Background. Stress fracture of the acromium and scapular spine is a common complication following reverse total shoulder arthroplasty (RSA), with a reported incidence of 3.1%–11%. There is some evidence associating osteoporosis with increased risk of acromial stress fractures, but little else is known about the causes of acromial stress fractures after RSA. This study aims to define better preoperative factors, including demographics, comorbidities, and diagnoses, which predispose patients to postoperative acromial stress fractures. Methods. We retrospectively identified patients who underwent primary or revision RSA for any indication between January 2013 and December 2018 by two surgeons at two separate hospitals. Stress fractures of the acromion were identified on plain radiographs or computed tomography, when necessary. Patient demographics, comorbidities, and surgical indications were compared between patients with and without acromial stress fractures. Results. A total of 1,488 arthroplasties were identified and met the inclusion criteria. Of the study sample, 54 patients were diagnosed with a postoperative acromial stress fracture, an incidence of 3.6%. Patients in the stress fracture cohort were significantly more likely to have preoperative rotator cuff pathology (p<0.001), be of female gender (p<0.001), older (p=0.002), and osteoporotic (p<0.001; Table I). Thyroid disease (p=0.045) and inflammatory or rheumatoid arthritis (p=0.02) were also more frequent among patients with acromial stress fractures (Table I). No other comorbidities, including obesity (p=0.21) and diabetes (p=0.58), correlated significantly with postoperative acromial stress fracture (Table I). Conclusions. Old age, female gender, diagnosed osteoporosis, inflammatory arthritis, thyroid disease, and preoperative rotator cuff deficiency may all be risk factors for postoperative acromial stress fractures. Given that rotator cuff pathology is among the predominant indications for RSA, further research is required to determine the etiology and biomechanical basis for acromial stress fractures. For any figures or tables, please contact the authors directly

Correct alignment of tibial and femoral components is one of the most important factors that determine favorable long-term results of total knee arthroplasty (TKA). Computer-assisted TKA allows for more accurate component positioning and continuous intraoperative monitoring of the alignment. However, the pinholes created by the temporally anchored pins used as reference points may cause problems. Here we report a case of tibial stress fracture that occurred after a TKA was performed with the use of a computer navigation system. Case report. The patient, a 76-year-old woman (height 157 cm, weight 73 kg and BMI 29.5 kg/m. 2. ) with bilateral knee osteoarthritis. The right knee was replaced first and recovered without complications. The left knee was replaced 2 weeks later. The patient underwent computer-assisted (Stryker Co., Allendale, NJ, USA), cemented, posterior cruciate ligament sacrificing replacement of the left knee (with a Zimmer Gender Solutions Knee). A midline skin incision was made and a 5.0 mm bicortical self-tapping anchoring pin was inserted 10 cm below the tibiofemoral joint line. The other anchoring pin was inserted into the femur at the same distance from the joint to the line. These pins were inserted bicortically, anterior to posterior. Femur and tibia resections were performed according to the light-emitting diode tracker on the navigation system and cutting jig. Femoral and tibial implants were fixed with cement. The anchoring screws were then removed after the fixation of all implants. For two weeks, the patient tolerated significant walking but experienced only vague pain and swelling at the site of the left proximal tibial area. Local heat or redness was not observed and inflammatory serological markers (erythrocyte sedimentation rate, c-reactive protein level and white blood cell count) were within normal limits. One week later the patient complained of more aggravated and persistent pain. The patient immediately had a radiography check-up which showed a long linear radiolucent line and cortical defect through the pinholes (Fig. 1A–D). Through close scrutiny of the radiographs taken immediately after and two weeks after the operation, it was realized that she had a tibial stress fracture resulting from a misplaced fixation pin (Fig. 2A, B). As a result, the patient wore a long leg splint and was instructed to avoid weight bearing for two weeks. She was then allowed to gradually put more weight after wearing along leg cast for four weeks. Clinically, a satisfactory outcome was reported by the patient with good recovery of her daily activities; crutches were no longer needed to walk after three months. Physical examination showed no tenderness and final ROM was 0–120 degrees. Radiography showed that the stress fracture was completely healed (Fig. 3A, B). Conclusively, we suggest that unicortical anchoring pins with a small diameter should be considered for use in the metaphyseal area and avoidance of transcortical drilling is recommended. Care should be taken to avoid stress fracture during rehabilitation in case of the development of pain after a pain-free period following computer assisted TKA

This edition of Cochrane Corner looks at some of the work published by the Cochrane Collaboration, covering interventions for treating distal femur fractures in adults; ultrasound and shockwave therapy for acute fractures in adults; and local corticosteroid injection versus placebo for carpal tunnel syndrome.

