Limits...
Initial evaluation on subsidence of cemented collarless polished tapered stem applied to the patients with narrow femoral medullar canal.

Dairaku K, Ishii M, Kobayashi S, Kawaji H, Sasaki K, Takakubo Y, Takagi M - Open Orthop J (2010)

Bottom Line: In 39 of 45 cases, subsidence was appeared within six months after operation.Marked progressive and excessive subsidence was not seen after the two years of follow-up.Short term radiographic results of THA with CPT stem to small femur were satisfactory with less unfavorable radiographic findings, which imply contribution to longer survivorship of the stem.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan.

ABSTRACT

Purpose: The geometry of the proximal femur is one of the important factors for choosing the suitable stem. We have been applied cemented collarless polished tapered (CPT) stem to the patients with small femur. Radiographic evaluation was performed to access the clinical feature of the stem in early stage of the follow-up.

Methods: One hundred total hip arthroplasties with CPT system were performed between October 2004 to February 2006. This study focused on the 53 cases to whom size 1 or smaller sized stem were implanted, and its post-operative period was 41 months (30-46 months). Morphologic classification of preoperative proximal femur, stem alignment, thickness of the cement mantle, cementing technique, subsidence of the stem, improvement in the bone-cement interface, and stress shielding were assessed.

Results: The size of the inserted stem was X-SMALL in one case, SMALL in two cases, SIZE 0 in 12 cases, and SIZE 1 in 38 cases. Canal shape of proximal femur was stovepipe type in five cases, normal type in 43 cases, and champagne-flute type in five cases. There was no subsidence in eight cases. 44 stems subsided within 1 mm, one stem subsided 1 to 2 mm, and no stem subsided over 2 mm. In 39 of 45 cases, subsidence was appeared within six months after operation. Marked progressive and excessive subsidence was not seen after the two years of follow-up.

Conclusions: Short term radiographic results of THA with CPT stem to small femur were satisfactory with less unfavorable radiographic findings, which imply contribution to longer survivorship of the stem.

No MeSH data available.


Related in: MedlinePlus

Canal shape and proximal femur. Canal shape was classified by canal flare index, defined as ratio of the intracortical width of the femur at a point 20 mm proximal to the lesser trochanter and at canal isthmus. (a): stovepipe (canal flare index < 3.0), (b): normal (3.0-4.7), (c) champagne-flute (4.7-6.5).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2864431&req=5

Figure 1: Canal shape and proximal femur. Canal shape was classified by canal flare index, defined as ratio of the intracortical width of the femur at a point 20 mm proximal to the lesser trochanter and at canal isthmus. (a): stovepipe (canal flare index < 3.0), (b): normal (3.0-4.7), (c) champagne-flute (4.7-6.5).

