Antegrade Intramedullary Screw Fixation: A Novel Approach to Metacarpal Fractures
2019; Elsevier BV; Volume: 1; Issue: 4 Linguagem: Inglês
10.1016/j.jhsg.2019.07.002
ISSN2589-5141
Autores Tópico(s)Bone fractures and treatments
ResumoMetacarpal fractures are common upper-extremity fractures. Surgical fixation is recommended for open injuries, segmental bone loss, multiple metacarpal fractures, irreducible fractures, and unstable fracture patterns. For transverse and short oblique metacarpal shaft fracture patterns, intramedullary headless compression screws have been added most recently as a surgical option. Intramedullary headless compression screw fixation has been performed in a retrograde manner in which a guidewire and then a cannulated headless screw are placed through a skin excision, a split in the sagittal band or extensor tendon, and the dorsal central articular cartilage surface of the metacarpal head. Here, we describe a step-by-step novel approach to fixation of transverse and short oblique proximal and midshaft metacarpal fractures through an antegrade approach using intramedullary headless compression screws with a detailed 4K high-definition video demonstration and 2 clinical cases involving the middle and ring metacarpals. This surgical alternative addresses many concerns with the retrograde technique and avoids creating defects in the extensor tendon, the sagittal hood, the articular surface of the metacarpal head at the metacarpophalangeal joint, and the articulating surface of the trapezium, capitate, and hamate at the carpometacarpal articulation. Metacarpal fractures are common upper-extremity fractures. Surgical fixation is recommended for open injuries, segmental bone loss, multiple metacarpal fractures, irreducible fractures, and unstable fracture patterns. For transverse and short oblique metacarpal shaft fracture patterns, intramedullary headless compression screws have been added most recently as a surgical option. Intramedullary headless compression screw fixation has been performed in a retrograde manner in which a guidewire and then a cannulated headless screw are placed through a skin excision, a split in the sagittal band or extensor tendon, and the dorsal central articular cartilage surface of the metacarpal head. Here, we describe a step-by-step novel approach to fixation of transverse and short oblique proximal and midshaft metacarpal fractures through an antegrade approach using intramedullary headless compression screws with a detailed 4K high-definition video demonstration and 2 clinical cases involving the middle and ring metacarpals. This surgical alternative addresses many concerns with the retrograde technique and avoids creating defects in the extensor tendon, the sagittal hood, the articular surface of the metacarpal head at the metacarpophalangeal joint, and the articulating surface of the trapezium, capitate, and hamate at the carpometacarpal articulation. Metacarpal fractures are among the most commonly treated upper-extremity fractures, accounting for up to 10% of all fractures. There are a number of available fixation options with indications based on fracture pattern morphology. AO treatment guidelines for transverse and short oblique metacarpal fractures do not allow interfragmentary lag screws. These are mostly treated with open reduction internal fixation (ORIF) with compression plates, providing absolute stability and strength of repair. This is achieved through an extensile dorsal incision and dissection, which leads to greater scarring and extensor tendon adhesion and can result in poor functional outcomes.1McNemar T.B. Howell J.W. Chang E. Management of metacarpal fractures.J Hand Ther. 2003; 16: 143-151Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar Another option includes intramedullary Kirschner wire fixation described by Lord in 1957.2Lord R.E. Intramedullary fixation of metacarpal fractures.JAMA. 1957; 164: 1746-1749Crossref PubMed Scopus (37) Google Scholar In 1975, Foucher introduced "bouquet pinning" using 3 Kirschner wires placed in an antegrade fashion.1McNemar T.B. Howell J.W. Chang E. Management of metacarpal fractures.J Hand Ther. 2003; 16: 143-151Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar In 2010, Boulton and Mudgal3Boulton C.L. Salzler M. Mudgal C.S. Intramedullary cannulated headless screw fixation of a comminuted subcapital metacarpal fracture: case report.J Hand Surg Am. 2010; 35: 1260-1263Abstract Full Text Full Text PDF PubMed Scopus (43) Google Scholar reported on a single use of an intramedullary cannulated headless compression screw (IMHCS) for stable fixation of a comminuted metacarpal head fracture. There are multiple reports in the literature detailing IMHCS fixation of metacarpal shaft fractures, which share a number of commonalities.4Tobert D.G. Klausmeyer M. Mudgal C.S. Intramedullary fixation of metacarpal fractures using headless compression screws.J Hand Microsurg. 