The Influence of Patellofemoral Degenerative Changes on the Outcome of the Unicompartmental Knee Replacement: A Prospective Study.

Unicompartmental knee arthroplasty (UKA) is a recognized procedure for treatment of medial compartment osteoarthritis. Patellofemoral (PF) joint degeneration is widely considered to be a contraindication to medial compartment UKA. We examined the validity of this preconception using information gathered prospectively on 147 consecutive patients who underwent the Repicci II UKA for medial compartment osteoarthritis between July 1999 and September 2000 by the same surgeon. The status of the PF joint was assessed intraoperatively in all patients, and accordingly patients were divided into two groups. Among them, 69 had associated PF osteoarthritis (group A), while 78 patients had a normal PF compartment (group B). Variables measured included the International Knee Society (IKS) score, limb alignment, and range of motion. Radiographs, demographic data, length of hospital stay, perioperative complications were also measured. All subsequent surgery and survivorship at 10 years were recorded. The mean follow-up was 9.4 years (range: 5-10.7 years) and results of the two groups were compared. We found no significant differences in terms of IKS scores, alignment, and flexion between the two groups. However, measured extension was significantly increased postoperatively in those patients with minimal or no PF joint degenerative disease (p < 0.05).

Protection of the Femoral Trunnion During Acetabular Revision Hip Surgery-A Novel Technique.

Revision of a failed acetabular component in the presence of an intact femoral prosthesis comprises approximately 20% of revision total hip replacements performed by the senior author. During this procedure, the femoral trunnion is at risk of damage because of scratching from retractors, reamers, or other instruments. Scratching can result in mechanically assisted crevice corrosion or adverse local-tissue reaction or trunnionosis leading to implant failure. We have used a variety of techniques for protection of the femoral taper over the last 30 years. We describe our current method of taper protection, using a cut segment of #5 silicon laryngeal airway, which is a simple and effective method.

Evaluation of lower limb axial alignment using digital radiography stitched films in pre-operative planning for total knee replacement.

BACKGROUND: For patients with knee osteoarthritis, even slight anatomical variations in the femur or the tibia could affect total limb alignment during total knee replacement (TKR). Our hypothesis implies that the femoral valgus correction angle (VCA) in patients indicated for TKR, is variable and higher than the reported norm of 6° utilized in most intramedullary instrumentation systems, and that tibial bowing may result to a disparity of the tibial mechanical axis to the anatomical axis. METHODS: Our study is a retrospective review of 216 pre-operative arthritic knees, which investigated the lower limb axial alignment using digitally-stitched films. Patients excluded from the study are those with history of previous tibial or femoral osteotomy, secondary gonarthrosis, rheumatoid arthritis, previous femoral or tibial fracture, patients for bilateral TKR, or history of hip surgery. RESULTS: The mean age was 68-years old (range 39-86 years). The mean VCA was 7° (4.7-9.3) for men and 6.6° (4.9-9) for women. However, 71 patients (33%) had more than 7° VCA. Subsequently, 46 patients (21%) had tibial bowing producing an angle >1.5° between its mechanical and anatomic axis. CONCLUSIONS: The 6° standard when used as a guide may result in suboptimal prosthesis positioning during conventional TKR surgery. Therefore our findings suggest that the femoral valgus correction angle has a broad range, and using standard femoral intramedullary guides should not be overlooked.

Revision of minimal resection resurfacing unicondylar knee arthroplasty to total knee arthroplasty: results compared with primary total knee arthroplasty.

We compared a cohort of patients undergoing revision of a minimal resection resurfacing unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) with a cohort of patients undergoing primary TKA. Both cohorts were matched in terms of age, sex, and body mass index. We collected data on preoperative and postoperative range of motion, International Knee Society scores, and radiologic data. We also collected data on the modes of failure of the primary UKA. There were 55 patients in each cohort. The average time the UKA was in place was 48.3 months. The average follow-up period from the time of revision was 39.2 months. The most common reason for revision was subsidence of the tibial base plate (58%). Forty percent of patients required particulate bone grafting for contained defects. Two patients required metal augments, and 1 required stems. There was no significant difference between the 2 groups in terms of range of motion, functional outcome, or radiologic outcomes. Revision of these types of implants to TKA is associated with similar results to primary TKA and is superior to revision of other forms of UKA.

Periprosthetic stress fractures at the sleeve/stem junction of the Sivash-Range of Motion modular femoral stem.

We report on 13 cases of periprosthetic stress fracture at the sleeve/stem junction using the Sivash-Range of Motion femoral prosthesis. Radioisotope bone scans confirmed the incidence of fracture, and review of the lateral radiographs revealed anteromedial notching of the distal sleeve on the metaphyseal throat of the femur. Treatment in all cases was expectant with full resolution of symptoms. However, there were 3 cases of recurrence, 1 of which needed revision to a more distally loading stem. This is a rare complication when using this prosthesis, but we recommend a slight alteration of the entry point for the femoral reamer when using this stem and advise nonsurgical management if it occurs, as the natural history is for the condition to settle.

