Clinical applications of volar portals in wrist arthroscopy

Triangular Fibrocartilage Complex (TFCC) - Anatomy, Imaging, and Classifications with Special Focus on the CUP Classification

The TFCC consists of several components whose functional significance has been recognized in detail in recent years. Existing classifications are partly incomplete. In addition, the TFCC requires specific and dedicated imaging techniques.This review describes the anatomy and pathoanatomy of the TFCC. The different types of TFCC lesions on MRI as well as MR and CT arthrography are explained and compared with the current literature. In addition, the novel CUP classification is presented and illustrated with image examples.Anatomically and functionally, the articular disc and radioulnar ligaments with their ulnar insertions and the inhomogeneously structured TFCC periphery must be differentiated. For accurate imaging, thin slices with high in-plane resolution and techniques to optimize contrast are required. Plain MRI is exclusively dependent on T2 contrast, while gadolinium-enhanced MRI offers the additional benefit of focal contrast enhancement, e.g., of fibrovascular repair tissue at the lesion site. However, the reference standard continues to be MR and CT arthrography, which should be used for focused indications. The CUP classification, which allows a comprehensive description and categorization of TFCC lesions, is presented and illustrated. · Anatomically, the TFCC consists of the central ulnocarpal disc, the dorsal and palmar radioulnar ligaments, and the ulnocarpal joint capsule including intracapsular ligaments and the meniscus homologue.. · The most important restraining structure of the TFCC is the lamina fovealis, which stabilizes the DRUJ. This structure constitutes the proximal (deep) continuation of the radioulnar ligaments at the ulnar insertion.. · Imaging of the TFCC requires high spatial and contrast resolution due to its minute structures. MR and CT arthrography are the reference standard in imaging.. · The CUP classification clearly describes all structures of the TFCC with the categorization of individual or combined lesion patterns.. · Schmitt R, Kunz AS, Reidler P et al. Triangular Fibrocartilage Complex (TFCC) - Anatomy, Imaging, and Classifications with Special Focus on the CUP Classification. Fortschr Röntgenstr 2024; DOI 10.1055/a-2411-8444.

Arthroscopic-Assisted Repair of the Triangular Fibrocartilage Complex

Triangular fibrocartilage complex (TFCC) injuries are a common cause of ulnar-side wrist pain and may progress to persistent pain, instability of the distal radioulnar joint, and arthritis if left untreated. Diagnosis and management of these injuries requires a nuanced understanding of features pertinent to the clinical presentation, imaging, and arthroscopic findings for accurate management. Arthroscopic-assisted repair techniques have revolutionized surgical management, providing detailed visualization and facilitating the repair of TFCC injuries and associated pathologies with minimally invasive techniques. In this review, we discuss the anatomy of the TFCC, history and examination of ulnar-sided pathology, imaging findings, and classification schemes and review surgical techniques for the treatment of TFCC injuries. We also touch on pearls and pitfalls of the techniques, complications, and results of treatment.

Volar Wrist Arthroscopy Portals Using the NanoScope Are Safer than Traditional Arthroscopy

BACKGROUND

The NanoScope, given its smaller size, may be further from critical structures when establishing volar wrist arthroscopy portals compared to the traditional 2.7-mm arthroscope.

METHODS

Ten fresh-frozen latex-injected cadaver specimens were utilized. The volar radial (VR) and volar ulnar (VU) portals were created using an inside-out approach. The volar radial midcarpal (VR-MC) and volar ulnar midcarpal (VU-MC) portals were created using an inside-out approach. The arm was then dissected under 3.5-mm loupe magnification. Digital calipers were used to measure the distance between the portals and the surrounding anatomic structures by two fellowship-trained hand surgeons.

RESULTS

The median nerve was on average 1.6, 7.2, 1.8, and 5.6 mm away from the trochar for the VR, VU, VR-MC, and VU-MC, respectively. The median nerve fascia was pierced by the VR portal in one specimen. The radial artery, ulnar artery, and ulnar nerve were not pierced in any specimen. Compared to historical controls, for the VR-MC portal, the NanoScope was further from all critical structures, aside from the radial artery, and did not pierce any neurovascular structures. For the VU-MC portal, the NanoScope was further from the ulnar artery and median nerve and did not pierce any neurovascular structures.