2016; 8: 134-139Crossref PubMed Google Scholar, 5Poggetti A. Nucci A.M. Giesen T. Calcagni M. Marchetti S. Lisanti M. Percutaneous intramedullary headless screw fixation and wide-awake anesthesia to treat metacarpal fractures: early results in 25 patients.J Hand Microsurg. 2018; 10: 16-21Crossref PubMed Google Scholar, 6Ruchelsman D.E. Puri S. Feinberg-Zadek N. Leibman M.I. Belsky M.R. Clinical outcomes of limited-open retrograde intramedullary headless screw fixation of metacarpal fractures.J Hand Surg Am. 2014; 39: 2390-2395Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar, 7del Piñal F. Moraleda E. Rúas J.S. de Piero G.H. Cerezal L. Minimally invasive fixation of fractures of the phalanges and metacarpals with intramedullary cannulated headless compression screws.J Hand Surg Am. 2015; 40: 692-700Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar, 8Jann D. Calcagni M. Giovanoli P. Giesen T. Retrograde fixation of metacarpal fractures with intramedullary cannulated headless compression screws.Hand Surg Rehabil. 2018; 37: 99-103Crossref PubMed Scopus (25) Google Scholar, 9Doarn M.C. Nydick J.A. Williams B.D. Garcia M.J. Retrograde headless intramedullary screw fixation for displaced fifth metacarpal neck and shaft fractures: short term results.Hand (N Y). 2015; 10: 314-318Crossref PubMed Scopus (39) Google Scholar, 10Beck C.M. Horesh E. Taub P.J. Intramedullary screw fixation of metacarpal fractures results in excellent functional outcomes: a literature review.Plast Reconstr Surg. 2019; 143: 1111-1118Crossref PubMed Scopus (28) Google Scholar, 11Eisenberg G. Clain J.B. Feinberg-Zadek N. Leibman M. Belsky M. Ruchelsman D.E. Clinical outcomes of limited open intramedullary headless screw fixation of metacarpal fractures in 91 consecutive patients [published online ahead of print March 17, 2019]. Hand (N Y).https://doi.org/10.1177/1558944719836235Google Scholar, 12Couceiro J. Ayala H. Sanchez M. De la Red M.L.A. Velez O. Del Canto F. Intramedullary screws versus Kirschner wires for metacarpal fixation, functional, and patient-related outcomes.Surg J (N Y). 2018; 4: e29-e33Google Scholar, 13Romo-Rodríguez R. Arroyo-Berezowsky C. Minimal invasive osteosynthesis with cannulated screws in metacarpal fractures [in Spanish].Acta Ortop Mex. 2017; 31: 75-81PubMed Google Scholar All cases were performed via a retrograde approach, requiring a split in the extensor tendon or the adjacent sagittal band, arthrotomy through the dorsal joint capsule, placement of a guide pin, and ultimately screw fixation through the dorsal central articular surface of metacarpal head extending proximal to the fracture site. This technique is relatively straightforward; the clinical results have been favorable with early initiation of active postoperative motion, stability without additional immobilization, and normal fracture union rates. In a series of 18 metacarpal fractures fixed with this technique, patients started moving at 1 week after surgery and achieved nearly normal range of motion (ROM) and grip strength comparable to those of the contralateral hand.4Tobert D.G. Klausmeyer M. Mudgal C.S. Intramedullary fixation of metacarpal fractures using headless compression screws.J Hand Microsurg. 2016; 8: 134-139Crossref PubMed Google Scholar A biomechanical study showed that peak load to failure strengths were twice those of intramedullary Kirschner wire fixation (3-point bending strength of 401.2 N and axial loading of 467.5 N compared with 205.3 and 198.3 N).14Avery D.M. Klinge S. Dyrna F. et al.Headless compression screw versus Kirschner wire fixation for metacarpal neck fractures: a biomechanical study.J Hand Surg Am. 2017; 42: 392.e1-392.e6Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar Whereas these studies suggest that limited open retrograde IMHCS fixation is safe and reliable for metacarpal neck, subcapital, and axial shaft fractures, additional studies have brought attention to drawbacks and limitations. Ruchelsman et al6Ruchelsman D.E. Puri S. Feinberg-Zadek N. Leibman M.I. Belsky M.R. Clinical outcomes of limited-open retrograde intramedullary headless screw fixation of metacarpal fractures.J Hand Surg Am. 2014; 39: 2390-2395Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar reported that 50% of patients had a residual extensor lag that generally resolved by 3 months. In 2 cases, shaft refractures occurred, drawing attention to the extensive