Dorsal Radiocarpal Dislocation with Radial Styloid Fracture Treated with Arthroscopy-Assisted Reduction and Internal Fixation: A Report of Two Cases.

Radiocarpal dislocation is an uncommon injury that is usually caused by high-energy trauma. Herein, we present two cases of dorsal radiocarpal dislocation with radial styloid fractures that were treated by arthroscopy-assisted reduction and internal fixation. Wrist arthroscopy provides accurate information on intra-articular fractures and carpal and/or intracarpal ligamentous tears of the radiocarpal joint. Furthermore, the procedure enables simultaneous anatomical reduction of intra-articular fractures and radiocarpal and/or intercarpal ligament repair. Arthroscopy-assisted reduction and internal fixation yield satisfactory outcomes for patients presenting with dorsal radiocarpal dislocation and radial styloid fractures.

Minimal Invasive Corrective Osteotomy with the Ilizarov Mini-Fixator for Malunited Fractures of Proximal Phalanges in Adolescence: Report of Three Cases and a Review of the Literature.

Posttraumatic malunion with combination of angular, rotational, and shortening deformity of the proximal phalanx may cause scissoring of a finger and impairment of hand function. Cosmetic disfigurement and severe dysfunction of fingers require surgical correction, most often via open corrective osteotomies and rigid fixation with a plate or screws. However, such an approach requires a longer incision, inevitably results in a scar, and has a higher potential for extensor tendon adhesion. Also, abruption of the periosteum and plating of the phalange requires longer bone healing time. Thus, we devised a technique of minimally invasive correction of phalangeal malunion using an external mini-fixator. We presented representative three cases of malunited fractures of phalanges treated with the Ilizarov mini-fixator in adolescence and review reports of similar cases. The usage of Ilizarov mini-fixator provided excellent outcomes for posttraumatic malunion of three fingers.

Volar Locking Plate Fixation for Intra-Articular Distal Radius Fractures with Volar Lunate Facet Fragments Distal to the Watershed Line.

BACKGROUND: Standard volar plating of distal radius fractures may not adequately fix the volar lunate facet (VLF) fragment, which can result in volar carpal subluxation. We hypothesized that the size of VLF fragments distal to the watershed line might affect reduction loss after distally placed volar locking plate fixation for intra-articular distal radius fracture and examined if the presence of small displaced VLF fragments was a risk factor for reduction loss. METHODS: Twenty-seven hands of 27 patients with intra-articular distal radius fractures with VLF fragments distal to the watershed line were treated by using Acu-Loc 2 volar distal radius locking plate fixation. RESULTS: At final follow-up, the mean Mayo Performance Score was 90.9, and the mean Quick Disabilities of Arm, Shoulder, and Hand score was 13.6. On radiography, 5 patients had a reduction loss of >2 mm in ulnar variance from immediately postoperatively to final follow-up (group 1), while 27 had no reduction loss (group 2). The mean longitudinal, transverse, and anteroposterior lengths and joint surface area of the VLF fragment were significantly smaller in group 1 than in group 2. Three-dimensional computed tomography revealed that the fracture patterns of the radiocarpal and distal radioulnar joints in group 1 were mainly volar-displaced VLF fragments. CONCLUSIONS: By stabilizing fragments, distally placed volar locking plate fixation effectively treated intra-articular distal radius fractures with VLF fragments distal to the watershed line. However, the presence of small displaced VLF fragments may increase the risk of reduction loss in ulnar variance.

Use of a Costal Osteochondral Graft for Reconstruction of a Proximal Phalanx Head with a Comminuted Fracture of the Proximal Interphalangeal Joint.

We report the use of costal osteochondral grafting with a pins and rubbers traction system (PRTS) for treatment of a complex cartilage defect of the proximal interphalangeal (PIP) joint in a 41-year-old male carpenter who had inadvertently incompletely severed his finger with a power saw. The skin laceration extended to the dorsal aspect of his ring finger and resulted in incomplete loss of the ulnar condyle and comminution of the radial condyle of the proximal phalanx of the PIP joint. The diagnosis was intra-articular PIP joint open fracture of the left ring finger with a 60% defect of the proximal phalanx joint surface. Three weeks after the injury, PIP joint reconstruction was performed with a costal osteochondral graft harvested at the osteochondral junction of the fifth rib. The volar side of the proximal phalanx cortex and the condyles of the proximal phalanx on each side, which included the origin of the collateral ligaments, were preserved. The graft was shaped to match the defect, and biplane fixation with three miniscrews was subsequently performed. Last, a PRTS was attached. At 6 months postoperatively, the patient returned to his job; at 12 months postoperatively, the joint was stable and free of pain. This technique enabled preservation of joint stabilizers and rigid fixation of the graft, resulting in a good outcome. Our modified costal osteochondral graft with a PRTS is useful for severe intra-articular fractures of the PIP joint and should be considered before salvage procedures.

