Intramedullary cannulated headless screw fixation of a comminuted subcapital metacarpal fracture: case report

Comparison of Intramedullary Screw Fixation, Plating, and K-Wires for Metacarpal Fracture Fixation: A Meta-Analysis

BACKGROUND

Metacarpal fractures are common injuries with multiple options for fixation. Our purpose was to compare outcomes in metacarpal fractures treated with intramedullary screw fixation (IMF), Kirschner wires (K-wires), or plating.

METHODS

A systematic literature review using the MEDLINE database was performed for studies investigating metacarpal fractures treated with IMF, plating, or K-wires. We identified 34 studies (9 IMF, 8 plating, 17 K-wires). A meta-analysis using both mixed and fixed effects models was performed. Outcome measures included mean Disabilities of the Arm, Shoulder, and Hand (DASH) scores, total active motion (TAM), grip strength, time to radiographic healing, and rates of infection and reoperation.

RESULTS

Patients with IMF had significantly lower DASH scores (0.6 [95% confidence interval [CI], 0.2-1.0]) compared with K-wires (7.4 [4.8-9.9]) and plating (9.8 [5.3-14.3]). Intramedullary screw fixation also had significantly lower rates of reoperation (4%, [2%-7%]), compared with K-wires (11% [7%-16%]) and plating (11% [0.07-0.17]). Grip strength was significantly higher in IMF (104.4% [97.0-111.8]) compared with K-wires (88.5%, [88.3-88.7]) and plating (90.3%, [85.4-95.2]). Mean odds ratio time was similar between IMF (21.0 minutes [10.4-31.6]) and K-wires (20.8 minutes [14.0-27.6]), but both were shorter compared with plating (52.6 minutes [33.1-72.1]). There were no statistically significant differences in time to radiographic healing, TAM, or rates of reoperation or infection.

CONCLUSIONS

This meta-analysis compared the outcomes of metacarpal fixation with IMF, K-wires, or plating. Intramedullary screw fixation provided statistically significant lower DASH scores, higher grip strength, and lower rates of reoperation, suggesting that it is a comparable method of fixation to K-wires and plating for metacarpal fractures.

Outcomes and Complications of Intramedullary Metacarpal Fixation

BACKGROUND

Metacarpal fractures are common orthopedic injuries with potentially debilitating outcomes. Ideal surgical treatment remains a topic of debate, with intramedullary fixation becoming popular as a technique to allow for earlier mobilization with few reported complications. The aim of this study was to report observed outcomes and complications of intramedullary metacarpal fixation using the ExsoMed INnate metacarpal nail.

METHODS

A retrospective chart review of 37 patients with 44 metacarpals treated with the ExsoMed INnate between July 2020 and December 2021 by a single fellowship-trained hand surgeon at a single level 1 trauma center was performed. Variables recorded included both patient and injury demographics, surgical complications, and postoperative outcomes. We also measured metacarpal isthmus diameter of the second to fifth metacarpals on all patients to determine the intramedullary canal diameter to assist in implant size selection.

RESULTS

Average follow-up was 5.84 weeks with average time to radiographic healing of 5.5 weeks, and time to full activity 6.32 weeks. The mean postsurgical active total arc of motion was 250°, while passive total arc of motion was 259.74°. A total of 10 complications (22%) were identified, including 4 bent screws which occurred as a result of a punching event postoperatively.

CONCLUSIONS

Intramedullary fixation of metacarpal fractures using the ExsoMed INnate metacarpal nail has shown to preserve range of motion and quick return to full activity, with a low rate of major complications. Our study highlights the potential major complication of the bent intramedullary screw and its association with an initial punching mechanism.

Fracture Fixation Strength in Metacarpal Plating Versus Intramedullary Nailing Using a 3-Point Bending Model: A Cadaveric, Biomechanical Study

PURPOSE

The purpose of our study was to evaluate the ultimate load to failure for 2 metacarpal fracture fixation strategies, plating versus intramedullary nailing, and then compare them to the native metacarpal. Our hypothesis was that the intramedullary nail after fracture fixation would more closely restore the native strength of the metacarpal when compared to plate fixation.

METHODS

Matched pairs of cadaveric hands (age range, 19-49; 5 men and 6 women) were dissected to produce 88 intact and equally distributed metacarpals (little, ring, middle, and index fingers). The metacarpals were then randomly selected to undergo either plate fixation or intramedullary nail fixation. A 3-point bending model was used to test the native metacarpal strength to the point of fracture and, subsequently, the fracture fixation construct. The data were then compared against the native metacarpal for normalized load to failure, normalized displacement, and stiffness.

RESULTS

The normalized maximum force (ratio of fixation:native) for the intramedullary nail specimens was significantly closer to normal than for the plated specimens for the little, middle, and index fingers, as well as for all metacarpals combined. We did not detect a difference in maximum force for the ring finger.

CONCLUSIONS

When compared to plate fixation, metacarpal intramedullary nailing more closely restores the ultimate load to failure of the native metacarpal after midshaft fracture.

CLINICAL RELEVANCE

For metacarpal fracture patterns amenable to intramedullary screw fixation, an intramedullary nail has biomechanical properties that are superior to a plate and screws in a 3-point bending model.

Outcomes Following Fully Threaded Intramedullary Nailing of Metacarpal Fractures

Purpose

Intramedullary screw fixation has emerged as a popular approach for the treatment of displaced metacarpal fractures. The purpose of this study was to investigate the functional and radiographic outcomes of a newly designed, headless noncompressive fully threaded intramedullary nail (TIMN) for the treatment of metacarpal fractures.

Methods

A retrospective chart review was performed on patients who were treated with the INnate TIMN (ExsoMed) at a single academic institution with a minimum of 1-year follow-up. Patient-reported functional outcomes included Quick Disabilities for the Arm, Shoulder, and Hand (QuickDASH) questionnaires, return to work and physical activity time, and overall satisfaction. Radiographs were retrospectively reviewed to determine radiographic union, change in angulation, and metacarpal shortening.

Results

A total of 49 patients (58 fractures) with a mean age of 36 years (range: 17-75 years) were included. The mean follow-up time was 2.7 years (range: 1.4-4.3 years). Overall, the mean patient satisfaction rating was 4.9 of 5 (range: 3-5). The mean return to work time was 7.2 weeks (range: 0.14-28 weeks), and the mean return to sport or activity was 8.3 weeks (range: 1-28 weeks). Average QuickDASH scores across all patients were 4 (range: 0-56.9). The median radiographic healing time was 6.1 weeks (range: 4.7-15.4 weeks). Mean postoperative shortening in the fifth metacarpal fracture was 3 mm (range: -4.2 to 8 mm) at the initial postoperative visit and 3.6 mm (range: -3.3 to 7.9 mm) at the final radiographic follow-up. Subgroup analysis showed that postoperative shortening was similar, regardless of the fracture pattern. The following four complications were reported: one case of persistent pain and stiffness, one case of carpal tunnel syndrome, one nonunion, and one fractured intramedullary nail.

Conclusions

Our findings suggest that the TIMN allows for a reliable return to work and physical activity, high patient satisfaction, low complication rate, and minimal shortening at the final radiographic follow-up.

Type of study/level of evidence

Therapeutic IV.

