One-stage oblique lateral corridor antibiotic-cement reconstruction for Candida spondylodiscitis in patients with major comorbidities: Preliminary experience

Fungal spondylodiscitis is rare (0.5%–1.6% of spondylodiscitis) and mainly caused by Candida albicans. Surgical intervention in spondylodiscitis patients is indicated for compression of neural elements, spinal instability, severe kyphosis, failure of conservative management and intractable pain. However, there is no evidence-based optimal surgical approach for spondylodiscitis. There have been only case reports of surgical treatment for Candida spondylodiscitis. We evaluated the preliminary results of the efficacy and safety of one-stage debridement via oblique lateral corridor with interbody fusion (OLIF) using stand-alone cement reconstruction after debridement for the treatment of Candida spondylodiscitis in patients with major co-morbidities. Five patients (4 males, 1 female, mean age: 64.2 years) suffering from Candida albicans lumbar spondylodiscitis who underwent this procedure were studied. Their predominant symptoms were unremitting back and leg pain and all had pre and postoperative anti-fungal therapy under microbiologist supervision. The operative time ranged from 137 minutes to 260 minutes (mean: 213.4 minutes). The mean blood loss was 160 mL (range: 100–200 mL). There were no perioperative complications. At follow-up all showed major improvement in pain and ambulatory status. CT scan showed radiological stability for all patients at 6–12 months. Our preliminary results showed stand-alone anterior debridement and spinal re-construction with cement through mini-open OLIF approach might be a safe and effective option for patients with spinal fungal infection and major comorbidities.     

Early results after vertebral body stenting for fractures of the anterior column of the thoracolumbar spine

Introduction

Vertebroplasty and balloon kyphoplasty have shown to improve pain and functional outcome in cases with symptomatic vertebral fractures. Although restoration of the vertebral body height and kyphosis seemed to be easier with balloon kyphoplasty, it became clear that some of the correction achieved by the balloon is lost once it was deflated. Vertebral body stent was developed to eliminate this phenomenon. To our knowledge this is the first study in describing this technique in clinical settings.

Materials and methods

Seventeen patients with 20 fractured vertebral bodies were included. All fractures were Type A1.3 or A3.1 (incomplete burst). Information about pain (visual analogue scale-VAS) and function (Oswestry disability index-ODI) and vertebral body deformity (vertebral angle-VA) was recorded in a prospective way at regular intervals. Patients were classified into osteoporotic group (7 patients) and traumatic groups (10 patients, younger than 60 years).

Results

There were 6 male and 11 female patients with mean age of 58.1 years (31–88 years). Mean follow up was 12 months. The preoperative pain level showed a mean VAS score of 8.9 in osteoporotic group and 9.7 in traumatic group. Postoperatively, in osteoporotic group, mean VAS was 4.8 at 6 weeks, 4.0 at 6 months and 2.5 at 12 months compared with traumatic fracture group where it was 2.7 at 6 weeks, 2.2 at 6 months and 1.6 at 12 months. Mean ODI in osteoporotic group was 41.7% (14–58%) and in traumatic group it was 20.4% (6–33%). Mean vertebral body angle prior to surgery in osteoporotic group was 9.7 whilst postoperatively it was 5.2°; so the mean correction achieved was 4.5°. In traumatic group preoperative VA was 13° whilst postoperatively it was 5.7°; therefore the mean correction achieved was 7.3°. None of the patients lost reduction at their last follow up.

Conclusion

Vertebral body stenting leads to satisfactory improvement in pain, function and kyphosis correction in the treatment of osteoporotic and traumatic fractures. Anterior spinal column, especially the fragmented superior endplate is nicely reconstructed by the stent provided it is inserted accurately. With addition of posterior transpedicular instrumentation, indications for this technique may be wider covering some Type B and C fractures with similar vertebral body damage.     

Workshop on the bone-joint implant interface

A workshop on the bone-implant interface, as related to loosening of total joint implants, was held in Chicago on September 14-16, 1983. More than 60 orthopaedic clinicians and researchers and basic connective tissue biologists met to review problems and potential solutions to joint implant loosening. The following is a synopsis of the presentations and discussions.     

