Arthroplasty Prosthesis Research Articles

Comparison of short-stem with conventional-stem prostheses in total hip arthroplasty: an 8-year follow-up study

PurposeCoxarthrosis is a common disease of the adult hip joint. Elderly patients have mainly been treated with total hip arthroplasty (THA); however, younger patients are increasingly affected. Short-stem prostheses were developed for this special patient group. There have been few studies on the clinical outcomes of this type of prosthesis. This study compared the mid-term results of a short-stem prosthesis and a standard-stem prosthesis 8 years after implantation.MethodsAccording to our clinical registry, patients who received a short-stem prosthesis before 2011 were identified. Patients in the standard-stem prosthesis group were matched based on the sex, age, height, weight, and degree of arthrosis. At the follow-up time, the modified Harris Hip Score (mHHS), University of California Los Angeles (UCLA) activity score and visual analog scale (VAS) pain score were collected and compared with the preoperative values.ResultsFifty-five patients could be matched and analyzed for both groups. No patients needed revision surgery. In both groups, there were significant improvements at the follow-up time. The pre- and postoperative mHHSs, UCLA scores, and VAS scores were 41.9 and 95 (p < 0.0001), 3.75 and 7.9 (p < 0.0001), and 7.6 and 0.9 (p < 0.0001), respectively, in the short-stem group and 44.8 and 96.25 (p < 0.0001), 3.6 and 7.7 (p < 0.0001), and 7.7 and 0.9 (p < 0.0001), respectively, in the control group, with no significant differences between the groups at the follow-up time.ConclusionThe short-stem prosthesis provides mid-term results comparable to those of a standard-stem prosthesis. In both groups, excellent patient-reported outcomes were achieved after an average of 8 years.Level of evidenceIV.

Clinical Outcomes of a Modern Total Knee Arthroplasty Prosthesis Compared to Its Predecessor at 5-Year Follow-Up: Matched Pair Analysis

BackgroundResidual pain is an important cause of patient dissatisfaction after total knee arthroplasty (TKA). A recent study at our institution found that a modern prosthesis was associated with less residual and anterior knee pain at 2-year follow-up when compared to its predecessor. The aim of this study is to evaluate these implants at 5-year follow-up. MethodsFrom July 2012 to December 2013, 100 consecutive modern TKAs were identified from our prospective Institutional Review Board approved database. All patients with 5-year clinical follow-up (n = 77) were matched in a one-to-one fashion based on age, gender, body mass index, and follow-up with a predecessor TKA. Clinical outcomes were assessed with a patient-administered questionnaire for specifically anterior knee pain, painless noise, painful crepitation, and satisfaction. Overall function was assessed using Knee Society Scores and Western Ontario and McMaster University Osteoarthritis Index. ResultsAt 5-year follow-up, there were no significant differences between the modern TKA and a predecessor TKA in the Knee Society pain or function scores (P = .24 and P = .54, respectively). The overall prevalence of residual pain was less with the modern TKA compared to its predecessor (19.5% vs 36.3%; P = .02), but the prevalence of isolated anterior knee pain was similar in both cohorts (11.7% vs 22.1%; P = .09). There was no difference in painless noise (19.5% vs 13.3%; P = .28) or satisfaction scores (7.9 ± 2.4 vs 7.6 ± 2.6; P = .25) between the modern and predecessor cohorts. ConclusionAt 5-year follow-up, we found that both the modern and predecessor prostheses provided excellent clinical outcomes. The modern TKA was associated with less residual pain compared to its predecessor, but we were unable to detect differences in the prevalence of isolated anterior knee pain, painless noise, Knee Society Scores, or radiographic evaluation.

Risk of Impingement on Polyethylene Liner of Total Hip Arthroplasty Prosthesis during Muslim Prayer (Salat) Activity

Total hip arthroplasty (THA) is one of the most successful orthopedic surgical procedures. Impingement believed to be the most common mechanism of dislocation after THA. Salat consist of several repeated physical movements which require several extreme hip joint movements. The potential impingement positions during salat activity have been revealed by the previous computer simulation study, some evidences of impingement from retrieved polyethylene liner also have been revealed from our recent preliminary data. Although further study is still needed in this field, we may give special advice to modify some movement for Muslim patient who receive THA when performing Salat activity.

