The influence of partial union on the mechanical strength of scaphoid fractures: a finite element study.

Assessment of scaphoid fracture union on computed tomography scans is not currently standardized. We investigated the extent of scaphoid waist fracture union required to withstand physiological loads in a finite element model, based on a high-resolution CT scan of a cadaveric forearm. For simulations, the scaphoid waist was partially fused at the radial and ulnar sides. A physiological load of 100 N was transmitted to the scaphoid and the minimal amount of union to maintain biomechanical stability was recorded. The orientation of the fracture plane was varied to analyse the effect on biomechanical stability. The results indicate that the scaphoid is more prone to re-fracture when healing occurs on the ulnar side, where at least 60% union is required. Union occurring from the radial side can withstand loads with as little as 25% union. In fractures more parallel to the radial axis, the scaphoid seems less resistant on the radial side, as at least 50% union is required. A quantitative CT scan analysis with the proposed cut-off values and a consistently applied clinical examination will guide the clinician as to whether mid-waist scaphoid fractures can be considered as truly united.

Comparison of AI-powered 3D automated ultrasound tomography with standard handheld ultrasound for the visualization of the hands-clinical proof of concept.

OBJECTIVE: To assess the ability of a newly developed AI-powered ultrasound 3D hand scanner to visualize joint structures in healthy hands and detect degenerative changes in cadaveric hands. MATERIALS AND METHODS: Twelve individuals (6 males, 6 females, age 43.5 ± 17.8 years) underwent four scans with the 3D ultrasound tomograph (right and left hand, dorsal and palmar, respectively) as well as four sets of handheld ultrasound of predefined anatomic regions. The 3D ultrasound tomographic images and the standard handheld ultrasound images were assessed by two radiologists with regard to visibility of bone contour, joint capsule and space, and tendons. In addition, three cadaveric hands were scanned with the 3D ultrasound tomograph and CT. RESULTS: Mean scan time for both hands was significantly faster with handheld ultrasound (10 min 30 s ± 95 s) compared to 3D ultrasound tomography (32 min 9 s ± 6 s; p < 0.001). Interreader and intermodality agreement was moderate (0.4 < κ ≤ 0.6) to substantial (0.6 < κ ≤ 0.8). Overall visibility of joint structures was comparable between the modalities at the level of the wrist (p = 0.408), and significantly better with handheld ultrasound at the level of the finger joints and the thumb (both p < 0.001). The 3D ultrasound tomograph was able to detect osteophytes in cadaveric hands which were confirmed by CT. CONCLUSION: The AI-powered 3D ultrasound tomograph was able to visualize joint structures in healthy hands and singular osteophytes in cadaveric hands. Further technical improvements are necessary to shorten scan times and improve automated scanning of the finger joints and the thumb.

Wrist Arthrolysis: A Systematic Review of Open and Arthroscopic Techniques.

Background Wrist arthrolysis is a viable option in wrist stiffness and can be performed via open or arthroscopic techniques. Purpose The aim of the study is to describe and evaluate the available techniques of open and arthroscopic arthrolysis of the radiocarpal joint and the distal radio ulnar joint (DRUJ) in posttraumatic wrist stiffness. Methods A systematic literature search was performed in PubMed to identify studies reporting on open and arthroscopic wrist arthrolysis. Key words included "open wrist arthrolysis," "arthroscopic wrist arthrolysis," "post-traumatic wrist stiffness," and "DRUJ arthrolysis." Data were extracted independently by a pair of reviewers. Results Overall, 637 studies were identified; 13 additional articles were found through previous publications (total 650 articles). A total of 612 records resulted after duplicates was removed. Fourteen studies were selected and only eight respected the inclusions criteria. One study focused on volar open arthrolysis and four studies on arthroscopic arthrolysis of the radiocarpal joint; two studies reported on open arthrolysis and two studies on arthroscopic DRUJ arthrolysis. Range of motion following open and arthroscopic wrist arthrolysis improved in all studies. Conclusion Both arthroscopic and open arthrolysis can lead to similar and satisfactory results in radiocarpal joint and DRUJ stiffness.. Level of Evidence This is a level 3a study.

[Pain In the Thumb and Other Fingers]. / Schmerzen im Daumen und anderen Fingern.

Pain In the Thumb and Other Fingers Abstract. As the population ages, symptoms of osteoarthritis in the hand are seen with increasing frequency. It can lead to substantial pain, physical disability and impair the patient's capacity to work in a population with an increasing retirement age. This article gives an overview about the most prevalent forms of osteoarthritis in the hand, its diagnosis and current treatment options, stressing that the multimodal form of therapy is the most effective.

