Lateral trochanteric bursa repair improves early hip function after posterior approach total hip arthroplasty: a prospective randomized control trial.

BACKGROUND: The trochanteric bursa (TB) is an anatomic structure, which is dissected during posterior/lateral hip approaches in Total Hip Arthroplasty (THA). Some surgeons prefer to simply resect the bursa as they believe that it may be responsible for postoperative lateral trochanteric pain (LTP). Others advocate that this tissue acts as a buffer minimizing friction between soft tissue and bone, and therefore its repair may prevent LTP after THA. AIM: The purpose of this prospective randomized controlled trial was to compare the clinical results of either resecting or repairing the TB during posterior approach THA. METHODS: Forty-two patients with primary hip osteoarthritis undergoing THA via a posterior hip approach were randomly assigned to two groups; Group A, or TB resection group and Group B, or TB repair group. All patients in both groups were evaluated postoperatively in terms of hip function, measured by the Harris Hip Score (HHS), at 6 weeks, 3 months, 6 months, and 12 months after surgery, as well as LTP during daily routine activities and lying on the operative side. RESULTS: Forty patients completed the study. Postoperative difference in terms of leg length and femoral offset was similar among the two groups (P = 0.467 and P = 0.39, respectively). At 6 weeks, patients in Group B had higher HHS (P = 0.052) and experienced less LTP when lying on the operative side (P = 0.046) but not during activities (P = 0.759). Thereafter, all functional parameters measured had comparable values in both groups. Subgroup analysis failed to identify any correlation between high offset stems and LTP. CONCLUSION: TB repair in posterior approach THA improves hip functional recovery as well as patients' ability to lie on the operative side during the early postoperative period.

Clinical accuracy of a patient-specific femoral osteotomy guide in minimally-invasive posterior hip arthroplasty.

INTRODUCTION: Patient specific guides can be a valuable tool in improving the precision of planned femoral neck osteotomies, especially in minimally invasive hip surgery, where bony landmarks are often inaccessible. The aim of our study was to validate the accuracy of a novel patient specific femoral osteotomy guide for THR through a minimally invasive posterior approach, the direct superior approach (DSA). METHODS: As part of our routine preoperative planning 30 patients underwent low dose CT scans of their arthritic hip. 3D printed patient specific femoral neck osteotomy guides were then produced. Intraoperatively, having cleared all soft tissue from the postero-lateral neck of the enlocated hip, the guide was placed and pinned onto the posterolateral femoral neck. The osteotomy was performed using an oscillating saw and the uncemented hip components were implanted as per routine. Postoperatively, the achieved level of the osteotomy at the medial calcar was compared with the planned level of resection using a 3D/2D matching analysis (Mimics X-ray module, Materialise, Belgium). RESULTS: A total of 30 patients undergoing uncemented Trinity acetabular and TriFit TS femoral component arthroplasty (Corin, UK) were included in our analysis. All but one of our analysed osteotomies were found to be within 3 mm from the planned height of osteotomy. In one patient the level of osteotomy deviated 5 mm below the planned level of resection. CONCLUSION: Preoperative planning and the use of patient specific osteotomy guides provides an accurate method of performing femoral neck osteotomies in minimally invasive hip arthroplasty using the direct superior approach. LEVEL OF EVIDENCE: IV (Case series).

Measuring the success of Medical Emergency Teams: potentially preventable deaths versus total cardiac arrest deaths. A single centre observational study.

BACKGROUND: Rapid response systems have been implemented with the aim of preventing patient deterioration, in-hospital cardiac arrests (IHCA) and related deaths. Not all 'unexpected deaths' are preventable, thus compromising the use of unexpected deaths as an outcome measure. AIMS: To assess temporal trends in potentially preventable deaths as a subset of total unexpected death rates over a 4-year period. METHODS: A single centre, cohort study of all unexpected deaths between 1 January 2010 and 31 December 2013. Unexpected deaths were identified from the rapid response systems database and patients' case histories were reviewed to reclassify the deaths into one of three categories: potentially preventable: if earlier MET activation may have prevented death; missed not for resuscitation opportunity; and not preventable. Total bed days were obtained from the hospital's patient administration system. RESULTS: The rate of potentially preventable deaths decreased from 5.3 to 0.7 per 100 000 bed days (incident rate ratio (IRR) 0.53 (95% CI 0.31-0.90), P = 0.02). The rate of total unexpected deaths was unchanged (IRR 0.96 (0.80-1.16), P = 0.70), as were the rates of non-preventable deaths (IRR 1.06 (0.78-1.42), P = 0.72) and missed NFR deaths (IRR 1.1 (0.83-1.42), P = 0.56). CONCLUSION: The rate of potentially preventable deaths has decreased by 47% per year over a 4-year period without any change in the overall rate of unexpected deaths. Distinguishing between potentially preventable deaths in contrast to total unexpected deaths enables more targeted evaluation of rapid response systems.

