Articular Fragment Detachment and Separate Fixation for the Treatment of Comminuted Patellar Fractures with Coronal Split Articular Fragments: Articular Detachment Technique.

Background: Treatment of comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments is a challenge. To treat this difficult fracture, we perform articular fragment detachment and separate fixation for coronal split articular and inferior pole fragments. We aimed to evaluate the radiological and clinical outcomes of our technique in comminuted patellar fractures at least 1 year after surgery. Methods: Between January 2019 and June 2022, 15 patients diagnosed with comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments based on preoperative computed tomography underwent surgery using the articular detachment technique. The key point of this technique was anatomical reduction and subchondral fixation of the coronal split articular fragment to the superior main fragment after complete detachment of the coronal split fragment from the inferior pole. The remaining inferior pole was fixed using a separate construct. Postoperative articular gap, articular step-off, and complications, including resorption, reduction loss, and avascular necrosis of fixed articular fragments, were evaluated as radiological outcomes. Range of motion and the Lysholm scores were used to evaluate clinical outcomes. Results: Among the 15 patients, the coronal split articular fragments were fixed using Kirschner wires in 13 patients and headless screws in 2 patients. The inferior poles were fixed using separate vertical wiring in 13 patients and tension-band wiring in 2 patients. A postoperative articular gap was noted in 7 patients, with an average articular gap of 1.0 mm (range, 0.7-1.6 mm). No articular step-off was observed. Bone union and normal range of motion were achieved in all patients. On the 1-year postoperative lateral radiograph, resorption of the articular fracture site was seen in 5 patients. There was no loss of reduction or avascular necrosis of the coronal split articular fragments. The average postoperative Lysholm score at 1 year was 89.3 ± 4.1 (range, 82-95). Conclusions: The technique would be a reliable and safe option for the surgical treatment of comminuted patellar fractures accompanied by coronal split articular and inferior pole fragments in terms of anatomical reduction and stable fixation of articular fragments without risk of avascular necrosis.

Management of complete intra-articular distal femur and patellar fractures in an achondroplastic young adult; small is challenging' revisited: a case-report.

BACKGROUND: People with achondroplasia exhibit distinct physical characteristics, but their cognitive abilities remain within the normal range. The challenges encountered during surgical procedures and perioperative care for achondroplastic individuals, are underrepresented in the existing literature. CASE PRESENTATION: In this report, the management of a 26-year-old North-African achondroplastic male is highlighted. The patient suffered a complete intra-articular distal femur fracture (AO/OTA 33-C1) and an ipsilateral patella fracture (AO/OTA 34-C1). The patient's unusual anatomical variations and the lack of suitable orthopedic implants posed significant surgical challenges, particularly in the context of a resource-limited developing country. Facial and spinal deformities, which are common in patients with achondroplasia, further complicated the anesthetic approach. CONCLUSIONS: The limited information on operative management of fractures in achondroplastic patients necessitated independent decision-making and diverging from the convenient approach where clear guidance is available in the literature.

Study on the therapeutic effect of Kirschner wire tension band combined with anchor cross-stitch technique in the treatment of comminuted patellar inferopolar fractures.

PURPOSES: Fractures of the inferior patellar pole, unlike other patellar fractures, present challenges for traditional surgical fixation methods. This article introduces the clinical technique and outcomes of using Kirschner wire tension band combined with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures. METHODS: This retrospective case series study included 14 patients with comminuted inferior patellar pole fractures treated at our institution from September 1, 2020, to April 30, 2022. All patients underwent surgery using the Kirschner wire tension band with anchor screw cross-stitch technique. Follow-up assessments involved postoperative X-rays to evaluate fracture healing, as well as clinical parameters such as healing time, Visual Analog Scale (VAS) scores, range of motion (ROM), and Bostman scores. RESULTS: All patients were followed for an average of over 12 months, with no cases of internal fixation failure. Knee joint stability and function were excellent. X-rays revealed an average healing time of approximately 10.79 ± 1.53 weeks, hospitalization lasted 5.64 ± 1.15 days, surgery took approximately 37.86 ± 5.32 minutes, and intraoperative blood loss was 33.29 ± 8.15 ml. One patient experienced irritation from the internal fixation material. At the final follow-up, the Bostman score averaged 28.29 ± 0.83, knee joint flexion reached 131.07° ± 4.88°, all patients achieved full knee extension, and the VAS score was 0.36 ± 0.63. CONCLUSION: Kirschner wire tension band with anchor screw cross-stitch fixation for comminuted inferior patellar pole fractures delivered satisfactory clinical outcomes. This surgical method, characterized by its simplicity and reliability, is a valuable addition to clinical practice.