There are several case reports or small series of stress tibial fracture around the OA knees in literature. Our study goes on 10 tibial stress fracture in 9 patients. All of the fractures have been distal to proximal tibial methaphysis. 8 of them have been in mid shaft or proximal of mid tibia, only 2 had fractures in distal half of tibia 8 were manage by braces for at least 8 months post TKA. Left side of the Bilateral one was fixed by simple IM nail and in 10 months was changed by TKA. Another very interesting case after failure of plate fixation without revision of knee was fixed by custom – made extended nail that attached to tibial tray. Conclusion: for all patients who are candidate to underwent T K A procedure, an update 3 – joints view is mandatory. Beside of patho anatomy and preoperative planning 3-joints view helps us to assure about peri arthicular stress (pathologic) fractures

Introduction. The emergence of a new variant of subtrochanteric stress fractures of the femur affecting patients on oral bisphosphonate therapy has only recently been described. This fracture is often preceded by pain and distinctive radiographic changes, and associated with a characteristic fracture pattern. We undertook a review of this cohort of patients in our service. Method. A retrospective review was carried out looking for patients with subtrochanteric fractures who were taking oral bisphosphonates presenting with a low velocity injury over a two year period. Clinical data and radiographs were assessed. Results. 11 fractures were found in 10 patients matching the inclusion criteria outlined. All were female, and taking bisphosphonates for a mean of 4.3 years. 5 of the 10 patients described prodromal symptoms, for an average of 7.8 months before fracture. Although all fractures were deemed low velocity, 5 of 11 were atraumatic. 3 patients have had bilateral subtrochanteric fractures. Presence of the distinctive radiological ‘bleb’ was common. Surveillance on 2 patients shows lateral cortical blebs on the contralateral femur which merit close follow up. Conclusion. Patients taking oral bisphosphonate therapy may be at risk of a new variant of stress fracture of the proximal femur. Awareness of the symptoms is key to ensure appropriate investigations are undertaken. Following such a fracture surveillance of the contralateral femur is recommended, and the option of discontinuing bisphosphonates should be discussed

Background. Stress fractures at tracker after computer navigated total knee replacement are rare. Periprosthetic fracture after Minimally Invasive Plate Osteosynthesis (MIPO) of stress fracture through femoral tracker is unique in orthopaedic literature. We are reporting this unique presentation of periprosthetic fractures after MIPO for stress fracture involving femoral pin site track in computer assisted total knee arthroplasty, treated by reconstruction nail (PFNA). Methods. A 75-year old female, who had computer navigated right total knee replacement, was admitted 6 weeks later with increasing pain over distal thigh for 3 weeks without trauma. Prior to onset of pain, she achieved a range of movements of 0–105 degrees. Perioperative radiographs did not suggest obvious osteoporosis, pre-existent benign or malignant lesion, or fracture. Radiographs demonstrated transverse fracture of distal third of femur through pin site track. We fixed the fracture with 11-hole combihole locking plate by MIPO technique. Eight weeks later, she was readmitted with periprosthetic fracture through screw hole at the tip of MIPO Plate and treated by Reconstruction Nail (PFNA), removal of locking screws and refixation of intermediate segment with unicortical locking screws. Then she was protected with plaster cylinder for 4 weeks and hinged brace for 2 months. Results. Retrograde nail for navigation pin site stress fracture entails intraarticular approach with attendant risks including scatches to prosthesis and joint infection. So we opted to fix by MIPO technique. Periprosthetic fracture at the top of MIPO merits fixation with antegrade nail in conjunction with conversion of screws in the proximal part of the plate to unicortical locking screws. Overlap of at least 3cms offers biomechanical superiority. She made an uneventful recovery and was started on osteoporosis treatment, pending DEXA scan. Conclusion. Reconstruction Nail (PFNA), refixation of intermediate segment with unicortical locking screws constitutes a logical management option for the unique periprosthetic fracture after MIPO of stress fracture involving femoral pin site track in computer assisted total knee replacement

