Less Postoperative Restrictions Following Total Hip Arthroplasty With Use of a Posterolateral Approach: A Prospective, Randomized, Noninferiority Trial.

BACKGROUND: Patient restrictions are prescribed after total hip arthroplasty (THA) to ensure proper healing and prevent early dislocation. It has been suggested that less or nonrestrictive protocols following THA do not lead to higher dislocation rates. Nonetheless, restrictions are still widely used. The aim of this study is to evaluate the rate of early dislocations when patients were restricted to supine sleeping or unrestricted sleeping in the first 8 weeks after THA using a posterolateral approach. METHODS: The study design was a single-center, parallel-group, stratified, randomized, noninferiority trial in which primary THA patients were allocated to either a restricted group or a nonrestricted group. The primary outcome was early (<8 weeks) dislocation rate. Secondary outcomes include pain (visual analog scale [VAS]), function in activities of daily living (Hip Disability and Osteoarthritis Outcome Score [HOOS]), and quality of life (EuroQoL 5 Dimension [EQ-5D]). RESULTS: A total of 408 patients were randomized into 2 groups: those who were restricted in their sleeping position (n = 203) and those who received no restrictions in sleeping position (n = 205). Three patients (1.48%) from the restricted group and 3 patients (1.46%) from the unrestricted group had a dislocation. The noninferiority of the restricted group compared to the nonrestricted group was established for early dislocation. In addition, no statistically significant differences were found for VAS, HOOS, and QoL-5D between both groups. Both groups showed a significant improvement in VAS, HOOS, and QoL-5D. CONCLUSION: Early dislocation rates in patients who were advised to comply to an unrestricted sleeping position following THA were not inferior to the dislocation rates in patients who were advised to sleep in a supine position following THA. The results of the present study strengthen the discussion regarding the relevance of providing patients with restrictions following THA.

Cancellous and cortical bone mineral density around an elastic press-fit socket in total hip arthroplasty.

Background and purpose - The acetabular component has remained the weakest link in hip arthroplasty for achievement of long-term survival. One of the possible explanatory factors for acetabular failure has been acetabular stress shielding. For this, we investigated the effects of a cementless elastic socket on acetabular bone mineral density (BMD). Patients and methods - During 2008-2009, we performed a single-center prospective cohort trial on 25 patients (mean age 64 (SD 4), 18 females) in whom we implanted a cementless elastic press-fit socket. Using quantitative BMD measurements on CT, we determined the change in BMD surrounding the acetabular component over a 2-year follow-up period. Results - We found a statistically significant decrease in cancellous BMD (-14% to -35%) and a stable level of cortical BMD (5% to -5%) surrounding the elastic press-fit cup during the follow-up period. The main decrease was seen during the first 6 months after implantation. During the second year, cancellous BMD showed a further decrease in the medial and lower acetabular regions. Interpretation - We found no evidence that an elastic press-fit socket would prevent acetabular stress shielding during a 2-year follow-up.

Assessment of asymmetric leg loading before and after total hip arthroplasty using instrumented shoes.

BACKGROUND: Total hip arthroplasty is a successful surgical treatment in patients with osteoarthritis of the hip. Different questionnaires are used by the clinicians to assess functional capacity and the patient's pain, despite these questionnaires are known to be subjective. Furthermore, many studies agree that kinematic and kinetic parameters are crucial to evaluate and to provide useful information about the patient's evolution for clinicians and rehabilitation specialists. However, these quantities can currently only be obtained in a fully equipped gait laboratory. Instrumented shoes can quantify gait velocity, kinetic, kinematic and symmetry parameters. The aim of this study was to investigate whether the instrumented shoes is a sufficiently sensitive instrument to show differences in mobility performance before and after total hip arthroplasty. METHODS: In this study, patients undergoing total hip arthroplasty were measured before and 6-8 months after total hip arthroplasty. Both measurement sessions include 2 functional mobility tasks while the subject was wearing instrumented shoes. Before each measurement the Harris Hip Score and the Traditional Western Ontario and McMaster Universities osteoarthritis index were administered as well. RESULTS: The stance time and the average vertical ground reaction force measured with the instrumented shoes during walking, and their symmetry index, showed significant differences before and after total hip arthroplasty. However, the data obtained with the sit to stand test did not reveal this improvement after surgery. CONCLUSIONS: Our results show that inter-limb asymmetry during a walking activity can be evaluated with the instrumented shoes before and after total hip arthroplasty in an outpatient clinical setting.

