Interscalene block applied by an experienced anesthesiologist has a good anesthetic effect, a long duration of action, and less postoperative pain after arthroscopic shoulder procedures independent of surgery type and operation duration.

OBJECTIVES: This study aims to evaluate the severity of postoperative pain and the time to the onset of pain after arthroscopic surgical treatment of rotator cuff tear or instability under interscalene block. PATIENTS AND METHODS: Between October 2015 and June 2016, a total of 172 patients (82 males, 90 females; mean age: 47.9±16.9 years; range, 15 to 83 years) who underwent shoulder arthroscopy under interscalene block by a single surgeon were retrospectively analyzed. The relationship between the postoperative 24-h Visual Analog Scale (VAS), the time to the onset of pain with the type of surgical procedure (rotator cuff repair, n=101 or instability surgery, n=71), and the duration of surgery (<30 min n=92; ≥30 min n=80) was examined. RESULTS: No significant relationship was found between the type of surgical procedure, VAS scores, and the onset of pain after the block (p=0.577 and p=0.780, respectively). No significant relationship was found between the operation duration, and VAS, and the onset of pain after the block (p=0.570 and p=0.408, respectively). The mean duration until the start of postoperative pain was 734±313 (range, 60 to 1,440) min. There was no statistically significant difference in the need for rescue analgesics at the postoperative 24th h and the duration of surgery between the two groups (p=0.393 and p=0.675, respectively). CONCLUSION: Our study results show no significant difference in the time for the onset of postoperative pain and the VAS scores according to the characteristics of the surgical procedure, operation duration, or age and sex of the patient. Shoulder arthroscopy performed by experienced surgeons under interscalene block eliminates the need for analgesics within the first 12 h postoperatively.

Does glenoid bone loss accompany posterior shoulder instability with only labral tear? A magnetic resonance imaging-based study.

BACKGROUND: The primary aim of this study was to investigate bone loss in the glenoid with magnetic resonance imaging in posterior shoulder instability with only a labral tear. METHODS: A total of 76 patients operated on because of posterior and anteroposterior shoulder instability only with a labral tear between 2006 and 2019 (n = 40 and n = 36, respectively) were included in this study. The instability type, a presence of an additional superior labrum anteroposterior (SLAP) lesion, the number of dislocations, and the magnetic resonance imaging-based measurements (the glenoid diameter and the bone defect size in the glenoid, the Hill-Sachs lesion [HSL] and the reverse HSL [rHSL] length, the angle and the arc length of HSL and rHSL, and the humerus head diameter and its area) were analyzed. RESULTS: The size of the anterior glenoid defect, the rHSL measurements (length, angle, and arc length), and the ratio of the anterior glenoid defect size to the glenoid diameter were significantly higher for anteroposterior instability (P < .01) cases. There was no significant difference (P = .49, .64, and .82, respectively) for the presence of an additional SLAP pathology, the glenoid diameter, the posterior glenoid defect, and the ratio of the posterior glenoid defect size to the glenoid diameter in posterior and anteroposterior instability groups. The increased number of dislocations was associated with increased rHSL length and total arc length (P = .04 and .03, respectively). An additional SLAP lesion in posterior shoulder instabilities was not associated with the bone defect size (P = .29). CONCLUSION: Although the posterior shoulder instability with only a labral tear is likely to cause a bone defect, we have shown that the instability is not expected to be caused by the bone defect. Therefore, this study points out that only soft tissue repair without considering the bone defect could be promising in this patient group.

Comparative effectiveness research on proximal femoral nail versus dynamic hip screw in patients with trochanteric fractures: a systematic review and meta-analysis of randomized trials.

