Bilateral heterotopic ossification following Total knee arthroplasty: The role of cultural practices in postoperative complications: A case report

Abstract

Introduction and importance

Heterotopic ossification (HO) is a relatively uncommon yet significant complication following total knee arthroplasty (TKA), with an incidence ranging from 3.8 % to 42 %. While surgical trauma and inflammation are known risk factors, cultural practices such as traditional oil massages may contribute to HO formation, though this remains underexplored.

Case presentation

We present a case of a 65-year-old woman with severe knee osteoarthritis who had uncomplicated bilateral TKA. The patient recovered well after surgery, experiencing notable pain alleviation and improved mobility. Imaging was prompted by minor knee stiffness and soreness at follow-up, which showed bilateral HO, with right side more prominent. Regular post-operative conventional oil massages were shown to be a possible contributing factor. Conservative treatment was started and because of the patient's minimal symptoms and retained functionality, radiotherapy and surgical excision were postponed.

Case discussion

Due to surgical stress and local inflammation, mesenchymal stem cells most likely undergo a transition into osteoblasts in HO after TKA. This instance illustrates how cultural customs, including oil massages, may exacerbate inflammation and lead to HO. Achieving positive results requires early diagnosis, patient education, and a multidisciplinary care strategy comprising physiotherapists, orthopedic surgeons, and rehabilitation specialists.

Conclusion

This case emphasizes the importance of preoperative counseling on traditional practices that may interfere with recovery and early detection of complications such as HO. Conservative management is often sufficient for mild cases, while patient with functional limitation may require invasive interventions. Further research is needed to improve outcomes in TKA patients.

Highlights

• •Bilateral heterotopic ossification (HO) developed after uncomplicated total knee arthroplasty (TKA), with traditional oil massages identified as a potential contributing factor.
• •Conservative management—cessation of oil massages, NSAIDs, and passive range of motion exercises—effectively controlled HO without invasive interventions.
• •The case highlights the importance of cultural competence in preoperative counseling to address traditional practices that may influence postoperative outcomes.
• •Early detection of risk factors and implementation of personalized, multidisciplinary care are vital for managing HO and optimizing recovery in TKA patients.

1. Introduction

Total knee arthroplasty (TKA) is well recognized as a viable treatment modality for patients with advanced knee osteoarthritis (OA) and has been shown to decrease pain and improve mobility significantly [2]. However, the procedure involves some complications such as infection, instability, and implant failure. One of these is heterotopic ossification (HO), a complication less frequently discussed. Knee HO occurs in 3.8–42 % of post-TKA patients, however bilateral HO is reported rarely. [1,3] HO involves ectopic bone formation in soft tissue, potentially limiting joint mobility and functional recovery [4].

There is an incomplete understanding of the pathogenesis of HO and multiple factors have been identified as contributors. Localized inflammation and irritation can occur after surgical trauma during TKA, a process that can transform fibroblasts into osteoblasts and facilitate ectopic bone formation. [5] Also, local irritants like traditional oil massages may worsen this process as added inflammation at the surgical site [6]. Studies suggest that inflammation has a critical role in the differentiation of mesenchymal progenitor cells to osteogenic lineages and that inflammatory mediators may be involved with the development of HO [7].

A case study of a patient who had an otherwise uneventful bilateral TKA, presenting with bilateral HO illustrates the importance of recognizing the potential impact of cultural practices, such as traditional oil massages, on postoperative outcomes. Early detection of HO is imperative for the successful management of HO and is important for determining the overall recovery trajectory of patients undergoing TKA. The patient's surgery and cultural background should be considered when planning their treatment. Management strategies should be personalized to fit their specific needs and context [8]. Since TKA is a positive treatment option for severe knee OA, HO being a possible TKA complication requires a deeper understanding of agents involved in HO formation and its possible risk factors. Proper care, including attention to these aspects, can help lower the risk of HO and improve patients' recovery outcomes.