Sensitivities of lumbar segmental kinematics and functional tissue loads in sagittal bending to design parameters of a ball-in-socket total disc arthroplasty prosthesis

Lumbar total disc arthroplasty (TDA) is an attractive option for the treatment of spinal disorders. However, post-operative complications may cause revision surgery. In this study, an in-depth biomechanical analysis was performed to test how sensitive post-operative spinal responses in sagittal bending were to design parameters of a widely used ball-in-socket TDA design. Our simulation results revealed that lowering the intervertebral distraction, posteriorly positioning the implant, or decreasing the radius of curvature of the metal-on-polyethylene bearing surface could result in spinal responses which better matched normal spinal kinematics, but deviated further from the normal spinal tissue load-sharing pattern.

Reduction in patient outcomes but implant-derived preservation of function following total knee arthroplasty: longitudinal follow-up of a randomized controlled trial.

There are comparatively few randomized studies evaluating knee arthroplasty prostheses, and fewer still that report longer-term functional outcomes. The aim of this study was to evaluate mid-term outcomes of an existing implant trial cohort to document changing patient function over time following total knee arthroplasty using longitudinal analytical techniques and to determine whether implant design chosen at time of surgery influenced these outcomes. A mid-term follow-up of the remaining 125 patients from a randomized cohort of total knee arthroplasty patients (initially comprising 212 recruited patients), comparing modern (Triathlon) and traditional (Kinemax) prostheses was undertaken. Functional outcomes were assessed with the Oxford Knee Score (OKS), knee range of movement, pain numerical rating scales, lower limb power output, timed functional assessment battery, and satisfaction survey. Data were linked to earlier assessment timepoints, and analyzed by repeated measures analysis of variance (ANOVA) mixed models, incorporating longitudinal change over all assessment timepoints. The mean follow-up of the 125 patients was 8.12 years (7.3 to 9.4). There was a reduction in all assessment parameters relative to earlier assessments. Longitudinal models highlight changes over time in all parameters and demonstrate large effect sizes. Significant between-group differences were seen in measures of knee flexion (medium-effect size), lower limb power output (large-effect size), and report of worst daily pain experienced (large-effect size) favouring the Triathlon group. No longitudinal between-group differences were observed in mean OKS, average daily pain report, or timed performance test. Satisfaction with outcome in surviving patients at eight years was 90.5% (57/63) in the Triathlon group and 82.8% (48/58) in the Kinemax group, with no statistical difference between groups (p = 0.321). At a mean 8.12 years, this mid-term follow-up of a randomized controlled trial cohort highlights a general reduction in measures of patient function with patient age and follow-up duration, and a comparative preservation of function based on implant received at time of surgery. Cite this article: Bone Joint J 2020;102-B(4):434-441.

Results of the Total Hip Arthroplasty Using 3D Printing Technology

Objectives: To study the value of 3D printing of custom THA femoral prostheses with conventional femoral prostheses in total hip arthroplasty for severe hip deformity. Methods: Total hip arthroplasty was used in the treatment of 107 severe hip joint deformity cases from June 2018 to June 2019. Fifty-six patients received conventional hip replacement stems and 51 patients received a custom 3D printed hip replacement stem designed to address their proximal deformity and leg length discrepancy. The operation time, intraoperative blood loss, postoperative weight-bearing time, Harris score before and after the operation, complications after surgery and the main angle measurement of compared to their contralateral hip were evaluated to determine the short-term efficacy of 3D printed total hip replacement femoral prosthesis compared to the common total hip replacement femoral prosthesis. Results: A total of 107 patients were followed up for an average of 12 months. The use of 3D printing technology in the preoperative design and custom prosthesis fabrication was associated with shortened operation time, less intraoperative blood loss, quicker time to postoperative full weight-bearing, and improved the Harris score in 1 year after the operation compared to conventional total hip replacement stem (p&lt;.05). Our results revealed that there was a significant reduction in the femoral anteversion with a value of 13.06 ± 1.93 degrees (mean ± SD) in the custom prosthesis group compared to the conventional hip replacement group. However, there was no significant difference in neck-shaft angle, acetabular angle, and Sharp angle between both groups (p&gt;.05). Conclusion: 3D printing technology created a virtual and realistic simulation, and personalized operation plan for patients with severe hip deformity, which was helpful for surgical treatment. The anatomical characteristics of patients with complex deformities were better addressed using the 3D printed femoral component and resulting in better patient outcomes and provided a new option for surgeons to manage these difficult cases.