BACKGROUND: The treatments for trochanteric fractures try to regain early mobility and limit morbidity and risk of reoperations. The most currently used dynamic hip screw (DHS) and the proximal femoral nail (PFN) are both with pros and cons. We aimed to assess the comparative effectiveness of these interventions for trochanteric fractures by evaluating the surgical performance and postoperative outcomes. METHODS: PubMed, Web of Science and Cochrane Central Register were searched for RCTs comparing DHS and PFN for trochanteric fractures. All selected studies and the risk of bias were assessed. Clinical data including operative time, intraoperative blood loss, intraoperative fluoroscopy time, successful closed reduction and complications like nonunion, implant failure and reoperation were recorded. Random-effects models were used in Review Manager software, and GRADE was applied for the interpretation of the evidence. RESULTS: From 286 identified trials, twelve RCTs including 1889 patients were eligible for inclusion; six RCTs directly comparing DHS with PFN, while other six compared DHS with proximal femoral nail antirotation (PFNA). Compared to DHS, PFN had shorter operative time and led to less intraoperative blood loss. However, DHS need less intraoperative fluoroscopy time than PFN. No difference was seen for the achievement of closed reduction. For risk of postoperative complications, no difference was seen between PFN and DHS for non-union, risk of implant failure and revision surgery. CONCLUSIONS: PFN(A) resulted in a shorter operative time and less intraoperative blood loss compared to DHS. However, no difference was seen for postoperative complications. Trial registration PROSPERO: CRD42021239974.

A New Augmentation Method for Improved Screw Fixation in Fragile Bone.

Pertrochanteric fractures (TF) due to osteoporosis constitute nearly half of all proximal femur fractures. TFs are treated with a surgical approach and fracture fixation is achieved using metallic fixation devices. Poor quality cancellous bone in osteoporotic patients makes anchorage of a fixation device challenging, which can lead to failure of the fracture fixation. Methods to reinforce the bone-implant interface using bone cement (PMMA) and other calcium phosphate cements in TFs have been described earlier but a clear evidence on the advantage of using such biomaterials for augmentation is weak. Furthermore, there is no standardized technique for delivering these biomaterials at the bone-implant interface. In this study, we firstly describe a method to deliver a calcium sulphate/hydroxyapatite (CaS/HA) based biomaterial for the augmentation of a lag-screw commonly used for TF fixation. We then used an osteoporotic Sawbones model to study the consequence of CaS/HA augmentation on the immediate mechanical anchorage of the lag-screw to osteoporotic bone. Finally, as a proof-of-concept, the method of delivering the CaS/HA biomaterial at the bone-implant interface as well as spreading of the CaS/HA material at this interface was tested in patients undergoing treatment for TF as well as in donated femoral heads. The mechanical testing results indicated that the CaS/HA based biomaterial increased the peak extraction force of the lag-screw by 4 times compared with un-augmented lag-screws and the results were at par with PMMA. The X-ray images from the patient series showed that it was possible to inject the CaS/HA material at the bone-implant interface without applying additional pressure and the CaS/HA material spreading was observed at the interface of the lag-screw threads and the bone. Finally, the spreading of the CaS/HA material was also verified on donated femoral heads and micro-CT imaging indicated that the entire length of the lag-screw threads was covered with the CaS/HA biomaterial. In conclusion, we present a novel method for augmenting a lag-screw in TFs, which could potentially reduce the risk of fracture fixation failure and reoperation in fragile osteoporotic patients.

Total Infrapatellar Fat Pad Excision Leads to Worse Isokinetic Performance in Total Knee Arthroplasty: A Randomized Controlled Trial.