countersinking of screws and violation of the medullary canal required to gain enough thread purchase proximal to the fracture site. In the study of del Piñal et al7del Piñal F. Moraleda E. Rúas J.S. de Piero G.H. Cerezal L. Minimally invasive fixation of fractures of the phalanges and metacarpals with intramedullary cannulated headless compression screws.J Hand Surg Am. 2015; 40: 692-700Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar of 48 unstable metacarpal fractures treated via retrograde ORIF with IMHCS, total active motion was favorable with a median of 249° but 2 patients had a permanent extensor lag greater than 30°. In addition, 20% of the metacarpophalangeal (MCP) articular joint surface was occupied by screw placement. Several studies have looked at the size of articular defects. A 3-dimensional computed tomography model looking at retrograde IMHCS fixation of metacarpal fractures demonstrated the articular defect to be over the dorsal central aspect of the joint surface, which makes contact with only the base of the proximal phalanx with joint hyperextension.15ten Berg P.W. Mudgal C.S. Leibman M.I. Belsky M.R. Ruchelsman D.E. Quantitative 3-dimensional CT analyses of intramedullary headless screw fixation for metacarpal neck fractures.J Hand Surg Am. 2013; 38: 322-330.e2Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar However, with increasing screw size, there is progressively more substantial violation of the metacarpal head articular surface: a 1.1-mm Kirschner wire violated 1 mm2 compared with 9 and 12 mm2 for 2.4 and 3.0 mm IMHCS. For a fifth metacarpal, a screw size of 4.0 mm or greater is often required for optimal fixation.7del Piñal F. Moraleda E. Rúas J.S. de Piero G.H. Cerezal L. Minimally invasive fixation of fractures of the phalanges and metacarpals with intramedullary cannulated headless compression screws.J Hand Surg Am. 2015; 40: 692-700Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar There are concerns regarding the long-term implications of the iatrogenic metacarpal articular cartilage defect and posttraumatic arthritis. Along with extensor tendon injury and metacarpal head articular defects, a major limitation of retrograde IMHCS fixation is providing stable fixation for more proximal fractures. Many commercially available headless compression screws are shorter than the length of the metacarpal. In multiple clinical patients, we have successfully treated proximal and midshaft metacarpal fractures with IMHCS placed in an antegrade fashion to avoid all of these issues. These clinical cases generated our interest in the current surgical technique report, in which we detail a limited open antegrade approach to IMHCS fixation of proximal third and midshaft metacarpal fractures. Surgical indications for performing antegrade placement of IMHCS were previously characterized and are similar regardless of the approach. Generally, surgery is recommended for displaced and irreducible metacarpal fractures, shortening of the metacarpal greater than 6 mm with resultant extensor lag, excessive dorsal angulation (greater than 40° for little fingers, greater than 30° for ring fingers, and greater than 10° for index or middle fingers), malrotation, or scissoring with composite fist flexion.1McNemar T.B. Howell J.W. Chang E. Management of metacarpal fractures.J Hand Ther. 2003; 16: 143-151Abstract Full Text Full Text PDF PubMed Scopus (60) Google Scholar Other indications for using this technique include multiple metacarpal shaft fractures, polytrauma with or without other hand or wrist fractures, and open fractures with severe soft tissue injury. Antegrade IMHCS fixation is specifically indicated for proximal third and midshaft fractures that can be difficult to reach with retrograde placement of a short IMHCS. Generally, few contraindications exist for performing this antegrade fixation approach to metacarpal fractures. Contraindications include extensive wound contamination, segmental metacarpal bone loss, and long oblique and spiral shaft fractures owing to their axial instability. The external morphology and intramedullary dimensions of metacarpals have been measured in great detail using radiographic films and a small series of cadaver specimens. The reported average and standard deviation of lengths and intramedullary widths of the thumb (46.46 ± 2.31 × 6.08 ± 0.83 mm), index (69.22 ± 4.25 × 4.79 ± 1.04 mm), middle (67.27 ± 3.42 × 5.04 ± 1.10 mm), ring (57.70 ± 3.03 × 4.26 ± 0.94 mm), and little (53.86 ± 2.93 × 4.32 ± 0.99) metacarpals coincide with measurements we have taken from computed tomography hand examinations from a cohort of 100 patients (unpublished data).16Lazar