High-resolution ultrasound approach to quadrangular joint in carpal boss: Everything musculoskeletal sonographer should know.

At the quadrangular joint (QAJ) of the carpus, a rare bony protuberance called carpal boss (CB) may occur. This bone abnormality may be due to osteophytes development or os styloideum. Symptomatic patients may complain pain, swelling, and restrictions in hand motion. These symptoms result from joint degenerative-inflammatory changes, development of ganglion cyst/bursitis, or tendons pathology. Correct diagnosis and appropriate management can be achieved through high-resolution ultrasonography (HR-US). The purpose of this review is to define the pathology spectrum around and within the QAJ in CB. The role of HR-US is highlighted and the standard technique for the QAJ assessment is described.

Radiocarpal Fusion: Indications, Technique, and Modifications.

Degenerative disorders of the wrist may affect isolated joints and inhibit normal functions of the wrist secondary to pain and stiffness. These processes that affect only the radiocarpal joint may be secondary to posttraumatic osteoarthritis, primary osteoarthritis, or rheumatoid arthritis. Radiocarpal wrist arthrodesis may help preserve some of the native wrist kinematics while alleviating pain and improving the range of motion. However, the surgeon must ensure that the patient's pathologic process primarily affects the radiocarpal articulations while relatively sparing the midcarpal articulations. Depending on the location of the pathology, isolated radiolunate or radioscapholunate arthrodesis have been described to preserve some motion in the midcarpal joint. To maximize motion in the midcarpal joint after radiocarpal arthrodesis, techniques for distal scaphoid and triquetrum excision have been described. We report patient outcomes for various techniques and describe our preferred technique for radioscapholunate arthrodesis using distal scaphoid excision.

Traumatic Nondissociative Carpal Instability: A Case Series.

PURPOSE: We report 8 cases of acute or subacute unilateral nondissociative carpal instability (CIND) in the context of nondisplaced scaphoid fractures. METHODS: Eight patients from 3 centers developed abnormal volar intercalated segment instability (VISI) or dorsal intercalated segment instability (DISI) following the diagnosis of a nondisplaced scaphoid fracture. An operative inspection in each patient confirmed intact scapholunate and lunotriquetral interosseous ligaments. We outline the demographic characteristics of our patient cohort, radiologic and operative findings of CIND-DISI and CIND-VISI, and the outcomes of acute and delayed treatment. RESULTS: Two patients were diagnosed with CIND-DISI and 6 with CIND-VISI associated with ipsilateral nondisplaced scaphoid fractures. The average time from injury to diagnosis of CIND was 11 weeks, and the mean clinical and radiographic follow-up was 18 months. Rapid healing of the scaphoid fractures was achieved in all patients (4 open reduction internal fixation, 4 cast). All patients underwent surgery to improve proximal carpal row alignment: in 3 of the 4 patients who were diagnosed and treated surgically within 12 weeks of injury, the radiolunate angle (RLA) was successfully restored. A contracture release and ligament repair or reconstruction with tendon graft 12 or more weeks following injury was unsuccessful in restoring proximal row alignment in all 4 patients. Two patients in the delayed treatment group required secondary surgery for partial fusion. CONCLUSIONS: Based on the arthroscopic, imaging, and operative findings, we propose that the ligamentous restraints to CIND-VISI are dorsal at the radiocarpal joint and volar at the midcarpal joint. Conversely, the ligamentous restraints to CIND-DISI are dorsal at the midcarpal joint and volar at both the radiocarpal and midcarpal joints. In our series, a delayed diagnosis and late reconstructive surgery were associated with no improvement in RLA. We recommend early recognition of traumatic CIND and prompt treatment of injured ligaments prior to the development of a fixed deformity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

A threshold volume of 10 ml is suggested for detecting articular cartilage defects in equine carpal joints using CT arthrography: Ex vivo pilot study.