There are concerns that total infrapatellar fat pad (IPFP) excision in total knee arthroplasty (TKA) results in patellar tendon shortening due to ischemic contracture, but individual preference of the surgeon is still the main determinant between total or partial excision. The aim of this randomized controlled study was to compare isokinetic performance and clinical outcome of TKAs with total and partial excision of the IPFP. Seventy-two patients scheduled to undergo TKA for primary knee osteoarthritis by a single surgeon were randomly assigned to either total or partial excision group. Patients were evaluated preoperatively and at postoperative 1 year, with Knee Society Score (KSS) and isokinetic measurements. The physiatrist performing isokinetic tests and patients were blinded to the study. There were no significant differences between the groups in respect of age, body mass index, gender, and preoperative KSS and isokinetic performance. Postoperatively, both groups had improved KSS knee and KSS function scores, with no difference determined. Knee extension peak torque was significantly higher postoperatively in the partial excision group at postoperative 1 year (p = 0.036). However, there were no significant differences in knee flexion peak torque following TKA (p = 0.649). The results of this study demonstrated that total excision of the IPFP during TKA is associated with worse isokinetic performance, which is most likely due to changes in the knee biomechanics with the development of patella baja. Partial excision of the IPFP appears to be a valid alternative to overcome this potential detrimental effect without impeding exposure to the lateral compartment. This is a Level I, therapeutic study.

A combined fracture and mortality risk index useful for treatment stratification in hip fragility fractures.

OBJECTIVES: In this study, we aimed to assess the stratification ability of the Fracture and Mortality Risk Evaluation (FAME) index for reoperation, new fragility fracture, and mortality during one-year follow-up. PATIENTS AND METHODS: Between November 2018 and July 2019, a total of 94 consecutive hip fragility fracture patients from two centers (20 males, 74 females; mean age: 79.3±8.9 years; range, 57 to 100 years) were retrospectively analyzed. The patients were classified into high, intermediate, and low fracture and mortality risk groups according to the Fracture Risk Assessment Tool (FRAX) score and Sernbo score, respectively, as well as nine combined categories according to the FAME index. Hospital records were reviewed to identify re-fractures (reoperations, implant failure, new fragility fractures on any site) and mortality at one year following the FAME index classification. RESULTS: Overall re-fracture and mortality rates were 20.2% and 33%, respectively. High fracture risk category (FRAX-H) was significantly associated with higher re-fracture (odds ratio [OR]: 2.9, 95% confidence interval [CI]: 1-8.2, p=0.037) and mortality rates compared to others (OR: 3.7, 95% CI: 1.5-9.3, p=0.003). The patients classified within the FRAX-H category (n=35) had different mortality rates according to their Sernbo classification; i.e., patients classified as low mortality risk (Sernbo-L) (n=17) had lower mortality rates compared to others in this group (n=18) (35.3% and 66.7%, respectively), indicating a low statistical significance (OR: 0.3, 95% CI: 0.1-1.1, p=0.063). Similarly, within patients classified in Sernbo-L category (n=64), those classified as high fracture risk (FRAX-H) (n=17) had significantly higher re-fracture rates compared to others in this group (n=47) (35.3% and 8.5%, respectively), (OR: 5.9; 95% CI: 1.4-24.5), (p=0.017). Multivariate logistic regression analyses adjusting for covariates (age, sex, length of hospital stay and BMI) yielded similar results. CONCLUSION: The FAME index appears to be a useful stratification tool for allocating patients in a randomized-controlled trial for augmentation of hip fragility fractures.

Different microbial and resistance patterns in primary total knee arthroplasty infections - a report on 283 patients from Lithuania and Sweden.