Novel Modification of Abductor Pollicis Longus Suspension Arthroplasty with Trapeziectomy for Thumb Carpometacarpal Osteoarthritis.

BACKGROUND: We compared the clinical results of a newly modified abductor pollicis longus (APL) suspension arthroplasty with trapeziectomy procedure (modified Thompson procedure) with those of the original APL suspension arthroplasty with trapeziectomy procedure (original Thompson procedure) for treatment of advanced osteoarthritis of the thumb carpometacarpal (CMC) joint and assessed the effectiveness of the modified Thompson procedure for thumb CMC osteoarthritis. METHODS: Ten hands of 10 patients (Group 1) were treated with the original Thompson procedure. Twenty hands of 16 patients (Group 2) were treated with the modified Thompson procedure, in which the bone tunnel positions were rearranged for a more dorsoradial passage of the transferred APL. RESULTS: Significant differences between values before and after surgery were noted in thumb palmar and radial abduction angles, pinch power, grip strength, Quick Disability of Arm, Shoulder, and Hand questionnaire (Quick DASH) score, and visual analog scale (VAS) score. There was no statistically significant difference in thumb palmar abduction angle, pinch power, grip strength, Quick DASH score, or VAS score between Groups 1 and 2. However, range of motion of radial abduction in the thumb was significantly better for patients in Group 2 than for those in Group 1. CONCLUSIONS: The modified Thompson procedure is a simple, effective technique that results in greater improvement in thumb radial abduction angle, as compared with the original technique, in patients with advanced thumb CMC osteoarthritis. Additionally, the modified technique is as useful as the original procedure for early restoration of thumb function and pain relief.

Pins and rubbers traction system for fractures of the proximal interphalangeal joint.

PURPOSE: We aimed to evaluate the clinical results using the pins and rubbers traction system (PRTS) as described by Suzuki et al. for unstable intra-articular fractures of the proximal interphalangeal (PIP) joint and to assess the efficacy and the indication of the technique of the PRTS. METHODS: Thirty-nine fingers in 39 patients (mean age 46.0 years) with unstable fractures of the PIP joint were treated by the PRTS. The mean interval between injury and surgery was 30.8 days. Active and passive exercise of range of motion of all fingers was started immediately after surgery. Radiographic and clinical results were evaluated at the final examination. RESULTS: The mean period the PRTS was applied was 6.4 weeks. The mean follow-up period was 8.9 months. Anatomical union was obtained in all patients. No joint instability, no malunion, nor osteomyelitis was observed. At the final examination, the average active range of motion of the PIP joint was 74.6°. The average Visual Analogue Scale for pain and Quick Disability of Arm, Shoulder, and Hand score were 1.2 and 3.2, respectively. CONCLUSIONS: The current study demonstrated good results of the PRTS for unstable intra-articular fractures of the PIP joint. Furthermore, satisfactory results were obtained in cases of an incomplete amputation at the PIP joint, a pathological fracture due to bone tumor, and an osteochondral defect due to comminuted fracture of the proximal phalangeal head, where costal osteochondral bone was transplanted. From this study, the PRTS is recommended as a useful treatment because it is widely effective for various unstable fractures of the PIP joint.

Trans-scaphoid Perilunate Fracture-dislocation with Concomitant Lunotriquetral Ligament Disruption: A Case Report.

