There is currently no commercially available and clinically successful treatment for scapholunate interosseous ligament rupture, the latter leading to the development of hand-wrist osteoarthritis. We have created a novel biodegradable implant which fixed the dissociated scaphoid and lunate bones and encourages regeneration of the ruptured native ligament. To determine if scaphoid and lunate kinematics in cadaveric specimens were maintained during robotic manipulation, when comparing the native wrist with intact ligament and when the implant was installed. Ten cadaveric experiments were performed with identical conditions, except for implant geometry that was personalised to the anatomy of each cadaveric specimen. Each cadaveric arm was mounted upright in a six degrees of freedom robot using k-wires drilled through the radius, ulna, and metacarpals. Infrared markers were attached to scaphoid, lunate, radius, and 3rd metacarpal. Cadaveric specimens were robotically manipulated through flexion-extension and ulnar-radial deviation by ±40° and ±30°, respectively. The cadaveric scaphoid and lunate kinematics were examined with 1) intact native ligament, 2) severed ligament, 3) and installed implant. Digital wrist models were generated from computed tomography scans and included implant geometry, orientation, and location. Motion data were filtered and aligned relative to neutral wrist in the digital models of each specimen using anatomical landmarks. Implant insertion points in the scaphoid and lunate over time were then calculated using digital models, marker data, and inverse kinematics. Root mean squared distance was compared between severed and implant configurations, relative to intact. Preliminary data from five cadaveric specimens indicate that the implant reduced distance between scaphoid and lunate compared to severed configuration for all but three trials. Preliminary results indicate our novel implant reduced scapho-lunate gap caused by ligament transection. Future analysis will reveal if the implant can achieve wrist kinematics similar to the native intact wrist

Abstract. Objectives. The scapholunate interosseous ligament (SLIL) has a unique C-shape following the arc of the scaphoid and lunate surfaces from distal dorsal around to distal volar. This ligament comprises of three subregions: dorsal, proximal and volar. The SLIL enthesis, a specialized region where this ligament attaches to the scaphoid and lunate, has not previously been studied despite its important mechanical function in the biomechanics of the wrist joint. This study therefore aims to compare the histomorphological differences between the SLIL subregions, including at their entheses. This study will examine the qualitative and quantitative differences between the three subregions, as well as between the scaphoid and lunate attachments. Methods. Twelve fresh-frozen human cadaveric wrists were dissected and the gross dimensions of each SLIL subregion measured. Subregions were then histologically processed for qualitative and quantitative morphological and compositional analyses, including quantification of enthesis calcified fibrocartilage (CF) area. Results. From the gross measurements taken, the dorsal subregion was the thickest. There were no significant differences in lengths and widths between the three subregions. Qualitatively, the dorsal and volar subregions had fibrocartilaginous entheses while the proximal subregion inserted into cortical bone via articular cartilage. Quantitatively, the dorsal subregion had significantly more CF than the volar subregion. There was no significant difference in the enthesis CF between scaphoid and lunate attachments in the three subregions. Conclusions. There are significant histomorphological differences between the SLIL subregions. The dorsal subregion has the largest amount of CF, which is consistent with the greater biomechanical force subjected to this subregion compared to the other subregions. This result confirms that the dorsal subregion is the strongest of the three subregions. The similar histomorphology of the ligament at the scaphoid and lunate entheses suggests that similar biomechanical forces are applied to both attachments. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

The pattern of injury to the carpal ligaments following wrist trauma is unclear. Different imaging techniques often prove inconclusive rendering the diagnosis difficult and hence the treatment controversial. This study aimed to observe and evaluate the differences in scapholunate kinematics before and after sectioning the scapholunate interosseous ligament (SLIL) and radioscaphocapitate ligament (RSC). Twenty two embalmed cadaveric wrists were used. There were four males and seven females with an average age of 84 years. Their medical records confirmed the absence of previous history of wrist diseases or injuries. The extensor and flexors tendons of the wrist were removed leaving the capsule intact. Two drill bits (1.5 mm) were used to make a hole each in scaphoid and lunate, one centimeter apart. The drill bits were left in the bones to act as metal wires for calibration. Each wrist was moved through a set of motions and each movement was performed thrice; first one with the ligaments intact, second with SLIL sectioned and the last one with RSC excised. Digital photographs were taken and angles measured with MB Ruler software. Analysis of variance was done using SPSS 12. There was no angle between the metal pointers when the ligaments were intact. There was movement and change in angle detected when SLIL and RSC were sectioned. The sectioning of the SLIL lead to a significant increase in the angle between the pointers in all the movements recorded (p value < 0.001). Subsequent sectioning of the RSC further increased this angle but this increase was much smaller compared to that after sectioning SLIL. On completion of the measurements the wrist capsule was opened to reveal that both the ligaments had been successfully sectioned and there were no degenerative changes in the bones or ligaments in any wrist. This first cadaveric evaluation of alterations in scapholunate motion with sectioning of SLIL and RSC revealed that SLIL has a significant influence on the scapholunate kinematics, where as sectioning of the RSC has little additional effect. This in-vivo finding might have implications of importance of preserving SLIL during wrist surgeries and its role in management of carpal instabilities