BACKGROUND: The microbiology and the susceptibility patterns of infected total knee arthroplasties (TKAs) vary depending on demographic, local antimicrobial stewardship, and surgical factors. We wanted to compare the recent microbial profile and antimicrobial resistance pattern in revisions due to infections after primary TKAs in Sweden and Lithuania. Our hypothesis was that there is a difference in bacteriology and resistance pattern based on patient related, societal and local hospital factors as almost similar praxis have been applied for TKA surgery, short term systemic prophylaxis and routine use of local gentamicin containing bone cement. METHODS: Primary TKAs revised for the first time due to verified or suspected infection were collected nationwide in Sweden during 2018, and in Lithuania between 2011 and 2020 from a single major TKA revision centre in Kaunas. We identified 202 TKAs in Sweden from the Swedish Knee Arthroplasty Register and 84 from Kaunas revised due to infection. We collected available culture reports and evaluated the type of microorganisms with antimicrobial resistance pattern at revision. RESULTS: The majority of the infected cases in Sweden were early-type prosthetic joint infection (PJI) (44%), whereas late-type PJI (52%) were more common in the Kaunas cases. Gram-positive bacteria prevailed in both Sweden (55%) and Lithuania (80%). Staphylococcus aureus was the most frequent organism identified in both countries (33% in Sweden and 34% in Lithuania). More polymicrobial infections were observed in Sweden than in Lithuania (16 and 6% respectively). Methicillin resistance in Staphylococcus aureus and coagulase-negative staphylococci were higher in Lithuania (4/28 and 19/29) than in Sweden (1/42 and 9/41). CONCLUSIONS: The type of infections, microbial profile, and drug resistance pattern differed between Sweden and Lithuania. Societal and local hospitals factors with emerging resistance in Lithuania are the most plausible explanation for the difference. Lack of complete data on a national level in Lithuania underlines the importance of adding microbiology of PJIs in implant registers for national aggregation and allow cross country comparisons.

Are preoperative complete blood count parameters in peripheral nerve sheath tumors useful diagnostic tools?

OBJECTIVES: This study aims to evaluate the diagnostic value of complete blood count (CBC) parameters in patients with peripheral nerve sheath tumors (PNSTs). PATIENTS AND METHODS: A total of 181 patients (83 males, 98 females; median age: 44 years; range, 15 to 83 years) who underwent surgical treatment for PNSTs in our tertiary oncology center between January 2010 and December 2019 were retrospectively analyzed. Eighty-two patients were diagnosed with a neurofibroma, 79 with a schwannoma, and 20 with a malignant PNST (MPNST). The patient group was evaluated as malignant (n=20) and benign (n=161). Age- and sex-matched patients admitted to our outpatient clinic of orthopedic and traumatology with non-specific symptoms other than tumor, infection, fracture, and rheumatological or hematological diseases were included as the control group (n=165). Data including age, sex, definitive histopathological diagnosis, and pre-treatment CBC values were obtained from the hospital records. Pre-treatment CBC values such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) were calculated for both malignant and benign groups and control groups. Diagnostic values of NLR, PLR, and LMR between PNST groups were assessed using the receiver operating characteristic (ROC) curve analysis. RESULTS: Neurofibroma, schwannoma, and MNPST groups had significantly higher median NLR, compared to the control group (p<0.001), while the median LMR was significantly lower in these groups (p<0.05). However, the median PLR was higher only in the MPNST group, compared to the control group (p<0.001). Post-hoc analyses revealed that median NLR, PLR, and LMR ratios were similar in PNST groups, compared to the control group. In addition, the median NLR, PLR, and LMR ratios were similar between malignant and benign patient groups. The highest area under the curve (AUC) was found for NLR (AUC=0.756) and LMR (AUC=0.716) in the MPNST group. CONCLUSION: Our study results suggest that NLR, PLR, and LMR may have an added value in the early diagnosis of PNSTs and are valuable for differentiating patients from healthy individuals, although their value in differential diagnosis is still unclear.

Unicompartmental knee arthroplasty results in a better gait pattern than total knee arthroplasty: Gait analysis with a smartphone application.

