Early range of motion results in good elbow function following conservative treatment of non-displaced radial head fractures.

INTRODUCTION: The aim of this study was to evaluate the range of motion (ROM), elbow function and predictors for good elbow function after conservative treatment of non-displaced radial head fractures. MATERIAL AND METHODS: All patients with non-displaced radial head fractures (displacement < 2 mm), that were diagnosed between January 1st 2017 and December 31st 2021 in a level I trauma center, were included in this retrospective case series and the charts were evaluated for ROM and elbow function. Elbow function was categorized as "good" or "bad" depending on the ROM measured defined by Morrey et al. Overall, 73 patients (33 male, 40 female) with an average age of 38 years (+/- 13 years) could be included. RESULTS: Conservative treatment had good clinical results for ROM and elbow function. After 6 weeks mean flexion was 131° (SD 13°), extension 8° (SD 7°), Pronation 83° (SD 11°) and Supination 83° (SD 13). Patients with a good elbow function after one week showed a good elbow function after completing the treatment. CONCLUSIONS: A clinical assessment after one week should always be performed and the study showed that it is a good predictor for good elbow function. In cases of bad elbow function further controls should be considered.

Correlation between kidney function and mortality in pyogenic spondylodiscitis: the glomerular filtration rate (GFR) as new predictive parameter?

OBJECTIVE: Pyogenic spondylodiscitis is a severe medical condition, often requiring surgical intervention. Numerous risk factors are known, such as obesity, neurological impairment and old age. In-hospital mortality remains high, therefore other factors may be contributing to the increased mortality. To evaluate kidney function as a risk factor for increased morbidity of pyogenic spondylodiscitis, the glomerular filtration rate (GFR) was correlated with the patients' clinical course. MATERIALS AND METHODS: We retrospectively reviewed the cases of 366 patients and 255 were included for analysis. Clinical, laboratory and surgical data were recorded with a minimum follow-up of three months. For clinical outcome measurement, mortality, length of stay and perioperative complications were analysed. RESULTS: The study included 255 patients (173 men, 82 women; mean age 66.3 years). Patients with a GFR < 59 mL/min spent an average of 5 days longer in the hospital than those with a GFR ≥ 60 mL/min (p = 0.071). The mortality rate increased significantly with a decrease in GFR: A GFR of 30-59 mL/min had a mortality rate of 17.6%, whereas a GFR of < 29 mL/min had one of 30.4% (p = 0.003). Patients with impaired GFR showed an increased rate of postoperative complications (OR 4.7 p = 0.002) and higher rate of intensive care unit (ICU) stay (OR 8.7 p = < 0.001). DISCUSSION: Preoperative GFR values showed a significant correlation with in-hospital mortality in patients with spondylodiscitis, when graded according to the KDIGO stages. Furthermore, a GFR of < 29 ml/mL contributes to a longer ICU stay, postoperative complications and a longer total hospital stay. Therefore, the preoperative GFR could be a marker of kidney function and as a valuable predictive risk factor regarding the clinical in-hospital course of patients suffering from pyogenic spondylodiscitis.

Projections From Surgical Use Models in Germany Suggest a Rising Number of Spinal Fusions in Patients 75 Years and Older Will Challenge Healthcare Systems Worldwide.

