The Importance of Restoring Anatomy of the Proximal Interphalangeal Joint in Dorsal Fracture Dislocations.

The proximal interphalangeal joint (PIPJ) is a complex anatomical structure. In managing fracture dislocations about the PIPJ, the aim is to restore a congruent joint that allows for smooth gliding motion. Detailed knowledge of the anatomy and biomechanics of the PIPJ is necessary in managing these injuries with predictable success. The breadth of techniques previously described in the treatment of such injuries is testament to the difficulties faced in achieving optimal clinical and radiological outcomes. In this article we detail the anatomy and biomechanics of the PIPJ and summarize current literature and principles for the treatment of dorsal fracture dislocations.

The Pathogenesis and Treatment of the Stiff Finger.

"Stiff finger," defined as a finger with decreased range of motion in one or more joints, is commonly found after hand injury and is classified into flexion or extension deformities. Pathogenesis is due to dysfunction in one or more of the following anatomic components: (1) osseous and articular; (2) capsuloligamentous; (3) musculotendinous units; (4) soft tissue and fascia. Evaluation and treatment are based on accurate identification and correction of pathologic structures. The mainstay of treatment is directed hand therapy with exercises and splinting to mobilize stiff joints. Operative interventions are offered after gains from therapy have been exhausted.

Redefining Zone II: Anatomy of the Flexor Digitorum Superficialis Insertion.

BACKGROUND: Flexor zone II is defined as the region spanning the proximal aspect of the A1 pulley to the insertion of the flexor digitorum superficialis (FDS) tendon. Descriptions of the FDS insertion are inconsistent in the literature, but zones of injury are frequently determined with reference to superficial landmarks. The purpose of this study was to describe the footprint of the FDS insertion and define its relationship to the proximal interphalangeal (PIP) skin crease. METHODS: The FDS insertion on the index, middle, ring, and small fingers was dissected in 6 matched pairs of fresh-frozen cadaveric hands. A Kirschner wire was used to mark the level of the PIP skin crease on bone before measurements of the FDS footprint and its position relative to the PIP skin crease were made using digital calipers. RESULTS: The radial and ulnar FDS slips inserted a mean distance of 3.22 mm from the distal aspect of the PIP skin crease and varied by digit. The mean distal extent of the FDS insertion was 8.29 mm. The mean length of the insertion of each FDS slip was 5.15 mm and the mean width was 1.9 mm. CONCLUSIONS: The radial and ulnar FDS slips insert on average 3.22 mm distal to the PIP skin crease and vary by digit. Knowledge of the FDS insertion is clinically relevant when differentiating between flexor zone I and zone II injuries, planning surgical approaches to the finger, and in guiding patient expectations for surgery given the variability in outcome based on zone of injury.

Anatomical Basis for Arthroscopy of the Proximal Interphalangeal Joints.

BACKGROUND: Arthroscopy is a widely used minimally invasive technique. Nevertheless, no report describes the arthroscopic anatomy of the proximal interphalangeal (PIP) joint for portal creation. To facilitate arthroscopy, this study elucidated the anatomy of the lateral bands of the extensor mechanism and collateral ligaments of PIP joints. METHODS: A total of 39 fingers from the right hands of 10 cadavers (4 males, 6 females) were evaluated in this study. We defined the extension line from the proximal interphalangeal volar crease as the C-line. We also defined an imaginary line along the distal edge of the proximal phalanx, which is parallel to the C-line, as the J-line. The distance between J-line and C-line was measured. On the C-line and J-line, we measured the following: from the dorsal skin to the lateral edge of the lateral band (LB), the dorsal edge of the collateral ligament (CL) and from the lateral band and the collateral ligament (D), the width of the finger (W). The finger half-width (M) was measured on the J-line. Comparison between the digits and comparison between radial and ulnar distance were measured and statistical analysis was performed. RESULTS: All PIP joint spaces were distal from the C-line, except for one ring finger. The average distances between the J-line and C-line were 1.8-3.2 mm. On the C-line, only 11 cases (14.1%) showed an interval between the lateral bands and the collateral ligaments, but, on the J-line 72, cases (92.3%) had such an interval. The interval was located 1.6-2.9 mm in a dorsal direction from the midlateral on the J-line. CONCLUSIONS: Portal creation at the J-line is safer than at the C-line. This study revealed that safe portals for arthroscopy of the PIP joint are 2 mm dorsal to the midlateral line of the finger on the J-line.