CONCLUSION

In developing volar portals, after placing the cannula through the volar capsule from an inside-out approach, we recommend making a volar incision and dissecting the local anatomic structures to guard against injury. Compared to historical controls, the NanoScope was typically further from neurovascular structures.

Is Wrist Arthroscopy Safer with the Nanoscope?

Background  Nanoscope, given its smaller size, may be safer when establishing dorsal wrist arthroscopy portals compared with the traditional 2.7 mm arthroscope. Case Description  Ten fresh frozen cadaver specimens were utilized. Dorsal radiocarpal portals were established with the Nanoscope and calipers were used to measure the distance between the portals and the surrounding anatomical structures. The only structure that was pierced during portal placement was the dorsal sensory branch of the ulnar nerve (DSUN) in one specimen when establishing the 6U portal. Our study did not note any tendon injuries. Literature Review  Traditional wrist arthroscopy may be performed with a 2.7 mm arthroscope. With its larger outer sheath cannula, this may place adjacent anatomical structures at risk of injury. Clinical Relevance  During wrist arthroscopy, the Nanoscope may be safer when creating portals to underlying structures. Level of Evidence  This is a Level IV study.

The Volar Distal Radioulnar Portal in Wrist Arthroscopy: An Anatomical Study

Background  Advances in wrist arthroscopy and the emergence of novel surgical techniques have created a need for new portals to the wrist. The aim of this study was to define and verify the safety of the volar distal radioulnar (VDRU) portal. Description of the Technique  The VDRU portal is located ∼5 to 10 mm proximal to the proximal wrist crease, just on the ulnar edge of flexor carpi ulnaris tendon and radial to the dorsal cutaneous branch of the ulnar nerve. The ulnar styloid marks the distal point of the portal. Methods  An anatomical study was performed on 12 upper extremity specimens of 6 human cadavers. Iatrogenic injuries of neurovascular structures potentially at risk were assessed, and the distance from the portal to these structures was measured. Results  No iatrogenic injuries of the structures at risk occurred. Mean distances from the VDRU portal to the ulnar neurovascular bundle, the radial branch of the dorsal sensory branches of the ulnar nerve (DSBUN), and the ulnar branch of the DSBUN were 9.29 ± 0.26 mm, 8.08 ± 0.25 mm, and 10.58 ± 0.23 mm, respectively. There were no differences between left and right wrists. The distances from the VDRU portal to the ulnar neurovascular bundle and the ulnar branch of the DSBUN were significantly shorter in women; this distance was not less than 7 mm in any case. Conclusions  The VDRU portal is safe, reproducible, and facilitates the implementation of various techniques related to triangular fibrocartilage complex pathology.

Volar Midcarpal Portals in Wrist Arthroscopy

PURPOSE

To describe the placement of volar midcarpal portals using the inside-out technique, and the surrounding anatomical structures at risk.

METHODS

Five fresh-frozen cadavers were used. Volar ulnar midcarpal (VUMC) and volar radial midcarpal (VRMC) portals were placed using an inside-out technique. The distance between these portals to surrounding anatomical structures was measured in millimeters using a caliper.

RESULTS

The VUMC portal pierced the flexor digitorum profundus tendon to the middle finger in 1 specimen. The portal was an average 3.7 and 8.4 mm away from the ulnar artery and nerve, respectively. The VRMC portal pierced the palmaris longus in 2 specimens. It usually was between the flexor pollicis longus, the palmaris longus, and the median nerve. It was an average of 1.0 and 1.95 mm away from the median nerve and palmar cutaneous branch of the median nerve, respectively and in 1 specimen, was in contact with the median nerve after piercing the mesoneurium.

