Development and current use of local antibiotic carriers in spondylodiscitis : Pilot study on reduction of duration of systemic treatment

BACKGROUND

The current study situation regarding the duration of systemic antibiotic treatment for spondylodiscitis is inhomogeneous and varies between 4-12 weeks. Due to the many undesirable side effects the aim is to achieve complete healing without recurrence or hematogenous scatter within the shortest possible period of time. The present pilot study investigated whether the additional application of a local antibiotic carrier to the surgically treated intervertebral disc space can contribute to a further reduction of treatment duration.

MATERIAL AND METHODS

In the pilot study 20 patients with acute spondylodiscitis and indications for surgical intervention were included. Surgical treatment was carried out by dorsal instrumentation, radical debridement of the site of infection, and cage interposition in the affected disc space. The remaining disc space was filled with homologous cancellous bone and antibiotic-loaded calcium sulfate hydroxyapatite pellets. A classification into a long-term and a short-term antibiotic group was performed. Both groups initially received a 10-day parenteral antibiotic administration. This was followed by oral antibiotics for 2 or 12 weeks, depending on the group. During the 12-month follow-up inflammation parameters, the local infection situation as well as the bony fusion and antibiotic tolerance were regularly checked.

RESULTS

The average age of the patients was 66.7 ± 11.2 years. Intraoperative detection of pathogens was successful in 65%. In 60% the antibiotic carrier was loaded with gentamicin, in 40% with vancomycin. At follow-up, all patients except one in the short-term antibiotic group had inflammation parameters within the normal range after 3 months. In the long-term antibiosis group, two patients still showed elevated infection values after 3 months, otherwise the values were within the normal range. After 12 months a complete cure of the infection was achieved in all patients. Antibiotic treatment intolerance occurred in 10% of the short-term antibiotic group and in 50% of the long-term group.

CONCLUSION

The results of the present pilot study show that with the additional use of absorbable local antibiotic carriers in the surgical treatment of bacterial spondylodiscitis it is possible to shorten the duration of systemic antibiotic treatment to 3 weeks. This can reduce the side effects and incompatibility of treatment and still achieve similar healing results.

[Classification and diagnosis of lumbar spinal stenosis]

BACKGROUND

Lumbar spinal stenosis is caused by various pathological conditions. With the diagnostic tools available, a precise classification of the condition should be made, which enables a consistent and appropriate therapeutic approach.

OBJECTIVES

In the present article, the currently used classifications of lumbar spinal stenosis are discussed and the diagnostic tools are presented, focussing on the imaging descriptions of morphological changes.

MATERIALS AND METHODS

This article is based on a PubMed literature search of the past 60 years and our own experiences.

RESULTS

Lumbar spinal stenosis is caused mainly by degenerative changes to the spine. MR tomographic imaging can result in precise anatomical illustration and classification of the stenosis.

CONCLUSIONS

Although modern imaging procedures deliver a very precise illustration of lumbar spinal stenosis, clinical symptoms make a considerable contribution to therapeutic decision-making. With the anatomical classification, differentiated surgical decompression of the spinal canal can be planned.

[Lumbar spinal canal stenosis : A historical perspective]

To know the history of a disease and its treatment is always instructive and helps us to understand the contexts better. It also shows what unbelievable preliminary work was necessary for us be able to treat patients today in the way we are used to. This article attempts to shed light on spinal canal stenosis from a historical perspective and to identify the pioneers who contributed to the understanding of the epidemiology, anatomy, pathogenesis, classification and diagnostic work-up of spinal canal stenosis. In addition, the efforts of scientists and clinicians who have participated in developing the treatment of lumbar spinal canal stenosis in the last seven decades should be recognized.