Survivorship and clinical outcome of Birmingham hip resurfacing: a minimum ten years' follow-up.

INTRODUCTION: Resurfacing as a percentage of total hip arthroplasty rose from 5.6 % in 2001 to 8.9 % in 2005 in Australia. During the same period the resurfacing to conventional prosthesis rose from 19.6 % to 29 % in the younger age group (less than 55 years). Long term (more than ten years) functional results of BHR are sparingly documented. Among the literatures available, the patient selection criteria vary from osteoarthritis, avascular necrosis, and dysplastic hip to slipped capital femoral epiphysis. The objective of the current study is to evaluate long term survivorship and functional outcome of Birmingham hip resurfacing surgery in osteoarthritic hip patients performed by a single surgeon. PATIENTS AND METHODS: In this retrospective clinical study, all patients who underwent hip resurfacing for osteoarthritis of hip between 1999 and 2004 are included. All surgeries were performed by single surgeon (SJM) and in all patients Smith & Nephew system (Midland Medical Technologies, Birmingham, United Kingdom)) was used. Revision surgery is considered the end point of survivorship. Means, standard deviations, and confidence interval were calculated for all continuous measures. Survival analysis was performed with the Kaplan-Meier method and 95 % confidence intervals were calculated. RESULT: The result is based on 222 patients (244 hips). This included 153 males and 69 females. Our mean follow up was 12.05 years and overall survival was 93.7 %. In terms of gender, survival in males was 95.43 % while in females it was 89.86 %. Failure was seen in 14 patients (16 hips), which included seven female (10.14 %) and seven male (4.57 %) patients. Failure of femoral components due to aseptic loosening and varus collapse was seen in eight patients after a mean 9.6 years. Metal allergy was seen in three patients (five hips), all of them were female of which two had bilateral resurfacing. Other complications included femoral neck stress fractures in two patients and acetabular component loosening in one patient. We observed that the failure rate is higher if the BHR femoral component size is 46 or less (ten out of 16 hips revised). CONCLUSION: If patient selection is judiciously done and surgical technique is meticulously followed, hip resurfacing offers acceptable survivorship, satisfactory range of motion and enables patients to resume high demand activities including sports. Future improvements in the bearing surfaces, and possibly in the design, might alleviate concerns posed by high serum metal level and provide options that continue to benefit younger patients in future.

Total hip arthroplasty using a short-stem prosthesis: restoration of hip anatomy.

PURPOSE: To evaluate hip parameters such as vertical centre of rotation (VCR), horizontal centre of rotation (HCR), femoral offset, and leg length after total hip arthroplasty (THA) using the Nanos short-stem prosthesis. METHODS: Medical records of 73 men and 74 women aged 25 to 92 (mean, 63) years who underwent THA using the Nanos short-stem prosthesis by a single surgeon were reviewed. Prior to the surgery, the optimal cup and stem size, head length, and level of the neck osteotomy were determined using radiographs. Intra-operatively, the leg length and femoral offset were checked, and the level of neck resection and head length were adjusted. VCR, HCR, femoral offset, and leg length of the operated and contralateral sides were compared. Functional outcomes were assessed using the Harris Hip Score (HHS). RESULTS: Compared with the normal contralateral hips, the operated hips had a mean increase of 0.4 mm in VCR (p=0.032), a mean decrease of 1.4 mm in HCR (p=0.027), a mean increase of 0.6 mm in femoral offset (p=0.043), and a mean increase of 0.36 mm in leg length (p=0.035). For these respective parameters, the difference between the normal contralateral side and the operated side was within 5 mm in 89%, 80%, 71%, and 96% of patients. The HHS improved from a mean of 53 to 91 at one year (p<0.001). CONCLUSION: THA using the Nanos short-stem prosthesis enabled restoration of hip anatomy (VCR, HCR, femoral offset, and leg length).

