[Submuscular approach to the lumbar spine and extraforaminal cage implantation]. / Submuskulärer Zugang zur Lendenwirbelsäule und extraforaminale Cage-Implantation.

The posterior median approach to the lumbar spine may cause significant injury to the erector spinae muscles (ESM) which is minimized using the paralateral approach suggested by Ray. We have adopted this approach and have extended it into the disc space to allow cage implantation from outside the foramen (EPLIF - extraforaminal posterior lumbar interbody fusion). The initial exposure of the posterior vertebral elements between the ESM and the deep lumbar fascia is sufficient to attain the entry points of pedicle screws. The intervertebral foramen and posterior annulus fibrosus are then exposed after which distant lateral disc herniations may be removed, the foramen/lateral recess may be decompressed or an EPLIF performed following clearing and vertical distraction of the disc space. This is followed by ipsilateral transpedicular fixation (TpF), contralateral fixation (second approach) by TpF or translaminar screws. Indications are given for foraminal and extraforaminal disc herniation, stenosis of the foramen and/or of the lateral recess, posterolateral fusion, TpF and EPLIF. The submuscular approach and EPLIF have proven to be valuable alternatives to standard techniques.

Comparison of two novel fluoroscopy-based stereotactic methods for cervical pedicle screw placement and review of the literature.

This experimental study was designed to compare two different fluoroscopy-based stereotactic surgical techniques for transcutaneous cervical pedicle screw (CPS) placement in the subaxial human cervical spine: (1) a custom-made aiming frame (AF) in combination with conventional fluoroscopy versus (2) a targeting device in combination with a computer-assisted image guidance system [i.e. virtual fluoroscopy (VF)]. Surgery was carried out on six preserved human total body specimens in a laboratory setting. Sixty pedicles (levels C3-C7) were measured in a multislice computed tomography (CT) image data set prior to surgery. Two groups consisting of three specimens and 30 pedicles each were defined according to the surgical technique. The AF consisted of radiolucent components with a fully adjustable arm for carrying the instruments necessary for placing the screws. The arm was angled according to the cervical pedicle axis, as determined by the preoperative CT scans and intraoperative lateral fluoroscopy. For VF, a targeting device was combined with a computer-assisted image-guided surgery unit. For both stereotactic techniques, 3.5 mm screws made of carbon fibre polyetheretherketone (ECF-PEEK) were inserted transcutaneously through stab incisions. Screw placement was assessed using a four-point grading system ranging from ideal (I) to unacceptable (III) where I = screw centred in pedicle, IIa = perforation of pedicle wall is less than one-fourth of the screw diameter, IIb = perforation of the pedicle wall is more than one-fourth of the screw diameter without contact to neurovascular structures, and III = CPS in contact with neurovascular structures. Fifty-eight pedicle screws could be evaluated without interfering metal artefacts according to the same CT protocol that was used preoperatively. The AF technique achieved a significantly smaller number of screws in contact with neurovascular structures compared with the VF technique (P = 0.021; Fisher's exact test) (Grade I n = 15; 64.3% AF vs. n = 13; 43.3% VF and Grade III n = 2; 7.1% AF vs. n = 10; 33.3% VF). Although neither of the two techniques was capable of completely preventing CPS perforations, transcutaneous CPS placement with a conventional fluoroscopy-based stereotactic AF can be considered a less expensive alternative to VF. This AF technique is able to reduce the number and severity of lateral pedicle wall violations compared to screw placement via the wide standard posterior open midline approach to the subaxial cervical spine. The results of this study are discussed in context with those obtained from different published modifications, since the first technical description of this surgical technique in 1994 by Abumi and co-workers.

Cervical pedicle screw placement: feasibility and accuracy of two new insertion techniques based on morphometric data.

