Adhesion formation after nerve repair: an experimental study of early protected mobilization in the rabbit

The common peroneal nerve and its surrounding muscles were cut and repaired in 14 rabbits. The injured limb was then either immobilized for 3 weeks or passively mobilized within a "safety range" every day. At 3 weeks after operation, the "stretch test" and "peel test" showed no difference in the biomechanical features of the adhesions between the nerve repair and the surrounding soft tissues.

Conservative treatment of intra-articular fractures of the distal radius--factors affecting functional outcome

One hundred and eleven intra-articular fractures of the distal radius in young adults that were conservatively treated were studied. At two years, 80% of fractures were rated as excellent or good by the modified Green and O'Brien scoring system. The rate of re-displacement within casts was 28%. Sixty five per cent of re-displaced fractures were treated with surgical fixation. Those re-displaced fractures treated with repeated manipulation had only 33% excellent or good result. Moreover, their initial alignment could not be preserved. Axial compression (>2 mm) and dorsal angulation (>15 degrees ) were directly related to worse functional outcome and diminished range of motion.

Expression of nm23 protein in human osteosarcoma in relationship with early metastasis

Nm23 protein expression was analyzed by immunohistochemical staining using formalin-fixed, paraffin-embedded sections from 39 cases with osteosarcomas and compared with the histologic findings and early metastasis for the purpose of detecting nm23 expression in osteosarcoma and elucidating the clinical significance of its expression. Immunoreactivity of nm23 protein was detected in 48.7% of the total cases. There was no statistical difference between nm23 expression and early metastasis, but there was a trend for cases with nm23 expression to progress to early metastasis within 1 year after operation. The role of nm23 as a tumor metastasis suppressor in osteosarcomas appeared less prominent.

A novel injectable bioactive bone cement for spinal surgery: a developmental and preclinical study

The injection of bone cement by minimally invasive techniques for the treatment of vertebral body fractures or for stabilization of an osteoporotic vertebral body is regarded as promising in spinal surgery. The purpose of this study was to develop a novel injectable bioactive bone cement to address such concerns. The cement was composed mainly of strontium-containing hydroxyapatite (Sr-HA) filler and Bisphenol A Diglycidylether Dimethacrylate (D-GMA) resin. The Sr-HA filler was prepared by precipitation and calcination, then analyzed with Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) patterns. Samples of strontium-containing hydroxyapatite cement (SrHAC) were formed by a combination of powder filler and resin matrix, with the setting time and peak temperature recorded. Cell relative growth rate (RGR), Tetrazolium bromide (MTT), and haemolysis tests were used to detect initial in vitro biocompatibility of the new cement. In vitro spinal biomechanical testing and morphological observation after bone cement injection were performed on pig spines. Results indicate that the setting time and peak temperature of the cement was 15 min and 55 degrees C, respectively. Cytotoxicity of the cement was class 1 (no cytotoxicity) and haemolysis was 1% (no haemolysis). Stiffness after cement injection and fatigue loading were 112% and 95% of the intact bone, respectively, which is similar to that of natural bone. Radiopacity of SrHAC allowed easy radiographic imaging. The use of SrHAC cement is, thus, promising in spinal surgery.

Biomechanical properties of thin skin flap after basic fibroblast growth factor (bFGF) administration

This study is designed to examine the effects of basic fibroblast growth factor (bFGF) administration on the biomechanical properties of thin skin flap healing. A total of 42 rats were used in this study, and skin flaps 10 cm long by 3 cm wide were raised in 28 rats. One injection of bFGF was applied at three different times (immediately postoperatively, and 24 h and 48 h postoperatively) between the flap and wound bed of 14 rats (the bFGF treated group), while the other 14 rats with flaps had the same tissue culture medium treatment but without bFGF (the untreated group). The remaining 14 rats without flaps constituted the control group (normal group). The rats were killed 10 days postoperatively, and 1. 0 cm x 6.0 cm sections of the skin flap taken for mechanical and histological testing. The load, deformation and tensile strength at failure were recorded. The average flap survival area in the bFGF treated group was 27 cm(2), significantly higher (P< 0.001) than that seen in the untreated group. The average elastic stiffness of the skin flap in the bFGF treated group was also observed to be higher than in the untreated group although this difference was not significant. The mean tensile strength of the bFGF treated group (61 N) was significantly higher than the untreated group (38 N, P< 0.01) however. Despite this, the tensile strengths at failure of both of these groups were found to be significantly lower than that of normal skin (101 N, P< 0.01). A relaxation in load of about 8% was seen in specimens from the normal group and the bFGF treated group, while the untreated group showed a relaxation of about 15%.