Management of posttraumatic finger contractures in adults.

This lecture will focus on posttraumatic finger contractures affecting the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints in adults. The pathophysiology, main causes and essential rehabilitation methods that can be used before resorting to surgical treatment are described, along with the clinical examination. The goal is to define the surgical indications, even though the literature shows the functional outcomes are disappointing. While there is little to no change in a joint's angular amplitude, the functional range of motion can be improved. There is practically no functional improvement except in cases of MCP extension contracture. For the PIP joint, the aim is to shift the range of motion into the functional range. Surgical approaches, surgical techniques and rehabilitation protocols are described in detail.

Ultrasonography could be used to predict extended insertion of the EPB tendon noninvasively.

INTRODUCTION: An abnormal distal insertion of the extensor pollicis brevis (EPB) tendon into the thumb interphalangeal joint (IP) has been observed in refractory cases of de Quervain's disease. This is associated with the extensor being wider at the midpoint of the proximal phalanx; however, there is no method to noninvasively measure this. This study evaluated the accuracy of measuring the extensor width using ultrasonography, to establish a noninvasive method for predicting an EPB extending the IP insertion. MATERIALS AND METHODS: Of 23 arms from 12 fresh frozen cadavers, the extensor tendon width at the midpoint of the proximal phalanx was measured using ultrasonography and directly at dissection. The association between these values was evaluated using correlation analysis. A cut-off value of extensor tendon width was obtained using receiver operating characteristic analysis. RESULTS: A strong correlation was observed between the ultrasonography and the measured values. The EPB tendons were normal in 13 arms (57%) and extended in 10 (43%), with a significant difference between these groups in the mean width of the extensor tendon (6.8 ± 1.1 vs. 8.4 ± 1.0 mm). A cut-off extensor tendon width of 8.0 mm yielded an EPB extending the IP. CONCLUSION: An EPB extending the IP tendon can be predicted by measuring the extensor tendon width at the midpoint of the proximal phalanx using ultrasonography. The cut-off tendon width value of ≥ 8.0 mm may be useful for assessments prior to surgery and for conservative care.

Minimally Invasive Proximal Interphalangeal Joint Arthrodesis Using Headless Screw: Surgical Technique.

Proximal interphalangeal (PIP) joint arthritis causes debilitating hand pain and instability leading to significant functional impairment. Arthrodesis remains the gold standard for treatment of PIP arthritis. We present a minimally invasive PIP arthrodesis that provides rigid fixation with a headless compression screw. Seven patients who presented to the senior author with PIP joint arthritis underwent PIP arthrodesis by minimally invasive technique. A 1 cm transverse incision is made over the PIP joint, incising skin, central band, and articular capsule. PIP joint is flexed to expose the articular surface. Articular surfaces are prepared with a fine tipped rongeur, exposing subchondral bone until flat surfaces are obtained. Under fluoroscopy a guide wire for cannulated headless screw (3.0, 2.4, or 2.0 mm) is inserted in an antegrade manner. It progresses from the center of the proximal phalangeal articular surface until it exits through the dorsal cortex and the distal end lies within the subchondral bone. This is the most critical step of the procedure because the guide wire angle determines the degree of flexion of the fusion. A 5 mmincision is made over the guide wire and the wire is advanced through the center of the medullary canal of the middle phalanx. The wire is then overdrilled, length is measured, and a headless compression screws is inserted. Reevaluate alignment after insertion of the screws because malrotation may be induced by torque during compression. Six consecutive patients underwent the procedure by the senior author. All patients healed the arthrodesis without complications and hardware removal was not needed. Minimally invasive PIP joint arthrodesis is a safe and viable procedure. Critical portions of the procedure include placing the wire at the angle of the desired angle of fusion and avoiding malrotation during screw insertion.

