Mechanical Failure of Primary Clavicle Locking Plate Osteosynthesis Following Early Postoperative Overloading: A Case Report

INTRODUCTION

Clavicle fractures account for approximately 2.5–5% of all adult fractures and 35–45% of shoulder girdle injuries, with 70–80% occurring in the middle third.¹ Fractures involving the junction of the middle and lateral thirds are relatively uncommon but are subjected to substantial biomechanical forces because of the opposing pull of surrounding muscles and the weight of the upper limb.¹

Historically, most clavicle fractures were managed conservatively.² However, displaced fractures have been associated with increased rates of non-union, malunion, cosmetic deformity, and persistent functional impairment.², Consequently, open reduction and internal fixation (ORIF) with pre-contoured locking plates has become the preferred treatment for significantly displaced fractures in young, active patients, offering superior functional outcomes, lower non-union rates, and earlier return to activity compared with non-operative management.^2-4

Pre-contoured locking plates provide stable fixation, restore clavicular length and alignment, and achieve union rates exceeding 95%.³ Despite excellent clinical outcomes, implant-related complications such as hardware prominence, implant irritation, screw loosening, plate breakage, and plate bending have been reported.^5,6 Mechanical implant failure is uncommon and is usually associated with excessive loading before fracture union, inadequate fixation, poor bone quality, or poor compliance with postoperative rehabilitation protocols.⁵

We report a rare case of early plastic deformation (plate bending) of a pre-contoured locking clavicle plate following premature heavy-weight lifting only three weeks after surgery, necessitating revision fixation. This case highlights the importance of patient education, strict adherence to postoperative rehabilitation, and compliance with activity restrictions to prevent avoidable mechanical implant failure.^7,8

CASE REPORT

A 19-year-old right-hand-dominant male presented to the emergency department with severe pain, swelling, and deformity over the left clavicle and inability to move the left upper limb following a road traffic accident. He sustained a direct impact to the left shoulder after being thrown from a two-wheeler. There was no history of loss of consciousness or associated injuries to the head, chest, abdomen, or other extremities.

Following the injury, he experienced severe pain in the left clavicle, aggravated by shoulder movement and partially relieved by immobilization. He also noticed swelling, deformity, and inability to use the affected limb. There were no symptoms of numbness, tingling, weakness, or vascular compromise. His medical and surgical history was unremarkable, with no previous fractures, metabolic bone disease, smoking, or alcohol abuse.

On examination, the patient was conscious, alert, and hemodynamically stable. Local examination revealed diffuse swelling over the middle and lateral clavicle with visible prominence of the medial fragment. There was localized tenderness and crepitus at the junction of the middle and lateral thirds of the clavicle, with painful restriction of shoulder movements. The skin was intact without abrasions or tenting, confirming a closed injury. Distal neurovascular examination was normal.

Routine laboratory investigations were within normal limits. Plain radiographs of the left clavicle (anteroposterior view with 15° cephalic tilt) demonstrated a displaced fracture at the junction of the middle and lateral thirds with superior displacement of the medial fragment and inferior displacement of the lateral fragment [Figure 1]. There was no significant comminution or associated acromioclavicular joint injury. Considering the patient's young age, high functional demands, and marked fracture displacement, open reduction and internal fixation (ORIF) was planned.

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Figure 1: Pre-operative X-ray.

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Following informed written consent, ORIF was performed under general anesthesia. The patient was positioned in the beach-chair position. Through a superior longitudinal incision, the fracture was exposed with minimal periosteal stripping. After evacuation of the fracture hematoma, anatomical reduction was achieved using pointed reduction forceps and was temporarily stabilized with Kirschner wires. Definitive fixation was performed using a pre-contoured 9-hole lateral-end locking clavicle plate with cortical and locking screws. Intraoperative fluoroscopy confirmed satisfactory reduction, restoration of clavicular length and alignment, and appropriate implant positioning. The wound was irrigated and closed in layers.

The postoperative period was uneventful. Immediate postoperative radiographs confirmed satisfactory reduction and implant position [Figure 2a]. The limb was supported in an arm sling, and active mobilization of the fingers, wrist, and elbow was initiated on the first postoperative day, followed by pendulum exercises as tolerated. The patient was discharged on the second postoperative day with instructions to avoid heavy lifting, overhead activities, contact sports, and strenuous shoulder movements for at least six weeks.

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Figure 2: a) Immediate postoperative X-ray following primary b) X-ray following early mechanical overloading.

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Three weeks later, he returned with a sudden onset of severe pain and swelling over the operative site after lifting a heavy object at home. He admitted to carrying a heavy load with the operated limb despite repeated counseling regarding postoperative restrictions. Examination revealed localized tenderness, swelling, mild recurrence of clavicular deformity, and painful restriction of shoulder movements. The surgical wound was well healed, and distal neurovascular examination remained normal.

Repeat radiographs demonstrated plastic deformation (bending) of the locking clavicle plate with displacement of the fracture fragments while all screws remained securely fixed, indicating acute mechanical overload rather than technical failure of fixation [Figure 2b]. Revision surgery was therefore undertaken.