3D CT scan-based study of glenoid morphology in Indian population: Clinical relevance in design of reverse total shoulder arthroplasty

BackgroundThe knowledge of normal anatomy of glenoid in a population has relevance in terms of comparison with other regional and national population. Furthermore, it could enable clinicians to judge whether the available sizes of reverse total shoulder arthroplasty (RTSA) prosthesis could provide optimal fit for the glenoid in Indian patients. MethodsWe evaluated consecutive 200 3-dimensional chest CT scans of 50 male and 50 female patients which included both shoulder joints and done for non-orthopaedic diseases at a tertiary care institute. The glenoid height, width, and version were measured using commercially available computer program. ResultsMean age of the patents was 38.6 ± 13.8 years (range, 19–59 years). The mean glenoid height was 33.9 ± 3.1 mm and maximum glenoid width was 24.2 ± 2.1 mm. Mean glenoid version in the study population was a retroversion of 3.47 ± 4.7°. The maximum glenoid width of 45% female and 15% male patients was less than 25 mm which is the diameter of smallest available glenoid baseplate among the commonly used RTSA systems. ConclusionsThe normal glenoid size of a large cohort of Indian population studied was smaller than that reported in cohorts from western countries. The glenoid width of substantial proportion of patients, especially female patients, was less than the diameter of smallest available glenoid baseplate. Clinical studies are needed in future in Indian patients undergoing RTSA to evaluate the glenoid bone-baseplate mismatch and ascertain the necessity of development of smaller size glenoid baseplate for optimal prosthesis fit in Indian patients.

The clinical outcome of the Metha short hip stem: a systematic scoping review.

Short femoral stems were designed to bridge the gap between conventional straight design stems and hip resurfacing prostheses in total hip arthroplasty (THA). A number of clinical trials have been recently conducted to assess the clinical and safety profile of the cementless, colarless, tapered Metha short hip stem in young or active middle-aged individuals. A systematic scoping review was conducted according to Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. 4 reviewers independently conducted the search using the MEDLINE/PubMed database and the Cochrane Database of Systematic Reviews. These databases were queried with the terms "short" AND "hip" AND "stem". From the initial 773 studies we finally chose 12 studies after applying our inclusion-exclusion criteria. The number of operated hips that were included in these studies was 5048 (mean BMI range: 22.7-35.2, mean age range: 44.4-60.4 years, mean follow-up range: 2-9 years). The mean modified Coleman methodology score was 52.3/100, while it ranged from 31/100 to 63/100. All mean clinical outcome scores that were used in the studies illustrated significant postoperative improvement when compared with the respective initial values. The revision rate of the Metha stem for component-related reasons was 2.5%, while the rate of major complications not requiring revision of the Metha stem was 2.8%. The Metha stem performs well in young or active middle-aged THA patients. Further studies are required for the assessment of the long-term results.

Application of a Customized Total Talar Prosthesis for Revision Total Ankle Arthroplasty.

Background:The rate of revision surgery for total ankle arthroplasty (TAA) is higher than for hip and knee arthroplasties. Tibiotalocalcaneal arthrodesis is widely used; however, it requires a large allograft. Thus, the use of a customized total talar prosthesis in combination with the tibial component of TAA (combined TAA) may be an effective strategy for talar component subsidence. This study aimed to evaluate the clinical and radiographic effectiveness of the combined TAA in such revision cases.Methods:Between 2000 and 2015, 10 patients (10 women; 10 ankles) were treated using the combined TAA for revision after standard TAA or combined procedures that included the use of a talar body prosthesis. In 6 patients, the tibial component was concurrently replaced. The median follow-up period was 49 months (interquartile range [IQR], 24.5 to 90 months). The Japanese Society for Surgery of the Foot (JSSF) ankle-hindfoot scale score, a numerical rating scale (NRS) pain score, passive range of motion of the ankle, and the presence of osteophytes and degenerative changes in the adjacent joints were assessed preoperatively and at final postoperative follow-up.Results:The median NRS pain score improved significantly, from 7 (IQR, 6.25 to 8.75) to 2 (IQR, 1 to 3). The median JSSF ankle-hindfoot scale total score improved significantly, from 64 (IQR, 56.25 to 71.5) to 88.5 (IQR, 79.75 to 96). In the subcategories of this scale, the median pain score improved from 20 (IQR, 20 to 27.5) to 35 (IQR, 30 to 40), and the median function score improved from 34 (IQR, 26.5 to 37) to 43.5 (IQR, 39.75 to 46). The median range of motion improved from 29° (IQR, 25.5° to 35°) to 35° (IQR, 31.25° to 43.75°). No significant difference in osteophyte formation was found. Degenerative changes in the adjacent joint were found only in the talonavicular joint.Conclusions:The combined TAA, used in revision for postoperative complications after standard TAA or combined procedures including the use of a talar body prosthesis, was associated with improved objective JSSF ankle-hindfoot scale scores, subjective pain assessment, and range of motion in the ankle.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