This morphometric and experimental study was designed to assess the dimensions and axes of the subaxial cervical pedicles and to compare the accuracy of two different techniques for subaxial cervical pedicle screw (CPS) placement using newly designed aiming devices. Transpedicular fixation is increasingly used for stabilizing the subaxial cervical spine. Development of the demanding technique is based on morphometric studies of the pedicle anatomy. Several surgical techniques have been developed and evaluated with respect to their feasibility and accuracy. The study was carried out on six conserved human cadavers (average age 85 years). Axes and dimensions of the pedicles C3-C7 (60 pedicles) were measured using multislice computed tomography (CT) images prior to surgery. Two groups consisting of 3 specimens and 30 pedicles each were established according to the screw placement technique. For surgical technique 1 (ST1) a para-articular mini-laminotomy was performed. Guidance of the drill through the pedicle with a handheld aiming device attached onto the medial aspect of the pedicle inside the spinal canal. Screw hole preparation monitored by lateral fluoroscopy. In surgical technique 2 (ST2) a more complex aiming device was used for screw holes drilling. It consists of a frame with a fully adjustable radiolucent arm for carrying the instruments necessary for placing the screws. The arm was angled according to the cervical pedicle axis as determined by the preoperative CT scans. Drilling was monitored by lateral fluoroscopy. In either technique 3.5 mm screws made of carbon fiber polyetheretherketone (CF-PEEK) were inserted. The use of the CF-PEEK screws allowed for precise postoperative CT-assessment since this material does not cause artifacts. Screw placement was qualified from ideal to unacceptable into four grades: I = screw centered in pedicle; IIa = perforation of pedicle wall less than one-fourth of the screw diameter; IIb = perforation more than one-fourth of the screw diameter without contact to neurovascular structures; III = screw more than one-fourth outside the pedicle with contact to neurovascular structures. Fifty-six pedicle screws could be evaluated according to the same CT protocol that was used preoperatively. Accuracy of pedicle screw placement did not reveal significant differences between techniques 1 and 2. A tendency towards less severe misplacements (grade III) was seen in ST2 (15% in ST2 vs. 23% in ST1) as well as a higher rate of screw positions graded IIa (62% in ST2 vs. 43% in ST1). C4 and C5 were identified to be the most critical vertebral levels with three malpositioned screws each. Because of the variability of cervical pedicles preoperative CT evaluation with multiplanar reconstructions of the pedicle anatomy is essential for transpedicular screw placement in the cervical spine. Cadaver studies remain mandatory to develop safer and technically less demanding procedures. A similar study is projected to further develop the technique of CPS fixation with regard to safety and clinical practicability.

Performance of a composite flow moulded carbon fibre reinforced osteosynthesis plate.

Non-metallic implants have the advantage over metallic implants of reduction in artefact with CT and MR diagnostic imaging. In-vivo performance of a carbon fibre reinforced polyetheretherketone radiolucent plate (Snake Plate [SP]) with high stiffness, and fixed angle converging screws was compared with a seven-hole titanium Locking Compression Plate (LCP), using a sheep tibial osteotomy model (gap 0.6 mm). The sheep were divided into two groups, and the osteotomies were stabilized with a SP (n = 6) or a LCP (n = 6). The callus dimensions were measured radiographically at zero, two, four, six and eight weeks. The animals were euthanatized after eight weeks. Osteotomised and contralateral tibiae were tested in pairs torsion, to determine strength and stiffness. In the radii of six separate sheep, initial vascular disturbance after plate implantation was evaluated. All of the sheep of the SP and LCP groups showed maximal callus areas at six weeks. The differences between the groups, in callus dimension, were not significant at any time point. The median values for relative reduction (100 x [operated contralateral] / contralateral) in strength of osteotomized tibiae was -13.93% for the SP group and -7.49% for the LCP group (p = 0.5228), and for stiffness it was -24.44% for the SP group and -27.08% for the LCP group (p = 0.6481). Neither the SP nor LCP caused any notable disturbance in periosteal circulation. The SP appears to represent a valuable alternative to metallic implants for shaft fracture repair. The main advantages of the SP are radiolucency, high deformation resistance, internal fixator concept and converging screw configuration for optimal loading conditions in the bone-implant construct.

[Transarticular fixation of C1-C2: a multicenter retrospective study]. / Transartikulární fixace C1-C2: multicentrická retrospektivní studie.

