Polyethylene spinout in the Attune® Cruciate-Retaining Rotating-Platform (CR RP) total knee arthroplasty performed with a cruciate-sacrificing and measured-resection technique.

INTRODUCTION: Polyethylene (PE) spinout is a known but uncommon complication when using a mobile-bearing (MB) total knee arthroplasty (TKA) design. Sacrificing the posterior cruciate ligament (PCL) is within the manufacturer's recommendations for the Attune® Cruciate-Retaining Rotating-Platform (CR RP) knee design. AIM: To discuss the potential aetiology and prevention of spinout in the Attune® CR RP knee. METHODS: We used a retrospective radiological review from two centres reporting a higher rate of spinout in the Attune® CR RP knee using a cruciate-sacrificing and measured-resection technique when compared to a gap-balancing technique. Three hundred and thirty-two patients were evaluated over a 3-year period. RESULTS: There were 8 out of 279 (2.86%) cases of spinout in our first cohort of patients using a measured-resection technique. There were 0 out of 53 cases of spinout in our second cohort of patients where a gap-balancing technique was used. One spinout was reduced closed, the other seven were initially revised to a thicker RP insert of the same design. Of these seven, three underwent a further revision TKA and one patient required a knee fusion/arthrodesis. CONCLUSIONS: This study reports a higher incidence of PE spinout in the Attune® CR RP TKA when a measured-resection technique in combination with PCL resection is performed. We recommend a gap-balancing technique with conservative soft-tissue release if the surgeon is planning to sacrifice the PCL in the Attune® CR RP.

Pseudoaneurysm of the Superficial Femoral Artery after Knee Arthroscopy.

An 84 year old gentleman underwent knee arthroscopy. He had x-ray proven left knee osteoarthritis. He had a number of medical co-morbidities including being on an anticoagulant for atrial fibrillation. He did not want a knee replacement. A knee arthroscopy was performed which confirmed severe left knee osteoarthritis. Debridement of degenerative meniscus was performed. Three weeks post-operatively, the patient presented to the emergency department complaining of swelling and pain in his lower limb. He underwent an ultrasound venogram to look for a deep venous thrombosis (DVT). He was diagnosed with a pseudoaneurysm (PSA) of the superficial femoral artery (SFA). Subsequently, he was referred to the vascular surgery service who treated the PSA with covered stenting. The thigh and knee pain dissipated almost immediately. We propose that this is the first PSA of the left SFA to be documented after a knee arthroscopy. The authors would like to acknowledge that knee arthroscopy for severe osteoarthritis is rarely performed in an octogenarian. However, as this patient had declined a total knee replacement (TKR) and injections were no longer providing him relief, knee arthroscopy was performed.

Longest Known Follow-up of a Hip Arthroplasty: The Last Chapter of a 65-Year Long Story.

INTRODUCTION: The Smith-Petersen vitallium mold arthroplasty was a real landmark in arthroplasty surgery as this was the first technique which produced predictable and satisfactory results. CASE REPORT: We present the longest known follow-up of any hip arthroplasty in literature. The arthroplasty was performed in 1949 in London on a 30-years-old female patient with congenital hip dysplasia, and it was revised in 2014 after 65 years. CONCLUSION: Total hip arthroplasties nowadays give better functional results, but the fact that the patient got 65 years of the relatively good function is noteworthy and is a tribute to Dr. Marius Nygaard Smith-Petersen.

The use of weekly departmental review of all orthopaedic intra-operative radiographs in order to improve quality, due to standardized peer expectations and the "Hawthorne effect".

INTRODUCTION: Clinical governance highlights risk management, clinical effectiveness and use of evidence based practice as key elements in the provision of a quality service. A change in the method of quality control in our orthopaedic trauma unit allowed us the opportunity to study if the quality of operative outcomes had changed as a result. The Hawthorne effect refers to phenomenon whereby employees work quality improves by virtue of their awareness that their labour is being assessed. METHODS: A new outcome appraisal forum was introduced in our department in 2009. This forum involved a weekly whole department review of all the previous week's intraoperative radiographs. We used the tip apex distance (TAD) of the dynamic hip screw (DHS) procedures in hip fracture patients as a surrogate marker, of any objective change in the quality and consistency of intra-operative radiographs, in the year prior to and after the introduction of this review system. RESULTS: We found that the mean TAD and the number of TAD measurements over 25 mm decreased significantly in the year after the new quality control mechanism was introduced. CONCLUSION: We would recommend the use of a weekly quality control meeting scrutinizing every intraoperative radiograph as a simple, cost effective method of incorporating many aspects of clinical governance, as well as fostering a culture of quality.

Subtrochanteric hip fractures treated with cerclage cables and long cephalomedullary nails: a review of 17 consecutive cases over 2 years.