G. Schulter-Ellis F.P. Intramedullary structure of human metacarpals.J Hand Surg. 1980; 5: 477-481Abstract Full Text PDF PubMed Scopus (19) Google Scholar It is difficult to study carpometacarpal (CMC) joints of the fingers; there is a paucity of kinematic data and biomechanical models characterizing their function, especially relative to other joints in the hand. An in vitro cadaveric study described the axes of rotation for the CMC joints. This 3-dimensional kinematic analysis of second through fifth CMC joints reported overall wrist flexion-extension motion of the second and third CMC joints to be more limited than that of the fourth and fifth CMC joints (11° and 7° to 20° and 27°, respectively; the fifth CMC joint motion with the fourth CMC joint unrestrained was 44°).17Singla A. Kalsi G. Masih N. Morphological and topographical anatomy of nutrient foramens in human metacarpals and their surgical importance.Surg Radiol Anat. 2017; 39: 1227-1233Crossref PubMed Scopus (6) Google Scholar, 18El-Shennawy M. Nakamura K. Patterson R.M. Viegas S.F. Three-dimensional kinematic analysis of the second through fifth carpometacarpal joints.J Hand Surg Am. 2001; 26: 1030-1035Abstract Full Text Full Text PDF PubMed Scopus (58) Google Scholar These findings confirm that the second and third metacarpals are relatively fixed to the carpus whereas the fourth and fifth are mobile. Buffi and others19Buffi J.H. Crisco J.J. Murray W.M. A method for defining carpometacarpal joint kinematics from three-dimensional rotations of the metacarpal bones captured in vivo using computed tomography.J Biomech. 2013; 46: 2104-2108Crossref PubMed Scopus (20) Google Scholar reported an in vivo kinematic analysis of fourth and fifth CMC joints showing that range of flexion and extension were 7.65° and 14.67°, respectively. Rainbow and others20Rainbow M.J. Kamal R.N. Leventhal E. et al.In vivo kinematics of the scaphoid, lunate, capitate, and third metacarpal in extreme wrist flexion and extension.J Hand Surg Am. 2013; 38: 278-288Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar reported the in vivo kinematic analysis of the carpus and third metacarpal in extreme flexion and extension. The third metacarpal rotation axis was located an average of 0.9 mm more dorsal (P < .05) than the capitate in extreme extension. The third metacarpal flexed 1.0° ± 1° (P < .05) farther than the capitate in extreme flexion and extended 4° ± 2° (P < .001) farther than the capitate in extreme extension. In theory, a guidewire placed along the dorsal axis of the third metacarpal as it is maximally flexed at the CMC joint can tangentially skive off and clear the dorsal cortex of the capitate with antegrade placement. Proper setup for this approach requires the patient to be on an operating table with the limb on an upper-extremity table (Video 1). Under fluoroscopy, fracture evaluation and closed reduction are performed. A mini-open approach can be used to access the fracture site to perform debridement of callus or soft tissue and mobilize the fracture fragments if the fracture is not easily reduced. Once manual reduction is achieved, a guidewire corresponding to the cannulated IMHCS is placed in a retrograde fashion through the metacarpal head. Reduction and correction of rotational deformities are achieved by holding all of the patient's fingers flexed at the MCP joints. The extensor tendon can be diverted radially or ulnarly with the fingertip while the guidewire is introduced percutaneously, directly through the palpable metacarpal head. However, no incision is made through the skin or extensor mechanism directly over the metacarpal head as with the retrograde approach. Under fluoroscopic evaluation, the wire is advanced from distal to proximal across the fracture site toward the dorsal aspect of the metacarpal base. Generally, the guidewire should be aimed dorsally to skive off the dorsal aspect of the corresponding carpal bone or clearing the carpus altogether. Thus, we avoid appreciable defects in the capitate and all defects in the trapezium and hamate. Placement of IMHCS in the second metacarpal uniformly creates a defect the size of the screw diameter in the trapezoid (unpublished cadaver study data). Afterward, a 5- to 10-mm skin incision is made overlying the area where the guidewire surfaces from the dorsal wrist and is palpable. Dissection is performed to retract the soft tissues and the finger extensor tendons. The guidewire is advanced out the dorsum of the wrist until the distal aspect of the guidewire is almost buried in the MCP joint. A depth gauge is used to select a screw of appropriate length (subtracting 4 to 6 mm to prevent using