CONCLUSIONS

With increasing use of volar midcarpal arthroscopy, the surgeon needs to have an understanding of the structures at risk when placing the VUMC and VRMC portals.

CLINICAL RELEVANCE

When developing the volar midcarpal portals, the surgeon needs to pay close attention to the anatomical structures at risk and, in particular, the median nerve from the VRMC portal.

Diagnostic Wrist Arthroscopy

After reviewing this article, readers should have a comprehensive understanding of the indications for diagnostic arthroscopy, technical considerations in performing a systematic evaluation of the wrist, and limitations of this technique.

Diagnosis and Arthroscopic Management of Dorsal Wrist Capsular Impingement

PURPOSE

Dorsal wrist capsular impingement (DWCI) is characterized by pain attributable to impingement of dorsal capsular tissue during wrist extension. The diagnostic criteria and management algorithm for this condition have not been well established. The aims of our study were (1) to retrospectively review the clinical presentation and arthroscopic findings of patients treated surgically for DWCI and (2) to evaluate the outcomes of arthroscopic debridement for this condition.

METHODS

A total of 19 patients were treated with arthroscopic debridement for isolated DWCI from 2006 to 2015 by two surgeons (M.J.R. and D.S.R.) at a single institution. A chart review was performed to gather information on clinical presentation, radiological findings, operative details, and outcomes including numeric pain scale rating, range of motion, Mayo wrist score, and Quick Disabilities of the Arm, Shoulder, and Hand score. Patients were contacted at the time of the study for final telephone follow-up.

RESULTS

Symptoms were present for a median of 12.5 months (range, 3.5-124.4 mo) prior to surgical intervention, and all patients had pain localized to the dorsal and central wrist with passive terminal wrist extension (100%; 19 of 19). We obtained magnetic resonance imaging in 66% of patients (12 of 19). Diagnostic arthroscopy yielded evidence of infolded, redundant dorsal capsular tissue in all cases (19 of 19), and there was no evidence of concomitant wrist pathology. Compared with preoperative values, postoperative improvements were seen in average numeric pain scale rating (6.0-1.9), Quick Disabilities of the Arm, Shoulder, and Hand score (45.8-4.8), and Mayo wrist score (50.0-87.8). These improvements were sustained at 41.6 months after surgery (range, 11.9-73.8 months). One complication of superficial cellulitis occurred.

CONCLUSIONS

Dorsal wrist capsular impingement is a clinical diagnosis; magnetic resonance imaging may be helpful in evaluating for other pathologies. Diagnostic arthroscopy yields evidence of redundant dorsal capsular tissue, and arthroscopic debridement of this tissue offers a safe and effective treatment to improve pain and functional scores.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Treatment of physeal fractures of the distal radius by volar intrafocal Kapandji method: surgical technique

BACKGROUND

Distal radial physeal fractures with volar displacement are rare. Several methods of operative treatment include volar plate without inserting distal screws, percutaneous technique using two anterior skin incisions and reversed Kapandji technique with pins introduced through a posterior approach and locked at the anterior cortex of the fracture.

METHODS

We report three cases along with a literature review of the surgical techniques described in the past and a novel surgical technique for this uncommon fracture termed "Volar Kapandji".

RESULTS

All patients had anatomic reduction at the last follow-up radiography, and all patients had a full range of motion and VAS 0 at the last follow-up. No complications were recorded.

CONCLUSIONS

This case study presents the minimally invasive option for treating rare cases of physeal distal radius fractures with volar displacement.

LEVEL OF EVIDENCE

V.

[Standard wrist arthroscopy: technique and documentation]

OBJECTIVE

Minimally invasive approach to the wrist in order to diagnose and treat different wrist pathologies.

INDICATIONS

Diagnosis of unclear chronic pain syndromes, cartilage status, intra-articular ligament structures as well as post-traumatic and inflammatory conditions of the wrist. Treatment of ulnar impaction syndrome, dorsal ganglia and also in fracture treatment and various different wrist interventions.

CONTRAINDICATIONS

Soft tissue infections around the wrist, severe scarring may impede access to the joint.