OBJECTIVES: The aim of this study was to compare the smartphone- based gait analysis data of patients who underwent total knee arthroplasty (TKA) and unicompartmental knee arthroplasty (UKA). PATIENTS AND METHODS: Between January 2016 and April 2019, a total of 51 patients (3 males, 48 females; mean age: 60.92 years; range, 51 to 70 years) who were operated with UKA or TKA in our clinic were retrospectively analyzed. The patients were divided into two groups according to the type of procedure as the UKA group (n=17) and unilateral TKA group (n=34). Gait analysis was made via a smartphone application (Gait Analyzer software version 0.9.95.0) with data acquired from the accelerometer of the smartphone. This analysis was performed using data collected from the Acceleration Sensor LSM6DSO into the Samsung Galaxy Note 10 Plus phone. Gait velocity, step time, step length, cadence, step time symmetry, step length symmetry, and vertical COM (vert-COM) parameters were measured. RESULTS: There were no statistically significant differences between the groups in respect of age, sex, body mass index, operated side, and follow-up duration. Compared to the TKA group, the UKA patients showed a better gait pattern in gait velocity (p=0.03), step time symmetry (p=0.005), and step length symmetry (p=0.024). No significant difference was detected in step time (p=0.807), step length (p=0.302), cadence (p=0.727) and vert-COM parameters (p=0.608). CONCLUSION: The gait of UKA patients is closer to the physiological pattern with a better gait velocity, step time symmetry, and step length symmetry than TKA patients. The surgical treatment option of UKA for knee medial compartment osteoarthritis leads to a better gait pattern than TKA.

No differences in clinical outcomes or isokinetic performance between cruciate-substituting ultra-congruent and posterior stabilized total knee arthroplasties: a randomized controlled trial.

PURPOSE: Whether ultra-congruent (UC) or posterior cruciate ligament-stabilized (PS) inserts should be used in posterior cruciate ligament (PCL)-sacrificing total knee arthroplasty (TKA) remains debatable. Therefore, the aim of this prospective randomized controlled study was to compare the isokinetic performance and clinical outcomes of these inserts in PCL-sacrificing TKA. METHODS: Sixty-six patients diagnosed with primary knee osteoarthritis were randomly assigned to either the UC or the PS group. There were no significant differences between the groups in terms of age, body mass index or sex. The Knee Society score (KSS) and isokinetic performance results for each patient were recorded preoperatively and at 3, 6 and 12 months postoperatively. The physiatrist that performed the isokinetic tests and the patients were blinded to the study groups. RESULTS: There were no significant differences between the groups in terms of the preoperative KSS or isokinetic performance. Gradual improvement in the KSS was observed in both groups, but no significant differences were detected between the groups during the whole follow-up period. The UC and PS groups exhibited similar peak extension and flexion torque values normalized to body weight at 3, 6 and 12 months postoperatively (p > 0.05). CONCLUSION: The use of UC or PS inserts in TKA did not affect the clinical outcomes or isokinetic performance.The clinical relevance of this study is that the potential differences in clinical outcomes and isokinetic performance between UC and PS inserts do not need to be considered when sacrificing the PCL in TKA. LEVEL OF EVIDENCE: I.

The Evolution of Publications in the Field of Scoliosis: A Detailed Investigation of Global Scientific Output Using Bibliometric Approaches.

AIM: To carry out an in-depth bibliometric analysis of scoliosis literature. MATERIAL AND METHODS: This study used the Web of Science database to identify relevant articles for analysis. The literature search used the keyword ?scolio*? and focused on the period between 1980-2019. Bibliometric network visualizations and mapping of specific results were done using VOSviewer software. RESULTS: The literature search yielded 9706 publications on scoliosis between 1980 and 2019. Of these, 6975 (71.9%) journal articles were included in the bibliometric summary. Orthopedics was the most common area of research (4581 articles, 65.67%), and the United States of America (USA) exhibited the highest publication productivity (2327 articles, 33.36%). Nanjing University in China had the highest number of publications among institutions (n=219, 3.13% of the total literature), and there were a total of 60130 citations in 6975 articles. Fifty-five articles had a minimum of 100 citations, and the journal with the highest number of publications was ?Spine? (number of article: 1628, 23.3%). CONCLUSION: This bibliometric analysis may be regarded as a summary and evaluation of global scientific output on scoliosis and can, therefore, be used a guide for researchers, clinicians and students. Furthermore, the keyword analysis can aid professionals in the field when planning new studies.