Computed tomographic arthrography (CTA) has been described as a method for detecting articular cartilage defects in equine carpal joints; however, published studies on the effects of contrast volume for lesion detection are currently lacking. The purpose of this prospective, experimental, pilot study was to determine a threshold volume of iodinated contrast for CTA of the antebrachiocarpal (ABC) and middle carpal (MC) joints for detection of articular cartilage surface defects. Articular cartilage defects were iatrogenically created in the surfaces of the ABC and MC joints of 20 equine cadaver limbs using arthroscopy. Unaltered articular surfaces within some joints acted as controls. Joints were imaged precontrast using multidetector CT. The ABC and MC joints were injected with a 150 mg iodine/ml nonionic contrast medium, in 5 ml increments from 5 to 50 ml per joint with CT performed subsequent to each increment. Cartilage defects were measured grossly using a caliper. Detection (qualitative) and measurement (quantitative) of the defects were independently performed by two board-certified radiologists using medical imaging software. At each volume of contrast, the interrater reliability for gross examination and the two observers in the detection of a defect was calculated (Gwet's AC1). Logistic mixed-effects models of selected volumes, 0, 5, 10, 15, and 50 ml, demonstrated that at 10 ml contrast and above, no statistically significant difference between either observer and gross examination for defect detection was identified for either joint. Findings supported using a dose of 10 ml for 150 mg iodine/ml concentration contrast media when performing CTA of equine carpal joints.

Comparative Analysis of 3 Techniques of Scapholunate Reconstruction for Dorsal Intercalated Segment Instability.

PURPOSE: The combination of scaphoid rotatory subluxation, dorsal intercalated segment instability, and dorsal scaphoid translation (DST) constitutes stage 5 scapholunate dissociation in the modified classification system of Garcia-Elias. The purpose of this study was to compare the static radiographic outcomes of reduction and association of the scaphoid and lunate (RASL), three-ligament tenodesis (TLT), and anatomic front and back (ANAFAB) reconstructions for stage 5 scaphoid and lunate malrotation and translation. METHODS: Stage 5 scapholunate dissociation was created in 15 fresh-frozen specimens by cutting the scapholunate interosseous ligament, long radiolunate ligament, dorsal intercarpal ligament, and scaphotrapeziotrapezoid ligament complex. Specimens were randomized to receive 1 of the 3 reconstructive techniques. Radiolunate angle (RLA), scapholunate angle, scapholunate gap, and DST were measured in static fluoroscopic posteroanterior and lateral views in 3 conditions: baseline, injured, and reconstructed. RESULTS: Reduction and association of the scaphoid and lunate showed an improved correction of scapholunate gap compared with TLT and ANAFAB. Anatomic front and back demonstrated an improved correction in RLA and scapholunate angle compared with RASL but not TLT. When the reconstruction was compared with baseline, there was a persistent lunate extension for TLT (RLA and scapholunate angle) and RASL (RLA); however, no significant difference in any parameter was found with ANAFAB. Anatomic front and back significantly improved DST, whereas TLT and RASL did not. CONCLUSIONS: In this cadaveric model of scapholunate dissociation with dorsal intercalated segment instability and DST, each of the 3 repairs had different effects on carpal posture and alignment. While only RASL statistically improved scapholunate gap, only ANAFAB significantly improved DST. Both TLT and RASL improved radiographic parameters; however, each had a persistent increase in the lunate extension following reconstruction. CLINICAL RELEVANCE: It may be prudent to consider different reconstructive techniques for different stages of scapholunate instability. Anatomic front and back, a repair that addresses both dorsal and volar ligament stabilizers, provides improved reduction of dorsal intercalated segment instability and DST in stage 5 scapholunate dissociation.

Structural, compositional, and functional effects of blunt and sharp cartilage damage on the joint: A 9-month equine groove model study.