SURGICAL TECHNIQUE

Supine position with the forearm upright and in neutral position, the elbow flexed by 90°, axial traction of 3-4 kg. Superficial stab incision, blunt preparation through joint capsule, insertion of optic through 3-4 portal and probe through 4-5 portal, and radial and ulnar midcarpal portals, respectively. Either sodium chloride, CO2 or air is used as arthroscopy medium. Diagnostic round with standardized examination of all parts of the joint. Standardized written and high quality photo and/or video documentation to facilitate understandability of the findings.

POSTOPERATIVE MANAGEMENT

Forearm cast for 1 week, limited load for 2 more weeks, then load is increased to normal.

Current indications for and the technique of wrist arthroscopy

Since its introduction more than 30 years ago, wrist arthroscopy has become an essential diagnostic and therapeutic tool in hand surgery. This procedure minimizes exposures and allows access to otherwise remotely located anatomic regions with minimal morbidity. Advances in anatomic understanding and wrist scope technology have standardized the procedure and expanded indications. Current applications are diagnostic staging of various wrist pathologies where arthroscopy allows for a direct, magnified, and tactile-assisted examination. This includes injuries to the triangular fibrocartilage complex (TFCC), osteochondral lesion of the carpus, and dynamic assessment of carpal instability and radiocarpal arthritis. Therapeutic applications have continued to expand and include arthroscopic-assisted fracture reductions, treatment of radiocarpal synovitis and arthritis, TFCC repairs, and arthroscopic management of soft tissue pathologies such as ganglion excisions and release of contractures.

Treatment of intra-articular distal radius fractures by the volar intrafocal Kapandji method: a case series

At present, the most common treatment for intra-articular fractures with a volar fragment is open reduction and internal fixation with a volar locking plate. This manuscript describes and evaluates the safety and efficacy of a modified Kapandji technique with insertion of a volar Kirschner wire for osteosynthesis of intra-articular distal radius fractures with a volar fragment. Four patients treated with the "volar Kapandji technique" completed follow-up of at least 12 (12 to 54) months. The mean age was 43 (23 to 53) years. The mean Disability of the Arm, Shoulder, and Hand score was 21.7 (0 to 41) and the mean Patient-Rated Wrist Evaluation score was 12.9 (0 to 25.8). The mean loss of flexion was 13.7 (0 to 30) degrees, the mean loss of extension was 10 (0 to 30) degrees, the mean loss of supination was 0 degrees, and the mean loss of pronation was 10 (0 to 20) degrees. There was no loss in dorsal angulation, radial inclination, or radial length compared with the other hand. No early or late complications were recorded.

The EWAS Classification of Scapholunate Tears: An Anatomical Arthroscopic Study

Treatment of scapho-lunate (SL) injuries is still a challenge for the surgeon, especially in chronic cases. The aim of the study isto experimentally cut, specific portions of scapholunate ligament and extrinsic ligaments and check their corresponding arthroscopic finding in order to understand the pathogenesis and develop a new classification system which is an evolution of the present arthroscopic classifications. Materials and Methods Thirteen cadaver wrists were studied under arthroscopy. Different portions of the scapho-lunate ligament were subsequently sectioned. In group A the sectioning sequence was: anterior SLIOL, RSC, LRL, SLIOL's proximal and posterior, DIC, DRC ligament and ST ligaments (8 cases). In group B it was: SLIOL's posterior and proximal, DIC, SLIOL's anterior, LRL, RSCL, DRC, ST ligaments (5 cases). The anatomo-pathological findings after each sectioning were correlated to the classification system proposed (Table 1). Results In group A, stage 3A was obtained when SL ligament's volar and intermediate portion and/ or SC/LRL ligaments were sectioned. A stage 3C was obtained when section of posterior SLIOL was sectioned as well. A stage IV when the DIC was also sectioned. In group B a stage 3B was obtained by cutting intermediate, posterior portion of the SLIOL ligament and DIC. A stage 3C was obtained when the anterior part of the SLIOL was also sectioned. In all cases, sectioning of the SLIOL lead to a stage 3C only if associated with sectioning of at least one of the extrinsic stabilizers (DIC or SC/LRL). Sectioning of DIC and SC ligament, in addition to SLIOL led to an arthroscopic stage IV. When ST, DRC and TH ligaments were also sectioned significant radiological signs appeared (stage V). Conclusions This study helps us to understand the anatomo-pathological scapho-lunate lesions in their different stages of partial lesions. Commonly called scapho-lunate lesions are complex, involving also extrinsic ligaments.