Polymethylmethacrylate augmentation of the pedicle screw: the cement distribution in the vertebral body

Many studies have proven that the polymethylmethacrylate (PMMA) augmentation of the pedicle screw can significantly increase stiffness and strength of spinal fixation. Some major complications have also been reported. However, there are no reports discussing cement distribution and its morphology in the osteoporotic vertebral body, which is critical in the analysis of the biomechanical strength of the pedicle screw and the risk of cement leakage after pedicle screw augmentation. In this study, we used computed tomography (CT) to evaluate the cement distribution in the osteoporotic vertebral body after PMMA augmentation of a pedicle screw and to analyze the factors leading to cement leakage. Two groups of patients were studied. Group A consisted 25 osteoporotic patients (mean age of 73 years) with spinal instrumentation who had a total of 145 pedicle screws and cement augmentation with biopsy needles. Group B consisted of 23 osteoporotic patients (mean age of 74.6 years) with spinal instrumentation who had a total of 125 cannulated pedicle screws with cement augmentation. All patients had CT evaluation of the cement distribution in the vertebral body after the surgery. The cement distribution in the vertebrae was divided into four zones in the axial CT view: anterior one-third, middle third, and posterior third of vertebral body, and the pedicle. The morphology of the cement distribution around the pedicle screw was defined as scattered type or concentrate type. The leakage pattern was divided to anterior–lateral, posterior–lateral, and canal leakage. The correlations among bone mineral density (BMD), the cement leakage rate, and cement distribution morphology were also analyzed. The results showed that most augmented pedicle screws had cement extension into three of the four zones of the vertebral body (66.3%), followed by two zones (20%), all four zones (11.5%), and only one zone (2.2%). Overall, 123 screws (84.8%) in Group A and 108 screws (86.4%) in Group B had cement concentrate type distribution. The cement leakage rate in Group A is 18.3% and 13.6% in Group B. Patients with a BMD <0.6 g/cm² had significantly higher rates of cement leakage and tended toward a scattered cement distribution. There was only one patient who had a symptomatic leakage (sciatica) in Group B. We concluded that the cement distribution after pedicle screw augmentation with biopsy needle or cannulated screw technique was mostly localized in three zones of the vertebral body, and patients with lower BMD had a higher risk of cement leakage and scattered cement distribution.     

Micro-CT evaluation of marginal and internal fit of cemented polymer infiltrated ceramic network material crowns manufactured after conventional and digital impressions

Purpose

Purpose of this study was to evaluate the accuracy of fit of cemented polymer infiltrated ceramic network (PICN) material crowns manufactured after digital and conventional impression techniques using micro computed tomography (CT). Furthermore to determine the cement space volume and porosities in the cement layer.

An experimental comparison of different devices for pulsatile high-pressure lavage and their relevance to cement intrusion into cancellous bone

Introduction Some of the systems marketed for pulsatile high-pressure lavage are clearly different in their mechanical pulse characteristics. To take the matter further we set up an experimental in vitro model to determine whether these different lavage systems might produce different cementation results because of their differing pulse characteristics, and whether the systems differed significantly in terms of cement depth penetration. Materials and methods A total of 48 femoral heads were obtained at operation from patients who had undergone endoprosthetic hip replacement. The specimens were subjected to manual rinsing or semiautomatic cleansing procedures with five different pulsatile lavage devices. After the cleansing procedures, polymethylmetacrylate bone cement was intruded into the cancellous bone under standardised conditions. Determination of cement penetration was done by computed tomography using an image processing software. Results Irrespective of the nature of the lavage system tested, superficial cement penetration, both up to 2 mm and up to 3 mm, was significantly better after pulsatile high-pressure lavage than it was after manual rinsing of the specimens with a bladder syringe (P < 0.001 in each case). Whereas our experimental model did not show any significant differences between the lavage systems as regards the cementation results to a depth of up to 2 mm (P = 0.996), there were significant differences at a target depth of 3 mm (P < 0.05). Conclusion As compared with manual rinsing, pulsatile high-pressure lavage in vitro makes highly significant improvements in cement penetration into cancellous bone and should be regarded as an indispensable component of modern cementation techniques for endoprosthetic surgery. Up to the present we have not been able to ascertain what influence the different pulse characteristics of a pulsatile lavage system may have on the intended cementation result, whether it is impact force, pulse shape, pulse duration, flow rate or frequency. Appropriate investigations will be necessary.     

