Bl factor is a key system parameter of the resonant blood viscoelastic sensor. In this paper, a dynamic measurement system for the spatial distribution of Bl factor based on velocity amplitude and motional impedance was designed. The system extracted the velocity amplitude and motional impedance of the coil under the dynamic condition of driving the sensor to generate simple harmonic oscillations using laser displacement and impedance analysis combined with in-phase/quadrature demodulation algorithm, and controlled the equilibrium position of the coil by adjusting the direct current component of the excitation current to realize the position scanning. In the position interval of [−240, 240] μm, the maximum coefficient of variation of the measurement results was 0.077 3%, and the maximum relative error to the simulation results was 2.937 9%, with a linear fitting correlation coefficient R2 = 0.996 8. The system can be used to accurately measure the spatial distribution of Bl factor of the resonant blood viscoelastic sensor, which provides a technical support for the verification of the design of the sensor magnetic circuit.
Objective To investigate the effectiveness of split nail in the emergency treatment of nail bed partial defect. Methods Between February 2008 and August 2011, 27 cases (30 fingers) of nail bed partial defect were treated. There were 19 males (22 fingers) and 8 females (8 fingers) with an average age of 27.4 years (range, 16-64 years). The causes of injury included machine injury in 25 cases and cutting injury in 2 cases. The injured fingers included 5 thumbs, 7 index fingers, 11 middle fingers, and 9 ring fingers. The disease duration ranged from 30 minutes to 7 hours with an average of 4.3 hours. The size of nail bed defect ranged from 4 mm × 3 mm to 9 mm × 5 mm. All defects were repaired with residual split nail (4 mm × 3 mm-10 mm × 6 mm in size). Results The split nail survived in 25 cases (28 fingers), and primary healing of wound was obtained. Exudation occurred in 2 cases (2 fingers) and was cured after symptomatic treatment. Twenty-three patients (25 fingers) were followed up 5-17 months (mean, 11.1 months). At 3-5 months after operation, the fingernail regeneration was observed in all fingers. Except 2 cases (2 fingers) of delayed healing having poor nail growth, the other patients had smooth nail and normal finger tip function without pain. According effectiveness standard for fingernail regeneration, the results were excellent in 15 fingers, good in 6 fingers, fair in 3 fingers, and poor in 1 finger, with an excellent and good rate of 84%. Conclusion It is a simple and effective method to use residual split nail for emergency treatment of nail bed partial defect.
Objective To investigate the effectiveness of dorsal metacarpal island flap for treating scar contracture of the finger web. Methods Between June 2009 and December 2010, 10 patients with scar contracture of the finger web were treated. There were 6 males and 4 females with an average age of 30 years (range, 14-57 years). Scar contracture was caused byinjury in 8 cases, by burn in 1 case, and by operation in 1 case. The locations were the 1st web space in 1 case, the 2nd web space in 3 cases, the 3rd web space in 5 cases, and the 4th web space in 1 case. The disease duration was 3 to 9 months with an average of 5 months. The maximum abduction was 10-20°. After web space scar release, the dorsal metacarpal island flap (3.5 cm × 1.2 cm-4.0 cm × 2.0 cm in size) was used to reconstruct web space (2.0 cm × 1.0 cm-3.0 cm × 1.8 cm in size). The donor site was directly sutured or repaired with local flaps. Results At 2 days after operation, necrosis occurred in 1 flap, which healed by extractive treatment. The other flaps survived and wound healed by first intention; all the flaps at donor sites survived and incision healed by first intention. Ten patients were followed up 6 to 15 months (mean, 9 months). The reconstructed web space had good appearance, the maximum abduction was 80 ° in 1 case of the 1st web space scars contracture, and the maximum abduction was 35-45° (mean, 40°) in the other 9 cases. In 8 scar patients causing by injury, no scar contracture recurred during follow-up. Conclusion It can achieve good results in appearance and function to use dorsal metacarpal island flap for treating scar contracture of the finger web.