The work has been reported in line with the SCARE criteria [9].

2. Case presentation

2.1. Patient history

A 65-year-old female presented with a 15-year history of progressively worsening bilateral knee pain and functional limitations. She reported chronic stiffness and difficulty performing activities such as walking and climbing stairs. Radiographic evaluation revealed bilateral knee osteoarthritis with Kellgren and Lawrence grade IV classification.

2.2. Medical history and lifestyle

She mentioned having had a myomectomy surgery twenty years prior with no documents available. Following the gradual onset of bilateral knee pain; patient started having some difficulties in performing her activities of daily living like walking stairs and squatting, although activity modification and regular physiotherapy were used. However, her symptoms were still persistent and worsening with time. The patient had no history of trauma and other chronic illnesses, allergies to medication, or prior injections into the affected joint.

2.3. Surgical and postoperative details

The patient underwent single stage bilateral TKA under torniquet using standard medial parapatellar approach by a well experienced arthroplasty surgeon with more than twenty years of experience in the field of arthroplasty in tertiary center (Kist Medicsl College And Teaching Hospital) within the standard time frame of around 45 min for each knee, 9 months before the current presentation. The surgery was performed without intraoperative complications and posterior stabilizing cruciate substituting non-press fit cemented implant was used. Postoperatively, she followed a standardized rehabilitation program, focusing on range of motion (ROM) exercises and strengthening periarticular muscles.

3. Clinical course

3.1. Early postoperative recovery

In the first two months post-surgery, the patient reported significant pain relief and functional improvement. By the third month, she achieved a ROM of 0–90° in both knees (Fig. 3, Fig. 4, Fig. 5, Fig. 6), walked independently with minimal discomfort, and adhered diligently to physiotherapy. Her varus deformity was corrected and her knees attained a normal bilateral Q angle of 15 deg. (Fig. 7).

Fig. 3.

Clinical photo with patient in supine position showing felxion ($\sim$90${}^{°}$) of right knee joint.

Fig. 4.

Clinical photo with patient in supine position showing felxion ($>$90${}^{°}$) of left knee joint.

Fig. 5.

Clinical photo with patient in supine position showing extension lag of 8${}^{°}$ of left knee joint.

Fig. 6.

Clinical photo with patient in supine position showing extension lag of 10${}^{°}$ of right knee joint.

Fig. 7.

Clinical photo with patient in standing position showing healed scar of TKA incison over bilateral knee joint.

3.2. Development of symptoms and diagnosis

At the three-month follow-up, the patient reported mild bilateral knee discomfort, with occasional stiffness more pronounced in the right knee. X-ray imaging revealed heterotopic ossification around anterolateral aspect of both knees (Fig. 1, Fig. 2), particularly on the right side. Despite this finding, the patient-maintained independence in daily activities and reported minimal functional impairment.

Fig. 1.

Plain radiograph of right and left knee (Antero-posterior view). The white arrow shows heterotopic ossifications on lateral aspect.

Fig. 2.

Plain radiograph of right and left knee (Ltaeral view). The white arrow shows heterotopic ossifications on anterior aspect.

We investigated for the possible risk factor like rheumatoid arthritis, ankylosing spondylitis, pre-operative knee deformity, obesity, prolonged operative time and extensive soft tissue handling. Pre-operative knee deformity and obesity are the only risk factor which was present in our case.

Upon further inquiry, the patient disclosed continuing regular oil massages on both knees, a traditional practice she had followed preoperatively. This might be one of the potential contributing factors to the development of HO.

Routine baseline investigation (CBC, ESR, CRP) along with ALP was performed. ALP came out to be 245 mg/dl (slightly raised) and other baseline investigation were within normal limit.

