Accuracy of the newly developed Zimmer Biomet Root Aiming guide in tibial tunnel creation compared with that of conventional guides.

Background/objective: Accurate tibial tunnel creation is crucial for successful transtibial pullout repair of medial meniscus (MM) posterior root tears (MMPRTs). This study aimed to evaluate the accuracy of the newly developed Zimmer Biomet Root Aiming (ZeBRA) guide for transtibial pullout repair of MMPRTs. Methods: This study included 50 patients who underwent transtibial pullout repair using the Unicorn Meniscal Root (UMR) (n = 25) and ZeBRA (n = 25) guides. The expected anatomic centre (AC) and tibial tunnel centre (TC) were assessed using three-dimensional postoperative computed tomography (CT) images. The expected AC was defined as the centre of the circle tangent to the triangular footprint of the MM posterior root. The expected AC and TC on the tibial surface were assessed using the percentage-based posterolateral location on the tibial surface. The absolute distance between the AC and TC (mm) was evaluated. Results: The mean AC location was 76.1% ± 3.1% posterior and 40.8% ± 2.1% lateral, whereas the mean TC location was 76.7% ± 5.3% posterior and 37.2% ± 3.6% lateral using the UMR guide and 75.8% ± 3.1% posterior and 36.5% ± 2.4% lateral using the ZeBRA guide. No significant difference was observed in the absolute distance between the UMR and ZeBRA guides (3.9 ± 1.4 and 3.8 ± 1.3 mm, respectively; p = 0.617). Conclusions: The newly developed ZeBRA guide allows accurate tibial tunnel creation, and its accuracy is comparable to that of the conventional UMR guide. Tibial tunnels were created at optimal positions using both guides, and the choice of the guide would depend on the surgeon's preference.

Mid- to long-term outcomes of a cemented, all-polyethylene pegged glenoid component in anatomic total shoulder arthroplasty.

BACKGROUND: The primary aim of this study was to evaluate mid- to long-term survival of an all-polyethylene pegged glenoid component used in anatomic total shoulder arthroplasty (TSA). The secondary aim was to review clinical and radiologic outcomes. METHODS: A retrospective analysis of a prospectively collected local arthroplasty register of consecutive patients undergoing TSA with an all-polyethylene pegged glenoid between January 2009 and December 2018 was undertaken. In total, 108 TSAs using this implant were performed in our unit in 98 patients (18 men and 80 women), with 10 patients undergoing bilateral TSA. The mean age at the time of the operation was 71.3 years (range, 44-87 years). The mean follow-up period was 5.1 years (range, 2-10.6 years). In addition to survival analysis, clinical evaluation included the postoperative Oxford Shoulder Score, Constant score, and visual analog scale (VAS) pain score, as well as range-of-motion assessment. Radiologic outcomes included an assessment of radiolucency based on the Lazarus grade. RESULTS: Kaplan-Meier survival analysis revealed a 6-year survival estimate of 94.1% for all-cause revision. Revision was required in 6 patients: 4 for cuff failure and 2 for instability. At follow-up, the mean Oxford Shoulder Score was 38.2 (standard deviation [SD], 12.3); mean Constant score, 59.3 (SD, 17.0); and mean VAS pain score, 1.8 (SD, 2.5). Mean forward elevation at final follow-up was 111° (SD, 26.6°); mean abduction, 102° (SD, 34.0°). Clinical outcomes were maintained at long-term follow-up (>8 years), with the exception of the VAS pain score, which increased by 2.1 points (P = .034). Radiologic assessment revealed that 28 patients had radiolucency consistent with Lazarus grade ≥ 3 with clinical outcomes not being affected. CONCLUSIONS: Mid- to long-term follow-up indicates a low revision rate and good clinical survivorship for cemented, all-polyethylene glenoid components. No patients, so far, have undergone revision for glenoid loosening, but radiographic follow-up has shown that 36% of these implants have signs of radiolucency. Further follow-up is required to determine longer-term survivorship.

High rate of tibial debonding and failure in a popular knee replacement : a follow-up review.