Articular Involvement With Retrograde Headless Compression Screw Fixation of the Metacarpal

PURPOSE

Retrograde headless compression screw (RHCS) fixation for metacarpal fractures can lead to metacarpal head articular cartilage violation. This study aimed to quantify the articular surface loss after insertion of the RHCS and determine the functional range of motion (ROM) of the metacarpophalangeal (MCP) joint at the point of contact between the proximal phalangeal (P1) base and the articular defect.

METHODS

Ten fresh-frozen cadaveric hand specimens were analyzed for prefixation MCP joint ROM. After screw insertion, the ROM at which the dorsal portion of the P1 base begins to engage the screw tract defect, as well as the ROM at which the midsagittal portion of the P1 bisector engages the screw tract defect, was recorded. The distal axial articular surface of the metacarpal and the defects from screw insertion were measured using a digital image software program.

RESULTS

Nine men and one woman (mean age, 69 years) were examined. The prefixation mean extension-flexion arc for all MCP joints ranged from 1° to 85°. After screw insertion, the mean MCP ROM at which the dorsal P1 articular surface first engaged the screw tract was 31°. Only 7 digits had screw tract engagement with the midsagittal bisector of the P1 base at a mean flexion angle of -18° (18° hyperextension). Mean articular surface violation increased from the index finger moving ulnarly, with an average of 3.9% involvement.

CONCLUSIONS

Articular surface loss of the metacarpal head following RHCS insertion is negligible in a cadaveric model, with minimal engagement between the corresponding defect and the P1 base during functional ROM.

CLINICAL RELEVANCE

Retrograde headless compression screw fixation of metacarpals inevitably damages the cartilage. However, the actual defect is small in proportion to the articular surface area and not engaged during functional activity. These biomechanical features may mitigate the surgeon's concern about joint destruction, while ensuring the benefits of early rehabilitation and minimal invasiveness of this technique.

Intramedullary K-wires versus Alternate Techniques for Metacarpal Shaft and Neck Fractures: A Systematic Review and Meta-analysis

Intramedullary K-wire (IMKW) fixation is one of the mainstays for surgically treating metacarpal shaft and neck fractures. However, there remains a lack of literature comparing outcomes of the various available surgical repair techniques in all indicated metacarpals. Therefore, we conducted a systematic review and meta-analysis to investigate the clinical advantages and drawbacks of IMKW compared with alternate fracture repair techniques. A comprehensive systematic literature review was performed to identify studies that compared clinical outcomes of IMKW to alternate metacarpal fixation modalities. Outcomes included Disabilities of the Arm, Shoulder, and Hand (DASH/ quick DASH) scores, grip strength, union rate, visual analog scale pain, operative time, and complications. A random-effects model was used to compare IMKW to the pooled effect of other fixation techniques. A total of 10 studies were included in our analysis, comprising 497 metacarpal fractures (220 shafts and 277 necks). IMKW fixation was identified as the control group in all studies. The pooled experimental group included plates, transverse K-wires (TKWs), interfragmentary screws (IFSs), and K-wire cross-pinning (CP). In treating metacarpal shaft fractures, IMKW showed significantly shorter operative time ( p  = 0.04; mean difference = - 13; 95% confidence interval = -26 to -0.64). No significant differences were observed in treating metacarpal neck fractures for disability, grip strength, healing rate, pain, operative time, or complication rate. This systematic review and meta-analysis found no difference in clinical outcomes among various surgical techniques for treating metacarpal shaft and neck fractures. Further high evidence studies are required that investigate the efficacy and safety of IFS, CP, TKW, and intramedullary screws versus IMKW for treating closed, unstable metacarpal fractures.

Intramedullary Screw Fixation of Metacarpal and Phalangeal Fractures

Metacarpal and phalangeal fractures are the second and third most common hand and wrist fractures seen in the emergency department. There are a multitude of operative fixation methods for metacarpal and phalangeal fractures, including closed reduction percutaneous pinning, open reduction internal fixation, external fixation, and intramedullary screw fixation. Although intramedullary fixation is a relatively new surgical technique, it is gaining in popularity as it allows patients to resume range of motion early in the postoperative period with excellent clinical outcomes.

Intramedullary fixation of metacarpal and phalangeal bone fractures with bioabsorbable Mg K-wire in 20 cases

PURPOSE

The treatment of irreducible or severely displaced metacarpal and phalangeal bone fractures is still much debated. The recent development of the bioabsorbable magnesium K-wire is thought to allow effective treatment upon insertion via intramedullary fixation by minimizing articular cartilage injuries without discomfort until pin removal and drawbacks, such as pin track infection and metal plate removal. Therefore, this study investigated and reported the effects of intramedullary fixation with the bioabsorbable magnesium K-wire in unstable metacarpal and phalangeal bone fractures.

METHODS

This study included 19 patients admitted to our clinic for metacarpal or phalangeal bone fractures from May 2019 to July 2021. As a result, 20 cases were examined among these 19 patients.

RESULTS

Bone union was observed in all 20 cases, with a mean bone union time of 10.5 (SD 3.4) weeks. Reduction loss was observed in six cases, all showing dorsal angulation with a mean angle of 6.6° (SD 3.5°) at 4.6 weeks as compared with that noted in the unaffected side. The gas cavity upon H2 gas formation was first observed approximately 2 weeks postoperatively. The mean DASH score was 33.5 for instrumental activity and 9.5 for work/task performance. No patient complained of notable discomfort after surgery.

CONCLUSION

Intramedullary fixation with the bioabsorbable magnesium K-wire may be used for unstable metacarpal and phalanx bone fractures. This wire is expected to be a particularly favorable indication for shaft fractures, although care should be taken due to the possibility of complications related to rigidity and deformity.

Antegrade Intramedullary Screws in Metacarpal Fractures of Pediatric Patients

Metacarpal fractures are common injuries in pediatric patients. In adults, cannulated intramedullary screws are an excellent stabilization option for metacarpal fractures and are widely used, but in pediatric patients with open physes, their use is a relative contraindication. The risk of injury to the physis in classic retrograde screw placement makes this type of osteosynthesis not an option. We present the case of an 8-year-old patient with fractures of two adjacent metacarpals with rotational malalignment and scissoring, in which closed reduction was performed, and stabilization with cannulated intramedullary screws using antegrade placement to avoid injury to the physis.

Intramedullary Threaded Nail Fixation Versus Plate and Screw Construct in Metacarpal Neck Fractures: A Biomechanical Study

BACKGROUND

Indicated surgical management of metacarpal neck fractures varies with techniques, including Kirschner wire fixation, plate fixation, intramedullary fixation, and headless compression screw fixation, without demonstrated superiority. This study compares intramedullary threaded nail (ITN) fixation with a locking plate construct.

METHODS

Index through small finger metacarpals were harvested from 10 embalmed cadavers. After application of appropriate exclusion criteria, remaining metacarpals underwent neck fracture creation by a three-point load to failure. Eight samples were randomly allocated to fixation with ITN fixation, and six were stabilized with a 2.3-mm seven-hole locking plate. Samples were then subjected to a second round of biomechanical testing using the same apparatus. Ultimate load between the intact tissue and the subsequently stabilized fracture was analyzed with a paired Student t-test. Percentage change in ultimate load in the intact tissue and stabilized tissue was calculated, and the magnitude of relative difference between the two groups was analyzed using unpaired Student t-tests. Statistical difference was defined by a P value of < 0.05.

