The cause of Charcot neuro-osteoarthropathy (CN) is diabetes in approximately 75% of patients. Most reports on the clinical course and complications of CN focus on diabetic CN, and reports on ...nondiabetic CN are scarce. No study, to our knowledge, has compared the clinical course of patients initially treated nonoperatively for diabetic and nondiabetic CN.
Among patients with CN, are there differences between patients with diabetes and those without in terms of (1) the frequency of major amputation as ascertained by a competing risks survivorship estimator; (2) the frequency of surgery as ascertained by a competing risks survivorship estimator; (3) frequency of reactivation, as above; or (4) other complications (contralateral CN development or ulcers)?
Between January 1, 2006, and December 31, 2018, we treated 199 patients for diabetic CN. Eleven percent (22 of 199) were lost before the minimum study follow-up of 2 years or had incomplete datasets and could not be analyzed, and another 9% (18 of 199) were excluded for other prespecified reasons, leaving 80% (159 of 199) for analysis in this retrospective study at a mean follow-up duration since diagnosis of 6 ± 4 years. During that period, we also treated 78 patients for nondiabetic Charcot arthropathy. Eighteen percent (14 of 78) were lost before the minimum study follow-up and another 5% (four of 78 patients) were excluded for other prespecified reasons, leaving 77% (60 of 78) of patients for analysis here at a mean of 5 ± 3 years. Patients with diabetic CN were younger (59 ± 11 years versus 68 ± 11 years; p < 0.01), more likely to smoke cigarettes (37% 59 of 159 versus 20% 12 of 60; p = 0.02), and had longer follow-up (6 ± 4 years versus 5 ± 3 years; p = 0.02) than those with nondiabetic CN. Gender, BMI, overall renal failure, dialysis, and presence of peripheral arterial disease did not differ between the groups. Age difference and length of follow-up were not considered disqualifying problems because of the later onset of idiopathic neuropathy and longer available patient follow-up in patients with diabetes, because our program adheres to the follow-up recommendations suggested by the International Working Group on the Diabetic Foot. Treatment was the same in both groups and included serial total-contact casting and restricted weightbearing until CN had resolved. Then, patients subsequently transitioned to orthopaedic footwear. CN reactivation was defined as clinical signs of the recurrence of CN activity and confirmation on MRI. Group-specific risks of the frequencies of major amputation, surgery, and CN reactivation were calculated, accounting for competing events. Group comparisons and confounder analyses were conducted on these data with a Cox regression analysis. Other complications (contralateral CN development and ulcers) are described descriptively to avoid pooling of complications with varying severity, which could be misleading.
The risk of major amputation (defined as an above-ankle amputation), estimated using a competing risks survivorship estimator, was not different between the diabetic CN group and nondiabetic CN group at 10 years (8.8% 95% confidence interval 4.2% to 15% versus 6.9% 95% CI 0.9% to 22%; p = 0.4) after controlling for potentially confounding variables such as smoking and peripheral artery disease. The risk of any surgery was no different between the groups as estimated by the survivorship function at 10 years (53% 95% CI 42% to 63% versus 58% 95% CI 23% to 82%; p = 0.3), with smoking (hazard ratio 2.4 95% CI 1.6 to 3.6) and peripheral artery disease (HR 2.2 95% CI 1.4 to 3.4) being associated with diabetic CN. Likewise, there was no between-group difference in CN reactivation at 10 years (16% 95% CI 9% to 23% versus 11% 95% CI 4.5% to 22%; p = 0.7) after controlling for potentially confounding variables such as smoking and peripheral artery disease. Contralateral CN occurred in 17% (27 of 159) of patients in the diabetic group and in 10% (six of 60) of those in the nondiabetic group. Ulcers occurred in 74% (117 of 159) of patients in the diabetic group and in 65% (39 of 60) of those in the nondiabetic group.
Irrespective of whether the etiology of CN is diabetic or nondiabetic, our results suggest that orthopaedic surgeons should use similar nonsurgical treatments, with total-contact casting until CN activity has resolved, and then proceed with orthopaedic footwear. A high frequency of foot ulcers must be anticipated and addressed as part of the treatment approach.
Level III, prognostic study.
