Increased vasculogenesis of endothelial cells in hyaluronic acid augmented fibrin-based natural hydrogels - from in vitro to in vivo models.

Vascularisation efficiency plays an essential role in the success of bulk transplantation, while biocompatibility and safety are major concerns in clinical applications. Fibrin-based hydrogels have been exploited as scaffolds for their advantages in biocompatibility, degradability and mass transportation in various forms. However, the mechanical strength and degree of vascularisation remain unsatisfactory for clinical usage. An interpenetrating hydrogel was developed by adding hyaluronic acid (HA) to a fibrin-based natural hydrogel. The vasculogenesis of endothelial cells (human umbilical vein endothelial cells, HUVECs) was characterised within the gel using both in vitro and in vivo animal studies. The in vitro vascular morphology analysis showed 17.9 % longer mean tube length and 14.3 % higher average thickness in 7 d cultivation within the HA-supplemented hydrogel. The in vivo results showed 51.6 % larger total tube area, 1.8 × longer average tube length and 81.6 % higher cell number in the HA-supplemented hydrogel compared to the hydrogel without HA. The experimental results demonstrated better vascularisation and cell recruitment in the HA- supplemented hydrogel. The material properties of the hydrogels were also analysed using atomic force microscopy (AFM). The results revealed 3.7 × higher elasticity of the HA-supplemented hydrogel, which provided better mechanical strength and support for easy handling during procedures. With the demonstrated advantages, the developed hydrogels showed promise for exploitation in various practical clinical applications.

Blood glucose rise after lactose tolerance testing in infants.

Lactose tolerance tests are used clinically to screen children and infants. It is assumed that absorption of a lactose challenge in infants would occur in a predictable pattern prior to weaning. Twenty-one infants from 3 to 12 months of age were studied. The maximum blood glucose rise over fasting levels ranged from 11.0 to 62.0 mg/100 ml; the mean was 32.6 mg/100 ml. Six infants had a maximum rise of less than 20 mg/100 ml. Eleven infants (52%) had a maximum rise of greater than 30 mg/100 ml. Signs of intolerance were not noted in any subject. Weight and length were normally disturbed. Results indicate the variance in glucose rise existing within a population of infants growing normally and consuming milk. Gastric emptying, digestion, and absorption may influence the blood glucose rise after a lactose test. Established glucose levels used as an index to lactose absorption in older children and adults may not accurately reflect lactase activity in infants.

Aerobically generated CO(2) stored during early exercise.

Previous studies have shown that a metabolic alkalosis develops in the muscle during early exercise. This has been linked to phosphocreatine hydrolysis. Over a similar time frame, the femoral vein blood pH and plasma K(+) and HCO(-)(3) concentrations increase without an increase in PCO(2). Thus CO(2) from aerobic metabolism is converted to HCO(-)(3) rather than being eliminated by the lungs. The purpose of this study was to quantify the increase in early CO(2) stores and the component due to the exercise-induced metabolic alkalosis (E-I Alk). To avoid masking the increase in CO(2) stores by CO(2) released as HCO(-)(3) buffers lactic acid, the transient increase in CO(2) stores was measured only for work rates (WRs) below the lactic acidosis threshold (LAT). The increase in CO(2) stores was evident at the airway starting at approximately 15 s; the increase reached a peak at approximately 60 s and was complete by approximately 3 min of exercise. The increase in CO(2) stores was greater, but the kinetics were unaffected at the higher WR. Three components of the change in aerobically generated CO(2) stores were considered relevant: the carbamate component of the Haldane effect, the increase in CO(2) stores due to increase in tissue PCO(2), and the E-I Alk. The Haldane effect was calculated to be approximately 5%. Physically dissolved CO(2) in the tissues was approximately 30% of the store increase. The remaining E-I Alk CO(2) stores averaged 61 and 68% for 60 and 80% LAT WRs, respectively. The kinetics of O(2) uptake correlated with the time course of the increase in CO(2) stores; the size of the O(2) deficit correlated with the size of the E-I Alk component of the CO(2) stores. We conclude that a major component of the aerobically generated increase in CO(2) stores is the new HCO(-)(3) generated as phosphocreatine is converted to creatine.