RESULTS

Both groups demonstrated the ability to handle a biomechanical load; however, both were significantly weaker than the intact tissue (paired Student t-test p ITN-fixed versus p ITN-intact = 0.006; p plate-fixed versus p plate-intact = 0.002). ITN samples demonstrated a higher load to failure (unpaired Student t-test p ITN-fixed versus p plate-fixed = 0.039).

CONCLUSION

ITN provides a biomechanically stronger fixation constructed for vertically oriented metacarpal neck fractures compared with locking plate fixation. Both ITN and locking plate constructs provide stabilization capable of tolerating a biomechanical load; however, both fixation modalities are weaker than the native tissue.

Intramedullary Fixation with Cannulated Screw After Resection of Enchondroma in the Hand: Technique Description and Case Series

Purpose

Enchondromas are primary, benign bone neoplasms that arise from intramedullary proliferation of hyaline cartilage cells. Slow and progressive in growth, enchondromas can lead to bone destruction, deformities, and fractures. The treatment of enchondromas remains controversial. We hereby describe the technique for bone fixation using headless intramedullary screws (HISs) after enchondroma resection in the long bones of the hand.

Methods

From January 2018 to June 2021, all patients treated with HISs after the resection of enchondroma of the hand were retrospectively assessed and included in the study. The series comprised four patients with a minimum postoperative follow-up period of 12 months. Postoperative functional results were measured according to Takigawa criteria and postoperative radiographic results were graded according to the Tordai system.

Results

After tumor resection and screw fixation, one patient had autologous bone grafting from the iliac crest, and another had the defect filled with calcium phosphate cement. All patients were followed up for at least 12 months, and the mean healing time of the pathologic fracture was 5 weeks. There were neither complications related to the procedure nor the need for a second surgery.

Conclusions

We describe the technique of intramedullary headless screws for bone fixation after enchondroma resection in the long bones of the hand, as well as the excellent functional, cosmetic, and radiographic results of four patients treated with the technique presented herewith.

Type of study/level of evidence

Therapeutic IV.

Intramedullary Metacarpal Fracture Fixation: A Biomechanical Study of Screw Diameter and Comparison With Intramedullary Wire Stabilization

PURPOSE

Interest in intramedullary metacarpal fracture fixation (IMFF) with screws is increasing. However, the optimal screw diameter for fracture fixation is not yet established. In theory, larger screws should be more stable, but there is concern about long-term sequelae of larger metacarpal head defects and extensor mechanism injury created during insertion as well as implant cost. Therefore, the purpose of this study was to compare different diameter screws for IMFF to a popular and more cost-effective alternative of intramedullary wiring.

METHODS

Thirty-two cadaveric metacarpals were used in a transverse metacarpal shaft fracture model. Treatment groups consisted of IMFF with 3.0 × 60 mm, 3.5 x 60 mm, and 4.5 x 60 mm screws as well as 4 1.1-mm intramedullary wires. Cyclic cantilever bending was performed with the metacarpals mounted at 45° to simulate physiologic loading. Cyclical loading at 10, 20, and 30 N was performed to determine fracture displacement, stiffness, and ultimate force.

RESULTS

At 10, 20, and 30 N of cyclical loading, all screw diameters tested provided similar stability as measured by fracture displacement and were superior to the wire group. However, ultimate force under load to failure testing was similar between the 3.5- and 4.5-mm screws and superior to 3.0-mm screws and wires.

CONCLUSIONS

For IMFF, 3.0, 3.5, and 4.5-mm diameter screws provide adequate stability for early active motion and are superior to wires. When comparing the different screw diameters, 3.5- and 4.5-mm diameter screws offer similar construct stability and strength superior to the 3.0-mm diameter screw. Therefore, to minimize metacarpal head morbidity, smaller screw diameters may be preferable.

CLINICAL RELEVANCE

This study suggests that IMFF with screws is biomechanically superior to wires in cantilever bending strength in the transverse fracture model. However, smaller screws may be sufficient to permit early active motion while minimizing metacarpal head morbidity.

Complications Following Intramedullary Screw Fixation for Metacarpal Fractures: A Systematic Review

PURPOSE

There has been a recent increase in the use of intramedullary screws (IMS) for the surgical treatment of metacarpal fractures. While IMS fixation has been shown to produce excellent functional outcomes, postoperative complications have yet to be fully explored in a comprehensive way. This systematic review quantified the incidence, treatment, and results of complications following IMS fixation for metacarpal fractures.

METHODS

A systematic review was performed using PubMed, Cochrane Central, EBSCO, and EMBASE databases. All clinical studies that documented IMS complications following metacarpal fracture fixation were included. Descriptive statistics were analyzed for all available data.

RESULTS

Twenty-six studies were included: 2 randomized trials, 4 cohort studies, 19 case series, and 1 case report. Among the 1,014 fractures studied, 47 complications were reported across all studies (4.6%). Stiffness was the most common, followed by extension lag, loss of reduction, shortening, and complex regional pain syndrome. Other complications included screw fracture, bending, and migration; early-onset arthrosis; infection; tendon adhesion; hypertrophic scar; hematoma; and nickel allergy. Eighteen of the 47 (38%) patients with complications underwent revision surgery.

CONCLUSIONS

Complications following IMS fixation of metacarpal fractures are relatively uncommon.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Anterograde Intramedullary Headless Compression Screw for Managing Extra-articular Thumb Metacarpal Base Fracture: Technique and Report

Extra-articular base fractures of the thumb are typical in hand surgeon practice. Nonoperative methods (spica) and operative methods are available for its management. There are operative methods described, such as plate and screws, Kirschner wires, and intramedullary screws. However, there is only a retrograde technique described. This study aims to present a new technique of an anterograde intramedullary headless compression screw to manage the extra-articular thumb metacarpal base fracture. This minimally invasive method allows an early range of motion and does not cross the articular surface of the thumb. This alternative fixation method has the advantage of low damage to soft tissues and good functional outcomes.

A Biomechanical Comparison of Fixation Techniques in Metacarpal Shaft Fractures

Background  Typically, metacarpal shaft fractures are treated with closed reduction percutaneous pinning, intramedullary nails, or plate fixation. Recently some surgeons have begun using intramedullary headless compression screws. Questions/Purposes  The purpose of this study was to compare intramedullary screw fixation to K-wire fixation, which is the standard of care in a transverse metacarpal midshaft fracture, using a cadaveric model. Our hypothesis was that intramedullary screw fixation would have a biomechanical advantage (higher stiffness and peak load to failure) when compared with dual Kirschner wire fixation of transverse metacarpal shaft fractures. Methods  Four-point bend testing was performed to compare stiffness and failure load values of seven paired 2nd and 3rd metacarpals instrumented with headless intramedullary compression screw fixation or Kirschner wire fixation. Similar testing was performed on 14 unpaired 4th metacarpals. Results  There was no significant difference in peak load ( p  = 0.60) or stiffness ( p  = 0.85) between fixation groups for the 2nd and 3rd instrumented metacarpals. For the instrumented 4th metacarpals, there was no significant difference in peak load ( p  = 0.14), but the stiffness was significantly greater ( p  = 0.01) for the compression screw group compared with the Kirschner wire fixation. Conclusions/Clinical Relevance  In this study, the load to failure was not different between the two fixation methods and likely both techniques can sustain physiologic loads needed for rehabilitation. The greater stiffness in the 4th metacarpal compression screw group may be related to the smaller canal morphology than in the 2nd and 3rd metacarpals. Larger diameter screws may be needed to obtain a better fit particularly in the 2nd and 3rd metacarpals.