Comminuted Intra-Articular Fracture of the Distal Radius - The Technique of Open Reduction and Internal Fixation With Plating

The technical details of open reduction and internal fixation with double plating for a patient with comminuted intra-articular fractures of the distal radius were described. The vital steps included the exposure, initial dorsal reduction, ventral reduction and fixation, checking of reduction, return to dorsal surface with final reduction and X-ray check, and wound closure. Special attention and other technical tips were also highlighted, and hopefully will shorten the learning curve of others who would like to use this rather demanding technique for their patients.

The Moberg pickup test: results of testing with a standard protocol

The purpose of this study was to propose a standard protocol for administering the Moberg pickup test. One hundred subjects (53 male and 47 female subjects, aged 11 to 77 years) volunteered. A wide variety of occupations were represented. No subjects had a history of upper extremity dysfunction. The materials and the testing procedures were clearly described to the subjects. Both hand dominance and gender difference were found to have significant effects on test performance. Norms were established for dominant/nondominant hands and for male/female subjects. Standard scores were calculated and used for comparison. The inter-rater reliability of the test was also determined. Administered with a standard protocol, the Moberg pickup test is a valuable test of functional sensibility. It is simple and quick to administer, easy to replicate, and inexpensive to acquire.

Intramedullary fixation by resorbable rods in a comminuted phalangeal fracture model. A biomechanical study

The mechanical rigidity of three different methods of resorbable intramedullary fixation (bone peg, and polyglycolide rods with and without interlocking) was assessed in a comminuted phalangeal fracture model and the results compared with two commonly used internal fixation devices (lateral plate, crossed K-wires) in a cadaver model. Each fixation technique was tested for its biomechanical strength in apex palmar bending, compression and torsion. Failure testing for the three resorbable methods was also done. The results showed that lateral plating provided the best rigidity in apex palmar bending and torsion, followed by intramedullary bone peg fixation. All resorbable intramedullary fixations had rigidity that was at least the same as crossed K-wires. For the torque test, polyglycolide rods with interlocking provided better rigidity than without interlocking. There was no significant difference between the different methods in the compression test, except that the intramedullary bone peg was significantly stiffer than K-wires.

Preliminary observation on the correlation between nm23 expression and Ki-67 antigen with early metastasis of human osteosarcoma

OBJECTIVES

To detect the nm23 expression in osteosarcoma, analyze the correlation between nm23 expression and early metastasis and to study the relation between nm23 expression with tumor differentiation and cell proliferation, as defined by Ki-67 labeling.

METHODS

nm23 oncoprotein expression was measured by immunohistochemical staining using formalin fixed, paraffin embedded sections of 39 surgically resected osteosarcomas and was compared with Ki-67 expression, histological findings and early metastasis. In each sample, the grading of immunoreactivity was recorded as 0, 1+, 2+ according to the percentage of nm23 and Ki-67 labeling cells respectively.

RESULTS

The cases with more than 25% positive immunoreactivity of nm23 protein were detected in 48.7% of the total cases. There was no statistical difference between nm23 expression and early metastasis, but the cases with nm23 expression appeared to have a trend to get early metastasis. nm23 expression was significantly correlated with Ki-67 expression, which was associated with differentiation of the tumor cells.

CONCLUSION

The role of nm23 as a tumor metastasis suppressor in osteosarcoma is less prominent. Both nm23 and Ki-67 may help predict the possibility of early metastasis in human osteosarcomas.

Biomechanical properties of absorbable implants in finger fractures

The mechanical rigidity of five different methods of pin fixation in two proximal phalangeal fracture models was studied and absorbable implants were compared with metallic implants in a biomechanical cadaver study. Thirty phalanges were tested in apex palmar bending, compression and torsion. Results showed that rigidity of absorbable implants was comparable with metallic implants, except in torsion.

Treatment of displaced intra-articular fractures of the distal end of the radius with plates

Thirty-four displaced intra-articular fractures of the distal aspect of the radius in thirty-four patients were treated with open reduction and internal fixation with plates and screws. Although there was a high rate of complications (nine [26 per cent] of thirty-four fractures), twenty-eight patients (82 per cent) had a good or excellent result according to the system of Gartland and Werley and twenty patients (59 per cent) had a good or excellent result according to the modified system of Green and O'Brien at the most recent evaluation. Immediately postoperatively, the articular surface of the distal aspect of the radius was restored to a mean of 2 degrees of volar tilt and 20 degrees of radial angulation and radial length was improved by a mean of ten millimeters compared with the preoperative length. The articular surface was restored to congruity or to at most one millimeter of step-off in twenty-six patients (76 per cent). By the time of the most recent evaluation, the initial postoperative alignment had changed markedly in three patients (9 per cent) and degenerative osteoarthrosis (grade II or III) had developed in six patients (18 per cent). We considered that the initial postoperative alignment had changed markedly when the articular surface was displaced by two millimeters or more, when the extra-articular alignment had changed by more than 10 degrees of radial tilt, or when there was more than five millimeters of radial shortening. The potential for restoration of normal alignment and the stability of the fixation are the main advantages of internal fixation with plates. Restoration of congruity to the joint was the major difficulty in this group of patients.

