Transverse patella fractures are commonly encountered in trauma surgery, open reduction and internal fixation are considered the gold standard treatment modality that could permit early knee motion and immediate rehabilitation. Many fixation methods had been defined and compared to each other's in many clinical and biomechanical studies. The aim of this study was to assess the safety and stability of our novel anatomical patella plate and to compare its stability with tension band-wire technique. A total of 12 cadaveric preserved knees (six right and six left patellae) with close patellar size were chosen to form two groups of six samples. Each group received either plate or tension band-wiring fixation for an experimentally created patella fracture. Cyclic load of an average of 350 N was applied for all specimens and after accomplishing 50 cycles the displacements of all fracture edges were recorded. After completing 50 cycles in each group, the average fracture edges displacement measured in the plate group was 1.98 ± 0.299 mm, whereas the average fracture edges displacement measured in the tension band-wire group was 2.85 ± 0.768 mm (p = 0.016). In the operative treatment of displaced transverse patellar fractures, the strength of fixation obtained by titanium curved plates is highly stronger when compared to the fixation with a tension band-wire technique. Fixation with titanium curved plates provides satisfactory stability at the fracture site which allow withstanding the cyclic loads during the postoperative rehabilitation

Introduction. Mechanical integrity of patella can be weakened by the technique of removing the articulating surface. The senior author developed the technique of maintaining subchondral bone of the lateral patellar facet in early 1980s. Though laboratory studies have demonstrated deleterious effect of excessive resection of patella on the strains in the remaining bone under load; clinical studies have not shown the importance of strong subchondral bone of lateral facet to have an effect on patellar fracture prevalence. We present the results of our patellar resection technique preserving the subchondral bone of lateral facet. Methods. 393 TKRs were performed between 1989 and 1996 using cruciate substituting modular knee with recessed femoral trochlear groove and congruent patello-femoral articulation. 45 patients with 48 knees died and 37 patients with 41 knees were lost to follow-up. Three hundred and four knees were followed for an average 10 years (range 5 -16 years). Patellar surface was resected with an oscillating saw without the use of cutting guide. The medial facet and most of the articular cartilage of the lateral facet was resected, while preserving the subchondral bone of lateral facet. An all-polyethylene implant with single peg was used in most cases. Results. There have been two fractures in the cohort with prevalence of 0.66%. Eight TKRs were revised for synovitis and osteolysis. Patellar osteolysis was found in 4 of these cases, with loosening of 3 of these patellae, and 1 patellar fracture. Two patellar implants had global radiolucencies and were considered loose. The average knee score in unrevised knees improved from 48.6 to 92.2, while functional scores improved from 50 to 81.1. Conclusion. We believe that maintaining this anatomic landmark allows for preserved patellar strength, and in association with a femoral component with a recessed trochlear groove, has resulted in our low patellar fracture rate in primary TKR and revision cases for patellar osteolysis

Patellar fractures account for approximately 1% of all fractures. Open reduction and internal fixation is recommended to restore extensor continuity and articular congruity. However, complications such as nonunion and symptomatic hardware, still exist. Furthermore, there is a risk of re-fracturing of the healed bone during the removal of the implants. Magnesium (Mg), a biodegradable metal, has elastic moduli and compressive yield strength that are comparable to those of natural bone. Our previous study showed that released Mg ions enhanced fracture healing. However, Mg-based implants degrade rapidly after implantation and lead to insufficient mechanical strength to support the fracture. Microarc oxidation (MAO) is a metal surface coating that reduces corrosion. We hypothesized that Mg pins, with or without MAO, would enhance fracture healing radiologically, mechanically, and histologically, while MAO would decrease degradation of Mg pins. Patellar fracture was performed on forty-eight 18-week-old female New Zealand White rabbits according to established protocol. Briefly, the patella is osteotomized transversely and a tunnel (1.1mm) was drilled longitudinally through the two bone fragments. A pin (1 mm, stainless steel, Mg, or MAO-Mg) was inserted into the tunnel. The reduced construct was stabilized with a figure-of-eight band wire (⊘ 0.6 mm stainless steel wire). Cast immobilization was applied for 6 weeks. The rabbits were euthanized at week 8 and 12 post-operation. Microarchitecture and mechanical properties of the repaired patella were analyzed with microCT and tensile testing respectively. Histological sections of the repaired patella were stained. To evaluate the effect of the MAO treatment on degradation rate of Mg pin, the volume of the Mg pins in the patella was measured with microCT. At week 8, both Mg and Mg-MAO showed higher ratio of bone volume to tissue volume (BV/TV) than the control while there was no significant different between Mg and Mg-MAO. At week 12, Control, Mg, and Mg-MAO groups showed enlarged patella when compared to the normal patella. Tissue volume (TV) and bone volume (BV) of the patella in Mg and Mg-MAO were larger than those in the Control group. However, the Control had higher ratio of bone volume to tissue volume (BV/TV), TV density, and BV density than Mg and Mg-MAO. Tensile testing showed that the mechanical properties of the repaired patella (failure load, stiffness, ultimate strength, and energy-to-failure) of Mg and Mg-MAO were higher than that of the control at both week 8 and week 12. Histological analysis showed that there was significant new bone formation in the Mg and Mg-MAO group compared with the Control group at week 8 and 12. The degradation rate of the MAO-coated Mg pins was significantly slower than those without MAO at week 8 but no significant difference was detected at week 12. Mechanical, microarchitectural, and histological assessments showed that Mg pins, with or without MAO, enhanced fracture healing of the repaired patella compared to the Control. MAO treatment enhanced the corrosion resistance of the Mg pins at the early time point