In older patients (>75 years of age), with an intact rotator cuff, requiring a total shoulder replacement (TSR) there is, at present, uncertainty whether an anatomic TSR (aTSR) or a reverse TSR (rTSR) is best for the patient. This comparison study of same age patients aims to assess clinical and radiological outcomes of older patients (≥75 years) who received either an aTSR or a rTSA. Consecutive patients with a minimum age of 75 years who received an aTSR (n=44) or rTSR (n=51) were prospectively studied. Pre- and postoperative clinical evaluations included the ASES score, Constant score, SPADI score, DASH score, range of motion (ROM) and pain and patient satisfaction for a follow-up of 2 years. Radiological assessment identified glenoid and humeral component osteolysis, including notching with a rTSR. Postoperative improvement for ROM and all clinical assessment scores for both groups was found. There were significantly better patient reported outcome scores (PROMs) in the aTSR group compared with the rTSR patients (p<0.001). Both groups had only minor osteolysis on radiographs. No revisions were required in either group. The main complications were scapular stress fractures for the rTSR patients and acromioclavicular joint pain for both groups. This study of older patients (>75 years) demonstrated that an aTSR for a judiciously selected patient with good rotator cuff muscles can lead to a better clinical outcome and less early complications than a rTSR

Introduction. Osteogenesis imperfect (OI) is a geno- and phenotypically heterogeneous group of congenital collagen disorders characterized by fragility and microfractures resulting in long bone deformities. OI can lead to progressive femoral coxa vara from bone and muscular imbalance and continuous microfracture about the proximal femur. If left untreated, patients develop Trendelenburg gait, leg length discrepancy, further stress fracture and acute fracture at the apex of the deformity, impingement and hip joint degeneration. In the OI patient, femoral coxa vara cannot be treated in isolation and consideration must be given to protecting the whole bone with the primary goal of verticalization and improved biomechanical stability to allow early loading, safe standing, re-orientation of the physis and avoidance of untreated sequelae. Implant constructs should therefore be designed to accommodate and protect the whole bone. The normal paediatric femoral neck shaft angle (FNSA) ranges from 135 to 145 degrees. In OI the progressive pathomechanical changes result in FNSA of significantly less than 120 degrees and decreased Hilgenreiner epiphyseal angles (HEA). Proximal femoral valgus osteotomy is considered the standard surgical treatment for coxa vara and multiple surgical techniques have been described, each with their associated complications. In this paper we present the novel technique of controlling femoral version and coronal alignment using a tubular plate and long bone protection with the use of teleoscoping rods. Methodology. After the decision to operate had been made, a CT scan of the femur was performed. A 1:1 scale 3D printed model (AXIAL3D, Belfast, UK) was made from the CT scan to allow for accurate implant templating and osteotomy planning. In all cases a subtrochanteric osteotomy was performed and fixed using a pre-bent 3.5 mm 1/3 tubular plate. The plate was bent to allow one end to be inserted into the proximal femur to act as a blade. A channel into the femoral neck was opened using a flat osteotome. The plate was then tapped into the femoral neck to the predetermined position. The final position needed to allow one of the plate holes to accommodate the growing rod. This had to be determined pre operatively using the 3D printed model and the implants. The femoral canal was reamed, and the growing rod was placed in the femur, passing through the hole in the plate to create a construct that could effectively protect both the femoral neck and the full length of the shaft. The distal part of the plate was then fixed to the shaft using eccentric screws around the nail to complete the construct. Results. Three children ages 5,8 and 13 underwent the procedure. Five coxa vara femurs have undergone this technique with follow-up out to 62 months (41–85 months) from surgery. Improvements in the femoral neck shaft angle (FNSA) were av. 18. o. (10–38. o. ) with pre-op coxa vara FNSA av. 99. o. (range 87–114. o. ) and final FNSA 117. o. (105–125. o. ). Hilgenreiner's epiphyseal angle was improved by av. 29. o. (2–58. o. ). However only one hip was restored to <25. o. In the initial technique employed for 3 hips, the plates were left short in the neck to avoid damaging the physis. This resulted in 2 of 3 hips fracturing through the femoral neck above the plate at approximately 1 year. There were revisions of the 3 hips to longer plates to prevent intra-capsular stress riser. All osteotomies united and both intracapsular fractures healed. No further fractures have occurred within the protected femurs and no other repeat operations have been required. Conclusions. Surgical correction of the OI coxa vara hip is complex. Bone mineral density, multiplanar deformity, a desire to maintain physeal growth and protection of the whole bone all play a role in the surgeon's decision making process. Following modifications, this technique demonstrates a novel method in planning and control of multiplanar proximal femoral deformity, resulting in restoration of the FNSA to a more appropriate anatomical alignment, preventing long bone fracture and improved femoral verticalization in the medium term follow-up