AIMS: Total knee arthroplasty (TKA) is a common and safe orthopaedic procedure. Zimmer Biomet's NexGen is the second most popular brand of implant used in the UK. The primary cause of revision after the first year is aseptic loosening. We present our experience of using this implant, with significant concerns around its performance with regards early aseptic loosening of the tibial component. METHODS: A retrospective, single-surgeon review was carried out of all of the NexGen Legacy Posterior Stabilized (LPS) TKAs performed in this institute. The specific model used for the index procedures was the NexGen Complete Knee System (Legacy Knee-Posterior Stabilized LPS-Flex Articular Surface, LPS-Flex Femoral Component Option, and Stemmed Nonaugmentable Tibial Component Option). RESULTS: Between 2013 and 2016, 352 NexGen TKAs were carried out on 331 patients. A total of 62 TKAs have been revised to date, giving an all-cause revision rate of 17.6% at a minimum of five years. Three of these revisions were due to infection. Overall, 59 of the revisions were performed for aseptic loosening (16.7%) of the tibial component. The tibial component was removed intraoperatively without instrumentation due to significant tibial debonding between the implant-cement interface. CONCLUSION: While overall, we believe that early aseptic loosening is multi-factorial in nature, the significantly high aseptic revision rate, as seen by an experienced fellowship-trained arthroplasty surgeon, has led us to believe that there is a fundamental issue with this NexGen implant design. Continued implant surveillance and rigorous review across all regions using this particular implant is warranted based on the concerning findings described here. Cite this article: Bone Jt Open 2022;3(6):495-501.

Minimum 5-Year Outcomes of a Multicenter, Prospective, Randomized Control Trial Assessing Clinical and Radiological Outcomes of Patient-Specific Instrumentation in Total Knee Arthroplasty.

BACKGROUND: Patient-specific instrumentation (PSI) was developed to produce more accurate alignment of components and consequently improve clinical outcomes when used in total knee arthroplasty. We compare radiological accuracy and clinical outcomes at a minimum of 5-year follow-up between patients randomized to undergo total knee arthroplasty performed using PSI or traditional cutting block techniques. METHODS: This multicenter, randomized control trial included patients blinded to the technique 1used. Outcome measures were coronal alignment measured radiologically, Euroqol-5D, Oxford knee score, and International Knee Society Score measured at 1- and 5-year follow-up. RESULTS: At a minimum 5-year follow-up, there were 38 knees in the PSI group and 39 in the conventional instrumentation group for analysis. Baseline demographics and clinical outcome scores were matched between groups. Overall, there was no significant difference in the coronal femoral angle (P = .59), coronal tibial angle (P = .37), tibiofemoral angle (P = .99), sagittal femoral angle (P = .34), or the posterior tibia slope (P = .12) between knees implanted using PSI and those implanted with traditional cutting blocks. On the measurement of coronal alignment, intraobserver reliability tests demonstrated substantial agreement (k = 0.64). Clinical outcomes at both 1-year and 5-year follow-up demonstrated statistically significant and clinically relevant improvement in scores from baseline in both groups, but no difference could be detected between the Euroqol-5D (P = .78), Oxford knee score (P = .24), or International Knee Society Score (P = .86) between the 2 groups. CONCLUSION: This study has shown no additional benefit to PSI in terms of improved alignment or functional outcomes at minimum 5-year follow-up over traditional techniques.

Preventing ceramic liner fracture after Delta ceramic-on-ceramic total hip arthroplasty.

BACKGROUND: The results of total hip arthroplasty (THA) with use of Delta ceramic articulation were successful at medium term follow-up. The use of this newest ceramic has markedly reduced the incidence of ceramic head fractures, but not the incidence of ceramic liner fractures. We tested a hypothesis that the ceramic fractures are prevented by use of a metal shell with 18° inner taper angle and a stem design with a reduced neck geometry. METHODS: We conducted a prospective multicenter study of cementless THA with use of 32/36-mm Delta ceramic bearing, Exceed ABT metal shell and Taperloc stem. We evaluated ceramic fracture, noise, clinical results, radiological changes and survival rate at a minimum of 5-year follow-up. RESULTS: From April 2010 to February 2012, 246 patients (274 THAs) were enrolled. Among them, 224 patients (130 men and 94 women, 250 hips) were followed-up for 5-8 years (mean 6.0 years). Ceramic malseating or fracture did not occur in any patient. Eight patients (8 hips, 3.2%) reported noise. Mean Harris hip score was 84 points at the latest follow-up. All acetabular and femoral components had bone-ingrown stability. Two hips were revised due to recurrent dislocation and periprosthetic fracture. The survival rate was 99.6% at 8 years postoperatively. CONCLUSION: Ceramic fractures can be prevented by a use of (1) 32/36-mm Delta ceramic bearing, (2) metal shell with 18° taper angle, and (2) stem with a reduced neck geometry. However, noise remains a concern of the Delta ceramic bearing. LEVEL OF EVIDENCE: Therapeutic level II.