This study aimed to quantify the long-term progression of blunt and sharp cartilage defects and their effect on joint homeostasis and function of the equine carpus. In nine adult Shetland ponies, the cartilage in the radiocarpal and middle carpal joint of one front limb was grooved (blunt or sharp randomized). The ponies were subjected to an 8-week exercise protocol and euthanized at 39 weeks. Structural and compositional alterations in joint tissues were evaluated in vivo using serial radiographs, synovial biopsies, and synovial fluid samples. Joint function was monitored by quantitative gait analysis. Macroscopic, microscopic, and biomechanical evaluation of the cartilage and assessment of subchondral bone parameters were performed ex vivo. Grooved cartilage showed higher OARSI microscopy scores than the contra-lateral sham-operated controls (p < 0.0001). Blunt-grooved cartilage scored higher than sharp-grooved cartilage (p = 0.007) and fixed charge density around these grooves was lower (p = 0.006). Equilibrium and instantaneous moduli trended lower in grooved cartilage than their controls (significant for radiocarpal joints). Changes in other tissues included a threefold to sevenfold change in interleukin-6 expression in synovium from grooved joints at week 23 (p = 0.042) and an increased CPII/C2C ratio in synovial fluid extracted from blunt-grooved joints at week 35 (p = 0.010). Gait analysis outcome revealed mild, gradually increasing lameness. In conclusion, blunt and, to a lesser extent, sharp grooves in combination with a period of moderate exercise, lead to mild degeneration in equine carpal cartilage over a 9-month period, but the effect on overall joint health remains limited.

Machine learning augmented near-infrared spectroscopy: In vivo follow-up of cartilage defects.

OBJECTIVE: To assess the potential of near-infrared spectroscopy (NIRS) for in vivo arthroscopic monitoring of cartilage defects. METHOD: Sharp and blunt cartilage grooves were induced in the radiocarpal and intercarpal joints of Shetland ponies and monitored at baseline (0 weeks) and at three follow-up timepoints (11, 23, and 39 weeks) by measuring near-infrared spectra in vivo at and around the grooves. The animals were sacrificed after 39 weeks and the joints were harvested. Spectra were reacquired ex vivo to ensure reliability of in vivo measurements and for reference analyses. Additionally, cartilage thickness and instantaneous modulus were determined via computed tomography and mechanical testing, respectively. The relationship between the ex vivo spectra and cartilage reference properties was determined using convolutional neural network. RESULTS: In an independent test set, the trained networks yielded significant correlations for cartilage thickness (ρ = 0.473) and instantaneous modulus (ρ = 0.498). These networks were used to predict the reference properties at baseline and at follow-up time points. In the radiocarpal joint, cartilage thickness increased significantly with both groove types after baseline and remained swollen. Additionally, at 39 weeks, a significant difference was observed in cartilage thickness between controls and sharp grooves. For the instantaneous modulus, a significant decrease was observed with both groove types in the radiocarpal joint from baseline to 23 and 39 weeks. CONCLUSION: NIRS combined with machine learning enabled determination of cartilage properties in vivo, thereby providing longitudinal evaluation of post-intervention injury development. Additionally, radiocarpal joints were found more vulnerable to cartilage degeneration after damage than intercarpal joints.

Recent advances in the surgical treatment of malunions in hand and forearm using three-dimensional planning and patient-specific instruments.

Malunions of the forearm and hand cause significant disability. Moreover, intraarticular deformities may contribute to early onset osteoarthritis. Such conditions require precise surgical correction in order to improve functional outcomes and prevent early or late complications. The purpose of this study was to describe the technical advantages of accurate anatomical reconstruction using 3D guided osteotomies and patient specific instruments (PSI) in multiple joints of the hand and forearm. Acquisition of three-dimensional (3D) datasets and surgical implementation of PSI was performed in a series of patients between December 2014 and July 2017. Patients had intra- or extra-articular malunions of the forearm, radiocarpal joint, trapeziometacarpal joint, or proximal interphalangeal joint. A previously described 3D surface model that incorporates CT data was used for segmentation (Mimics®, Materialise™, Belgium). For all the cases, CT scans of both forearms were acquired to use the contralateral uninjured side as the anatomic reconstruction template. Computer-assisted assessment of the deformity, the preoperative plan, and the design of PSI are described. Outcomes were determined by evaluating step-off correction, fusion, changes in range of motion (ROM) and grip strength. Six patients were included in the study; all achieved fusion. Improved clinical outcomes including pain reduction, better ROM and grip strength were obtained. Complete correction of intraarticular step-off was achieved in all cases with intraarticular malunions. 3D guided osteotomies are an established surgical treatment option for malunions of the hand and forearm. 3D analysis is a helpful diagnostic tool that provides detailed information about the underlying deformity. PSI can be developed and used for surgical correction with maximal accuracy for both intraarticular step-off and angular deformity.

