Effect of intermittent cigarette smoke inhalation on tibial lengthening: experimental study on rabbits

We investigated the effect of intermittent cigarette smoke inhalation on the bone healing of tibial lengthening in rabbits. Thirty-eight male rabbits were divided into two groups of 19 animals each. The first group went through intermittent cigarette smoke inhalation, and the second group did not go through intermittent cigarette smoke inhalation. Each animal's right tibia was lengthened 5 mm using an uniplanar lengthening device. Five animals of each group were killed at 4, 6, and 8 weeks postoperatively for biomechanical testing, and one animal of each group was killed at 2, 4, 6, and 8 weeks postoperatively for histologic study. Using the contralateral nonoperated tibia as an internal control, we found that torsional strength of the lengthened tibia of the smoke inhalation group was decreased significantly compared with the non-smoke inhalation group. The mean percent of maximal torque at 4, 6, and 8 weeks were 22.0, 66.3, and 78.6%, respectively, in the smoke inhalation group, whereas the mean percent of maximal torque were 48.0, 84.1, and 90.8% %, respectively, in non-smoke inhalation group (one-tailed t test, p < 0.01, p < 0.01, and p < 0.05 at 4, 6, and 8 weeks, respectively). Our histologic observations revealed that the granulation tissue resorption, bone formation, and remodeling were delayed in smoke inhalation group. The results of this study suggest that intermittent inhalation of cigarette smoke delays, but does not prevent, the bone healing in tibial lengthening.

[Metastatic spine disease: surgical treatment by anterior corpectomy and Ziekel's VDS fixation]

The spine is the common site of skeletal metastases. The goal of surgical treatment of metastatic spine disease is to improve the quality of remaining life, by relief of pain, the preservation or restoration of neurologic function, and reconstruction of the spinal stability. From 1984 through June 1993, 40 consecutive patients underwent surgical treatment by anterior corpectomy, and bone cement with VDS fixation for corporal metastatic diseases. There were 28 men and 12 women. The average age was 53.2 years, range from 21 to 76 years. Twenty-four patients had metastasis to the thoracic spine, 12 to the lumbar spine, and 4 had both thoracic and lumbar metastases. The primary malignancies were lung cancers in 10 cases, colorectal carcinomata in 6, hepatomas in 5, thyroid cancers in 4, cancer of stomach, renal, breast, nasopharynx, long bone, skin, cervical in 1 case respectively. A primary carcinoma was never identified in 8 patients. In the present series, 4 patients died within one month, 36 patients were allowed for follow-up study. Thirty-two patients (89%) attained pain relief. Thirty patients presented with neurologic compromise. After operation, neurologic improvement was noted in 21 (70%). No patient's neurologic function deteriorated secondary to surgical intervention. We conclude that anterior corpectomy to decompress neural encroachment with VDS and cement fixation to stabilize the collapsed spine is an adjunctive treatment to reduce pain and restore the neurologic function in these highly selected patients.

Biomechanical analysis of location of lag screw of a dynamic hip screw in treatment of unstable intertrochanteric fracture

OBJECTIVE

The aim of this study was to assess the most adequate location of a lag screw of a dynamic hip screw in the treatment of an unstable intertrochanteric fracture.

METHODS

Six pairs of proximal femora obtained from fresh adult cadavers were inflicted with iatrogenic unstable intertrochanteric fractures. Fractures of both sides were stabilized with two different favored locations of a lag screw and tested by a Material Testing System machine with increased loads to evaluate the relative migration of the femoral head.

RESULTS

There was significant difference (p < 0.05) with less migration of the femoral head by inferior insertion of a lag screw in the frontal plane and central insertion in the coronal plane.

CONCLUSIONS

Based on theoretical and experimental considerations, the most adequate location of a lag screw of a dynamic hip screw should be inferior in the frontal plane and central in the coronal plane.

Reduction-fixation spinal system in spondylolisthesis

Posterior transpedicular instrumentation with short segmental fixation represents a current trend in surgery for unstable spinal problems, such as spondylolisthesis. A reduction-fixation spinal system with 5.75- to 6.25-mm diameter pedicle screws of variable angles and an 8-mm diameter rod can achieve a rather rigid, short-segment fixation and satisfactory reduction of spondylolisthetic deformities. In clinical applications, 84% of 85 patients with spinal instability had good-to-excellent results for back pain, 88% for sciatica, and 86% for claudication; 91% achieved solid posterolateral fusion from the roentgenographic studies. This reduction-fixation system achieved a reduction of 71% +/- 5.3% of slipping width in this population. Posterior lumbar interbody fusion is mandatory for effective and lasting reduction. Complications from reduction fixation including pedicle-screw loosening (12%), pedicle screw breakage (7%), adjacent instability (7%), and nerve root injury (2%).