Introduction. The goal of arthrodesis around the ankle or of triple (hind foot) arthrodesis is a painless, plantigrade, and stable foot. Stress fracture is a differential diagnosis for pain following an ankle/subtalar arthrodesis. Management of stress fractures following sound ankle/subtalar fusion is extremely difficult as the entire movement tends to occur at the fracture site, hence hampering healing. Methods and materials. 33 patients underwent ankle/subtalar arthrodesis at our institute from 2000-2008. The average age of the patients was 69 years and the male: female ratio was 2:1. The minimum follow-up was for one year. Although there were some variations in technique, all the arthrodesis were performed by removal of articular cartilage, bone grafting of any defects and rigid internal fixation. Results. 2/33 patients developed a stress fracture of the distal tibia following successful ankle/subtalar fusion. An angle of ankle/subtalar fusion showed an average of 0 degrees +/− 3 degrees in the sagital plane, except for the two cases that developed the stress fracture. The angles in these cases were 13 and 11 degrees. The stress fractures occurred proximal to the level of the previous arthrodesis internal fixation devices (arthrodesis nail/cancellous screws). Intramedullary and extramedullary devices were utilised to obtain union across the stress fracture sites, without success. Discussion. Equinus of more than 10 degrees following ankle/subtalar arthrodesis is a high risk factor for developing a stress fracture of the distal tibia following ankle/subtalar arthrodesis. Stress fracture following successful ankle/subtalar arthrodesis causes severe morbidity. They are extremely difficult to treat, hence are best avoided if possible

The senior author has treated a series of patients with subtrochanteric and diaphyseal femoral stress fractures associated with long-term alendronate or other bisphosphonate usage. Several patients completely fractured their femurs prior to referral. Most patients had consulted other physicians and were referred for presumed neoplasms. All patients had been diagnosed with osteoporosis and had been treated with bisphosphonates. Their plane radiographs revealed abnormalities that are pathognomonic of bisphosphonate-associated stress fractures. However, due to the subtle nature of these new unfamiliar abnormalities, most were unrecognized as such by clinicians (including experienced ISTA member hip surgeons) and radiologists. This series is presented to illustrate this pattern of impending fracture. The authors have reviewed and will present a series (n=17) of femoral stress fractures in bisphosphonate-treated patients to illustrate the clinical and radiographic pattern of these stress fractures, and review their treatment. The most common lesion is a subtrochanteric lateral cortical thickening that in actuality is a horizontal plane “dreaded black line” of a stress fracture with surrounding proximal and distal cortical thickening of the endosteal and periosteal bone. The stress fracture line is obscured unless a near-perfect radiographic projection is obtained. The lesion is best seen with CT scans. MRI scans reveal the stress fracture lines with surrounding edema (Fig 1), which may be misinterpreted as a tumor. Without treatment, a low-impact completed fracture will likely occur. Many bisphosphonate-associated impending subtrochanteric femoral stress fractures are misdiagnosed as trochanteric bursitis, leading to subsequent displaced subtrochanteric fractures [Fig. 2 - Note subtle impending fracture lesion on right, completed fracture on left]. The clinical and subtle radiographic findings must be recognized by orthopaedic surgeons, particularly hip surgeons, to prevent these complete fractures. These fractures are preventable with internal fixation. Long-term administration of bisphosphonates can have adverse effects, and alternatives to long-term continuous dosing must be investigated to determine optimal administration regimens