We report a case of trans-scaphoid perilunate fracture-dislocation with concomitant lunotriquetral ligament disruption of the right wrist in a 44-year-old man, sustained from a 10-m fall landing on his outstretched right hand. Open reduction was performed 1 day after injury; at first the palmar dislocation of the lunate was reduced with the palmar approach. Under direct view with the dorsal approach, the scaphoid was comminuted and then treated with open reduction and internal fixation with a double threshold screw using a dorsal approach and a bone graft from the distal radius. Although the scapholunate ligament was intact, the lunotriquetral ligament was disrupted and required repair with metal suture anchors. At the 28-month follow-up evaluation, the patient had no residual pain in his wrist and returned to work. Trans-scaphoid perilunate fracture-dislocations often accompany a comminuted fracture of the scaphoid and disruptions of the intercarpal ligaments, and bone union and ligament healing time is delayed. Prolonged immobilization of the wrist may restrict its range of motion and limit daily activities. Therefore, open reduction and internal fixation with a bone graft for the scaphoid and simultaneous repair of interosseous intercarpal ligaments are essential for satisfactory recovery from perilunate fracture-dislocations.

Minimally invasive modified Camitz opponensplasty for severe carpal tunnel syndrome.

PURPOSE: We aimed to compare the clinical results and the complications between the minimally invasive modified Camitz opponensplasty and the conventional Camitz opponensplasty for severe carpal tunnel syndrome (CTS), and to evaluate the efficacy of the modified technique for CTS. METHODS: Twenty-eight hands in 24 patients with severe CTS who had disorder of the thumb opposition with thenar muscle atrophy (group 1) were treated by minimally invasive modified Camitz opponensplasty, passing the transferred palmaris longus (PL) tendon under the abductor pollicis brevis (APB) fascia using only palm and thumb incision, and no incision to either wrist crease or forearm. Ten hands in 10 patients (group 2) were treated by the conventional Camitz opponensplasty. Clinical evaluation was made by comparing the results before and after surgery for the angle of the thumb palmar abduction, pinch power, and grip strength. RESULTS: All clinical findings significantly improved after surgery compared with before surgery in all patients. In group 1, there were no complications including transferred tendon bowstring, painful wrist scar, or injury to the palmar cutaneous branch of the median nerve in all hands. Conversely, patients in group 2 had four painful wrist scars and nine bowstrings of the transferred tendon. CONCLUSIONS: Several complications have been considered to attribute to the long incision and an extensive dissection crossing the wrist crease from the palm to the wrist in the conventional Camitz procedure. The current modified Camitz opponensplasty by minimally invasive incision without straddling the wrist crease is a simple and effective procedure that can decrease the risk of painful scar around the wrist crease in severe CTS patients with disorder of thumb opposition. Additionally, this technique, by passing the transferred PL tendon under the APB fascia, is useful in restoring the thumb opposition immediately, and in preventing the bowstringing of the transferred tendon.

Irreducible Elbow Fracture and Dislocation due to Incarceration of the Medial Epicondyle of the Humerus in a Child.

Medial epicondyle fractures of the humerus account for 11%-20% of all elbow injuries in children. Although intra-articular incarceration of the medial epicondyle occurs in 5%-18% of medial epicondyle fractures associated with an elbow dislocation, the mechanism of intrusion of the fracture fragment is unknown. We report a case of an irreducible elbow fracture and dislocation due to incarceration of the medial epicondyle fragment of the humerus, classified as a Watson-Jones type 3 fracture of the medial epicondyle, and present the mechanism of the intra-articular incarceration of the medial epicondyle fragment. The patient was a 9-year-old boy who injured his right elbow in a fall, and was diagnosed with a Watson-Jones type 3 fracture of the medial epicondyle. As we could not achieve a good reduction under fluoroscopic imaging, surgery was immediately performed using a medial approach. We discovered that the incarcerated fracture fragment was attached to the flexor-pronator muscles, the medical collateral ligament (MCL), and the anterior articular capsule. The medial epicondyle was fixed with Kirschner-wires augmented with tension band wiring. After fixation, there was no remaining instability. After 4 months the patient's fracture had proceeded to union and the internal fixation was removed. After 30 months he was asymptomatic and able to perform all of his daily life activities without any limitation. Our case, a Watson-Jones type 3 medial epicondyle fracture, is suggestive of the mechanism of incarceration of the medial epicondyle fragment into the elbow joint. Our findings support the idea that the attachment of both the MCL and the articular capsule can result in the entrapment of a fracture fragment in the elbow joint.

Ultrasonographic movement of the flexor pollicis longus tendon before and after removal of a volar plate for the distal radius fracture.