Adaptive Morse-coded single-switch communication system for the disabled

Automatic recognition of Morse-code is generally developed at a fixed typing rate. However, this is not suitable for the disabled due to their difficulty in maintaining a stable typing rate. In this paper, a system recognizing varying typing speeds is developed using an adaptive technique, the Least-Mean Square (LMS) algorithm. This system helps the disabled have a wide latitude and varying typing speeds in single-switch communication with the Morse-code.

Management of large infected tibial defects with radical debridement and staged double-rib composite free transfer

Seven patients with tibial fractures complicated by large infected tibial defects were treated with a two-stage protocol. In the first stage, antibiotic-impregnated polymethylmethacrylate (PMMA) bead chains were used to obliterate the debrided osseous defect, and a meshed porcine skin was used for temporary wound coverage. In the second stage, the bead chains were removed, and the defects were reconstructed with a microvascularized double-rib and serratus anterior muscle composite free transfer. The interval between the first and second operations was 2 to 4 weeks. The bone defects ranged from 6 to 9 cm, and the skin defect areas ranged from 20 to 40 cm2. Wound healing and bony union was achieved in all seven cases. Minor pin track infection was seen in one patient. Stress fractures in two cases were successfully managed with patellar tendon short-leg bracing for 6 months in one case and a plate internal fixation in the other case. Within 2 years, all seven patients returned to light work without any external support, and all of their most recent radiographs showed good consolidation and hypertrophy of grafted rib bones. No occurrence of osteomyelitis was observed during an average follow-up of 37 months (out of a range of 24 to 50 months). We conclude that this treatment protocol provides rapid recovery from osteomyelitis and the double-rib graft is a useful, durable alternative for large tibial defect management.

Vastus lateralis flaps for chronic recalcitrant hip infection

Between January 1991 and May 1994, 11 patients with chronic recalcitrant infection of the hip joint were successfully treated by transposition of a vastus lateralis flap. The average duration of the infection was 7.9 months. The patients had undergone an average of 2.8 procedures in an attempt to eradicate the infection before transposition of the flap. Three patients had recurrence of drainage after the procedure and were successfully treated with antibiotics and local debridement. Delayed exchange total hip arthroplasty was performed in 2 patients. All the patients achieved wound healing and infection resolution. This flap has several advantages. The donor site has not usually been scarred from previous operations; the flap has a consistent vascular pedicle which permits a wide arc of rotation; knee extension is unaffected; the transposed portion of the vastus lateralis can act as a cushion between the acetabulum and the proximal femur; it may also act as a tether to prevent extreme proximal migration of the femur. In the management of chronic recalcitrant infection of the hip, use of a transposition flap can be combined with a Girdlestone arthroplasty. It can also be an interim procedure before a further total joint arthroplasty.

Calorimetric characterization of the formation of acrylic type bone cements

The formation of acrylic bone cements upon heating was investigated by differential scanning calorimetry (DSC). The effects of the contents of initiators, accelerator, biocompatibilizer, and crosslinking agents on the rate and the heat of polymerization during DSC heating were studied. The rate and the heat of polymerization (delta H) were characterized by the peak temperature and the area of the DSC exotherm, respectively. It was found that both the rate and heat of polymerization decreased with increasing heating rate. The delta H was increased considerably with increasing benzoyl peroxide (BPO) initiator concentration from 1 to 10% (w/v), whereas the rate of polymerization was reduced significantly. An increase in azobisisobutyronitrile (AIBN) initiator concentration also induced an increase in delta H, but the rate of reaction was not affected considerably. The addition of accelerator promoted the rate of reaction but resulted in a drop in delta H. The rate of polymerization for the system containing BPO initiator was increased quite significantly with the addition of hydroxyethyl methacrylate (HEMA) biocompatibilizer, while the delta H was slightly increased. For the system using AIBN as the initiator, the rate of polymerization was decreased slightly and the delta H dropped significantly with the addition of HEMA. The effect of ethylene glycol dimethacrylate (EGDMA) crosslinking agent was also examined. Polymerization became more rapid with the addition of EGDMA in the bone cement using BPO initiator, while it remained approximately constant for the system using AIBN as the initiator. No systematic change in delta H was observed with the addition of EGDMA in both systems. This study demonstrated that DSC is a potential tool to measure the amount of heat released and also the rate of polymerization for bone cements.

