Matthias Schürmann

Analysis of Efficacy and Failure in Proximal Humerus Fractures Treated With Locking Plates

Objective: The purpose of this study was to determine the efficacy of proximal humerus locking plates (PHLP) and to clarify predictors of loss of fixation. Design: Retrospective review of patients with proximal humerus fractures fixed with a PHLP. Setting: Five Level 1 trauma centers. Patients: One hundred fifty-three patients (111 female, 42 male) 18 years or older with a displaced fracture or fracture-dislocation of the proximal humerus treated with a PHLP between January 1, 2001 and July 31, 2005. Intervention: Demographic data, trauma mechanism, surgical approach, and perioperative complications were collected from the medical records. Fracture classification according to the AO/OTA, radiographic head-shaft angle, and screw tip-articular surface distance in true anteroposterior (AP) and axillary lateral radiographs of the shoulder were measured postoperatively. Varus malreduction was defined as a head-shaft angle of <120 degrees. Main Outcome Measurements: Statistical analysis was done to establish correlations between loss of fixation and postoperative head-shaft angle in the true AP radiograph, patient age, fracture type, trauma mechanism, number of locking head screws, and type of plate. Results: The mean age was 62.3 ± 15.4 years (22-92) and the mean injury severity score (ISS) was 9.5 ± 10.16 (4-57; n = 73). The surgical approach was deltopectoral (90.2%) or transdeltoid (9.8%). No intraoperative complications were reported. The mean postoperative head-shaft angle was 130 degrees (95 degrees to 160 degrees; SD = 13). The overall incidence of loss of fixation was 13.7%. There was a statistically significant association between varus reduction (<120 degrees) and loss of fixation (30.4% when the head-shaft angle was <120 degrees versus 11% when the head-shaft angle was ≥120 degrees; P = 0.02). Conclusion: This series presents the experience using PHLP in 5 Level 1 trauma centers. There were no intraoperative complications related to the locking plate systems. Despite the use of fixed-angle devices, loss of fixation occurred, primarily in the presence of varus malreduction. Our findings suggest that avoiding varus should substantially decrease the risk of postoperative failures.

Assessment of peripheral sympathetic nervous function for diagnosing early post-traumatic complex regional pain syndrome type I

Clinical diagnosis of complex regional pain syndrome type I (CRPS I) in post-traumatic patients is often delayed since the clinical appearance of this disease resembles normal post-traumatic states to a certain extent (pain, edema, loss of function). The purpose of this study was to assess the incidence of specific clinical features in CRPS I patients and normal post-traumatic patients and to evaluate the diagnostic value of a bedside test that measures the sympathetic nervous function. Fifty patients with post-traumatic CRPS I of the upper limb and 50 patients 8 weeks after distal radius fracture with an undisturbed course of disease were subjected to a detailed clinical examination. Pain was assessed using the VAS (visual analog scale), skin temperature measured with an infrared camera and grip-strength with a pneumatic manometer. In CRPS I patients, motor disturbances defined as an impaired active range of motion of the hand, were most frequent (96%, fracture patients: 40%), followed by edema (88%, fracture patients: 80%) and spontaneous pain (VAS 4.0 +/- 2.3, fracture patients: VAS 1.3 +/- 0.6). Systematic temperature differences (>1 degree C) between the affected and unaffected limbs were seen in only 42% of CRPS I patients and in 34% of the fracture patients. Further sensory, sudomotor or trophic changes of the hands were rare. As expected, there were significant differences in the quantity of edema, motor disturbances and sensory disturbances between CRPS I patients and normal fracture patients. However, normal fracture patients still suffered from several of the evaluated symptoms 8 weeks after trauma, which makes an early clinical diagnosis of the complication more difficult. Using a newly developed bedside test, the peripheral sympathetic nervous function was assessed in both groups of patients and in 50 age-matched healthy controls. The decrease in skin blood flow following sympathetic provocation maneuvers, detected by laser Doppler flowmetry, was quantified as sympathetic reactivity. In the affected hands of CRPS I patients, as well as in the contralateral hands, the sympathetic reactivity was obliterated or diminished in contrast to the age-matched controls and normal fracture patients. A multivariate analysis did not reveal any correlation between sympathetic function and the severity of any clinical symptom. Sympathetic reactivity seems to be an independent variable in CRPS I and the test presented may facilitate the difficult clinical diagnosis of this disease.

