Proximal Carpal Row Research Articles

Modification of proximal row carpectomy (PRC) technique for adaptive wrist collapse (pilot study)

Introduction Proximal carpal row resection has been used for many decades as a “salvage procedure” for progressive wrist collapse. Improving the technique of its implementation, as well as introducing various modifications of the technique into practice are an important area for achieving better results of surgical treatment.The purpose of this work was to demonstrate aspects of the modified proximal row carpectomy (PRC) technique and the immediate results of its use.Materials and methods Eight patients aged from 24 to 57 years (seven men and one woman) were treated with the modified PRC technique. Treatment results were assessed using an adapted QuickDASH questionnaire, a visual analogue scale (VAS), based on patient satisfaction and radiographic results.Results The average duration of surgical intervention was (149.0 ± 35.5) minutes. In the postoperative period, six patients (75 %) underwent fixation with an Ilizarov apparatus, the rest with a plaster splint. The average range of motion of flexion and extension was (67.5 ± 18.3)°, range: 40–95°. The patients had an average of (35.6 ± 16.13)° extension, range: 10–65° and (31.87 ± 10.9)° flexion, range: 10–45°. Patients reported decreased grip strength after surgery. Pain syndrome according to VAS at rest was equal to 0–1 points and 3–4 points when the affected limb was loaded. Six patients completed the QuickDASH survey, with a mean score of (14.83 ± 4.25) points. All patients are satisfied with the result of treatment and the absence of pain at rest. Patients returned to their usual work.Discussion Unlike the conventional dorsal approach through the III–IV tendon canals, the use of two mini-approaches provides a better cosmetic effect and makes it easier to restore the integrity of the tendon canals, which are important for the prevention of desmogenic contractures. The use of the Ilizarov apparatus has proven to be the method of choice, providing absolute stability and reduction of pain in the postoperative period. For patients under 45 years of age with increased functional demands, a balanced approach is required when choosing PRC or intercarpal arthrodesis, depending on which functional parameters are more important to the patient.Conclusion The analysis of short-term results of using the modified PRC technique shows that it reduces the invasiveness of the operation, improves its esthetic result, provides pain relief and a satisfactory range of motion and grip strength.

Spontaneous union of neglected proximal pole scaphoid fracture: A case report

Scaphoid fractures are the most common carpal bone fractures and usually occur due to trauma, typically a fall on an outstretched hand. The scaphoid bone is integral to wrist biomechanics, linking the proximal carpal row to the distal row. Neglected scaphoid fractures can lead to significant long-term complications, with degenerative changes likely to occur. The most common consequence of a neglected scaphoid fracture is known as scaphoid non-union advanced collapse, which typically begins within five years following the injury. It is widely accepted that scaphoid fractures, in general, should be treated to avoid long-term complications. Many surgeons aggressively treat proximal pole fractures with surgical fixation due to the high risk of avascular necrosis. Although some surgeons may consider a period of immobilization, none would argue against the need for treatment of proximal pole fractures, either through immobilization or surgical fixation. In this case, we present an instance of spontaneous union of a neglected proximal pole fracture non-union in a mature adult. This report aims to provide awareness of the possible spontaneous union of neglected proximal pole scaphoid fracture. It also challenges the call for acute aggressive surgical intervention in such fractures. Radiographs and magnetic resonance imaging scan images before and after union are presented, along with a review of the available literature.