Distal tibial nonunion treated by intramedullary reaming with external immobilization

Seventeen distal tibial nonunions were treated by a combination of metal removal with closed intramedullary reaming for internal bone graft and application of a long leg cast for aseptic nonunions and an external fixator for quiescent septic nonunions. The nonunions were present for a median of 1.8 years (range, 1.2-3.4 years). All achieved a solid union with a union period of 5.2 +/- 1.6 months. There was one complication of a renewed infection in a septic nonunion. The functional rating score improved from all unsatisfactory before treatment to 13 satisfactory after treatment. The other four (all were infected nonunions) also improved from poor to a fair outcome. In conclusion, the technique described is a simple and effective method to treat some complex distal tibial nonunions.

Back pain after thoracolumbar fracture treated with long instrumentation and short fusion

The purposes of this retrospective study are to evaluate the degeneration of facets in unfused segments immobilized by Harrington rods and to see how often back pain developed after treatment with this method. Sixty patients with thoracolumbar fracture were treated with the Harrington rod long-fuse short technique. Harrington rods are removed an average of 14 months after initial surgery. Every case showed solid fusion during implant removal exploration. Thereafter, all cases were followed for a minimum of 5 years. Roentgenographic studies and a bone scan were performed to evaluate the degeneration of facet joints. Back pain complaint was found in 11 patients (18.3%). The degeneration of unfused facets was visualized in six patients by roentgenograms. Increased activity in the instrumented spine by bone scan examination also was noted in six patients: three cases were at unfused area, one at a fused area, and two at fused and unfused areas. In conclusion, degeneration in the immobilized and unfused segments after rod long and fused short was rarely seen clinically after long-term follow-up. Back pain was experienced in only 18.3% of the patients and seldom required medication.

Prevalence of antibody to hepatitis E virus among healthy individuals in southern Taiwan

The seroprevalence of hepatitis E virus (HEV) among 997 healthy individuals aged 6 to 84 years, collected between July 1993 and June 1994 at Kaohsiung-Pingtung area in Southern Taiwan was studied. Of the study populations of vegetable farmers, elementary school children, volunteer blood donors and college students, the prevalence of IgG anti-HEV ranged from 6.4% to 8.8%. In suburban elemantary school children of Mang-Chou Village at Pingtung-Hsien, the seroprevalence rate (9.6%) was significantly higher than the positive rate (1.5%) found in rural aboriginal elementary school of San-Min Village at Kaohsiung-Hsien. IgG anti-HEV antibodies were widely distributed among all age groups, with a significantly higher percentage (13.1%) in the age group of 46-55 years old.

Ilizarov femoral lengthening in adults

From January 1990 to December 1991, we treated 12 cases of length discrepancy due to femoral inequality with the technique of Ilizarov femoral lengthening. The patients' ages ranged from 20 to 33 years (average, 28 years). Of these, nine patients were men and three were women. Corticotomy was performed either at the distal metaphysis or at the junction of distal metaphysis and diaphysis. After a latency of seven to ten days, distraction commenced at a rate 0.25 mm every six to twelve hours. Bone generation was obtained in all patients without the need of bone grafting. The average length gained in femoral bone was 4.7 cms (range, 3 to 7 cms). The average duration of total treatment was 10.1 months (range, 7 to 15 months). The healing index was 2.2 (number of months per 1 cm elongation) on average. All patients were satisfied with the results, but all felt that it was an uncomfortable procedure. According to our experience, we conclude that the method of Ilizarov is an useful technique for femoral lengthening. However, it is an uncomfortable and tedious procedure.

The quantitative measurements of hip isometric muscle torques in Chinese young adults--a preliminary report

A standard procedure for measurement of hip muscle strength (maximal isometric torque) with the Cybex 340 isokinetic dynamometer is presented. Twenty-two healthy males aged 30-40 years (average 34.3 years) were tested on hip flexors, extensors and abductors; in which the factors as sex, age, dominant side and testing session were all eliminated. The test was redone two weeks later on the same 10 males to evaluate its reproducibility. The results disclosed the maximal isometric torque of the hip flexors was stronger than that of extensors and abductors in both sides hips. The comparison between two sides hips showed only the abductors of right side hip significantly stronger than that of left side (P = 0.0259). The tests between the two different periods were quite compatible. The results have clinical implications for objective assessment of preoperative and postoperative hip strengths in patients with hip arthropathy and thus giving a reasonable guidance for physiotherapeutic management.

