Eduardo Benegas

Estudo biomecânico de resistência à tração de âncoras metálicas de sutura em diferentes ângulos de inserção

O objetivo deste trabalho e verificar se o ângulo de insercao das âncoras de sutura interfere na sua resistencia quando submetidas a uma forca de tracao constante. Foram realizados 20 ensaios com âncoras metalicas de sutura inseridas em 4 angulacoes diferentes (30°, 45°, 60°, 90°), em osso de cadaver humano (femur distal) e mais 20 ensaios em osso artificial (SawboneTM). Os testes foram realizados na Maquina Universal de Ensaios modelo Kratos, sendo as âncoras tracionadas a 90° em relacao ao seu plano de insercao na superficie ossea. Os valores encontrados no osso de cadaver humano nao foram estatisticamente significantes, ou seja, o ângulo de insercao nao influiu na resistencia a tracao. No osso artificial verificou-se que houve maior resistencia na insercao a 90o, com relevância estatistica em relacao aos demais ângulos testados.

An anatomical study of the subcoracoid space

PURPOSE To evaluate the amplitude of the subcoracoid space under maximum internal and external rotations of the humeral head and measure the distance between the apex of the coracoid process and the following anatomical structures: (a) point of entry of the musculocutaneous nerve and its branches into the coracobrachial muscles and into the short head of the biceps brachii muscle; (b) acromial artery; (c) lesser tubercle of the humerus. METHOD Thirty shoulders of fresh cadavers, without any kind of shoulder pathology, (9 males and 6 females) were dissected, and the distances (in mm) were measured between the anatomical structures defined above and the apex of the coracoid process. RESULTS The mean distance between the apex of the coracoid process and the musculocutaneous nerve was 49.2 mm (in all specimens a proximal branch of the nerve was identified 34.2 mm away from the apex of the coracoid process), which was not significantly different between the sexes or body sides; the mean distance between the apex of the coracoid process and the acromial artery was 12.4 mm, which was not significantly different between the sexes or body sides; the mean distance between the apex of the coracoid process and the lesser tubercle of the humerus, with the humeral head under internal rotation, was 10.6 mm in men and 8.6 mm in women, values that were significantly different between the sexes. DISCUSSION In women, the smaller distance between the apex of the coracoid process and the lesser tubercle of the humerus in the arm internal rotation suggests a higher chance of impingement between those bone structures among the female sex.

Osteoarticular complications related to HIV infection and highly active antiretroviral therapy

With the significant increase in life expectancy for HIV-infected patients in the era of high potency antiretroviral therapy, major metabolic changes have been observed due to the prolonged period of the viral infection and the treatment itself. Osteoarticular changes resulting from these processes are mainly reported in long term HIV-infected patients receiving high potency antiretroviral therapy and include osteopenia/osteoporosis, osteonecrosis, carpal tunnel syndrome and adhesive capsulitis of the shoulder.

PROCEDIMENTO DE LATARJET ARTROSCÓPICO: AVALIAÇÃO DA SEGURANÇA EM CADÁVERES

OBJECTIVE: To evaluate the safety of arthroscopic Latarjet procedure in cadavers. METHODS : Twelve cadaveric shoulders underwent arthroscopic Latarjet procedure in our laboratory for arthroscopy, by four different surgeons. Following surgery, the specimens were subjected to radiographic examination and evaluated by an independent examiner. Nineteen parameters were evaluated, including the coracoid graft fixation, positioning and angulation of the screws, neurological damage and integrity of tendons. RESULTS : Four procedures were considered to be satisfactory, with no difference among the surgeons. The mean angulation of the screws was 27.2°. The subscapularis splitting was, on average, 17.8mm from the upper edge. The coracoid graft was properly positioned relative to equator of the glenoid in 11 cases. There was no injury to the axillary or musculocutaneous nerves. The main complications were: interposition of soft tissue, suprascapular nerve injury, articular deviation of the graft, diastasis and conjoined tendon injury. CONCLUSION : The arthroscopic Latarjet procedure is a complex technique in which each step must be precise to reduce the risk of complications. Our study showed a high risk of failure of the procedure. Level of Evidence IV, Case Series.

