Arthroscopic Diagnosis of Carpal Ligament Injuries with Distal Radius Fractures

Published on 18/03/2015 by admin

Last modified 22/04/2025

Print this page

This article have been viewed 2936 times

CHAPTER 45 Arthroscopic Diagnosis of Carpal Ligament Injuries with Distal Radius Fractures

Carpal ligament injuries have been found in association with distal radius fractures (Fig. 45-1)¹^–³ and with scaphoid and other fractures (Fig. 45-2).^4,⁵ In contrast to these injuries, which sometimes are radiographically visible, there are other associated soft tissue injuries involving the median nerve, the radial artery (Fig. 45-3), or flexor tendons with ruptures. In addition, numerous articles have highlighted the extent of associated cartilage and ligament injuries with displaced distal radius fractures, especially in nonosteoporotic individuals.⁶^–¹⁰ These injuries occasionally can be found with fluoroscopy or magnetic resonance imaging,¹¹ but are most often found when the distal radius fracture is managed with wrist arthroscopy as an adjunct.

FIGURE 45-1 A and B, Scapholunate dissociation found before and after treatment of displaced distal radius fracture.

FIGURE 45-2 Scapholunate dissociation found in association with a distal ulnar fracture.

FIGURE 45-3 A to D, Dorsally dislocated distal radius fracture, which after manipulation still had an unacceptable displacement. E, At open reduction with a palmar approach, the radial artery was injured and interposed in the fracture.

There has been a tendency to overlook these injuries, in contrast to the awareness of similarly important injuries in the lower extremity (Fig. 45-4). To minimize the impact of missed associated injuries, we have to improve our knowledge about them and improve our management of distal radius fractures. We should try to define, classify, and treat the devastating “syndesmosis” injuries of the wrist as soon as possible (Fig. 45-5).

FIGURE 45-4 Syndesmosis injury in an ankle without fracture. This devastating ligament injury is defined and classified and receives full treatment and attention in the orthopaedic community.

FIGURE 45-5 “Syndesmosis” injury of the wrist with an undetected, untreated ulnoradial ligament (peripheral triangular fibrocartilage complex) tear where the signs of the healed distal radius fracture can be seen.

Assessment and Decision Making for Associated Injuries

Injuries associated with distal radius fractures should be looked for at least at the following opportunities when the fracture is reviewed and management is discussed:

1. At the time of the fracture when the initial radiographs are reviewed

2. At the fracture clinic during the first week

3. At the fracture clinic at the 10- to 14-day follow-up

4. At the time of surgical treatment

5. At a later follow-up about 3 months after the fracture

At the Time of the Fracture When Initial Radiographs Are Reviewed

There is an obvious difference between patients and their needs, which can be clearly seen already at the initial presentation, where a range of associated, but preexisting conditions can be found (Fig. 45-6). Sometimes the associated injuries are obvious, but in most situations the soft tissue injuries are not evident at all (Fig. 45-7). We then either have to find them or have to exclude that such associated injuries exist.

FIGURE 45-6 A and B, Preexisting rheumatoid arthritis (A) and osteoarthritis (B) at the initial presentation of a distal radius fracture. Knowledge of preexisting problems helps the orthopaedist understand how to manage the acute fracture.

FIGURE 45-7 A, Trans-styloid perilunate dislocation with all the signs of the Mayfield chain of intercarpal ligament injuries. B and C, Distal radial fracture at the initial presentation (B) and with stress views reflecting an ulnoradial ligament injury (C).

At the Initial Presentation, at the Fracture Clinic during the First Week, and at the 10- to 14-Day Follow-up

The radiographs should always be reviewed with the utmost scrutiny regarding degree of displacement, including the ulnar styloid fracture, which may indicate an ulnoradial ligament detachment (peripheral triangular fibrocartilage complex [TFCC] injury) (Fig. 45-8). The three carpal arcs of Gilula¹² (Fig. 45-9), which are indicative of intercarpal ligament injury, always should be checked.

FIGURE 45-8 A, Ulnar styloid fracture at the base, which may represent a destabilizing ulnoradial ligament tear causing instability of the distal radioulnar joint. B, The ulnar styloid is avulsed in a radial direction as a sign of involvement of the ulnoradial ligament being attached to the avulsed ligaments like two reins.

