Can tibial coverage in total knee replacement be reliably evaluated with three-dimensional image-based digital templating?

Evolution of orthopaedic diseases through four thousand three hundred years: from ancient Egypt with virtual examinations of mummies to the twenty-first century

PURPOSE

This study conducts a comprehensive comparative analysis of bone pathologies between ancient Egypt and today. We aim to elucidate the prevalence, types, and potential aetiological factors influencing skeletal disorders in these two distinct temporal and cultural contexts.

METHODS

The research employs a multidisciplinary approach, integrating osteological, paleopathological, and historical data to understand bone pathologies in mummies and the actual world. Applying radiographs and CT scans as noninvasive techniques has shed new light on past diseases such as fractures, dysplasia, osteoarthritis, surgery, and tuberculosis. Virtual inspection has almost replaced classical autopsy and is essential, especially when dealing with museum specimens.

RESULTS

Findings indicate no significant disparities in the prevalence and types of bone pathologies through 4300 years of evolution. Moreover, this study sheds light on the impact of sociocultural factors on bone health. Examination of ancient Egypt's burial practices and associated cultural beliefs provides insights into potential behavioral and ritualistic influences on bone pathologies and the prevalence of specific pathologies in the past and present.

CONCLUSION

This comparative analysis illuminates the dynamic of bone pathologies, highlighting the interplay of biological, cultural, and environmental factors. By synthesizing archeological and clinical data, this research contributes to a more nuanced understanding of skeletal health's complexities in ancient and modern societies, offering valuable insights for anthropological and clinical disciplines.

The effect of tibial component sizing on patient reported outcome measures following uncemented total knee replacement

When performing total knee replacement (TKR), surgeons are required to decide on the most appropriate size of tibial component. As implants are predominantly selected from incremental sizes of a preferred design, it may be necessary for a surgeon to slightly under or oversize the component. There are concerns that overhang could lead to pain from irritation of soft tissues, and an undersized component could lead to subsidence and failure. Patient reported outcome measures were recorded in 154 TKRs at one year postoperatively (in 100 TKRs) and five years post-operatively (in 54 TKRs) in 138 patients. The Oxford Knee Score (OKS), WOMAC and SF-12 were recorded, and a composite pain score was derived from the OKS and WOMAC pain questions. Tibial component size and position were assessed on scaled radiographs and implants were grouped into anatomic sized tibial component (78 TKRs), undersized component (48 TKRs), minor overhang one to three mm (10 TKRs) or major overhang ≥ 3 mm (18 TKRs). There was no statistically significant difference between the mean post-operative OKS, WOMAC, SF-12 or composite pain score of each group. Furthermore, localisation of the site of pain did not correlate with medial or lateral overhang of the tibial component. Our results suggest that tibial component overhang or undersizing is not detrimental to outcome measures or pain.

LEVEL OF EVIDENCE

II.

Tibial base design and patient morphology affecting tibial coverage and rotational alignment after total knee arthroplasty

PURPOSE

To understand interactions between total knee arthroplasty tibial base design attributes, variations in tibial morphology, and the resulting tibial coverage and rotational alignment.

METHODS

Tibial anthropometric measurements, including aspect ratio (medial-lateral width/anterior-posterior length) and tibial asymmetry, were taken for 14,791 total knee arthroplasty patients and compared with the ability of four different commercial tibial base designs to cover the resected plateau. The anthropometric measurements were also compared with the resulting tibial base rotation, which occurred when rotating the base to maximize coverage.

RESULTS

All four tibial base designs resulted in similar coverage ranging from 80.2 (4.7)% to 83.8 (4.6)%. Mean tibial base rotation when placed to maximize coverage ranged from 3.7 (4.4)° (internal) to 3.8 (4.5)° (external) relative to the medial third of the tibial tubercle. More asymmetric tibiae and tibiae with a lower aspect ratios resulted in increased internal tibial base rotation.

CONCLUSIONS

The four tibial base designs assessed provided similar levels of tibial bone coverage across the patient population, despite different design features. Rotating the tibial base to maximize coverage did not significantly increase the tibial coverage, but induced variability in tibial base alignment. Certain tibial anthropometrics may predispose particular patients to internal tibial base mal-rotation.