To assess the outcome and implant removal rate following surgical stabilisation of patella fracture. Sixty-seven patients who underwent surgical stabilisation of patella fracture between January 1999 and December 2004 were retrospectively reviewed to determine the adequacy of fracture stabilisation, fracture union and implant removal rate. Forty-three were men and 24 were women with a mean age of 49 years (ranged 14–90 years). Table below demonstrates the injury, fracture patterns and fixation methods. There were 3 open fractures and associated injuries were noted in 22 patients. All fractures united even though the fixation was inadequate in 46 patients. Two superficial infections responded to oral antibiotics. One patient had revision surgery at 6 weeks. Twenty-two patients required implant removal between 2 and 20 months (average 11 months) for implant related symptoms. Of the 22 (32.8%) patients requiring implant removal, 16/40 (40%) were less than 60 years and 6/27 (22.2%) were over 60 years. Mean follow up in asymptomatic patients was 8 months (3 to 18 months) and in patients with implant related problems was 17 months (10 to 36 months). Four patients were lost to follow up. Surgical stabilisation by current techniques demonstrated satisfactory fracture union. However, one in three required second surgery for implant related symptoms. In the under 60 years group, the implant removal rate increased to 40%. Newer techniques to avoid skin irritation need to be considered

For the management of displaced patellar fractures, surgical fixation using cannulated screws along with anterior tension band wiring is getting popular. Clinical and biomechanical studies have reported that using cannulated screws and a wire instead of the modified tension band with Kirschner wires improves the stability of fractured patellae. However, the biomechanical effect of screw proximity on the fixed construction remains unclear. The aim of this study was to evaluate the mechanical behaviors of the fractured patella fixed with two cannulated screws and tension band at different depths of the patella using finite element method. A patella model with simple transverse fracture [AO 34-C1] was developed; the surgical fixation consisted of two 4.0-mm parallel partial-threaded cannulated screws with a figure-of-eight anterior tension band wiring using a 1.25-mm stainless steel cable. Two different locations, including the screws 5-mm and 10-mm away from the leading edge of the patella, were used. A tension force of 850 N was applied on the patellar apexes at two loading angles (45° and 0° [parallel] to the long axis) to simulate different loading conditions while knee ambulation. The proximal side (base) of the patella was fixed, and the inferior articular surface was defined as a compression-only support in ANSYS to simulate the support from distal femur condyles. Compression-only support enables the articular surfaces of the present patella to only bear compression and no tension forces. Under different loading conditions, the fixed fractured patella yielded higher stability during 0° loading of tension force than during 45° loading. When the screws were parallel placed at the depth of 5 mm away from the patellar surface, the deformation of patellar fragment and maximum gap opening at the fracture site were smaller than those obtained by screws placed at the depth of 10 mm away from the patellar surface. Compared to the superficial screw placement, the deeper placement (10 mm) increased the maximum gap opening at the fracture site by 1.56 times under 45° loading, and 1.58 times under 0° loading. The load on the tension band wire of the 10-mm screw placement was 3.12 times (from 230 to 717 N) higher than that of the 5-mm placement. Under the wire, the contact pressure on the patellar surface was higher with the 10-mm screw placement than the 5-mm screw placement. The peak bone contact pressures with the 10-mm placement were 7.7 times (99.5 to 764 MPa) higher. This is the first numerical study to examine the biomechanical effects of different screw locations on the fixation of a fractured patella using screws and tension band. Based on a higher stability and lower cable tension obtained by the superficial screws placement, the authors recommended the superficial screw placement (5 mm below the leading edge of the patella) rather than the deep screws while fixing the transverse patellar fracture with cannulated screws and cable

