Decision-Making in Complex-Fracture Dislocation of the Hip with Acetabulum Involvement and Sciatic Nerve Palsy

Manoj Pahukar¹, Vinay Mahale^1*

¹Department of Orthopaedics and Joint Replacement, Max Super Speciality Hospital, Nagpur, Maharashtra

Abstract

Introduction: An uncommon fracture pattern involves a complex posterior hip dislocation with fractures of the acetabulum and femur neck, accompanied by sciatic nerve palsy. These injuries present with management issues because they are linked to high-velocity trauma. The choice between hip replacement and preservation procedures for middle-aged individuals is controversial. The risks associated with fixation include avascular necrosis (AVN), post-traumatic osteoarthritis, and non-union in the hip necessitating a subsequent total hip replacement (THR)

Case Report: : Following a high-velocity trauma, a 33-year-old male patient came to us with complex posterior hip dislocation with acetabulum and femur neck fracture and sciatic nerve palsy. He underwent implant-assisted acetabular reconstruction, sciatic nerve decompression, and acute primary uncemented total hip arthroplasty (THA). After 1-year, sciatic nerve recovery was observed thus allowing him to perform his everyday activities with normal locomotion.

Conclusion: :Complex posterior hip dislocation with acetabulum and femur neck fracture and sciatic nerve palsy managed with acetabular reconstruction with sciatic nerve exploration and primary THR is a feasible therapeutic option compared to osteosynthesis, despite its rarity. This makes it easier to recover from surgery and prevents additional procedures in case AVN or secondary arthritis develops.

Key words: Sciatic Nerve Palsy, Acute Total Hip Arthroplasty, Hip Dislocation, Femur Neck Fracture, Acetabular Reconstruction, Acetabulum Fracture Posterior Lip

Introduction

Ninety percent of complex femur dislocations occur in the posterior aspect. Nearly 30% of femoral head dislocations are posterior and are linked to ipsilateral acetabular fractures, which are seen in high velocity and road traffic accident (RTA) trauma.¹

Previously, in cases of osteoarthritis following trauma and AVN, studies showed that osteosynthesis resulted in minimal functional improvement and morbidity, often leading to the need for total hip replacement (THR) in the future. Some publications suggest initial THR for these types of injuries in older individuals.2 However, because of the deformed anatomy and fracture comminution, performing primary total hip arthroplasty (THA) and acetabular fixation is challenging and complex, often leading to uncertain outcomes.2,3 Because there is little research to support the optimal course of treatment, young individuals face a dilemma to preserve the head of the femur or to excise.¹

Furthermore, because the mechanisms underlying these two injuries are not identical, complex posterior hip dislocation with acetabulum and neck femur fracture and sciatic nerve palsy, is not an often-documented injury. Accordingly, there have been very few published cases of early therapy of this combination of injuries with acetabular reconstruction combined with sciatic nerve decompression and acute uncemented primary THA.

Here, we describe a case with the aforementioned combination along with a thorough explanation of the surgical difficulties.

Case report

A 33-year-old male, presented to the emergency room with pain and swelling in his left hip. The patient had sustained a fourwheeler RTA 7 days back, where he was seated in the driver's seat, his hips and knees flexed, suggesting a classic dashboard injury. Physical examination revealed that he was unable to extend his right lower leg fully. The leg appeared shortened, internally twisted, and flexed compared to the uninjured limb. Palpation indicated right hip and pubic area discomfort. He also had sciatic nerve palsy with foot drop. Posterior dislocation of the right hip was observed on radiographs and a computed tomography (CT) scan (Figure. 1), along with acetabulum and neck femur fracture and sciatic nerve palsy. Pre-operative evaluation, discussion and consent were completed with reference to the type of injury, available treatments, and Potential side effects

Figure 1: Pre-operative X-rays and CT scans of right hip

Using a posterior approach, we performed surgery while the patient was in the lateral decubitus posture. During surgery, it was found that the sciatic nerve was compressed by the fractured, dislocated head, and the short external rotators of the hip were torn with ragged borders. The femur (Pauwel type 3) neck fracture showed posterosuperior comminution, and the fracture line extended from the base of the femur's head to the cervical neck with impacted articular damage to the head of the femur. Using 3.5mm inter-fragmentary screw, the acetabulum was stabilized definitively. It was first stabilized with k-wire before being fastened firmly with two cortical screws of 3.5mm each (Figure. 2). The acetabulum's fracture shape was then restored. An uncemented THR was carried out with a dual mobility cup (52mm, size 3), a 28mm femoral head with a standard ceramic neck and a 52mm polyethylene liner. There was a 450ml intraoperative blood loss during the 80-minute operation

The post-operative phase was uncomplicated, and radiographs showed good component alignment (Figure. 3). After being nonweight bearing for a month, he was progressively allowed to resume weight bearing with assistance. His sciatic nerve palsy recovered gradually. At the 6-month follow-up, radiographs revealed a repaired fracture with a stable implant and complete sciatic nerve recovery (Figures. 4 & 5). Full weight bearing was observed. He had a Harris Hip Score of 90 and satisfactory hip function at the 1-year follow-up, with properly positioned implants and acceptable stability (Figure 6).⁴

