Proximal Carpal Row Research Articles

Treating mid carpal instability conservatively

Carpal/Wrist instability is the result of a large variety of conditions. Any alteration of the shape of the wrist bones or the connections between them can affect the dynamic balance of forces and the wrists unique multi-plane movements. Sensorimotor function is a term used to describe sensory, motor and central processes pertaining to joint stability. Wrist joint proprioception and sensorimotor function provides a platform for neuromuscular joint stability.Afferent information from nerve endings affects the neuromuscular control of the wrist joint. An understanding of these systems as well as the biomechanics of the wrist is critical in its rehabilitation, particularly given the complexity and number of articulations and ligaments within this complex joint. Mechanoreceptors are sensory end organs reactive to joint pressure, motion and velocity. Ruffini Ending, Pacini Corpuscle and Golgi tendon organs are different mechanoreceptors. Ruffini ending is the predominant mechanoreceptor type found in wrist ligaments. They are slowly adapting, low threshold receptor, which are constantly reactive during joint motion. They react to axial loading and tensile strain in the ligament, but not to ‘weight bearing’ type compressive joint forces. Therefore they signal joint position and rotation. The Golgi tendon organ has only been identified in the large dorsal wrist ligaments, the dorsal radiocarpal and dorsal intercarpal which transvers both the radiocarpal and midcarpal joints. This receptor is important in monitoring tensile strain in the ligament during end range. The DIC ligament is important in maintain stability of the proximal carpal row as well as indirect stability of dorsal midcarpal joint space The Pacini Corpuscle are rapidly adapting, high threshold receptors sensitive to joint acceleration/deceleration and compressive but not tensile forces. Unlike the ankle, where they are found in abundance, they have minor importance in the wrist where they are less prevalent. The receptors are most pronounced in the dorsal and triquetral wrist ligaments - DRC, DIC, SL, Palmar Lunotriquetral and triquetrocapitate/hamate ligaments. The arrangements of the wrist ligaments are unique in that the ligaments of the radial column are dense, designed to with stand axial loads given 80% of axial force is transmitted through this side. The dorsal and triquetral ligaments are sensory important structures, and since they traverse both the radiocarpal and midcarpal joints signal throughout wrist joint motion. Proprioceptive reflexes between wrist ligaments and forearm muscles have recently been demonstrated particularly in the antagonist muscles in each wrist position, indicating a joints protective function. Ongoing global stability of the wrist joint is evident in later reactions, which initiate simultaneous co-activation of the wrist flexors and extensors. This delicate balance of co-contraction is also believed important in maintaining smooth and even joint motions. After a wrist injury or wrist surgery, most patients have been immobilized during the posttraumatic or postoperative period. Therefore all of the afferent kinesthetic information from the wrist joint, the skin, and muscle spindles has been lost. Complete with the reduced visual feedback a patient’s total conscious awareness is diminished. Furthermore after ligament injury periarticular muscles are frequently weak, which will result in a neuromuscular imbalance during concentric contractions.

Hoxd11 Influences Growth Plate Organization in the Mammalian Pisiform

The typical mammalian pisiform is rod‐shaped, forms from two centers of ossification, and contains an organized growth plate at the palmar end. The pisiform is the only carpal to form a growth plate; however, humans possess a short pisiform that forms from a single ossification center and lacks a growth plate. In the mouse, Hoxa11 and Hoxd11 mutations lead to abnormal shortening of this bone, and variable fusion between bones in the proximal carpal row. We have previously observed that Hoxd11 expression is present in tissues surrounding the developing pisiform in embryonic mice. This study seeks to examine the structure of shortened pisiforms in Hoxd11 mutant mice during development and determine if the growth plate is affected by deletion of one or both Hoxd11 alleles. We conducted histological analyses of the carpus in juvenile mice, comparing wild type (+/+) to heterozygotes (+/‐) and homozygotes (‐/‐) for a Hoxd11 deletion. Pisiforms from +/+ and +/‐ mice have organized resting, columnar, and hypertrophic cartilaginous zones, while ‐/‐ mice have disorganized cartilage where the growth plate typically forms. We also observe fusion of the pisiform and triquetral in ‐/‐ mice, consistent with observations in previous studies. These results support the role of Hox genes in growth plate specification, and indicate that presence of Hoxd11 expression around the developing pisiform may signal formation of its growth plate. Additionally, these data may help to explain the developmental processes underlying evolutionary differences within the piso‐triquetral complex among apes and humans, including the loss of a growth plate and substantial shortening of the human pisiform. This research is funded by the Hill Fellowship awarded by the Department of Anthropology at Penn State.