Cefuroxime-impregnated cement at primary total knee arthroplasty in diabetes mellitus. A prospective, randomised study.

We have performed a prospective single-blinded randomised study to evaluate the role of antibiotic-impregnated cement in the prevention of deep infection at primary total knee arthroplasty (TKA) in patients with diabetes mellitus. We studied prospectively 78 arthroplasties performed for osteoarthritis in such patients. They were randomly separated into two groups. In group 1 (41 knees), cefuroxime-impregnated cement was used while in group 2 (37 knees) cefuroxime was not added to the cement. The preoperative, intraoperative and postoperative management was the same for both groups. The mean follow-up was 50 months (26 to 88). There were no cases of deep infection in group 1, but five (13.5%) occurred in group 2 (p = 0.021). We conclude that cefuroxime-impregnated cement is effective in the prevention of deep infection at primary TKA in patients with diabetes mellitus.

Undisplaced femoral neck fracture in the elderly.

The results and the related conditions of 250 undisplaced femoral neck fractures managed by percutaneous Knowles pinning were evaluated. All of the patients were over 59 years old, and the protocol of management and follow-up was determined prospectively. The duration from injury to management was 3.0 (range 1-12) days, the operation time was 20 (range 10-44) min, and most of the patients were discharged without hospitalization. The follow-up period was 74 (range 24-138) months. The final results showed 226 (90.4%) fractures with smooth course of union (mean union time: 24 weeks), 15 (6.0%) fractures with nonunion, and 9 (3.6%) fractures with implant problems. Eighteen (7.2%) hips developed avascular necrosis of femoral head after union. The analysis showed that the rate of complications was higher in elderly persons with undisplaced femoral neck fractures.

Sudomotor abnormalities in reflex sympathetic dystrophy.

BACKGROUND: Intractable pain and sweating dysfunction can occur in patients with reflex sympathetic dystrophy (RSD). We, therefore, investigated autonomic function by measuring sympathetic skin response (SSR) in these patients. This method provides useful information regarding the pathophysiologic changes in and clinical evaluation of RSD. METHODS: Twenty-six RSD patients and 22 age-matched normal subjects were involved in our investigation. Three significant stages of RSD were classified through three-phase bone scanning of the wrist, carpal and metacarpal bones. There were 11 patients in stage I RSD, nine in stage II and six in stage III. SSRs were recorded from the bilateral palms of each subject simultaneously using electrical stimulation of the median nerve in the wrist. Latency and amplitude side ratios were calculated and compared with the control group. RESULTS: The affected/normal (A/N) hand amplitude ratios were significantly lower in stage I RSD, and stage II RSD patients exhibited significantly higher A/N amplitude ratios compared with the control group. A/N amplitude and A/N latency ratios in stage III RSD did not change significantly. The A/N latency ratios in stage I RSD were significantly higher than those of the control group and those of stage II RSD. In one stage I patient and three stage III patients, SSRs were bilaterally unobtainable. CONCLUSIONS: It appears that abnormal SSRs may be associated with autonomic disturbance in RSD patients.

Surgery for old ankle fracture. 13 cases followed for 9 (5-15) years.

Between 1978 and 1988, we treated 13 cases of neglected ankle fractures by open reduction and internal fixation or osteotomy 11 (2-36) months after the accident. Having been followed for 9 (5-15) years, the results were evaluated. All the patients were improved, even though restoration of the anatomy of the joint often was difficult. Those operated on after less than 6 months had better function than those with longer delays.

Avascular necrosis of femoral head after gamma-nailing for unstable intertrochanteric fractures.

We reported on 7 cases of avascular necrosis of the femoral head after treatment of an unstable intertrochanteric fracture with the Asian Pacific gamma-nail. The incidence was about 1.16% (7 of 604) in our series. Good reduction and good implant position were achieved in all 7 men. Avascular necrosis was found about 6 months to 3 years after the initial operation, and all the fractures were solidly united at the final diagnosis. The possible etiologies were initial high energy trauma and combining basal neck fracture and iatrogenic damage of the blood supply to the femoral head.