Finite element analysis of two cephalomedullary nails in treatment of elderly reverse obliquity intertrochanteric fractures: zimmer natural nail and proximal femoral nail antirotation-ΙΙ.

BACKGROUND: More elderly patients are suffering from intertrochanteric fractures. However, the choice of internal fixation is still controversial, especially in the treatment of unstable intertrochanteric fracture; thus, previous implants continue to be improved, and new ones are being developed. The purpose of our study was to compare the biomechanical advantages between the zimmer natural nail (ZNN) and proximal femoral nail antirotation-II (PFNA-II) in the treatment of elderly reverse obliquity intertrochanteric fractures. METHODS: A three-dimensional finite element was applied for reverse obliquity intertrochanteric fracture models (AO31-A3.1) fixed with the ZNN or PFNA-II. The distribution, peak value and position of the von Mises stress and the displacement were the criteria for comparison between the two groups. RESULTS: The stresses of the internal fixation and femur in the ZNN model were smaller than those in the PFNA-II model, and the peak values of the two groups were 364.8 MPa and 171.8 MPa (ZNN) and 832.3 MPa and 1795.0 MPa (PFNA-II). The maximum amount of displacement of the two groups was similar, and their locations were the same, i.e., in the femoral head vertex (3.768 mm in the ZNN model and 3.713 mm in the PFNA-II model). CONCLUSIONS: The displacement in the two models was similar, but the stresses in the implant and bone were reduced with the ZNN. Therefore, the ZNN implant may provide biomechanical advantages over PFNA-II in reverse obliquity intertrochanteric fractures, as shown through the finite element analysis. These findings from our study may provide a reference for the perioperative selection of internal fixations.

Titanium neck-titanium stem taper corrosion in a modular neck stem.

An 81-year-old woman presented with progressive groin pain after metal-on-polyethylene total hip arthroplasty with a modular neck stem and was found to have adverse local tissue reaction. As we report for the first time with this implant, we observed titanium neck-titanium stem taper corrosion intraoperatively. We also found head-neck taper corrosion. The patient underwent revision surgery to a modular fluted tapered stem with ceramic head and was asymptomatic at 3-year follow-up visit. In conclusion, consideration should be given to avoiding the routine use of this modular neck stem in total hip arthroplasty. Patients with this prosthesis should be closely monitored for adverse local tissue reaction.

Biomet stock temporomandibular joint prosthesis: Long-term outcomes of the use of titanium condyles secured with four or five condylar fixation screws.

PURPOSE: The aim of this study was to determine the long-term outcomes following TMJ replacement using the stock Zimmer-Biomet TMJ device. In particular, investigated whether the titanium condylar implant and number of screws used to fixate it to the mandibular ramus had any impact on outcomes. METHODS: Subjects who underwent surgical implantation of a stock Zimmer-Biomet TMJ prosthesis were identified for this retrospective study. All patients received a titanium condylar component secured with four or five screws and ultra-high molecular weight polyethylene (UHMWPE) fossa with no metal reinforcement. Pre- and postoperative pain scores (VAS) and maximum interincisal opening (MIO) data were collected. Additional data included patient demographics, as well as operative, postoperative and follow-up details. Data were analysed with IBM SPSS 2.0 through the use of paired t-tests, and ANOVA and ANCOVA analysis. RESULTS: 190 subjects were identified. Following exclusions, the remaining study population (n = 60) consisted of 58 females and two males with a mean age of 53.5 years at time of surgery. Preoperative VAS and MIO values were 6.08 (SD = 2.24) and 31.88 mm (SD = 7.38 mm), respectively. 90% of the cohort required four screws to fix the prosthetic condylar component in place. After a median follow up of 5.2 years (95% CI: 4.73-5.62 years), with a range of 2-9 years, the VAS was 0.91 (SD = 1.89; p < 0.001) and the MIO was 34.8 mm (SD = X; p = 0.015). Only one device failed over the 9-year study period. CONCLUSION: The results of this study demonstrate good VAS and MIO outcomes following the implantation of a stock Zimmer-Biomet TMJ device. Additionally, good long-term outcomes were obtained with a titanium condylar component, fixed to the mandibular ramus with only four or five screws, and a UHMWPE fossa with no metal reinforcement.

