paper describes the design considerations for the implementation of a bedside computer system in an intensive care environment. Specific issues discussed include application design, implementation problems, design revisions, and design solutions. Specific examples of the above issues include passive data acquisition from bedside devices and computer systems, automated nursing assessments, respiratory therapy assessments and integrated reports.

Comparative evaluation of bone marrow aspirate particle smears, imprints and biopsy sections

Comparative evaluation of bone marrow aspirate particle smears, imprints and biopsy sections was done on 30 haematological problems. Core needle biopsy of the bone marrow is a safe and useful procedure. It is a valuable diagnostic aid for measurement of marrow cellularity, metastatic tumours and fibrosis. It should not be taken as a substitute for examination of the marrow by aspiration smear but is a complementary procedure which affords several advantages. Bone marrow biopsy was of maximum utility in myelofibrosis which was diagnosed on biopsy alone. There were three additional cases with normal bone marrow aspiration in which specific diagnosis could only be made from bone marrow biopsy sections. New methodologies i.e. plastic embedding and semi thin sections of undecalcified bone marrow, can be expected to improve the cytological details of tissue obtained by biopsy. Imprint preparations obtained from biopsy can be useful in patients of malignancy but we have found them to be of limited value except in cases of dry tap.

A comparative study of rural athletes of four states of India

In the present study 22 rural athletes of four different states of India have been studied for 23 anthropometric parameters--weight, height, sitting height, six diameters, six circumferences and eight skin and subcutaneous tissue folds. Rural athletes of Punjab and Haryana have been found to be comparable pertaining to all the anthropometric variables. Athletes of Madhya Pradesh show minimum values for most of the variables. The order of best anthropometry is athletes of Punjab and Haryana followed by Assam and Madhya Pradesh. Athletes of Madhya Pradesh are lacking behind in all the parameters except skin and subcutaneous tissue folds as compared to athletes of Assam.

Age of menarche in various categories of Indian sportswomen

Data on the age of menarche has been collected on 264 Indian sportswomen, and 108 girls forming the control group, all hailing from the Punjab, Haryana, chandigarh and Delhi. Outstanding athletes and players of hockey, basketball and volleyball were included. The combined mean age at menarche for sportswomen is 15.21 years and for the control sample is 14.05 years. The differences in the two series are statistically significant. The mean age at menarche in hockey, basketball, volleyball and athletes is found to be 15.15, 15.40, 15.05 and 15.27 years respectively. The differences in these groups, however, are not found to be statistically significant.