Treatment of Proximal Interphalangeal Joint Contracture.

Proximal interphalangeal joint (PIPJ) flexion contracture is a challenging and often frustrating problem. Treatment of PIPJ contracture begins with conservative measures. With good compliance and prolonged use, favorable results can be achieved using these modalities. For contractures that fail to respond to conservative treatment, surgical intervention can be considered. The affected structures that can be released during surgery include the accessory collateral ligaments, volar plate, checkrein ligaments, retinacular ligaments, and the flexor and extensor tendons. A stepwise approach to release is typically favored in which active motion is tested after each release to determine the need for subsequent releases.

Complications of Proximal Interphalangeal Joint Injuries: Prevention and Treatment.

Proximal interphalangeal joint injuries are one of the most common injuries of the hand. The severity of injury can vary from a minor sprain to a complex intra-articular fracture. Because of the complex anatomy of the joint, complications may occur even after an appropriate treatment. This article provides a comprehensive review on existing techniques to manage complications and imparts practical points to help prevent further complications after proximal interphalangeal joint injury.

Estudio morfológico y biométrico de los vínculos de los tendones de los músculos flexores superficial y profundo de los dedos de la mano humana / Anatomic and biometric study of the vincula of the tendons of flexor digitorum superficialis and profundus muscles of the human hand

Los vínculos son estructuras especializadas inherentes a los tendones flexores de los dedos, y tienen gran importancia en la nutrición de los mismos, además de facilitar la flexión de los dedos después de una transección distal del tendón (es), permitiendo que éste (os) actuen indirectamente a través de las articulaciones interfalángicas. El presente estudio tuvo como objetivo revisar aspectos morfofuncionales de los vínculos largos y cortos de los músculos flexores de los dedos de la mano. El trabajo fue realizado en 60 manos de cadáveres formolizados de individuos adultos, brasileños, con una edad promedio de 53,1±17,8 años. Los vínculos cortos fueron encontrados en 100 % de los casos, tanto en los músculos flexores superficiales de los dedos como en los profundos, siempre en número de uno en cada tendón y su localización siempre estuvo en la extremidad del tendón, antes de la inserción de éste en la articulación interfalángica proximal. Los vínculos largos presentaron gran variación morfológica, con una presencia promedio de 61,3 % en los tendones del músculo flexor superficial y de 77,9 % en el músculo flexor profundo. El número de vínculos por tendón varió aún más, no siendo posible identificar un patrón independientemente del músculo. En relación a la localización de los vínculos largos, en los tendones del músculo flexor superficial de los dedos, están insertos en la vaina fibrosa de la falange proximal, con un trayecto oblicuo y próximo a la articulación interfalángica proximal; los vínculos de los tendones del músculo flexor profundo estaban localizados en su mayoría (86,7 %) entre los tendones a nivel de la articulación interfalángica proximal, presentando un trayecto rectilíneo entre esos dos tendones, mientras que en 13,3 % estuvieron localizados muy próximos a la abertura del tendón del músculo flexor superficial para el paso del tendón del músculo flexor profundo. Los vínculos son estructuras escenciales en la mantención de la nutrición y de los movimientos de los dedos aún en presencia de lesiones, por lo tanto, es importante tener una comprensión clara de ellos para una correcta evaluación clínica pensando en la reparación, reconstrucción y rehabilitación de las disfunciones de la mano.

