Proximal Diaphyseal Tibial Fracture Stabilisation with a Humeral Nail Before Below-knee Amputation: A Case Report

Abstract

Case report

A 76-year-old female sustained catastrophic bilateral lower extremity trauma following a pedestrian-vs-auto collision, resulting in a traumatic right lower extremity amputation and a vascularly compromised left proximal tibial shaft fracture. The patient's left lower extremity was successfully treated with a proximal humerus nail to stabilise the fracture, immediately followed by a below-knee amputation (BKA) in the same setting.

Conclusion

This case highlights a novel application of an upper extremity implant to preserve limb length in the setting of bilateral lower extremity amputations due to polytrauma.

Introduction

Bilateral lower extremity amputations present profound clinical and functional challenges, especially among patients for whom preserving partial limb function could substantially improve quality of life.^1,2 The choice between limb salvage and amputation affects both survival and long-term outcomes. For patients undergoing lower limb amputations, the level of amputation can be particularly impactful when assessing for post-operative energy expenditure, gait efficiency, and metabolic demand.^3,4 Compared to below-knee amputation (BKA), above-knee amputation (AKA) is associated with higher levels of oxygen consumption, slower walking speeds, and lower likelihood of independent ambulation.^4,5 Knee preservation reduces metabolic cost and improves mobility.^4,6,7

The decision surrounding amputation level may be complicated by additional traumatic injuries. Proximal tibial shaft fractures can make BKAs particularly difficult. Stabilising these injuries with standard tibial intramedullary nailing is not possible in patients undergoing BKA since the shortest available length for a tibial nail is 160 mm.^8–12 A prior case study has demonstrated the use of a humerus nail for management of tibia diaphyseal fracture in a short-stature patient to adjust for short limb length.¹³ However, we are not aware of the use of a humerus nail for management of a proximal tibial shaft fracture for a patient undergoing BKA. We present a rare scenario in which a patient received a proximal humerus intramedullary nail for acute tibial stabilisation of a proximal tibial fracture, followed by immediate BKA.

Informed consent for publication could not be obtained from the patient. In keeping with the journal's guidelines, the medical and research teams take responsibility for ensuring that the patient is fully anonymised in this manuscript.

Case Report

A 76-year-old woman presented as a trauma activation following a pedestrian-vs-auto collision in which she was reportedly pinned against a fence. She arrived in hemorrhagic shock with polytraumatic injuries. Orthopaedic injuries included a traumatic right BKA, right segmental femur fracture, pelvic ring injury, an open left calcaneus fracture, left midshaft humerus fracture, and left proximal tibia and fibular shaft fractures (Fig. 1). Her relevant medical history included type 2 diabetes (HbA1c 6.5%).

Figs 1A to D.

Radiographs available at the time of the patient's initial presentation to the hospital. (A) Anterior-posterior; and (B) Lateral radiograph of the tibia and fibula obtained in the trauma bay; (C) Anterior-posterior; and (D) Lateral radiograph of the tibia and fibula obtained after immobilisation in a long leg splint

After assessment and initiation of antibiotics, she underwent emergent exploratory laparotomy and debridement of the right traumatic BKA by general surgery. Her orthopaedic injuries were temporised with splints and skeletal traction. Definitive fixation was deferred until stabilisation.

Once optimised, the orthopaedic team performed a revision AKA of the right lower extremity through the supracondylar fracture, intramedullary nail fixation of the subtrochanteric femur fracture, and excisional debridement of the open left calcaneal fracture with minimal residual soft tissue available for primary closure. Vascular assessment included a computed tomography angiogram (CTA) concerning popliteal dissection with no operative intervention recommended (Fig. 2). Plastic surgery deemed left limb salvage high risk due to medical status and possible arterial abnormalities. The surrogate decision maker consented to amputation.

Fig. 2.

Axial computed tomography angiography (CTA) images of the left lower extremity. The imaging denotes area of possible extravasation for which there was an interdisciplinary concern for a possible popliteal artery dissection

The proximal tibial fracture was located 36.4 mm distal to the tibial tubercle (Fig. 3). This amputation level would have limited prosthetic fitting. Therefore, the decision was made to stabilise the proximal tibial fracture and preserve tibial length with a more distal osteotomy. An 8 mm by 150 mm proximal humerus nail (Stryker, Kalamazoo, MI) was selected as the length of the implant was optimal for the planned osteotomy, and the 6° valgus bend closely matched the recurvatum of a standard tibial nail. Furthermore, the interlocking options of a proximal humerus nail are more similar to those of tibial nails. Other implants were felt to have less favorable screw trajectories. For example, hindfoot nails typically have posterior-to-anterior screw paths through the calcaneus; when used in the tibia with an infrapatellar entry portal, this could translate to an anterior-to-posterior trajectory, creating a potentially dangerous screw path.