Diagnostic role of neutrophil-to-lymphocyte ratio and monocyte-to-lymphocyte ratio in patients with enchondroma and low-grade chondrosarcoma.

OBJECTIVES: This study aims to evaluate the role of elevated neutrophil-to-lymphocyte ratio (NLR) and monocyte-to- lymphocyte ratio (MLR) in differential diagnosis of enchondroma and low-grade chondrosarcoma. PATIENTS AND METHODS: One-hundred-and-one patients (44 males, 57 females; mean age 53.6±11.5 years; range, 21 to 85 years) diagnosed with enchondroma and low-grade chondrosarcoma in Ankara Oncology Training and Research Hospital between January 2010 and December 2019 were included in this retrospective study. Patients' age, gender, location and type of tumor, and pre-treatment complete blood count results were acquired. One-hundred patients (48 males, 52 females; mean age 50.9±13.6 years; range, 19 to 76 years) with complete blood count results admitted to the same center for reasons other than fracture, infection or tumors with similar age and gender to the aforementioned study group were included as healthy controls. RESULTS: Neutrophil-to-lymphocyte ratio and MLR of the study group were found to be significantly higher than the control group (p<0.001). Neutrophil-to-lymphocyte ratio and MLR held diagnostic importance with statistically significant cut-off values. Statistically significant cut-offs for NLR and MLR were ≥2.0 (sensitivity=73.3%, specificity=67%) and ≥0.2 (sensitivity=76.2%, specificity=63%), respectively. Multivariate logistic regression analysis was performed adjusting for age and gender and NLR ≥2 [odds ratio (OR)=3.1] or MLR ≥0.2 (OR=2.9) were found to be associated with approximately three-fold risk for diagnosis of enchondroma or low-grade chondrosarcoma. CONCLUSION: The NLR and MLR have diagnostic value in cartilaginous tumors such as enchondroma and low-grade chondrosarcoma. However, our results do not support utilization of NLR and MLR as diagnostic value for differentiation of enchondroma and low-grade chondrosarcoma.

Is gluteus medius injured in patients treated with a trochanter tip entry intramedullary nail? Clinical, electrophysiological and functional outcomes.

OBJECTIVES: This study aims to assess the functional outcomes, static-dynamic postural stability of patients and evaluate electromyographic activity of gluteus medius (GMed) muscle during gait and spatiotemporal parameters of gait in patients after antegrade intramedullary nailing (IMN) of femoral shaft fractures with trochanter tip entry. PATIENTS AND METHODS: Sixteen patients (15 males, 1 female; mean age 34.8±15.2 years; range, 18 to 58 years) who were treated with an antegrade trochanteric IMN between January 2009 and July 2013 and eight healthy male controls (mean age 39.3±9.8 years; range, 27 to 57 years) were included in this retrospective study. Muscle strength, static and dynamic postural stability and fall risk were evaluated. In addition, spatiotemporal parameters of gait were assessed using a validated wireless inertial sensing device and a wireless electromyography (EMG) device was used to measure electromyographic activity of GMed muscle in both groups. RESULTS: There were significant differences in muscle strength, functional and dynamic balance test scores between operated and intact sides (one-leg hop test score p=0.009, balance test scores p<0.001-0.033). There were significant differences in functional and quality of life physical function test scores between groups (one-leg hop test score p=0.014). However, no significant differences were found in EMG results, dynamics balance, and statics postural stability test scores between groups (p>0.05). CONCLUSION: After isolated femur fracture, patients treated with antegrade trochanteric IMN demonstrated good static and dynamic stability and poor functional outcomes compared to controls. In conclusion, patients with antegrade trochanteric IMN have good balance but poor functional performance; however, further studies are needed to find out the primary reason for these results.

Combined fracture and mortality risk evaluation for stratifying treatment in hip fracture patients: A feasibility study.