Clinical Outcomes Following Midcarpal Hemiarthroplasty of the Wrist

Introduction Wrist hemiarthroplasty by means of proximal carpal row resurfacing is indicated for patients suffering from radiocarpal arthritis with a preserved distal carpal row. Compared with alternative procedures, such as total arthroplasty or arthrodesis, resurfacing the proximal carpal row preserves the anatomic center of rotation and radial length without ligamentous disruption and maintains the natural coupled motion of the wrist at the midcarpal articulation.

Arthroscopic Ligament Plication for Palmar Midcarpal Instability

Introduction Palmar midcarpal instability (PMCI) is a painful condition characterized by a kinematic dysfunction of the proximal carpal row (PCR). Although its etiology is still poorly understood, it is believed to be due to congenital (or traumatic) laxity of the ligaments that stabilize the PCR, primarily, the dorsal radiotriquetral (DRT) ligament and the ulnar arm of the palmar arcuate ligament. This laxity causes an unphysiologic coupling of the midcarpal joint, which is clinically evident as a painful clunk with ulnar wrist deviation. Most symptomatic PMCI patients benefit from nonoperative management, which is based on splinting and proprioceptive neuromuscular rehabilitation. However, patients that do not respond to nonoperative management are candidates for surgical treatment. Cases with mild to moderate symptoms may be treated with soft tissue procedures, such as dorsal capsular reefing (Lichtman, 2006) or arthroscopic shrinkage (Mason, 2007; Lichtman, 2003). The purpose of this study was to present our results with a personal technique of arthroscopic ligament plication (ALP) for PMCI.

Dart-Splint: An innovative orthosis that can be integrated into a scapho-lunate and palmar midcarpal instability re-education protocol

The Authors describe a novel hinged orthosis that permits selective midcarpal mobilization along the plane of the dart throwing motion. This orthotic device can be used to assist rehabilitation protocols aimed to limit radiocarpal joint mobility and scapho-lunate ligament overload and to accelerate wrist functional recovery after ligamentous injuries around the proximal carpal row. - VictoriaW.Priganc, PhD, OTR, CHT, CLT, Practice Forum Editor.

Osseous Scaphotrapezial Coalition.

Osseous scaphotrapezial coalition is one of the rarest forms of carpal coalition of the hand. Often discovered incidentally, pain and functional limitation have not been reported. Carpal coalitions occurring across the carpal rows are thought to occur as a result of some insult or congenital anomaly. Isolated scaphotrapezial coalition calls into question the traditional thinking that fusion between the proximal and distal carpal rows must be acquired or associated with congenital syndromes.