Aim. This study reviewed the efficacy of a CT arthrogram in clinical decision making for wrist disorders. Methods. Sixty four consecutive CT arthrograms done in a three year period at Glenfield Hospital were selected. All patients were referred by hand consultants at the Glenfield Hospital and all investigations were performed by a single senior musculoskeletal radiologist. CT arthrograms focussed on the following areas: scapholunate interosseous ligament (SLIL), lunotriquetral interosseous ligament (LTIL), peripheral and central triangular fibrocartilage complex (TFCC) tears, and articular surface disorders. Referral and clinic letters for all patients were obtained. We collected patient demographic detail, prescan diagnosis and clinical plan, CT arthrogram findings, postscan diagnosis and clinical plan and the final outcome. A decision was made whether the scan helped in the clinician's management plan and if so how it helped. Results. There were 35 male and 29 female patients with a mean age of 44.1 years. The right wrist was involved in 42 and the left in 22 patients. Sixty three of the 64 patients had their management based on the CT scan. In 54 of these the CT arthrogram either confirmed and calibrated the diagnosis or identified a new diagnosis. In 10 patients the scan was normal and allowed patient reassurance. Thirty six patients had ulnar sided problems, 20 had radial sided disorders and eight had midcarpal abnormality. The most common abnormality noted was a TFCC tear (24). The next most common was chondral damage/arthritis (14) followed by scapholunate interosseous ligament tear (12). The diagnosis was either confirmed and its extent established (31) or identified in addition to the primary diagnosis (19). Conclusions. The CT arthrogram is a helpful tool in the management of intra-articular wrist pathology. We found it to be useful in both confirming and calibrating the diagnosis and also diagnosing occult patho

Aim:. To assess the clinical outcomes of patients that had perilunate or lunate dislocations treated with either open or closed reduction and wiring without repair of the scapholunate interosseous ligament (SLIL). Background:. Current literature states that acute perilunate dislocations should be treated with open reduction and repair of the dorsal scapholunate ligament. This is to prevent dissociative carpal instability and potential long term degenerative arthrosis. Methods:. A retrospective review of patients who sustained a perilunate or lunate dislocation, with no associated radial or carpal fracture was conducted. All were treated by reduction and percutaneous wiring without repair of the SLIL. Patients were examined and data was collected regarding patient's pain, range of motion, grip strength, instability and return to work. All patients had a Mayo wrist score. Pre and post-surgical radiographs were assessed and the scapholunate distance, scapholunate angle and the radiolunate angle were measured. The presence of a high riding scaphoid and osteoarthritis was recorded. Results:. A total of 13 patients were included in the study, with an average follow up of 32 months. 92% of patients had no pain in their wrist at final follow up. Range of movement was 78% of the normal side. 70% of patients returned to work. 92% of patients had no clinical wrist instability. Grip strength was 82% of the opposite side. Radiographic assessment showed an average scapholunate distance of 2.6 mm, a scapholunate angle of 65° and radiolunate angle of 11°. One of the 13 patients had a high riding scaphoid. 23% of patients had arthritic changes of the carpus on plain radiographs. Of the 13 patients, 3 had excellent mayo scores, 4 good, and 6 fair. No patients had poor scores. Of the 13 patients reviewed 10 returned to work, those that did not were not able to due to other disabilities acquired at the time of their accident. Conclusion:. Acute management of perilunate dislocations with reduction and percutaneous wiring without repair of the SLIL, resulted in the majority of patients having a pain free, stable, mobile wrist with an above average Mayo wrist score and no arthritic change on radiographic assessment

Purpose: The purpose of this study is to investigate the external and internal vascular anatomy of the lunate bone. The genesis of lunatomalacia requires some combination of load, vascular risk and mechanical predisposition. The findings will be correlated with the major existing theories of the cause of lunatomalacia and the most frequent fractures associated with Kienbocks disease: transverse shear fracture and midcoronal fracture. Material and methods: We studied 21 cadaver upper limbs using latex injection and Spalteholz technique. We investigated the extra- and intraosseous blood supply. In 17 wrists we evaluate the incidence and distribution of anatomic features, arthrosis, and soft tissue lesions. Results: The lunate morphology was 5 Type I (29.4%), 11 Type II (64.7%) and 1 Type III (5.9%). The lunate was found to have a separate facet for the hamate in 47.1% (Size 3–6 mm). Most frequent arthrosis was identified in the radius (88.2%) and lunate (94.1%). The triangular fibrocartilage complex (TFCC) was found torn in 47%, the lunotriquetral interosseous ligament (LTIL) was torn in 23.5%, and the scapholunate interosseous ligament (SLIL) was torn in 53% of the wrists. Statistical analysis found a correlation between the presence of arthrosis at the proximal pole of the hamate and the presence of a lunate facet. There was also a correlation between the presence of a tear in the SLIL and the presence of cartilage erosion in the scaphoid (p= 0.002). Arthrosis on the lunate was found to have a correlation with an SLIL tear or TFCC tear. The nutrient vessels entered the lunate throught the dorsal and volar poles in all the specimens. Dorsal vessels enter the bone through one or two foramina in the proximal, ulnar, and nonarticular aspect of the bone. Two to six nutrient vessels were observed entering the volar pole throught a ligament insertion: radioscapholunate ligament of Testut-Kuentz, radio-lunate-triquetrum ligament and ulnar-lunate-triquetrum ligament. Conclusions: The lunate had consistent dorsal and palmar arteries entering the bone in all the specimens. The supply blood and foramina number is more important in the volar pole of the lunate than the dorsal pole. The vascular patterns support a theory of compression fracture from repeated trauma, or anatomical predispositions as the most likely cause of Kienbocks disease

The August 2012 Wrist & Hand Roundup³⁶⁰ looks at: the Herbert ulnar head prosthesis; the five-year outcome for wrist arthroscopic surgery; four-corner arthrodesis with headless screws; balloon kyphoplasty for Kienböck's disease; Mason Type 2 radial head fractures; local infiltration and intravenous regional anaesthesia for endoscopic carpal tunnel release; perilunate injuries; and replanting the amputated fingertip.