Complex Axial Carpal Dislocation with Scapholunate Ligament Injury

Abstract Background Axial carpal dislocations (ACDs) are high-impact injuries, involving both proximal and distal carpal rows, adding complexity to the diagnostic and treatment challenges. This article explores a distinctive case of axial radial carpal dislocation, highlighting an irreducible second carpometacarpal joint (CMCJ) and concomitant scapholunate (SL) ligament injury. Understanding the background of axial carpal injuries is crucial for recognizing and addressing these complex cases effectively. Description A 27-year-old man presented with a left wrist injury following a motorcycle accident, revealing an irreducible second CMCJ with a unique ligamentous injury pattern. Despite unsuccessful closed reduction attempts, the surgical intervention involved a dorsal midline incision, fixation of the second CMCJ and SL interval, and ligament repair. Postoperative assessment demonstrated proper alignment with a mild gap in the SL interval, revealing the intricate nature of the injury. Literature Review Existing studies describe a type of axial dislocation starting at the third webspace, traveling through capitate–hamate intervals leading to scaphoid dislocation. However, in the article, we describe a variant of ACD through second CMCJ causing an SL interval instability. Clinical Relevance Recognizing and comprehensively addressing axial radial carpal dislocations are crucial for optimal patient outcomes. The case report contributes valuable insights into the rare pattern of ACD involving SL instability that was missed on initial radiographs but detected through computed tomography scan and thereby managed appropriately. Any CMCJ dislocation should raise a suspicion of axial dislocation unless proved otherwise.

Perilunate Dislocations: Cadaveric Model K-Wire Versus Compression Staple Fixation

Repair of perilunate dislocations requires stabilization of the carpal bones, although there is limited research on the preferred method(s) of stabilization. We compared the biomechanical characteristics of K-wire versus staple fixation of scapholunate (SL) and lunotriquetral (LT) intervals in the wrist. After creating a grade IV instability model, 20 cadaver wrists were randomized into 2 stabilization model groups using K-wires or surgical staples across the SL and LT intervals. For each ligament, two K-wires or one surgical staple was used to stabilize the proximal carpal row. Each wrist was loaded with 15 N of force and cycled 5,000 times at an angular velocity of 10 rpm. Displacement between bones was measured at different cycles (10, 100, 500, 1,000, 2,000, 3,000, 4,000, and 5,000). A t test was used for comparisons. For the LT K-wire group, the average displacement at 10 cycles was 0.08 mm, and at 5,000 cycles, 0.163 mm. For the SL K-wire group, the average displacement at 10 cycles was 0.025 mm, and at 5,000 cycles, 0.129 mm. For the LT and SL staple fixation models, the average shifts at 10 cycles were 0.029 and 0.063 mm, and at 5,000 cycles, 0.098 and 0.176 mm, respectively. No significant difference between the fixation models was found at any interval. Notably, in each group, a similar number of small outliers with higher amounts of displacement was observed. Either K-wire or surgical staple stabilization is suitable for perilunate dislocations. The surgical method should be selected based on patient-specific circumstances and the provider's judgment. Therapeutic III.

Tendon ball arthroplasty and proximal carpal stabilization with tendon graft for advanced Kienbock's disease.

This study reports the surgical technique and outcomes of tendon ball arthroplasty combined with proximal carpal stabilization using the extensor carpi radialis longus tendon for treating advanced Kienbock's disease. The collapsed lunate is excised and a tendon ball inserted as a spacer. A distally based extensor carpi radials longus graft is passed through the scaphoid, tendon ball and triquetrum, reconstructing the proximal carpal row. In total, 16 patients were included and the mean follow-up was 25 months. Pain improved from 5.6 preoperatively to 1.3 postoperatively on a 10-point visual analogue scale. Mean wrist motion improved by 17.8° and grip strength compared with the non-operative side increased by 22.1% on average. Radiographic outcomes demonstrated correction of scaphoid flexion and carpal height ratio. The modified tendon ball arthroplasty may be an alternative wrist salvage procedure for the treatment of advanced Kienbock's disease.Level of evidence: IV.

Pyrocarbon Lunate Arthroplasty: An Option for the Young Patient with Advanced Kienbock Disease.

Kienbock disease, or avascular necrosis of the lunate, is an uncommon cause of a painful and stiff wrist. Management options range from conservative treatment in the form of immobilization and corticosteroid injections to a wide variety of surgical treatments that depend on the structural integrity of the lunate, intercarpal relationships, and the condition of the articular cartilage of the wrist. A particularly difficult problem lies in the management of young patient in whom vascularized bone grafting of the lunate has failed but in whom arthritis has not yet developed. Pyrocarbon lunate implant arthroplasty is a newer treatment option for such a patient, and allows the preservation of the remainder of the proximal carpal row while directly addressing the degenerative lunate. This article describes the evidence and surgical technique for lunate implant arthroplasty and presents an illustrative case example.