BACKGROUND: Spinal fusion is a well-established procedure in the treatment of degenerative spinal diseases. Previous research shows that the use of this operative treatment has been growing in recent decades in industrialized countries and has become one of the most cost-intensive surgical procedures. It seems that in some countries such as Germany-with its large, industrialized, European population-this increase is mainly driven by demographic changes with low fertility rates, increasing life expectancy, and an aging population. Based on current projections, however, Germany faces a population trend that many other countries are likely to follow within a few decades. An increasingly shrinking and aging working population may eventually put the healthcare system under enormous pressure, with greater demands for spinal fusions and associated higher costs. Thus, we aimed to provide reliable projections regarding the future demand for posterior spinal fusion procedures including age- and gender-related trends up to 2060, which will be necessary for future resource planning and possible improvements in actual treatment strategies. QUESTIONS/PURPOSES: (1) How is the use of posterior spinal fusions in Germany expected to change from 2019 through 2060, if currents trends continue? (2) How is the use of posterior spinal fusions in Germany expected to change depending on patients' age and gender during this time period? METHODS: Comprehensive nationwide data provided by the Federal Statistical Office, the official institution for documenting all data on operations and procedures performed in Germany, were used to quantify posterior spinal fusion rates as a function of calendar year, age, and gender. Because there is a lack of evidence regarding future trends in the use of posterior spinal fusions, an autoregressive integrated moving average model on historical procedure rates from 2005 to 2019 in relation to official population projections from 2020 to 2060 was chosen to forecast future absolute numbers and incidence rates of this procedure in Germany. Long-term forecasting is more prone to unexpected disruptions than forecasting over short-term periods; however, longer spans facilitate estimates of how trends may challenge future healthcare systems if those trends continue, and thus are useful for research and planning. RESULTS: The incidence rate of posterior spinal fusion was projected to increase by approximately 83% (95% CI 28% to 139%) to 102% per 100,000 inhabitants (95% CI 71% to 133%) in 2060, with a 1.3-fold higher rate of women undergoing surgery in terms of absolute numbers. The highest increase identified by the model occurred in patients 75 years and older with 38,974 (95% CI 27,294 to 50,653) posterior spinal fusions in 2060, compared with 14,657 in 2019. This trend applied for both women and men, with a 246% (95% CI 138% to 355%) increase in the total number of posterior spinal fusions for women 75 years and older and a 296% (95% CI 222% to 370%) increase for men 75 years and older. At the same time, posterior spinal fusions in all age groups younger than 55 years were projected to follow a constant or even negative trend up to 2060. CONCLUSION: Our findings suggest that increasing use of posterior spinal fusion, particularly in patients 75 years and older, will challenge healthcare systems worldwide if current trends persist. This study may serve as a model for many other industrialized countries facing similar demographic and procedure-specific developments in the future. This emphasizes the need to focus on frailty research as well as appropriate financial and human resource management. Effective perioperative medical management, multidisciplinary treatment, and interinstitutional protocols are warranted, especially in older patients as we attempt to manage these trends in the future. LEVEL OF EVIDENCE: Level III, economic and decision analysis.

Optimal K-Wire Placement for Indirect Cannulated Screw Fixation of Coronoid Process Fractures: A Radiology-Based Guide.

PURPOSE: Indirect fixation of coronoid process fractures of the ulna, especially arthroscopically, offers the possibility to avoid extensive medial surgical approaches. However, optimal placement of K-wires for cannulated screw fixation is technically challenging. The aim of the present study was to present guide values for K-wire placement for indirect screw fixation of coronoid tip (COT) and anteromedial facet (AMF) fractures of the ulna. METHODS: Computed tomography scans of the elbows of 197 patients with an uninjured ulna were identified and evaluated following a standard measuring protocol. Optimal placement of K-wires was defined as the bisector between the anterior and articular cortex while respecting a 1.6-mm safe zone for each placement. This placement of the K-wires in the COT and the AMF was analyzed by measuring the wire angulation in relation to the posterior ulnar cortex (AUC), the distance from the entry point to the posterior olecranon edge (DPE), and the intraosseous length (IOL). Because the coronoid has a curved shape, measurements of the COT and AMF were expected to differ significantly. Sex was also expected to influence measurements. To determine whether this optimal placement of K-wires can be reliably identified, interobserver and intraobserver reliabilities were evaluated. RESULTS: To address tip fragments, we determined a mean AUC of 64°, DPE of 36 mm, and IOL of 38 mm. Regarding wire placement toward the AMF, the means for the AUC, DPE, and IOL were 79°, 27 mm, and 33 mm, respectively. Statistically significant differences were found between the COT and the AMF for the AUC, DPE, and IOL. Our measuring protocol showed good interobserver and intraobserver reliability. CONCLUSIONS: K-wire placement toward the COT demands a smaller angle, a longer IOL, and a more distal entry point than wires placed toward AMF. These differences reflect the curved and complex anatomy of the coronoid. CLINICAL RELEVANCE: This measuring algorithm can be used to plan osteosynthesis, and the obtained reference values can help understand the coronoid's complex anatomy.

Suggestion of a safe zone for C1 pedicle screws depending on anatomical peculiarities.

