Cementless total hip arthroplasty specifically designed for asians: clinical and radiologic results at a mean of 10 years

Varus morphology and its surgical implication in osteoarthritic knee and total knee arthroplasty

BACKGROUND

Knee varus alignment represents a notorious cause of knee osteoarthritis. It can be caused by tibial deformity, combined tibial-femoral deformity and/or ligament imbalance. Understanding malalignment is crucial in total knee arthroplasty to restore frontal plane neutral mechanical axis. The aim of this study was to determine which factor contributes the most to varus osteoarthritic knee and its related surgical implications in performing a total knee arthroplasty.

METHODS

We retrospectively evaluated 140 patients operated for total knee arthroplasty due to a varus knee. Full-leg hip to ankle preoperative X-rays were taken. Radiological parameters recorded were: mechanical axis deviation, hip-knee-ankle, anatomical-mechanical angle, medial neck shaft angle, mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), lateral proximal femoral angle, lateral distal tibial angle (LDTA), femoral bowing, and length of tibia and femur. We also determined ideals tibial and femoral cuts in mm according to mechanical alignment technique. A R2 was calculated based on the linear regression between the predicted values and the observed data.

RESULTS

The greatest contributor to arthritic varus (R = 0.444) was MPTA. Minor contributors were mLDFA (R = 0.076), JLCA (R = 0.1554), LDTA (R = 0.065), and femoral bowing (R = 0.049). We recorded an average of 7.6 mm in lateral tibial cut thickness to restore neutral alignment.

CONCLUSIONS

The radiological major contributor to osteoarthritic varus knee alignment is related to proximal tibia deformity. As a surgical consequence, during performing total knee arthroplasty, the majority of the correction should therefore be made on tibial cut.

Clinical experience of the use of reamer irrigator aspirator in Japanese patients: A report of the first 42 cases

BACKGROUND

A reamer irrigator aspirator (RIA) can be used to harvest substantial amounts of autologous bone and debride the intramedullary canal. Clinical experience using reamer irrigator aspirators in Japan is very limited. The applicability of the reamer irrigator aspirator head with a minimum diameter of 12 mm for Japanese people is often questioned as the Japanese are smaller than Americans and Europeans. There are no reports of complications in Japanese patients. This study aimed to retrospectively review clinical cases and describe reamer irrigator aspirator use in Japanese patients.

METHODS

All patients for whom a reamer irrigator aspirator was used during surgery at our hospital between January 2014 and September 2018 were included. The patients' clinical and radiographic data were retrospectively reviewed.

RESULTS

Data of 40 patients (42 cases) were collected. The reamer irrigator aspirator was used for bone graft harvesting in 32 cases, intramedullary debridement and irrigation in 9 cases, and reaming for exchange nailing in 1 case. The diameter of the reamer irrigator aspirator reamer head was 12 mm in 22 cases (53.7%), 12.5 mm in 4 cases (9.8%), 13 mm in 9 cases (22.0%), 13.5 mm in 1 case (2.4%), 14.0 mm in 1 case (2.4%), 14.5 mm in 1 case (2.4%), and 15 mm in 4 cases (9.8%). Mean intraoperative bleeding volume was 1158.6 mL (range, 100-3800 mL). We experienced no difficulty inserting the reamer irrigator aspirator into the intramedullary canals and no cases of insertion-related intraoperative fracture. Five cortical perforations (11.9%) were observed on postoperative computed tomography scans, although no patient was symptomatic. One case (2.4%) of postoperative femur fracture occurred.

CONCLUSIONS

Reamer irrigator aspirators can be used in Japanese patients. Smaller reamer head sizes were mainly used in our experience. We should manage complications as in previous reports from Western countries.

Definition of a Novel Proximal Femur Classification in the Sagittal Plane According to the Femur Morphometric Analysis

BACKGROUND

Studies on prosthesis positioning and implant design in total hip arthroplasty (THA) have generally focused on the anatomy of the proximal femur in the coronal plane. The aim of this study was to investigate the proximal femur morphology in the sagittal plane to provide better positioning of the femoral component in THA and contribute to the determination of proximal femur morphology through possible outcomes that can be shown also by considering the sagittal plane in the selection and design of the femoral component.

METHODS

Computerized tomography scans were obtained from 270 femoral bones belonging to adult skeletons, followed by 3D reconstruction using Leonardo Dr/Dsa Va30a software (Siemens, Erlangen, Germany) and measurements. Canal widths were measured in the coronal and sagittal planes at the lesser trochanter (LT) level, at 20 millimeters proximal to the LT(LT+20) and at various levels distal to the lesser trochanter in 25 mm jumps up to 200 mm from the lesser trochanter.

