Total hip arthroplasty (THA) is one of the most successful orthopedic interventions, with more than 220,000 THAs performed in the United States between 1998 and 2008.1 Perforation of the medial acetabular wall during reaming is not an uncommon consequence of the procedure.2 Rarely, it is associated with complications such as hematomas in the iliacus or psoas muscles or cement herniation.3 Hematomas are more prone to occur in patients receiving anticoagulation or antiplatelet therapy or with hematologic disorders.4 These complications could result in delayed sciatic nerve palsy after THA.4,5
The authors describe a case of sciatic nerve palsy due to a massive compressive hematoma following THA for a patient receiving both anticoagulation and anti-platelet therapy. Additionally, the authors discuss the importance of early diagnosis of this entity because of its impact on the long-term neurological outcome.
A 66-year-old woman with a history of diabetes, obesity, and coronary artery disease, weighing 210 lb, initially presented with right hip pain. She successfully underwent total hip replacement surgery for degenerative joint disease by an outside orthopedic surgeon. Preoperatively, the patient was receiving an 81-mg aspirin and clopidogrel regimen for coronary stents that had been placed 13 years earlier. Postoperatively, she was switched to an 81-mg aspirin and Coumadin (Bristol-Myers Squibb, New York, New York) regimen. Ten days postoperatively, while the patient was attempting to sit, she felt a pop in her right hip but did not have antecedent trauma. Following that incident, she developed severe lower back pain radiating to her foot. On examination, she had right lower extremity paresthesias in multiple dermatomes; 4/5 motor strength in hip flexion and knee extension; and 0/5 motor strength in knee flexion, hip abduction/adduction, foot dorsi-/plantar-flexion, and foot inversion/eversion. Her left lower extremity sensory and motor examination yielded normal results and her presenting international normalized ratio value was 1.3. She was referred to the authors' institution for a neurosurgical consultation for the suspected diagnosis of lumbar spinal stenosis.
Magnetic resonance imaging and computed tomography myelography showed that the patient had minimal lumbar stenosis (Figure 1), thereby excluding lumbar stenosis as the etiology of her neurologic deficit. Further workup with a pelvic computed tomography scan showed a large gluteal hematoma at the surgical site (Figure 2). Follow-up right hip magnetic resonance imaging showed a 500-mL subfascial mixed-intensity hematoma with extensive edema and inflammatory changes in the gluteal muscles from the sciatic notch to the popliteal fossa (Figure 3).
Sagittal (A) and axial (B) T2-weighted magnetic resonance images of the lumbar spine showing multilevel mild spondylosis that would not explain the patient's symptoms.
Coronal pelvic computed tomography scan showing the right-sided hip implant as well as a large lateral hematoma (arrow).
Coronal (A) and axial (B) magnetic resonance images of the acetabular implant showing the superficial hematoma (a), the acetabular implant (b), the deep hematoma (c), and the sciatic nerve (d).
The orthopedic surgery service at the authors' institution was consulted and surgically evacuated the hematoma 24 hours following the magnetic resonance imaging. Intraoperatively, the surgeon (G.S.G.) identified 1000 mL of tense liquid hematoma between the skin and the fascia. On opening the fascia, approximately 500 mL of both gelatinous and liquid hematoma was expressed. The sciatic nerve was clearly compressed, with indentation of the course of the nerve to the bifurcation. Debridement of the hematoma followed by epineurolysis of the sciatic nerve from the sciatic notch to the ischial tuberosity allowed for complete decompression.
Postoperatively, the patient received antibiotics pending surgical site cultures. Her right lower extremity radiculopathy pain had resolved; however, she still had a significant amount of paresthesia and hyperalgesia and she was still unable to plantar- or dorsiflex her right foot. She was discharged to a skilled nursing facility for rehabilitation and further care.
Nontraumatic acute foot drop is rare.6 The most common etiology of acute foot drop is due to neural compression within the spinal canal from herniated lumbar disks,7 spondylolisthesis, and lateral recess syndrome.6 Rare causes of acute foot drop include multiple sclerosis,8 brain lesions, gas-filled intradural cysts,9 lumbar ligamentum flavum hematoma10 spinal vascular malformations, and compressive spinal tumors.6 Extra-spinal causes of compression of peripheral nerves may also result in acute foot drop. Compression of the sciatic nerve anywhere along its course may cause acute foot drop, as shown on the current patient's magnetic resonance imaging. The sciatic nerve is most at risk of compression in the pelvis around the sciatic notch, especially following a surgical intervention. Although various mechanisms of injury from hematomas have been suggested, it is widely agreed that a compartment syndrome causes pressure build-up within fascial enclosures, which leads to compression and ischemia of the peripheral nerves.2,11 More distal pathology such as popliteal fossa hematoma following a popliteal vein aneurysm resection or peroneal nerve entrapment with or without a tibiofibular cyst also cause similar symptomatology.12 In this context, the neurologic examination becomes paramount to determine the location of the lesion. The current patient had some weakness in hip flexion and knee extension, which is most likely attributed to the size of the compressive hematoma and to the associated pain.