Surgical treatment for deltoid contracture in adults

In a retrospective study, 60 shoulders in 38 adults with deltoid contracture were surgically treated by proximal or distal releases. Twenty-three patients, representing 34 treated shoulders, were followed up for at least 2 years (median was 4 years). By the last follow-up, all patients achieved satisfactory outcomes: freedom from pain, full range of motion, and normal muscle power. The proximal release was used in patients with one-portion (one of the deltoid origins) involvement, and the distal release was used in patients with two- or three-portion involvement. Three shoulders (5%) had postoperative complications in the form of intramuscular hematomas, which were resorbed spontaneously within 3 weeks. The authors recommend surgical release to treat deltoid contracture whenever indicated.

Surgical treatment of tuberculous spondylitis. 50 patients followed for 2-8 years

We treated 50 adult patients with tuberculous spondylitis surgically and followed them for a mean of 5 (2-8) years. All had persistent back pain, 32 had neurologic deficit, and 13 had gibbus deformity. Anterior debridement and fusion were the main operative procedures. Additional posterior stabilization was performed in 14 patients who had loss of a vertebral body or for correction of severe kyphosis. 30 of the 32 patients with neurological impairment had an improvement of 1-3 Frankel's grades after operation. All patients had some relief of pain. Solid bony union of the fusion was found in 46 patients and 4 had nonunion after anterior operation only. The average correction of the kyphotic angle was 10 degrees.

Double-rib composite free transfer to reconstruct a single-spared lower extremity defect

The case of a 43-year-old man is reported in which a 15-cm defect of the tibia sustained 8 months previously was treated by the double-rib composite microvascular free transfer. The fracture site united, and the grafted ribs showed some hypertrophy at 1 year. He returned to his job. At 5 years follow-up, the x-ray film showed good hypertrophy of the grafted ribs.

Pulmonary tuberculosis as a source of infection after total hip arthroplasty. A report of two cases

Two cases of septic loosening due to a tuberculosis infection occurred 18 months and 14 years after total hip arthroplasties. The primary source was pulmonary tuberculosis. Treatment was by removal of the prosthesis and radical debridement with the local implantation of gentamicin PMMA beads, followed by antituberculosis chemotherapy for one year. In the first case, a revision arthroplasty was carried out 20 months later; the second was reconstructed with a vastus lateralis transposition one month later. There was no recurrence of infection after a follow up of 3 and 2 years respectively. Although this is a rare complication, the possibility must be born in mind. Early diagnosis and treatment of pulmonary tuberculosis may prevent the secondary infection of a total hip arthroplasty.

[Floating shoulder (ipsilateral scapular neck and clavicle fracture)--two cases report]

Fracture of either clavicle or scapular neck alone are generally stable and have satisfactory results by conservative treatment. However, displaced scapular neck and ipsilateral clavicle fractures are relatively unstable. Those sequelae as drooping shoulder and limited range of motion may develop if treated conservatively. Surgical intervention either fixation of clavicle alone or fixation of clavicle and scapular neck simultaneously can achieve stable reduction of the fractures and prevent those sequelae. We present two cases of floating shoulder treated surgically with excellent results.

Incorporation of allograft for acetabular reconstruction. Single photon emission CT in 21 hip arthroplasties followed for 2.5-5 years

We studied 21 hips in 20 patients who had acetabular reconstruction with a femoral head allograft in primary (n 2) and secondary (n 19) total hip arthroplasty. The fate of the graft was evaluated by serial bone SPECTs (single photon emission computed tomography). With a mean follow-up period of 37 (30-60) months, 14 of the 21 hips showed evidence of incorporation at earliest 13 (6-18) months after operation. There was no correlation between the fate of allograft and the compatibility of A, B, O blood typing between host and donor, the use of bone cement in the fixation of acetabular component, or loosening of the acetabular component.

Irreducible volar rotatory dislocation of the proximal interphalangeal joint

Volar rotatory dislocation of the proximal interphalangeal (PIP) joint often cannot be reduced by closed manipulation because of interposition of soft tissues. In this case, the condyle of the proximal phalanx was trapped between the central slip and the lateral band. This case is reported to reemphasize the importance of recognizing serious injuries involving the soft tissues around the PIP joint. Deprival of its normal dorsal stabilizing forces can cause a loss of both static and dynamic joint support. Secondary scarring and contractures affect all damaged structures of the joint.

The intra-articular migration of the broken wire: a rare complication of circumferential wiring in patellar fractures

Patellar fractures are frequently encountered in emergency situations. With proper treatment, the outcome is usually favorable. This study focuses on a rare complication of circumferential wiring in a case of patellar fracture treated by open reduction. A technical error which may have caused this complication is analyzed.