The bent plate was removed through the previous incision, and fibrous tissue with early callus was debrided. After refreshing the fracture ends, anatomical reduction was achieved, and stable fixation was performed using a longer pre-contoured anatomical locking clavicle plate with multiple bicortical locking screws. Intraoperative fluoroscopy confirmed satisfactory reduction and implant position, and postoperative radiographs demonstrated restoration of clavicular alignment with stable fixation [Figure 3].

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Figure 3: Revision surgery post-operative X-ray.

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Following revision surgery, the patient received extensive counseling regarding strict adherence to postoperative rehabilitation and avoidance of heavy lifting until radiological union. At subsequent follow-up, serial radiographs demonstrated progressive fracture union with maintenance of reduction. The patient regained satisfactory shoulder function with healthy wound healing [Figure 4], without recurrence of implant failure.

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Figure 4: Post-operative clinical image of a) primary and b) secondary procedure.

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DISCUSSION

Clavicle fractures account for 2.5–5% of all adult fractures and 35–45% of shoulder girdle injuries, with nearly 80% involving the middle third because of its narrow anatomy and exposure to significant bending forces.¹ Displaced midshaft fractures are particularly prone to shortening and displacement due to the opposing pull of surrounding muscles and the weight of the upper limb.¹ Although non-operative treatment was historically the standard of care, randomized controlled trials have demonstrated that open reduction and internal fixation (ORIF) using pre-contoured locking plates provides superior functional outcomes, lower non-union rates, and earlier return to activity in appropriately selected patients.^2-4

Locking plate fixation restores clavicular length and alignment, provides angular stability, and achieves union rates exceeding 95%.³ However, implant-related complications, including hardware prominence, infection, non-union, malunion, screw loosening, and plate failure, remain clinically important.^5-7 Overall complication rates following plate fixation range from 6% to 30%, whereas true mechanical implant failure is relatively uncommon, occurring in approximately 1–8% of cases.⁵

The present case demonstrates an unusual pattern of early implant failure characterized by plastic deformation of a superior locking plate only three weeks after surgery without screw loosening or pull-out. Immediate postoperative radiographs confirmed satisfactory reduction and implant positioning, whereas follow-up radiographs demonstrated plate bending with loss of fracture alignment despite intact screw fixation. This radiographic pattern strongly suggests acute mechanical overload rather than technical failure of fixation.^5,6 The patient's history of lifting a heavy object during the early postoperative period, despite clear postoperative instructions, further supports excessive mechanical loading as the primary cause of failure.

During the initial weeks after ORIF, the fixation construct bears most of the physiological load because biological fracture healing is incomplete.⁵ Activities involving lifting, pushing, pulling, or overhead movements generate substantial bending and torsional forces across the clavicle.⁶ Although locking plates provide greater stiffness and angular stability than conventional plates, excessive loading beyond the implant's yield strength can result in permanent deformation, loss of fracture reduction, and construct failure requiring revision surgery.^5,6

Patient compliance plays a critical role in preventing implant failure. Premature return to manual labor, heavy lifting, or sporting activities has been associated with fixation failure despite technically satisfactory surgery.^2,3 Young, physically active patients may be particularly vulnerable because early postoperative pain relief often creates a false perception of complete recovery, resulting in non-compliance with rehabilitation protocols.⁶ Implant-related factors such as inadequate plate length, insufficient fixation, poor screw distribution, or suboptimal plate positioning should also be considered when evaluating construct failure.^5,6 In the present case, intact screw purchase and satisfactory implant positioning at revision surgery excluded technical error, supporting excessive postoperative loading as the predominant mechanism of failure.

Plate bending should be distinguished from plate breakage, as these represent different biomechanical failure mechanisms. Plate breakage generally reflects fatigue failure associated with delayed union or established non-union, whereas plate bending usually indicates a single episode of acute overload before fracture consolidation.^5,6 Once mechanical failure occurs, revision fixation is recommended to restore stability and facilitate fracture healing.^3,5 Early recognition in the present case enabled successful revision plating before non-union developed, thereby avoiding the need for bone grafting.

This case highlights that successful management of displaced clavicle fractures depends not only on accurate fracture reduction and stable fixation but also on strict adherence to postoperative rehabilitation. Current rehabilitation protocols recommend avoiding lifting more than 1–2 kg until radiographic union is achieved, typically between 6 and 12 weeks.^2-4 Thorough patient education, repeated counseling, and close follow-up are essential to improve compliance, prevent avoidable implant failure, and optimize functional outcomes following clavicle plate fixation.^5,6

CONCLUSION

ORIF with plate fixation is an effective treatment for displaced clavicle fractures in young adults. However, successful outcomes depend not only on surgical fixation but also on adherence to postoperative rehabilitation protocols. This case demonstrates that premature heavy-weight lifting can result in early plate bending and implant failure despite technically sound fixation. Prompt recognition, revision plating, and reinforced patient education resulted in satisfactory fracture union and restoration of shoulder function. Greater emphasis on patient counseling and compliance may help reduce preventable implant-related complications.