Lateral parapatellar approach with tibial tubercle osteotomy for the treatment of non-correctable valgus knee osteoarthritis: a retrospective clinical study.

BACKGROUND: The aim of this retrospective study was to evaluate the efficacy of a lateral parapatellar approach combined with a tibial tubercle osteotomy (TTO) in patients undergoing total knee arthroplasty (TKA) with non-correctable valgus knee osteoarthritis. METHODS: We studied 53 consecutive patients (57 knees) who had a primary TKA via lateral parapatellar approach with a global step-cut "coffin" type TTO over a 10-year period. All patients had non-correctable grade II valgus deformity according to the Ranawat classification. The average age of patients was 71 years (45 to 77) and the mean follow-up was 39 months (20 to 98). RESULTS: Post-surgery, there was a significant improvement in knee extension (p=0.002), flexion (p=0.006), Knee Society Pain and Function Scores (p<0.001) and WOMAC Osteoarthritis Index (p<0.001). The tibiofemoral angle changed from a preoperative median value of 11 deg (10 to 17) to a postoperative value of 3.75 deg (0 to 9). Congruent patellar tracking was observed in all cases. All but one osteotomy united in a median period of 16.7 weeks (9 to 28) and no hardware removal was required. One knee developed infection treated with two-stage reconstruction. A proximal tibial stress fracture also occurred in a patient on long-term bisphosphonate therapy. CONCLUSION: Lateral parapatellar approach along with TTO is an effective technique for addressing non-correctable valgus knee deformity during TKA.

Effect of flexion and rotation on measures of coronal alignment after TKA.

Attainment of a neutral mechanical axis is one of the primary goals in total knee arthroplasty (TKA). The accuracy of the procedure is evaluated by measuring the hip-knee-ankle angle (HKAA) on long leg radiographs. Rotation of the lower limb and knee flexion could possibly affect the HKAA measured on plain radiographs. In this study, a TKA was performed on a saw-bone model of the lower limb. Long leg radiographs from the femoral head to the ankle were obtained after sequentially varying the alignment of the knee model in 5-degree increments of flexion and rotation, from 0 to 20 degrees. Flexion or external rotation alone, up to 20 degrees changed the HKAA by no more than 1 degree. A combination of flexion and external rotation progressively altered the HKAA. The HKAA was altered by 5 degrees at a combination of 15- or 20-degree flexion and 20-degree external rotation. While flexion or external rotation alone had little effect on the HKAA, a combination of the two altered it substantially.

Arthroplasty options in femoral-neck fracture: answers from the national registries.

PURPOSE: Femoral-neck fracture in the elderly population is a problem that demands the attention of the orthopaedic community as life expectancy continues to increase. There are several different treatment options in use, and this variety in and of itself indicates the absence of an ideal single treatment option. Recent debate has focussed on the probable superiority of total hip arthroplasty (THA) over hemiarthroplasty for femoral-neck fracture. Clinical trials and systematic reviews of such trials have not provided a convincing answer to this question. METHODS: We analysed data from national registries evaluating prosthetic replacements for femoral-neck fracture in the elderly. We compared revision and reoperation rates of hemiarthroplasty and THA, analysed the prognostic variables that influenced implant survival and the major causes of failure. RESULTS: Data from the Australian and Italian registries indicate that THA has an increased revision rate compared with bipolar hemiarthroplasty in femoral-neck fracture in the elderly. The registries identify that age over 75 years and the use of the anterior surgical approach are associated with better survivorship in patients who have a hemiarthroplasty. Cemented fixation of the femoral stem in hemiarthroplasty and THA is supported by registry data. Acetabular erosion accounted for a very low percentage of hemiarthroplasty revisions and reoperations. CONCLUSION: Our review of data from national registries supports the continued use of bipolar hemiarthroplasty in femoral-neck fracture in the elderly and identifies age, method of fixation and surgical approach as important prognostic variables in determining implant survival.

In vivo response of bone defects filled with PMMA in an ovine model.