OBJECTIVE: For surgical treatment of instable upper cervical injuries, the Harms technique using lateral mass screws provides rigid fixation and favourable clinical outcomes. The use of the posterior arch of C1 as a "pedicle" allows for screw anchorage, giving improved biomechanical stability. Therefore, the aim of this study was to introduce a bilateral safe zone for C1 pedicle screws, regarding screw angulation and pedicle height. MATERIAL AND METHODS: We retrospectively reviewed the CT scans of 500 patients. Three-dimensional reformats were generated for detailed measurements. Centre screw entry point (EP), length of lateral mass as screw trajectory, lateral mass width (LMW), length of screw trajectory (ST), maximal divergence (DI) and maximal convergence (CON) from EP without perforation, and pedicle height (PH) of the posterior arch were measured. RESULTS: The 500 cases consisted of 335 males and 165 females, with a mean age of 49.5 years. Measurements did not demonstrate significant side-related differences. The mean screw entry point was 22.8 mm from the midline-axis (left 22.6 mm; right 23.0 mm). From this point, a safe zone between 11.6° of divergence and 19.6° of convergence was detected. Measurements of female patients were generally smaller, with significant differences from male patients (p < 0.05). 158 subjects (31.6%) had a PH < 4 mm. DISCUSSION: C1 pedicle screws were feasible in the majority of patients. Proposing a safe zone for screw angulation may provide safety and avoid screw perforation. However, detailed knowledge of the individual C1 anatomy and the preoperative measurement is essential in the operative planning.

Development of disorder-specific normative data for growth in children with cerebral palsy.

The purpose of this study was to create growth-percentiles for Caucasian children with cerebral palsy (CP). The studied parameters were height and age. In a retrospective analysis, we converted measurements collected in our center to create disorder-specific percentiles of normative data. Patients were stratified due to sex (male and female) and to mobility levels using the gross motor function classification system (GMFCS) (A = walking; GMFCS I-III, B = non walking; GMFCS IV-V) into four groups. In total, 2363 measurements in patients 0-18 years were collected. The mean age for group "Am" was 6.8 years (n = 862), group "Bm" 7.6 years (n = 563), group "Af" 7.7 years (n = 600), and group "Bf" 8.2 years (n = 366). The created percentiles for all groups were below the reference percentiles for healthy Caucasian children (KiGGS). The median curve for children with GMFCS levels I-III is slightly above the 3rd percentile, whereas the 50th percentile for GMFCS levels IV-V is mostly below the 3rd KiGGS centile.Conclusion: In conclusion, children with cerebral palsy are smaller than healthy children. The difference between 50th percentile of CP patients compared to healthy children supports the need for the use of disorder-specific growth charts. Those charts can help clinicians differentiate growth disorders in patients with CP. What is Known: • Children with cerebral palsy are shorter than healthy children and height is influenced by level of ambulation. • Currently, only reference percentiles of American children with mixed ethical backgrounds are available to evaluate growth. What is New: • This paper presents disorder-specific reference percentiles for longitudinal growth of Caucasian children with cerebral palsy depending on motor function. • These percentiles allow to asses longitudinal growth in children with cerebral palsy to detect other additional diseases impairing growth.

Impact of the blood group on postoperative CRP and leukocyte levels after primary total hip and knee arthroplasty.

BACKGROUND: C-reactive protein (CRP)- and leukocyte levels are common parameters to evaluate the inflammatory response after orthopaedic surgery and rule out infectious complications. Nevertheless, both parameters are vulnerable to disturbing biases and therefore leave room for interpretation. OBJECTIVE: Since blood groups are repeatedly discussed to influence inflammatory response, our aim was to observe their impact on CRP and leukocyte levels after total hip and knee arthroplasty (THA/TKA). METHODS: Short term postoperative CRP and leukocyte levels of 987 patients, who received either primary TKH (n= 479) or THA (n= 508), were retrospectively correlated with their blood group. ABO, Rhesus and a combination of both blood groups were differentiated. RESULTS: CRP levels after TKA were significantly higher in blood type AB than in type A and O on day 2-4 and also than in type A on day 6-8. Leukocyte levels after THA were significantly higher in blood group type O than in type A on day 6-8 while still remaining in an apathological range. We observed no significant differences between Rhesus types and Rhesus types and CRP or leukocyte levels. CONCLUSION: We observed significantly increased CRP levels after TKA in patients with blood group AB. Since the elevated CRP levels do not account for early periprosthetic infection, surgeons should include this variation in their postoperative evaluation.

Increased stability due to symmetric cement volume in augmented pedicle screws? A biomechanical study.

Pedicle screw instrumentation has become "state of the art" in surgical treatment of many spinal disorders. Loosening of pedicle screws due to poor bone mineral density is a frequent complication in osteoporotic patients. As prevalence of osteoporosis and spinal disorders are increasing with an aging demographic, optimizing the biomechanical properties of pedicle screw constructions and therefore outcome after spinal surgery in osteoporotic patients is a key factor in future surgical therapy. Therefore, this biomechanical study investigated the stability of polymethylmethacrylate (PMMA)-augmented pedicle screw-rod constructions under a deviating distribution of PMMA applied to the instrumentation in osteoporotic human cadaveric vertebrae. We showed that PMMA-augmented pedicle screw-rod constructions tend to be more stable than those with non-augmented pedicle screws. Further, there appears to be a larger risk of screw loosening in unilateral augmented pedicle screws than in non-augmented, therefore a highly asymmetrically distributed PMMA should be avoided.

