Subchondral impaction fractures of the non-weight-bearing portion of the lateral femoral condyle

Subchondral Insufficiency Fractures of the Knee: A Clinical Narrative Review

» Subchondral insufficiency fractures of the knee (SIFKs) are subchondral plate fractures with a prevalence of 2% to 4% of all knee injuries.» Magnetic resonance imaging is the gold standard for evaluating SIFK, while plain radiographs have limited the use in the diagnosis of SIFK.» Among patients with SIFK, 50% to 100% have meniscal pathology.» Medical therapies and standard treatments traditionally used in the management of knee osteoarthritis differ from recommended management of SIFK patients.» Randomized controlled trials and cohort studies with long-term follow-up are needed to determine the optimal rehabilitation protocol, interventional therapy, and prognosis of SIFK patients.

Lateral femoral condyle insufficiency fractures: imaging findings, demographics, and analysis of outcomes

OBJECTIVE

To describe imaging characteristics and demographics of lateral femoral condyle insufficiency fractures (LFCIFs) and identify characteristics associated with progression to epiphyseal collapse.

MATERIALS AND METHODS

A retrospective review of 105 consecutive patients with LFCIF was performed (mean age 58.1 years) after excluding post-traumatic and pathological fractures. Lesion size and location, presence of bone marrow edema-like signal, soft tissue edema, chondrosis grade, and meniscus pathology were documented. Demographics were recorded from the electronic patient record. Follow-up MRI and/or radiographs were evaluated for healing/stability or progression to epiphyseal collapse. Bone mineral density was assessed from dual-energy x-ray absorptiometry (DEXA) scans and/or radiographs.

RESULTS

Fifty-six female and 49 male subjects were included. Female subjects were older at presentation (60.5 versus 56.3 years, p = .02). A total of 61.7% of the subjects with available DEXA and/or radiographs had osteopenia/osteoporosis. The central weight-bearing (61%) and outer condyle (54.3%) were most involved. High-grade chondrosis was present in ≥ 1 compartment in 70.5% including 42% in the lateral compartment. A total of 67.6% had ≥ 1 meniscus tear with similar frequency of medial and lateral tears (47.6% versus 41%). Bone marrow edema-like signal was present in all cases; soft tissue edema was present in 83.8%. Fifty-three subjects had available follow-up MRI (n = 24) and/or radiographs (n = 29). Increased age, fracture dimensions, presence of medial meniscus tears, and high-grade patellofemoral chondrosis were associated with progression (p ≤ .05).

CONCLUSION

LFCIFs are associated with meniscus tears, high-grade chondrosis, and osteopenia/osteoporosis with more global knee pathology present when compared with medial femoral condyle insufficiency fracture. Increased age, medial meniscus tears, fracture dimensions, and high-grade patellofemoral chondrosis were associated with progression.

Technique for Treatment of Subchondral Compression Fracture of the Lateral Femoral Condyle Associated With ACL Tear

Excessive knee pivoting that causes a complete anterior cruciate ligament (ACL) tear may result in a subchondral compression fracture on the lateral femoral condyle after impacting the lateral tibial condyle. Because this mechanism is similar to the humeral head that has an impact on the glenoid during an anterior shoulder dislocation, such an osteochondral fracture can be considered equivalent to a "Hill-Sachs lesion of the knee." Restoring the native anatomy of the lateral femoral condyle articular surface is crucial, because its depression alters knee biomechanics, leading to bony knee instability, potentially greatly elevating the risk of ACL reconstruction failure and meniscal tears. In addition, bony knee instability increases the forces acting on the cartilage, which may impair one's quality of life and lead to the development of osteoarthritis. The fact that many patients with complete ACL tears are relatively young emphasizes the key role of osteoarthritis prevention. The aim of this report is to present a minimally invasive procedure to treat the "Hill-Sachs-like" knee lesion, a tricky enemy of knee stability.

Nomenclature of Subchondral Nonneoplastic Bone Lesions

OBJECTIVE. The purpose of this article is to summarize the nomenclature of nonneoplastic conditions affecting subchondral bone through a review of the medical literature and expert opinion of the Society of Skeletal Radiology Subchondral Bone Nomenclature Committee. CONCLUSION. This consensus statement summarizes current understanding of the pathophysiologic characteristics and imaging findings of subchondral nonneoplastic bone lesions and proposes nomenclature to improve effective communication across clinical specialties and help avoid diagnostic errors that could affect patient care.

Magnetic resonance imaging of subchondral insufficiency fractures of the lower limb

Subchondral insufficiency fracture (SIF) is a non-traumatic condition that has historically been associated with elderly, osteoporotic women and patients with systemic conditions. There has been much work done to determine the pathogenesis of SIF, which has previously been regarded as idiopathic, rapid-progressive osteoarthritis or osteonecrosis of the hip, spontaneous osteonecrosis of the knee (SONK), osteochondral defect (OCD) of the talus and adult-onset Freiberg infraction of the metatarsal head. Early diagnosis and management are crucial to prevent subchondral collapse, secondary osteonecrosis and early-onset osteoarthritis. Magnetic resonance imaging (MRI) plays an important role in the diagnosis of SIF, which is often inconspicuous on initial radiographs. In this article, the authors provide an update on the role of MRI in identifying key imaging features of SIF in various joints of the lower limb to aid in its correct diagnosis.

Subchondral Insufficiency Fracture in the Lateral Compartment of the Knee in a 64-Year-Old Marathon Runner

A 64-year-old marathon runner presented to our clinic with a history of worsening pain in her left knee. Following magnetic resonance imaging, the diagnosis of subchondral insufficiency fracture of the knee (SIFK) was made. A course of conservative management via bisphosphonates was initiated. The patient successfully recovered and returned to full athletic function, having recently returned to competitive marathon running. This article aims to present this unusual case of lateral compartment SIFK and summarise the literature on this uncommon condition.

Subchondral Impaction Fractures of the Medial Femoral Condyle in Weightlifters: A Report of 5 Cases

Although subchondral impaction fractures have already been reported in the non-weight-bearing portion of the lateral femoral condyle, this study reveals the presence of an intra-articular impaction fracture of the postero-superior region of the non-weight-bearing portion of the medial femoral condyle recognized in 5 of a group of 22 representatives of the Polish national Olympic weightlifting team, who underwent 1.5T magnetic resonance imaging examination. Articular cartilage lesions varied with regard to the type of injury and its severity ranging from healed or subchronic injuries to acute trauma. All described individuals had no clinical history of acute knee trauma and only 3 of them had minor pain symptoms. The accumulation of microtraumas occurring during participation in particular activities associated with weightlifting training seems to be responsible for the development of this type of contusion. This is the first description of impaction fracture observed in this location in professional weightlifters.

Subchondral insufficiency fracture of the knee: a non-traumatic injury with prolonged recovery time

Subchondral insufficiency fractures are non-traumatic fractures that occur immediately below the cartilage of a joint. Although low bone density may be present concurrently, it is not the underlying cause of subchondral insufficiency fractures in the majority of patients. Patients with subchondral insufficiency fracture characteristically have unremarkable plain radiographs, while MRI examination may reveal extensive bone marrow oedema and subchondral bone collapse. This article presents a 51-year-old postmenopausal woman, a physician, who had subchondral insufficiency fractures of the knee associated with prolonged standing during clinical work. She was treated with partial weight bearing on crutches until 14 months after the injury, viscosupplementation at 4 months to treat osteoarthritis and teriparatide treatment to improve bone healing at 7 months. By 26 months after the injury, she tolerated independent walking with a fabric knee support but still experienced mild posterolateral knee pain and numbness on prolonged standing.