We introduce a new approach for a continuous loop tendon-graft preparation, benchmarking it against established graft preparation techniques widely used in conjunction with non-adjustable ...interference screw fixation. A four-strand bovine tendon graft was prepared using the following graft preparation techniques: standard graft using the baseball stitch technique (M-tech group); continuous loop graft using the GraftLink
technique (Arthrex-tech group); continuous loop graft using the Kessler anastomosis technique (Kessler-tech group); and continuous loop graft using a Double-Z anastomosis technique (Double Z-tech group). Each group of eight specimens underwent cyclic loading followed by a load-to-failure test. The M-technique yielded a smaller graft diameter (8.4 ± 0.5 mm) compared to the statistically equivalent diameters of the three continuous loop techniques (8.9 ± 0.6 mm of Arthrex-tech group, 9.1 ± 0.4 mm of Kessler-tech group and 9.2 ± 0.6 mm of Double Z-Tech group). The continuous loop grafts formed by the Double Z-Technique showed outstanding performance among the tested techniques in terms of ultimate failure load (982 ± 121 N) and cyclic elongation (3.7 ± 1.0 mm). There was no significant difference between the four groups in cyclic stiffness. Of the assessed techniques, the Arthrex technique resulted in the lowest ultimate elongation (2.0 ± 0.7 mm), followed by the Double Z-tech (4.5 ± 1.8 mm), the M-tech (5.2 ± 3.9 mm), and the Kessler-tech (5.3 ± 2.4 mm). The Arthrex-tech group (5.98 ± 0.38 min) displayed the shortest graft preparation time, followed by the M-Tech (7.94 ± 0.58 min), Kessler-tech (9.03 ± 0.39 min) and Double Z-Tech (13.29 ± 1.14 min). Double Z-Tech can improve the construct of continuous loop tendon graft with regard to mechanical performance.
Augmented Reality (AR) is a rapidly emerging technology finding growing acceptance and application in different fields of surgery. Various studies have been performed evaluating the precision and ...accuracy of AR guided navigation. This study investigates the feasibility of a commercially available AR head mounted device during orthopedic surgery.
Thirteen orthopedic surgeons from a Swiss university clinic performed 25 orthopedic surgical procedures wearing a holographic AR headset (HoloLens, Microsoft, Redmond, WA, USA) providing complementary three-dimensional, patient specific anatomic information. The surgeon's experience of using the device during surgery was recorded using a standardized 58-item questionnaire grading different aspects on a 100-point scale with anchor statements.
Surgeons were generally satisfied with image quality (85 ± 17 points) and accuracy of the virtual objects (84 ± 19 point). Wearing the AR device was rated as fairly comfortable (79 ± 13 points). Functionality of voice commands (68 ± 20 points) and gestures (66 ± 20 points) provided less favorable results. The greatest potential in the use of the AR device was found for surgical correction of deformities (87 ± 15 points). Overall, surgeons were satisfied with the application of this novel technology (78 ± 20 points) and future access to it was demanded (75 ± 22 points).
AR is a rapidly evolving technology with large potential in different surgical settings, offering the opportunity to provide a compact, low cost alternative requiring a minimum of infrastructure compared to conventional navigation systems. While surgeons where generally satisfied with image quality of the here tested head mounted AR device, some technical and ergonomic shortcomings were pointed out. This study serves as a proof of concept for the use of an AR head mounted device in a real-world sterile setting in orthopedic surgery.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose
Patient-specific instruments (PSIs) are helpful tools in high tibial osteotomy (HTO) in patients with symptomatic varus malalignment of the mechanical leg axis. However, the precision of HTO ...can decrease with malpositioned PSI. This study investigates the influence of malpositioned PSI on axis correction, osteotomy, and implant placement.
Methods
With a mean three-dimensional (3D) model (0.8° varus), PSI-navigated HTOs were computer simulated. Two different guide designs, one with stabilising hooks and one without, were used. By adding rotational and translational offsets of different degrees, wrong placements of PSI were simulated. After 5° valgisation of the postoperative mechanical axis, the distance between joint-plane and osteotomy screws, respectively, were measured. The same simulations were performed in a patient with varus deformity (7.4° varus).
Results
In the mean 3D model, the postoperative mechanical axis was within 3.9°–4.5° valgus with mean value of 4.1° ± 0.1° (correct axis 4.2° valgus). Surgical failure concerning osteotomy occurred in 17 of 76 HTOs. Significantly safer screw placement was observed using PSI with stabilising hooks (
p
= 0.012). In the case of the 3D model with 7.4° varus deformity, the postoperative mechanical axis was within 3.2°–3.9° valgus with mean value of 3.8° ± 0.2° (correct axis 3.9° valgus). Surgical failure concerning osteotomy occurred in 3 of 38 HTOs. Screws were always within the safety distance.
Conclusion
The clinical relevance of the presented study is that malpositioning of a PSI within the possible degrees of freedom does not have a relevant influence on the axis correction. The most vulnerable plane for surgical failure is the sagittal plane, wherefore the treating surgeon should verify correct guide placement to prevent surgical failure, particularly in this plane.
Level of evidence
III.
Objective
To develop a new magnetic resonance imaging(MRI) scoring system for evaluation of active Charcot foot and to correlate the score with a duration of off-loading treatment ≥ 90 days.