ObjectiveTo discuss the clinical curative effect of internal fixation for metacarpal and phalanx fractures using stainless steel mini-plate and the early rehabilitation. MethodsThe study included 47 cases treated from January 2006 to June 2011, including 25 cases of 72 phalangeal fractures, 17 cases of 43 metacarpal fractures, and 5 cases of 23 complex metacarpal and phalangeal fractures. All the patients underwent open reduction and micro-plate internal fixation. Three days after surgery, passive function training was initiated. Patients accompanied with blood vessel damage began the training one week later. The training was carried out based on the early rehabilitation schedule. ResultsPrimary healing occurred in all the 47 cases. There was one case of broken plate because of crashing. Postoperative follow-up lasted for 4 to 10 months, and the fractures were healed in 138 lesions. X-ray examination showed that bone union took place at week 8 to 11 averaging at 10. According to the functional evaluation of total autive movement scales, the excellent and good rate was 83.0%. ConclusionThe stainless steel mini-plate in the treatment of metacarpal and phalangeal fractures has a firm fixation and is advantageous. Combined with early rehabilitation training, it can maximize the recovery of hand function with satisfactory clinical results.
Objective To discuss the surgical procedures and curative effect of stiff 2-5 metacarpophalangeal (MP) joints after crash injury in hand. Methods Between January 2006 and June 2009, 7 cases of stiff 2-5 MP joints were treated by releasing the stiff MP joints and reconstructing the function of lumbrical muscle in one stage. There were 6 males and 1 female with an average age of 32 years (range, 18-56 years). All injuries were caused by crash. Six cases suffered from multiple metacarpal fracture or complex dislocation of MP joint and 1 case suffered from complete amputation at level of middle palm of hand. The interval from initial wound heal ing to hospital ization was 3 to 15 months. Before operation, the X-ray films showed fracture healed and the results of nipping paper test were positive. All hands were treated with physical therapy for 1 month. After the plaster external fixation for 6 weeks, the physical therapy and function training were given. Results All wounds healed by first intention. The patients had no joint instabil ity and extensor tendon side-sl ipping with normal finger function. Six patients were followed up from 6 months to 3 years. The extension and flexion of MP joint were 0° and 67-90°, respectively. The average grip strength of injured dominant hand reached 86.70% of normal side and non-dominant hand reached 66.70% of normal side. The average injured dominant tip pinch strength reached 83.52% of normal side and non-dominant tip pinch strength reached 61.30% of normal side. Based on total active motion (TAM) system of Chinese Medical Association for Hand Surgery, the results were excellent in 4 cases, good in 1 case, and fair in 1 case; the excellent and good rate was 83.33%. Conclusion In patients with stiff MP joint and lumbrical muscle defect, releasing stiff MP joint and reconstructing lumbrical function in one stage can recover the function of MP joint and achieve good outcome. Physical therapy plays an important role before operation.
Objective To investigate the method and cl inical outcomes of repairing the skin and tissue defect of the finger pulp with transverse digital palmar island flap. Methods From August 2007 to September 2008, 9 patients with skin and tissue defects of the finger pulp were treated, including 6 males and 3 females aged 18-48 years old. The defect was caused bycrush injury by machine in 6 cases, pressure injury by heavy objects in 2 cases, and abrasion injury by grinding wheel in 1 case. The defect was located in the index finger in 4 cases, the middle finger in 2 cases, the ring finger in 3 cases, the proximal phalanx in 1 case, the middle phalanx in 7 cases, and the distal phalanx in 1 case. The defect size ranged from 1.3 cm × 1.0 cm to 2.5 cm × 1.5 cm. The defect was compl icated with unilateral blood vessel and nerve defect in 8 cases, bone fracture in 2 cases, and tendon exposure in 5 cases. The time between injury and hospital admission was 20 minutes-14 hours. Transverse digital palmar island flaps (2.0 cm × 1.2 cm-4.0 cm × 1.7 cm) were used to repair the soft tissue defect during operation. The donor site was repaired with full-thickness skin graft. Results All the flaps and skin graft at the donor site survived uneventfully. All the wounds healed by first intention. Nine patients were followed up for 6-17 months. The appearance of the flaps was similar to that of the uninjured side, there was no occurrence of obvious pigmentation and scar contracture, and the two-point discrimination value was 8-11 mm. According to the function evaluation standard for the replantation of severed finger by Chinese Medical Association Hand Surgery Academy, 8 cases were graded as excellent, 1 as good. Conclusion Repairing the skin and tissue defects in the finger pulp of middle and distal phalanx with transverse digital palmar island flap can simpl ify the operation procedure, reduce the suffering of the patient, and provide satisfying therapeutic effect.