What Is Midcarpal Instability (Wrist Instability)?

Watson's Test: en.wikipedia.org/wiki/Watson%27s_test

Watson's test is a diagnostic test of the wrist for scapho-lunate instability.

To perform the test, the examiner grasps the wrist with their thumb over the patient's scaphoid tuberosity.

The patient's wrist is then moved from ulnar to radial deviation.

The examiner will feel a significant 'clunk' and the patient will experience pain (even on the normal side). For completeness, the test must be performed to both wrists.

If the scapho-lunate ligament is disrupted, the scaphoid will tend to turn down and the lunate to turn up.

This procedure reproduces the subluxation: en.wikipedia.org/wiki/Subluxation

Carpal Instability in the Weight-Bearing Upper Extremity

The prevalence of carpal instability in a paraplegic population was investigated to establish an association between chronic repetitive stress on the wrist and the development of such instability.

Nine of 162 paraplegic patients had static carpal instability and no history of an acute injury of the wrist.

The predominant pattern of instability, found in eleven wrists (six patients), was non-dissociative volar intercalated segmental instability.

The prevalence of carpal instability increased with the duration of weight-bearing on the upper extremity.

Eighteen per cent of the patients in whom the spinal cord injury had occurred more than twenty years before the study had carpal instability.

Carpal instability in these weight-bearing upper extremities and the increase in its prevalence with the duration of the forces across the wrist demonstrate an association between chronic repetitive stress on the wrist and carpal instability.

In conclusion, the present study of a paraplegic population demonstrated an association between carpal instability and chronic repetitive stress on the wrist.

Static carpal instability was found in 6 per cent of our entire study population and in 18 per cent of the patients who had had the spinal cord injury for more than twenty years.

This increase in the prevalence with the duration
of stress on the wrist suggests chronic repetitive stress as an etiology of carpal instability.

The predominant pattern of carpal instability was non-dissociative volar intercalated segmental instability.<br><br>Post edited by: Scott_1984, at: 2009/02/08 10:01

ARTHROSCOPIC CAPSULAR SHRINKAGE FOR MIDCARPAL INSTABILITY OF THE WRIST: proceedings.jbjs.org.uk/cgi/content/abstract/85-B/SUPP_II/177-c

This prospective study evaluated our results of arthroscopic electrothermal capsular shrinkage intrinsic (palmar) for midcarpal instability.

This method of treatment has not been described in the wrist in current literature.

Following clinical and video fluoroscopic diagnosis arthroscopy of the wrist and capsular shrinkage was performed on five patients.

A radiofrequency probe was mainly used on the ulnar arm of the volar arcuate ligament and the dorsal capsule of the radiocarpal joint.

One patient was lost to follow up. At a mean follow up of 11 months the results were: one excellent, two good and one fair using the Green and O’Brien wrist scoring system (Table1).

The average range of motion was 95 percent of the opposite wrist.

We concluded that arthroscopic radiofrequency capsular shrinkage is an effective, minimally invasive method of treatment for intrinsic midcarpal instability.

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Thermal Capsulorrhaphy for Midcarpal Instability: Meeting/Minutes of meeting held in November 2006 for THE BRITISH SOCIETY FOR SURGERY OF THE HAND (The British Hand Club) AUTUMN MEETING on 02nd &amp; 03rd of November 2006: (Page: 47) (Journal Attached): wristinstability.multiply.com/notes/item/6 & msngroup.aimoo.com/PalmarMidcarpalInstabilityPMCIRSD
Discussion: 15:38 Thermal Capsulorrhaphy for Midcarpal Instability:

Mr W T M Mason, Mr D Hargreaves (Southampton):

Introduction: Midcarpal instability is an uncommon but troublesome problem. For those in whom conservative measures fail, open ligament reconstruction or fusions have been described. We prospectively studied seventeen wrists in fourteen patients who underwent arthroscopic thermal capsulorrhaphy for midcarpal instability.

Methods: All patients were assessed clinically, by fluoroscopy and arthroscopy to confirm the diagnosis. Wrist arthroscopy with four portals was performed and monopolar radiofrequency thermal capsulorrhaphy was performed using a 2.3mm probe.

Results: 100% follow-up was achieved at a a mean of 42 months. Symptoms of instability were resolved completely in four wrists and almost completely in the remaining thirteen. The patients’ subjective overall assessment of the wrist was “much better” in twelve wrists, “better” for two wrists and “worse” for three wrists. These three cases had persistent pain despite the improvement in stability.