Accuracy of sonographically guided and palpation guided scaphotrapeziotrapezoid joint injections

OBJECTIVES

The purpose of this study was to determine and compare the accuracies of sonographically guided and palpation guided scaphotrapeziotrapezoid (STT) joint injections in a cadaveric model.

METHODS

A clinician with 6 years of experience performing sonographically guided procedures injected 1.0 mL of a diluted latex solution into the STT joints of 20 unembalmed cadaveric wrist specimens using a palmar approach. At a minimum of 24 hours after injection, an experienced clinician specializing in hand care completed palpation guided injections in the same specimens using a dorsal approach and 1 mL of a different-colored latex. A fellowship-trained hand surgeon blinded to the injection technique then dissected each specimen to assess injection accuracy. Injections were graded as accurate if the colored latex was found in the STT joint, whereas inaccurate injections resulted in no latex being found in the joint.

RESULTS

All sonographically guided injections were accurate (100%; 95% confidence interval, 81%-100%), whereas only 80% of palpation guided injections were accurate (95% confidence interval, 61%-99%). Sonographically guided injections were significantly more accurate than palpation guided injections, as determined by the ability to deliver latex into the joint (P < .05).

CONCLUSIONS

Sonographic guidance can be used to inject the STT joint with a high degree of accuracy and is more accurate than palpation guidance within the limits of this study design. Clinicians should consider using sonographic guidance to perform STT joint injections when precise intra-articular placement is desired. Further clinical investigation examining the role of sonographically guided STT joint injections in the treatment of patients with radial wrist pain syndromes is warranted.

Foveal TFCC tear classification and treatment

During the last two decades, increased knowledge of functional anatomy and pathophysiology of the triangular fibrocartilage complex (TFCC) have contributed to a change in surgeons' perspective toward it. The earlier concept of the TFCC as the "hammock" structure of the ulnar carpus has updated to the "iceberg" concept, whereby the much larger "submerged" part represents the foveal insertions of the TFCC and functions as the stabilizer of the distal radioulnar joint and the ulnar carpus, thus lending it greater functional importance. This article presents an algorithm of the treatment of traumatic peripheral TFCC tear based on clinical, radiological, and arthroscopic findings.

Differential strain of the axially loaded scapholunate interosseus ligament

PURPOSE

To directly measure strain changes in the scapholunate ligament via magnetic resonance imaging (MRI) when axially loading the wrist in the neutral and extended positions.

METHODS

Six asymptomatic male volunteers without known history of previous wrist injury were enrolled in this MRI-based study. Each subject underwent 3 MRI scans in a 3T scanner: in resting neutral position, in neutral with axial load applied, and in extension with axial load applied. Axial load was applied via extension of an elastic band with known force/elongation curve. We analyzed images and converted them to 3-dimensional stereolithographs. Attachment points of the palmar, proximal, and dorsal sections of the scapholunate interosseus ligament (SLIL) were identified. The lengths of the resulting vectors were recorded for each position. Strain, defined as change in length divided by original length, was calculated for the axially loaded neutral and extended wrists. We used the Bonferroni adjusted multiple comparisons from an analysis of variance model, with statistical significance defined as p < .05.

RESULTS

Strains were significantly greater in the palmar (p = .02) and proximal (p = .01) subregions of the SLIL in loaded extension versus loaded neutral positions. In contrast, the strain on the dorsal component in extension was not statistically greater than in the neutral position (p = .45). Axial load in neutral resulted in minimal strain of all 3 components of the SLIL complex, and these were not significantly different from each other (p > .99). With extension, the strains of the palmar (p = .03) and proximal (p = .006) regions were statistically greater than that of the dorsal component.

