Minimally Invasive Computer-Assisted Total Knee Arthroplasty Compared With Conventional Total Knee Arthroplasty: A Prospective 9-Year Follow-Up.

BACKGROUND: Studies on minimally invasive computer-assisted total knee arthroplasty (MICA-TKA) have shown promising results, but are limited by short follow-up. The purpose of this study was to compare the midterm radiographic features and functional outcomes between patients who underwent MICA-TKA and conventional TKA. METHODS: A total of 108 patients who were randomized to undergo MICA-TKA or conventional TKA during 2004 and 2005 were contacted for a prospective follow-up review. Patients who were lost to contact, have passed away, or declined to participate in the study were excluded. Objective functional measurements and radiographs were obtained for assessment. RESULTS: By the time of this study, 2 patients from the conventional group had undergone revision TKA, one due to infection and one due to aseptic loosening. A total of 67 patients (62.04%) were followed up for an average period of 9.07 years (8.51-9.61 years). At follow-up, functional scores were comparable between the 2 groups. No significant intergroup differences were found in mechanical knee alignment and component placement angle in the coronal views. No statistical or clinical significance were noticed in radiographic signs of component loosening. CONCLUSIONS: MICA-TKA provided similar clinical, functional, and radiographic outcomes compared with conventional TKA after an average of 9-year follow-up. This technique can be used to exploit its short-term advantages without compromising midterm outcomes.

Acetabular Prosthetic Protrusio after Bipolar Hemi-Arthroplasty of the Hip: Case Report and Review of the literature.

INTRODUCTION: Bipolar hemi-arthroplasty of the hip is a commonly performed procedure in elderly patients with intra-capsular fracture of the neck of the femur with good short-term results for pain relief, return to activity and morbidity. The incidence of intra-pelvic prosthesis migration or protrusion is rare and one of the inciting factors is chronic low-grade sepsis. Acetabular prosthesis protrusion poses a difficult and challenging surgical problem due to surrounding neurovascular structures. CASE PRESENTATION: We present a case report of 60-year-old Chinese female suffering from chronic sepsis of the hip joint causing acetabular prosthetic protrusion with a concomitant peri-prosthetic femoral shaft fracture secondary to a fall, 5 years post index surgery of bipolar hemiarthroplasty for an intra-capsular neck of femur fracture. This patient subsequently underwent a two-stage revision total hip arthroplasty. We aim to discuss the diagnostic approach and surgical management of this complex case of infected protruded bipolar hip hemi-arthroplasty. CONCLUSION: We highlight three recommendations from this clinical experience. Firstly, there should be a high index of suspicion for chronic infection in protruded prostheses following low energy trauma. Secondly, pre-operative planning for infected protruded prosthetic hips is essential, including arteriogram and a two-staged procedure to tackle possible soft tissue complications. Thirdly, the combined use of serological markers, fluid aspiration as well as intra-operative frozen section is important in the management of PJI and to confirm bacterial eradication before re-implantation.

Necrotizing Fasciitis Caused by Cryptococcus gattii.

Necrotizing fasciitis (NF) is a severe soft-tissue infection that can lead to high morbidity and mortality. The etiology of NF is often polymicrobial. Although rare, fungal organisms have been known to cause NF. Cryptococcus is a fungal infection that may lead to NF. Here we report the case of a 73-year-old man who had diabetes and presented with pain and swelling in the left hand after being bitten by an insect over the dorsum of the hand. Operative débridement revealed NF caused by Cryptococcus gattii. Antifungal medication was started, and the patient underwent multiple débridements of the hand with subsequent skin grafting. Four months later, the hand wound was completely healed. Authors have reported several cases of NF secondary to Cryptococcus neoformans in immunocompromised patients. The emerging C gattii pathogen affects immunocompetent patients. Although the transmission route is mainly respiratory, direct inoculation has been described as well. Ours is the first reported case of NF secondary to C gattii. It is important to consider fungal elements as a source of NF. Appropriate treatment includes aggressive surgical débridement and antifungal therapy.

Minimally invasive compared with open lumbar laminotomy: no functional benefits at 6 or 24 months after surgery.