3.3. Follow-up and monitoring

Initial Management: A multidisciplinary team approach was employed to address the HO. Key steps included:

• 1.Cessation of Oil Massages: the patient was advised to stop the practice of oil massaging to minimize local irritation and further HO progression.
• 2.Pain Management: To deal with discomfort and inflammation, a low-dose NSAID (Indomethacin 75 g once a day) schedule was given after confirming normal level of creatinine.
• 3.Physiotherapy: The rehabilitation program was continued which include knee ROM exercises, ankle pump, periarticular muscles stretching and strengthening exercises.

3.4. Avoidance of invasive interventions

Radiotherapy, while effective in preventing HO progression, was deferred after weighing the potential side effects (e.g. fibrosis, malignancy) associated with radiotherapy due to the patient's mild symptoms and preserved functionality [3]. Surgical excision of the ossified tissue was also not pursued due to the absence of significant pain, no mobility restrictions and radiographs suggestive of immaturity of HO.

3.5. Continued monitoring

The patient achieved significant pain relief, with a preoperative visual analog scale (VAS) score of 8/10, reduced to 2/10 at the three-month follow-up. Range of motion improved from a preoperative 0–60° to 0–90° postoperatively. Despite the development of HO, the patient retained functional independence with minimal symptoms, as evidenced by a HO classification of IB for the right knee and IA for the left knee. The patient was scheduled for further regular follow-ups to monitor the progression of HO through clinical assessment and imaging. The focus remained on maintaining joint function and preventing further complications. Her knee range of motion improved gradually and pain alleviated with conservative measures.

4. Discussion

HO following TKA is still a relatively unknown complication, particularly when compared to its incidence in total hip replacement. HO can be said to occur through a process which involves conversion of mesenchymal stem cells into osteoblasts in response to factors such as surgical trauma, mechanical irritation or systematic inflammation [10]. Modifiable surgical risk factors include the extent of soft tissue dissection, bone trauma, residual bone debris (such as reaming, marrow, or dust left in the surgical area), the presence of a hematoma. Prolonged operative time and non-cemented prosthesis, ankylosing spondylitis, rheumatoid arthritis, obesity, pre-operative knee deformity are other common risk factor. (11) However, the exact functions of external practices like oil massages have not been described much; mechanical stimulation is assumed to stimulate inflammations and ossification [3].

We encountered HO on both sides; which is rarely reported, in this patient at three-months follow-up imaging after uneventful surgery and strict postoperative rehabilitation. The lack of more extensive symptoms and relatively low degree of activity limitation suggested a mild-moderate disease, for which conservative approach to treatment was justified. It was therefore probably precipitated by the patient's cultural practice of oil massage, and underlines the importance of preoperative education on preoperative traditional practices and their effect on post operative results.

The management of HO is based on the extent of pathology, symptoms, as well as the functional consequences of the condition as shown in Fig. 9. Initially conservative management like intensive physiotherapy during the disease's maturation phase is considered to minimize stiffness, but its effectiveness is unclear. NSAIDs or radiotherapy have no role in treating existing HO but only considered as prophylaxis to prevent recurrence. NSAIDs reduce HO incidence by 50–66 % but can cause gastrointestinal issues, renal impairment, or bleeding risks. Indomethacin is commonly used and more of evidence based but may affect bone healing in fractures or uncemented implants. The efficacy of indomethacin in preventing HO has been demonstrated in many studies. This treatment is attractive because of its simplicity and low cost. Radiotherapy as a single dose of 7–8 Gy within 4 h pre-op or 72 h post-op is also considered effective and convenient. Radiation-induced complications (e.g., tumors or testicular damage) are rare with doses <30 Gy. In our case it was believed to be not necessarily due to the patient's relatively mild symptoms as well as sufficiently acceptable functional status.

Fig. 9.