RESULTS

The average width was wider at the level of the lesser trochanter and all points distal to it in the sagittal plane compared to the coronal plane except LT-200 mm. At each levels from LT-25 to LT-175, the differences were statistically significant (P < .05). The ratio of the femoral width at the lesser trochanter level to the width 50 mm distal to the LT was stated as the most prevalent one, and a novel classification in the sagittal plane was developed in accordance with these findings.

CONCLUSION

A novel and simple classification in the sagittal plane was developed based on the findings of this study, and this classification may improve the accuracy, validity, and reliability of femoral stem fixation in total hip arthroplasty.

Is It Time to Phase Out the Austin Moore Hemiarthroplasty? A Propensity Score Matched Case Control Comparison versus Cemented Hemiarthroplasty

We compared the Austin Moore hemiarthroplasty versus cemented hemiarthroplasties using a propensity score matched cased control study. For a consecutive cohort of 450 patients with displaced intracapsular neck of femur fractures, 128 matched cases in each group were selected based on age, gender, walking status, nursing home residency, delays in surgery, ASA score, and the Charlson comorbidity score. At a mean follow-up of 16.3 months, we evaluated their outcomes. Significantly more patients with AMA experienced thigh pain (RR = 3.5, 95% CI: 1.67-7.33, p = 0.000), overall complications (RR = 4.47, 95% CI: 1.77-11.3, p = 0.000), and implant loosening (RR = 8.42, 95% CI: 2.63-26.95, p = 0.000). There were no definite cement related deaths in this series. There was no significant difference in mortality, walking status, and the number of revisions between the groups. We support the routine use of cemented hemiarthroplasty instead of the Austin Moore for treating elderlies with displaced intracapsular neck of femur fractures.

A Case Series of Total Hip Arthroplasty Using Cementless Hip Stem Customized for Patients of a Specific Race: 10- to 15-Year Results

We report a minimum of 10-year results of patients undergoing total hip arthroplasty (THA) using the cementless BiCONTACT N stem, which was developed to fit the femur in a specific race in which the predominant etiology of hip diseases was developmental dysplasia. A total of 108 hips were evaluated with a mean follow-up of 11.9 ± 1.4 years. The etiology for THA was secondary osteoarthritis due to developmental dysplasia in 90.3% of patients. No evidence of aseptic loosening of the BiCONTACT N stem was observed. The survivorship with the end point as revision surgery for any reason was 94.4% (95% confidence interval 88.7%-97.3%) at 15.0 years postoperatively. BiCONTACT N stem may be an effective alternative for patients with developmental dysplasia of the hip.

Reamer Irrigator Aspirator bone graft harvesting: complications and outcomes in an Asian population

INTRODUCTION

Autologous bone grafting has been accepted as the gold standard in the treatment of non-unions and in definitive filling of segmental bone defects. However, there have been well-recognised complications associated with their harvest. The Reamer Irrigator Aspirator (RIA) system is an alternative technique of autologous bone graft harvesting. Studies have been published in the Western population showing the efficacy and outcome of this technique. No prior studies were done in the Asian population, who has smaller average canals, different femoral geometry as compared to Caucasians and weaker bone density in both genders. We aim to present the findings and discuss its suitability in the Asian population when dealing with segmental bone loss and non-unions requiring reconstruction.

METHODS

We conducted a retrospective analysis of all trauma patients with segmental bone loss and non-unions treated with RIA bone grafting over a 4.5 year period. A total of 57 cases of RIA bone grafting were conducted on 53 patients. The amount of bone graft harvested, blood loss and post-operative pain were measured. Patients were followed up for union rate as well as complications of the procedure.

RESULTS

Union was achieved in 86.8% of patients. The mean time to union was 17.64 weeks. Seven patients did not achieve union after the first RIA surgery, in which six of seven were open fractures initially and six were smokers. One major intra-operative complication was recorded, that being a fractured femoral shaft due to thinning of the cortex by the RIA harvester. There were two patients who developed donor site superficial soft tissue infection that resolved after a course of antibiotics. There were no long-term complications seen in all patients.

CONCLUSIONS

The safety and efficacy of RIA bone graft harvesting for the management of non-union in the Asian population is promising, with adequate graft quantities, high success and low complication rates that are comparable to the Caucasian population. The diameter of the medullary canal in our population is suitable for this procedure. We believe that RIA bone graft harvesting provides a reliable and safe alternative source of autologous bone grafts for bone grafting of non-union sites.