Breakage of the Tail Portion of the Lag Screw during Removal of Proximal Femoral Zimmer Natural Nail: Report of Two Cases with Technical Notes.

Proximal femoral cephalomedullary nailing is one of the treatments of choice for intertrochanteric fracture. Zimmer Natural Nail® (ZNN; Zimmer) is one of the alternatives. We report two cases of broken tail portion of the ZNN lag screw during the removal procedure. This may be the first reported cases in scientific literature with this pattern of failure. We report these cases to highlight one of the possible problems that could occur during removal of this implant which can possibly prolong the operation time significantly if the required device is not prepared.

Outcomes for a large metaphyseal volume hemiarthroplasty in complex fractures of the proximal humerus.

BACKGROUND: A large metaphyseal volume shoulder hemiarthroplasty has been in use within our department since 2008; however, no clinical outcome data are available for this prosthesis apart from the designer surgeon series. MATERIALS AND METHODS: During a 5-year period, data were collected for 40 patients (30 women, 10 men) treated consecutively with the Zimmer Anatomical Shoulder Fracture hemiarthroplasty system (Zimmer, Warsaw, IN, USA). RESULTS: The final analysis included 26 patients. The median age was 79 years (range, 58-91 years), and the median follow-up was 3.7 years (range, 2.0-5.8 years). The median Constant Score was 34 points (range, 16-70 points), and the median Oxford Shoulder Score was 27 points (range, 5-46 points). The greater tuberosity healed satisfactorily in 12 patients. Resorption of the greater tuberosity was seen radiologically in 18 patients. The presence of resorption had no significant effect on the Constant Score (P = .264) or the Oxford Shoulder Score (P = .469). Three patients (12%) required revision. CONCLUSIONS: This is the first report from a nondesigner center for outcomes for this prosthesis to date. The results demonstrate reduced functional performance compared with the designer series.

Breakage of the Tail Portion of the Lag Screw during Removal of Proximal Femoral Zimmer Natural Nail: Report of Two Cases with Technical Notes / 대한고관절학회지

Proximal femoral cephalomedullary nailing is one of the treatments of choice for intertrochanteric fracture. Zimmer Natural Nail® (ZNN; Zimmer) is one of the alternatives. We report two cases of broken tail portion of the ZNN lag screw during the removal procedure. This may be the first reported cases in scientific literature with this pattern of failure. We report these cases to highlight one of the possible problems that could occur during removal of this implant which can possibly prolong the operation time significantly if the required device is not prepared.

Breakage of the Tail Portion of the Lag Screw during Removal of Proximal Femoral Zimmer Natural Nail: Report of Two Cases with Technical Notes / 대한고관절학회지

Proximal femoral cephalomedullary nailing is one of the treatments of choice for intertrochanteric fracture. Zimmer Natural Nail® (ZNN; Zimmer) is one of the alternatives. We report two cases of broken tail portion of the ZNN lag screw during the removal procedure. This may be the first reported cases in scientific literature with this pattern of failure. We report these cases to highlight one of the possible problems that could occur during removal of this implant which can possibly prolong the operation time significantly if the required device is not prepared.

Total Ankle Arthroplasty: An Overview of the Canadian Experience.

Total ankle arthroplasty use has increased across Canada over the last two decades. Multiple implant designs are readily available and implanted across Canada. Although arthrodesis is a reliable procedure for treating end-stage ankle arthritis, ankle replacement is often the preferred surgical treatment by patients. A recent prospective study evaluated intermediate-term outcomes of ankle replacement and arthrodesis at multiple centers across Canada, with variability in prosthesis type, surgeon, and surgical technique. Intermediate-term clinical outcomes of total ankle replacement and ankle arthrodesis were comparable in a diverse cohort in which treatment was tailored to patient presentation; however, rates of reoperation and major complications were higher after ankle replacement.