Antibiotic prophylaxis before tissue biopsy has no effect on culture results in presumed aseptic revision total hip arthroplasty.

Background: Antibiotic prophylaxis (AP) is considered to be the gold standard for revision total hip arthroplasty (R-THA) due to the high incidence of prosthetic joint infection (PJI). To diagnose PJI, intraoperative tissue biopsies for culture are of particular importance. However, antibiotic interference could theoretically lead to less reliable culture results. Currently, there is no consensus on whether AP should be administered before or after tissue biopsy. In this study, we aimed to investigate the effect of AP timing on culture results and PJI rates in presumed aseptic R-THA. Methods: A retrospective single-center cohort study among 490 patients was performed; 61 patients received AP pre-incision, and 429 patients received AP post-biopsy. At least three intraoperative tissues were sampled for each patient and cultured for a minimum of 2 weeks. Minimum follow-up was 6 months. Epidemiological and clinical data (including culture results and incidence of PJI during follow-up) were gathered and analyzed. Results: Positive (4.9 % vs. 5.4 %, p=0.89) and contaminated culture results (23.0 % vs. 22.6 %, p=0.95) were not significantly different between pre-incisional and post-biopsy AP administration. Post-operative PJI incidence during follow-up was 1.6 % and 3.0 %, respectively. This difference was not statistically significant (p=0.54). Conclusion: Pre-incisional AP administration does not yield fewer culture results compared to post-biopsy AP administration. Although statistically not significant, PJI during follow-up was almost twice as high when AP was withheld until after tissue biopsy. Other literature also supports the additional protective benefit of pre-incisional AP. Therefore, we believe pre-incisional AP administration is preferable for presumed aseptic R-THA.

Pre-operative ambulatory measurement of asymmetric lower limb loading during walking in total hip arthroplasty patients.

BACKGROUND: Total hip arthroplasty is a successful surgical procedure to treat hip osteoarthritis. Clinicians use different questionnaires to assess the patient's pain and functional capacity. Furthermore, they assess the quality of gait in a very global way. This clinical evaluation usually shows significant improvement after total hip arthroplasty, however, does not provide objective, quantifiable information about the movement patterns underlying the functional capacity, which can currently only be obtained in a gait laboratory. Instrumented force shoes can quantify gait velocity, ground reaction forces and the gait pattern easily in an outpatient setting. The main goal of this study was to investigate how mobility characteristics during walking, relate to gait velocity and questionnaire outcomes of patients with hip osteoarthritis in an outpatient setting. METHODS: 22 patients with primary osteoarthritis of the hip selected for a total hip arthroplasty participated in this study. For each patient the Harris Hip Score, the Traditional Western Ontario and the McMaster Universities osteoarthritis index were administered. Subsequently, the patients were instructed to walk through the corridor while wearing instrumented shoes. The gait velocity estimated with the instrumented force shoes was validated measuring the time required to walk a distance of 10 m using a stopwatch and a measuring tape as a reference system. A regression analysis between spatial, temporal, ground reaction force parameters, including asymmetry, and the gait velocity and the questionnaires outcomes was performed. RESULTS: The velocity estimated with the instrumented shoes did not differ significantly from the velocity measured independently. Although gait parameters correlated significantly with velocity, symmetry index parameters were not correlated with velocity. These symmetry index parameters show significant inter-limb asymmetry during walking. No correlation was found between any of the variables studied and questionnaires outcomes. CONCLUSION: Inter-limb asymmetry can be evaluated with the instrumented shoes supplying important additional information about the individual gait pattern, which is not represented by gait velocity and questionnaires usually used. Therefore, this new ambulatory measurement system is able to provide complementary information to gait velocity and questionnaires outcomes to assess the functional capacity of patients with hip osteoarthritis.

Periacetabular bone mineral density changes after resurfacing hip arthroplasty versus conventional total hip arthroplasty. A randomized controlled DEXA study.