Figure 2: Intra-operative images of THR

Figure 3: Post-operative X-ray with proper reduction seen

Figure 4: Oblique view X-rays with stable THR and stabilized acetabular fixation

Figure 5: At the last follow-up, clinical photos of the right hip demonstrate adequate hip function and joint mobility

Figure 6: Post-operative X-ray with proper reduction seen

Discussion

It is essentially an uncommon occurrence to witness a complex posterior hip dislocation with acetabulum and femur neck fracture and sciatic nerve palsy; 75% of these patients are less than 50 years old.¹ The choice between femoral head replacement surgery and preservation is still debatable because the injury pattern is uncommon, there is no clear classification scheme, and there is disagreement about how best to treat the condition.¹ The length of time between the damage and therapy, the type of surgical procedure, and the choice of implant may affect the final clinical result.

Studies have suggested that the femoral head should be preserved, particularly in younger patients, as this preserves the patient's natural bone supply and prevents complications from loosening of the prosthesis and dislocation.^1,5 Nevertheless, some patients have complex pattern of fractures, and there is little chance in saving the head of femur & unfixable fractures. Up to 13%-67% of these patients will require an arthroplasty in the near future due to unfavourable outcomes like non-union, osteoarthritis and AVN.^2,5-8

Therefore, since acute THA results in early function restoration, higher survival rates and shorter immobilization time and avoidance of further problems, it makes sense to use it as the final treatment in these instances.7,8 Technical challenges, poor cementing techniques and stability issues—can all be blamed for the disappointing outcomes of previous acute primary arthroplasty procedures for acetabular fractures.^2-4,7

Due to the complicated and uncommon fracture pattern, sciatic nerve palsy, dual mobility hydroxyapatite (HA) coated stem and uncemented THR for definitive therapy, our case was distinct. In our situation, the posterior technique was chosen because

it was appropriate for addressing the dislocated head of femur and it provided a convenient way for acetabular restoration and sciatic nerve decompression, while protecting the anterior components from additional iatrogenic soft tissue damage. Therefore, K wires can be employed for temporary stability prior to final fixation.^2,6 Thus, our case study highlights the need for creating a standardized system for classifying and managing complex trauma.

Late THA following unsuccessful primary fixation has less favourable outcomes and higher complication rates compared to primary THA. This is because of extensive scarring, the need for wide soft-tissue dissection, the potential infections in the bone and/or remaining hardware, and anatomic or structural problems resulting from defects in the bone or residual abnormalities.^6-8 In recent times, acute primary THA following acetabular fractures has shown outstanding clinical and functional outcomes because of the use of highly porous metal components, which allow for quick biological ingrowth, and enhance stability.^2,3,6

Although satisfactory results could be expected after open reduction and internal fixation (ORIF) for patients with these types of fractures without hip dislocation, we believe that uncemented initial THR with acetabulum restoration and sciatic nerve decompression can be a viable option for adults and senior citizens with posterior hip dislocation and associated acetabulum and femoral head fracture. This approach addresses concerns about AVN and non-union and helps avoid the need for repeat procedures.^6-8

CONCLUSION:

Complex traumatic fractures such as those involving femur head dislocation, acetabular comminuted fractures and sciatic nerve palsy, present significant challenges for the surgeons. Acetabular reconstruction with implants and initial uncemented THA, can serve as an effective alternative to ORIF. This approach can produce satisfactory functional and radiological outcomes in addition to hastening the restoration of hip function.

References

Tannast M, Mack PW, Klaeser B, et al. Hip dislocation and femoral neck fracture: decision-making for head preservation. Injury. 2009;40(10):1118-24.
De Bellis UG, Legnani C, Calori GM. Acute total hip replacement for acetabular fractures: a systematic review of the literature. Injury. 2014;45(2):356-61.
Malhotra R, Gautam D. Acute total hip arthroplasty in acetabular fractures using modern porous metal cup. Journal of Orthopaedic Surgery. 2019;27(2):2309499019855438.
Harris WH. Traumatic arthritis of the hip after dislocation and acetabular fractures: treatment by mold arthroplasty: an endresult study using a new method of result evaluation. JBJS. 1969;51(4):737-55.
O’Toole RV, Hui E, Chandra A, et al. How often does open reduction and internal fixation of geriatric acetabular fractures lead to hip arthroplasty?. Journal of orthopaedic trauma. 2014;28(3):148-53.
Makridis KG, Obakponovwe O, Bobak P, et al. Total hip arthroplasty after acetabular fracture: incidence of complications, reoperation rates and functional outcomes: evidence today. The Journal of Arthroplasty. 2014;29(10):1983-90.
Mears DC, Velyvis JH. Acute total hip arthroplasty for selected displaced acetabular fractures: two to twelve-year results. JBJS. 2002;84(1):1-9.
Kreder HJ, Rozen N, Borkhoff CM, et al. Determinants of functional outcome after simple and complex acetabular fractures involving the posterior wall. The Journal of Bone & Joint Surgery British Volume. 2006;88(6):776-82.