Micro-CT and micro-FE analysis of pedicle screw fixation under different loading conditions

Anchorage of pedicle screw instrumentation in the elderly spine with poor bone quality remains challenging. In this study, micro finite element (µFE) models were used to assess the specific influence of screw design and the relative contribution of local bone density to fixation mechanics. These were created from micro computer tomography (µCT) scans of vertebras implanted with two types of pedicle screws, including a full region-or-interest of 10 mm radius around each screw, as well as submodels for the pedicle and inner trabecular bone of the vertebral body. The local bone volume fraction (BV/TV) calculated from the µCT scans around different regions of the screw (pedicle, inner trabecular region of the vertebral body) were then related to the predicted stiffness in simulated pull-out tests as well as to the experimental pull-out and torsional fixation properties mechanically measured on the corresponding specimens. Results show that predicted stiffness correlated excellently with experimental pull-out strength (R² > 0.92, p < .043), better than regional BV/TV alone (R2 = 0.79, p = .003). They also show that correlations between fixation properties and BV/TV were increased when accounting only for the pedicle zone (R² = 0.66-0.94, p ≤  .032), but with weaker correlations for torsional loads (R² < 0.10). Our analyses highlight the role of local density in the pedicle zone on the fixation stiffness and strength of pedicle screws when pull-out loads are involved, but that local apparent bone density alone may not be sufficient to explain resistance in torsion.

Behandlungsalgorithmus von Wundinfektionen an der Wirbelsäule mit ersten Ergebnissen einer retrospektiven Studie zur Behandlung von postoperativen Wundinfektionen mit Vakuumsystemen

Die postoperative Wundinfektion ist eine der häufigsten Komplikationen in der Wirbelsäulenchirurgie. Sie verlängert den Leidensweg des Patienten und stellt oftmals eine große Herausforderung an das gesamte Behandlungsteam dar. Zahlreiche Risikofaktoren sind in der Literatur bereits beschrieben, die es präoperativ zu optimieren gilt, um Infektionen zu vermeiden. Bezüglich der Therapie von Wundinfektionen gibt es bei mangelnder Studienlage keine einheitlichen Richtlinien. Oftmals sind mehrere Revisionen erforderlich, bis eine Wundinfektion zur Ausheilung kommt. Im vorliegenden Artikel wird ein interner Algorithmus zur Behandlung postoperativer Wundinfektionen vorgestellt. Unter Zuhilfenahme der VAC-Therapie bei tiefen Wundinfektionen zeigt sich eine erfolgreiche Infektsanierung vor allem auch im Hinblick auf den Implantaterhalt. Zukünftige Studien können helfen die Therapie der Wundinfektionen weiter zu optimieren, die Anzahl der Revisionen zu senken und allgemeingültige Standards zu entwickeln.

Transforaminal lumbar interbody fusion using polyetheretherketone oblique cages with and without a titanium coating: a randomised clinical pilot study

AIMS

We compared the clinical and radiological outcomes of using a polyetheretherketone cage with (TiPEEK) and without a titanium coating (PEEK) for instrumented transforaminal lumbar interbody fusion (TLIF).

MATERIALS AND METHODS

We conducted a randomised clinical pilot trial of 40 patients who were scheduled to undergo a TLIF procedure at one or two levels between L2 and L5. The Oswestry disability index (ODI), EuroQoL-5D, and back and leg pain were determined pre-operatively, and at three, six, and 12 months post-operatively. Fusion rates were assessed by thin slice CT at three months and by functional radiography at 12 months.

RESULTS

At final follow-up, one patient in each group had been lost to follow-up. Two patients in each of the PEEK and TiPEEK groups were revised for pseudarthrosis (p = 1.00). The rate of complete or partial fusion at three months was 91.7% in both groups. Overall, there were no significant differences in ODI or in radiological outcomes between the groups.

CONCLUSION

Favourable results with identical clinical outcomes and a high rate of fusion was seen in both groups. The titanium coating appears to have no negative effects on outcome or safety in the short term. A future study to determine the effect of titanium coating is warranted. Cite this article: Bone Joint J 2017;99-B:1366-72.

[Therapy of scoliosis from a historical perspective]

Scoliosis can be considered as one of the classical orthopedic diseases of the spine. The history of orthopedics is closely connected to the development of the therapy of scoliosis. In the eighteenth and the beginning of the nineteenth centuries the therapy of scoliosis was mainly a conservative corrective orthopedic treatment with a variety of corset forms and extension bed treatment. In the middle of the nineteenth century physiotherapy (movement therapy) became established as an supplementary active treatment. The first operations for treatment of scoliosis were carried out in 1839. The real success with surgical procedures for improvement in corrective options was connected to the introduction of metal spinal implants in the early 1960s.

[Posterior lumbar interbody fusion implants. Software assisted planning--preliminary results]

BACKGROUND

Sagittal imbalance, adjacent segment degeneration, and loss of correction due to cage sintering are the main reasons for revision surgery after lumbar fusion. Based on the experience from hip and knee replacement surgery, preoperative software-assisted planning combined with the corresponding cages is helpful to achieve better long-term results.

