Retrograde fixation of metacarpal fractures with intramedullary cannulated headless compression screws

Complications of osteosynthesis for long-finger metacarpal and phalanx fracture

Fractures of the metacarpals and phalanges represent a significant proportion of hand fractures. Although non-operative treatment is generally effective, some fractures require surgery. Historically, osteosynthesis using K-wires was widely used, but screw plates and then cannulated intramedullary screws have emerged as therapeutic alternatives. We assessed the complications associated with the different osteosynthesis techniques: stiffness, infection, bone consolidation and hardware-related problems. Each osteosynthesis technique has advantages and disadvantages, and choice depends on several factors. An individualized approach according to patient and fracture is essential to optimize clinical results.

Screw Position Following Percutaneous Versus Mini-Open Intramedullary Retrograde Screw Fixation of Metacarpal Fractures

BACKGROUND

Metacarpal fracture fixation using the retrograde intramedullary screw technique can be performed through two different approaches. The mini-open approach requires greater soft tissue dissection but allows for direct visualization of the metacarpal head compared with the percutaneous approach. Our aim was to determine which approach resulted in optimal screw position.

METHODS

Eighty-one consecutive patients that underwent intramedullary screw fixation for metacarpal fractures from 2016 to 2021 were identified. Patients were treated by 4 fellowship-trained orthopedic hand surgeons who employed the mini-open or percutaneous approach. Postoperative radiographs were reviewed for screw position.

RESULTS

A total of 81 patients (41 mini-open, 40 percutaneous) were included in this study. There were no significant differences between the two groups in age, sex, hand dominance, or affected digit. Postoperative screw position at first postoperative visit was not significantly different between the two groups on anteroposterior or lateral radiographs.

CONCLUSION

Postoperative screw position is not significantly different between the mini-open and percutaneous approaches for intramedullary screw fixation of metacarpal fractures.

LEVEL OF EVIDENCE

Level III, therapeutic.

Early Return of Motion in Patients With Intramedullary Screw Placement for Metacarpal and Phalangeal Fracture Fixation

INTRODUCTION

Hand fractures are associated with significant morbidity. Current management standards often result in prolonged immobilization, stiffness, and delayed return to functional use. Intramedullary (IM) compression screws offer minimal soft tissue disruption and early postoperative active motion. In this study, we describe our outcomes after intraosseous fracture fixation using IM cannulated headless screws for a multitude of fracture patterns.

METHODS

This study is a retrospective review of patients who underwent IM screw placement for fixation of metacarpal and phalangeal fractures by a single surgeon from 2017 to 2022. Data were collected to include patient demographics, fracture details, postoperative complications, and follow-up. Time to range of motion and return to unrestricted motion was recorded.

RESULTS

There were 69 patients with 92 fractures (n = 54 metacarpal, n = 38 phalanx). The median patient age was 45 years (range, 18-89 years) with 75.4% males. Majority presented with a single fracture (n = 50, 72.5%), and 38 patients (55.1%) had open fractures. Small finger was the most affected digit (n = 35, 37.6%). The median time to allow range of motion from surgery was 8.7 days (interquartile range, 0-32) with 32 days (interquartile range, 10-62) for unrestricted use of the hand. Thirty-five patients (50.7%) were allowed controlled motion from the first postoperative day. One patient had loss of reduction requiring reintervention for hardware removal, and 1 patient had superficial skin infection managed with oral antibiotics.

CONCLUSIONS

Our findings indicate that the IM screw provides reliable fixation for a wide variety of fracture patterns with a low complication rate and offers early return to functional use.

Comparison Between Intramedullary Nail and Percutaneous Pin Fixation in Proximal Phalanx Fractures

BACKGROUND

Percutaneous pinning has been the predominant technique for fixation of proximal phalanx fractures, but stiffness is a reported complication. The introduction of intramedullary (IM) nail fixation of proximal phalanx fractures provides a stronger biomechanical fixation for amenable fracture patterns with the added benefit of not tethering the soft tissue. The goal of this study was to compare the surgical outcomes of IM nail and percutaneous pin fixation in isolated proximal phalanx fractures.

