An accessory abductor digiti minimi as possible risk factor of the median and ulnar nerves compression / Músculo abductor digiti minimi accesorio como posible factor de riesgo de la compresión de los nervios mediano y ulnar

SUMMARY: During routine dissection of a left upper limb of a 68-year-old male human cadaver, an unusual muscle was observed originating from the radius and flexor retinaculum, and continued in the hypothenar region with the muscle belly of the abductor digiti minimi. We checked that it was an accessory abductor digiti minimi (ADM). Its muscular belly was in close relation to the median and ulnar nerves. We review the literature regarding such muscle variations and discuss the potential for compression of the median and ulnar nerves. Although the accessory ADM is usually asymptomatic and only rarely results in nerve compression, it should be taken into account by surgeons when establishing a differential diagnosis in the compression neuropathies of the median and ulnar nerves. An ultrasound scanning can help establish the differential diagnosis.

RESUMEN: Durante la disección de rutina de un miembro superior izquierdo de un cadáver humano masculino de 68 años, se observó un músculo inusual que se originaba en el radio y el retináculo flexor del carpo, y continuuaba en la región hipotenar con el vientre muscular del abductor digiti minimi manus. Verificamos que se trataba del músculo abductor digiti minimi accessorius (ADMA). Su vientre muscular se encontraba en estrecha relación con los nervios mediano y ulnar. Revisamos la literatura sobre variaciones musculares y discutimos la potencial compresión de los nervios mediano y ulnar. Aunque el ADMA suele ser asintomático y rara vez produce compresión nerviosa, los cirujanos deben tenerlo en cuenta al establecer un diagnóstico diferencial en las neuropatías de compresión de los nervios mediano y ulnar. Una ecografía puede ayudar a establecer el diagnóstico diferencial.

Comparison of Coracoid Graft Position and Fixation in the Open Versus Arthroscopic Latarjet Techniques: A Cadaveric Study.

BACKGROUND: Since the description of the arthroscopic Latarjet technique, discussion about the superiority of the open or arthroscopic procedure has arisen. The appropriate placement of the coracoid graft (CG) on the anterior glenoid neck is reported to be the most important step of the Latarjet procedure. PURPOSE: To verify if there are differences in the parameters that may affect the final position and fixation of CG obtained from the open and arthroscopic Latarjet techniques. STUDY DESIGN: Controlled laboratory study. METHODS: Twenty fresh-frozen human paired cadaveric shoulder specimens were randomly distributed in 2 surgery groups (open group [OG] and arthroscopic group [AG]) with 10 specimens in each. Two surgeons, each with experience performing open and arthroscopic Latarjet techniques, executed these procedures: one surgeon performed all open techniques, and the other performed all arthroscopic techniques, respectively. After surgery, a computerized tomography scan was performed. The surgical time, the position of each CG, a series of variables that might affect the CG fixation, and the level of the subscapularis muscle split were evaluated. RESULTS: The mean surgical time was significantly longer in the AG (mean, 26 minutes for OG and 57 minutes for AG). Three intraoperative complications (30%) were identified in the AG, consisting of graft fractures. The CG was determined to be in an optimal cranial-caudal position in 90% of specimens of the OG and 44% of the AG (Fisher, P = .057). In both groups, the CG was placed in an optimal medial-lateral position in all specimens. In the OG, the degree of parallelism between the major axes of the glenoid surface and CG was significantly greater than in the AG (mean, 3.8º for OG and 15.1º for AG). No significant differences were observed in superior and inferior screw orientation between the groups. In the longitudinal and transverse directions, significant differences were found in the centering of the superior screw, being closer to the ideal point in the OG than in the AG. The location where the longitudinal subscapularis muscle split was performed was significantly higher in the AG. CONCLUSION: The open Latarjet technique required less surgical time; presented a lower number of intraoperative complications; and allowed more adequate placement of the CG, better centering of the screws, and a subscapularis muscle split closer to the ideal position. CLINICAL RELEVANCE: The reported benefits of the arthroscopic Latarjet technique seem less clear if we take into account the added surgery time and complications.

Early stages of development of the alar fascia (human specimens at 6-12 weeks of development).

In recent years, there has been much discussion concerning the cervical fasciae. The aim of this study is to confirm and to describe the development of the alar fascia as well as its relationship with nearby structures. Histological preparations of 25 human embryos (6-8 weeks of development) and 25 human fetuses (9-12 weeks of development) were studied bilaterally using a conventional optical microscope. Our study confirms the existence of the alar fascia and permits three stages to be established during its development. The initial stage (1st), corresponding to the 6th week of development (Carnegie stages 18-19), is characterized by the beginning of the alar fascia primordium in the retroesophageal space at the level of C7-T1. In the formation stage (2nd), corresponding to the 7th and 8th weeks of development (Carnegie stages 20-23), the alar fascia primordium grows upwards and reaches the level of C2-C3. In the maturation stage (3rd), beginning in the 9th week of development, the visceral, alar and prevertebral fasciae can be identified. The alar fascia divides the retrovisceral space (retropharyngeal and retroesophageal) into two spaces: one anterior (between the alar fascia and the visceral fascia and extending from C1 to T1, named retropharyngeal or retroesophageal space according to the level) and the other posterior (between the alar fascia and the prevertebral fascia, named danger space). We suggest that this latter space be named the retroalar space. This study suggests that alar fascia development is related to mechanical factors and that the alar fascia permits the sliding of the pharynx and the oesophagus during swallowing.

Repair of long-bone pseudoarthrosis with autologous bone marrow mononuclear cells combined with allogenic bone graft.

BACKGROUND AIMS: Long-bone pseudoarthrosis is a major orthopedic concern because of numerous factors such as difficulty of the treatment, high recurrence, high costs and the devastating effects on the patients' quality of life, which sometimes ends in amputation. Although the "gold standard" for the treatment of this pathology is autologous bone grafting, which has high osteogenic, osteoconductive and osteoinductive properties, this treatment presents some restrictions such as the limited amount of bone that can be taken from the patient and donor site morbidity. Bone marrow mononuclear cells (BM-MNCs) comprise progenitor and stem cells with pro-angiogenic and pro-osteogenic properties. Allogenic cancellous bone graft is a natural and biodegradable osteoconductive and osteoinductive scaffold. Combination of these two components could mimic the advantages of autologous bone grafting while avoiding its main limitations. METHODS: Long-bone pseudoarthrosis was treated in seven patients with autologous BM-MNCs from iliac crest combined with frozen allogenic cancellous bone graft obtained from the tissue bank. RESULTS: All patients showed complete bone consolidation 5.3 ± 0.9 months (range, 2-9 months) after cell transplantation. Moreover, limb pain disappeared in all of them. The mean follow-up was 35.8 ± 4.6 months after transplantation (range, 24-51 months) without pseudoarthrosis recurrence or pain reappearing. CONCLUSIONS: Combination of autologous BM-MNCs and allogenic bone graft could constitute an easy, safe, inexpensive and efficacious attempt to treat long-bone pseudoarthrosis and non-union by reproducing the beneficial properties of autologous bone grafting while restricting its disadvantages.