One-Year Outcomes of the Anatomical Front and Back Reconstruction for Scapholunate Dissociation

Anatomical front and back (ANAFAB) reconstruction addresses the critical volar and dorsal ligaments associated with scapholunate dissociation. We hypothesized that patients with symptomatic, chronic, late-stage scapholunate dissociation would demonstrate improvements in all radiographic parameters and patient-reported outcomes (PROMs) after ANAFAB reconstruction. From 2018 to 2021, 21 ANAFAB reconstructions performed by a single surgeon were followed prospectively, with 20 patients having a minimum follow-up of 12 months. In total, 17 men and four women were included, with an average age of 49 years. Three patients had modified Garcia-Elias stage 3 disease, eight stage 4, seven stage 5, and three stage 7. ANAFAB reconstruction of intrinsic and extrinsic ligament stabilizers was performed using a hybrid synthetic tape/tendon graft in a transosseous reconstruction. Pre- and postoperative radiographic parameters, grip, pinch strength, the Patient-Rated Wrist Evaluation, PROMIS Upper Extremity Function, and PROMIS Pain Interference outcome measures were compared. Mean follow-up was 17.9 months (range: 12-38). Radiographic parameters were improved at follow-up, including the following: scapholunate angle (mean 75.3° preoperatively to 69.2°), scapholunate gap (5.9-4.2 mm), dorsal scaphoid translation (1.2-0.2 mm), and radiolunate angle (13.5° to 1.8°). Mean Patient-Rated Wrist Evaluation scores for pain and function decreased from 40.6 before surgery to 10.4. We were unable to detect a significant difference in grip or pinch strength or radioscaphoid angle with the numbers tested. There were two minor complications, and two complications required re-operations, one patient who was converted to a proximal row carpectomy for failure of fixation, and one who required tenolysis/arthrolysis for arthrofibrosis. At 17.9-month average follow-up, radiographic and patient-reported outcome parameters improved after reconstruction of the critical dorsal and volar ligament stabilizers of the proximal carpal row with the ANAFAB technique. Therapeutic study IV.

Carpal instability after partial trapeziectomy, total trapeziectomy and the resection of the distal scaphoid pole: a cadaveric study.

Non-dissociative carpal instability (CIND) may lead to severe functional impairment. Destabilisation of the scapho-trapezial-trapezoidal (STT) ligament complex seems to result in a CIND. In one group with eight cadaver arms, distal scaphoid pole was resected with the adjacent ligaments. In the other eight cadavers, hemitrapeziectomy was performed followed by total trapeziectomy. CT scans were performed in different wrist positions, and the changed positions of the scaphoid, lunate and capitate were measured in comparison to non-operated wrists. Mainly in clenched fist position, dissociation between proximal and distal row can be determined after total trapeziectomy and resection of distal scaphoid pole. Capitate rotates dorsally up to 24°, the scaphoid up to 17° and the lunate up to 7° compared to the non-operated wrists. Resection of the distal scaphoid pole results in dorsal rotation of capitate and scaphoid of about 14° and the lunate 8°. Relative scapholunate and capitolunate angle increased significantly after total trapeziectomy, especially in clenched fist position. After scaphoid pole resection, significant SL and CL angles changescould be seen in almost every wrist position. Destabilisation of the STT ligament complex by total trapeziectomy or distal scaphoid pole resection results in dissociation of the proximal and distal carpal row without instability within the proximal or distal row, corresponding to a CIND. III.

Scaphoid fracture and nonunion: new directions.

The scaphoid is the largest of the carpal bones, articulating with both proximal and distal carpal rows. If scaphoid fractures are not appropriately diagnosed and treated, there is a risk of nonunion, osteonecrosis and degenerative arthritis. Operative management of the scaphoid fracture is primarily determined by the fracture location and amount of displacement. There is increased momentum for dual screw fixation constructs, intended to provide greater stability and reduce the risk of nonunion. Our current practice is to utilize two screws without graft as a first-line treatment for scaphoid nonunion with or without humpback deformity and cyst formation. This review will discuss the management of acute scaphoid fractures and the treatment of nonunion.