A randomized controlled trial was performed to evaluate acetabular bone mineral density (BMD) changes after hip resurfacing (RHA) versus an established conventional total hip arthroplasty (THA). A total of 71 patients were allocated randomly to receive either an RHA press-fit cobalt-chromium cup (n=38) or a THA with a threaded titanium cup and polyethylene-metal-inlay insert (n=33). The BMD in five separate periacetabular regions of interest (ROI) was prospectively quantified preoperative until 24 months. We conclude that, in contrast to our hypothesis, periacetabular BMD was better preserved after RHA than after placement of a conventional THA. Long term follow-up studies are necessary to see whether this benefit in bone preservation sustains over longer time periods and whether it is turned into clinical benefits at future revision surgery.

A cementless, elastic press-fit socket with and without screws.

BACKGROUND: The acetabular component has remained the weakest link in hip arthroplasty regarding achievement of long-term survival. Primary fixation is a prerequisite for long-term performance. For this reason, we investigated the stability of a unique cementless titanium-coated elastic monoblock socket and the influence of supplementary screw fixation. PATIENT AND METHODS: During 2006-2008, we performed a randomized controlled trial on 37 patients (mean age 63 years (SD 7), 22 females) in whom we implanted a cementless press-fit socket. The socket was implanted with additional screw fixation (group A, n = 19) and without additional screw fixation (group B, n = 18). Using radiostereometric analysis with a 2-year follow-up, we determined the stability of the socket. Clinically relevant migration was defined as > 1 mm translation and > 2º rotation. Clinical scores were determined. RESULTS: The sockets without screw fixation showed a statistically significantly higher proximal translation compared to the socket with additional screw fixation. However, this higher migration was below the clinically relevant threshold. The numbers of migratory sockets were not significantly different between groups. After the 2-year follow-up, there were no clinically relevant differences between groups A and B regarding the clinical scores. 1 patient dropped out of the study. In the others, no sockets were revised. INTERPRETATION: We found that additional screw fixation is not necessary to achieve stability of the cementless press-fit elastic RM socket. We saw no postoperative benefit or clinical effect of additional screw fixation.

Long-term survivorship analysis of the cementless Spotorno femoral component in patients less than 50 years of age.

The long-term survival of the cementless Spotorno (CLS) femoral component (Zimmer Inc, Warsaw, USA) was evaluated in a consecutive series of 85 patients (100 hips) less than 50 years of age. The mean follow-up was 12.3 years. Two patients (3 hips) were lost to follow-up, and 3 (4 hips) died. The survival rate of the CLS stem was 96.9% (confidence interval [CI], 93.6%-100%) after 13 years based on revision of the stem for any reason. The survival of the stem with revision for aseptic loosening as the end point was 97.9% (CI, 95.1%-100%) at 13 years. The mean Harris hip score at time of follow-up was 94. The long-term survival of the CLS stem is excellent in patients less than 50 years of age.

A cementless elastic monoblock socket in young patients: a ten to 18-year clinical and radiological follow-up.

The survival of acetabular components depends on several factors: wear, osteolysis and septic or aseptic loosening. Osteolysis seems to be the main cause for concern in cementless arthroplasties. Acetabular osteolysis results from particle debris and segmental unloading of acetabular bone by rigid sockets. We investigated a cementless elastic monoblock socket with regard to acetabular osteolysis and aseptic loosening in a cohort of young patients. We evaluated 158 hip arthroplasties with a minimum follow-up of ten years (ten to 18) and a mean age of 42 years (18-50). The overall revision rate at 14 years was 80% with a 98% survival rate for aseptic loosening. The mean polyethylene wear rate was 0.11 mm/year. Progressive acetabular osteolysis was seen in 3% of patients evaluated. In conclusion, we found low pelvic osteolysis rates, acceptable overall wear rates, satisfactory overall survival and excellent survival rates for aseptic loosening of a cementless elastic monoblock socket in patients younger than 50 years. Ongoing tribology developments and knowledge about acetabular bone adaptations behind acetabular implants will further lower wear and osteolysis rates and optimise survival rates of cementless sockets.

Is there evidence for a superior method of socket fixation in hip arthroplasty? A systematic review.