METHODS

A retrospective review was performed at our institution between the years 2018 and 2022 for patients treated for proximal phalanx fractures. Patients that underwent fixation with IM nails or percutaneous fixation for isolated extraarticular proximal phalanx fractures were included. Patients were excluded if they had concomitant hand fractures, tendon injury, or intraarticular extension.

RESULTS

A total of 50 patients were included in this study. Twenty-eight patients received percutaneous pin fixation, and 22 patients underwent IM nail or screw fixation. There was no significant difference in injury patterns or demographics between these two groups. Patients that underwent IM nail fixation had a significantly quicker return to active motion, shorter duration of orthosis treatment, and fewer occupational therapy visits. In addition, patients in the IM fixation group had significantly improved range of motion (ROM) at 6 weeks postoperatively.

CONCLUSIONS

This study demonstrates that patients receiving percutaneous pin or IM nail fixation have equivocal union and complication rates. The IM nail fixation group was able to have quicker return to mobilization, fewer required occupational therapy visits, and improved early ROM.

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.

Extensor Tendon Integrity After Percutaneous Placement of Intramedullary Metacarpal Screws: A Cadaveric Study

BACKGROUND

Intramedullary implants are an increasingly common method for fixation of metacarpal fractures. Numerous techniques for instrumentation have been described with varied consideration for the risk of extensor tendon injury. The current cadaveric study evaluates the prevalence and degree of extensor tendon injury and compares percutaneous approaches with different drilling techniques.

METHODS

Ninety-six metacarpals (thumbs excluded) from 24 fresh-frozen cadaveric upper extremities were used to compare 2 percutaneous approaches and 2 drilling techniques. This resulted in 4 subgroups available for comparison: oscillate to bone (OB), forward to bone (FB), oscillating through the skin (OS), and forward through the skin (FS). After instrumentation, the extensor tendons were dissected and disruption was characterized. The main outcome measures were tendon "hit rate" and relative extensor tendon defect width.

RESULTS

Tendon hit rate was significantly higher in the long finger (LF), that is, 79.2%, compared with other metacarpals: index finger, 20.8%; ring finger, 12.5%; and small finger 25%. The mean relative tendon disruption was significantly less in the OB group (16.05%) compared with the other groups: FB (31.84%), FS (31.50%), and OS (29.85%).

CONCLUSION

Retrograde intramedullary screw fixation of metacarpal fractures can be performed using percutaneous approaches without a significant disruption of the extensor mechanism. Instrumentation through a longitudinal stab incision down to the metacarpal head and the use of drill oscillation minimize injury to the extensor tendons. The LF extensor tendon is most at risk with retrograde intramedullary implant placement.

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.

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.

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.

Threaded intramedullary headless nail fixation for fractures requiring carpometacarpal stabilization

Carpometacarpal (CMC) fracture-dislocations are uncommon hand injuries, with few studies available regarding their treatment. The current operative treatment options include fixation with K-wires, mini-screws, or plates, though there is no standardized approach because of varying injury patterns and complications associated with each device. The INnate™ threaded intramedullary nail is a relatively novel treatment option that has shown promise in metacarpal fracture fixation by facilitating faster mobilization and recovery with enhanced rotational stability and no compression to prevent fracture displacement and shortening. This study assesses the efficacy of the INnate™ nail for fixation of CMC fracture-dislocations of the second through fifth joints. Nine patients with fourteen CMC fracture-dislocations treated with the INnate™ nail at the University Medical Center between 2019 and 2021 were enrolled in the study. We evaluated postoperative outcomes in terms of pain, total active range of motion (TAM), and return to normal activities. Of the nine patients, seven returned for follow-up. The average time to radiographic union was 11.5 weeks. At final follow-up, no patient reported pain (n = 6). Four patients had 100% TAM, 1 had 95% TAM, and 1 had 25% TAM. The average percentage of normal activity resumed was 84.0% (n = 5). No significant complications were reported. One patient had a dorsal spanning plate; hence, we were unable to record outcomes measures regarding the CMC injury. An additional patient had diminished ROM of the injured hand, but his last follow-up was only 1 month postop. Our pilot data overall suggest that the INnate™ threaded intramedullary nail has the potential to improve treatment algorithms for CMC fracture-dislocations.

