Overview
Secondary osteoarthritis (OA) of the subtalar joint often arises as a complication following previous joint surgeries, such as total ankle replacement, or due to significant trauma and repetitive stress injuries. This condition can lead to significant pain, stiffness, and functional impairment, necessitating a multifaceted approach to management. The subtalar joint, crucial for foot motion and stability, becomes particularly vulnerable to degenerative changes that can severely impact gait and quality of life. Treatment strategies aim to alleviate symptoms, restore joint function, and prevent further deterioration, often involving surgical interventions tailored to the extent of joint damage and patient-specific factors.
Diagnosis
Diagnosing secondary OA of the subtalar joint typically begins with a thorough clinical evaluation, including a detailed patient history focusing on prior surgeries, trauma, and symptoms such as pain, swelling, and decreased range of motion. Physical examination highlights tenderness over the subtalar joint, crepitus, and limited ankle and foot motion. Radiographic imaging, including plain X-rays, is fundamental, revealing characteristic changes such as joint space narrowing, osteophyte formation, subchondral cysts, and subluxation or dislocation indicative of advanced disease. Advanced imaging modalities like MRI and CT scans can provide additional insights into soft tissue involvement and bone morphology, aiding in the assessment of joint damage and guiding treatment planning.
Management
Surgical Interventions
#### Component Revision and Advanced Surgical Techniques
In cases complicated by failed total ankle replacements, such as the transition from INBONE I to INBONE II, surgical management becomes critical. A notable case study [PMID:26407743] illustrates the complexity involved in managing massive cystic changes due to aseptic osteolysis. The intervention included not only component revision from INBONE I to INBONE II sulcus talar component but also additional procedures to enhance joint function. Specifically, percutaneous tendo-Achilles lengthening and posterior capsule release were performed to improve ankle mobility, addressing both structural and functional limitations. This multifaceted approach underscores the necessity of tailored surgical strategies to address both mechanical failures and functional deficits.
#### Bone Grafting and Minimally Invasive Techniques
The use of advanced grafting materials and minimally invasive techniques has gained prominence in managing bone defects associated with secondary OA. Impaction cancellous allograft bone graft, impregnated with autogenous proximal tibia bone marrow aspirate, has shown promise in promoting bone healing and integration [PMID:26407743]. This method leverages the osteogenic potential of bone marrow to enhance graft incorporation and stimulate new bone formation, crucial for stabilizing the joint post-revision surgery.
Minimally invasive techniques are increasingly favored for their reduced trauma and faster recovery times. In vitro studies have highlighted the efficacy of specific materials like AccuFill® in achieving successful injection into simulated trabecular models, demonstrating adequate implantation without phase separation at higher pressures [PMID:26213362]. This is particularly relevant for treating bone defects in conditions like secondary OA affecting the subtalar joint, where precise material placement is essential. Conversely, many bone substitute materials (BSMs) failed to inject successfully, often separating at higher pressures, limiting their utility in minimally invasive procedures [PMID:26213362]. Therefore, selecting appropriate biomaterials is crucial for successful outcomes.
#### Arthrodesis and Access Techniques
For severe cases where joint preservation is not feasible, arthrodesis (fusion) of the subtalar joint may be considered. A minimally invasive posterolateral approach, situated between the Achilles tendon and lateral malleolus, allows for resection of approximately 65% of the subtalar articular surface with minimal risk to major vessels and nerves [PMID:14767780]. This technique minimizes postoperative complications such as sensory and motor deficits and wound healing issues, focusing on preserving foot function while achieving stability. The ability to drill open the articular surface effectively, destroying a significant portion of the joint surface, while avoiding critical anatomical structures, exemplifies the precision required in such interventions.
Non-Surgical Management
Non-surgical management strategies play a supportive role in conjunction with surgical interventions. These include:
Key Recommendations
These recommendations aim to provide a balanced approach, addressing both the structural and functional aspects of secondary OA in the subtalar joint, thereby improving patient quality of life and functional outcomes.
References
1 Roukis TS. Management of Massive Hindfoot Osteolysis Secondary to Failed INBONE I Total Ankle Replacement. Clinics in podiatric medicine and surgery 2015. link 2 Colon DA, Yoon BV, Russell TA, Cammisa FP, Abjornson C. Assessment of the injection behavior of commercially available bone BSMs for Subchondroplasty® procedures. The Knee 2015. link 3 Schmeiser G, Kunze C, Militz M, Bühren V, Putz R. Anatomic basis for a minimally invasive approach to the subtalar joint. Archives of orthopaedic and trauma surgery 2004. link