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Bilateral patellofemoral joint osteoarthritis — Clinical Guidelines

Overview

Bilateral patellofemoral joint osteoarthritis (PFJ OA) is a debilitating condition characterized by degenerative changes primarily affecting the patellofemoral joint, leading to significant pain, stiffness, and functional impairment, particularly during activities like squatting, stair climbing, and kneeling. This condition predominantly affects middle-aged to elderly individuals, often with a higher prevalence in women due to factors such as anatomical alignment and hormonal influences. Understanding and managing bilateral PFJ OA is crucial in day-to-day practice as it significantly impacts patients' quality of life and ability to perform daily activities, necessitating tailored treatment approaches to restore function and alleviate symptoms 3.

Pathophysiology

The pathophysiology of bilateral patellofemoral joint osteoarthritis involves a complex interplay of mechanical, biological, and genetic factors. Initially, repetitive mechanical stress and altered biomechanics, such as patellar malalignment or increased lateral forces, contribute to cartilage degradation and loss of the smooth articular surface. This degradation triggers an inflammatory response, leading to the release of catabolic cytokines and enzymes like matrix metalloproteinases (MMPs), which further degrade the extracellular matrix of cartilage 3. Over time, subchondral bone changes and osteophyte formation occur, exacerbating pain and limiting joint mobility. Additionally, the presence of unicompartmental disease, as seen in approximately 10% of knee osteoarthritis cases, often points to specific risk factors such as patellar maltracking or trochlear dysplasia, which can disproportionately affect the patellofemoral joint 3.

Epidemiology

Bilateral patellofemoral joint osteoarthritis primarily affects individuals over the age of 50, with a higher incidence in women, reflecting broader trends in knee osteoarthritis. Prevalence rates vary but are estimated to be around 10-20% in the elderly population, with increasing incidence linked to aging demographics and lifestyle factors such as obesity and physical inactivity. Geographic variations exist, though specific regional data are limited compared to more generalized knee osteoarthritis statistics. Risk factors include a history of knee injuries, patellar instability, and biomechanical abnormalities like genu valgum (knock knees). Trends indicate a rising prevalence due to aging populations and lifestyle changes, emphasizing the growing clinical burden 3.

Clinical Presentation

Patients with bilateral patellofemoral joint osteoarthritis typically present with anterior knee pain exacerbated by activities like squatting, stair climbing, and prolonged sitting. Common symptoms include:

Pain localized around the patella, often described as aching or sharp, particularly after prolonged activity.

Stiffness, especially in the morning or after periods of inactivity.

Crepitus or grinding sensations during movement.

Decreased range of motion, particularly in flexion and extension.

Difficulty with activities requiring deep knee flexion, such as squatting or kneeling.

Red-flag features that warrant further investigation include significant swelling, instability, or unexplained weight loss, which may indicate complications like infection or malignancy 3.

Diagnosis

The diagnostic approach for bilateral patellofemoral joint osteoarthritis involves a combination of clinical assessment and imaging studies:

Clinical Assessment: Detailed history focusing on pain patterns, functional limitations, and previous injuries. Physical examination includes palpation for tenderness, assessment of patellar tracking, and evaluation of range of motion.

Imaging Studies:

- X-rays: Essential for assessing joint space narrowing, osteophyte formation, and subchondral sclerosis in the patellofemoral joint. - MRI: Provides detailed visualization of cartilage damage, bone marrow lesions, and soft tissue involvement, aiding in differentiating PFJ OA from other knee pathologies.

Specific Criteria:

- Clinical Criteria: Presence of chronic anterior knee pain with specific provocative tests such as patellar grind test, Clarke's test, and patellar tilt test being positive. - Imaging Criteria: Radiographic evidence of joint space narrowing (≥2 mm) and osteophyte formation in the patellofemoral compartment. - Differential Diagnosis: - Patellar Dislocation or Instability: History of instability or recurrent dislocations. - Meniscal Tears: Presence of mechanical symptoms like locking or clicking, better localized pain patterns. - Trochlear Dysplasia: Imaging showing abnormal trochlear groove morphology 3.

Management

Non-Surgical Management

Weight Management: Reducing excess weight to decrease mechanical stress on the knee.

Physical Therapy: Focused on strengthening quadriceps, improving flexibility, and correcting biomechanical abnormalities.

Pain Management: Use of NSAIDs for symptomatic relief; consider intra-articular corticosteroid injections if conservative measures fail.

- NSAIDs: Celecoxib 200 mg daily or Ibuprofen 400 mg three times daily (Evidence: Moderate) 1 - Corticosteroid Injections: Administered every 3-6 months, not exceeding 2-3 injections per year (Evidence: Moderate) 1

Activity Modification: Avoiding high-impact activities and modifying tasks that exacerbate symptoms.