A Kinematic Analysis of Wrist and Carpal Function Using Four-Dimensional Computed Tomography Technology: A Dynamic Perspective

An emerging imaging modality, four-dimensional computed tomography, can provide dynamic evaluation of carpal motion, which allows for a better understanding of how the carpals work together to achieve range of motion. The objective of this work was to examine kinematic motion of the carpus through a flexion/extension arc of motion using four-dimensional computed tomography. A convenience sample of 20 uninjured participants underwent a four-dimensional computed tomography scanning protocol through a complete arc of flexion/extension motion. Kinematic changes in motion were quantified using helical axes motion data for each carpal. Rotation angles were compared between bones to identify differences in kinematic motion between bones. The bones within the proximal carpal row, the lunate, scaphoid, and triquetrum, rotate significantly to differing magnitudes at the ends of motion (40° of flexion and 40° of extension). The scaphoid rotates to the highest magnitude, followed by the triquetrum, and lastly, the lunate. The distal carpal row bones rotate to similar magnitudes throughout the entire range of motion. This work describes the kinematics of the carpals throughout dynamic invivo flexion and extension. This study adds to an understanding of wrist mechanics and the possible clinical implications of pathological deviation from baseline kinematics.

Immediate Proximal Row Carpectomy for Severe Perilunate Dislocation Injuries: A Minimum 5-Year Follow-Up.

Background: In patients with perilunate injuries (PLI) with multiple ligamentous and bony injuries involving the proximal carpal row, open reduction and internal fixation (ORIF) can be difficult and lead to poor functional outcomes. Proximal row carpectomy (PRC) is an alternative procedure that has been used for severely comminuted fractures. The aim of our study is to evaluate the long-term functional outcome (minimum 5 years) of patients that underwent an emergency PRC for PLI. Methods: We conducted a retrospective study of patients who underwent PRC at our centre between 2001 and 2016. Only patients with follow-up data of more than 5 years were included in the study. We evaluated range of motion, grip strength, Mayo Modified Wrist Score (MMWS) and Quick Disabilities of Arm, Shoulder and Hand (Quick-DASH). Radiographic analyses were performed to assess the presence of radiocarpal osteoarthritis and the space between the radius and capitate. Results: Thirteen patients were included, with an average follow-up of 78.07 months (6.5 years). The MMWS was 65 points (four excellent and good, four fair and five poor results) and the Quick-DASH score was 30 points. X-ray analysis reported only 15.3% of patients with radiocarpal arthrosis and an average radio-capitate joint space of 1.92 mm. Conclusions: The outcomes of PRC in the management of PLI are comparable to the results reported in literature for conventional ORIF. PRC is a simpler procedure that minimises the need for re-intervention. Level of Evidence: Level IV (Therapeutic).

Midcarpal Instability.

Midcarpal instability (MCI) of the wrist represents multiple distinct clinical entities that all have in common abnormal force transmission across the midcarpal joint. This can be asymptomatic but can also result in painful wrist motion, a characteristic catch-up clunk, and symptoms of instability. The carpus is stabilized by numerous extrinsic and intrinsic ligaments. Dynamic joint reactive forces between the proximal and distal carpal rows help create reciprocal motion, which results in smooth, physiologic wrist mechanics. Diagnosis of MCI requires a thorough history, physical examination, and adequate imaging. MCI can be managed nonsurgically with activity modification, physical therapy, specialized orthotics, medications, and corticosteroid injections. A variety of surgical treatment options exists to treat symptomatic MCI. These include arthroscopic thermal capsulorrhaphy, ligament repair or reconstruction, radial osteotomies, and limited radiocarpal or intercarpal fusions. Capsulorrhaphy or ligament repair is favored for mild to moderate cases; osteotomies can be used for the correction of bony deformities contributing to instability, whereas partial wrist arthrodesis is indicated for severe or recurrent instability and fixed deformities.

Force Transfer through the Scaphotrapeziotrapezoid (STT) Joint.