Tension band versus locking plate fixation for patella fractures - a protocol of a randomised controlled trial.

INTRODUCTION: Following surgical management of patella fractures, patients commonly report pain; difficulties with weight-bearing tasks such as walking, running and climbing stairs; and restrictions in quality of life. Recently, a locking plate system for surgical management of patella fractures has been introduced. To date, no studies have compared standard treatment with tension band wiring with locking plate fixation in a randomised study design. We aim to compare the one-year patient-reported Knee Injury and Osteoarthritis Outcome subscale scores (KOOS5-subscales) after standard care tension band fixation with locking plate fixation for patients with patella fractures. METHODS: This is a multicentre randomised and prospective clinical trial. A total of 122 patients will be included in the study, and the primary outcome will be the KOOS subscales at 12 months after surgery. CONCLUSIONS: Findings from the present study are expected to advance our understanding of outcome following surgical treatment of patella fractures. FUNDING: This study is funded, in part, by the Novo Nordisk Foundation, Denmark. CLINICALTRIALS: gov ID: NCT04891549.

IMPORTANCE OF JOINT LINE RESTORATION IN TOTAL KNEE ARTHROPLASTY.

The restoration of the joint line is important for a good functional outcome after a Total Knee Arthroplasty(TKA). Knee joint biomechanics need to be restored as near normal as possible. Joint line elevation leads to anterior knee pain, decrease in range of motion, patella baja ,mid-flexion instability and impingement of patellar tendon. Joint line depression on the other hand leads to patella alta, risk of patellar subluxation and mid-flexion instability of the knee. Various studies have demonstrated various range of acceptable joint line variation but there is no clear acceptable range of joint line variation. More studies are required for establishing the acceptable range of joint line variation and standard practices should be established for arthroplasty surgeons for preventing variation of joint line.

Patella Cartilage Status Does Not Affect the Clinical Outcomes of Non-resurfaced Patella in Mobile-Bearing Total Knee Arthroplasty.

Background: During total knee arthroplasty (TKA), patellar retention is performed when the cartilage is fairly well preserved and the thickness of the patella is relatively thin. However, clinical outcomes of the non-resurfaced patella in TKA according to the cartilage status are lacking in the literature. The purpose of this study was to compare patient-reported outcome measures (PROMs) according to the grade and location of the patellar cartilage lesion in TKA patients. Methods: The outcomes of 165 osteoarthritis patients (186 knees) who underwent cemented mobile-bearing TKA without patellar resurfacing were assessed and classified according to the grade and location of the patellar cartilage lesion. PROMs using the Western Ontario and MacMaster Universities Osteoarthritis index, the Knee Society Score (Knee Society Function Score and Knee Society Knee Score), and the Hospital for Special Surgery score were evaluated preoperatively and at postoperative 2, 4, 6, and 8 years. The correlations between PROMs and the grade and location of the cartilage lesion were assessed. Additionally, radiologic outcomes including the patellar tilt angle and patellar height were assessed and their correlation with the grade of cartilage lesion was analyzed. Analysis of variance was used to determine statistical significance. Results: There was no significant difference between PROMs according to the grades and locations of cartilage lesions at any postoperative follow-up. Radiologic parameters also showed no significant differences according to the grades of patellar cartilage lesions. Conclusions: The grade and location of the patellar cartilage lesion had no influence on clinical outcomes in mobile-bearing TKA with patellar retention at short- and long-term follow-up.

Reconstruction of the extensor mechanism using polypropylene mesh in a displaced pathological fracture of the patella affected by giant cell tumour.

A man in his 30s came to our clinic with a year-long history of progressive pain and swelling in his knee. Diagnostic imaging revealed a displaced patellar fracture with an osteolytic, septated lesion and thinned expanded cortex in both fracture fragments. A core needle biopsy confirmed the diagnosis of giant cell tumour. Treatment involved wide excision of the tumour and the use of polypropylene mesh and a peroneal longus tendon autograft to reconstruct the extensor mechanism of the knee joint. One year postoperatively, the patient experienced no pain, demonstrated full range of motion and showed no signs of functional impairment or local tumour recurrence. This case highlights that reconstruction of the extensor mechanism of the knee after tumour excision with synthetic mesh is an affordable, user-friendly and widely accessible method. It can address large defects effectively while minimising the risks of disease transmission and graft lengthening, resulting in satisfactory outcomes.

