Expandable nailing system for tibial shaft fractures.

OBJECTIVE: To evaluate and present our current clinical experience in the treatment of closed and open tibial shaft fractures using the expandable intramedullary nailing system. DESIGN: Prospective study. SETTING: One level-1 trauma centre. PARTICIPANTS: Twenty-six patients with acute tibial shaft fractures with at least 10 cm of intact cortex on both sides of the fracture. INTERVENTION: Internal fixation using the Fixion expandable intramedullary nail (Disc-O-Tech Medical Technologies Ltd., Herzliya, Israel). MAIN OUTCOME MEASUREMENTS: Operative and fluoroscopy time, healing time and perioperative complications were recorded. RESULTS: Twenty-six tibial fractures were treated (OTA classification: 3 type A1, 8 A2, 8 A3, 3 B1, 3 B2, and 1 B3), six of which were open. All fractures healed by week 18.5 with an mean of 12.8+/-3.8 weeks. The operating time ranged from 20 to 50 min with an mean of 40+/-12.17 min. The fluoroscopy time ranged from 6 to 22s with a mean of 10+/-5s. In one case the nail failed to expand, as detected by X-ray control, and had to be exchanged intraoperatively. Two patients reported anterior knee pain during the follow up, but did not wish any further treatment. In a low demanding patient rotational malalignment was noted and no further action needed. CONCLUSION: According to the results of this study, the use of the Fixion nailing system, where indicated, is associated with minimal complications and very good functional outcomes in fractures OTA types A and B. The advantages of the expandable nail include the decrease in the operating and fluoroscopy time and the simplicity of its application.

Impact energy absorption by specimens from the upper end of the human femur.

A cadaveric biomechanical study was performed to investigate the fracture energy absorbed by strips of bone from the proximal femur in relation to age and gender, under impact loading conditions. Four groups (young male, young female, old male, old female) of four cadaveric proximal femurs were used in each case. Four bone strips were taken from the neck and four from the subtrochanteric area and these were tested under dynamic-impact conditions using the Charpy impact test. The fracture energy was calculated as the energy needed to achieve fracture per unit area, and expressed in J/m2. Bone specimens from young males are significantly tougher under impact conditions to those of females (p = 0.001), whereas between the old male and female groups, fracture energy does not significantly differ (p = 0.165). There was also significant difference (p < 0.0005) between the young and the old groups in both genders. The fracture energy absorption of the subtrochanteric area compared to that of the femoral neck for the same group of age and gender is in general slightly higher for all groups. In conclusion, gender in the young age group played a significant role in bone resistance in breaking whereas in the older age group it played a less important role.

Viscoelastic properties of cartilage-subchondral bone complex in osteoarthritis.

OBJECTIVE: This study examines viscoelastic properties of the 'unaffected' tibial condyle in unicompartmental osteoarthritic knees, in order to determine whether to preserve it or not in knee replacement operations. DESIGN: The viscoelastic properties of longitudinal strips of cartilage and subchondral bone from osteoarthritic and healthy knees were studied. METHODS: Nine medial compartment osteoarthritic and nine cadaveric knees, all age- and gender-matched, were studied. Samples from polyethylene and methacrylate cement were also obtained and all then tested in the DMA (Dynamic Mechanical Analysis) testing apparatus. The dynamic modulus of elasticity (E(dyn)) and the loss factor (tan delta) were measured. RESULTS: The medial compartment in osteoarthritic knees had lost its viscoelastic properties, having a significantly higher E(dyn) compared to the lateral one, and lower values of loss factor. In healthy knees there was no significant difference (p=0.18) in viscoelastic properties between both compartments and with the unaffected side of the osteoarthritic knee. Polyethylene and cement appear to have a high modulus of elasticity compared to both the healthy and the osteoarthritic knees. CONCLUSIONS: The 'unaffected' (lateral) tibial condyles in medial compartment osteoarthritic knees seem to preserve their viscoelastic properties; it is worth considering a hemiarthroplasty. The significant modulus of elasticity difference between the condyles-polyethylene-cement results in different deformation in the interface between them and induces micromotion and loosening.

Therapeutic Intervention Scoring System-28 as a tool of post ICU outcome prognosis and prevention.