三次元手関節モデルを用いた橈・尺屈シミュレーション

The primary objective of this study was to numerically simulate the carpal bone kinematics during radioulnar deviation of the wrist. Based on computed tomography (CT) images of the human arm, we constructed a biomechanical model comprising the arm and wrist (humerus, ulna, radius, and the bones of the hand). The carpal bones were fused into a single functional unit, while the humerus, ulna, and radius were rigidly fixed, allowing only the wrist joint to move. Further, the ligaments connecting the radius and the ulna to the carpal bones were approximated by wire models. In this study, five palmar and four dorsal ligaments were included. For the muscles controlling radial deviation, the flexor carpi radialis and extensor carpi radialis longus were selected. For the muscles responsible for ulnar deviation, the flexor carpi ulnaris and extensor carpi ulnaris were selected. These muscles were represented with muscle spring models. Two types of muscle spring models were employed: a linear muscle spring model and tendon-modulated muscle spring model. In the linear muscle spring model, the points of muscle origin and insertion were linked with linear springs. These springs simulated muscle stretching and relaxation, without allowing for deformations. The tendon-modulated muscle spring model comprised elements simulating contractible the muscle fibers and elastic tendons that transmitted muscle force to the bone. To compare with the simulation results, CT images of the human wrist joint were obtained at different radioulnar deviation angles. The results of having carried out radioulnar deviation in both models, the linear muscle spring model yielded a maximum ulnar deviation angle of 10° and a maximum radial deviation angle of 3.5°. The tendon-modulated muscle spring model provided a maximum ulnar deviation angle of no less than 30° and a maximum radial deviation angle of no less than 20°. We used the tendon-modulated muscle spring model to estimate the translation of anatomic landmarks (the trapezium and scaphoid) at different degrees of radioulnar deviation, and these simulation results were compared with the human imaging data. For the trapezium, the traveled distances were comparable, whereas the results were incongruent for the scaphoideum. These discrepancies were probably attributable to the improper modeling of the proximal carpal row movement associated with ulnar deviation.

Surgical Techniques for the Management of Midcarpal Instability.

Palmar midcarpal instability (PMCI) is an uncommon and poorly understood disorder. Its etiology is believed to be due to traumatic or congenital laxity of the ligaments (volar and dorsal) that stabilize the proximal row. This laxity results in hypermobility of the proximal carpal row and unphysiologic coupling of the midcarpal joint. Clinically, the condition is manifested by a painful clunk with ulnar and radial wrist deviation. The purpose of this article is to chronicle our personal experience with this condition and to review our current treatment recommendations and outcomes.

Osteology and Functional Morphology of the Forelimb of the Marine Sloth Thalassocnus (Mammalia, Tardigrada)

Thalassocnus is a genus of “ground sloths” known from Neogene deposits, for the great majority of specimens, of the Pisco Formation (Peru). Five species are recognized, their description being currently restricted, for the most part, to the skull, mandible, and dentition. The bones of the forelimb are here described, and compared among the species of Thalassocnus and to other pilosans. The main characteristics of the forelimb of Thalassocnus relative to other sloths are the shortness of the humerus and radius, and the specialized digits. Moreover, the late species of the genus are characterized by the development of the pronator ridge of the radius, stoutness of the ulna, widening of the proximal carpal row, and shortening of the metacarpals. Analogies with extant tetrapods are proposed in order to infer plausible aquatic functions of the forelimb of Thalassocnus. In addition to paddling, it is argued that the forelimb of Thalassocnus was involved in bottom-walking, a function similarly found in extant sirenians. However, the function of the forelimb of Thalassocnus differs drastically from that of the latter, since it was likely involved in an activity related to obtaining food such as uprooting seagrass rhizomes.

Muscular control of scapholunate instability. An experimental study

PurposeAs long as the neuromuscular stabilizers are intact, a lesion of the scapholunate ligament may or may not progress to a carpal instability. The mechanisms by which the muscles compensate this defect are not very well known. We designed an experimental study with the aim of clarifying these mechanisms. Material and methodUsing 10 fresh wrists, with no pre-existing lesions, we studied the movements of the scaphoid, triquetrum and capitate produced by the isometrical loading of the muscles which move the wrist, each of them isolated or combined, before and after cutting off the scapholunate ligaments. To do this, we placed sensors in each of these bones and used the Fastrack® system to record these movements. ResultsThe simultaneous loading of the muscles of the wrist produce rotational movements in flexion and supination of the proximal carpal row. After cutting off the scapholunate ligaments, the scaphoid rotates in pronation and flexion, while the triquetrum rotates in pronation and extension. In this situation of a scapholunate lesion, the muscles that worsen the carpal dexasation are the extensor carpi ulnaris and flexor carpi ulnaris. On the other hand, the isolated loading of the radial muscles reduces the scapholunate diastasis, thus improving the carpal alignment. ConclusionIn dynamic scapholunate instabilities, isometric contraction of the ulnar carpal muscles must be avoided, as it promotes the scapholunate diastasis. The rest of the muscles have the opposite effect, stabilizing the carpus when primary stabilizers have failed.

