Objective: We aimed to determine the risk factors and thresholds of cup protrusion for iliopsoas impingement (IPI) after total hip arthroplasty (THA).

Methods: This retrospective case-control study evaluated 633 primary THAs performed by a single surgeon in a single center. In all THAs, the cup was inserted with the assistance of the computed tomography (CT)-based navigation system. Twenty-seven patients with THAs (4.3%) were identified to have symptoms of IPI and were included in group I. Control group 1 (C1) comprised 606 THAs, whereas control group 2 (C2) was formed by recruiting three data-matched controls per patient in C1. Risk factors for IPI were assessed in group I and C1, respectively. Further analysis was performed in the group I and C2 to evaluate radiological data.

Results: Multivariate logistic regression analysis confirmed that the anterolateral approach was associated with a higher risk of IPI (odds ratio [OR], 2.77). There was no association found between the design of the acetabular component or the cup insert and IPI. Axial protrusion length≥12 mm (Odds ratio, 23.4; sensitivity=70.0; specificity=90.0) was determined as an independent predictor of IPI. In multiple linear regression analyses, higher native acetabular version and lower cup anteversion were related to cup protrusion.

Conclusion: This single center study determined the threshold of cup protrusion length for IPI and identified associated factors increasing cup protrusion. The results are useful for orthopedic surgeons in determining cup position and alignment when undertaking THAs.

Background: Two-stage revision is the current gold standard for the treatment of periprosthetic joint (PPJ) infection. However, treatment strategies of the two-stage revision process remain controversial. Specifically, the duration of the antibiotic-laden free period, reimplantation timing, and antibiotic administration vary among surgeons.

Design: We have treated periprosthetic hip infections using our hospital’s protocol since 2004. This study aimed to investigate the clinical results and validity of our treatment strategies during two-stage revision for PPJ infection.

Methods: Twenty patients with PPJ hip infection were treated with two-stage revision. In the first stage, all components were removed and radical debridement was performed. Antibiotic-loaded cement spacers or beads were then inserted. Intravenous antibiotics and rifampicin were administered for three weeks. After infection suppression was confirmed, revision total hip arthroplasty was performed. Intravenous antibiotics and rifampicin were administered again for three weeks, and then rifampicin and minomycin were continued for at least three months. The interim interval and clinical outcomes were investigated.

Results: Seven antibiotic-resistant microorganisms were identified, and all patients were treated using the same protocol. The mean interim interval was 8.4 weeks. Infection recurred in one hip six months after the revision. The remaining hips were ultimately reimplanted without infection. The clinical outcomes were not affected by infection onset, microorganism type, or reconstruction method.

Conclusion: After radical debridement and the use of antibiotic-loaded cement spacers or beads combined with three-weeks of intravenous antibiotic therapy and rifampicin administration, 19 hips (95%) were successfully treated for acute or chronic infections, as well as for antibiotic-sensitive or antibiotic-resistant microorganism infections, respectively. The mean interim interval was 8.4 weeks.

Objective: We analyzed the treatment and outcomes for patients with surgical site infections (SSIs) after total knee arthroplasty (TKA) in our hospital. We also present a discussion of the current literature.

Methods: From 2002 to 2017 inclusive, TKA was performed in 1,672 patients at our hospital and SSI occurred in seven knees in seven patients, respectively. We also treated three cases of SSI in three knees after TKA was performed at another hospital. All 10 cases (2 males and 8 females) were originally treated for osteoarthritis. The average age was 71.6 years (range: 62-85 years). The therapy for SSI, Segawa classification, outcomes, cement mold placement time, and Japan Orthopaedic Association (JOA) scores were analyzed in these patients.

Results: With respect to the Segawa classification, the SSI cases encompassed type 2 (early postoperative infection, n=1), type 3 (acute hematogenous infection, n=7), and type 4 (n=2), respectively. Isolated bacteria included Pseudomonas aeruginosa (n=2), Escherichia coli (n=2), hemolytic streptococci (n=2), Staphylococcus epidermidis (n=1), coagulase-negative staphylococci (n=1), Streptococcus pneumoniae (n=1), and methicillin-susceptible Staphylococcus aureus (n=1). There were no cases with methicillin-resistant Staphylococcus aureus.

 One case was treated with irrigation, debridement and removal of the polyethylene implant, which resulted in the elimination of infection. The other nine cases underwent two-stage revision TKA with initial placement of a cement mold once (n=7) or twice (n=2), respectively. The median implantation time of the cement mold was 2.3 months (range: 8-32 months). Reimplantation was performed at a mean period after initial surgery of 64.1 months (2-185 months). Seven cases had no subsequent infection. The mean JOA scores in the 10 patients were 29 points preoperatively and 69 points at the last follow-up.

Conclusion: SSI occurred in 10 TKA cases. The time to the start of therapy from onset of infection was linked to retention of the prosthesis. A good clinical outcome was obtained using a two-stage TKA with an articulating spacer.

Objective: The purpose of this study was to investigate the usefulness of esflurbiprofen (SFP) tape which is a newly developed nonsteroidal anti-inflammatory drug (NSAID) tape for osteoarthritis of the knee (OAK) by comparing it with other established treatments, and to clarify its effective method of use.