Intramedullary Headless Screw Fixation for Metacarpal Fractures - Technical Tips

Metacarpal fractures are a common injury in the hand. When surgical intervention is indicated, there are multiple approaches and techniques of fixation. Intramedullary fixation has become an increasingly versatile method of fixation. The limited dissection needed for its insertion, rotational stability provided by the isthmic fit and lack of requisite hardware removal are improvements over conventional K-wire or plate fixation techniques. Multiple outcome studies have confirmed its safety and effectiveness. In this technical note, we provide some tips that can help surgeons considering intramedullary headless screw fixation of metacarpal fractures. Level of Evidence: Level V (Therapeutic).

Ideal Length and Diameter for Intramedullary Screw Fixation of Metacarpal Fractures: A Biomechanical Study

Purpose

This biomechanical study evaluated the effect of intramedullary screw diameter and length relative to 3-point bending force and torsional force when used to stabilize metacarpal shaft fractures.

Methods

Transverse osteotomies were made in the proximal metacarpal shaft in 36 middle finger metacarpal fourth-generation composite Sawbones. To compare screw diameters, antegrade intramedullary screws of 30-mm length were placed in 6 metacarpals, which included 4.7-mm Acutrak 2, Standard Acutrak 2 (4.0 mm), and Mini-Acutrak 2 (3.5 mm) screws. To compare screw lengths, metacarpals were fixated with Standard Acutrak 2 screws of 26, 30, or 34 mm in length, with screw tips bypassing the osteotomy by 6, 10, or 14 mm, respectively. A 6 degrees of freedom robot was used for torsional and 3-point bending testing.

Results

Increasing screw diameter demonstrated significant differences in both 3-point bending and torsional strengths. Maximum torsional loads were 69 Ncm (4.7-mm Acutrak 2), 45 Ncm (Standard Acutrak 2), and 27 Ncm (Mini-Acutrak 2) (P < .05). Loads to failure in the 3-point bending tests were 916 N (4.7-mm Acutrak 2), 713 N (Standard Acutrak 2), and 284 N (Mini-Acutrak 2) (P < .05). Differing screw lengths demonstrated significant differences with maximum torsional loads when comparing the 26-mm screws (22 Ncm) with 30- and 34-mm screws (45 and 55 Ncm, respectively) (P < .05). The 3-point dorsal bending strengths were significantly different between the 26-mm screws (320 N) and 30- and 34-mm screws (713 N and 702 N, respectively) (P < .05).

Conclusions

The results demonstrated significantly higher torsional strength and resistance to 3-point bending with larger intramedullary screw diameters. Further, when selecting the intramedullary screw length, the screw tip should pass at least 10 mm beyond the fracture.

Clinical Relevance

This study provided biomechanical evidence to guide surgeons in selecting intramedullary screw diameter and length for treating metacarpal fractures.

Threaded Intramedullary Nails Are Biomechanically Superior to Crossed K-wires for Metacarpal Neck Fractures

BACKGROUND

Intramedullary nail (IMN) fixation of metacarpal fractures is an alternative to Kirschner wire (K-wire) fixation. The goal of this study was to compare the biomechanical properties of K-wire fixation with a threaded IMN (InNate; ExsoMed, Aliso Viejo, California).

METHODS

The study design was based on previously described biomechanical models for evaluating metacarpal fractures. Sixteen fresh frozen small finger-matched and ring finger-matched pairs were randomized to either IMN or 0.045 in K-wire fixation after receiving a standardized neck osteotomy. Proper implant placement was confirmed with plain radiographs. Specimens then underwent loading in a 3-point bend configuration. Load to failure (LTF), stiffness, and fracture displacement were recorded. Mechanical failure was defined by a sharp change in the load-displacement curve.

RESULTS

Age, sex, sidedness (left or right), and digit (ring or small finger) were evenly distributed between groups. The IMN had a significantly higher LTF than K-wires (546 N vs 154 N, P < .001). The K-wire fixation demonstrated plastic deformation between 75 and 150 N. Intramedullary nail stiffness was higher than that of K-wires (155.89 N/mm vs 59.28 N/mm, P < .001).

CONCLUSIONS

When surgical fixation is indicated for metacarpal neck and shaft fractures, the threaded IMN is biomechanically superior to crossed K-wires with the application of 3-point bend.

Retrograde Intramedullary Screw Fixation for Metacarpal Fractures: A Systematic Review

Common forms of fixation of metacarpal fractures have historically included percutaneous Kirschner wire fixation, plates and screws, and, more recently, intramedullary screw fixation. Retrograde intramedullary screws (RISs) are a novel modality first described 10 years ago. The purpose of this review is to critically evaluate the published literature assessing outcomes of RIS fixation for metacarpal fractures and create a complication profile for this novel technique. A comprehensive literature search was performed using electronic databases for both clinical and biomechanical studies in relation to RIS fixation published from 2000 to 2020. A total of 19 studies (13 clinical and 6 biomechanical) met the inclusion criteria. The clinical studies examined 603 metacarpal fractures and demonstrated adequate functional outcomes in terms of grip strength, total active motion, and time to return to work. The biomechanical studies examined 80 metacarpal fractures, finding that load to failure in RISs was often equal to or higher than Kirschner wires but less than plate and screws. The complication rate in reviewed studies was 2.8%, with the most prevalent complications being stiffness and extension lag. RIS use in metacarpal fractures appears to provide adequate stability with satisfactory clinical outcomes and minimal complications, although more high-quality studies are needed to fully examine this modality.

Intra-medullary Cannulated Headless Compression Screw for Bone Graft Fixation in Metacarpal Fractures

High energy metacarpal fracture presenting with critical bone loss requires bone graft and hardware stabilisation. Early bone grafting and rigid internal fixation allow expedited patient recovery. Plate fixation is the most described technique when an autologous bone graft is being used. In this report, we present an alternative technique to secure bone grafts to metacarpal shafts with intra-medullary headless compression screws (HCS). In the presented patient, significant bone defects of the fourth and fifth metacarpals were bridged using iliac crest cortico-cancellous bone grafts and fixed with HCS. This method of fixation allowed controlled early active mobilisation. Bone graft incorporation and excellent active range of motion were demonstrated. Level of Evidence: Level V (Therapeutic).

Intramedullary Compression Screw Fixation of Proximal Phalangeal Fractures: A Systematic Literature Review

Proximal phalangeal fractures have traditionally been fixed via either Kirschner wires or dorsal plating. Concerns regarding lack of compression and potential for infection with wire fixation, and adhesion formation and stiffness with plating, have lead to alternative fixation methods, such as intramedullary screw fixation. However, the literature regarding this modality is limited. Methods: A systematic review was performed to review the literature regarding intramedullary screw fixation for proximal phalangeal fractures. English language studies that reported original data and commented on at least one postoperative measure of function were eligible for inclusion. 4 studies were eligible for inclusion, with a further 3 studies assessing proximal and middle phalanges analysed separately. Total active motion was greater than 240° in all proximal phalangeal studies; mean post-operative DASH was 3.62. 6% of patients sustained a major complication. Intramedullary screw fixation of proximal phalangeal fractures is safe, providing stable fixation to allow early motion.