Patient-related risk factors and lifestyle factors for lumbar degenerative disc disease: a systematic review.

OBJECTIVE: Back pain is a very widespread disease pattern and is one of the most frequent causes for consultation of a physician in general. In most cases, discogenic changes are the pathomorphological correlate of back pain. Numerous risk factors have been identified for these degenerative changes, but the influence and significance of the risk factors remain unclear, which was the aim of this systematic review. METHODS: A systematic literature search of the commonly used Pubmed database was performed using specific MESH terms. Further selection of the included studies was performed according to the PRISMA scheme, taking into account scientific merit as well as the relation to the research question. RESULTS: A total of 111 studies out of 1035 found were finally included in the literature search. 134 risk factors for disc degeneration and disc herniation were identified. These were divided into (1) patient-specific risk factors (n░=░34), (2) radiological risk factors (n░=░31), (3) lifestyle risk factors (n░=░6), (4) workplace-related risk factors (n░=░12), (5) genetic risk factors (n░=░50), and (6) other risk factors (n░=░1). Non-adjustable risk factors were age >50 years (OR 1.7/year), female gender (OR 1.41), family disposition (OR 4.0), comorbidities like atherosclerosis (OR 2.24), arthritic changes in other joints (OR 3.1) and history of injuries of the back (OR 3.1). Adjustable factors were elevated BMI (OR 2.77), comorbidities like hypertension (OR 1.25), dyslipidemia (OR 1.26) and diabetes mellitus (OR 6.8), as well as lifestyle habits like smoking (OR 3.8). DISCUSSION: In summary, intervertebral disc degenerations and herniations represent multifactorial events whose risk factors can be partly influenced and partly not influenced. This systematic review highlights the current state of knowledge as a basis for creating patient-specific algorithms to calculate risk for the development or progression of degenerative disc changes and disc herniations.

Pedicle or lateral mass screws in Goel-Harms construct? A biomechanical analysis.

BACKGROUND: The use of the posterior arch of C1 as pedicle has shown beneficial stability regarding screw loosening, however, the C1 pedicle screw placement is challenging. Therefore, the study aimed to analyse the bending forces of the Harms construct used in fixation of C1/C2 when using pedicle screws compared to lateral mass screws. METHODS: Five cadaveric specimens with a mean age of 72 years at death and bone mineral density measuring for 512.4 Hounsfield Units (HU) on average were used. A custom-made biomechanical setup was used to test the specimens with a C1/C2 Harms construct each with the use of lateral mass screws and pedicle screws in sequence. Strain gauges were used to analyse the bending forces from C1 to C2 in cyclic axial compression (µm/m). All underwent cyclic biomechanical testing using 50, 75 and 100 N. FINDINGS: In all specimens, placement of lateral mass screws and pedicle screws was feasible. All underwent cyclic biomechanical testing. For the lateral mass screw, a bending of 142.04 µm/m at 50 N, 166.56 µm/m at 75 N and 188.54 µm/m at 100 N was measured. For the pedicle screws, bending force was slightly elevated with 165.98 µm/m at 50 N, 190.58 µm/m at 75 N and 195.95 µm/m at 100 N. However, bending forces did not vary significantly. In all measurements, no statistical significance was found when comparing pedicle screws and lateral mass screws. INTERPRETATION: The lateral mass screw used in the Harms Construct to stabilize C1/2 showed less bending forces, therefore the construct with lateral mass screws appears more stable in axial compression compared to the one with pedicle screws. However, bending forces did not vary significantly.

When to remove? Evaluation of postoperative drainage volume after single-level posterior lumbar interbody fusion.

Study design: prospective, observational. Background: Wound drainage's indwelling duration and general use are the centre of ongoing discussion. The aim of our prospective observational study was to evaluate the total drainage volume postoperatively and its course after lumbar interbody fusion surgeries to define an ideal point in time for drainage removal. Methods: We included all patients who underwent monosegmental lumbar interbody fusion via transforaminal or posterior lumbar interbody fusion (TLIF/PLIF). After application of the exclusion criteria, 27 patients were included in our study. Drainage volume was measured three times a day and at the time of drain removal. Results: The PLIF group reached higher total drainage volume (337.14 ml) than the TLIF group (215.5 ml) (p = 0.047. Drainage volume's plateau was reached after 33.0 h (±1.8 h) in the TLIF group and 25.3 h (±1.7 h) in the PLIF group following surgery. Conclusions: Our study shows, that drainage volume did not increase significantly after the evening of the first postoperative day at latest. This was on average 33.0 h after surgery. Therefore, extraction of the drainage tube hereafter can be assumed to be safe.

