Patellar Fracture Surgery Performed Autonomously by Residents, Yields Similar Short-Term Outcomes to Surgery Performed by Fellowship-Trained Surgeons.

BACKGROUND: Open reduction and internal fixation are the gold-standard treatment for displaced patellar fractures. The current literature remains inconclusive on the relationship between resident participation in the operating room and optimal patient outcomes. We hypothesize that surgeries performed solely by residents, without attending supervision, can provide similar outcomes to those performed by fellowship-trained orthopedic surgeons, providing new insights into the relationship between resident autonomy and surgical outcomes in the field of orthopedic trauma. METHODS: A tertiary trauma center cohort was retrospectively reviewed for all surgically treated patellar fractures between 2015 and 2020. The cohort was divided into 2 groups: patients operated by residents and patients operated by orthopedic trauma specialists. Demographics, surgical parameters, and radiographs were compared between the groups to evaluate complications and reoperation rates, radiographic outcomes (such as hardware failure, or loss of reduction), and clinical outcomes (including residual pain, painful hardware, decreased range of motion, and infections). RESULTS: A total of 129 patellar fractures were included in the study. Demographics and ASA were similar between the groups. There were no significant differences in complications (p = 0.900) or reoperation rates (p = 0.817), with an average follow-up time of 8 months (SD ± 5.3). Residents had significantly longer surgery duration (p =0.002). However, the overall length of stay was shorter in the resident group (p < 0.001). CONCLUSION: The study shows patellar fracture surgery performed by adequately trained residents can provide similar outcomes to those performed by fellowship-trained orthopaedic trauma surgeons. These findings highlight the significance of surgical autonomy in residency and its role in contemporary surgical education.

Prospective assessment of functional and clinical results of surgical patellar stabilization in rural and urban populations. Equal chance to success?

INTRODUCTION AND OBJECTIVE: Patella dislocation represents 3.3% of all knee injuries often leading to persistent instability. Medial patello-femoral ligament(MPFL) reconstruction is the standard method of treatment in the patellar instability. Rehabilitation after MPFL-R is a long and demanding procedure. The hypothesis presented reflects the idea that despite relatively good access to hospital care and surgical options, the post-operative rehabilitation care system is still inferior in rural areas versus the one offered in major cities and towns. MATERIAL AND METHODS: Between January 2015 - January 2018, 47 patients met the study inclusion criteria, diagnosed and operated on due to patellar instability. 8 patients were lost for full follow-up. Finally, 39 patients were included, divided into two groups - group A (19 from cities), group B (20 from rural area). Prospective KOOS and Kujala scales assessments were conducted: preoperative, 6 and 12 months after surgery. Knee isokinetic muscle strength was measured at 3 stages; prior to surgery, 6 and 12 months after reconstruction. RESULTS: All patients showed significant improvement measured in the KOOS and Kujala scales after the procedure, compared to the pre-operational results. Despite equal clinical improvement, patients from Group A(city) achieved better functional outcomes as presented in the results of knee extensor functional tests using a Biodex dynamometer. CONCLUSIONS: Rehabilitation after MPFL reconstruction improves muscle strength and clinical outcome. Patients from rural areas had inferior functional results in comparison to the patients from major cities, even 12 months after surgical patella stabilization. Despite the development of roads and transport according to the EU cohesion policy, there are still differences in rehabilitation results between rural and city areas.

Ultrasound assessment of medial crural cutaneous nerve and infrapatellar branch and of the saphenous nerve: establishing a safety zone for preventing nerve injury in knee surgery and injections.