Graft choices for revision anterior cruciate ligament (ACL) reconstruction and complex ligament reconstructions of the knee are controversial. The aim of our study was to analyze the biomechanical effect of harvesting bone plugs from both the distal and proximal poles of the patella, to simulate a simultaneous harvesting of a Bone – Patellar Tendon – Bone and Quadriceps Tendon – Bone grafts, in a transverse stress environment.

Sixty Bovine Patellae were analysed. They were divided into 4 groups – based on the residual bone bridge (percentage of total length of patella) remaining after bone plug resection. 0 – 10%, 11 – 20%, 21 – 30% and > 30%. All patellae were tested in a modified 4 – point bending environment, to a maximum load of 10,000N, in a customized designed jig. This method simulates the axial bending stress on the patella during knee flexion. All dimensions of the patellae were recorded including Depth of patella at bone resection and wall thickness adjacent to plug resection site.

All patellae with a 0% bone bridge fractured (Ultimate Tensile Strength/UTS) at a mean Tensile Force of 5863N (Range 3140 – 8730N). There was a subgroup of incomplete fractures – extra-articular fractures – which fractured at 6542N (Range 5085 – 9180N). The remaining specimens failed to fracture. Comparing the UTS and the patellar dimensions, using Weibull’s Statistical Analysis we demonstrated that less than 60% bone plug resection carried a very low probability of fracture.

This study demonstrates the safe criteria for bone – tendon graft harvesting from both the proximal and distal poles of the patella. With regards to a normal human patella, a 40% bone – bridge is approximately a 20mm bone – bridge. We conclude that the simultaneous harvesting of Bone – Patellar Tendon – Bone and Quadriceps Tendon – bone grafts from a patella has no significant increase in the fracture risk of the patella.

Treatment of simple and complex patella fractures represents a challenging clinical problem. Controversy exists regarding the most appropriate fixation method. Tension band wiring, aiming to convert the pulling forces on the anterior aspect of the patella into compression forces across the fracture site, is the standard of care, however, it is associated with high complication rates. Recently, anterior variable-angle locking plates have been developed for treatment of simple and comminuted patella fractures. The aim of this study was to investigate the biomechanical performance of the novel anterior variable-angle locking plates versus tension band wiring used for fixation of simple and complex patella fractures. Sixteen pairs of human cadaveric 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 with a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral and an inferior 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 an anterior variable-angle locking core plate. The knees with complex fractures were pairwise treated with either tension band wiring through two parallel cannulated screws plus circumferential cerclage wiring, or an anterior variable-angle locking three-hole 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 from 90° flexion to full knee extension. Interfragmentary movements were captured by motion tracking. For both fracture types, the articular displacements, measured between the proximal and distal fragments at the central aspect of the patella between 1000 and 5000 cycles, together with the relative rotations of these fragments around the mediolateral axis were all significantly smaller following the anterior variable-angle locked plating compared with the tension band wiring, p < 0.01. From a biomechanical perspective, anterior locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring

Treatment of both simple and complex patella fractures is a challenging clinical problem. 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. Twelve pairs of human anatomical knees were used to simulate either two-part transverse simple AO/OTA 34C1 or five-part complex AO/OTA 34C3 patella fractures by means of osteotomies, with each fracture model created in six pairs. The complex fracture pattern was characterized by a medial and a lateral proximal fragment, together with an inferomedial, an inferolateral, and an inferior 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 knee extension. Interfragmentary movements were captured via motion tracking. For both fracture types, the longitudinal and shear 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. Lateral rim locked plating of both simple and complex patella fractures provides superior construct stability versus tension band wiring under dynamic loading