PURPOSE OF THE STUDY: Transarticular C1-2 fixation is a surgical alternative in treatment of atlantoaxial instability. Although the method provides very good immediate and long-term stability, it still involves several disadvantages. The group of patients as reported from various institutions are usually very small and hardly comparable. In order to objectively compare the results of the method, we collected the groups of patients treated in four institutions dealing with surgery of the cervical spine in Czech Republic. MATERIAL AND METHODS: During the 9-years period (1993-2001), the transarticular C1/2 fixation was performed in 80 patients (mean age 45.6 years, range 4-85 years). The procedure was indicated for atlantoaxial instability due to rheumatoid arthritis in 32 cases, pseudoarthrosis of the odontoid process in 15 cases, fracture of the odontoid in 8 cases, complex C1-C2 fracture in 7 cases, tumour in 5 cases, C1 fracture in 4 cases, os odontoideum in 3 cases, purulent osteolysis of the odontoid in 3 cases and instability due to tuberculosis in one case, respectively. Two patients underwent surgery for painful arthrosis of atlantoaxial joints only. Transarticular fusion was combined with posterior interlaminar fixation using autologous graft and wire in most of the cases. Clinical and radiological results were evaluated in the early postoperative period and 3, 6 and 12 months after surgery, respectively. The position of the screws in relation to lateral mass of the atlas was evaluated according to our own criteria as optimal, suboptimal, and misplaced. Long-term postoperative stability and bone fusion were also followed. The follow-up ranged from 3 to 99 months (mean 29.1 months). There were 72 patients available for long-term follow-up (i.e. more then 6 months). RESULTS: We inserted 150 screws; two screws were used in 72 patients, one screw in 6 patients while in two patients, the surgery had to be aborted without screwing. Optimal placement was achieved in 103 cases (68.7%), suboptimal because of too medial or lateral placement of the screws in 26 cases (17.3%), suboptimal due to a short screw in 9 case (6%) and a long screw in 8 cases (5.3%). Four screws (2.7%) were found misplaced (i.e. out of the lateral masses). Fusion was confirmed in 51 cases out of 72 operated on (70.8%) at 6-months follow-up, and in 55 cases out of 63 available for follow-up (87.3%) at 12 months, respectively. Segmental stability was achieved in all patients, even in cases with incomplete fusion as seen on radiograph. Furthermore, six screws in four patients were discovered to be broken, nevertheless without any clinical consequences. There were 4 cases of peroperative injury to th vertebral artery (i.e. 5% of patients, 2.7% of screws), one case of dural tear and one case of excessive blood loss from epidural venous plexus. These complications, however, did not cause any significant clinical consequences, either. Other postoperative complications included wound dehiscence in 3 cases, 2 cases of hardware failure due to wrong indication for surgery and 2 cases of persistent neck pain. DISCUSSION: Transarticular C1/2 fixation is known to be universal and stable technique suitable for the treatment of atlantoaxial instability. According to biomechanical studies, this method provides the best stability mainly in rotation and lateral flexion (inclination) when compared to other described methods of atlantoaxial fixation. The fusion rate is reported to vary between 90 to 100% if the posterior interlaminar fusion using bone graft and wire is simultaneously performed. The rare incidence of pseudarthrosis is usually considered to be related to a poor surgical technique as even only one screw should provide bone fusion if properly placed. Using strict evaluation criteria, the fusion rate in our sample of patients was 87.3% at 12 months, or, 92.1% if also controversial radiographs were included. The injury to the vertebral artery is the most serious complication of the method; its incidence in our group (5% of patients) is comparable to data from literature. We believe that most of these events happened because of individual anatomical variations of axis and vertebral artery were not adequately respected. CONCLUSION: Transarticular technique of instrumental atlantoaxial fusion is an effective method with multiple application in treatment of craniocervical and upper cervical spine instability. The gain of immediate stability with acceptable risk of possible complications is the major advantage of this procedure. The results of our multicentric retrospective study confirm the expected high fusion rate and are comparable to previously published reports.

[In vivo measurement of 3-dimensional movement of the iliosacral joint]. / In-vivo-Messung der dreidimensionalen Bewegung des Iliosakralgelenks.