AIM: To examine the effects of severity upon discharge from Intensive Care Unit (ICU) status, as assessed by the Therapeutic Intervention Scoring System-28 (TISS-28) on subsequent post ICU outcome. METHODS: One-year retrospective observational study. Six bed general ICU in a general hospital with no High Dependency ICU unit (HDU) available. We used data from all patients admitted to the ICU. From all discharged patients, data on mean length of ICU stay, APACHE II upon admission and TISS-28 upon discharge were collected. RESULTS: Eighty-six patients, mean age 63.2, were discharged to hospital wards between January 1999 and December 1999. Age is a significant factor to contribute to outcome prediction, (p=0.0478). TISS-28 is statistically significant related to survival status. Thirteen patients that did not survive had higher TISS-28 values (p=0.0032). Length of ICU stay has a borderline association (p=0.063) with survival. CONCLUSION: Patients discharged from ICU have post ICU hospital length of stay and prognosis related to their age, time of hospitalization in ICU and their severity status upon discharge from the ICU. We believe that, based on the TISS-28 scoring system, high risk patients can be identified and either ideally transferred to a HDU or discharged from ICU when further improvement has been achieved. TIS-28 is a valuable tool in post ICU outcome prediction and subsequently, in hospital mortality reduction. At the same time, through TISS-28 use, each hospital can locally identify the quality of care provided outside the ICU, given the outcomes measured in groups of patients at various severity levels.

Experimental investigation of the tension band in fractures of the patella.

We investigated the strain pattern developed in the anterior and posterior part of the fixed patella during knee motion. Eight fresh cadaver knees were used but two were excluded because of non reliable measurements due to misplacement of gauges. Two strain gauges were bonded in the midline of the anterior and two in the posterior surface of the patella. Threaded steel rods were cemented into the intramedullary femoral and tibial canals. The knee was placed on a special device. The quadriceps tendon was gripped and a 4.5 kg weight was attached to the tibial rod 16.5 cm distal to the joint line. Ten flexion/extension cycles were performed before testing. Initially the intact patella was tested. A transverse osteotomy was performed before being stabilized by the AO recommended tension band technique. The knee was retested again as above. Finally an additional circular wire was passed around the patella and the knee was tested again under the same loading configuration. The intact patella showed weak tensile strain on the anterior and compressive strain on the posterior surface through the range of knee motion. Tension band fixation produced weak tensile strains in the first few degrees of flexion and then weak compressive strains in the posterior surface. The presence of the additional circular wire significantly increased the compressive strain. The classical tension band is highly effective for the fixation of the fractured patella but is improved by an additional circular wire.

Strain development in carpal scaphoid for various wrist positions: a cadaveric study using strain gauges.

In order to investigate the ideal position in which the wrist should be immobilized during scaphoid fracture, treatment the strains which are developed in the carpal scaphoid for various wrist positions has been recorded in cadaveric wrists, using strain gauges. The data obtained shows that during radial deviation with neutral or slight palmar flexion of the wrist the waist of the scaphoid tends to compress because of the development of strong compressive strains, while the strain development parallel to the fracture site that tends to shift the scaphoid waist is minimum. This position seems to be the best for stable scaphoid fracture immobilization.

Rigid or sliding plate. A mechanical evaluation of osteotomy fixation in sheep.

Fracture fixation using rigid plates leads to direct bone union, but it also may lead to complications because of stress protection osteopenia. This study aims to compare the mechanical characteristics restored during the callus formation after an osteotomy is fixed with two types of internal plate fixation. Twenty-four adult female sheep were divided randomly into three groups of eight each, which were euthanized at 2, 4, and 6 months after operation. Half of them had their osteotomized radius fixed with a seven hole dynamic compression plate, whereas in the remainder a sliding plate was used. The sliding plate consists of two halves connected together in such a way as to permit axial sliding of the one within the other, thus allowing cyclic axial load transfer at the fracture site. Bone strips obtained from the healthy (control) and the surgically treated side were subjected to four-point bending tests. The effective modulus of elasticity, ultimate bending strength, and energy absorption to fracture (toughness) were calculated. All parameters were restored more quickly in the sliding plate group, but there was no statistically significant difference observed at 6 months when all the osteotomies were united completely. Thus, the sliding plate, by allowing axial loading at the fracture site, led to a faster callus maturation and hence bony union, which, hopefully, will permit earlier full weightbearing and functional recovery of the injured limb.

Adherence of Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans to human buccal epithelial cells, from healthy persons and HIV carriers, under the influence of Broncho Vaxom in vitro and ascorbic acid in vivo.