Imaging in early posttraumatic complex regional pain syndrome. A comparison of diagnostic methods

ObjectivesThe complex regional pain syndrome type I (CRPS I) still is difficult to diagnose in posttraumatic patients. As CRPS I is a clinical diagnosis the characteristic symptoms have to be differentiated from normal posttraumatic states. Several diagnostic procedures are applied to facilitate an early diagnosis, although their value for diagnosing posttraumatic CRPS I is unclear. MethodsOne hundred fifty-eight consecutive patients with distal radial fracture were followed up for 16 weeks after trauma. To assess the diagnostic value of the commonly applied methods a detailed clinical examination was carried out 2, 8, and 16 weeks after trauma in conjunction with bilateral thermography, plain radiographs of the hand skeleton, three phase bone scans (TPBSs), and contrast-enhanced magnetic resonance imaging (MRI). All imaging procedures were assessed blinded. ResultsAt the end of the observation period 18 patients (11%) were clinically identified as having CRPS I and 13 patients (8%) revealed an incomplete clinical picture which were defined as CRPS borderline cases. The sensitivity of all diagnostic procedures used was poor and decreased between the first and the last examinations (thermography: 45% to 29%; TPBS: 19% to 14%; MRI: 43% to 13%; bilateral radiographs: 36%). In contrast a high specificity was observed in the TPBS and MRI at the eighth and sixteenth-week examinations (TPBS: 96%, 100%; MRI: 78%, 98%) and for bilateral radiographs 8 weeks after trauma (94%). The thermography presented a fair specificity that improved from the second to the sixteenth week (50% to 89%). DiscussionThe poor sensitivity of all tested procedures combined with a reasonable specificity produced a low positive predictive value (17% to 60%) and a moderate negative predictive value (79% to 86%). These results suggest, that those procedures cannot be used as screening tests. Imaging methods are not able to reliably differentiate between normal posttraumatic changes and changes due to CRPS I. Clinical findings remain the gold standard for the diagnosis of CRPS I and the procedures described above may serve as additional tools to establish the diagnosis in doubtful cases.

Clinical and physiologic evaluation of stellate ganglion blockade for complex regional pain syndrome type I

Objective: The efficacy of peripheral sympathetic interruption after stellate ganglion blockade was assessed by a sympathetic function test. Results were compared with clinical signs such as temperature changes, pain reduction, and the development of Horner syndrome to evaluate the correlation with clinical investigations. Design: Stellate ganglion blockade with local anesthetics was carried out via an anterior paratracheal approach in 33 patients suffering from complex regional pain syndrome type I. Patients were examined before and after the procedure. For assessment of sympathetic nervous function, the vasoconstrictor response to sympathetic stimuli was assessed using laser Doppler flowmetry. Clinical parameters like surface temperature changes (thermography), pain relief (visual analogue scale), and Horner syndrome were monitored. Results: Twenty-three (70%) of 33 patients developed an increase in temperature difference between the treated hand and the contralateral hand of more than 1.5°C after the procedure, which is a clinical sign of sympathicolysis. In 48% (n = 11) of these patients, the sympathetic function test showed an undisturbed sympathetic nervous function. In 10 patients, no significant increase in temperature difference was observed. Although these patients presented with a normal sympathetic vasoconstrictor response, 4 felt pain relief of more than 50%, suggesting a placebo effect. Only 7 patients with pain relief revealed both clinical sympathicolysis and extinguished sympathetic nervous function and qualified for sympathetically maintained pain. Conclusions: Clinical investigation is not reliable in the assessment of stellate ganglion blockade. Proof of sympathetically maintained pain based on pain relief after stellate ganglion blockade is not conclusive.

Long-term results after posterior fixation of thoraco-lumbar burst fractures.

Current concepts of treating thoraco-lumbar burst-compression injuries are based on posterior transpedicular fixation techniques which are angular stable. However, the long-term results of this approach are controversial due to inconsistent reports and due to a paucity of data on late outcome. In the present study we analyzed 50 patients retrospectively who had an unstable burst-compression injury at T 11-L 2 (type A 3 according to Magerl) without a neurological deficit. All fractures were stabilized by an internal fixator either with or without transpedicular spongiosa grafting. Patients were treated between 1991 and 1997. Follow-up times ranged from 36 to 103 months. Follow-up examinations collected occupational, subjective and clinical data (activity score, Hannover spine score) and included radiographic measurements. The latter were used to calculate the sagittal index (SI) which measures deformities of the fractured vertebral body, and the sagittal plane kyphosis (SPK) which additionally describes an eventual destruction of the affected intervertebral disc. Compared with the preinjury status, the percentage of subjects who were able to do physical labor was reduced by half at follow-up, and four times as many patients had a permanent disability. Correspondingly, activity scores and Hannover spine scores declined significantly. After the initial surgical correction SI remained stable until follow-up, whereas SPK decreased again towards pre-operative values indicating a progressive deformity of the intervertebral disc space. Clinical results did not correlate with radiographic results, and neither the time until follow-up nor the type of fracture n or the use of transpedicular bone grafting affected clinical or radiographic results significantly.