INTRODUCTION: The purpose of this study was to compare the movement of the flexor pollicis longus (FPL) tendon on the distal radius during wrist and finger motions before and after removal of a volar plate in patients with distal radius fractures using transverse ultrasound and to evaluate the kinematic effects on the FPL by the removal. METHODS: Twenty-five patients with distal radius fracture were evaluated quantitatively by transverse ultrasound using coordinates for the movement of the FPL on the distal radius during wrist and finger motions before and after the plate removal. RESULTS: At all wrist positions, during finger motion, the FPL moved significantly more palmarly away from the radius after plate removal compared to before. However, the FPL was still situated more dorsoulnarly compared with unaffected side. Moreover, the FPL moved significantly most dorsally both before and after removal at the wrist dorsal flexion position with finger flexion. CONCLUSIONS: These findings suggested that any adhesion between the FPL and the pronator quadratus (PQ) muscle was released by removing the plate and that the FPL would approach original tendon movement. Additionally, it is speculated that any remaining atrophy and fibrosis of the PQ may be the reason for more dorsoulnar location of the FPL in the affected side compared with the unaffected one. This ultrasound evaluation may be useful in further understanding the FPL kinematics on the distal radius, and in appropriate treatment of the distal radius fracture with plate fixation for preventing FPL rupture.

Median nerve movement in the carpal tunnel before and after carpal tunnel release using transverse ultrasound.

PURPOSE: We aimed to compare the movement of the median nerve within the carpal tunnel during wrist and finger motions between before and after carpal tunnel release (CTR) using transverse ultrasound in carpal tunnel syndrome (CTS) patients and to evaluate the biomechanical efficacy of CTR for CTS. METHODS: Twenty-four patients with CTS were examined by transverse ultrasound. The location of the median nerve within the carpal tunnel was examined quantitatively as a coordinate at varied wrist positions with finger extension and flexion, respectively, before and after CTR. RESULTS: We found that the median nerve moved statistically significantly more palmarly after CTR than before at all wrist positions during finger motion. The average median nerve displacement toward the palmar side at the palmar flexion position in finger flexion was the greatest among all positions. Additionally, the displacement amounts of the median nerve during finger motion at all wrist positions were statistically significantly smaller after CTR than before. CONCLUSIONS: The current study demonstrated the movement patterns of the median nerve in the carpal tunnel during wrist and finger motions compared before and after CTR using transverse ultrasound in CTS patients. The findings suggested that as the median nerve shifted greatly palmarly away from the tendons after CTR, the nerve avoids compression or shearing stress from the tendons. This ultrasound information could offer further understanding of the pathomechanics of CTS and provide a more accurate diagnosis of CTS and better treatment by CTR.

Electrophysiological Assessment for Splinting in the Treatment of Carpal Tunnel Syndrome.

An electrophysiological study is commonly used to decide a therapeutic strategy for carpal tunnel syndrome (CTS). In this study, the electrophysiological parameter measurement as a prognostic indicator for CTS after wrist splinting was assessed to identify appropriate candidates for wrist splinting for CTS. One hundred and six hands in 78 patients with CTS were treated by wrist splinting, and three electrophysiological parameters; median distal motor latency (DML) of the abductor pollicis brevis (APB) muscle, median distal sensory latency (DSL) of the index finger, and second lumbrical-interossei latency difference (2L-INT LD); were statistically analyzed to compare with clinical results by Kelly's evaluation respectively. Clinical results were excellent in 15 hands, good in 51 hands, fair in 19 hands, and poor in 21 hands. The recordable rate in 2L-INT LD (99.1%) was higher than DML (96.2%) and DSL (79.2%). Patients with DML less than 6.5 ms, DSL less than 5.7 ms, or 2L-INT LD less than 2.5 ms had significantly excellent or good clinical results. The odds ratios of the DML, DSL, and the 2L-INT LD were 7.93, 8.81, and 12.8, respectively. This study demonstrated that CTS patients with DML less than 6.5 ms, DSL less than 5.7 ms, or 2L-INT less than 2.5 ms were good candidates for wrist splinting. Especially, the 2L-INT LD could be the most reliable indicator to predict clinical results for all grades of CTS. This electrophysiological information could be useful in further improvement of accurate diagnosis of CTS, and may help in the assessment of appropriate treatment for CTS with wrist splinting.