The use of PMMA cement is common in arthroplasty for cemented fixation and defect filling. Concerns remain regarding effects of cement curing temperature on the viability of cancellous bone. In this study we filled surgically-created defects (mean volume 0.585±0.251 mL) in the cancellous bone of the distal femur and proximal tibia of 6 sheep with PMMA and measured temperature changes in surrounding bone whilst the cement cured, using 3 thermocouples per defect. Animals were euthanised at 3 (n=3) and 12 (n=3) weeks postoperatively and the bone-cement interface assessed histologically. Despite mean maximum temperatures of 49.3±10.2 °C (range: 40.9 °C - 82.2 °C) thermonecrosis was not a common histological feature at either timepoint. The exposure of bone to high cement temperatures in this study has not led to bone necrosis and/or tissue damage.

Vascularity of the femoral head after Birmingham hip resurfacing. A technetium Tc 99m bone scan/single photon emission computed tomography study.

To investigate the vascularity of femoral heads after Birmingham hip resurfacing (BHR), we used a visual scale to assess technetium Tc 99m HDP planar and single photon emission computed tomography bone scans of 36 arthroplasties in 32 asymptomatic patients for an average of 26 months after BHR. The validity of this method was demonstrated by comparing levels of radiation detected from within and immediately adjacent to a BHR prosthesis placed on a technetium Tc 99m radioisotope tracer-filled hollow tube and further validated in vivo by comparing radiation levels from bilateral hip scans in human subjects with 2 normal hips and with unilateral BHR. All femoral heads scanned postoperatively appeared vascular. We speculate that preserved femoral head vascularity after BHR may be related to increased intraosseous blood supply from metaphyseal vessels in arthritic hips.

Cardiovascular actions of the venom from the Irukandji (Carukia barnesi) jellyfish: effects in human, rat and guinea-pig tissues in vitro and in pigs in vitro.

1. We have investigated the cardiovascular pharmacology of the crude venom extract (CVE) from the potentially lethal, very small carybdeid jellyfish Carukia barnesi, in rat, guinea-pig and human isolated tissues and anaesthetized piglets. 2. In rat and guinea-pig isolated right atria, CVE (0.1-10 microg/mL) caused tachycardia in the presence of atropine (1 micromol/L), a response almost completely abolished by pretreatment with tetrodotoxin (TTX; 0.1 micromol/L). In paced left atria from guinea-pig or rat, CVE (0.1-3 microg/mL) caused a positive inotropic response in the presence of atropine (1 micromol/L). 3. In rat mesenteric small arteries, CVE (0.1-30 microg/mL) caused concentration-dependent contractions that were unaffected by 0.1 micromol/L TTX, 0.3 micromol/L prazosin or 0.1 micromol/L omega-conotoxin GVIA. 4. Neither the rat right atria tachycardic response nor the contraction of rat mesenteric arteries to CVE were affected by the presence of box jellyfish (Chironex fleckeri) antivenom (92.6 units/mL). 5. In human isolated driven right atrial trabeculae muscle strips, CVE (10 microg/mL) tended to cause an initial fall, followed by a more sustained increase, in contractile force. In the presence of atropine (1 micromol/L), CVE only caused a positive inotropic response. In separate experiments in the presence of propranolol (0.2 micromol/L), the negative inotropic effect of CVE was enhanced, whereas the positive inotropic response was markedly decreased. 6. In anaesthetized piglets, CVE (67 microg/kg, i.v.) caused sustained tachycardia and systemic and pulmonary hypertension. Venous blood samples demonstrated a marked elevation in circulating levels of noradrenaline and adrenaline. 7. We conclude that C. barnesi venom may contain a neural sodium channel activator (blocked by TTX) that, in isolated atrial tissue (and in vivo), causes the release of transmitter (and circulating) catecholamines. The venom may also contain a 'direct' vasoconstrictor component. These observations explain, at least in part, the clinical features of the potentially deadly Irukandji syndrome.

Eye injury after jellyfish sting in temperate Australia.

Although jellyfish stings are an uncommon medical problem in temperate Australia, significant morbidity can occur, particularly in association with infestations of large numbers of jellyfish in public swimming areas. We report a case of a jellyfish sting-related eye injury, probably caused by the "hair" jellyfish (Cyanea capillata) from southeast Australia. The patient, a 54-year-old man, was stung while swimming without goggles in a jellyfish-infested bay. He experienced severe pain in his right eye, requiring narcotic analgesia, and had decreased visual acuity associated with right-sided facial swelling. Although usually brief and self-limiting, eye injuries after jellyfish stings should be assessed and treated as early as possible to reduce the risk of longer term sequelae. Water safety campaigns should incorporate information on the prevention and early treatment of such stings.