Is human bone matrix a sufficient augmentation method revising loosened pedicle screws in osteoporotic bone? - A biomechanical evaluation of primary stability.

INTRODUCTION: Despite good screw anchorage and safe screw trajectory, screw loosening occurs in several cases, especially in osteoporotic individuals. The aim of this biomechanical analysis was to evaluate the primary stability of revision screw placement in individuals with reduced bone quality. Therefore, revision via enlarged diameter screws was compared to the use of human bone matrix as augmentation to improve the bone stock and screw coverage. METHODS: 11 lumbar vertebral bodies from cadaveric specimens with a mean age of 85.7 years (± 12.0 years) at death were used. 6.5 mm diameter pedicle screws were inserted in both pedicles and hereafter loosened using a fatigue protocol. Screws were revised inserting a larger diameter screw (8.5 mm) in one pedicle and a same diameter screw with human bone matrix augmentation in the other pedicle. The previous loosening protocol was then reapplied, comparing maximum load and cycles to failure between both revision techniques. Insertional torque was continuously measured during insertion of both revision screws. FINDINGS: The number of cycles and the maximum load until failure were significantly greater in enlarged diameter screws than in augmented screws. The enlarged screws' insertional torque was also significantly higher than of the augmented screws. INTERPRETATION: Human bone matrix augmentation does not reach the same ad-hoc fixation strength as enlarging the screw's diameter by 2 mm and is therefore biomechanically inferior. Regarding the immediate stability, a thicker screw should therefore be prioritised.

Is the rod necessary? Biomechanical comparison of static knee spacers during axial loading.

BACKGROUND: Knee Spacers are required in two-stage revision surgery of periprosthetic joint infection of the knee. Extended bone and ligamentous defects are often temporarily arthrodised via a static spacer. Regarding their weight-bearing potential and construction, there is no current consent. Our aim was to evaluate three individual static spacer variants with regard to their axial loading capacity. METHODS: The static spacer variants were tested in a cadaver model. One after the other, a spacer with metal-reinforced rods, a spacer without metal reinforcement and a rod-less spacer were implanted and tested up to an axial loading of 1000 Newton. Target parameters were plastic deformation, stiffness and spacer movement at both the femoral and tibial surface. Loading was applied up to 1000 Newton. Radiological controls of the bone substance were performed. FINDINGS: The spacer variants did not differ regarding deformation, stiffness or spacer movement. However, deformation increased significantly with the axial load in all spacer variants. Radiographs showed no fracture or spacer-dislocation resulting from testing. INTERPRETATION: While the spacer reinforcement or the sheer presence of a rod did not influence the axial loading capacity in this in vitro study, weightbearing should be discouraged to limit further bone erosion.

Postoperative Surgical Site Infections in Spine Surgery: Can the Duration of Surgery Predict the Pathogen Spectrum?

BACKGROUND/AIM: Surgical site infection (SSI) is a severe complication of spinal surgery, which typically results in prolonged length of hospital stay, an increased number of revision surgeries, re-hospitalizations, worse clinical functional outcomes, and increased healthcare costs. The aim of the present study was to analyse if the duration of surgery can predict the spectrum of pathogens causing SSI in orthopaedic spine surgery. PATIENTS AND METHODS: We conducted a retrospective study over a period of two years at the University Hospital of Cologne in which all patients with postoperative surgical site infections were included. In addition to descriptive characteristics (such as sex, age, BMI), the duration of the surgery, the administration of intra-operative antibiotics, the main diagnosis, the postoperative course of the infection parameters (CRP & WBC) and the responsible pathogens were analysed. RESULTS: A total of 75 patients were included with a median age of 64 years. The mean time of operation time was 131.52±70.91 min (range=23-285 min). The most frequently isolated germs in the postoperative blood culture were S. aureus (n=7), S. haemolyticus and S. hominis (n=2). There was a significant correlation between the duration of the primary surgical intervention and the postoperatively detected pathogens (p=0.002). CONCLUSION: A significant correlation was shown between the duration of surgery and the species of pathogens detected causing postoperative SSI. The use of perioperative antibiotics, the use of longer-lasting antibiotics or the repeated intravenous administration of prophylactic antibiotics should be evaluated.