Acetabular defect recognition and classification remains a challenging field of practice for orthopedic surgeons. Recently, the Acetabular Defect Classification (ADC) has been introduced to provide a reliable, reproducible and intuitive classification system. In order to improve ease of use and efficiency of the ADC, a browser-based application has been created. We hypothesized that the ADC application can improve rating performance of non-specialists (medical students) to achieve good inter- and intra-rater agreement and will compare favorable to the results of specialists (experienced surgeons) without the help of the application.The ADC is based on the integrity of the acetabular rim and the supporting structures. It consists of four main types of defects ascending in severity. These defects are further subdivided in A-C, narrowing down defect location. 80 randomized radiographs were graded according to ADC by three non-specialists (medical students) with help of the ADC application and by three specialists (orthopedic surgeons) without help of the application to evaluate the difference in inter-rater agreement between groups. To account for intra-rater agreement, the rating process was repeated after a reasonable wash-out period.Inter-rater and intra-rater agreement within the non-specialist group rated lower when compared to the specialist group while still falling into the good agreement range. The student group presented with k values of 0.61 for inter-rater agreement and 0.68 for intra-rater agreement, while the surgeon group displayed k values of 0.72 for inter-rater agreement and 0.83 for intra-rater agreement.The app-guided assessment of acetabular defects offers a promising innovative approach to simplify complex situations. It makes the challenging field of acetabular revision arthroplasty more approachable especially for less experienced surgeons and offers insight and guidance in the planning stage as well as intra-operative setting.
To evaluate the comparative effectiveness and safety of anterior cervical corpectomy with fusion (ACCF), laminoplasty (LP), and laminectomy and instrumented fusion (LF) in the treatment of ossification of the posterior longitudinal ligament (OPLL).Embase, Pubmed, and Cochrane library were searched from their date of inception to June 13, 2020. Relevant randomized controlled trials (RCTs) and cohort studies comparing different procedures among ACCF, LP, and LF were identified, data were extracted to perform a network meta-analysis (NMA). The outcomes were the Japanese Orthopedic Association (JOA) score and complications.We deemed 14 trials eligible, including 877 patients. In NMA, ACCF showed a significant improvement of JOA score compared with LP [MD= -0.89, 95% CI (-1.73, -0.18)], but no significant difference was found when compared LF with ACCF or LP. No significant differences in complications were found when compared LF with LP or ACCF, while ACCF showed significantly higher in complications than LP [OR = 1.99, 95% CI (1.10, 3.35)]. The surface under the cumulative ranking curves (SUCRA) showed that the rank of JOA score improvement is as follows: ACCF (82.5%), LF (79.5%), and LP (2.3%). And the rank of complication rate is as follows: LF (65.8%), ACCF (68.4%), and LP (2.1%).The biggest limitation was that none of the included studies were RCTs.Despite the higher probability of complications than LP, ACCF was the more recommended procedure for its highest ranking spectrums of JOA score improvement to treat the OPLL.
In view of the increased attention to reverse shoulder arthroplasty (rTSA) as a treatment for complex proximal humeral fractures in the elderly, the present study analyzes in-hospital complications and the postoperative management of rTSA versus open reduction and internal fixation (ORIF).We retrospectively reviewed patients hospitalized from 2016 to 2018 for proximal humeral fractures (ICD-9 codes: S42.21), III- and IV-part, who underwent an ORIF with locking plates, rTSA or nonoperative treatment. In-hospital complications and postoperative management in both groups were included in the analysis.We included n 190 patients (ORIF 90, rTSA 71, nonoperative 29), more likely to be female (82.1% vs 17.9%; P < .01) with an average age of 82years (min. 72, max. 99; SD 6.4). The ORIF and the rTSA groups showed comparable complication rates (15.6% vs 15%, P = .87) but with a significantly shorter hospital stay (8.6 vs 11.5days; P = .01) and shorter duration of surgery (72.9 vs 87.2 minutes; P = .01) in the ORIF group. Significantly more patients after ORIF achieved an independent life postoperatively (53.3% vs 40.8%; P = .013).In this retrospective analysis, ORIF is related to a shorter duration of surgery, a shorter hospital stay and a higher likelihood of independence. Despite the popularity of the rTSA, ORIF remains a reliable treatment option for proximal humeral fractures in the elderly.Level of evidence: III.