Fig. 3.

Lateral radiograph of initial tibia/fibula measuring the distance from the inferior border of the tibial tubercle to the fracture site

A medial parapatellar incision was used. A 6 mm carbide drill (DePuy Synthes, Raynham, Massachusetts) and a series of diamond tip burrs were used to create a custom interlock hole at the distal aspect of the nail. The modified nail was inserted and seated appropriately. We then placed four interlocking screws through the targeting arm. A medial to lateral interlock screw was placed through the custom hole using the perfect circle technique, and a cortical replacement screw was placed anterior to the nail to limit motion of the distal segment (Fig. 4). Proximally, the implant was stable. Distally, there was limited bone stock for fixation, so in addition to an interlocking screw, a cortical replacement screw was placed to create an interference fit. The construct was designed to provide relative stability and promote secondary bone healing, where a degree of motion is acceptable and even beneficial. The osteotomy level for the BKA was marked following nail insertion, approximately 120 mm distal to the tibial tubercle. An oscillating saw was utilised to complete the tibial cut with an anterior bevel. The fibula was then cut proximal to the level of the tibial, and the soft tissue amputation was then completed. Using the posterior fascia, a muscle flap was rotated anteriorly over the bone and sutured to the anterior fascia. Post-operatively, the patient was transferred to the intensive care unit in critical condition.

Figs 4A and B.

(A) Final anterior-posterior; and (B) Lateral fluoroscopic images of the tibia and fibula obtained intra-operatively

Following 21 days in the ICU, the patient was discharged to a long-term acute care facility. Upon discharge, she was hemodynamically stable, and she was made weightbearing as tolerated on the left upper extremity and non-weightbearing on the bilateral lower extremities. She was placed in a posterior mold splint to the left lower residual limb, which was worn until follow-up. At her 4 weeks post-operative follow-up, she was still in the rehabilitation unit and medically doing well (Fig. 5). Her incisions were well healed, and she was progressed to weight bearing as tolerated in all extremities. At that time in her rehabilitation, the patient worked with physical therapy but did not achieve weight-bearing in either limb given her overall injury burden. At 12 weeks post-operatively, the patient continued to be doing well and began fitting for prostheses (Fig. 6). She continued to not achieve weight-bearing status with her physical therapy team. Her pain was well-tolerated in the post-operative phase, primarily with standing acetaminophen, oxycodone, and gabapentin in the early post-operative phase and with strict instructions to hold opioids for confusion. The patient was unable to attend her 1 year follow-up in the orthopaedic clinic; however, discussion with her primary care team revealed she is currently doing well and primarily uses a wheelchair for ambulation. In summary, this is a geriatric patient that suffered from a severely polytraumatised state, which likely contributed to her use of a wheelchair. She had a high injury burden and was severely deconditioned. She also suffered from impaired cognition, decreased activity tolerance and endurance as well as impaired balance. Her 1 year post-operative X-rays showed a well-healed fracture (Fig. 7).

Figs 5A and B.

(A) Anterior-posterior; and (B) Lateral radiograph of the tibia and fibula obtained at the patient's 4 weeks post-operative visit

Figs 6A and B.

(A) Anterior-posterior; and (B) Lateral radiograph of the tibia and fibula obtained at the patient's 12 weeks post-operative visit

Figs 7A and B.

(A) Anterior-posterior; and (B) Lateral radiograph of the tibia and fibula obtained at the patient's 1 year post-operative anniversary

Discussion

Bilateral lower extremity trauma requiring amputation can present significant surgical and rehabilitative challenges, especially in the polytraumatised patient.¹⁴ The management of this injury profile requires the optimisation of post-operative function, which may be achieved by preserving the knee joint.^4,15–17 In salvaging an extremity at the level of a BKA rather than an AKA, a patient may benefit from more efficient energy expenditure and decreased metabolic demand post-operatively.^4,18 A study conducted by MacKenzie et al. showed that, among patients with trauma-related lower-extremity amputations, those who had a BKA performed better on a timed test for walking speed than those who had an AKA.¹⁹ This highlights the benefits of limb preservation.