The cause of the pain was unrelated to the procedure or the initial pathology.

All patients were satisfied with the outcome and would undergo the same procedure again. Functional improvement was confirmed by an improvement in the mean DASH score from 38.3% pre-operatively to 17.0% at final follow-up. Mean wrist flexion and extension decreased by 25% and 17% respectively. There were no significant complications.

Conclusions: Thermal capsulorrhaphy greatly reduces symptoms of instability in patients with midcarpal instability. Longer follow-up is planned to observe whether these encouraging mid-term results deteriorate over time, as has been witnessed in the shoulder.<br><br>Post edited by: Scott_1984, at: 2009/02/08 09:55

A Slide Show Of Information, Surgeries, Therapiesa, &amp; More, On Carpal Instability: www.slideshare.net/hoc/carpal-instability

Palmar midcarpal instability: www.emedicine.com/orthoped/topic619.htm

Various authors have called palmar midcarpal instability (PMCI) by many names, including ulnar midcarpal instability, capitolunate instability pattern, ulnocarpal instability, and midcarpal instability. The most likely etiology in patients presenting with a painful midcarpal clunk is dysfunction of key ligaments that causes a loss of normal joint reactive forces between the proximal and distal rows. These ligaments include the arcuate, triquetrohamate, and capitolunate ligaments volarly and/or the radiotriquetral ligament dorsally.

In a normal wrist with ulnar deviation, the distal row translates from volar to dorsal as the proximal row rotates from flexion to extension. With laxity, attenuation, or traumatic disruption of these ligaments, the coupled rotation of the carpus is no longer present. Instead, the proximal row stays flexed, and the distal row remains excessively volarly translated until the extreme of ulnar deviation is reached, causing the proximal row to abruptly snap back into extension and the distal row to reduce (translate dorsally). The diagnosis is frequently based on the history and radiographic studies, in addition to the results of physical examination and midcarpal shift testing.

Patients present with painful clunking that occurs with ulnar deviation and pronation of the wrist. A history of trauma may or may not be present. Patients may describe a long period of asymptomatic clunking that has now become painful. The other extremity should be assessed for similar symptoms because the instability is frequently bilateral. Clinical findings may include a volar sag at the ulnar wrist with a prominent-appearing ulnar head with the wrist at neutral. If a localized synovitis is present, tenderness may be present over the ulnar carpus, particularly at the triquetrohamate joint. If the patient is unable to actively reproduce the clunk, it may be passively reproduced with the midcarpal shift test.

Plain radiographic findings are often unremarkable because PMCI is a dynamic disorder. Videofluoroscopy is the imaging study of choice. Both posteroanterior and lateral projections should be taken as the patient moves the wrist form radial to ulnar deviation in an attempt to reproduce the clunk. In addition, arthroscopy can enable the surgeon to definitively exclude any other lesion, particularly proximal low ligament tears. The role of MRI in the evaluation of PMCI has not yet been defined.

Nonoperative treatment may include activity modification, use of NSAIDs, steroid injections, and splinting.

Surgical options include limited midcarpal arthrodesis, distal advancement of the volar ulnar arm of the arcuate ligament, dorsal radiocarpal capsulodesis, and suturing the palmar radioscaphocapitate ligament to the radiolunotriquetral ligament to close the space of Poirier.

Ulnar-Sided Wrist Pain - Author: Mr. David M Litchman - 21-06-2004: www.emedicine.com/orthoped/topic619.htm

Wrist Instability - Edited By: Ueli Buchler - from: 1996, as in chapter: 5 on page: 30 it says:

Midcarpal Instability:

Adaptive Carpus - Definition: Malalignment between first and second row which no longer colinear. This may be a consequence of:

*Distal Radial Fracture Malunion
*Scaphoid Fracture Nonunion or Malunion
*Other Causes Of Carpal Collopse Such As Advanced Kienbock's Disease, Capitat Bone Osteonecrosis.

Midcarpal Ligament Tear or Attenuation:

*Pain and 'Clunk' in hyperlax young patient after light injury or repeated stress
*After rotational significant injury in normal patients.

Preview Wrist Instability - Edited By: Ueli Buchler - From: 1996

wristinstability.multiply.com/journal/item/5

Post edited by: Scott_1984, at: 2009/02/08 10:00