Abstract. Background. Atypical femur fracture (AFF) is a well known complication of Bisphosphonate therapy. Due to prolonged suppression of bone re-modelling in these fractures, surgical complications are difficult to manage. The aim of this study was to analyze the causes of surgical complications in AFF fixations and provide algorithm for management. Method. In this retrospective 10-year study (2010–2020), we identified patients surgically treated for AFF. We included patients who underwent revision surgery for any cause. Data collection included demographics, surgical complications, details of revision surgery and time to union. Result. Out of 57 patients who were operated for AFF, 17 underwent revision fixation. The average age was 69 with only 2 males. Around two-third (64%) were sub-trochanteric fractures and method of fixation in 64% cases was intra-medullary nail. The most common complication was non-union (12), followed by stress fracture and infection in 3 and 2 cases respectively. In most cases inadequate reduction and sub-optimal fixation was perceived as cause of failure except two cases which got infected. Revision fixation in all cases included improved bone contact (non-union site osteotomy), use of bone morphogenic proteins and improved fixation with augmentation device (either nail or plate). Follow up at 1 year showed fracture union in 12 cases, remaining 5 revision fixations failed, 3 of which were managed with proximal femur replacement. Conclusion. High rate of non-union after fixation in AFF. Optimizing the fixation construct results in union in most cases. However, arthroplasty should be considered in elderly patients with poor bone quality

Recruits undergoing arduous training at Commando Training Centre Royal Marines (CTCRM) carry a higher risk of femoral neck stress fractures than many other military populations. This injury has serious sequelae and requires urgent operative fixation if it is displaced. Existing literature advocates a low threshold for imaging patients where this injury is suspected, due to the prognostic advantage conferred by early intervention. CTCRM uses a locally produced scoring system based on history and clinical assessment, to guide the requirement for imaging. Since 2015 access to MRI has been possible through a fast track provider. Between 2012 and 2015, 3522 Royal Marine Recruits entered training. Over the period, 95 MRI scans of the hip were performed, of which 12 utilised private pathways. 13 stress fractures of the femoral neck were identified; 23% (n=3) were displaced and required fixation. The overall incidence rate for this injury is therefore 37 per 10,000, with a displaced incidence rate of 9 per 10,000. We compare these data with previous studies, discuss the use and efficacy of the scoring tool, and assess the benefit conferred by the local private MRI agreement

INTRODUCTION. Determining proper joint tension in reverse total shoulder arthroplasty (rTSA) can be a challenging task for shoulder surgeons. Often, this is a subjective metric learned by feel during fellowship training with no real quantitative measures of what proper tension encompasses. Tension too high can potentially lead to scapular stress fractures and limitation of range of motion (ROM), whereas tension too low may lead to instability. New technologies that detect joint load intraoperatively create the opportunity to observe rTSA joint reaction forces in a clinical setting for the first time. The purpose of this study was to observe the differences in rTSA loads in cases that utilized two different humeral liner sizes. METHODS. Ten different surgeons performed a total of 37 rTSA cases with the same implant system. During the procedure, each surgeon reconstructed the rTSA implants to his or her own preferred tension. A wireless load sensing humeral liner trial (VERASENSE for Equinoxe, OrthoSensor, Dania Beach, FL) was used in lieu of a traditional plastic humeral liner trial to provide real-time load data to the operating surgeon during the procedure. Two humeral liner trial sizes were offered in 38mm and 42mm curvatures and were selected each case based on surgeon preference. To ensure consistent measurements between surgeons, a standardized ROM assessment consisting of four dynamic maneuvers (maximum internal to external rotation at 0°, 45°, and 90° of abduction, and a maximum flexion/extension maneuver) and three static maneuvers (arm overhead, across the body, and behind the back) was completed in each case. Deidentified load data in lbf was collected and sorted based on which size liner was selected. Differences in means for minimum and maximum load values for the four dynamic maneuvers and differences in means for the three static maneuvers were calculated using 2-tailed unpaired t-tests. RESULTS. No significant differences were observed for the flexion/extension maneuver between the 38mm and 42mm liner sizes, but a significant difference was observed for every internal/external rotation assessment at 0°, 45°, and 90° of abduction. No significant differences were observed for the across the body and overhead maneuvers, but a significant difference was observed for the behind the back maneuver (p = 0.015). Standard deviations were pronounced across all maneuvers. CONCLUSION. This study observed significant differences in intraoperative load values in rTSA when comparing different humeral liner sizes. Limitations of this study include the small sample sizes and large standard deviations observed, as well as comparing across multiple patients and multiple surgeons. Area for future work includes comparing load values with postoperative functional results and complication risks for short, midterm, and long-term outcomes in efforts to find the optimal load range for a given patient