The midterm results of a cohort study of patellofemoral arthroplasty from a non-designer centre using an asymmetric trochlear prosthesis

PurposePatellofemoral arthroplasty (PFA) prosthesis with asymmetric trochlear component was introduced as an improvement from existing designs for surgical treatment of symptomatic isolated patellofemoral arthritis. The purpose of this study was to evaluate midterm results in patients who underwent PFA procedure using such prosthesis. MethodsOur study involved a continuous retrospective cohort of patients who underwent PFA using Journey PFA prosthesis with an asymmetric trochlear component, performed between June 2007 and July 2016 at a non-designer centre. The Patient Reported Outcome Measures and patient satisfaction questionnaires were collected for final evaluation. ResultsA total of 103 PFA performed on 79 patients were evaluated. Median age at the time of surgery was 58years (range 42 to 78years); the mean follow-up period was 6 years (range 2 to 11years). Four knees were revised to Total Knee Arthroplasty for reasons not related to the implant. The cumulative survival estimated by the Kaplan–Meier method was 94.3% (95% confidence interval: 88.4%–100%). There were statistically significant improvements in functional outcome scores. ConclusionThis series of patients who underwent PFA with the asymmetric trochlear component has shown promising mid-term results with no implant-related complications.

Relationship between Femoral Intercondylar Notch Narrowing in Radiography and Anatomical and Histopathologic Integrity of Anterior Cruciate Ligament in Patients Undergoing Total Knee Replacement Surgery.

The presence of cruciate ligaments is very important for normal knee kinematics. Knee arthroplasty prostheses, in which these ligaments are maintained, have better kinematics. The aim of the present study was to investigate the association between femoral intercondylar notch (FIN) narrowing in radiography and clinical and histopathologic integrity of anterior cruciate ligament (ACL) in patients undergoing knee replacement surgery. FIN index was measured in tunnel view radiography of the knees of 102 candidates of knee replacement surgery. The anatomical status of ACL was also examined during total knee arthroplasty (TKA). ACL was removed and sent for histopathologic examination to assess its degeneration rate. The association between the FIN index and the clinical and histopathological health of ACL was investigated. Among 102 patients with mean age of 69.73 ± 7.81 years , 39 patients (38.32%) had no or torn ACL, 31 patients (30.39%) had weak ACL, and 32 (31.37%) had normal ACL. There was a significant association between age and clinical status of ACL during surgery (P=0.017). There was a significant difference in FIN and ACL health status during surgery between the two groups with an index of more and less than 0.252 (P=0.019 and P=0.019, respectively). There was no significant difference in the mean total degeneration score (TDS) of ACL between the two groups with FIN more and less than 0.252 (P=0.816). There was a significant difference between the age and FIN narrowing (less than 0.252) as well as ACL clinical status during surgery. FIN narrowing had no significant effect on the severity of ACL degeneration and there was no significant difference in the severity of degenerative histopathologic changes between healthy and attenuated ACLs. This indicates that if ACL exists, although apparently attenuated, it has the histologic characteristic of a healthy ligament.

First-generation total ankle arthroplasty

Ankle prostheses are a source of disagreement within the orthopedic community due to the poor initial results. The lack of alternatives to arthrodesis has promoted the evolution of arthroplasties. Biomechanical compatibility has been improved, new surgical techniques and instrumentation devices have been developed, and biological techniques for fixation of the various components have been introduced. The first-generation arthroplasty prostheses introduced in the 1970s were cemented and had a stable constrictive design, but because they required extensive bone resection for implantation, they failed due to loosening and extensive osteolysis. We report a case of left total ankle arthroplasty performed in 1980 that is still “in situ”. Based on the bibliographic research performed, this case seems to represent the longest-lasting implant reported to date. Level of Evidence V; Therapeutic Studies; Expert Opinion.

