The comparison of freehand fluoroscopic guidance and electromagnetic navigation for distal locking of intramedullary implants

INTRODUCTION

In locking intramedullary nails, the most important problem is to put the distal interlocking screw accurately and quickly with minimum radiation exposure. The purpose of this clinical study was to compare the fluoroscopic time and surgical time required for distal locking with either free-hand fluoroscopic guidance or with an electromagnetic navigation system.

MATERIALS AND METHODS

The study comprised 54 patients with 58 fractures of the lower extremity. The patients were divided in two groups: distal locking with freehand fluoroscopic guidance (group I) and distal locking with electromagnetic navigation (group II). The primary outcome in this study was fluoroscopy time. The secondary outcome was the operative time in distal interlocking.

RESULTS

In group I, the mean operation time was 108 (81-135) min, the mean time for distal interlocking was 18.35 (9-27) min, the total fluoroscopy time was 47.77 (19-74) s, the mean fluoroscopy time during distal interlocking was 18.29 (2-29) s and the mean attempt at number of distal locking for two screws was 9.96 (2-18) times. In group II, the mean operation time was 80.96 (63-100) min, the mean time for distal interlocking was 7.85 (6.5-10) min, the total fluoroscopy time was 22.59 (15-32) s, the mean fluoroscopy time during distal interlocking was 1.62 (0-2) s and the mean attempt number of distal interlocking was 2 (2-2).

CONCLUSION

Fluoroscopy time to achieve equivalent precision is significantly reduced with electromagnetism-based surgical navigation compared with free hand fluoroscopic guidance. Also the operative time is significantly reduced with electromagnetic based navigation.

Compression of common peroneal nerve caused by an extraneural ganglion cyst mimicking intermittent claudication

Peripheral neuropathies caused by ganglion cysts are rare. They seldom cause serious complications especially in the lower extremities. The case was a 51-year-old woman referred by her physician to the vascular surgeon with diagnosis including intermittent (vascular) claudication and deep venous thrombosis. Primarily vascular surgeon performed a doppler ultrasound of the lower extremity and calculation of the ankle-brachial index. There were no abnormal pathological findings. Careful physical examination revealed soft swelling and tenderness around the fibular head and neck. Weakness was observed in foot eversion and dorsiflexion. There was pain and tingling in the distribution of the peroneal nerve. and referring the patient to orthopedic surgeon owing to concern for a potential compressive lesion at the right proximal tibiofibular region. Electromyogram studies and physical examination confirmed a diagnosis of compression neuropathy of common peroneal nerve. Magnetic resonance imaging revealed a fluid-filled, lobulated mass indicating a ganglion cyst. One months after decompression, the patient had no complaint. Fast diagnosis and immediate management are essential to regain best possible recovery.

Urotensin II (U-II), a novel cyclic peptide, possibly associated with the pathophysiology of osteoarthritis

Synovial fibrosis is one of the main outcomes of osteoarthritis. Some authors have reported that urotensin-II (U-II) may cause pathologic fibrosis in cardiovascular system, lung and liver. However there are no previous reports available in the literature about its relationship with the synovial fibrosis in osteoarthritis. The aim of this study was to compare the U-II levels in knee synovial fluids obtained from osteoarthritic and non-osteoarthritic patients. Two groups were created, the osteoarthritis group and non-osteoarthritic control group. The control group was consisted of patients who underwent arthroscopic surgery for other reasons than cartilage disorders. In the osteoarthritis group all patients had grade 4 primer degenerative osteoarthritis and were treated with total knee arthroplasty. Minimum 1 mL knee synovial fluids were obtained during operation. Levels of U-II were measured by using ELISA kit U-II levels were significantly higher in the osteoarthritic group than that in the control group. No correlation was found between U-II levels and age. In conclusion, the significantly high U-II levels in the knee synovial fluid of osteoarthritic patients supported our hypothesis that "U-II may be associated with the synovial fibrosis in osteoarthritis".

A new anchor augmentation technique with a cancellous screw in osteoporotic rotator cuff repair: an in vitro biomechanical study on sheep humerus specimens

PURPOSE

The aim of this study was to test a simple technique to augment the pullout resistance of an anchor in an over-drilled sheep humerus model.

METHODS

Sixty-four paired sheep humeri were harvested from 32 male sheep aged 18 months. Specimens were divided into an augmented group and non-augmented group. FASTIN RC 5-mm titanium screw anchors (DePuy Mitek, Raynham, MA) double loaded with suture material (braided polyester, nonabsorbable USP No. 2) were used in both groups. Osteoporosis was simulated by over-drilling with a 4.5-mm drill. Augmentation was performed by fixing 1 of the sutures 1.5 cm inferior to the anchor insertion site with a washer screw. This was followed by a pull-to-failure test at 50 mm/min. The ultimate load (the highest value of strength before anchor pullout) was recorded. A paired t test was used to compare the biomechanical properties of the augmented and non-augmented groups.

RESULTS

In all specimens the failure mode was pullout of the anchor. The ultimate failure loads were statistically significantly higher in the augmented group (P < .0001). The mean pullout strength was 121.1 ± 10.17 N in the non-augmented group and 176.1 ± 10.34 N in the augmented group.

CONCLUSIONS

The described augmentation technique, which is achieved by inferior-lateral fixation of 1 of the sutures of the double-loaded anchor to a fully threaded 6.5-mm cancellous screw with a washer, significantly increases the ultimate failure loads in the over-drilled sheep humerus model.

CLINICAL RELEVANCE

Our technique is simple, safe, and inexpensive. It can be easily used in all osteoporotic patients and will contribute to the reduction of anchor failure. This technique might be difficult to apply arthroscopically. Cannulated smaller screws would probably be more practical for arthroscopic use. Further clinical studies are needed.

Liberação percutânea do dedo em gatilho com micro bisturi oftalmológico vitreorretiniano de lâmina 19

OBJETIVO: Desenvolver uma nova técnica de liberação percutânea do dedo em gatilho, usando microbisturi oftalmológico vitreorretiniano (MVR) de lâmina 19. MÉTODO: O tratamento conservador do dedo em gatilho inclui, com frequência, injeção local de esteroide. Esse método apresenta alta taxa de falha, sendo necessárias injeções repetitivas. Quando o tratamento conservador falha, recomenda-se a liberação a céu aberto da polia A1. Foram relatados vários métodos que empregam diversos instrumentos. Usamos um microbisturi oftalmológico vitreorretiniano (MVR, de microvitreoretinal blade) de lâmina 19 na liberação percutânea do dedo em gatilho. RESULTADOS: Liberamos 50 dedos em gatilho por via percutânea com essa lâmina. CONCLUSÃO: Foram obtidos resultados satisfatórios em 45 deles (90%). Nivel de Evidência VI, série de casos.