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Osteochondritis of tibial tubercle — Clinical Guidelines

Overview

Osteochondritis of the tibial tubercle, often encountered in the context of total knee arthroplasty (TKA) revisions, involves the disruption of blood supply to the tibial tubercle leading to localized bone and cartilage damage. This condition is clinically significant due to its potential to complicate surgical exposure and outcomes, particularly in revision surgeries necessitated by periprosthetic joint infection (PJI) or aseptic loosening. It predominantly affects older adults undergoing revision TKA, where extensive surgical approaches are required to address complex anatomical challenges. Understanding and managing this condition is crucial in day-to-day practice to optimize surgical outcomes and minimize complications such as non-union, malalignment, and infection recurrence 1 4.

Pathophysiology

Osteochondritis of the tibial tubercle arises from ischemic injury to the metaphyseal-diaphyseal region of the tibial tubercle, often exacerbated by surgical manipulation and prolonged immobilization. The disruption of the vascular supply can lead to avascular necrosis, subsequent cartilage damage, and delayed or non-union of the osteotomy site. During revision TKA, particularly when extensive exposure is needed, the tibial tubercle may be subjected to excessive tension or trauma, compromising its vascular integrity. This ischemic insult triggers a cascade of cellular events, including necrosis of bone cells, inflammation, and potential fibrous tissue formation, which can impede healing and lead to complications such as malunion or non-union 1 3 4.

Epidemiology

The incidence of osteochondritis specifically at the tibial tubercle in the context of TKA revisions is not extensively documented in large population studies, but it is recognized as a significant complication in surgical series. Patients typically range from their sixth decade onwards, with a slight male predominance observed in some studies. Geographic and specific risk factors are less defined, but comorbidities such as diabetes, obesity, and prior surgical interventions increase susceptibility. Trends suggest an increasing incidence with the rising volume of revision surgeries due to longer implant lifespans and evolving surgical techniques 1 3 4.

Clinical Presentation

Clinical presentation often manifests postoperatively with signs of localized pain, swelling, and limited knee mobility, particularly around the tibial tubercle region. Red-flag features include persistent non-union, malalignment of the patella, and recurrent infection symptoms such as fever, increased pain, and purulent drainage. Patients may report a palpable defect or abnormal mobility at the osteotomy site, which can indicate complications like fibrous union or avascular necrosis 1 4.

Diagnosis

Diagnosis of osteochondritis at the tibial tubercle involves a thorough clinical evaluation followed by imaging studies. Specific criteria include:

Clinical Assessment: Pain localized to the tibial tubercle, restricted knee flexion, and palpable bony irregularity.

Imaging:

- Radiographs: Look for signs of non-union, malalignment, or bone fragmentation around the tibial tubercle. - CT/MRI: Provide detailed visualization of bone and soft tissue structures, aiding in assessing the extent of necrosis and healing status.

Differential Diagnosis:

- Patellar Maltracking: Often presents with similar symptoms but lacks localized bony changes. - Infection Recurrence: Signs of persistent inflammation and systemic symptoms differentiate it from localized osteochondritic changes. - Hardware-Related Complications: Such as loosening or breakage, which can mimic symptoms of osteochondritis 1 3 4.

Management

Initial Management

Surgical Debridement: Removal of necrotic tissue and ensuring adequate vascular supply to the remaining bone.

Osteosynthesis: Secure fixation using AO laces or screws, with preference for AO laces to minimize complications 3 4.

Secondary Management

Revised Surgical Approach: If initial fixation fails, consider alternative approaches like revision osteotomy or additional soft tissue releases.

Biomechanical Support: Use of post-operative braces to stabilize the knee and promote proper alignment and healing.

#### Specific Interventions

Fixation Techniques:

- AO Laces: Preferred for secure fixation and reduced risk of complications. - Screw Fixation: Consider pre-drilling holes for optimal placement.

Post-Operative Care:

- Immobilization: Initial immobilization with a hinged knee brace for TTO group. - Weight-Bearing: Gradual progression to full weight-bearing as tolerated. - Rehabilitation: Early mobilization and ROM exercises to prevent stiffness and promote healing 1 3 4.

Complications

Non-Union and Malunion: Risk factors include inadequate vascular supply, improper fixation, and excessive tension on the osteotomy site.

Infection: Recurrent or persistent infection can complicate healing and necessitate further surgical intervention.

Patellar Malalignment: Resulting from improper osteotomy or fixation, leading to functional impairment.

Referral Triggers: Persistent pain, lack of radiographic union by 4-6 months, or signs of infection warrant referral to a specialist 1 4.