[The Painful Wrist]. / Das schmerzhafte Handgelenk.

The Painful Wrist Abstract. Wrist pain is a problem that can significantly limit patients in their daily activities. The causes are manifold, and treatment is often challenging. A systematic approach is therefore helpful in working up the correct diagnosis. This article aims to demonstrate a straightforward approach to the evaluation of wrist pain in adults.

[Tendinopathies - Common Diagnoses in Hand Surgery]. / Tendinopathien ­ häufige Diagnosen in der Handchirurgie.

Tendinopathies - Common Diagnoses in Hand Surgery Abstract. Tendinopathies are among the most frequent reasons for consulting a hand surgeon. The diagnosis can usually be made clinically. A supplementary ultrasound examination helps to visualize the pathology. Most of these diseases respond to non-surgical treatment. If surgical treatment is necessary, it can usually be performed as an outpatient procedure under local anesthesia. This article provides an overview of the most common tendinopathies of the hand and wrist, their diagnosis and treatment.

[Neuropathic Pain - Differential Diagnosis and Treatment from the Hand Surgeon's Perspective]. / Neuropathische Schmerzen ­ Handchirurgische Differenzialdiagnose und Therapie.

Neuropathic Pain - Differential Diagnosis and Treatment from the Hand Surgeon's Perspective Abstract. Neuropathic pain of the wrist and hand can be caused by a multitude of pathologies, such as trauma, iatrogenic damage, local peripheral nerve compression, nerve tumors and systemic diseases. Neuropathic pain can lead to chronification and disability, severely affecting the patients' quality of life and the ability to work. A precise diagnosis is the key to an adequate therapy with satisfactory functional results. An interdisciplinary and multimodal approach is a prerequisite when treating neuropathic pain. This review article provides an insight into the diagnosis and therapy of pathologies associated with neuropathic pain of the wrist and hand.

Editorial Commentary: Fracture Risk After Arthroscopic Osteochondroplasty for Femoroacetabular Impingement-How Can We Become Better?

There is an increased risk of fracture following osteochondroplasty at the femoral head-neck junction for cam-type femoroacetabular impingement. The amount of safe resection has previously been investigated through several biomechanical models, including composite bone, cadaver, animal, and finite element models. Translation of ex vivo results regarding safe resection to an arthroscopic procedure on an actual patient remains a research and clinical challenge.

Surgical correction of kyphotic deformity in a patient with Proteus syndrome.

BACKGROUND CONTEXT: Proteus syndrome (PS) is an extremely rare congenital disorder causing asymmetric overgrowth of different tissues. The etiology remains unclear. Limb deformities are common and often necessitate amputations. Only a few cases associated with spinal deformities have been described. PURPOSE: The aim was to report a rare case of PS associated with spinal deformity and its surgical management. STUDY DESIGN: A case of young boy with PS causing vertebral hypertrophy and kyphoscoliotic deformity, which was surgically corrected, is presented. METHODS: The patient was assessed clinically and with whole spine plain radiographs, computed tomography, and magnetic resonance imaging. Surgical correction was performed. RESULTS: Satisfactory correction of the deformity was achieved by posterior spinal fusion with instrumentation from T4-L5, five Ponte osteotomies T8-L1, and an L2 pedicle subtraction osteotomy. The kyphosis was corrected from 87° to 55°; there was improvement in all spinopelvic parameters. One year after surgery, there was maintenance of the deformity correction with no deterioration of the sagittal balance, and the patient was free of pain and had no loss of neurologic function. CONCLUSIONS: Proteus syndrome can be associated with spinal stenosis and deformity. Although the syndrome can be progressive in nature, the symptomatic spinal pathology should be treated appropriately.

Pelvic incidence-lumbar lordosis mismatch predisposes to adjacent segment disease after lumbar spinal fusion.