The Ilizarov Mini-External Fixator for the Treatment of First Metatarsal Fracture: A Case Report.

Forefoot fractures are frequently accompanied by severe soft tissue damage. Therefore, treatment should focus not only on fractures but also on soft tissue damage, for which external fixation can be used as a surgical option. A 63-year-old woman presented to the emergency clinic of our hospital with forefoot pain after a motorcycle accident. Comminuted fracture of the proximal part of the metatarsal was diagnosed. Because of the swollen foot and fracture comminution, an operation using the Ilizarov mini external fixator was performed to prevent further damage to the soft tissue. Weight-bearing was permitted seven weeks after the operation, and the extraction of the apparatus was performed nine weeks postoperatively. One year later, the patient had no pain and had returned to ballroom dancing, a hobby which she performed five days a week, with no difficulties. Our results suggest that the Ilizarov mini external fixator should be considered not only for temporary treatment, but also for the entire duration of treatment of first metatarsal fractures associated with severe soft tissue damage.

Three-dimensional dynamic motion analysis of the first carpometacarpal ligaments.

PURPOSE: The purpose of this study was to analyze the dynamic motion of the first carpometacarpal (CMC) ligaments on a three-dimensional (3-D) surface model and to examine the changes in the ligament lengths during the motion of the first CMC joint. METHODS: Six fresh-frozen cadaver wrists were used to analyze the motion of the first CMC ligaments on a 3-D coordinate system using a digitizer. Four ligaments, namely, dorsoradial ligament (DRL), posterior oblique ligament (POL), superficial anterior oblique ligament (SAOL), and deep anterior oblique ligament (dAOL), were dissected and identified. Their attachments were digitized and represented on 3-D bone images. The distances between the ligament attachments of the first metacarpal and the trapezium, which were the ligament lengths, were measured during the extension-flexion and adduction-abduction of the first CMC joint. RESULTS: Both the DRL and POL lengthened during flexion of the first CMC joint, and both the SAOL and dAOL lengthened during extension. Both the DRL and SAOL lengthened during adduction, and both the POL and dAOL lengthened during abduction. The DRL alone lengthened significantly at flexion and adduction when the first CMC joint was in dorsoradial dislocation. CONCLUSIONS: The lengths of four ligaments changed significantly during first CMC joint motion. This study suggested that the DRL contributes substantial stability to the first CMC joint, preventing dorsoradial dislocation. This 3-D information improves the knowledge and understanding of the function of individual ligaments and their roles in the stability of the first CMC joint.

Color Doppler ultrasound assessment for identifying perforator arteries of the second dorsal metacarpal flap.

PURPOSE: The second dorsal metacarpal (SDMC) perforator flap has been widely used for the soft tissue reconstruction of the hand. However, it is difficult to identify the depth and branches of the perforators of the second dorsal metacarpal artery (SDMA) using only handheld acoustic Doppler flowmetry (HADF), which is the most common method. The purpose of this study was to compare the results of examination by color Doppler ultrasonography (CDU) with those of HADF and to evaluate the efficacy of CDU for detection of the perforators to be used in the design of the SDMC flap. METHODS: Twenty-two healthy volunteers (42 hands) were examined using both CDU and HADF. All locations identified as the perforators of the SDMA by the two examinations were mapped respectively. RESULTS: The total perforator arteries detected with CDU in all hands were 111 branches, 49 branches of which could not be identified with HADF. The average number of perforators of the SDMA per hand found with CDU was 2.8 branches, while that for HADF was only 1.8 branches. The detection rates of the cutaneous perforators of the SDMA by CDU were 100% in the proximal one-third of the second metacarpal and 95% in the distal one-fourth of the second metacarpal. CONCLUSION: This study demonstrated the superiority of CDU compared with HADF for detection of the perforators of the SDMA. The CDU examination could easily identify the locations of the cutaneous perforators and help in the useful assessment of vascularity for the SDMC flap.

Transverse ultrasound assessment of the flexor pollicis longus tendon movement on the distal radius during wrist and finger motion in distal radius fracture with volar plating.

