Arthroscopy of the wrist and small joints was born in the 1980s, although the first publication appeared in 1979 [1] and developed later in the 1990s. The European group of arthroscopy (EWAS—European Wrist Arthroscopy Society) was founded on 15 March 2005, by a group of friends who shared the same passion: Da Rin, Levadoux, Martinache, Rigault Mouton, Samson, Dumontier, Mathoulin, Moreel, Tchenio, Limousin, Cousin, Messina, Wilson, Amin, Fontes, Roure, Haerle and Lingo, Camps, with the collaboration of J. Dupuy (Storz). The first president of the group was Christian Dumontier and the first secretary Christophe Mathoulin [2]. Currently the members of the company are about 450 around the world, indicating that this technique is increasingly relevant in the wrist-hand surgery. The realization of increasingly small and sophisticated tools simplified the techniques and led to new endoscopic surgeries.

The system uses dedicated tools, such as optical ranging from 1 to 2.7 mm. They are positioned a 30° obliquity in order to get a broader view of the area. The optical fibre enters the trocar; together they have a length of 8–10 cm. It has two adjustable valves for the entry and exit of water. The motorized instruments have a thickness which spans from 1.2 to 2.7 mm. Not only the palpators are small in the apex—1/2 mm—but they are also short, in order to bring the hand of the operator close to the patient’s, for better stability. Since we are working in such a small area, very few millimetres can change completely the field of view. Other tools dedicated to specific surgeries were gradually produced, such as baskets with straight, left or right blade, grippers and compasses to dig holes in the bone or to perform reductions of fractures or osteotomies (Fig. 5.1).

Fig. 5.1
figure 1

The basic instruments used in arthroscopy. The camera has a controlled zoom and the possibility to adjust the brightness directly from the surgeon

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When we perform this technique, the patient is positioned supine on the operating table. The limb we must operate is lying on a table located on the side of the bed.

We normally use regional anaesthesia of the axillary plexus. Depending on the intervention, we eventually apply a tourniquet to the root of the limb.

After the sterile field is prepared, we apply a traction which can be vertical or horizontal, depending on the requirements:

  • If the traction is vertical, the arm rests on the table, the elbow is flexed to 90° and the forearm and the hand are in a vertical position.

  • If the traction is horizontal, the arm, forearm, wrist and hand are lying on the table along the same axis and the traction is fixed on the same table.

The pulling tower we use must have certain characteristics:

  1. (a)

    It must be able to be used both horizontally and vertically.

  2. (b)

    It should allow the evaluation of the traction with dynamometers.

  3. (c)

    It should permit the use of X-rays and intraoperative arthroscopy.

  4. (d)

    It must allow the forced and lasting flexion or extension of the wrist.

  5. (e)

    It must allow the transition from pronation to supination and vice versa during surgery.

  6. (f)

    It must be sterilizable.

In our practice, we used the pulley tower Borelli, which had all those characteristics.

Finger tractions are different in structure and material: those can be made of metal or plastic; the spatula-shaped traction can simultaneously grasp all the fingers of the hand, with an interlocking system.

The finger traps all have this same feature: they must tighten their finger during the traction and release them when the traction is removed; they also have to be sterile and sterilizable.

The traction is applied depending on the district that is going to be operated and on the pathology. For example, if you need to work on the thumb for a rhizo arthritis, the traction applies only to this finger. If you want to work on the wrist in all its completeness, the traction will be applied instead on the third and second finger of the hand. The tension also depends on what you must do. Considering the first example, for the thumb, a traction of 1.5 kg in a woman is enough, while for a man, it can even reach 3 kg. In the traction of the wrist, the tension can reach 6–8 kg, but not more than that. The weight of the traction also depends on the duration of the operation.

Normally we use a saline solution that can be injected with or without the pump, normally with gravitational drop. Some operators do not use water, especially in the recent wrist fractures, because the water could expand between the fracture lines. We typically make the first reconnaissance without water. Eventually, by opening and closing the valve of the trocar, we can regulate the flow and pressure.

There are also some tools which are prepared before starting the operation. They are both motorized and radio-frequency devices, both of which have a small size and are specifically made for this type of technique. Needles are also prepared and can be used for minor repairs. Finally, small, curved Klemmer can be used to open the arthroscopic access.