Femoral neck stress fractures (FNSF) are uncommon, representing 3.5% to 8% of all stress fractures in military recruits. The majority of displaced FNSF undergo operative fixation and are at risk of avascular necrosis (AVN) and non union with a 40–100% medical discharge rate. We aimed to review the incidence and outcome of displaced FNSF in Royal Marine Recruits. Retrospective review identified 6 Royal Marine recruits, aged 17 to 25, who had suffered a displaced FNSF over a 6 and a half year period. Incidence was 0.93 per 1000 recruits. Patients were treated urgently by operative fixation with a 2 hole dynamic hip screw device, in 3 cases supplemented with an anti-rotation screw. There were no cases of AVN, no surgical complications and no further procedures were required. All united with a mean time to union of 11 months. 50% had a union time greater than 1 year. 2 completed training, 2 are still in rehabilitation and 2 (33%) were discharged before completion of training. These fractures are slow to unite compared to other fractures at this site or stress fractures elsewhere. With urgent surgical intervention and stable fixation all however went onto successful union with time and all returned to rehabilitation or training with minimal complications. Awareness of the length of time to union has been invaluable in guiding treatment and rehabilitation. It can help avoid the risks of unnecessary secondary interventions for delay to union

Diphosphonates remain among the most common drug treatments for osteoporosis. Recent evidence has implicated diphosphonate therapy, specifically, alendronate, with low-energy fractures of the subtrochanteric region of the femur. The general conclusion is that prolonged suppression of bone remodelling with alendronate may be associated with a new form of insufficiency fracture of the femur. Three case reports of patients with alendronate related insufficiency are discussed here with their treatment modalities and lessons learnt. One of the three patients had bilateral subtrochanteric stress fracture. A comprehensive review of the literature is presented with the best evidence for investigating, treating and preventing these fractures. Our experience in Launceston has increased awareness amongst the local medical community regarding the long term use of Diphosphnates and the fractures they may cause. Changes to our practice have included: Increased suspicion of patients with hip pain on diphosphonate therapy, imaging the contralateral femur to rule out stress fractures, reassuring GP's and Patients that benefits of Diphosphonate therapy far outweigh the potential risks. There are many unresolved questions about the prolonged use of diphosphonates, but there is sufficient evidence to show subtrochanteric stress fractures do occur. We, as Orthopaedic Surgeons, must be able to recognize this new entity and educate our medical colleagues appropriately

Background. Locked anterior shoulders (LAS) with static instability and anterior glenoid bone loss are challenging in the elderly population. Reverse shoulder arthroplasty (RSA) has been employed in treating these patients. No study has compared RSA for LAS to classically indicated RSA. Methods. A case-control study of patients treated with RSA for LAS with glenoid bone loss and static instability was performed using matched controls treated with primary RSA for classic indications. Twenty-four cases and 48 controls were evaluated. Average follow-up was 25.5 months and median age was 76. Motion, outcome assessments, and postoperative radiographs were compared. Results. Preoperatively, LAS had significantly less rotation and lower baseline outcome scores. Glenoid bone grafting was more common (p=0.05) in control group (26%) than LAS group (6.3%). Larger glenospheres were utilized more often (p=0.001) in LAS group (75%) than control group (29%). Both groups demonstrated significant improvements in pain, function, and outcome scores. Postoperatively, control group had significantly better elevation and functional outcome scores. With the exception of flexion and SST, effectiveness of treatment was similar between groups. Postoperative acromion stress fractures were seen in 21% of LAS and 9% of control (p=0.023) with a predominance of type 3 fractures in LAS. Two LAS patients remained dislocated. Conclusion. Treatment with RSA for LAS may anticipate improvements in pain and function using larger glenospheres often without the need for glenoid bone grafting. Worse postoperative motion, function, and a higher incidence of acromion stress fracture may be expected