Morphological Analysis of Metacarpal Shafts With Respect to Retrograde Intramedullary Headless Screw Fixation

Background: The use of retrograde intramedullary headless compression screw fixation for metacarpal neck and shaft fractures has been described in the literature. The purpose of this study was to perform a computed tomography (CT)-based morphological analysis of metacarpal size to help surgeons anticipate expected hardware needs. Methods: In all, 108 consecutive hand CT scans were evaluated for the medullary diameter in the volar-dorsal and radial-ulnar planes at the narrowest point of the canal, as well as for the distance from the articular surface to this point. Results were then analyzed by finger and by sex. Results: The ring finger had the smallest average medullary canal diameter for both men and women (2.7 and 2.6 mm, respectively); the small finger had the largest average diameter (3.9 mm) for men and the middle finger (3.6 mm) for women. Radial-ulnar was the rate-limiting dimension in the index, middle, and ring fingers, whereas volar-dorsal was the smallest dimension in the small finger, regardless of sex. Medullary diameter tended to be larger in patients aged more than 50 years. More than 50% of fingers have diameters >3.0 mm, and at least 40% of index, middle, and small fingers have diameters >3.5 mm, which are common diameters of commercially available headless compression screws. Conclusions: When preparing to perform open reduction internal fixation of a metacarpal using retrograde intramedullary headless compression screws, the surgeon needs to be prepared with screws of larger diameters to optimize fixation. Screws of larger diameters are needed to achieve endosteal purchase, regardless of sex.

Corrective Fifth Metacarpal Neck Osteotomy and Intramedullary Screw Fixation Technique: Technique and Case Report

Malunion of metacarpal fractures can result in severe functional and esthetic impairment to the patient, thus requiring surgical correction. Traditionally, the fixation methods most commonly used for these fractures are the Kirschner wires or the plates and screws. However, one of the options for the fixation of metacarpal fractures is intramedullary fixation with a headless screw. This minimally invasive method can also be used for corrective metacarpal osteotomies. It has the advantages of being a minimally invasive technique and allowing the early range of motion. This minimally invasive method can also be used to stabilize the corrective metacarpal osteotomies for malunion. This case report presents a minimally invasive technique for corrective dorsal metacarpal osteotomy and fixation with a headless intramedullary screw. This alternative fixation method has the advantage of low damage to soft tissues and good functional outcomes.

Headless Compression Screw for Metacarpal Nonunion: Description of a New Technique and Report of 4 Cases

Nonunion is a rare complication of metacarpal fractures and is usually associated with compound, open fractures with tissue loss and infection, or after failed surgical treatment. Repair by rigid osteosynthesis with plate and screws combined with autologous bone grafting has always been the treatment of choice for most patients. Such method allows early motion, although it has been proven that the presence of hardware may cause local soft tissue irritation. Often, hardware removal and tendon releases are necessary. We describe an original technique with a fixation method for the treatment of metacarpal nonunions, considering the excellent results attained with an intramedullary, headless screw for metacarpal fracture fixation. We report a series of three cases that evolved to bone healing with excellent clinical, functional, and radiographic outcomes.

Intramedullary Headless Screw Fixation of Metacarpal Fractures: A Radiographic Analysis for Optimal Screw Choice

Background: The purpose of this study was to investigate variations in radiographic metacarpal anatomy as it relates to intramedullary (IM) fixation of metacarpal fractures and to compare this anatomy with available headless screw dimensions. Methods: We radiographically analyzed posteroanterior and lateral (LAT) radiographs of 120 metacarpals across 30 patients without structural abnormalities. Primary outcomes included IM isthmus diameter, isthmus location, metacarpal cascade, and head entry point collinear with IM canal. Measurements were compared with a list of commercially available headless screws used for IM fixation. Results: The average largest isthmus diameter was in the small metacarpal (3.4 mm), followed by the index (2.8 mm), long (2.7 mm), and ring (2.7 mm) metacarpals. The average cascade angle between long and index, long and ring, and long and small metacarpals was 0°, 24°, and 27°, respectively. The appropriate head entry point ranged between 25% and 35% from the dorsal surface of the metacarpal head on a LAT view. The retrograde isthmus location of the index and long finger was 39.2 and 38.1 mm, respectively. Twenty-five screws from 7 manufacturers were analyzed with sizes ranging from 1.7 to 4.5 mm. Only 8 of 17 screws between 2.3 and 3.5 mm had a length range above 35 mm. Conclusions: Metacarpal head entry point and cascade angle can help identify the appropriate reduction with the guide pin starting point in the dorsal 25% to 35% of the metacarpal head. Surgeons should be mindful to choose the appropriate fixation system in light of the variations between metacarpal isthmus size, isthmus location, and available screw lengths.

Intramedullary Fixation with Headless Screws versus Bouquet in Unstable Metacarpal Neck Fractures in Active Patients: A Randomized Study

Objeticve  To compare the range of motion (ROM), return-to-work time, visual analogue score (VAS), disability of the arm, shoulder, and hand (QuickDASH), and radiographic outcomes of two methods of definitive internal fixation in active patients with boxer's fractures, operated in the first week.

Methods  This was a prospective, randomized trial, in which 50 patients, with a mean age range of 18 to 40 years old, were randomized and treated to definitive intramedullary fixation using 2 headless screws ( n  = 20) or bouquet (2 or 3 Kirschner wires) ( n  = 20). The patients were assessed on return-to-work time, ROM, patient reported QuickDASH outcome, VAS, and radiographic evaluation at 6 months.

Results  At 6 months, there were no differences between the two groups in terms of ROM, postoperative pain (VAS), or QuickDASH score. The overall complication rate was 4.76% in the screw group, compared with 5% in the bouquet-fixation group.

Conclusions  In the treatment of the active patients with unstable boxer's fractures, headless screws and bouquet fixation proved to be a safe and reliable treatment. The outcomes were similar in both groups.

Intramedullary Screw Fixation Comprehensive Technique Guide for Metacarpal and Phalanx Fractures: Pearls and Pitfalls

Background:

Phalangeal and metacarpal fractures are the second and third most common upper extremity fractures after distal radius fractures with varying methods of fixation techniques. Intramedullary screw fixation is an increasingly preferred method of fixation. Benefits include early range of motion, faster recovery, limited dissection, and reduced complications. Improper technique, which is readily avoidable, can lead to suboptimal results.

Methods:

A review of recent literature on current techniques aims to summarize the biomechanics of intramedullary screw fixation and outline appropriate technique of placing headless compression screws for metacarpal and phalangeal fractures.

Results:

We discuss through images and videos the indications, preoperative workup, and technical pearls and pitfalls to encourage surgeons to add this technique to their armamentarium and improve outcomes.

Conclusions:

intrameduallry screw fixation is a powerful option for metacarpal and phalanx fixation that allows rigid stability, enabling early return of function with excellent rates of union and total active motion. With knowledge of technical pearls presented in this article, common mistakes can be avoided to improve efficiency of screw placement and optimize patient outcomes.