Sciatic nerve injury is a recognized complication of THA in between 0.5% and 2% of cases.13 The mechanism of injury could involve screws, trochanteric wire pieces, methyl methacrylate cement, metal cages, or hematomas.2,4,14,15 It is crucial to note the importance of a prompt diagnosis of the hematoma as a possible etiology of acute foot drop. At the outside facility, the current patient was returned to anticoagulation and antiplatelet therapy shortly after the THA. Anticoagulation has been reported to be a risk factor for the formation of postoperative hematomas, especially in patients who weigh less than 70 kg.4
Management approaches to hematomas after THA vary. Some cases in the literature advocate conservative measures with complete bed rest and physical therapy and report excellent results, indicating that surgery is only to be used in certain situations.2 Suggested criteria for nonsurgical management include hemodynamic stability, stable neurological findings, and no suspicion of active bleeding in the hematoma. Surgical treatment is recommended in cases of worsening neurological symptoms or hemodynamic instability.2 Other reports advocate that early decompression of the sciatic/femoral nerve by evacuation of the hematoma correlates with better neurological outcomes and prevents irreversible nerve damage.4,14 In the current case, the patient was having severe neurological deficits and the decision was made to urgently evacuate the hematoma.
Prompt diagnosis of hematomas following THA, especially in patients receiving anticoagulation, is crucial in cases of acute foot drop. It is the authors' recommendation that compressive hematomas after THA be evacuated as early as possible, as this would probably lead to improved overall neurological outcomes. The speed of recovery of function in the lower extremity will depend on the promptness of the diagnosis and the intervention.
- Kurtz S, Mowat F, Ong K, Chan N, Lau E, Halpern M. Prevalence of primary and revision total hip and knee arthroplasty in the United States from 1990 through 2002. J Bone Joint Surg Am. 2005; 87(7):1487–1497. doi:10.2106/JBJS.D.02441 [CrossRef]
- Gogus A, Ozturk C, Sirvanci M, Aydogan M, Hamzaoglu A. Femoral nerve palsy due to iliacus hematoma occurred after primary total hip arthroplasty. Arch Orthop Trauma Surg. 2008; 128(7):657–660. doi:10.1007/s00402-007-0489-2 [CrossRef]
- Oleksak M, Edge AJ. Compression of the sciatic nerve by methylmethacrylate cement after total hip replacement. J Bone Joint Surg Br. 1992; 74(5):729–730.
- Butt AJ, McCarthy T, Kelly IP, Glynn T, McCoy G. Sciatic nerve palsy secondary to postoperative haematoma in primary total hip replacement. J Bone Joint Surg Br. 2005; 87(11):1465–1467. doi:10.1302/0301-620X.87B11.16736 [CrossRef]
- Katsimihas M, Hutchinson J, Heath P, Smith E, Travlos J. Delayed transient sciatic nerve palsy after total hip arthroplasty. J Arthroplasty. 2002; 17(3):379–381. doi:10.1054/arth.2002.30775 [CrossRef]
- Yücesoy K, Acar F, Koyuncuoglu M. Acute foot drop caused by thrombosed epidural vein. Acta Neurochir (Wien). 2001; 143(6):631–632. doi:10.1007/s007010170070 [CrossRef]
- Mahapatra AK, Gupta PK, Pawar SJ, Sharma RR. Sudden bilateral foot drop: an unusual presentation of lumbar disc prolapse. Neurol India. 2003; 51(1):71–72.
- Albrecht H, Pollmann W, König N. Acute foot drop paralysis in multiple sclerosis: peroneal nerve compression as differential diagnosis of acute onset [in German]. Nervenarzt. 1996; 67(2):163–169.
- Jeon CH, Park JU, Choo HS, Chung NS. Increased size of a gas-filled intradural cyst causing acute foot drop: a case report. Skeletal Radiol. 2013; 42(12):1747–1750. doi:10.1007/s00256-013-1668-6 [CrossRef]
- Kono H, Nakamura H, Seki M, Motoda T. Foot drop of sudden onset caused by acute hematoma in the lumbar ligamentum flavum: a case report and review of the literature. Spine (Phila Pa 1976). 2008; 33(16):E573–E575. doi:10.1097/BRS.0b013e31817c6cb5 [CrossRef]
- Rochman AS, Vitarbo E, Levi AD. Femoral nerve palsy secondary to traumatic pseudo- aneurysm and iliacus hematoma. J Neurosurg. 2005; 102(2):382–385. doi:10.3171/jns.2005.102.2.0382 [CrossRef]
- Donaldson CW, Oklu R, Watkins MT, et al. Popliteal venous aneurysms: characteristics, management strategies, and clinical outcomes. A modern single-center series. Ann Vasc Surg. 2014; 28(8):1816–1822. doi:10.1016/j.avsg.2014.06.065 [CrossRef]
- Stiehl JB, Stewart WA. Late sciatic nerve entrapment following pelvic plate reconstruction in total hip arthroplasty. J Arthroplasty. 1998; 13(5):586–588. doi:10.1016/S0883-5403(98)90060-2 [CrossRef]
- Fleming RE Jr, Michelsen CB, Stinchfield FE. Sciatic paralysis: a complication of bleeding following hip surgery. J Bone Joint Surg Am. 1979; 61(1):37–39.
- Austin MS, Klein GR, Sharkey PF, Hozack WJ, Rothman RH. Late sciatic nerve palsy caused by hematoma after primary total hip arthroplasty. J Arthroplasty. 2004; 19(6):790–792. doi:10.1016/j.arth.2004.02.033 [CrossRef]