INTRODUCTION: We investigated the movement of the flexor pollicis longus (FPL) tendon on the distal radius during wrist and finger motions using transverse ultrasound in patients with distal radius fractures who underwent volar locking plating. METHODS: Both wrists of 39 distal radius fracture patients with volar locking plate fixation were evaluated by transverse ultrasound to examine the location of the FPL tendon on the distal radius at varied wrist positions in full finger extension and flexion. RESULTS: At all wrist positions during finger motion, the FPL tendon shifted significantly more dorsally on the affected side than on the unaffected side. Additionally, at the wrist dorsal flexion position with finger flexion, the FPL tendon moved significantly the most dorsally, and the distance between the FPL tendon and the plate or the radius was the smallest among all wrist positions during finger motion. CONCLUSIONS: This study showed that the wrist dorsal flexion position with finger flexion could be the appropriate position to examine FPL tendon irritation after plating. Moreover, it would be effective for preventing FPL rupture to cover the FPL transverse gliding area approximately 10 mm radial to the vertex of the palmar bony prominence of the distal radius with the pronator quadratus and the intermediate fibrous zone.

Ultrasound Evaluation of the Transverse Movement of the Flexor Pollicis Longus Tendon on the Distal Radius during Wrist and Finger Motion in Healthy Volunteers.

PURPOSE: This study aimed to evaluate the kinematics of the flexor pollicis longus tendon (FPL) at the wrist by examining the movement of the FPL on the distal radius during various wrist and finger motions using transverse ultrasound in healthy volunteers. METHODS: Forty-eight wrists of 24 asymptomatic volunteers were examined by transverse ultrasound to observe the location of the FPL on the distal radius at 5 wrist positions (neutral, 60° dorsal flexion, 60° palmar flexion, 40° ulnar deviation, and 10° radial deviation) with all 5 fingers in full extension and full flexion, and isolated thumb in full flexion, respectively. RESULTS: We found that the FPL was situated statistically significantly more ulnodorsally at the wrist dorsal and ulnar deviation positions, more ulnopalmarly at the wrist palmar flexion position, and more radiopalmarly at the wrist radial deviation-position than at the wrist neutral position with all 5 fingers at full extension. Especially, it moved statistically significantly most ulnodorsally at the wrist dorsal flexion position during finger motion. The FPL moved most statistically significantly ulnopalmarly at the wrist palmar flexion position with all 5 fingers in full extension among all wrist positions during finger motion. During finger motion, the wrist dorsal flexion position induced significant displacement of the FPL to the distal radius and compressed it between the flexor tendons and the distal radius. The average distance between the FPL and the volar surface of the distal radius in the palmar-dorsal direction at wrist dorsal flexion position in all fingers at full flexion was 1.9 mm, the smallest among all wrist positions during finger motion. CONCLUSIONS: There is a significant relationship between the transverse movement of the FPL at the distal radius and wrist and finger motions. Our findings indicated that the irritation of the FPL caused by the movement of both the FPL itself and of the flexor digitorum superficialis and profundus is most induced with the wrist in dorsal flexion with all 5 fingers at full flexion compared to other wrist positions during finger motion. This wrist position might be the optimum one at which to evaluate the irritation of the FPL from volar locking plates in patients with distal radius fracture. We believe that our transverse ultrasound results can play a role in the gaining of a better understanding of the kinematics of the FPL. Moreover, they have potential to lead to improved diagnosis of and treatment for fractures of the distal radius and help to minimize the risk of FPL rupture related to volar locking plates.

Transverse Ultrasound Assessment of the Displacement of the Median Nerve in the Carpal Tunnel during Wrist and Finger Motion in Healthy Volunteers.

