The October 2012 Research Roundup³⁶⁰ looks at: whether you can escape your genes; oral prophylaxis for DVT; non-responders and the internet; metal-on-metal, mice and damaged livers; sleeping on the job; cartilage contact stress in the normal human hip; and a perfect reason to subscribe to 360.

The October 2012 Hip & Pelvis Roundup³⁶⁰ looks at: diagnosing the infected hip replacement; whether tranexamic acid has a low complication rate; the relationship between poor cementing technique and early failure of resurfacing; debridement and retention for the infected replacement; triple-tapered stems and bone mineral density; how early discharge can be bad for your sleep; an updated QFracture algorithm to predict the risk of an osteoporotic fracture; and local infiltration analgesia and total hip replacement.

We identified 16 patients with a mean age of 56.5 years (31 to 86) from a large consecutive series of patients with proximal humeral fractures over a 15-year period, who had sustained a fracture with skin compromise after a blunt injury. The study group represented 0.2% of 7825 proximal humeral fractures treated during this period and all had a displaced Neer two-part fracture pattern. Two patterns of skin injury were identified: in ten patients there was skin penetration at the time of the original injury, and the other six patients initially had closed injuries. These six patients had fracture fragments penetrating the muscular envelope to lie subcutaneously producing either early skin tethering (two patients) or delayed skin penetration and sinus formation (four patients). The pattern of injury to the soft-tissue envelope and the fracture pattern were similar for all injuries. Treatment of these injuries was determined by the initial severity of the soft-tissue injury and the medical status of the patient. We currently favour open reduction and internal fixation of these fractures wherever possible, owing to the high rate of nonunion with non-operative management.

Objectives

To determine the morbidity and mortality outcomes of patients presenting with a fractured neck of femur in an Australian context. Peri-operative variables related to unfavourable outcomes were identified to allow planning of intervention strategies for improving peri-operative care.

We evaluated the potential of a vastus lateralis muscle flap in controlling infection after resection arthroplasty of the hip. We retrospectively reviewed 119 patients with 120 chronic infections after resection arthroplasty treated with this procedure. The flap was fixed with Mitek anchors in the acetabular cavity. The mean duration of infection after resection before the muscle flap procedure was 6.5 months (2 to 13). The patients had previously undergone a mean of 4.9 operations (2 to 25). In all patients the infected cavity was the origin of the persistent infection. The mean follow-up was for 2.6 years (1.0 to 4.7).

No patient had recurrent infection post-operatively and all had an improvement in the pain and better quality of life.

This study was performed to review the safety and outcome of total shoulder replacements in patients who are ≥ 80 years of age. A total of 50 total shoulder replacements in 44 patients at a mean age of 82 years (80 to 89) were studied. Their health and shoulder status, the operation and post-operative course were analysed, including pain, movement, patient satisfaction, medical and surgical complications, radiographs, the need for revision surgery, and implant and patient survival. A total of 27 patients had an ASA classification of III or IV and medical abnormalities were common. Of the 13 shoulders with bony deficiency of the glenoid, nine required grafting. The duration of hospital stay was prolonged and blood transfusions were common. There were no peri-operative deaths. The mean follow-up was for 5.5 years (2 to 12). Pain was significantly reduced (p < 0.001) and movement improved in active elevation and both external and internal rotation (p < 0.001). Using the Neer scale for assessing outcome, 40 (80%) shoulders had an excellent or satisfactory result. There were medical or surgical complications in 17 cases. Four shoulders developed radiological evidence of loosened glenoid components, and three of these had a poor outcome. Three other shoulders required revision, two for instability. By the time of this review 39 of the patients had died from unrelated causes at a mean of 7.5 years (0.8 to 16.4) after surgery.

Total shoulder replacement is a relatively effective treatment in this elderly group of patients. However, there is a requirement for more intense patient care in the peri-operative period, and non-fatal medical or surgical complications are common. Most of these elderly patients will have a comfortable functional shoulder for the rest of their lives.

We have evaluated the extent to which diabetes affects the revision rate following total hip replacement (THR). Through the Danish Hip Arthroplasty Registry we identified all patients undergoing a primary THR (n = 57 575) between 1 January 1996 and 31 December 2005, of whom 3278 had diabetes. The presence of diabetes among these patients was identified through the Danish National Registry of Patients and the Danish National Drug Prescription Database. We estimated the relative risk for revision and the 95% confidence intervals for patients with diabetes compared to those without, adjusting for the confounding factors. Diabetes is associated with an increased risk of revision due to deep infection (relative risk = 1.45 (95% confidence interval 1.00 to 2.09), particularly in those with type 2 diabetes (relative risk = 1.49 (95% confidence interval 1.02 to 2.18)), those with diabetes for less than five years prior to THR (relative risk = 1.69 (95% confidence interval 1.24 to 2.32)), those with complications due to diabetes (relative risk = 2.11 (95% confidence interval 1.41 to 3.17)), and those with cardiovascular comorbidities prior to surgery (relative risk = 2.35 (95% confidence interval 1.39 to 3.98)).

Patients and surgeons should be aware of the relatively elevated risk of revision due to deep infection following THR in diabetes particularly in those with insufficient control of their glucose level.

There are no long-term published results on the survival of a third-generation cemented total shoulder replacement. We describe a clinical and radiological study of the Aequalis total shoulder replacement for a minimum of ten years. Between September 1996 and May 1998, 39 consecutive patients underwent a primary cemented total shoulder replacement using this prosthesis. Data were collected prospectively on all patients each year, for a minimum of ten years, or until death or failure of the prosthesis. At a follow-up of at least ten years, 12 patients had died with the prosthesis intact and two had emigrated, leaving 25 available for clinical review. Of these, 13 had rheumatoid arthritis and 12 osteoarthritis. One refused radiological review leaving 24 with fresh radiographs.

Survivorship at ten years was 100% for the humeral component and 92% for the glenoid component. The incidence of lucent lines was low. No humeral component was thought to be at risk and only two glenoid components. The osteoarthritic group gained a mean 65° in forward flexion and their Constant score improved by a mean 41.4 points (13 to 55). The rheumatoid group gained a mean of 24° in flexion and their Constant score improved by 29.4 points. This difference may have been due to failure of the rotator cuff in 75% of the patients with rheumatoid arthritis.

Thus a third-generation total shoulder replacement gives an excellent result in patients with osteoarthritis and an intact rotator cuff. Patients with rheumatoid arthritis have a 75% risk of failure of the rotator cuff at ten years.

We carried out a retrospective cohort study of 3309 patients undergoing primary total hip replacement to examine the impact of tobacco use and body mass index on the length of stay in hospital and the risk of short term post-operative complications.

Heavy tobacco use was associated with an increased risk of systemic post-operative complications (p = 0.004). Previous and current smokers had a 43% and 56% increased risk of systemic complications, respectively, when compared with non-smokers. In heavy smokers, the risk increased by 121%. A high body mass index was significantly associated with an increased mean length of stay in hospital of between 4.7% and 7%. The risk of systemic complications was increased by 58% in the obese. Smoking and body mass index were not significantly related to the development of local complications.

Greater efforts should be taken to reduce the impact of preventable life style factors, such as smoking and high body mass index, on the post-operative course of total hip replacement.