Morphometric evaluation of proximal femur in patients with unilateral total hip prosthesis

It is important to know the morphometric characteristics of the proximal femur. This is necessary to reduce the risk of complications related to surgical procedures performed in the area due to vascular, metabolic, or traumatic causes. It is of importance for achieving the alignment of the prosthesis to be implanted as well. The aim of this study was to evaluate the morphometric characteristics of the proximal femur and to establish a database for making and performing total hip prosthesis. Anteroposterior (AP) pelvic radiographs of 162 cases, with a mean age of 65.6 years, who had undergone unilateral total hip arthroplasty were used in this study. Femoral head diameter (FHD), femoral neck width (FNW), femoral neck length (FNL), femoral neck axis length (FNAL), intertrochanteric line length (ILL), and neck-shaft angle (NSA) were measured on radiographs obtained digitally using setrapacs media. FHD was found to be 48.1 ± 3.7 mm, FNW 35.4 ± 4.2 mm, FNL 30.8 ± 6.1 mm, FNAL 98.6 ± 9.4 mm, ILL 81.1 ± 7.9 mm, and NSA 130.4 ± 5.1° on average. The comparison of the mean values for females and males revealed a statistically significant difference between the FHD, FNW, FNL, FNAL, and ILL (P = 0.000). There was no statistically significant difference in NSA between males and females (P = 0.356). A weak correlation was found between age and parameter values using correlation analysis (r < 0.24, P > 0.05). In morphometric assessment of the proximal femur, taking into consideration regional and sexual differences is of importance for prosthesis design and surgical success.

The effects of age and gender on the diameter of the femoral canal in patients who undergo total hip replacement

With greater numbers of younger patients undergoing total hip replacement (THR), the effect of patient age on the diameter of the femoral canal may become more relevant. This study aimed to investigate the relationship between the diameter of the diaphysis of the femoral canal with increasing age in a large number of patients who underwent THR. A total of 1685 patients scheduled for THR had their femoral dimensions recorded from calibrated radiographs. There were 736 males and 949 females with mean ages of 67.1 years (34 to 92) and 70.2 years (29 to 92), respectively. The mean diameter of the femoral canal was 13.3 mm (8.0 to 23.0) for males and 12.7 mm (6.0 to 26.0) for females. There was a poor correlation between age and the diameter of the canal in males (r = 0.071, p = 0.05) but a stronger correlation in females (r = 0.31, p < 0.001). The diameter of the femoral canal diameter of a female patient undergoing THR could be predicted to increase by 3.2 mm between the ages of 40 and 80 years, in contrast a male would be expected to experience only a 0.6 mm increase during the same period. This increase in the diameter of the canal with age might affect the long-term survival of the femoral component in female patients.

Exeter short stems compared with standard length Exeter stems: experience from the Australian Orthopaedic Association National Joint Replacement Registry

The standard Exeter stem has a length of 150 mm with offsets 37.5 to 56 mm. Shorter stems of lengths 95, 115 and 125 mm with offsets 35.5 mm or less are available for patients with smaller femurs. Concern has been raised regarding the behavior of the smaller implants. This paper analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry comparing survivorship of stems of offset 35.5 mm or less with the standard stems of 37.5 mm offset or greater. At 7 years, there was no significant difference in the cumulative percent revision rate in the short stems (3.4%, 95% CI 2.4-4.8%) compared with the standard length stems (3.5%, 95% CI 3.3-3.8%) despite its use in a greater proportion of potentially more difficult developmental dysplasia of the hip cases.

Total hip arthroplasty with an HPF stem: the radiological findings around the cementless anatomical-shape stem for developmental dysplasia of the hip

BACKGROUND

We developed the HPF stem to suit the Japanese femoral bone marrow canal in developmental dysplasia of the hip. This anatomical-shape cementless stem improves canal occupation by the lateral and anterior flares. We report the clinical performance of the stem and details of the change in the X-rays, especially of the femoral side.

MATERIALS AND METHODS

We investigated 53 joints of total hip arthroplasty using the stem in 48 cases. The follow-up period was 8 years on average. We checked the Harris hip score (HHS) for clinical assessment. Existence of postoperative thigh pain was also investigated. For radiological assessment, the direction of stem insertion and initial fixation mode immediately after surgery were estimated. At the latest follow-up, we estimated the radiological findings of bone atrophy, spot welds, radiolucent zone, osteolysis, and sinking of the stem over 2 mm. Biological fixation was classified into four types: bone ingrowth, ingrowth suspected, suboptimum, and unstable fixation.

RESULTS

HHS was improved from 44 points before surgery to 92 points at the final follow-up. Light thigh pain appeared temporarily in three joints after surgery. Press-fit was achieved in femurs including total fit in 12 femurs, proximal fit in 4, middle fit in 25, and distal fit in 2. First degree stress shielding was seen in 25 femurs and second degree in 28. Forty-eight joints showed bone-ingrowth fixation, and five joints were ingrowth-suspected.

DISCUSSION

The clinical performance was excellent. Total or proximal fit was seen in only 30%. In these joints, cortical hypertrophy at the middle part of the stem and slight proximal bone atrophy appeared frequently, suggesting the stress transmission to the stem middle or distal portion, and there is a limit to the stress shielding evasion by the anatomical-shape stem.