We examined the in vitro effect of Broncho Vaxom (BV) (an immunobiotherapeutic preparation containing a lysate made from bacteria often involved in respiratory tract infections) on adherence of Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans to human buccal epithelial cells (BEC) of healthy volunteers and HIV carriers. We also examined the ex vivo effect of ascorbic acid on the adherence of the same microorganisms to BEC of HIV carriers. The study reached the following conclusions: The presence of BV in vitro significantly reduces the adherence of the tested strains to BEC from healthy persons and HIV carriers. No significant difference was observed between healthy persons and HIV carriers regarding the adherence of the tested strains to BEC. Significant difference in the adherence of the tested strains to BEC was observed between HIV carriers who had been taking ascorbic acid over a 3-month period and those who had not. There was no further reduction in the adherence of the tested strains to BEC from HIV carriers who had been taking ascorbic acid in the presence of BV in vitro.

The place of myeloid growth factors in the treatment of hairy-cell leukaemia.

A patient with hairy-cell leukaemia was treated with granulocyte colony stimulating factor lenograstim (Granocyte) 300 micrograms daily by subcutaneous injections. His pre-existing neutropenia remitted and the therapy was continued for a total of 4 months. When the therapy was discontinued the neutropenia returned. There was no evidence that the growth factor itself had any disease modifying activity.

Pattern of screw loosening in fractures fixed with conventional and functional plates.

Plate fixation depends mainly on the holding power of the screws. In the present study the pattern of screw loosening was investigated. Thirty-two adult female sheep divided into four groups were used. A mid-diaphyseal transverse osteotomy was made on the right radius of each animal, and then plated on the anterior (tension) surface. Half of each group were plated using a standard narrow 7-hole AO Dynamic Compression Plate (DCP), whereas in the remaining animals a 6-hole newly designed sliding plate (SP) was applied. The required torque of tightening intraoperatively, as well as for releasing the screws after killing the animals was recorded with a tension-calibrated screwdriver. The pattern of loosening was similar for all the screws and the three phases could be recognized. An initial loosening was observed 1 month after the operation. A slow recovery of the torque was measured from the second month onwards, becoming highest by the fourth month after the operation, whereas a slow decrease in torque was observed from the fourth to the sixth month. In the SP group, the overall loosening was much lower than the DCP group (P < 0.05), whereas there was no difference in the loosening between the proximally placed screws and the distally placed ones (P > 0.05) for both plates.

Comparative study of callus performance achieved by rigid and sliding plate osteosynthesis based upon dynamic mechanical analysis.

Operative management of long bone fractures is considered to be the treatment of choice all over the world. This could be achieved either by intramedullary nailing or plating. The former allows delivery of stresses into the fracture site, but it requires a well-equipped operating theatre and an experienced surgeon who is, unfortunately, continuously exposed to radiation. On the other hand, plates could easily be applied in every orthopaedic clinic, but the existing ones are rigid and protect the fracture site from stresses to which it is ordinarily exposed. Recently, various experimental attempts have been made to provide plates which allow partial loading on the fracture site and enhance callus formation (secondary fracture healing). Bearing that in mind, a two-part sliding plate (SP) has been developed at the Orthopaedic Clinic of Patras University, which allows intermittent loading into the fracture site. Both the conventional AO rigid plate and SP were applied to osteotomized sheep radii. The dynamic properties of the callus were estimated with its two dynamic mechanical characteristics (dynamic modulus of elasticity and the relative loss factor), whereas its static properties (strength) were evaluated by measuring the ultimate bending strength. A superiority of callus produced by the sliding plate was observed concerning all the parameters under consideration.

Trigger digit: the needle or the knife?

We report our experience in conservative treatment of 30 patients with trigger digits followed up for an average of 22.3 months. In 26 patients (86.6%) the pain disappeared and the others experienced a remarkable improvement. Locking resolved in 23 patients (76.6%): in 19 patients immediately after the injection and in the other four gradually thereafter. Only three patients needed a second injection. All were satisfied and none required any other form of treatment.

Acute osteomyelitis of the patella 50 years after a knee fusion for septic arthritis. A case report.

Nontraumatic, hematogenous osteomyelitis of an unfused patella occurred in a 62-year-old female patient, 50 years after septic arthritis of the knee was treated in childhood by femorotibial fusion. This extremely rare condition was successfully treated by a patellectomy, continuous irrigation, and antibiotics. This occurrence seems not to have been reported previously in English literature.