Thoracoscopic repair of thoracic spine trauma.

SummaryModern concepts of treating thoracic and lumbar spinal trauma are based on posterior transpedicular fixation techniques which confer angular stability and instrument only a few levels of the spine. In addition, to prevent secondary losses in postoperative reduction of kyphotic deformities, transpedicular resection of torn dises, and inter-and intracorporeal bone grafting are included in the repair procedures for the entire damaged motion segment. However, due to the small size of the pedicles, a transpedicular approach to the injured vertebral body is not possible in the upper thoracic spine. Patients whose thoracic spine trauma is not serious enough to require ventral instrumentation through open thoracotomy, but who present with an unstable vertebral fracture, may profit from additional ventral bone grafting to stabilize the fracture. The present study examined the feasibility of thoracoscopic ventral bone grafting in seven patients with unstable fractures of the upper thoracic spine. For primary repair, we stabilized the fracture by using posterior transpedicular screw systems (rods or plates). Simultaneously, spongiosa was harvested from the posterior iliac crest and deepfrozen. Repair was completed a few days later via a ventral thoracoscopic approach. The main location of the ventral osseous defect was identified by intraoperative radiology. After mechanical removal of destroyed connective tissue and disc material, fusion was performed using the previously harvested spongiosa, which was placed into the intervertebral disc space and the anterior osseous defect. Our results show thoracoscopic bone grafting to be technically possible and associated with low morbidity, with a potential of yielding satisfactory long-term results.

Assessment of the Peripheral Microcirculation Using Computer-Assisted Venous Congestion Plethysmography in Post-Traumatic Complex Regional Pain Syndrome Type I

In complex regional pain syndrome type I (CRPS-I), edema of the affected limb is a common finding. Therefore, the changes in macro- and microcirculatory parameters were investigated to elucidate the underlying pathophysiology. Twenty-four patients with post-traumatic CRPS-I and 25 gender- and age-matched healthy subjects were examined by means of an advanced computer-assisted venous congestion strain-gauge plethysmograph. The recording of the volume response of the forearm to a stepwise inflation of an occlusion cuff placed at the upper arm enabled the calculation of the arterial blood flow into the arm (Q_a), the vascular compliance (C), the peripheral venous pressure (P_v), the isovolumetric venous pressure (P_vi; = hydrostatic pressure needed to achieve net fluid filtration) and the capillary filtration capacity (CFC) – an index of microvascular permeability. The study revealed no difference in any of the parameters between the right and left hand of healthy subjects. In CRPS-I patients, however Q_a, P_v, P_vi and CFC were significantly (p < 0.01/0.001) elevated in the affected arm (Q_a 11.2 ± 7.0 ml min^–1 100 ml^–1, P_v 20.2 ± 8.1 mm Hg, P_vi 24.7 ± 4.2 mm Hg, CFC 0.0058 ± 0.0015 ml min^–1 100 ml^–1 mm Hg^–1) compared to the unaffected arm (Q_a 4.2 ± 2.4 ml min^–1 100 ml^–1, P_v 10.0 ± 5.1 mm Hg, P_vi 13.2 ± 3.7 mm Hg, CFC 0.0038 ± 0.0005 ml min^–1 100 ml^–1 mm Hg^–1) and the values obtained in healthy controls (Q_a 5.1 ± 1.3 ml min^–1 100 ml^–1, P_v 10.4 ± 4.3 mm Hg, P_vi 15.7 ± 3.3 mm Hg, CFC 0.0048 ± 0.0012 ml min^–1 100 ml^–1 mm Hg^–1). Whereas the values in the unaffected arm of CRPS-I patients revealed no difference in Q_a, P_v and P_vi but a lower CFC (p < 0.01) compared to those from healthy controls. These results suggest profound changes in both macro- and microvascular perfusion in the affected arm of CRPS-I patients. The high CFC contributes to the edema formation, and combined with the elevated P_vi, they are in agreement with the hypothesis of an inflammatory origin of CRPS.

Sympathetic dysfunction as a temporary phenomenon in acute posttraumatic CRPS I.