Complications in surgical treatment of undisplaced femoral neck fracture.

BACKGROUND: Percutaneous Knowles' pinning is a well accepted treatment of undisplaced femoral neck fracture, but there are some complications that have seldom been discussed. METHODS: One hundred and eighty two patients with undisplaced femoral neck fractures, at a mean age of 67 years, were treated by percutaneous Knowles' pinning between 1983 to 1989, and followed for an average of 102 months. The clinical results and complications were evaluated. The data were collected on the basis of age and bone density. Student's t-test was used to evaluate the significance of the results. RESULTS: The mean union time was 20 weeks. In all the patients, 85.8% had good results, 3.8% patients had acceptable results and 10.4% patients had poor results. Old age (> or = 65 years) and osteoporosis (Singh index < or = 3) were two factors of the poor result. Thirty-two cases (17.6%) developed complications. The incidence of nonunion or implant problems was apparently higher in the older or osteoporosis group, but avascular necrosis of femoral head correlated little with old age or osteoporosis. CONCLUSIONS: Although percutaneous Knowles' pinning is simple, safe, economic and reasonably effective for the treatment of undisplaced femoral neck fractures, we should pay more attention to the uncooperative, old, and osteoporotic patients.

Surgical treatment of displaced acetabular fractures - 72 cases followed for 10 (6-14) years.

Seventy-two displaced acetabular fractures managed surgically were evaluated retrospectively. The follow-up period was 10 (6-14) yr. The commonest fractures were posterior wall (28) and both columns (10). The surgical approaches were Kocher-Langenbeck (47), ilioinguinal (19) and extended iliofemoral (6). No neural monitoring was used in operations and no preventive agents for heterotopic ossification or thromboembolism were used perioperatively. Reduction was rated congruent in 59 (81.9%) and noncongruent in 13 (18.1%). The early postoperative complications were 1 vascular injury, 1 iatrogenic sciatic nerve injury, 1 deep vein thrombosis and 2 wound infections. The late complications were heterotopic ossification in 20 patients, avascular necrosis of the femoral head in 4 and symptomatic arthritis in 10. Functional outcomes were rated as excellent in 31, good in 23, fair in 7 and poor in 11. Our results show that traditional management is effective enough for displaced acetabular fractures.

Treatment of acute closed humeral shaft fractures with Ender nails.

The effect of semirigid Ender nails (EN) in the treatment of closed humeral shaft fractures was reviewed and analyzed. Clinical study was set retrospectively with detailed parameters. One hundred and eighteen closed humeral shaft fractures, treated with closed reduction and internal fixation with ENs, were collected. The follow-up period was 78 (24-175) months. The average operation blood loss was 105 cc, operation time was 57 min, hospital stay was 6.5 days, and union time was 10.5 weeks. The postoperative complications included three superficial infections, one iatrogenic radial nerve palsy, eight nail backouts, and eight nonunions. In our experience, for closed humeral shaft fractures fixed surgically, EN is a good choice for its simplicity and efficacy, but the fracture gap should be minimized after fixation and postoperative care should be closely observed.

Multiple glomus tumors: a case report.

Multiple glomus tumor (MGT) is rare in incidence. A 37-year-old male was diagnosed to have localized MGT over his right leg. With the characteristics of unusual location (right lower leg), development in sequence, and distribution along the course of the lateral sural cutaneous nerve. Its pathological findings were also characteristic. When the overall presentations showed in cases with recurrent symptoms and signs of glomus tumor after surgical excision, recurrence and multiplicity should be considered.

Management of avulsion injury of the PCL with reattachment.

Twenty-eight cases of avulsion injury of the posterior cruciate ligament (PCL) treated by reattachment were followed up to evaluate the results. Evaluation was based on appropriate functional and dynamic criteria: the results are classified as good, fair or poor. The interval between injury and repair ranged from 3 days to 2 months with a mean 4 weeks. The follow-up period ranged from 3 to 10 years with a mean of 5 years. The evaluation revealed 27 (96 per cent) good, one (4 per cent) fair and no poor results. It is apparent that operative reattachment is the treatment of choice for avulsion injury of the PCL, especially in early cases.

