The clinical symptoms include wrist pain and postactivity ache. Physical findings demonstrate tenderness at the scapholunate joint and a positive scaphoid shift test.
The clinical symptoms include wrist pain and postactivity ache. Physical findings demonstrate tenderness at the scapholunate joint and a positive scaphoid shift test.
The plain radiograph PA (Fig. 1) shows Terry Thomas sign: widening of the gap between scaphoid and lunate.
PA and lateral view X-rays of the wrist in neutral position provide a diagnosis in the event of a suspected dislocation of the lunate or perilunate.
The lateral view (Fig. 2), which normally shows an alignment between the distal surfaces of the radius, lunate, capitate and third metacarpal, shows -in these
particular circumstances- an alteration of this alignment.
MR arthrography (Fig. 3) documents the placement and spreading of the contrast material into the middle compartment.
The MR imaging protocol includes T1 weighted Spin-Echo with and without fat saturation, in the coronal and transverse planes and gradient T2 weighted in sagittal plain:
All MRI are performed on a 1.5 T scanner utilizing a dedicated wrist coil (flex 17x36 cm).
The treatment is arthroscopic surgery.
The scapholunate interosseous ligament is the primary stabiliser and the radio-scapho-capitate and scapho-trapezial ligaments are secondary stabilisers of the scapholunate articulation.
The partial tear of the scapholunate ligament (pre-dynamic stage of SLD) as well as the complete tear (dynamic stage) does not lead to carpal misalignment. However, if the completely ruptured ligament is accompanied by lesions of the extrinsic ligaments, both the scaphoid and the lunate are misaligned already at rest (static stage of SLD). Later, osteoarthritis will develop, beginning in the radioscaphoid compartment, progressing to the midcarpal joint, and ending in a carpal collapse (SLAC).
Radiography is the initial examination of choice; radiographic features depend on the site of involvement and the patient’s age.
Radiography shows scapholunate and radio-scaphoid angles out of the normal range, scapholunate distances are abnormal and dorsiflexed intercalated segment instability is recognized.
From a lateral view X-ray, it is possible to observe the capitolunate angle and the scapholunate angle: as defined by Linscheid and colleagues, normal values range from 30 to 60 degrees, with an average of 47 degrees. Angles greater than 80 degrees should be considered a definite indication of scapholunate dissociation.
Tomograms are not particularly helpful in the evaluation and treatment of carpal dislocations, but they may help in localizing more subtle areas of injury, such as osteochondral fractures of the carpal bones.
MR Arthrography is a suitable tool for detecting lesions of the partial and total scapholunate interosseous ligament. The distinction between the types of lesions has clinical implications for treatment procedures.
It shows the precise location and magnitude of ligamentous defects of all parts of the SLIL, correlates well with wrist arthroscopy and has potential implications for
diagnosis and treatment planning.
A surgical approach is recommended if conservative treatment is unsuccessful. The procedure used should be based on the time that has elapsed since injury, the degree of carpal instability and the presence of osteoarthritis in the carpal bones.
Scapho-lunate lesion
1. From the anteroposterior and lateral X-ray images of the wrist, the following can be observed:
• The alignment between the distal radius and the carpal bones appears abnormal, especially between the scaphoid and lunate (the scapholunate joint), suggesting separation or abnormal positioning.
• The scaphoid demonstrates increased inclination. In some images, there is a visible widening of the scapholunate interval, indicating a possible scapholunate ligament injury.
• On the lateral view, measurements show an increased scapholunate angle (normal range: 30–60 degrees, average approx. 47 degrees; if >80 degrees, this strongly suggests scapholunate dissociation).
• There may be dorsal angulation in the intermediate carpal row, raising the possibility of dorsal intercalated segment instability (DISI).
2. From MRI images (especially in arthrographic sequences), the following are noted:
• The scapholunate interosseous ligament (SLIL) shows partial signal abnormalities or a defect, suggesting a partial or complete tear; deep contrast ingress into the scapholunate interval further indicates compromised ligament integrity.