PURPOSE: Total hip arthroplasty has been a very succesful orthopaedic procedure. The optimal fixation method of the acetabular component however, has not yet been defined. METHODS: We performed a systematic review using the Medline and Embase databases to find evidence for the superiority of cemented or cementless acetabular components on short- and long-term clinical and radiological parameters. Methodological quality for randomised trials was assessed using the van Tulder checklist, and for the non randomised studies we used the Newcastle-Ottawa quality assessment scale. RESULTS: Our search strategy revealed 16 randomised controlled trials (RCT) and 19 non RCT studies in which cemented and cementless acetabular components are compared. A best evidence analysis for complications, wear, osteolysis, migration and clinical scores showed no superiority for either cemented or cementless socket in the RCTs. A best evidence analysis for non RCT studies revealed better osteolysis, migration properties and aseptic loosening survival for cementless sockets; however, wear and overall survival favoured the cemented sockets. CONCLUSIONS: We recommend that an orthopaedic surgeon should choose an established cemented or cementless socket for hip replacement based on patient characteristics, knowledge, experience and preference.

Between hope and fear: A qualitative study on perioperative experiences and coping of patients after lumbar fusion surgery.

OBJECTIVE: Recovery following lumbar fusion surgery is frequently accompanied by post-operative pain, and patients often continue to experience some level of chronic pain. There is a scarcity of qualitative research focusing on patient experiences regarding lumbar fusion surgery. This study aims to clarify how lumbar fusion surgery patients experience the perioperative period; their hopes, their post-operative pain experiences, their fluctuating physical condition and accompanying emotions. METHODS: Semi-structured interviews were conducted with 12 lumbar fusion surgery patients. Transcripts of these interviews were open and axial coded by two coders using Atlas.ti software and Thematic Analysis. RESULTS: A total of thirteen categories and four overarching themes were generated from the data. Participants described their beliefs and experiences surrounding surgery, including a long preoperative illness process, tumultuous recovery and unfulfilled preoperative expectations. Participants used various forms of pain coping including activity avoidance and endurance, and emotion regulation strategies such as acceptance. CONCLUSION: This study demonstrates that, for lumbar fusion patients, surgery seems to be a last resort. Professionals should fulfill the patients need for information and focus on managing realistic expectations while respecting the distress and strain the illness process has on a patient, thereby potentially increasing patient satisfaction and enhancing postoperative recovery.

Anterior cruciate ligament- and hamstring tendon-derived cells: in vitro differential properties of cells involved in ACL reconstruction.

Anterior cruciate ligament (ACL) reconstruction involves the replacement of the torn ligament with a new graft, often a hamstring tendon (HT). Described as similar, the ACL and HT have intrinsic differences related to their distinct anatomical locations. From a cellular perspective, identifying these differences represents a step forward in the search for new cues that enhance recovery after the reconstruction. The purpose of this study was to characterize the phenotype and multilineage potential of ACL- and HT-derived cells. ACL- and HT-derived cells were isolated from tissue harvest from patients undergoing total knee arthroplasty (TKA) or ACL reconstruction. In total, three ACL and three HT donors were investigated. Cell morphology, self-renewal potential (CFU-F), surface marker profiling, expression of tendon/ligament-related markers (PCR) and multilineage potential were analysed for both cell types; both had fibroblast-like morphology and low self-renewal potential. No differences in the expression of tendon/ligament-related genes or a selected set of surface markers were observed between the two cell types. However, differences in their multilineage potential were observed: while ACL-derived cells showed a high potential to differentiate into chondrocytes and adipocytes, but not osteoblasts, HT-derived cells showed poor potential to form adipocytes, chondrocytes and osteoblasts. Our results demonstrated that HT-derived cells have low multilineage potential compared to ACL-derived cells, further highlighting the need for extrinsic signals to fully restore the function of the ACL upon reconstruction. Copyright © 2015 John Wiley & Sons, Ltd.

CT-based quantification of bone stock in large head metal-on-metal unilateral total hip replacements.