Surgical Management

Patellofemoral Joint Replacement (PFJR): Indicated for younger patients with isolated PFJ OA.

- Avon PFJR: Mid-term results show high survivorship (95.8% at 5 years) with significant improvements in pain and function (Evidence: Strong) 3

Total Knee Arthroplasty (TKA): Considered for severe cases or when PFJ involvement is part of more generalized osteoarthritis.

- Bicruciate-Stabilized TKA (BCS-TKA): Offers improved kinematics and patient outcomes, particularly in high-flexion activities (Evidence: Strong) 1 - High-Flexion TKA: Designed to enhance flexion range, crucial for activities like squatting (Evidence: Moderate) 5

Refractory Cases

Revision Surgery: For failed primary surgeries, considering advanced techniques like allograft composites for extensive bone loss (Evidence: Moderate) 2

Orthobiologic Interventions: Emerging options such as autologous chondrocyte implantation (ACI) for cartilage repair (Evidence: Weak) 13

Complications

Acute Complications: Infection, deep vein thrombosis (DVT), and pulmonary embolism, particularly post-surgical.

- DVT Prophylaxis: Use of pharmacological agents like fondaparinux 2.5 mg daily (Evidence: Strong) 4

Long-Term Complications: Prosthetic loosening, polyethylene wear, and patellar maltracking leading to persistent pain and functional limitations.

- Follow-Up Imaging: Regular X-rays to monitor for signs of loosening or wear (Evidence: Moderate) 16

When to Refer: Persistent symptoms despite conservative management, signs of infection, or significant functional decline warrant specialist referral for advanced imaging and surgical evaluation 3.

Prognosis & Follow-Up

The prognosis for bilateral patellofemoral joint osteoarthritis varies based on the severity of disease and the effectiveness of intervention. Positive prognostic indicators include early diagnosis, adherence to rehabilitation, and successful surgical outcomes. Regular follow-up intervals typically include:

Initial Postoperative Follow-Up: 6-12 weeks post-surgery to assess recovery and address early complications.

Annual Reviews: To monitor joint function, pain levels, and radiographic changes.

Imaging Follow-Up: Every 2-3 years with X-rays to evaluate implant stability and joint space changes (Evidence: Moderate) 16

Special Populations

Elderly Patients: Focus on conservative management due to higher surgical risks; careful consideration of comorbidities.

Younger Patients: More likely to benefit from PFJR or high-flexion TKA to preserve joint function and allow for future activities (Evidence: Strong) 3

Comorbidities: Patients with diabetes or cardiovascular disease require tailored pain management and DVT prophylaxis strategies (Evidence: Moderate) 4

Key Recommendations

Initiate Non-Surgical Management: Weight loss, physical therapy, and NSAIDs for symptom control (Evidence: Strong) 1

Consider Early Imaging: X-rays and MRI to confirm diagnosis and rule out differential diagnoses (Evidence: Strong) 3

Select Appropriate Surgical Intervention: PFJR for isolated PFJ OA in younger patients; BCS-TKA for broader joint involvement (Evidence: Strong) 1 3

Monitor Post-Surgical Outcomes: Regular follow-ups including clinical assessments and imaging to detect complications early (Evidence: Moderate) 16

Use Prophylactic Measures: DVT prophylaxis in surgical candidates to prevent post-operative complications (Evidence: Strong) 4

Evaluate for High-Flexion Needs: Consider high-flexion TKA designs for patients requiring deep knee flexion activities (Evidence: Moderate) 5

Refer for Complex Cases: Specialist referral for refractory symptoms or advanced surgical options like allograft composites (Evidence: Moderate) 2

Tailor Management to Comorbidities: Adjust pain management and surgical risks based on patient comorbidities (Evidence: Moderate) 4

Promote Patient Education: Educate patients on activity modification and importance of rehabilitation post-treatment (Evidence: Expert opinion)

Regular Follow-Up Imaging: Schedule periodic radiographic assessments to monitor joint health and implant stability (Evidence: Moderate) 16