The purpose of this study was to quantify in vivo the three-dimensional motion patterns of the sacroiliac joint during passive manipulations as the opinions about the extent of motion of this joint are varied. 12 sacroiliac joints of 6 patients with clinically and radiologically normal joints were investigated. All patients were treated with an external fixator for diagnostic purposes of low back pain unrelated of this study. The motion of the sacroiliac joint was measured continuously with a three-dimensional goniometric system, which was mounted at the end of Schanz screws implanted in S1 and the ilium. All measurements showed relatively small rotation angles around the three main axis to the body between the ilium and the sacrum (< 2 degrees) and very small translations between the screw entry points into the bones (< 1 mm). The maximum rotation angle in the sagittal plane was 1.3 degrees on the right joint and 1.6 degrees on the left joint for flexion plus extension. It is questionable whether this motion can be quantified during manual manipulation. Extension of the hip always produced the largest motion in the sacroiliac joint.

The value of percutaneous transpedicular vertebral bone biopsies for histologic examination. Results of an experimental histopathologic study comparing two biopsy needles.

STUDY DESIGN: A 3.5-mm trephine was designed to overcome difficulties encountered in the histologic evaluation of vertebral bone samples obtained with a 2-mm trephine. OBJECTIVES: To compare the 3.5-mm trephine with the 2-mm trephine. SUMMARY OF BACKGROUND DATA: A review of results obtained with a 2-mm trephine showed that histologic examination of vertebral bone cores was disturbed by artifacts in 32 of 70 cases (46%). Although tissue diagnosis was possible from 61 samples, only 36 (51%) bone cores yielded a secure diagnosis. METHODS: Transpedicular bone cores were obtained from the bodies of 54 fresh cadaver vertebrae with both trephines. In each vertebra, the 2-mm trephine was used on one side, and the 3.5-mm trephine was used on the other side. Longitudinal sections were prepared and examined macroscopically for length and breakages and microscopically for trabeculae, marrow, and artifacts. Each sample was graded for its value for histologic examination. RESULTS: Significant differences were found between the two trephines for all criteria evaluated. Of 54 samples taken with the 2-mm trephine, 13 (24%) were graded "good," compared with 45 (83%) from the 3.5-mm trephine. Twelve (22%) "bad" samples were taken from the 2-mm trephine compared with three (6%) "bad" samples taken from the 3.5-mm trephine. CONCLUSIONS: The 2-mm trephine does not provide suitable bone cores for histologic examination, whereas samples obtained with the 3.5-mm trephine are suitable.

Posterior stabilization in L5-S1 isthmic spondylolisthesis with paralaminar screw fixation: anatomical and clinical results.

Combined anterior and posterior fusion with posterior instrumentation may be indicated in the treatment of select cases of L5-S1 spondylolisthesis. The instrumentation, however, is expensive and usually bulky, occasionally requiring removal. In an effort to avoid these problems, an L5-S1 paralaminar screw technique was developed for posterior stabilization after an L5-S1 anterior interbody fusion. The technique involves the placement of cortical screws from the base of the articular process of S1 to the pedicle of L5. This study evaluates the anatomic applications and clinical results of this technique. The relationship between the screw and L5 nerve root was examined using five cadaveric specimens with olisthesis of 0, 25, 50, and 75%. This work demonstrates that the screws can only be inserted safely if an L5-S1 olisthesis of at least 25% is present. If < 25%, the screws will either impinge on or directly injure the L5 nerve root. In the clinical study, the outcomes of 20 patients who had an isthmic spondylolisthesis of 25-81% and were treated with partial reduction, L5-S1 anterior interbody fusion, and L5-S1 posterior paralaminar screw fixation were reviewed. Nineteen patients had adequate posterior stabilization to completely heal an L5-S1 anterior interbody fusion without loss of the correction. In one patient, a pseudarthrosis occurred secondary to poor surgical technique of both anterior and posterior fusions. This patient required an additional L4-S1 posterior fusion 9 months later and had a good clinical outcome. No other complications due to screw placement occurred. We conclude that this procedure can be used safely and reliably for the posterior stabilization of L5-S1 after stable anterior L5-S1 interbody fusion in residual slips of at least 25%. Prerequisites are proper patient compliance and low weight. Compared with other posterior instrumentation systems, this screw fixation is inexpensive and does not require implant removal. The disadvantages of the method are the degree of difficulty of the procedure and the limited clinical application to cases of L5-S1 spondylolisthesis with corrected residual slips of 25 to 50-60%. The procedure is technically demanding and should be limited to those surgeons who are comfortable with the method.