OBJECTIVES

Evaluation of the procedure regarding intraoperative application of preoperative planning and examination to what extent the planning was correct.

MATERIALS AND METHODS

In all, 30 patients were included in the period from September 2012 to May 2013 in an observational study, planned preoperatively with the planning software, and treated with the corresponding PLIF cages. The radiological evaluation was performed by thin-layer CT after 3 months.

RESULTS

A total of 24 (80%) patients were followed up after 3 months. In these 24 patients, the preoperative planning actually was correct in 17 cases with the intraoperatively implanted cage, which corresponds to a match of about 71%. The fusion rate for these 24 patients who underwent full examinations was 91.7%.

CONCLUSION

The results of this observational study to evaluate the planning of intervertebral cages show positive experience with this novel therapeutic concept. Despite the limited number of participants, good results were observed for the intraoperative implementation of the planned cages and an adequate fusion rate was obtained. Irrespective of this, a software-based surgical planning must be questioned critically any time. Ultimately, it is the surgeon's responsibility to modify the planned procedure intraoperatively if necessary. Currently, the influence of this planning regarding the long-term course and the important question of adjacent segment instability remains unanswered.

[Systemic and local antibiotic therapy of conservative and operative treatment of spondylodiscitis]

An evidence-based recommendation for a standardized antibiotic therapy of spondylodiscitis has not yet been published. Crucial for conservative therapy is the verification of the causative organism and an appropriate antibiotic therapy. Intravenous antibiotic therapy should be administered for 2-3 weeks and a switched to oral administration for 6-12 weeks is then possible. If an empirical antimicrobial therapy is required a combination of ciprofloxacin and clindamycin, alternatively a combination of cefotaxim and flucloxacillin is recommended. Surgical removal of the infection by extensive debridement with stabilization and filling the resulting bone defect is desirable. Under the perception of a high local dose of antibiotic the defect filling with a mixture of cancellous bone and antibiotic-loaded hydroxyapatite and calcium sulfate is advisable.

[Revision strategies for ventral implant failure in the lumbar spine exemplified by stand-alone cages]

This article gives a review of the possible revision strategies after repeated operative treatment of degenerative spinal diseases using stand-alone cages. Own clinical experiences and reports from the literature were taken into consideration. Dorsal stabilization is the main consideration for all access routes even if it can be discussed, albeit controversially, whether ventral removal of an installed cage is justified, because this contains a significantly higher perioperative risk. The increased risk of neurological complications by dorsal revision and for vascular complications by ventral access, especially at the L4/5 level must be particularly considered. Clinical data and own experience have shown that in the majority of cases an additional dorsal stabilization should be favored for revision surgery. Currently large clinical studies which deal with the revision problematic of stand-alone cages with respect to the access route are still lacking.

[Filler materials for augmentation of osteoporotic vertebral fractures]

In the recent years augmentation of vertebral compression fracture has been widely used with satisfactory clinical results. The filler materials for use in vertebral body augmentation have to meet many requirements. They should be biocompatible, be able to stabilize the fractured vertebral body, and their biomechanical properties should approximate those of cancellous bone. Furthermore, for a minimally invasive method that involves percutaneous injection of bone substitutes, the materials should be injectable and possess good radiopacity for the fluoroscopically guided procedure. At the present, polymethylmethacrylate is the most commonly used filler material for vertebral body augmentation. Due to the lack of bioactivity of polymethylmethacrylate that remains as an inert material in the bony tissue, new resorbable filler materials like calcium phosphate cement are increasingly in the focus of interest. In the following paper, the currently used filler materials for vertebral body augmentation and their characteristics are presented.

[Deformities following spinal injury at the thoracolumbar junction]

Due to anatomical characteristics, posttraumatic deformities following spinal injury occur in particular at the transition from the flexible lumbar spine to the rigid thoracic spine. Incorrectly classified vertebral body fractures can lead to the development of posttraumatic kyphosis due to incorrect treatment. It is likewise important to evaluate the integrity of adjacent discs and assess the sagittal index. Management of kyphosis is difficult and requires radiological evaluation following exact planning. Reconstruction of the sagittal anatomical contour is crucial to prevent stress in the compensatory curves. Performing a dorso-ventral or dorso-ventro-dorsal approach, pedicle subtraction osteotomy or an eggshell procedure is also helpful to achieve good correction without anterior reconstructive surgery. The clinical result is not dependent on correct repositioning alone; poor results can be expected in cases with pseudarthrosis, neurological deficits and severe kyphotic deformities. This article gives an overview of pathogenesis, diagnostic steps and therapeutic options for corrective spinal surgery.