Management of insufficiency of posterior cruciate ligaments.

BACKGROUND: This study aims to evaluate the role of different methods in management of insufficiency of posterior cruciate ligament (PCL) that were used in VGH-Taipei. METHODS: 129 cases with insufficiency of PCL were collected to evaluate, according to functional and dynamic criteria, the results of different managements which were graded as good, fair, or poor. The patients were divided into 3 groups, i.e. group 1 with conservative rehabilitation therapy, group II with surgical reattachment, and group III with surgical ligament reconstruction that had 3 subgroups including IIIa reconstruction with medial head of gastrocnemius, IIIb with patellar tendon and IIIc with artificial ligament. The artificial ligaments used were Leeds-Keio ligament (group IIIcl), Dacron ligament (group IIIc2) and Goretex ligament (group IIIc3). The duration from injury to treatment varied from 3 days to 12 years with mean 45 weeks. The followup period was from 38 months to 112 months with mean 62 months. RESULTS: The results revealed 6 cases of good grade (25%) and 18 cases of fair grade (75%) in group 1, 20 cases of good grade (95%) and 1 case of fair grade (5%) in group II, 14 cases of good grade (40%), 10 cases of fair grade (29%) and 11 cases of poor grade (31%) in group IIIa, 3 cases of good grade (100%) in group IIIb, 13 cases of good grade (82%) and 3 cases of fair grade (18%) in group IIIcl, 19 cases of good grade (83%), 3 cases of fair grade (12%) and 1 case of poor grade (4%) in group IIIc2, and 3 cases of good grade (43%), 3 cases of fair grade (43%), and 1 case of poor grade (14%) in group IIIc3. CONCLUSIONS: Conservative intervention could be satisfactory in some cases with PCL insufficiency, especially in cases with isolated PCL injury, while surgical methods is mandatory in the others, especially in cases with chronic symptomatic PCL insufficiency.

Delayed treatment of ankle fracture.

BACKGROUND: Cases of old ankle fractures with different delayed treatments in different conditions were collected and evaluated to determine which treatments were optimal for individual type of fractures. METHODS: Sixteen cases of old ankle fractures were managed by open reduction and internal fixation, osteotomy, or removal of loose fragment according to the condition of the fractures between 1977 and 1987. The follow-up period was from 5 to 15 years with mean 7.9 years. The final result was evaluated by a modified performance index. RESULTS: All the 12 patients treated with open reduction and internal fixation for malposition got improved with the mean performance score rising from 37 before operation to 76 after operation. Improvement was also noted in all the 3 patients treated with osteotomy for malunion without significant arthritis, rising from 44 to 88. One patient had painful non-united fragment of medial malleolus, and removal of the loose fragment was done to improve the score from 58 to 96. CONCLUSIONS: Management of old ankle fractures can be effective and beneficial when appropriate treatments are given according to the different conditions of the fracture and joint.

Salmonella infection in total hip replacement--report of successful reimplantation and review of the literature.

A case of Salmonella enteritidis group C infection following total hip replacement was treated by resectional arthroplasty and appropriate antibiotics. Total hip replacement with reimplantation of an antibiotic-impregnated cemented hip prosthesis was performed five months later. The postoperative course was smooth and hip function was good, without any sign of infection recurrence throughout 10 years of follow-up. The treatment protocol and clinical results are discussed along with a review of the literature.

Cerclage wiring in displaced both-column fractures of the acetabulum.