Abstract. Background. Aim of this study is to determine the difference between re-operation rates after conventional Methods of fixation of patella fractures using Metallic implants and novel technique of all suture fixation using Ethibond or fiber tape. Methods. This is a retrospective comparative analysis involving 62 patients who had a transverse patellar fracture and underwent surgery between January 2013 to December 2021. Selected patients were divided, based on different fixation methods used, into four groups - TBW group, CC screw group, Encirclage group and Suture Fixation Group. Patients were followed till bone union was evident on radiographs. Number of patients in Metallic implant group undergoing repeat operation were compared with the patients who underwent patella fracture fixation using all suture technique. Mean and standard deviation (SD) were calculated for all continuous variables. Mean of the two groups was compared using unpaired t-test. Results. TBW was the most common method of fixation used in 41(66.1%) patients. 7 patients each underwent surgery using CC screw, Encirclage +/− TBW, and suture fixation respectively. Bone union was seen in about 85% of patients in all the groups suggesting all treatment modalities lead to good fracture healing. 15 patients(36.6%) of patients in TBW group and 3 patients(42.9%) in encirclage group had implant removal because of hardware-related complications (p<0.001). None of the patient who underwent All suture Fixation underwent re-operation. Conclusion. The results suggest that Suture fixation of patellar fractures is a valid treatment modality giving excellent results with similar bone union rates without any complications

Abstract. Objectives. The outcomes from patella fracture have remained dissatisfactory despite advances in treatment, especially from operative fixation1. Frequently, reoperation is required following open reduction and internal fixation (ORIF) of the patella due to prominent hardware since the standard technique for patella ORIF is tension band wiring (TBW) which inevitably leaves a bulky knot and irritates soft tissue given the patella's superficial position2. We performed a systematic review to determine the optimal treatment of patella fractures in the poor host. Methods. Three databases (EMBASE/Medline, ProQuest and PubMed) and one register (Cochrane CENTRAL) were searched. 476 records were identified and duplicates removed. 88 records progressed to abstract screening and 73 were excluded. Following review of complete references, 8 studies were deemed eligible. Results. Complication rates were shown to be high in our systematic review. Over one-fifth of patients require re-operation, predominantly for removal of symptomatic for failed hardware. Average infection rate was 11.95% which is higher than rates reported in the literature for better hosts. Nevertheless, reported mortality was low at 0.8% and thromboembolic events only occurred in 2% of patients. Average range of movement achieved following operative fixation was approximately 124 degrees. Upon further literature review, novel non-operative treatment options have shown acceptable results in low-demand patients, including abandoning weight-bearing restrictions altogether and non-operatively treating patients with fracture gaps greater than 1cm. Regarding operative management, suture/cable TBW has been investigated as a viable option with good results in recent years since the materials used show comparable biomechanics to stainless steel. Additionally, ORIF with locking plates have shown favourable results and have enabled aggressive post-operative rehabilitation protocols. TBW with metallic implants has shown higher complication rates, especially for anterior knee pain, reoperation and poor functional outcomes. Conclusion. There is sparse literature regarding patella fracture in the poor host. Nevertheless, it is clear that ORIF produces better outcomes than conservative treatment but the optimal technique for patella ORIF remains unclear. TBW with metallic implants should not remain the standard technique for ORIF; low-profile plates of suture TBW are more attractive solutions. Non-operative treatment may be considered for low-demand individuals however any form of patellectomy should be avoided if possible. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Introduction. The Tour de France, commonly recognised and the hardest physical endurance event on the planet, is an iconic cycling competition with a history of ever impressive performances and increasingly notable injuries. This study aims to methodologically catalogue and analyse injuries sustained by professional riders over a span of six years and understand the operative workload created by this prestigious race. (2018–2023). Methods. Data was gathered from multiple publicly available sources, including pro-cycling stats, news articles, team press releases and independent medical reports. Each injury was categorized by year, rider, and injury type. Results. From 2018–2023, there was a significant diversity in both injured body part and mechanism of injury. Of the 124 recorded race ending incidents clavicle fractures accounted 19.4%, laceration/contusions 12.1%, patella fractures 10.5% and elbow fractures 7.3%. Other. notable other body areas undergoing surgical intervention were hand fractures 5.6%, pelvic fractures 2.4% and femoral fracture 1.6%. At a mean of 20.67 injuries per tour, this accounts for almost exactly one race ending injury per day where an athlete finishes the day on the operating table, rather than the team bus. Discussion. The Tour de France's rigorous challenges are mirrored in its injury statistics. Over six years, clavicle fractures were most prevalent, likely due to cyclists' instinct to brace during crashes. Lacerations, contusions, and patella fractures also featured prominently. Alarmingly, each race stage averaged an injury severe enough for surgical intervention. This data highlights the imperative need for enhanced protective measures, race regulations, and medical preparedness to protect these elite athletes