Analysis of 3 Different Operative Techniques for Extra-articular Fractures of the Phalanges and Metacarpals

Background: Several techniques have been described for treating metacarpal and phalangeal fractures. We sought to compare the 3 techniques most frequently used for extra-articular metacarpal and phalangeal fractures: plate screw (PS), Kirschner wire (KW), and retrograde intramedullary screw (RIS) fixation. We aimed to determine whether using an RIS provides better clinical outcomes than using either a PS or a KW fixation. Methods: We conducted a retrospective review of patients who underwent surgical treatment of metacarpal and phalangeal fractures from January 2011 to December 2017 in our department. Only patients with an acutely displaced short oblique or transverse extra-articular metacarpal or phalangeal fracture were included. Patients were classified into 3 groups depending on the treatment they received: PS, KW, or RIS fixation. The duration of each procedure was recorded. Clinical assessments included measuring total active motion (TAM), grip strength, and an evaluation of plain radiographs through to ultimate healing. A Disabilities of the Arm, Shoulder and Hand (QuickDASH) score was collected on all patients. Data were analyzed by analysis of variance or Kruskal-Wallis rank test, as indicated. Results: A total of 253 fractures (202 metacarpal and 51 phalangeal) in 230 patients were included in analysis. In all, 135 fractures (53.3%) underwent PS fixation; 53 (20.9%), KW fixation; and 65 (25.6%), RIS fixation. In the KW fixation group, Bouquet pinning was performed for metacarpal fractures and cross pinning for phalangeal fractures. When more than 1 fracture coexisted in the same patient, they were considered separate instances. No differences among the 3 groups were observed when evaluating mean time to radiological union, grip strength, TAM, or QuickDASH score. Mean surgery time was significantly shorter with KW (20 minutes) and RIS (25 minutes), than with PS (32 minutes). Mean return to work or routine activities time was significantly less in the RIS (7.8 weeks) group than in the PS and KW groups (8.3 and 9.2 weeks, respectively). Conclusions: Surgical treatment is recommended in patients with unstable metacarpal and phalangeal fractures. The use of RIS was associated with shorter mean surgery duration and return to work times than PS and KW, respectively.

Intramedullary Metacarpal Screw Fracture Fixation: A Retrospective Review of the Rehabilitation Literature and an Illustrative Case Report With a Postoperative Therapy Protocol

ABSTRACT

Intramedullary metacarpal screw fixation has shown promising results and quick functional recovery with the proper postoperative rehabilitation. The rehabilitative process after this procedure has not been compared across literature. A retrospective review of literature was used to recommend a therapy timeline, activity and recommendations to allow for proper postoperative rehabilitation for optimal results. An illustrative case report is presented to explain technique and outcomes.

Minimally Invasive Intramedullary Screw Versus Plate Fixation for Proximal Phalanx Fractures: A Biomechanical Study

PURPOSE

To compare the maximum interfragmentary displacement of short oblique proximal phalanx (P1) fractures fixed with an intramedullary headless compression screw (IMHCS) versus a plate-and-screws construct in a cadaveric model that generates finger motion via the flexor and extensor tendons of the fingers.

METHODS

We created a 30° oblique cut in 24 P1s of the index, middle, ring, and little fingers for 3 matched pairs of cadaveric hands. Twelve fractures were stabilized with an IMHCS using an antegrade, dorsal articular margin technique at the P1 base. The 12 matched-pair P1 fractures were stabilized with a radially placed 2.0-mm plate with 2 bicortical nonlocking screws on each side of the fracture. Hands were mounted to a frame allowing a computer-controlled, motor-driven, linear actuator powered movement of fingers via the flexor and extensor tendons. All fingers underwent 2,000 full-flexion and extension cycles. Maximum interfragmentary displacement was continuously measured using a differential variable reluctance transducer.

RESULTS

The observed mean displacement differences between IMHCS and plate-and-screws fixation was not statistically significant throughout all time points during the 2,000 cycles. A 2 one-sided test procedure for paired samples confirmed statistical equivalence in fracture displacement between fixation methods at the final 2,000-cycle time point.

CONCLUSIONS

The IMHCS provided biomechanical stability equivalent to plate-and-screws for short oblique P1 fractures at the 2,000-cycle mark in this cadaveric model.

CLINICAL RELEVANCE

Short oblique P1 fracture fixation with an IMHCS may provide adequate stability to withstand immediate postoperative active range of motion therapy.

Intramedullary percutaneous fixation of metacarpal fractures: screw versus connected K-wires

The purpose of the present study was to determine clinical and radiographic outcomes in patients treated with limited-open retrograde intramedullary headless screw fixation for metacarpal neck and shaft fractures (group I) versus percutaneous antegrade and retrograde intramedullary double pinning linked by a connector (group II). We designed a retrospective comparative study, with the inclusion of two groups (20 patients each) of metacarpal unstable fractures. Both groups showed similar outcomes at the final follow-up, except for extension lag (significantly better in group II) and return to sport (significantly better in group I). Intramedullary screw fixation did not accelerate bone union and range of motion recovery in the early follow-up. In conclusion, limited-open retrograde intramedullary headless screw fixation and percutaneous connected antegrade and retrograde intramedullary double pinning are both reliable techniques of fixation for metacarpal neck and shaft fractures. LEVEL OF EVIDENCE: III.

Evaluation of Antegrade Intramedullary Compression Screw Fixation of Metacarpal Shaft Fractures in a Cadaver Model

PURPOSE

Surgical options for displaced metacarpal shaft fractures include the use of Kirschner wires, plates and screws, and most recently, intramedullary headless compression screws (IMHCS), which have been reported using only retrograde insertion through the metacarpal head. We evaluated IMHCS fixation of metacarpal shaft fractures through an antegrade approach in a cadaver model.

METHODS

We performed antegrade placement of IMHCS in 10 cadaver hands including all 5 digits (total of 50). Displaced transverse proximal metacarpal shaft fractures were created and reduced with a retrograde guidewire from the metacarpal head across the shaft fracture and exiting the metacarpal base. This was retrieved through a 6-mm dorsal wrist incision and overdrilled before the placement of a 4.1-mm-diameter IMHCS in the ring finger and a 4.7-mm screw in all other metacarpals. After IMHCS placement, carpometacarpal (CMC) joint violation was measured along with the optimal starting point for the guidewire on the metacarpal head relative to the dorsal cortex.

RESULTS

In all 50 metacarpals, we achieved successful fracture reduction and fixation without violating the extensor mechanism at the wrist. Our retrograde guidewire entry point through the metacarpal head ranged from 4.2 to 4.7 mm volar to the dorsal cortex. The actual area of CMC joint violated by IMHCS placement was largest in the index CMC joint (4.9%), followed by the middle (3.7%), little (2.9%), ring (0.5%), and thumb joints (0.2%).

CONCLUSIONS

Placement of IMHCS through an antegrade approach from the CMC joint can be performed effectively for all transverse metacarpal fractures, including the thumb, using a limited incision. There is minimal violation of the articular surfaces of the trapezium, capitate, and hamate for the thumb, middle, ring, and little metacarpals.