PURPOSE: Our study aimed to illustrate the positional relationship of the two branches of the saphenous nerve: the infrapatellar branch of the saphenous nerve (IPBSN) and medial crural cutaneous nerve (MCCN), as well as the anatomical landmarks using high-resolution ultrasound (HRUS) to help prevent iatrogenic nerve injury. METHODS: We used HRUS to explore the positional relationships among the anatomical landmarks, IPBSN, and MCCN in 40 knees of 20 participants. The distances from these branches to key reference points were recorded. Using the ultrasound caliper mode, we measured the depth from the skin surface to the nerves at four distinct points. RESULTS: The average distances between IPBSN and medial border of patella (MBP) and IPBSN and medial border of patellar ligament (MBPL) were 47 ± 7 mm and 42 ± 9 mm, respectively. MCCN showed mean distances of 94 ± 9 mm and 96 ± 9 mm to MBP and MBPL, respectively. The mean distance from the upper edge of pes anserine to IPBSN at the patellar apex (PA) level was 24 ± 10 mm and to MCCN was 34 ± 9 mm. CONCLUSION: We used high-resolution ultrasound to evaluate IPBSN and MCCN and their positions relative to anatomical landmarks. The study results offer valuable insights into the course of these nerves, which can help establish a safety zone to prevent accidental nerve injuries during knee surgeries and injections.

Assessment of Patellar Vascularity after Patellar Cartilage Restoration via Lateral Parapatellar Approach: Analysis Using Dynamic Contrast-Enhanced Magnetic Resonance Imaging.

OBJECTIVE: Patellofemoral cartilage restoration procedures, including osteochondral allograft, particulated juvenile cartilage, and matrix-induced autologous chondrocyte implantation, have been shown to be effective treatments for patellofemoral cartilage lesions. However, concerns exist regarding disruption of the patellar vascular supply and secondary stabilizers of the patellofemoral joint during medial parapatellar approaches, especially when combined with a lateral release. A lateral parapatellar approach affords the possibility of avoiding disruption of the medial blood supply to the patella, while also allowing laterally-based soft tissue stabilization procedures. The purpose of this study was to investigate in vivo changes in patellar vascularity following patellofemoral cartilage restoration procedures performed via a lateral parapatellar approach via use of dynamic contrast-enhanced magnetic resonance (MR) imaging. DESIGN: This study is a prospective case series of 5 adult patients undergoing patellofemoral cartilage restoration procedures via a lateral parapatellar approach with pre-operative and post-operative dynamic contrast-enhanced MR imaging to assess changes in patellar vascularity. Secondary outcomes included knee range of motion, need for revision surgery, and complications. RESULTS: There was no significant post-operative difference in patellar vascularity in patients undergoing patellofemoral cartilage restoration procedures via a lateral parapatellar approach, as evaluated by qualitative MR imaging. CONCLUSION: Our results suggest that a lateral parapatellar approach for cartilage restoration procedures may preserve patellar vascularity, while also allowing for lateral release to be performed through the same incision.

Developments in the epidemiology and surgical management of patella fractures in Germany.

BACKGROUND: Patella fractures account for approximately 1% of all skeletal injuries. Treatment options are vast and no definitive conclusion on what option is the most beneficial could be made so far. Plate osteosynthesis appears to gain in importance. We aim to give insight into the more recent trends and developments as well as establish the epidemiology of patella fractures in Germany by analysing treatment and epidemiological data from a national database. METHODS: Anonymised data was retrieved form a national database. In the period of 2006 to 2020, all patients with patella fractures as defined in ICD-10 GM as their main diagnosis, who were treated in a German hospital were included. Patients were divided into subgroups based on gender and age. Age groups were created in 10-year intervals from 20 years old up to 80 years old with one group each encompassing all those above the age of 80 years old and below 20 years old and younger. Linear regression was performed were possible to determine statistical significance of possible trends. RESULTS: A total of 151,435 patellar fractures were reported. 95,221 surgical interventions were performed. Women were about 1.5 times more likely to suffer from patella fracture than men. The relative number of surgical interventions rose from about 50% in 2006 to 75% in 2020. Most surgical interventions are performed in those over the age of 50. The incidence of complex fractures and plate osteosynthesis has significantly increased throughout the analysed period. CONCLUSIONS: We found a clear trend for surgical treatment in Germany with an increase in surgical procedures. We could also show that this ratio is age-related, making it more likely for younger patients in the age groups from 0 to 70 years old to receive surgical treatment for their patella fracture.

