Aim

The liver is the major source of acute phase proteins (APPs) and serum concentrations of several APPs are widely used as markers of inflammation and infection. The aim of the present study was to explore if a local extra hepatic osseous acute phase response occurs during osteomyelitis.

Objectives

Metal-on-metal hip resurfacing (MOMHR) is available as an alternative option for younger, more active patients. There are failure modes that are unique to MOMHR, which include loosening of the femoral head and fractures of the femoral neck. Previous studies have speculated that changes in the vascularity of the femoral head may contribute to these failure modes. This study compares the survivorship between the standard posterior approach (SPA) and modified posterior approach (MPA) in MOMHR.

Pseudotumours (soft-tissue masses relating to the hip joint) following metal-on-metal hip resurfacing arthroplasty (MoMHRA) have been associated with elevated serum and hip aspirate metal ion levels, suggesting that pseudotumours occur when there is increased wear. This study aimed to quantify the wear of implants revised for pseudotumours and a control group of implants revised for other reasons of failure.

A total of 30 contemporary MoMHRA implants in two groups were investigated: (1) 8 MoMHRA implants revised due to pseudotumour; (2) 22 MoMHRA implants revised due to other reasons of failure. The linear wear of retrieved implants was measured using a Taylor-Hobson Roundness machine. The average linear wear rate was defined as the maximum linear wear depth divided by the duration of the implant in vivo.

In comparison with the non-pseudotumour implant group, the pseudotumour implant group was associated with: (1) significantly higher median linear wear rate of the femoral component: 8.1 um/year (range 2.75-25.4 um/year) vs. 1.97 um/year (range 0.82-13.00 um/year), p=0.002; and (2) significantly higher median linear wear rate of the acetabular component: 7.36 um/year (range 1.61-24.9 um/year) vs. 1.28 um/year (range 0.18-3.33 um/year), p=0.001. Wear on the acetabular cup components in the pseudotumour group always involved the edge, indicating edge-loading of the bearing.

Significantly greater linear wear rates of the MoMHRA implants revised due to pseudotumour support the in vivo elevated metal ion concentrations in patients with pseudotumours. This study is the first to confirm that pseudotumour occurs when there is increased wear at the MoM articulation. Furthermore, edge-loading may be the dominant wear generation mechanism in patients with pseudotumour.

Introduction

The advantage of using SPECT-CT over conventional bone scanning is that it has the promise of linking the multiplanar reconstructional images of CT with the functional analysis of bone scintigraphy. It delivers information regarding new pathology and is regarded as more sensitive and specific. We present our experience of use of the SPECT-CT in the analysis of continued or recurrent pain post-foot and ankle arthrodesis.

Introduction

Total elbow arthroplasty (TEA) is a widely accepted for the treatment for damaged rheumatoid elbows to achieve sufficient joint function. The current prospective study reports the long term follow-up of TEA with an unlinked stem type (Stemmed Kyocera type I, SKC-I) with a solid trochlea on patients who have rheumatoid arthritis (RA). SKC-1 is derived from an unlinked surface replacement prosthesis using polycrystalline alumina ceramics on high-density polyethylene (Kyocera type I), which was developed in 1979, based on the measurement study on the cadaveric elbows.

Materials and Methods

57 elbows (Larsen’s grade IV and V) from 45 RA patients replaced by SKC-1 were investigated. Cement fixation was used in all cases. The duration of follow-up ranged from 36 to 154 (average 73. 7) months. The clinical condition of each elbow before and after operation was assessed according to the scoring system of Japanese Orthopaedic Association (JOA) elbow scoring system (maximum 100 points), which is composed of scores for pain, activity of daily life, muscle strength, range of motion, instability, and deformity of the joint. On the basis of this system, the results are defined as excellent (90–100 points), good (75–89), fair (60–74), and poor (< 60). Radiographic loosening was defined as a progressive radiolucent line of more than two millimeters that completely surrounded the prosthesis.

Results

The average postoperative JOA score improved from 43. 5±10. 2^° to 81. 0±}10. 3^°, with marked pain relief. The mean range of motion (ROM) of extension/flexion before the surgery was –35. 7±}22. 4/117. 1±}19. 1^° and at last follow-up was −17 5±}12. 7/136. 3±}11. 4^°. The mean ROM of pronation /supination improved from 51. 1±}23. 4/56. 5±}28. 5^° to 78. 3±}16. 8/82. 3±}16. 5^°. Of the 57 elbows, 9 elbows were judged to have excellent results, 37 had good results, 8 had fair results, and 3 had poor results.

There were no instances of ulnar nerve palsy, triceps avulsion, or postoperative infection. Medial or lateral epicondylar fracture occurred in 2 cases during the operation, and union was achieved 3 months later. Massive instability with joint dislocation was seen in 3 cases of mutilans arthritis, resulting in poor results. Aseptic loosening was seen in 3 elbows. Revision surgery was performed in 1 case of accidental post-operative distal humerus fracture, and in another of olecranon fracture with the breakage of the ulnar component. With loosening defined as the end point, Kaplan-Meier curve of the cumulative probability of survivorship demonstrates the likelihood of survival of the prosthesis at 93. 8 percent for as long as 10 years.

Discussion

The results of the current study showed a high reliability of the SKC-1 prosthesis with the novel alumina ceramic component over a long period when implanted with cement. However, the use of non-constrained devices is limited by the amount of bone and by the need for ligamentous stability. If soft tissues are damaged along with marked bone loss or inflammatory changes, the ligament should be repaired or a semiconstrained type of prosthesis is indicated. It is important to note that a high level of surgical technique is required for TEA in RA elbows to avoid typical postoperative complications.