We present a case of a patient with polytraumatic injuries notable for complex bilateral lower extremity injuries, including a left proximal tibial shaft fracture that required amputation. To preserve limb length, a standard intramedullary tibial nail could not be used as the length of the nail would extend beyond the planned level of amputation.²⁰ The surgical team employed a proximal humerus intramedullary nail, which, due to its shorter length and 6° insertion angle, provided a viable alternative for stabilising the proximal tibial shaft fracture while preserving enough length to facilitate a BKA. To date, there are no prior cases, to our knowledge, that have shown this particular approach. A single previous report, however, did show the use of a 220 mm humeral nail in the fixation of a tibial shaft fracture in a patient with small stature when the shortest available tibial nail was 260 mm.¹³ This technique was extrapolated for the preservation of the proximal tibia to optimise an ipsilateral BKA. Plate fixation was also considered, though surface implants can create pressure points and wound issues with prosthetic wear.²¹ A standard tibial nail, cut to the ideal length with custom interlock holes drilled, was also considered. However, this would require additional modification of the tibial nail vs the humeral nail and compromise the implant integrity further. Lastly, another treatment option was a standard length BKA with nonoperative treatment of the proximal tibial fracture. The instability at the fracture site raised concern for nonunion and the lack of fixation may inhibit early mobilisation.

Limitations

This case report is limited by its nature as a single-patient observation, which restricts the generalizability of its findings. While the use of a humerus nail for tibial fixation in the context of an ipsilateral BKA proved effective in this instance, broader conclusions about its safety or long-term outcomes would require larger studies. Additionally, the patient's multiple traumatic injuries complicate the ability to isolate the functional benefits of knee preservation alone. Long-term follow-up data, including prosthetic use, gait efficiency, and quality of life metrics, are also limited at the time of writing, which constrains the ability to assess functional outcomes beyond the early post-operative period.

The current case described the novel technique of using a proximal humerus intramedullary nail for tibial fixation in the context of lower extremity limb length preservation. The indication for lower extremity amputation in the face of a contralateral AKA can pose significant challenges for both the surgical team and the patient. By prioritising a BKA over an AKA, a patient may have better clinical and quality of life outcomes. The surgical team was able to accommodate the patient's fracture morphology and preserve the knee joint for improved mobilisation and metabolic preservation. The authors suggest orthopaedic implant design and manufacturers consider the variable length of patient stature and long bone injury morphology.

Conclusion

Amputation level can have a significant impact on metabolic demand and long-term functional outcomes for patients. This case illustrates the successful use of a proximal humerus nail as an alternative fixation method for a proximal tibial shaft fracture to preserve sufficient length for a BKA. Customised intramedullary implants may provide an alternative method for diaphyseal stabilisation in the setting of extreme pathoanatomic limitations, although the time-sensitive nature of fracture care may limit their use.

Clinical Significance

The case study demonstrates a novel method for preserving limb length and knee function in a polytrauma patient undergoing bilateral lower extremity amputation. The use of a proximal humerus intramedullary nail allowed stabilisation of a proximal tibial fracture while maintaining sufficient residual tibial length for BKA, potentially reducing post-operative energy expenditure. This technique may provide orthopaedic surgeons with an alternative fixation strategy in situations where standard tibial implants are incompatible.

Ethical Approval

Institutional Review Board approval was not required for this study, as it represents a single-patient case report and was determined not to constitute human subjects research according to institutional policy. All patient information was de-identified in accordance with ethical standards and journal guidelines.

Data Availability Declaration

The data supporting the findings of this case report are contained within the article. No additional datasets were generated or analysed. Patient-specific data have been withheld to maintain confidentiality and privacy.

Artificial Intelligence (AI) Disclosure

No AI tools or generative language models were used in the writing, analysis, or preparation of this manuscript.

Acknowledgement

None.

Authors' Contributions

Rimel N Mwamba performed the chart review, conducted the literature review, and wrote the initial manuscript draft. Tony Da Lomba contributed to chart review, obtained and organised the radiographic images, and contributed to manuscript writing and revision. Mary K Erdman was the treating attending surgeon for the patient, supervised the project, and critically reviewed and revised the manuscript. All authors reviewed and approved the final manuscript.