Biomechanical assessment of patellar tendon advancement in patients with cerebral palsy and crouch gait.

BACKGROUND: Patellar height is a valuable measure to evaluate the effect of patellar tendon advancement (PTA) on knee function. In the literature, there is no validated procedure to measure the patellar height. In this study we aimed to (1) determine the patella position through musculoskeletal modeling, (2) investigate the effects of two surgical procedures applied for PTA, and (3) assess the effect of PTA in combination with single-event multilevel surgery (SEMLS) on the knee kinematics of patients with cerebral palsy (CP) and crouch gait. METHOD: Three-dimensional gait and X-ray data of children with CP and crouch gait were retrospectively analyzed if they had received a SEMLS in combination with PTA (PTA group, n = 18) or without PTA (NoPTA group, n = 18). A computational musculoskeletal model was used to quantify patella position, knee extension moment arm, and knee kinematics pre- and postoperatively. RESULTS: Patellar height significantly decreased in the PTA group (P = 0.004), while there was no difference in the NoPTA group (P > 0.05). The bony procedure for PTA provided a better Insall-Salvati ratio than the soft tissue procedure. The peak knee extension moment arm significantly increased in the PTA group (P = 0.008). In terms of postoperative knee joint kinematics, the PTA group was closer to typically developed children than the NoPTA group. CONCLUSION: Musculoskeletal modeling was found to be an effective tool for the determination of the patellar height. PTA improved the patella position, knee extension moment arm, and knee kinematics and was an effective procedure for the surgical management of crouch gait in patients with CP.

Patella resurfacing during total knee arthroplasty is cost-effective and has lower re-operation rates compared to non-resurfacing.

BACKGROUND: The decision to resurface the patella as part of total knee arthroplasty may be influenced by the surgeon's preference, education, training, tradition and geographic location. Advocates for non-resurfacing or selectively resurfacing may claim no difference in patient reported outcomes, and that resurfacing is associated with increased risks such as extensor mechanism injury or malalignment, problems with the design of the patella component and technical issues intraoperatively. AIMS: To critically examine factors that should be considered in addition to patient reported outcomes in the decision process of resurfacing or non-resurfacing of the patella in total knee arthroplasty. METHOD: A comprehensive literature search was conducted to identify factors that may influence decision making in addition to knee specific patient reported outcome measures such as surgical risks, patient quality of life, procedure cost, re-operation rate, implant design, surgeons learning curve and the fate of remaining cartilage in native patellae. RESULTS: Patient-reported outcomes are equivocal for resurfacing and non-resurfacing. Critical analysis of the available literature suggests that the complications of resurfacing the patella are historic, which is now lower with improved implant design and surgical technique. Routine resurfacing was cost-effective in the long term (potential saving £104 per case) and has lower rates of revision (absolute risk reduction 4%). Finally, surgical judgment in selective resurfacing was prone to errors. CONCLUSION: Patella resurfacing and non-resurfacing had similar patient-reported outcomes. However, patella resurfacing was cost-effective and was associated with a lower rate of re-operation compared to non-resurfacing.

Arthroscopic Treatment of Patellar and Trochlear Cartilage Lesions with Matrix Encapsulated Chondrocyte Implantation versus Microfracture: Quantitative Assessment with MRI T2-Mapping and MOCART at 4-Year Follow-up.