The vincula are specialized structures inherent in the flexor tendons of the fingers, and are of great importance in their nutrition. In addition they facilitate flexion of the fingers following a distal transection of this tendon, allowing it to operate indirectly across the interphalangeal joints. The aim of the present study was to describe anatomic and biometric aspects of the long and short vincula of the flexor muscles of the fingers. The work was carried out in hands of 60 adult Brazilian corpses, of both sexes, with an average age between 17.8±53.1 years. The short vincula were found in 100 % of cases of flexor digitorum superficialis tendons and flexor digitorum profundus muscles, and only one in each tendon, with its location always at the extremity of the tendon, prior to insertion in the proximal interphalangeal joint. The long vincula presented great morphological variation, with an average presence of 61.3 % in tendons of the flexor digitorum superficialis and 77.9 % in the flexor digitorum profundus muscle. Furthermore, the number of vincula per tendon changed, and it was not possible to identify a pattern independently of the muscle. With respect to the location of the long vincula, in the flexor superficial tendons they are inserted in the fibrous sheath of the proximal phalanx, with an oblique course and next to the proximal interphalangeal joint. The vincula of the tendons of the flexor digitorum profundus were located (86.7 %) between both tendons to level of the proximal interphalangeal joint, presenting a rectilinear course between these two tendons, whereas in 13.3 % they were located very close to the opening of the flexor superficialis muscle tendon for passage of the flexor digitorum profundus muscle tendon. The vincula are essential structures in nutrition and finger motion even when injuries are present. It is therefore, important to have a clear understanding of these structures forproper clinical evaluation in the repair, reconstruction and rehabilitation of hand dysfunctions.

The prevalence of the extensor indicis tendon and its variants: a systematic review and meta-analysis.

The tendon of the extensor indicis (EI) is frequently used to restore the loss of function in other digits. However, it shows many variations which include splitting of the extensor indicis proprius (EIP) into two or three distal slips, attachment to fingers other than the index such as the extensor medii proprius (EMP), attachment onto the index and the third finger such as the extensor indicis et medii communis, or attachment to both the index and the thumb such as the extensor pollicis et indicis (EPI). This systematic review gathers the available data on the prevalence of EI tendon and its variation in the hand. Twenty-nine cadaveric studies met the inclusion criteria with a total of 3858 hands. Meta-analysis results yielded an overall pooled prevalence estimate (PPE) of EI of 96.5% and PPEs of 92.6, 7.2 and 0.3% for the single-, double- and triple-slip EIP, respectively. The single-slip EIP is frequently inserted on the ulnar side of the extensor digitorum communis of the index (EDC-index) in 98.3%. The double-slip EIP is located on the ulnar side of the EDC-index in 53.5%, on its radial side in 17% and on both sides in 28.7%. Indian populations showed the highest rate of single-slip EIP and the lowest rate of double-slip EIP when compared to Japanese, Europeans and North Americans. The pooled prevalence of EMP, EMIC and EPI were 3.7, 1.6 and 0.75%, respectively. Knowledge of the variants of the EI tendon and their prevalence should help surgeons in correctly choosing the tendon to transfer in hand surgery.

[The quadriga syndrome: a rarely recognized alteration in hand surgery]. / Quadrigaszindróma: Ritkán felismert tünetegyüttes a kézsebészetben.

The tendons of flexor digitorum profundus are most often interconnected and making them less able to move independently than the superficial tendons. The reason for this is the cross connective tissue-ligamentous connection between the tendons of the profundus. The recognition of this so called quadriga phenomenon is important in the clinical practice, when the presence of this syndrome hinders the strength and the movement of the tendons after operative reconstruction. In his work the author describes the anatomical foundation, the biomechanical correlations and the clinical importance of the quadriga syndrome in the mirror of literature data.

Morphology of the proximal and middle phalanx of fingers with regard to the Ascension PyroCarbon PIP total joint.

