Corrigendum to 'Long-Term Results of Delta Ceramic-On-Ceramic Total Hip Arthroplasty' [Arthroplasty Today Volume 13, February 2022, Pages 130-135].

[This corrects the article DOI: 10.1016/j.artd.2021.11.006.].

Long-Term Results of Delta Ceramic-on-Ceramic Total Hip Arthroplasty.

BACKGROUND: Ceramic-on-ceramic (COC) bearings in total hip arthroplasty (THA) have long been considered the coupling with the lowest overall wear. However, concerns about complications such as ceramic breakage and noise, combined with the improved performance of polyethylene, have limited its use in the United States. This postapproval follow-up reports long-term (10 years) results of Delta COC in THA patients primarily enrolled in an Investigational Device Exemption study. METHODS: Patients received Delta COC THA in a prospective multicenter study with either 28-mm (N = 105 hips in 104 patients) or 36-mm (N = 81) articulations. Annual clinical and radiographic evaluations were performed for years 5 to 10, and study patients were asked about hip noises and reproducibility. RESULTS: There have been 4 additional reports of noise in 4 patients (COC 28, n = 3; COC 36, n = 1). The cumulative incidence rate for squeaking or noise at 10 years is 5.9% for COC 28 and 13.5% for COC 36. There have been 2 additional reports of dislocation in 2 patients (COC 28, n = 1; COC 36, n = 1). The cumulative incidence rate for dislocation at 10 years is 3.7% for COC 28 and 3.5% for COC 36. At 10 years, there were greater than 40 hips available for follow-up. At mean 10-year follow-up, there were a total of 3 ceramic liner fractures, but none since the previous report. There were no revisions in the 28-mm cohort, and 2 revisions in the 36-mm cohort (1 for recurrent dislocation and 1 for pain and noise). Overall Kaplan-Meier survivorship was 95.96% at 10.5 years (28 mm: 97.68% at 10.2 years; 36 mm: 94.11% at 10.4 years.). CONCLUSIONS: At 10-year follow-up, we report excellent results in regard to survivorship, with one patient revised for pain with associated squeaking.

Midterm Results of Delta Ceramic-on-Ceramic Total Hip Arthroplasty.

This study reports mid-term results of Delta ceramic on ceramic (COC) in total hip arthroplasty (THA). Subjects received Delta COC THA in a prospective multi-center study with either 28 mm (n=177) or 36 mm (n=168) articulations. Annual clinical and radiographic evaluations were performed, and patients were asked about hip noises. At mean 5.3-year follow-up there were 3 (0.9%) post-operative liner fractures. Nine revisions were performed (2 liner fracture, 4 stem loosening, 3 deep infection). Kaplan-Meier survivorship at 6 years was 96.9% (94.0-98.4). Twenty-six (7.5%) subjects reported squeaking, of whom none were revised. One (0.3%) subject could reproduce a sound in clinic. More patients reported squeaking with a 36 mm bearing (28 mm: 7/177, 36 mm: 19/168, P=0.013).

Implant choices, technique, and results in revision acetabular surgery: a review.

Acetabular reconstruction in revision total hip arthroplasty can successfully be achieved with hemispherical components featuring a porous or roughened ingrowth surface and options for placement of multiple screws. Most defects can be reconstructed with large hemispherical or "jumbo" cups. Achieving component stability and sufficient contact area on adequate host bone is mandatory. Defects with greater bony loss or compromised columns require either the use of modular augments combined with a hemispherical shell, reconstruction cages, structural allografts, or custom triflange acetabular components. This paper will detail the necessary pre-operative evaluation, the intra-operative details, and the reported results of these acetabular revisions.

Surgical technique: a cup-in-cup technique to restore offset in severe protrusio acetabular defects.

BACKGROUND: Severe medial and/or superior defects encountered in revision THA are currently managed with jumbo (≥ 66 mm) acetabular components and modular augments, with reconstruction cages, or with the cup-cage technique. Preoperative planning can indicate when these techniques may not restore vertical and horizontal offset. Failure to restore offset can lead to impingement, leg length inequality, abductor weakness, and dislocation. SURGICAL TECHNIQUE: We developed a "cup-in-cup" technique in which a porous tantalum acetabular shell was impacted into supportive medial host bone. A second tantalum shell was then cemented in, and this shell's diameter could be selected based on preoperative planning to achieve restoration of horizontal and vertical offset. PATIENTS AND METHODS: We implanted porous tantalum hemispheric shells in seven patients undergoing eight revision THAs. The average age was 73 years at the time of the procedure. Preoperative defects per the classification of Paprosky et al. were three IIC, four IIIA, and one IIIB. All patients were followed clinically and radiographically for a minimum of 12 months (average, 28 months; range, 12-50 months). RESULTS: Abductor strength was either improved by one grade (four hips) or unchanged (four hips). Horizontal offset was increased an average of 10.5 mm (range, 8-16 mm), and vertical offset improved by an average of 18.4 mm (range, 10-29 mm). There was no evidence of loosening or migration at the time of final followup. CONCLUSIONS: At short-term followup, the early experience cautiously supports the use of this construct. Long-term followup and a larger patient experience will be required to determine the durability of this novel technique. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

In vivo assessment of total hip femoral head separation from the acetabular cup during 4 common daily activities.

In vivo video fluoroscopies of well-functioning total hip arthroplasties (THA) have shown that femoral head separation from the medial articular bearing surface occurs during gait. Other activities may cause the same phenomenon. We examined this while patients performed the following 4 activities of daily living: pivoting to each side in stance, shoe tying, sitting down, and standing up. Ten healthy patients (5 men, 5 women, average age 66 years) all 1 year or more after cementless THA performed for degenerative arthritis, with Harris Hip Scores ≥90, were studied. Each patient performed the activities of daily living while data was captured using video fluoroscopy. Based on previously reported criteria, femoral head separation (the femoral head sliding lateral to the acetabular liner) was determined to be reliably predicted if the distance between the femoral head and acetabular cup was ≥0.5. Results showed that the greatest femoral head separation occurred during the pivoting activity (mean, 1.53 mm; range, 0.00-3.34 mm; SD, 1.05 mm). The separation values identified during pivoting occurred at the extremes of internal or external rotation for all patients. The other 3 activities showed lower separation distances. Separation during the pivoting activity exceeded the reported separations occurring during walking. This finding was seen in a small group of patients, and the data should be interpreted with caution. We conclude from this study that the evaluation of gait alone may not be sufficient to accurately assess femoral head separation occurring during activities of daily living for healthy, active patients.

Fracture of a cross-linked polyethylene liner: a multifactorial issue.

A limited number of reports have detailed the cause of fracture of a highly cross-linked polyethylene liner. Typically, the fractures have occurred in a region of thin and/or unsupported polyethylene, in association with superiorly directed edge loading conditions secondary to an excessively inclinated acetabular component. This case report details an unusual fracture mechanism of a 5-mrad cross-linked liner caused by horizontal loading conditions. The report details several factors that were felt to be etiologic including the specific liner locking mechanism. The treatment options are discussed.