METHODS: Seventeen patients aged 18 to 55 years with symptomatic full-thickness cartilage lesions on either patella or trochlea were treated with matrix autologous chondrocyte implantation (MACI) or microfracture (MF). Both procedures combined with unloading/realigning techniques. Clinical assessment and T2-mapping were evaluated at 48-months. RESULTS: Clinically results from pre-op to 48-months improved significantly in MACI and MF for Lysholm (p = 0.001, p = 0.001), IKDC-S (p = 0.001, p = 0.002), KOOS-P (p = 0.000, p = 0.002), KOOS-DLA (p = 0.002, p = 0.003), KOOS-Sports/Rec (p = 0.000, p = 0.004), KOOS-QoL (p = 0.000, p = 0.003), KOOS-symptoms (p = 0.001, p = 0.020), and Kujala (p = 0.000, p = 0.01), respectively. Tegner was significant between baseline and 48 months only for MACI (p < 0.008) compared with MF (p = 0.25). No significant difference was observed between groups for any score at 3, 12, 24, and 48-months (p > 0.05). T2-mapping values improved significantly over time in MACI compared with MF at 24 months (39.35 vs. 50.44, p = 0.007) and 48 months (36.54 vs. 48.37, p = 0.005). When comparing control values to MACI at 12-m (p = 0.714), 24-m (p = 0.175), and 48-m (p = 0.097), no significant difference was found. MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score comparison gave no statistical difference between groups. CONCLUSIONS: Clinically both techniques improved significantly over time. However, quantitative assessment showed that only newly formed tissue with MACI technique improves significantly since 12-months and maintains stable values compared with native cartilage until 48-month follow-up. MF results were never comparable to those native values. Level of evidence II.

The sagittal geometry of the trochlear groove could be described as a circle: an intraoperative assessment with navigation.

PURPOSE: The aim of this study was to describe the sagittal geometry of the trochlear groove in patients who underwent primary TKA, based on intraoperative data acquired with a navigation system. METHODS: Intraoperative navigation data were collected from 110 patients. All operations were guided by a non-image-based navigation system (BLU-IGS, Orthokey Italia Srl). The trochlear groove has been described on the three anatomical planes; in particular, on the sagittal plane the hypothesis has been verified that the acquired points are referable to a circle. Using the data collected during intraoperative navigation, possible correlation between the radius of the trochlear groove and other femur dimension (length, AP dimension) was analyzed; the orientation of the trochlear sulcus with respect to the mechanical axis and the posterior condyle axis was analyzed too, searching for possible correlation between groove alignment (frontal and axial) or groove radius and the hip-knee-ankle (HKA). RESULTS: The average radius of curvature of the femoral trochlea was 25.5 ± 5.6 mm; the difference was not statistically significant between the men and women (n.s. p value). No correlation was found between the trochlear groove radius and the femur length (r = - 0.02) or the HKA-phenotypes (r = 0.03) and between the groove alignment and HKA-phenotypes. On axial plane, the trochlear groove was 3.2° ± 4.3° externally rotated, with respect to the posterior condylar axis; on frontal plane, the trochlear groove was 3.9° ± 5.3° externally rotated, with respect to the mechanical axis. In both cases, no statistically significant differences were found between male and female and between left and right limb (p > 0.05). CONCLUSION: The present study shows that the sagittal plane geometry of the femoral trochlea in patients affected by osteoarthritis could be described accurately as a circle. The acquisition of the trochlear morphology intraoperatively can lead to more anatomically shape definition, to investigate deeper its radius of curvature and geometry. Trochlear shape could be used as landmarks for femoral component positioning, thus customizing the implant design, optimize the outcomes and improving anterior knee pain after TKA. LEVEL OF EVIDENCE: IV.

Computed Tomographic Assessment of Block Recession Trochleoplasty and Partial Parasagittal Patellectomy in Cats.

