Total knee arthroplasty in patients with multiple hereditary exostoses

Total Knee Replacement for Varus Deformity in Osteoarthritis of Knee with Multiple Hereditary Exostoses - A Rare Case Report

Introduction

Multiple hereditary exostosis (MHE) is a genetic condition inherited in an autosomal dominant manner, resulting from point mutations in exostosin genes. Knee deformities, such as genu valgus, are common in individuals with MHE, often localized to the proximal tibial metaphysis, and occasionally involving the femur. Osteochondromas at the knee can lead to an oblique joint line orientation, contributing to earlier onset arthritis. Increased angulation may also lead to lateral patella subluxation and patellofemoral complaints, necessitating earlier interventions compared to the general population. While total knee arthroplasty (TKA) for osteoarthritis in MHE with varus deformity is rarely reported in the literature, we present a case of a high body mass index (BMI) female with MHE and varus knee deformity successfully treated with TKA using a standard posterior stabilized implant, without additional constraints or extensive releases.

Case Report

A 54-year-old Indian woman, homemaker presented to the clinic due to progressive left knee pain and varus deformity. Her BMI was 40. With no significant family history . The surgery was performed using a tourniquet. Using standard instrumentation for conventional TKA . The angle of bone resection was determined preoperatively through manual radiographic templating. The sizing of femoral component was done precariously since the anatomy of distal femur was altered with no prominent anterolateral ridge and an anterior referencing system was done to avoid notching. Tibial rotational alignment was based on anatomic landmarks. Patellofemoral tracking was excellent and did not require lateral retinacular release.

Conclusion

Careful attention to technical aspects, selection of implants and the unique anatomy involved, is crucial in planning this procedure. Ensuring proper balance of the ligaments tented by the osteochondromas and meticulous sizing of the femur are essential for favorable functional outcomes in such cases.

Planned Realignment Osteotomies Ahead of Knee Arthroplasty for Pronounced Joint Malalignment: A Case Report in Hereditary Multiple Exostoses Disease

Various approaches have been reported to achieve correctly aligned total knee arthroplasty in cases of knee arthritis with pronounced extra-articular bone malalignment. Revision instrumentation and implants have enabled bone correction coincident with knee arthroplasty in notable tibial and/or femoral deviation, however increasing operative complexity and inherent risks. In the presented patient with hereditary multiple exostoses disease and progressing knee arthritis for extra-articular malalignment, elected treatment strategy was to primarily correct joint plane deformity through femoral and tibial osteotomies, ahead of and preparing for later knee arthroplasty. Staged osteotomies prior to total knee arthroplasty are effective for managing severe extra-articular malalignment, improving surgical outcome and prosthetic longevity.

Total Knee Arthroplasty With Patient-Specific Instrumentation to Correct Severe Valgus Deformity in a Patient With Hereditary Multiple Exostoses

Patients with hereditary multiple exostosis develop several benign osseocartilaginous bulge lesions throughout the body. A 62-year-old woman presented for evaluation of worsening left knee valgus deformity, and left knee pain. She had been diagnosed with hereditary multiple exostosis at the age of 12 years. Radiographic evaluation of the left knee revealed exostoses that caused continuous bulges from cortical bone at the metaphyseal regions of the femur and tibia as well as extra-articular deformity. We used patient-specific instrumentation to indicate the direction of the stem into curved metaphyseal bone regions and then corrected the patient’s left knee deformity by performing total knee arthroplasty with titanium-constrained prostheses. Soft tissue release was performed with only complete iliotibial band release at a minimum, and stability was obtained.

Arthroscopic anterior cruciate ligament reconstruction in a patient with multiple hereditary exostoses

Background Multiple hereditary exostoses (MHE) also known as Multiple Osteochondromas is a rare benign bone tumour disease, characterized by multiple osteocartilaginous masses. The knee is one of the most affected sites. Anterior cruciate ligament (ACL) surgery is the most common and generally most successful surgical knee procedure; however, the association between MHE and ACL reconstruction is very rare and may represent a challenging procedure because of the anatomical anomaly related to presence of multiple masses around the knee. Here, we present a case report of ACL reconstruction in a patient affected by multiple exostoses. Case report The patient was a 30-year-old woman affected by MHE, with an ACL tear arising after knee trauma. As the patient complained of pain, swelling and the knee "giving way", she successfully underwent arthroscopic-assisted ACL reconstruction using quadrupled hamstring tendon grafts, with femoral suspension and double tibial fixations. Conclusion Symptomatic ACL tears in a patient affected by MHE should be considered for arthroscopic reconstruction, which requires that particular attention be paid to tendons harvesting, tunnel placement and the choice of graft fixation system, given the presence of multiple masses around the knee.

Accelerometer-Based, Computer-Navigated Total Knee Arthroplasty to Correct a Complex Deformity in a Patient With Multiple Hereditary Exostoses

Background

Accelerometer-based computer-assisted navigation systems (ABCANSs) have been shown to improve alignment accuracy in total knee arthroplasty (TKA) and are effective in treating complex extra-articular deformity. We present an ABCANS-assisted TKA performed in a 68-year-old male with end-stage arthritis of the right knee, in the setting of a severe valgus deformity secondary to multiple hereditary exostoses.

Methods

The KneeAlign 2 system (OrthAlign, Inc.; Aliso Viejo, CA) was used to perform the TKA in this clinical scenario, given its functionality, which allows angular correction to be tailored to a given deformity, and its reported accuracy in performance of bony resection in TKA. The patient was prospectively followed up for one year postoperatively. Radiographs, PROMs, and patient satisfaction were reported.

Results

After the ABCANS-assisted TKA, the patient's alignment was improved from 25° to 4° of valgus. His final range of motion was 0-135° without an instability. In addition, the patient reported excellent scores on multiple joint-specific outcome measures, including the Knee Injury and Osteoarthritis Outcome Score for Joint Replacement, the Forgotten Joint Score, and the Oxford Knee Score.

Conclusion

This case report illustrates the rationale, technique, and the excellent clinical outcomes achieved in a complex patient with extra-articular deformity using an ABCANS-assisted TKA.