Total Knee Arthroplasty in Patients Who Have Skeletal Dysplasia: A Center’s Experience With a Mean 9-Year Follow-Up

Background

Total knee arthroplasty (TKA) in patients who have skeletal dysplasia (SD) is a technically challenging surgery due to deformity, joint contracture, and associated comorbidities. Patients presenting with this condition have traditionally been treated with conservative measures, leading to poor outcomes. The aim of this study was to follow-up on patients who had SD following TKA, specifically with regards to clinical outcomes.

Methods

A total of 31 knees (22 patients) with SD that had undergone TKA in our institution were included in our study. The mean follow-up from index surgery was 110.3 months (range: 20 to 291). The type of dysplasia, implant used, and clinical outcomes with patient-reported outcome measures are presented.

Results

There were 8 patients (36.3%) who had a diagnosis of achondroplasia, followed by multiple epiphyseal dysplasia (31.8%) and spondyloepiphyseal dysplasia (22.7%). There were 14 men and 8 women who had a mean age of 51 years (range: 28 to 73). Custom implants were required in 12 cases (38.7%), custom jigs were used in 6 cases (19.4%), and robotic-assisted surgery was used in 2 (6.5%) TKAs. Hinged prostheses were used in 17 cases (54.8%), posterior-stabilized in 9 (29.0%), and cruciate-retaining implants in 5 (16.1%). There was 1 patient who sustained an intraoperative medial tibial plateau fracture treated with concomitant open reduction and internal fixation. There was 1 revision that occurred during the follow-up period with a patella resurfacing for continued anterior knee pain. Postoperatively, Oxford Knee Scores improved on average by 12.2 points. The 10-year and 20-year all-cause revision-free survival was 96.8, respectively.

Conclusions

Despite the technical challenges and complexity associated with this unique patient cohort, we demonstrated excellent implant survivorship and clinical outcomes post-TKA with mid-term to long-term follow-up of more than 20 years. We recommend preoperative cross-sectional imaging for precise planning and implant templating with multidisciplinary team decision-making. Despite our results, functional outcomes remain inferior to primary arthroplasty within the general population, although we still recommend this treatment modality to appropriately counseled patients.

Level of Evidence

III.