Position of Hip Resurfacing Component Affects Strain and Resistance to Fracture in the Femoral Neck

Vail, Thomas P.; Glisson, Richard R.; Dominguez, D.; Kitaoka, Kenichi; Ottaviano, Danielle

doi:10.2106/jbjs.f.00788

Cited by 45 publications

(24 citation statements)

References 16 publications

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“…Preoperative AP pelvis radiographs were measured to determine the neck-shaft angle (NSA). The NSA was determined by measuring the angle between the midline of the proximal femoral diaphysis and the anatomic axis of the femoral neck [46] (Fig. 1).…”

Section: Methodsmentioning

confidence: 99%

The Learning Curve for Adopting Hip Resurfacing Among Hip Specialists

Nunley

Zhu

Brooks

et al. 2010

Clinical Orthopaedics &Amp; Related Research

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Patient demand and surgeon interest in hip resurfacing has recently increased, but surgeons in the United States are relatively inexperienced with this procedure. We determined the learning curve associated with hip resurfacing and compared the rate of early complications of the first 650 hip resurfacings between five experienced hip surgeons and a national safety survey database study we previously published, which included 89 surgeons and 537 hip resurfacings. Patient demographics and adverse events were recorded. Specific features on pre-and postoperative radiographs were measured in a blinded fashion by a single observer. There were 13 major complications (2.0%), which is 3.7 times lower than our national safety survey complication rate of 7.4%. All fractures occurred in the first 25 cases performed. The complication rate was higher for the first 25 procedures (5.6%) compared with the second 25 procedures (1

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Section: Methodsmentioning

confidence: 99%

The Learning Curve for Adopting Hip Resurfacing Among Hip Specialists

Nunley

Zhu

Brooks

et al. 2010

Clinical Orthopaedics &Amp; Related Research

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“…Major short-term risks include periprosthetic femoral neck fracture and early aseptic loosening of the femoral component [4,5]. In this context, non-optimal positioning of the prosthesis and femoral neck notching are critical [6][7][8][9][10][11]. Furthermore, inadequate implant orientation is associated with a higher risk of bone/implant impingement and complications related to increased metal wear [12,13].…”

Section: Introductionmentioning

confidence: 99%

The First SICOT Oral Presentation Award 2011: Imageless computer-assisted femoral component positioning in hip resurfacing: a prospective randomised trial

Stiehler

Goronzy

Hartmann

et al. 2013

International Orthopaedics (SICOT)

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Purpose The aim of the study was to evaluate the effects of imageless computer-assisted surgery (CAS) on the accuracy of positioning of the femoral component and on the shortterm clinical outcome in hip resurfacing (HR) using a randomised prospective design. Methods A total of 75 consecutive patients undergoing HR were randomly allocated to CAS and conventional implantation, respectively. Preoperatively and six months postoperatively standardised pelvic anteroposterior X-ray images, the total Western Ontario and McMaster Universities Osteoarthritis Index, the Harris Hip Score and the EQ-5D utility index were evaluated in a blinded manner. The primary end point of the study was a post-operative femoral component malpositioning in five degrees or more either varus or valgus absolute deviation from the planned stem shaft angle. Results Patient demographics and algofunctional scores did not differ between the CAS and conventional implantation samples. Using CAS fewer femoral components were positioned in five or more degrees absolute deviation (4/37 vs 12/38, Fisher's exact p=0.047; 95 % confidence interval for the primary end point's incidence difference: +3 %; +39 %); the respective incidences of five or more degrees of varus deviation were 0/37 vs 5/38. One conversion to a stemmed prosthesis (CAS group) was performed for periprosthetic femoral neck fracture. Radiological signs of superolateral femoral neck/implant impingement were observed in two cases (one CAS-based and one conventional implantation). Conclusions The accuracy of femoral HR component positioning was significantly improved using CAS. However, one major complication necessitated early revision in the CAS group at six months of observation. Apart from that adverse event no inter-group differences were observed for the short-term clinical outcome. Future studies need to address the clinical long-term relevance of CAS in HR.

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“…Other contributing factors include notching of the neck, 6,37 overimpaction causing bone microcracks, 38 and malalignment. 37,39 We analyzed only one implant design and size, while data from national registries show differences among implant designs and sizes, with a higher failure rate for smaller heads. 1 To investigate the effect of thermal necrosis on mechanical failure relative to these other factors would require mechanical modeling of femoral neck fracture in parametric analyses.…”

Section: Discussionmentioning

confidence: 99%

Effect of cementing technique and cement type on thermal necrosis in hip resurfacing arthroplasty—a numerical study

Janssen

Scheerlinck

2011

Journal Orthopaedic Research

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Femoral fractures within resurfacing implants have been associated with bone necrosis, possibly resulting from heat generated by cement polymerization. The amount of heat generated depends on cement mantle volume and type of cement. Using finite element analysis, the effect of cement type and volume on thermal necrosis was analyzed. Based on CT-data of earlier implantations, two different models were created: a thick mantle model, representing a low-viscosity ''cement filling'' technique, and a thin mantle model, representing a high viscosity ''cement packing'' technique. Six cement types were analyzed. The polymerization heat generation and its effect on bone necrosis were predicted. In the thin cement mantle models, no thermal necrosis was predicted. Thick cement mantle models produced thermal necrosis at the cement-bone interface depending on cement type. In the worst case, 6% of the bone at the cement-bone interface became necrotic, covering almost the entire cross-sectional area. The current findings suggest a potential thermal drawback of thick cement mantles, although it is unclear whether thermal bone necrosis significantly affects implant fixation or increases the fracture risk. Furthermore, our study showed distinct differences between the heat generated and resulting thermal damage caused by the various cement types. Keywords: finite element analysis; bone cement; thermal necrosis; hip resurfacing arthroplasty Hip resurfacing arthroplasty is an alternative for total hip arthroplasty (THA), with the proposed benefits of bone stock preservation and increased stability. The most common causes for revision of resurfacing arthroplasty are fracture, loosening, and lysis. 1 Although most fractures occur at the implant rim, 20% occur within the femoral component. 2 These fractures have been associated with bone necrosis, 3 often occurring in the bone-cement interface region. It has been hypothesized that this necrotic layer is caused by heat generated by polymerizing bone cement, inducing thermal damage to the bone. 4 Since polymerization of bone cement is an exothermic reaction, the amount of heat generated is proportional to its volume. As a result, hip resurfacings with larger amounts of cement in the femoral head display more fibrous tissue at the cement-bone interface. 5,6 The size and shape of the cement mantle depends on the cementing technique and the type of cement. [7][8][9] The use of low viscosity cement poured into the femoral component 10 leads to a relatively deep cement penetration into the femoral head, 7-9 and a large total cement volume especially when anchoring holes are used. 8 In contrast, when high viscosity cement is manually applied to the femoral head, a more homogeneous, thinner cement mantle is obtained. 8,11 Another factor affecting the temperature rise is the polymerization properties of the cement. 12,13 A fast polymerizing cement will cause a higher peak temperature that will last for a short time, while slower polymerizing cement will cause a lower peak temperature t...

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Position of Hip Resurfacing Component Affects Strain and Resistance to Fracture in the Femoral Neck

Cited by 45 publications

References 16 publications

The Learning Curve for Adopting Hip Resurfacing Among Hip Specialists

The Learning Curve for Adopting Hip Resurfacing Among Hip Specialists

The First SICOT Oral Presentation Award 2011: Imageless computer-assisted femoral component positioning in hip resurfacing: a prospective randomised trial

Effect of cementing technique and cement type on thermal necrosis in hip resurfacing arthroplasty—a numerical study

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