Patients with long-segment cervical spinal fusion resulting from spinal ankylosing disorders (SADs) are at high risk for highly unstable cervical spine fractures necessitating surgery as the treatment of choice; however, without an existing gold standard. Specifically, patients without concomitant myelo- pathy, representing a rare entity, may benefit from a minimized surgical approach of a single-stage posterior stabilization without bone grafting for posterolateral fusion. This retrospective monocenter study in a Level I trauma center included all patients treated with navigated posterior stabilization without posterolateral bone grafting between January 2013 and January 2019 for cervical spine fractures in preexisting SADs without myelopathy. The outcomes were analyzed based on complication rates, revision frequency, neurologic deficits, and fusion times and rates. Fusion was evaluated by X-ray and computed tomography. 14 patients (11 male, 3 female) with a mean age of 72.7 ± 17.6 years were included. Five fractures were at the upper and nine at the subaxial cervical spine (predominantly C5-7). There was one surgery-specific complication of postoperative paresthesia. There was no infection, implant loosening, or dislocation, and no revision surgery necessary. All fractures healed after a median time of 4 months and 12 months being the latest time of fusion in one patient. Single-stage posterior stabilization without posterolateral fusion is an alternative for patients with SADs and cervical spine fractures without myelopathy. They can benefit from a minimization of surgical trauma while having equal times of fusion and no increased rate of complications.
Consideration of biomechanical aspects during computer assisted orthopaedic surgery (CAOS) is recommendable in order to obtain satisfactory long-term results in total hip arthroplasty (THA). In addition to the absolute value of the hip joint resultant force R the pre- and post-operative orientation of R is an important aspect in the context of the development of a planning module for computer-assisted THA and furthermore for planning of acetabular orientation in periacetabular osteotomy interventions. It is possible to estimate the orientation of hip joint resultant force R for individual patients based on geometrical and anthropometrical parameters. The aim of this study was to examine how far the choice of the mathematical model influences the computational results for the orientation of R in the frontal plane. A further aspect was the comparison of the results with in-vivo data published in the open access OrthoLoad database (www.orthoload.com). Our comparative study included the 2D-models suggested by Pauwels, Blumentritt and Debrunner as well as the 3D-model suggested by Iglic and three patient datasets from the Orthoload database. As computation of R according to each model relies on standardized X-ray imaging, three anterior-posterior (a.p.) digitally reconstructed radiographs (DRRs) were generated from CT data (x21_x21, x8_x8, x12_x12). The orientation of R was expressed in terms of the angle δ for these three patient individual datasets. The angle δ is defined as the angle between the longitudinal axis and R. The computation results were also compared with in vivo telemetric measurement data from the OrthoLoad database. The following data were used to evaluate R in the frontal plane: the highest load peak of the single leg stance (static conditions) of three patients (EBL, HSR, KWR) respectively in the same manner for planar gait (dynamic conditions) of one patient (KWR). The mean value of the orientation of R under static conditions in single leg stance was calculated in order to get a reference value. For the orientation of R under dynamic conditions δ was calculated by using only the highest peak of three cycles (heel strike to toe off) determined in one single patient (among the three patients involved in the measurements under static conditions) of the database. The following values of δ were obtained: Pauwels: 18.26°/20.34°/17.31° (x21_x21/x8_x8/x12_x12) Debrunner: 12.37°/14.30°/12.59° Blumentritt: 5.18°/6.52°/6.14° Iglic: 9.24°/9.01°/9.20° OrthoLoad database (in-vivo): 28.41°/17.08°/13.32°-static (EBL/HSR/KWR) 16.44°-dynamic (KWR) The differences in the computational results appear to depend more on the hip model than on