an overly long screw). Next, a soft tissue protector is placed over the guidewire along with a cannulated drill corresponding to the selected IMHCS. The metacarpal is drilled past the fracture site in an antegrade fashion. The IMHCS is placed over the guidewire and advanced to obtain fixation of the fracture. Fluoroscopy is used to monitor screw advancement, maximizing attention to placement of enough screw threads distal to the fracture line while avoiding over-advancement, which sacrifices axial stability in the proximal fracture segment. It is helpful to hold the patient's fingers with the MCP and proximal interphalangeal joints flexed to 90° to continue to control for rotational deformities while the screw advances. After reduction and fixation is confirmed with fluoroscopy, the wound is irrigated and skin incisions are closed. After surgery, patients are placed in a short-arm plaster orthosis in intrinsic plus position. Patients begin hand therapy at 4 to 5 days after surgery for active ROM exercises. They are given removable thermoplast orthoses for nighttime use and support during at-risk activities for 4 weeks. Strengthening exercises and weightbearing can be initiated with radiographic and clinical evidence of healing, generally between 6 and 12 weeks. Several pearls of advice can optimize the technique of antegrade IMHCS reduction and fixation of transverse and short oblique metacarpal shaft fractures. Percutaneous placement of the IMHCS guidewire should center on the metacarpal head roughly 4 to 5 mm from the dorsal cortex. The extensor mechanism can be protected by diverting the tendon radially or ulnarly with the thumb tip of the contralateral hand holding the fingers flexed at the MCP joint. Starting slightly more volarly on the metacarpal head along with maximal flexion of the CMC joint allows the guidewire to traverse the axis of the metacarpal shaft and exit on the dorsal half of the metacarpal base, avoiding the corresponding CMC joint carpal. After a 5- to 10-mm skin incision is made over the palpable guidewire tip, blunt dissection is used to free and retract extensor tendon. A Frazier suction tip cannula is used to control the tip of the guidewire as it is advanced through the subcutaneous tissue for a more direct passage from skin to the metacarpal base. This is particularly helpful to avoid long subcutaneous tracts in patients with thicker adiposity. Placing a hemostat on the distal aspect of the guidewire at the MCP joint before using the cannulated drill and screw prevents loss of the guidewire and fracture reduction and promotes retrieval of broken hardware. Maintaining all finger MCP joints flexed during the entire procedure can help with reduction and prevent malreduction with rotational deformity. We have found that the choice of length and width of the IMHCS used for fixation is extremely important to the success of the surgery. The screw length chosen should be enough to generate axial stability proximal and distal to the fracture site. The screw width chosen should be enough to provide an interference fit in the intramedullary canal and achieve rotational stability at the fracture site. Table 1 depicts appropriate screw lengths and widths for fixation of transverse and short oblique metacarpal fractures by digit. With comminuted fractures, adequate interference fit within the intramedullary canal is even more critical. Use of a smaller screw diameter will result in toggling of the screw within the metacarpal canal and ultimately poor fixation and stability. We also advocate using a longer screw to avoid excessive countersinking. Ultimately, exacting technique is necessary to avoid the extreme difficulty of removing a countersunk and buried screw. Many headless compression screws are available. It is important to know the sizes and lengths available for each system.Table 1Practical Screw Lengths and Widths Appropriate for Fixation of Transverse and Short Oblique Metacarpal Fractures by Finger to Maintain Axial and Rotational StabilityMetacarpalAppropriate Screw Length, mmAppropriate Screw Width, mmThumb35–454.7–5.5Index45–554.7Middle45–554.7Ring35–503.6–4.1Little35–454.1–4.7 Open table in a new tab Complications of ORIF of metacarpal fractures using IMHCS in multiple case series have mostly been minor.4Tobert D.G. Klausmeyer M. Mudgal C.S. Intramedullary fixation of metacarpal fractures using headless compression screws.J Hand Microsurg. 2016; 8: 134-139Crossref PubMed Google Scholar, 5Poggetti A. Nucci A.M. Giesen T. Calcagni M. Marchetti S. Lisanti M. Percutaneous intramedullary headless screw fixation and wide-awake anesthesia to treat metacarpal fractures: early results in 25 patients.J Hand Microsurg. 