Laminar flow does not affect risk of prosthetic joint infection after primary total knee replacement in Asian patients.

BACKGROUND: The role of laminar flow (LAF) is contradictory with several studies failing to replicate risk reduction. The 2016 World Health Organization guidelines identified this lack of good comparative studies. AIM: To analyse the use of LAF and the incidence of prosthetic joint infections (PJIs) in Asian patients undergoing total knee replacement (TKR). METHODS: Patients who underwent standard cemented posterior-stabilized TKR from 2004 to 2014 were reviewed from a prospectively collected single-surgeon database. Revision, traumatic and/or inflammatory cases were excluded. The type of airflow used was identified. The technique and surgical protocol for all procedures were similar. Tourniquets and inserted drains were routinely used. Patellar resurfacing was not performed. Patients were followed up at the outpatient clinics at regular intervals up to two years. At each visit, the patient was assessed for the occurrence of PJI. FINDINGS: Of the 1028 procedures, 453 (44.1%) were performed in an LAF operating theatre (OT) whereas 575 (55.9%) were performed in a non-LAF OT. There were no significant differences between the two groups in terms of age, gender, or side of procedure. The overall incidence of PJI was 0.6% (N = 6). Three (50%) occurred in an LAF OT whereas three (50%) occurred in a non-LAF OT. This was not statistically significant. CONCLUSION: Laminar flow systems are costly to procure and maintain. With modern aseptic techniques, patient optimization, and use of prophylactic antibiotics, laminar flow does not appear to further reduce risk of PJI in Asian patients after TKR.

Missed posterior fracture-dislocation of the humeral head following an electrocution injury to the arm.

Posterior dislocation of the shoulder is a rare and commonly missed injury. While prompt diagnosis and treatment is important to prevent untoward sequelae, it is often diagnosed and treated too late. The first reported case of a posterior fracture-dislocation of the humeral head following a domestic electrocution accident in Singapore is described in a 52-year-old man. The injury was missed by several doctors before a humeral head replacement was done. The diagnostic pitfalls and management of this injury and ways to avoid a missed or delayed diagnosis are discussed.

Assessment of blood-induced cartilage damage in rabbit knees using scanning electron microscopy.

PURPOSE: To investigate the harmful effects of a single episode of intra-articular bleeding on articular cartilage of rabbit knees using scanning electron microscopy. METHODS: Autologous blood was injected into the right knee joints of 18 New Zealand white rabbits. Surface and cellular damages were examined by the scanning electron microscope (n=9) and light microscope (n=34), respectively. The injected right knees were then compared with the corresponding control left knees at one, 3, and 6 weeks after the blood injection. RESULTS: The articular surface of the injected knees turned uniformly rough with multiple pits after one week. Maximal changes with elevations and depressions were observed at 3 weeks. These changes reversed at 6 weeks with the irregularities smoothing out. A similar pattern of transient cartilage damage was noted histologically. CONCLUSION: Both scanning electron microscopic and light microscopic findings suggest that a single episode of intra-articular bleeding leads to articular cartilage damage but this appears to be reversible. Our findings of transient damage to the articular cartilage suggest that there is no need for intra-articular evacuation and washout following an acute episode of haemarthrosis.

Arthroscopic Bankart repair for traumatic anterior shoulder instability with the use of suture anchors.

INTRODUCTION: The arthroscopic method offers a less invasive technique of Bankart repair for traumatic anterior shoulder instability. The results continue to improve with the advancements made in instrumentation and technique. This study aims to evaluate the outcome of arthroscopic Bankart repair with the use of suture anchors for cases that were followed-up for at least two years from the date of surgery. METHODS: This was a consecutive series of 40 shoulders in 37 patients who underwent arthroscopic Bankart repair with suture anchor. The mean age at the time of operation was 26.3 years. The patients were assessed with two different outcome measurement tools (the University of California at Los Angeles [UCLA] shoulder rating scale and simple shoulder test [SST] score). The mean duration of follow-up was 30.2 months. The recurrence rate, range of motion, and postoperative function were evaluated. RESULTS: The two shoulder scores significantly improved after surgery (p-value is less than 0.05). According to the UCLA scale, 37 shoulders (92.5 percent) had excellent or good scores, one shoulder (2.5 percent) had a fair score, and two (five percent) had poor scores. All 12 components of SST showed improvement, which was statistically significant. Overall, the rate of postoperative recurrence was 7.5 percent (three shoulders). All patients either maintained or demonstrated improvement of range of motion. There was no loss of external rotation range of motion postoperatively. CONCLUSION: Arthroscopic Bankart repair with the use of suture anchors is a reliable treatment method that can provide a good clinical outcome with excellent postoperative shoulder motion and low recurrence rate.

Posterior fracture-dislocation of the humeral head treated without the use of metallic implants.

Posterior fracture-dislocation of the humeral head is an uncommon injury, usually associated with seizures, electrocution injury and high-impact trauma. Prompt diagnosis and treatment are important to prevent avascular necrosis of the humeral head. Various methods to treat such injury have been described. We report a 34-year-old man who had a four-part humeral head fracture with concomitant posterior dislocation that was treated with open reduction and internal fixation with non-absorbable polyester sutures. The diagnosis and operative techniques are described and factors influencing our choice of management are discussed. A review of the literature is also included.