["Isolated injury" of the alar ligaments: MRI diagnosis and surgical therapy]

Spinal distortions caused by traffic collisions play a large role in medical expert opinions. Prolonged or chronic conditions present particular difficulties. The radiologist E. Volle developed and published a system for the classification of isolated injuries of the alar ligaments. As a result, surgery on the craniocervical junction was carried out in a large number of patients and the results published on multiple occasions. This article describes the anatomy of the alar ligaments, complicated injuries, the concept of the isolated lesion of the alar ligaments and their surgical management. German and international publications are evaluated.

RESULT

It was impossible to substantiate isolated injuries to alar ligaments. According to current knowledge, the published results are based on a misinterpretation of MRI findings. These results are to be considered as artefacts. There is no anatomical correlation for the classification of isolated injuries to alar ligaments. Surgical stabilisation due to an allegedly isolated injury to the alar ligaments is therefore not indicated. This statement does not apply to injuries sustained in high-speed trauma in combination with complex injuries of the atlanto-occipital and atlanto-dental-joint (joint capsules, atlanto-occipital membrane) with clear signs of instability.

[Pedicle screw-based systems for dynamic stabilization : An insight into the philosophy, technique, indications and success of these systems]

Pedicle screw-based dorsal dynamic systems for segmental stabilization of the lumbar spine are an addition to established surgical methods. They differ in terms of their kinetics as well as their materials. The long-term load on these systems is much higher than in spondylodesis systems, which can only successfully bear loads until bone fusion; cases of implant failure and screw loosening are not rare.Pedicle screw-based systems represent a therapeutic option when conservative treatment proves unsuccessful and fusion seems to be too early. Finding the correct indication versus that of established methods is complex given our limited knowledge to date; symptomatic segments with moderate degenerative changes in facet joints and disc height, as well as Modic 2-3 signs seem to be appropriate cases. The same is true of segments adjacent to planned fusions. Dynamic stabilization can be considered in the case of long fusion, cranial location in the lumbar spine and high likelihood of instability and deformity.

Effect of lumbar disc replacement on the height of the disc space and the geometry of the facet joints: a cadaver study

In a study on ten fresh human cadavers we examined the change in the height of the intervertebral disc space, the angle of lordosis and the geometry of the facet joints after insertion of intervertebral total disc replacements. SB III Charité prostheses were inserted at L3-4, L4-5, and L5-S1. The changes studied were measured using computer navigation software applied to CT scans before and after instrumentation. After disc replacement the mean lumbar disc height was doubled (p < 0.001). The mean angle of lordosis and the facet joint space increased by a statistically significant extent (p < 0.005 and p = 0.006, respectively). By contrast, the mean facet joint overlap was significantly reduced (p < 0.001). Our study indicates that the increase in the intervertebral disc height after disc replacement changes the geometry at the facet joints. This may have clinical relevance.

[Pain therapy after spinal surgery]

A dorsal approach during spinal surgery offers the possibility to distribute drugs directly to the nerve root or epidurally. This can be done via a single intraoperative dose or by placing an epidural catheter. A safe and effective analgesia can thereby be achieved. As placement is done under visual control, no major complications are to be expected. In nerve root compressions, additional local application of steroids and preoperative gabapentin seems sensible. No advantage of preemptive administration of other analgesics can be determined. Another problem, especially of ventral fusions, is the commonly needed autologous pelvic bone grafts. Here the local application of local anesthetics or opioids makes sense. In transthoracic approaches epidural analgesia is recommended by thoracic surgeons, but this is difficult to perform especially in children with deformities. Furthermore it is generally important not to compromise neuralgic controls by analgesic measures.

