Biomechanical effects of metastasis in the osteoporotic lumbar spine: A Finite Element Analysis.

BACKGROUND: Cancer patients are likely to undergo osteoporosis as consequence of hormone manipulation and/or chemotherapy. Little is known about possible increased risk of fracture in this population. The aim of this study was to describe the biomechanical effect of a metastatic lesion in an osteoporotic lumbar spine model. METHODS: A finite element model of two spinal motion segments (L3-L5) was extracted from a previously developed L3-Sacrum model and used to analyze the effect of metastasis size and bone mineral density (BMD) on Vertebral bulge (VB) and Vertebral height (VH). VB and VH represent respectively radial and axial displacement and they have been correlated to burst fracture. A total of 6 scenarios were evaluated combining three metastasis sizes (no metastasis, 15% and 30% of the vertebral body) and two BMD conditions (normal BMD and osteoporosis). RESULTS: 15% metastasis increased VB and VH by 178% and 248%, respectively in normal BMD model; while VB and VH increased by 134% and 174% in osteoporotic model. 30% metastasis increased VB and VH by 88% and 109%, respectively, when compared to 15% metastasis in normal BMD model; while VB and VH increased by 59% and 74% in osteoporotic model. CONCLUSION: A metastasis in the osteoporotic lumbar spine always leads to a higher risk of vertebral fracture. This risk increases with the size of the metastasis. Unexpectedly, an increment in metastasis size in the normal BMD spine produces a greater impact on vertebral stability compared to the osteoporotic spine.

Conservative and surgical management of acute isolated syndesmotic injuries: ESSKA-AFAS consensus and guidelines.

PURPOSE: Correct management of syndesmotic injuries is mandatory to avoid scar tissue impingement, chronic instability, heterotopic ossification, or deformity of the ankle. The aim of the present study was to perform a systematic review of the current treatments of these injuries to identify the best non-surgical and surgical management for patients with acute isolated syndesmotic injuries. METHODS: A review of the literature was performed according to the PRISMA guidelines. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase, and Google Scholar databases was performed using the following keywords: "ankle injury", "syndesmotic injury", "chronic", "acute", "treatment", "conservative", "non-operative" "operative", "fixation", "osteosynthesis", "screw", "synostosis", "ligamentoplasties" over the years 1962-2015. RESULTS: The literature search and cross-referencing resulted in a total of 345 references, of which 283 were rejected due to off-topic abstract and/or failure to fulfil the inclusion criteria. After reading the remaining full-text articles, we included four studies, describing non-surgical management, and only two studies investigating surgical management of acute isolated injuries. CONCLUSIONS: The ESSKA-AFAS consensus panel provided recommendations to improve the management of patients with isolated acute syndesmotic injury in clinical practice. Non-surgical management is recommended for stable ankle lesions and includes: 3-week non-weight bearing, a below-the-knee cast, rest and ice, followed by proprioceptive exercises. Surgery is recommended for unstable lesions. Syndesmotic screw is recommended to achieve a temporary fixation of the mortise. Suture-button device can be considered a viable alternative to a positioning screw. Partial weight bearing is allowed 6 weeks after surgery. LEVEL OF EVIDENCE: IV.

Bone loss in patients with posterior gleno-humeral instability: a systematic review.

PURPOSE: The aim of this systematic review was to analyse outcomes of surgical procedures for glenoid and/or humeral bony defects, performed singularly or in combination, in patients with posterior gleno-humeral instability. A secondary aim was to establish in clinical settings which percentage of glenoid or humeral bone loss should be treated with a bony procedure to avoid recurrence of dislocation. METHODS: A systematic review of the literature according to the PRISMA guidelines was performed. A comprehensive search of PubMed, Medline, CINAHL, Cochrane, Embase, Ovid, and Google Scholar databases was performed using various combinations of the keywords "shoulder", "posterior instability", "dislocation", "bone loss", "reversed bony Bankart", "osseous glenoid defects", "glenoid bone grafting", "glenoid", "humeral head", "surgery", "gleno-humeral", "reversed Hill-Sachs", over the years 1966-2014. Data were independently extracted by all the investigators: demographics, previous surgery, imaging assessment, bone defect measurement, diagnosis, surgical management, return to sport, complications, and outcome measurements. The outcome parameters were recurrence of dislocation and clinical scores. RESULTS: Nineteen articles, describing patients with glenoid bony defects, humeral bony defects, or both in the setting of posterior gleno-humeral instability were included. A total of 328 shoulders in 321 patients were included, with a median age at surgery of 33.4 years, ranging from 14 to 79 years. Patients were assessed at a median follow-up period of 3.6 years (ranging from 8 months to 22 years). A redislocation event occurred in 32 (10 %) shoulders. The redislocation event occurred in 2 (10 %) of 20 shoulders with glenoid bony defect and in 12 (11 %) of 114 shoulders with humeral bony defect. CONCLUSION: Even though the general principle of treating recognized glenoid and humeral bone defects in patients with posterior gleno-humeral instability is widely accepted, to date few studies in the literature accurately establish which bone defects should be treated with bony procedures and the exact correlation between percentage of bone loss and higher risk of redislocation in clinical settings. A limitation to the present systematic review is the small number of included patients, due to the rare entity of posterior bone defects/reversed Hill-Sachs. The clinical relevance is that the results of this systematic review can be helpful to guide clinicians in the management of patients with posterior gleno-humeral instability and glenoid and/or humeral bony defects. This manuscript also highlights the need for accurate description of results in further investigations. The main drawback of the available articles in the topic is that they rarely clarify the percentage of bone loss in patients undergoing a redislocation event. LEVEL OF EVIDENCE: IV.