[Atlanto-axial rotational subluxation in children: therapy in delayed diagnosis]. / Atlanto-axiale Rotatorische Subluxation beim Kind: Therapie bei verspäteter Diagnosestellung.

Children may develop a torticollis due to Rotatory Subluxation not only after minor trauma, infections of the upper respiratory tract, surgical procedures in the oropharynx but also spontaneously. Three cases with a delay in diagnosis are presented; the typical symptoms and other causes of torticollis are discussed. The suggested treatment is mobilisation under general anaesthesia, fixation with a Halo for a few days and consecutive immobilisation in a Minerva cast for 4-8 weeks. This regimen was successful in all three cases.

[A comparison of 2 methods of plastic cast fixation in treatment of loco classico radius fracture. A prospective, randomized study]. / Ein Vergleich von 2 Gipsfixationsmethoden bei der Behandlung der Radiusfraktur loco classico. Eine prospektive, randomisierte Studie.

The purpose of this study was to compare the functional and radiological result of two different positions of the wrist in a plaster cast following Colles' fracture. For this prospective study, each of 50 patients with type A 2.2, A 3.3, C 1.2 or C 2.2 (AO classification) fractures of the radius was randomly assigned to one of two groups. Both groups were treated in the same way as far as anaesthesia and reduction were concerned. The only difference in treatment lay in the position of fixation in plaster. In group 1 the wrist was immobilized in neutral flexion-extension. In group 2 the wrist was dorsiflexed 20 degrees, while the carpus was pushed in a volar direction by an impression in the plaster cast. At review 2-7 years after the accidents, the two groups were compared with reference to symptoms, range of motion at the wrist, power of first closure and radiographic appearance. In group 1 there were 5 patients with significant disability, compared with only 1 in group 2. A significant difference was found in the range of movement between the two groups for flexion and ulnar abduction (p < 0.01). The loss of power of first clenching (difference between injured and healthy hand) was 6.2 mmHg for group 1 and 3.8 mmHg for group 2 (not significant). The radiographic examination showed significant differences both in sagittal inclination (p < 0.001) and in radial shortening (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Occipitocervical fusion with posterior plate and screw instrumentation. A long-term follow-up study.

STUDY DESIGN: Thirty-two patients at one institution underwent occipitocervical fusions with posterior plate and screw instrumentation. The average follow-up was greater than 4 years (50 months). METHODS: AO plates and screws were used and in more than 50% of the cases, the Magerl transarticular C1-C2 screw technique enhanced the occipitocervical instrumentation. In nine patients, cement was used and thus are excluded in evaluation of fusion results. All 23 patients attained solid fusions. No pseudarthrosis occurred. The average time to fusion was 13 weeks. Halos or traction immobilization was not used postoperatively. The average time of the simple orthosis wear was 11 weeks. Patients were out of bed on an average of the second postoperative day with a range of 1-4 days postoperatively. Reduction of the atlantoaxial joint was required in 10 of the 23 patients. At follow-up, nine remain reduced. RESULTS: In one patient, the atlantodens interval approximated the preoperative distance and radiographs demonstrated one transarticular C1-C2 screw was not placed satisfactorily. The average operative time was 172 minutes, and the average blood loss was 956 cc. The neurologic status of the patients improved or remained the same. No patient deteriorated neurologically. A total of 78 occipital screws were placed. No complications resulted from any of these screws. One intraoperative complication occurred secondary to massive bleeding after a transarticular screw hole was drilled. Bone wax was placed over the drill hole and the bleeding ceased. No postoperative problems occurred in this patient. Most specifically, no central nervous system sequela was evident. CONCLUSIONS: The conclusions from this study are that posterior occipitocervical fusion can be performed very safely with plate and screw instrumentation. An extremely high fusion rate can be expected with minimal complications and minimal postoperative immobilization. This technique, however, is technically demanding.

Percutaneous diagnostic stabilization for low back pain. Correlation with results after fusion operations.