PLATELET-RICH PLASMA IN ARTHROSCOPIC REPAIRS OF COMPLETE TEARS OF THE ROTATOR CUFF.

Objective: To evaluate shoulder functional results and the retear rate of arthroscopic repair of the rotator cuff augmented with platelet-rich plasma (PRP).Methods: Prospective case series with single-row arthroscopic repair of the rotator cuff augmented with PRP. Only cases of isolated supraspinatus tears with retraction of less than 3 cm were included in this series. The PRP used was obtained by apheresis. It was applied on liquid consistency in its activated form, with the addition of autologous thrombin. Patients were evaluated after 12 months of the surgical procedure. The Constant-Murley, UCLA and VAS scales were used, and the retear rate was assessed using magnetic resonance imaging (MRI). Results: Fourteen patients were evaluated (14 shoulders). The mean Constant-Murley score was 45.64 ± 12.29 before the operation and evolved to 80.78 ± 13.22 after the operation (p < 0.001). The UCLA score increased from 13.78 ± 5.66 to 31.43 ± 3.9 (p < 0.001). The patients’ pain level decreased from a median of 7.5 (p25% = 6, p75% = 8) to 0.5 (p25% = 0, p75% = 3) (p = 0.0013) according to the VAS score. None of the patients presented complete retear. Three patients (21.4%) showed partial retear, without transfixation. Only one patient developed complications (adhesive capsulitis). Conclusion: Patients submitted to arthroscopic rotator cuff repair augmented with PRP showed significant functional improvement and none of them had complete retearing.

RESULTS FROM FILLING “REMPLISSAGE” ARTHROSCOPIC TECHNIQUE FOR RECURRENT ANTERIOR SHOULDER DISLOCATION

Objective: To evaluate the clinical result from the filling (“remplissage”) technique in association with Bankart lesion repair for treating recurrent anterior shoulder dislocation. Methods: Nine patients (10 shoulders), with a mean follow-up of 13.7 months, presented traumatic recurrent anterior shoulder dislocation. All of them had a Bankart lesion, associated with a Hill-Sachs lesion showing the “engaging” sign. The Hill-Sachs lesion defect was measured and showed an average bone loss of 17.3% (7.7% to 26.7%) in relation to the diameter of the humeral head. All the cases underwent arthroscopic repair of the Bankart lesion, together with filling of the Hill-Sachs lesion by means of tenodesis of the infraspinatus. Results: The Rowe score ranged from 22.5 (10 to 45) before the operation to 80.5 (5 to 100) after the operation (p > 0.001). The UCLA score ranged from 18.0 (8 to 29) to 31.1 (21 to 31) (p > 0.001). The measurements of external and internal rotation at abduction of 90° after the operation were 63.5° (45° to 90°) and 73° (50° to 92°) respectively. Two patients presented recurrence (one with dislocation and the other with subluxation). None of the patients presented pain in the region of the infraspinatus tendon after the operation. Conclusion: Over the short term, the filling (“remplissage”) arthroscopic technique produced improvements in functional scores and a low complication rate when used for treating glenohumeral instability associated with Hill-Sachs lesions.