the variability of patient-specific geometrical and anthropometrical parameters. The results obtained with in-vivo measurement data are best approximated by using Pauwels9 model. The mean values of Pauwels (18.64°), Debrunner (13.09°) and Iglic (9.15°) are a little bit more vertically orientated than the mean value of the static in-vivo results (19.60°). Only Pauwels9 model result has a larger angle δ than the in-vivo dynamic result (KWR = 16.44°). By comparing the in-vivo values obtained under dynamic conditions, i.e. gait, (16.44°) with the static in-vivo values of the same patient (13.32°), it could be recognized that the static values are a little bit more vertically orientated than the dynamic result. But both are in the same range as the mathematical models. The computational biomechanical hip models try to approximate the physiological conditions of the hip joint and the OrthoLoad database represents the physiological reconstructed (artificial) hip joint. Therefore, we think our validation approach is useful for a comparison of the biomechanical computation models. In contrast, Blumentritt9s model outcomes have the largest deviation from the other models as well as from the in-vivo data (static and dynamic conditions). Blumentritt used the weight bearing surface as a reference. He defined it being perpendicular to the longitudinal axis [3]. He postulated that a valid and optimal orientation of R is approximately perpendicular on the weight bearing surface respectively parallel to the longitudinal axis. This approach for validation is questionable because the results show that in the three included and analysed DDR9s the orientation is in the mean value 5.95° to the longitudinal axis. It can be concluded that Blumentritt9s model assumptions have to be carefully reviewed due to the deviations from in-vivo measurement data. Among the limitations of our study is the fact that the OrthoLoad database offers only a small number of patient datasets. There is only one dataset for the direct comparison of static (single leg stance) and dynamic (free planar gait) in-vivo measurement data of the same patient included. Furthermore, the individual anatomic geometry data of the patients included in the database are not revealed. Additionally, a source of errors could be an inaccuracy during the data acquisition from the DRR. Further research seems to be recommendable in the context of implementing a biomechanical hip model in a planning module for computer-assisted THA or periacetabular osteotomy interventions, respectively. Sensitivity analyses and parameter studies for different mathematical models using a multi-body-simulation system are objectives of our ongoing work.
INTRODUCTION: PMMA-augmentation of pedicle screws strengthens the bone-screw-interface reducing cut-out risk. Injection of fluid cement bears a higher risk of extravasation, with difficulty of application because of inconsistent viscosity and limited injection time. OBJECTIVE: To test a new method of cement augmentation of pedicle screws using radiofrequency-activated PMMA, which is suspected to be easier to apply and have less extravasations. METHODS: Twenty-seven fresh-frozen human cadaver lumbar spines were divided into 18 osteoporotic (BMD ≤ 0.8 g/cm2) and 9 non-osteoporotic (BMD > 0.8 g/cm2) vertebral bodies. Bipedicular cannulated pedicle screws were implanted into the vertebral bodies; right screws were augmented with ultra-high viscosity PMMA, whereas un-cemented left pedicle screws served as negative controls. Cement distribution was controlled with fluoroscopy and CT scans. Axial pullout forces of the screws were measured with a material testing machine, and results were analyzed statistically. RESULTS: Fluoroscopy and CT scans showed that in all cases an adequately big cement depot with homogenous form and no signs of extravasation was injected. Pullout forces showed significant differences (p < 0.001) between the augmented and non-augmented pedicle screws for bone densities below 0.8 g/cm2 (661.9 N ± 439) and over 0.8 g/cm2 (744.9 N ± 415). CONCLUSIONS: Pullout-forces were significantly increased in osteoporotic as well as in non-osteoporotic vertebral bodies without a significant difference between these groups using this standardized, simple procedure with increased control and less complications like extravasation.