OBJECTIVE: The aim of this study was to assess computed tomography (CT) images of cadaveric feline stifles and record the relationship between the patella and femoral trochlea in normal stifles; then to investigate the effect of block recession trochleoplasty (BRT) with and without partial parasagittal patellectomy (PPP) on patellofemoral contact, depth of patellar recession and size of trochlea and patella. MATERIALS AND METHODS: The sample population included six cat cadavers (12 stifles). Preoperative CT scans with stifles in three positions: extended (155-165°), neutral (85-95°) and flexed (35-45°). Lateral stifle arthrotomy was followed by BRT. CT scans were taken as above. PPP was performed so the width of the patella was 1 mm narrower than the BRT. CT scans were repeated and CT measurements were taken. RESULTS: The area of contact between the patella and femoral trochlea was significantly reduced after BRT and then significantly increased after PPP. The depth of patellar recession was unchanged after BRT, but then was significantly higher after PPP. The patella was wider than the trochlea preoperatively and post-BRT and narrower post-PPP. Reduction in bone volume following PPP (mean: 20%) was 50% the reduction in patella width (mean: 40%). CONCLUSION: Block recession trochleoplasty did not improve patellar recession and decreased patellofemoral contact area. Following BRT, the patella rides the trochlear ridges and loses contact with the trochlear sulcus. Block recession trochleoplasty alone should not be performed in cats. Instead, BRT should be combined with PPP.

Arthroscopic assessment of patella tracking correlates with recurrent patellar instability.

PURPOSE: For recurrent lateral patellar instability surgical algorithm, an arthroscopic assessment of patellar tracking can aid with the decision of adding a tibial tubercle transfer procedure based on knee flexion angle at which patella centrally engages in its groove. Tibial tubercle-trochlear groove distance is variable in normal values and has discrepancies between imaging modalities. The aims of our study were to assess correlation of arthroscopic patellar tracking technique with recurrent patellar instability, and to assess the accuracy and reproducibility of this technique. METHODS: 157 patients were evaluated, 64 control patients with no patellar instability, and 93 patients with recurrent patellar instability. This included 57 consecutive knee arthroscopy procedures evaluated for accuracy and reproducibility of our technique. The technique involved low flow arthroscopy and anterolateral viewing portal. Patients' knees were extended from a flexed position of 120°, and paused when the patella disengaged from its groove. The KFA was then estimated by the primary surgeon, and compared with a goniometer measurement. The assisting surgeon, blinded to the primary surgeon measurements, repeated this process. For the primary outcome, goniometer readings for KFA from the primary surgeon were used to correlate with patellar instability diagnosis. RESULTS: Patients with patellar instability had a mean KFA of 118° compared to 44°for patients without patellar instability (p < 0.001). The mean difference between goniometer reading and estimation of KFA by each surgeon was 5° (p < 0.001) with intra-class correlation of 0.99. The mean difference between the two surgeons' goniometer readings was 8° (p < 0.001) with intra-class correlation of 0.99. CONCLUSION: This study confirms arthroscopic assessment of patella tracking is accurate, reproducible, and a knee flexion angle of greater than 44° correlates with patellar instability diagnosis. Patella tracking can be used as an adjunct or an alternative assessment method to tibial tubercle-trochlear groove distance to determine the need for tibial tubercle transfer in patellar stabilisation surgery. LEVEL OF EVIDENCE: Prospective Cohort Study, Level III.

Cost-efficacy of Knee Cartilage Defect Treatments in the United States.

BACKGROUND: Multiple knee cartilage defect treatments are available in the United States, although the cost-efficacy of these therapies in various clinical scenarios is not well understood. PURPOSE/HYPOTHESIS: The purpose was to determine cost-efficacy of cartilage therapies in the United States with available mid- or long-term outcomes data. The authors hypothesized that cartilage treatment strategies currently approved for commercial use in the United States will be cost-effective, as defined by a cost <$50,000 per quality-adjusted life-year over 10 years. STUDY DESIGN: Systematic review. METHODS: A systematic search was performed for prospective cartilage treatment outcome studies of therapies commercially available in the United States with minimum 5-year follow-up and report of pre- and posttreatment International Knee Documentation Committee subjective scores. Cost-efficacy over 10 years was determined with Markov modeling and consideration of early reoperation or revision surgery for treatment failure. RESULTS: Twenty-two studies were included, with available outcomes data on microfracture, osteochondral autograft, osteochondral allograft (OCA), autologous chondrocyte implantation (ACI), and matrix-induced ACI. Mean improvement in International Knee Documentation Committee subjective scores at final follow-up ranged from 17.7 for microfracture of defects >3 cm2 to 36.0 for OCA of bipolar lesions. Failure rates ranged from <5% for osteochondral autograft for defects requiring 1 or 2 plugs to 46% for OCA of bipolar defects. All treatments were cost-effective over 10 years in the baseline model if costs were increased 50% or if failure rates were increased an additional 15%. However, if efficacy was decreased by a minimum clinically important amount, then ACI (periosteal cover) of femoral condylar lesions ($51,379 per quality-adjusted life-year), OCA of bipolar lesions ($66,255) or the patella ($66,975), and microfracture of defects >3 cm2 ($127,782) became cost-ineffective over 10 years. CONCLUSION: Currently employed treatments for knee cartilage defects in the United States are cost-effective in most clinically acceptable applications. Microfracture is not a cost-effective initial treatment of defects >3 cm2. OCA transplantation of the patella or bipolar lesions is potentially cost-ineffective and should be used judiciously.