Fracture of ceramic heads in total hip replacement

After introduction of ceramics in total hip replacement, there have been several studies on wear and fracture of the femoral head component. Though reports on fractures are few, we saw four fractures within 2 months. In all patients, a cementless hip prosthesis by four different surgeons was implanted between 3/2001 and 2/2004. In three patients, a ceramic-on-polyethylene pair and in one, a ceramic-on-ceramic pair was used. Only one patient suffered an adequate trauma. The mean survival of the ceramic head was 27 months (11-42). In two patients with polyethylene inlays, the inlay showed signs of wear out due to the fractured head. All four revision surgeries had a good outcome with satisfying results and no complications. Though we observe the postoperative development after implantation of ceramic components closely, we still believe that ceramics in total hip replacement in young and active patients are indicated with good long term results.

[Historical development of arthrodesis of pes cavus]

In contrast to the present, the diagnosis and treatment of pes cavus was a major subject of research at the beginning of last century. This was due to the high incidence of certain neurological disorders (poliomyelitis, myelodysplasia) which led to the development of this foot deformity. Advances in anaesthetic technique and the establishment of antisepsis contributed largely to the development of the surgical treatment of pes cavus. Ladislaus Leo Freiherr von Lesser performed the first surgically induced ankylosis of the ankle by denuding the joint surfaces of cartilage followed by fixation with a metal nail. This procedure was then introduced as arthrodesis; a word derived from the Greek meaning "binding of the joint". Numerous methods and modifications of arthrodesis have been developed for the correction of foot deformities. With increasing knowledge of the pathogenesis of pes cavus, soft tissue and tendon transfer procedures were added to the surgical treatment. Today, the philosophy of arthrodesis in the treatment of foot deformity is the same, but the development of fixation techniques and implant materials could improve postoperative care and outcome.

[Wiplash injury and "railway spine"]

Although post-traumatic stress disorder was only recently admitted into the international classification systems, psychological reactions to traumatic incidents have been frequently described for more than 100 years. The article deals with the mental reactions to a trauma in different historical situations. Included are the "railway spine" injuries of the 19th century, victims of accidents where third party liability could be claimed, accident insurance, the psychological consequences of National Socialism and whiplash injury. The analysis suggests that different reactions don't describe an identical disorder. It seems that reactions to injuries are mainly influenced by the historical and social background and the fact of beeing insured.

[Orthopedics and patients under national socialism dictatorship]

The 12-year dictatorship of National Socialism represents a decisive event in the history of orthopedics in Germany. Treatment and care was limited to those patients whose prognosis promised their reintegration into the work force. Those orthopedic patients with mental and psychological handicaps no longer came under the care of orthopedists and were potential candidates for annihilation. Despite concerted efforts to the contrary, as can be gleaned from the lists of topics at the annual meetings, the prevailing political circumstances encumbered scientific activities. The almost total isolation from international contacts had a negative effect. Orthopedists were hindered in their work by the law on sterilization, which provided for sterilization in cases of severe physical deformity. Some orthopedists even considered the presence of hip dysplasia to be an indication. The roles played by Georg Hohmann, Hellmut Eckhardt, Lothar Kreuz, and other leading orthopedists are described in detail. It can be regarded as certain that Hohmann and Eckhardt were able to prevent dire consequences for their orthopedic patients and the profession by cautious tactics. The ethnical problems of involvement with National Socialism are thoroughly discussed.

[Historical development of sports orthopedics]

The history of German sports medicine was decisively influenced by the surgeon August Bier at the beginning of the twentieth century. Initially, general medical and physiological problems were emphasized. Individual treatment of injured athletes played an increasing role at the end of last century. Operative treatment of injured athletes and earlier rehabilitation has changed therapeutic standards of orthopedic treatment. During critical discussion of the historical development of the treatment of ruptured anterior cruciate ligaments and meniscal tears, it becomes evident that treatment methods once rejected may now prove to be useful and correct.

Elution characteristics of vancomycin, teicoplanin, gentamicin and clindamycin from calcium sulphate beads

The in vitro release of vancomycin, teicoplanin, gentamicin and clindamycin from biodegradable calcium sulphate (CaSO(4)) carrier beads is described. All antibiotics showed prolonged release from the carrier beads, which was elevated during the first 24 h, with peak levels exceeding 2500 microg/bead. Doubling the antibiotic load of the beads revealed a more prolonged elution and a two-fold increase in antibiotic release. Local carrier-associated antibiotic treatment with CaSO(4) beads may prove to be effective in the management of chronic bone infections.