2018; 10: 16-21Crossref PubMed Google Scholar, 6Ruchelsman D.E. Puri S. Feinberg-Zadek N. Leibman M.I. Belsky M.R. Clinical outcomes of limited-open retrograde intramedullary headless screw fixation of metacarpal fractures.J Hand Surg Am. 2014; 39: 2390-2395Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar, 7del Piñal F. Moraleda E. Rúas J.S. de Piero G.H. Cerezal L. Minimally invasive fixation of fractures of the phalanges and metacarpals with intramedullary cannulated headless compression screws.J Hand Surg Am. 2015; 40: 692-700Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar, 8Jann D. Calcagni M. Giovanoli P. Giesen T. Retrograde fixation of metacarpal fractures with intramedullary cannulated headless compression screws.Hand Surg Rehabil. 2018; 37: 99-103Crossref PubMed Scopus (25) Google Scholar, 9Doarn M.C. Nydick J.A. Williams B.D. Garcia M.J. Retrograde headless intramedullary screw fixation for displaced fifth metacarpal neck and shaft fractures: short term results.Hand (N Y). 2015; 10: 314-318Crossref PubMed Scopus (39) Google Scholar, 10Beck C.M. Horesh E. Taub P.J. Intramedullary screw fixation of metacarpal fractures results in excellent functional outcomes: a literature review.Plast Reconstr Surg. 2019; 143: 1111-1118Crossref PubMed Scopus (28) Google Scholar, 11Eisenberg G. Clain J.B. Feinberg-Zadek N. Leibman M. Belsky M. Ruchelsman D.E. Clinical outcomes of limited open intramedullary headless screw fixation of metacarpal fractures in 91 consecutive patients [published online ahead of print March 17, 2019]. Hand (N Y).https://doi.org/10.1177/1558944719836235Google Scholar, 12Couceiro J. Ayala H. Sanchez M. De la Red M.L.A. Velez O. Del Canto F. Intramedullary screws versus Kirschner wires for metacarpal fixation, functional, and patient-related outcomes.Surg J (N Y). 2018; 4: e29-e33Google Scholar, 13Romo-Rodríguez R. Arroyo-Berezowsky C. Minimal invasive osteosynthesis with cannulated screws in metacarpal fractures [in Spanish].Acta Ortop Mex. 2017; 31: 75-81PubMed Google Scholar The antegrade technique would not be expected to have complications different from those previously described, including pseudoclawing, extension lag, malrotation, and stiffness. Two cases of refractures were reported after reaching full union after repeat high-energy trauma.6Ruchelsman D.E. Puri S. Feinberg-Zadek N. Leibman M.I. Belsky M.R. Clinical outcomes of limited-open retrograde intramedullary headless screw fixation of metacarpal fractures.J Hand Surg Am. 2014; 39: 2390-2395Abstract Full Text Full Text PDF PubMed Scopus (54) Google Scholar Reports of malunion, nonunion, hardware failure, and hardware infection are rare. Our group performed antegrade fixation in all 5 metacarpal fractures in 7 patients; they progressed to successful union without complications of malunion, extension lag, or infection. Furthermore, we evaluated antegrade screw fixation of 50 metacarpal fractures in 10 cadaver hands and there was minimal to no disruption of the carpus associated with the CMC joint and no extensor mechanism violation. A 75-year-old, right-handed woman experienced a traumatic crush injury when the left hand was caught between an excavator and log, resulting in closed displaced transverse shaft fractures of the third, fourth, and fifth metacarpals (Fig. 1). The fractures were approximately midshaft at the fifth metacarpal but progressively more proximal from the fourth to the third metacarpal. During surgery, we approached the fifth metacarpal fracture via a classic retrograde approach involving a 1-cm longitudinal incision over the metacarpal head. The ulnar aspect of the sagittal band and joint capsule was incised by 1 cm to expose the metacarpal head. The guidewire was placed through the metacarpal head down the distal metacarpal fracture fragment; with adequate fracture reduction, it was advanced further into the proximal aspect of the fragment, achieving provisional fixation of the metacarpal shaft. A cannulated drill was used over the guidewire and then a 4.1 × 34-mm standard Acutrak 2 screw (Acumed, Hillsboro, OR) was placed into the shaft of the metacarpal to achieve fracture fixation. The fourth metacarpal fracture was approached similarly in a retrograde fashion. However because of its proximal nature, we had to countersink a longer and much narrower compression headless screw (3.0 × 48-mm, DePuy Synthes, Westchester, PA) to span the entire fracture. The third metacarpal fracture was approached uniquely in an antegrade fashion as described earlier. The guidewire was driven out the base of the third metacarpal and a 1-cm incision was made over the wrist instead of the