Control muscular de la inestabilidad escafolunar. Estudio experimental

PurposeAs long as the neuromuscular stabilizers are intact, a lesion of the scapholunate ligament may or may not progress to a carpal instability. The mechanisms by which the muscles compensate this defect are not very well known. We designed an experimental study with the aim of clarifying these mechanisms. Material and methodUsing 10 fresh wrists, with no pre-existing lesions, we studied the movements of the scaphoid, triquetrum and capitate produced by the isometrical loading of the muscles which move the wrist, each of them isolated or combined, before and after cutting off the scapholunate ligaments. To do this, we placed sensors in each of these bones and used the Fastrack system to record these movements. ResultsThe simultaneous loading of the muscles of the wrist produce rotational movements in flexion and supination of the proximal carpal row. After cutting off the scapholunate ligaments, the scaphoid rotates in pronation and flexion, while the triquetrum rotates in pronation and extension. In this situation of a scapholunate lesion, the muscles that worsen the carpal dexasation are the extensor carpi ulnaris and flexor carpi ulnaris. On the other hand, the isolated loading of the radial muscles reduce the scapholunate diastasis, thus improving the carpal alignment. ConclusionIn dynamic scapholunate instabilities, isometric contraction of the ulnar carpal muscles must be avoided, as it promotes the scapholunate diastasis. The rest of the muscles have the opposite effect, stabilizing the carpus when primary stabilizers have failed.

A Systematic Method of Arthroscopic Testing of Extrinsic Carpal Ligaments

Several biomechanical studies have shown that the scapholunate and lunotriquetral ligaments are not the only stabilizers of the proximal carpal row. However, no study has yet analyzed the spectrum of ligamentous lesions in vivo, leading to instability. We describe an arthroscopic technique for evaluating the extrinsic carpal ligaments. The testing relies on visualization and palpation of different ligaments. Their integrity is assessed with a 4-stage scale. Radiocarpal arthroscopy enables assessment of the following ligaments: the radiocarpal part of the radio-scapho-capitate, the long radiolunate, the short radiolunate, the ulnolunate, the ulnotriquetral, and the dorsal radiocarpal. Midcarpal arthroscopy enables assessment of the mid part of the radio-scapho-capitate, the triquetrocapitate, the scaphotrapezial, and the dorsal intercarpal. Above assessment is proposed in addition to assessing the articular cartilage, scapholunate, and lunotriquetral ligaments. This method allows a precise arthroscopic assessment of the extrinsic ligaments of the wrist. It could give an important help in the understanding of carpal instability.

Proximal Row Carpectomy: Minimum 20-Year Follow-Up

Proximal row carpectomy (PRC) is a motion-sparing procedure for degenerative disorders of the proximal carpal row. Reported results at a minimum 10-year follow-up consistently show maintenance of strength, motion, and satisfaction with an average conversion rate to radiocarpal arthrodesis of 12%. We hypothesized that PRC would continue to provide a high level of satisfaction and function at a minimum of 20 years. Seventeen wrists in 16 patients, including 7 laborers, underwent PRC for symptomatic degenerative disorders of the proximal carpal row at an average age of 36 years. Patients returned for radiographic and clinical evaluation, and the Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire and Patient-Related Wrist Evaluation were used for subjective assessment. Follow-up was a minimum of 20 years (average, 24 y). Eleven wrists (65%) underwent no further surgery at a minimum 20-year follow-up. The average time to failure of PRC, defined as the time from PRC to radiocarpal arthrodesis, was 11 years (range, 8 mo to 20 y). Ten of 11 patients who did not undergo radiocarpal arthrodesis continued to be satisfied, with minimal decrease in motion and grip strength compared with the uninvolved side. Average score for QuickDASH was 16 and for Patient-Related Wrist Evaluation was 26. The flexion-extension arc was 68°, and grip strength was 72% of the contralateral side. All patients returned to their original employment. There was no correlation between degenerative radiographic changes and satisfaction level. The predicted probability of failure revealed a higher risk in patients who underwent PRC at a younger age, which leveled off at age 40 years. PRC provides satisfaction at a minimum of 20 years with a survival rate of 65%. Whereas we recommend a minimum age for PRC between 35 and 40 years, young patients should not be excluded as PRC candidates; these patients should undergo appropriate preoperative counseling of their increased failure risk secondary to their young age. Therapeutic IV.