OBJECTIVES: This study aims to test the feasibility of the Fracture and Mortality Risk Evaluation (FAME) Index. PATIENTS AND METHODS: Two academic centers in Lithuania and Turkey participated in this retrospective study conducted between November 2018 and July 2019. A total of 100 consecutive patients (22 males, 78 females; mean age 78.9 years; range, 45 to 100 years) with low energy proximal femur fractures admitted for surgery were included in the study. Fracture Risk Assessment tool (FRAX) and the Sernbo scores were calculated and patients were classified into one of the nine subcategories of the FAME Index. RESULTS: Demographics and FAME Index classifications were similar between centers. Patients with high risk of fracture and low risk of mortality accounted for 18% of all patients, which is the FAME Index subcategory to theoretically benefit from cancellous bone augmentation during internal fixation of a fragility hip fracture the most. CONCLUSION: The FAME Index was successfully applied in clinical emergency setting utilizing a simple form, and demonstrated promising potential in stratification of hip fractures most suitable for screw and device augmentation. Larger studies with at least one-year of follow-up are warranted to verify the validity of FAME Index.

Higher Risk of Loosening for a Four-Pegged TKA Tibial Baseplate Than for a Stemmed One: A Register-based Study.

BACKGROUND: Modern modular implants allow surgeons to mix different combinations of components within the same brand. From 1999 to 2012, the NexGen®-CR Option femoral component, together with a NexGen® Option Stemmed tibial plate (stemmed baseplate), which uses a short central stem, was the most-frequently used NexGen® combination in the Swedish Knee Arthroplasty Register. However, from 1999 to 2012, the same femoral component was also used along with the NexGen® Precoat four-pegged tibial baseplate (pegged baseplate). Considering the difference in the fixation concepts for these two tibial baseplates, we wanted to study whether their revision rates differed. QUESTIONS/PURPOSES: To investigate the difference in (1) all-cause revision and (2) the risk of revision for aseptic loosening between the NexGen® pegged and stemmed baseplates when used with the NG-CR Option femoral component and the same two types of inserts. METHODS: The Swedish Knee Arthroplasty Register provided data. The register, which was started in 1975, has since 1999 registered part numbers for individual implant components, allowing it to assess the combinations of components used in each patient. It has been shown to have high completeness (97%) and validity [12, 15]. The inclusion period was 1999 to 2012; during that time, 137,143 primary knee arthroplasties were registered, of which 125,094 were TKAs. Only TKAs performed for osteoarthritis and without patellar resurfacing were included, since not resurfacing the patella is the standard procedure in Sweden. This left 15,287 knees with the stemmed baseplate and 2479 with the pegged baseplate, or 12% and 2% of the total number of TKAs, respectively. Two general hospitals used the pegged baseplate exclusively during that period. Thus, specific patients were not selected for having the pegged plate. The mean age, mortality, and length of followup were similar for the two groups.We used the Kaplan-Meier statistics to calculate the cumulative revision rate (CRR) and Cox regression to compare risk ratios after adjusting for age and sex. The end point was a knee revision for respective all causes or aseptic loosening. The study ended on December 31, 2016. Due to the free healthcare system in Sweden it is highly unusual for patients to seek elective revision abroad, and by use of the extensive Swedish census register, we estimate the level of followup approximately 97%. RESULTS: Knees with the pegged baseplate had a higher risk for all-cause revision than did those with the stemmed baseplate (5.8% [95% confidence interval {CI}, 4-8.3] and 3% [95% CI, 2.6-3.5] at 15 years; p = 0.003). After controlling for age and sex, the aseptic loosening risk in the pegged baseplate group was still higher than that in the stemmed group (relative risk, 5.40; 95% CI, 3.64-8.02; p < 0.001). CONCLUSIONS: In this Swedish registry study, we observed a higher loosening risk with the pegged baseplate than the stemmed one, even after controlling for age and sex. Because this was only a comparison of implants from one vendor, and because there may have been other between-group differences for which we could not fully control, this concerning finding should be explored using data from other registries. LEVEL OF EVIDENCE: Level III, therapeutic study.