PURPOSE: To explore ipsilateral and contralateral acetabular roof bone stock density in unilateral large head MoM THA whether there is a significant lower acetabular bone stock in the hip with a metal-on-metal (MoM) total hip replacement compared to the contralateral side. Second part of this study is to examine if there are any associates with regard to potential bone stock density difference. MATERIALS & METHODS: A database of 317 patients with unilateral metal-on-metal (MoM) total hip replacements was set up retrospectively for this study. On computed tomography scans, conducted after a relative short in situ time period averaging 2.8 years, regions-of-interests were drawn in the trabecular bone of the acetabulum to measure average Hounsfield Units (HU). HU differences were calculated and tested by Wilcoxon signed-rank test. Univariate analysis was conducted to examine associates of potential bone loss. RESULTS: In a population of 317 patients (156 male, 161 female) with an average age of 61.9 ± 7.8, the median HU on the side of the MoM replacement was 123.3 (7.6-375.4). On the contralateral side, median HU was 144.7 (-0.4 to 332.8). The median HU difference was 21.4 after a mean post-operative in situ time of 2.8 years. The Wilcoxon signed-rank test proved a significant difference (p<0.001). Univariate analyses show that the in situ time of the MoM THA has a significant correlation with the bone density difference. CONCLUSION: Results show a significant lower bone density at the acetabular roof at the side of the prosthesis compared with the contralateral side after short in situ time of the MoM THA in patients with unilateral MoM total hip replacements. In our patient population, the in situ time showed a significant association with the acetabular bone density difference. As acetabular roof bone stock measurements are feasible and show temporal decline this could become an important parameter to be used in orthopedic decision making for revision surgery.

Preoperative ambulatory measurement of asymmetric leg loading during sit-to-stand in hip arthroplasty patients.

Total hip arthroplasty (TGA) is a successful surgical procedure to treat patients with hip osteoarthritis. Clinicians use different questionnaires to evaluate these patients. Gait velocity and these questionnaires; usually show significant improvement after TGA . This clinical evaluation does, however, not provide objective, quantifiable information about the movement patterns underlying the functional capacity, which is clinically important and can currently only be obtained in a gait laboratory. There is a need to improve patient instructions and to quantify the rehabilitation process. The sit-to-stand (STS) movement is an objective performance-based task, whose assessment is related with the evaluation of functional recovery. Twenty two patients with hip osteoarthritis participated in this study. For each patient, validated questionnaires were administered and gait velocity was measured. Time, ground reaction forces, and lower limb asymmetry parameters were calculated using the instrumented force shoes (IFS) during STS movement with and without armrest. Significant inter-limb asymmetry was observed. No correlation was found between any parameter and gait velocity and questionnaires outcomes. Significant differences in time and force parameters between with/without armrest were found. Concluding, inter-limb asymmetry can be evaluated with the IFS supplying important additional information not represented by gait velocity and questionnaires usually used.

Trochlear osteotomy for patellar instability: satisfactory minimum 2-year results in patients with dysplasia of the trochlea.

Trochlear dysplasia is a predisposing factor for recurrent patellar instability. We evaluated the results of an anterior lateral femoral condyle open wedge osteotomy for treating patellar instability. A total of 16 consecutive patients (19 knees) with symptoms of recurrent patellar instability and trochlear dysplasia identified using a true lateral radiograph of the knee underwent an anterior lateral femoral osteotomy. Outcomes were documented at 2 years minimum follow-up using the Lysholm scale, the patellofemoral score, WOMAC score and standard conventional radiographs. In 17 knees, patients reported good improvement in stability (no dislocations) and most patients had a marked improvement in pain and functional scores at follow-up (mean follow-up 51 months). No serious complications occurred. Anterior femoral osteotomy of the lateral condyle appears to be a satisfactory and safe method for treating patients with patellofemoral joint instability caused by trochlea dysplasia. In selected cases this procedure can be used to correct trochlea dysplasia. In our opinion, the key to a successful treatment of patellofemoral instability is to successfully distinguish the anatomic deficiencies and to correct the anatomical abnormality.

No benefits with computer assistance in triple pelvic osteotomy.

We evaluated computer-assisted surgery (CAS) used for 21 triple pelvic osteotomies on 20 patients with symptomatic acetabular dysplasia and compared the intraoperative and immediate postoperative data with those of 32 patients who underwent 40 pelvic osteotomies without CAS. The use of the CAS system was abandoned during 9/21 operations mostly because of technical and CT data failure. The peroperative blood loss and duration of surgery were greater, while neurovascular damage occurred less often in the CAS group. We found that the CAS system for pelvic osteotomy was not better than conventional methods.