No difference in failure rates or clinical outcomes between non-stemmed constrained condylar prostheses and posterior-stabilized prostheses for primary total knee arthroplasty.

There has been an increase in the use of unlinked constrained condylar knee (CCK) prostheses in primary total knee arthroplasty (TKA) for cases with significant deformities that cannot be adequately balanced in flexion and extension. However, the literature on its outcomes is limited. The goal of this study is to evaluate whether there are any clinic or radiographic outcome differences for a primary, non-stemmed, unlinked constrained TKA as compared to a control group of posterior-stabilized (PS) TKA using the same implant design. Clinical and radiographic outcome measures for 404 cemented, non-stemmed, primary TKAs performed by two surgeons at the same institution were retrospectively reviewed. All patients underwent primary, non-stemmed components; 241 used CCK inserts and 163 used PS inserts. Preoperative deformity, knee society scores (KSS), range-of-motion (ROM), radiographic data and revision rates were compared between the CCK and PS groups. Both groups had comparable demographics and preoperative ROM and KSS. At similar mean follow-up times (6.1 ± 1.0years for the CCK group and 6.3 ± 1.2years for the PS group), no significant difference was found in ROM, KSS or radiographic outcomes. Revision rates were higher for the CCK group (2%) as compared to the HF-PS (0.6%) group (n.s). The particular design of cemented, primary, non-stemmed, unlinked CCK-TKA examined in this study provided similar clinical and radiographic outcomes to that of PS-TKA at midterm follow-up. III.

Rotating Hinge Implants in Knee Arthroplasty

Due to demographic transition an increasing number of primary knee arthroplasty is expected. A consequence is a rise in frequency in revision knee arthroplasty. Rotating hinge prostheses are a development of former hinge prostheses, due to changes in implant design the outcome of modern rotating hinge implants clearly improved in comparison to former models. Interpretation of outcome in present literature is difficult due to the small number of cases and the heterogeneous indications. Nevertheless the use of rotating hinge knee prostheses in primary and revision arthroplasty is associated with good clinical outcomes, when indicated appropriately.

Tibiofemoral rotation is related to differences in the lateral femoral condyle configuration in both normal subjects and women with hip dysplasia: a three-dimensional analysis

BackgroundWe assessed the morphological differences in the knee joint related to knee rotation angle in patients with hip dysplasia. These results may explain the anatomy of the knee in patients with hip dysplasia and aid in planning knee surgery.MethodsWe enrolled 73 women (146 legs, 35.6 ± 9.0 years) with bilateral hip dysplasia and 45 healthy women (90 legs, 49.0 ± 18.9 years) without lumbago, knee symptoms, or osteoarthritic findings of the knee or spine on plain radiographs. We examined the parameters affecting knee rotation angle, such as the condylar twist angle and femoral condyle measurements with a three-dimensional bone model using the correlation coefficients of each parameter.ResultsThe condylar twist angle and the length of the posterior part of the lateral femoral condyle were statistically positively correlated with knee rotation angle in both the normal (condylar twist angle: r = 0.286, p = 0.007, posterolateral: r = 0.429, p < 0.001) and developmental dysplasia of the hip groups (condylar twist angle: r = 0.230, p = 0.033, posterolateral: r = 0.272, p = 0.005). Knee rotation angle had no statistical correlation with femoral neck anteversion in the developmental dysplasia of the hip group (r = 0.094, p = 0.264), but had a statistical correlation with femoral neck anteversion in the normal group (r = 0.243, p = 0.039).ConclusionsKnee joint morphology is affected by hip dysplasia. We found that the length of the posterior part of the lateral femoral condyle was significantly positively correlated with knee rotation angle in both the normal and developmental dysplasia of the hip groups, and this finding indicates that a greater posterolateral dimension was associated with a greater knee rotation angle. These morphological knee joint differences in patients with hip dysplasia may help determine the alignment of prostheses in total knee arthroplasty.

Outcomes of Core Decompression with or without Nonvascularized Fibular Grafting in Avascular Necrosis of Femoral Head: Short Term Followup study.