The Ascension PyroCarbon prosthesis has been used in proximal interphalangeal joint osteoarthritis. The dimensions of the intramedullary distal metadiaphyseal canal (isthmus) of the proximal phalanx and the base of the middle phalanx of cadaver fingers were investigated radiographically (n = 304) and macroscopically (n = 152). In up to 30% of the phalanges, the isthmus was smaller than the stem of the smallest proximal component size. The distal component head was always smaller than the middle phalanx base. Insertion and success of the Ascension PyroCarbon prosthesis is strongly dependent on bone morphology. A critical examination of the isthmus in radiographs is recommended in planning. If the isthmus is clearly smaller than the smallest proximal component, insertion of the prosthesis could be inadvisable. A clear mismatch between the distal component and the middle phalanx base should be avoided due to the potential risk for late subsidence and failure of the prosthesis.

Three-dimensional analysis of the palmar plate and collateral ligaments at the proximal interphalangeal joint.

The purpose of this study was to analyze the palmar plate complex at the proximal interphalangeal joint using a three-dimensional (3D) technique, which makes it easier to understand the dimensions of structures and their relationship to the adjacent components. This method allows individual elements to be removed virtually, facilitating clearer observation of each component. Sixteen cadaveric specimens were dissected and reconstructed in a 3D virtual environment. The palmar plate is made up of a distal, fibrous portion and a proximal, membranous portion, which anchors distally on the base of the middle phalanx and is continuous with the bilateral check-rein ligaments proximally. The accessory collateral ligaments and the A3 pulley suspend the palmar plate laterally.

The connective tissue and ligaments of the distal interphalangeal joint: a review and investigation using ultra-high field 16.4 Tesla magnetic resonance imaging.

This study reviews the literature on the anatomy of the connective tissues surrounding the distal interphalangeal joint and further characterizes the three-dimensional relationships of these structures with ultra-high field magnetic resonance imaging. Ten cadaver fingers, fixed in a solution of 5% agar and 4% formalin, were imaged utilising an ultrashield 16.4 Tesla ultra-high field magnetic resonance imaging, yielding a total of 4000 images. Images were analysed using Osirix™ (version 5.5.1 32 bit edition) for three-dimensional reconstruction. We found numerous conflicting descriptions of the connective tissue structures around the distal interphalangeal joint. Based upon our literature review and imaging studies we have defined precisely Cleland's ligaments, the oblique proximal septum, Grayson's ligaments, the dorsal plate, and the interosseous ligaments of the distal interphalangeal joint.

Possibility of the hamatum carpometacarpal joint as a new joint donor site for interphalangeal joint restoration.

OBJECTIVE: This research investigates the anatomic basis for the repair and reconstruction of hand joints using transposition of the carpometacarpal (CMC) joint of the hamatum. METHODS: The morphology and structure of the CMC joints of the hamatum and the base joints of the middle phalanx were observed on 22 freshly frozen wrist specimens at Shanghai 6th People's Hospital Research Institute of Microsurgery. The volar dorsal dia, radioulnar dia, depth of concave, and area of the joints were measured. Data were obtained through statistical analysis, and the resemblance of joints was compared in terms of morphology, structure, area, length, and diameter. RESULTS: The radioulnar dia of the CMC joints of the hamatum (13.54 ± 1.15 mm) did not exhibit any evident differences in the middle phalanx of the forefinger, middle finger, and ring finger, and in the distal phalanx of the thumb. The volar dorsal dia of the CMC joints of the hamatum (10.71 ± 0.93 mm) exhibited an evident difference in the middle phalanx of the ring finger. In all fingers, the depth of the ulnar and radial concave of the CMC joints of the hamatum (1.30 ± 0.08 and 0.95 ± 0.05 mm, respectively) and the area of the CMC joints of the hamatum (139.89 ± 5.44 mm(2)) showed an evident difference. CONCLUSION: The CMC joint of the hamatum could be considered a new and viable joint donor site that could be used to repair and reconstruct the base joints of the middle phalanx.

Current trends in the management of proximal interphalangeal joint injuries of the hand.