Results of dynamic splintage following extensor tendon repair

We report a prospective study of dynamic splintage following extensor tendon repair. Eighty-four patients with 101 extensor tendon injuries were studied. Using Dargan's evaluation system, there were 97% excellent results for the thumb and 93% excellent and good results for the fingers. The average total active motions were 107 degrees for thumbs and 245 degrees for fingers. Over 80% of patients regained good power grip. Patients with associated digital fractures or with ragged lacerations had poorer results. Overall, we found that dynamic splintage was a satisfactory method after extensor repair.

External fixation for comminuted phalangeal fractures. A biomechanical cadaver study

The mechanical rigidity obtained by external fixation in a comminuted phalangeal fracture model was assessed and the results compared with two other types of internal fixation commonly used (lateral plate and crossed Kirschner wires) in a biomechanical cadaver study. Each fixation technique was tested in apex palmar bending, compression and torsion. The results showed that lateral plating provided the best rigidity in apex palmar bending and compression and that external fixation and Kirschner wires showed the same mechanical properties. For the torque test, external fixation provided the best rigidity.

Fixation for comminuted phalangeal fractures. A biomechanical study of five methods

The rigidities of five fixation methods have been studied with a comminuted phalangeal fracture model. Mechanical testing of compression, bending and torsion were performed for each fixation. Lateral plating with six screws seems to provide the most rigid fixation. If such lateral plating is not practicable, the four-Kirschner wire method would be a satisfactory alternative.

Seasonal variation of fractures of the hip in elderly persons

A prospective study was made of 1500 elderly patients who suffered from acute hip fractures from 1986 to 1990. There were 36 per cent more fractures in the 6 colder months from November to April than in the rest of the year (P < 0.001). A strong correlation between the monthly adjusted fracture rate and the average lowest ambient temperature was also observed (P < 0.001). The fractures occurred in the older and less active patients during the 6 colder months. More importantly, they needed to wait longer for the operation during this 'high' season. This might be responsible for the higher medical complication rate after the operation. Better health care planning to help with the increased patient load in the 'high' season is essential to reduce the waiting time for the operation and the postoperative medical complication rate.

A prospective study of 924 digital fractures of the hand

A prospective study of 1129 patients with 1358 digital fractures of the hand was carried out between March 1984 and March 1994; of these, 924 fulfilled the criteria for inclusion. Functionally stable fractures with acceptable alignment were managed with immediate active mobilization. Unstable fractures, or fractures with unacceptable alignment, were openly reduced and fixed internally so that active mobilization could begin immediately after operation. The function results using various systems of evaluation were excellent or good in over 90 per cent of the fractured thumbs, and excellent or good in 58.7 per cent to 76.5 per cent of the fingers. Patients who did not require surgery did much better than those in the operated group. Comminuted, open and multiple fractures proved to be of poor prognostic value. However, rigid fixation was statistically significant in influencing the outcome.

Delay of the denervation process in skeletal muscle by sensory ganglion graft and its clinical application

We examined the effects of dorsal root ganglion isografts on the denervation process of skeletal muscle. A segment of sciatic nerve was removed from each of 25 inbred Wistar-Kyoto rats. Fifteen were set aside as controls. In the remaining 10 rats, isogeneic cervical dorsal root ganglia were grafted to the severed distal stump of the common peroneal nerve. Between day 72 and day 286 postoperatively, both controls and recipients were killed after twitch and tetanic tension recording of the extensor digitorum longus was performed. The wet muscle weight and the twitch and tetanic tensions of the denervated extensor digitorum longus in the graft group were significantly greater than those in the control group. The mean area of the denervated tibialis anterior muscle fibers in the graft group also was significantly larger than that in the control group. In electron and light microscopic images, nerve cells along the periphery of each dorsal root ganglion were found surviving with regenerating axons throughout the experimental period. Numerous myelinated axons were observed in the common peroneal nerve of the graft group, and there were significantly more axonal branches in the extensor digitorum longus of the graft group than in the extensor digitorum longus of the control group. Thus sensory nerve fibers from the grafted dorsal root ganglia had certain beneficial effects to slow the denervation process, presumably secreting trophic factors into the denervated muscle. Clinically, we have transferred avulsed dorsal root ganglia in cases of total brachial plexus avulsion directly into denervated skeletal muscle. This procedure, accompanied by nerve crossing procedures, will probably keep denervated skeletal muscle in a better condition until regenerating motor axons from the repair site reach their target muscle.