Methods
...An outpatient clinic database was searched retrospectively for MRIs of patients with active Charcot foot who completed off-loading treatment. Images were assessed by two radiologists (readers 1 and 2) and an orthopedic surgeon (reader 3). Sanders/Frykberg regions I–V were evaluated for soft tissue edema, bone marrow edema, erosions, subchondral cysts, joint destruction, fractures, and overall regional manifestation using a score according to degree of severity (0–3 points). Intraclass correlations (ICC) for interreader agreement and receiver operating characteristic analysis between MR findings and duration of off-loading-treatment were calculated.
Results
Sixty-five feet in 56 patients (34 men) with a mean age of 62.4 years (range: 44.5–85.5) were included. Region III (reader 1/reader 2: 93.6/90.8%) and region II (92.3/90.8%) were most affected. The most common findings in all regions were soft tissue edema and bone marrow edema. Mean time between MRI and cessation of off-loading-treatment was 150 days (range: 21–405). The Balgrist Score was defined in regions II and III using soft tissue edema, bone marrow edema, joint destruction, and fracture. Interreader agreement for Balgrist Score was excellent: readers 1/2: ICC 0.968 (95% CI: 0.948, 0.980); readers 1/2/3: ICC 0.856 (0.742, 0.917). A cutoff of ≥ 9.0 points in Balgrist Score (specificity 72%, sensitivity 66%) indicated a duration of off-loading treatment ≥ 90 days.
Conclusion
The Balgrist Score is a new MR scoring system for assessment of active Charcot foot with excellent interreader agreement. The Balgrist Score can help to identify patients with off-loading treatment ≥ 90 days.
Objectives
To investigate the value of extensive perilesional muscle edema for the differentiation between myositis ossificans (MO) and malignant intramuscular soft tissue tumors on MRI.
Materials ...and methods
Two blinded readers analyzed MR examinations of 90 consecutive patients with intramuscular soft tissue masses (group 1: MO,
n
= 20; group 2: malignant tumors,
n
= 70). Extent of edema around lesions was graded (0, none; 1, minimal edema; 2, moderate edema; 3, extensive edema). Edema-lesion ratio (ELR = ratio of the maximal diameter of the edema and the maximal diameter of the central lesion) was calculated. ROC analysis, Mann-Whitney
U
test, and Kappa test were used.
Results
A total of 70% and 60% of patients with MO had edema grade 3 (reader 1/reader 2), 30%/40% edema grade 2. For the patients with malignant tumors, it was 2.9%/1.4% (edema grade 3) and 16%/23% (edema grade 2). Interrater reliability was substantial (kappa = 0.66). Extent of edema was significantly higher for patients of group 1 (
p
< 0.0001, both readers). Mean ELR was 3.60 (group 1) and 1.35 (group 2), with statistically significant differences (
p
< 0.0001). Grade 3 edema showed a sensitivity/specificity of 70%/97.1% (reader 1) and 60%/99% (reader 2) for diagnosing MO. For ELR > 2.0, sensitivity was 90% and specificity 91% for diagnosing MO.
Conclusions
Extensive perilesional muscle edema on MRI of more than double the size of the central lesion is highly specific, but not pathognomonic for myositis ossificans in the early/intermediate stage in the differentiation to malignant intramuscular soft tissue lesions.
Background In our clinic, a substantial number of patients present with transtibial residual limb pain of no specific somatic origin. Silicone liner induced tissue compression may reduce blood flow, ...possibly causing residual limb pain. Thus, as a first step we investigated if the liner itself has an effect on transcutaneous oxygen pressure (TcPO2). Methods Persons with unilateral transtibial amputation and residual limb pain of unknown origin were included. Medical history, including residual limb pain, was recorded, and the SF-36 administered. Resting TcPO2 levels were measured in the supine position and without a liner at 0, 10, 20 and 30 minutes using two sensors: one placed in the Transverse plane over the tip of the Tibia End (= TTE), the other placed in the Sagittal plane, distally over the Peroneal Compartment (= SPC). Measurements were repeated with specially prepared liners avoiding additional pressure due to sensor placement. Statistical analyses were performed using SPSS. Results Twenty persons (9 women, 11 men) with a mean age of 68.65 years (range 47-86 years) participated. The transtibial amputation occurred on average 43 months prior to study entry (range 3-119 months). With liner wear, both sensors measured TcPO2 levels that were significantly lower than those measured without a liner (TTE: p 0.001; SPC: p = 0.002) after 10, 20 and 30 minutes. No significant differences were found between TcPO2 levels over time between the sensors. There were no significant associations between TcPO2 levels and pain, smoking status, age, duration of daily liner use, mobility level, and revision history. Conclusion Resting TcPO2 levels decreased significantly while wearing a liner alone, without a prosthetic socket. Further studies are required to investigate the effect of liner wear on exercise TcPO2 levels.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Introduction
Internal partial forefoot amputation (IPFA) is a treatment option for osteomyelitis and refractory and recurrent chronic ulcers of the forefoot. The aim of our study was to assess the ...healing rate of chronic ulcers, risk of ulcer recurrence at the same area or re-ulceration at a different area and revision rate in patients treated with IPFA.