The patella is an important component of the extensor mechanism of the knee. Patellar fractures need to be fixed if displacement occurs more than 2 mm. Transverse fractures comprise the largest category. Several different techniques for internal fixation have been employed. The aim of this work was to evaluate the results of treatment of transverse patellar fractures with figure of eight wiring through cannulated screws. Twenty patients were included in the study, all suffering from displaced transverse patellar fractures. All were treated by open reduction and internal fixation with figure of eight tension band wire through 4.0 mm cannulated screws. All patients were assessed after 1 month, 3 months and 6 months according to a modified Hospital for special surgery (HSS) knee scoring system. Because varus and valgus knee alignment and stability are not affected by patellar fracture fixation, the ten points assigned to these functions are eliminated, making the highest score ninety points. Excellent results are considered with points from 75 to 90, good from 60 to 74, fair from 50 to 59 and poor with points below 50. The final results of the study showed fourteen patients (70%) had excellent results, five (25%) good result, one (5%) fair result and no patient had a poor result. There was a statistically significant improvement of the patients' score throughout the follow up period. The complications occurred included knee pain in one patient (5%), loss of terminal flexion of knee occurred in three patients (15%), one patient lost 30 degrees, another lost 20 degrees while the last lost 10 degrees. There were no cases with extension lag in this series. Treatment of patellar fractures using figure of eight wiring through cannulated screws is an easy technique which gives good stability leading to good results with a low complication rate

Patella fractures constitute 1% of all fractures and may disrupt the extensor mechanism of the knee. The mainstay of treatment for most patella fractures is operative fixation; however, patients with intact extensor mechanisms may be treated with splinting. We describe a series of patients with patella fractures managed non- operatively, without restricted weight bearing or splinting. A consecutive series of 21 patients presenting with a patella fracture to two metropolitan hospitals were included in this study. All patients had an intact extensor mechanism but no distinction was made on age or fracture type. All patients were treated non-operatively with analgesia, were allowed to fully weight-bear and were not splinted. A retrospective review of the case notes was performed and data was collected with phone interview. The main outcome measure was the Western Ontario and McMaster Universities. Osteoarthritis (WOMAC) index, which has a maximum (worst) possible score of 240, and which provides an aggregate score of pain, stiffness and function. Mean time at follow up was 24 months (range 5–49 months). WOMAC scores were excellent (mean=18 of possible maximum 240; range 0–84). Only one patient had a significant complication related to their fracture (deep venous thrombosis), which was detected during hospital admission. Most patients had returned to usual work (9/14). No patients required operative fixation. There was no association between adjusted WOMAC score and age, sex, compensation status, time of follow up, or whether the patient had a significant ipsilateral injury. Patients who had returned to work (p=0.02) or who had lower levels of education (p=0.03) had better WOMAC scores. Management of patella fractures with an intact extensor mechanism does not require restricted weight bearing or splinting

Introduction. Throughout the years treatment of patellar fractures have been held in much controversy and various treatment procedures have been described. In the literature, there are only a few studies that compare the results of the different treatment modalities. Materials & Methods. This study reviews our experience with patellar fractures and correlates results of different treatment modalities to grade of patellar comminution and to the length of follow-up. It consists of 114 patients (71 M, 43 F, 17–76 year old: mean- 43 years), followed for 2–9 years (mean- 3.5 years). Patients were treated by P.O.P. cast for undisplaced fractures (12 Pts), and by various surgical modalities for displaced or comminuted fractures such as O.R.I.F (53 Pts), partial patellectomy (37 Pts) and total patellectomy (12 Pts). Patients were evaluated by Lisholm functional score, by objective knee tests, and radiographically. Results. Correlation to treatment modalities showed that functional results were excellent and good in 86% of the patients following conservative treatment by P.O.P. cast, 77% treated by O.R.I.F., 75% treated by partial patellectomy and 78% treated by total patellectomy (objective results −79%, 72%, 72%, 66.66% respectively). No statistical differences were found between these groups. However, the correlation between these treatment modalities to grade of patellar comminution revealed that in two fragment fractures similar results were observed following partial patellectomy and O.R.I.F., whereas in patients with three or more fragment fractures, a significantly better outcome was observed after partial patellectomy (79% and 62% respectively). The patients with comminuted patellar fractures treated by partial patellectomy had also a better short and long-term outcome than with all other techniques. Conclusions. Based on this study it seems that O.R.I.F. remains as the first optimal treatment in simple two parts patellar fractures, where partial patellectomy should be considered as the treatment of choice in patients with patellar fractures of three or more fragments. Total patellectomy is the optional treatment in patients with comminuted fractures