Evaluation of a 3D-printed total knee arthroplasty using radiostereometric analysis: assessment of highly porous biological fixation of the tibial baseplate and metal-backed patellar component.

AIMS: Our intention was to investigate if the highly porous biological fixation surfaces of a new 3D-printed total knee arthroplasty (TKA) achieved adequate fixation of the tibial and patellar components to the underlying bone. PATIENTS AND METHODS: A total of 29 patients undergoing primary TKA consented to participate in this prospective cohort study. All patients received a highly porous tibial baseplate and metal-backed patella. Patient-reported outcomes measures were recorded and implant migration was assessed using radiostereometric analysis. RESULTS: Patient function significantly improved by three months postoperatively (p < 0.001). Mean difference in maximum total point motion between 12 and 24 months was 0.021 mm (-0.265 to 0.572) for the tibial implant and 0.089 mm (-0.337 to 0.758) for the patellar implant. The rate of tibial and patellar migration was largest over the first six postoperative weeks, with no changes in mean tibia migration occurring after six months, and no changes in mean patellar migration occurring after six weeks. One patellar component showed a rapid rate of migration between 12 and 24 months. CONCLUSION: Biological fixation appears to occur reliably on the highly porous implant surface of the tibial baseplate and metal-backed patellar component. Rapid migration after 12 months was measured for one patellar component. Further investigation is required to assess the long-term stability of the 3D-printed components and to determine if the high-migrating components achieve fixation. Cite this article: Bone Joint J 2019;101-B(7 Supple C):40-47.

Routine Patellar Resurfacing During Total Knee Arthroplasty Is Not Cost-Effective in Patients Without Patellar Arthritis.

BACKGROUND: Currently, the decision to resurface the patella is often made irrespective of the presence of patellar arthritis. The purpose of this study is to utilize the existing literature to assess cost-utility of routinely vs selectively resurfacing the patella. METHODS: Prospective randomized studies of patella resurfacing vs non-resurfacing in total knee arthroplasty (TKA) were identified through literature review. Data from these studies represented probabilities of varied outcomes following TKA dependent upon patella resurfacing. Using previously validated utility scores from the McKnee modified Health Utilities Index, endpoint utility values were provided for each potential outcome. RESULTS: Literature review yielded a total of 14 studies with 3,562 patients receiving 3,823 TKAs, of which 1,873 (49.0%) patellae were resurfaced. Persistent postoperative anterior knee pain occurred in 20.9% vs 13.2% (P < .001) and patella reoperation was performed in 3.7% vs 1.6% (P < .001) of unresurfaced and resurfaced patella, respectively. In studies excluding those with arthritic patellae, the incidence of anterior knee pain was equivalent between groups and reoperation decreased to 1.2% vs 0% (P = .06). Patella resurfacing provided marginally improved quality-adjusted life-years (QALY) for both selective and indiscriminate patella resurfacing. When including all studies, the incremental cost per QALY was $3,032. However, when analyzing only those studies with nonarthritic patellae, the incremental cost per QALY to resurface the patella increased to $183,584. CONCLUSION: Patellar resurfacing remains a controversial issue in TKA. Utilizing data from new prospective randomized studies, this analysis finds that routinely resurfacing arthritis-free patellae in TKA are not cost-effective.