PURPOSE: Several risk factors and causes of adjacent segment disease have been debated; however, no quantitative relationship to spino-pelvic parameters has been established so far. A retrospective case-control study was carried out to investigate spino-pelvic alignment in patients with adjacent segment disease compared to a control group. METHODS: 45 patients (ASDis) were identified that underwent revision surgery for adjacent segment disease after on average 49 months (7-125), 39 patients were selected as control group (CTRL) similar in the distribution of the matching variables, such as age, gender, preoperative degenerative changes, and numbers of segments fused with a mean follow-up of 84 months (61-142) (total n = 84). Several radiographic parameters were measured on pre- and postoperative radiographs, including lumbar lordosis measured (LL), sacral slope, pelvic incidence (PI), and tilt. RESULTS: Significant differences between ASDis and CTRL groups on preoperative radiographs were seen for PI (60.9 ± 10.0° vs. 51.7 ± 10.4°, p = 0.001) and LL (48.1 ± 12.5° vs. 53.8 ± 10.8°, p = 0.012). Pelvic incidence was put into relation to lumbar lordosis by calculating the difference between pelvic incidence and lumbar lordosis (∆PILL = PI-LL, ASDis 12.5 ± 16.7° vs. CTRL 3.4 ± 12.1°, p = 0.001). A cutoff value of 9.8° was determined by logistic regression and ROC analysis and patients classified into a type A (∆PILL <10°) and a type B (∆PILL ≥10°) alignment according to pelvic incidence-lumbar lordosis mismatch. In type A spino-pelvic alignment, 25.5 % of patients underwent revision surgery for adjacent segment disease, whereas 78.3 % of patients classified as type B alignment had revision surgery. Classification of patients into type A and B alignments yields a sensitivity for predicting adjacent segment disease of 71 %, a specificity of 81 % and an odds ratio of 10.6. CONCLUSION: In degenerative disease of the lumbar spine a high pelvic incidence with diminished lumbar lordosis seems to predispose to adjacent segment disease. Patients with such pelvic incidence-lumbar lordosis mismatch exhibit a 10-times higher risk for undergoing revision surgery than controls if sagittal malalignment is maintained after lumbar fusion surgery.

Opening wedge osteotomy for distal radius malunion: dorsal or palmar approach?

Background There are various technical variations to consider when performing a corrective osteotomy of a distal radius malunion. We chose two of the more commonly reported techniques and compared the results of volar (palmar) osteotomy and fixation with dorsal osteotomy and fixation. Method Within a continuous cohort of patients who had undergone corrective osteotomy for a malunited Colles fracture, two groups could be identified retrospectively. In 8 patients a dorsal approach was used. A structural trapezoidal graft, subtending the amount of correction, was inserted into the osteotomy gap and stabilization was performed with a thin round-hole mini-fragment plate. In 14 patients a palmar approach and a palmar fixed-angle plate was used for correction of the malunion and for angular stable rigid fixation of the two fragments. The osteotomy gap was loosely filled with nonstructural cancellous bone chips. A retrospective comparison of the two groups was performed to see whether the outcome was affected by the use of either operative technique.The demographics, the preoperative amount of deformity, range of motion, pain, and force were comparable for both groups. All osteotomies healed without loss of correction. After a minimal follow-up of one year, radiographic appearance, objective functional parameters were assessed and subjective data (Disabilities of the Arm, Shoulder, and Hand [DASH] score and special pain and function questionnaire) obtained. Results These data did not show statistical difference for the two groups except for the amount of final wrist flexion. This parameter was significantly better in patients who had palmar approaches and fixed-angle plates. Conclusion Corrective osteotomies of distal radius malunions can be done in either way. It might result in some better flexion, if performed volarly.

Influence of resection geometry on fracture risk in the treatment of femoroacetabular impingement: a finite element study.

BACKGROUND: A fracture is the most serious complication of surgical resection of the femoral head-neck junction in the treatment of cam-type femoroacetabular impingement (FAI). PURPOSE: To investigate the influence of resection length, width, and depth on postoperative fracture risk in activities of daily living. STUDY DESIGN: Descriptive laboratory study. METHODS: The femoral anatomy used for the finite element model was based upon a publicly available standardized model. For descriptive validation, the fracture location was compared with radiographs of patients who had suffered from a femoral neck fracture after surgical treatment of FAI in our institution. Additionally, a 2-part quantitative validation against previously published experimental data was performed. To simulate surgery, round resections were made in which length and width were varied at 10%, 20%, and 30%. The fracture loads were compared with published in vivo loads measured during activities of daily living with telemetric hip implants. RESULTS: Validation showed that the model predicted fracture locations comparable with clinical cases and fracture loads within published experimental values. Femoral fracture loads were 325% more sensitive to resection deepening and 70% more sensitive to widening than lengthening. CONCLUSION: Although resection depth is the most important determinant of bone resistance, it should be considered in combination with resection length and width. Even a resection depth as low as 10% may lead to a fracture in case of stumbling. CLINICAL RELEVANCE: We show that for resection depths of 20% or less and resection length of less than 35% of the femoral neck, normal activities of daily living are safe. Resection widths typically achieved in practice did not induce fractures during activities of daily living. Patients who have undergone surgical resection should be counseled on how to try to avoid stumbling.