• Surrounding supportive ligaments, such as the radio-scapho-capitate and scapho-trapezial ligaments, may also exhibit varying degrees of stress changes or weakened signal.
• The articular surfaces and cartilage layers may show localized wear. Although secondary degenerative changes are not marked, some malalignment of the carpal bones is evident.
Based on the imaging findings and the patient’s clinical symptoms (wrist pain, soreness after activity, marked tenderness over the scapholunate joint on examination, a positive scaphoid shift test, etc.), the following potential diagnoses are considered:
Of these, a scapholunate ligament injury best explains the widened scapholunate space, increased scapholunate angle, and dorsal intercalated segment instability.
Considering the patient’s gender, age, clinical symptoms (notably wrist pain, increased pain upon making a fist, a positive scaphoid shift test), imaging findings (X-ray showing a widened scapholunate interval and a significantly increased scapholunate angle, MRI showing evident abnormal signal or disruption of the scapholunate ligament), the most likely diagnosis is:
Scapholunate Ligament Injury (Scapholunate Dissociation)
1. Treatment Strategy
• Conservative Treatment: In cases of partial tear or early injury, short-term casting or bracing (e.g., wrist immobilization for 4–6 weeks) can be attempted to reduce stress from movement, combined with anti-inflammatory and analgesic medications.
• Arthroscopic Evaluation and Ligament Repair: If conservative measures fail or a complete tear is suspected, arthroscopic examination can be considered to identify the location and severity of the tear. Surgical repair or reconstruction of the ligament may be needed.
• Further Surgical Intervention: In chronic or severe cases of scapholunate instability with pronounced deformity or degenerative changes, more comprehensive surgical approaches (e.g., ligament reconstruction, osseous realignment, or even fusion) may be required to prevent further deterioration.
2. Rehabilitation and Exercise Prescription (FITT-VP Principle)
(1) Recovery Phase (early post-injury or postoperative, typically 2–4 weeks)
• Frequency (F): 2–3 times daily of light joint movements. If casting or bracing is used, maintain the immobilization as directed.
• Intensity (I): Avoid any action that places high stress on the wrist joint, and pay attention to pain feedback.
• Time (T): 5–10 minutes per session, progressively increasing as tolerated.
• Type (T): Finger gripping exercises, forearm rotation drills, and gentle active or passive flexion-extension of the wrist.
• Volume & Progression (VP): Gradually expand the range of motion or increase resistance based on pain levels and joint stability.
(2) Intermediate Rehabilitation Phase (6–12 weeks)
• Frequency: 3–4 times per week, gradually increasing active and resistance exercises for the wrist.
• Intensity: Progress from minimal resistance to moderate resistance (e.g., using light resistance bands or dumbbells for wrist flexion-extension and pronation-supination).
• Time: 15–20 minutes per session, including 1–2 sets of exercises targeting the small muscles of the wrist.
• Type: Emphasize wrist stability training, including forearm rotations, wrist flexion-extension, and hand gripping exercises, combined with proprioceptive training. Ensure proper form.
• Volume & Progression: Increase resistance and difficulty gradually, guided by wrist stability and pain levels. Avoid sudden high-load exercises.
(3) Late-Stage Exercise Training (12 weeks and beyond)
• Frequency: 3–5 times per week.
• Intensity: Able to handle higher resistance with a progressive increase in load (e.g., heavier resistance bands or dumbbells).
• Time: 20–30 minutes per session, focusing on functional wrist training and endurance of smaller muscle groups.
• Type: Transition to functional training relevant to daily activities or specific sports, such as weight-bearing on the wrist, gripping stability, etc. Avoid repetitive extreme wrist extension or radial deviation.
• Volume & Progression: Advance to functional and sports-specific training according to rehabilitation assessments, ensuring gradual improvements in wrist stability and strength.
This report is based on the available imaging and provided information for reference and auxiliary value only. It does not replace an in-person consultation or the professional advice of a physician. If you have any concerns or if symptoms worsen, please seek immediate medical care and consult a specialist.
Scapho-lunate lesion