Modified AO Arthrodesis of the Wrist (With Proximal Row Carpectomy)

A technique that has proven highly predictable and successful for arthrodesis of the wrist involves combining rigid internal fixation with concomitant removal of the proximal carpal row bones, which are then morselized and used for bone graft. Advantages of this procedure are (1) no distant bone graft site is required and (2) rigid internal fixation allows virtually immediate rehabilitation.

Evaluation of Associated Carpal Bone Fractures in Distal Radial Fractures

BackgroundThe purpose of this study was to investigate the frequency and distribution of associated carpal bone fractures (CBFs) in distal radial fractures (DRFs).MethodsThree hundred and thirteen patients who underwent surgical treatment for DRFs between March 2007 and January 2010 were reviewed retrospectively. In this study, 223 patients who had preoperative computed tomography (CT) were included. We investigated the frequency and distribution of associated CBFs on CT scans. The relationship between the frequency of associated CBFs and patient factors such as age, gender, body mass index, and the mechanism of injury was assessed.ResultsCBFs were complicated in 46 of 223 DRFs (20.9%). The distribution of CBFs was 23 cases in the triquetrum, 16 in the lunate, 12 in the scaphoid, five in the hamate, and four in the pisiform. Among the 46 cases, a fracture of one carpal bone occurred in 36 cases, two in seven cases, three in two cases, and four in one case. In 10 of the 46 cases, associated CBFs occurred in more than two carpal bones. No significant differences were observed for age, sex, body mass index, or the mechanism of injury between patients with DRFs and CBFs and those without CBFs.ConclusionsBecause CBFs that mainly occur in the proximal carpal row are complicated in DRFs at a relatively high frequency, assessment of carpal bones using CT scans is beneficial.

Avascular necrosis of the proximal carpal row of the wrist. A possible complication of bisphosphonate administration

Reports of coexisting osteonecrosis of more than one carpal bone are rare. We report an osteonecrosis of the entire proximal carpal row of the wrist, started briefly after intravenous bisphosphonate administration. The use of bisphosphonates for the treatment of osteoporosis is increasing. Osteonecrosis of the jaw (ONJ) is one of the known adverse effects during chronic treatment with bisphosphonates. This case is reported to make clinicians aware of a possible causative link between bisphosphonate use and osteonecrosis of other bones.

Unusual Proximal Dislocation without Fracture: A Case Report

Carpal instability includes a broad spectrum of osseous and ligamentous injuries which have been subclassified into greater and lesser arc injuries, in addition to combinations of both (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). The injuries typically occur from a fall on the outstretched hand with the wrist in ulnar deviation, hyperextension, and intercarpal supination (Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). The force classically propagates from the radial to the ulnar side of the wrist resulting in a fracture (greater arc) or dislocation (lesser arc) pattern with the extent of the injury occurring in an orderly pattern depending upon the degree of hyperextension and the duration and magnitude of the force (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985). Multiple variations occur, including transradial styloid fractures as well as fractures through carpal bones surrounding the lunate (Mayfield et al. J Hand Surg [Am] 5:226-241, 1980; Yaeger et al. Skeletal Radiol 13(2):120-30, 1985; Kozin SH. J Am Acad Orthop Surg 6 (2): 114-20, 1998. Although carpal dislocations have been noted for many years, the mechanisms and classification have only been recently clarified. We report a case of a complex dislocation involving the entire proximal carpal row without an associated fracture. While this type of complex carpal dislocation has been previously described, to our knowledge, it has never been reported without a fracture of the forearm, wrist, or hand.

