Metacarpal fractures account for about 40% of all hand injuries ^[1,2,3]. Metacarpal fractures are common hand injuries, accounting for 30–50% of all hand fractures ^[4]. Few metacarpal fractures necessitate surgical intervention, and the majority can be treated conservatively. The treatment aims to restore function, maintain joint mobility, and ensure early return to daily activities ^[5,6]. Various fixation methods have evolved to provide stable fixation and allow early mobilization. Improperly treated hand injuries result in shortening, rotation, and angulation of the metacarpals, resulting in severe functional disability, loss of strength, and flexibility of the hand – even affecting the day-to-day activities of the patient. Although undisplaced metacarpal fractures are treated conservatively, displaced metacarpal shaft fractures need proper reduction and internal fixation to limit the disability ^[7,8]. Various methods of fixation are available for metacarpal shaft fractures, such as K-wire fixation, miniplate fixation, and Herbert screw fixation ^[9,10]. K-wire fixation was the first surgical modality employed in the treatment of displaced metacarpal shaft fractures. However, as it leads to less stable fracture fixation – more cases of malunion, non-union and infection had been reported paving the way for new modalities of fixation like miniplates and headless intramedullary compression screws – Herbert screws ^[11,12]. Miniplates are not so popular due to the potential complications of implant irritation and skin necrosis.

Aim

This study aims to find out the functional outcome of metacarpal shaft fractures treated by K-wires and Herbert screws and to evaluate grip strength, pain, and return to daily activities.

The present study is a prospective study carried out over a 3-year period (March 2022 to February 2025) in the Department of Orthopedics at Government Thoothukudi Medical College Hospital, Tamil Nadu, India. Patients with displaced metacarpal fractures requiring surgical treatment were enrolled in the study after taking informed written consent, two groups were enrolled in the study. Group A (case) consisted of 20 metacarpal fractures for whom K-wire fixation done and Group B (control) consisted of 20 metacarpal fractures for whom Herbert screw fixation done. Surgical method of K-wire fixation and Herbert screw fixation was divided on alternate basis to avoid bias. We included multiple metacarpal shaft fractures with an age range from 18 to 60 years and fractures sustained with <1 week duration. Intra-articular fractures, comminuted fractures, pathological fractures and compound fractures were excluded from the study.

Surgical technique

Group A (K-wire fixation)

Patient in supine, with affected limb in arm table, parts painted and draped. Retrograde K-wire technique was used. A skin incision of size 0.5 cm was made over the dorsal aspect of metacarpophalangeal (MCP) joint. Extensor tendons incised and retracted medially and laterally. A 1.5 mm K-wire was selected and inserted over the dorsal aspect of the metacarpal head after closed reduction of the fracture by traction and digital manipulation under fluoroscopic guidance. With fracture in reduction, K-wire was passed across the fracture site up to the base of the metacarpal. Protruding K-wire was bent and cut externally (Fig. 1a, b, c, d).

Figure 1: (a and b) Pre-operative X-ray left hand showing # of 3rd, 4th, 5th metacarpals, and (c and d) Post-operative X-ray after K-wire fixation.

Post-operative immobilization was done with a volar splint for 4 weeks by protocol in fear of loss of fracture reduction. Out of 20 cases, three cases needed percutaneous reduction of fracture. Initially, for the first six cases, we used only single K-wires, and after we started using multiple K-wires (Fig. 2a, b, c).

Figure 2: (a) # of 4th, 5th metacarpal shaft, (b) fixed with multiple K-wires, and (c) after wire removal at 10th week.

Group B (Herbert screw fixation)

Patient in supine, with affected limb in arm table, parts painted and draped. A skin incision of size 1 cm was made over the dorsal aspect of MCP joint. Extensor tendons incised longitudinally with proximal phalanx in maximal flexion to expose the metacarpal head. After closed reduction of the fracture, a guide wire was inserted from the metacarpal head and passed across the fracture site. With fracture in reduction, medullary canal reaming is done with a cannulated drill bit. Appropriate size Herbert screw inserted and tightened – interfragmentary compression achieved (Fig. 3a, b, c, d). Head of the screw must be buried under the metacarpal head to prevent joint irritation (Fig. 4a, b, c, d). Wound wash given. Suturing done in layers. Sterile dressing done. Post-operative immobilization was not done. Out of 20 cases, two cases needed percutaneous reduction of fracture.

Figure 3: (a and b) Pre-operative X-ray left hand showing # of 4th, 5th metacarpals, and (c and d) after Herbert screw fixation.