Kickstand Technique for Intraoperative Reduction of Fifth Metacarpal Neck Fractures

This article reports a novel intraoperative technique for the reduction of angulated metacarpal neck fractures undergoing retrograde headless intramedullary screw fixation. This technique is a useful reduction maneuver, especially for hand surgeons operating without a first assistant, because it eliminates the need to hold manual reduction during implant placement.

[Osteosynthesis by intramedullary headless screw in digital fractures: A retrospective scannographic and anatomical study]

INTRODUCTION

Long finger skeletal fractures are common injuries. In displaced forms, surgical treatment is required. With the advent of headless cannulated screws, the technique has been simplified and allows reduction in both planes. The objective of our study was to evaluate the functional recovery of patients operated on by this technique.

MATERIAL AND METHOD

We conducted a retrospective single-center study between 2019 and 2022. Eleven patients were followed and 12 fractures analyzed. A radio-clinical follow-up was carried out at 1 month then at the last follow-up with an evaluation of the articular amplitudes and a quality of life score (QuickDash, QD). The time to return to professional and sporting activities, pain (EVA) was collected. An anatomical/scannographic evaluation was performed to assess tendon and cartilage damage.

RESULTS

At the last follow-up, the average global flexion was 266° and the extension was total. An average QD score of 15.9 and a Jamar force of 106% compared to the healthy side were observed. The return to physical and professional activities was earlier and the pain quickly tolerable. No secondary displacement was objectified and all were consolidated at the last follow-up, without malunion. No patient had been operated on secondarily.

CONCLUSION

This technique seems to be a safe and non-traumatic. It allows a faster return to sports and professional activities with fewer complications and no need to remove the material.

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.

Biomechanical comparison of intramedullary screw fixation, dorsal plating and K-wire fixation for stable metacarpal shaft fractures

We compared four methods of metacarpal shaft fixation: 2.2 mm intramedullary headless compression screw; 3.0 mm intramedullary headless compression screw; intramedullary K-wire fixation; and dorsal plate fixation. Transverse mid-diaphyseal fractures were created in 64 metacarpal sawbones and were assigned into four groups. Peak load to failure and stiffness were measured in cantilever bending and torsion. We found that dorsal plating had the highest peak load to failure. However, initial bending stiffness of the 3.0 mm intramedullary headless compression screw was higher than that of the dorsal plates. In torsion testing, dorsal plating had the highest peak torque, but there was no significant difference in torsional stiffness between the plate and intramedullary headless compression screw constructs. We concluded that intramedullary headless compression screw fixation is biomechanically superior to K-wires in cantilever bending and torsion; however, it is less stable than dorsal plating. In our study, the initial stability provided by K-wire fixation was sufficient to cope with expected loads in the early rehabilitation period, whereas dorsal plates and IHCS constructs provided stability far in excess of what is required.

A comparison of intramedullary cannulated screws versus miniplates for fixation of unstable metacarpal diaphyseal fractures

We carried out a prospective randomized study to compare the clinical and radiological results of metacarpal diaphyseal fractures treated with retrograde intramedullary headless cannulated screws (IHCS) and plates. Fractures were fixed with IHCS in 34 patients (37 metacarpals) and locked miniplates in 35 patients (40 metacarpals). The mean age was 33 years (range 18-61) in the IHCS group and 32 years (range 17-68) in plate group. All patients were followed up for 1 year. All fractures in the IHCS group united but there was one nonunion in the plate group. At final follow-up, there was no significant difference between the groups in total active movement, visual analogue pain score, Disabilities of the Arm, Shoulder, and Hand score and grip strength, although the study was not sufficiently powered to exclude differences with certainty. IHCS is a safe and fast technique that is a good alternative to plate fixation in metacarpal diaphyseal fractures.Level of evidence: I.