Scaphoid Motion of the Wrist with Scapho-trapezio-trapezoidal Osteoarthritis-A Pilot Study.

BACKGROUND: The purpose of this study was to investigate scaphoid motion within the scapho-trapezio-trapezoidal (STT) joint during wrist motion in the presence of STT joint osteoarthritis (OA). METHODS: We studied 11 wrists with STT OA and 5 normal wrists. Computed tomography (CT) images were acquired in five wrist positions (maximum active flexion, extension, radial deviation, ulnar deviation, and neutral position). The 3-dimensional surface models of the radius and scaphoid were constructed and the motion of scaphoid relative to the radius was calculated. RESULTS AND CONCLUSIONS: During wrist flexion/extension motion, the scaphoid rotated mostly in the flexion/extension plane. The angle tended to be smaller in STT OA than in normal. During wrist radioulnar deviation, the scaphoid was in an extended position in neutral wrist in STT OA. The motion of scaphoid in STT OA was divided into two types: a rigid type and mobile type. The mobile type rotated closer to the flexion/extension plane than the rigid type. Taking into account scaphoid motion during wrist movement before surgery may provide better results in the treatment of STT OA.

Scapholunate, lunotriquetral and TFCC ligament injuries associated with intraarticular distal radius fractures: Arthroscopic assessment and correlation with fracture types.

The aim of this study was to evaluate the prevalence of arthroscopic scapholunate (SL) and/or lunotriquetral (LQ) laxity and triangular fibrocartilaginous complex (TFCC) injuries in patients who have an intraarticular fracture of the distal radius and to correlate these lesions with fracture type. Fifty-seven intraarticular radius fractures, whether or not they were associated with an ulnar styloid fracture, were evaluated and treated by arthroscopy. Scapholunate and lunotriquetral ligament injuries were classified according to the EWAS classification. TFCC lesions were assessed according to Palmer's classification. Each injury was documented through preoperative X-rays and a CT scan. Fracture type and soft tissue injury were not significantly associated one to another. Arthroscopic examination revealed at least one soft tissue injury in 39 intraarticular fractures of the distal radius (68.4%). Twenty-five percent of arthroscopic SL laxities (including severe EWAS 3 injuries) were not detected on standard radiographs. Arthroscopic SL laxity was present in 8 of 11 cases (72.7%) of radial styloid fracture and in 15 of 25 cases (60%) of fractures with at least one radial styloid component. There was no association between LQ integrity and fracture type. Ulnar styloid fractures (base or tip) and TFCC lesions were significantly correlated (P<0.0001). The prevalence of soft tissue lesions secondary to intraarticular fractures of the distal radius was 68.4%. However, there was no statistically significant relationship between the different types of radius fractures and soft tissue injuries. On the other hand, ulnar styloid fracture was predictive of TFCC injury.

Evaluation and Management of Scaphoid-Trapezium-Trapezoid Joint Arthritis.

Degenerative arthritis at the articulation of the scaphoid, trapezium, and trapezoid (STT or triscaphe joint) is a common degenerative disease of the wrist. Pain and weakness with grip strength reduction and functional limitations when performing routine daily tasks are common complaints of patients with STT arthritis. Initial conservative treatments for STT arthritis include splinting, bracing, activity modification, anti-inflammatory medication, and steroid injections for pain relief. Failure of conservative treatment is the main indication for surgery, which may include distal scaphoid excision, with or without filling of the void after excision, trapeziectomy, STT arthrodesis, or STT implant arthroplasty.

Arthroscopic treatment of scaphoid nonunion with humpback deformity and DISI with corticocancellous bone grafting: Technical note.

