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

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.

Arterial Perfusion of the Proximal Phalanx Revisited: New Insights Based on Micro-Computed Tomography

PURPOSE

To characterize the periosteal and endosteal arterial perfusion of the proximal phalanx using micro-computed tomography angiography (micro-CTA).

METHODS

Cadaveric upper extremities were injected with a barium sulfate/gelatin suspension. Phalanges were imaged using micro-CTA and analyzed with a focus on osseous arterial anatomy. Periosteal and endosteal perfusion was characterized by number of vessels, length, anatomic course, and caliber.

RESULTS

The base of the proximal phalanx had a significantly greater number (8.0 ± 3.5) of periosteal vessels than those of the shaft (4.1 ± 1.6) and head (1.3 ± 1.1). One-third (34.4%) of the specimens demonstrated a complete absence of periosteal vessels in the head. A nutrient endosteal vessel was noted in 100% of the specimens. Entering at the junction of the middle and distal third of the bone (25.8 ± 3.9 mm from base), the nutrient vessel entered the proximal phalanx of the index finger along its ulnar aspect (8 of 8 specimens), the middle finger along its radial aspect (6 of 8), the ring finger along its ulnar aspect (5 of 8), and the little finger along its radial aspect (7 of 8). The nutrient vessel branched into proximal and distal extensions toward the shaft and head, respectively, with an average endosteal length of 10.7 ± 5.2 mm and average diameter of 0.36 ± 0.11 mm.

CONCLUSIONS

Periosteal contributions to the perfusion of the proximal phalanx appear to diminish distally. The endosteal arterial anatomy remains consistent, with a single nutrient vessel entering the intramedullary canal with reliable laterality on each digit. This is often the only vessel supplying the head of the proximal phalanx, making this area particularly susceptible to vascular compromise.

CLINICAL RELEVANCE

An understanding of the patterns of perfusion of the proximal phalanx provides some insight into clinically observed pathology, as well as guidance for operative management.

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.

Dorsal Plating, Lateral Plating, and Intramedullary Screw Fixation of Extra-Articular Proximal Phalangeal Fractures: A Cadaveric Biomechanical Comparison

PURPOSE

To provide a biomechanical comparison of dorsal plating, lateral plating and intramedullary screw [IMS] fixation for extra-articular proximal phalangeal fractures.

METHODS

Midshaft osteotomies were performed on 36 cadaveric proximal phalanges. The phalanges were fixed by dorsal plating, lateral plating or IMS fixation, and subjected to a four-point bending force. Force was applied to achieve displacement of 1 mm/s, until construct failure or to a maximum of 10 mm of displacement. Clinical failure was defined as 2 mm of displacement, and force required to result in 1 mm and 2 mm of displacement was recorded, as was mode of failure.

RESULTS

Dorsal plating [127.5 N ± 52.6; 46.51-229.17] and lateral plating [77.1 N ± 25.1; 48.3-113.8] required significantly greater force to achieve 1 mm of displacement when compared to IMS [41.2 N ± 12.4; 20.6-62.3]. Dorsal plating [339.2 N ± 91.8; 158.5-538.6] required significantly greater force than lateral plating [154.5 N ± 33.8; 99.0 -204.4] and intramedullary screw fixation [110.0 ± 38.6; 51.1-189.3] to result in 2 mm of displacement. Lateral and dorsal plating constructs failed through plate bending, screw cut-out or plate failure, whilst IMS failed via implant deformity. All three constructs required greater force to result in even 1 mm of displacement than what is likely subjected through rehabilitation via active motion.

CONCLUSIONS

Lateral plating and IMS fixation offer sufficient stiffness to withstand the likely forces subjected via early active motion without displacement.

CLINICAL RELEVANCE

Dorsal plating required significantly greater force than lateral plating and intramedullary screw fixation to achieve 1 mm of displacement when used in extra-articular proximal phalangeal fractures in an in vitro setting. However, all three modalities confer enough stability to likely withstand the forces associated with active range of motion.

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.

Intramedullary Compression Screw Fixation for Middle Phalangeal Fractures

PURPOSE

This study aimed to evaluate short- and medium-term clinical and patient-reported outcomes of intramedullary compression screw fixation for extra-articular middle phalangeal fractures.

METHODS

A retrospective study was performed on a series of 20 patients (with a total of 23 fractured digits) who underwent fixation of middle phalangeal fractures between January 2020 and March 2023. The results from this cohort were compared against those for plate and K-wire fixation in the literature.

RESULTS

Total active motion was 246°; Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score was 4.9; verbal numerical pain score was 1.1 of 10; mean time for return to work was 62.5 days; and a single complication was noted in the entire cohort.