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.

Changes in Patellar Height and Tibial Posterior Slope after Biplanar High Tibial Osteotomy with Computer-Designed Personalized Surgical Guides: A Retrospective Study.

OBJECTIVE: Medial opening-wedge high tibial osteotomy (MOWHTO) is a surgical procedure to treat medial compartment osteoarthritis in the knee with varus deformity. However, factors such as patellar height (PH) and the sagittal plane's posterior tibial slope angle (PTSA) are potentially overlooked. This study investigated the impact of alignment correction angle guided by computer-designed personalized surgical guide plate (PSGP) in MOWHTO on PH and PTSA, offering insights for enhancing surgical techniques. METHODS: This retrospective study included patients who underwent 3D-printed PSGP-assisted MOWHTO at our institution from March to September 2022. The paired t-tests assessed differences in all preoperative and postoperative measurement parameters. Multivariate linear regression analysis examined correlations between PTSA, CDI (Caton-Deschamps Index), and the alignment correction magnitude. Receiver operating characteristic (ROC) curve analysis determined the threshold of the correction angle, calculating sensitivity, specificity, and area under the curve. RESULTS: A total of 107 patients were included in our study. The CDI changed from a preoperative mean of 0.97 ± 0.13 (range 0.70-1.34) to a postoperative mean of 0.82 ± 0.13 (range 0.55-1.20). PTSA changed from a preoperative mean of 8.54 ± 2.67 (range 2.19-17.55) to a postoperative mean of 10.54 ± 3.05 (range 4.48-18.05). The t-test revealed statistically significant changes in both values (p < 0.05). A significant alteration in patellar height occurred when the correction angle exceeded 9.39°. Moreover, this paper illustrates a negative correlation between CDI change and the correction angle and preoperative PTSA. Holding other factors constant, each 1-degree increase in the correction angle led to a 0.017 decrease in postoperative CDI, and each 1-degree increase in preoperative PTSA resulted in a 0.008 decrease in postoperative CDI. PTSA change was positively correlated only with the correction angle; for each 1-degree increase in the opening angle, postoperative PTS increased by 0.188, with other factors constant. CONCLUSION: This study highlights the effectiveness and precision of PSGP-assisted MOWHTO, focusing on the impact of alignment correction on PH and PTSA. These findings support the optimization of PSGP technology, which offers simpler, faster, and safer surgeries with less radiation and bleeding than traditional methods. However, PSGP's one-time use design and the learning curve required for its application are limitations, suggesting areas for further research.

A retrospective investigation on clinical and radiographic outcomes of distal tibial fractures after intramedullary nailing using the lateral parapatellar extra-articular approach.

INTRODUCTION: According to reports, the modified extra-articular parapatellar approach allows the performance of tibial nailing in the semi-extended position without the concern of joint violation. However, there remains no special study that has provided a detailed assessment of the benefits and risks of this approach for treating distal tibial fractures (DTFs). The aim of this retrospective study was to investigate the clinical and radiological outcomes of patients with DTFs after intramedullary nailing using a lateral parapatellar extra-articular (LPE) approach in comparison to using the suprapatellar (SP) and transpatellar (TP) approaches. METHODS: Data were collected from 99 patients with a minimum follow-up period of 12 months. Comparisons were conducted between the groups regarding the number of intraoperative fluoroscopies, complications, knee pain, knee range of motion (ROM), the Lysholm Knee Scale (LKS), the Olerud-Molander Ankle Score (OMAS) and radiological findings. RESULTS: The demographic characteristics were comparable between the groups. Fewer intraoperative fluoroscopies were performed in the LPE (27.47 ± 4.98) and SP (26.03 ± 5.12) groups than in the TP group (30.20 ± 7.42; P<0.001). When compared with the other two approaches, the LPE approach was associated with less knee pain (P<0.001) and better knee ROM (P<0.001) at one week postoperative. No significant intergroup differences were detected in the incidence of complications, LKS scores (P = 0.687) and OMAS (P = 0.926). Radiological findings demonstrated that postoperative tibial alignment (P = 0.853), the time of bony union and rate of non-union were similar between the groups. CONCLUSION: The LPE approach can serve as a safe and effective option for tibial nailing, as it offers favourable outcomes in knee pain relief and knee ROM in the early postoperative period and is equivalent to the other two approaches in terms of the incidence of complications, fracture healing, functional recovery and postoperative alignment for patients with DTFs.