Injuries to the proximal interphalangeal joint are commonly encountered by the hand surgeon. Proper diagnosis and treatment are vital for optimal outcomes. Proper treatment of these injuries requires a working knowledge of the anatomy of the joint and an appreciation for principles for reduction, stabilization, and early rehabilitation to provide the best outcomes possible. Injuries can include fractures of the head of the proximal phalanx, dislocations, fracture dislocations, and fractures of the base of the middle phalanx. Similar to other aspects of plastic surgery, there is little high-level evidence guiding treatment and thus most treatment is based on level III or IV evidence. The goal for treatment of any injury around the proximal interphalangeal joint is to establish a congruent joint and allow for early motion. Stiffness and posttraumatic arthritis are common following these injuries. Salvage procedures are limited to arthrodesis and arthroplasty, neither of which can restore the normal function of the hand.

Morphological study of cutaneous ligaments of phalanges / Estudio morfológico de los ligamentos cutáneos de las falanges

The cutaneous ligaments of phalanges of palm and foot are fine and sender fibrous strips running from tendon sheath to flexor and extensor aspect of skin over phalanges. They are playing important role in stabilizing skin during movements and supporting digital neurovascular bundle. Such ligaments have carried lot of surgical value in microsurgery of hand. The morphology of such ligaments is studied in 80 digits of 8 cadavers of 20-80 years (6 males and 2 females). They are studied in detail in terms of attachments, thickness & length. The morphological data will be helpful in surgical implication of Duputren's Contracture, replantation, revascularization of the digit.

Los ligamentos cutáneos de las falanges de los dedos de la mano y del pie son delgadas cintas fibrosas que recorren bajo la piel y sobre las falanges la vaina de los tendones de los músculos flexor y extensor de los dedos. Tienen un rol importante en la estabilización de la piel durante los movimientos y mantienen el paquete neurovascular digital. Estos ligamentos tienen un gran valor quirúrgico en procedimientos como la microcirugía de mano. Se estudió la morfología de estos ligamentos en 80 dedos de 8 cadáveres de individuos entre 20 y 80 años de edad (6 hombres y 2 mujeres). Fue estudiada en detalle la anatomía en términos de uniones, espesor y longitud de estos ligamentos. Los datos morfológicos serán de utilidad en procedimientos quirúrgicos como el Síndrome de Duputren, reimplantación y revascularización de los dedos.

Muscle fibre types of the lumbrical, interossei, flexor, and extensor muscles moving the index finger.

The aim of this study was to determine the fibre types of the muscles moving the index fingers in humans. Fifteen forearms of eight adult cadavers were used. The sampled muscles were the first lumbrical (LM), first volar interosseous (VI), first dorsal interosseus (DI), second flexor digitorum profundus (FDP), second flexor digitorum superficialis (FDS), and extensor digitorum (ED). Six micrometer thick sections were stained for fast muscle fibres. The procedure was performed by applying mouse monoclonal anti-skeletal myosin antibody (fast) and avidin-biotin peroxidase complex staining. Rectangular areas (0.38 mm × 0.38 mm) were photographed and the boundaries of the muscle areas were marked on the translucent film. The numbers and sizes of the muscle fibres in each part were evaluated by the image analyser program and calculated per unit area (1 mm(2)). The proportion of the fast fibres was significantly (p = 0.012) greater in the intrinsic muscles (55.7 ± 17.1%) than in the extrinsic muscles (45.9 ± 17.1%). Among the six muscles, the VI had a significantly higher portion (59.3%) of fast fibres than the FDS (40.6%) (p = 0.005) or the FDP (45.1%) (p = 0.023). The density of the non-fast fibres was significantly (p = 0.015) greater in the extrinsic muscles (539.2 ± 336.8/mm(2)) than in the intrinsic muscles (383.4 ± 230.4/mm2). Since the non-fast fibres represent less fatigable fibres, it is thought that the extrinsic muscles have higher durability against fatigue, and the intrinsic muscles, including the LM, should move faster than the FDS or FDP because the MP joint should be flexed before the IP joint to grip an object.