The Repicci II® unicondylar knee arthroplasty: 9-year survivorship and function.

BACKGROUND: Unicompartmental knee arthroplasty (UKA) is a recognized procedure for treatment of medial compartment osteoarthritis. UKA using minimally invasive surgery (MIS) has the theoretical advantage of less bone resection and quicker rehabilitation. Whether the function of patients with UKA compares with that of patients with conventional TKA is unclear. QUESTIONS/PURPOSES: We determined (1) the length of stay and complications associated with a short-stay MIS protocol; (2) whether MIS techniques allow for accurate positioning of the implant and alignment of the limb; (3) the change in functional scores; (4) the revision rate, reasons for revision, and survival of this implant. PATIENTS AND METHODS: We prospectively followed 100 patients who had 114 UKAs. All completed an International Knee Society (IKS) score preoperatively, at 1 year, and at last followup. We determined survivorship. Minimum followup was 5.2 years (mean, 7.4 years; range, 5.2-9 years). RESULTS: Mean length of stay was 1.2 days, with 41% discharged the same day. The perioperative complication rate was 6%. The mean IKS score improved from 77 to 93 and was 86 at last followup. The mean hip-knee-ankle axis changed from 6° varus to 1.7° varus. Twenty-two patients underwent a revision procedure at a mean 6.2 years after the index procedure. Survivorship of the prosthesis was 78% at 9 years. CONCLUSIONS: The short-stay protocol was not associated with a high perioperative complication rate. This technique is associated with improvement in function and restoration of limb alignment, allowing accurate positioning of the implant. Compared with other reports of survival of UKA, this implant had a lower survivorship and increased revision rate.

Hypokalaemia with severe rebound hyperkalaemia after therapeutic barbiturate coma.

Severe disturbance of potassium balance is a rare but life-threatening complication of therapeutic barbiturate coma. A 14-yr-old patient was treated with a thiopental infusion for management of increased intracranial pressure after severe head injury. The patient had persistent hypokalaemia during the thiopental infusion. On cessation of the infusion the patient rapidly developed a tachydysrhythmia associated with a serum K+ of 7.0. Possible mechanisms of this phenomenon are discussed. We conclude that aggressive treatment of hypokalaemia during barbiturate coma should be avoided, and advocate a tapering dose of thiopental and not abrupt cessation of an infusion. Severe disturbance of plasma potassium balance is a rare but life-threatening complication of therapeutic barbiturate coma. Awareness of this complication should be raised and management altered to less aggressive treatment of hypokalaemia occurring during thiopental infusion, with a tapering dose used on discontinuation to limit a rebound phenomenon.

Small changes lead to large effects.

It appears that the U.S. consumer has finally awakened the giant (e.g., Wal-Mart, Target, CVS, Walgreens). Healthcare is now providing its first consumer-driven business model. It is an opportunity for the healthcare system to better serve the needs of the community and improve access to health services. CCCs can be the catalyst that is needed to improve deliverables in primary and urgent care. It can also be the role model for price transparency and be a part of a long-term investment strategy for many healthcare organizations. As with most business opportunities, there is risk. Entering the retail clinic arena may not be the correct path for all health systems, but for some it may present a viable business opportunity and a chance to be on the cutting edge of the growing consumerism movement in our country.

A single-centre prospective study of clinical and haemostatic risk factors for venous thromboembolism following lower limb arthroplasty.

Previous studies report conflicting results concerning the potential significance of thrombophilic genotypes in postarthroplasty venous thromboembolism (VTE). This study assessed thrombophilic genotypes, haemostatic and clinical variables as independent risk factors for VTE postarthroplasty. A total number of 569 patients undergoing elective lower limb arthroplasty at a single centre were prospectively studied. All patients were interviewed and had blood samples collected preoperatively. Bilateral lower limb ultrasonography was performed at day 7 +/- 2 postoperatively in all patients (ventilation/perfusion lung scanning in symptomatic patients only). The incidence of inhospital postoperative VTE was 26%. In univariate analysis - increased age, knee arthroplasty, recent surgery, general anaesthesia, shorter operation time, non-receipt of blood transfusion and differences in surgical practice (including use of pneumatic calf compression, surgical drains and postoperative bandaging techniques) were significantly associated with VTE. Factor V Leiden, prothrombin G20210A and MTHFR C677T mutations were not significant risk factors for VTE, and of all haemostatic variables tested, only median activated partial thromboplastin time showed significant difference between VTE and non-VTE patients (34 s vs. 33 s). Multiple logistic regression analysis demonstrated that increased age, knee arthroplasty and individual surgeon's routine practices were the only significant independent risks for VTE; hence routine preoperative blood screening for a potential hypercoaguable state is not indicated in this surgical setting.

Usefulness of left atrial emptying fraction to predict exercise capacity in patients with normal systolic left ventricular function and without myocardial ischemia.

The association of left atrial volume at rest and the left atrial emptying fraction with exercise capacity during stress echocardiography was examined in patients with normal left ventricular function and without ischemia. The left atrial emptying fraction, along with body mass index, was found to be an independent predictor of poor exercise capacity (<5 METs).