Algorithm for management of Heterotrophic ossification. The chart outlines an algorithm for managing Heterotopic Ossification (HO). It begins with assessing whether the HO is symptomatic or asymptomatic. For asymptomatic cases, conservative management and continuous monitoring are recommended. For symptomatic cases, intensive physiotherapy and pain management using NSAIDs are advised, along with monitoring for symptom progression and HO maturation. If symptoms persist, the focus shifts to determining the maturation of HO and continuing conservative measures. In cases where symptoms are severe or persistent, surgical excision followed by radiotherapy is considered.

In some cases, surgical excision improves mobility, as shown in studies of post-total hip replacement (THR) patients. It is typically delayed until ossification matures (12–24 weeks). The surgical approach prioritizes safe exposure, protection of neurovascular structures and precise dissection of ossified tissue. Surgical excision that was a last resort for conditions that produce severe pain and impaired mobility so was not considered in our case [11].

Management of the HO patient depends upon the clinical symptoms. For symptomatic patient treatment may be conservative or operative, which depends upon pain, joint stiffness and limitation in range of motion as shown in Fig. 8.

Fig. 8.

Treatment options for treatment of HO.

This chart outlines the treatment options for heterotopic ossification (HO) following total knee arthroplasty (TKA). It includes conservative management with physical therapy, analgesics, and radiation therapy and surgical intervention for symptomatic cases.

In analogy to the Brooker system for classification of heterotopic bone formation in total hip arthroplasty, Furia et al. developed a classification system for total knee arthroplasty. Two grades of heterotopic ossification were defined, based on the size of the largest visible bone segment:

Grade A ≤ 5 cm and Grade B > 5 cm, with class I heterotopic ossification consisting of is lands of bone localized to the suprapatellar soft tissue areas of the distal femur, and class II heterotopic formation, organized into areas of ossification continuous with the anterior surface of the distal femur. (11).

The case presented here could then be classified as IB for right and IA for left side.

This case also brings the fact into light of importance of the multimodal conventional and surgical management of HO involving orthopedic surgeon, physiotherapist, and rehabilitation specialist. Imaging and clinical assessment was carried out in order to avoid invasive procedure while at the same time monitoring the functional outcomes of the patient.

The implications derived from this case study conform to suggestions from scientific literature that HO patients should receive tailored treatment plans. It also points to a topic for future study—studying the relationship between adhering to cultural practices and developing complications in TKA patients.

5. Conclusion

Heterotopic ossification is a comparatively rare but sometime troublesome side effect that can affect outcome after TKA. This case shows that even traditional practice can cause issue of HO. Early diagnosis, and personalized multidisciplinary intervention are the keys in treating HO.

In mild cases, conservative management, such as discontinuing traditional practices like oil massage, administering non-steroidal anti-inflammatory drugs, and physiotherapy, is usually adequate, as in this patient. However, for severe forms, measures such as radiotherapy or surgical excision remain within reach, but the choice should be based upon clinical condition and individual preference.

In conclusion, this case brings out a need of cultural competence in dealing with patients especially where patients are reluctant to undergo multiple surgeries. More studies should be conducted in order to dissect the risk factors, early identification and efficient treatment intervention to improve overall results for the potential difficult complication of HO in patients undergoing TKA.

Consent

Informed consent was obtained from the patient to publish this case report, including any accompanying images or data.

Ethical approval

Ethical approval for this case report is not required as it's just a case report.

Guarantor

Dr. Gaurav Bir Bajracharya.

Sources of funding

This research received no specific grant from public, commercial, or not-for-profit funding agencies.

Registration of research studies

Not a first in man study.

Author contribution

Dr. Gaurav Bir Bajracharya (A): Conceptualization, Methodology, Data and information collection, Writing original draft, Review and editing.

Prof. Dr. Dirgha Raj RC: Writing – Review and editing.

Prof. Dr. Shriraj Shrestha: Writing – Review and editing.

Dr. Pramod Bhandari: Writing – Review and editing.

Dr. Anup Thapa: Writing – Review and editing.

Declaration of competing interest

There are no conflicts of interest regarding the publication of this case report.