For two decades, scaphoid nonunion has been treated arthroscopically. However, compressed cancellous bone graft does not have the same mechanical properties as corticocancellous bone graft for reducing the scaphoid humpback deformity and DISI tilt. Here, we describe an arthroscopic technique to treat Alnot stage IIB scaphoid nonunion. We treated a 27-year-old male patient for scaphoid waist nonunion with humpback deformity and DISI. A 8×8×10 mm cylindrical corticocancellous bone graft was harvested from the dorsal aspect of the radius using a single-use osteochondral autograft transfer system (OATS®, Arthrex Inc., Naples, USA). It was inserted in the nonunion site through an arthroscopic volar approach. Bone union was obtained at 3 months with lasting correction of the scaphoid humpback deformity and DISI. The functional result at 6 months was excellent. There were no complications. Scaphoid nonunion with humpback deformity and DISI may be treated arthroscopically with a corticocancellous bone graft.

Computational Simulation of Synovial Fluid Kinematics of the Scapholunate Joint.

Background: The interaction between wrist kinematics and synovial fluid pressure has yet to be studied. To our knowledge, this is the first study to determine the effect of scapholunate joint kinematics on synovial fluid pressure change using finite volume method. Methods: The carpal bones of a cadaveric hand were obtained from Computed Tomography (CT) scans. CT images of the carpal bones were segmented and reconstructed into 3D model. The 3D synovial fluid model between the scaphoid and lunate was constructed and then used for computational simulations. The kinematics data of scapholunate joint obtained from radioulnar deviation of the wrist was investigated. Results: It was found that the pressure in synovial fluid varied from -1.68 to 2.64 Pa with maximum pressure located at the scaphoid-fluid interface during the radial deviation. For ulnar deviation, the pressure increased gradually from the scaphoid-fluid interface towards the lunate-fluid interface (-1.37 to 0.37 Pa). Conclusions: This new computational model provides a basis for the study of pathomechanics of ligament injury with the inclusion of synovial fluid.

Dorsal Extrinsic Ligament Injury and Static Scapholunate Diastasis on Magnetic Resonance Imaging Scans.

PURPOSE: Current biomechanical data suggest that static scapholunate (SL) ligament dissociation occurs only when there is loss of competence of the extrinsic ligaments either acutely or with attenuation over time. We aimed to identify whether patients with an SL gap greater than 2 mm demonstrated concomitant dorsal radiocarpal ligament (DRC) and dorsal intercarpal ligament (DIC) ligament changes on magnetic resonance imaging (MRI) scans that were identified as having an SL ligament tear. METHODS: We included 90 patients who had a posttraumatic MRI scan of the wrist diagnosed with an SL injury. We recorded basic demographics; 2 attending fellowship-trained musculoskeletal radiologists evaluated the integrity of the SL, DRC, and DIC ligaments and graded these as normal, low-grade injury (sprain or partial tear) or full-thickness tear. The association between the integrity of the DRC and DIC ligaments and the presence of a scapholunate gap of 2 mm or greater was analyzed. RESULTS: A total of 48 patients (53%) had an SL distance of 2 mm or greater on MRI. Of these patients, 28 (58%) had a partial or total tear of the DIC and/or DRC ligament. Compared with patients with an SL interval less than 2 mm, patients with an SL interval 2 mm or greater more often demonstrated DIC signal change (31% vs 12%), DRC signal change (52% vs 14%), or combined or isolated DIC and/or DRC signal change (52% vs 14%). CONCLUSIONS: Dorsal extrinsic ligaments demonstrate MRI signal change suggestive of acute or chronic injury in patients with an SL interval 2 mm or greater more often than in patients with an SL interval less than 2 mm. These results reinforce that MRI findings of SL ligament tear need to be interpreted in a larger context, perhaps with additional attention to the DIC and DRC appearance upon MRI. In addition, MRI evaluation of dorsal extrinsic ligaments may aid in clinical decision-making for patients with SL injury. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic IV.

