Anatomical variations of the lumbrical muscles causing carpal tunnel syndrome

Many anatomical variations exist in and around the carpal tunnel. However, symptomatic anomalies causing carpal tunnel syndrome is rare. Additionally, carpal tunnel surgery is considered a simple operation commonly done by junior surgeons who are usually unaware of variations resulting in unfavorable surgical outcomes. We highlight a case of lumbrical muscle variation causing carpal tunnel syndrome. A 73-year-old male presented with numbness and pain of both hands associated with abnormal fullness over both wrists and distal forearms. Initially the right hand was numb and subsequently a year later, the left hand became numb. Physical examination was positive for Durkan, Phalen and Tinel signs at the carpal tunnel. Magnetic Resonance Imaging (MRI) showed abnormal muscle tissues in the carpal tunnel. During the carpal tunnel release and exploratory surgery, we noted an abnormally proximal origin of the lumbrical muscles in the forearm rather than the typical palmar origin. He also had lumbrical muscle hypertrophy in the left side. These two factors resulted in overcrowding within the carpal tunnel. Post-operatively the patient recovered well with pain relief and gradual improvement of his numbness. Variations in the anatomy of the lumbrical muscles is not uncommon and may result in carpal tunnel syndrome. Hence, carpal tunnel release surgeries may not be as straight forward as expected and surgeons should be aware of this possibility

A black finger does not equal a dead finger

Revascularisation and replant surgery occasionally produces sub-optimal results. We present two cases of near total amputation of the digits. The first patient was an 11-year-old boy with a middle finger avulsion injury sustained after the finger was caught in a washing machine with the flexor digitorum profundus still attached. The second patient was a 42-year-old male who sustained a machete attack and had near total amputation of his small and ring fingers with a 2 cm skin bridge still attached. All patients underwent revascularization with repair of only one digital artery for each finger as the opposite artery was non-viable. No digital veins were repaired. Relief of venous congestion was done by pin-prick six times a day up till one week. At one week post-surgery, the fingers were discoloured black but had good pulp turgor and full contour with arterial bleed on pin-prick. Inexperienced surgeons may view this as gangrene and amputate the fingers. However, we continued observation and at one month post-surgery, the black skin had desloughed and the underlying skin was pink

Adhesions as an uncommon complication of k-wiring in paediatric phalangeal fractures

Paediatric hand fractures are common and prompt management is mandatory to achieve a good functional outcome. However many fail to realize that treating a fracture does not only involve bones but the soft tissues, as well. K-wiring itself can be difficult with multiple attempts inadvertently injuring the flexor or extensor tendons and resulting in adhesions. We highlight this possible complication of K-wiring which we believe is under reported due to the perception that K-wiring is a simple procedure. We present a case of a 9-year-old child, who sustained a closed displaced fracture of the base of the proximal phalanx (Salter Harris type 2) of the left index finger. He underwent percutaneous K-wiring but was complicated with severe adhesions of the flexor digitorum profundus (FDP) and flexor digitorum superficialis tendons (FDS). He was unable to flex the proximal and distal interphalangeal joints of the affected finger. We subsequently performed tendon adhesiolysis twice together with A2 pulley reconstruction, to restore movement of the finger. K-wiring of the fingers are not just simple bony procedures but also involve soft tissue components which can be prone to adhesions

Genomic Selection and Association Mapping in Rice (<i>Oryza sativa</i>): Effect of Trait Genetic Architecture, Training Population Composition, Marker Number and Statistical Model on Accuracy of Rice Genomic Selection in Elite, Tropical Rice Breeding Lines

<div><p>Genomic Selection (GS) is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS) in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute's (IRRI) irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline.</p></div