Treatment of a combined deformity following tibial tubercle ventromedialization with single proximal tibial closing wedge osteotomy.

Patellar instability in skeletally immature patients must be approached with concern of potential damage to physes. In this article, we present a case of combined knee deformity consisting of genu recurvatum, genu valgum and patella baja which arose subsequent to a pediatric tibial tubercle ventromedialization. Patient was a female who was 22 years old upon first admission. After confirming cartilage to be in good health, the deformity was corrected with a single supratubercular posteriorly and medially based proximal tibial closing wedge osteotomy. At the seventh year follow-up, patient was pain free, functionally satisfied and radiographic evaluation showed correct alignment. This case illustrates the consequent difficulties faced if physeal damage occurs during treatment of patellar instability as well as effectiveness of a single well-planned supratubercular proximal tibial osteotomy treating combined genu recurvatum, genu valgum and patella baja deformities; although anatomic and clinical studies are required to generalize its use.

Biomodulation of an implant for enhanced bone-implant anchorage.

Aseptic loosening of implants is the major cause for revision surgery. By modulating the bone-implant interface, early bone-implant anchorage could be improved. Implant surface manipulation by the addition of osteopromotive molecules locally and systemically to promote implant integration has been described with limited success. This study describes a novel approach by making the implant capable of biologically modulating its surroundings. It was hypothesized that the early implant fixation would improve by filling the interior of the implant with a carrier providing spatio-temporal release of bone active drugs with known osteogenic effect. The implant consisted of a threaded polyether ether ketone (PEEK) hollow chamber with holes at the bottom. The implant was filled with a calcium sulphate (CaS)/hydroxyapatite (HA) carrier, delivering two bone active molecules; zoledronic acid (ZA) and bone morphogenic protein-2 (BMP-2). At first, a rat abdominal muscle pouch model indicated a sustained in-vivo release of both 125I-rhBMP-2 (57%) and 14C-ZA (22%) from the CaS/HA carrier over a period of 4-weeks. The biomodulated implant was then inserted in the proximal tibia in rats with the following experimental groups: G1) Empty implant, G2) Implant + CaS/HA, G3) Implant + CaS/HA + ZA and G4) Implant + CaS/HA + ZA + rhBMP-2. Significantly higher bone volume (BV) was seen around the implant in groups G3 (3.3 ±â€¯0.7 mm3) and G4 (3.1 ±â€¯0.7 mm3) compared to the control (1.3 ±â€¯0.4 mm3) using micro-computed tomography and qualitative histology. Group G3, also exhibited significantly higher pull-out force and absorbed energy when compared to the control group G1. These findings indicate that a low dose of ZA alone, released in a controlled manner from within a fenestrated implant is enough to improve implant anchorage without the need of adding rhBMP-2. This simple method of using a fenestrated implant containing a ceramic carrier releasing bone active molecules improved bone anchorage and could clinically reduce prosthetic failure. STATEMENT OF SIGNIFICANCE: Aseptic loosening remains as a major cause for implant revisions and early reaction of surrounding bone to the prosthesis is important for longevity. A novel approach to enhance early bone-implant anchorage is presented. The implant is filled with a carrier providing controlled release of bone active molecules. In an animal model, a calcium sulphate (CaS)/hydroxyapatite (HA) carrier was used to provide a spatio-temporal release of bone morphogenic protein-2 (BMP-2) and zoledronic acid (ZA). Significantly better bone-implant integration was achieved using ZA alone, thereby eliminating the need for adding BMP-2. The developed method of implant biomodulation holds potential to prevent implant loosening and is an alternative to prosthetic coatings or systemic drug treatment. Importantly, all constituents are approved for clinical use.