Objectives. Proximal tibial fracture is one of the most common postoperative complications of unilateral knee arthroplasty (UKA). The objective of the present study is to investigate the risk factors of these fractures, occurred after UKA in our facility. Method. We performed 314 UKAs between May 2006 and December 2013. All cases were done using Oxford UKA. Proximal tibial fractures were observed in 5 cases. 4 cases were female and 1 case was male, and the age at the operation ranged from 73 to 90. All cases were osteoarthritis. 4 cases were diagnosed as stress fracture with minimum displacement, and 1 case was fracture with displacement. We investigated the risk factors of the tibial fracture among those 5 cases. Low bone mineral density(BMD), the presence of medial tibial cortex pinhole, excessive vertical cut, and adjacence of keel and posterior tibia cortex were estimated as risk factors. Results. The loss in BMD was seen in all cases. Medial tibial cortex pinhole was recognized in 2 cases. Excessive vertical cut was recognized in 3 cases. Adjacence of keel and posterior tibia bone cortex was recognized in 3 cases, and the distance between keel and posterior tibia bone cortex was less than 3mm in all of these 3 cases. 4 cases those diagnosed as stress fractures, healed spontaneously with conservative treatment, but the case with displaced fragment needed ORIF. Discussion. Loss in BMD was seen in all cases as predicted, and this is one of the highest risk factors in UKA patient. Preoperative PTH use is recommended when low BMD was seen. Other risk factors are, medial tibial cortex pinhole, excessive vertical cut, and adjacence of keel and posterior tibial cortex. These risk factors are preventable if some cares are taken during the operation. Medial inclination of the tibial plateau should be checked preoperatively to avoid excessive vertical cut. If the distance between keel and posterior tibial cortex is less than 3mm at the preoperative planning, we should consider converting the implant. Furthermore, it is important to pay attention to intraoperative procedures. We should not use heavy hammer and avoid excessive varus force during cementing. For the prevention of tibial fractures after UKA, both strict preoperative planning and prevention of intraoperative errors are important

Resurfacing the patella is performed the majority of the time in the United States and in many regions it is considered standard practice. In many countries, however, the patella is left un-resurfaced an equal amount of the time or even rarely ever resurfaced. Patella resurfacing is not a simple or benign procedure. There are numerous negative sequelae of resurfacing including loosening, fragmentation, avascular necrosis, lateral facet pain, stress fracture, acute fracture, late fracture, and restricted motion. In a study by Berend, Ritter, et al, failures of the patella component were reported 4.2% of the time at an average of only 2.6 years. A study was undertaken at Washington University in recent years to determine rather more clinical problems were observed following total knee replacement with or without patella resurfacing. Records were maintained on all problem total knees cases with well localised anterior knee pain. The referral area for this clinic is St. Louis which is among the largest American cities, with the highest percentage of total knees that are performed without patella resurfacing. During 4 years of referrals of total knee patients with anterior knee pain, 47 cases were identified of which 36 had a resurfaced patella and 11 had a non-resurfaced patella. Eight of 36 resurfaced patellae underwent surgery while only 2 of 11 non-resurfaced patellae underwent subsequent surgery. More than 3 times as many painful total knees that were referred for evaluation had already had their patella resurfaced. In spite of the fact that approximately equal number of total knees were performed in this area without patella resurfacing, far more patients presented to clinic with painful total knee in which the patella had been resurfaced. The numerous pathologies requiring a treatment following patella resurfacing included patella loosening, fragmentation of the patella, avascular necrosis patella, late stress fracture, lateral facet pain, oblique resurfacing, and too thick of a patellar composite. In a large multi-center randomised clinical trial at 5 years from the United Kingdom in over 1700 knees from 34 centers and 116 surgeons, there was no difference in the Oxford Score, SF-12, EQ-5D, or need for further surgery or complications. The authors concluded, “We see no difference in any score, if there is a difference, it is too small to be of any clinical significance”. In a prospective of randomised clinical trial performed at Tulane University over 20 years ago, no differences were observed in knee score, a functional patella questionnaire, or the incidence of anterior knee pain between resurfaced and un-resurfaced patellae at time intervals of 2–4 years, 5–7 years, or greater than 10 years. Beyond 10 years the knee scores of total knee patients with a resurfaced patella had declined significantly greater than those with a non-resurfaced patella. There are numerous advantages of not resurfacing the patella including less surgical time, less expense, a lower risk of “major” complications (especially late complications), and if symptoms develop in an un-resurfaced patella, it is an easier salvage situation with more options available. A small percentage of total knee patients will be symptomatic whether or not their patella is resurfaced. Not resurfacing the patella retains more options and has fewer complications. The major determinant of clinical result and the presence of anterior knee pain after knee replacement is surgical technique and component design not whether or not the patella is resurfaced. Patella resurfacing is occasionally necessary for patients with inflammatory arthritis, a deformed or maltracking patella, or symptoms and pathology that are virtually restricted to the patellofemoral joint. For the vast majority of patients, however, patella resurfacing is not necessary