PURPOSE: The purpose of this study was to investigate the displacement of the median nerve in the carpal tunnel during finger motion at varied wrist positions using transverse ultrasound in healthy volunteers, in order to clarify the appropriate position of a wrist splint in treating carpal tunnel syndrome. METHODS: Fifty wrists of 25 asymptomatic volunteers were evaluated by transverse ultrasound. The location of the median nerve in the carpal tunnel was examined at 5 wrist positions (neutral, 60° dorsiflexion, 60° palmar flexion, 40° ulnar flexion, 10° radial flexion) with all 5 fingers in full extension, all 5 fingers in full flexion, and isolated thumb in full flexion, respectively. RESULTS: The median nerve was located significantly (p<0.05) more dorsally at the wrist dorsal flexion position, more ulnopalmarly at the wrist palmar flexion position, more radially at the wrist radial flexion position, and more radially at the wrist ulnar flexion position than at the wrist neutral position in all 5 fingers at full extension. The median nerve moved the most significantly dorsally among all wrist positions during finger motion at the wrist dorsal flexion position (p<0.05). Conversely, the median nerve moved the most significantly ulnopalmarly at the wrist palmar flexion position with all 5 fingers in full flexion among all wrist positions during finger motion (p<0.05). This latter wrist and finger position induced significant displacement of the median nerve toward the transverse carpal ligament, and compressed it between the flexor tendons and the transverse carpal ligament. CONCLUSIONS: This study showed that there is a significant relationship between the median nerve displacement in the carpal tunnel and the motion of the wrist and fingers. This finding suggests that the compression or the shearing stress of the median nerve caused by the movement of the flexor tendons is reduced in the wrist dorsal flexion position compared with other wrist positions. This wrist dorsal flexion position could be the appropriate position for a wrist splint in the treatment for carpal tunnel syndrome. This ultrasound information provides further knowledge and understanding of the biomechanics and pathophysiology of the carpal tunnel. It could also help in the accurate analysis and assessment of diagnostic images and treatment for carpal tunnel syndrome.

Transverse Movement of the Median Nerve in the Carpal Tunnel during Wrist and Finger Motion in Patients with Carpal Tunnel Syndrome.

Carpal tunnel syndrome (CTS) is the most common peripheral compression neuropathy of the upper extremity. Repetitive wrist and finger motion has been suggested as a major factor of pathogenesis of CTS. However, little is known about the pathomechanics of CTS. We aimed to evaluate the movement of the median nerve in the carpal tunnel during wrist and finger motions using transverse ultrasound in 21 patients with CTS (5 men and 16 women with mean age 69.0 years). We examined quantitatively the median nerve location as a coordinate within the carpal tunnel at varied wrist positions with all fingers full extension and flexion respectively in the affected and unaffected sides. We thus found that at all wrist positions during finger motion, the median nerve moved significantly more ulnopalmarly in the affected side compared to the unaffected side (p < 0.05). Especially, at the wrist palmar-flexion position as a provocative test, the nerve moved significantly (p < 0.05) the most ulnopalmarly among all wrist positions in the affected side. The nerve was the most strongly compressed against the transverse carpal ligament by the flexor tendons. Additionally, the displacement amount of the nerve in the dorsal-palmar direction was significantly smaller in the affected side than in the unaffected side. These findings indicate that such a pattern of nerve movement has the potential to distinguish affected from unaffected individuals. This ultrasound information could be useful in better understanding of the pathomechanics of CTS, and in further improvement of diagnosis and treatment for CTS.

Three-dimensional Analysis of the Attachment and Path of the Transverse Carpal Ligament.

PURPOSE: The purpose of this study was to describe and evaluate the detailed anatomic locations and areas of ligamentous attachments and paths of the transverse carpal ligament (TCL) on a three-dimensional (3-D) surface model. METHODS: Ten fresh-frozen cadaver wrists were used to dissect and identify the TCL. Their ligament attachments and whole bone surfaces were digitized three-dimensionally and their areas evaluated. The attachments of each ligament were represented in a model combining CT surfaces overlaid by a digitized 3-D surface, and were also visually depicted with a different color for each on 3-D images of the bones. RESULTS: The TCL was found to be composed of two or three discrete ligaments. Both the trapezium-hook of hamate ligament and the trapezium-pisiform ligament were identified in all ten specimens. The scaphoid-pisiform ligament was found in only two of the ten specimens. The average areas of the attachments of the TCL were 42.7 mm(2) on the trapezium, 30.0 mm(2) on the hook of hamate, 21.6 mm(2) on the pisiform, and 12.7 mm(2) on the scaphoid. CONCLUSIONS: The anatomic 3-D attachment sites of the TCL were visually shown qualitatively, and their areas quantified. This 3-D information offers further knowledge and understanding of the anatomy and biomechanics of the TCL. It could also help in the accurate assessment of radiographic images and treatment of various wrist injuries and diseases when performing such procedures as carpal tunnel release, Guyon's canal release, trapeziectomy, hook of hamate excision, or arthroscopy.