Synthetic Graft Compared With Allograft Reconstruction for Extensor Mechanism Disruption in Total Knee Arthroplasty: A Multicenter Cohort Study.

BACKGROUND: Extensor mechanism disruption after total knee arthroplasty is a serious complication leading to notable patient morbidity. The purpose of this study is to compare the outcomes of extensor mechanism allograft with synthetic graft reconstruction. METHODS: We retrospectively identified all patients who underwent extensor mechanism reconstruction using either allograft or synthetic graft from two high-volume academic arthroplasty institutions between 2006 and 2017. We collected extensor lag, need for ambulatory aids, and patient-reported outcome measures, as well as the incidence of postoperative complications and revision surgeries. We evaluated cost differences, considering both material cost and the need for revision surgery. RESULTS: We identified 27 cases. A significantly greater postoperative extensor lag was found in the allograft group (P = 0.05). Graft failure after synthetic reconstruction was zero, with an overall revision surgery rate of 15%. Graft failure was 21%, and the revision surgery rate was 43% after allograft reconstruction. The allograft cost was significantly higher compared with the synthetic graft cost (P = 0.001). The mean total cost was 4,733.08 CAD for the synthetic group and 24,050.40 CAD for the allograft group (P = 0.17). DISCUSSION: Synthetic reconstruction for extensor mechanism disruption shows benefit in postoperative extensor lag, graft failure, revision surgery, and cost when compared with allograft. LEVEL OF EVIDENCE: Level III.

Patellar Resurfacing in Total Knee Arthroplasty: A Cost-Effectiveness Analysis.

BACKGROUND: This study estimates the cost-effectiveness of patellar resurfacing in total knee arthroplasty (TKA). METHODS: We conducted a cost-effectiveness analysis using a decision analytic model representing a hypothetical TKA cohort, with or without patellar resurfacing, using data from the 2014 Australian Registry. The model represents 3 possible postoperative health states: (1) well, (2) patellofemoral pain, or (3) serious adverse event (any event resulting in a revision). Our effectiveness outcome was the quality-adjusted life year, from published utility scores. We estimated cost-effectiveness from a Canadian public healthcare payer perspective. Costs and quality of life were valued in 2015 United States dollars and discounted annually at 5%. RESULTS: Our results suggest that TKA with resurfacing is cost-effective compared to nonresurfacing. Unresurfacing the patellae resulted in higher costs ($13,296.63 vs $12,917.01) and lower quality-adjusted life year (5.37 vs 6.01) at 14 years. Sensitivity analysis suggests that if rates of secondary resurfacing are <0.5%, there was no cost difference. CONCLUSION: Over 14 years postoperative, patellar resurfacing appears to be cost-effective, due to higher revision rates for unresurfaced TKA. Although our results suggest resurfacing improves quality of life, our model is limited by the availability and validity of long-term utility outcomes reported for TKA. Our cost-effectiveness analysis showed superiority of the resurfacing compared to retention of the patella.

Subvastus versus Medial Parapatellar Approach in Primary Total Knee Replacement: An Assessment of Early Function.

BACKGROUND: Total knee replacements are increasingly being carried out for the arthritic knee. This procedure is constantly being improved upon in order to improve outcome. There is currently no consensus of the best surgical approach for primary total knee arthroplasty. This study aims to test the hypothesis that the subvastus approach has significantly better early functional outcomes compared to the medial parapatellar approach. STUDY DESIGN: Patients with bilateral knee arthritis who met the inclusion criteria were randomised into either the subvastus or medial parapatellar approach over a twelve month period. All patients had the same prosthesis inserted by one surgeon. Primary outcome measures were the Knee Society Score (KSS) at six (6) weeks post-operatively and evaluation of postoperative pain using the Visual Analogue Score (VAS) on the 2nd and 5th postoperative day. Secondary outcomes included blood loss and transfusion requirements. RESULTS: Twenty-four knees recruited with 11 knees in the subvastus and 13 in the medial parapatellar group. Results showed a significantly lower postoperative pain in the subvastus group versus the medial parapatellar group (2.8 versus 4.62 p < 0.05). Transfusion requirements for subvastus group was half that needed for the medial parapatellar group; this however was not statistically significant. Evaluation of knee score at six weeks did not show any difference in outcome (80.8 versus 84.27 p > 0.05). CONCLUSION: Post-operative pain is significantly reduced in the subvastus group, however short term knee function is not affected by surgical approach.