FIGURE 45-9 The three carpal lines of Gilula (arrows), which, if disrupted, reveal an intercarpal ligament injury.

The most important prognostic factor for a bad outcome after distal fractures is the ulnar-positive variance ¹³; there is a 2.5 times increased risk for a bad outcome in nonosteoporotic individuals if the ulnar-positive variance is more than 2 mm. An ulnar-positive variance more than 2 mm also has been shown to give a 3.9 relative risk (95% confidence interval 1.1 to 13.3; P = .01) of a grade 3 to 4 scapholunate (SL) ligament injury (Lindau classification system).^7,¹⁴

The second most important prognostic factor is articular involvement; an intra-articular incongruency of more than 1 mm leads to osteoarthritis).¹⁵ An intra-articular fracture also has been shown to be a potentially important factor for a poor outcome in nonosteoporotic patients.¹³ Fractures that have a partial intra-articular (AO type B) or combined extra-articular and intra-articular involvement (AO type C) have been shown to increase the risk for a Lindau grade 3 to 4 SL ligament injury^7,¹⁴ at the time of injury and to increase the risk for radiographic dynamic or static SL dissociation 1 year after the trauma.¹⁴

Patient age, metaphyseal comminution of the fracture, and ulnar variance have been shown to be the most consistent predictors of radiographic outcome.^13,¹⁶ Dorsal angulation and radial length have not been shown to be associated with a bad outcome,^13,¹⁶ which may explain why the AO and Frykman classifications¹⁷ have failed to correlate with the outcome.¹⁸

An evidence-based algorithm can be very helpful in managing distal radius fractures (Fig. 45-10), where the search for associated injuries is added to the general decisions regarding management of the fracture. There is a special emphasis in the algorithm on the differences between nonosteoporotic and osteoporotic patients.¹⁹ The differences are in regard to fracture pattern, associated injuries, treatment alternatives, and outcome, which reflect the future need of patients for their wrists after the injury. Initial assessment also should address the potential risks not obvious on an x-ray, where palmarly displaced fragments especially can cause radial artery injuries, flexor tendon ruptures, or median nerve entrapments (carpal tunnel syndrome).

FIGURE 45-10 Evidence-based algorithm with a flow chart for distal radius fractures in adults.

At the Time of Surgical Treatment

If surgical treatment is necessary according to the initial assessments and the pathways of the evidence-based algorithm (see Fig. 45-10), we have the golden opportunity to assess, find, and treat all injured parts of the wrist.

Arthroscopy—the Gold Standard of Detecting and Treating Associated Injuries

If surgery is necessary, there is a paramount reason to consider arthroscopy as an adjunct to the final treatment. General arthroscopic technique is applied with the following guidelines ²:

• Arthroscopy is done after 2 to 5 days.

• Traction of about 2 to 5 kg is applied.

• Swelling distorts the anatomical landmarks for the normal portals.

• Radiocarpal portals are developed around 3-4 (in between the third and fourth extensor compartments).

• Access to the joint is with blunt technique.

• Lavage of the joint and additional shaving to clear out debris are performed.

A standard setup is used with a mobile cart with a monitor at the foot end of the patient. Arthroscopy can be done as either a standard vertical setup or with horizontal arthroscopy,²⁰ which gives the surgeon several options for additional treatment after the initial arthroscopy has been done.

After the joint has been cleared, the arthroscopy-assisted reduction starts by disimpacting the fragments followed by elevating the fragments, securing the reduction with Kirschner wires (K-wires) or percutaneous fixation, and finally verifying the reduction. The joint surface should be reduced by starting with the ulnar fragments because they cause a “double joint incongruency” (i.e., the radiocarpal joint and the distal radioulnar joint [DRUJ]).² Various techniques have been described for special fracture situations.

