1.1. Femoral head material and size

Table 1 shows the relative use of different modular heads. The use of ceramic heads has increased by 6% since 2018.

Table 1

Frequency of material chosen for femoral heads in procedures performed in 2020.

Table 2 shows the frequency of use of different femoral head sizes. 32mm modular heads are the most dominant size with 49% of the market share. Ceramic on ceramic bearings use more 36mm femoral heads than 32mm. The use of 36mm heads has increased by 4% at the expense of 28mm which has decreased by 6% since 2018.

Table 2

Frequency of femoral head sizes for hip procedures performed in 2020.

1.2. Brand sales of conventional total hips and resurfacing prostheses

Tables 3 to 8 show the most frequently used brands in England, Wales, Northern Ireland, the Isle of Man and the States of Guernsey during 2020, as assessed by their rate of entry into the registry.

Table 3(a)

Cemented cup brands for primary hip procedures performed in 2020.

Table 3(b)

Cemented cup brands for revision hip procedures performed in 2020.

Table 4(a)

Cementless cup brands for primary hip procedures performed in 2020.

Table 4(b)

Cementless cup brands for revision hip procedures performed in 2020.

Table 5(a)

Cemented stem brands for primary hip procedures performed in 2020.

Table 5(b)

Cemented stem brands for revision hip procedures performed in 2020.

Table 6 (a)

Cementless stem brands for primary hip procedures performed in 2020.

Table 6(b)

Cementless stem brands for revision hip procedures performed in 2020.

Table 7

Brands of resurfacing head for primary hip procedures performed in 2020.

1.3. Combinations of cups and stems

Tables 8 (a) and 8 (b) detail the combinations of cup and stem brands used in primary and revision hip procedures respectively. Table 8 (a) also details which combinations have a different stem and cup manufacturer – a practice known as ‘mix and match’. For 57,791 hip primary replacement procedures in the 2020 data, both the cup and stem brand were known and a total of 648 different combinations of cup and stem brands were recorded. This is a decrease of 88 cup stem combinations when compared to 2018.

Table 8(a)

Stem/cup brand combinations for primary hip procedures performed in 2020.

Table 8 (b)

Stem/cup brand combinations for revision hip procedures performed in 2020.

The most common stem/cup combination for primary procedures is the Exeter V40 stem combined with the Trident cup. Of the 57,791 primary procedures, 4,414 (8.3%) used ‘mix and match’ stem/cup combinations from different suppliers.

Of the 1,765 revision hip procedures where both the cup and stem were replaced, 349 stem/cup combinations were used. The most common stem/cup combination for revision procedures remained the Exeter V40 stem combined with the Tritanium cup, both from Stryker.

The practice of ‘mix and match’ remains contrary to MHRA and manufacturers’ guidelines for usage.

1.4. Summary

The total number of brands of acetabular cups and femoral stems used in procedures recorded in the registry has increased significantly since its inception. There were 112 brands of acetabular cups (excluding resurfacing cups) used in 2020, which is an increase of three when compared to 2018. There were 119 brands of femoral stems used in 2020. There has been no increase in the number of stem brands used over the past two years.

Whilst material selection for femoral heads used between 2003 and 2007 remained constant (76% metal and 24% ceramic) by 2020, 48% of modular heads used were ceramic. There has been a continued increase in the use of a polyethylene acetabulum articulation with a ceramic head. The percentage of 32mm modular heads used in procedures accounts for 49% of procedures whereas 28mm heads have been steadily decreasing and are now used in 19% of procedures.

2.1. Prostheses entered into the registry

A total of 54 brands of total condylar knee prostheses were used in primary procedures and 35 were used in revision procedures. In addition, there were 16 brands of unicondylar prostheses, seven brands of patellofemoral replacements and 16 brands of hinged knees.

Tables 9 (a) and 9 (b) show the brands of primary and revision total condylar knee replacement prosthesis recorded in the registry for 2020.

Table 9 (a)

Brands for total condylar knee primary procedures performed in 2020.

Table 9 (b)

Brands for total condylar knee revision procedures performed in 2020.

Table 10 (a)

Brands for unicondylar knee replacement primary procedures performed in 2020.

Table 10 (b)

Brands for unicondylar knee replacement revision procedures performed in 2020.

Table 11

Brands for patellofemoral joint replacement primary and revision knee procedures performed in 2020.

Table 12

Fixed and rotating hinged knee brands for primary and revision knee procedures performed in 2020.

2.2. Usage of fixed versus mobile bearing tibial inserts

Table 13 (a)

Tibial insert type for total knee primary procedures performed in 2020.

Table 13 (b)

Tibial insert type for total knee primary procedures performed in 2020.