Materials and methods
All patients who underwent IPFA of a phalanx and/or metatarsal head and/or sesamoids at our institution because of chronic ulceration of the forefoot and/or osteomyelitis from 2004 to 2014 were included. Information about patient characteristics, ulcer healing, new ulcer occurrence, and revision surgery were collected. Kaplan–Meier survival curves were plotted for new ulcer occurrence and revision surgery.
Results
A total of 102 patients were included (108 operated feet). 55.6% of our patients had diabetes. In 44 cases, an IPFA of a phalanx was performed, in 60 cases a metatarsal head resection and in 4 cases an isolated resection of sesamoids. The mean follow-up was 40.9 months. 91.2% of ulcers healed after a mean period of 1.3 months. In 56 feet (51.9%), a new ulcer occurred: 11 feet (10.2%) had an ulcer in the same area as initially (= ulcer recurrence), in 45 feet (41.7%) the ulcer was localized elsewhere (= re-ulceration). Revision surgery was necessary in 39 feet (36.1%). Only one major amputation and five complete transmetatarsal forefoot amputations were necessary during the follow-up period. Thus, the major amputation rate was 0.9%, and the minor amputation rate on the same ray was 13.9%.
Conclusions
IPFA is a valuable treatment of chronic ulcers of the forefoot. However, new ulceration is a frequent event following this type of surgery. Our results are consistent with the reported re-ulceration rate after conservative treatment of diabetic foot ulcers. The number of major amputations is low after IPFA.
Level of evidence
Retrospective Case Series Study (Level IV).
Abstract
Background
Several hip and knee pathologies are associated with aberrant femoral torsion. Diagnostic workup includes computed tomography (CT) and magnetic resonance imaging (MRI). For ...three-dimensional (3D) analysis of complex deformities it would be desirable to measure femoral torsion from MRI data to avoid ionizing radiation of CT in a young patient population. 3D measurement of femoral torsion from MRI has not yet been compared to measurements from CT images. We hypothesize that agreement will exist between MRI and CT 3D measurements of femoral torsion.
Methods
CT and MRI data from 29 hips of 15 patients with routine diagnostic workup for suspected femoroacetabular impingement (FAI) were used to generate 3D bone models. 3D measurement of femoral torsion was performed by two independent readers using the method of Kim et al. which is validated for CT. Inter-modalitiy and inter-reader intraclass correlation coefficients (ICC) were calculated.
Results
Between MRI and CT 3D measurements an ICC of 0.950 (0.898; 0.976) (reader 1) respectively 0.950 (0.897; 0.976) (Reader 2) was found. The ICC (95% CI) expressing the inter-reader reliability for both modalities was 0.945 (0.886; 0.973) for MRI and 0.957 (0.910; 0.979) for CT, respectively. Mean difference between CT and MRI measurement was 0.42° (MRI – CT, SD: 2.77°,
p
= 0.253).
Conclusions
There was consistency between 3D measurements of femoral torsion between computer rendered MRI images compared to measurements with the “gold standard” of CT images. ICC for inter-modality and inter-reader consistency indicate excellent reliability. Accurate, reliable and reproducible 3D measurement of femoral torsion is possible from MRI images.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Athletic performance relies on tendons, which enable movement by transferring forces from muscles to the skeleton. Yet, how load-bearing structures in tendons sense and adapt to physical demands is ...not understood. Here, by performing calcium (Ca
) imaging in mechanically loaded tendon explants from rats and in primary tendon cells from rats and humans, we show that tenocytes detect mechanical forces through the mechanosensitive ion channel PIEZO1, which senses shear stresses induced by collagen-fibre sliding. Through tenocyte-targeted loss-of-function and gain-of-function experiments in rodents, we show that reduced PIEZO1 activity decreased tendon stiffness and that elevated PIEZO1 mechanosignalling increased tendon stiffness and strength, seemingly through upregulated collagen cross-linking. We also show that humans carrying the PIEZO1 E756del gain-of-function mutation display a 13.2% average increase in normalized jumping height, presumably due to a higher rate of force generation or to the release of a larger amount of stored elastic energy. Further understanding of the PIEZO1-mediated mechanoregulation of tendon stiffness should aid research on musculoskeletal medicine and on sports performance.
PDF