Carpal malalignment following intra-articular fractures of the distal radius in a working population

In a review of 52 consecutive intra-articular fractures of the wrist (mean age 41 years), 18 developed one of five carpal malalignment patterns. Seven patients developed a volar intercalated collapse pattern. Although showing some loss of motion and/or grip strength, this group remains relatively pain free on follow-up. Patients who developed dorsal translation (six cases) or a dorsal intercalated collapse pattern (one case) were the most symptomatic, with loss of grip strength, decreased range of motion and pain being prevalent.

Closed avulsion of both flexor tendons of the ring finger

Closed avulsion of both flexor digitorum profundus and superficialis from the same finger is rare. Only ten cases have been described in the literature. The majority were treated with a two stage reconstruction of the flexor digitorum profundus. We describe a case in which primary repair of both tendons was performed.

Cancellous screw fixation for subcapital femoral neck fractures

Experience in treating 80 subcapital femoral neck fractures by AO/ASIF cancellous screws is reported. Immediate full-weight bearing was allowed routinely. The mean follow-up was 28 months. Non-union occurred in 2% and late segmental collapse in 12% of patients with undisplaced fractures. Non-union occurred in 16.7% and late segmental collapse in 30% of patients for displaced fractures. Regression of screws occurred in 30% of patients, all of which were detected within the first month after the operation. It was associated with a significantly higher risk of non-union and late segmental collapse for both undisplaced (P < 0.01) and displaced (P < 0.001) fractures.

Titanium-mesh block replacement of the intervertebral disk

A prospective clinical trial was conducted involving patients with prolapsed lumbar intervertebral disk proven myelographically, who had anterior diskectomy and disk replacement with a titanium-mesh block implant. A pilot study was done in 1971 on six patients. In this trial, 28 patients were operated on with informed consent. Twenty-three had a minimum of five years' follow-up study. There were 14 men and boys, and nine women and girls. The average follow-up period was eight years and four months (range, five to 12 years three months). The average age at operation was 36 years four months (range, 13-66 years). Symptomatic improvement were divided into three groups. Sixteen patients were in Group 1, three in Group 2, and three in Group 3. Flexion-extension radiographs showed 14 patients with no movement between the vertebral bodies adjacent to the operated disk, five with minimal movement, and four with definite movement. At the implant-bone interface, no radiolucent zone was seen in 18 patients, and a definite radiolucent zone was seen in five. Twenty implants were intact, three implants had developed a crack, and three were deformed. There were no complications. The titanium-mesh block implant is an effective substitute for autogenous bone grafting in interbody fusion.

Can a divided digital nerve on one side of the finger be left unrepaired?

72 fingers with divided digital nerves on one side alone had their nerves repaired and the sensory recovery assessed at different intervals of up to 2 years. Another 36 fingers with similar digital nerve injuries had their divided nerves left unrepaired and sensory recovery similarly assessed for comparison. In the "repaired" group, the result continued to improve and by 2 years, 90% reached S3+ or above. In the "unrepaired" group, improvement plateaued after 6 months, and at 2 years only 6% reached S3+ or above, although all had regained some protective sensibility.

Plastic adhesive drapes and wound infection after hip fracture surgery

One hundred and twenty patients with acute hip fractures treated operatively were randomized into two groups. In the 'drape' group (n = 65) the operation site was covered with plastic adhesive drape after preparation. In the 'no drape' group (n = 55) the operation site was left uncovered. The two groups were otherwise matched. Swabs for culture were taken from skin adjacent to the wound before closure. The drape group had four positive wound swabs. There was only one positive wound swab for the no-drape group. There was no difference in the post-operative wound infection rates.

The significance of venous drainage in free flap transfer

A skin flap in the anterior abdominal wall of the S-D rat was designed so that it was supplied by the superficial epigastric branch of the femoral artery on the right side. Venous drainage was effected through one of five designs: (1) the superficial epigastric vein on the same side, (2) the lateral abdominal vein on the same side, (3) the lateral abdominal vein on the opposite side, (4) the superficial epigastric vein on the opposite side, or (5) a combination of the latter three. Seventy-seven rats were available for final analysis. The surviving percentage area of the flap was found to improve with increased venous drainage and when the arterial blood had to traverse the flap to reach the diagonally situated draining vein. The use of venae commitante as the draining vein is not satisfactory.