So, once you established where to apply the traction—depending on the pathology to be treated—and how much weight you can apply to the fingers, you can proceed with the surgery.

This technique can be used in several ways:

  1. (a)

    As a diagnostic

  2. (b)

    As intra-articular surgery (removing movable bodies, repairing TFCs, etc.)

  3. (c)

    As an aid to external surgery [3, 4]

It is necessary to establish the anatomic landmarks. Especially at the beginning, it is recommended to draw the landmarks; this can be done with the traction applied. If they are drawn without, they can be changed once the traction is in position.

The most used portal is the 3/4. We begin by drawing Lister’s tubercle: a bone crest placed on the transition area between the long thumb extender and long radial extensor of the carpus. Once the tubercle is located, placing the thumb transversely on this structure, we can distally incise the skin. We can incise transversally, which is more aesthetic or we can incise vertically, which allows near-distal corrections or vice versa, in case the joint is not well-centred. Before the incision, we can reach with a needle the articular space and inject water. The water, by widening the joint, will favour the entry of the arthroscopic trocar (Fig. 5.2).

Fig. 5.2
figure 2

We can see portal 3/4, distally from Lister’s tubercle. (Adapted with permission from Adravanti P, Denti M, Mazzola C, Randelli P, Zorzi C. Artroscopia Base ed Avanzata. Rome: CIC Edizioni Internazionali)

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The entrance follows certain rules, which are shown in Fig. 5.3.

Fig. 5.3
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The arthroscopic introduction in the radio-carpal through portal 3/4. (a) The first step is to locate Lister’s tubercle (TL), the extensor digitorum communis (EDC) and the extensor pollicis longus (EPL). (b) We lean with the thumb on the tubercle and, 1–1.5 cm distally, we locate the articular space of the portal 3/4. (c) It is possible, especially at the beginning, to use a guide needle with water, which helps to open wide the joint. (d) Incision of the skin, in this case transversely. (e) Entrance with a curved Klemmer which is best suited to go around the epiphysis of the radius. (f) At this point we enter with the trocar and, leaving the sheath, (g) we enter with the arthroscope. (Reproduced with permission from Adravanti P, Denti M, Mazzola C, Randelli P, Zorzi C. Artroscopia Base ed Avanzata. Rome: CIC Edizioni Internazionali)

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Portals are different and they all have a function, depending on what you need to see and what you need to do. Some portals allow the optical fibre vision, while others allow the entrance with appropriate tools and to perform the designed operation. We will now analyse every portal, and for each one, we will describe what can be seen in the condition of anatomical normality. As you will see, they are named referring to the nearby anatomical structures, especially tendons. It should be considered that these portals are interchangeable between optic fibre and instrumentation and are used for both [5]. For the description of the ligaments, you can refer to (Fig. 5.4).

Fig. 5.4
figure 4

The volar (a) and dorsal (b) ligaments are illustrated in this drawing. It is highlighted how there is a conjunction between the two chains of the carpal on the radius, with a vertex on the capitate. Dorsally the connection is between the radius and triquetrum with passing on the lunate. There is a ligament that, from the triquetrum, crosses transversally all the carpal bones; the vertex is precisely on the triquetrum. All of it is for a complete stability of the radio-ulnar-carpal ensemble. (Adapted with permission from Adravanti P, Denti M, Mazzola C, Randelli P, Zorzi C. Artroscopia Base ed Avanzata. Rome: CIC Edizioni Internazionali)

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5.1 Dorsal Portals

5.1.1 Portal 1/2

By this portal we can access the radio-carpal joint radially. It then passes between the first (AbLP and EBP) and the second (ERCL and ERCB) dorsal channels. There are some precautions to locate it: we must remember that the styloid is raised to about 10° between the two radial and ulnar limits; therefore we are not on the same line as the portal 3/4, but somewhat more distal. We also must consider the dorso-volar angle of about 15° to position the arthroscope. We are in an anatomical area that presents the radial artery that leads to the anatomical snuffbox and the sensory branch of the radial nerve. It is therefore advisable to stay close to the carpal extensors. We can observe the scaphoid up to its distal recess, the styloid and radio-carpal ligaments radial from the styloid. In front of us we see the radius-scaphoid-capitate ligaments (RSC), the long radio-lunate ligament (RLL) and, closer to the ulna, the radius-scaphoid-lunate ligament (RSL or ligament of Testut) originating from the anterior limit of the radius. Between the RSC and RLL ligaments, there is a space which is often the origin of the cysts of the pulse. Beyond this space we meet the carpal flexion tendon (FCR). By turning the optic fibre, you can see all the radio-carpal dorsal capsules.