Resurfacing the patella is performed the majority of the time in the US and in many regions it is considered standard practice. In many countries, however, the patella is left unresurfaced an equal amount of the time or even rarely ever resurfaced. Patella resurfacing is not a simple or benign procedure. There are numerous negative sequelae of resurfacing including loosening, fragmentation, avascular necrosis, lateral facet pain, stress fracture, acute fracture, late fracture, and restricted motion. In a study by Berend, Ritter, et al, failures of the patella component were reported 4.2% of the time at an average of only 2.6 years. A study was undertaken at Washington University in recent years to determine whether more clinical problems were observed following total knee replacement with or without patella resurfacing. Records were maintained on all problem total knees cases with well localised anterior knee pain. The referral area for this clinic is St. Louis which is among the largest American cities, with the highest percentage of total knees that are performed without patella resurfacing. During 4 years of referrals of total knee patients with anterior knee pain, 47 cases were identified of which 36 had a resurfaced patella and 11 had a non-resurfaced patella. Eight of 36 resurfaced patellae underwent surgery while only 2 of 11 non-resurfaced patellae underwent subsequent surgery. More than 3 times as many painful total knees that were referred for evaluation had already had their patella resurfaced. In spite of the fact that approximately equal number of total knees were performed in this area without patella resurfacing, far more patients presented to clinic with painful total knee in which the patella had been resurfaced. The numerous pathologies requiring a treatment following patella resurfacing included patella loosening, fragmentation of the patella, avascular necrosis patella, late stress fracture, lateral facet pain, oblique resurfacing, and too thick of a patellar composite. In a large multi-center randomised clinical trial at 5 years from the United Kingdom in over 1700 knees from 34 centers and 116 surgeons, there was no difference in the Oxford Score, SF-12, EQ-5D, or need for further surgery or complications. The authors concluded, “We see no difference in any score, if there is a difference, it is too small to be of any clinical significance”. In a prospective randomised clinical trial performed at Tulane University over 20 years ago, no differences were observed in knee score, a functional patella questionnaire, or the incidence of anterior knee pain between resurfaced and unresurfaced patellae at time intervals of 2–4 years, 5–7 years, or greater than 10 years. Beyond 10 years the knee scores of total knee patients with a resurfaced patella had declined significantly greater than those with a non-resurfaced patella. There are numerous advantages of not resurfacing the patella including less surgical time, less expense, a lower risk of “major” complications (especially late complications), and if symptoms develop in an unresurfaced patella, it is an easier salvage situation with more options available. A small percentage of total knee patients will be symptomatic whether or not their patella is resurfaced. Not resurfacing the patella retains more options and has fewer complications. The major determinant of clinical result and the presence of anterior knee pain after knee replacement is surgical technique and component design not whether or not the patella is resurfaced. Patella resurfacing is occasionally necessary for patients with inflammatory arthritis, a deformed or maltracking patella, or symptoms and pathology that are virtually restricted to the patellofemoral joint. For the vast majority of patients, however, patella resurfacing is not necessary

Achieving a primary outcome with revision UKR is possible but it depends on an understanding of the main failure modes and avoiding the obvious pitfalls. The most common failure mode in the long term is lateral compartment progression at 2.5% at 28 years. The most common failure overall is misdiagnosis of a painful radiolucency leading to unnecessary revision. There are a number of potential pitfalls:. Do not revise for unexplained pain. 75% of patients will go on to fail because of continuing pain. A distinction must be made to differentiate between a physiological radiolucency (with a narrow lucency accompanied by a sclerotic margin which is normal) and a pathological radiolucency (with a poorly defined lucency without surrounding sclerotic margin which is indicative of loosening and/or infection). Femoral loosening can present with subtle findings. Flexion/extension views are helpful to diagnose this problem. Wear can be a problem with fixed bearing in the second decade and can present with subtle findings. Infection can present with contralateral compartment joint space narrowing. The approach and exposure is usually straightforward and component removal is generally easy. Tibial resection is undertaken referenced from the normal lateral condyle removing 10mm of bone. Femoral preparation is generally straightforward but care must be taken to dial in correct rotation in the absence of the posterior medial condyle which was resected in the first operation. Generally a CR or PS primary implant is used with 2–4mm extra polyethylene thickness than is used in primary case. Revision for infection and stress fracture led to difficult revisions where revision components are usually required. The results for Revision UKR approach those of a primary procedure in all cases except revision for unexplained pain, infection and a stress fracture