Biomedical subjects

A Y Lim

Publications and source records attributed to A Y Lim.

6 recordsLinked to original sources

PubMed2001

The long head of the triceps brachii as a free functioning muscle transfer.

This anatomic study investigates the possibility of using the long head of the triceps brachii muscle as a free functioning muscle transfer for the upper limb. It has been reported that the long head is not difficult to harvest and that its loss does not create significant donor-site morbidity. The muscle was studied in 23 fresh frozen upper limbs. The long head in all 23 specimens had a constant and proximal vascular pedicle from the profunda brachii artery and vein. The mean pedicle was long (4 cm) and had large-caliber vessels (diameter, 3-mm artery and 4-mm vein). Angiograms were carried out in five specimens and dye perfusion studies in six specimens. A single branch from the radial nerve of at least 7 cm in length innervated the muscle. Muscle architecture was studied in 12 specimens and revealed that the long head of the triceps is better suited for forearm reconstruction than either the gracilis or the latissimus dorsi muscles. The mean physiologic cross-sectional area (8.36 cm(2)) and fiber length (10.8 cm on the superficial surface and 8.2 cm on the deep surface) of the long head match more closely those of the flexor digitorum profundus and the extensor digitorum communis, the muscles most commonly replaced.

Aged↗

PubMed1999

Split flexor carpi radialis muscle.

A detailed anatomic and intramuscular neural staining study in 22 human and 5 monkey upper limbs revealed that the flexor carpi radialis can be raised on its proximal neurovascular pedicle and that the muscle can be split along its tendon into two independently functioning neuromuscular compartments, each with its own nerve and blood supply. A study of the muscle architecture in the human specimens found the radial compartment to have significantly longer fiber length and a larger physiologic cross-sectional area than the ulnar compartment. Independence of function of each compartment was demonstrated in electrical stimulation studies in six monkeys (Macaca fascicularis), but no significant difference was noted in the peak isometric load between the two compartments (p = 0.68) in the monkey. The extra functioning muscle units become important in local transfers for restoring function in multiple nerve palsies as in Hansen's disease, severe traumatic loss of muscle in crush injuries and compartment syndromes, and after wide resection in infective and neoplastic conditions in the forearm and hand.

Animals↗

PubMed1999

Independent function in a tendon transfer of the split flexor carpi ulnaris.

This case demonstrates the efficacy of the split flexor carpi ulnaris transfer to restore thumb and finger extension. The humeral and ulnar compartments retained their viability and their function. In addition, they were able to work independently, and the patient has secured two separate functions from one muscle. The versatility and simplicity of this technique give it advantages over more complex reconstructive procedures.

Adult↗

PubMed1999

The neuromuscular compartments of the flexor carpi ulnaris.

LEARNING OBJECTIVES: After studying this article, the participant should be able to: 1. Report on the vascular supply and innervation pattern of the flexor carpi ulnaris. 2. Describe the muscle architecture of the flexor carpi ulnaris, including the physiological cross-sectional area and fiber length. 3. State the uses of the flexor carpi ulnaris both for resurfacing defects in the vicinity of the elbow and in local functional tendon transfers. 4. Understand the principles of splitting skeletal muscles based on neurovascular supply to enhance its utilization in reconstructive procedures. The aim of this study was to describe the intramuscular innervation and vascular supply of the human flexor carpi ulnaris, with confirmation of findings by a similar study in the primate. Two distinct intramuscular nerve branches running parallel to each other, on either side of a central tendon, from the proximal quarter of the muscle belly to its insertion were found. The muscle could then be split into a humeral and an ulnar compartment, each with its own primary nerve branch. Perfusion studies confirmed the adequacy of circulation to the two compartments. In the primate flexor carpi ulnaris, electrical stimulation of the respective branches revealed independent contraction of each compartment. This study provides useful information for enabling the local transfer of the muscle as a whole, both for resurfacing in the vicinity of the elbow and for functional tendon transfers. It will also enable the transfer of the muscle as one or two separate compartments (for resurfacing, in tendon transfers for muscle paralysis, congenital defects, and muscle defects resulting from trauma, and after resections for neoplasm and infection).

Animals↗

PubMed1998

Traumatic posterior fossa extradural haematomas (PFEDH).

OBJECTIVES: While posterior fossa extradural haematomas (PFEDH) may lead to rapid neurological deterioration and death because of brainstem compression, prompt treatment often leads to a good outcome. The non-specific clinical signs and the rarity of this lesion in craniocerebral trauma adds to the difficulty in diagnosis. The aim of this study was to identify features which could lead to an early diagnosis. METHODS: Seventeen patients with posterior fossa extradural haematomas were operated on over 4 1/2 years, accounting for 7.5% of the 226 surgically operated extradural haematomas in the Department of Neurosurgery, Tan Tock Seng Hospital, Singapore. Four patients were excluded from this study due to non-availability of the case records. The remaining 13 patients formed the study group in this retrospective analysis. RESULTS: The majority of cases (77%) presented acutely within 24 hours. The mechanism of injury varied from a fall in 7 cases, a road traffic accident in 4 cases and assault in 2. Nine patients had evidence of external injury to the occiput, 8 patients had skull fractures, and diastasis of the lambdoid suture was seen in 2 cases. Presence of aerocele was noted in the CT scan of 4 cases. All 9 cases admitted with a high GCS score of more than 8 had a very good outcome. CONCLUSION: An early CT scan head is recommended if a combination of the following features is present: occipital soft tissue injury, drowsiness, occipital fracture or diastasis of the lambdoid suture.

Accidental Falls↗

PubMed1988

HLA and antibiotic allergic skin eruption.

Chinese patients with cutaneous eruption due to antibiotics were found to be positively associated with HLA-BW46 (RR = 2.5; 95% confidence limit 1.2-4.9) and negatively associated with HLA-B40 (RR = 0.46; 95% confidence limit 0.22-0.98). The association with HLA-BW46 was even higher in patients with ampicillin sensitivity (RR = 3.5; 95% confidence limit 1.4-9.0).

Anti-Bacterial Agents↗