5.1.2 Portal 3/4

It is the most used portal because of its central position into the wrist. This gives us a good overview for the initial evaluation of the radio-carpal. This portal is thus accessed in the beginning of wrist arthroscopy.

Once entered, we face the long radius-scaphoid-lunate ligament (RSL) or ligament of Testut. The ligament continues with the scaphoid-lunate ligament in its volar part. From here with the palpator, we can test its endurance. We can also note the crest which separates the scaffold of radius from the semilunate of the radius. In the direction of the radius, we will see the same ligaments we saw in portal 1/2 and the radial face of the scaphoid. Moving in the direction of the ulna, on the volar side, we meet the short radiolunate ligament (RLC). This ligament has an oblique radial part which forms an inverted “V” with the RLL. The apex of the V—still in the volar part—meets the scaphoid-lunate (SL). Continuing in the ulnar side, we see the triangular ligament with some of its components:

  • The insertion on the radius: it’s difficult to see with the optical fibre, although you can palpate it.

  • The palmar radio-ulnar ligament: it’s the main stabilizer of the triangular ligament on the volar side.

Then we see the ulno-lunate (UL) and ulno-triquetrum (UT) ligaments. Between the two of them, we should be able to identify the ligament ulno-triquetrum-capitate (UPC), also called ulno-capitate (UC). It forms a “V” with the ligament RSC. On the apex of the “V”, there is the capitate. The two of them stabilize the two chains in the volar side. The UPC ligament seems to be a more superficial reinforcement than the ligament UP. Therefore, it is not visible from the inside of the joint. We can see the carpal surface of the pyramid until the prestyloid recess and the interosseous luno-triquetrum ligament. This also must be palpated to test its stability.

5.1.3 Portal 4/5

This portal is placed between the extensor digitorum (ED) and the extensor digiti minimi (EDM). This is usually a small space. It is therefore advisable to stick to the ulnar margin of the ED, because it is the most evident upon palpation. This is not particularly difficult; the intra-articular vision is better in the ulnar sector. We will have a good view of the insertion of the triangular ligament on the radius and of the ligaments and bone surfaces we saw in the compartment 3/4. By turning the optic fibre, we can observe the dorsal part of scaphoid-lunate and its continuity on the dorsal capsule. Pushing the optic fibre a little to the volar direction, you can get to the pisiform-triquetral articulation and pre-styloid ulnar recesses.

5.1.4 Portal 6R

This portal is located on the radius side of the tendon of extensor carpi ulnaris (ECU). It is placed distally to the triangular ligament. Therefore, the reference for the entry point is the ulnar styloid, not the epiphyseal edge of the ulna. With this portal, we can observe very well:

  • The triangular ligament in all its length, the UL and UP ligaments.

  • The pre-styloid recesses and pisiform-triquetral articulation can be viewed in their entirety.

  • The semilunar fossa of the radius.

  • The surface of the lunate and of the triquetrum up to the distal ulnar apex.

  • The ulnocarpal ligaments

  • The interosseous luno-triquetral ligament.

  • Also, by lowering proximally, we can see the space below the triangular ligament, between the caput ulnae and the triangular ligament.

5.1.5 Portal 6U

This portal is placed ulnarly compared to the ECU tendon. It presents the risk of damaging the ulnar dorsal sensory nerve which passes near this entrance. It is therefore advisable to stay adherent to the tendon. This practice does not eliminate completely the risk of iatrogenic injury. Then, it is also advisable to make an incision of 1 cm, staying more superficially than the tendon. After that we will divaricate with a chamfer tool the skin until we reach the vicinity of the tendon. Only then we will use the trocar to enter the joint. The part we can better observe with this entry is the triangular ligament. It is also visible in its dorsal part with the radio-ulnar distal dorsal ligament (RUDD) and the radio-ulnar distal palmar ligament. They both lead to the fovea at the base of the ulnar styloid and give stability to the distal radio-ulnar joint.