CONCLUSIONS

In extension, strain is greatest in the palmar and proximal portions of the intact SLIL. Axial load in neutral applies minimal strain to the SLIL complex. Avoiding axial loading in extension and encouraging loading in neutral position may allow for decreased injury and more effective healing of the scapholunate ligament.

The incidence of dorsal radiocarpal ligament tears in patients having diagnostic wrist arthroscopy for wrist pain

PURPOSE

The goal of this study was to examine the incidence of dorsal radiocarpal ligament (DRCL) tears in patients having diagnostic arthroscopy for chronic wrist pain.

METHODS

A chart review was performed of 64 patients who had diagnostic wrist arthroscopy for chronic wrist pain that was refractory to conservative measures. For each case, interosseous ligament instability/tears were graded according to the Geissler classification. Tears of the triangular fibrocartilage complex and the presence or absence of a DRCL tear were noted.

RESULTS

There were 35 of 64 wrists (in 64 patients) with DRCL tears. The average duration of wrist pain prior to treatment was 20 months. Only 10 patients could recall a specific injury. Five patients had an isolated DRCL tear. A scapholunate interosseous ligament injury was identified in 13 patients, of whom 7 had a concomitant DRCL tear. A lunotriquetral interosseous ligament injury was present in 7 patients, of whom 2 had a concomitant DRCL tear. Two patients had a capitohamate ligament tear: 1 of these patients had a DRCL tear. There were 7 patients with a solitary triangular fibrocartilage complex tear: 6 of 7 were in association with a DRCL tear. One patient had a chronic ulnar styloid nonunion and a DRCL tear. Two or more lesions were present in 23 patients; DRCL tears were present in 12.

CONCLUSIONS

DRCL tears are commonly seen with injuries to the primary wrist stabilizers. Recognition of this condition and further research into treatment methods are needed.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

Wrist arthroscopy

Arthroscopic surgery, a minimally invasive, outpatient procedure, is a valuable tool in the diagnosis and treatment of most disorders of the wrist. It offers direct visualization of the structures of the joint anatomy and existing disease processes while causing minimal damage to surrounding soft tissue. Other benefits of arthroscopic treatment compared to traditional open procedures include less postoperative pain, shorter recovery times, and fewer surgical complications.

Distal radioulnar joint arthroscopy and the volar ulnar portal

Pain on the ulnar side of the wrist remains poorly understood. As attention has shifted toward the myriad causes of ulnar-sided wrist pain, the utility of viewing the wrist from a volar ulnar (VU) perspective has emerged. Lunotriquetral ligament tears have been implicated in the pathogenesis of volar intercalated segmental instabilities. They often originate in the palmar subregion, which is most important for maintaining stability. These tears are difficult to visualize through the 4, 5, or 6R portals. They are well seen through a VU portal, and the direct line of sight facilitates debridement. The VU portal has potential use in the arthroscopic diagnosis and treatment of patients with injuries to the ulnar sling mechanism. It aids in triangular fibrocartilage repairs especially those involving the dorsal aspect between the ulnar styloid and the radial insertion, because the proximity of the 4, 5, and 6R portals makes triangulation of the instruments difficult. Although arthroscopy of the dorsal aspect of the distal radioulnar joint has been well described, it has largely remained a curiosity, with few clinical indications. Recent biomechanical studies have highlighted the importance of the deep attachment of the triangular fibrocartilage complex in maintaining distal radioulnar joint stability. The volar distal radioulnar portal is useful for assessing the foveal attachment. It may be used where there is the suspicion of a peripheral triangular fibrocartilage detachment due to a loss of its normal tension despite the lack of a visible tear during radiocarpal arthroscopy. The judicious use of these portals deserves consideration for inclusion as part of a thorough arthroscopic examination of selected patients with ulnar-sided wrist pain.