Transverse patella fracture fixation: A cadaveric biomechanical comparison of cannulated screws and anterior tension band versus low-profile, multiplanar mesh plating.

INTRODUCTION: Multiplanar mesh plating of patella fractures has become more popular in recent years. It was the goal of this study to compare the biomechanical stability of cannulated screw with anterior tension band to multiplanar mesh plating for fixation of transverse patella fractures in cadaver specimens. MATERIALS AND METHODS: Eight matched pairs of fresh frozen cadaveric knees were obtained and soft tissues dissected leaving the extensor mechanism, joint capsule, and retinaculum intact. Transverse fractures were created at the mid-portion of the patella. For each pair, one specimen was repaired using cannulated screws with anterior tension band, and the second was repaired using multiplanar mesh plating. Each specimen underwent cyclic extension loading with loads increasing by 1.1 kg after every 50 cycles. Interfragmentary displacement was measured at the end of each interval at both 5° and 45° of knee flexion angle, with fixation failure defined by >2 mm displacement. RESULTS: The specimens fixed with multiplanar mesh plating survived more cycles and higher loads than the specimens fixed with cannulated screws with anterior tension band (p = 0.011 comparing survival plots). After 150 cycles of extension loading, 3 of 8 of the specimens fixed with screws/tension band had failed, whereas none of the mesh plated specimens had failed. After 400 cycles, 7 of 8 of the screws/tension band had failed, whereas half of the mesh plated specimens had failed. CONCLUSIONS: While a more technically challenging and expensive technique, mesh plating for patella fractures appears to offer greater durability than traditional cannulated screw with tension banding.

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.

Incidence of patella baja and pseudopatella baja in aseptic revision total knee arthroplasty.

INTRODUCTION: There are two variants regarding the low location of the patella in relation to the tibio-femoral joint line: patella baja (PB) and pseudo-patella baja (PPB). The purpose of this study is to investigate the incidence of PB and PPB in a cohort of patients that underwent revision total knee arthroplasty (rTKA) for aseptic reasons and describe any differences in each group's ROM. METHODS: This retrospective study included 114 patients that underwent aseptic revision TKA surgery between 2017 and 2022. Patients were revised either for stiffness (Group 1) or aseptic loosening/instability (Group 2). The Insall-Salvati ratio (ISR) and Blackburne-Peel ratio (BPR) were used to evaluate the patellar position. ISR < 0.8 defined PB, while cases with ISR ≥ 0.8 and BPI < 0.54 were defined as PPB. ROM was measured and a subanalysis was conducted to investigate the progression of the values of ISR and BPR. RESULTS: 55 patients comprised Group 1, and 59 patients comprised Group 2. Overall, 13 cases (11.4%) had PB before rTKA and 24 (21%) had PB after rTKA. Cases with PPB were 13 (11.4%) before and 34 (29.9%) after rTKA. Group 1 patients presented with more PB before and after rTKA (12.8% vs 10.2% and 27.3% vs 15.2% respectively). However, after rTKA Group 1 patients presented with less PPB (20%) compared to Group 2 (39%) (p = 0.02). In Group 1, patients with PPB after rTKA had less ROM compared to those without PPB [83.2 (± 21.9) vs 102.1 (± 19.9) (p = 0.025)]. The subanalysis (69 patients) showed a statistically significant decrease in ISR before and after rTKA (p = 0.041), and from the native knee to post-rTKA (p = 0.001). There was a statistically significant decrease in BPR before and after rTKA (p = 0.001) and from the native knee to both pre- and post-rTKA (p < 001). CONCLUSION: After undergoing rTKA, the incidences of both patella baja (PB) and pseudo-patella baja (PPB) increased. Stiffness in the knee was associated with a higher incidence of PB, while non-stiffness cases showed a significantly higher incidence of PPB. Patients with stiff knees and PPB after rTKA experienced a significant reduction in range of motion (ROM). Additionally, the study revealed a noteworthy decrease in ISR and BPR with each subsequent surgery. This information is crucial for healthcare providers, as it sheds light on potential risks and outcomes of rTKA, allowing for improved patient management and surgical decision-making. LEVEL OF EVIDENCE: III.