Preoperative Diagnosis Can Predict Conversion Total Knee Arthroplasty Outcomes.

BACKGROUND: Compared to total knee arthroplasty (TKA) for primary osteoarthritis, conversion TKAs in the post-traumatic setting are associated with increased operative times, infection rates, and readmissions. We aim at determining how post-traumatic osteoarthritis and previous knee surgery influence postoperative outcomes in conversion TKA. METHODS: Seventy-two conversion TKA procedures with prior knee trauma at a single institution between April 2012 and 2016 were examined. Twenty-seven (37.5%) cases had a preoperative site-specific diagnosis such as fracture of the proximal tibia, distal femur, or patella whereas 45 (62.5%) cases had a preoperative diagnosis of significant soft-tissue trauma. These 2 groups were compared in terms of total implant cost, length of stay, complications, and readmission and reoperation rates. A subanalysis was conducted to evaluate the effects of previous knee surgery on surgical outcomes. RESULTS: The postfracture TKA cohort suffered significantly higher early surgical site complications (22% vs 4.4%, P = .02) and 90-day readmissions (14.8% vs 2.2%, P = .042) compared to the soft-tissue trauma cohort. Operative time, total implant costs, length of stay, medical complications, 30-day readmissions, and 90-day reoperation rates did not significantly differ. It was also found that patients with multiple prior knee surgeries compared to one prior knee surgery are younger (53.0 vs 63.1, P = .003), healthier, and receive significantly more expensive implants (1.72 vs 1.07, P = .026). In addition, patients with previous open reduction internal fixations experience more surgical site complications than patients with previous arthroscopies (31% vs 3.3%, P = .042). CONCLUSION: Patients with previous site-specific fracture are more likely to experience surgical site complications and 90-day readmissions after conversion TKA than patients with previous soft-tissue knee trauma. Multiple previous knee surgeries appear to serve as an independent factor in the selection of costlier implants irrespective of preoperative diagnosis.

Functional outcome and economic burden of operative management of patellar fractures: the pivotal role of onerous implants.

OBJECTIVES: The complication rate following operative treatment of patellar fractures remains high and is associated with a poor functional outcome. The primary goal of this study was to evaluate our functional outcome of patellar fracture osteosynthesis and define strategies to improve the outcome. The healthcare costs and utilization were calculated. METHODS: All demographic, clinical, radiographic variables and hospital-related costs of 111 patients with 113 surgically treated patellar fractures between January 2005 and December 2014 were analyzed. Fractures were grouped as either simple or complex. Functional outcome was assessed using Knee Injury and Osteoarthritis Outcome Score (KOOS). RESULTS: There were 67 simple fractures (59.3%) and 46 complex fractures (40.7%). The overall complication rate was 48.7%, including 19.5% implant-related complications. In 69 patients (61.1%), implants were removed. The outcome was rather poor, with considerable impairment in all KOOS subscales with the knee-related quality of life rated worst (median 62.5, IQR 37.5-81.25). Poor outcome correlated significantly with complex patellar fractures and extensive tension-band constructs. CONCLUSIONS: The operative treatment of patellar fractures was associated with a high complication rate, functional impairment and reduced quality of life. Complex patellar fractures and extensive tension-band constructs were identified as the main determinants of poor outcome and increased economic burden due to higher reinterventions rates. Strategies to reduce complications and improve outcome should focus on less onerous implants.