CLINICAL RELEVANCE

Antegrade IMHCS fixation successfully avoids the potential morbidity of creating a metacarpal head articular surface or extensor mechanism defect at the metacarpophalangeal joint seen with the retrograde approaches.

Intramedullary screw fixation of metacarpal and phalangeal fractures - A systematic review of 837 patients

Intramedullary screw (IMS) fixation is increasingly used as an alternative treatment option in metacarpal and phalangeal fractures of the hand. However, this technique is currently the subject of controversy among hand surgeons. The aim of this systematic review was to gain insight on radiological, functional and patient-rated outcomes reported in literature. A comprehensive literature search of PubMed, Embase, CENTRAL and CINAHL databases was conducted on March 1st, 2021. All studies reporting on fracture union, complications, and functional and patient-rated outcome in IMS fixation of metacarpal and/or phalangeal fractures were selected. Two prospective and 16 retrospective cohort studies were included, encompassing a total of 837 patients with 958 fractures (693 metacarpal, 222 proximal phalangeal and 43 middle phalangeal). Mean surgery duration was 26.4 min (range 5-60 min). Union was ultimately achieved in all fractures in a mean of 5.7 weeks (range 2-12 weeks). The procedure-related complication rate was 3.2%. The most frequently reported complication was limitation of joint motion, occurring in 2.0% of cases. Incidence of other complications, including loss of reduction, infection and screw protrusion did not exceed 1%. Overall mean total active motion averaged 243° and grip strength reached 97.5% of the contralateral side. The Disabilities of the Arm, Shoulder and Hand (DASH) score averaged 3.7 points. Duration of sick leave was 7.3 weeks. According to the findings of this systematic review, IMS fixation is a time-saving and safe minimally invasive solution for both metacarpal and phalangeal fractures, with a low rate of complications and promising functional and patient-rated results.

Osteosynthesis of Fractures of the Metacarpal Neck with Self-Compressing Screw - Preliminary Analysis of 21 Cases

Objective  The present study aims to analyze the clinical results of the surgical treatment of metacarpal neck fractures with retrograde intramedullary fixation using cannulated headless screws (Herbert type).

Methods  Retrospective study of 21 closed fractures deviated from the metacarpal neck in 21 patients operated between April 2015 and November 2018.

Results  The sample included 19 men and 2 women. The mechanisms that caused the trauma were punching, falling to the ground and motor vehicle accident (n = 14, 5 and 2). The affected metacarpals were the 5 ^th , 3 ^rd , and 2 ^nd (n = 19, 1 and 1). Surgical indications were neck-shaft diaphysis of the metacarpal > 30° for the 2 ^nd and 3 ^rd metacarpals and > 40° for the 5 ^th metacarpal, shortening ≥ 5mm, rotational deviation, and the desire of the patient not to use plaster cast. In the immediate postoperative period, patients remained without immobilization and were instructed to mobilize their fingers according to tolerance. All patients had total active mobility > 240° and returned to their former occupations. All fractures consolidated and there were no reinterventions.

Discussion  The great advantages of the headless screw technique are its low morbidity, sufficient stability to avoid external immobilization, and reproducibility at low cost.

Conclusion  This is an easy, fast technique that has excellent results for the surgical treatment of displaced fractures of the neck of the metacarpals.

An Anatomical Study of Metacarpal Morphology Utilizing CT Scans: Evaluating Parameters for Antegrade Intramedullary Compression Screw Fixation of Metacarpal Fractures

PURPOSE

This study evaluated metacarpal morphology for antegrade placement of intramedullary headless compression screws (IMHCS) for metacarpal fracture fixation.

METHODS

We analyzed 100 hand computed tomography scans to quantify cortical thickness, intramedullary diameter, and metacarpal lengths. In addition, dorsal or ulnar overhang of the metacarpals over their respective carpal bones was measured. We also predicted optimal entry points for guidewire placement at the metacarpal head.

RESULTS

The ring finger metacarpal had the narrowest medullary canal width (coronal, 2.8 mm; sagittal, 3.5 mm). Not counting the thumb, the little finger metacarpal had the widest midshaft medullary width of 4.1 mm in the coronal plane and the middle metacarpal was widest in the sagittal plane with canal width of 3.9 mm. On average, there was maximal dorsal overhang at the base of the middle metacarpal (4.2 mm) and maximal ulnar overhang at the base of the small metacarpal (3.9 mm). The optimal entry point for guidewire placement over each metacarpal head was approximately 3.5 to 3.8 mm volar to the dorsal cortex.

CONCLUSIONS

Minimum IMHCS diameters of 3.5 mm for the ring and 4.0 mm for the index, middle and little fingers are necessary to achieve interference fit within the medullary canal. Minimum screw lengths of 38 mm would be needed to ensure 6 mm fixation past the midshaft of the metacarpals. Antegrade IMHCS for fixation of proximal metacarpal fractures may be most feasible with thumb, middle, and little finger metacarpals because there was larger dorsal or ulnar overhang to allow screw placement without violating the carpometacarpal joints.

CLINICAL RELEVANCE

Our analysis provides a reference guide for intramedullary screw sizes for each metacarpal of the hand to achieve interference fit with fracture fixation. Furthermore, the dorsal and ulnar overhangs of the metacarpal bases suggest the practicality of antegrade IMHCS fixation.

Intramedullary compression screw fixation of metacarpal and phalangeal fractures

The intramedullary headless compression screw (IMCS) technique represents a reliable alternative to percutaneous Kirschner-wire and plate fixation with minimal complications.

Transverse fractures of the metacarpal shaft represent a good indication for this technique. Non-comminuted subcapital and short oblique fractures can also be treated with IMCS.

This technique should not be used in the presence of an open epiphysis, infection and, most of all, in subchondral fractures, because of the lack of purchase for the head of the screw.

A double screw construct is recommended for comminuted subcapital fractures of the metacarpal to avoid metacarpal shortening. IMCS can even be applied for peri-articular fractures of the proximal third of the phalanx and in some multi-fragmentary proximal and middle phalangeal fractures.

Usually the intramedullary screws are not removed. The main indications for screw removal are joint protrusion, infection and screw breakage after new fracture.

Cite this article: EFORT Open Rev 2020;5:624-629. DOI: 10.1302/2058-5241.5.190068

Clinical Outcomes of Limited Open Intramedullary Headless Screw Fixation of Metacarpal Fractures in 91 Consecutive Patients

Background: The objective of the study is to evaluate clinical and radiographic outcomes in patients treated with limited-open retrograde intramedullary headless screw (IMHS) fixation for metacarpal neck and shaft fractures. Methods: Retrospective review of 91 consecutive patients (79 men; 12 women), mean age 28 (range =15-69) years, treated with IMHS fixation for acute displaced metacarpal neck (N = 56) and shaft (N = 35) fractures at a single institution. Mean follow-up was 10 (range = 1-71, median = 3) months. Preoperative mean magnitude of metacarpal neck angulation was 48° (range = 0°-90°), and mean shaft angulation was 42° (range = 0°-70°). Active motion was initiated within 5 days postoperatively. Clinical outcomes were assessed with digital goniometry, grip strength, and return to full activity. The time to radiographic union and radiographic arthrosis was assessed. Results: All 91 patients achieved full functional arc of metacarpophalangeal (MCP) motion, and all achieved full active MCP extension or hyperextension. At mean follow-up of 10 months, postoperative mean MCP joint flexion-extension arc was 88° (range = 55°-110°). Grip strength was available for 52 patients and measured 104.1% of the contralateral hand (range = 58%-230%). Radiographic union data were available for 86 patients. Seventy-six percent (65/86) achieved radiographic union by the end of week 6 (range = 2-10 weeks). Early arthrosis was noted in 1 patient at the MCP. There were 3 cases of shaft refracture after recurrent blunt trauma, following prior evidence of full osseous union. Conclusions: The IMHS fixation is safe, reliable, and durable for metacarpal neck/subcapital, axially stable shaft fractures, and select delayed unions or malunions. It allows for early postoperative motion without affecting union rates and obviates immobilization. This technique offers distinct advantages over formal open reduction and percutaneous Kirschner wire techniques.