Lateral rim variable angle locked plating versus tension band wiring of simple and complex patella fractures: a biomechanical study.

INTRODUCTION: Treatment of both simple and complex patella fractures is a challenging clinical problem. Although tension band wiring has been the standard of care, it can be associated with high complication rates. The aim of this study was to investigate the biomechanical performance of recently developed lateral rim variable angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. MATERIALS AND METHODS: Sixteen pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34-C1 or five-part complex AO/OTA 34-C3 patella fractures by means of osteotomies, with each fracture model created in eight pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior (central distal) fragment mimicking comminution around the distal patellar pole. The specimens with simple fractures were pairwise assigned for fixation with either tension band wiring through two parallel cannulated screws or a lateral rim variable angle locking plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring or a lateral rim variable angle locking plate. Each specimen was tested over 5000 cycles by pulling on the quadriceps tendon, simulating active knee extension and passive knee flexion within the range of 90° flexion to full extension. Interfragmentary movements were captured via motion tracking. RESULTS: For both fracture types, the articular displacements measured between the proximal and distal fragments at the central patella aspect between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the lateral rim variable angle locked plating compared with tension band wiring, p ≤ 0.01. CONCLUSIONS: From a biomechanical perspective, lateral rim variable angle locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading.

Dorsal Hook Plating of Patella Fractures With Immediate Range of Motion Results in Reliable Fixation, Low Implant Removal Rates, and Satisfactory Clinical Outcomes.

OBJECTIVES: To evaluate radiographic and clinical patient-reported outcomes following dorsal hook plating of displaced patella fractures with permittance of immediate postoperative active closed chain range of motion. DESIGN: Retrospective review of prospectively collected data. SETTING: Urban academic level 1 trauma center. PATIENT SELECTION CRITERIA: Adult patients with displaced patella fractures (OTA/AO 34C1-3) who underwent dorsal plating with immediate range of motion between 2018 and 2023. OUTCOME MEASURES AND COMPARISONS: Numerical Rating Scale for Pain, Knee Outcome Score (KOS-ADL), Tegner-Lysholm score, radiographic union, and wound complications were collected. RESULTS: Sixty-one patients were included (47 female) with an average age of 63 years (SD 14.7, range 22-86 years). The mean BMI was 24.2 (SD 3.6, range 16.6-33.3). There were 13 34-C2 and 48 34-C3 fractures. All but 2 patients (96.7%) achieved bony union after the index procedure. 89% (n = 54) of patients completed outcome surveys with at least 6-month follow-up. Six patients (9.8%) underwent removal of plate implant at a mean of 15.1 months postoperatively. The mean KOS-ADL score was 91.4, the mean Tegner-Lysholm score was 78.1, and the mean NRS was 2.7. CONCLUSIONS: Dorsal hook plating offers secure fixation to allow early range of motion, reliable fixation with low nonunion and implant failure rates, low implant removal rates, and satisfactory patient-reported outcomes. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Inferior patellar mobility before and after knee arthroplasty: A comparison with healthy knees.

PURPOSE: The aim of this study was to evaluate patellar mobility in patients before and after knee arthroplasty (KA) and compare it with that of healthy subjects. It was hypothesised that patellar mobility is diminished in patients with osteoarthritis (OA) and remains unchanged after KA. METHODS: A total of 101 patients (59 females and 42 males) with a mean age of 70.9 ± 9.9 years underwent KA and were compared with 25 healthy individuals (seven females and 18 males) with a mean age of 32.3 ± 9.3 years. Mediolateral patellar displacement was measured by applying a force of 10 N, and the medial and lateral patellar shifts were recorded separately using a validated novel patellostabilometer. Patients were examined preoperatively and at 3 months postoperatively, assessing the range of knee motion and the clinical and functional status based on the Oxford Knee Score (OKS), Kujala Score, subjective Knee Society Score (sKSS), Forgotten Joint Score (FJS) and Western Ontario and McMaster Universities Arthritis Index (WOMAC). RESULTS: Total patellar displacement was 42.1 ± 6 mm for healthy subjects, 31 ± 6 mm before surgery and 32.8 ± 7.8 mm after surgery in osteoarthritic patients (p < 0.01). The mean lateral patellar shift differed significantly between healthy individuals (17.9 ± 4 mm) and osteoarthritic patients (15.1 ± 6 mm) (p < 0.01). The mean medial patellar mobility of healthy individuals (24.2 ± 7 mm) was significantly greater than that of osteoarthritic patients (15.8 ± 4.8 mm) (p < 0.01). All scores improved significantly postoperatively. No correlation was found between patellar mobility and OKS, Kujala Score, sKSS, FJS and WOMAC (r = -0.11). Improvement in patellar mobility also showed no correlation with clinical outcomes according to OKS, Kujala Score, sKSS, FJS and WOMAC (r = 0.08). CONCLUSION: This study has demonstrated reduced patellar mobility in patients with OA. While patellar mobility significantly improved after KA, it may not hold clinical significance (p = 0.04). No impact on clinical outcome can be expected when the presurgical patella mobility is preserved in KA. LEVEL OF EVIDENCE: Level IV.