Carpal Instability Nondissociative

Carpal instability nondissociative (CIND) represents a spectrum of conditions characterized by kinematic dysfunction of the proximal carpal row, often associated with a clinical "clunk." CIND is manifested at the midcarpal and/or radiocarpal joints, and it is distinguished from carpal instability dissociative (CID) by the lack of disruption between bones within the same carpal row. There are four major subcategories of CIND: palmar, dorsal, combined, and adaptive. In palmar CIND, instability occurs across the entire proximal carpal row. When nonsurgical management fails, surgical options include arthroscopic thermal capsulorrhaphy, soft-tissue reconstruction, or limited radiocarpal or intercarpal fusions. In dorsal CIND, the capitate subluxates dorsally from its reduced resting position. Dorsal CIND usually responds to nonsurgical management; refractory cases respond to palmar ligament reefing and/or dorsal intercarpal capsulodesis. Combined CIND demonstrates signs of both palmar and dorsal CIND and can be treated with soft-tissue or bony procedures. In adaptive CIND, the volar carpal ligaments are slackened and are less capable of inducing the physiologic shift of the proximal carpal row from flexion into extension as the wrist ulnarly deviates. Treatment of choice is a corrective osteotomy to restore the normal volar tilt of the distal radius.

Carpal Instability Nondissociative

Carpal instability nondissociative (CIND) represents a spectrum of conditions characterized by kinematic dysfunction of the proximal carpal row, often associated with a clinical “clunk.” CIND is manifested at the midcarpal and/or radiocarpal joints, and it is distinguished from carpal instability dissociative (CID) by the lack of disruption between bones within the same carpal row. There are four major subcategories of CIND: palmar, dorsal, combined, and adaptive. In palmar CIND, instability occurs across the entire proximal carpal row. When nonsurgical management fails, surgical options include arthroscopic thermal capsulorrhaphy, soft-tissue reconstruction, or limited radiocarpal or intercarpal fusions. In dorsal CIND, the capitate subluxates dorsally from its reduced resting position. Dorsal CIND usually responds to nonsurgical management; refractory cases respond to palmar ligament reefing and/or dorsal intercarpal capsulodesis. Combined CIND demonstrates signs of both palmar and dorsal CIND and can be treated with soft-tissue or bony procedures. In adaptive CIND, the volar carpal ligaments are slackened and are less capable of inducing the physiologic shift of the proximal carpal row from flexion into extension as the wrist ulnarly deviates. Treatment of choice is a corrective osteotomy to restore the normal volar tilt of the distal radius.

Midcarpal Hemiarthroplasty for Wrist Arthritis: Rationale and Early Results

Midcarpal hemiarthroplasty is a novel motion-preserving treatment for radiocarpal arthritis and is an alternative to current procedures that provide pain relief at the expense of wrist biomechanics and natural motion. It is indicated primarily in active patients with a well-preserved distal row and debilitating arthritic symptoms. By resurfacing the proximal carpal row, midcarpal arthroplasty relieves pain while preserving the midcarpal articulation and the anatomic center of wrist rotation. This technique has theoretical advantages when compared with current treatment options (i.e., arthrodesis and total wrist arthroplasty) since it provides coupled wrist motion, preserves radial length, is technically simple, and avoids the inherent risks of nonunion and distal component failure. The KinematX midcarpal hemiarthroplasty has an anatomic design and does not disrupt the integrity of the wrist ligaments. We have implanted this prosthesis in nine patients with promising early results. The indications for surgery were as follows: scapholunate advanced collapse wrist (three), posttraumatic osteoarthritis (three), inflammatory arthritis (two), and Keinböck disease (one). Prospective data has been collected and the results are preliminary given the infancy of the procedure. The mean follow-up was 30.9 weeks (range: 16 to 56 weeks). The mean Mayo wrist score increased from 31.9 preoperatively to 58.8 (p < 0.05) and the mean DASH score improved significantly from 47.8 preoperatively to 28.7 (p < 0.05). There was a trend toward increased motion but statistical significance was not reached. Two patients required manipulation for wrist stiffness. There was no evidence of prosthetic loosening or capitolunate narrowing. The procedure is simple (average surgical time was 49 minutes) and maintains coupled wrist motion through preservation of the midcarpal articulation. The preliminary data show that it appears safe but considerably longer follow-up is required before conclusions can be drawn as to its durability, reliability, and overall success. The level of evidence for this study is therapeutic level IV (case series).