Background:Avascular necrosis (AVN) of the femoral head usually occurs in the third to fifth decade. The treatment options depend on the stage of disease varying from nonoperative treatment to surgical procedure including core decompression (CD) with or without nonvascularized or vascularized fibular graft, muscle pedicle bone grafting, osteotomies, and arthroplasty. Finite life of the total hip arthroplasty (THA) prosthesis limits its use in young adults or in middle aged. In this study, we envisage to evaluate the clinicoradiological outcomes of CD and nonvascularized fibular grafting in early stages of AVN femoral head.Materials and Methods:Our study is longitudinal observational study including 76 hips (46 patients) in the age group of 18–48 years (mean 30.07 years). Ficat and Arlet staging system was used and only early stages, that is, Stage 1 (n = 36 hips) and Stage 2 (n = 40 hips) were included in the study. The cases with traumatic AVN were excluded. All patients in Stage 1 underwent CD (Group 1) and those in Stage 2 underwent CD and fibular grafting (Group 2). Preoperative Harris Hip Score (HHS), visual analog score (VAS), plain radiographs, and magnetic resonance imaging (MRI) were compared with serial postoperative HHS, VAS, plain radiographs, and MRI taken at different intervals.Results:Average period of followup was 53.5 months (44–63 months). Radiological progression was not seen in 55 hips out of 76 hips (72.3%), whereas 21 hips (27.6%) demonstrated signs of progression and collapse. Failure of surgery was defined as progression of the disease, which was 25% (n = 9) in Group 1and 30% (n = 12) Group 2. Median values of HHS at the end of the followup in Group 1 was 77 and in Group 2 was 71.5 compared to the preoperative HHS of 48 and 62 in Group 1 and 2, respectively. Median values of VAS at the end of the followup in Stage 1 was 0 and in Stage 2 was 2 compared to the preoperative VAS of 6 and 8 in Group 1 and Group 2, respectively.Conclusion:CD with or without fibular grafting is effective in preserving the sphericity of the femoral head and to delay the progression of the AVN of femoral head in the early stages, that is, Stage 1 and Stage 2 and aids in the early revascularization of ischemic femoral head and is a useful modality to negate or delay the requirement of THA.

Long-term results of total knee arthroplasty with single-radius versus multi-radius posterior-stabilized prostheses

BackgroundSingle-radius (SR) prostheses and multi-radius (MR) prostheses have different theoretical advantages; however, there has been a paucity of evaluations comparing the two. This study was designed to compare the 10-year clinical, radiological, and survival outcomes of SR and MR posterior-stabilized prostheses in total knee arthroplasty (TKA).MethodsIn this retrospective cohort study, 220 consecutive patients undergoing TKA between October 2006 and October 2007 were divided into the SR group (106 patients, Stryker Scorpio NRG) and the MR group (114 patients, DePuy Sigma PFC), with a minimum follow-up of 10 years. Clinical, functional, and radiological outcomes, as well as satisfaction rates and survival results, were evaluated.ResultsHospital for Special Surgery and Short Form-12 health survey scores were all significantly improved in both groups at the final follow-up (P < 0.05), but the groups did not differ. The SR group had significantly less anterior knee pain (AKP) and painless crepitation (P < 0.05). Radiological results in terms of radiolucent lines and component position angle showed no differences between groups. The Kaplan-Meier survival curve estimates at 10 years were not significantly different between the groups (P = 0.4172).ConclusionBoth SR and MR posterior-stabilized prostheses can lead to satisfactory outcomes. The SR prosthesis design gave less anterior knee pain than did the MR prostheses. Two prostheses showed no differences in terms of clinical scales, radiological results, satisfaction rates, and survival results at a long-term follow-up. More accurate measurements are required.

Total Knee Arthroplasty Using a Medial Pivot or Posterior Cruciate-Stabilizing Prosthesis in Chinese Patients.

There is an unmet need for a prosthesis designed according to the anatomical parameters of the Chinese population. This study aims to compare the use of a medial pivot (MP) implant or posterior cruciate ligament (PCL) substitution (posterior-stabilized [PS]) prosthesis for unilateral total knee arthroplasty (TKA) in a Chinese population. The medical records of patients undergoing unilateral TKA with an MP implant (Group A) or a PS prosthesis (Group B) at our institution between January 2010 and December 2011 were retrospectively reviewed. Patients were followed up for 5 years. Preoperatively and at the December 2016 postoperative follow-up, the Hospital for Special Surgery scoring system (HSS knee score) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were measured to evaluate TKA outcomes. This study included 49 patients in Group A and 51 in Group B. As of December 2016, there were no significant differences in the preoperative/postoperative changes in any category of the HSS knee score or WOMAC score between the groups. There were no postoperative complications in either group during the 5-year follow-up. There were no periprosthetic infections or need for revision surgery. One patient in Group A experienced aching and a small amount of effusion in the articular cavity that was attributed to overexertion. In conclusion, there were no significant differences in midterm outcomes in Chinese patients receiving an MP implant or a PS prosthesis for unilateral TKA. These data suggest that the MP and PCL substitution design are safe and effective for unilateral TKA in China.

