Materials and Methods

K-MAX HS-3 THA (Kyocera, Japan), with tapered cemented stem with small collar and all polyethylene cemented socket, was used for THA implants (Fig.1). Basically the third generation cementing technique was used for THA using bone cement. The socket fixation was performed with bone cement (Endurance, DePuy) and HA granules (Ca10(PO4)6(OH)2, Boneceram P; G-2, 0.3–0.6mm in size, Olympus, Japan) (Fig.2). In original IBBC technique, HA granules were dispersed on reamed acetabulum before cementing. In M-IBBC technique, HA granules were attached to bone cement on plastic plate, then inserted to reamed acetabulum and pressurized (Fig.3). 112 hip joints (95 cases) were operated between June 2010 and March 2014, and followed. The average follow-up period was 6.5 years, and average age at operation was 66.5 years. The clinical results were evaluated by Japan Orthopaedic Association Hip Score (JOA score), and X-p findings were evaluated using antero-posterior radiographs. The locations of radiolucent lines were identified according to the zones described by Delee and Charnley for acetabular components, and Zone 1 was divided into two parts, outer Zone 1a and inner Zone 1b.

Materials and Methods

In K-MAX HS-3 THA (Kyocera Medical, Kyoto, Japan), cemented titanium alloy stem and all polyethylene cemented socket are used. This stem has the double tapered symmetrical stem design, allowing the rotational stability and uniform stress distribution. The features of this stem are; 1. Vanadium-free high-strength titanium alloy (Ti-15Mo-5Zr-3Al), 2. Double-tapered design, 3. Smooth surface (Ra 0.4µm), 4. Broad proximal profile, 5. Small collar.

Previous type stem, which was made of the same smooth-surface titanium alloy, has the design with cylindrical stem tip, allowing the maximum filling of the femoral canal. Osteolysis at the distal end of the stem had been reported in a few cases in previous type with cylindrical stem tip, probably due to the local stress concentration. Therefore the tapered stem was designed, expecting better clinical results.

157 THAs using HS-3 taper type stem were performed at Kitano Hospital between March 2004 and March 2008. And 101 THAs, followed for more than 10 years, were investigated (follow-up rate; 64.3%). The average age of the patients followed at the operation was 61.7 years and the average follow-up period was 10.9 years. The all-polyethylene socket was fixed by bone cement, and the femoral head material was CoCr (22mm; 5 hips, 26 mm; 96 hips).

Materials and Methods

In K-MAX HS-3 THA (Kyocera Medical, Kyoto, Japan), cemented titanium alloy stem and all polyethylene cemented socket are used. This stem has the double tapered symmetrical stem design, allowing the rotational stability and uniform stress distribution (Type T) (Fig. 1). The features of this stem are; 1. Vanadium-free high-strength titanium alloy (Ti-15Mo-5Zr-3Al), 2. Double-tapered design, 3. Smooth surface (Ra 0.4μm), 4. Broad proximal profile, 5. Small collar. In contrast, previous type stem, which was made of the same smooth-surface titanium alloy, has the design with cylindrical stem tip, allowing the maximum filling of the femoral canal (Type C) (Fig. 2). Osteolysis at the distal end of the stem had been reported in a few cases in Type C, probably due to the local stress concentration. Therefore the tapered stem was designed, expecting better clinical results.

All surgery was performed at Kitano Hospital between September 2003 and June 2006. 72 THA were performed (Type T; 52 hips, Type C; 20 hips). The average age of the patients at the operation was 61 and 69 years and the average follow-up period was 10.1 and 10.4 years for the Type T and C, respectively. The all-polyethylene socket was fixed by bone cement, and the femoral head material was alumina or CoCr (22 or 26 mm).

Materials and Methods

K-MAX HS-3 THA (Kyocera Medical, Japan), with cemented stem and all polyethylene cemented socket, was used for THA implants. Basically the third generation cementing technique was used for THA using bone cement. The socket fixation was performed with bone cement (Endurance, DePuy) and hydroxyapatite (HA) granules (Ca10(PO4)6(OH)2, Boneceram P; G-2, Olympus, Japan). In original IBBC technique, HA granules were dispersed on reamed acetabulum before cementing. In M-IBBC technique, HA granules were attached to bone cement on plastic plate, then inserted to reamed acetabulum and pressurized. HA granules (G-2) are 0.3–0.6mm in size, with 35–38% porosity and sintered at 1150â��. 51 hip joints (49 cases) were operated between June 2010 and December 2011, and followed. The average follow-up was 3.9 years, and average age at operation was 66.5 years. The clinical results were evaluated by Japan Orthopaedic Association Hip Score (JOA score), and X-p findings were evaluated using antero-posterior radiographs. The locations of radiolucent lines were identified according to the zones described by Delee and Charnley for acetabular components, and Zone 1 was divided into two parts, outer Zone 1a and inner Zone 1b.

Materials and Methods

K-MAX HS-3 THA (JMM, Japan), with cemented titanium alloy stem and all polyethylene cemented socket, was used for THA implants. The third generation cement technique was used for the conventional THA (Group C) using bone cement (Endurance, DePuy). In the IBBC group (Group BC), the socket fixation was performed by the third generation cement technique with HA granules (Boneceram P; G-2, Olympus, Japan) according to the Ohnishi's method. In both groups, the stems were fixed by conventional cementing technique using cement gun. 76 hip joins (69 cases) were operated between April 2005 and August 2007, and followed. The group C (22 hips, 19 cases, average follow-up; 5.6 years, average age at operation; 64 years) and the group BC (54 hips, 50 cases, 5.4 years, 65 years) were investigated