Classification and diagnosis of acute isolated syndesmotic injuries: ESSKA-AFAS consensus and guidelines.

PURPOSE: The aim of the present study was to perform a systematic review of the current classification systems, and the clinical and radiological tests for the acute isolated syndesmotic injuries to identify the best method of classification and diagnosis allowing the surgeon to choose the appropriate management. METHODS: A systematic review of the literature according to the PRISMA guidelines has been performed. A comprehensive search using various combinations of the keywords "classification", "grading system", "ankle injury", "ligament", "syndesmotic injury", "internal fixation", "acute", "synostosis", "ligamentoplasties", "clinical", "radiological" over the years 1962-2015 was performed. The following databases were searched: MEDLINE, Google Scholar, EMBASE and Ovid. RESULTS: The literature search resulted in 345 references for classification systems and 308 references for diagnosis methods, of which 283 and 295 were rejected due to off-topic abstract and/or failure to fulfil the inclusion criteria. After reading the remaining full-text articles, we included 27 articles describing classification systems and 13 articles describing diagnostic tests for acute isolated syndesmotic injuries. CONCLUSIONS: The ESSKA-AFAS consensus panel recommends distinguishing acute isolated syndesmotic injury as stable or unstable. Stable injuries should be treated non-operatively with a short-leg cast or brace, while unstable injuries should be managed operatively. The recommended clinical tests include: tenderness on palpation over the anterior tibiofibular ligament, the fibular translation test and the Cotton test. Radiographic imaging must include an AP view and a mortise view of the syndesmosis to check the tibiofibular clear space, medial clear space overlap, tibial width and fibular width. LEVEL OF EVIDENCE: IV.

The effect of humeral version on teres minor muscle moment arm, length, and impingement in reverse shoulder arthroplasty during activities of daily living.

BACKGROUND: External rotation can be compromised after reverse total shoulder arthroplasty (RTSA). A functional teres minor (TM) is relatively common in patients with posterosuperior tears of the rotator cuff, and its function should be enhanced for better postoperative results. The aim of this study was to investigate how the version of humeral fixation can affect the TM rotational moment arm and muscle length as well as impingement after RTSA. METHODS: A 3-dimensional shoulder model was used to describe RTSA. Four humeral fixation versions were tested: +20°, 0°, -20°, and -40° (+, anteverted; -, retroverted). TM rotational moment arm and length as well as impingement-free range of motion were calculated for a set of 3 simple clinical motions: (1) scapula plane abduction (0°-150°); (2) internal/external rotation with the arm in adduction; and (3) internal/external rotation with the arm in abduction. Six common activities of daily living were also evaluated. RESULTS: An anteverted fixation maximized TM moment arms, but it also resulted in very short muscle length (compared with normal) and increased inferior impingement. In contrast, 40° humeral retroversion resulted in the longest TM muscle length, but it also showed the smallest moment arms and increased anterior impingement in some of the activities of daily living. CONCLUSIONS: Even if TM external rotation moment arm is higher in RTSA than in a normal shoulder, the decreased length could impair its force generation. The 0° and 20° retroversion was the optimum compromise between sufficient TM length and moment arm with minimum impingement.

Current strategies of tissue engineering in talus chondral defects.

Due to the nature of articular cartilage of being poorly vascularized the capabilities of self repair are limited. Mesenchymal stem cells transplantation is a modern technique which has been developed after the high success rates obtained by microfracturing and drilling techniques which promote the release of growth factors and the infiltration of bone marrow derived cells in the lesion. In order to increase the concentration of bone marrow derived cells appropriate devices, the scaffolds, are necessary. These three dimensional constructs mimic the physiological ambient of chondrogenesis.The race for new scaffold materials, which will show high biocompatibility to prevent inflammatory response, high cellular adhesion properties with three dimensional architecture, high bioactivity to deliver growth factor appropriately and possibly high biodegrability has just begun. New studies will concentrate on the role, on the interaction and on the temporal sequence of growth factors to improve ostheocondral differentiation, but the necessity to increase the number of clinical studies with more patients and longer follow ups seems mandatory. The aim of this review is to update and summarise the evidence-based knowledge of treatment of talus chondral defect with new tissue engineering techniques.