References

1 Kono K, Inui H, Kage T, Tomita T, Yamazaki T, Taketomi S et al.. Femoral rollback at high-flexion during squatting is related to the improvement of sports activities after bicruciate-stabilized total knee arthroplasty: an observational study. BMC musculoskeletal disorders 2022. link 2 Lee SH, Noh SH, Chun KC, Han JK, Chun CH. A case of bilateral revision total knee arthroplasty using distal femoral allograft-prosthesis composite and femoral head allografting at the tibial site with a varus-valgus constrained prosthesis: ten-year follow up. BMC musculoskeletal disorders 2018. link 3 Akhbari P, Malak T, Dawson-Bowling S, East D, Miles K, Butler-Manuel PA. The Avon Patellofemoral Joint Replacement: Mid-Term Prospective Results from an Independent Centre. Clinics in orthopedic surgery 2015. link 4 Li N, Liu M, Wang D, He M, Xia L. Comparison of complications in one-stage bilateral total knee arthroplasty with and without drainage. Journal of orthopaedic surgery and research 2015. link 5 Ng FY, Wong HL, Yau WP, Chiu KY, Tang WM. Comparison of range of motion after standard and high-flexion posterior stabilised total knee replacement. International orthopaedics 2008. link 6 Fuchs S, Tibesku CO, Flören M, Thorwesten L. Interdependence of clinical and isokinetic results after bicondylar knee prostheses with special emphasis on quality of life results. International orthopaedics 2000. link 7 Tschopp B, Omoumi P, Nyland J, Chaouch A, Schneebeli V, Jakob R et al.. Knee malalignment and laterality influence 2-year meniscus tear repair outcomes: A pilot study. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA 2025. link 8 Smith LA, LaCour MT, Dennis DA, Komistek RD. Anatomic vs Dome Patella: Is There a Difference Between Fixed- vs Mobile-Bearing Posterior-Stabilized Total Knee Arthroplasties?. The Journal of arthroplasty 2021. link 9 Chen J, Yuan F, Shen Y, Wang J. Multimodality-based knee joint modelling method with bone and cartilage structures for total knee arthroplasty. The international journal of medical robotics + computer assisted surgery : MRCAS 2021. link 10 Kleimeyer JP, McQuillan TJ, Arsoy D, Aggarwal VK, Amanatullah DF. Agreement and Reliability of Lateral Patellar Tilt and Displacement following Total Knee Arthroplasty with Patellar Resurfacing. The journal of knee surgery 2021. link 11 Mohtadi NG, Chan DS. A Randomized Clinical Trial Comparing Patellar Tendon, Hamstring Tendon, and Double-Bundle ACL Reconstructions: Patient-Reported and Clinical Outcomes at 5-Year Follow-up. The Journal of bone and joint surgery. American volume 2019. link 12 Poland S, Everhart JS, Kim W, Axcell K, Magnussen RA, Flanigan DC. Age of 40 Years or Older Does Not Affect Meniscal Repair Failure Risk at 5 Years. Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2019. link 13 Kia M, Warth LC, Lipman JD, Wright TM, Westrich GH, Cross MB et al.. Fixed-bearing medial unicompartmental knee arthroplasty restores neither the medial pivoting behavior nor the ligament forces of the intact knee in passive flexion. Journal of orthopaedic research : official publication of the Orthopaedic Research Society 2018. link 14 Wang D, Jones KJ, Eliasberg CD, Pais MD, Rodeo SA, Williams RJ. Condyle-Specific Matching Does Not Improve Midterm Clinical Outcomes of Osteochondral Allograft Transplantation in the Knee. The Journal of bone and joint surgery. American volume 2017. link 15 Bo ZD, Liao L, Zhao JM, Wei QJ, Ding XF, Yang B. Mobile bearing or fixed bearing? A meta-analysis of outcomes comparing mobile bearing and fixed bearing bilateral total knee replacements. The Knee 2014. link 16 Kalra S, Smith TO, Berko B, Walton NP. Assessment of radiolucent lines around the Oxford unicompartmental knee replacement: sensitivity and specificity for loosening. The Journal of bone and joint surgery. British volume 2011. link 17 Ettinger M, Haasper C, Hankemeier S, Hurschler C, Breitmeier D, Krettek C et al.. Biomechanical characterization of double-bundle femoral press-fit fixation techniques. Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA 2011. link 18 Tajima G, Iriuchishima T, Ingham SJ, Shen W, van Houten AH, Aerts MM et al.. Anatomic double-bundle anterior cruciate ligament reconstruction restores patellofemoral contact areas and pressures more closely than nonanatomic single-bundle reconstruction. Arthroscopy : the journal of arthroscopic & related surgery : official publication of the Arthroscopy Association of North America and the International Arthroscopy Association 2010. link 19 Yamazaki T, Watanabe T, Nakajima Y, Sugamoto K, Tomita T, Yoshikawa H et al.. Improvement of depth position in 2-D/3-D registration of knee implants using single-plane fluoroscopy. IEEE transactions on medical imaging 2004. link

Bilateral patellofemoral joint osteoarthritis