The final fixation of the fragments can be done with a “closed” reduction of the ulnar fragments with a mini-invasive reduction and percutaneous pinning according to the technique recommended by Geissler and colleagues.²¹ Kapandji intrafocal pinning²² is a useful option in selected cases. Another option is an open reduction of ulnar-sided fractures, which can be part of managing a combined intra-articular and extra-articular fracture. This can be fixed according to the surgeon’s preference with various types of dorsal or palmar plates, including the currently popular locking plates. The final fixation of the extra-articular components of the fracture is facilitated with the horizontal position at the initial arthroscopy, which is converted easily into the final open fixation.²⁰

Ulnar Styloid Fractures May Represent a Destabilizing Injury

Fracture of the ulnar styloid has been found with and without a destabilizing injury to the ulnoradial ligament (peripheral tear of the TFCC).^7,⁹ af Ekenstam and coworkers²³ did not find any statistical difference regarding either redislocation or healing of the styloid or functional outcome of the distal radial fracture. A fracture of the ulnar styloid has not been associated with a development of DRUJ laxity 1 year after the fracture.²⁴ Consequently, an ulnar styloid fracture is not a good indicator for severity, as stated by Frykman,¹⁷ which probably explains why the Frykman classification¹⁷ has failed to correlate to final outcome.¹⁸

Ulnar styloid fracture at its base with initial displacement more than 2 mm should be treated with open reduction and internal fixation (see Fig. 45-7A).^21,²⁵ Use of open reduction and internal fixation is even more important if the dislocation is in a radial direction (detaching the ulnoradial ligament; see Fig. 45-8B) than in an axial, distal direction (detaching the ulnotriquetral collateral ligament; see Fig. 45-7A). The fixation can be done with a single K-wire,^26,²⁷ tension band wiring,²¹ a wire loop/suture,²⁶ or screw fixation.²⁸

Triangular Fibrocartilage Complex Tears Are the Most Common Destabilizing Injuries

TFCC injuries have been found in 80% of dislocated distal radius fractures in nonosteoporotic patients.⁷ They have been associated with shortening (ulna positive) and dorsal angulation of the radius fracture.⁹ The most important of these injuries are the tears to the ulnoradial ligaments (peripheral TFCC tears), which have been shown to cause laxity 1 year after the fracture.²⁴ Peripheral TFCC tears probably should be repaired, which can be done with an arthroscopically assisted technique and reattachment to the fovea (Fig. 45-11).² A central perforation tear of the TFCC is stable and can be débrided with a suction punch (Fig. 45-12).²

FIGURE 45-11 Triangular fibrocartilage complex (TFCC) reattachment with an arthroscopy-assisted technique showing two sutures that have tightened the avulsed ligament. The radius is seen between 6 and 9 o’clock. The lunate is on top between 11 and 1 o’clock. TFCC is between 5 and 9 o’clock with the ulnar side toward the right.

FIGURE 45-12 A, Central perforation tear of the triangular fibrocartilage complex (TFCC). Radius in between 4 and 9 o’clock. TFCC above and the probe lifting the torn membranous disc of the TFCC. Dorsal to the right. B, Débridement with a suction punch of such a lesion. Dorsal to the right.

Scapholunate Ligament Injury Leads to Scapholunate Dissociation

SL ligament tears have been found in 50% of dislocated distal radius fractures in nonosteoporotic patients.⁷ At radiocarpal arthroscopy, the ligament appearance can be assessed, and with comparison of the midcarpal appearance the diastasis and step-off can be measured to classify the grade of SL injury according to Geissler²⁹ or Lindau⁷ (Table 45-1). With this assessment, we have shown that a grade 3 to 4 SL ligament injury (Lindau classification⁷ [see Table 45-1]) that was found at the time of the distal radial fracture, but not treated, leads to radiographic dissociation 1 year after the injury.¹⁴

TABLE 45-1 Classification System for Interosseous Scapholunate and Lunotriquetral Ligament Injuries and Mobility of the Joints

In the absence of prospective randomized studies, it is reasonable to treat grade 3 injuries with reduction of the displaced carpal bones by positioning K-wires in the lunate and the scaphoid. The reduction of the incongruent SL joint is monitored in the midcarpal joint, and the K-wires are secured into the bones. Fluoroscopy can verify the reduction and fixation.² The pins should be kept for 6 weeks.