Low Rate of Complications Following Intramedullary Headless Compression Screw Fixation of Metacarpal Fractures

Background: There has been a recent increase in the use of headless compression screws for fixation of metacarpal neck and shaft fractures as they offer several advantages, and minimal complications have been reported. This study aimed to evaluate the clinical complications and their solutions following retrograde intramedullary headless compression screw fixation of metacarpal fractures. We describe complications and the approach to their management. Methods: We performed a multicenter case series through retrospective review of all patients treated with intramedullary headless screw fixation of metacarpal fractures by 3 fellowship-trained hand surgeons. Patient demographics, implant used, type of complication, pre- and postoperative radiographs, operative reports, and sequelae were reviewed for each case. We defined complications as infection, loss of fixation, hardware failure, malrotation, nonunion, malunion, metal allergy, and any repeat surgical intervention. Results: Four complications (2.5%) were identified through the review of 160 total metacarpal fractures. One complication was a nickel allergy, one was a broken screw after repeat trauma, and 2 patients had bent intramedullary screws. Screw removal in 3 patients was simple and without complications or persistent limitations. One bent screw with a refracture was left in place. No serious complications were seen. Conclusion: Intramedullary screw fixation of metacarpal fractures is safe with a low incidence of complications (2.5%) that can be safely and effectively managed.

Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws

PURPOSE

The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model.

METHODS

A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine.

RESULTS

Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup.

CONCLUSIONS

Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability.

CLINICAL RELEVANCE

Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties.

Clinical Outcomes of Ready-Made J-Shaped Nail Fixation for Unstable Metacarpal Fractures

Background: The purpose of this study was to report the clinical outcomes of ready-made J-shaped intramedullary nail fixation for unstable metacarpal fractures. Methods: A total of 25 unstable fractures from 24 patients were evaluated in this retrospective study, comprising 20 metacarpal neck and 5 metacarpal shaft fractures. The mean follow-up was 22 weeks. Functional outcomes were assessed based on the range of motion of the metacarpophalangeal joint. Radiographic outcomes were evaluated by four projections of the postoperative plain radiographs at the final follow-up, and then were rated as excellent if projections at the fracture site showed no correction loss or angular deformity greater than 10°. Surgery time and complications during the treatments were recorded for each case. Results: All 25 fractures obtained bony union. The mean range of motion of the metacarpophalangeal joint was 78° (range, 45°-90°). Radiographic outcomes were excellent in 24 (96%) of 25 fractures. Only one fracture had correction loss. The mean surgery time was 29 minutes (range, 14-61 minutes). Two cases had extensor tendon adhesion at the insertion site, which was easily released when the implant was removed. Conclusions: This study demonstrates that intramedullary fixation with a ready-made J-shaped nail is a reliable treatment option for unstable metacarpal fractures.

Intramedullary screw fixation for metacarpal shaft fractures: a biomechanical human cadaver study

Intramedullary cannulated compression screws have been introduced for the fixation of unstable metacarpal fractures. In the present study, this technique was compared with dorsal compression plating to evaluate its biomechanical performance in stabilizing metacarpal shaft fractures. In a first set of experiments, the biomechanical characteristics of the screws were analysed in an artificial bone model. In subsequent experiments, midshaft osteotomies were performed in human cadaver metacarpals, followed by plating or intramedullary screw osteosynthesis. The metacarpals were tested to failure in cantilever bending, following a stepwise increasing cyclic loading protocol. We found a significantly lower load at failure and a significantly lower number of cycles to failure in the intramedullary screw group, but both methods offered sufficient stability under these loads. With reference to published loads on the metacarpals during use of the hand, we conclude that intramedullary osteosynthesis yields sufficient strength and stiffness for early active motion. A difference in its fixation stability is noted compared with plate fixation, which may not be clinically relevant.

Retrograde intramedullary headless compression screws for treatment of extra-articular thumb metacarpal base fractures

The purpose of the study was to evaluate clinical and radiological outcomes of extra-articular fractures involving the base of the thumb metacarpal treated with fixation using a retrograde intramedullary cannulated headless screw. A review of prospectively collected data was conducted on a consecutive series of 13 patients, treated with headless screw fixation for acute displaced fractures. All workers resumed full duties, while non-workers returned to unlimited leisure activities within a mean of 42 days. At 3 months follow-up, all range of motion measurements in the treated and untreated thumb were similar. Mean visual analogue pain score was 0.8 at rest and 1.4 during exercise and mean Quick Disabilities of the Arm, Shoulder, and Hand score was 5. All patients achieved radiographic union by 8 weeks. We conclude that the intramedullary headless screw fixation is safe and reliable for base of thumb metacarpal fractures, allowing for early postoperative motion and good functional recovery. Level of evidence: IV.

Intramedullary Headless Screw Fixation for Metacarpal Fractures

Multiple techniques have been proposed for metacarpal fracture fixation, including percutaneous Kirschner-wires, interfragmentary screws, plate and screw constructs, intramedullary (IM) nails, and cannulated IM headless screws. Each of these treatment options has its proposed advantages and disadvantages, and there remains no consensus on the optimal mode of treatment. We describe a technique of retrograde IM headless screw fixation for extra-articular metacarpal fractures.

Fixation of Metacarpal Fractures Using Intramedullary Headless Compression Screws: A Tertiary Care Institution Experience

Introduction

Metacarpal fractures account for the majority of hand fractures. Inadequate management can cause functional deficit which can lead to loss of fine hand movements. Adequate management has proven to give good outcomes. The use of intramedullary screws has given better results than the use of Kirschner wires (K-wires).

Method

This study was conducted at Dr. Ruth Phau Civil Hospital, Karachi (CHK) between August 1, 2018 and January 31, 2019. A total of 32 patients presented with metacarpal fractures. They were surgically managed with intramedullary headless screw fixation. Post-operatively, grip strength, range of motion, and presence of any disabilities were recorded. Patients were followed up to three months.

Results

Out of 32 patients, six were females. Mean age was found to be 29.1 ± 10.5 years. Post-operatively the mean grip strength was found to be 37.8 ± 7.3 kilograms. The mean total active range of motion was found to be 242.8 ±14.5 degrees. The mean days to return back to work were 25 ± 5.4 days. The mean patient satisfaction score was 8.1 ± 0.79. Three patients developed post-operative stiffness of the joint.

Conclusion

Patients with intramedullary screw fixation have good post-operative results with early return to work.