BACKGROUND CONTEXT: Comparative studies between open and minimally invasive surgical (MIS) approaches for the treatment of spinal stenosis have mainly investigated immediate postoperative parameters. PURPOSE: We aimed to compare the postoperative improvements in functional and pain scores between open versus MIS lumbar laminotomy and to describe the complications of each method. STUDY DESIGN/SETTING: We conducted as retrospective review of prospectively collected data. PATIENT SAMPLE: We included 113 patients. OUTCOME MEASURES: Visual analog scale for back and leg pain, Oswestry Disability Index (ODI), the North American Spine Society score on neurogenic symptoms (NS), and average Short Form Health Survey-36 (SF-36) score. Accidental durotomies and patients with reoperations are presented. METHODS: We obtained a list of patients who underwent either MIS or open unilateral one-level lumbar laminotomy for the treatment of neural foraminal or lateral recess stenosis with unilateral leg NS. Outcome measures are presented at 6 and 24 months postoperatively. RESULTS: From 2000 to 2008, 113 patients (30 open, 83 MIS) underwent a one-level lumbar laminotomy and had complete postoperative data available for analysis. Between the approaches, there were no differences in baseline demographic data or functional scores. At 6 and 24 months after surgery, there were no differences in improvement in back or leg pain, or improvement in ODI, NS, or SF-36 scores. The MIS group reported greater satisfaction with treatment at 6 months (p=.009) but not at 24 months. Within the MIS group, three patients (3.6%) experienced an inadvertent durotomy and two patients (2.4%) underwent fusion of the operated segment within 24 months. CONCLUSIONS: Compared with an open approach, MIS lumbar laminotomy gave no clear advantages in longer term functional or pain scores. The MIS group also had patients with inadvertent durotomies and reoperation within 2 years. In any lumbar decompressive surgery, the purported advantages of an MIS approach should be carefully weighed against potential complications. For a relatively simple surgery such as laminotomy, the open approach remains a safe and straightforward option.

Multiple locations of nerve compression: an unusual cause of persistent lower limb paresthesia.

A paucity of appreciation exists that the "double crush" phenomenon can account for persistent leg symptoms even after spinal neural decompression surgery. We present an unusual case of multiple locations of nerve compression causing persistent lower limb paresthesia in a 40-year old male patient. The patient's lower limb paresthesia was persistent after an initial spinal surgery to treat spinal lateral recess stenosis thought to be responsible for the symptoms. It was later discovered that he had peroneal muscle herniations that had caused superficial peroneal nerve entrapments at 2 separate locations. The patient obtained much symptomatic relief after decompression of the peripheral nerve. The "double crush" phenomenon and multiple levels of nerve compression should be considered when evaluating lower limb neurogenic symptoms, especially after spinal nerve root surgery.

Unconstrained arthroplasty in type II valgus knees: posterior stabilized or cruciate retaining?

PURPOSE: Type II valgus knees are defined by medial collateral ligament laxity. This paper studies the results of posterior stabilized (PS) and cruciate retaining (CR) knee implants in type II valgus knees. METHODS: From 1999 to 2009, there were 100 type II valgus knees in 95 patients eligible for study (63 PS, 37 CR). Patients had prospectively collected clinical data up to 2 years after surgery. RESULTS: At 24 months after surgery, the CR group had reduced range of motion (PS: median 126.0°, CR: median 114°; n.s.) and a marginally but statistically significant increased valgus alignment (PS: median 5°, CR: median 6°; p = 0.011). Despite this, both groups produced equal and marked improvements in SF-36, function score and knee score of the Knee Society score, and Oxford knee score. CONCLUSIONS: Overall, both PS and CR implants performed equally well in type II valgus knees at 24 months post-operatively. Further longer-term studies would be warranted to assess for late instability. LEVEL OF EVIDENCE: Retrospective, Level III.

Positive ProbeTec tests in fresh specimens from malignant musculoskeletal tumors: a case series.

OBJECTIVE: To report a case series of patients with high-grade musculoskeletal sarcomas whose biopsies of fresh specimens yielded positive Becton Dickinson ProbeTec tests, in addition to confirming diagnoses of high-grade sarcomas. METHODS: Fresh biopsies of high-grade musculoskeletal sarcomas were subjected to ProbeTec tests. RESULTS: The biopsies of three Chinese patients aged 65, 49 and 78 years with high-grade musculoskeletal sarcomas had positive Becton Dickinson ProbeTec tests. These patients' overall clinical pictures were not consistent with active tuberculous infections, which suggested that the ProbeTec test results were false-positives. The reason for this is not known but it is postulated that there is homology between the primers used for the ProbeTec test and the molecular properties of high-grade sarcomas. CONCLUSION: With the increasing use of the ProbeTec test in clinical practice, fellow surgeons and pathologists are encouraged to be aware of this phenomenon.