Background The scaphotrapeziotrapezoidal (STT) joint transfers forces to the proximal carpal row from the thumb and fingers. Clinically, STT joint osteoarthritis is frequently observed on plain radiographs though its role in the mechanics of the wrist joint remains unclear. Questions/Purposes Our purpose was to use a model of normal wrist types, to predict STT motion upon load. Patients and Methods Five normal computed tomography scans of a wrist type 1 and five wrist type 2 were used to model the wrist. A 200-N force was split and applied to the trapezoid and capitate to replicate forces during a knuckle pushup. The bony movement was predicted by the model as bony movement using finite element analysis. Results We found differences in force transfer through the STT joint between the two wrist types when loading the index and middle fingers. Type 1 wrists moved quantitatively more anterior-posterior, type 2 wrists moved more medially-laterally and more proximally-distally. The trapezium in type 1 wrists moved more in the coronal plane than in type 2 wrists. The trapezoid moved more from distal to proximal in a type 2 wrist, p = 0.03. Conclusion/Clinical Relevance This study found differences in motion upon loading through the STT joint between type 1 and 2 wrists. Type 2 wrists moved more radially toward the proximal scaphoid and scapholunate ligament. This study may provide a mechanical basis for degenerative configurations. By linking observed patterns of degeneration to their mechanical causes we can aid in prevention of arthritis.

FOUR-DIMENSIONAL COMPUTED TOMOGRAPHY-DERIVED RADIOLUNATE ARTHROKINEMATICS WITH A CASE STUDY IN FOUR-CORNER ARTHRODESIS

The radiocarpal joint, which includes articulations between the radius and the proximal carpal row, transmits force through the central column of the wrist. Chronic disruptions to radiocarpal biomechanics are associated with the development of scapholunate advanced collapse (SLAC) pattern OA. While the radiolunate joint is thought to be typically spared in SLAC progression, degenerative changes can present on the proximal lunate. An investigation of radiolunate arthrokinematics may improve understanding of posttraumatic and postsurgical outcomes, including salvage procedures for SLAC wrist such as scaphoid excision with four-corner arthrodesis (SEFCA). Four-dimensional CT, which captures CT volumes over time or motion, has enhanced our ability to quantify arthrokinematics during functional tasks. We hypothesize that 4DCT-derived radiolunate arthrokinematics during flexion-extension and radioulnar deviation will differ between healthy, uninjured wrists and a wrist three years post-SEFCA. Data were collected from the uninjured wrists of ten participants enrolled in a prospective study of unilateral wrist injury and one participant following SEFCA (n=11, 36% female). The SEFCA arthrodesis was fixed using Kirschner wires prepositioned in the head of the capitate and subsequently advanced into the lunate. Included participants were aged between 18 and 60 years; exclusion criteria included history of injury, surgery, or congenital variant in the contralateral wrist; rheumatologic disease; or connective tissue disease. Static-neutral and dynamic CT data were collected using a dual-source scanner (SOMATOM Flash, Siemens, DE) and commercially-available cardiac sequential scan protocol. 4DCT data were collected over a 1.5-second period as signaled by an ECG simulator. CT volumes were collected at a temporal resolution of 66 ms as participants moved at a cadence of 70 beats per minute (voxel size: 0.234mm × 0.234mm × 0.600mm). Nearest mesh-vertex distances between vertices on the radius and lunate within distance (2.5 mm) and surface-normal angular (60°) thresholds were calculated to define interosseous proximity distributions. Median interosseous proximities at each time point were calculated. Ten participants were aged mean (SD) 30.3 (6.8) years at the time of imaging; the SEFCA participant was 52 years of age and three years postoperative. Median radiolunate interosseous proximities are presented during flexion-extension and radioulnar deviation (Fig. 1). 4DCT has advanced our understanding of wrist arthrokinematics during functional tasks. The current study reveals that radiolunate interosseous proximities in healthy, uninjured wrists remain relatively constant over wrist flexion-extension and radioulnar deviation, with greatest proximities occurring near the extrema of motion. In the SEFCA participant, interosseous proximities were closest in flexion and ulnar deviation; this may be associated with high articular contact pressures in these positions. Interosseous proximities reveal how restricting midcarpal motion in SEFCA impacts adjacent articulations during wrist motion. This study represents a novel use of 4DCT to assess post-arthrodesis outcomes.