Horizontal (Transverse) Intraarticular Metacarpal Head Fracture in a Young Adult

Metacarpal head fractures are rare injuries that usually occur during trauma. These fractures are classified into 10 groups, with horizontal (transverse) being the rarest type of fractures. To our knowledge, very few cases have been reported in the literature to date. Here, we present the case of a 21-year-old male who sustained multiple ipsilateral hand injuries accompanied by a horizontal (transverse) fracture of the fourth metacarpal. He underwent open reduction and fixation with Kirschner wires followed by intensive rehabilitation. He finally regained complete active range of motion and grip strength three months after the operation. However, at nine months postoperatively, he developed avascular necrosis, which was asymptomatic and did not need any intervention. Therefore, it is important to maintain a high index of suspicion for possible complications and follow patients regularly, probably even for as long as 12 months after the initial injury.

How to Manage Complications Related to the Use of Intramedullary Screws in Metacarpal Fractures: Case Series

The use of intramedullary screws has been increasing among hand surgeons in cases of metacarpal fractures due to their low morbidity, and because they minimize incisions and dissection, and require less tissue manipulation and deperiostization. However, there are few published articles on the complications that arise from its use. Therefore, the purpose of the current study is to present a series of cases of complications following the use of intramedullary screws in metacarpal fractures that required surgical intervention, and to describe the surgical technique used to solve them .

Methods We performed a retrospective multicenter study in which we reviewed the clinical history, surgical descriptions and radiographs of the patients submitted to fixation of intramedullary compression screws for metacarpal fractures. We defined as complications infection, lesion to the extensor apparatus, bending of the implant, loss of reduction, hardware failure, malrotation, and non-union.

Results Out of a total of 45 patients, we reported 3 cases of complication: 1 patient with loss of reduction, and 2 patients with bending of the implant. In the three cases, the screw was removed without complications, and the focus of the fracture was stabilized.

Conclusion Intramedullary fixation with compression screws is increasingly being used for metacarpal fractures, with reports of low rates of complications. In the series of cases herein reported, the complications were solved without difficulty, and the patients showed a good recovery in hand function in the follow-up. Knowledge of the possible complications and their management enables us to provide more safety to the patient at the time of choosing this technique.

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.

Minimally Invasive Corrective Osteotomy for Metacarpal Malrotation

Metacarpal fractures can be complicated by malrotation. This can cause functional problems with overriding or underriding of the fingers with flexion. Surgical treatment consists of corrective osteotomy and derotation. This is typically performed open and different techniques for osteotomy and fixation have been described. Postoperative complications include finger stiffness and hardware irritation. We propose a technique for minimally invasive corrective osteotomy of malunited metacarpal fractures with rotational malalignement. Advantages are quick rehabilitation and no prominent hardware.

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

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.

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.

Cartilage and extensor tendon defects after headless compression screw fixation of phalangeal and metacarpal fractures

Osteosynthesis of metacarpal and phalangeal fractures with headless compression screws leads to a defect in the articular surface and possibly damage to the extensor tendons. This study aimed to quantify the articular surface defect and extensor tendon injuries after implant placement in cadaveric hands. Defect size was assessed with computed tomography. Extensor tendon injuries were assessed by direct visualization and measurement after dissection. In the middle phalanx, the defect size in relation to the joint surface was significantly smaller after anterograde screw placement when compared with retrograde placement. Also, a mini-open approach was found to cause significantly less tendon injury than a percutaneous approach, but there was no difference in tendon damage between retrograde and antegrade screw insertion into the middle phalanx.

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.