Methods: Two clinical studies were conducted. In study 1, patients with OAK with existing use of tape and a visual analogue scale (VAS) value of 30 mm or more were included. The VAS improvement after four weeks was compared between the group that continued the existing tape (n=10) and the group that switched to the SFP tape (n=10), respectively. In study 2, patients with OAK who were untreated and had a VAS value of 40 mm or more were included. Intra-articular injection of hyaluronic acid was performed for six weeks in combination with either intra-articular injection of corticosteroid (n=10), an oral NSAID (n=10) or SFP tape (n=10), respectively. The change in VAS was then compared.

Results: In study 1, the VAS value was significantly improved by switching from the existing tape to the SFP tape. The amount of improvement of VAS was significantly larger in SFP tape group than in the existing tape group. In study 2, the VAS value improved significantly from start to end of the study in all groups. The amount of improvement in the VAS score was significantly larger in the SFP tape group than in the other groups, respectively.

Conclusion: SFP tape showed a strong analgesic effect, suggesting that it is useful either alone or in combination with intra-articular hyaluronic acid.

Objective: The superior approach (SA) in hip arthroplasty (HA) is a method to preserve the short rotator muscles and not to dislocate the femoral head. The procedure is sometimes difficult in cases with high greater trochanter and varus deformity of femoral neck. We analyzed radiographic factors influencing operative durations of HA.

Methods: We included 57 HAs using the SA for femoral neck fractures without contralateral hip fractures or postoperative conditions. We divided the surgical procedure into the five phases. We examined the association between the surgical parameters and radiographic index. This included ①the height of the greater trochanter, ②the length between the top of the greater trochanter of the healthy hip and the acetabular edge, ③the healthy femoral offset, and ④the enter edge angle. We examined the association between the surgical parameters and patients characteristic including their height, body weight (BW) and body mass index (BMI).

Results: The mean age was 80±9.5 years. The mean operative time and bleeding quantity were 56±15 minutes and 130±91.7 g, respectively. There were no statistically significant associations between the radiographic index and surgical procedures. Higher BW and BMI increased the total operation time and the head removal duration (P<0.05).

Conclusion: The radiographic index did not influence any phases of the SA, which can be performed in any case.

 Periprosthetic fractures are technically demanding to treat, as they require the skills of revision arthroplasty as well as those of trauma surgery. The elderly population is particularly vulnerable to low energy periprosthetic fractures attributed to osteopenia or osteoporosis leaving limited reconstruction options to the hip revision surgeon.

 We report a case of revision total hip arthroplasty (THA) with femoral bone deficiency. For preventing intraoperative periprosthetic femoral fracture, femoral impaction bone grafting (IBG) with locking compression plate (LCP) for revision THA was undertaken. However, it was necessary to perform a third surgery for postoperative Vancouver B1 periprosthetic femoral fracture, by treatment with LCP and auto-fibula fixation.

 A 76-year-old woman underwent bipolar hip arthroplasty in our hospital for femoral neck fracture 14 years before presentation, and revision surgery for stem loosening. She underwent revision THA using femoral IBG with LCP four months later. The patient fell down when standing and a periprosthetic femoral shaft fracture (Vancouver classification type B1) was observed on the plain radiographs. She was treated with LCP fixation and autograft fibula fixation using ultra-high molecular weight polyethylene adding with morselized and cancellous allografts around the periprosthetic fracture. Two years after surgery, clinical and radiographic follow-up revealed that the fracture had healed without deformity or shortening.

 She currently walks smoothly and without pain using a single walking stick.

Case: We report a case of femoral neck fracture in a patient with femoral bowing deformity. An 89-year-old lady had received bilateral total knee arthroplasties (TKAs) for osteoarthritis of the knee. The right side was operated eight years previously, and the left side was operated three months before presentation. Although she had been able to ambulate without pain, her left hip developed arthralgia resulting in an antalgic ambulatory posture from two weeks prior to visiting our outpatient clinic. At presentation, a radiographic study showed a left femoral neck fracture with Garden classification stage 4 accompanied with remarkable curvature deformation of her bilateral femurs. Bipolar THA using cement was performed for the left side. During rehabilitation, partial weight bearing (50%) was commenced one week postoperatively, and full weight bearing began from week two onwards. At six weeks postoperatively, she was able to ambulate on flat ground with a T-cane. When reviewed in our outpatient clinic at six months, she was able to walk unassisted and she could also climb stairs.

Discussion: While there are some reports that varus installation of stems with cement will not affect the results, there are also reports that cement will collapse at an early stage. There are also reports that cementless varus placement of stem has no influence in short- to mid-term results, and some other reports suggest that cementless varus placement leads to severe stress shielding, although this is still controversial. In the preoperative planning for this patient, we selected the varus insertion of the stem with cement because we were concerned that the tip of the stem would be in front of the lordosis or the outer curve at the intermediate insertion. Although good results were obtained in this case, long-term observation is necessary.

 Alcaptonuria is a rare autosomal recessive metabolic disorder caused by the deficiency of an enzyme that results in the accumulation in tissues of homogentisic acid. This case report concerns a 76-year-old gentleman who developed severe pain during walking. Studies demonstrated typical ochronotic arthropathy of both hips. He underwent bilateral total hip arthroplasty, with good short-term results.