We evaluated the effect of cerclage wiring in the open reduction and internal fixation of displaced both-column fractures of the acetabulum. This was a prospective clinical evaluation of such cases where the main surgical strategy was open reduction and internal fixation with cerclage wire and supplemental reconstruction plates. Data on 35 cases treated by open reduction (all via the triradiate approach)/internal fixations with cerclage wire and reconstruction plates were collected. The follow-up period was 40 months (18-69). Reduction with a fracture gap of less than 2 mm without articular stepping was achieved in all 35 cases. Postoperative complications developed in seven cases, including subcutaneous haematoma in two, wound infection in two and heterotopic ossification in three. All the complications had no adverse effect on the clinical outcome, and all the cases had good to excellent final results. Cerclage wiring is very useful and effective in the reduction and fixation of displaced both-column fractures of the acetabulum, and supplemental fixation with reconstruction plates and screws is necessary.

Ipsilateral hip and distal femoral fractures.

We tried to find the trauma mechanism and treatment rationale of ipsilateral concomitant hip and distal femoral fractures involving the articular surface. Between 1988 and 1995, 15 cases of ipsilateral hip (confined to neck or trochanteric areas of the femur) and distal (confined to supra- and intercondylar area of the femur) femoral articular fractures were collected. The hip fractures consisted of 10 trochanteric fractures and five neck fractures, which were managed with reduction and fixation in 14 (Knowles' pin in eight, DHS in four and standard Gamma nail in two), and primary bipolar hemiarthroplastry in one. The distal femoral articular fractures were open in 11; these were managed with radical debridement, implantation of Septopal chains and immediate internal fixation, followed by prophylactic autogenous bone grafting 6 weeks later in the recent six cases (five Judet plates, four dynamic condylar screws and two condylar plates). The other four closed distal femoral fractures were managed with early reduction and internal fixation (two Judet plate, one dynamic condylar screw and one condylar plate). The union time was 20.3 (12-48) weeks for proximal fractures and 23.7 (12-36) weeks for distal fractures. Early infection developed in three cases. Nonunion of a femoral neck fracture developed in one case. The other complications were implant failure in one, coxa vara in one, refracture in one, delayed union in one and knee stiffness in one.

Treatment of acetabular fractures: 10-year experience.

BACKGROUND: Acetabular fracture is a controversial and difficult fracture to manage. We retrospectively evaluated the outcome of the traditional management of acetabular fractures. METHODS: From 1987 to 1996, 112 cases of acetabular fracture presented at the Taipei Veterans General Hospital and were managed surgically in 73 cases and nonsurgically in 39 cases. The follow-up period was 90 (36-140) months. RESULTS: In the nonsurgically managed group, congruent reduction was achieved in 29 cases (74.3%) and good to excellent functional results were achieved in 25 cases (64.1%). In the surgically managed group, congruent reduction was achieved in 60 cases (82.2%) and good to excellent functional results were achieved in 57 cases (74.3%). In 51 (45.5%) cases, early or late complications developed after management, including one femoral artery perforation, one screw penetration, three wound infections, one iatrogenic sciatic nerve injury, one deep vein thrombosis, 21 heterotopic ossifications, two chondrolyses, three avascular necroses of the femoral head and 18 cases of symptomatic traumatic arthritis. CONCLUSIONS: The functional results correlated well with the final congruity of the joints and the severity of the complications.

Bateman bipolar hemiarthroplasty for displaced intracapsular femoral neck fractures. Uncemented versus cemented.

Four hundred forty-seven patients with 451 displaced fractures of the femoral neck were treated with Bateman bipolar hemiarthroplasty (190 cemented and 261 uncemented) between 1985 and 1990 in the authors' institution. During a follow-up period of at least two years, the authors found less thigh pain (13% versus 46.2%) and higher Harris hip scores (86 versus 79) in the cemented group in comparison with the uncemented group. Radiographic examination showed less radiolucent zones and subsidence in the cemented group. Heterotopic ossification was more common in the cemented group. Despite the fact that the cemented group had longer operative times (average, 20 minutes) and more blood loss (average, 160 ml) during the operation, there was no significant difference in the early mortality rate observed between these two groups. The cemented prostheses provided better functional and radiographic results and fewer failures in the early stage. In addition, the cemented prostheses did not lead to more complications and higher mortality rates. Thus, for elderly patients who need early ambulation and functional recovery, the cemented Bateman bipolar prosthesis appears to be a better choice than the uncemented Bateman prosthesis.