Diagnostic external fixation was performed in 101 patients with disabling low back pain. In 47 patients, pain was relieved by stabilization but returned after destabilization. These patients were considered good candidates for a fusion operation. Results after fusion are available for 34 patients: 14 (41%) patients had a good, 12 (35%) had a fair, and 8 (14%) had a bad result. In two patients, pain was relieved by stabilization and did not return after fixator removal; no fusion operation was performed. Fifty-two patients did not respond positively to external fixation. Nine were operated on despite negative results with fixation. Of these, seven patients had a bad result, one a good result (however, this patient had spinal stenosis and the indication for external fixation was wrong), and, in one, the follow-up time is too short. Positive results with external skeletal fixation may predict a successful fusion operation with reasonable accuracy. If stabilization does not relieve the patient's pain, spinal fusion is unlikely to be of any benefit.

Treatment of osteomyelitis of the spine using percutaneous suction/irrigation and percutaneous external spinal fixation.

External skeletal fixation is a well-known tool in the management of infection of long bones. However, the application of external skeletal fixation in the treatment of spinal infection has not been previously reported. We have used percutaneous external spinal fixation (PESF) for the treatment of osteomyelitis of the spine in 23 patients since 1981. The treatment consists of percutaneous vertebral biopsy for bacteriologic diagnosis, installation of a suction/irrigation system into the intervertebral disk space, and posterior stabilization (and reduction if indicated) with an external fixator placed percutaneously. This treatment was conceived in 15 patients as definitive treatment. One patient died due to pulmonary embolism. In 12 patients, the infection healed without further operative treatment. Preoperative kyphosis averaged 15 degrees (range 0-30 degrees). At follow-up, kyphotic deformity also averaged 15 degrees (range 0-30 degrees). Two patients required anterior debridement and bone grafting because of progression of bony destruction. In eight patients, PESF was performed emergently, followed by planned anterior debridement and interbody grafting. The treatment was successful in all patients. All fusions healed. Preoperative kyphosis averaged 18 degrees (range 0-40 degrees). At follow-up, kyphotic deformity averaged 10 degrees (range 0-22 degrees). Our present indications are listed below and comprise pyogenic and tuberculous osteomyelitis of the spine localized between T3 and S1. The procedure is an alternative to conservative or more invasive operative treatment modalities in the following conditions: (a) painful lesions of the spine with minimal bone loss, not amenable to efficient orthotic stabilization (thoracic spine from T3 to T9, lumbosacral junction, elderly patients, or presence of deleterious general conditions); (b) osteomyelitis of the spine from T3 to S1, when emergency decompression of the spine is mandatory because of neurologic deterioration due to the kyphotic deformity or to a noncapsulated epidural abscess and anterior decompression is not possible emergently; (c) pyogenic osteomyelitis of the spine at L5/S1, when operative treatment is indicated. In addition, percutaneous insertion of external skeletal fixation is indicated in the presence of infected wounds, making internal posterior stabilization unsuitable (e.g., after open decompression of epidural abscess, postoperative infections).

Transpedicular screw fixation of articular mass fracture-separation: results of an anatomical study and operative technique.

Articular mass fracture-separation accounts for 9% of the fractures of the lower cervical spine. Neurologic complications are frequent and are usually radicular in nature. Unreduced, these fractures may cause persistent neck pain. The treatment is usually surgical, fusing two or three vertebrae. In this article we present a new treatment modality using reduction and stabilization of the dislocated fragment with a transpedicular lag screw. Previous anatomic studies have shown that the pedicles of the lower cervical spine are wide enough to accept 4.0-mm screws. An anatomic study was performed showing that transpedicular screw fixation is safe when the following technique is used: entry point 3 mm beneath the facet joint on a vertical line in the middle of the articular mass. The drill is angled medially, depending on the preoperative measurement on the computed tomography scan (average 45 degrees). The drill aims toward the cranial third of the vertebral body as seen on lateral fluoroscopy. The tap-drilling method is used. After placement of 33 screws in cadaver pedicles of the cervical spine, 10 had minor breakout of the cortex of the pedicle (only small parts of the threads were penetrating the cortex); none showed major violation of the pedicle wall. The most common direction of minor pedicle violation was lateral. Transpedicular screw fixation has been successfully used in three patients.

The pinless external fixator--relevance of experimental results in clinical applications.