Effect of preservation of Hoffa's fat pad on patellar height in primary total knee arthroplasty procedures.

BACKGROUND: We have previously reported our experience of the effect of complete excision of Hoffa's fat pad on patella height post TKR. In this study, we compared the change of patellar height post TKR before and after the senior author changed his practice to preserving Hoffa's fat pad. METHODS: This was a retrospective analysis of a prospective series of TKRs performed or directly supervised by the senior author. In Group 1 were 72 patients performed before April 2011 who had complete excision of Hoffa's fat pad to maximise exposure during the procedure. In Group 2 were 138 patients performed after April 2011 who had the minimum excision of Hoffa's fat pad to allow adequate surgical exposure. The surgical technique and rehabilitation protocol were identical in all other respects. Patellar height was assessed using the Caton-Deschamps Index both immediately postoperative and at a minimum follow up of 1 year. RESULTS: Group 1 included 28 males, 44 females with mean age 68.36 years. The mean CDI in this group changed from 0.54 immediately post-operatively to 0.46 at minimum one year follow-up (P = 0.001) indicating progressive patella baja. Group 2 included 56 males, 82 females with mean age 65 years. The mean CDI changed from 0.67 immediately post-operative to 0.68 at minimum one year post follow-up (P = 0.32) indicating no statistically or clinically relevant post-operative change in patellar height. CONCLUSION: Total excision of Hoffa's fat pad is associated with progressive post-operative patella baja. This can be avoided by resecting the minimum amount of fat pad to allow adequate exposure during the procedure.

Nonmetallic tension band fixation is a viable and low-complication surgical technique in patellar fractures: a five-year retrospective study.

BACKGROUND: Traditionally, patellar fractures (PFs) have been managed using metallic tension band fixation, a method often associated with a notable rate of complications. Considering these challenges, this study explores the potential of nonmetallic fixation as a treatment option for PFs. This research aims to provide robust evidence supporting the use of the nonmetallic tension band fixation technique as an effective alternative to conventional metallic tension band fixation, thereby advancing the standard of care in treating these fractures. METHODS: This retrospective study analyzed a consecutive patient series presenting with PFs from 2008 to 2021, treated with a nonmetallic tension band fixation technique. Inclusion criteria were strictly defined to include individuals over 18 years of age with isolated PFs requiring surgical intervention. The study focused on evaluating postoperative complications and clinical outcomes, as measured by standardized scoring systems, at the final follow-up point to assess the efficacy and safety of the employed surgical technique. RESULTS: In this study, with a mean follow-up of 64 ± 7 months, a total of 64 patients who received open reduction and internal fixation (ORIF) for PFs were enrolled. Among these, five cases required additional surgical interventions. Specifically, two cases were due to knee stiffness, while the remaining three involved complications such as superficial infection, skin irritation, or delayed wound healing. The mean postoperative values recorded for the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Oxford knee score (OKS), and visual analog scale (VAS) were 20.4 ± 2.3, 35.5 ± 5.3, and 1.6 ± 0.4, respectively. There were no complications related to the nonmetallic fixation technique or instances of loss of reduction. CONCLUSION: This study substantiates that nonmetallic tension band fixation is a safe and effective alternative to traditional metallic tension band fixation for patellar fractures. The study's low-complication rate and reoperation frequency underscore the value of nonmetallic implants in mitigating adverse effects and enhancing clinical outcomes. LEVEL OF EVIDENCE: IV.