The Lateral-W Construct: An Anatomical Variant of the Dorsal Wrist Ligaments.

Background The dorsal intercarpal ligament (DIC) is an elegant dorsal stabilizer of the proximal carpal row, including the scaphoid's proximal pole and scapholunate joint. Along with the dorsal radiocarpal (DRC) ligament, it acts as a dorsal radioscaphoid stabilizer, with dynamism due to its ability to modify its length up to threefold by changing the angles between its V-shaped bundle morphology. The DIC ligament consistently originates from the dorsal tubercle of the triquetrum on the ulnar side. It spans transversely, attaching to the dorsal groove of the scaphoid (97-100%), lunate (75-90%), and proximal rim of the trapezium (12.5-50%), and overlapping the lunotriquetral interosseous ligament and the scapholunate interosseous ligament. Together with the DRC, Viegas et al (Viegas SF, Yamaguchi S, Boyd NL, Patterson RM. The dorsal ligaments of the wrist: anatomy, mechanical properties, and function. J Hand Surg Am 1999;24(3):456-468) proposed that this ligament complex should be called the "lateral-V construct." Anatomical Variant The authors present a unique type C variant of the DIC ligament, showing a distinct thick bundle directed at the dorsal aspect of the second metacarpal base that thus creates a "lateral-W construct." This dorsal triquetro-metacarpal 2 (dTqMC2) ligament acts as restraint to the body of the capitate and will provide enhanced stability of the dorsal midcarpal joint by limiting dorsal translation of the capitate in relation to the lunate. Clinical Relevance Our finding may contribute to the increasing knowledge of the dorsal ligament complex and its role in dorsal midcarpal instability, as well as surgical repair techniques.

Arthroscopic Radiocarpal Tendinous Inter-Position for Grade 2 Scapholunate Advanced Collapse - Surgical Technique.

Grade 2 scapholunate advanced collapse (SLAC 2) can be treated by proximal row carpectomy with satisfactory results. However, this method is invasive and can limit function. The senior author had proposed an arthroscopic alternative with tendon interposition between the radius and proximal carpal row (arthroscopic interposition tendon arthroplasty [AITA]). However, this arthroscopic technique is technically difficult and requires a risky palmar arthroscopic portal. We report a modification of AITA, the one-loop arthroscopic radiocarpal tendon inter-position (1L-ARTI) that is simpler and needs only dorsal arthroscopic portals. Level of Evidence: Level V (Therapeutic).

Anatomical study of all carpal and adjoining bones of the wrist using 3D CT reconstruction –Finding the ultimate biomechanical theory

BackgroundThe complex interplay of single wrist bones acting in combination with their ligamentous connections is still not fully understood. In this regard various theories exist, divisible in columnar and ring/row theories. The object of this study was to examine the mobility of the individual carpal bones as well as the ulna and metacarpals relative to each other in wrists of cadaveric hands using CT scans. MethodsThe regular wrist mobility of a total of 21 cadaveric hands was examined by CT imaging in neutral position, radial/ulnar abduction as well as wrist flexion and extension. The data were evaluated as 3D models by using a standardized global coordinate system and object coordinate systems. Rotation and translation of each carpal bone as well as radius/ulna and all metacarpal bones were evaluated. ResultsThe principal motion took place in the carpus between the radius and the proximal carpal row followed by the midcarpal joint and the carpometacarpal joints and not mainly between the individual bones of a row. The scaphoid moves out of its row aggregate mainly during flexion and adapts to the motion of the distal carpal row. The trapezium and first metacarpal bones play a specific role detached from the remaining bones. ConclusionsWith this study, a better understanding of the motion of the individual bones of the carpus, the metacarpals and the radius/ulna is shown. The study supports the row theory, where most motion takes place between the individual rows and not between the carpal bones, leaving the scaphoid and the first ray in a special role between the rows.