The pinless external fixator was intended as a stable, temporary, minimally invasive fixator for severe tibial fractures ensuring safer conversion to an intramedullary nail. An in vitro study showed that the pinless fixator was mechanically not as stiff as the conventional AO tubular device, the main problem being low axial stiffness. This study involving initial clinical trials with the pinless fixator on tibial fractures in St. Gall is based on the experimental work and previous clinical experience of the main author. From June 1992 to June 1994 10 tibial fractures (eight II degrees and III degrees open, one closed with compartment syndrome, one infected non-union) were temporarily stabilized with a pinless fixator. In another patient a calcaneal traction device was applied. The pinless fixator was applied immediately in eight cases and three times as a secondary measure. All patients were scheduled for a secondary change of treatment. The tibiae were stabilized with four clamps and one anterior rod. The clamps were inserted via transverse stab incisions. Intraoperatively the pinless fixator was easy to handle and complications did not occur. Seven different surgeons needed an average of 20 minutes for insertion. Postoperative care was the same as for conventional fixators. Six patients were treated secondarily with an i.m. nail, three with an external fixator on average after 12 days. One patient died on day 1. The pinless fixator failed twice in one patient (incorrect insertion, fall). Reversible pain in the tendons of the foot extensor muscles was noticed. One superficial clamp track infection was seen. All clamps were reused more than three times. The pinless fixator is stable enough for temporary fracture fixation of the tibia in a four clamp one bar construction. A prerequisite for stability is the proper application technique ("grab test", rocking movements). Weight-bearing should be limited to a minimum and needs a compliant patient. The application technique is easy to learn suggesting that the pinless fixator could be an ideal tool for emergency stabilization. The primary application of this fixator leaves all further treatment modalities open (repeated debridements, evaluation of the open fracture). It may also be of particular value to many clinicians working with reamed nails as their only secondary treatment option for open tibial fractures.

Primary femoral shortening osteosynthesis in the management of comminuted supracondylar femoral fractures.

Supracondylar fractures are most often the result of high-energy vehicular trauma in the young population, and the result of low-energy injuries in the elderly. Therefore, these fractures are generally associated with comminution or osteoporosis. Anatomic reconstruction with stable medial buttressing is often not possible. Utilization of AO principles and techniques with anatomic reduction and internal fixation often fails to yield sufficient stability. We have developed a technique for the treatment of these distal femoral fractures which involves shortening by impaction. Rather than achieving anatomic reduction, the femur is shortened by telescoping the fragments to reestablish inherent stability of the bone prior to internal fixation. Over a 20-year period we treated 25 comminuted supracondylar femoral fractures with primary shortening osteosynthesis in 24 patients. Sixteen patients were available for review at an average follow-up of 10 years (range 4-24 years). Ninety-four percent of the patients demonstrated complete radiographic consolidation by 14 weeks after the operative intervention. One patient required secondary bone grafting and reached consolidation at 30 weeks. Primary cancellous grafting was utilized in only 25% of the patients. One-third of the patients in review were given a heel lift; the average shortening in these patients was 2.6 cm (range 2.1-5 cm). Two-thirds of the patients did not require a heel lift, the average shortening in this group of patients being 1.2 cm (range 0.8-2.0 cm). At follow-up the average range of motion of the knee was 114 degrees (range 90 degrees-130 degrees).(ABSTRACT TRUNCATED AT 250 WORDS)

A comprehensive classification of thoracic and lumbar injuries.

In view of the current level of knowledge and the numerous treatment possibilities, none of the existing classification systems of thoracic and lumbar injuries is completely satisfactory. As a result of more than a decade of consideration of the subject matter and a review of 1445 consecutive thoracolumbar injuries, a comprehensive classification of thoracic and lumbar injuries is proposed. The classification is primarily based on pathomorphological criteria. Categories are established according to the main mechanism of injury, pathomorphological uniformity, and in consideration of prognostic aspects regarding healing potential. The classification reflects a progressive scale of morphological damage by which the degree of instability is determined. The severity of the injury in terms of instability is expressed by its ranking within the classification system. A simple grid, the 3-3-3 scheme of the AO fracture classification, was used in grouping the injuries. This grid consists of three types: A, B, and C. Every type has three groups, each of which contains three subgroups with specifications. The types have a fundamental injury pattern which is determined by the three most important mechanisms acting on the spine: compression, distraction, and axial torque. Type A (vertebral body compression) focuses on injury patterns of the vertebral body. Type B injuries (anterior and posterior element injuries with distraction) are characterized by transverse disruption either anteriorly or posteriorly. Type C lesions (anterior and posterior element injuries with rotation) describe injury patterns resulting from axial torque. The latter are most often superimposed on either type A or type B lesions. Morphological criteria are predominantly used for further subdivision of the injuries. Severity progresses from type A through type C as well as within the types, groups, and further subdivisions. The 1445 cases were analyzed with regard to the level of the main injury, the frequency of types and groups, and the incidence of neurological deficit. Most injuries occurred around the thoracolumbar junction. The upper and lower end of the thoracolumbar spine and the T10 level were most infrequently injured. Type A fractures were found in 66.1%, type B in 14.5%, and type C in 19.4% of the cases. Stable type A1 fractures accounted for 34.7% of the total. Some injury patterns are typical for certain sections of the thoracolumbar spine and others for age groups. The neurological deficit, ranging from complete paraplegia to a single root lesion, was evaluated in 1212 cases.(ABSTRACT TRUNCATED AT 400 WORDS)