Cooling Devices in Laser therapy.

Cooling devices and methods are now integrated into most laser systems, with a view to protecting the epidermis, reducing pain and erythema and improving the efficacy of laser. On the basis of method employed, it can be divided into contact cooling and non-contact cooling. With respect to timing of irradiation of laser, the nomenclatures include pre-cooling, parallel cooling and post-cooling. The choice of the cooling device is dictated by the laser device, the physician's personal choice with respect to user-friendliness, comfort of the patient, the price and maintenance costs of the device. We hereby briefly review the various techniques of cooling, employed in laser practice.

Application of uniform design to improve dental implant system.

This paper introduces the application of uniform experimental design to improve dental implant systems subjected to dynamic loads. The dynamic micromotion of the Zimmer dental implant system is calculated and illustrated by explicit dynamic finite element analysis. Endogenous and exogenous factors influence the success rate of dental implant systems. Endogenous factors include: bone density, cortical bone thickness and osseointegration. Exogenous factors include: thread pitch, thread depth, diameter of implant neck and body size. A dental implant system with a crest module was selected to simulate micromotion distribution and stress behavior under dynamic loads using conventional and proposed methods. Finally, the design which caused minimum micromotion was chosen as the optimal design model. The micromotion of the improved model is 36.42 µm, with an improvement is 15.34% as compared to the original model.

Analysis of the Result Treated with Locking Compression Plate-Distal Tibia and Zimmer Periarticular Locking Plate in Distal Tibia Fracture

PURPOSE: To evaluate the clinical and radiological results of minimally invasive plate, osteosynthesis, using either a locking compression plate-distal tibia (LCP-DT) or Zimmer periarticular locking plate (ZPLP) for distal tibia fractures. MATERIALS AND METHODS: Fifty one patients (51 cases), who underwent minimally invasive osteosynthesis using locking compression plate for distal tibia fractures between October 2008 and August 2011, were followed for more than six months. Eighteen patients were treated with LCP-DT and 33 patients with ZPLP. Time to bony union and anatomic alignment were evaluated radiologically. Clinically, American Orthopedic Foot & Ankle Society ankle-hindfoot scales (AOFAS score) and range of ankle motion were assessed and compared between two groups. RESULTS: All patients achieved bony union at an average of 18 weeks on LCP-DT group and 16weeks on ZPLP group. The average American Orthopedic Foot & Ankle Society ankle-hindfoot scales was 83.3 points on the LCP-DT group, 84.6 points on the ZPLP group, and range of ankle motion averaged at 45 degrees, 48 degrees, respectively. CONCLUSION: Both types of locking compression plates were effective when performing minimally invasive osteosynthesis for distal tibia fractures.

Comparative Study of Proximal Femoral Nail Antirotation and Zimmer Natural Nail for the Treatment of Stable Intertrochanteric Fractures

PURPOSE: To compare the results between Proximal femoral nail antirotation II (PFNA II) and Zimmer natural nail Asia type (ZNN) for the treatment of stable intertrochanteric fractures. MATERIALS AND METHODS: Between September 2011 and September 2012, 40 consecutive patients with stable intertrochanteric femoral fractures were treated with PFNA II or ZNN. We reviewed 20 cases of PFNA II and 20 cases of ZNN prospectively. We evaluated the operation time, amount of bleeding, mean hospital day, and capability of mobility and function using 'mobility score of Parker and Palmer' and 'social score of Jensen'. We also evaluated the reduction state by the Fogagnolo, Cleveland index, change of tip and apex distance (TAD), sliding distance of cervical screw, change of neck shaft angle and bone union time. RESULTS: There were no significant differences between the groups treated with PFNA and ZNN. Both groups showed good clinical results. PFNA showed less TAD change and ZNN showed a shorter sliding distance of cervical screw, but they were not statistically different. The bone union time was approximately 13 weeks in both groups. CONCLUSION: PFNA and ZNN produced good clinical and radiologic results in the treatment of stable intertrochanteric fractures. There were no significant differences between the groups. Both implants provide good stability and union, so we can conclude that they are both suitable for the treatment of stable intertrochanteric fractures.