Effect of Proximal Row Carpectomy and Wrist Arthrodesis on the Resting Length of Extrinsic Digit Flexor Tendons: A Cadaveric Study

Background Spastic joint contractures remain a complex and challenging condition. For patients with upper extremity spastic dysfunction, improving the muscle balance is essential to maximize their hand function. Multiple procedures, including proximal row carpectomy (PRC) and wrist arthrodesis (WA), are considered among the different surgical alternatives. However, the biomechanical consequences of these two procedures have not been well described in current literature. Hence, the objective of our study is to assess the change in the extrinsic digit flexor tendon resting length after proximal row carpectomy and wrist arthrodesis.Methods Six fresh-frozen cadaver upper extremities (four females and two males) with no obvious deformity underwent dissection, PRC, and WA. All the flexor digitorum profundus (FDP), flexor digitorum superficialis (FDS), and flexor pollicis longus (FPL) tendons were marked proximally 1-cm distal to their respective myotendinous junction and cut distally at the marked point. The overlapping segment of each distal flexor tendon from its proximal mark was considered the amount of flexor tendon resting length change after PRC and WA. A descriptive evaluation was performed to assess the increment in tendon resting length. Additionally, a regression analysis was performed to evaluate the relation between the tendon resting length and the proximal carpal row height.Results Following PRC and WA, the mean digit flexor tendon resting length increment achieved across all tendons was 1.88 cm (standard deviation [SD] = 0.45; range: 1.00–3.00 cm). A weak direct relationship (R = 0.0334) between the increment in tendon resting length and proximal carpal row height was initially suggested, although no statistical significance was demonstrated (p = 0.811).Conclusion This study provides an anatomic description of the increased extrinsic digit flexor tendon resting length after PRC and WA in cadaveric specimens. Findings provide a useful framework to estimate the amount of extrinsic digit flexor resting length increment achieved after wrist fusion and the proximal carpal row removal.

Biomechanical Finite Element Method Model of the Proximal Carpal Row and Experimental Validation.

The Finite Element Method (FEM) models are valuable tools to create an idea of the behavior of any structure. The complexity of the joints, materials, attachment areas, and boundary conditions is an open issue in biomechanics that needs to be addressed. Scapholunate instability is the leading cause of wrist pain and disability among patients of all ages. It is needed a better understanding of pathomechanics to develop new effective treatments. Previous models have emulated joints like the ankle or the knee but there are few about the wrist joint. The elaboration of realistic computational models of the carpus can give critical information to biomedical research and surgery to develop new surgical reconstructions. Hence, a 3D model of the proximal carpal row has been created through DICOM images, making a reduced wrist model. The materials, contacts, and ligaments definition were made via open-source software to extract results and carry on a reference comparison. Thus, considering the limitations that a reduced model could carry on (unbalanced forces and torques), the stresses that result in the scapholunate interosseous ligament (SLIL) lead us to a bones relative displacement, which support the kinematics hypothesis in the literature as the distal carpal row moves as a rigid solid with the capitate bone. Also, experimental testing is performed, successfully validating the linear strength values of the scapholunate ligament from the literature.

En bloc resection and vascularized ulnar pedicle graft reconstruction with plate fixation for giant cell tumour of the distal radius.

We retrospectively reviewed the medical records of ten patients (five men and five women) who were treated in our unit for Campanacci Grade III giant cell tumour of the distal radius between July 2017 and December 2019. Following en bloc resection of a giant cell tumour of the distal radius, the wrist was reconstructed by transposing a vascularized pedicle graft from the ipsilateral ulnar shaft. The graft was fixed to the radial shaft and proximal carpal row with plates. At a mean follow-up of 23.5 months (range 18 to 31), bony union was achieved in all cases and there were no tumour recurrences. All patients had a good range of pronation and supination, but flexion and extension of the wrist was limited. DASH scores ranged from 5 to 11. This reconstruction method is a safe and effective procedure that provides good aesthetic outcomes, removes the need for microvascular techniques and reduces donor site morbidity.Level of evidence: IV.