ObjectiveSympathetic testing was carried out in patients in the acute phase of “complex regional pain syndrome type I” (CRPS I) shortly after trauma to the upper limb. Repeated measurements were used to detect changes in peripheral sympathetic function during the course of the disease.Material and methodsIn a busy trauma center, 10 consecutive patients who developed CRPS I following trauma or surgery of the upper limb were diagnosed according to the 1999 modified IASP diagnostic criteria for CRPS I. Clinical signs and symptoms and bilateral hand temperature (infrared thermometry) were recorded. Vasoconstrictor response to sympathetic provocation (inspiratory gasp, contralateral cooling) at the tip of the middle finger of both hands was measured employing laser Doppler flowmetry (LDF). Sympathetic reaction was quantified by the magnitude of blood flow decrease after provocation (SRF parameter).ResultsThe diagnosis CRPS I could be established 63 days (46–72 days) post-injury. The mean follow-up time after diagnosis was 83±15 days. Pain measured by a visual analog scale (VAS 0–10) showed an average of 5.0±2.0 at the time of diagnosis and decreased to 1.7±1.9 at the last examination. Edema and active range of motion improved substantially during the follow-up period. On the ipsilateral hand marked sympathetic dysfunction was seen early after the onset of CRPS I (mean SRF parameter: 0.14±0.01), slowly returning to normal sympathetic reaction three months after the onset of symptoms (mean SRF parameter: 0.42±0.21). Diminished sympathetic function was seen even on the contralateral hand.ConclusionsSympathetic dysfunction is regularly seen at the onset of CRPS I and normalizes during the course of the disease. This temporary phenomenon suggests a posttraumatic sympathetic deficit playing a decisive role in the genesis of CRPS I.

Early Diagnosis in Post-traumatic Complex Regional Pain Syndrome

Since prospective studies confirmed an incidence of >10% of complex regional pain syndrome complication in patients after distal radial fracture, early diagnosis is important. Therapy should be commenced immediately with a systematic approach to avoid chronicity of the disease. Despite this, epidemiological studies revealed an extreme delay in effective treatment among complex regional pain syndrome patients, who were repeatedly referred to different physicians and often treated inadequately before being referred to specialized pain clinics. In post-traumatic patients, the clinical examination still is preferred to establish the diagnosis of complex regional pain syndrome. First, possible differential diagnoses must be excluded. Next the clinical criteria of the consensus definition should be checked and documented, if possible with the help of verifying procedures. Imaging methods could be applied; however, they are not useful for early diagnosis since sensitivity is low and the consequences of trauma may interfere with potential complex regional pain syndrome findings. In questionable cases repeated examinations after short periods detect the presence of complex regional pain syndrome in orthopedic patients, particularly if symptoms are progressive or an expected improvement does not occur.

Clinical and finite element analysis of a modular femoral prosthesis consisting of a head and stem component in the treatment of pertrochanteric fractures.

OBJECTIVE To determine the biomechanical characteristics and potential clinical efficacy of a cementless modular femoral prosthesis consisting of a variable head (50 to 80 millimeters) and stem (length 120 to 280 millimeters, diameter 10 to 20 millimeters) component in patients with pertrochanteric femoral fracture. DESIGN Finite element analysis (FEA) of different lengths and diameters of prosthesis components and first clinical prospective study in pertrochanteric femoral fracture. METHOD Using a 3D-CAD program, a model of femoral cortical bone with a pertrochanteric fracture was created and combined with a model of the prosthesis. This model was transferred into an FEA program. After applying a torsion-bending load of 2,000 N (25 degrees, 45 degrees) on the prosthesis, stress distribution in the cortical bone was determined for different lengths (160 to 240 millimeters) and diameters (10 and 12 millimeters) of stem. PATIENTS Twenty-eight patients with pertrochanteric fractures (very unstable or osteoarthritis) were treated with a modular hip arthroplasty. Complications, fracture healing, and results at first follow-up (average 13 months) were determined. RESULTS FEA analysis indicated that reduction in stress was less when a prosthesis with a short stem was used. Shear stress in the interface bone/prosthesis was not affected by stem length. Prostheses with thin stems produced higher sheer stresses than those with thick stems. Results of FEA were used as the basis for clinical application of the device. None of the patients died, and all patients were able to walk, although some needed a cane or walker after surgery. There was no increase in thigh pain compared with reported pretrauma levels. Radiographs showed subsidence of up to 5 millimeters in 20 percent of patients. However, all but one prosthesis was stable at follow-up. Fracture healing was achieved in all patients. CONCLUSIONS If proximal fixation of a femoral uncemented stem cannot be achieved, stem diameter should provide maximum cortical contact to reduce sheer stress. Longer stems do not necessarily provide additional stability. By using this prosthesis and selection method, a good outcome at first follow-up was observed.