5.2 Medio-carpal Radial (MCR) Portal

This portal is located approximately 1 cm distally from the portal 3/4. It forms an angle with the horizontal, from top to bottom and from dorsal to volar, of about 15°. In addition, the range of extensors tends to widen distally. Therefore, if we climb vertically from the portal 3/4, we can damage the tendon of the second finger of the extensor digitorum. It is therefore advisable to take as a reference the metacarpal phalngeal (MF) of the second finger and draw a line with the entry of the portal 3/4. We must then palpate the tendon and, keeping ourselves close to it, penetrate the joint. We are now in the medio-carpal, in the space between the scaphoid and lunate, above the round face of the capitate. In front of us there is the RSC ligament. Ulnarly we can observe the distal face of the lunate, the space between the lunate and triquetrum and the distal articular surface of the triquetrum. By moving distally around the proximal pole of the capitate and volarly from the UPC ligament, we are able to identify the articulation between the triquetrum and hamate. From the radial side, we can see the entire distal surface of the scaphoid until the scaphoid-trapezium-trapezoid (STT).

5.2.1 Midcarpal Ulnar Portal (MCU)

The portal is placed at 1–1.5 cm distally from the portal 4/5. We will perform the same operation we did for MCR portal. This time we will mark the line which connects the entrance point 4/5 with the epiphysis of the fifth metacarpal in a depression between the trapezium and the hamate. The direction is the same: inclined from dorsal to volar and from distal to proximal of about 15°. We are at the meeting of the four defined corners for the arthrodesis (four corners). It is more difficult to see the STT. We can see instead the distal articular surface of the trapezium, the semilunar and the scaphoid. We can also see so the interposed ligaments (scaphoid-lunate and triquetrum-lunate). Distally we can follow the proximal pole of the capitate. Volarly we identify the UPC ligaments in the portion triquetrum-capitate, which meet in the inverted “V” with the RSC. We can see the space between the triquetrum, the semilunar, the capitate and the hamate, until the hook of the hamate.

5.2.2 Anterior Portals

Recently, surgeons have developed volar portals to view the articulation from palmar to dorsal, especially to see in full the S-L and L-P ligaments in their entirety.

We can also use them to see dorsal ligaments and for some surgeries. Volar portals have also been used for a long time in case of repair of wrist fractures with the use of volar plaques. In this case the access did not require any caution, being open-air surgery.

5.2.3 Volar Radial Portal (VR)

This is a portal which has been used recently and is performed, according to Slutsky [6], by incising the skin over the FCR tendon. Then, once located, we move it either medially or laterally, and we access below the tendon itself. We prefer to access in another way: before surgery, if we want a volar access, by using the Doppler scan, we locate the radial artery and mark it on the skin. We mark, then, the FCR tendon. We prepare the traction, and through the portal 3/4, we locate the space between the RSC and RLL and we place the optic fibre in the established point. We remove the optics leaving the trocar sheath, with a switching stick we enter the sheath and, with the optic placed on another radio-carpal portal, we observe. We push the stick ulnarly to the FCR tendon, which is usually the safest passage (Fig. 5.5). With this portal, we can see the scaphoid-lunate ligament in its front portion and the triquetrum-lunate with all the carpal bone surfaces of the scaphoid and of the semilunar. The triquetrum vision is a bit more difficult, because there is the pisiform which blocks the motility of the optic fibre. We can see the articular surface of the radius, with the crest and the two articular faces: one for the scaphoid and one for the lunate, the radio-lunate-triquetrum (RLP) ligament. We can also see the triangular ligament in its insertion on the radius with its inferior radial lateral ligament (RUID), which is the other stabilizing component of the triangular ligament.

Fig. 5.5
figure 5

In this anatomic cross-section the structures and portals are reported, in A of the radio-ulno-carpic and in B the medium-carpic. The portals of the trapezium-metacarpal, the distal radio-ulnar and the radio-ulno-carpal portal are not reported here. The pisiforme is not evident. (Adopted from Atzei A, Luchetti R, Sgarbossa A, Carità E, Llusàc M. Installation, voies d’abord et exploration normale en arthroscopie du poignet. Chirurgie de la Main. 2006;25:S131–44)

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5.2.4 Ulnar Volar Portal (VU)

The entrance technique is the same as the in-out, but this time the landmark is the tendon of the flexor carpi ulnaris (FCU), the ulnar artery and the ulnar nerve. Another landmark is the pisiform. Slutsky [7], on the other hand, uses a more medial approach by using the flexor digitorum superficialis as a reference point: once isolated and moved radially, he passes behind it, thus entering the articulation. With this portal, we see better the ulnar compartment, especially the LP ligament.