BACKGROUND: The conflict between the anatomist and biologist surgeons is exemplified by the debate about subtrochanteric hip fractures. Closed intramedullary nailing is biologically friendly but may result in prolonged procedures and malunion. By contrast, accurate anatomical open reduction may disturb the biological composition of the fracture environment. METHODS: There were 17 patients at our institution over a 2-year period whose long oblique subtrochanteric fractures would not reduce perfectly in an anatomical fashion using closed methods. All these patients had their fractures treated identically using a new policy at our unit. This strategy involved reduction of the fracture through an open approach, and then employing cerclage cables to stabilise the fracture in an anatomical position before finally inserting a cephalomedullary nail. These patients were retrospectively reviewed at an average of 18 months postoperatively, to assess their progressive functional and radiological outcome up to that point. RESULTS: One patient had nonunion and required a secondary procedure. One patient died 8 days postoperatively from a medical complication. The remaining 15 healed within 6 months and all returned to independent living. CONCLUSIONS: The results demonstrate that judicious use of cerclage cables to augment fixation of subtrochanteric femur fractures does not have a deleterious effect on healing. One should endeavour, however, to minimise the number of cables used. The basic science literature underpinning our approach to these unstable fractures is also discussed.

Monocular blindness following elective hip arthroplasty.

Visual loss is a devastating complication of non-ophthalmic surgery. It is documented following cardiac, spinal, and transplant surgery. Patients with carotid artery occlusion are at increased risk for ocular ischaemia. Pre-operative assessment as well as early diagnosis and treatment is essential in cases of high-risk patients. We discuss the case of an 82-year-old man who underwent an elective total hip replacement and was left with monocular hemispherical blindness as a result of branch retinal artery occlusion.

Stability of the metastatic spine pre and post vertebroplasty.

OBJECTIVE: Vertebrae with lytic metastases have an elevated risk of burst fracture and resultant neurologic compromise. Prophylactic vertebroplasty has the potential to reduce pain and the risk of burst fracture in the metastatic spine. The purpose of this study was to quantify the ability of vertebroplasty to stabilize metastatically involved vertebrae against the risk of burst fracture initiation with a standardized model of vertebral metastases. METHODS: Metastases were simulated in eight fresh-frozen cadaveric thoracolumbar spinal motion segments by removing a central core of trabecular bone and filling the defect with tumor tissue. Specimens were tested under a physiologic level of axial compression, intact, with a simulated tumor and post-vertebroplasty, and ultimately tested to failure. Axial load induced canal narrowing (CN) was used as a measure of the risk of burst fracture initiation. Following testing, vertebrae were axially sectioned to visualize cement fill. RESULTS: Vertebrae with simulated metastases exhibited significantly higher CN than intact specimens (227%+/-109%; P<0.05). Post vertebroplasty, three vertebrae exhibited reduced CN compared with the simulated tumor configuration, whereas the other five had increased CN. Specimens with reduced CN were found to have cement posterior to the tumor, whereas specimens with an increase in CN had cement anterior and lateral to the tumor only. Percutaneous vertebroplasty is effective in decreasing CN if tumor is surrounded posteriorly with cement. However, injecting cement into the posterior third of the vertebral body is risky due to potential extravasation into the canal. CONCLUSION: Future work aimed at improving cement fill is necessary for safe and consistent stabilization of the metastatic spine with vertebroplasty.

A biomechanical analysis of intravertebral pressures during vertebroplasty of cadaveric spines with and without simulated metastases.

STUDY DESIGN: A biomechanical cadaveric study of thoracic and lumbar vertebrae with simulated metastases quantifying intravertebral pressures during transpedicular vertebroplasty. OBJECTIVE: To compare intravertebral pressures during percutaneous vertebroplasty in vertebrae with and without simulated lytic metastases. SUMMARY OF BACKGROUND DATA: Percutaneous vertebroplasty is designed to provide stability to vertebrae weakened by osteoporosis or metastatic disease. The complication rate is higher when the procedure is used for the treatment of lytic vertebral lesions. The major complications reported are radiculopathy, spinal cord compression, and embolic phenomena. METHODS: Ten fresh-frozen cadaveric vertebrae were tested intact (7 lumbar, 3 thoracic) and 7 were tested with simulated lytic defects (4 lumbar, 3 thoracic). Defects were created by replacing a core of cancellous bone with soft tumor tissue in the center of the vertebral body. Simplex P (Howmedica Osteonics, Mahwah, NJ) cement was injected into each vertebra through a unipedicular approach at a constant rate of 3 mL per minute. Cement volume, injection force, and intravertebral pressures at the posterior vertebral body wall were recorded. Following the procedure, the vertebrae were sectioned to visualize cement and tumor disbursement. RESULTS: There was no significant difference between the two groups for age, size, trabecular density, and cement volume. Vertebrae with simulated metastases generated an average maximum pressure of 39.66 kPa during cement injection versus 6.83 kPa in intact vertebrae (P < 0.05). Higher pressures were also generated in smaller vertebrae based on a power relationship (r2 = 0.71 intact, r2 = 0.43 tumor). CONCLUSIONS: Percutaneous vertebroplasty produces higher intravertebral pressures in vertebrae containing a simulated lytic metastasis than in intact vertebrae. Pressures generated in the tumor specimens are sufficiently elevated to cause embolic phenomena.