Mentions: One hundred total hip arthroplasties with CPT system were performed between October 2004 to February 2006 at Department of Orthopaedic Surgery, Yamagata University School of Medicine and Saiseikai Yamagata Saisei Hospital. This study focused on the 53 joints to whom SIZE 1 or smaller sized stem were implanted. Forty-five patients were female (50 joints) and three were male (three joints). Mean age at surgery was 60.6 years (44-80 years), and mean body weight was 54.3 kg (37.2-75.0 kg), and its post-operative period was 41 months (30-46 months). Preoperative diagnosis was osteoarthritis in 46 cases, rheumatoid arthritis in one case, and rapidly destructive coxarthrosis in one case. All operations were performed by lateral position and postero-lateral approach. Forty of 53 cases were performed by consultant surgeon, nine cases were by junior surgeon, and one case was by resident surgeon. Acetabular reconstruction was performed with cemented cup (ZCA, Zimmer, Warsaw, USA) in 47 cases, cemented cup (FPW, JMM, Osaka, Japan) in one case, and cementless cup (Trilogy, Zimmer, Warsaw, USA) in five cases. CPT stem was inserted with distal centralizer after the filling the medullary cavity with bone cement (Endurance, DePuy, Leeds, UK), followed by proximal femoral pressurization. Anterior and lateral projection of radiographs were obtained before operation, just after operation, at three months, six months, one year, and yearly thereafter. Morphologic classification of proximal femur, as described by Noble et al. [3], was assessed from radiograph taken before operation (Fig. 1). Canal shape was classified by canal flare index, defined as ratio of the intracortical width of the femur at a point 20 mm proximal to the lesser trochanter and at canal isthmus. Canal flare index of less than 3.0 described stovepipe, 3.0-4.7 was normal and 4.7-6.5 was champagne-flute. Stem alignment, thickness of the cement mantle and cementing technique, as described by Barrack et al. [4], were assessed in all the 14 zone of Gruen et al. [5] and from radiographs taken just after operation. The proximal femur was delineated into 1-7 zones from the anteroposterior radiographs and 8-14 zones from lateral radiographs. As for cementing technique by Barrack, so-called white-out at the cement-bone interface was defined as grade A, the presence of slight radiolucency of the cement-bone interface was defined as Grade B, the presence of radiolucency involving 50% to 99% was defined as Grade C, and the presence of radiolucency involving 100% in any injection, or a failure to fill the canal with cement such that the tip of the stem was defined as Grade D. Subsidence of the stem was evaluated according to the method described by Fowler et al. [6]. The amount of the subsidence was evaluated by measurement of lucent line that appeared between stem and cement in the part of so-called “the shoulder” of the stem (Fig. 2). When cement was absent at the shoulder of the stem, the amount of stem tip migration in centralizer was measured. Improvement in the bone-cement interface, which can be seen as an increase in the density of the cancellous bone, described by Wroblewski et al. [7] which based on subjective view, although quantitative analysis such as DEXA or CT was not performed. This type of analysis would be required for further analysis in this type of study. All assessments were performed with radiographs taken at least two years after operation. Cortical hypertrophy and fracture of cement mantle, correlation between canal shape and cement technique, and degree of subsidence were evaluated. Correlation between improvement in the bone-cement interface and gender, age, body weight was also assessed. Chi-square test, Fisher’s exact probably test, and Mann-Whitney U test were used for statistical analysis. A value of p < 0.05 was considered to be statistically significant.


Initial evaluation on subsidence of cemented collarless polished tapered stem applied to the patients with narrow femoral medullar canal.

Dairaku K, Ishii M, Kobayashi S, Kawaji H, Sasaki K, Takakubo Y, Takagi M - Open Orthop J (2010)

Canal shape and proximal femur. Canal shape was classified by canal flare index, defined as ratio of the intracortical width of the femur at a point 20 mm proximal to the lesser trochanter and at canal isthmus. (a): stovepipe (canal flare index < 3.0), (b): normal (3.0-4.7), (c) champagne-flute (4.7-6.5).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2864431&req=5