Intercarpal Ligament Injuries Associated With Distal Radius Fractures.

Injuries to the scapholunate (SL) and lunotriquetral (LT) interosseous ligaments occur in approximately one third of distal radius fractures. The diagnosis of these injuries is challenging because plain radiographs are not reliably diagnostic. Wrist arthroscopy may be the most accurate way to examine and diagnose soft-tissue injuries of the carpus adjacent to a distal radius fracture. Treatment options for SL and LT ligament injuries include open repair and/or percutaneous pinning. Because the natural history of these injuries is unclear, the necessity of diagnosing and treating these SL and LT interosseous ligament defects remains speculative.

Treatment of chronic scapholunate instability: Results with three-ligament tenodesis vs. scapholunate and intercarpal ligamentoplasty.

In this retrospective case control/comparison study, we compared the clinical and radiological outcomes in patients with chronic scapholunate dissociation treated with three-ligament tenodesis (3 LT) versus scapholunate and intercarpal ligamentoplasty (SLICL). Twenty patients with a mean age of 43 years were treated with the 3 LT procedure and 26 patients with a mean age of 44 years with the SLICL procedure. All patients had chronic reducible scapholunate dissociation without chondral lesions. The two groups of patients were operated on by senior surgeons, at the same facility, over two different time periods. All patients were evaluated (pain, motion, strength, function, X-rays) with a mean follow-up of 28 months (12-49) in the 3 LT group and 36 months (12-54) in the SLICL group. In the both groups, we found a significant improvement in pain levels, grip strength and functional scores (DASH and PRWE). The SLICL group had significantly less pain and greater grip strength than the 3 LT group. Patients in the SLICL group had a greater improvement in their DASH and PRWE Scores. The mean range of motion in flexion-extension was 82° (102° preoperative) in the 3 LT group and 113° (115° preoperative) in the SLICL group. In the 3 LT, there was no significant improvement in the mean static and dynamic scapholunate gaps (3.6 and 4.8 mm postoperatively versus 3.9 and 4.9 mm preoperatively), or the scapholunate angle (75° versus 72°). In the SLICL group, the mean static and dynamic gaps improved significantly (2.3 and 3.0 mm postoperatively versus 3.2 and 4.6 mm preoperatively), as did the scapholunate angle (62° versus 73°). In the 3 LT group, 4 patients developed osteoarthritis. In conclusion, the SLICL procedure for scapholunate ligament reconstruction led to better clinical and early radiological results than the 3 LT technique.

A four-dimensional-CT study of in vivo scapholunate rotation axes: possible implications for scapholunate ligament reconstruction.

Additional fixation of the palmar scapholunate interosseous ligament has been advocated to improve the long-term results of dorsal scapholunate interosseous ligament reconstruction. To investigate the validity of this approach, we determined normal scapholunate motion patterns and calculated the location of the scapholunate rotation axis. We hypothesized that the optimal location of the scapholunate interosseous ligament insertion could be determined from the scapholunate rotation axis. Four-dimensional computerized tomography was used to study the wrist motion in 21 healthy participants. During flexion-extension motions, the scaphoid rotates 38° (SD 0.6°) relative to the lunate; the rotation axis intersects the dorsal ridge of the proximal pole of the scaphoid and the dorsal ridge of the lunate. Minimal scapholunate motion is present during radioulnar deviation. Since the scapholunate rotation axis runs through the dorsal proximal pole of the scaphoid, this is probably the optimal location for attaching the scapholunate ligament during reconstructive surgery.

Long-term results of arthroscopic debridement and percutaneous pinning for chronic dynamic scapholunate instability.

There are various treatments for chronic dynamic scapholunate instability and there is still much debate about the best method of treatment. We retrospectively analysed 42 patients who had been treated by arthroscopic debridement and percutaneous pinning for chronic dynamic scapholunate instability. All patients were clinically improved without radiographic changes after surgery and were still satisfied at a mean follow-up of 68 months. Arthroscopic debridement and percutaneous pinning may be a good option for treating chronic dynamic scapholunate instability. Level of evidence: IV.