Arthroplasty of the proximal interphalangeal joint with the Tactys® modular prosthesis: Results in case of index finger and clinodactyly

There are various surgical solutions for arthrosis of the proximal interphalangeal (PIP) joint: arthrodesis or denervation. Clinodactyly that is major and the index fingers are traditional contraindications for PIP arthroplasty prostheses. The recurrence of clinodactyly with ligament imbalance and mechanical complications are known complications. The purpose of our study was to evaluate the objective and subjective clinical results and radiological complications of Tactys® prostheses on the PIP joint of the index fingers or with clinodactyly of more than 5° in the other fingers. Two surgeons have implanted 35 total gliding modular Tactys® prostheses in 29 women and 3 men since 2010. The indications for surgery were arthrotic and painful PIP joints. Average pre-op clinodactyly was 7.03° (5–30°) with ulnar deviation (29 cases). Eleven index fingers presented with average clinodactyly of 14.2° (10–20°). The digits operated on were as follows: 13 index fingers, 14 middle fingers, 5 ring fingers and 3 little fingers. Arthrosis was primitive in 23 cases, post-traumatic in 6 cases and rheumatoid in 6 cases. The average age of patients undergoing surgery was 63.7 years (40–85). Objective (mobility, strength, index finger exclusion, scores, clinodactyly) and subjective (patient satisfaction, pain) functional results were collected by a neutral and independent observer, as were radiological complications. With an average follow-up of 2.6 years (1–6.3), the range of motion in all digits improved by 5.4° on average (55.5–60.8). The improvement in range of motion in the index fingers was 4.5° (57–61.5). Clinodactyly in all fingers was corrected by 1.36° (0–20). In the index fingers, average clinodactyly was 1.3° (0–10). The pinch strength in all PIP joints improved significantly from 2.3 kg (0.5–5) to 3.7 kg (1–8). On the PIP of the index fingers, the pinch strength had increased significantly from 2.5 kg (1–4) before surgery to 3.8 kg (1–7.5) post-op. Functional scores improved: PRWE (from 55.36 to 26.7/100), Quick DASH (from 54.6 to 30.5/100). Patient satisfaction was excellent in 15 cases, good in 8 cases, average in 10 cases, poor in 2 cases. The average VAS Pain Score improved from 5.6 to 1.45. We found 3 major complications requiring surgery: 2 stiffening and 1 mechanical loosening with secondary arthrodesis. Five patients presented with non-troublesome, reducible swan neck deformity and one algodystrophy. A gliding, fixed Tactys® prosthesis allowed us to restore ligament balance and to optimally rebalance the periarticular structures. The improvement in range of motion and the correction of clinodactyly was maintained over time. Total arthroplasty of the PIP with a Tactys® is no longer a formal contraindication for the index fingers and in cases of clinodactyly of more than 5°.

A New Total Knee Arthroplasty Design Has Significantly Better Early Implant Survivorship than a Previous Gold-Standard Design-A Retrospective Analysis of 1,000 Cases.

This study examined whether a new total knee arthroplasty (TKA) prosthesis improved implant survivorship and reoperation rates compared with a gold-standard, established TKA. A retrospective analysis of the first 500 consecutive new TKAs was compared with a consecutive series of the last 500 currently available TKAs performed by a single senior surgeon in one center. The primary outcome measure was revision of the femoral, tibial, or patellar component. A secondary outcome was reoperation for any reason. The new-TKA group had a significantly reduced revision rate at up to 5 years follow-up (p = 0.02). Reoperation rates for any reason were similar (p = 0.3). The new TKA design has a significantly better early revision rate compared with a currently available gold-standard TKA. This is the largest study of 1,000 cases comparing a new TKA design with a currently available design with excellent midterm results. It demonstrates very favorable early clinical results for the new TKA design, providing reassurance for patients, surgeons, and regulatory bodies.