This is a detailed step by step instruction through the set up and procedure of a diagnostic wrist arthroscopy using the Acumed TM ARC Tower traction system.
Wrist arthroscopy is an expanding speciality and with the improvement in diagnostics with 3T MRI scanning it is being used less for diagnostic procedures and more for definitive surgical interventions.
Diagnostic wrist arthroscopy is an excellent way to become familiar with the procedure and develop skills to advance onto more invasive procedures using wrist arthroscopy.
If a diagnostic arthroscopy is used to confirm a MRI or clinical finding then an further open or arthroscopic procedure can be often performed at the same sitting if the patient has been appropriately consented.
Despite the improvement in MRI scanning and interpretation, wrist arthroscopy is still the gold standard for many conditions although the invasive nature and cost of the procedure certainly has some disadvantages compared with MRI. Conditions particularly difficult to determine on MRI are Luno-triquetral interosseous ligament (LTIL) injuries and injuries causing symptomatic mid-carpal instability. Bony injuries are much better seen on MRI and unlikely to be missed due to the oedema seen in the bone.
Following a diagnostic wrist arthroscopy, patients are usually placed in plaster cast for 1 week for comfort then allowed to mobilise to reduced stiffness. The individual post-operative rehabilitation or further intervention will clearly depend on the arthroscopic findings and patient wishes.
Complications in diagnostic wrist arthroscopy or rare and usually minor however it has been shown that when surgeons are learning this skill, tendon injuries and iatrogenic cartilage injuries are more frequent.
Author: Mr Mark Brewster FRCS (Tr & Orth)
Institution: The Royal Orthopaedic Hospital, Birmingham, UK.
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- Positioning and Preparation:
- joint is distended w/ finger traps (to index and long fingers) w/ about 10 lbs, using a pulley system;
- counter traction is applied to the arm w/ use of a second 10 lb pulley - this allows the elbow to be flexed 90 deg;
- gravity assistant inflow;
- initially inject about 6 cm of lidocaine w/ epinephrine to distend the capsule;
- 2.7 mm or 3 mm wrist scope;
- wrap out the forearm with carefully applied sterile Coband which will help prevent extravasation of fluid from the frx site into the forearm;
- don't forget to mark out the dorsal wrist veins before wraping out and elevating the tourniquet;
- if the veins are transected, a larger portal skin incision will be needed to achieve hemostasis;
- Wrist Portals:
- distraction is not always required for routine wrist arthroscopy;
- in the report by Huracek and Troeger (2000), the authors describe a technique for arthroscopy of wrist which is carried out without traction and with the arm lying horizontally on the operating table;
- wrist is not immobilised, which makes it possible to assess the extent of instability after a ligamentous tear;
- advantages were that the horizontal position of the arm allows the surgeon to proceed directly from arthroscopic diagnosis to treatment, and that no change of position is required for fluoroscopy;
- Wrist arthroscopy without distraction. A technique to visualize instability of the wrist after a ligamentous tear.
- outflow cannula:
- use 14 gauge angiocath;
- placed just ulnar to ECU (6U portal);
- note the proximity of the dorsal ulnar cutaneous branch;
- some surgeons will use this as an outflow portal;
- arthroscopic portal:
- 3-4 portal: (between ECRL and EPL)
- lies 1 cm distal to the Lister's tubercle;
- insert the scope in line with the dorsal radial slope;
- instrumentation portal:
- 4-5 portal: (between EDC and EDQ)
- the arthroscope may be inserted thru this portal inorder to visualize a TFCC tear;
- mid-carpal portal:
- lies in the scaphocapitate interval;
- inserted radial to the third ray, distal to the proximal row, just radial to the EDC to the index finger;
- 1-2 wrist portal:
- may serve as the the inflow cannula;
- lies in the 1-2 wrist portal (between the ECRB and the APL;
- note that the radial artery courses along the volar aspect of this interval;
- the portal should be inserted near the proximal and dorsal portion of the snuff box adjacent to EPL and the ECRL, in order to avoid artery