CONCLUSION

Intramedullary screw fixation is a viable option in the treatment of extra-articular middle phalangeal fractures. It offers a favorable postoperative range of motion, good duration for return to function, excellent rates of complication, and low pain scores.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Metacarpal and Phalangeal Nonunions

The majority of phalangeal and metacarpal fractures will proceed to union when appropriately treated. However, when a nonunion does occur, it can lead to significant functional impairment for patients and societal costs. Operative intervention is typically required in these cases, but the technique can vary depending on each individual patient scenario. This article provides an overview of nonunions of the metacarpals and phalanges in the hand, including incidence, risk factors, current treatment options, and postoperative care.

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.

Comparison of three different minimally invasive intramedullary screw for proximal phalanx fractures. A biomechanical study

BACKGROUND AND OBJECTIVE

Phalangeal fractures are the most common hand fractures. In the last years, intramedullary compression screw (IMHCS) for instable transverse or short oblique proximal P1 fractures have been described. Although both anterograde (intraarticular or trans-articular) and retrograde IMHCS techniques have shown good results, no comparison between anterograde and retrograde screw in P1 fractures has been published. We sought to determine stability with retrograde IMHCS and anterograde IMHCS, both trans-articular and intra-articular technique, in a cadaveric transverse proximal P1 fracture model, at two different levels.

MATERIAL AND METHODS

We performed a biomechanical study in 30 fresh-frozen human cadaveric P1 fracture model. Fracture was performed at 9-mm from the metacarpo-phalangeal (MCP) joint in 15 specimens, whereas it was done at 15 mm in the other 15. In turn, in each group, five fractures were stabilized with an anterograde intra-articular IMHCS, five with anterograde trans-articular IMHCS and other five with retrograde IMHCS.

RESULTS

Anterograde IMHCS fixation in 9-mm P1 fractures (both trans- and intra-articular technique, 62.74 N and 70.86 N, respectively) was found to be more stable than retrograde IMHCS one (32.72 N) (p = 0.022). Otherwise, retrograde IMHCS fixation was found to be more stable in more distal P1 fractures (90.52 N retrograde vs. 57.64 N trans-articular vs. 42.92 N intra-articular; p = 0.20).

CONCLUSIONS

Anterograde IMHCS fixation in proximal transverse P1 bone cut in a cadaveric model provides more stability than retrograde IMHCS, while retrograde screw provides more stability when the bone cut is located more distal.

[Translated article] Comparison of three different minimally invasive intramedullary screw for proximal phalanx fractures. A biomechanical study

BACKGROUND AND OBJECTIVE

Phalangeal fractures are the most common hand fractures. In the last years, intramedullary compression screw (IMHCS) for instable transverse or short oblique proximal P1 fractures have been described. Although both anterograde (intraarticular or trans-articular) and retrograde IMHCS techniques have shown good results, no comparison between anterograde and retrograde screw in P1 fractures has been published. We sought to determine stability with retrograde IMHCS and anterograde IMHCS, both trans-articular and intra-articular technique, in a cadaveric transverse proximal P1 fracture model, at two different levels.

MATERIAL AND METHODS

We performed a biomechanical study in 30 fresh-frozen human cadaveric P1 fracture model. Fracture was performed at 9-mm from the metacarpo-phalangeal (MCP) joint in 15 specimens, whereas it was done at 15mm in the other 15. In turn, in each group, five fractures were stabilised with an anterograde intra-articular IMHCS, five with anterograde trans-articular IMHCS and other five with retrograde IMHCS.

RESULTS

Anterograde IMHCS fixation in 9-mm P1 fractures (both trans- and intra-articular technique, 62.74N and 70.86N, respectively) was found to be more stable than retrograde IMHCS one (32.72N) (p=0.022). Otherwise, retrograde IMHCS fixation was found to be more stable in more distal P1 fractures (90.52N retrograde vs. 57.64N trans-articular vs. 42.92N intra-articular; p=0.20).

CONCLUSIONS

Anterograde IMHCS fixation in proximal transverse P1 bone cut in a cadaveric model provides more stability than retrograde IMHCS, while retrograde screw provides more stability when the bone cut is located more distal.

Intramedullary Headless Screw Fixation for Phalanx Fractures: Technique and Review of Current Literature

Fractures of the phalanges can often be managed nonoperatively, but displaced phalangeal fracture patterns, including malrotation, are more amenable to operative treatment. There are several described methods for surgical management of phalanx fractures, but there remains no consensus on a clearly superior method of fixation. Percutaneous Kirschner wires, interfragmentary screws, plate and screw constructs, intramedullary nails, and cannulated intramedullary headless screws are all utilized in the treatment of these fractures. Intramedullary headless screws for phalanx fractures may provide suitable fixation allowing early motion and recovery. Here, we describe a technique for antegrade and retrograde intramedullary headless screw fixation for phalanx fractures.