Patella fracture after total knee arthroplasty has a variety of etiologies and has been reported to occur with an incidence ranging from 3% to 21%. Heavy patients with full flexion are at greatest risk for sustaining patella fracture. Overstuffing the patellofemoral joint with an oversized femoral component, an anteriorised femoral component or a femoral component placed in excessive extension can also overload the underlying patella. A similar phenomenon may be seen with underrsection of the patella or use of a thick button. Excessive patellar resection can predispose to patellar fracture as well. It has been demonstrated that a residual patella thickness of less than 15 mm can substantially increase anterior patellar strain. Asymmetric patellar resection can also critically alter the mechanical strength of the patella making it vulnerable to failure. Elevation of the tibiofemoral joint line, from excessive femoral resection and hastened by posterior cruciate ligament release, will result in a relative patella baja. This can cause early patellofemoral articulation, which may result in patellar impingement on the tibial insert in late flexion and ultimately predispose the patella to fracture. Surgical approach and soft tissue dissection should be as atraumatic to the patellar blood supply as possible to preserve the superolateral geniculate artery when performing a lateral retinacular release. The classification used by Goldberg, et al is helpful for planning appropriate intervention:. Type I fractures: Avulsion type fractures generally involving the periphery of the patella without involving the implant. Type II fractures: Disrupt the cement-prosthesis interfaces of the quadriceps mechanism. Type IIIA fractures: Involve the pole of the patella with disruption of the patella ligament. Type IV fractures: Fracture dislocations of the patella. Non-operative treatment is preferred when fractures are non-displaced

Hypothesis: 1. Increased wear results from modularity. 2. Modification of the patello-femoral articulation will decrease patellar fractures. Materials & Methods: A prospective comparison of 100 consecutive Non-modular Insall Burstein Posterior Stabilized (IBPS) knee prostheses (1986–1989) with 100 consecutive modular IBPS II knee replacements (1989–1990). No patient was lost. Results: IBI: Nine re-operations of which 6 were complete revisions: two for sepsis, one for tibial loosening, one for patellar wear and two for undiagnosed pain. Of seven patellar fractures, five required surgery. IBII: Nineteen re-operations of which six were complete revisions: two for sepsis, one for tibial loosening from catastrophic osteolysis, two for instability and one for stiffness. There were no revisions for patellar complications. Of 12 non-revision re-operations, two were for patellar fractures, three for dislocation of the posterior stabilized mechanism and one for failure of the modular locking mechanism. Six knees suffered patellar “clunks” treated arthroscopically. Discussion: The femoral component patellar groove was smoothed and the posterior stabilized mechanism was relocated on the IB II. This increased motion and decreased patellar fractures but caused scar on the quadriceps tendon to “clunk” and lead to dislocations of the “spine and cam”. All failures occurred in the first five years. Clinical Relevance: Specific patellar problems were improved with design modifications. New problems have been addressed and long-term survival has not been compromised by modularity

Introduction. Although tension band wiring fixation of patellar fracture has been the most widely used technique, the metal implants related complications including implant loosening, postoperative pain are very common and additional surgeries are often necessary. Hypothesis. A totally metal free technique of transosseous suturing method could outperform the traditional fixation technique. Materials & Methods. A total of 25 patients (mean age of 59.60 years) with displaced patellar fracture treated by transosseous suturing technique were compared with a 1:1 matched historical control group who underwent modified tension band wiring fixation of patellar fracture. Union time, union rate, operation time, number of procedures, mean hospitalization days and the complications were compared between cases and controls. Results. Union time (8.43 ±2.92 weeks versus 8.64 ±2.82 weeks) and operation time (69.00 ±19.31 versus 64.89 ±14.27 minutes) were not different between two groups. Mean hospitalization days (4.04 ±1.40 versus 5.76 ±1.50 days; P < 0.001), number of procedures and the frequency of complications were significantly lower among transosseous suturing group (P< 0.001). Conclusions. Transosseous suturing technique is safe and effective in the transverse or comminuted fractures of patella. The complication rate is significantly lower than that of conventional tension band wiring technique