The results with the arthroscopy-assisted technique are encouraging; Whipple ³⁰ showed that 33 of 40 patients maintained reduction and relief of symptoms if the injury was less than 3 months and the gap was less than 3 mm. In contrast, if there was more than 3 months and more than 3 mm of gap, the improvement occurred in only 21 of 40 patients. Time is consequently of the essence in finding these injuries, and if they are found in time, the results are good in 85% after 2 to 7 years.³⁰ No further long-term studies have been done in this area. Finally, it also seems reasonable to assume that grade 4 injuries, especially injuries with a dissociation already on the trauma films, probably should be treated with an open repair.²

Lunotriquetral Ligament Injuries Are Uncommon

Lunotriquetral ligament tears have been found in 10% of dislocated distal radius fractures in nonosteoporotic patients.⁷ There are no long-term studies in this area, but complete tears with severe mobility (grade 4 [see Table 45-1]⁷) probably have to be pinned for 6 weeks.² Pinning of acute lunotriquetral tears has shown to have a good outcome with 16 of 20 patients excellent or good after years and 18 of 20 with improved grip strength.³¹

Cartilage Injuries Lead to Osteoarthritis

Subchondral hematoma and cartilage avulsions have been found in one third of patients with dislocated fractures among nonosteoporotic patients.⁷ These lesions result in radiographic subchondral bone plate changes and osteoarthritis after 1 year.³² The implication is that subchondral hematoma after injury is a possible explanation of development of osteoarthritis in other joints. There is currently no treatment other than débridement for these injuries. The most tempting, but unproven, option would be the microfracture treatment used in similar injuries in the knee. If found, these cartilage injuries may lead, however, to changes in treatment in the sense that a comminuted intra-articular fracture might be treated with a partial wrist fusion. It also would give the surgeon an awareness of an expected bad outcome.

Other Options at the Time of Surgical Treatment

In the absence of arthroscopy, a fluoroscopic assessment, including stress views, before reduction and fixation is mandatory to plan the surgical approach appropriately. Fluoroscopy is done with examination with an ulnar and radial deviation to see any gapping between the carpal bones. A traction view also may be tried to see whether the Gilula lines ¹² are disrupted. The DRUJ is difficult to assess before the distal radius fracture has been stabilized.

After reduction and fixation of the distal radius fracture, a new assessment of the intercarpal ligaments (see Fig. 45-1) and DRUJ stability (see Fig. 45-7B and C) should be done. The focus should not be on the fracture alone. One should try to avoid overdistracting the soft tissues if external fixation is used (Fig. 45-13), and one should try to understand if a fragment may represent the insertion of a crucial radiocarpal stabilizing ligament (Fig. 45-14).

FIGURE 45-13 Distal radius fracture treated with external fixator in which the emphasis has been on reducing the bony fracture only. Ligamentotaxis is overstretching the radiocarpal and intercarpal ligaments.

FIGURE 45-14 Distal radial fracture with a palmar fragment that was recognized after the initial reduction and external fixation. It represents the important radiocarpal ligament, which causes radiocarpal instability if it is not detected and addressed with open reduction and internal fixation.

At a Later Follow-up about 3 Months after the Fracture

At assessment at approximately 3 months after a moderate to severe distal radius fracture, occasional ache, decreased grip strength at about 50% to 65% of the contralateral hand, and limited range of motion are acceptable. Signs of pain and instability and clicking or clunking of the wrist are unacceptable.

At this stage, one should reassess everything, including all radiographs through the treatment; do a thorough clinical examination; and probably have new x-rays taken. At the clinical examination, one should look for signs of sagging of the hand compared with the distal forearm and look out for a prominent ulnar head (Fig. 45-15). This may represent an avulsed dorsal radiotriquetral ligament causing the sagging lateral view and potentially development of a midcarpal instability. The DRUJ should be examined; the stability test has been shown to be useful and reproducible.³³ Additional radiographs, including stress views such as clenched fist views, should be considered and thereafter possibly arthrography, computed tomography, or magnetic resonance imaging depending on access to these imaging modalities. The final option to understand fully the reasons for complicating symptoms and signs 3 months after a distal radius fracture is to do a wrist arthroscopy.