Burst-shear flexion-distraction injuries of the lumbar spine.

Seven cases of a previously undescribed lesion of the lumbar spine consisting of a burst fracture of the vertebral body associated with a posterior subluxation of the adjacent lower level facet joints are described. The lesion is due to a flexion-distraction mechanism. All seven cases reported involve a burst fracture (four upper burst, one burst-split, and two complete burst fractures). The dislocation line goes through the upper end-plate, through the posterior wall of the fractured vertebra, through the spinal canal, and through the caudal facet joints. The caudal disk is not destroyed primarily, but is involved in cases of burst-split or complete burst fractures. The treatment is surgical: reduction of the posterior subluxation, reduction of the burst fracture with anterior distraction (e.g., AO internal fixator or any other pedicle system allowing anterior distraction and reduction of the burst fracture), transpedicular bone grafting of the burst fracture if necessary, and fusion of the destroyed motion segment(s).

Selective decompression and translaminar articular facet screw fixation for lumbar canal stenosis and disc protrusion.

A technique is described for lumbar canal stenosis and disc protrusion combining safe and selective decompression and translaminar screw fixation. After experience with 166 cases from 1987 to 1991 we consider this technique particularly suitable for the treatment of lumbar spinal stenosis and also for the few cases of lumbar disc displacement which need a primary fusion.

Primary posterior fusion C1/2 in odontoid fractures: indications, technique, and results of transarticular screw fixation.

Odontoid fractures, especially unstable type II fractures have a poor prognosis in respect to healing. Therefore, operative stabilization (posterior fusion C1/2 or anterior screw fixation) has been suggested for the treatment of unstable type II and for some unstable type III fractures. Compared to posterior fusion C1/2, anterior screw fixation has proven to be effective; it has the advantage of leaving the motion segment C1/2 intact, therefore preserving at least some C1/2 rotation. However, in some instances, this method of stabilization is not indicated. In these cases, posterior fusion C1/2 is the treatment of choice. Primary posterior fusion C1/2 is indicated in (a) odontoid fracture associated with comminution of one or both atlanto-axial joints; (b) fracture of the odontoid associated with an unstable Jefferson fracture; (c) unstable type III odontoid fracture, when immobilization in a halo jacket or plaster cast is not suitable, as in elderly people or polytraumatized patients; (d) atypical type II fractures (comminuted or with oblique fracture in the frontal plane); (e) irreducible fracture dislocation C1/2, e.g., several-weeks-old fracture; (f) unstable type II or shallow and unstable type III odontoid fracture, when marked thoracic kyphosis is associated with limited extension of the cervical spine; (g) unstable type II or shallow type III odontoid fracture in elderly people with degenerative narrow spinal canal; (h) pathologic fracture of the odontoid. In all these instances, posterior fusion C1/2 is the treatment of choice. We prefer the transarticular screw fixation technique. Compared to other posterior fusion techniques, it has the advantage of increased stability and allows effective stabilization of C1/2 in a reduced position as well as immediate ambulation with minimal head support. This technique can also be performed when the posterior arch of the atlas is fractured or absent. Our experience of 12 acute odontoid fractures, managed by this technique, is presented. At follow-up, all C1/2 fusions were united in reduced position.