In vitro long-term fatigue endurance of the secondary "Cement Injection Stem" hip prosthesis

A secondary cementation hip stem (Cement Injection Stem; Aesculap, Tuttlingen, Germany) was designed to reduce the risk of fat embolism, and achieve precise implant position and high-quality cement mantle. A validated long-term in vitro simulation was carried out that replicated 24 years of activity of a very demanding patient. Inducible and permanent micromotions were monitored. The cement mantle was sectioned and inspected for signs of fatigue damage. The stem-cement interface was inspected for fretting. Results were compared against previously published results for a conventionally implanted stem with comparable design (Centrament; Aesculap) from which this project was derived. Comparable micromotions were found (slightly larger proximally, in correspondence to the precured centralizer). No sign of fretting was observed. All fatigue damage indicators were comparable or significantly better than those for the conventionally implanted stem. The few cement cracks found were mainly localized in proximity of a proximal drainage hole. It is foreseen that when this detail is optimized, long-term endurance will further improve.     

Clinical effectiveness of antibiotic-impregnated cement spacers for the treatment of infected implants of the hip joint

It is difficult to treat an infected implant of the hip joints, as it requires long-term treatment and eventually may lead to amputation or arthrodesis, involving immeasurable physical and psychological suffering for the patient. We utilized antibiotic-impregnated cement spacers for 17 infections after total hip arthroplasty and bipolar arthroplasty with good clinical results. We thoroughly removed any foreign material and formed an antibiotic-impregnated cement spacer into a shape similar to that of the implants. This enabled high-concentration antibiotics to act on the infected sites. It also can prevent leg-length discrepancy and atrophy of bones or muscles. Although cement spacers have been reported to have problems regarding shape and strength, we achieved good results with cement spacer molds in the present study. All revision surgeries were performed using a two-stage procedure. No infection has recurred at a mean follow-up of 3 years 2 months.     

Height restoration and maintenance after treating unstable osteoporotic vertebral compression fractures by cement augmentation is dependent on the cement volume used

Background

Two different procedures, used for percutaneous augmentation of vertebral compression fractures were compared, with respect to height restoration and maintenance after cyclic loading. Additionally the impact of the cement volume used was investigated.

Methods

Wedge compression fractures were created in 36 human cadavaric vertebrae (T10-L3). Twenty-seven vertebrae were treated with the SpineJack® with different cement volumes (maximum, intermediate, and no cement), and 9 vertebrae were treated with Balloon Kyphoplasty. Vertebral heights were measured pre- and postfracture as well as after treatment and loading. Cyclic loading was performed with 10,000 cycles (1 Hz, 100–600 N).

Findings

The average anterior height after restoration was 85.56% for Kyphoplasty; 96.20% for SpineJack® no cement; 93.44% for SpineJack® maximum and 96% for the SpineJack® intermediate group. The average central height after restoration was 93.89% for Kyphoplasty; 100.20% for SpineJack® no cement; 99.56% for SpineJack® maximum and 101.13% for the SpineJack® intermediate group. The average anterior height after cyclic loading was 85.33 % for Kyphoplasty; 87.30% in the SpineJack® no cement, 92% in the SpineJack® maximum and 87% in the SpineJack® intermediate group. The average central height after cyclic loading was 92% for Kyphoplasty; 93.80% in the SpineJack® no cement; 98.56% in the SpineJack® maximum and 94.25% in the SpineJack® intermediate group.

Interpretation

Height restoration was significantly better for the SpineJack® group compared to Kyphoplasty. Height maintenance was dependent on the cement volume used. The group with the SpineJack® without cement nevertheless showed better results in height maintenance, yet the statistical significance could not be demonstrated.