metacarpal head. Using a similar cannulated drill, another 4.1 × 34-mm standard Acutrak 2 screw was placed in an antegrade fashion to stabilize the third metacarpal proximal third shaft fracture successfully without violating the capitate proximally and to avoid injury to the metacarpal head and extensor mechanism distally (Fig. 2). After surgery, the patient began hand therapy and gentle ROM at 2 weeks with support of a thermoplastic hand orthosis at all other times. At the patient's last clinic visit at 6 weeks after surgery, the patient had postoperative films revealing progression toward healing of the fractures (Fig. 3), resolution of all pain, and ROM consistent with extension lag of the ring and little fingers of 10° and 15°, respectively, whereas the middle finger had an extension lag of less than 5°. There were no rotational or scissoring deformities with composite fist formation.Figure 2Case illustration A: Intraoperative left hand image intensification films revealing reduction and fixation of metacarpal fractures with IMHCS placed in a retrograde fashion for the fourth and fifth metacarpal fractures and antegrade for the third metacarpal fracture.View Large Image Figure ViewerDownload (PPT)Figure 3Case illustration A: Six-week postoperative left posteroanterior, oblique, and lateral hand x-ray films reveal interval healing of third, fourth, and fifth metacarpal fractures with stable placement of IMHCS.View Large Image Figure ViewerDownload (PPT) An otherwise healthy 50-year-old man had a 50-ton sheet metal press slam down onto the back of the left hand at work. He experienced open second, closed third, and fourth metacarpal transverse shaft fractures that were severely displaced. Similar to patient A, the fractures were in the proximal third of the metacarpals (Fig. 4). During surgery, we extended a poke hole wound over the second metacarpal to expose the fracture. This fracture was reduced and fixed with a 2.0-mm plate and corresponding screws. However, the other fractures were reduced and fixed using IMHCS in an antegrade fashion. We were able to flex down the third and fourth CMC joints and advance the guidewire out through the dorsal aspect of the CMC joints to place 4.1 × 34-mm standard Acutrak 2 screws (Fig. 5). We confirmed under fluoroscopy that the screws spanned the fracture lines with adequate purchase of the distal fragments, without rotational or axial instability. Furthermore, we confirmed that there was no violation of the capitate or hamate. After surgery, the patient started hand therapy and gentle ROM at 10 days with support of a thermoplastic hand orthosis at all other times. At the patient's 6-month postoperative clinic visit, the radiographs demonstrated interval healing of the fractures (Fig. 6), resolution of pain, and motion consisting of 0° to 60° (MCP joints) and 0° to 85° (proximal interphalangeal joints) in all fingers. No rotational or scissoring defects were found upon examination.Figure 5Case illustration B: Intraoperative left hand image intensification films revealing reduction and fixation of metacarpal fractures with plate and screws for the second metacarpal and antegrade IMHCS placed for the third and fourth metacarpal fractures.View Large Image Figure ViewerDownload (PPT)Figure 6Case illustration B: Six-month postoperative posteroanterior, oblique, and lateral left hand x-ray films reveal interval healing and stable placement of hardware of the second (plate), third, and fourth (antegrade IMHCS) metacarpal fractures.View Large Image Figure ViewerDownload (PPT) This study was funded by Acumed (Grant ID: A141803). https://www.jhsgo.org/cms/asset/22571830-bb1d-4c61-aac1-965829e5cb4d/mmc1.mp4Loading ... Download .mp4 (103.54 MB) Help with .mp4 files Video 1Full-length 4K high-definition video depicting surgical technique of antegrade placement of IMHCS for transverse and short oblique metacarpal shaft fractures in a cadaver model. ErratumJournal of Hand Surgery Global OnlineVol. 3Issue 5PreviewIn the article by Hoang et al in the October 2019 issue of Journal of Hand Surgery Global Online ("Antegrade Intramedullary Screw Fixation: A Novel Approach to Metacarpal Fractures", Vol. 1, No. 4, p 229-235), the declaration of interests was not included. The declaration appears as follows: Declaration of interests: Acumed provided funding to obtain cadavers as well as intramedullary screws for use in this project. J. Huang is a paid consultant for Acumed. No benefits in any form have been received or will be received by the authors related directly or indirectly to the subject of this article. Full-Text PDF Open Access
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