Prognosis & Follow-Up

The prognosis for osteochondritis of the tibial tubercle varies based on the extent of initial damage and the effectiveness of surgical intervention. Prognostic indicators include timely union, absence of infection, and proper alignment post-surgery. Recommended follow-up intervals include:

Immediate Post-Op: Weekly clinical assessments and radiographs at 2-4 weeks.

3-6 Months: Radiographic evaluation to confirm union and assess alignment.

1 Year: Comprehensive clinical and functional assessment using scores like the Knee Society Score (KSS) 1 4.

Special Populations

Elderly Patients: Higher risk of complications due to comorbid conditions; careful surgical planning and meticulous post-operative care are essential.

Patients with Comorbidities: Such as diabetes or peripheral vascular disease, require heightened vigilance for infection and healing issues.

Revision Surgeries for Infection: Increased complexity; timing and technique of TTO are critical to prevent reinfection and ensure proper healing 1 4.

Key Recommendations

Preoperative Planning: Carefully assess knee ROM and surgical approach needs to minimize tibial tubercle manipulation [Evidence: Moderate]

Choice of Surgical Approach: Select TTO over QS based on preoperative ROM (<60° for TTO) to optimize exposure and reduce complications [Evidence: Moderate]

Fixation Technique: Prefer AO laces for tibial tubercle fixation to minimize non-union and malunion risks [Evidence: Moderate]

Post-Operative Immobilization: Use hinged knee braces in TTO cases to ensure proper alignment and stabilization [Evidence: Moderate]

Early Mobilization: Initiate passive and active ROM exercises early to prevent stiffness and promote healing [Evidence: Moderate]

Radiographic Monitoring: Regular follow-up radiographs to assess union and alignment at 2-4 weeks, 3-6 months, and 1 year post-surgery [Evidence: Moderate]

Infection Surveillance: Vigilant monitoring for signs of infection, especially in revision surgeries for PJI [Evidence: Strong]

Special Considerations for Comorbid Patients: Tailor surgical and post-operative care to manage comorbidities effectively [Evidence: Expert opinion]

Revised Surgical Interventions: Consider alternative approaches if initial fixation fails, focusing on biomechanical support and soft tissue management [Evidence: Moderate]

Patient Education: Inform patients about potential complications and the importance of adherence to rehabilitation protocols [Evidence: Expert opinion]

References

1 Di Benedetto P, Buttironi M, Giardini P, Mancuso F, Cainero V, Causero A. Total knee revision arthroplasty: comparison between tibial tubercle osteotomy and quadriceps snip approach. Complication rate. Acta bio-medica : Atenei Parmensis 2020. link 2 Feczko PZ, Pijls BG, van Steijn MJ, van Rhijn LW, Arts JJ, Emans PJ. Tibial component rotation in total knee arthroplasty. BMC musculoskeletal disorders 2016. link 3 Wishart M, Arnold MP, Huegli RW, Amsler F, Friederich NF, Hirschmann MT. Anterolateral approach using tibial tubercle osteotomy for total knee arthroplasty: can we predict failure?. International orthopaedics 2012. link 4 Cance N, Batailler C, Shatrov J, Canetti R, Servien E, Lustig S. Tibial Tubercle Osteotomy in Revision Total Knee Arthroplasty for Periprosthetic Infection: Indications and Outcomes. The Journal of bone and joint surgery. American volume 2023. link 5 Yike D, Tianjun M, Heyong Y, Chongyang X, Hongrui Z, Ai G et al.. Different rotational alignment of tibial component should be selected for varied tibial tubercle locations in total knee arthroplasty. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA 2022. link 6 Kitridis D, Givissis P, Chalidis B. Timing of tibial tubercle osteotomy in two-stage revision of infected total knee arthroplasty does not affect union and reinfection rate. A systematic review. The Knee 2020. link 7 Arkader A, Schur M, Refakis C, Capraro A, Woon R, Choi P. Unicortical Fixation is Sufficient for Surgical Treatment of Tibial Tubercle Avulsion Fractures in Children. Journal of pediatric orthopedics 2019. link 8 Pretell-Mazzini J, Kelly DM, Sawyer JR, Esteban EM, Spence DD, Warner WC et al.. Outcomes and Complications of Tibial Tubercle Fractures in Pediatric Patients: A Systematic Review of the Literature. Journal of pediatric orthopedics 2016. link 9 Segur JM, Vilchez-Cavazos F, Martinez-Pastor JC, Macule F, Suso S, Acosta-Olivo C. Tibial tubercle osteotomy in septic revision total knee arthroplasty. Archives of orthopaedic and trauma surgery 2014. link 10 Davis K, Caldwell P, Wayne J, Jiranek WA. Mechanical comparison of fixation techniques for the tibial tubercle osteotomy. Clinical orthopaedics and related research 2000. link

Osteochondritis of tibial tubercle