5.3 Portals to STT

5.3.1 STT Portal

We should immediately point out that, in this case, the traction is applied only to the thumb and usually consists of 2–3 kg. It depends on the subject, age and articular condition. Until now we have seen the radio-carpal and intercarpal portals. Now we will see the access portals to STT. The STT-U portal is into the space at the apex of the scaphoid. We must pay attention to the presence of the radial artery and the radial nerve sensory branch. Usually, we use the MCR portal and we move to the apex of the scaphoid. Then we palpate and see with the optics where we are palpating; this way we can understand our external position and introduce a needle. Also in this case, with a preoperative Doppler scan, we can draw the artery on the skin. It is also useful to draw the tendons of extensor pollicis longus (EPL) and extensor pollicis brevis (EBP). Once entered, with the trocar we switch the optics: in this space, we see the distal pole of the scaphoid, the proximal articular surface of the trapezium and the trapezoid. If we must work here, it is useful to use the optics in the MCR portal and the tools in the STT portal. Otherwise we can access from a more volar portal at the base of the thenar, called STT-R portal [8].

5.4 Trapezium-Metacarpal Portals

5.4.1 Trapezium-Metacarpal Radial Portal (TMR, Also Called 1R)

This portal is located radially to the longitudinal axis of the abductor pollicis longus. It allows to view the distal surface of the trapezium, the proximal surface of the metacarpal, the dorsal radial ligaments (DR), posterior oblique ligament (LPO) and ulnar collateral ligament (UCL).

5.4.2 Trapezoidal-Metacarpal-Ulnar Portal (TMU, Also Called 1U)

This portal is located either between the tendon of EPL and EBP or ulnarly to EPL. The radial artery is very close to the portal. In order to avoid it, it is advisable to stay closer to EBP. It shows, as for the 1R portal, the articulations described. We can see them, unlike the 1R, from an ulnar-radial view. The anterior oblique ligament (AOL) and the ulnar collateral ligament (UCL) are highlighted.

There are two more portals which favour a vision of the dorsal portion of this articulation. One is the Orellana portal, bearing the name of the one who used it first, presented in 2003. It is placed more radially and before the 1R, and it is also called 2R. The other was developed by Slutsky in 2007. It passes between the first and second metacarpals and reaches the trapezium-metacarpal, highlighting the dorsal surface of this articulation and the carpal ligament. It is called 2D.

5.5 Radio-ulnar Distal (RUD) Articulation Portals [9, 10]

Returning dorsally, we can use some portals to highlight the radio-ulnar distal articulation. It is raising increasingly more interest because of the evaluation of the stability and because of the view of the triangular ligament from the proximal part and the sigmoidal articulation.

5.5.1 Radio-ulnar Distal Lower (RUDL) Portal

This portal is identified by looking for the articulation between the radius and ulna. It is placed at about 0.5–1 cm from the 6R portal, slightly more radicalized. If finding it proves difficult, we can use the portal 3/4. We palpate the end of the triangular ligament on its insertion to the radio. Below there is the Distal radio-ulnar joint (RUD) at 0.5, which is the thickness of the triangular ligament. With this portal, we can see the proximal part of the triangular ligament, the entire articulation surface of the epiphysis and the insertion into the fovea of ​​the deep part of the triangular ligament. From the radial side, we can see the sigmoid depression of the radius. A practical aspect should be considered: a vertical traction is useful to view the deep part of the triangular ligament; too much traction, on the other side, closes the distal radio-ulnar joint.

5.5.2 Proximal Lower Radio-ulnar Portal (PLRUP)

This portal is about 1–1.5 cm below the RUDL portal, on the same direction. It is used to work on the RUD articulation, between RUID and RUIP. It views the proximal part of caput ulnae and the proximal face of the sigmoid radial surface. In conclusion, it views the RUD articulation, more proximally.