Figure 4: (a and b) Pre-operative X-ray left hand showing # of 4th, 5th metacarpals, and (c and d) after Herbert screw fixation.

Post-operative follow-up

Patients in both groups were followed up for a period of 6 months. They were reviewed at 3^rd week, 6^th week, 10^th week, and 16^th week postoperatively. During those reviews, X-rays were taken to find out the radiological evidence of union. Furthermore, during each visit- the functional assessment was done by range of movements, return to activity, grip strength and disability of arm, shoulder and hand (DASH) questionnaire ^[13]. After obtaining the data, results were interpreted statistically.

Demography characteristic

In our study, the mean age was higher in the K-wire group, and male predominance were noted in both the groups. There was almost equal number of fracture distribution pertaining to the fracture pattern in both the groups (Table 1).

Table 1: The various demography characteristic in both the groups

Functional outcome analysis and DASH score ^[14]

We observed that the duration of surgical time was comparatively less in K-wire group, but the range of motion, DASH score and radiological healing were good in Herbert screw group (Table 2).

Table 2: The functional analysis and its characteristics

The length of the involved metacarpal was compared to the opposite side and we noticed that there was only few mm length difference in both the groups. Furthermore, the rotational deformity was very minimum. Grip strength and total active motion of fingers comparatively good in Herbert screw group at 3–6 months follow-up (Table 3 and 4). There was an excellent outcome for 13 cases in the Herbert screw group and three cases of poor outcome in K-wire group (Table 3).

Table 3: Outcome analysis assessed by DASH score

Table 4: The grip strength and TAM%

Complications

In our series, we noted stiffness of MCP and interphalangeal joints was more in K-wire group compared to Herbert screw group. At the same time, recovery of finger stiffness was early in Herbert screw group. We also noted pin tract infection in K-wire group, which also lead to implant loosening, and subsequently they were removed at 3–4 weeks (Table 5).

Table 5: Observed complications

Metacarpal fractures are often neglected or regarded as trivial injuries. Hand injury may cause significant disability from loss of sensation, loss of strength, and flexibility ^[15,16]. Considerable judgment is required to select the appropriate modality. K-wire fixation is cost-effective, simpler, and widely used, but carries risks such as pin tract infection, secondary displacement, and need for wire removal ^[1]. Herbert screws offer rigid internal fixation, allow early mobilization, and are buried beneath the skin, reducing infection risk and discomfort. In our study, the Herbert screw group showed significantly better functional outcomes, less pain, and faster return to activities. However, Herbert screws require more technical expertise, are costlier, and are only suitable for certain fracture patterns; surgery is inevitable in unstable and displaced hand fractures. Out of various treatment options available for internal fixation, K-wires and Herbert screw fixations predominates. Results of the previous studies comparing these two treatment modalities were inconclusive. The present study was thus planned to evaluate the clinical and radiological outcome of patients of metacarpal fractures with Herbert screw fixation and K-wire. A previous study done by Lv F. et al. ^[17] revealed more operating time in the Herbert screw group ^[16]. Most common location of fractures was observed as shaft followed by base and then neck. The results of our study showed that fracture healing time of Herbert screw group was significantly shorter than K-wire group which matched the previous study done by Lv F, et al. ^[17]. The incidence of post-operative complications in our study in Herbert screw group was lower than that in K-wire group with a statistically significant difference. The previous comparative study was done by  Lv F, et al. ^[17]. The clinical results were similar in K-wire and Herbert screw group. In our study, the clinical results were significantly better in Herbert screw group in terms of grip strength of hand, DASH score and time of union.

The present study observed that fixation of fracture metacarpal with Herbert screw is a better option than K-wire fixation. It effectively provides patients with better stability, which promotes faster fracture healing and early joint function recovery. Better functional outcome was observed after Herbert screw fixation, along with a lower incidence of post-operative complications. Hence, we conclude that Herbert screw fixation is more effective than K-wire fixation in the management of metacarpal fractures. We recommend Herbert screw fixation in transverse or short oblique fractures with good bone stock. However, K-wire remains a viable option in resource-limited settings or in comminuted fractures unsuitable for screw fixation. Further large-scale studies with longer follow-up are recommended.

Both K-wire and Herbert screw fixation are effective in achieving union in non-thumb metacarpal shaft fractures. However, Herbert screw fixation demonstrates superior early functional outcomes, allows quicker return to activity, and is associated with fewer complications.