Figure 1: Canal shape and proximal femur. Canal shape was classified by canal flare index, defined as ratio of the intracortical width of the femur at a point 20 mm proximal to the lesser trochanter and at canal isthmus. (a): stovepipe (canal flare index < 3.0), (b): normal (3.0-4.7), (c) champagne-flute (4.7-6.5).
Mentions: One hundred total hip arthroplasties with CPT system were performed between October 2004 to February 2006 at Department of Orthopaedic Surgery, Yamagata University School of Medicine and Saiseikai Yamagata Saisei Hospital. This study focused on the 53 joints to whom SIZE 1 or smaller sized stem were implanted. Forty-five patients were female (50 joints) and three were male (three joints). Mean age at surgery was 60.6 years (44-80 years), and mean body weight was 54.3 kg (37.2-75.0 kg), and its post-operative period was 41 months (30-46 months). Preoperative diagnosis was osteoarthritis in 46 cases, rheumatoid arthritis in one case, and rapidly destructive coxarthrosis in one case. All operations were performed by lateral position and postero-lateral approach. Forty of 53 cases were performed by consultant surgeon, nine cases were by junior surgeon, and one case was by resident surgeon. Acetabular reconstruction was performed with cemented cup (ZCA, Zimmer, Warsaw, USA) in 47 cases, cemented cup (FPW, JMM, Osaka, Japan) in one case, and cementless cup (Trilogy, Zimmer, Warsaw, USA) in five cases. CPT stem was inserted with distal centralizer after the filling the medullary cavity with bone cement (Endurance, DePuy, Leeds, UK), followed by proximal femoral pressurization. Anterior and lateral projection of radiographs were obtained before operation, just after operation, at three months, six months, one year, and yearly thereafter. Morphologic classification of proximal femur, as described by Noble et al. [3], was assessed from radiograph taken before operation (Fig. 1). Canal shape was classified by canal flare index, defined as ratio of the intracortical width of the femur at a point 20 mm proximal to the lesser trochanter and at canal isthmus. Canal flare index of less than 3.0 described stovepipe, 3.0-4.7 was normal and 4.7-6.5 was champagne-flute. Stem alignment, thickness of the cement mantle and cementing technique, as described by Barrack et al. [4], were assessed in all the 14 zone of Gruen et al. [5] and from radiographs taken just after operation. The proximal femur was delineated into 1-7 zones from the anteroposterior radiographs and 8-14 zones from lateral radiographs. As for cementing technique by Barrack, so-called white-out at the cement-bone interface was defined as grade A, the presence of slight radiolucency of the cement-bone interface was defined as Grade B, the presence of radiolucency involving 50% to 99% was defined as Grade C, and the presence of radiolucency involving 100% in any injection, or a failure to fill the canal with cement such that the tip of the stem was defined as Grade D. Subsidence of the stem was evaluated according to the method described by Fowler et al. [6]. The amount of the subsidence was evaluated by measurement of lucent line that appeared between stem and cement in the part of so-called “the shoulder” of the stem (Fig. 2). When cement was absent at the shoulder of the stem, the amount of stem tip migration in centralizer was measured. Improvement in the bone-cement interface, which can be seen as an increase in the density of the cancellous bone, described by Wroblewski et al. [7] which based on subjective view, although quantitative analysis such as DEXA or CT was not performed. This type of analysis would be required for further analysis in this type of study. All assessments were performed with radiographs taken at least two years after operation. Cortical hypertrophy and fracture of cement mantle, correlation between canal shape and cement technique, and degree of subsidence were evaluated. Correlation between improvement in the bone-cement interface and gender, age, body weight was also assessed. Chi-square test, Fisher’s exact probably test, and Mann-Whitney U test were used for statistical analysis. A value of p < 0.05 was considered to be statistically significant.

Bottom Line: In 39 of 45 cases, subsidence was appeared within six months after operation.Marked progressive and excessive subsidence was not seen after the two years of follow-up.Short term radiographic results of THA with CPT stem to small femur were satisfactory with less unfavorable radiographic findings, which imply contribution to longer survivorship of the stem.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthopaedic Surgery, Yamagata University School of Medicine, 2-2-2 Iida-Nishi, Yamagata 990-9585, Japan.

ABSTRACT

Purpose: The geometry of the proximal femur is one of the important factors for choosing the suitable stem. We have been applied cemented collarless polished tapered (CPT) stem to the patients with small femur. Radiographic evaluation was performed to access the clinical feature of the stem in early stage of the follow-up.

Methods: One hundred total hip arthroplasties with CPT system were performed between October 2004 to February 2006. This study focused on the 53 cases to whom size 1 or smaller sized stem were implanted, and its post-operative period was 41 months (30-46 months). Morphologic classification of preoperative proximal femur, stem alignment, thickness of the cement mantle, cementing technique, subsidence of the stem, improvement in the bone-cement interface, and stress shielding were assessed.

Results: The size of the inserted stem was X-SMALL in one case, SMALL in two cases, SIZE 0 in 12 cases, and SIZE 1 in 38 cases. Canal shape of proximal femur was stovepipe type in five cases, normal type in 43 cases, and champagne-flute type in five cases. There was no subsidence in eight cases. 44 stems subsided within 1 mm, one stem subsided 1 to 2 mm, and no stem subsided over 2 mm. In 39 of 45 cases, subsidence was appeared within six months after operation. Marked progressive and excessive subsidence was not seen after the two years of follow-up.

Conclusions: Short term radiographic results of THA with CPT stem to small femur were satisfactory with less unfavorable radiographic findings, which imply contribution to longer survivorship of the stem.

No MeSH data available.


Related in: MedlinePlus