Tratamento artroscópico da luxação acromioclavicular aguda com âncoras

OBJETIVO: Apresentar os resultados clinicos e radiograficos de uma serie de casos com diagnostico de Luxacao Acromioclavicular (LAC) Aguda, tratados atraves da fixacao coracoclavicular com âncoras por via artroscopica. METODO: Vinte pacientes apresentando LAC com menos de 30 dias de evolucao foram operados pela tecnica da estabilizacao coracoclavicular com âncoras por via artroscopica. Duas âncoras metalicas com dois fios cada, foram inseridas no coracoide. Os fios foram amarrados sobre a clavicula passando por tuneis transosseos claviculares. Para a avaliacao radiografica, foi utilizada a medida comparativa da distância coracoclavicular com o lado contralateral e a avaliacao funcional atraves dos escores de Constant e UCLA o seguimento foi de seis meses. RESULTADO: Dos vinte casos inicialmente selecionados, seis necessitaram de novo procedimento cirurgico e foram excluidos do estudo. Dos quatorze pacientes restantes, apenas dois mantiveram reducao da articulacao acromioclavicular, enquanto os demais apresentaram algum grau de desvio no decorrer da evolucao. Desconsiderando os pacientes excluidos, os escores de Constant e UCLA tiveram media 94,79 (82-100) e, 32,64 (26-35), respectivamente. CONCLUSAO: A tecnica apresentou um alto indice de perda da reducao ao longo da evolucao de seis meses. A avaliacao funcional apresentou resultado satisfatorio com escore medio elevado de Evidencia: Nivel de Evidencia: Nivel III, estudo retrospectivo.

Lipoma arborescens: rare case of rotator cuff tear associated with the presence of lipoma arborescens in the subacromial-subdeltoid and glenohumeral bursa

Lipoma arborescens is a rare intra-articular disease that is usually monoarticular and is characterized by extensive proliferation of the synovial villi and hyperplasia of the subsynovial fat. The synovial tissue is progressively replaced by mature fat cells in the synovial membrane. The present study reports a case of a rare condition of lipoma arborescens that was simultaneously intra-articular (glenohumeral joint) and in the subacromial-subdeltoid bursa, in association with a torn supraspinatus tendon. The clinical, histological and radiographic presentations and treatment are discussed here. The description of this case includes radiographic and magnetic resonance evaluations and pathological examination. Although lipoma arborescens is a rare condition, it should be taken into consideration in cases presenting synovial hyperproliferation and synovial fat replacement.

Lipoma arborescens: caso raro de ruptura do manguito rotador associado à presença de lipoma arborescens na bursa subacromial-subdeltoidea e glenoumeral

Lipoma arborescens is a rare intra-articular disease that is usually monoarticular and is characterized by extensive proliferation of the synovial villi and hyperplasia of the subsynovial fat. The synovial tissue is progressively replaced by mature fat cells in the synovial membrane. The present study reports a case of a rare condition of lipoma arborescens that was simultaneously intra-articular (glenohumeral joint) and in the subacromial-subdeltoid bursa, in association with a torn supraspinatus tendon. The clinical, histological and radiographic presentations and treatment are discussed here. The description of this case includes radiographic and magnetic resonance evaluations and pathological examination. Although lipoma arborescens is a rare condition, it should be taken into consideration in cases presenting synovial hyperproliferation and synovial fat replacement.

Biomechanical evaluation on tendon reinsertion by comparing trans-osseous suture and suture anchor at different stages of healing: Experimental study on rabbits

BACKGROUND Through an experimental biomechanical study on rabbits, tendon reinsertion by means of trans-osseous suture on a spongy bone bed and suture anchor were evaluated comparatively at different phases of healing. METHODS Twenty-four New Zealand White rabbits were used: 2 as pilots, 4 as the control group, and 18 as the experimental group. These 18 animals underwent sectioning and reinsertion of the Achilles tendon bilaterally, using the technique of trans-osseous suture on 1 side and suture anchor on the other. All the pelvic limbs that underwent the procedure were then immobilized for 3 weeks. The experimental group was divided into 3 groups that were sacrificed, respectively, 3, 6, and 12 weeks later. The tendon-bone complex was subjected to biomechanical tests to evaluate the parameters of maximum strength, stiffness, and yield strength. RESULTS There was no statistically significant difference between the suture anchor group and the trans-osseous suture group, in relation to yield strength (3 weeks, P = .222; 6 weeks, P = .465; and 12 weeks, P = .200) or maximum strength (3 weeks, P = .222; 6 weeks, P = .076; and 12 weeks, P = .078). In relation to stiffness, the suture anchor group showed a statistically significant difference only at 3 weeks of healing (P = .032) over the trans-osseous suture group. CONCLUSION The technique of suturing with an anchor was shown to be similar to the technique of trans-osseous suture for the studied parameters.