Objective. The purpose of the present study was to compare the clinical and radiographic results after TKA using a patellofemoral design modified prosthesis and its predecessor. The other purpose was to investigate whether the use of the recent prosthesis increase the risk of posterior tibial cortex injury or patellar fracture. Materials and Methods. The clinical and radiographic results of 300 knees which underwent TKA using the Attune®prosthesis (group A) were compared with those in a paired match-control group who underwent TKA using the P.F.C. Sigma® prosthesis (group B). The preoperative demographic data between the 2 groups did not differ significantly. The WOMAC, Feller and Kujala scores, and range of motion (ROM) were compared. The minimal distance between the tibial component stem to posterior tibial cortex, and the remnant patella thickness were compared. Results. The postoperative WOMAC score was better in the group A than in the group B (17.7 vs. 18.8, p=0.004). The postoperative ROM was greater in the group A than in the group B (131.4° vs. 129.0°, p=0.008). The postoperative Feller score was not different, but postoperative Kujala score was better in the group A. The minimal distance between the tibial component stem and posterior tibial cortex was significantly shorter in group A than in the group B (6.3mm vs 7.0mm, p<0.001). The proportion of high risk group for posterior tibial cortical injury, which had the minimal distance less than 4mm, was higher in the group A (20.0% vs 10.7%, p=0.002). The remnant patella was thinner in the group A than in the group B (14.8mm vs 15.7mm, p<0.001). The proportion of high risk group for patella fracture with remnant thickness of <12mm was higher in the group A (7.5% vs 2.1%, p=0.003). Conclusion. When comparing the clinical and radiographic results after TKA using the two prostheses of a design modified prosthesis and its predecessor, TKA using the recent prosthesis provided better satisfactory results. However, the risk of injury in the posterior cortex of the tibial metaphysis or remnant patella should be considered in this design modified prosthesis. Level of Evidence. Level III

MPFL reconstruction has demonstrated a very high success rate with improved patella stability, physical function, and patient-reported outcomes. However technical error and a lack of consideration of anatomic risk factors have been shown to contribute to failure after MPFL reconstruction. Previous research has also reported a complication rate of 26% following surgery. The purposes of this study were to determine the re-dislocation rate, type and number of complications, and most common additional surgical procedures following MPFL reconstruction. Patients with symptomatic recurrent patellofemoral instability underwent an MPFL reconstruction (n = 268) and were assessed with a mean follow-up of 31.5 months (minimally 24-months). Concomitant procedures were performed in addition to the MPFL reconstruction in order to address significant anatomic or biomechanical characteristics. Failure of the patellofemoral stabilization procedure was defined as post-operative re-dislocation of the patella. Rates of complications and re-procedures were assessed for all patients. The re-dislocation rate following MPFL reconstruction was 5.6% (15/268). There were no patella fractures. A total of 49/268 patients (18.3%) returned to the operating room for additional procedures following surgery. The most common reason for additonal surgery was removal of symptomatic tibial tubercle osteotomy hardware in 24/268 patients (8.9%). A further 9.3% of patients underwent addtional surgery including revision MPFL reconstruction: with trochleoplasty 8/268 (3.0%), with tibial tubercule osteotomy 4/286 (1.5%) and with femoral derotation osteotomy 3/268 (1.1%); manipulation under anaesthesia for reduced knee range of motion 4/268 (1.5%); knee arthroscopy for pain 8/268 (3.0%); and cartilage restoration procedures 3/268 (1.1%). There was 1 case of wound debridement for surgical incision infection. MPFL reconstruction using an a la carte approach to surgical selection demonstrated a post-operative redislocation rate of 5.6%. The rate of complications following surgical stabilization was low, with the most common reason for additional surgery being removal of hardware

The August 2012 Trauma Roundup. 360. looks at: pelvic fractures, thromboembolism and the Japanese; venous thromboembolism risk after pelvic and acetabular fractures; the displaced clavicular fracture; whether to use a nail or plate for the displaced fracture of the distal tibia; the dangers of snowboarding; how to predict the outcome of lower leg blast injuries; compressive external fixation for the displaced patellar fracture; broken hips in Morocco; and spinal trauma in mainland China